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From bf4541f9313754f5f025e2780fb6d80412140899 Mon Sep 17 00:00:00 2001
From: Mel Gorman <mgorman@techsingularity.net>
Date: Thu, 21 Mar 2024 12:04:09 +0000
Subject: [PATCH] printk: Update the printk series.

References: bsc#1214683 (PREEMPT_RT prerequisite backports)
Git-commit: da042bbb7a3ffcb2d18fc69e01f8a2f1ff0f0aab
Patch-mainline: v6.6.20

This is an all-in-one update of the printk series. It updates from the
previous version to the current development version which is under
discussion plus the PREEMPT_RT bits for the atomic console.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Mel Gorman <mgorman@suse.de>

---
 drivers/tty/serial/21285.c                  |    8 +-
 drivers/tty/serial/8250/8250.h              |  269 +---
 drivers/tty/serial/8250/8250_aspeed_vuart.c |    8 +-
 drivers/tty/serial/8250/8250_bcm7271.c      |   49 +-
 drivers/tty/serial/8250/8250_core.c         |   77 +-
 drivers/tty/serial/8250/8250_dma.c          |    8 +-
 drivers/tty/serial/8250/8250_dw.c           |   19 +-
 drivers/tty/serial/8250/8250_exar.c         |   73 +-
 drivers/tty/serial/8250/8250_fsl.c          |    9 +-
 drivers/tty/serial/8250/8250_mtk.c          |   38 +-
 drivers/tty/serial/8250/8250_omap.c         |   73 +-
 drivers/tty/serial/8250/8250_pci1xxxx.c     |    8 +-
 drivers/tty/serial/8250/8250_port.c         |  580 +++++----
 drivers/tty/serial/8250/Kconfig             |    1 -
 drivers/tty/serial/altera_jtaguart.c        |   30 +-
 drivers/tty/serial/altera_uart.c            |   20 +-
 drivers/tty/serial/amba-pl010.c             |   20 +-
 drivers/tty/serial/amba-pl011.c             |  145 +--
 drivers/tty/serial/apbuart.c                |   10 +-
 drivers/tty/serial/ar933x_uart.c            |   26 +-
 drivers/tty/serial/arc_uart.c               |   16 +-
 drivers/tty/serial/atmel_serial.c           |   24 +-
 drivers/tty/serial/bcm63xx_uart.c           |   22 +-
 drivers/tty/serial/digicolor-usart.c        |   18 +-
 drivers/tty/serial/dz.c                     |   32 +-
 drivers/tty/serial/fsl_linflexuart.c        |   26 +-
 drivers/tty/serial/fsl_lpuart.c             |   95 +-
 drivers/tty/serial/icom.c                   |   26 +-
 drivers/tty/serial/imx.c                    |  142 +--
 drivers/tty/serial/ip22zilog.c              |   36 +-
 drivers/tty/serial/jsm/jsm_neo.c            |    4 +-
 drivers/tty/serial/jsm/jsm_tty.c            |   16 +-
 drivers/tty/serial/liteuart.c               |   20 +-
 drivers/tty/serial/lpc32xx_hs.c             |   26 +-
 drivers/tty/serial/mcf.c                    |   20 +-
 drivers/tty/serial/men_z135_uart.c          |    8 +-
 drivers/tty/serial/meson_uart.c             |   30 +-
 drivers/tty/serial/milbeaut_usio.c          |   16 +-
 drivers/tty/serial/mpc52xx_uart.c           |   12 +-
 drivers/tty/serial/mps2-uart.c              |   16 +-
 drivers/tty/serial/msm_serial.c             |   38 +-
 drivers/tty/serial/mvebu-uart.c             |   18 +-
 drivers/tty/serial/omap-serial.c            |   65 +-
 drivers/tty/serial/owl-uart.c               |   26 +-
 drivers/tty/serial/pch_uart.c               |   10 +-
 drivers/tty/serial/pic32_uart.c             |   20 +-
 drivers/tty/serial/pmac_zilog.c             |   52 +-
 drivers/tty/serial/pxa.c                    |   30 +-
 drivers/tty/serial/qcom_geni_serial.c       |   18 +-
 drivers/tty/serial/rda-uart.c               |   34 +-
 drivers/tty/serial/rp2.c                    |   20 +-
 drivers/tty/serial/sa1100.c                 |   20 +-
 drivers/tty/serial/samsung_tty.c            |  155 ++-
 drivers/tty/serial/sb1250-duart.c           |   12 +-
 drivers/tty/serial/sc16is7xx.c              |  366 +++---
 drivers/tty/serial/serial-tegra.c           |   32 +-
 drivers/tty/serial/serial_core.c            |  116 +-
 drivers/tty/serial/serial_mctrl_gpio.c      |    4 +-
 drivers/tty/serial/serial_port.c            |    4 +-
 drivers/tty/serial/serial_txx9.c            |   26 +-
 drivers/tty/serial/sh-sci.c                 |   68 +-
 drivers/tty/serial/sifive.c                 |   16 +-
 drivers/tty/serial/sprd_serial.c            |   30 +-
 drivers/tty/serial/st-asc.c                 |   24 +-
 drivers/tty/serial/stm32-usart.c            |   42 +-
 drivers/tty/serial/sunhv.c                  |   28 +-
 drivers/tty/serial/sunplus-uart.c           |   26 +-
 drivers/tty/serial/sunsab.c                 |   34 +-
 drivers/tty/serial/sunsu.c                  |   46 +-
 drivers/tty/serial/sunzilog.c               |   42 +-
 drivers/tty/serial/timbuart.c               |    8 +-
 drivers/tty/serial/uartlite.c               |   18 +-
 drivers/tty/serial/ucc_uart.c               |    5 +-
 drivers/tty/serial/vt8500_serial.c          |    8 +-
 drivers/tty/serial/xilinx_uartps.c          |   56 +-
 drivers/tty/tty.h                           |   13 +-
 drivers/tty/tty_audit.c                     |    7 +-
 drivers/tty/tty_io.c                        |    6 +-
 fs/proc/consoles.c                          |    6 +-
 include/linux/console.h                     |  235 ++--
 include/linux/printk.h                      |   29 +-
 include/linux/serial_8250.h                 |    9 +-
 include/linux/serial_core.h                 |   95 +-
 kernel/locking/lockdep.c                    |    5 +
 kernel/panic.c                              |   33 +-
 kernel/printk/Makefile                      |    2 +-
 kernel/printk/internal.h                    |  164 +--
 kernel/printk/nbcon.c                       | 1664 ++++++++++++++++++++++++
 kernel/printk/printk.c                      |  737 ++++++-----
 kernel/printk/printk_nobkl.c                | 1825 ---------------------------
 kernel/printk/printk_ringbuffer.c           |  360 +++++-
 kernel/printk/printk_ringbuffer.h           |   54 +-
 kernel/printk/printk_safe.c                 |   31 +-
 kernel/rcu/tree_stall.h                     |    5 +-
 94 files changed, 4436 insertions(+), 4437 deletions(-)

diff --git a/drivers/tty/serial/21285.c b/drivers/tty/serial/21285.c
index d756fcc884cb..4de0c975ebdc 100644
--- a/drivers/tty/serial/21285.c
+++ b/drivers/tty/serial/21285.c
@@ -185,14 +185,14 @@ static void serial21285_break_ctl(struct uart_port *port, int break_state)
 	unsigned long flags;
 	unsigned int h_lcr;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	h_lcr = *CSR_H_UBRLCR;
 	if (break_state)
 		h_lcr |= H_UBRLCR_BREAK;
 	else
 		h_lcr &= ~H_UBRLCR_BREAK;
 	*CSR_H_UBRLCR = h_lcr;
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static int serial21285_startup(struct uart_port *port)
@@ -272,7 +272,7 @@ serial21285_set_termios(struct uart_port *port, struct ktermios *termios,
 	if (port->fifosize)
 		h_lcr |= H_UBRLCR_FIFO;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/*
 	 * Update the per-port timeout.
@@ -309,7 +309,7 @@ serial21285_set_termios(struct uart_port *port, struct ktermios *termios,
 	*CSR_H_UBRLCR = h_lcr;
 	*CSR_UARTCON = 1;
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static const char *serial21285_type(struct uart_port *port)
diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index 2ec04e071a65..1aa3e55c8b47 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -176,271 +176,6 @@ static inline void serial_dl_write(struct uart_8250_port *up, u32 value)
 	up->dl_write(up, value);
 }
 
-static inline bool serial8250_is_console(struct uart_port *port)
-{
-	return uart_console(port) && !hlist_unhashed_lockless(&port->cons->node);
-}
-
-/**
- * serial8250_init_wctxt - Initialize a write context for
- *	non-console-printing usage
- * @wctxt:	The write context to initialize
- * @cons:	The console to assign to the write context
- *
- * In order to mark an unsafe region, drivers must acquire the console. This
- * requires providing an initialized write context (even if that driver will
- * not be doing any printing).
- *
- * This function should not be used for console printing contexts.
- */
-static inline void serial8250_init_wctxt(struct cons_write_context *wctxt,
-					 struct console *cons)
-{
-	struct cons_context *ctxt = &ACCESS_PRIVATE(wctxt, ctxt);
-
-	memset(wctxt, 0, sizeof(*wctxt));
-	ctxt->console = cons;
-	ctxt->prio = CONS_PRIO_NORMAL;
-}
-
-/**
- * __serial8250_console_acquire - Acquire a console for
- *	non-console-printing usage
- * @wctxt:	An uninitialized write context to use for acquiring
- * @cons:	The console to assign to the write context
- *
- * The caller is holding the port->lock.
- * The caller is holding the console_srcu_read_lock.
- *
- * This function should not be used for console printing contexts.
- */
-static inline void __serial8250_console_acquire(struct cons_write_context *wctxt,
-						struct console *cons)
-{
-	for (;;) {
-		serial8250_init_wctxt(wctxt, cons);
-		if (console_try_acquire(wctxt))
-			break;
-		cpu_relax();
-	}
-}
-
-/**
- * serial8250_enter_unsafe - Mark the beginning of an unsafe region for
- *		non-console-printing usage
- * @up:	The port that is entering the unsafe state
- *
- * The caller should ensure @up is a console before calling this function.
- *
- * The caller is holding the port->lock.
- * This function takes the console_srcu_read_lock and becomes owner of the
- * console associated with @up.
- *
- * This function should not be used for console printing contexts.
- */
-static inline void serial8250_enter_unsafe(struct uart_8250_port *up)
-{
-	struct uart_port *port = &up->port;
-
-	lockdep_assert_held_once(&port->lock);
-
-	for (;;) {
-		up->cookie = console_srcu_read_lock();
-
-		__serial8250_console_acquire(&up->wctxt, port->cons);
-
-		if (console_enter_unsafe(&up->wctxt))
-			break;
-
-		console_srcu_read_unlock(up->cookie);
-		cpu_relax();
-	}
-}
-
-/**
- * serial8250_exit_unsafe - Mark the end of an unsafe region for
- *		non-console-printing usage
- * @up:	The port that is exiting the unsafe state
- *
- * The caller is holding the port->lock.
- * This function releases ownership of the console associated with @up and
- * releases the console_srcu_read_lock.
- *
- * This function should not be used for console printing contexts.
- */
-static inline void serial8250_exit_unsafe(struct uart_8250_port *up)
-{
-	struct uart_port *port = &up->port;
-
-	lockdep_assert_held_once(&port->lock);
-
-	if (console_exit_unsafe(&up->wctxt))
-		console_release(&up->wctxt);
-
-	console_srcu_read_unlock(up->cookie);
-}
-
-/**
- * serial8250_in_IER - Read the IER register for
- *		non-console-printing usage
- * @up:	The port to work on
- *
- * Returns:	The value read from IER
- *
- * The caller is holding the port->lock.
- *
- * This is the top-level function for non-console-printing contexts to
- * read the IER register. The caller does not need to care if @up is a
- * console before calling this function.
- *
- * This function should not be used for printing contexts.
- */
-static inline int serial8250_in_IER(struct uart_8250_port *up)
-{
-	struct uart_port *port = &up->port;
-	bool is_console;
-	int ier;
-
-	is_console = serial8250_is_console(port);
-
-	if (is_console)
-		serial8250_enter_unsafe(up);
-
-	ier = serial_in(up, UART_IER);
-
-	if (is_console)
-		serial8250_exit_unsafe(up);
-
-	return ier;
-}
-
-/**
- * __serial8250_set_IER - Directly write to the IER register
- * @up:		The port to work on
- * @wctxt:	The current write context
- * @ier:	The value to write
- *
- * Returns:	True if IER was written to. False otherwise
- *
- * The caller is holding the port->lock.
- * The caller is holding the console_srcu_read_unlock.
- * The caller is the owner of the console associated with @up.
- *
- * This function should only be directly called within console printing
- * contexts. Other contexts should use serial8250_set_IER().
- */
-static inline bool __serial8250_set_IER(struct uart_8250_port *up,
-					struct cons_write_context *wctxt,
-					int ier)
-{
-	if (wctxt && !console_can_proceed(wctxt))
-		return false;
-	serial_out(up, UART_IER, ier);
-	return true;
-}
-
-/**
- * serial8250_set_IER - Write a new value to the IER register for
- *	non-console-printing usage
- * @up:		The port to work on
- * @ier:	The value to write
- *
- * The caller is holding the port->lock.
- *
- * This is the top-level function for non-console-printing contexts to
- * write to the IER register. The caller does not need to care if @up is a
- * console before calling this function.
- *
- * This function should not be used for printing contexts.
- */
-static inline void serial8250_set_IER(struct uart_8250_port *up, int ier)
-{
-	struct uart_port *port = &up->port;
-	bool is_console;
-
-	is_console = serial8250_is_console(port);
-
-	if (is_console) {
-		serial8250_enter_unsafe(up);
-		while (!__serial8250_set_IER(up, &up->wctxt, ier)) {
-			console_srcu_read_unlock(up->cookie);
-			console_enter_unsafe(&up->wctxt);
-		}
-		serial8250_exit_unsafe(up);
-	} else {
-		__serial8250_set_IER(up, NULL, ier);
-	}
-}
-
-/**
- * __serial8250_clear_IER - Directly clear the IER register
- * @up:		The port to work on
- * @wctxt:	The current write context
- * @prior:	Gets set to the previous value of IER
- *
- * Returns:	True if IER was cleared and @prior points to the previous
- *		value of IER. False otherwise and @prior is invalid
- *
- * The caller is holding the port->lock.
- * The caller is holding the console_srcu_read_unlock.
- * The caller is the owner of the console associated with @up.
- *
- * This function should only be directly called within console printing
- * contexts. Other contexts should use serial8250_clear_IER().
- */
-static inline bool __serial8250_clear_IER(struct uart_8250_port *up,
-					  struct cons_write_context *wctxt,
-					  int *prior)
-{
-	unsigned int clearval = 0;
-
-	if (up->capabilities & UART_CAP_UUE)
-		clearval = UART_IER_UUE;
-
-	*prior = serial_in(up, UART_IER);
-	if (wctxt && !console_can_proceed(wctxt))
-		return false;
-	serial_out(up, UART_IER, clearval);
-	return true;
-}
-
-/**
- * serial8250_clear_IER - Clear the IER register for
- *		non-console-printing usage
- * @up:	The port to work on
- *
- * Returns:	The previous value of IER
- *
- * The caller is holding the port->lock.
- *
- * This is the top-level function for non-console-printing contexts to
- * clear the IER register. The caller does not need to care if @up is a
- * console before calling this function.
- *
- * This function should not be used for printing contexts.
- */
-static inline int serial8250_clear_IER(struct uart_8250_port *up)
-{
-	struct uart_port *port = &up->port;
-	bool is_console;
-	int prior;
-
-	is_console = serial8250_is_console(port);
-
-	if (is_console) {
-		serial8250_enter_unsafe(up);
-		while (!__serial8250_clear_IER(up, &up->wctxt, &prior)) {
-			console_srcu_read_unlock(up->cookie);
-			console_enter_unsafe(&up->wctxt);
-		}
-		serial8250_exit_unsafe(up);
-	} else {
-		__serial8250_clear_IER(up, NULL, &prior);
-	}
-
-	return prior;
-}
-
 static inline bool serial8250_set_THRI(struct uart_8250_port *up)
 {
 	/* Port locked to synchronize UART_IER access against the console. */
@@ -449,7 +184,7 @@ static inline bool serial8250_set_THRI(struct uart_8250_port *up)
 	if (up->ier & UART_IER_THRI)
 		return false;
 	up->ier |= UART_IER_THRI;
-	serial8250_set_IER(up, up->ier);
+	serial_out(up, UART_IER, up->ier);
 	return true;
 }
 
@@ -461,7 +196,7 @@ static inline bool serial8250_clear_THRI(struct uart_8250_port *up)
 	if (!(up->ier & UART_IER_THRI))
 		return false;
 	up->ier &= ~UART_IER_THRI;
-	serial8250_set_IER(up, up->ier);
+	serial_out(up, UART_IER, up->ier);
 	return true;
 }
 
diff --git a/drivers/tty/serial/8250/8250_aspeed_vuart.c b/drivers/tty/serial/8250/8250_aspeed_vuart.c
index e813de4fd5b0..021949f252f8 100644
--- a/drivers/tty/serial/8250/8250_aspeed_vuart.c
+++ b/drivers/tty/serial/8250/8250_aspeed_vuart.c
@@ -281,16 +281,16 @@ static void __aspeed_vuart_set_throttle(struct uart_8250_port *up,
 	up->ier &= ~irqs;
 	if (!throttle)
 		up->ier |= irqs;
-	serial8250_set_IER(up, up->ier);
+	serial_out(up, UART_IER, up->ier);
 }
 static void aspeed_vuart_set_throttle(struct uart_port *port, bool throttle)
 {
 	struct uart_8250_port *up = up_to_u8250p(port);
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	__aspeed_vuart_set_throttle(up, throttle);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void aspeed_vuart_throttle(struct uart_port *port)
@@ -340,7 +340,7 @@ static int aspeed_vuart_handle_irq(struct uart_port *port)
 	if (iir & UART_IIR_NO_INT)
 		return 0;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	lsr = serial_port_in(port, UART_LSR);
 
diff --git a/drivers/tty/serial/8250/8250_bcm7271.c b/drivers/tty/serial/8250/8250_bcm7271.c
index 0950d41cf542..ff0662c68725 100644
--- a/drivers/tty/serial/8250/8250_bcm7271.c
+++ b/drivers/tty/serial/8250/8250_bcm7271.c
@@ -567,7 +567,7 @@ static irqreturn_t brcmuart_isr(int irq, void *dev_id)
 	if (interrupts == 0)
 		return IRQ_NONE;
 
-	spin_lock_irqsave(&up->lock, flags);
+	uart_port_lock_irqsave(up, &flags);
 
 	/* Clear all interrupts */
 	udma_writel(priv, REGS_DMA_ISR, UDMA_INTR_CLEAR, interrupts);
@@ -581,7 +581,7 @@ static irqreturn_t brcmuart_isr(int irq, void *dev_id)
 	if ((rval | tval) == 0)
 		dev_warn(dev, "Spurious interrupt: 0x%x\n", interrupts);
 
-	spin_unlock_irqrestore(&up->lock, flags);
+	uart_port_unlock_irqrestore(up, flags);
 	return IRQ_HANDLED;
 }
 
@@ -608,10 +608,10 @@ static int brcmuart_startup(struct uart_port *port)
 	 *
 	 * Synchronize UART_IER access against the console.
 	 */
-	spin_lock_irq(&port->lock);
+	uart_port_lock_irq(port);
 	up->ier &= ~UART_IER_RDI;
-	serial8250_set_IER(up, up->ier);
-	spin_unlock_irq(&port->lock);
+	serial_port_out(port, UART_IER, up->ier);
+	uart_port_unlock_irq(port);
 
 	priv->tx_running = false;
 	priv->dma.rx_dma = NULL;
@@ -629,7 +629,7 @@ static void brcmuart_shutdown(struct uart_port *port)
 	struct brcmuart_priv *priv = up->port.private_data;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	priv->shutdown = true;
 	if (priv->dma_enabled) {
 		stop_rx_dma(up);
@@ -645,7 +645,7 @@ static void brcmuart_shutdown(struct uart_port *port)
 	 */
 	up->dma = NULL;
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 	serial8250_do_shutdown(port);
 }
 
@@ -788,15 +788,9 @@ static int brcmuart_handle_irq(struct uart_port *p)
 	 * interrupt but there is no data ready.
 	 */
 	if (((iir & UART_IIR_ID) == UART_IIR_RX_TIMEOUT) && !(priv->shutdown)) {
-		spin_lock_irqsave(&p->lock, flags);
+		uart_port_lock_irqsave(p, &flags);
 		status = serial_port_in(p, UART_LSR);
 		if ((status & UART_LSR_DR) == 0) {
-			bool is_console;
-
-			is_console = serial8250_is_console(p);
-
-			if (is_console)
-				serial8250_enter_unsafe(up);
 
 			ier = serial_port_in(p, UART_IER);
 			/*
@@ -817,12 +811,9 @@ static int brcmuart_handle_irq(struct uart_port *p)
 				serial_port_in(p, UART_RX);
 			}
 
-			if (is_console)
-				serial8250_exit_unsafe(up);
-
 			handled = 1;
 		}
-		spin_unlock_irqrestore(&p->lock, flags);
+		uart_port_unlock_irqrestore(p, flags);
 		if (handled)
 			return 1;
 	}
@@ -840,7 +831,7 @@ static enum hrtimer_restart brcmuart_hrtimer_func(struct hrtimer *t)
 	if (priv->shutdown)
 		return HRTIMER_NORESTART;
 
-	spin_lock_irqsave(&p->lock, flags);
+	uart_port_lock_irqsave(p, &flags);
 	status = serial_port_in(p, UART_LSR);
 
 	/*
@@ -857,24 +848,14 @@ static enum hrtimer_restart brcmuart_hrtimer_func(struct hrtimer *t)
 	/* re-enable receive unless upper layer has disabled it */
 	if ((up->ier & (UART_IER_RLSI | UART_IER_RDI)) ==
 	    (UART_IER_RLSI | UART_IER_RDI)) {
-		bool is_console;
-
-		is_console = serial8250_is_console(p);
-
-		if (is_console)
-			serial8250_enter_unsafe(up);
-
 		status = serial_port_in(p, UART_IER);
 		status |= (UART_IER_RLSI | UART_IER_RDI);
 		serial_port_out(p, UART_IER, status);
 		status = serial_port_in(p, UART_MCR);
 		status |= UART_MCR_RTS;
 		serial_port_out(p, UART_MCR, status);
-
-		if (is_console)
-			serial8250_exit_unsafe(up);
 	}
-	spin_unlock_irqrestore(&p->lock, flags);
+	uart_port_unlock_irqrestore(p, flags);
 	return HRTIMER_NORESTART;
 }
 
@@ -1173,10 +1154,10 @@ static int __maybe_unused brcmuart_suspend(struct device *dev)
 	 * This will prevent resume from enabling RTS before the
 	 *  baud rate has been restored.
 	 */
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	priv->saved_mctrl = port->mctrl;
 	port->mctrl &= ~TIOCM_RTS;
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	serial8250_suspend_port(priv->line);
 	clk_disable_unprepare(priv->baud_mux_clk);
@@ -1215,10 +1196,10 @@ static int __maybe_unused brcmuart_resume(struct device *dev)
 
 	if (priv->saved_mctrl & TIOCM_RTS) {
 		/* Restore RTS */
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 		port->mctrl |= TIOCM_RTS;
 		port->ops->set_mctrl(port, port->mctrl);
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 	}
 
 	return 0;
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 7de38c1150d7..30434718fad8 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -256,34 +256,18 @@ static void serial8250_timeout(struct timer_list *t)
 static void serial8250_backup_timeout(struct timer_list *t)
 {
 	struct uart_8250_port *up = from_timer(up, t, timer);
-	struct uart_port *port = &up->port;
 	unsigned int iir, ier = 0, lsr;
 	unsigned long flags;
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 
 	/*
 	 * Must disable interrupts or else we risk racing with the interrupt
 	 * based handler.
 	 */
 	if (up->port.irq) {
-		bool is_console;
-
-		/*
-		 * Do not use serial8250_clear_IER() because this code
-		 * ignores capabilties.
-		 */
-
-		is_console = serial8250_is_console(port);
-
-		if (is_console)
-			serial8250_enter_unsafe(up);
-
 		ier = serial_in(up, UART_IER);
 		serial_out(up, UART_IER, 0);
-
-		if (is_console)
-			serial8250_exit_unsafe(up);
 	}
 
 	iir = serial_in(up, UART_IIR);
@@ -306,9 +290,9 @@ static void serial8250_backup_timeout(struct timer_list *t)
 		serial8250_tx_chars(up);
 
 	if (up->port.irq)
-		serial8250_set_IER(up, ier);
+		serial_out(up, UART_IER, ier);
 
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 
 	/* Standard timer interval plus 0.2s to keep the port running */
 	mod_timer(&up->timer,
@@ -513,6 +497,7 @@ static struct uart_8250_port *serial8250_setup_port(int index)
 
 	up = &serial8250_ports[index];
 	up->port.line = index;
+	up->port.port_id = index;
 
 	serial8250_init_port(up);
 	if (!base_ops)
@@ -607,18 +592,17 @@ serial8250_register_ports(struct uart_driver *drv, struct device *dev)
 
 #ifdef CONFIG_SERIAL_8250_CONSOLE
 
-static void univ8250_console_port_lock(struct console *con, bool do_lock, unsigned long *flags)
+#ifdef CONFIG_SERIAL_8250_LEGACY_CONSOLE
+static void univ8250_console_write(struct console *co, const char *s,
+				   unsigned int count)
 {
-	struct uart_8250_port *up = &serial8250_ports[con->index];
+	struct uart_8250_port *up = &serial8250_ports[co->index];
 
-	if (do_lock)
-		spin_lock_irqsave(&up->port.lock, *flags);
-	else
-		spin_unlock_irqrestore(&up->port.lock, *flags);
+	serial8250_console_write(up, s, count);
 }
-
+#else
 static bool univ8250_console_write_atomic(struct console *co,
-					  struct cons_write_context *wctxt)
+					  struct nbcon_write_context *wctxt)
 {
 	struct uart_8250_port *up = &serial8250_ports[co->index];
 
@@ -626,13 +610,28 @@ static bool univ8250_console_write_atomic(struct console *co,
 }
 
 static bool univ8250_console_write_thread(struct console *co,
-					  struct cons_write_context *wctxt)
+					  struct nbcon_write_context *wctxt)
 {
 	struct uart_8250_port *up = &serial8250_ports[co->index];
 
 	return serial8250_console_write_thread(up, wctxt);
 }
 
+static void univ8250_console_driver_enter(struct console *con, unsigned long *flags)
+{
+	struct uart_port *up = &serial8250_ports[con->index].port;
+
+	__uart_port_lock_irqsave(up, flags);
+}
+
+static void univ8250_console_driver_exit(struct console *con, unsigned long flags)
+{
+	struct uart_port *up = &serial8250_ports[con->index].port;
+
+	__uart_port_unlock_irqrestore(up, flags);
+}
+#endif /* CONFIG_SERIAL_8250_LEGACY_CONSOLE */
+
 static int univ8250_console_setup(struct console *co, char *options)
 {
 	struct uart_8250_port *up;
@@ -731,14 +730,20 @@ static int univ8250_console_match(struct console *co, char *name, int idx,
 
 static struct console univ8250_console = {
 	.name		= "ttyS",
+#ifdef CONFIG_SERIAL_8250_LEGACY_CONSOLE
+	.write		= univ8250_console_write,
+	.flags		= CON_PRINTBUFFER | CON_ANYTIME,
+#else
 	.write_atomic	= univ8250_console_write_atomic,
 	.write_thread	= univ8250_console_write_thread,
-	.port_lock	= univ8250_console_port_lock,
+	.driver_enter	= univ8250_console_driver_enter,
+	.driver_exit	= univ8250_console_driver_exit,
+	.flags		= CON_PRINTBUFFER | CON_ANYTIME | CON_NBCON,
+#endif
 	.device		= uart_console_device,
 	.setup		= univ8250_console_setup,
 	.exit		= univ8250_console_exit,
 	.match		= univ8250_console_match,
-	.flags		= CON_PRINTBUFFER | CON_ANYTIME | CON_NO_BKL,
 	.index		= -1,
 	.data		= &serial8250_reg,
 };
@@ -1027,11 +1032,11 @@ static void serial_8250_overrun_backoff_work(struct work_struct *work)
 	struct uart_port *port = &up->port;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	up->ier |= UART_IER_RLSI | UART_IER_RDI;
 	up->port.read_status_mask |= UART_LSR_DR;
-	serial8250_set_IER(up, up->ier);
-	spin_unlock_irqrestore(&port->lock, flags);
+	serial_out(up, UART_IER, up->ier);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 /**
@@ -1076,6 +1081,7 @@ int serial8250_register_8250_port(const struct uart_8250_port *up)
 			uart_remove_one_port(&serial8250_reg, &uart->port);
 
 		uart->port.ctrl_id	= up->port.ctrl_id;
+		uart->port.port_id	= up->port.port_id;
 		uart->port.iobase       = up->port.iobase;
 		uart->port.membase      = up->port.membase;
 		uart->port.irq          = up->port.irq;
@@ -1228,9 +1234,9 @@ void serial8250_unregister_port(int line)
 	if (uart->em485) {
 		unsigned long flags;
 
-		spin_lock_irqsave(&uart->port.lock, flags);
+		uart_port_lock_irqsave(&uart->port, &flags);
 		serial8250_em485_destroy(uart);
-		spin_unlock_irqrestore(&uart->port.lock, flags);
+		uart_port_unlock_irqrestore(&uart->port, flags);
 	}
 
 	uart_remove_one_port(&serial8250_reg, &uart->port);
@@ -1238,6 +1244,7 @@ void serial8250_unregister_port(int line)
 		uart->port.flags &= ~UPF_BOOT_AUTOCONF;
 		uart->port.type = PORT_UNKNOWN;
 		uart->port.dev = &serial8250_isa_devs->dev;
+		uart->port.port_id = line;
 		uart->capabilities = 0;
 		serial8250_init_port(uart);
 		serial8250_apply_quirks(uart);
diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c
index 7fa66501792d..8b30ca8fdd3f 100644
--- a/drivers/tty/serial/8250/8250_dma.c
+++ b/drivers/tty/serial/8250/8250_dma.c
@@ -22,7 +22,7 @@ static void __dma_tx_complete(void *param)
 	dma_sync_single_for_cpu(dma->txchan->device->dev, dma->tx_addr,
 				UART_XMIT_SIZE, DMA_TO_DEVICE);
 
-	spin_lock_irqsave(&p->port.lock, flags);
+	uart_port_lock_irqsave(&p->port, &flags);
 
 	dma->tx_running = 0;
 
@@ -35,7 +35,7 @@ static void __dma_tx_complete(void *param)
 	if (ret || !dma->tx_running)
 		serial8250_set_THRI(p);
 
-	spin_unlock_irqrestore(&p->port.lock, flags);
+	uart_port_unlock_irqrestore(&p->port, flags);
 }
 
 static void __dma_rx_complete(struct uart_8250_port *p)
@@ -70,7 +70,7 @@ static void dma_rx_complete(void *param)
 	struct uart_8250_dma *dma = p->dma;
 	unsigned long flags;
 
-	spin_lock_irqsave(&p->port.lock, flags);
+	uart_port_lock_irqsave(&p->port, &flags);
 	if (dma->rx_running)
 		__dma_rx_complete(p);
 
@@ -80,7 +80,7 @@ static void dma_rx_complete(void *param)
 	 */
 	if (!dma->rx_running && (serial_lsr_in(p) & UART_LSR_DR))
 		p->dma->rx_dma(p);
-	spin_unlock_irqrestore(&p->port.lock, flags);
+	uart_port_unlock_irqrestore(&p->port, flags);
 }
 
 int serial8250_tx_dma(struct uart_8250_port *p)
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index d38f122c5fe6..53c284bb271d 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -263,20 +263,20 @@ static int dw8250_handle_irq(struct uart_port *p)
 	 * so we limit the workaround only to non-DMA mode.
 	 */
 	if (!up->dma && rx_timeout) {
-		spin_lock_irqsave(&p->lock, flags);
+		uart_port_lock_irqsave(p, &flags);
 		status = serial_lsr_in(up);
 
 		if (!(status & (UART_LSR_DR | UART_LSR_BI)))
 			(void) p->serial_in(p, UART_RX);
 
-		spin_unlock_irqrestore(&p->lock, flags);
+		uart_port_unlock_irqrestore(p, flags);
 	}
 
 	/* Manually stop the Rx DMA transfer when acting as flow controller */
 	if (quirks & DW_UART_QUIRK_IS_DMA_FC && up->dma && up->dma->rx_running && rx_timeout) {
-		spin_lock_irqsave(&p->lock, flags);
+		uart_port_lock_irqsave(p, &flags);
 		status = serial_lsr_in(up);
-		spin_unlock_irqrestore(&p->lock, flags);
+		uart_port_unlock_irqrestore(p, flags);
 
 		if (status & (UART_LSR_DR | UART_LSR_BI)) {
 			dw8250_writel_ext(p, RZN1_UART_RDMACR, 0);
@@ -357,9 +357,9 @@ static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios,
 	long rate;
 	int ret;
 
+	clk_disable_unprepare(d->clk);
 	rate = clk_round_rate(d->clk, newrate);
-	if (rate > 0 && p->uartclk != rate) {
-		clk_disable_unprepare(d->clk);
+	if (rate > 0) {
 		/*
 		 * Note that any clock-notifer worker will block in
 		 * serial8250_update_uartclk() until we are done.
@@ -367,8 +367,8 @@ static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios,
 		ret = clk_set_rate(d->clk, newrate);
 		if (!ret)
 			p->uartclk = rate;
-		clk_prepare_enable(d->clk);
 	}
+	clk_prepare_enable(d->clk);
 
 	dw8250_do_set_termios(p, termios, old);
 }
@@ -523,7 +523,10 @@ static int dw8250_probe(struct platform_device *pdev)
 	if (!regs)
 		return dev_err_probe(dev, -EINVAL, "no registers defined\n");
 
-	irq = platform_get_irq(pdev, 0);
+	irq = platform_get_irq_optional(pdev, 0);
+	/* no interrupt -> fall back to polling */
+	if (irq == -ENXIO)
+		irq = 0;
 	if (irq < 0)
 		return irq;
 
diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c
index 6e33ad7d3db9..07ad21336301 100644
--- a/drivers/tty/serial/8250/8250_exar.c
+++ b/drivers/tty/serial/8250/8250_exar.c
@@ -47,6 +47,12 @@
 #define PCI_SUBDEVICE_ID_USR_2980		0x0128
 #define PCI_SUBDEVICE_ID_USR_2981		0x0129
 
+#define PCI_DEVICE_ID_SEALEVEL_710xC		0x1001
+#define PCI_DEVICE_ID_SEALEVEL_720xC		0x1002
+#define PCI_DEVICE_ID_SEALEVEL_740xC		0x1004
+#define PCI_DEVICE_ID_SEALEVEL_780xC		0x1008
+#define PCI_DEVICE_ID_SEALEVEL_716xC		0x1010
+
 #define UART_EXAR_INT0		0x80
 #define UART_EXAR_8XMODE	0x88	/* 8X sampling rate select */
 #define UART_EXAR_SLEEP		0x8b	/* Sleep mode */
@@ -78,9 +84,6 @@
 
 #define UART_EXAR_RS485_DLY(x)	((x) << 4)
 
-#define UART_EXAR_DLD			0x02 /* Divisor Fractional */
-#define UART_EXAR_DLD_485_POLARITY	0x80 /* RS-485 Enable Signal Polarity */
-
 /*
  * IOT2040 MPIO wiring semantics:
  *
@@ -186,10 +189,6 @@ static void xr17v35x_set_divisor(struct uart_port *p, unsigned int baud,
 
 static int xr17v35x_startup(struct uart_port *port)
 {
-	struct uart_8250_port *up = up_to_u8250p(port);
-
-	spin_lock_irq(&port->lock);
-
 	/*
 	 * First enable access to IER [7:5], ISR [5:4], FCR [5:4],
 	 * MCR [7:5] and MSR [7:0]
@@ -202,9 +201,9 @@ static int xr17v35x_startup(struct uart_port *port)
 	 *
 	 * Synchronize UART_IER access against the console.
 	 */
-	spin_lock_irq(&port->lock);
-	serial8250_set_IER(up, 0);
-	spin_unlock_irq(&port->lock);
+	uart_port_lock_irq(port);
+	serial_port_out(port, UART_IER, 0);
+	uart_port_unlock_irq(port);
 
 	return serial8250_do_startup(port);
 }
@@ -446,46 +445,8 @@ static int generic_rs485_config(struct uart_port *port, struct ktermios *termios
 	return 0;
 }
 
-static int sealevel_rs485_config(struct uart_port *port, struct ktermios *termios,
-				  struct serial_rs485 *rs485)
-{
-	u8 __iomem *p = port->membase;
-	u8 old_lcr;
-	u8 efr;
-	u8 dld;
-	int ret;
-
-	ret = generic_rs485_config(port, termios, rs485);
-	if (ret)
-		return ret;
-
-	if (rs485->flags & SER_RS485_ENABLED) {
-		old_lcr = readb(p + UART_LCR);
-
-		/* Set EFR[4]=1 to enable enhanced feature registers */
-		efr = readb(p + UART_XR_EFR);
-		efr |= UART_EFR_ECB;
-		writeb(efr, p + UART_XR_EFR);
-
-		/* Set MCR to use DTR as Auto-RS485 Enable signal */
-		writeb(UART_MCR_OUT1, p + UART_MCR);
-
-		/* Set LCR[7]=1 to enable access to DLD register */
-		writeb(old_lcr | UART_LCR_DLAB, p + UART_LCR);
-
-		/* Set DLD[7]=1 for inverted RS485 Enable logic */
-		dld = readb(p + UART_EXAR_DLD);
-		dld |= UART_EXAR_DLD_485_POLARITY;
-		writeb(dld, p + UART_EXAR_DLD);
-
-		writeb(old_lcr, p + UART_LCR);
-	}
-
-	return 0;
-}
-
 static const struct serial_rs485 generic_rs485_supported = {
-	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND,
+	.flags = SER_RS485_ENABLED,
 };
 
 static const struct exar8250_platform exar8250_default_platform = {
@@ -529,8 +490,7 @@ static int iot2040_rs485_config(struct uart_port *port, struct ktermios *termios
 }
 
 static const struct serial_rs485 iot2040_rs485_supported = {
-	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND |
-		 SER_RS485_RX_DURING_TX | SER_RS485_TERMINATE_BUS,
+	.flags = SER_RS485_ENABLED | SER_RS485_RX_DURING_TX | SER_RS485_TERMINATE_BUS,
 };
 
 static const struct property_entry iot2040_gpio_properties[] = {
@@ -606,9 +566,6 @@ pci_xr17v35x_setup(struct exar8250 *priv, struct pci_dev *pcidev,
 	port->port.rs485_config = platform->rs485_config;
 	port->port.rs485_supported = *(platform->rs485_supported);
 
-	if (pcidev->subsystem_vendor == PCI_VENDOR_ID_SEALEVEL)
-		port->port.rs485_config = sealevel_rs485_config;
-
 	/*
 	 * Setup the UART clock for the devices on expansion slot to
 	 * half the clock speed of the main chip (which is 125MHz)
@@ -695,6 +652,8 @@ exar_pci_probe(struct pci_dev *pcidev, const struct pci_device_id *ent)
 		nr_ports = BIT(((pcidev->device & 0x38) >> 3) - 1);
 	else if (board->num_ports)
 		nr_ports = board->num_ports;
+	else if (pcidev->vendor == PCI_VENDOR_ID_SEALEVEL)
+		nr_ports = pcidev->device & 0xff;
 	else
 		nr_ports = pcidev->device & 0x0f;
 
@@ -934,6 +893,12 @@ static const struct pci_device_id exar_pci_tbl[] = {
 	EXAR_DEVICE(COMMTECH, 4224PCI335, pbn_fastcom335_4),
 	EXAR_DEVICE(COMMTECH, 2324PCI335, pbn_fastcom335_4),
 	EXAR_DEVICE(COMMTECH, 2328PCI335, pbn_fastcom335_8),
+
+	EXAR_DEVICE(SEALEVEL, 710xC, pbn_exar_XR17V35x),
+	EXAR_DEVICE(SEALEVEL, 720xC, pbn_exar_XR17V35x),
+	EXAR_DEVICE(SEALEVEL, 740xC, pbn_exar_XR17V35x),
+	EXAR_DEVICE(SEALEVEL, 780xC, pbn_exar_XR17V35x),
+	EXAR_DEVICE(SEALEVEL, 716xC, pbn_exar_XR17V35x),
 	{ 0, }
 };
 MODULE_DEVICE_TABLE(pci, exar_pci_tbl);
diff --git a/drivers/tty/serial/8250/8250_fsl.c b/drivers/tty/serial/8250/8250_fsl.c
index 24c76e46ed11..f522eb5026c9 100644
--- a/drivers/tty/serial/8250/8250_fsl.c
+++ b/drivers/tty/serial/8250/8250_fsl.c
@@ -30,11 +30,11 @@ int fsl8250_handle_irq(struct uart_port *port)
 	unsigned int iir;
 	struct uart_8250_port *up = up_to_u8250p(port);
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 
 	iir = port->serial_in(port, UART_IIR);
 	if (iir & UART_IIR_NO_INT) {
-		spin_unlock_irqrestore(&up->port.lock, flags);
+		uart_port_unlock_irqrestore(&up->port, flags);
 		return 0;
 	}
 
@@ -54,7 +54,7 @@ int fsl8250_handle_irq(struct uart_port *port)
 	if (unlikely(up->lsr_saved_flags & UART_LSR_BI)) {
 		up->lsr_saved_flags &= ~UART_LSR_BI;
 		port->serial_in(port, UART_RX);
-		spin_unlock_irqrestore(&up->port.lock, flags);
+		uart_port_unlock_irqrestore(&up->port, flags);
 		return 1;
 	}
 
@@ -70,8 +70,7 @@ int fsl8250_handle_irq(struct uart_port *port)
 	if ((orig_lsr & UART_LSR_OE) && (up->overrun_backoff_time_ms > 0)) {
 		unsigned long delay;
 
-		up->ier = serial8250_in_IER(up);
-
+		up->ier = port->serial_in(port, UART_IER);
 		if (up->ier & (UART_IER_RLSI | UART_IER_RDI)) {
 			port->ops->stop_rx(port);
 		} else {
diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index 899d3febca4e..23457daae8a1 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -102,7 +102,7 @@ static void mtk8250_dma_rx_complete(void *param)
 	if (data->rx_status == DMA_RX_SHUTDOWN)
 		return;
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 
 	dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
 	total = dma->rx_size - state.residue;
@@ -128,7 +128,7 @@ static void mtk8250_dma_rx_complete(void *param)
 
 	mtk8250_rx_dma(up);
 
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 }
 
 static void mtk8250_rx_dma(struct uart_8250_port *up)
@@ -222,44 +222,18 @@ static void mtk8250_shutdown(struct uart_port *port)
 
 static void mtk8250_disable_intrs(struct uart_8250_port *up, int mask)
 {
-	struct uart_port *port = &up->port;
-	bool is_console;
-	int ier;
-
 	/* Port locked to synchronize UART_IER access against the console. */
 	lockdep_assert_held_once(&up->port.lock);
 
-	is_console = serial8250_is_console(port);
-
-	if (is_console)
-		serial8250_enter_unsafe(up);
-
-	ier = serial_in(up, UART_IER);
-	serial_out(up, UART_IER, ier & (~mask));
-
-	if (is_console)
-		serial8250_exit_unsafe(up);
+	serial_out(up, UART_IER, serial_in(up, UART_IER) & (~mask));
 }
 
 static void mtk8250_enable_intrs(struct uart_8250_port *up, int mask)
 {
-	struct uart_port *port = &up->port;
-	bool is_console;
-	int ier;
-
 	/* Port locked to synchronize UART_IER access against the console. */
 	lockdep_assert_held_once(&up->port.lock);
 
-	is_console = serial8250_is_console(port);
-
-	if (is_console)
-		serial8250_enter_unsafe(up);
-
-	ier = serial_in(up, UART_IER);
-	serial_out(up, UART_IER, ier | mask);
-
-	if (is_console)
-		serial8250_exit_unsafe(up);
+	serial_out(up, UART_IER, serial_in(up, UART_IER) | mask);
 }
 
 static void mtk8250_set_flow_ctrl(struct uart_8250_port *up, int mode)
@@ -394,7 +368,7 @@ mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
 	 * Ok, we're now changing the port state.  Do it with
 	 * interrupts disabled.
 	 */
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/*
 	 * Update the per-port timeout.
@@ -442,7 +416,7 @@ mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
 	if (uart_console(port))
 		up->port.cons->cflag = termios->c_cflag;
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 	/* Don't rewrite B0 */
 	if (tty_termios_baud_rate(termios))
 		tty_termios_encode_baud_rate(termios, baud, baud);
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index ae160b8c0da7..5e0fbf340ef6 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -338,7 +338,8 @@ static void omap8250_restore_regs(struct uart_8250_port *up)
 
 	/* drop TCR + TLR access, we setup XON/XOFF later */
 	serial8250_out_MCR(up, mcr);
-	serial8250_set_IER(up, up->ier);
+
+	serial_out(up, UART_IER, up->ier);
 
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 	serial_dl_write(up, priv->quot);
@@ -400,7 +401,7 @@ static void omap_8250_set_termios(struct uart_port *port,
 	 * interrupts disabled.
 	 */
 	pm_runtime_get_sync(port->dev);
-	spin_lock_irq(&port->lock);
+	uart_port_lock_irq(port);
 
 	/*
 	 * Update the per-port timeout.
@@ -503,7 +504,7 @@ static void omap_8250_set_termios(struct uart_port *port,
 	}
 	omap8250_restore_regs(up);
 
-	spin_unlock_irq(&up->port.lock);
+	uart_port_unlock_irq(&up->port);
 	pm_runtime_mark_last_busy(port->dev);
 	pm_runtime_put_autosuspend(port->dev);
 
@@ -528,19 +529,19 @@ static void omap_8250_pm(struct uart_port *port, unsigned int state,
 	pm_runtime_get_sync(port->dev);
 
 	/* Synchronize UART_IER access against the console. */
-	spin_lock_irq(&port->lock);
+	uart_port_lock_irq(port);
 
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 	efr = serial_in(up, UART_EFR);
 	serial_out(up, UART_EFR, efr | UART_EFR_ECB);
 	serial_out(up, UART_LCR, 0);
 
-	serial8250_set_IER(up, (state != 0) ? UART_IERX_SLEEP : 0);
+	serial_out(up, UART_IER, (state != 0) ? UART_IERX_SLEEP : 0);
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 	serial_out(up, UART_EFR, efr);
 	serial_out(up, UART_LCR, 0);
 
-	spin_unlock_irq(&port->lock);
+	uart_port_unlock_irq(port);
 
 	pm_runtime_mark_last_busy(port->dev);
 	pm_runtime_put_autosuspend(port->dev);
@@ -659,7 +660,7 @@ static irqreturn_t omap8250_irq(int irq, void *dev_id)
 		unsigned long delay;
 
 		/* Synchronize UART_IER access against the console. */
-		spin_lock(&port->lock);
+		uart_port_lock(port);
 		up->ier = port->serial_in(port, UART_IER);
 		if (up->ier & (UART_IER_RLSI | UART_IER_RDI)) {
 			port->ops->stop_rx(port);
@@ -669,7 +670,7 @@ static irqreturn_t omap8250_irq(int irq, void *dev_id)
 			 */
 			cancel_delayed_work(&up->overrun_backoff);
 		}
-		spin_unlock(&port->lock);
+		uart_port_unlock(port);
 
 		delay = msecs_to_jiffies(up->overrun_backoff_time_ms);
 		schedule_delayed_work(&up->overrun_backoff, delay);
@@ -716,10 +717,10 @@ static int omap_8250_startup(struct uart_port *port)
 	}
 
 	/* Synchronize UART_IER access against the console. */
-	spin_lock_irq(&port->lock);
+	uart_port_lock_irq(port);
 	up->ier = UART_IER_RLSI | UART_IER_RDI;
-	serial8250_set_IER(up, up->ier);
-	spin_unlock_irq(&port->lock);
+	serial_out(up, UART_IER, up->ier);
+	uart_port_unlock_irq(port);
 
 #ifdef CONFIG_PM
 	up->capabilities |= UART_CAP_RPM;
@@ -732,9 +733,9 @@ static int omap_8250_startup(struct uart_port *port)
 	serial_out(up, UART_OMAP_WER, priv->wer);
 
 	if (up->dma && !(priv->habit & UART_HAS_EFR2)) {
-		spin_lock_irq(&port->lock);
+		uart_port_lock_irq(port);
 		up->dma->rx_dma(up);
-		spin_unlock_irq(&port->lock);
+		uart_port_unlock_irq(port);
 	}
 
 	enable_irq(up->port.irq);
@@ -760,10 +761,10 @@ static void omap_8250_shutdown(struct uart_port *port)
 		serial_out(up, UART_OMAP_EFR2, 0x0);
 
 	/* Synchronize UART_IER access against the console. */
-	spin_lock_irq(&port->lock);
+	uart_port_lock_irq(port);
 	up->ier = 0;
-	serial8250_set_IER(up, 0);
-	spin_unlock_irq(&port->lock);
+	serial_out(up, UART_IER, 0);
+	uart_port_unlock_irq(port);
 	disable_irq_nosync(up->port.irq);
 	dev_pm_clear_wake_irq(port->dev);
 
@@ -788,10 +789,10 @@ static void omap_8250_throttle(struct uart_port *port)
 
 	pm_runtime_get_sync(port->dev);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	port->ops->stop_rx(port);
 	priv->throttled = true;
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	pm_runtime_mark_last_busy(port->dev);
 	pm_runtime_put_autosuspend(port->dev);
@@ -806,14 +807,14 @@ static void omap_8250_unthrottle(struct uart_port *port)
 	pm_runtime_get_sync(port->dev);
 
 	/* Synchronize UART_IER access against the console. */
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	priv->throttled = false;
 	if (up->dma)
 		up->dma->rx_dma(up);
 	up->ier |= UART_IER_RLSI | UART_IER_RDI;
 	port->read_status_mask |= UART_LSR_DR;
-	serial8250_set_IER(up, up->ier);
-	spin_unlock_irqrestore(&port->lock, flags);
+	serial_out(up, UART_IER, up->ier);
+	uart_port_unlock_irqrestore(port, flags);
 
 	pm_runtime_mark_last_busy(port->dev);
 	pm_runtime_put_autosuspend(port->dev);
@@ -957,7 +958,7 @@ static void __dma_rx_complete(void *param)
 	unsigned long flags;
 
 	/* Synchronize UART_IER access against the console. */
-	spin_lock_irqsave(&p->port.lock, flags);
+	uart_port_lock_irqsave(&p->port, &flags);
 
 	/*
 	 * If the tx status is not DMA_COMPLETE, then this is a delayed
@@ -966,18 +967,18 @@ static void __dma_rx_complete(void *param)
 	 */
 	if (dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state) !=
 			DMA_COMPLETE) {
-		spin_unlock_irqrestore(&p->port.lock, flags);
+		uart_port_unlock_irqrestore(&p->port, flags);
 		return;
 	}
 	__dma_rx_do_complete(p);
 	if (!priv->throttled) {
 		p->ier |= UART_IER_RLSI | UART_IER_RDI;
-		serial8250_set_IER(p, p->ier);
+		serial_out(p, UART_IER, p->ier);
 		if (!(priv->habit & UART_HAS_EFR2))
 			omap_8250_rx_dma(p);
 	}
 
-	spin_unlock_irqrestore(&p->port.lock, flags);
+	uart_port_unlock_irqrestore(&p->port, flags);
 }
 
 static void omap_8250_rx_dma_flush(struct uart_8250_port *p)
@@ -1032,7 +1033,7 @@ static int omap_8250_rx_dma(struct uart_8250_port *p)
 			 * callback to run.
 			 */
 			p->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
-			serial8250_set_IER(p, p->ier);
+			serial_out(p, UART_IER, p->ier);
 		}
 		goto out;
 	}
@@ -1082,7 +1083,7 @@ static void omap_8250_dma_tx_complete(void *param)
 	dma_sync_single_for_cpu(dma->txchan->device->dev, dma->tx_addr,
 				UART_XMIT_SIZE, DMA_TO_DEVICE);
 
-	spin_lock_irqsave(&p->port.lock, flags);
+	uart_port_lock_irqsave(&p->port, &flags);
 
 	dma->tx_running = 0;
 
@@ -1111,7 +1112,7 @@ static void omap_8250_dma_tx_complete(void *param)
 		serial8250_set_THRI(p);
 	}
 
-	spin_unlock_irqrestore(&p->port.lock, flags);
+	uart_port_unlock_irqrestore(&p->port, flags);
 }
 
 static int omap_8250_tx_dma(struct uart_8250_port *p)
@@ -1248,12 +1249,12 @@ static void am654_8250_handle_rx_dma(struct uart_8250_port *up, u8 iir,
 		 * periodic timeouts, re-enable interrupts.
 		 */
 		up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
-		serial8250_set_IER(up, up->ier);
+		serial_out(up, UART_IER, up->ier);
 		omap_8250_rx_dma_flush(up);
 		serial_in(up, UART_IIR);
 		serial_out(up, UART_OMAP_EFR2, 0x0);
 		up->ier |= UART_IER_RLSI | UART_IER_RDI;
-		serial8250_set_IER(up, up->ier);
+		serial_out(up, UART_IER, up->ier);
 	}
 }
 
@@ -1277,7 +1278,7 @@ static int omap_8250_dma_handle_irq(struct uart_port *port)
 		return IRQ_HANDLED;
 	}
 
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 
 	status = serial_port_in(port, UART_LSR);
 
@@ -1580,7 +1581,7 @@ static int omap8250_remove(struct platform_device *pdev)
 
 	err = pm_runtime_resume_and_get(&pdev->dev);
 	if (err)
-		dev_err(&pdev->dev, "Failed to resume hardware\n");
+		return err;
 
 	up = serial8250_get_port(priv->line);
 	omap_8250_shutdown(&up->port);
@@ -1757,15 +1758,15 @@ static int omap8250_runtime_resume(struct device *dev)
 		up = serial8250_get_port(priv->line);
 
 	if (up && omap8250_lost_context(up)) {
-		spin_lock_irq(&up->port.lock);
+		uart_port_lock_irq(&up->port);
 		omap8250_restore_regs(up);
-		spin_unlock_irq(&up->port.lock);
+		uart_port_unlock_irq(&up->port);
 	}
 
 	if (up && up->dma && up->dma->rxchan && !(priv->habit & UART_HAS_EFR2)) {
-		spin_lock_irq(&up->port.lock);
+		uart_port_lock_irq(&up->port);
 		omap_8250_rx_dma(up);
-		spin_unlock_irq(&up->port.lock);
+		uart_port_unlock_irq(&up->port);
 	}
 
 	priv->latency = priv->calc_latency;
diff --git a/drivers/tty/serial/8250/8250_pci1xxxx.c b/drivers/tty/serial/8250/8250_pci1xxxx.c
index a3b25779d921..53e238c8cc89 100644
--- a/drivers/tty/serial/8250/8250_pci1xxxx.c
+++ b/drivers/tty/serial/8250/8250_pci1xxxx.c
@@ -225,10 +225,10 @@ static bool pci1xxxx_port_suspend(int line)
 	if (port->suspended == 0 && port->dev) {
 		wakeup_mask = readb(up->port.membase + UART_WAKE_MASK_REG);
 
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 		port->mctrl &= ~TIOCM_OUT2;
 		port->ops->set_mctrl(port, port->mctrl);
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 
 		ret = (wakeup_mask & UART_WAKE_SRCS) != UART_WAKE_SRCS;
 	}
@@ -251,10 +251,10 @@ static void pci1xxxx_port_resume(int line)
 	writeb(UART_WAKE_SRCS, port->membase + UART_WAKE_REG);
 
 	if (port->suspended == 0) {
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 		port->mctrl |= TIOCM_OUT2;
 		port->ops->set_mctrl(port, port->mctrl);
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 	}
 	mutex_unlock(&tport->mutex);
 }
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 866cedfc4628..437a7d3d34cd 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -557,6 +557,11 @@ static int serial8250_em485_init(struct uart_8250_port *p)
 	if (!p->em485)
 		return -ENOMEM;
 
+#ifndef CONFIG_SERIAL_8250_LEGACY_CONSOLE
+	if (uart_console(&p->port))
+		dev_warn(p->port.dev, "no atomic printing for rs485 consoles\n");
+#endif
+
 	hrtimer_init(&p->em485->stop_tx_timer, CLOCK_MONOTONIC,
 		     HRTIMER_MODE_REL);
 	hrtimer_init(&p->em485->start_tx_timer, CLOCK_MONOTONIC,
@@ -689,7 +694,7 @@ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
 
 	if (p->capabilities & UART_CAP_SLEEP) {
 		/* Synchronize UART_IER access against the console. */
-		spin_lock_irq(&p->port.lock);
+		uart_port_lock_irq(&p->port);
 		if (p->capabilities & UART_CAP_EFR) {
 			lcr = serial_in(p, UART_LCR);
 			efr = serial_in(p, UART_EFR);
@@ -697,18 +702,38 @@ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
 			serial_out(p, UART_EFR, UART_EFR_ECB);
 			serial_out(p, UART_LCR, 0);
 		}
-		serial8250_set_IER(p, sleep ? UART_IERX_SLEEP : 0);
+		serial_out(p, UART_IER, sleep ? UART_IERX_SLEEP : 0);
 		if (p->capabilities & UART_CAP_EFR) {
 			serial_out(p, UART_LCR, UART_LCR_CONF_MODE_B);
 			serial_out(p, UART_EFR, efr);
 			serial_out(p, UART_LCR, lcr);
 		}
-		spin_unlock_irq(&p->port.lock);
+		uart_port_unlock_irq(&p->port);
 	}
 
 	serial8250_rpm_put(p);
 }
 
+/*
+ * Only to be used by write_atomic() and the legacy write(), which do not
+ * require port lock.
+ */
+static void __serial8250_clear_IER(struct uart_8250_port *up)
+{
+	if (up->capabilities & UART_CAP_UUE)
+		serial_out(up, UART_IER, UART_IER_UUE);
+	else
+		serial_out(up, UART_IER, 0);
+}
+
+static inline void serial8250_clear_IER(struct uart_8250_port *up)
+{
+	/* Port locked to synchronize UART_IER access against the console. */
+	lockdep_assert_held_once(&up->port.lock);
+
+	__serial8250_clear_IER(up);
+}
+
 #ifdef CONFIG_SERIAL_8250_RSA
 /*
  * Attempts to turn on the RSA FIFO.  Returns zero on failure.
@@ -738,9 +763,9 @@ static void enable_rsa(struct uart_8250_port *up)
 {
 	if (up->port.type == PORT_RSA) {
 		if (up->port.uartclk != SERIAL_RSA_BAUD_BASE * 16) {
-			spin_lock_irq(&up->port.lock);
+			uart_port_lock_irq(&up->port);
 			__enable_rsa(up);
-			spin_unlock_irq(&up->port.lock);
+			uart_port_unlock_irq(&up->port);
 		}
 		if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16)
 			serial_out(up, UART_RSA_FRR, 0);
@@ -760,7 +785,7 @@ static void disable_rsa(struct uart_8250_port *up)
 
 	if (up->port.type == PORT_RSA &&
 	    up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) {
-		spin_lock_irq(&up->port.lock);
+		uart_port_lock_irq(&up->port);
 
 		mode = serial_in(up, UART_RSA_MSR);
 		result = !(mode & UART_RSA_MSR_FIFO);
@@ -773,7 +798,7 @@ static void disable_rsa(struct uart_8250_port *up)
 
 		if (result)
 			up->port.uartclk = SERIAL_RSA_BAUD_BASE_LO * 16;
-		spin_unlock_irq(&up->port.lock);
+		uart_port_unlock_irq(&up->port);
 	}
 }
 #endif /* CONFIG_SERIAL_8250_RSA */
@@ -972,10 +997,8 @@ static int broken_efr(struct uart_8250_port *up)
  */
 static void autoconfig_16550a(struct uart_8250_port *up)
 {
-	struct uart_port *port = &up->port;
 	unsigned char status1, status2;
 	unsigned int iersave;
-	bool is_console;
 
 	/* Port locked to synchronize UART_IER access against the console. */
 	lockdep_assert_held_once(&up->port.lock);
@@ -1094,11 +1117,6 @@ static void autoconfig_16550a(struct uart_8250_port *up)
 		return;
 	}
 
-	is_console = serial8250_is_console(port);
-
-	if (is_console)
-		serial8250_enter_unsafe(up);
-
 	/*
 	 * Try writing and reading the UART_IER_UUE bit (b6).
 	 * If it works, this is probably one of the Xscale platform's
@@ -1134,9 +1152,6 @@ static void autoconfig_16550a(struct uart_8250_port *up)
 	}
 	serial_out(up, UART_IER, iersave);
 
-	if (is_console)
-		serial8250_exit_unsafe(up);
-
 	/*
 	 * We distinguish between 16550A and U6 16550A by counting
 	 * how many bytes are in the FIFO.
@@ -1174,19 +1189,12 @@ static void autoconfig(struct uart_8250_port *up)
 	 *
 	 * Synchronize UART_IER access against the console.
 	 */
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	up->capabilities = 0;
 	up->bugs = 0;
 
 	if (!(port->flags & UPF_BUGGY_UART)) {
-		bool is_console;
-
-		is_console = serial8250_is_console(port);
-
-		if (is_console)
-			serial8250_enter_unsafe(up);
-
 		/*
 		 * Do a simple existence test first; if we fail this,
 		 * there's no point trying anything else.
@@ -1216,15 +1224,11 @@ static void autoconfig(struct uart_8250_port *up)
 #endif
 		scratch3 = serial_in(up, UART_IER) & UART_IER_ALL_INTR;
 		serial_out(up, UART_IER, scratch);
-
-		if (is_console)
-			serial8250_exit_unsafe(up);
-
 		if (scratch2 != 0 || scratch3 != UART_IER_ALL_INTR) {
 			/*
 			 * We failed; there's nothing here
 			 */
-			spin_unlock_irqrestore(&port->lock, flags);
+			uart_port_unlock_irqrestore(port, flags);
 			DEBUG_AUTOCONF("IER test failed (%02x, %02x) ",
 				       scratch2, scratch3);
 			goto out;
@@ -1248,7 +1252,7 @@ static void autoconfig(struct uart_8250_port *up)
 		status1 = serial_in(up, UART_MSR) & UART_MSR_STATUS_BITS;
 		serial8250_out_MCR(up, save_mcr);
 		if (status1 != (UART_MSR_DCD | UART_MSR_CTS)) {
-			spin_unlock_irqrestore(&port->lock, flags);
+			uart_port_unlock_irqrestore(port, flags);
 			DEBUG_AUTOCONF("LOOP test failed (%02x) ",
 				       status1);
 			goto out;
@@ -1317,7 +1321,7 @@ static void autoconfig(struct uart_8250_port *up)
 	serial8250_clear_IER(up);
 
 out_unlock:
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	/*
 	 * Check if the device is a Fintek F81216A
@@ -1341,7 +1345,6 @@ static void autoconfig_irq(struct uart_8250_port *up)
 	unsigned char save_ICP = 0;
 	unsigned int ICP = 0;
 	unsigned long irqs;
-	bool is_console;
 	int irq;
 
 	if (port->flags & UPF_FOURPORT) {
@@ -1351,20 +1354,16 @@ static void autoconfig_irq(struct uart_8250_port *up)
 		inb_p(ICP);
 	}
 
-	is_console = serial8250_is_console(port);
-
-	if (is_console) {
+	if (uart_console(port))
 		console_lock();
-		serial8250_enter_unsafe(up);
-	}
 
 	/* forget possible initially masked and pending IRQ */
 	probe_irq_off(probe_irq_on());
 	save_mcr = serial8250_in_MCR(up);
 	/* Synchronize UART_IER access against the console. */
-	spin_lock_irq(&port->lock);
+	uart_port_lock_irq(port);
 	save_ier = serial_in(up, UART_IER);
-	spin_unlock_irq(&port->lock);
+	uart_port_unlock_irq(port);
 	serial8250_out_MCR(up, UART_MCR_OUT1 | UART_MCR_OUT2);
 
 	irqs = probe_irq_on();
@@ -1377,9 +1376,9 @@ static void autoconfig_irq(struct uart_8250_port *up)
 			UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2);
 	}
 	/* Synchronize UART_IER access against the console. */
-	spin_lock_irq(&port->lock);
+	uart_port_lock_irq(port);
 	serial_out(up, UART_IER, UART_IER_ALL_INTR);
-	spin_unlock_irq(&port->lock);
+	uart_port_unlock_irq(port);
 	serial_in(up, UART_LSR);
 	serial_in(up, UART_RX);
 	serial_in(up, UART_IIR);
@@ -1390,17 +1389,15 @@ static void autoconfig_irq(struct uart_8250_port *up)
 
 	serial8250_out_MCR(up, save_mcr);
 	/* Synchronize UART_IER access against the console. */
-	spin_lock_irq(&port->lock);
+	uart_port_lock_irq(port);
 	serial_out(up, UART_IER, save_ier);
-	spin_unlock_irq(&port->lock);
+	uart_port_unlock_irq(port);
 
 	if (port->flags & UPF_FOURPORT)
 		outb_p(save_ICP, ICP);
 
-	if (is_console) {
-		serial8250_exit_unsafe(up);
+	if (uart_console(port))
 		console_unlock();
-	}
 
 	port->irq = (irq > 0) ? irq : 0;
 }
@@ -1416,7 +1413,7 @@ static void serial8250_stop_rx(struct uart_port *port)
 
 	up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
 	up->port.read_status_mask &= ~UART_LSR_DR;
-	serial8250_set_IER(up, up->ier);
+	serial_port_out(port, UART_IER, up->ier);
 
 	serial8250_rpm_put(up);
 }
@@ -1449,7 +1446,7 @@ void serial8250_em485_stop_tx(struct uart_8250_port *p)
 		serial8250_clear_and_reinit_fifos(p);
 
 		p->ier |= UART_IER_RLSI | UART_IER_RDI;
-		serial8250_set_IER(p, p->ier);
+		serial_port_out(&p->port, UART_IER, p->ier);
 	}
 }
 EXPORT_SYMBOL_GPL(serial8250_em485_stop_tx);
@@ -1462,13 +1459,13 @@ static enum hrtimer_restart serial8250_em485_handle_stop_tx(struct hrtimer *t)
 	unsigned long flags;
 
 	serial8250_rpm_get(p);
-	spin_lock_irqsave(&p->port.lock, flags);
+	uart_port_lock_irqsave(&p->port, &flags);
 	if (em485->active_timer == &em485->stop_tx_timer) {
 		p->rs485_stop_tx(p);
 		em485->active_timer = NULL;
 		em485->tx_stopped = true;
 	}
-	spin_unlock_irqrestore(&p->port.lock, flags);
+	uart_port_unlock_irqrestore(&p->port, flags);
 	serial8250_rpm_put(p);
 
 	return HRTIMER_NORESTART;
@@ -1650,12 +1647,12 @@ static enum hrtimer_restart serial8250_em485_handle_start_tx(struct hrtimer *t)
 	struct uart_8250_port *p = em485->port;
 	unsigned long flags;
 
-	spin_lock_irqsave(&p->port.lock, flags);
+	uart_port_lock_irqsave(&p->port, &flags);
 	if (em485->active_timer == &em485->start_tx_timer) {
 		__start_tx(&p->port);
 		em485->active_timer = NULL;
 	}
-	spin_unlock_irqrestore(&p->port.lock, flags);
+	uart_port_unlock_irqrestore(&p->port, flags);
 
 	return HRTIMER_NORESTART;
 }
@@ -1705,7 +1702,7 @@ static void serial8250_disable_ms(struct uart_port *port)
 	mctrl_gpio_disable_ms(up->gpios);
 
 	up->ier &= ~UART_IER_MSI;
-	serial8250_set_IER(up, up->ier);
+	serial_port_out(port, UART_IER, up->ier);
 }
 
 static void serial8250_enable_ms(struct uart_port *port)
@@ -1724,7 +1721,7 @@ static void serial8250_enable_ms(struct uart_port *port)
 	up->ier |= UART_IER_MSI;
 
 	serial8250_rpm_get(up);
-	serial8250_set_IER(up, up->ier);
+	serial_port_out(port, UART_IER, up->ier);
 	serial8250_rpm_put(up);
 }
 
@@ -1938,7 +1935,7 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
 	if (iir & UART_IIR_NO_INT)
 		return 0;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	status = serial_lsr_in(up);
 
@@ -2008,9 +2005,9 @@ static int serial8250_tx_threshold_handle_irq(struct uart_port *port)
 	if ((iir & UART_IIR_ID) == UART_IIR_THRI) {
 		struct uart_8250_port *up = up_to_u8250p(port);
 
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 		serial8250_tx_chars(up);
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 	}
 
 	iir = serial_port_in(port, UART_IIR);
@@ -2025,10 +2022,10 @@ static unsigned int serial8250_tx_empty(struct uart_port *port)
 
 	serial8250_rpm_get(up);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	if (!serial8250_tx_dma_running(up) && uart_lsr_tx_empty(serial_lsr_in(up)))
 		result = TIOCSER_TEMT;
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	serial8250_rpm_put(up);
 
@@ -2090,13 +2087,13 @@ static void serial8250_break_ctl(struct uart_port *port, int break_state)
 	unsigned long flags;
 
 	serial8250_rpm_get(up);
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	if (break_state == -1)
 		up->lcr |= UART_LCR_SBC;
 	else
 		up->lcr &= ~UART_LCR_SBC;
 	serial_port_out(port, UART_LCR, up->lcr);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 	serial8250_rpm_put(up);
 }
 
@@ -2184,10 +2181,9 @@ static void serial8250_put_poll_char(struct uart_port *port,
 	serial8250_rpm_get(up);
 	/*
 	 *	First save the IER then disable the interrupts
-	 *
-	 *	Best-effort IER access because other CPUs are quiesced.
 	 */
-	__serial8250_clear_IER(up, NULL, &ier);
+	ier = serial_port_in(port, UART_IER);
+	serial8250_clear_IER(up);
 
 	wait_for_xmitr(up, UART_LSR_BOTH_EMPTY);
 	/*
@@ -2200,7 +2196,7 @@ static void serial8250_put_poll_char(struct uart_port *port,
 	 *	and restore the IER
 	 */
 	wait_for_xmitr(up, UART_LSR_BOTH_EMPTY);
-	__serial8250_set_IER(up, NULL, ier);
+	serial_port_out(port, UART_IER, ier);
 	serial8250_rpm_put(up);
 }
 
@@ -2211,7 +2207,6 @@ int serial8250_do_startup(struct uart_port *port)
 	struct uart_8250_port *up = up_to_u8250p(port);
 	unsigned long flags;
 	unsigned char iir;
-	bool is_console;
 	int retval;
 	u16 lsr;
 
@@ -2233,17 +2228,17 @@ int serial8250_do_startup(struct uart_port *port)
 		 *
 		 * Synchronize UART_IER access against the console.
 		 */
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 		up->acr = 0;
 		serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B);
 		serial_port_out(port, UART_EFR, UART_EFR_ECB);
-		serial8250_set_IER(up, 0);
+		serial_port_out(port, UART_IER, 0);
 		serial_port_out(port, UART_LCR, 0);
 		serial_icr_write(up, UART_CSR, 0); /* Reset the UART */
 		serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B);
 		serial_port_out(port, UART_EFR, UART_EFR_ECB);
 		serial_port_out(port, UART_LCR, 0);
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 	}
 
 	if (port->type == PORT_DA830) {
@@ -2252,10 +2247,10 @@ int serial8250_do_startup(struct uart_port *port)
 		 *
 		 * Synchronize UART_IER access against the console.
 		 */
-		spin_lock_irqsave(&port->lock, flags);
-		serial8250_set_IER(up, 0);
+		uart_port_lock_irqsave(port, &flags);
+		serial_port_out(port, UART_IER, 0);
 		serial_port_out(port, UART_DA830_PWREMU_MGMT, 0);
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 		mdelay(10);
 
 		/* Enable Tx, Rx and free run mode */
@@ -2353,8 +2348,6 @@ int serial8250_do_startup(struct uart_port *port)
 	if (retval)
 		goto out;
 
-	is_console = serial8250_is_console(port);
-
 	if (port->irq && !(up->port.flags & UPF_NO_THRE_TEST)) {
 		unsigned char iir1;
 
@@ -2371,10 +2364,7 @@ int serial8250_do_startup(struct uart_port *port)
 		 *
 		 * Synchronize UART_IER access against the console.
 		 */
-		spin_lock_irqsave(&port->lock, flags);
-
-		if (is_console)
-			serial8250_enter_unsafe(up);
+		uart_port_lock_irqsave(port, &flags);
 
 		wait_for_xmitr(up, UART_LSR_THRE);
 		serial_port_out_sync(port, UART_IER, UART_IER_THRI);
@@ -2386,10 +2376,7 @@ int serial8250_do_startup(struct uart_port *port)
 		iir = serial_port_in(port, UART_IIR);
 		serial_port_out(port, UART_IER, 0);
 
-		if (is_console)
-			serial8250_exit_unsafe(up);
-
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 
 		if (port->irqflags & IRQF_SHARED)
 			enable_irq(port->irq);
@@ -2412,7 +2399,7 @@ int serial8250_do_startup(struct uart_port *port)
 	 */
 	serial_port_out(port, UART_LCR, UART_LCR_WLEN8);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	if (up->port.flags & UPF_FOURPORT) {
 		if (!up->port.irq)
 			up->port.mctrl |= TIOCM_OUT1;
@@ -2443,14 +2430,10 @@ int serial8250_do_startup(struct uart_port *port)
 	 * Do a quick test to see if we receive an interrupt when we enable
 	 * the TX irq.
 	 */
-	if (is_console)
-		serial8250_enter_unsafe(up);
 	serial_port_out(port, UART_IER, UART_IER_THRI);
 	lsr = serial_port_in(port, UART_LSR);
 	iir = serial_port_in(port, UART_IIR);
 	serial_port_out(port, UART_IER, 0);
-	if (is_console)
-		serial8250_exit_unsafe(up);
 
 	if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) {
 		if (!(up->bugs & UART_BUG_TXEN)) {
@@ -2462,7 +2445,7 @@ int serial8250_do_startup(struct uart_port *port)
 	}
 
 dont_test_tx_en:
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	/*
 	 * Clear the interrupt registers again for luck, and clear the
@@ -2482,7 +2465,7 @@ int serial8250_do_startup(struct uart_port *port)
 	if (up->dma) {
 		const char *msg = NULL;
 
-		if (is_console)
+		if (uart_console(port))
 			msg = "forbid DMA for kernel console";
 		else if (serial8250_request_dma(up))
 			msg = "failed to request DMA";
@@ -2533,17 +2516,17 @@ void serial8250_do_shutdown(struct uart_port *port)
 	 *
 	 * Synchronize UART_IER access against the console.
 	 */
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	up->ier = 0;
-	serial8250_set_IER(up, 0);
-	spin_unlock_irqrestore(&port->lock, flags);
+	serial_port_out(port, UART_IER, 0);
+	uart_port_unlock_irqrestore(port, flags);
 
 	synchronize_irq(port->irq);
 
 	if (up->dma)
 		serial8250_release_dma(up);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	if (port->flags & UPF_FOURPORT) {
 		/* reset interrupts on the AST Fourport board */
 		inb((port->iobase & 0xfe0) | 0x1f);
@@ -2552,7 +2535,7 @@ void serial8250_do_shutdown(struct uart_port *port)
 		port->mctrl &= ~TIOCM_OUT2;
 
 	serial8250_set_mctrl(port, port->mctrl);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	/*
 	 * Disable break condition and FIFOs
@@ -2788,14 +2771,14 @@ void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk)
 	quot = serial8250_get_divisor(port, baud, &frac);
 
 	serial8250_rpm_get(up);
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	uart_update_timeout(port, termios->c_cflag, baud);
 
 	serial8250_set_divisor(port, baud, quot, frac);
 	serial_port_out(port, UART_LCR, up->lcr);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 	serial8250_rpm_put(up);
 
 out_unlock:
@@ -2832,7 +2815,7 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
 	 * Synchronize UART_IER access against the console.
 	 */
 	serial8250_rpm_get(up);
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	up->lcr = cval;					/* Save computed LCR */
 
@@ -2899,7 +2882,7 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
 	if (up->capabilities & UART_CAP_RTOIE)
 		up->ier |= UART_IER_RTOIE;
 
-	serial8250_set_IER(up, up->ier);
+	serial_port_out(port, UART_IER, up->ier);
 
 	if (up->capabilities & UART_CAP_EFR) {
 		unsigned char efr = 0;
@@ -2935,7 +2918,7 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
 		serial_port_out(port, UART_FCR, up->fcr);	/* set fcr */
 	}
 	serial8250_set_mctrl(port, port->mctrl);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 	serial8250_rpm_put(up);
 
 	/* Don't rewrite B0 */
@@ -2958,15 +2941,15 @@ void serial8250_do_set_ldisc(struct uart_port *port, struct ktermios *termios)
 {
 	if (termios->c_line == N_PPS) {
 		port->flags |= UPF_HARDPPS_CD;
-		spin_lock_irq(&port->lock);
+		uart_port_lock_irq(port);
 		serial8250_enable_ms(port);
-		spin_unlock_irq(&port->lock);
+		uart_port_unlock_irq(port);
 	} else {
 		port->flags &= ~UPF_HARDPPS_CD;
 		if (!UART_ENABLE_MS(port, termios->c_cflag)) {
-			spin_lock_irq(&port->lock);
+			uart_port_lock_irq(port);
 			serial8250_disable_ms(port);
-			spin_unlock_irq(&port->lock);
+			uart_port_unlock_irq(port);
 		}
 	}
 }
@@ -3318,8 +3301,8 @@ void serial8250_init_port(struct uart_8250_port *up)
 	struct uart_port *port = &up->port;
 
 	spin_lock_init(&port->lock);
-	port->pm = NULL;
 	port->ctrl_id = 0;
+	port->pm = NULL;
 	port->ops = &serial8250_pops;
 	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE);
 
@@ -3356,21 +3339,17 @@ EXPORT_SYMBOL_GPL(serial8250_set_defaults);
 
 #ifdef CONFIG_SERIAL_8250_CONSOLE
 
-static bool serial8250_console_putchar(struct uart_port *port, unsigned char ch,
-				       struct cons_write_context *wctxt)
+static void serial8250_console_putchar(struct uart_port *port, unsigned char ch)
 {
 	struct uart_8250_port *up = up_to_u8250p(port);
 
 	wait_for_xmitr(up, UART_LSR_THRE);
-	if (!console_can_proceed(wctxt))
-		return false;
 	serial_port_out(port, UART_TX, ch);
+
 	if (ch == '\n')
 		up->console_newline_needed = false;
 	else
 		up->console_newline_needed = true;
-
-	return true;
 }
 
 /*
@@ -3399,255 +3378,260 @@ static void serial8250_console_restore(struct uart_8250_port *up)
 	serial8250_out_MCR(up, up->mcr | UART_MCR_DTR | UART_MCR_RTS);
 }
 
-static bool __serial8250_console_write(struct uart_port *port, struct cons_write_context *wctxt,
-		const char *s, unsigned int count,
-		bool (*putchar)(struct uart_port *, unsigned char, struct cons_write_context *))
+#ifdef CONFIG_SERIAL_8250_LEGACY_CONSOLE
+/*
+ * Print a string to the serial port using the device FIFO
+ *
+ * It sends fifosize bytes and then waits for the fifo
+ * to get empty.
+ */
+static void serial8250_console_fifo_write(struct uart_8250_port *up,
+					  const char *s, unsigned int count)
 {
-	bool finished = false;
-	unsigned int i;
-
-	for (i = 0; i < count; i++, s++) {
-		if (*s == '\n') {
-			if (!putchar(port, '\r', wctxt))
-				goto out;
+	int i;
+	const char *end = s + count;
+	unsigned int fifosize = up->tx_loadsz;
+	bool cr_sent = false;
+
+	while (s != end) {
+		wait_for_lsr(up, UART_LSR_THRE);
+
+		for (i = 0; i < fifosize && s != end; ++i) {
+			if (*s == '\n' && !cr_sent) {
+				serial_out(up, UART_TX, '\r');
+				cr_sent = true;
+			} else {
+				serial_out(up, UART_TX, *s++);
+				cr_sent = false;
+			}
 		}
-		if (!putchar(port, *s, wctxt))
-			goto out;
 	}
-	finished = true;
-out:
-	return finished;
-}
-
-static bool serial8250_console_write(struct uart_port *port, struct cons_write_context *wctxt,
-		const char *s, unsigned int count,
-		bool (*putchar)(struct uart_port *, unsigned char, struct cons_write_context *))
-{
-	return __serial8250_console_write(port, wctxt, s, count, putchar);
 }
 
-static bool atomic_print_line(struct uart_8250_port *up,
-			      struct cons_write_context *wctxt)
+/*
+ *	Print a string to the serial port trying not to disturb
+ *	any possible real use of the port...
+ *
+ *	The console_lock must be held when we get here.
+ *
+ *	Doing runtime PM is really a bad idea for the kernel console.
+ *	Thus, we assume the function is called when device is powered up.
+ */
+void serial8250_console_write(struct uart_8250_port *up, const char *s,
+			      unsigned int count)
 {
+	struct uart_8250_em485 *em485 = up->em485;
 	struct uart_port *port = &up->port;
+	unsigned long flags;
+	unsigned int ier, use_fifo;
+	int locked = 1;
 
-	if (up->console_newline_needed &&
-	    !__serial8250_console_write(port, wctxt, "\n", 1, serial8250_console_putchar)) {
-		return false;
-	}
+	touch_nmi_watchdog();
 
-	return __serial8250_console_write(port, wctxt, wctxt->outbuf, wctxt->len,
-					  serial8250_console_putchar);
-}
+	if (oops_in_progress)
+		locked = uart_port_trylock_irqsave(port, &flags);
+	else
+		uart_port_lock_irqsave(port, &flags);
 
-static void atomic_console_reacquire(struct cons_write_context *wctxt,
-				     struct cons_write_context *wctxt_init)
-{
-	memcpy(wctxt, wctxt_init, sizeof(*wctxt));
-	while (!console_try_acquire(wctxt)) {
-		cpu_relax();
-		memcpy(wctxt, wctxt_init, sizeof(*wctxt));
-	}
-}
+	/*
+	 *	First save the IER then disable the interrupts
+	 */
+	ier = serial_port_in(port, UART_IER);
+	__serial8250_clear_IER(up);
 
-bool serial8250_console_write_atomic(struct uart_8250_port *up,
-				     struct cons_write_context *wctxt)
-{
-	struct cons_write_context wctxt_init = { };
-	struct cons_context *ctxt_init = &ACCESS_PRIVATE(&wctxt_init, ctxt);
-	struct cons_context *ctxt = &ACCESS_PRIVATE(wctxt, ctxt);
-	bool finished = false;
-	unsigned int ier;
+	/* check scratch reg to see if port powered off during system sleep */
+	if (up->canary && (up->canary != serial_port_in(port, UART_SCR))) {
+		serial8250_console_restore(up);
+		up->canary = 0;
+	}
 
-	touch_nmi_watchdog();
+	if (em485) {
+		if (em485->tx_stopped)
+			up->rs485_start_tx(up);
+		mdelay(port->rs485.delay_rts_before_send);
+	}
 
-	/* With write_atomic, another context may hold the port->lock. */
+	use_fifo = (up->capabilities & UART_CAP_FIFO) &&
+		/*
+		 * BCM283x requires to check the fifo
+		 * after each byte.
+		 */
+		!(up->capabilities & UART_CAP_MINI) &&
+		/*
+		 * tx_loadsz contains the transmit fifo size
+		 */
+		up->tx_loadsz > 1 &&
+		(up->fcr & UART_FCR_ENABLE_FIFO) &&
+		port->state &&
+		test_bit(TTY_PORT_INITIALIZED, &port->state->port.iflags) &&
+		/*
+		 * After we put a data in the fifo, the controller will send
+		 * it regardless of the CTS state. Therefore, only use fifo
+		 * if we don't use control flow.
+		 */
+		!(up->port.flags & UPF_CONS_FLOW);
 
-	ctxt_init->console = ctxt->console;
-	ctxt_init->prio = ctxt->prio;
-	ctxt_init->thread = ctxt->thread;
+	if (likely(use_fifo))
+		serial8250_console_fifo_write(up, s, count);
+	else
+		uart_console_write(port, s, count, serial8250_console_putchar);
 
 	/*
-	 * Enter unsafe in order to disable interrupts. If the console is
-	 * lost before the interrupts are disabled, bail out because another
-	 * context took over the printing. If the console is lost after the
-	 * interrutps are disabled, the console must be reacquired in order
-	 * to re-enable the interrupts. However in that case no printing is
-	 * allowed because another context took over the printing.
+	 *	Finally, wait for transmitter to become empty
+	 *	and restore the IER
 	 */
+	wait_for_xmitr(up, UART_LSR_BOTH_EMPTY);
 
-	if (!console_enter_unsafe(wctxt))
-		return false;
-
-	if (!__serial8250_clear_IER(up, wctxt, &ier))
-		return false;
-
-	if (!console_exit_unsafe(wctxt)) {
-		atomic_console_reacquire(wctxt, &wctxt_init);
-		goto enable_irq;
+	if (em485) {
+		mdelay(port->rs485.delay_rts_after_send);
+		if (em485->tx_stopped)
+			up->rs485_stop_tx(up);
 	}
 
-	if (!atomic_print_line(up, wctxt)) {
-		atomic_console_reacquire(wctxt, &wctxt_init);
-		goto enable_irq;
-	}
+	serial_port_out(port, UART_IER, ier);
 
-	wait_for_xmitr(up, UART_LSR_BOTH_EMPTY);
-	finished = true;
-enable_irq:
 	/*
-	 * Enter unsafe in order to enable interrupts. If the console is
-	 * lost before the interrupts are enabled, the console must be
-	 * reacquired in order to re-enable the interrupts.
+	 *	The receive handling will happen properly because the
+	 *	receive ready bit will still be set; it is not cleared
+	 *	on read.  However, modem control will not, we must
+	 *	call it if we have saved something in the saved flags
+	 *	while processing with interrupts off.
 	 */
-	for (;;) {
-		if (console_enter_unsafe(wctxt) &&
-		    __serial8250_set_IER(up, wctxt, ier)) {
-			break;
-		}
-
-		/* HW-IRQs still disabled. Reacquire to enable them. */
-		atomic_console_reacquire(wctxt, &wctxt_init);
-	}
-	console_exit_unsafe(wctxt);
+	if (up->msr_saved_flags)
+		serial8250_modem_status(up);
 
-	return finished;
+	if (locked)
+		uart_port_unlock_irqrestore(port, flags);
 }
-
-/*
- *	Print a string to the serial port trying not to disturb
- *	any possible real use of the port...
- *
- *	The console_lock must be held when we get here.
- *
- *	Doing runtime PM is really a bad idea for the kernel console.
- *	Thus, we assume the function is called when device is powered up.
- */
+#else
 bool serial8250_console_write_thread(struct uart_8250_port *up,
-				     struct cons_write_context *wctxt)
+				     struct nbcon_write_context *wctxt)
 {
-	struct cons_write_context wctxt_init = { };
-	struct cons_context *ctxt_init = &ACCESS_PRIVATE(&wctxt_init, ctxt);
-	struct cons_context *ctxt = &ACCESS_PRIVATE(wctxt, ctxt);
 	struct uart_8250_em485 *em485 = up->em485;
 	struct uart_port *port = &up->port;
-	unsigned int count = wctxt->len;
-	const char *s = wctxt->outbuf;
-	bool rs485_started = false;
-	bool finished = false;
+	bool done = false;
 	unsigned int ier;
 
-	ctxt_init->console = ctxt->console;
-	ctxt_init->prio = ctxt->prio;
-	ctxt_init->thread = ctxt->thread;
-
-	/*
-	 * Enter unsafe in order to disable interrupts. If the console is
-	 * lost before the interrupts are disabled, bail out because another
-	 * context took over the printing. If the console is lost after the
-	 * interrutps are disabled, the console must be reacquired in order
-	 * to re-enable the interrupts. However in that case no printing is
-	 * allowed because another context took over the printing.
-	 */
-
-	if (!console_enter_unsafe(wctxt))
-		return false;
+	touch_nmi_watchdog();
 
-	if (!__serial8250_clear_IER(up, wctxt, &ier))
+	if (!nbcon_enter_unsafe(wctxt))
 		return false;
 
-	if (!console_exit_unsafe(wctxt)) {
-		atomic_console_reacquire(wctxt, &wctxt_init);
-		goto enable_irq;
-	}
+	/* First save IER then disable the interrupts. */
+	ier = serial_port_in(port, UART_IER);
+	serial8250_clear_IER(up);
 
-	/* check scratch reg to see if port powered off during system sleep */
+	/* Check scratch reg if port powered off during system sleep. */
 	if (up->canary && (up->canary != serial_port_in(port, UART_SCR))) {
-		if (!console_enter_unsafe(wctxt)) {
-			atomic_console_reacquire(wctxt, &wctxt_init);
-			goto enable_irq;
-		}
 		serial8250_console_restore(up);
-		if (!console_exit_unsafe(wctxt)) {
-			atomic_console_reacquire(wctxt, &wctxt_init);
-			goto enable_irq;
-		}
 		up->canary = 0;
 	}
 
 	if (em485) {
-		if (em485->tx_stopped) {
-			if (!console_enter_unsafe(wctxt)) {
-				atomic_console_reacquire(wctxt, &wctxt_init);
-				goto enable_irq;
-			}
+		if (em485->tx_stopped)
 			up->rs485_start_tx(up);
-			rs485_started = true;
-			if (!console_exit_unsafe(wctxt)) {
-				atomic_console_reacquire(wctxt, &wctxt_init);
-				goto enable_irq;
+		mdelay(port->rs485.delay_rts_before_send);
+	}
+
+	if (nbcon_exit_unsafe(wctxt)) {
+		int len = READ_ONCE(wctxt->len);
+		int i;
+
+		/*
+		 * Write out the message. Toggle unsafe for each byte in order
+		 * to give another (higher priority) context the opportunity
+		 * for a friendly takeover. If such a takeover occurs, this
+		 * context must reacquire ownership in order to perform final
+		 * actions (such as re-enabling the interrupts).
+		 *
+		 * IMPORTANT: wctxt->outbuf and wctxt->len are no longer valid
+		 *	      after a reacquire so writing the message must be
+		 *	      aborted.
+		 */
+		for (i = 0; i < len; i++) {
+			if (!nbcon_enter_unsafe(wctxt)) {
+				nbcon_reacquire(wctxt);
+				break;
 			}
-		}
-		if (port->rs485.delay_rts_before_send) {
-			mdelay(port->rs485.delay_rts_before_send);
-			if (!console_can_proceed(wctxt)) {
-				atomic_console_reacquire(wctxt, &wctxt_init);
-				goto enable_irq;
+
+			uart_console_write(port, wctxt->outbuf + i, 1, serial8250_console_putchar);
+
+			if (!nbcon_exit_unsafe(wctxt)) {
+				nbcon_reacquire(wctxt);
+				break;
 			}
 		}
+		done = (i == len);
+	} else {
+		nbcon_reacquire(wctxt);
 	}
 
-	if (!serial8250_console_write(port, wctxt, s, count, serial8250_console_putchar)) {
-		atomic_console_reacquire(wctxt, &wctxt_init);
-		goto enable_irq;
-	}
+	while (!nbcon_enter_unsafe(wctxt))
+		nbcon_reacquire(wctxt);
 
+	/* Finally, wait for transmitter to become empty and restore IER. */
 	wait_for_xmitr(up, UART_LSR_BOTH_EMPTY);
-	finished = true;
-enable_irq:
-	/*
-	 * Enter unsafe in order to stop rs485_tx. If the console is
-	 * lost before the rs485_tx is stopped, the console must be
-	 * reacquired in order to stop rs485_tx.
-	 */
 	if (em485) {
 		mdelay(port->rs485.delay_rts_after_send);
-		if (em485->tx_stopped && rs485_started) {
-			while (!console_enter_unsafe(wctxt))
-				atomic_console_reacquire(wctxt, &wctxt_init);
+		if (em485->tx_stopped)
 			up->rs485_stop_tx(up);
-			if (!console_exit_unsafe(wctxt))
-				atomic_console_reacquire(wctxt, &wctxt_init);
-		}
 	}
+	serial_port_out(port, UART_IER, ier);
 
 	/*
-	 * Enter unsafe in order to enable interrupts. If the console is
-	 * lost before the interrupts are enabled, the console must be
-	 * reacquired in order to re-enable the interrupts.
+	 * The receive handling will happen properly because the receive ready
+	 * bit will still be set; it is not cleared on read.  However, modem
+	 * control will not, we must call it if we have saved something in the
+	 * saved flags while processing with interrupts off.
 	 */
-	for (;;) {
-		if (console_enter_unsafe(wctxt) &&
-		    __serial8250_set_IER(up, wctxt, ier)) {
-			break;
-		}
-		atomic_console_reacquire(wctxt, &wctxt_init);
-	}
+	if (up->msr_saved_flags)
+		serial8250_modem_status(up);
+
+	/* Success if no handover/takeover and message fully printed. */
+	return (nbcon_exit_unsafe(wctxt) && done);
+}
+
+bool serial8250_console_write_atomic(struct uart_8250_port *up,
+				     struct nbcon_write_context *wctxt)
+{
+	struct uart_port *port = &up->port;
+	unsigned int ier;
+
+	/* Atomic console not supported for rs485 mode. */
+	if (up->em485)
+		return false;
+
+	touch_nmi_watchdog();
+
+	if (!nbcon_enter_unsafe(wctxt))
+		return false;
 
 	/*
-	 *	The receive handling will happen properly because the
-	 *	receive ready bit will still be set; it is not cleared
-	 *	on read.  However, modem control will not, we must
-	 *	call it if we have saved something in the saved flags
-	 *	while processing with interrupts off.
+	 * First save IER then disable the interrupts. The special variant to
+	 * clear IER is used because atomic printing may occur without holding
+	 * the port lock.
 	 */
-	if (up->msr_saved_flags)
-		serial8250_modem_status(up);
+	ier = serial_port_in(port, UART_IER);
+	__serial8250_clear_IER(up);
 
-	console_exit_unsafe(wctxt);
+	/* Check scratch reg if port powered off during system sleep. */
+	if (up->canary && (up->canary != serial_port_in(port, UART_SCR))) {
+		serial8250_console_restore(up);
+		up->canary = 0;
+	}
+
+	if (up->console_newline_needed)
+		uart_console_write(port, "\n", 1, serial8250_console_putchar);
+	uart_console_write(port, wctxt->outbuf, wctxt->len, serial8250_console_putchar);
+
+	/* Finally, wait for transmitter to become empty and restore IER. */
+	wait_for_xmitr(up, UART_LSR_BOTH_EMPTY);
+	serial_port_out(port, UART_IER, ier);
 
-	return finished;
+	/* Success if no handover/takeover. */
+	return nbcon_exit_unsafe(wctxt);
 }
+#endif /* CONFIG_SERIAL_8250_LEGACY_CONSOLE */
 
 static unsigned int probe_baud(struct uart_port *port)
 {
diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
index b8896596c557..ee17cf5c44c6 100644
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -9,7 +9,6 @@ config SERIAL_8250
 	depends on !S390
 	select SERIAL_CORE
 	select SERIAL_MCTRL_GPIO if GPIOLIB
-	select HAVE_ATOMIC_CONSOLE
 	help
 	  This selects whether you want to include the driver for the standard
 	  serial ports.  The standard answer is Y.  People who might say N
diff --git a/drivers/tty/serial/altera_jtaguart.c b/drivers/tty/serial/altera_jtaguart.c
index 6203ca1de769..7090b251dd4d 100644
--- a/drivers/tty/serial/altera_jtaguart.c
+++ b/drivers/tty/serial/altera_jtaguart.c
@@ -110,7 +110,7 @@ static void altera_jtaguart_set_termios(struct uart_port *port,
 
 static void altera_jtaguart_rx_chars(struct uart_port *port)
 {
-	unsigned long status;
+	u32 status;
 	u8 ch;
 
 	while ((status = readl(port->membase + ALTERA_JTAGUART_DATA_REG)) &
@@ -147,14 +147,14 @@ static irqreturn_t altera_jtaguart_interrupt(int irq, void *data)
 	isr = (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) >>
 	       ALTERA_JTAGUART_CONTROL_RI_OFF) & port->read_status_mask;
 
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 
 	if (isr & ALTERA_JTAGUART_CONTROL_RE_MSK)
 		altera_jtaguart_rx_chars(port);
 	if (isr & ALTERA_JTAGUART_CONTROL_WE_MSK)
 		altera_jtaguart_tx_chars(port);
 
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 
 	return IRQ_RETVAL(isr);
 }
@@ -180,14 +180,14 @@ static int altera_jtaguart_startup(struct uart_port *port)
 		return ret;
 	}
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* Enable RX interrupts now */
 	port->read_status_mask = ALTERA_JTAGUART_CONTROL_RE_MSK;
 	writel(port->read_status_mask,
 			port->membase + ALTERA_JTAGUART_CONTROL_REG);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return 0;
 }
@@ -196,14 +196,14 @@ static void altera_jtaguart_shutdown(struct uart_port *port)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* Disable all interrupts now */
 	port->read_status_mask = 0;
 	writel(port->read_status_mask,
 			port->membase + ALTERA_JTAGUART_CONTROL_REG);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	free_irq(port->irq, port);
 }
@@ -264,33 +264,33 @@ static void altera_jtaguart_console_putc(struct uart_port *port, unsigned char c
 	unsigned long flags;
 	u32 status;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	while (!altera_jtaguart_tx_space(port, &status)) {
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 
 		if ((status & ALTERA_JTAGUART_CONTROL_AC_MSK) == 0) {
 			return;	/* no connection activity */
 		}
 
 		cpu_relax();
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 	}
 	writel(c, port->membase + ALTERA_JTAGUART_DATA_REG);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 #else
 static void altera_jtaguart_console_putc(struct uart_port *port, unsigned char c)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	while (!altera_jtaguart_tx_space(port, NULL)) {
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 		cpu_relax();
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 	}
 	writel(c, port->membase + ALTERA_JTAGUART_DATA_REG);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 #endif
 
diff --git a/drivers/tty/serial/altera_uart.c b/drivers/tty/serial/altera_uart.c
index a9c41942190c..77835ac68df2 100644
--- a/drivers/tty/serial/altera_uart.c
+++ b/drivers/tty/serial/altera_uart.c
@@ -164,13 +164,13 @@ static void altera_uart_break_ctl(struct uart_port *port, int break_state)
 	struct altera_uart *pp = container_of(port, struct altera_uart, port);
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	if (break_state == -1)
 		pp->imr |= ALTERA_UART_CONTROL_TRBK_MSK;
 	else
 		pp->imr &= ~ALTERA_UART_CONTROL_TRBK_MSK;
 	altera_uart_update_ctrl_reg(pp);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void altera_uart_set_termios(struct uart_port *port,
@@ -187,10 +187,10 @@ static void altera_uart_set_termios(struct uart_port *port,
 		tty_termios_copy_hw(termios, old);
 	tty_termios_encode_baud_rate(termios, baud, baud);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	uart_update_timeout(port, termios->c_cflag, baud);
 	altera_uart_writel(port, baudclk, ALTERA_UART_DIVISOR_REG);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	/*
 	 * FIXME: port->read_status_mask and port->ignore_status_mask
@@ -264,12 +264,12 @@ static irqreturn_t altera_uart_interrupt(int irq, void *data)
 
 	isr = altera_uart_readl(port, ALTERA_UART_STATUS_REG) & pp->imr;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	if (isr & ALTERA_UART_STATUS_RRDY_MSK)
 		altera_uart_rx_chars(port);
 	if (isr & ALTERA_UART_STATUS_TRDY_MSK)
 		altera_uart_tx_chars(port);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return IRQ_RETVAL(isr);
 }
@@ -313,13 +313,13 @@ static int altera_uart_startup(struct uart_port *port)
 		}
 	}
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* Enable RX interrupts now */
 	pp->imr = ALTERA_UART_CONTROL_RRDY_MSK;
 	altera_uart_update_ctrl_reg(pp);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return 0;
 }
@@ -329,13 +329,13 @@ static void altera_uart_shutdown(struct uart_port *port)
 	struct altera_uart *pp = container_of(port, struct altera_uart, port);
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* Disable all interrupts now */
 	pp->imr = 0;
 	altera_uart_update_ctrl_reg(pp);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	if (port->irq)
 		free_irq(port->irq, port);
diff --git a/drivers/tty/serial/amba-pl010.c b/drivers/tty/serial/amba-pl010.c
index b5a7404cbacb..eabbf8afc9b5 100644
--- a/drivers/tty/serial/amba-pl010.c
+++ b/drivers/tty/serial/amba-pl010.c
@@ -207,7 +207,7 @@ static irqreturn_t pl010_int(int irq, void *dev_id)
 	unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
 	int handled = 0;
 
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 
 	status = readb(port->membase + UART010_IIR);
 	if (status) {
@@ -228,7 +228,7 @@ static irqreturn_t pl010_int(int irq, void *dev_id)
 		handled = 1;
 	}
 
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 
 	return IRQ_RETVAL(handled);
 }
@@ -270,14 +270,14 @@ static void pl010_break_ctl(struct uart_port *port, int break_state)
 	unsigned long flags;
 	unsigned int lcr_h;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	lcr_h = readb(port->membase + UART010_LCRH);
 	if (break_state == -1)
 		lcr_h |= UART01x_LCRH_BRK;
 	else
 		lcr_h &= ~UART01x_LCRH_BRK;
 	writel(lcr_h, port->membase + UART010_LCRH);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static int pl010_startup(struct uart_port *port)
@@ -385,7 +385,7 @@ pl010_set_termios(struct uart_port *port, struct ktermios *termios,
 	if (port->fifosize > 1)
 		lcr_h |= UART01x_LCRH_FEN;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/*
 	 * Update the per-port timeout.
@@ -438,22 +438,22 @@ pl010_set_termios(struct uart_port *port, struct ktermios *termios,
 	writel(lcr_h, port->membase + UART010_LCRH);
 	writel(old_cr, port->membase + UART010_CR);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void pl010_set_ldisc(struct uart_port *port, struct ktermios *termios)
 {
 	if (termios->c_line == N_PPS) {
 		port->flags |= UPF_HARDPPS_CD;
-		spin_lock_irq(&port->lock);
+		uart_port_lock_irq(port);
 		pl010_enable_ms(port);
-		spin_unlock_irq(&port->lock);
+		uart_port_unlock_irq(port);
 	} else {
 		port->flags &= ~UPF_HARDPPS_CD;
 		if (!UART_ENABLE_MS(port, termios->c_cflag)) {
-			spin_lock_irq(&port->lock);
+			uart_port_lock_irq(port);
 			pl010_disable_ms(port);
-			spin_unlock_irq(&port->lock);
+			uart_port_unlock_irq(port);
 		}
 	}
 }
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index aadde3104bb5..19200ab2af75 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -347,9 +347,9 @@ static int pl011_fifo_to_tty(struct uart_amba_port *uap)
 				flag = TTY_FRAME;
 		}
 
-		spin_unlock(&uap->port.lock);
+		uart_port_unlock(&uap->port);
 		sysrq = uart_handle_sysrq_char(&uap->port, ch & 255);
-		spin_lock(&uap->port.lock);
+		uart_port_lock(&uap->port);
 
 		if (!sysrq)
 			uart_insert_char(&uap->port, ch, UART011_DR_OE, ch, flag);
@@ -544,7 +544,7 @@ static void pl011_dma_tx_callback(void *data)
 	unsigned long flags;
 	u16 dmacr;
 
-	spin_lock_irqsave(&uap->port.lock, flags);
+	uart_port_lock_irqsave(&uap->port, &flags);
 	if (uap->dmatx.queued)
 		dma_unmap_single(dmatx->chan->device->dev, dmatx->dma,
 				dmatx->len, DMA_TO_DEVICE);
@@ -565,7 +565,7 @@ static void pl011_dma_tx_callback(void *data)
 	if (!(dmacr & UART011_TXDMAE) || uart_tx_stopped(&uap->port) ||
 	    uart_circ_empty(&uap->port.state->xmit)) {
 		uap->dmatx.queued = false;
-		spin_unlock_irqrestore(&uap->port.lock, flags);
+		uart_port_unlock_irqrestore(&uap->port, flags);
 		return;
 	}
 
@@ -576,7 +576,7 @@ static void pl011_dma_tx_callback(void *data)
 		 */
 		pl011_start_tx_pio(uap);
 
-	spin_unlock_irqrestore(&uap->port.lock, flags);
+	uart_port_unlock_irqrestore(&uap->port, flags);
 }
 
 /*
@@ -1004,7 +1004,7 @@ static void pl011_dma_rx_callback(void *data)
 	 * routine to flush out the secondary DMA buffer while
 	 * we immediately trigger the next DMA job.
 	 */
-	spin_lock_irq(&uap->port.lock);
+	uart_port_lock_irq(&uap->port);
 	/*
 	 * Rx data can be taken by the UART interrupts during
 	 * the DMA irq handler. So we check the residue here.
@@ -1020,7 +1020,7 @@ static void pl011_dma_rx_callback(void *data)
 	ret = pl011_dma_rx_trigger_dma(uap);
 
 	pl011_dma_rx_chars(uap, pending, lastbuf, false);
-	spin_unlock_irq(&uap->port.lock);
+	uart_port_unlock_irq(&uap->port);
 	/*
 	 * Do this check after we picked the DMA chars so we don't
 	 * get some IRQ immediately from RX.
@@ -1086,11 +1086,11 @@ static void pl011_dma_rx_poll(struct timer_list *t)
 	if (jiffies_to_msecs(jiffies - dmarx->last_jiffies)
 			> uap->dmarx.poll_timeout) {
 
-		spin_lock_irqsave(&uap->port.lock, flags);
+		uart_port_lock_irqsave(&uap->port, &flags);
 		pl011_dma_rx_stop(uap);
 		uap->im |= UART011_RXIM;
 		pl011_write(uap->im, uap, REG_IMSC);
-		spin_unlock_irqrestore(&uap->port.lock, flags);
+		uart_port_unlock_irqrestore(&uap->port, flags);
 
 		uap->dmarx.running = false;
 		dmaengine_terminate_all(rxchan);
@@ -1186,10 +1186,10 @@ static void pl011_dma_shutdown(struct uart_amba_port *uap)
 	while (pl011_read(uap, REG_FR) & uap->vendor->fr_busy)
 		cpu_relax();
 
-	spin_lock_irq(&uap->port.lock);
+	uart_port_lock_irq(&uap->port);
 	uap->dmacr &= ~(UART011_DMAONERR | UART011_RXDMAE | UART011_TXDMAE);
 	pl011_write(uap->dmacr, uap, REG_DMACR);
-	spin_unlock_irq(&uap->port.lock);
+	uart_port_unlock_irq(&uap->port);
 
 	if (uap->using_tx_dma) {
 		/* In theory, this should already be done by pl011_dma_flush_buffer */
@@ -1345,41 +1345,11 @@ static void pl011_start_tx_pio(struct uart_amba_port *uap)
 	}
 }
 
-static void pl011_rs485_tx_start(struct uart_amba_port *uap)
-{
-	struct uart_port *port = &uap->port;
-	u32 cr;
-
-	/* Enable transmitter */
-	cr = pl011_read(uap, REG_CR);
-	cr |= UART011_CR_TXE;
-
-	/* Disable receiver if half-duplex */
-	if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
-		cr &= ~UART011_CR_RXE;
-
-	if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
-		cr &= ~UART011_CR_RTS;
-	else
-		cr |= UART011_CR_RTS;
-
-	pl011_write(cr, uap, REG_CR);
-
-	if (port->rs485.delay_rts_before_send)
-		mdelay(port->rs485.delay_rts_before_send);
-
-	uap->rs485_tx_started = true;
-}
-
 static void pl011_start_tx(struct uart_port *port)
 {
 	struct uart_amba_port *uap =
 	    container_of(port, struct uart_amba_port, port);
 
-	if ((uap->port.rs485.flags & SER_RS485_ENABLED) &&
-	    !uap->rs485_tx_started)
-		pl011_rs485_tx_start(uap);
-
 	if (!pl011_dma_tx_start(uap))
 		pl011_start_tx_pio(uap);
 }
@@ -1400,9 +1370,9 @@ static void pl011_throttle_rx(struct uart_port *port)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	pl011_stop_rx(port);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void pl011_enable_ms(struct uart_port *port)
@@ -1420,7 +1390,7 @@ __acquires(&uap->port.lock)
 {
 	pl011_fifo_to_tty(uap);
 
-	spin_unlock(&uap->port.lock);
+	uart_port_unlock(&uap->port);
 	tty_flip_buffer_push(&uap->port.state->port);
 	/*
 	 * If we were temporarily out of DMA mode for a while,
@@ -1445,7 +1415,7 @@ __acquires(&uap->port.lock)
 #endif
 		}
 	}
-	spin_lock(&uap->port.lock);
+	uart_port_lock(&uap->port);
 }
 
 static bool pl011_tx_char(struct uart_amba_port *uap, unsigned char c,
@@ -1461,12 +1431,42 @@ static bool pl011_tx_char(struct uart_amba_port *uap, unsigned char c,
 	return true;
 }
 
+static void pl011_rs485_tx_start(struct uart_amba_port *uap)
+{
+	struct uart_port *port = &uap->port;
+	u32 cr;
+
+	/* Enable transmitter */
+	cr = pl011_read(uap, REG_CR);
+	cr |= UART011_CR_TXE;
+
+	/* Disable receiver if half-duplex */
+	if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
+		cr &= ~UART011_CR_RXE;
+
+	if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
+		cr &= ~UART011_CR_RTS;
+	else
+		cr |= UART011_CR_RTS;
+
+	pl011_write(cr, uap, REG_CR);
+
+	if (port->rs485.delay_rts_before_send)
+		mdelay(port->rs485.delay_rts_before_send);
+
+	uap->rs485_tx_started = true;
+}
+
 /* Returns true if tx interrupts have to be (kept) enabled  */
 static bool pl011_tx_chars(struct uart_amba_port *uap, bool from_irq)
 {
 	struct circ_buf *xmit = &uap->port.state->xmit;
 	int count = uap->fifosize >> 1;
 
+	if ((uap->port.rs485.flags & SER_RS485_ENABLED) &&
+	    !uap->rs485_tx_started)
+		pl011_rs485_tx_start(uap);
+
 	if (uap->port.x_char) {
 		if (!pl011_tx_char(uap, uap->port.x_char, from_irq))
 			return true;
@@ -1551,7 +1551,7 @@ static irqreturn_t pl011_int(int irq, void *dev_id)
 	unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
 	int handled = 0;
 
-	spin_lock_irqsave(&uap->port.lock, flags);
+	uart_port_lock_irqsave(&uap->port, &flags);
 	status = pl011_read(uap, REG_RIS) & uap->im;
 	if (status) {
 		do {
@@ -1581,7 +1581,7 @@ static irqreturn_t pl011_int(int irq, void *dev_id)
 		handled = 1;
 	}
 
-	spin_unlock_irqrestore(&uap->port.lock, flags);
+	uart_port_unlock_irqrestore(&uap->port, flags);
 
 	return IRQ_RETVAL(handled);
 }
@@ -1653,14 +1653,14 @@ static void pl011_break_ctl(struct uart_port *port, int break_state)
 	unsigned long flags;
 	unsigned int lcr_h;
 
-	spin_lock_irqsave(&uap->port.lock, flags);
+	uart_port_lock_irqsave(&uap->port, &flags);
 	lcr_h = pl011_read(uap, REG_LCRH_TX);
 	if (break_state == -1)
 		lcr_h |= UART01x_LCRH_BRK;
 	else
 		lcr_h &= ~UART01x_LCRH_BRK;
 	pl011_write(lcr_h, uap, REG_LCRH_TX);
-	spin_unlock_irqrestore(&uap->port.lock, flags);
+	uart_port_unlock_irqrestore(&uap->port, flags);
 }
 
 #ifdef CONFIG_CONSOLE_POLL
@@ -1799,7 +1799,7 @@ static void pl011_enable_interrupts(struct uart_amba_port *uap)
 	unsigned long flags;
 	unsigned int i;
 
-	spin_lock_irqsave(&uap->port.lock, flags);
+	uart_port_lock_irqsave(&uap->port, &flags);
 
 	/* Clear out any spuriously appearing RX interrupts */
 	pl011_write(UART011_RTIS | UART011_RXIS, uap, REG_ICR);
@@ -1821,7 +1821,7 @@ static void pl011_enable_interrupts(struct uart_amba_port *uap)
 	if (!pl011_dma_rx_running(uap))
 		uap->im |= UART011_RXIM;
 	pl011_write(uap->im, uap, REG_IMSC);
-	spin_unlock_irqrestore(&uap->port.lock, flags);
+	uart_port_unlock_irqrestore(&uap->port, flags);
 }
 
 static void pl011_unthrottle_rx(struct uart_port *port)
@@ -1829,7 +1829,7 @@ static void pl011_unthrottle_rx(struct uart_port *port)
 	struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port);
 	unsigned long flags;
 
-	spin_lock_irqsave(&uap->port.lock, flags);
+	uart_port_lock_irqsave(&uap->port, &flags);
 
 	uap->im = UART011_RTIM;
 	if (!pl011_dma_rx_running(uap))
@@ -1837,7 +1837,7 @@ static void pl011_unthrottle_rx(struct uart_port *port)
 
 	pl011_write(uap->im, uap, REG_IMSC);
 
-	spin_unlock_irqrestore(&uap->port.lock, flags);
+	uart_port_unlock_irqrestore(&uap->port, flags);
 }
 
 static int pl011_startup(struct uart_port *port)
@@ -1857,7 +1857,7 @@ static int pl011_startup(struct uart_port *port)
 
 	pl011_write(uap->vendor->ifls, uap, REG_IFLS);
 
-	spin_lock_irq(&uap->port.lock);
+	uart_port_lock_irq(&uap->port);
 
 	cr = pl011_read(uap, REG_CR);
 	cr &= UART011_CR_RTS | UART011_CR_DTR;
@@ -1868,7 +1868,7 @@ static int pl011_startup(struct uart_port *port)
 
 	pl011_write(cr, uap, REG_CR);
 
-	spin_unlock_irq(&uap->port.lock);
+	uart_port_unlock_irq(&uap->port);
 
 	/*
 	 * initialise the old status of the modem signals
@@ -1929,12 +1929,12 @@ static void pl011_disable_uart(struct uart_amba_port *uap)
 	unsigned int cr;
 
 	uap->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS);
-	spin_lock_irq(&uap->port.lock);
+	uart_port_lock_irq(&uap->port);
 	cr = pl011_read(uap, REG_CR);
 	cr &= UART011_CR_RTS | UART011_CR_DTR;
 	cr |= UART01x_CR_UARTEN | UART011_CR_TXE;
 	pl011_write(cr, uap, REG_CR);
-	spin_unlock_irq(&uap->port.lock);
+	uart_port_unlock_irq(&uap->port);
 
 	/*
 	 * disable break condition and fifos
@@ -1946,14 +1946,14 @@ static void pl011_disable_uart(struct uart_amba_port *uap)
 
 static void pl011_disable_interrupts(struct uart_amba_port *uap)
 {
-	spin_lock_irq(&uap->port.lock);
+	uart_port_lock_irq(&uap->port);
 
 	/* mask all interrupts and clear all pending ones */
 	uap->im = 0;
 	pl011_write(uap->im, uap, REG_IMSC);
 	pl011_write(0xffff, uap, REG_ICR);
 
-	spin_unlock_irq(&uap->port.lock);
+	uart_port_unlock_irq(&uap->port);
 }
 
 static void pl011_shutdown(struct uart_port *port)
@@ -2098,7 +2098,7 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	bits = tty_get_frame_size(termios->c_cflag);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/*
 	 * Update the per-port timeout.
@@ -2172,7 +2172,7 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios,
 	old_cr |= UART011_CR_RXE;
 	pl011_write(old_cr, uap, REG_CR);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void
@@ -2190,10 +2190,10 @@ sbsa_uart_set_termios(struct uart_port *port, struct ktermios *termios,
 	termios->c_cflag &= ~(CMSPAR | CRTSCTS);
 	termios->c_cflag |= CS8 | CLOCAL;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	uart_update_timeout(port, CS8, uap->fixed_baud);
 	pl011_setup_status_masks(port, termios);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static const char *pl011_type(struct uart_port *port)
@@ -2323,24 +2323,15 @@ pl011_console_write(struct console *co, const char *s, unsigned int count)
 {
 	struct uart_amba_port *uap = amba_ports[co->index];
 	unsigned int old_cr = 0, new_cr;
-	unsigned long flags = 0;
+	unsigned long flags;
 	int locked = 1;
 
 	clk_enable(uap->clk);
 
-	/*
-	 * local_irq_save(flags);
-	 *
-	 * This local_irq_save() is nonsense. If we come in via sysrq
-	 * handling then interrupts are already disabled. Aside of
-	 * that the port.sysrq check is racy on SMP regardless.
-	*/
-	if (uap->port.sysrq)
-		locked = 0;
-	else if (oops_in_progress)
-		locked = spin_trylock_irqsave(&uap->port.lock, flags);
+	if (uap->port.sysrq || oops_in_progress)
+		locked = uart_port_trylock_irqsave(&uap->port, &flags);
 	else
-		spin_lock_irqsave(&uap->port.lock, flags);
+		uart_port_lock_irqsave(&uap->port, &flags);
 
 	/*
 	 *	First save the CR then disable the interrupts
@@ -2366,7 +2357,7 @@ pl011_console_write(struct console *co, const char *s, unsigned int count)
 		pl011_write(old_cr, uap, REG_CR);
 
 	if (locked)
-		spin_unlock_irqrestore(&uap->port.lock, flags);
+		uart_port_unlock_irqrestore(&uap->port, flags);
 
 	clk_disable(uap->clk);
 }
diff --git a/drivers/tty/serial/apbuart.c b/drivers/tty/serial/apbuart.c
index d3cb341f2c55..716cb014c028 100644
--- a/drivers/tty/serial/apbuart.c
+++ b/drivers/tty/serial/apbuart.c
@@ -122,7 +122,7 @@ static void apbuart_tx_chars(struct uart_port *port)
 {
 	u8 ch;
 
-	uart_port_tx_limited(port, ch, port->fifosize,
+	uart_port_tx_limited(port, ch, port->fifosize >> 1,
 		true,
 		UART_PUT_CHAR(port, ch),
 		({}));
@@ -133,7 +133,7 @@ static irqreturn_t apbuart_int(int irq, void *dev_id)
 	struct uart_port *port = dev_id;
 	unsigned int status;
 
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 
 	status = UART_GET_STATUS(port);
 	if (status & UART_STATUS_DR)
@@ -141,7 +141,7 @@ static irqreturn_t apbuart_int(int irq, void *dev_id)
 	if (status & UART_STATUS_THE)
 		apbuart_tx_chars(port);
 
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 
 	return IRQ_HANDLED;
 }
@@ -228,7 +228,7 @@ static void apbuart_set_termios(struct uart_port *port,
 	if (termios->c_cflag & CRTSCTS)
 		cr |= UART_CTRL_FL;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* Update the per-port timeout. */
 	uart_update_timeout(port, termios->c_cflag, baud);
@@ -251,7 +251,7 @@ static void apbuart_set_termios(struct uart_port *port,
 	UART_PUT_SCAL(port, quot);
 	UART_PUT_CTRL(port, cr);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static const char *apbuart_type(struct uart_port *port)
diff --git a/drivers/tty/serial/ar933x_uart.c b/drivers/tty/serial/ar933x_uart.c
index 924c1a89347c..ffd234673177 100644
--- a/drivers/tty/serial/ar933x_uart.c
+++ b/drivers/tty/serial/ar933x_uart.c
@@ -133,9 +133,9 @@ static unsigned int ar933x_uart_tx_empty(struct uart_port *port)
 	unsigned long flags;
 	unsigned int rdata;
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 	rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG);
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 
 	return (rdata & AR933X_UART_DATA_TX_CSR) ? 0 : TIOCSER_TEMT;
 }
@@ -220,14 +220,14 @@ static void ar933x_uart_break_ctl(struct uart_port *port, int break_state)
 		container_of(port, struct ar933x_uart_port, port);
 	unsigned long flags;
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 	if (break_state == -1)
 		ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
 				    AR933X_UART_CS_TX_BREAK);
 	else
 		ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG,
 				      AR933X_UART_CS_TX_BREAK);
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 }
 
 /*
@@ -318,7 +318,7 @@ static void ar933x_uart_set_termios(struct uart_port *port,
 	 * Ok, we're now changing the port state. Do it with
 	 * interrupts disabled.
 	 */
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 
 	/* disable the UART */
 	ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG,
@@ -352,7 +352,7 @@ static void ar933x_uart_set_termios(struct uart_port *port,
 			AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S,
 			AR933X_UART_CS_IF_MODE_DCE << AR933X_UART_CS_IF_MODE_S);
 
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 
 	if (tty_termios_baud_rate(new))
 		tty_termios_encode_baud_rate(new, baud, baud);
@@ -450,7 +450,7 @@ static irqreturn_t ar933x_uart_interrupt(int irq, void *dev_id)
 	if ((status & AR933X_UART_CS_HOST_INT) == 0)
 		return IRQ_NONE;
 
-	spin_lock(&up->port.lock);
+	uart_port_lock(&up->port);
 
 	status = ar933x_uart_read(up, AR933X_UART_INT_REG);
 	status &= ar933x_uart_read(up, AR933X_UART_INT_EN_REG);
@@ -468,7 +468,7 @@ static irqreturn_t ar933x_uart_interrupt(int irq, void *dev_id)
 		ar933x_uart_tx_chars(up);
 	}
 
-	spin_unlock(&up->port.lock);
+	uart_port_unlock(&up->port);
 
 	return IRQ_HANDLED;
 }
@@ -485,7 +485,7 @@ static int ar933x_uart_startup(struct uart_port *port)
 	if (ret)
 		return ret;
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 
 	/* Enable HOST interrupts */
 	ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
@@ -498,7 +498,7 @@ static int ar933x_uart_startup(struct uart_port *port)
 	/* Enable RX interrupts */
 	ar933x_uart_start_rx_interrupt(up);
 
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 
 	return 0;
 }
@@ -632,9 +632,9 @@ static void ar933x_uart_console_write(struct console *co, const char *s,
 	if (up->port.sysrq)
 		locked = 0;
 	else if (oops_in_progress)
-		locked = spin_trylock(&up->port.lock);
+		locked = uart_port_trylock(&up->port);
 	else
-		spin_lock(&up->port.lock);
+		uart_port_lock(&up->port);
 
 	/*
 	 * First save the IER then disable the interrupts
@@ -654,7 +654,7 @@ static void ar933x_uart_console_write(struct console *co, const char *s,
 	ar933x_uart_write(up, AR933X_UART_INT_REG, AR933X_UART_INT_ALLINTS);
 
 	if (locked)
-		spin_unlock(&up->port.lock);
+		uart_port_unlock(&up->port);
 
 	local_irq_restore(flags);
 }
diff --git a/drivers/tty/serial/arc_uart.c b/drivers/tty/serial/arc_uart.c
index ad4ae19b6ce3..1aa5b2b49c26 100644
--- a/drivers/tty/serial/arc_uart.c
+++ b/drivers/tty/serial/arc_uart.c
@@ -279,9 +279,9 @@ static irqreturn_t arc_serial_isr(int irq, void *dev_id)
 	if (status & RXIENB) {
 
 		/* already in ISR, no need of xx_irqsave */
-		spin_lock(&port->lock);
+		uart_port_lock(port);
 		arc_serial_rx_chars(port, status);
-		spin_unlock(&port->lock);
+		uart_port_unlock(port);
 	}
 
 	if ((status & TXIENB) && (status & TXEMPTY)) {
@@ -291,12 +291,12 @@ static irqreturn_t arc_serial_isr(int irq, void *dev_id)
 		 */
 		UART_TX_IRQ_DISABLE(port);
 
-		spin_lock(&port->lock);
+		uart_port_lock(port);
 
 		if (!uart_tx_stopped(port))
 			arc_serial_tx_chars(port);
 
-		spin_unlock(&port->lock);
+		uart_port_unlock(port);
 	}
 
 	return IRQ_HANDLED;
@@ -366,7 +366,7 @@ arc_serial_set_termios(struct uart_port *port, struct ktermios *new,
 	uartl = hw_val & 0xFF;
 	uarth = (hw_val >> 8) & 0xFF;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	UART_ALL_IRQ_DISABLE(port);
 
@@ -391,7 +391,7 @@ arc_serial_set_termios(struct uart_port *port, struct ktermios *new,
 
 	uart_update_timeout(port, new->c_cflag, baud);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static const char *arc_serial_type(struct uart_port *port)
@@ -521,9 +521,9 @@ static void arc_serial_console_write(struct console *co, const char *s,
 	struct uart_port *port = &arc_uart_ports[co->index].port;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	uart_console_write(port, s, count, arc_serial_console_putchar);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static struct console arc_console = {
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 88cdafa5ac54..1946fafc3f3e 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -861,7 +861,7 @@ static void atmel_complete_tx_dma(void *arg)
 	struct dma_chan *chan = atmel_port->chan_tx;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	if (chan)
 		dmaengine_terminate_all(chan);
@@ -893,7 +893,7 @@ static void atmel_complete_tx_dma(void *arg)
 				  atmel_port->tx_done_mask);
 	}
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void atmel_release_tx_dma(struct uart_port *port)
@@ -1711,9 +1711,9 @@ static void atmel_tasklet_rx_func(struct tasklet_struct *t)
 	struct uart_port *port = &atmel_port->uart;
 
 	/* The interrupt handler does not take the lock */
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 	atmel_port->schedule_rx(port);
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 }
 
 static void atmel_tasklet_tx_func(struct tasklet_struct *t)
@@ -1723,9 +1723,9 @@ static void atmel_tasklet_tx_func(struct tasklet_struct *t)
 	struct uart_port *port = &atmel_port->uart;
 
 	/* The interrupt handler does not take the lock */
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 	atmel_port->schedule_tx(port);
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 }
 
 static void atmel_init_property(struct atmel_uart_port *atmel_port,
@@ -2175,7 +2175,7 @@ static void atmel_set_termios(struct uart_port *port,
 	} else
 		mode |= ATMEL_US_PAR_NONE;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	port->read_status_mask = ATMEL_US_OVRE;
 	if (termios->c_iflag & INPCK)
@@ -2377,22 +2377,22 @@ static void atmel_set_termios(struct uart_port *port,
 	else
 		atmel_disable_ms(port);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void atmel_set_ldisc(struct uart_port *port, struct ktermios *termios)
 {
 	if (termios->c_line == N_PPS) {
 		port->flags |= UPF_HARDPPS_CD;
-		spin_lock_irq(&port->lock);
+		uart_port_lock_irq(port);
 		atmel_enable_ms(port);
-		spin_unlock_irq(&port->lock);
+		uart_port_unlock_irq(port);
 	} else {
 		port->flags &= ~UPF_HARDPPS_CD;
 		if (!UART_ENABLE_MS(port, termios->c_cflag)) {
-			spin_lock_irq(&port->lock);
+			uart_port_lock_irq(port);
 			atmel_disable_ms(port);
-			spin_unlock_irq(&port->lock);
+			uart_port_unlock_irq(port);
 		}
 	}
 }
diff --git a/drivers/tty/serial/bcm63xx_uart.c b/drivers/tty/serial/bcm63xx_uart.c
index 0dd8cceb837c..4a08fd5ee61b 100644
--- a/drivers/tty/serial/bcm63xx_uart.c
+++ b/drivers/tty/serial/bcm63xx_uart.c
@@ -201,7 +201,7 @@ static void bcm_uart_break_ctl(struct uart_port *port, int ctl)
 	unsigned long flags;
 	unsigned int val;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	val = bcm_uart_readl(port, UART_CTL_REG);
 	if (ctl)
@@ -210,7 +210,7 @@ static void bcm_uart_break_ctl(struct uart_port *port, int ctl)
 		val &= ~UART_CTL_XMITBRK_MASK;
 	bcm_uart_writel(port, val, UART_CTL_REG);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 /*
@@ -332,7 +332,7 @@ static irqreturn_t bcm_uart_interrupt(int irq, void *dev_id)
 	unsigned int irqstat;
 
 	port = dev_id;
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 
 	irqstat = bcm_uart_readl(port, UART_IR_REG);
 	if (irqstat & UART_RX_INT_STAT)
@@ -353,7 +353,7 @@ static irqreturn_t bcm_uart_interrupt(int irq, void *dev_id)
 					       estat & UART_EXTINP_DCD_MASK);
 	}
 
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 	return IRQ_HANDLED;
 }
 
@@ -451,9 +451,9 @@ static void bcm_uart_shutdown(struct uart_port *port)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	bcm_uart_writel(port, 0, UART_IR_REG);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	bcm_uart_disable(port);
 	bcm_uart_flush(port);
@@ -470,7 +470,7 @@ static void bcm_uart_set_termios(struct uart_port *port, struct ktermios *new,
 	unsigned long flags;
 	int tries;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* Drain the hot tub fully before we power it off for the winter. */
 	for (tries = 3; !bcm_uart_tx_empty(port) && tries; tries--)
@@ -546,7 +546,7 @@ static void bcm_uart_set_termios(struct uart_port *port, struct ktermios *new,
 
 	uart_update_timeout(port, new->c_cflag, baud);
 	bcm_uart_enable(port);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 /*
@@ -712,9 +712,9 @@ static void bcm_console_write(struct console *co, const char *s,
 		/* bcm_uart_interrupt() already took the lock */
 		locked = 0;
 	} else if (oops_in_progress) {
-		locked = spin_trylock(&port->lock);
+		locked = uart_port_trylock(port);
 	} else {
-		spin_lock(&port->lock);
+		uart_port_lock(port);
 		locked = 1;
 	}
 
@@ -725,7 +725,7 @@ static void bcm_console_write(struct console *co, const char *s,
 	wait_for_xmitr(port);
 
 	if (locked)
-		spin_unlock(&port->lock);
+		uart_port_unlock(port);
 	local_irq_restore(flags);
 }
 
diff --git a/drivers/tty/serial/digicolor-usart.c b/drivers/tty/serial/digicolor-usart.c
index 128b5479e813..5004125f3045 100644
--- a/drivers/tty/serial/digicolor-usart.c
+++ b/drivers/tty/serial/digicolor-usart.c
@@ -133,7 +133,7 @@ static void digicolor_uart_rx(struct uart_port *port)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	while (1) {
 		u8 status, ch, ch_flag;
@@ -172,7 +172,7 @@ static void digicolor_uart_rx(struct uart_port *port)
 				 ch_flag);
 	}
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	tty_flip_buffer_push(&port->state->port);
 }
@@ -185,7 +185,7 @@ static void digicolor_uart_tx(struct uart_port *port)
 	if (digicolor_uart_tx_full(port))
 		return;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	if (port->x_char) {
 		writeb_relaxed(port->x_char, port->membase + UA_EMI_REC);
@@ -211,7 +211,7 @@ static void digicolor_uart_tx(struct uart_port *port)
 		uart_write_wakeup(port);
 
 out:
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static irqreturn_t digicolor_uart_int(int irq, void *dev_id)
@@ -333,7 +333,7 @@ static void digicolor_uart_set_termios(struct uart_port *port,
 		port->ignore_status_mask |= UA_STATUS_OVERRUN_ERR
 			| UA_STATUS_PARITY_ERR | UA_STATUS_FRAME_ERR;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	uart_update_timeout(port, termios->c_cflag, baud);
 
@@ -341,7 +341,7 @@ static void digicolor_uart_set_termios(struct uart_port *port,
 	writeb_relaxed(divisor & 0xff, port->membase + UA_HBAUD_LO);
 	writeb_relaxed(divisor >> 8, port->membase + UA_HBAUD_HI);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static const char *digicolor_uart_type(struct uart_port *port)
@@ -398,14 +398,14 @@ static void digicolor_uart_console_write(struct console *co, const char *c,
 	int locked = 1;
 
 	if (oops_in_progress)
-		locked = spin_trylock_irqsave(&port->lock, flags);
+		locked = uart_port_trylock_irqsave(port, &flags);
 	else
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 
 	uart_console_write(port, c, n, digicolor_uart_console_putchar);
 
 	if (locked)
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 
 	/* Wait for transmitter to become empty */
 	do {
diff --git a/drivers/tty/serial/dz.c b/drivers/tty/serial/dz.c
index 667f52e83277..6df7af9edc1c 100644
--- a/drivers/tty/serial/dz.c
+++ b/drivers/tty/serial/dz.c
@@ -268,9 +268,9 @@ static inline void dz_transmit_chars(struct dz_mux *mux)
 	}
 	/* If nothing to do or stopped or hardware stopped. */
 	if (uart_circ_empty(xmit) || uart_tx_stopped(&dport->port)) {
-		spin_lock(&dport->port.lock);
+		uart_port_lock(&dport->port);
 		dz_stop_tx(&dport->port);
-		spin_unlock(&dport->port.lock);
+		uart_port_unlock(&dport->port);
 		return;
 	}
 
@@ -287,9 +287,9 @@ static inline void dz_transmit_chars(struct dz_mux *mux)
 
 	/* Are we are done. */
 	if (uart_circ_empty(xmit)) {
-		spin_lock(&dport->port.lock);
+		uart_port_lock(&dport->port);
 		dz_stop_tx(&dport->port);
-		spin_unlock(&dport->port.lock);
+		uart_port_unlock(&dport->port);
 	}
 }
 
@@ -415,14 +415,14 @@ static int dz_startup(struct uart_port *uport)
 		return ret;
 	}
 
-	spin_lock_irqsave(&dport->port.lock, flags);
+	uart_port_lock_irqsave(&dport->port, &flags);
 
 	/* Enable interrupts.  */
 	tmp = dz_in(dport, DZ_CSR);
 	tmp |= DZ_RIE | DZ_TIE;
 	dz_out(dport, DZ_CSR, tmp);
 
-	spin_unlock_irqrestore(&dport->port.lock, flags);
+	uart_port_unlock_irqrestore(&dport->port, flags);
 
 	return 0;
 }
@@ -443,9 +443,9 @@ static void dz_shutdown(struct uart_port *uport)
 	int irq_guard;
 	u16 tmp;
 
-	spin_lock_irqsave(&dport->port.lock, flags);
+	uart_port_lock_irqsave(&dport->port, &flags);
 	dz_stop_tx(&dport->port);
-	spin_unlock_irqrestore(&dport->port.lock, flags);
+	uart_port_unlock_irqrestore(&dport->port, flags);
 
 	irq_guard = atomic_add_return(-1, &mux->irq_guard);
 	if (!irq_guard) {
@@ -491,14 +491,14 @@ static void dz_break_ctl(struct uart_port *uport, int break_state)
 	unsigned long flags;
 	unsigned short tmp, mask = 1 << dport->port.line;
 
-	spin_lock_irqsave(&uport->lock, flags);
+	uart_port_lock_irqsave(uport, &flags);
 	tmp = dz_in(dport, DZ_TCR);
 	if (break_state)
 		tmp |= mask;
 	else
 		tmp &= ~mask;
 	dz_out(dport, DZ_TCR, tmp);
-	spin_unlock_irqrestore(&uport->lock, flags);
+	uart_port_unlock_irqrestore(uport, flags);
 }
 
 static int dz_encode_baud_rate(unsigned int baud)
@@ -608,7 +608,7 @@ static void dz_set_termios(struct uart_port *uport, struct ktermios *termios,
 	if (termios->c_cflag & CREAD)
 		cflag |= DZ_RXENAB;
 
-	spin_lock_irqsave(&dport->port.lock, flags);
+	uart_port_lock_irqsave(&dport->port, &flags);
 
 	uart_update_timeout(uport, termios->c_cflag, baud);
 
@@ -631,7 +631,7 @@ static void dz_set_termios(struct uart_port *uport, struct ktermios *termios,
 	if (termios->c_iflag & IGNBRK)
 		dport->port.ignore_status_mask |= DZ_BREAK;
 
-	spin_unlock_irqrestore(&dport->port.lock, flags);
+	uart_port_unlock_irqrestore(&dport->port, flags);
 }
 
 /*
@@ -645,12 +645,12 @@ static void dz_pm(struct uart_port *uport, unsigned int state,
 	struct dz_port *dport = to_dport(uport);
 	unsigned long flags;
 
-	spin_lock_irqsave(&dport->port.lock, flags);
+	uart_port_lock_irqsave(&dport->port, &flags);
 	if (state < 3)
 		dz_start_tx(&dport->port);
 	else
 		dz_stop_tx(&dport->port);
-	spin_unlock_irqrestore(&dport->port.lock, flags);
+	uart_port_unlock_irqrestore(&dport->port, flags);
 }
 
 
@@ -811,7 +811,7 @@ static void dz_console_putchar(struct uart_port *uport, unsigned char ch)
 	unsigned short csr, tcr, trdy, mask;
 	int loops = 10000;
 
-	spin_lock_irqsave(&dport->port.lock, flags);
+	uart_port_lock_irqsave(&dport->port, &flags);
 	csr = dz_in(dport, DZ_CSR);
 	dz_out(dport, DZ_CSR, csr & ~DZ_TIE);
 	tcr = dz_in(dport, DZ_TCR);
@@ -819,7 +819,7 @@ static void dz_console_putchar(struct uart_port *uport, unsigned char ch)
 	mask = tcr;
 	dz_out(dport, DZ_TCR, mask);
 	iob();
-	spin_unlock_irqrestore(&dport->port.lock, flags);
+	uart_port_unlock_irqrestore(&dport->port, flags);
 
 	do {
 		trdy = dz_in(dport, DZ_CSR);
diff --git a/drivers/tty/serial/fsl_linflexuart.c b/drivers/tty/serial/fsl_linflexuart.c
index 249cb380c3c6..7fa809a405e8 100644
--- a/drivers/tty/serial/fsl_linflexuart.c
+++ b/drivers/tty/serial/fsl_linflexuart.c
@@ -203,7 +203,7 @@ static irqreturn_t linflex_txint(int irq, void *dev_id)
 	struct circ_buf *xmit = &sport->state->xmit;
 	unsigned long flags;
 
-	spin_lock_irqsave(&sport->lock, flags);
+	uart_port_lock_irqsave(sport, &flags);
 
 	if (sport->x_char) {
 		linflex_put_char(sport, sport->x_char);
@@ -217,7 +217,7 @@ static irqreturn_t linflex_txint(int irq, void *dev_id)
 
 	linflex_transmit_buffer(sport);
 out:
-	spin_unlock_irqrestore(&sport->lock, flags);
+	uart_port_unlock_irqrestore(sport, flags);
 	return IRQ_HANDLED;
 }
 
@@ -230,7 +230,7 @@ static irqreturn_t linflex_rxint(int irq, void *dev_id)
 	unsigned char rx;
 	bool brk;
 
-	spin_lock_irqsave(&sport->lock, flags);
+	uart_port_lock_irqsave(sport, &flags);
 
 	status = readl(sport->membase + UARTSR);
 	while (status & LINFLEXD_UARTSR_RMB) {
@@ -266,7 +266,7 @@ static irqreturn_t linflex_rxint(int irq, void *dev_id)
 		}
 	}
 
-	spin_unlock_irqrestore(&sport->lock, flags);
+	uart_port_unlock_irqrestore(sport, flags);
 
 	tty_flip_buffer_push(port);
 
@@ -369,11 +369,11 @@ static int linflex_startup(struct uart_port *port)
 	int ret = 0;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	linflex_setup_watermark(port);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	ret = devm_request_irq(port->dev, port->irq, linflex_int, 0,
 			       DRIVER_NAME, port);
@@ -386,14 +386,14 @@ static void linflex_shutdown(struct uart_port *port)
 	unsigned long ier;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* disable interrupts */
 	ier = readl(port->membase + LINIER);
 	ier &= ~(LINFLEXD_LINIER_DRIE | LINFLEXD_LINIER_DTIE);
 	writel(ier, port->membase + LINIER);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	devm_free_irq(port->dev, port->irq, port);
 }
@@ -474,7 +474,7 @@ linflex_set_termios(struct uart_port *port, struct ktermios *termios,
 		cr &= ~LINFLEXD_UARTCR_PCE;
 	}
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	port->read_status_mask = 0;
 
@@ -507,7 +507,7 @@ linflex_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	writel(cr1, port->membase + LINCR1);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static const char *linflex_type(struct uart_port *port)
@@ -646,14 +646,14 @@ linflex_console_write(struct console *co, const char *s, unsigned int count)
 	if (sport->sysrq)
 		locked = 0;
 	else if (oops_in_progress)
-		locked = spin_trylock_irqsave(&sport->lock, flags);
+		locked = uart_port_trylock_irqsave(sport, &flags);
 	else
-		spin_lock_irqsave(&sport->lock, flags);
+		uart_port_lock_irqsave(sport, &flags);
 
 	linflex_string_write(sport, s, count);
 
 	if (locked)
-		spin_unlock_irqrestore(&sport->lock, flags);
+		uart_port_unlock_irqrestore(sport, flags);
 }
 
 /*
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 385b41275e8b..6d0cfb2e86b4 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -532,9 +532,9 @@ static void lpuart_dma_tx_complete(void *arg)
 	struct dma_chan *chan = sport->dma_tx_chan;
 	unsigned long flags;
 
-	spin_lock_irqsave(&sport->port.lock, flags);
+	uart_port_lock_irqsave(&sport->port, &flags);
 	if (!sport->dma_tx_in_progress) {
-		spin_unlock_irqrestore(&sport->port.lock, flags);
+		uart_port_unlock_irqrestore(&sport->port, flags);
 		return;
 	}
 
@@ -543,7 +543,7 @@ static void lpuart_dma_tx_complete(void *arg)
 
 	uart_xmit_advance(&sport->port, sport->dma_tx_bytes);
 	sport->dma_tx_in_progress = false;
-	spin_unlock_irqrestore(&sport->port.lock, flags);
+	uart_port_unlock_irqrestore(&sport->port, flags);
 
 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 		uart_write_wakeup(&sport->port);
@@ -553,12 +553,12 @@ static void lpuart_dma_tx_complete(void *arg)
 		return;
 	}
 
-	spin_lock_irqsave(&sport->port.lock, flags);
+	uart_port_lock_irqsave(&sport->port, &flags);
 
 	if (!lpuart_stopped_or_empty(&sport->port))
 		lpuart_dma_tx(sport);
 
-	spin_unlock_irqrestore(&sport->port.lock, flags);
+	uart_port_unlock_irqrestore(&sport->port, flags);
 }
 
 static dma_addr_t lpuart_dma_datareg_addr(struct lpuart_port *sport)
@@ -651,7 +651,7 @@ static int lpuart_poll_init(struct uart_port *port)
 
 	sport->port.fifosize = 0;
 
-	spin_lock_irqsave(&sport->port.lock, flags);
+	uart_port_lock_irqsave(&sport->port, &flags);
 	/* Disable Rx & Tx */
 	writeb(0, sport->port.membase + UARTCR2);
 
@@ -675,7 +675,7 @@ static int lpuart_poll_init(struct uart_port *port)
 
 	/* Enable Rx and Tx */
 	writeb(UARTCR2_RE | UARTCR2_TE, sport->port.membase + UARTCR2);
-	spin_unlock_irqrestore(&sport->port.lock, flags);
+	uart_port_unlock_irqrestore(&sport->port, flags);
 
 	return 0;
 }
@@ -703,7 +703,7 @@ static int lpuart32_poll_init(struct uart_port *port)
 
 	sport->port.fifosize = 0;
 
-	spin_lock_irqsave(&sport->port.lock, flags);
+	uart_port_lock_irqsave(&sport->port, &flags);
 
 	/* Disable Rx & Tx */
 	lpuart32_write(&sport->port, 0, UARTCTRL);
@@ -724,7 +724,7 @@ static int lpuart32_poll_init(struct uart_port *port)
 
 	/* Enable Rx and Tx */
 	lpuart32_write(&sport->port, UARTCTRL_RE | UARTCTRL_TE, UARTCTRL);
-	spin_unlock_irqrestore(&sport->port.lock, flags);
+	uart_port_unlock_irqrestore(&sport->port, flags);
 
 	return 0;
 }
@@ -879,9 +879,9 @@ static unsigned int lpuart32_tx_empty(struct uart_port *port)
 
 static void lpuart_txint(struct lpuart_port *sport)
 {
-	spin_lock(&sport->port.lock);
+	uart_port_lock(&sport->port);
 	lpuart_transmit_buffer(sport);
-	spin_unlock(&sport->port.lock);
+	uart_port_unlock(&sport->port);
 }
 
 static void lpuart_rxint(struct lpuart_port *sport)
@@ -890,7 +890,7 @@ static void lpuart_rxint(struct lpuart_port *sport)
 	struct tty_port *port = &sport->port.state->port;
 	unsigned char rx, sr;
 
-	spin_lock(&sport->port.lock);
+	uart_port_lock(&sport->port);
 
 	while (!(readb(sport->port.membase + UARTSFIFO) & UARTSFIFO_RXEMPT)) {
 		flg = TTY_NORMAL;
@@ -956,9 +956,9 @@ static void lpuart_rxint(struct lpuart_port *sport)
 
 static void lpuart32_txint(struct lpuart_port *sport)
 {
-	spin_lock(&sport->port.lock);
+	uart_port_lock(&sport->port);
 	lpuart32_transmit_buffer(sport);
-	spin_unlock(&sport->port.lock);
+	uart_port_unlock(&sport->port);
 }
 
 static void lpuart32_rxint(struct lpuart_port *sport)
@@ -968,7 +968,7 @@ static void lpuart32_rxint(struct lpuart_port *sport)
 	unsigned long rx, sr;
 	bool is_break;
 
-	spin_lock(&sport->port.lock);
+	uart_port_lock(&sport->port);
 
 	while (!(lpuart32_read(&sport->port, UARTFIFO) & UARTFIFO_RXEMPT)) {
 		flg = TTY_NORMAL;
@@ -1170,12 +1170,12 @@ static void lpuart_copy_rx_to_tty(struct lpuart_port *sport)
 
 	async_tx_ack(sport->dma_rx_desc);
 
-	spin_lock_irqsave(&sport->port.lock, flags);
+	uart_port_lock_irqsave(&sport->port, &flags);
 
 	dmastat = dmaengine_tx_status(chan, sport->dma_rx_cookie, &state);
 	if (dmastat == DMA_ERROR) {
 		dev_err(sport->port.dev, "Rx DMA transfer failed!\n");
-		spin_unlock_irqrestore(&sport->port.lock, flags);
+		uart_port_unlock_irqrestore(&sport->port, flags);
 		return;
 	}
 
@@ -1244,7 +1244,7 @@ static void lpuart_copy_rx_to_tty(struct lpuart_port *sport)
 	dma_sync_sg_for_device(chan->device->dev, &sport->rx_sgl, 1,
 			       DMA_FROM_DEVICE);
 
-	spin_unlock_irqrestore(&sport->port.lock, flags);
+	uart_port_unlock_irqrestore(&sport->port, flags);
 
 	tty_flip_buffer_push(port);
 	if (!sport->dma_idle_int)
@@ -1335,9 +1335,9 @@ static void lpuart_timer_func(struct timer_list *t)
 		mod_timer(&sport->lpuart_timer,
 			  jiffies + sport->dma_rx_timeout);
 
-	if (spin_trylock_irqsave(&sport->port.lock, flags)) {
+	if (uart_port_trylock_irqsave(&sport->port, &flags)) {
 		sport->last_residue = state.residue;
-		spin_unlock_irqrestore(&sport->port.lock, flags);
+		uart_port_unlock_irqrestore(&sport->port, flags);
 	}
 }
 
@@ -1802,14 +1802,14 @@ static void lpuart_hw_setup(struct lpuart_port *sport)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&sport->port.lock, flags);
+	uart_port_lock_irqsave(&sport->port, &flags);
 
 	lpuart_setup_watermark_enable(sport);
 
 	lpuart_rx_dma_startup(sport);
 	lpuart_tx_dma_startup(sport);
 
-	spin_unlock_irqrestore(&sport->port.lock, flags);
+	uart_port_unlock_irqrestore(&sport->port, flags);
 }
 
 static int lpuart_startup(struct uart_port *port)
@@ -1859,7 +1859,7 @@ static void lpuart32_hw_setup(struct lpuart_port *sport)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&sport->port.lock, flags);
+	uart_port_lock_irqsave(&sport->port, &flags);
 
 	lpuart32_hw_disable(sport);
 
@@ -1869,7 +1869,7 @@ static void lpuart32_hw_setup(struct lpuart_port *sport)
 	lpuart32_setup_watermark_enable(sport);
 	lpuart32_configure(sport);
 
-	spin_unlock_irqrestore(&sport->port.lock, flags);
+	uart_port_unlock_irqrestore(&sport->port, flags);
 }
 
 static int lpuart32_startup(struct uart_port *port)
@@ -1932,7 +1932,7 @@ static void lpuart_shutdown(struct uart_port *port)
 	unsigned char temp;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* disable Rx/Tx and interrupts */
 	temp = readb(port->membase + UARTCR2);
@@ -1940,7 +1940,7 @@ static void lpuart_shutdown(struct uart_port *port)
 			UARTCR2_TIE | UARTCR2_TCIE | UARTCR2_RIE);
 	writeb(temp, port->membase + UARTCR2);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	lpuart_dma_shutdown(sport);
 }
@@ -1952,7 +1952,7 @@ static void lpuart32_shutdown(struct uart_port *port)
 	unsigned long temp;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* clear status */
 	temp = lpuart32_read(&sport->port, UARTSTAT);
@@ -1969,7 +1969,7 @@ static void lpuart32_shutdown(struct uart_port *port)
 			UARTCTRL_TIE | UARTCTRL_TCIE | UARTCTRL_RIE | UARTCTRL_SBK);
 	lpuart32_write(port, temp, UARTCTRL);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	lpuart_dma_shutdown(sport);
 }
@@ -2069,7 +2069,7 @@ lpuart_set_termios(struct uart_port *port, struct ktermios *termios,
 	if (old && sport->lpuart_dma_rx_use)
 		lpuart_dma_rx_free(&sport->port);
 
-	spin_lock_irqsave(&sport->port.lock, flags);
+	uart_port_lock_irqsave(&sport->port, &flags);
 
 	sport->port.read_status_mask = 0;
 	if (termios->c_iflag & INPCK)
@@ -2124,7 +2124,7 @@ lpuart_set_termios(struct uart_port *port, struct ktermios *termios,
 			sport->lpuart_dma_rx_use = false;
 	}
 
-	spin_unlock_irqrestore(&sport->port.lock, flags);
+	uart_port_unlock_irqrestore(&sport->port, flags);
 }
 
 static void __lpuart32_serial_setbrg(struct uart_port *port,
@@ -2304,7 +2304,7 @@ lpuart32_set_termios(struct uart_port *port, struct ktermios *termios,
 	if (old && sport->lpuart_dma_rx_use)
 		lpuart_dma_rx_free(&sport->port);
 
-	spin_lock_irqsave(&sport->port.lock, flags);
+	uart_port_lock_irqsave(&sport->port, &flags);
 
 	sport->port.read_status_mask = 0;
 	if (termios->c_iflag & INPCK)
@@ -2345,12 +2345,9 @@ lpuart32_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	lpuart32_write(&sport->port, bd, UARTBAUD);
 	lpuart32_serial_setbrg(sport, baud);
-	/* disable CTS before enabling UARTCTRL_TE to avoid pending idle preamble */
-	lpuart32_write(&sport->port, modem & ~UARTMODIR_TXCTSE, UARTMODIR);
-	/* restore control register */
-	lpuart32_write(&sport->port, ctrl, UARTCTRL);
-	/* re-enable the CTS if needed */
 	lpuart32_write(&sport->port, modem, UARTMODIR);
+	lpuart32_write(&sport->port, ctrl, UARTCTRL);
+	/* restore control register */
 
 	if ((ctrl & (UARTCTRL_PE | UARTCTRL_M)) == UARTCTRL_PE)
 		sport->is_cs7 = true;
@@ -2362,7 +2359,7 @@ lpuart32_set_termios(struct uart_port *port, struct ktermios *termios,
 			sport->lpuart_dma_rx_use = false;
 	}
 
-	spin_unlock_irqrestore(&sport->port.lock, flags);
+	uart_port_unlock_irqrestore(&sport->port, flags);
 }
 
 static const char *lpuart_type(struct uart_port *port)
@@ -2480,9 +2477,9 @@ lpuart_console_write(struct console *co, const char *s, unsigned int count)
 	int locked = 1;
 
 	if (oops_in_progress)
-		locked = spin_trylock_irqsave(&sport->port.lock, flags);
+		locked = uart_port_trylock_irqsave(&sport->port, &flags);
 	else
-		spin_lock_irqsave(&sport->port.lock, flags);
+		uart_port_lock_irqsave(&sport->port, &flags);
 
 	/* first save CR2 and then disable interrupts */
 	cr2 = old_cr2 = readb(sport->port.membase + UARTCR2);
@@ -2498,7 +2495,7 @@ lpuart_console_write(struct console *co, const char *s, unsigned int count)
 	writeb(old_cr2, sport->port.membase + UARTCR2);
 
 	if (locked)
-		spin_unlock_irqrestore(&sport->port.lock, flags);
+		uart_port_unlock_irqrestore(&sport->port, flags);
 }
 
 static void
@@ -2510,9 +2507,9 @@ lpuart32_console_write(struct console *co, const char *s, unsigned int count)
 	int locked = 1;
 
 	if (oops_in_progress)
-		locked = spin_trylock_irqsave(&sport->port.lock, flags);
+		locked = uart_port_trylock_irqsave(&sport->port, &flags);
 	else
-		spin_lock_irqsave(&sport->port.lock, flags);
+		uart_port_lock_irqsave(&sport->port, &flags);
 
 	/* first save CR2 and then disable interrupts */
 	cr = old_cr = lpuart32_read(&sport->port, UARTCTRL);
@@ -2528,7 +2525,7 @@ lpuart32_console_write(struct console *co, const char *s, unsigned int count)
 	lpuart32_write(&sport->port, old_cr, UARTCTRL);
 
 	if (locked)
-		spin_unlock_irqrestore(&sport->port.lock, flags);
+		uart_port_unlock_irqrestore(&sport->port, flags);
 }
 
 /*
@@ -3092,7 +3089,7 @@ static int lpuart_suspend(struct device *dev)
 	uart_suspend_port(&lpuart_reg, &sport->port);
 
 	if (lpuart_uport_is_active(sport)) {
-		spin_lock_irqsave(&sport->port.lock, flags);
+		uart_port_lock_irqsave(&sport->port, &flags);
 		if (lpuart_is_32(sport)) {
 			/* disable Rx/Tx and interrupts */
 			temp = lpuart32_read(&sport->port, UARTCTRL);
@@ -3104,7 +3101,7 @@ static int lpuart_suspend(struct device *dev)
 			temp &= ~(UARTCR2_TE | UARTCR2_TIE | UARTCR2_TCIE);
 			writeb(temp, sport->port.membase + UARTCR2);
 		}
-		spin_unlock_irqrestore(&sport->port.lock, flags);
+		uart_port_unlock_irqrestore(&sport->port, flags);
 
 		if (sport->lpuart_dma_rx_use) {
 			/*
@@ -3117,7 +3114,7 @@ static int lpuart_suspend(struct device *dev)
 			lpuart_dma_rx_free(&sport->port);
 
 			/* Disable Rx DMA to use UART port as wakeup source */
-			spin_lock_irqsave(&sport->port.lock, flags);
+			uart_port_lock_irqsave(&sport->port, &flags);
 			if (lpuart_is_32(sport)) {
 				temp = lpuart32_read(&sport->port, UARTBAUD);
 				lpuart32_write(&sport->port, temp & ~UARTBAUD_RDMAE,
@@ -3126,11 +3123,11 @@ static int lpuart_suspend(struct device *dev)
 				writeb(readb(sport->port.membase + UARTCR5) &
 				       ~UARTCR5_RDMAS, sport->port.membase + UARTCR5);
 			}
-			spin_unlock_irqrestore(&sport->port.lock, flags);
+			uart_port_unlock_irqrestore(&sport->port, flags);
 		}
 
 		if (sport->lpuart_dma_tx_use) {
-			spin_lock_irqsave(&sport->port.lock, flags);
+			uart_port_lock_irqsave(&sport->port, &flags);
 			if (lpuart_is_32(sport)) {
 				temp = lpuart32_read(&sport->port, UARTBAUD);
 				temp &= ~UARTBAUD_TDMAE;
@@ -3140,7 +3137,7 @@ static int lpuart_suspend(struct device *dev)
 				temp &= ~UARTCR5_TDMAS;
 				writeb(temp, sport->port.membase + UARTCR5);
 			}
-			spin_unlock_irqrestore(&sport->port.lock, flags);
+			uart_port_unlock_irqrestore(&sport->port, flags);
 			sport->dma_tx_in_progress = false;
 			dmaengine_terminate_sync(sport->dma_tx_chan);
 		}
diff --git a/drivers/tty/serial/icom.c b/drivers/tty/serial/icom.c
index 819f957b6b84..a75eafbcbea3 100644
--- a/drivers/tty/serial/icom.c
+++ b/drivers/tty/serial/icom.c
@@ -929,7 +929,7 @@ static inline void check_modem_status(struct icom_port *icom_port)
 	char delta_status;
 	unsigned char status;
 
-	spin_lock(&icom_port->uart_port.lock);
+	uart_port_lock(&icom_port->uart_port);
 
 	/*modem input register */
 	status = readb(&icom_port->dram->isr);
@@ -951,7 +951,7 @@ static inline void check_modem_status(struct icom_port *icom_port)
 				      port.delta_msr_wait);
 		old_status = status;
 	}
-	spin_unlock(&icom_port->uart_port.lock);
+	uart_port_unlock(&icom_port->uart_port);
 }
 
 static void xmit_interrupt(u16 port_int_reg, struct icom_port *icom_port)
@@ -1093,7 +1093,7 @@ static void process_interrupt(u16 port_int_reg,
 			      struct icom_port *icom_port)
 {
 
-	spin_lock(&icom_port->uart_port.lock);
+	uart_port_lock(&icom_port->uart_port);
 	trace(icom_port, "INTERRUPT", port_int_reg);
 
 	if (port_int_reg & (INT_XMIT_COMPLETED | INT_XMIT_DISABLED))
@@ -1102,7 +1102,7 @@ static void process_interrupt(u16 port_int_reg,
 	if (port_int_reg & INT_RCV_COMPLETED)
 		recv_interrupt(port_int_reg, icom_port);
 
-	spin_unlock(&icom_port->uart_port.lock);
+	uart_port_unlock(&icom_port->uart_port);
 }
 
 static irqreturn_t icom_interrupt(int irq, void *dev_id)
@@ -1186,14 +1186,14 @@ static unsigned int icom_tx_empty(struct uart_port *port)
 	int ret;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	if (le16_to_cpu(icom_port->statStg->xmit[0].flags) &
 	    SA_FLAGS_READY_TO_XMIT)
 		ret = TIOCSER_TEMT;
 	else
 		ret = 0;
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 	return ret;
 }
 
@@ -1276,7 +1276,7 @@ static void icom_send_xchar(struct uart_port *port, char ch)
 
 	/* wait .1 sec to send char */
 	for (index = 0; index < 10; index++) {
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 		xdata = readb(&icom_port->dram->xchar);
 		if (xdata == 0x00) {
 			trace(icom_port, "QUICK_WRITE", 0);
@@ -1284,10 +1284,10 @@ static void icom_send_xchar(struct uart_port *port, char ch)
 
 			/* flush write operation */
 			xdata = readb(&icom_port->dram->xchar);
-			spin_unlock_irqrestore(&port->lock, flags);
+			uart_port_unlock_irqrestore(port, flags);
 			break;
 		}
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 		msleep(10);
 	}
 }
@@ -1307,7 +1307,7 @@ static void icom_break(struct uart_port *port, int break_state)
 	unsigned char cmdReg;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	trace(icom_port, "BREAK", 0);
 	cmdReg = readb(&icom_port->dram->CmdReg);
 	if (break_state == -1) {
@@ -1315,7 +1315,7 @@ static void icom_break(struct uart_port *port, int break_state)
 	} else {
 		writeb(cmdReg & ~CMD_SND_BREAK, &icom_port->dram->CmdReg);
 	}
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static int icom_open(struct uart_port *port)
@@ -1365,7 +1365,7 @@ static void icom_set_termios(struct uart_port *port, struct ktermios *termios,
 	unsigned long offset;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	trace(icom_port, "CHANGE_SPEED", 0);
 
 	cflag = termios->c_cflag;
@@ -1516,7 +1516,7 @@ static void icom_set_termios(struct uart_port *port, struct ktermios *termios,
 	trace(icom_port, "XR_ENAB", 0);
 	writeb(CMD_XMIT_RCV_ENABLE, &icom_port->dram->CmdReg);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static const char *icom_type(struct uart_port *port)
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index c77831e91ec2..7e9652f68c65 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -421,13 +421,13 @@ static void imx_uart_stop_tx(struct uart_port *port)
 	ucr1 = imx_uart_readl(sport, UCR1);
 	imx_uart_writel(sport, ucr1 & ~UCR1_TRDYEN, UCR1);
 
-	ucr4 = imx_uart_readl(sport, UCR4);
 	usr2 = imx_uart_readl(sport, USR2);
-	if ((!(usr2 & USR2_TXDC)) && (ucr4 & UCR4_TCEN)) {
+	if (!(usr2 & USR2_TXDC)) {
 		/* The shifter is still busy, so retry once TC triggers */
 		return;
 	}
 
+	ucr4 = imx_uart_readl(sport, UCR4);
 	ucr4 &= ~UCR4_TCEN;
 	imx_uart_writel(sport, ucr4, UCR4);
 
@@ -468,7 +468,8 @@ static void imx_uart_stop_tx(struct uart_port *port)
 	}
 }
 
-static void imx_uart_stop_rx_with_loopback_ctrl(struct uart_port *port, bool loopback)
+/* called with port.lock taken and irqs off */
+static void imx_uart_stop_rx(struct uart_port *port)
 {
 	struct imx_port *sport = (struct imx_port *)port;
 	u32 ucr1, ucr2, ucr4, uts;
@@ -490,7 +491,7 @@ static void imx_uart_stop_rx_with_loopback_ctrl(struct uart_port *port, bool loo
 	/* See SER_RS485_ENABLED/UTS_LOOP comment in imx_uart_probe() */
 	if (port->rs485.flags & SER_RS485_ENABLED &&
 	    port->rs485.flags & SER_RS485_RTS_ON_SEND &&
-	    sport->have_rtscts && !sport->have_rtsgpio && loopback) {
+	    sport->have_rtscts && !sport->have_rtsgpio) {
 		uts = imx_uart_readl(sport, imx_uart_uts_reg(sport));
 		uts |= UTS_LOOP;
 		imx_uart_writel(sport, uts, imx_uart_uts_reg(sport));
@@ -502,16 +503,6 @@ static void imx_uart_stop_rx_with_loopback_ctrl(struct uart_port *port, bool loo
 	imx_uart_writel(sport, ucr2, UCR2);
 }
 
-/* called with port.lock taken and irqs off */
-static void imx_uart_stop_rx(struct uart_port *port)
-{
-	/*
-	 * Stop RX and enable loopback in order to make sure RS485 bus
-	 * is not blocked. Se comment in imx_uart_probe().
-	 */
-	imx_uart_stop_rx_with_loopback_ctrl(port, true);
-}
-
 /* called with port.lock taken and irqs off */
 static void imx_uart_enable_ms(struct uart_port *port)
 {
@@ -584,7 +575,7 @@ static void imx_uart_dma_tx_callback(void *data)
 	unsigned long flags;
 	u32 ucr1;
 
-	spin_lock_irqsave(&sport->port.lock, flags);
+	uart_port_lock_irqsave(&sport->port, &flags);
 
 	dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
 
@@ -609,7 +600,7 @@ static void imx_uart_dma_tx_callback(void *data)
 		imx_uart_writel(sport, ucr4, UCR4);
 	}
 
-	spin_unlock_irqrestore(&sport->port.lock, flags);
+	uart_port_unlock_irqrestore(&sport->port, flags);
 }
 
 /* called with port.lock taken and irqs off */
@@ -697,14 +688,9 @@ static void imx_uart_start_tx(struct uart_port *port)
 				imx_uart_rts_inactive(sport, &ucr2);
 			imx_uart_writel(sport, ucr2, UCR2);
 
-			/*
-			 * Since we are about to transmit we can not stop RX
-			 * with loopback enabled because that will make our
-			 * transmitted data being just looped to RX.
-			 */
 			if (!(port->rs485.flags & SER_RS485_RX_DURING_TX) &&
 			    !port->rs485_rx_during_tx_gpio)
-				imx_uart_stop_rx_with_loopback_ctrl(port, false);
+				imx_uart_stop_rx(port);
 
 			sport->tx_state = WAIT_AFTER_RTS;
 
@@ -780,11 +766,11 @@ static irqreturn_t imx_uart_rtsint(int irq, void *dev_id)
 	struct imx_port *sport = dev_id;
 	irqreturn_t ret;
 
-	spin_lock(&sport->port.lock);
+	uart_port_lock(&sport->port);
 
 	ret = __imx_uart_rtsint(irq, dev_id);
 
-	spin_unlock(&sport->port.lock);
+	uart_port_unlock(&sport->port);
 
 	return ret;
 }
@@ -793,9 +779,9 @@ static irqreturn_t imx_uart_txint(int irq, void *dev_id)
 {
 	struct imx_port *sport = dev_id;
 
-	spin_lock(&sport->port.lock);
+	uart_port_lock(&sport->port);
 	imx_uart_transmit_buffer(sport);
-	spin_unlock(&sport->port.lock);
+	uart_port_unlock(&sport->port);
 	return IRQ_HANDLED;
 }
 
@@ -909,11 +895,11 @@ static irqreturn_t imx_uart_rxint(int irq, void *dev_id)
 	struct imx_port *sport = dev_id;
 	irqreturn_t ret;
 
-	spin_lock(&sport->port.lock);
+	uart_port_lock(&sport->port);
 
 	ret = __imx_uart_rxint(irq, dev_id);
 
-	spin_unlock(&sport->port.lock);
+	uart_port_unlock(&sport->port);
 
 	return ret;
 }
@@ -976,7 +962,7 @@ static irqreturn_t imx_uart_int(int irq, void *dev_id)
 	unsigned int usr1, usr2, ucr1, ucr2, ucr3, ucr4;
 	irqreturn_t ret = IRQ_NONE;
 
-	spin_lock(&sport->port.lock);
+	uart_port_lock(&sport->port);
 
 	usr1 = imx_uart_readl(sport, USR1);
 	usr2 = imx_uart_readl(sport, USR2);
@@ -1046,7 +1032,7 @@ static irqreturn_t imx_uart_int(int irq, void *dev_id)
 		ret = IRQ_HANDLED;
 	}
 
-	spin_unlock(&sport->port.lock);
+	uart_port_unlock(&sport->port);
 
 	return ret;
 }
@@ -1129,7 +1115,7 @@ static void imx_uart_break_ctl(struct uart_port *port, int break_state)
 	unsigned long flags;
 	u32 ucr1;
 
-	spin_lock_irqsave(&sport->port.lock, flags);
+	uart_port_lock_irqsave(&sport->port, &flags);
 
 	ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_SNDBRK;
 
@@ -1138,7 +1124,7 @@ static void imx_uart_break_ctl(struct uart_port *port, int break_state)
 
 	imx_uart_writel(sport, ucr1, UCR1);
 
-	spin_unlock_irqrestore(&sport->port.lock, flags);
+	uart_port_unlock_irqrestore(&sport->port, flags);
 }
 
 /*
@@ -1151,9 +1137,9 @@ static void imx_uart_timeout(struct timer_list *t)
 	unsigned long flags;
 
 	if (sport->port.state) {
-		spin_lock_irqsave(&sport->port.lock, flags);
+		uart_port_lock_irqsave(&sport->port, &flags);
 		imx_uart_mctrl_check(sport);
-		spin_unlock_irqrestore(&sport->port.lock, flags);
+		uart_port_unlock_irqrestore(&sport->port, flags);
 
 		mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
 	}
@@ -1183,9 +1169,9 @@ static void imx_uart_dma_rx_callback(void *data)
 	status = dmaengine_tx_status(chan, sport->rx_cookie, &state);
 
 	if (status == DMA_ERROR) {
-		spin_lock(&sport->port.lock);
+		uart_port_lock(&sport->port);
 		imx_uart_clear_rx_errors(sport);
-		spin_unlock(&sport->port.lock);
+		uart_port_unlock(&sport->port);
 		return;
 	}
 
@@ -1214,9 +1200,9 @@ static void imx_uart_dma_rx_callback(void *data)
 		r_bytes = rx_ring->head - rx_ring->tail;
 
 		/* If we received something, check for 0xff flood */
-		spin_lock(&sport->port.lock);
+		uart_port_lock(&sport->port);
 		imx_uart_check_flood(sport, imx_uart_readl(sport, USR2));
-		spin_unlock(&sport->port.lock);
+		uart_port_unlock(&sport->port);
 
 		if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ)) {
 
@@ -1474,7 +1460,7 @@ static int imx_uart_startup(struct uart_port *port)
 	if (!uart_console(port) && imx_uart_dma_init(sport) == 0)
 		dma_is_inited = 1;
 
-	spin_lock_irqsave(&sport->port.lock, flags);
+	uart_port_lock_irqsave(&sport->port, &flags);
 
 	/* Reset fifo's and state machines */
 	imx_uart_soft_reset(sport);
@@ -1547,7 +1533,7 @@ static int imx_uart_startup(struct uart_port *port)
 
 	imx_uart_disable_loopback_rs485(sport);
 
-	spin_unlock_irqrestore(&sport->port.lock, flags);
+	uart_port_unlock_irqrestore(&sport->port, flags);
 
 	return 0;
 }
@@ -1572,21 +1558,21 @@ static void imx_uart_shutdown(struct uart_port *port)
 			sport->dma_is_rxing = 0;
 		}
 
-		spin_lock_irqsave(&sport->port.lock, flags);
+		uart_port_lock_irqsave(&sport->port, &flags);
 		imx_uart_stop_tx(port);
 		imx_uart_stop_rx(port);
 		imx_uart_disable_dma(sport);
-		spin_unlock_irqrestore(&sport->port.lock, flags);
+		uart_port_unlock_irqrestore(&sport->port, flags);
 		imx_uart_dma_exit(sport);
 	}
 
 	mctrl_gpio_disable_ms(sport->gpios);
 
-	spin_lock_irqsave(&sport->port.lock, flags);
+	uart_port_lock_irqsave(&sport->port, &flags);
 	ucr2 = imx_uart_readl(sport, UCR2);
 	ucr2 &= ~(UCR2_TXEN | UCR2_ATEN);
 	imx_uart_writel(sport, ucr2, UCR2);
-	spin_unlock_irqrestore(&sport->port.lock, flags);
+	uart_port_unlock_irqrestore(&sport->port, flags);
 
 	/*
 	 * Stop our timer.
@@ -1597,7 +1583,7 @@ static void imx_uart_shutdown(struct uart_port *port)
 	 * Disable all interrupts, port and break condition.
 	 */
 
-	spin_lock_irqsave(&sport->port.lock, flags);
+	uart_port_lock_irqsave(&sport->port, &flags);
 
 	ucr1 = imx_uart_readl(sport, UCR1);
 	ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_RXDMAEN |
@@ -1619,7 +1605,7 @@ static void imx_uart_shutdown(struct uart_port *port)
 	ucr4 &= ~UCR4_TCEN;
 	imx_uart_writel(sport, ucr4, UCR4);
 
-	spin_unlock_irqrestore(&sport->port.lock, flags);
+	uart_port_unlock_irqrestore(&sport->port, flags);
 
 	clk_disable_unprepare(sport->clk_per);
 	clk_disable_unprepare(sport->clk_ipg);
@@ -1682,7 +1668,7 @@ imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
 	baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
 	quot = uart_get_divisor(port, baud);
 
-	spin_lock_irqsave(&sport->port.lock, flags);
+	uart_port_lock_irqsave(&sport->port, &flags);
 
 	/*
 	 * Read current UCR2 and save it for future use, then clear all the bits
@@ -1810,7 +1796,7 @@ imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
 	if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
 		imx_uart_enable_ms(&sport->port);
 
-	spin_unlock_irqrestore(&sport->port.lock, flags);
+	uart_port_unlock_irqrestore(&sport->port, flags);
 }
 
 static const char *imx_uart_type(struct uart_port *port)
@@ -1872,7 +1858,7 @@ static int imx_uart_poll_init(struct uart_port *port)
 
 	imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
 
-	spin_lock_irqsave(&sport->port.lock, flags);
+	uart_port_lock_irqsave(&sport->port, &flags);
 
 	/*
 	 * Be careful about the order of enabling bits here. First enable the
@@ -1900,7 +1886,7 @@ static int imx_uart_poll_init(struct uart_port *port)
 	imx_uart_writel(sport, ucr1 | UCR1_RRDYEN, UCR1);
 	imx_uart_writel(sport, ucr2 | UCR2_ATEN, UCR2);
 
-	spin_unlock_irqrestore(&sport->port.lock, flags);
+	uart_port_unlock_irqrestore(&sport->port, flags);
 
 	return 0;
 }
@@ -2015,9 +2001,9 @@ imx_uart_console_write(struct console *co, const char *s, unsigned int count)
 	if (sport->port.sysrq)
 		locked = 0;
 	else if (oops_in_progress)
-		locked = spin_trylock_irqsave(&sport->port.lock, flags);
+		locked = uart_port_trylock_irqsave(&sport->port, &flags);
 	else
-		spin_lock_irqsave(&sport->port.lock, flags);
+		uart_port_lock_irqsave(&sport->port, &flags);
 
 	/*
 	 *	First, save UCR1/2/3 and then disable interrupts
@@ -2045,7 +2031,7 @@ imx_uart_console_write(struct console *co, const char *s, unsigned int count)
 	imx_uart_ucrs_restore(sport, &old_ucr);
 
 	if (locked)
-		spin_unlock_irqrestore(&sport->port.lock, flags);
+		uart_port_unlock_irqrestore(&sport->port, flags);
 }
 
 /*
@@ -2203,10 +2189,10 @@ static enum hrtimer_restart imx_trigger_start_tx(struct hrtimer *t)
 	struct imx_port *sport = container_of(t, struct imx_port, trigger_start_tx);
 	unsigned long flags;
 
-	spin_lock_irqsave(&sport->port.lock, flags);
+	uart_port_lock_irqsave(&sport->port, &flags);
 	if (sport->tx_state == WAIT_AFTER_RTS)
 		imx_uart_start_tx(&sport->port);
-	spin_unlock_irqrestore(&sport->port.lock, flags);
+	uart_port_unlock_irqrestore(&sport->port, flags);
 
 	return HRTIMER_NORESTART;
 }
@@ -2216,14 +2202,15 @@ static enum hrtimer_restart imx_trigger_stop_tx(struct hrtimer *t)
 	struct imx_port *sport = container_of(t, struct imx_port, trigger_stop_tx);
 	unsigned long flags;
 
-	spin_lock_irqsave(&sport->port.lock, flags);
+	uart_port_lock_irqsave(&sport->port, &flags);
 	if (sport->tx_state == WAIT_AFTER_SEND)
 		imx_uart_stop_tx(&sport->port);
-	spin_unlock_irqrestore(&sport->port.lock, flags);
+	uart_port_unlock_irqrestore(&sport->port, flags);
 
 	return HRTIMER_NORESTART;
 }
 
+static const struct serial_rs485 imx_no_rs485 = {};	/* No RS485 if no RTS */
 static const struct serial_rs485 imx_rs485_supported = {
 	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND |
 		 SER_RS485_RX_DURING_TX,
@@ -2307,6 +2294,8 @@ static int imx_uart_probe(struct platform_device *pdev)
 	/* RTS is required to control the RS485 transmitter */
 	if (sport->have_rtscts || sport->have_rtsgpio)
 		sport->port.rs485_supported = imx_rs485_supported;
+	else
+		sport->port.rs485_supported = imx_no_rs485;
 	sport->port.flags = UPF_BOOT_AUTOCONF;
 	timer_setup(&sport->timer, imx_uart_timeout, 0);
 
@@ -2333,13 +2322,19 @@ static int imx_uart_probe(struct platform_device *pdev)
 	/* For register access, we only need to enable the ipg clock. */
 	ret = clk_prepare_enable(sport->clk_ipg);
 	if (ret) {
-		dev_err(&pdev->dev, "failed to enable ipg clk: %d\n", ret);
+		dev_err(&pdev->dev, "failed to enable per clk: %d\n", ret);
 		return ret;
 	}
 
 	ret = uart_get_rs485_mode(&sport->port);
-	if (ret)
-		goto err_clk;
+	if (ret) {
+		clk_disable_unprepare(sport->clk_ipg);
+		return ret;
+	}
+
+	if (sport->port.rs485.flags & SER_RS485_ENABLED &&
+	    (!sport->have_rtscts && !sport->have_rtsgpio))
+		dev_err(&pdev->dev, "no RTS control, disabling rs485\n");
 
 	/*
 	 * If using the i.MX UART RTS/CTS control then the RTS (CTS_B)
@@ -2419,6 +2414,8 @@ static int imx_uart_probe(struct platform_device *pdev)
 		imx_uart_writel(sport, ucr3, UCR3);
 	}
 
+	clk_disable_unprepare(sport->clk_ipg);
+
 	hrtimer_init(&sport->trigger_start_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 	hrtimer_init(&sport->trigger_stop_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 	sport->trigger_start_tx.function = imx_trigger_start_tx;
@@ -2434,7 +2431,7 @@ static int imx_uart_probe(struct platform_device *pdev)
 		if (ret) {
 			dev_err(&pdev->dev, "failed to request rx irq: %d\n",
 				ret);
-			goto err_clk;
+			return ret;
 		}
 
 		ret = devm_request_irq(&pdev->dev, txirq, imx_uart_txint, 0,
@@ -2442,7 +2439,7 @@ static int imx_uart_probe(struct platform_device *pdev)
 		if (ret) {
 			dev_err(&pdev->dev, "failed to request tx irq: %d\n",
 				ret);
-			goto err_clk;
+			return ret;
 		}
 
 		ret = devm_request_irq(&pdev->dev, rtsirq, imx_uart_rtsint, 0,
@@ -2450,14 +2447,14 @@ static int imx_uart_probe(struct platform_device *pdev)
 		if (ret) {
 			dev_err(&pdev->dev, "failed to request rts irq: %d\n",
 				ret);
-			goto err_clk;
+			return ret;
 		}
 	} else {
 		ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_int, 0,
 				       dev_name(&pdev->dev), sport);
 		if (ret) {
 			dev_err(&pdev->dev, "failed to request irq: %d\n", ret);
-			goto err_clk;
+			return ret;
 		}
 	}
 
@@ -2465,12 +2462,7 @@ static int imx_uart_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, sport);
 
-	ret = uart_add_one_port(&imx_uart_uart_driver, &sport->port);
-
-err_clk:
-	clk_disable_unprepare(sport->clk_ipg);
-
-	return ret;
+	return uart_add_one_port(&imx_uart_uart_driver, &sport->port);
 }
 
 static int imx_uart_remove(struct platform_device *pdev)
@@ -2486,9 +2478,9 @@ static void imx_uart_restore_context(struct imx_port *sport)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&sport->port.lock, flags);
+	uart_port_lock_irqsave(&sport->port, &flags);
 	if (!sport->context_saved) {
-		spin_unlock_irqrestore(&sport->port.lock, flags);
+		uart_port_unlock_irqrestore(&sport->port, flags);
 		return;
 	}
 
@@ -2503,7 +2495,7 @@ static void imx_uart_restore_context(struct imx_port *sport)
 	imx_uart_writel(sport, sport->saved_reg[2], UCR3);
 	imx_uart_writel(sport, sport->saved_reg[3], UCR4);
 	sport->context_saved = false;
-	spin_unlock_irqrestore(&sport->port.lock, flags);
+	uart_port_unlock_irqrestore(&sport->port, flags);
 }
 
 static void imx_uart_save_context(struct imx_port *sport)
@@ -2511,7 +2503,7 @@ static void imx_uart_save_context(struct imx_port *sport)
 	unsigned long flags;
 
 	/* Save necessary regs */
-	spin_lock_irqsave(&sport->port.lock, flags);
+	uart_port_lock_irqsave(&sport->port, &flags);
 	sport->saved_reg[0] = imx_uart_readl(sport, UCR1);
 	sport->saved_reg[1] = imx_uart_readl(sport, UCR2);
 	sport->saved_reg[2] = imx_uart_readl(sport, UCR3);
@@ -2523,7 +2515,7 @@ static void imx_uart_save_context(struct imx_port *sport)
 	sport->saved_reg[8] = imx_uart_readl(sport, UBMR);
 	sport->saved_reg[9] = imx_uart_readl(sport, IMX21_UTS);
 	sport->context_saved = true;
-	spin_unlock_irqrestore(&sport->port.lock, flags);
+	uart_port_unlock_irqrestore(&sport->port, flags);
 }
 
 static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
diff --git a/drivers/tty/serial/ip22zilog.c b/drivers/tty/serial/ip22zilog.c
index 845ff706bc59..320b29cd4683 100644
--- a/drivers/tty/serial/ip22zilog.c
+++ b/drivers/tty/serial/ip22zilog.c
@@ -432,7 +432,7 @@ static irqreturn_t ip22zilog_interrupt(int irq, void *dev_id)
 		unsigned char r3;
 		bool push = false;
 
-		spin_lock(&up->port.lock);
+		uart_port_lock(&up->port);
 		r3 = read_zsreg(channel, R3);
 
 		/* Channel A */
@@ -448,7 +448,7 @@ static irqreturn_t ip22zilog_interrupt(int irq, void *dev_id)
 			if (r3 & CHATxIP)
 				ip22zilog_transmit_chars(up, channel);
 		}
-		spin_unlock(&up->port.lock);
+		uart_port_unlock(&up->port);
 
 		if (push)
 			tty_flip_buffer_push(&up->port.state->port);
@@ -458,7 +458,7 @@ static irqreturn_t ip22zilog_interrupt(int irq, void *dev_id)
 		channel = ZILOG_CHANNEL_FROM_PORT(&up->port);
 		push = false;
 
-		spin_lock(&up->port.lock);
+		uart_port_lock(&up->port);
 		if (r3 & (CHBEXT | CHBTxIP | CHBRxIP)) {
 			writeb(RES_H_IUS, &channel->control);
 			ZSDELAY();
@@ -471,7 +471,7 @@ static irqreturn_t ip22zilog_interrupt(int irq, void *dev_id)
 			if (r3 & CHBTxIP)
 				ip22zilog_transmit_chars(up, channel);
 		}
-		spin_unlock(&up->port.lock);
+		uart_port_unlock(&up->port);
 
 		if (push)
 			tty_flip_buffer_push(&up->port.state->port);
@@ -504,11 +504,11 @@ static unsigned int ip22zilog_tx_empty(struct uart_port *port)
 	unsigned char status;
 	unsigned int ret;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	status = ip22zilog_read_channel_status(port);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	if (status & Tx_BUF_EMP)
 		ret = TIOCSER_TEMT;
@@ -664,7 +664,7 @@ static void ip22zilog_break_ctl(struct uart_port *port, int break_state)
 	else
 		clear_bits |= SND_BRK;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	new_reg = (up->curregs[R5] | set_bits) & ~clear_bits;
 	if (new_reg != up->curregs[R5]) {
@@ -674,7 +674,7 @@ static void ip22zilog_break_ctl(struct uart_port *port, int break_state)
 		write_zsreg(channel, R5, up->curregs[R5]);
 	}
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void __ip22zilog_reset(struct uart_ip22zilog_port *up)
@@ -735,9 +735,9 @@ static int ip22zilog_startup(struct uart_port *port)
 	if (ZS_IS_CONS(up))
 		return 0;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	__ip22zilog_startup(up);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 	return 0;
 }
 
@@ -775,7 +775,7 @@ static void ip22zilog_shutdown(struct uart_port *port)
 	if (ZS_IS_CONS(up))
 		return;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	channel = ZILOG_CHANNEL_FROM_PORT(port);
 
@@ -788,7 +788,7 @@ static void ip22zilog_shutdown(struct uart_port *port)
 	up->curregs[R5] &= ~SND_BRK;
 	ip22zilog_maybe_update_regs(up, channel);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 /* Shared by TTY driver and serial console setup.  The port lock is held
@@ -880,7 +880,7 @@ ip22zilog_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	baud = uart_get_baud_rate(port, termios, old, 1200, 76800);
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 
 	brg = BPS_TO_BRG(baud, ZS_CLOCK / ZS_CLOCK_DIVISOR);
 
@@ -894,7 +894,7 @@ ip22zilog_set_termios(struct uart_port *port, struct ktermios *termios,
 	ip22zilog_maybe_update_regs(up, ZILOG_CHANNEL_FROM_PORT(port));
 	uart_update_timeout(port, termios->c_cflag, baud);
 
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 }
 
 static const char *ip22zilog_type(struct uart_port *port)
@@ -1016,10 +1016,10 @@ ip22zilog_console_write(struct console *con, const char *s, unsigned int count)
 	struct uart_ip22zilog_port *up = &ip22zilog_port_table[con->index];
 	unsigned long flags;
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 	uart_console_write(&up->port, s, count, ip22zilog_put_char);
 	udelay(2);
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 }
 
 static int __init ip22zilog_console_setup(struct console *con, char *options)
@@ -1034,13 +1034,13 @@ static int __init ip22zilog_console_setup(struct console *con, char *options)
 
 	printk(KERN_INFO "Console: ttyS%d (IP22-Zilog)\n", con->index);
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 
 	up->curregs[R15] |= BRKIE;
 
 	__ip22zilog_startup(up);
 
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 
 	if (options)
 		uart_parse_options(options, &baud, &parity, &bits, &flow);
diff --git a/drivers/tty/serial/jsm/jsm_neo.c b/drivers/tty/serial/jsm/jsm_neo.c
index 0c78f66276cd..2bd640428970 100644
--- a/drivers/tty/serial/jsm/jsm_neo.c
+++ b/drivers/tty/serial/jsm/jsm_neo.c
@@ -816,9 +816,9 @@ static void neo_parse_isr(struct jsm_board *brd, u32 port)
 		/* Parse any modem signal changes */
 		jsm_dbg(INTR, &ch->ch_bd->pci_dev,
 			"MOD_STAT: sending to parse_modem_sigs\n");
-		spin_lock_irqsave(&ch->uart_port.lock, lock_flags);
+		uart_port_lock_irqsave(&ch->uart_port, &lock_flags);
 		neo_parse_modem(ch, readb(&ch->ch_neo_uart->msr));
-		spin_unlock_irqrestore(&ch->uart_port.lock, lock_flags);
+		uart_port_unlock_irqrestore(&ch->uart_port, lock_flags);
 	}
 }
 
diff --git a/drivers/tty/serial/jsm/jsm_tty.c b/drivers/tty/serial/jsm/jsm_tty.c
index 222afc270c88..ce0fef7e2c66 100644
--- a/drivers/tty/serial/jsm/jsm_tty.c
+++ b/drivers/tty/serial/jsm/jsm_tty.c
@@ -152,14 +152,14 @@ static void jsm_tty_send_xchar(struct uart_port *port, char ch)
 		container_of(port, struct jsm_channel, uart_port);
 	struct ktermios *termios;
 
-	spin_lock_irqsave(&port->lock, lock_flags);
+	uart_port_lock_irqsave(port, &lock_flags);
 	termios = &port->state->port.tty->termios;
 	if (ch == termios->c_cc[VSTART])
 		channel->ch_bd->bd_ops->send_start_character(channel);
 
 	if (ch == termios->c_cc[VSTOP])
 		channel->ch_bd->bd_ops->send_stop_character(channel);
-	spin_unlock_irqrestore(&port->lock, lock_flags);
+	uart_port_unlock_irqrestore(port, lock_flags);
 }
 
 static void jsm_tty_stop_rx(struct uart_port *port)
@@ -176,13 +176,13 @@ static void jsm_tty_break(struct uart_port *port, int break_state)
 	struct jsm_channel *channel =
 		container_of(port, struct jsm_channel, uart_port);
 
-	spin_lock_irqsave(&port->lock, lock_flags);
+	uart_port_lock_irqsave(port, &lock_flags);
 	if (break_state == -1)
 		channel->ch_bd->bd_ops->send_break(channel);
 	else
 		channel->ch_bd->bd_ops->clear_break(channel);
 
-	spin_unlock_irqrestore(&port->lock, lock_flags);
+	uart_port_unlock_irqrestore(port, lock_flags);
 }
 
 static int jsm_tty_open(struct uart_port *port)
@@ -241,7 +241,7 @@ static int jsm_tty_open(struct uart_port *port)
 	channel->ch_cached_lsr = 0;
 	channel->ch_stops_sent = 0;
 
-	spin_lock_irqsave(&port->lock, lock_flags);
+	uart_port_lock_irqsave(port, &lock_flags);
 	termios = &port->state->port.tty->termios;
 	channel->ch_c_cflag	= termios->c_cflag;
 	channel->ch_c_iflag	= termios->c_iflag;
@@ -261,7 +261,7 @@ static int jsm_tty_open(struct uart_port *port)
 	jsm_carrier(channel);
 
 	channel->ch_open_count++;
-	spin_unlock_irqrestore(&port->lock, lock_flags);
+	uart_port_unlock_irqrestore(port, lock_flags);
 
 	jsm_dbg(OPEN, &channel->ch_bd->pci_dev, "finish\n");
 	return 0;
@@ -307,7 +307,7 @@ static void jsm_tty_set_termios(struct uart_port *port,
 	struct jsm_channel *channel =
 		container_of(port, struct jsm_channel, uart_port);
 
-	spin_lock_irqsave(&port->lock, lock_flags);
+	uart_port_lock_irqsave(port, &lock_flags);
 	channel->ch_c_cflag	= termios->c_cflag;
 	channel->ch_c_iflag	= termios->c_iflag;
 	channel->ch_c_oflag	= termios->c_oflag;
@@ -317,7 +317,7 @@ static void jsm_tty_set_termios(struct uart_port *port,
 
 	channel->ch_bd->bd_ops->param(channel);
 	jsm_carrier(channel);
-	spin_unlock_irqrestore(&port->lock, lock_flags);
+	uart_port_unlock_irqrestore(port, lock_flags);
 }
 
 static const char *jsm_tty_type(struct uart_port *port)
diff --git a/drivers/tty/serial/liteuart.c b/drivers/tty/serial/liteuart.c
index d881cdd2a58f..a25ab1efe38f 100644
--- a/drivers/tty/serial/liteuart.c
+++ b/drivers/tty/serial/liteuart.c
@@ -139,13 +139,13 @@ static irqreturn_t liteuart_interrupt(int irq, void *data)
 	 * if polling, the context would be "in_serving_softirq", so use
 	 * irq[save|restore] spin_lock variants to cover all possibilities
 	 */
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	isr = litex_read8(port->membase + OFF_EV_PENDING) & uart->irq_reg;
 	if (isr & EV_RX)
 		liteuart_rx_chars(port);
 	if (isr & EV_TX)
 		liteuart_tx_chars(port);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return IRQ_RETVAL(isr);
 }
@@ -195,10 +195,10 @@ static int liteuart_startup(struct uart_port *port)
 		}
 	}
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	/* only enabling rx irqs during startup */
 	liteuart_update_irq_reg(port, true, EV_RX);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	if (!port->irq) {
 		timer_setup(&uart->timer, liteuart_timer, 0);
@@ -213,9 +213,9 @@ static void liteuart_shutdown(struct uart_port *port)
 	struct liteuart_port *uart = to_liteuart_port(port);
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	liteuart_update_irq_reg(port, false, EV_RX | EV_TX);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	if (port->irq)
 		free_irq(port->irq, port);
@@ -229,13 +229,13 @@ static void liteuart_set_termios(struct uart_port *port, struct ktermios *new,
 	unsigned int baud;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* update baudrate */
 	baud = uart_get_baud_rate(port, new, old, 0, 460800);
 	uart_update_timeout(port, new->c_cflag, baud);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static const char *liteuart_type(struct uart_port *port)
@@ -382,9 +382,9 @@ static void liteuart_console_write(struct console *co, const char *s,
 	uart = (struct liteuart_port *)xa_load(&liteuart_array, co->index);
 	port = &uart->port;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	uart_console_write(port, s, count, liteuart_putchar);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static int liteuart_console_setup(struct console *co, char *options)
diff --git a/drivers/tty/serial/lpc32xx_hs.c b/drivers/tty/serial/lpc32xx_hs.c
index b38fe4728c26..5149a947b7fe 100644
--- a/drivers/tty/serial/lpc32xx_hs.c
+++ b/drivers/tty/serial/lpc32xx_hs.c
@@ -140,15 +140,15 @@ static void lpc32xx_hsuart_console_write(struct console *co, const char *s,
 	if (up->port.sysrq)
 		locked = 0;
 	else if (oops_in_progress)
-		locked = spin_trylock(&up->port.lock);
+		locked = uart_port_trylock(&up->port);
 	else
-		spin_lock(&up->port.lock);
+		uart_port_lock(&up->port);
 
 	uart_console_write(&up->port, s, count, lpc32xx_hsuart_console_putchar);
 	wait_for_xmit_empty(&up->port);
 
 	if (locked)
-		spin_unlock(&up->port.lock);
+		uart_port_unlock(&up->port);
 	local_irq_restore(flags);
 }
 
@@ -298,7 +298,7 @@ static irqreturn_t serial_lpc32xx_interrupt(int irq, void *dev_id)
 	struct tty_port *tport = &port->state->port;
 	u32 status;
 
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 
 	/* Read UART status and clear latched interrupts */
 	status = readl(LPC32XX_HSUART_IIR(port->membase));
@@ -333,7 +333,7 @@ static irqreturn_t serial_lpc32xx_interrupt(int irq, void *dev_id)
 		__serial_lpc32xx_tx(port);
 	}
 
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 
 	return IRQ_HANDLED;
 }
@@ -404,14 +404,14 @@ static void serial_lpc32xx_break_ctl(struct uart_port *port,
 	unsigned long flags;
 	u32 tmp;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
 	if (break_state != 0)
 		tmp |= LPC32XX_HSU_BREAK;
 	else
 		tmp &= ~LPC32XX_HSU_BREAK;
 	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 /* port->lock is not held.  */
@@ -421,7 +421,7 @@ static int serial_lpc32xx_startup(struct uart_port *port)
 	unsigned long flags;
 	u32 tmp;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	__serial_uart_flush(port);
 
@@ -441,7 +441,7 @@ static int serial_lpc32xx_startup(struct uart_port *port)
 
 	lpc32xx_loopback_set(port->mapbase, 0); /* get out of loopback mode */
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	retval = request_irq(port->irq, serial_lpc32xx_interrupt,
 			     0, MODNAME, port);
@@ -458,7 +458,7 @@ static void serial_lpc32xx_shutdown(struct uart_port *port)
 	u32 tmp;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
 		LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B;
@@ -466,7 +466,7 @@ static void serial_lpc32xx_shutdown(struct uart_port *port)
 
 	lpc32xx_loopback_set(port->mapbase, 1); /* go to loopback mode */
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	free_irq(port->irq, port);
 }
@@ -491,7 +491,7 @@ static void serial_lpc32xx_set_termios(struct uart_port *port,
 
 	quot = __serial_get_clock_div(port->uartclk, baud);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* Ignore characters? */
 	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
@@ -505,7 +505,7 @@ static void serial_lpc32xx_set_termios(struct uart_port *port,
 
 	uart_update_timeout(port, termios->c_cflag, baud);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	/* Don't rewrite B0 */
 	if (tty_termios_baud_rate(termios))
diff --git a/drivers/tty/serial/mcf.c b/drivers/tty/serial/mcf.c
index 1666ce012e5e..91b15243f6c6 100644
--- a/drivers/tty/serial/mcf.c
+++ b/drivers/tty/serial/mcf.c
@@ -135,12 +135,12 @@ static void mcf_break_ctl(struct uart_port *port, int break_state)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	if (break_state == -1)
 		writeb(MCFUART_UCR_CMDBREAKSTART, port->membase + MCFUART_UCR);
 	else
 		writeb(MCFUART_UCR_CMDBREAKSTOP, port->membase + MCFUART_UCR);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 /****************************************************************************/
@@ -150,7 +150,7 @@ static int mcf_startup(struct uart_port *port)
 	struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* Reset UART, get it into known state... */
 	writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
@@ -164,7 +164,7 @@ static int mcf_startup(struct uart_port *port)
 	pp->imr = MCFUART_UIR_RXREADY;
 	writeb(pp->imr, port->membase + MCFUART_UIMR);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return 0;
 }
@@ -176,7 +176,7 @@ static void mcf_shutdown(struct uart_port *port)
 	struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* Disable all interrupts now */
 	pp->imr = 0;
@@ -186,7 +186,7 @@ static void mcf_shutdown(struct uart_port *port)
 	writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
 	writeb(MCFUART_UCR_CMDRESETTX, port->membase + MCFUART_UCR);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 /****************************************************************************/
@@ -252,7 +252,7 @@ static void mcf_set_termios(struct uart_port *port, struct ktermios *termios,
 		mr2 |= MCFUART_MR2_TXCTS;
 	}
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	if (port->rs485.flags & SER_RS485_ENABLED) {
 		dev_dbg(port->dev, "Setting UART to RS485\n");
 		mr2 |= MCFUART_MR2_TXRTS;
@@ -273,7 +273,7 @@ static void mcf_set_termios(struct uart_port *port, struct ktermios *termios,
 		port->membase + MCFUART_UCSR);
 	writeb(MCFUART_UCR_RXENABLE | MCFUART_UCR_TXENABLE,
 		port->membase + MCFUART_UCR);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 /****************************************************************************/
@@ -350,7 +350,7 @@ static irqreturn_t mcf_interrupt(int irq, void *data)
 
 	isr = readb(port->membase + MCFUART_UISR) & pp->imr;
 
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 	if (isr & MCFUART_UIR_RXREADY) {
 		mcf_rx_chars(pp);
 		ret = IRQ_HANDLED;
@@ -359,7 +359,7 @@ static irqreturn_t mcf_interrupt(int irq, void *data)
 		mcf_tx_chars(pp);
 		ret = IRQ_HANDLED;
 	}
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 
 	return ret;
 }
diff --git a/drivers/tty/serial/men_z135_uart.c b/drivers/tty/serial/men_z135_uart.c
index d2502aaa3e8c..8048fa542fc4 100644
--- a/drivers/tty/serial/men_z135_uart.c
+++ b/drivers/tty/serial/men_z135_uart.c
@@ -392,7 +392,7 @@ static irqreturn_t men_z135_intr(int irq, void *data)
 	if (!irq_id)
 		goto out;
 
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 	/* It's save to write to IIR[7:6] RXC[9:8] */
 	iowrite8(irq_id, port->membase + MEN_Z135_STAT_REG);
 
@@ -418,7 +418,7 @@ static irqreturn_t men_z135_intr(int irq, void *data)
 		handled = true;
 	}
 
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 out:
 	return IRQ_RETVAL(handled);
 }
@@ -708,7 +708,7 @@ static void men_z135_set_termios(struct uart_port *port,
 
 	baud = uart_get_baud_rate(port, termios, old, 0, uart_freq / 16);
 
-	spin_lock_irq(&port->lock);
+	uart_port_lock_irq(port);
 	if (tty_termios_baud_rate(termios))
 		tty_termios_encode_baud_rate(termios, baud, baud);
 
@@ -716,7 +716,7 @@ static void men_z135_set_termios(struct uart_port *port,
 	iowrite32(bd_reg, port->membase + MEN_Z135_BAUD_REG);
 
 	uart_update_timeout(port, termios->c_cflag, baud);
-	spin_unlock_irq(&port->lock);
+	uart_port_unlock_irq(port);
 }
 
 static const char *men_z135_type(struct uart_port *port)
diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c
index 9388b9ddea3b..4c1d2089a0bb 100644
--- a/drivers/tty/serial/meson_uart.c
+++ b/drivers/tty/serial/meson_uart.c
@@ -129,14 +129,14 @@ static void meson_uart_shutdown(struct uart_port *port)
 
 	free_irq(port->irq, port);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	val = readl(port->membase + AML_UART_CONTROL);
 	val &= ~AML_UART_RX_EN;
 	val &= ~(AML_UART_RX_INT_EN | AML_UART_TX_INT_EN);
 	writel(val, port->membase + AML_UART_CONTROL);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void meson_uart_start_tx(struct uart_port *port)
@@ -238,7 +238,7 @@ static irqreturn_t meson_uart_interrupt(int irq, void *dev_id)
 {
 	struct uart_port *port = (struct uart_port *)dev_id;
 
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 
 	if (!(readl(port->membase + AML_UART_STATUS) & AML_UART_RX_EMPTY))
 		meson_receive_chars(port);
@@ -248,7 +248,7 @@ static irqreturn_t meson_uart_interrupt(int irq, void *dev_id)
 			meson_uart_start_tx(port);
 	}
 
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 
 	return IRQ_HANDLED;
 }
@@ -284,7 +284,7 @@ static int meson_uart_startup(struct uart_port *port)
 	u32 val;
 	int ret = 0;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	val = readl(port->membase + AML_UART_CONTROL);
 	val |= AML_UART_CLEAR_ERR;
@@ -301,7 +301,7 @@ static int meson_uart_startup(struct uart_port *port)
 	val = (AML_UART_RECV_IRQ(1) | AML_UART_XMIT_IRQ(port->fifosize / 2));
 	writel(val, port->membase + AML_UART_MISC);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	ret = request_irq(port->irq, meson_uart_interrupt, 0,
 			  port->name, port);
@@ -341,7 +341,7 @@ static void meson_uart_set_termios(struct uart_port *port,
 	unsigned long flags;
 	u32 val;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	cflags = termios->c_cflag;
 	iflags = termios->c_iflag;
@@ -405,7 +405,7 @@ static void meson_uart_set_termios(struct uart_port *port,
 					    AML_UART_FRAME_ERR;
 
 	uart_update_timeout(port, termios->c_cflag, baud);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static int meson_uart_verify_port(struct uart_port *port,
@@ -464,14 +464,14 @@ static int meson_uart_poll_get_char(struct uart_port *port)
 	u32 c;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	if (readl(port->membase + AML_UART_STATUS) & AML_UART_RX_EMPTY)
 		c = NO_POLL_CHAR;
 	else
 		c = readl(port->membase + AML_UART_RFIFO);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return c;
 }
@@ -482,7 +482,7 @@ static void meson_uart_poll_put_char(struct uart_port *port, unsigned char c)
 	u32 reg;
 	int ret;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* Wait until FIFO is empty or timeout */
 	ret = readl_poll_timeout_atomic(port->membase + AML_UART_STATUS, reg,
@@ -506,7 +506,7 @@ static void meson_uart_poll_put_char(struct uart_port *port, unsigned char c)
 		dev_err(port->dev, "Timeout waiting for UART TX EMPTY\n");
 
 out:
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 #endif /* CONFIG_CONSOLE_POLL */
@@ -563,9 +563,9 @@ static void meson_serial_port_write(struct uart_port *port, const char *s,
 	if (port->sysrq) {
 		locked = 0;
 	} else if (oops_in_progress) {
-		locked = spin_trylock(&port->lock);
+		locked = uart_port_trylock(port);
 	} else {
-		spin_lock(&port->lock);
+		uart_port_lock(port);
 		locked = 1;
 	}
 
@@ -577,7 +577,7 @@ static void meson_serial_port_write(struct uart_port *port, const char *s,
 	writel(val, port->membase + AML_UART_CONTROL);
 
 	if (locked)
-		spin_unlock(&port->lock);
+		uart_port_unlock(port);
 	local_irq_restore(flags);
 }
 
diff --git a/drivers/tty/serial/milbeaut_usio.c b/drivers/tty/serial/milbeaut_usio.c
index 70a910085e93..db3b81f2aa57 100644
--- a/drivers/tty/serial/milbeaut_usio.c
+++ b/drivers/tty/serial/milbeaut_usio.c
@@ -207,9 +207,9 @@ static irqreturn_t mlb_usio_rx_irq(int irq, void *dev_id)
 {
 	struct uart_port *port = dev_id;
 
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 	mlb_usio_rx_chars(port);
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 
 	return IRQ_HANDLED;
 }
@@ -218,10 +218,10 @@ static irqreturn_t mlb_usio_tx_irq(int irq, void *dev_id)
 {
 	struct uart_port *port = dev_id;
 
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 	if (readb(port->membase + MLB_USIO_REG_SSR) & MLB_USIO_SSR_TBI)
 		mlb_usio_tx_chars(port);
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 
 	return IRQ_HANDLED;
 }
@@ -267,7 +267,7 @@ static int mlb_usio_startup(struct uart_port *port)
 	escr = readb(port->membase + MLB_USIO_REG_ESCR);
 	if (of_property_read_bool(port->dev->of_node, "auto-flow-control"))
 		escr |= MLB_USIO_ESCR_FLWEN;
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	writeb(0, port->membase + MLB_USIO_REG_SCR);
 	writeb(escr, port->membase + MLB_USIO_REG_ESCR);
 	writeb(MLB_USIO_SCR_UPCL, port->membase + MLB_USIO_REG_SCR);
@@ -282,7 +282,7 @@ static int mlb_usio_startup(struct uart_port *port)
 
 	writeb(MLB_USIO_SCR_TXE  | MLB_USIO_SCR_RIE | MLB_USIO_SCR_TBIE |
 	       MLB_USIO_SCR_RXE, port->membase + MLB_USIO_REG_SCR);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return 0;
 }
@@ -337,7 +337,7 @@ static void mlb_usio_set_termios(struct uart_port *port,
 	else
 		quot = 0;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	uart_update_timeout(port, termios->c_cflag, baud);
 	port->read_status_mask = MLB_USIO_SSR_ORE | MLB_USIO_SSR_RDRF |
 				 MLB_USIO_SSR_TDRE;
@@ -367,7 +367,7 @@ static void mlb_usio_set_termios(struct uart_port *port,
 	writew(BIT(12), port->membase + MLB_USIO_REG_FBYTE);
 	writeb(MLB_USIO_SCR_RIE | MLB_USIO_SCR_RXE | MLB_USIO_SCR_TBIE |
 	       MLB_USIO_SCR_TXE, port->membase + MLB_USIO_REG_SCR);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static const char *mlb_usio_type(struct uart_port *port)
diff --git a/drivers/tty/serial/mpc52xx_uart.c b/drivers/tty/serial/mpc52xx_uart.c
index 916507b8f31d..a252465e745f 100644
--- a/drivers/tty/serial/mpc52xx_uart.c
+++ b/drivers/tty/serial/mpc52xx_uart.c
@@ -1096,14 +1096,14 @@ static void
 mpc52xx_uart_break_ctl(struct uart_port *port, int ctl)
 {
 	unsigned long flags;
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	if (ctl == -1)
 		psc_ops->command(port, MPC52xx_PSC_START_BRK);
 	else
 		psc_ops->command(port, MPC52xx_PSC_STOP_BRK);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static int
@@ -1214,7 +1214,7 @@ mpc52xx_uart_set_termios(struct uart_port *port, struct ktermios *new,
 	}
 
 	/* Get the lock */
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* Do our best to flush TX & RX, so we don't lose anything */
 	/* But we don't wait indefinitely ! */
@@ -1250,7 +1250,7 @@ mpc52xx_uart_set_termios(struct uart_port *port, struct ktermios *new,
 	psc_ops->command(port, MPC52xx_PSC_RX_ENABLE);
 
 	/* We're all set, release the lock */
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static const char *
@@ -1477,11 +1477,11 @@ mpc52xx_uart_int(int irq, void *dev_id)
 	struct uart_port *port = dev_id;
 	irqreturn_t ret;
 
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 
 	ret = psc_ops->handle_irq(port);
 
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 
 	return ret;
 }
diff --git a/drivers/tty/serial/mps2-uart.c b/drivers/tty/serial/mps2-uart.c
index ea5a7911cb15..2a4c09f3a834 100644
--- a/drivers/tty/serial/mps2-uart.c
+++ b/drivers/tty/serial/mps2-uart.c
@@ -188,12 +188,12 @@ static irqreturn_t mps2_uart_rxirq(int irq, void *data)
 	if (unlikely(!(irqflag & UARTn_INT_RX)))
 		return IRQ_NONE;
 
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 
 	mps2_uart_write8(port, UARTn_INT_RX, UARTn_INT);
 	mps2_uart_rx_chars(port);
 
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 
 	return IRQ_HANDLED;
 }
@@ -206,12 +206,12 @@ static irqreturn_t mps2_uart_txirq(int irq, void *data)
 	if (unlikely(!(irqflag & UARTn_INT_TX)))
 		return IRQ_NONE;
 
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 
 	mps2_uart_write8(port, UARTn_INT_TX, UARTn_INT);
 	mps2_uart_tx_chars(port);
 
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 
 	return IRQ_HANDLED;
 }
@@ -222,7 +222,7 @@ static irqreturn_t mps2_uart_oerrirq(int irq, void *data)
 	struct uart_port *port = data;
 	u8 irqflag = mps2_uart_read8(port, UARTn_INT);
 
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 
 	if (irqflag & UARTn_INT_RX_OVERRUN) {
 		struct tty_port *tport = &port->state->port;
@@ -244,7 +244,7 @@ static irqreturn_t mps2_uart_oerrirq(int irq, void *data)
 		handled = IRQ_HANDLED;
 	}
 
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 
 	return handled;
 }
@@ -356,12 +356,12 @@ mps2_uart_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	bauddiv = DIV_ROUND_CLOSEST(port->uartclk, baud);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	uart_update_timeout(port, termios->c_cflag, baud);
 	mps2_uart_write32(port, bauddiv, UARTn_BAUDDIV);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	if (tty_termios_baud_rate(termios))
 		tty_termios_encode_baud_rate(termios, baud, baud);
diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c
index 90953e679e38..597264b546fd 100644
--- a/drivers/tty/serial/msm_serial.c
+++ b/drivers/tty/serial/msm_serial.c
@@ -444,7 +444,7 @@ static void msm_complete_tx_dma(void *args)
 	unsigned int count;
 	u32 val;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* Already stopped */
 	if (!dma->count)
@@ -476,7 +476,7 @@ static void msm_complete_tx_dma(void *args)
 
 	msm_handle_tx(port);
 done:
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static int msm_handle_tx_dma(struct msm_port *msm_port, unsigned int count)
@@ -549,7 +549,7 @@ static void msm_complete_rx_dma(void *args)
 	unsigned long flags;
 	u32 val;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* Already stopped */
 	if (!dma->count)
@@ -587,16 +587,16 @@ static void msm_complete_rx_dma(void *args)
 		if (!(port->read_status_mask & MSM_UART_SR_RX_BREAK))
 			flag = TTY_NORMAL;
 
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 		sysrq = uart_handle_sysrq_char(port, dma->virt[i]);
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 		if (!sysrq)
 			tty_insert_flip_char(tport, dma->virt[i], flag);
 	}
 
 	msm_start_rx_dma(msm_port);
 done:
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	if (count)
 		tty_flip_buffer_push(tport);
@@ -762,9 +762,9 @@ static void msm_handle_rx_dm(struct uart_port *port, unsigned int misr)
 			if (!(port->read_status_mask & MSM_UART_SR_RX_BREAK))
 				flag = TTY_NORMAL;
 
-			spin_unlock(&port->lock);
+			uart_port_unlock(port);
 			sysrq = uart_handle_sysrq_char(port, buf[i]);
-			spin_lock(&port->lock);
+			uart_port_lock(port);
 			if (!sysrq)
 				tty_insert_flip_char(tport, buf[i], flag);
 		}
@@ -824,9 +824,9 @@ static void msm_handle_rx(struct uart_port *port)
 		else if (sr & MSM_UART_SR_PAR_FRAME_ERR)
 			flag = TTY_FRAME;
 
-		spin_unlock(&port->lock);
+		uart_port_unlock(port);
 		sysrq = uart_handle_sysrq_char(port, c);
-		spin_lock(&port->lock);
+		uart_port_lock(port);
 		if (!sysrq)
 			tty_insert_flip_char(tport, c, flag);
 	}
@@ -951,7 +951,7 @@ static irqreturn_t msm_uart_irq(int irq, void *dev_id)
 	unsigned int misr;
 	u32 val;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	misr = msm_read(port, MSM_UART_MISR);
 	msm_write(port, 0, MSM_UART_IMR); /* disable interrupt */
 
@@ -983,7 +983,7 @@ static irqreturn_t msm_uart_irq(int irq, void *dev_id)
 		msm_handle_delta_cts(port);
 
 	msm_write(port, msm_port->imr, MSM_UART_IMR); /* restore interrupt */
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return IRQ_HANDLED;
 }
@@ -1128,13 +1128,13 @@ static int msm_set_baud_rate(struct uart_port *port, unsigned int baud,
 	unsigned long flags, rate;
 
 	flags = *saved_flags;
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	entry = msm_find_best_baud(port, baud, &rate);
 	clk_set_rate(msm_port->clk, rate);
 	baud = rate / 16 / entry->divisor;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	*saved_flags = flags;
 	port->uartclk = rate;
 
@@ -1266,7 +1266,7 @@ static void msm_set_termios(struct uart_port *port, struct ktermios *termios,
 	unsigned long flags;
 	unsigned int baud, mr;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	if (dma->chan) /* Terminate if any */
 		msm_stop_dma(port, dma);
@@ -1338,7 +1338,7 @@ static void msm_set_termios(struct uart_port *port, struct ktermios *termios,
 	/* Try to use DMA */
 	msm_start_rx_dma(msm_port);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static const char *msm_type(struct uart_port *port)
@@ -1620,9 +1620,9 @@ static void __msm_console_write(struct uart_port *port, const char *s,
 	if (port->sysrq)
 		locked = 0;
 	else if (oops_in_progress)
-		locked = spin_trylock(&port->lock);
+		locked = uart_port_trylock(port);
 	else
-		spin_lock(&port->lock);
+		uart_port_lock(port);
 
 	if (is_uartdm)
 		msm_reset_dm_count(port, count);
@@ -1661,7 +1661,7 @@ static void __msm_console_write(struct uart_port *port, const char *s,
 	}
 
 	if (locked)
-		spin_unlock(&port->lock);
+		uart_port_unlock(port);
 
 	local_irq_restore(flags);
 }
diff --git a/drivers/tty/serial/mvebu-uart.c b/drivers/tty/serial/mvebu-uart.c
index ea924e9b913b..0255646bc175 100644
--- a/drivers/tty/serial/mvebu-uart.c
+++ b/drivers/tty/serial/mvebu-uart.c
@@ -187,9 +187,9 @@ static unsigned int mvebu_uart_tx_empty(struct uart_port *port)
 	unsigned long flags;
 	unsigned int st;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	st = readl(port->membase + UART_STAT);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return (st & STAT_TX_EMP) ? TIOCSER_TEMT : 0;
 }
@@ -249,14 +249,14 @@ static void mvebu_uart_break_ctl(struct uart_port *port, int brk)
 	unsigned int ctl;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	ctl = readl(port->membase + UART_CTRL(port));
 	if (brk == -1)
 		ctl |= CTRL_SND_BRK_SEQ;
 	else
 		ctl &= ~CTRL_SND_BRK_SEQ;
 	writel(ctl, port->membase + UART_CTRL(port));
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void mvebu_uart_rx_chars(struct uart_port *port, unsigned int status)
@@ -540,7 +540,7 @@ static void mvebu_uart_set_termios(struct uart_port *port,
 	unsigned long flags;
 	unsigned int baud, min_baud, max_baud;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	port->read_status_mask = STAT_RX_RDY(port) | STAT_OVR_ERR |
 		STAT_TX_RDY(port) | STAT_TX_FIFO_FUL;
@@ -589,7 +589,7 @@ static void mvebu_uart_set_termios(struct uart_port *port,
 		uart_update_timeout(port, termios->c_cflag, baud);
 	}
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static const char *mvebu_uart_type(struct uart_port *port)
@@ -735,9 +735,9 @@ static void mvebu_uart_console_write(struct console *co, const char *s,
 	int locked = 1;
 
 	if (oops_in_progress)
-		locked = spin_trylock_irqsave(&port->lock, flags);
+		locked = uart_port_trylock_irqsave(port, &flags);
 	else
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 
 	ier = readl(port->membase + UART_CTRL(port)) & CTRL_BRK_INT;
 	intr = readl(port->membase + UART_INTR(port)) &
@@ -758,7 +758,7 @@ static void mvebu_uart_console_write(struct console *co, const char *s,
 	}
 
 	if (locked)
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 }
 
 static int mvebu_uart_console_setup(struct console *co, char *options)
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 916f2edfd7ea..90369adc33f0 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -390,10 +390,10 @@ static void serial_omap_throttle(struct uart_port *port)
 	struct uart_omap_port *up = to_uart_omap_port(port);
 	unsigned long flags;
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 	up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
 	serial_out(up, UART_IER, up->ier);
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 }
 
 static void serial_omap_unthrottle(struct uart_port *port)
@@ -401,10 +401,10 @@ static void serial_omap_unthrottle(struct uart_port *port)
 	struct uart_omap_port *up = to_uart_omap_port(port);
 	unsigned long flags;
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 	up->ier |= UART_IER_RLSI | UART_IER_RDI;
 	serial_out(up, UART_IER, up->ier);
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 }
 
 static unsigned int check_modem_status(struct uart_omap_port *up)
@@ -527,7 +527,7 @@ static irqreturn_t serial_omap_irq(int irq, void *dev_id)
 	irqreturn_t ret = IRQ_NONE;
 	int max_count = 256;
 
-	spin_lock(&up->port.lock);
+	uart_port_lock(&up->port);
 
 	do {
 		iir = serial_in(up, UART_IIR);
@@ -563,7 +563,7 @@ static irqreturn_t serial_omap_irq(int irq, void *dev_id)
 		}
 	} while (max_count--);
 
-	spin_unlock(&up->port.lock);
+	uart_port_unlock(&up->port);
 
 	tty_flip_buffer_push(&up->port.state->port);
 
@@ -579,9 +579,9 @@ static unsigned int serial_omap_tx_empty(struct uart_port *port)
 	unsigned int ret = 0;
 
 	dev_dbg(up->port.dev, "serial_omap_tx_empty+%d\n", up->port.line);
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 
 	return ret;
 }
@@ -647,13 +647,13 @@ static void serial_omap_break_ctl(struct uart_port *port, int break_state)
 	unsigned long flags;
 
 	dev_dbg(up->port.dev, "serial_omap_break_ctl+%d\n", up->port.line);
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 	if (break_state == -1)
 		up->lcr |= UART_LCR_SBC;
 	else
 		up->lcr &= ~UART_LCR_SBC;
 	serial_out(up, UART_LCR, up->lcr);
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 }
 
 static int serial_omap_startup(struct uart_port *port)
@@ -701,13 +701,13 @@ static int serial_omap_startup(struct uart_port *port)
 	 * Now, initialize the UART
 	 */
 	serial_out(up, UART_LCR, UART_LCR_WLEN8);
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 	/*
 	 * Most PC uarts need OUT2 raised to enable interrupts.
 	 */
 	up->port.mctrl |= TIOCM_OUT2;
 	serial_omap_set_mctrl(&up->port, up->port.mctrl);
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 
 	up->msr_saved_flags = 0;
 	/*
@@ -742,10 +742,10 @@ static void serial_omap_shutdown(struct uart_port *port)
 	up->ier = 0;
 	serial_out(up, UART_IER, 0);
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 	up->port.mctrl &= ~TIOCM_OUT2;
 	serial_omap_set_mctrl(&up->port, up->port.mctrl);
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 
 	/*
 	 * Disable break condition and FIFOs
@@ -815,7 +815,7 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 	 * Ok, we're now changing the port state. Do it with
 	 * interrupts disabled.
 	 */
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 
 	/*
 	 * Update the per-port timeout.
@@ -1013,7 +1013,7 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	serial_omap_set_mctrl(&up->port, up->port.mctrl);
 
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 	dev_dbg(up->port.dev, "serial_omap_set_termios+%d\n", up->port.line);
 }
 
@@ -1213,9 +1213,9 @@ serial_omap_console_write(struct console *co, const char *s,
 	int locked = 1;
 
 	if (up->port.sysrq || oops_in_progress)
-		locked = spin_trylock_irqsave(&up->port.lock, flags);
+		locked = uart_port_trylock_irqsave(&up->port, &flags);
 	else
-		spin_lock_irqsave(&up->port.lock, flags);
+		uart_port_lock_irqsave(&up->port, &flags);
 
 	/*
 	 * First save the IER then disable the interrupts
@@ -1242,7 +1242,7 @@ serial_omap_console_write(struct console *co, const char *s,
 		check_modem_status(up);
 
 	if (locked)
-		spin_unlock_irqrestore(&up->port.lock, flags);
+		uart_port_unlock_irqrestore(&up->port, flags);
 }
 
 static int __init
@@ -1479,13 +1479,6 @@ static struct omap_uart_port_info *of_get_uart_port_info(struct device *dev)
 	return omap_up_info;
 }
 
-static const struct serial_rs485 serial_omap_rs485_supported = {
-	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND |
-		 SER_RS485_RX_DURING_TX,
-	.delay_rts_before_send = 1,
-	.delay_rts_after_send = 1,
-};
-
 static int serial_omap_probe_rs485(struct uart_omap_port *up,
 				   struct device *dev)
 {
@@ -1500,9 +1493,6 @@ static int serial_omap_probe_rs485(struct uart_omap_port *up,
 	if (!np)
 		return 0;
 
-	up->port.rs485_config = serial_omap_config_rs485;
-	up->port.rs485_supported = serial_omap_rs485_supported;
-
 	ret = uart_get_rs485_mode(&up->port);
 	if (ret)
 		return ret;
@@ -1537,6 +1527,13 @@ static int serial_omap_probe_rs485(struct uart_omap_port *up,
 	return 0;
 }
 
+static const struct serial_rs485 serial_omap_rs485_supported = {
+	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND |
+		 SER_RS485_RX_DURING_TX,
+	.delay_rts_before_send = 1,
+	.delay_rts_after_send = 1,
+};
+
 static int serial_omap_probe(struct platform_device *pdev)
 {
 	struct omap_uart_port_info *omap_up_info = dev_get_platdata(&pdev->dev);
@@ -1603,11 +1600,17 @@ static int serial_omap_probe(struct platform_device *pdev)
 		dev_info(up->port.dev, "no wakeirq for uart%d\n",
 			 up->port.line);
 
+	ret = serial_omap_probe_rs485(up, &pdev->dev);
+	if (ret < 0)
+		goto err_rs485;
+
 	sprintf(up->name, "OMAP UART%d", up->port.line);
 	up->port.mapbase = mem->start;
 	up->port.membase = base;
 	up->port.flags = omap_up_info->flags;
 	up->port.uartclk = omap_up_info->uartclk;
+	up->port.rs485_config = serial_omap_config_rs485;
+	up->port.rs485_supported = serial_omap_rs485_supported;
 	if (!up->port.uartclk) {
 		up->port.uartclk = DEFAULT_CLK_SPEED;
 		dev_warn(&pdev->dev,
@@ -1615,10 +1618,6 @@ static int serial_omap_probe(struct platform_device *pdev)
 			 DEFAULT_CLK_SPEED);
 	}
 
-	ret = serial_omap_probe_rs485(up, &pdev->dev);
-	if (ret < 0)
-		goto err_rs485;
-
 	up->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
 	up->calc_latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
 	cpu_latency_qos_add_request(&up->pm_qos_request, up->latency);
diff --git a/drivers/tty/serial/owl-uart.c b/drivers/tty/serial/owl-uart.c
index e99970a9437f..919f5e5aa0f1 100644
--- a/drivers/tty/serial/owl-uart.c
+++ b/drivers/tty/serial/owl-uart.c
@@ -125,12 +125,12 @@ static unsigned int owl_uart_tx_empty(struct uart_port *port)
 	u32 val;
 	unsigned int ret;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	val = owl_uart_read(port, OWL_UART_STAT);
 	ret = (val & OWL_UART_STAT_TFES) ? TIOCSER_TEMT : 0;
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return ret;
 }
@@ -232,7 +232,7 @@ static irqreturn_t owl_uart_irq(int irq, void *dev_id)
 	unsigned long flags;
 	u32 stat;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	stat = owl_uart_read(port, OWL_UART_STAT);
 
@@ -246,7 +246,7 @@ static irqreturn_t owl_uart_irq(int irq, void *dev_id)
 	stat |= OWL_UART_STAT_RIP | OWL_UART_STAT_TIP;
 	owl_uart_write(port, stat, OWL_UART_STAT);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return IRQ_HANDLED;
 }
@@ -256,14 +256,14 @@ static void owl_uart_shutdown(struct uart_port *port)
 	u32 val;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	val = owl_uart_read(port, OWL_UART_CTL);
 	val &= ~(OWL_UART_CTL_TXIE | OWL_UART_CTL_RXIE
 		| OWL_UART_CTL_TXDE | OWL_UART_CTL_RXDE | OWL_UART_CTL_EN);
 	owl_uart_write(port, val, OWL_UART_CTL);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	free_irq(port->irq, port);
 }
@@ -279,7 +279,7 @@ static int owl_uart_startup(struct uart_port *port)
 	if (ret)
 		return ret;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	val = owl_uart_read(port, OWL_UART_STAT);
 	val |= OWL_UART_STAT_RIP | OWL_UART_STAT_TIP
@@ -291,7 +291,7 @@ static int owl_uart_startup(struct uart_port *port)
 	val |= OWL_UART_CTL_EN;
 	owl_uart_write(port, val, OWL_UART_CTL);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return 0;
 }
@@ -311,7 +311,7 @@ static void owl_uart_set_termios(struct uart_port *port,
 	u32 ctl;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	ctl = owl_uart_read(port, OWL_UART_CTL);
 
@@ -371,7 +371,7 @@ static void owl_uart_set_termios(struct uart_port *port,
 
 	uart_update_timeout(port, termios->c_cflag, baud);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void owl_uart_release_port(struct uart_port *port)
@@ -515,9 +515,9 @@ static void owl_uart_port_write(struct uart_port *port, const char *s,
 	if (port->sysrq)
 		locked = 0;
 	else if (oops_in_progress)
-		locked = spin_trylock(&port->lock);
+		locked = uart_port_trylock(port);
 	else {
-		spin_lock(&port->lock);
+		uart_port_lock(port);
 		locked = 1;
 	}
 
@@ -541,7 +541,7 @@ static void owl_uart_port_write(struct uart_port *port, const char *s,
 	owl_uart_write(port, old_ctl, OWL_UART_CTL);
 
 	if (locked)
-		spin_unlock(&port->lock);
+		uart_port_unlock(port);
 
 	local_irq_restore(flags);
 }
diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
index cc83b772b7ca..436cc6d52a11 100644
--- a/drivers/tty/serial/pch_uart.c
+++ b/drivers/tty/serial/pch_uart.c
@@ -1347,7 +1347,7 @@ static void pch_uart_set_termios(struct uart_port *port,
 	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
 
 	spin_lock_irqsave(&priv->lock, flags);
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 
 	uart_update_timeout(port, termios->c_cflag, baud);
 	rtn = pch_uart_hal_set_line(priv, baud, parity, bits, stb);
@@ -1360,7 +1360,7 @@ static void pch_uart_set_termios(struct uart_port *port,
 		tty_termios_encode_baud_rate(termios, baud, baud);
 
 out:
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 	spin_unlock_irqrestore(&priv->lock, flags);
 }
 
@@ -1581,10 +1581,10 @@ pch_console_write(struct console *co, const char *s, unsigned int count)
 		port_locked = 0;
 	} else if (oops_in_progress) {
 		priv_locked = spin_trylock(&priv->lock);
-		port_locked = spin_trylock(&priv->port.lock);
+		port_locked = uart_port_trylock(&priv->port);
 	} else {
 		spin_lock(&priv->lock);
-		spin_lock(&priv->port.lock);
+		uart_port_lock(&priv->port);
 	}
 
 	/*
@@ -1604,7 +1604,7 @@ pch_console_write(struct console *co, const char *s, unsigned int count)
 	iowrite8(ier, priv->membase + UART_IER);
 
 	if (port_locked)
-		spin_unlock(&priv->port.lock);
+		uart_port_unlock(&priv->port);
 	if (priv_locked)
 		spin_unlock(&priv->lock);
 	local_irq_restore(flags);
diff --git a/drivers/tty/serial/pic32_uart.c b/drivers/tty/serial/pic32_uart.c
index e308d5022b3f..3a95bf5d55d3 100644
--- a/drivers/tty/serial/pic32_uart.c
+++ b/drivers/tty/serial/pic32_uart.c
@@ -243,7 +243,7 @@ static void pic32_uart_break_ctl(struct uart_port *port, int ctl)
 	struct pic32_sport *sport = to_pic32_sport(port);
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	if (ctl)
 		pic32_uart_writel(sport, PIC32_SET(PIC32_UART_STA),
@@ -252,7 +252,7 @@ static void pic32_uart_break_ctl(struct uart_port *port, int ctl)
 		pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA),
 					PIC32_UART_STA_UTXBRK);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 /* get port type in string format */
@@ -274,7 +274,7 @@ static void pic32_uart_do_rx(struct uart_port *port)
 	 */
 	max_count = PIC32_UART_RX_FIFO_DEPTH;
 
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 
 	tty = &port->state->port;
 
@@ -331,7 +331,7 @@ static void pic32_uart_do_rx(struct uart_port *port)
 
 	} while (--max_count);
 
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 
 	tty_flip_buffer_push(tty);
 }
@@ -410,9 +410,9 @@ static irqreturn_t pic32_uart_tx_interrupt(int irq, void *dev_id)
 	struct uart_port *port = dev_id;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	pic32_uart_do_tx(port);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return IRQ_HANDLED;
 }
@@ -580,9 +580,9 @@ static void pic32_uart_shutdown(struct uart_port *port)
 	unsigned long flags;
 
 	/* disable uart */
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	pic32_uart_dsbl_and_mask(port);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 	clk_disable_unprepare(sport->clk);
 
 	/* free all 3 interrupts for this UART */
@@ -604,7 +604,7 @@ static void pic32_uart_set_termios(struct uart_port *port,
 	unsigned int quot;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* disable uart and mask all interrupts while changing speed */
 	pic32_uart_dsbl_and_mask(port);
@@ -672,7 +672,7 @@ static void pic32_uart_set_termios(struct uart_port *port,
 	/* enable uart */
 	pic32_uart_en_and_unmask(port);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 /* serial core request to claim uart iomem */
diff --git a/drivers/tty/serial/pmac_zilog.c b/drivers/tty/serial/pmac_zilog.c
index 13668ffdb1e7..c8bf08c19c64 100644
--- a/drivers/tty/serial/pmac_zilog.c
+++ b/drivers/tty/serial/pmac_zilog.c
@@ -246,9 +246,9 @@ static bool pmz_receive_chars(struct uart_pmac_port *uap)
 #endif /* USE_CTRL_O_SYSRQ */
 		if (uap->port.sysrq) {
 			int swallow;
-			spin_unlock(&uap->port.lock);
+			uart_port_unlock(&uap->port);
 			swallow = uart_handle_sysrq_char(&uap->port, ch);
-			spin_lock(&uap->port.lock);
+			uart_port_lock(&uap->port);
 			if (swallow)
 				goto next_char;
 		}
@@ -435,7 +435,7 @@ static irqreturn_t pmz_interrupt(int irq, void *dev_id)
 	uap_a = pmz_get_port_A(uap);
 	uap_b = uap_a->mate;
 
-	spin_lock(&uap_a->port.lock);
+	uart_port_lock(&uap_a->port);
 	r3 = read_zsreg(uap_a, R3);
 
 	/* Channel A */
@@ -456,14 +456,14 @@ static irqreturn_t pmz_interrupt(int irq, void *dev_id)
 		rc = IRQ_HANDLED;
 	}
  skip_a:
-	spin_unlock(&uap_a->port.lock);
+	uart_port_unlock(&uap_a->port);
 	if (push)
 		tty_flip_buffer_push(&uap->port.state->port);
 
 	if (!uap_b)
 		goto out;
 
-	spin_lock(&uap_b->port.lock);
+	uart_port_lock(&uap_b->port);
 	push = false;
 	if (r3 & (CHBEXT | CHBTxIP | CHBRxIP)) {
 		if (!ZS_IS_OPEN(uap_b)) {
@@ -481,7 +481,7 @@ static irqreturn_t pmz_interrupt(int irq, void *dev_id)
 		rc = IRQ_HANDLED;
 	}
  skip_b:
-	spin_unlock(&uap_b->port.lock);
+	uart_port_unlock(&uap_b->port);
 	if (push)
 		tty_flip_buffer_push(&uap->port.state->port);
 
@@ -497,9 +497,9 @@ static inline u8 pmz_peek_status(struct uart_pmac_port *uap)
 	unsigned long flags;
 	u8 status;
 	
-	spin_lock_irqsave(&uap->port.lock, flags);
+	uart_port_lock_irqsave(&uap->port, &flags);
 	status = read_zsreg(uap, R0);
-	spin_unlock_irqrestore(&uap->port.lock, flags);
+	uart_port_unlock_irqrestore(&uap->port, flags);
 
 	return status;
 }
@@ -685,7 +685,7 @@ static void pmz_break_ctl(struct uart_port *port, int break_state)
 	else
 		clear_bits |= SND_BRK;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	new_reg = (uap->curregs[R5] | set_bits) & ~clear_bits;
 	if (new_reg != uap->curregs[R5]) {
@@ -693,7 +693,7 @@ static void pmz_break_ctl(struct uart_port *port, int break_state)
 		write_zsreg(uap, R5, uap->curregs[R5]);
 	}
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 #ifdef CONFIG_PPC_PMAC
@@ -865,18 +865,18 @@ static void pmz_irda_reset(struct uart_pmac_port *uap)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&uap->port.lock, flags);
+	uart_port_lock_irqsave(&uap->port, &flags);
 	uap->curregs[R5] |= DTR;
 	write_zsreg(uap, R5, uap->curregs[R5]);
 	zssync(uap);
-	spin_unlock_irqrestore(&uap->port.lock, flags);
+	uart_port_unlock_irqrestore(&uap->port, flags);
 	msleep(110);
 
-	spin_lock_irqsave(&uap->port.lock, flags);
+	uart_port_lock_irqsave(&uap->port, &flags);
 	uap->curregs[R5] &= ~DTR;
 	write_zsreg(uap, R5, uap->curregs[R5]);
 	zssync(uap);
-	spin_unlock_irqrestore(&uap->port.lock, flags);
+	uart_port_unlock_irqrestore(&uap->port, flags);
 	msleep(10);
 }
 
@@ -896,9 +896,9 @@ static int pmz_startup(struct uart_port *port)
 	 * initialize the chip
 	 */
 	if (!ZS_IS_CONS(uap)) {
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 		pwr_delay = __pmz_startup(uap);
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 	}	
 	sprintf(uap->irq_name, PMACZILOG_NAME"%d", uap->port.line);
 	if (request_irq(uap->port.irq, pmz_interrupt, IRQF_SHARED,
@@ -921,9 +921,9 @@ static int pmz_startup(struct uart_port *port)
 		pmz_irda_reset(uap);
 
 	/* Enable interrupt requests for the channel */
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	pmz_interrupt_control(uap, 1);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return 0;
 }
@@ -933,7 +933,7 @@ static void pmz_shutdown(struct uart_port *port)
 	struct uart_pmac_port *uap = to_pmz(port);
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* Disable interrupt requests for the channel */
 	pmz_interrupt_control(uap, 0);
@@ -948,19 +948,19 @@ static void pmz_shutdown(struct uart_port *port)
 		pmz_maybe_update_regs(uap);
 	}
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	/* Release interrupt handler */
 	free_irq(uap->port.irq, uap);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	uap->flags &= ~PMACZILOG_FLAG_IS_OPEN;
 
 	if (!ZS_IS_CONS(uap))
 		pmz_set_scc_power(uap, 0);	/* Shut the chip down */
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 /* Shared by TTY driver and serial console setup.  The port lock is held
@@ -1247,7 +1247,7 @@ static void pmz_set_termios(struct uart_port *port, struct ktermios *termios,
 	struct uart_pmac_port *uap = to_pmz(port);
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);	
+	uart_port_lock_irqsave(port, &flags);	
 
 	/* Disable IRQs on the port */
 	pmz_interrupt_control(uap, 0);
@@ -1259,7 +1259,7 @@ static void pmz_set_termios(struct uart_port *port, struct ktermios *termios,
 	if (ZS_IS_OPEN(uap))
 		pmz_interrupt_control(uap, 1);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static const char *pmz_type(struct uart_port *port)
@@ -1896,7 +1896,7 @@ static void pmz_console_write(struct console *con, const char *s, unsigned int c
 	struct uart_pmac_port *uap = &pmz_ports[con->index];
 	unsigned long flags;
 
-	spin_lock_irqsave(&uap->port.lock, flags);
+	uart_port_lock_irqsave(&uap->port, &flags);
 
 	/* Turn of interrupts and enable the transmitter. */
 	write_zsreg(uap, R1, uap->curregs[1] & ~TxINT_ENAB);
@@ -1908,7 +1908,7 @@ static void pmz_console_write(struct console *con, const char *s, unsigned int c
 	write_zsreg(uap, R1, uap->curregs[1]);
 	/* Don't disable the transmitter. */
 
-	spin_unlock_irqrestore(&uap->port.lock, flags);
+	uart_port_unlock_irqrestore(&uap->port, flags);
 }
 
 /*
diff --git a/drivers/tty/serial/pxa.c b/drivers/tty/serial/pxa.c
index 73c60f5ea027..46e70e155aab 100644
--- a/drivers/tty/serial/pxa.c
+++ b/drivers/tty/serial/pxa.c
@@ -225,14 +225,14 @@ static inline irqreturn_t serial_pxa_irq(int irq, void *dev_id)
 	iir = serial_in(up, UART_IIR);
 	if (iir & UART_IIR_NO_INT)
 		return IRQ_NONE;
-	spin_lock(&up->port.lock);
+	uart_port_lock(&up->port);
 	lsr = serial_in(up, UART_LSR);
 	if (lsr & UART_LSR_DR)
 		receive_chars(up, &lsr);
 	check_modem_status(up);
 	if (lsr & UART_LSR_THRE)
 		transmit_chars(up);
-	spin_unlock(&up->port.lock);
+	uart_port_unlock(&up->port);
 	return IRQ_HANDLED;
 }
 
@@ -242,9 +242,9 @@ static unsigned int serial_pxa_tx_empty(struct uart_port *port)
 	unsigned long flags;
 	unsigned int ret;
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 
 	return ret;
 }
@@ -295,13 +295,13 @@ static void serial_pxa_break_ctl(struct uart_port *port, int break_state)
 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
 	unsigned long flags;
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 	if (break_state == -1)
 		up->lcr |= UART_LCR_SBC;
 	else
 		up->lcr &= ~UART_LCR_SBC;
 	serial_out(up, UART_LCR, up->lcr);
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 }
 
 static int serial_pxa_startup(struct uart_port *port)
@@ -346,10 +346,10 @@ static int serial_pxa_startup(struct uart_port *port)
 	 */
 	serial_out(up, UART_LCR, UART_LCR_WLEN8);
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 	up->port.mctrl |= TIOCM_OUT2;
 	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 
 	/*
 	 * Finally, enable interrupts.  Note: Modem status interrupts
@@ -383,10 +383,10 @@ static void serial_pxa_shutdown(struct uart_port *port)
 	up->ier = 0;
 	serial_out(up, UART_IER, 0);
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 	up->port.mctrl &= ~TIOCM_OUT2;
 	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 
 	/*
 	 * Disable break condition and FIFOs
@@ -434,7 +434,7 @@ serial_pxa_set_termios(struct uart_port *port, struct ktermios *termios,
 	 * Ok, we're now changing the port state.  Do it with
 	 * interrupts disabled.
 	 */
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 
 	/*
 	 * Ensure the port will be enabled.
@@ -504,7 +504,7 @@ serial_pxa_set_termios(struct uart_port *port, struct ktermios *termios,
 	up->lcr = cval;					/* Save LCR */
 	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
 	serial_out(up, UART_FCR, fcr);
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 }
 
 static void
@@ -608,9 +608,9 @@ serial_pxa_console_write(struct console *co, const char *s, unsigned int count)
 	if (up->port.sysrq)
 		locked = 0;
 	else if (oops_in_progress)
-		locked = spin_trylock(&up->port.lock);
+		locked = uart_port_trylock(&up->port);
 	else
-		spin_lock(&up->port.lock);
+		uart_port_lock(&up->port);
 
 	/*
 	 *	First save the IER then disable the interrupts
@@ -628,7 +628,7 @@ serial_pxa_console_write(struct console *co, const char *s, unsigned int count)
 	serial_out(up, UART_IER, ier);
 
 	if (locked)
-		spin_unlock(&up->port.lock);
+		uart_port_unlock(&up->port);
 	local_irq_restore(flags);
 	clk_disable(up->clk);
 
diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index 2e1b1c827dfe..7e78f97e8f43 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -482,9 +482,9 @@ static void qcom_geni_serial_console_write(struct console *co, const char *s,
 
 	uport = &port->uport;
 	if (oops_in_progress)
-		locked = spin_trylock_irqsave(&uport->lock, flags);
+		locked = uart_port_trylock_irqsave(uport, &flags);
 	else
-		spin_lock_irqsave(&uport->lock, flags);
+		uart_port_lock_irqsave(uport, &flags);
 
 	geni_status = readl(uport->membase + SE_GENI_STATUS);
 
@@ -520,7 +520,7 @@ static void qcom_geni_serial_console_write(struct console *co, const char *s,
 		qcom_geni_serial_setup_tx(uport, port->tx_remaining);
 
 	if (locked)
-		spin_unlock_irqrestore(&uport->lock, flags);
+		uart_port_unlock_irqrestore(uport, flags);
 }
 
 static void handle_rx_console(struct uart_port *uport, u32 bytes, bool drop)
@@ -851,21 +851,19 @@ static void qcom_geni_serial_stop_tx(struct uart_port *uport)
 }
 
 static void qcom_geni_serial_send_chunk_fifo(struct uart_port *uport,
-					     unsigned int chunk)
+					     unsigned int remaining)
 {
 	struct qcom_geni_serial_port *port = to_dev_port(uport);
 	struct circ_buf *xmit = &uport->state->xmit;
-	unsigned int tx_bytes, c, remaining = chunk;
+	unsigned int tx_bytes;
 	u8 buf[BYTES_PER_FIFO_WORD];
 
 	while (remaining) {
 		memset(buf, 0, sizeof(buf));
 		tx_bytes = min(remaining, BYTES_PER_FIFO_WORD);
 
-		for (c = 0; c < tx_bytes ; c++) {
-			buf[c] = xmit->buf[xmit->tail];
-			uart_xmit_advance(uport, 1);
-		}
+		memcpy(buf, &xmit->buf[xmit->tail], tx_bytes);
+		uart_xmit_advance(uport, tx_bytes);
 
 		iowrite32_rep(uport->membase + SE_GENI_TX_FIFOn, buf, 1);
 
@@ -972,7 +970,7 @@ static irqreturn_t qcom_geni_serial_isr(int isr, void *dev)
 	if (uport->suspended)
 		return IRQ_NONE;
 
-	spin_lock(&uport->lock);
+	uart_port_lock(uport);
 
 	m_irq_status = readl(uport->membase + SE_GENI_M_IRQ_STATUS);
 	s_irq_status = readl(uport->membase + SE_GENI_S_IRQ_STATUS);
diff --git a/drivers/tty/serial/rda-uart.c b/drivers/tty/serial/rda-uart.c
index be5c842b5ba9..d824c8318f33 100644
--- a/drivers/tty/serial/rda-uart.c
+++ b/drivers/tty/serial/rda-uart.c
@@ -139,12 +139,12 @@ static unsigned int rda_uart_tx_empty(struct uart_port *port)
 	unsigned int ret;
 	u32 val;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	val = rda_uart_read(port, RDA_UART_STATUS);
 	ret = (val & RDA_UART_TX_FIFO_MASK) ? TIOCSER_TEMT : 0;
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return ret;
 }
@@ -246,7 +246,7 @@ static void rda_uart_set_termios(struct uart_port *port,
 	unsigned int baud;
 	u32 irq_mask;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	baud = uart_get_baud_rate(port, termios, old, 9600, port->uartclk / 4);
 	rda_uart_change_baudrate(rda_port, baud);
@@ -325,7 +325,7 @@ static void rda_uart_set_termios(struct uart_port *port,
 	/* update the per-port timeout */
 	uart_update_timeout(port, termios->c_cflag, baud);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void rda_uart_send_chars(struct uart_port *port)
@@ -408,7 +408,7 @@ static irqreturn_t rda_interrupt(int irq, void *dev_id)
 	unsigned long flags;
 	u32 val, irq_mask;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* Clear IRQ cause */
 	val = rda_uart_read(port, RDA_UART_IRQ_CAUSE);
@@ -425,7 +425,7 @@ static irqreturn_t rda_interrupt(int irq, void *dev_id)
 		rda_uart_send_chars(port);
 	}
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return IRQ_HANDLED;
 }
@@ -436,16 +436,16 @@ static int rda_uart_startup(struct uart_port *port)
 	int ret;
 	u32 val;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	ret = request_irq(port->irq, rda_interrupt, IRQF_NO_SUSPEND,
 			  "rda-uart", port);
 	if (ret)
 		return ret;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	val = rda_uart_read(port, RDA_UART_CTRL);
 	val |= RDA_UART_ENABLE;
@@ -456,7 +456,7 @@ static int rda_uart_startup(struct uart_port *port)
 	val |= (RDA_UART_RX_DATA_AVAILABLE | RDA_UART_RX_TIMEOUT);
 	rda_uart_write(port, val, RDA_UART_IRQ_MASK);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return 0;
 }
@@ -466,7 +466,7 @@ static void rda_uart_shutdown(struct uart_port *port)
 	unsigned long flags;
 	u32 val;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	rda_uart_stop_tx(port);
 	rda_uart_stop_rx(port);
@@ -475,7 +475,7 @@ static void rda_uart_shutdown(struct uart_port *port)
 	val &= ~RDA_UART_ENABLE;
 	rda_uart_write(port, val, RDA_UART_CTRL);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static const char *rda_uart_type(struct uart_port *port)
@@ -515,7 +515,7 @@ static void rda_uart_config_port(struct uart_port *port, int flags)
 		rda_uart_request_port(port);
 	}
 
-	spin_lock_irqsave(&port->lock, irq_flags);
+	uart_port_lock_irqsave(port, &irq_flags);
 
 	/* Clear mask, so no surprise interrupts. */
 	rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
@@ -523,7 +523,7 @@ static void rda_uart_config_port(struct uart_port *port, int flags)
 	/* Clear status register */
 	rda_uart_write(port, 0, RDA_UART_STATUS);
 
-	spin_unlock_irqrestore(&port->lock, irq_flags);
+	uart_port_unlock_irqrestore(port, irq_flags);
 }
 
 static void rda_uart_release_port(struct uart_port *port)
@@ -597,9 +597,9 @@ static void rda_uart_port_write(struct uart_port *port, const char *s,
 	if (port->sysrq) {
 		locked = 0;
 	} else if (oops_in_progress) {
-		locked = spin_trylock(&port->lock);
+		locked = uart_port_trylock(port);
 	} else {
-		spin_lock(&port->lock);
+		uart_port_lock(port);
 		locked = 1;
 	}
 
@@ -615,7 +615,7 @@ static void rda_uart_port_write(struct uart_port *port, const char *s,
 	rda_uart_write(port, old_irq_mask, RDA_UART_IRQ_MASK);
 
 	if (locked)
-		spin_unlock(&port->lock);
+		uart_port_unlock(port);
 
 	local_irq_restore(flags);
 }
diff --git a/drivers/tty/serial/rp2.c b/drivers/tty/serial/rp2.c
index de220ac8ca54..d46a81cddfcd 100644
--- a/drivers/tty/serial/rp2.c
+++ b/drivers/tty/serial/rp2.c
@@ -276,9 +276,9 @@ static unsigned int rp2_uart_tx_empty(struct uart_port *port)
 	 * But the TXEMPTY bit doesn't seem to work unless the TX IRQ is
 	 * enabled.
 	 */
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 	tx_fifo_bytes = readw(up->base + RP2_TX_FIFO_COUNT);
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 
 	return tx_fifo_bytes ? 0 : TIOCSER_TEMT;
 }
@@ -323,10 +323,10 @@ static void rp2_uart_break_ctl(struct uart_port *port, int break_state)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	rp2_rmw(port_to_up(port), RP2_TXRX_CTL, RP2_TXRX_CTL_BREAK_m,
 		break_state ? RP2_TXRX_CTL_BREAK_m : 0);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void rp2_uart_enable_ms(struct uart_port *port)
@@ -383,7 +383,7 @@ static void rp2_uart_set_termios(struct uart_port *port, struct ktermios *new,
 	if (tty_termios_baud_rate(new))
 		tty_termios_encode_baud_rate(new, baud, baud);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* ignore all characters if CREAD is not set */
 	port->ignore_status_mask = (new->c_cflag & CREAD) ? 0 : RP2_DUMMY_READ;
@@ -391,7 +391,7 @@ static void rp2_uart_set_termios(struct uart_port *port, struct ktermios *new,
 	__rp2_uart_set_termios(up, new->c_cflag, new->c_iflag, baud_div);
 	uart_update_timeout(port, new->c_cflag, baud);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void rp2_rx_chars(struct rp2_uart_port *up)
@@ -440,7 +440,7 @@ static void rp2_ch_interrupt(struct rp2_uart_port *up)
 {
 	u32 status;
 
-	spin_lock(&up->port.lock);
+	uart_port_lock(&up->port);
 
 	/*
 	 * The IRQ status bits are clear-on-write.  Other status bits in
@@ -456,7 +456,7 @@ static void rp2_ch_interrupt(struct rp2_uart_port *up)
 	if (status & RP2_CHAN_STAT_MS_CHANGED_MASK)
 		wake_up_interruptible(&up->port.state->port.delta_msr_wait);
 
-	spin_unlock(&up->port.lock);
+	uart_port_unlock(&up->port);
 }
 
 static int rp2_asic_interrupt(struct rp2_card *card, unsigned int asic_id)
@@ -516,10 +516,10 @@ static void rp2_uart_shutdown(struct uart_port *port)
 
 	rp2_uart_break_ctl(port, 0);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	rp2_mask_ch_irq(up, up->idx, 0);
 	rp2_rmw(up, RP2_CHAN_STAT, 0, 0);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static const char *rp2_uart_type(struct uart_port *port)
diff --git a/drivers/tty/serial/sa1100.c b/drivers/tty/serial/sa1100.c
index ad011f1e2f4d..be7bcd75d9f4 100644
--- a/drivers/tty/serial/sa1100.c
+++ b/drivers/tty/serial/sa1100.c
@@ -115,9 +115,9 @@ static void sa1100_timeout(struct timer_list *t)
 	unsigned long flags;
 
 	if (sport->port.state) {
-		spin_lock_irqsave(&sport->port.lock, flags);
+		uart_port_lock_irqsave(&sport->port, &flags);
 		sa1100_mctrl_check(sport);
-		spin_unlock_irqrestore(&sport->port.lock, flags);
+		uart_port_unlock_irqrestore(&sport->port, flags);
 
 		mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
 	}
@@ -247,7 +247,7 @@ static irqreturn_t sa1100_int(int irq, void *dev_id)
 	struct sa1100_port *sport = dev_id;
 	unsigned int status, pass_counter = 0;
 
-	spin_lock(&sport->port.lock);
+	uart_port_lock(&sport->port);
 	status = UART_GET_UTSR0(sport);
 	status &= SM_TO_UTSR0(sport->port.read_status_mask) | ~UTSR0_TFS;
 	do {
@@ -276,7 +276,7 @@ static irqreturn_t sa1100_int(int irq, void *dev_id)
 		status &= SM_TO_UTSR0(sport->port.read_status_mask) |
 			  ~UTSR0_TFS;
 	} while (status & (UTSR0_TFS | UTSR0_RFS | UTSR0_RID));
-	spin_unlock(&sport->port.lock);
+	uart_port_unlock(&sport->port);
 
 	return IRQ_HANDLED;
 }
@@ -321,14 +321,14 @@ static void sa1100_break_ctl(struct uart_port *port, int break_state)
 	unsigned long flags;
 	unsigned int utcr3;
 
-	spin_lock_irqsave(&sport->port.lock, flags);
+	uart_port_lock_irqsave(&sport->port, &flags);
 	utcr3 = UART_GET_UTCR3(sport);
 	if (break_state == -1)
 		utcr3 |= UTCR3_BRK;
 	else
 		utcr3 &= ~UTCR3_BRK;
 	UART_PUT_UTCR3(sport, utcr3);
-	spin_unlock_irqrestore(&sport->port.lock, flags);
+	uart_port_unlock_irqrestore(&sport->port, flags);
 }
 
 static int sa1100_startup(struct uart_port *port)
@@ -354,9 +354,9 @@ static int sa1100_startup(struct uart_port *port)
 	/*
 	 * Enable modem status interrupts
 	 */
-	spin_lock_irq(&sport->port.lock);
+	uart_port_lock_irq(&sport->port);
 	sa1100_enable_ms(&sport->port);
-	spin_unlock_irq(&sport->port.lock);
+	uart_port_unlock_irq(&sport->port);
 
 	return 0;
 }
@@ -423,7 +423,7 @@ sa1100_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	del_timer_sync(&sport->timer);
 
-	spin_lock_irqsave(&sport->port.lock, flags);
+	uart_port_lock_irqsave(&sport->port, &flags);
 
 	sport->port.read_status_mask &= UTSR0_TO_SM(UTSR0_TFS);
 	sport->port.read_status_mask |= UTSR1_TO_SM(UTSR1_ROR);
@@ -485,7 +485,7 @@ sa1100_set_termios(struct uart_port *port, struct ktermios *termios,
 	if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
 		sa1100_enable_ms(&sport->port);
 
-	spin_unlock_irqrestore(&sport->port.lock, flags);
+	uart_port_unlock_irqrestore(&sport->port, flags);
 }
 
 static const char *sa1100_type(struct uart_port *port)
diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index 6b8d4b4402e9..ee51a0368a55 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -64,6 +64,7 @@
 #define RXSTAT_DUMMY_READ (0x10000000)
 
 enum s3c24xx_port_type {
+	TYPE_S3C24XX,
 	TYPE_S3C6400,
 	TYPE_APPLE_S5L,
 };
@@ -127,6 +128,8 @@ struct s3c24xx_uart_dma {
 };
 
 struct s3c24xx_uart_port {
+	unsigned char			rx_claimed;
+	unsigned char			tx_claimed;
 	unsigned char			rx_enabled;
 	unsigned char			tx_enabled;
 	unsigned int			pm_level;
@@ -245,7 +248,7 @@ static void s3c24xx_serial_rx_enable(struct uart_port *port)
 	unsigned int ucon, ufcon;
 	int count = 10000;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	while (--count && !s3c24xx_serial_txempty_nofifo(port))
 		udelay(100);
@@ -259,7 +262,7 @@ static void s3c24xx_serial_rx_enable(struct uart_port *port)
 	wr_regl(port, S3C2410_UCON, ucon);
 
 	ourport->rx_enabled = 1;
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void s3c24xx_serial_rx_disable(struct uart_port *port)
@@ -268,14 +271,14 @@ static void s3c24xx_serial_rx_disable(struct uart_port *port)
 	unsigned long flags;
 	unsigned int ucon;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	ucon = rd_regl(port, S3C2410_UCON);
 	ucon &= ~S3C2410_UCON_RXIRQMODE;
 	wr_regl(port, S3C2410_UCON, ucon);
 
 	ourport->rx_enabled = 0;
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void s3c24xx_serial_stop_tx(struct uart_port *port)
@@ -341,7 +344,7 @@ static void s3c24xx_serial_tx_dma_complete(void *args)
 				dma->tx_transfer_addr, dma->tx_size,
 				DMA_TO_DEVICE);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	uart_xmit_advance(port, count);
 	ourport->tx_in_progress = 0;
@@ -350,7 +353,7 @@ static void s3c24xx_serial_tx_dma_complete(void *args)
 		uart_write_wakeup(port);
 
 	s3c24xx_serial_start_next_tx(ourport);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void enable_tx_dma(struct s3c24xx_uart_port *ourport)
@@ -616,7 +619,7 @@ static void s3c24xx_serial_rx_dma_complete(void *args)
 	received  = dma->rx_bytes_requested - state.residue;
 	async_tx_ack(dma->rx_desc);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	if (received)
 		s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
@@ -628,7 +631,7 @@ static void s3c24xx_serial_rx_dma_complete(void *args)
 
 	s3c64xx_start_rx_dma(ourport);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport)
@@ -719,7 +722,7 @@ static irqreturn_t s3c24xx_serial_rx_chars_dma(void *dev_id)
 	utrstat = rd_regl(port, S3C2410_UTRSTAT);
 	rd_regl(port, S3C2410_UFSTAT);
 
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 
 	if (!(utrstat & S3C2410_UTRSTAT_TIMEOUT)) {
 		s3c64xx_start_rx_dma(ourport);
@@ -748,7 +751,7 @@ static irqreturn_t s3c24xx_serial_rx_chars_dma(void *dev_id)
 	wr_regl(port, S3C2410_UTRSTAT, S3C2410_UTRSTAT_TIMEOUT);
 
 finish:
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 
 	return IRQ_HANDLED;
 }
@@ -846,9 +849,9 @@ static irqreturn_t s3c24xx_serial_rx_chars_pio(void *dev_id)
 	struct s3c24xx_uart_port *ourport = dev_id;
 	struct uart_port *port = &ourport->port;
 
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 	s3c24xx_serial_rx_drain_fifo(ourport);
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 
 	return IRQ_HANDLED;
 }
@@ -929,11 +932,11 @@ static irqreturn_t s3c24xx_serial_tx_irq(int irq, void *id)
 	struct s3c24xx_uart_port *ourport = id;
 	struct uart_port *port = &ourport->port;
 
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 
 	s3c24xx_serial_tx_chars(ourport);
 
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 	return IRQ_HANDLED;
 }
 
@@ -1030,7 +1033,7 @@ static void s3c24xx_serial_break_ctl(struct uart_port *port, int break_state)
 	unsigned long flags;
 	unsigned int ucon;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	ucon = rd_regl(port, S3C2410_UCON);
 
@@ -1041,7 +1044,7 @@ static void s3c24xx_serial_break_ctl(struct uart_port *port, int break_state)
 
 	wr_regl(port, S3C2410_UCON, ucon);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p)
@@ -1163,6 +1166,29 @@ static void s3c24xx_serial_release_dma(struct s3c24xx_uart_port *p)
 	}
 }
 
+static void s3c24xx_serial_shutdown(struct uart_port *port)
+{
+	struct s3c24xx_uart_port *ourport = to_ourport(port);
+
+	if (ourport->tx_claimed) {
+		free_irq(ourport->tx_irq, ourport);
+		ourport->tx_enabled = 0;
+		ourport->tx_claimed = 0;
+		ourport->tx_mode = 0;
+	}
+
+	if (ourport->rx_claimed) {
+		free_irq(ourport->rx_irq, ourport);
+		ourport->rx_claimed = 0;
+		ourport->rx_enabled = 0;
+	}
+
+	if (ourport->dma)
+		s3c24xx_serial_release_dma(ourport);
+
+	ourport->tx_in_progress = 0;
+}
+
 static void s3c64xx_serial_shutdown(struct uart_port *port)
 {
 	struct s3c24xx_uart_port *ourport = to_ourport(port);
@@ -1208,6 +1234,48 @@ static void apple_s5l_serial_shutdown(struct uart_port *port)
 	ourport->tx_in_progress = 0;
 }
 
+static int s3c24xx_serial_startup(struct uart_port *port)
+{
+	struct s3c24xx_uart_port *ourport = to_ourport(port);
+	int ret;
+
+	ourport->rx_enabled = 1;
+
+	ret = request_irq(ourport->rx_irq, s3c24xx_serial_rx_irq, 0,
+			  s3c24xx_serial_portname(port), ourport);
+
+	if (ret != 0) {
+		dev_err(port->dev, "cannot get irq %d\n", ourport->rx_irq);
+		return ret;
+	}
+
+	ourport->rx_claimed = 1;
+
+	dev_dbg(port->dev, "requesting tx irq...\n");
+
+	ourport->tx_enabled = 1;
+
+	ret = request_irq(ourport->tx_irq, s3c24xx_serial_tx_irq, 0,
+			  s3c24xx_serial_portname(port), ourport);
+
+	if (ret) {
+		dev_err(port->dev, "cannot get irq %d\n", ourport->tx_irq);
+		goto err;
+	}
+
+	ourport->tx_claimed = 1;
+
+	/* the port reset code should have done the correct
+	 * register setup for the port controls
+	 */
+
+	return ret;
+
+err:
+	s3c24xx_serial_shutdown(port);
+	return ret;
+}
+
 static int s3c64xx_serial_startup(struct uart_port *port)
 {
 	struct s3c24xx_uart_port *ourport = to_ourport(port);
@@ -1235,7 +1303,7 @@ static int s3c64xx_serial_startup(struct uart_port *port)
 	ourport->rx_enabled = 1;
 	ourport->tx_enabled = 0;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	ufcon = rd_regl(port, S3C2410_UFCON);
 	ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8;
@@ -1245,7 +1313,7 @@ static int s3c64xx_serial_startup(struct uart_port *port)
 
 	enable_rx_pio(ourport);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	/* Enable Rx Interrupt */
 	s3c24xx_clear_bit(port, S3C64XX_UINTM_RXD, S3C64XX_UINTM);
@@ -1273,7 +1341,7 @@ static int apple_s5l_serial_startup(struct uart_port *port)
 	ourport->rx_enabled = 1;
 	ourport->tx_enabled = 0;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	ufcon = rd_regl(port, S3C2410_UFCON);
 	ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8;
@@ -1283,7 +1351,7 @@ static int apple_s5l_serial_startup(struct uart_port *port)
 
 	enable_rx_pio(ourport);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	/* Enable Rx Interrupt */
 	s3c24xx_set_bit(port, APPLE_S5L_UCON_RXTHRESH_ENA, S3C2410_UCON);
@@ -1558,7 +1626,7 @@ static void s3c24xx_serial_set_termios(struct uart_port *port,
 		ulcon |= S3C2410_LCON_PNONE;
 	}
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	dev_dbg(port->dev,
 		"setting ulcon to %08x, brddiv to %d, udivslot %08x\n",
@@ -1616,7 +1684,7 @@ static void s3c24xx_serial_set_termios(struct uart_port *port,
 	if ((termios->c_cflag & CREAD) == 0)
 		port->ignore_status_mask |= RXSTAT_DUMMY_READ;
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static const char *s3c24xx_serial_type(struct uart_port *port)
@@ -1624,6 +1692,8 @@ static const char *s3c24xx_serial_type(struct uart_port *port)
 	const struct s3c24xx_uart_port *ourport = to_ourport(port);
 
 	switch (ourport->info->type) {
+	case TYPE_S3C24XX:
+		return "S3C24XX";
 	case TYPE_S3C6400:
 		return "S3C6400/10";
 	case TYPE_APPLE_S5L:
@@ -1683,6 +1753,27 @@ static void s3c24xx_serial_put_poll_char(struct uart_port *port,
 			 unsigned char c);
 #endif
 
+static const struct uart_ops s3c24xx_serial_ops = {
+	.pm		= s3c24xx_serial_pm,
+	.tx_empty	= s3c24xx_serial_tx_empty,
+	.get_mctrl	= s3c24xx_serial_get_mctrl,
+	.set_mctrl	= s3c24xx_serial_set_mctrl,
+	.stop_tx	= s3c24xx_serial_stop_tx,
+	.start_tx	= s3c24xx_serial_start_tx,
+	.stop_rx	= s3c24xx_serial_stop_rx,
+	.break_ctl	= s3c24xx_serial_break_ctl,
+	.startup	= s3c24xx_serial_startup,
+	.shutdown	= s3c24xx_serial_shutdown,
+	.set_termios	= s3c24xx_serial_set_termios,
+	.type		= s3c24xx_serial_type,
+	.config_port	= s3c24xx_serial_config_port,
+	.verify_port	= s3c24xx_serial_verify_port,
+#if defined(CONFIG_SERIAL_SAMSUNG_CONSOLE) && defined(CONFIG_CONSOLE_POLL)
+	.poll_get_char = s3c24xx_serial_get_poll_char,
+	.poll_put_char = s3c24xx_serial_put_poll_char,
+#endif
+};
+
 static const struct uart_ops s3c64xx_serial_ops = {
 	.pm		= s3c24xx_serial_pm,
 	.tx_empty	= s3c24xx_serial_tx_empty,
@@ -1745,6 +1836,7 @@ static void s3c24xx_serial_init_port_default(int index) {
 	port->iotype = UPIO_MEM;
 	port->uartclk = 0;
 	port->fifosize = 16;
+	port->ops = &s3c24xx_serial_ops;
 	port->flags = UPF_BOOT_AUTOCONF;
 	port->line = index;
 }
@@ -1862,6 +1954,16 @@ static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
 		ourport->tx_irq = ret + 1;
 	}
 
+	switch (ourport->info->type) {
+	case TYPE_S3C24XX:
+		ret = platform_get_irq(platdev, 1);
+		if (ret > 0)
+			ourport->tx_irq = ret;
+		break;
+	default:
+		break;
+	}
+
 	/*
 	 * DMA is currently supported only on DT platforms, if DMA properties
 	 * are specified.
@@ -1981,6 +2083,9 @@ static int s3c24xx_serial_probe(struct platform_device *pdev)
 			&ourport->drv_data->def_cfg;
 
 	switch (ourport->info->type) {
+	case TYPE_S3C24XX:
+		ourport->port.ops = &s3c24xx_serial_ops;
+		break;
 	case TYPE_S3C6400:
 		ourport->port.ops = &s3c64xx_serial_ops;
 		break;
@@ -2271,14 +2376,14 @@ s3c24xx_serial_console_write(struct console *co, const char *s,
 	if (cons_uart->sysrq)
 		locked = false;
 	else if (oops_in_progress)
-		locked = spin_trylock_irqsave(&cons_uart->lock, flags);
+		locked = uart_port_trylock_irqsave(cons_uart, &flags);
 	else
-		spin_lock_irqsave(&cons_uart->lock, flags);
+		uart_port_lock_irqsave(cons_uart, &flags);
 
 	uart_console_write(cons_uart, s, count, s3c24xx_serial_console_putchar);
 
 	if (locked)
-		spin_unlock_irqrestore(&cons_uart->lock, flags);
+		uart_port_unlock_irqrestore(cons_uart, flags);
 }
 
 /* Shouldn't be __init, as it can be instantiated from other module */
diff --git a/drivers/tty/serial/sb1250-duart.c b/drivers/tty/serial/sb1250-duart.c
index f3cd69346482..dbec29d9a6c3 100644
--- a/drivers/tty/serial/sb1250-duart.c
+++ b/drivers/tty/serial/sb1250-duart.c
@@ -610,7 +610,7 @@ static void sbd_set_termios(struct uart_port *uport, struct ktermios *termios,
 	else
 		aux &= ~M_DUART_CTS_CHNG_ENA;
 
-	spin_lock(&uport->lock);
+	uart_port_lock(uport);
 
 	if (sport->tx_stopped)
 		command |= M_DUART_TX_DIS;
@@ -632,7 +632,7 @@ static void sbd_set_termios(struct uart_port *uport, struct ktermios *termios,
 
 	write_sbdchn(sport, R_DUART_CMD, command);
 
-	spin_unlock(&uport->lock);
+	uart_port_unlock(uport);
 }
 
 
@@ -839,22 +839,22 @@ static void sbd_console_write(struct console *co, const char *s,
 	unsigned int mask;
 
 	/* Disable transmit interrupts and enable the transmitter. */
-	spin_lock_irqsave(&uport->lock, flags);
+	uart_port_lock_irqsave(uport, &flags);
 	mask = read_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2));
 	write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2),
 		     mask & ~M_DUART_IMR_TX);
 	write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_EN);
-	spin_unlock_irqrestore(&uport->lock, flags);
+	uart_port_unlock_irqrestore(uport, flags);
 
 	uart_console_write(&sport->port, s, count, sbd_console_putchar);
 
 	/* Restore transmit interrupts and the transmitter enable. */
-	spin_lock_irqsave(&uport->lock, flags);
+	uart_port_lock_irqsave(uport, &flags);
 	sbd_line_drain(sport);
 	if (sport->tx_stopped)
 		write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS);
 	write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), mask);
-	spin_unlock_irqrestore(&uport->lock, flags);
+	uart_port_unlock_irqrestore(uport, flags);
 }
 
 static int __init sbd_console_setup(struct console *co, char *options)
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index dd06461eae8b..e5031658a4a6 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -24,7 +24,6 @@
 #include <linux/tty_flip.h>
 #include <linux/spi/spi.h>
 #include <linux/uaccess.h>
-#include <linux/units.h>
 #include <uapi/linux/sched/types.h>
 
 #define SC16IS7XX_NAME			"sc16is7xx"
@@ -301,8 +300,8 @@
 
 
 /* Misc definitions */
-#define SC16IS7XX_SPI_READ_BIT		BIT(7)
 #define SC16IS7XX_FIFO_SIZE		(64)
+#define SC16IS7XX_REG_SHIFT		2
 #define SC16IS7XX_GPIOS_PER_BANK	4
 
 struct sc16is7xx_devtype {
@@ -323,8 +322,7 @@ struct sc16is7xx_one_config {
 
 struct sc16is7xx_one {
 	struct uart_port		port;
-	struct regmap			*regmap;
-	struct mutex			efr_lock; /* EFR registers access */
+	u8				line;
 	struct kthread_work		tx_work;
 	struct kthread_work		reg_work;
 	struct kthread_delayed_work	ms_work;
@@ -335,6 +333,7 @@ struct sc16is7xx_one {
 
 struct sc16is7xx_port {
 	const struct sc16is7xx_devtype	*devtype;
+	struct regmap			*regmap;
 	struct clk			*clk;
 #ifdef CONFIG_GPIOLIB
 	struct gpio_chip		gpio;
@@ -344,6 +343,7 @@ struct sc16is7xx_port {
 	unsigned char			buf[SC16IS7XX_FIFO_SIZE];
 	struct kthread_worker		kworker;
 	struct task_struct		*kworker_task;
+	struct mutex			efr_lock;
 	struct sc16is7xx_one		p[];
 };
 
@@ -361,35 +361,48 @@ static void sc16is7xx_stop_tx(struct uart_port *port);
 #define to_sc16is7xx_port(p,e)	((container_of((p), struct sc16is7xx_port, e)))
 #define to_sc16is7xx_one(p,e)	((container_of((p), struct sc16is7xx_one, e)))
 
-static u8 sc16is7xx_port_read(struct uart_port *port, u8 reg)
+static int sc16is7xx_line(struct uart_port *port)
 {
 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+
+	return one->line;
+}
+
+static u8 sc16is7xx_port_read(struct uart_port *port, u8 reg)
+{
+	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
 	unsigned int val = 0;
+	const u8 line = sc16is7xx_line(port);
 
-	regmap_read(one->regmap, reg, &val);
+	regmap_read(s->regmap, (reg << SC16IS7XX_REG_SHIFT) | line, &val);
 
 	return val;
 }
 
 static void sc16is7xx_port_write(struct uart_port *port, u8 reg, u8 val)
 {
-	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
+	const u8 line = sc16is7xx_line(port);
 
-	regmap_write(one->regmap, reg, val);
+	regmap_write(s->regmap, (reg << SC16IS7XX_REG_SHIFT) | line, val);
 }
 
 static void sc16is7xx_fifo_read(struct uart_port *port, unsigned int rxlen)
 {
 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
-	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+	const u8 line = sc16is7xx_line(port);
+	u8 addr = (SC16IS7XX_RHR_REG << SC16IS7XX_REG_SHIFT) | line;
 
-	regmap_noinc_read(one->regmap, SC16IS7XX_RHR_REG, s->buf, rxlen);
+	regcache_cache_bypass(s->regmap, true);
+	regmap_raw_read(s->regmap, addr, s->buf, rxlen);
+	regcache_cache_bypass(s->regmap, false);
 }
 
 static void sc16is7xx_fifo_write(struct uart_port *port, u8 to_send)
 {
 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
-	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+	const u8 line = sc16is7xx_line(port);
+	u8 addr = (SC16IS7XX_THR_REG << SC16IS7XX_REG_SHIFT) | line;
 
 	/*
 	 * Don't send zero-length data, at least on SPI it confuses the chip
@@ -398,15 +411,32 @@ static void sc16is7xx_fifo_write(struct uart_port *port, u8 to_send)
 	if (unlikely(!to_send))
 		return;
 
-	regmap_noinc_write(one->regmap, SC16IS7XX_THR_REG, s->buf, to_send);
+	regcache_cache_bypass(s->regmap, true);
+	regmap_raw_write(s->regmap, addr, s->buf, to_send);
+	regcache_cache_bypass(s->regmap, false);
 }
 
 static void sc16is7xx_port_update(struct uart_port *port, u8 reg,
 				  u8 mask, u8 val)
 {
-	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
+	const u8 line = sc16is7xx_line(port);
+
+	regmap_update_bits(s->regmap, (reg << SC16IS7XX_REG_SHIFT) | line,
+			   mask, val);
+}
+
+static int sc16is7xx_alloc_line(void)
+{
+	int i;
+
+	BUILD_BUG_ON(SC16IS7XX_MAX_DEVS > BITS_PER_LONG);
 
-	regmap_update_bits(one->regmap, reg, mask, val);
+	for (i = 0; i < SC16IS7XX_MAX_DEVS; i++)
+		if (!test_and_set_bit(i, &sc16is7xx_lines))
+			break;
+
+	return i;
 }
 
 static void sc16is7xx_power(struct uart_port *port, int on)
@@ -448,7 +478,7 @@ static const struct sc16is7xx_devtype sc16is762_devtype = {
 
 static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg)
 {
-	switch (reg) {
+	switch (reg >> SC16IS7XX_REG_SHIFT) {
 	case SC16IS7XX_RHR_REG:
 	case SC16IS7XX_IIR_REG:
 	case SC16IS7XX_LSR_REG:
@@ -456,6 +486,7 @@ static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg)
 	case SC16IS7XX_TXLVL_REG:
 	case SC16IS7XX_RXLVL_REG:
 	case SC16IS7XX_IOSTATE_REG:
+	case SC16IS7XX_IOCONTROL_REG:
 		return true;
 	default:
 		break;
@@ -466,7 +497,7 @@ static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg)
 
 static bool sc16is7xx_regmap_precious(struct device *dev, unsigned int reg)
 {
-	switch (reg) {
+	switch (reg >> SC16IS7XX_REG_SHIFT) {
 	case SC16IS7XX_RHR_REG:
 		return true;
 	default:
@@ -476,14 +507,9 @@ static bool sc16is7xx_regmap_precious(struct device *dev, unsigned int reg)
 	return false;
 }
 
-static bool sc16is7xx_regmap_noinc(struct device *dev, unsigned int reg)
-{
-	return reg == SC16IS7XX_RHR_REG;
-}
-
 static int sc16is7xx_set_baud(struct uart_port *port, int baud)
 {
-	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
 	u8 lcr;
 	u8 prescaler = 0;
 	unsigned long clk = port->uartclk, div = clk / 16 / baud;
@@ -506,7 +532,7 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud)
 	 * because the bulk of the interrupt processing is run as a workqueue
 	 * job in thread context.
 	 */
-	mutex_lock(&one->efr_lock);
+	mutex_lock(&s->efr_lock);
 
 	lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG);
 
@@ -515,17 +541,17 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud)
 			     SC16IS7XX_LCR_CONF_MODE_B);
 
 	/* Enable enhanced features */
-	regcache_cache_bypass(one->regmap, true);
+	regcache_cache_bypass(s->regmap, true);
 	sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
 			      SC16IS7XX_EFR_ENABLE_BIT,
 			      SC16IS7XX_EFR_ENABLE_BIT);
 
-	regcache_cache_bypass(one->regmap, false);
+	regcache_cache_bypass(s->regmap, false);
 
 	/* Put LCR back to the normal mode */
 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
 
-	mutex_unlock(&one->efr_lock);
+	mutex_unlock(&s->efr_lock);
 
 	sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
 			      SC16IS7XX_MCR_CLKSEL_BIT,
@@ -536,10 +562,10 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud)
 			     SC16IS7XX_LCR_CONF_MODE_A);
 
 	/* Write the new divisor */
-	regcache_cache_bypass(one->regmap, true);
+	regcache_cache_bypass(s->regmap, true);
 	sc16is7xx_port_write(port, SC16IS7XX_DLH_REG, div / 256);
 	sc16is7xx_port_write(port, SC16IS7XX_DLL_REG, div % 256);
-	regcache_cache_bypass(one->regmap, false);
+	regcache_cache_bypass(s->regmap, false);
 
 	/* Put LCR back to the normal mode */
 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
@@ -675,8 +701,6 @@ static void sc16is7xx_handle_tx(struct uart_port *port)
 
 	if (uart_circ_empty(xmit))
 		sc16is7xx_stop_tx(port);
-	else
-		sc16is7xx_ier_set(port, SC16IS7XX_IER_THRI_BIT);
 	uart_port_unlock_irqrestore(port, flags);
 }
 
@@ -695,10 +719,11 @@ static unsigned int sc16is7xx_get_hwmctrl(struct uart_port *port)
 static void sc16is7xx_update_mlines(struct sc16is7xx_one *one)
 {
 	struct uart_port *port = &one->port;
+	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
 	unsigned long flags;
 	unsigned int status, changed;
 
-	lockdep_assert_held_once(&one->efr_lock);
+	lockdep_assert_held_once(&s->efr_lock);
 
 	status = sc16is7xx_get_hwmctrl(port);
 	changed = status ^ one->old_mctrl;
@@ -724,77 +749,74 @@ static void sc16is7xx_update_mlines(struct sc16is7xx_one *one)
 
 static bool sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
 {
-	bool rc = true;
-	unsigned int iir, rxlen;
 	struct uart_port *port = &s->p[portno].port;
-	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
 
-	mutex_lock(&one->efr_lock);
-
-	iir = sc16is7xx_port_read(port, SC16IS7XX_IIR_REG);
-	if (iir & SC16IS7XX_IIR_NO_INT_BIT) {
-		rc = false;
-		goto out_port_irq;
-	}
-
-	iir &= SC16IS7XX_IIR_ID_MASK;
-
-	switch (iir) {
-	case SC16IS7XX_IIR_RDI_SRC:
-	case SC16IS7XX_IIR_RLSE_SRC:
-	case SC16IS7XX_IIR_RTOI_SRC:
-	case SC16IS7XX_IIR_XOFFI_SRC:
-		rxlen = sc16is7xx_port_read(port, SC16IS7XX_RXLVL_REG);
-
-		/*
-		 * There is a silicon bug that makes the chip report a
-		 * time-out interrupt but no data in the FIFO. This is
-		 * described in errata section 18.1.4.
-		 *
-		 * When this happens, read one byte from the FIFO to
-		 * clear the interrupt.
-		 */
-		if (iir == SC16IS7XX_IIR_RTOI_SRC && !rxlen)
-			rxlen = 1;
-
-		if (rxlen)
-			sc16is7xx_handle_rx(port, rxlen, iir);
-		break;
+	do {
+		unsigned int iir, rxlen;
+		struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+
+		iir = sc16is7xx_port_read(port, SC16IS7XX_IIR_REG);
+		if (iir & SC16IS7XX_IIR_NO_INT_BIT)
+			return false;
+
+		iir &= SC16IS7XX_IIR_ID_MASK;
+
+		switch (iir) {
+		case SC16IS7XX_IIR_RDI_SRC:
+		case SC16IS7XX_IIR_RLSE_SRC:
+		case SC16IS7XX_IIR_RTOI_SRC:
+		case SC16IS7XX_IIR_XOFFI_SRC:
+			rxlen = sc16is7xx_port_read(port, SC16IS7XX_RXLVL_REG);
+
+			/*
+			 * There is a silicon bug that makes the chip report a
+			 * time-out interrupt but no data in the FIFO. This is
+			 * described in errata section 18.1.4.
+			 *
+			 * When this happens, read one byte from the FIFO to
+			 * clear the interrupt.
+			 */
+			if (iir == SC16IS7XX_IIR_RTOI_SRC && !rxlen)
+				rxlen = 1;
+
+			if (rxlen)
+				sc16is7xx_handle_rx(port, rxlen, iir);
+			break;
 		/* CTSRTS interrupt comes only when CTS goes inactive */
-	case SC16IS7XX_IIR_CTSRTS_SRC:
-	case SC16IS7XX_IIR_MSI_SRC:
-		sc16is7xx_update_mlines(one);
-		break;
-	case SC16IS7XX_IIR_THRI_SRC:
-		sc16is7xx_handle_tx(port);
-		break;
-	default:
-		dev_err_ratelimited(port->dev,
-				    "ttySC%i: Unexpected interrupt: %x",
-				    port->line, iir);
-		break;
-	}
-
-out_port_irq:
-	mutex_unlock(&one->efr_lock);
-
-	return rc;
+		case SC16IS7XX_IIR_CTSRTS_SRC:
+		case SC16IS7XX_IIR_MSI_SRC:
+			sc16is7xx_update_mlines(one);
+			break;
+		case SC16IS7XX_IIR_THRI_SRC:
+			sc16is7xx_handle_tx(port);
+			break;
+		default:
+			dev_err_ratelimited(port->dev,
+					    "ttySC%i: Unexpected interrupt: %x",
+					    port->line, iir);
+			break;
+		}
+	} while (0);
+	return true;
 }
 
 static irqreturn_t sc16is7xx_irq(int irq, void *dev_id)
 {
-	bool keep_polling;
-
 	struct sc16is7xx_port *s = (struct sc16is7xx_port *)dev_id;
 
-	do {
-		int i;
+	mutex_lock(&s->efr_lock);
 
-		keep_polling = false;
+	while (1) {
+		bool keep_polling = false;
+		int i;
 
 		for (i = 0; i < s->devtype->nr_uart; ++i)
 			keep_polling |= sc16is7xx_port_irq(s, i);
-	} while (keep_polling);
+		if (!keep_polling)
+			break;
+	}
+
+	mutex_unlock(&s->efr_lock);
 
 	return IRQ_HANDLED;
 }
@@ -802,15 +824,20 @@ static irqreturn_t sc16is7xx_irq(int irq, void *dev_id)
 static void sc16is7xx_tx_proc(struct kthread_work *ws)
 {
 	struct uart_port *port = &(to_sc16is7xx_one(ws, tx_work)->port);
-	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
+	unsigned long flags;
 
 	if ((port->rs485.flags & SER_RS485_ENABLED) &&
 	    (port->rs485.delay_rts_before_send > 0))
 		msleep(port->rs485.delay_rts_before_send);
 
-	mutex_lock(&one->efr_lock);
+	mutex_lock(&s->efr_lock);
 	sc16is7xx_handle_tx(port);
-	mutex_unlock(&one->efr_lock);
+	mutex_unlock(&s->efr_lock);
+
+	uart_port_lock_irqsave(port, &flags);
+	sc16is7xx_ier_set(port, SC16IS7XX_IER_THRI_BIT);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void sc16is7xx_reconf_rs485(struct uart_port *port)
@@ -913,9 +940,9 @@ static void sc16is7xx_ms_proc(struct kthread_work *ws)
 	struct sc16is7xx_port *s = dev_get_drvdata(one->port.dev);
 
 	if (one->port.state) {
-		mutex_lock(&one->efr_lock);
+		mutex_lock(&s->efr_lock);
 		sc16is7xx_update_mlines(one);
-		mutex_unlock(&one->efr_lock);
+		mutex_unlock(&s->efr_lock);
 
 		kthread_queue_delayed_work(&s->kworker, &one->ms_work, HZ);
 	}
@@ -999,6 +1026,7 @@ static void sc16is7xx_set_termios(struct uart_port *port,
 				  struct ktermios *termios,
 				  const struct ktermios *old)
 {
+	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
 	unsigned int lcr, flow = 0;
 	int baud;
@@ -1057,13 +1085,13 @@ static void sc16is7xx_set_termios(struct uart_port *port,
 		port->ignore_status_mask |= SC16IS7XX_LSR_BRK_ERROR_MASK;
 
 	/* As above, claim the mutex while accessing the EFR. */
-	mutex_lock(&one->efr_lock);
+	mutex_lock(&s->efr_lock);
 
 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
 			     SC16IS7XX_LCR_CONF_MODE_B);
 
 	/* Configure flow control */
-	regcache_cache_bypass(one->regmap, true);
+	regcache_cache_bypass(s->regmap, true);
 	sc16is7xx_port_write(port, SC16IS7XX_XON1_REG, termios->c_cc[VSTART]);
 	sc16is7xx_port_write(port, SC16IS7XX_XOFF1_REG, termios->c_cc[VSTOP]);
 
@@ -1082,12 +1110,12 @@ static void sc16is7xx_set_termios(struct uart_port *port,
 			      SC16IS7XX_EFR_REG,
 			      SC16IS7XX_EFR_FLOWCTRL_BITS,
 			      flow);
-	regcache_cache_bypass(one->regmap, false);
+	regcache_cache_bypass(s->regmap, false);
 
 	/* Update LCR register */
 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
 
-	mutex_unlock(&one->efr_lock);
+	mutex_unlock(&s->efr_lock);
 
 	/* Get baud rate generator configuration */
 	baud = uart_get_baud_rate(port, termios, old,
@@ -1133,6 +1161,7 @@ static int sc16is7xx_config_rs485(struct uart_port *port, struct ktermios *termi
 static int sc16is7xx_startup(struct uart_port *port)
 {
 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
 	unsigned int val;
 	unsigned long flags;
 
@@ -1149,7 +1178,7 @@ static int sc16is7xx_startup(struct uart_port *port)
 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
 			     SC16IS7XX_LCR_CONF_MODE_B);
 
-	regcache_cache_bypass(one->regmap, true);
+	regcache_cache_bypass(s->regmap, true);
 
 	/* Enable write access to enhanced features and internal clock div */
 	sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
@@ -1167,7 +1196,7 @@ static int sc16is7xx_startup(struct uart_port *port)
 			     SC16IS7XX_TCR_RX_RESUME(24) |
 			     SC16IS7XX_TCR_RX_HALT(48));
 
-	regcache_cache_bypass(one->regmap, false);
+	regcache_cache_bypass(s->regmap, false);
 
 	/* Now, initialize the UART */
 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_WORD_LEN_8);
@@ -1395,8 +1424,7 @@ static int sc16is7xx_setup_gpio_chip(struct sc16is7xx_port *s)
 /*
  * Configure ports designated to operate as modem control lines.
  */
-static int sc16is7xx_setup_mctrl_ports(struct sc16is7xx_port *s,
-				       struct regmap *regmap)
+static int sc16is7xx_setup_mctrl_ports(struct sc16is7xx_port *s)
 {
 	int i;
 	int ret;
@@ -1425,8 +1453,8 @@ static int sc16is7xx_setup_mctrl_ports(struct sc16is7xx_port *s,
 
 	if (s->mctrl_mask)
 		regmap_update_bits(
-			regmap,
-			SC16IS7XX_IOCONTROL_REG,
+			s->regmap,
+			SC16IS7XX_IOCONTROL_REG << SC16IS7XX_REG_SHIFT,
 			SC16IS7XX_IOCONTROL_MODEM_A_BIT |
 			SC16IS7XX_IOCONTROL_MODEM_B_BIT, s->mctrl_mask);
 
@@ -1441,7 +1469,7 @@ static const struct serial_rs485 sc16is7xx_rs485_supported = {
 
 static int sc16is7xx_probe(struct device *dev,
 			   const struct sc16is7xx_devtype *devtype,
-			   struct regmap *regmaps[], int irq)
+			   struct regmap *regmap, int irq)
 {
 	unsigned long freq = 0, *pfreq = dev_get_platdata(dev);
 	unsigned int val;
@@ -1449,20 +1477,16 @@ static int sc16is7xx_probe(struct device *dev,
 	int i, ret;
 	struct sc16is7xx_port *s;
 
-	for (i = 0; i < devtype->nr_uart; i++)
-		if (IS_ERR(regmaps[i]))
-			return PTR_ERR(regmaps[i]);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
 
 	/*
 	 * This device does not have an identification register that would
 	 * tell us if we are really connected to the correct device.
 	 * The best we can do is to check if communication is at all possible.
-	 *
-	 * Note: regmap[0] is used in the probe function to access registers
-	 * common to all channels/ports, as it is guaranteed to be present on
-	 * all variants.
 	 */
-	ret = regmap_read(regmaps[0], SC16IS7XX_LSR_REG, &val);
+	ret = regmap_read(regmap,
+			  SC16IS7XX_LSR_REG << SC16IS7XX_REG_SHIFT, &val);
 	if (ret < 0)
 		return -EPROBE_DEFER;
 
@@ -1496,8 +1520,10 @@ static int sc16is7xx_probe(struct device *dev,
 			return -EINVAL;
 	}
 
+	s->regmap = regmap;
 	s->devtype = devtype;
 	dev_set_drvdata(dev, s);
+	mutex_init(&s->efr_lock);
 
 	kthread_init_worker(&s->kworker);
 	s->kworker_task = kthread_run(kthread_worker_fn, &s->kworker,
@@ -1509,17 +1535,11 @@ static int sc16is7xx_probe(struct device *dev,
 	sched_set_fifo(s->kworker_task);
 
 	/* reset device, purging any pending irq / data */
-	regmap_write(regmaps[0], SC16IS7XX_IOCONTROL_REG,
-		     SC16IS7XX_IOCONTROL_SRESET_BIT);
+	regmap_write(s->regmap, SC16IS7XX_IOCONTROL_REG << SC16IS7XX_REG_SHIFT,
+			SC16IS7XX_IOCONTROL_SRESET_BIT);
 
 	for (i = 0; i < devtype->nr_uart; ++i) {
-		s->p[i].port.line = find_first_zero_bit(&sc16is7xx_lines,
-							SC16IS7XX_MAX_DEVS);
-		if (s->p[i].port.line >= SC16IS7XX_MAX_DEVS) {
-			ret = -ERANGE;
-			goto out_ports;
-		}
-
+		s->p[i].line		= i;
 		/* Initialize port data */
 		s->p[i].port.dev	= dev;
 		s->p[i].port.irq	= irq;
@@ -1539,9 +1559,16 @@ static int sc16is7xx_probe(struct device *dev,
 		s->p[i].port.rs485_supported = sc16is7xx_rs485_supported;
 		s->p[i].port.ops	= &sc16is7xx_ops;
 		s->p[i].old_mctrl	= 0;
-		s->p[i].regmap		= regmaps[i];
+		s->p[i].port.line	= sc16is7xx_alloc_line();
+
+		if (s->p[i].port.line >= SC16IS7XX_MAX_DEVS) {
+			ret = -ENOMEM;
+			goto out_ports;
+		}
 
-		mutex_init(&s->p[i].efr_lock);
+		ret = uart_get_rs485_mode(&s->p[i].port);
+		if (ret)
+			goto out_ports;
 
 		/* Disable all interrupts */
 		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_IER_REG, 0);
@@ -1554,25 +1581,20 @@ static int sc16is7xx_probe(struct device *dev,
 		kthread_init_work(&s->p[i].tx_work, sc16is7xx_tx_proc);
 		kthread_init_work(&s->p[i].reg_work, sc16is7xx_reg_proc);
 		kthread_init_delayed_work(&s->p[i].ms_work, sc16is7xx_ms_proc);
-
 		/* Register port */
-		ret = uart_add_one_port(&sc16is7xx_uart, &s->p[i].port);
-		if (ret)
-			goto out_ports;
-
-		set_bit(s->p[i].port.line, &sc16is7xx_lines);
+		uart_add_one_port(&sc16is7xx_uart, &s->p[i].port);
 
 		/* Enable EFR */
 		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_LCR_REG,
 				     SC16IS7XX_LCR_CONF_MODE_B);
 
-		regcache_cache_bypass(regmaps[i], true);
+		regcache_cache_bypass(s->regmap, true);
 
 		/* Enable write access to enhanced features */
 		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFR_REG,
 				     SC16IS7XX_EFR_ENABLE_BIT);
 
-		regcache_cache_bypass(regmaps[i], false);
+		regcache_cache_bypass(s->regmap, false);
 
 		/* Restore access to general registers */
 		sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_LCR_REG, 0x00);
@@ -1592,7 +1614,7 @@ static int sc16is7xx_probe(struct device *dev,
 				s->p[u].irda_mode = true;
 	}
 
-	ret = sc16is7xx_setup_mctrl_ports(s, regmaps[0]);
+	ret = sc16is7xx_setup_mctrl_ports(s);
 	if (ret)
 		goto out_ports;
 
@@ -1627,9 +1649,10 @@ static int sc16is7xx_probe(struct device *dev,
 #endif
 
 out_ports:
-	for (i = 0; i < devtype->nr_uart; i++)
-		if (test_and_clear_bit(s->p[i].port.line, &sc16is7xx_lines))
-			uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
+	for (i--; i >= 0; i--) {
+		uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
+		clear_bit(s->p[i].port.line, &sc16is7xx_lines);
+	}
 
 	kthread_stop(s->kworker_task);
 
@@ -1651,8 +1674,8 @@ static void sc16is7xx_remove(struct device *dev)
 
 	for (i = 0; i < s->devtype->nr_uart; i++) {
 		kthread_cancel_delayed_work_sync(&s->p[i].ms_work);
-		if (test_and_clear_bit(s->p[i].port.line, &sc16is7xx_lines))
-			uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
+		uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
+		clear_bit(s->p[i].port.line, &sc16is7xx_lines);
 		sc16is7xx_power(&s->p[i].port, 0);
 	}
 
@@ -1674,52 +1697,26 @@ static const struct of_device_id __maybe_unused sc16is7xx_dt_ids[] = {
 MODULE_DEVICE_TABLE(of, sc16is7xx_dt_ids);
 
 static struct regmap_config regcfg = {
-	.reg_bits = 5,
-	.pad_bits = 3,
+	.reg_bits = 7,
+	.pad_bits = 1,
 	.val_bits = 8,
 	.cache_type = REGCACHE_RBTREE,
 	.volatile_reg = sc16is7xx_regmap_volatile,
 	.precious_reg = sc16is7xx_regmap_precious,
-	.writeable_noinc_reg = sc16is7xx_regmap_noinc,
-	.readable_noinc_reg = sc16is7xx_regmap_noinc,
-	.max_raw_read = SC16IS7XX_FIFO_SIZE,
-	.max_raw_write = SC16IS7XX_FIFO_SIZE,
-	.max_register = SC16IS7XX_EFCR_REG,
 };
 
-static const char *sc16is7xx_regmap_name(u8 port_id)
-{
-	switch (port_id) {
-	case 0:	return "port0";
-	case 1:	return "port1";
-	default:
-		WARN_ON(true);
-		return NULL;
-	}
-}
-
-static unsigned int sc16is7xx_regmap_port_mask(unsigned int port_id)
-{
-	/* CH1,CH0 are at bits 2:1. */
-	return port_id << 1;
-}
-
 #ifdef CONFIG_SERIAL_SC16IS7XX_SPI
 static int sc16is7xx_spi_probe(struct spi_device *spi)
 {
 	const struct sc16is7xx_devtype *devtype;
-	struct regmap *regmaps[2];
-	unsigned int i;
+	struct regmap *regmap;
 	int ret;
 
 	/* Setup SPI bus */
 	spi->bits_per_word	= 8;
-	/* For all variants, only mode 0 is supported */
-	if ((spi->mode & SPI_MODE_X_MASK) != SPI_MODE_0)
-		return dev_err_probe(&spi->dev, -EINVAL, "Unsupported SPI mode\n");
-
+	/* only supports mode 0 on SC16IS762 */
 	spi->mode		= spi->mode ? : SPI_MODE_0;
-	spi->max_speed_hz	= spi->max_speed_hz ? : 4 * HZ_PER_MHZ;
+	spi->max_speed_hz	= spi->max_speed_hz ? : 15000000;
 	ret = spi_setup(spi);
 	if (ret)
 		return ret;
@@ -1734,20 +1731,11 @@ static int sc16is7xx_spi_probe(struct spi_device *spi)
 		devtype = (struct sc16is7xx_devtype *)id_entry->driver_data;
 	}
 
-	for (i = 0; i < devtype->nr_uart; i++) {
-		regcfg.name = sc16is7xx_regmap_name(i);
-		/*
-		 * If read_flag_mask is 0, the regmap code sets it to a default
-		 * of 0x80. Since we specify our own mask, we must add the READ
-		 * bit ourselves:
-		 */
-		regcfg.read_flag_mask = sc16is7xx_regmap_port_mask(i) |
-			SC16IS7XX_SPI_READ_BIT;
-		regcfg.write_flag_mask = sc16is7xx_regmap_port_mask(i);
-		regmaps[i] = devm_regmap_init_spi(spi, &regcfg);
-	}
+	regcfg.max_register = (0xf << SC16IS7XX_REG_SHIFT) |
+			      (devtype->nr_uart - 1);
+	regmap = devm_regmap_init_spi(spi, &regcfg);
 
-	return sc16is7xx_probe(&spi->dev, devtype, regmaps, spi->irq);
+	return sc16is7xx_probe(&spi->dev, devtype, regmap, spi->irq);
 }
 
 static void sc16is7xx_spi_remove(struct spi_device *spi)
@@ -1786,8 +1774,7 @@ static int sc16is7xx_i2c_probe(struct i2c_client *i2c)
 {
 	const struct i2c_device_id *id = i2c_client_get_device_id(i2c);
 	const struct sc16is7xx_devtype *devtype;
-	struct regmap *regmaps[2];
-	unsigned int i;
+	struct regmap *regmap;
 
 	if (i2c->dev.of_node) {
 		devtype = device_get_match_data(&i2c->dev);
@@ -1797,14 +1784,11 @@ static int sc16is7xx_i2c_probe(struct i2c_client *i2c)
 		devtype = (struct sc16is7xx_devtype *)id->driver_data;
 	}
 
-	for (i = 0; i < devtype->nr_uart; i++) {
-		regcfg.name = sc16is7xx_regmap_name(i);
-		regcfg.read_flag_mask = sc16is7xx_regmap_port_mask(i);
-		regcfg.write_flag_mask = sc16is7xx_regmap_port_mask(i);
-		regmaps[i] = devm_regmap_init_i2c(i2c, &regcfg);
-	}
+	regcfg.max_register = (0xf << SC16IS7XX_REG_SHIFT) |
+			      (devtype->nr_uart - 1);
+	regmap = devm_regmap_init_i2c(i2c, &regcfg);
 
-	return sc16is7xx_probe(&i2c->dev, devtype, regmaps, i2c->irq);
+	return sc16is7xx_probe(&i2c->dev, devtype, regmap, i2c->irq);
 }
 
 static void sc16is7xx_i2c_remove(struct i2c_client *client)
diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
index d4ec943cb8e9..6d4006b41975 100644
--- a/drivers/tty/serial/serial-tegra.c
+++ b/drivers/tty/serial/serial-tegra.c
@@ -411,7 +411,7 @@ static int tegra_set_baudrate(struct tegra_uart_port *tup, unsigned int baud)
 		divisor = DIV_ROUND_CLOSEST(rate, baud * 16);
 	}
 
-	spin_lock_irqsave(&tup->uport.lock, flags);
+	uart_port_lock_irqsave(&tup->uport, &flags);
 	lcr = tup->lcr_shadow;
 	lcr |= UART_LCR_DLAB;
 	tegra_uart_write(tup, lcr, UART_LCR);
@@ -424,7 +424,7 @@ static int tegra_set_baudrate(struct tegra_uart_port *tup, unsigned int baud)
 
 	/* Dummy read to ensure the write is posted */
 	tegra_uart_read(tup, UART_SCR);
-	spin_unlock_irqrestore(&tup->uport.lock, flags);
+	uart_port_unlock_irqrestore(&tup->uport, flags);
 
 	tup->current_baud = baud;
 
@@ -522,13 +522,13 @@ static void tegra_uart_tx_dma_complete(void *args)
 	dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state);
 	count = tup->tx_bytes_requested - state.residue;
 	async_tx_ack(tup->tx_dma_desc);
-	spin_lock_irqsave(&tup->uport.lock, flags);
+	uart_port_lock_irqsave(&tup->uport, &flags);
 	uart_xmit_advance(&tup->uport, count);
 	tup->tx_in_progress = 0;
 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 		uart_write_wakeup(&tup->uport);
 	tegra_uart_start_next_tx(tup);
-	spin_unlock_irqrestore(&tup->uport.lock, flags);
+	uart_port_unlock_irqrestore(&tup->uport, flags);
 }
 
 static int tegra_uart_start_tx_dma(struct tegra_uart_port *tup,
@@ -598,13 +598,13 @@ static unsigned int tegra_uart_tx_empty(struct uart_port *u)
 	unsigned int ret = 0;
 	unsigned long flags;
 
-	spin_lock_irqsave(&u->lock, flags);
+	uart_port_lock_irqsave(u, &flags);
 	if (!tup->tx_in_progress) {
 		unsigned long lsr = tegra_uart_read(tup, UART_LSR);
 		if ((lsr & TX_EMPTY_STATUS) == TX_EMPTY_STATUS)
 			ret = TIOCSER_TEMT;
 	}
-	spin_unlock_irqrestore(&u->lock, flags);
+	uart_port_unlock_irqrestore(u, flags);
 	return ret;
 }
 
@@ -727,7 +727,7 @@ static void tegra_uart_rx_dma_complete(void *args)
 	struct dma_tx_state state;
 	enum dma_status status;
 
-	spin_lock_irqsave(&u->lock, flags);
+	uart_port_lock_irqsave(u, &flags);
 
 	status = dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state);
 
@@ -749,7 +749,7 @@ static void tegra_uart_rx_dma_complete(void *args)
 		set_rts(tup, true);
 
 done:
-	spin_unlock_irqrestore(&u->lock, flags);
+	uart_port_unlock_irqrestore(u, flags);
 }
 
 static void tegra_uart_terminate_rx_dma(struct tegra_uart_port *tup)
@@ -836,7 +836,7 @@ static irqreturn_t tegra_uart_isr(int irq, void *data)
 	bool is_rx_int = false;
 	unsigned long flags;
 
-	spin_lock_irqsave(&u->lock, flags);
+	uart_port_lock_irqsave(u, &flags);
 	while (1) {
 		iir = tegra_uart_read(tup, UART_IIR);
 		if (iir & UART_IIR_NO_INT) {
@@ -852,7 +852,7 @@ static irqreturn_t tegra_uart_isr(int irq, void *data)
 			} else if (is_rx_start) {
 				tegra_uart_start_rx_dma(tup);
 			}
-			spin_unlock_irqrestore(&u->lock, flags);
+			uart_port_unlock_irqrestore(u, flags);
 			return IRQ_HANDLED;
 		}
 
@@ -969,11 +969,11 @@ static void tegra_uart_hw_deinit(struct tegra_uart_port *tup)
 		}
 	}
 
-	spin_lock_irqsave(&tup->uport.lock, flags);
+	uart_port_lock_irqsave(&tup->uport, &flags);
 	/* Reset the Rx and Tx FIFOs */
 	tegra_uart_fifo_reset(tup, UART_FCR_CLEAR_XMIT | UART_FCR_CLEAR_RCVR);
 	tup->current_baud = 0;
-	spin_unlock_irqrestore(&tup->uport.lock, flags);
+	uart_port_unlock_irqrestore(&tup->uport, flags);
 
 	tup->rx_in_progress = 0;
 	tup->tx_in_progress = 0;
@@ -1292,7 +1292,7 @@ static void tegra_uart_set_termios(struct uart_port *u,
 	int ret;
 
 	max_divider *= 16;
-	spin_lock_irqsave(&u->lock, flags);
+	uart_port_lock_irqsave(u, &flags);
 
 	/* Changing configuration, it is safe to stop any rx now */
 	if (tup->rts_active)
@@ -1341,7 +1341,7 @@ static void tegra_uart_set_termios(struct uart_port *u,
 	baud = uart_get_baud_rate(u, termios, oldtermios,
 			parent_clk_rate/max_divider,
 			parent_clk_rate/16);
-	spin_unlock_irqrestore(&u->lock, flags);
+	uart_port_unlock_irqrestore(u, flags);
 	ret = tegra_set_baudrate(tup, baud);
 	if (ret < 0) {
 		dev_err(tup->uport.dev, "Failed to set baud rate\n");
@@ -1349,7 +1349,7 @@ static void tegra_uart_set_termios(struct uart_port *u,
 	}
 	if (tty_termios_baud_rate(termios))
 		tty_termios_encode_baud_rate(termios, baud, baud);
-	spin_lock_irqsave(&u->lock, flags);
+	uart_port_lock_irqsave(u, &flags);
 
 	/* Flow control */
 	if (termios->c_cflag & CRTSCTS)	{
@@ -1382,7 +1382,7 @@ static void tegra_uart_set_termios(struct uart_port *u,
 	if (termios->c_iflag & IGNBRK)
 		tup->uport.ignore_status_mask |= UART_LSR_BI;
 
-	spin_unlock_irqrestore(&u->lock, flags);
+	uart_port_unlock_irqrestore(u, flags);
 }
 
 static const char *tegra_uart_type(struct uart_port *u)
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 95a5bef81959..e38ebe899cf0 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -79,7 +79,7 @@ static inline void uart_port_deref(struct uart_port *uport)
 	({								\
 		struct uart_port *__uport = uart_port_ref(state);	\
 		if (__uport)						\
-			spin_lock_irqsave(&__uport->lock, flags);	\
+			uart_port_lock_irqsave(__uport, &flags);	\
 		__uport;						\
 	})
 
@@ -87,7 +87,7 @@ static inline void uart_port_deref(struct uart_port *uport)
 	({								\
 		struct uart_port *__uport = uport;			\
 		if (__uport) {						\
-			spin_unlock_irqrestore(&__uport->lock, flags);	\
+			uart_port_unlock_irqrestore(__uport, flags);	\
 			uart_port_deref(__uport);			\
 		}							\
 	})
@@ -133,9 +133,8 @@ static void uart_stop(struct tty_struct *tty)
 	uart_port_unlock(port, flags);
 }
 
-static void __uart_start(struct tty_struct *tty)
+static void __uart_start(struct uart_state *state)
 {
-	struct uart_state *state = tty->driver_data;
 	struct uart_port *port = state->uart_port;
 	struct serial_port_device *port_dev;
 	int err;
@@ -170,7 +169,7 @@ static void uart_start(struct tty_struct *tty)
 	unsigned long flags;
 
 	port = uart_port_lock(state, flags);
-	__uart_start(tty);
+	__uart_start(state);
 	uart_port_unlock(port, flags);
 }
 
@@ -180,12 +179,12 @@ uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
 	unsigned long flags;
 	unsigned int old;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	old = port->mctrl;
 	port->mctrl = (old & ~clear) | set;
 	if (old != port->mctrl && !(port->rs485.flags & SER_RS485_ENABLED))
 		port->ops->set_mctrl(port, port->mctrl);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 #define uart_set_mctrl(port, set)	uart_update_mctrl(port, set, 0)
@@ -220,7 +219,7 @@ static void uart_change_line_settings(struct tty_struct *tty, struct uart_state
 	/*
 	 * Set modem status enables based on termios cflag
 	 */
-	spin_lock_irq(&uport->lock);
+	uart_port_lock_irq(uport);
 	if (termios->c_cflag & CRTSCTS)
 		uport->status |= UPSTAT_CTS_ENABLE;
 	else
@@ -239,9 +238,9 @@ static void uart_change_line_settings(struct tty_struct *tty, struct uart_state
 		if (!old_hw_stopped)
 			uport->ops->stop_tx(uport);
 		else
-			__uart_start(tty);
+			__uart_start(state);
 	}
-	spin_unlock_irq(&uport->lock);
+	uart_port_unlock_irq(uport);
 }
 
 /*
@@ -552,7 +551,7 @@ uart_get_divisor(struct uart_port *port, unsigned int baud)
 }
 EXPORT_SYMBOL(uart_get_divisor);
 
-static int uart_put_char(struct tty_struct *tty, unsigned char c)
+static int uart_put_char(struct tty_struct *tty, u8 c)
 {
 	struct uart_state *state = tty->driver_data;
 	struct uart_port *port;
@@ -581,8 +580,7 @@ static void uart_flush_chars(struct tty_struct *tty)
 	uart_start(tty);
 }
 
-static int uart_write(struct tty_struct *tty,
-					const unsigned char *buf, int count)
+static int uart_write(struct tty_struct *tty, const unsigned char *buf, int count)
 {
 	struct uart_state *state = tty->driver_data;
 	struct uart_port *port;
@@ -594,10 +592,8 @@ static int uart_write(struct tty_struct *tty,
 	 * This means you called this function _after_ the port was
 	 * closed.  No cookie for you.
 	 */
-	if (!state) {
-		WARN_ON(1);
+	if (WARN_ON(!state))
 		return -EL3HLT;
-	}
 
 	port = uart_port_lock(state, flags);
 	circ = &state->xmit;
@@ -619,7 +615,7 @@ static int uart_write(struct tty_struct *tty,
 		ret += c;
 	}
 
-	__uart_start(tty);
+	__uart_start(state);
 	uart_port_unlock(port, flags);
 	return ret;
 }
@@ -660,10 +656,8 @@ static void uart_flush_buffer(struct tty_struct *tty)
 	 * This means you called this function _after_ the port was
 	 * closed.  No cookie for you.
 	 */
-	if (!state) {
-		WARN_ON(1);
+	if (WARN_ON(!state))
 		return;
-	}
 
 	pr_debug("uart_flush_buffer(%d) called\n", tty->index);
 
@@ -708,11 +702,11 @@ static void uart_send_xchar(struct tty_struct *tty, char ch)
 	if (port->ops->send_xchar)
 		port->ops->send_xchar(port, ch);
 	else {
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 		port->x_char = ch;
 		if (ch)
 			port->ops->start_tx(port);
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 	}
 	uart_port_deref(port);
 }
@@ -1091,9 +1085,9 @@ static int uart_tiocmget(struct tty_struct *tty)
 
 	if (!tty_io_error(tty)) {
 		result = uport->mctrl;
-		spin_lock_irq(&uport->lock);
+		uart_port_lock_irq(uport);
 		result |= uport->ops->get_mctrl(uport);
-		spin_unlock_irq(&uport->lock);
+		uart_port_unlock_irq(uport);
 	}
 out:
 	mutex_unlock(&port->mutex);
@@ -1229,16 +1223,16 @@ static int uart_wait_modem_status(struct uart_state *state, unsigned long arg)
 	uport = uart_port_ref(state);
 	if (!uport)
 		return -EIO;
-	spin_lock_irq(&uport->lock);
+	uart_port_lock_irq(uport);
 	memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
 	uart_enable_ms(uport);
-	spin_unlock_irq(&uport->lock);
+	uart_port_unlock_irq(uport);
 
 	add_wait_queue(&port->delta_msr_wait, &wait);
 	for (;;) {
-		spin_lock_irq(&uport->lock);
+		uart_port_lock_irq(uport);
 		memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
-		spin_unlock_irq(&uport->lock);
+		uart_port_unlock_irq(uport);
 
 		set_current_state(TASK_INTERRUPTIBLE);
 
@@ -1283,9 +1277,9 @@ static int uart_get_icount(struct tty_struct *tty,
 	uport = uart_port_ref(state);
 	if (!uport)
 		return -EIO;
-	spin_lock_irq(&uport->lock);
+	uart_port_lock_irq(uport);
 	memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
-	spin_unlock_irq(&uport->lock);
+	uart_port_unlock_irq(uport);
 	uart_port_deref(uport);
 
 	icount->cts         = cnow.cts;
@@ -1438,9 +1432,9 @@ static int uart_rs485_config(struct uart_port *port)
 	uart_set_rs485_termination(port, rs485);
 	uart_set_rs485_rx_during_tx(port, rs485);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	ret = port->rs485_config(port, NULL, rs485);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 	if (ret) {
 		memset(rs485, 0, sizeof(*rs485));
 		/* unset GPIOs */
@@ -1457,9 +1451,9 @@ static int uart_get_rs485_config(struct uart_port *port,
 	unsigned long flags;
 	struct serial_rs485 aux;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	aux = port->rs485;
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	if (copy_to_user(rs485, &aux, sizeof(aux)))
 		return -EFAULT;
@@ -1487,7 +1481,7 @@ static int uart_set_rs485_config(struct tty_struct *tty, struct uart_port *port,
 	uart_set_rs485_termination(port, &rs485);
 	uart_set_rs485_rx_during_tx(port, &rs485);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	ret = port->rs485_config(port, &tty->termios, &rs485);
 	if (!ret) {
 		port->rs485 = rs485;
@@ -1496,7 +1490,7 @@ static int uart_set_rs485_config(struct tty_struct *tty, struct uart_port *port,
 		if (!(rs485.flags & SER_RS485_ENABLED))
 			port->ops->set_mctrl(port, port->mctrl);
 	}
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 	if (ret) {
 		/* restore old GPIO settings */
 		gpiod_set_value_cansleep(port->rs485_term_gpio,
@@ -1521,9 +1515,9 @@ static int uart_get_iso7816_config(struct uart_port *port,
 	if (!port->iso7816_config)
 		return -ENOTTY;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	aux = port->iso7816;
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	if (copy_to_user(iso7816, &aux, sizeof(aux)))
 		return -EFAULT;
@@ -1552,9 +1546,9 @@ static int uart_set_iso7816_config(struct uart_port *port,
 		if (iso7816.reserved[i])
 			return -EINVAL;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	ret = port->iso7816_config(port, &iso7816);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 	if (ret)
 		return ret;
 
@@ -1771,9 +1765,9 @@ static void uart_tty_port_shutdown(struct tty_port *port)
 	if (WARN(!uport, "detached port still initialized!\n"))
 		return;
 
-	spin_lock_irq(&uport->lock);
+	uart_port_lock_irq(uport);
 	uport->ops->stop_rx(uport);
-	spin_unlock_irq(&uport->lock);
+	uart_port_unlock_irq(uport);
 
 	uart_port_shutdown(port);
 
@@ -1787,10 +1781,10 @@ static void uart_tty_port_shutdown(struct tty_port *port)
 	/*
 	 * Free the transmit buffer.
 	 */
-	spin_lock_irq(&uport->lock);
+	uart_port_lock_irq(uport);
 	buf = state->xmit.buf;
 	state->xmit.buf = NULL;
-	spin_unlock_irq(&uport->lock);
+	uart_port_unlock_irq(uport);
 
 	free_page((unsigned long)buf);
 
@@ -1933,10 +1927,10 @@ static bool uart_carrier_raised(struct tty_port *port)
 	 */
 	if (WARN_ON(!uport))
 		return true;
-	spin_lock_irq(&uport->lock);
+	uart_port_lock_irq(uport);
 	uart_enable_ms(uport);
 	mctrl = uport->ops->get_mctrl(uport);
-	spin_unlock_irq(&uport->lock);
+	uart_port_unlock_irq(uport);
 	uart_port_deref(uport);
 
 	return mctrl & TIOCM_CAR;
@@ -2053,9 +2047,9 @@ static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
 		pm_state = state->pm_state;
 		if (pm_state != UART_PM_STATE_ON)
 			uart_change_pm(state, UART_PM_STATE_ON);
-		spin_lock_irq(&uport->lock);
+		uart_port_lock_irq(uport);
 		status = uport->ops->get_mctrl(uport);
-		spin_unlock_irq(&uport->lock);
+		uart_port_unlock_irq(uport);
 		if (pm_state != UART_PM_STATE_ON)
 			uart_change_pm(state, pm_state);
 
@@ -2394,9 +2388,9 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
 	 */
 	if (!console_suspend_enabled && uart_console(uport)) {
 		if (uport->ops->start_rx) {
-			spin_lock_irq(&uport->lock);
+			uart_port_lock_irq(uport);
 			uport->ops->stop_rx(uport);
-			spin_unlock_irq(&uport->lock);
+			uart_port_unlock_irq(uport);
 		}
 		goto unlock;
 	}
@@ -2411,7 +2405,7 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
 		tty_port_set_suspended(port, true);
 		tty_port_set_initialized(port, false);
 
-		spin_lock_irq(&uport->lock);
+		uart_port_lock_irq(uport);
 		ops->stop_tx(uport);
 		if (!(uport->rs485.flags & SER_RS485_ENABLED))
 			ops->set_mctrl(uport, 0);
@@ -2419,7 +2413,7 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
 		mctrl = uport->mctrl;
 		uport->mctrl = 0;
 		ops->stop_rx(uport);
-		spin_unlock_irq(&uport->lock);
+		uart_port_unlock_irq(uport);
 
 		/*
 		 * Wait for the transmitter to empty.
@@ -2491,9 +2485,9 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
 			uart_change_pm(state, UART_PM_STATE_ON);
 		uport->ops->set_termios(uport, &termios, NULL);
 		if (!console_suspend_enabled && uport->ops->start_rx) {
-			spin_lock_irq(&uport->lock);
+			uart_port_lock_irq(uport);
 			uport->ops->start_rx(uport);
-			spin_unlock_irq(&uport->lock);
+			uart_port_unlock_irq(uport);
 		}
 		if (console_suspend_enabled)
 			console_start(uport->cons);
@@ -2504,10 +2498,10 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
 		int ret;
 
 		uart_change_pm(state, UART_PM_STATE_ON);
-		spin_lock_irq(&uport->lock);
+		uart_port_lock_irq(uport);
 		if (!(uport->rs485.flags & SER_RS485_ENABLED))
 			ops->set_mctrl(uport, 0);
-		spin_unlock_irq(&uport->lock);
+		uart_port_unlock_irq(uport);
 		if (console_suspend_enabled || !uart_console(uport)) {
 			/* Protected by port mutex for now */
 			struct tty_struct *tty = port->tty;
@@ -2517,11 +2511,11 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
 				if (tty)
 					uart_change_line_settings(tty, state, NULL);
 				uart_rs485_config(uport);
-				spin_lock_irq(&uport->lock);
+				uart_port_lock_irq(uport);
 				if (!(uport->rs485.flags & SER_RS485_ENABLED))
 					ops->set_mctrl(uport, uport->mctrl);
 				ops->start_tx(uport);
-				spin_unlock_irq(&uport->lock);
+				uart_port_unlock_irq(uport);
 				tty_port_set_initialized(port, true);
 			} else {
 				/*
@@ -2624,11 +2618,11 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
 		 * keep the DTR setting that is set in uart_set_options()
 		 * We probably don't need a spinlock around this, but
 		 */
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 		port->mctrl &= TIOCM_DTR;
 		if (!(port->rs485.flags & SER_RS485_ENABLED))
 			port->ops->set_mctrl(port, port->mctrl);
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 
 		uart_rs485_config(port);
 
@@ -3521,7 +3515,7 @@ EXPORT_SYMBOL_GPL(uart_handle_cts_change);
  * @flag: flag for the character (see TTY_NORMAL and friends)
  */
 void uart_insert_char(struct uart_port *port, unsigned int status,
-		 unsigned int overrun, unsigned int ch, unsigned int flag)
+		      unsigned int overrun, u8 ch, u8 flag)
 {
 	struct tty_port *tport = &port->state->port;
 
diff --git a/drivers/tty/serial/serial_mctrl_gpio.c b/drivers/tty/serial/serial_mctrl_gpio.c
index 7d5aaa8d422b..e51ca593ab86 100644
--- a/drivers/tty/serial/serial_mctrl_gpio.c
+++ b/drivers/tty/serial/serial_mctrl_gpio.c
@@ -184,7 +184,7 @@ static irqreturn_t mctrl_gpio_irq_handle(int irq, void *context)
 
 	mctrl_gpio_get(gpios, &mctrl);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	mctrl_diff = mctrl ^ gpios->mctrl_prev;
 	gpios->mctrl_prev = mctrl;
@@ -205,7 +205,7 @@ static irqreturn_t mctrl_gpio_irq_handle(int irq, void *context)
 		wake_up_interruptible(&port->state->port.delta_msr_wait);
 	}
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return IRQ_HANDLED;
 }
diff --git a/drivers/tty/serial/serial_port.c b/drivers/tty/serial/serial_port.c
index 862423237007..88975a4df306 100644
--- a/drivers/tty/serial/serial_port.c
+++ b/drivers/tty/serial/serial_port.c
@@ -35,10 +35,10 @@ static int serial_port_runtime_resume(struct device *dev)
 		goto out;
 
 	/* Flush any pending TX for the port */
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	if (__serial_port_busy(port))
 		port->ops->start_tx(port);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 out:
 	pm_runtime_mark_last_busy(dev);
diff --git a/drivers/tty/serial/serial_txx9.c b/drivers/tty/serial/serial_txx9.c
index be08fb6f749c..eaa980722455 100644
--- a/drivers/tty/serial/serial_txx9.c
+++ b/drivers/tty/serial/serial_txx9.c
@@ -335,13 +335,13 @@ static irqreturn_t serial_txx9_interrupt(int irq, void *dev_id)
 	unsigned int status;
 
 	while (1) {
-		spin_lock(&up->lock);
+		uart_port_lock(up);
 		status = sio_in(up, TXX9_SIDISR);
 		if (!(sio_in(up, TXX9_SIDICR) & TXX9_SIDICR_TIE))
 			status &= ~TXX9_SIDISR_TDIS;
 		if (!(status & (TXX9_SIDISR_TDIS | TXX9_SIDISR_RDIS |
 				TXX9_SIDISR_TOUT))) {
-			spin_unlock(&up->lock);
+			uart_port_unlock(up);
 			break;
 		}
 
@@ -353,7 +353,7 @@ static irqreturn_t serial_txx9_interrupt(int irq, void *dev_id)
 		sio_mask(up, TXX9_SIDISR,
 			 TXX9_SIDISR_TDIS | TXX9_SIDISR_RDIS |
 			 TXX9_SIDISR_TOUT);
-		spin_unlock(&up->lock);
+		uart_port_unlock(up);
 
 		if (pass_counter++ > PASS_LIMIT)
 			break;
@@ -367,9 +367,9 @@ static unsigned int serial_txx9_tx_empty(struct uart_port *up)
 	unsigned long flags;
 	unsigned int ret;
 
-	spin_lock_irqsave(&up->lock, flags);
+	uart_port_lock_irqsave(up, &flags);
 	ret = (sio_in(up, TXX9_SICISR) & TXX9_SICISR_TXALS) ? TIOCSER_TEMT : 0;
-	spin_unlock_irqrestore(&up->lock, flags);
+	uart_port_unlock_irqrestore(up, flags);
 
 	return ret;
 }
@@ -399,12 +399,12 @@ static void serial_txx9_break_ctl(struct uart_port *up, int break_state)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&up->lock, flags);
+	uart_port_lock_irqsave(up, &flags);
 	if (break_state == -1)
 		sio_set(up, TXX9_SIFLCR, TXX9_SIFLCR_TBRK);
 	else
 		sio_mask(up, TXX9_SIFLCR, TXX9_SIFLCR_TBRK);
-	spin_unlock_irqrestore(&up->lock, flags);
+	uart_port_unlock_irqrestore(up, flags);
 }
 
 #if defined(CONFIG_SERIAL_TXX9_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
@@ -517,9 +517,9 @@ static int serial_txx9_startup(struct uart_port *up)
 	/*
 	 * Now, initialize the UART
 	 */
-	spin_lock_irqsave(&up->lock, flags);
+	uart_port_lock_irqsave(up, &flags);
 	serial_txx9_set_mctrl(up, up->mctrl);
-	spin_unlock_irqrestore(&up->lock, flags);
+	uart_port_unlock_irqrestore(up, flags);
 
 	/* Enable RX/TX */
 	sio_mask(up, TXX9_SIFLCR, TXX9_SIFLCR_RSDE | TXX9_SIFLCR_TSDE);
@@ -541,9 +541,9 @@ static void serial_txx9_shutdown(struct uart_port *up)
 	 */
 	sio_out(up, TXX9_SIDICR, 0);	/* disable all intrs */
 
-	spin_lock_irqsave(&up->lock, flags);
+	uart_port_lock_irqsave(up, &flags);
 	serial_txx9_set_mctrl(up, up->mctrl);
-	spin_unlock_irqrestore(&up->lock, flags);
+	uart_port_unlock_irqrestore(up, flags);
 
 	/*
 	 * Disable break condition
@@ -625,7 +625,7 @@ serial_txx9_set_termios(struct uart_port *up, struct ktermios *termios,
 	 * Ok, we're now changing the port state.  Do it with
 	 * interrupts disabled.
 	 */
-	spin_lock_irqsave(&up->lock, flags);
+	uart_port_lock_irqsave(up, &flags);
 
 	/*
 	 * Update the per-port timeout.
@@ -676,7 +676,7 @@ serial_txx9_set_termios(struct uart_port *up, struct ktermios *termios,
 	sio_out(up, TXX9_SIFCR, fcr);
 
 	serial_txx9_set_mctrl(up, up->mctrl);
-	spin_unlock_irqrestore(&up->lock, flags);
+	uart_port_unlock_irqrestore(up, flags);
 }
 
 static void
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index a560b729fa3b..84ab434c94ba 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1205,7 +1205,7 @@ static void sci_dma_tx_complete(void *arg)
 
 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	uart_xmit_advance(port, s->tx_dma_len);
 
@@ -1229,7 +1229,7 @@ static void sci_dma_tx_complete(void *arg)
 		}
 	}
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 /* Locking: called with port lock held */
@@ -1320,7 +1320,7 @@ static void sci_dma_rx_complete(void *arg)
 	dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
 		s->active_rx);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	active = sci_dma_rx_find_active(s);
 	if (active >= 0)
@@ -1347,20 +1347,20 @@ static void sci_dma_rx_complete(void *arg)
 
 	dma_async_issue_pending(chan);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 	dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
 		__func__, s->cookie_rx[active], active, s->active_rx);
 	return;
 
 fail:
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 	dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
 	/* Switch to PIO */
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	dmaengine_terminate_async(chan);
 	sci_dma_rx_chan_invalidate(s);
 	sci_dma_rx_reenable_irq(s);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void sci_dma_tx_release(struct sci_port *s)
@@ -1409,13 +1409,13 @@ static int sci_dma_rx_submit(struct sci_port *s, bool port_lock_held)
 fail:
 	/* Switch to PIO */
 	if (!port_lock_held)
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 	if (i)
 		dmaengine_terminate_async(chan);
 	sci_dma_rx_chan_invalidate(s);
 	sci_start_rx(port);
 	if (!port_lock_held)
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 	return -EAGAIN;
 }
 
@@ -1437,14 +1437,14 @@ static void sci_dma_tx_work_fn(struct work_struct *work)
 	 * transmit till the end, and then the rest. Take the port lock to get a
 	 * consistent xmit buffer state.
 	 */
-	spin_lock_irq(&port->lock);
+	uart_port_lock_irq(port);
 	head = xmit->head;
 	tail = xmit->tail;
 	buf = s->tx_dma_addr + tail;
 	s->tx_dma_len = CIRC_CNT_TO_END(head, tail, UART_XMIT_SIZE);
 	if (!s->tx_dma_len) {
 		/* Transmit buffer has been flushed */
-		spin_unlock_irq(&port->lock);
+		uart_port_unlock_irq(port);
 		return;
 	}
 
@@ -1452,7 +1452,7 @@ static void sci_dma_tx_work_fn(struct work_struct *work)
 					   DMA_MEM_TO_DEV,
 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 	if (!desc) {
-		spin_unlock_irq(&port->lock);
+		uart_port_unlock_irq(port);
 		dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
 		goto switch_to_pio;
 	}
@@ -1464,12 +1464,12 @@ static void sci_dma_tx_work_fn(struct work_struct *work)
 	desc->callback_param = s;
 	s->cookie_tx = dmaengine_submit(desc);
 	if (dma_submit_error(s->cookie_tx)) {
-		spin_unlock_irq(&port->lock);
+		uart_port_unlock_irq(port);
 		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
 		goto switch_to_pio;
 	}
 
-	spin_unlock_irq(&port->lock);
+	uart_port_unlock_irq(port);
 	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
 		__func__, xmit->buf, tail, head, s->cookie_tx);
 
@@ -1477,10 +1477,10 @@ static void sci_dma_tx_work_fn(struct work_struct *work)
 	return;
 
 switch_to_pio:
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	s->chan_tx = NULL;
 	sci_start_tx(port);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 	return;
 }
 
@@ -1497,17 +1497,17 @@ static enum hrtimer_restart sci_dma_rx_timer_fn(struct hrtimer *t)
 
 	dev_dbg(port->dev, "DMA Rx timed out\n");
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	active = sci_dma_rx_find_active(s);
 	if (active < 0) {
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 		return HRTIMER_NORESTART;
 	}
 
 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
 	if (status == DMA_COMPLETE) {
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 		dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
 			s->active_rx, active);
 
@@ -1525,7 +1525,7 @@ static enum hrtimer_restart sci_dma_rx_timer_fn(struct hrtimer *t)
 	 */
 	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
 	if (status == DMA_COMPLETE) {
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 		dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
 		return HRTIMER_NORESTART;
 	}
@@ -1546,7 +1546,7 @@ static enum hrtimer_restart sci_dma_rx_timer_fn(struct hrtimer *t)
 
 	sci_dma_rx_reenable_irq(s);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return HRTIMER_NORESTART;
 }
@@ -1770,9 +1770,9 @@ static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
 	struct uart_port *port = ptr;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	sci_transmit_chars(port);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return IRQ_HANDLED;
 }
@@ -1786,11 +1786,11 @@ static irqreturn_t sci_tx_end_interrupt(int irq, void *ptr)
 	if (port->type != PORT_SCI)
 		return sci_tx_interrupt(irq, ptr);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	ctrl = serial_port_in(port, SCSCR);
 	ctrl &= ~(SCSCR_TE | SCSCR_TEIE);
 	serial_port_out(port, SCSCR, ctrl);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return IRQ_HANDLED;
 }
@@ -2187,7 +2187,7 @@ static void sci_break_ctl(struct uart_port *port, int break_state)
 		return;
 	}
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	scsptr = serial_port_in(port, SCSPTR);
 	scscr = serial_port_in(port, SCSCR);
 
@@ -2201,7 +2201,7 @@ static void sci_break_ctl(struct uart_port *port, int break_state)
 
 	serial_port_out(port, SCSPTR, scsptr);
 	serial_port_out(port, SCSCR, scscr);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static int sci_startup(struct uart_port *port)
@@ -2233,7 +2233,7 @@ static void sci_shutdown(struct uart_port *port)
 	s->autorts = false;
 	mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	sci_stop_rx(port);
 	sci_stop_tx(port);
 	/*
@@ -2243,7 +2243,7 @@ static void sci_shutdown(struct uart_port *port)
 	scr = serial_port_in(port, SCSCR);
 	serial_port_out(port, SCSCR, scr &
 			(SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot));
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 #ifdef CONFIG_SERIAL_SH_SCI_DMA
 	if (s->chan_rx_saved) {
@@ -2545,7 +2545,7 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
 		serial_port_out(port, SCCKS, sccks);
 	}
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	sci_reset(port);
 
@@ -2667,7 +2667,7 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
 	if ((termios->c_cflag & CREAD) != 0)
 		sci_start_rx(port);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	sci_port_disable(s);
 
@@ -3052,9 +3052,9 @@ static void serial_console_write(struct console *co, const char *s,
 	if (port->sysrq)
 		locked = 0;
 	else if (oops_in_progress)
-		locked = spin_trylock_irqsave(&port->lock, flags);
+		locked = uart_port_trylock_irqsave(port, &flags);
 	else
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 
 	/* first save SCSCR then disable interrupts, keep clock source */
 	ctrl = serial_port_in(port, SCSCR);
@@ -3074,7 +3074,7 @@ static void serial_console_write(struct console *co, const char *s,
 	serial_port_out(port, SCSCR, ctrl);
 
 	if (locked)
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 }
 
 static int serial_console_setup(struct console *co, char *options)
diff --git a/drivers/tty/serial/sifive.c b/drivers/tty/serial/sifive.c
index d195c5de52e7..b296e57a9dee 100644
--- a/drivers/tty/serial/sifive.c
+++ b/drivers/tty/serial/sifive.c
@@ -521,11 +521,11 @@ static irqreturn_t sifive_serial_irq(int irq, void *dev_id)
 	struct sifive_serial_port *ssp = dev_id;
 	u32 ip;
 
-	spin_lock(&ssp->port.lock);
+	uart_port_lock(&ssp->port);
 
 	ip = __ssp_readl(ssp, SIFIVE_SERIAL_IP_OFFS);
 	if (!ip) {
-		spin_unlock(&ssp->port.lock);
+		uart_port_unlock(&ssp->port);
 		return IRQ_NONE;
 	}
 
@@ -534,7 +534,7 @@ static irqreturn_t sifive_serial_irq(int irq, void *dev_id)
 	if (ip & SIFIVE_SERIAL_IP_TXWM_MASK)
 		__ssp_transmit_chars(ssp);
 
-	spin_unlock(&ssp->port.lock);
+	uart_port_unlock(&ssp->port);
 
 	return IRQ_HANDLED;
 }
@@ -653,7 +653,7 @@ static void sifive_serial_set_termios(struct uart_port *port,
 				  ssp->port.uartclk / 16);
 	__ssp_update_baud_rate(ssp, rate);
 
-	spin_lock_irqsave(&ssp->port.lock, flags);
+	uart_port_lock_irqsave(&ssp->port, &flags);
 
 	/* Update the per-port timeout */
 	uart_update_timeout(port, termios->c_cflag, rate);
@@ -670,7 +670,7 @@ static void sifive_serial_set_termios(struct uart_port *port,
 	if (v != old_v)
 		__ssp_writel(v, SIFIVE_SERIAL_RXCTRL_OFFS, ssp);
 
-	spin_unlock_irqrestore(&ssp->port.lock, flags);
+	uart_port_unlock_irqrestore(&ssp->port, flags);
 }
 
 static void sifive_serial_release_port(struct uart_port *port)
@@ -795,9 +795,9 @@ static void sifive_serial_console_write(struct console *co, const char *s,
 	if (ssp->port.sysrq)
 		locked = 0;
 	else if (oops_in_progress)
-		locked = spin_trylock(&ssp->port.lock);
+		locked = uart_port_trylock(&ssp->port);
 	else
-		spin_lock(&ssp->port.lock);
+		uart_port_lock(&ssp->port);
 
 	ier = __ssp_readl(ssp, SIFIVE_SERIAL_IE_OFFS);
 	__ssp_writel(0, SIFIVE_SERIAL_IE_OFFS, ssp);
@@ -807,7 +807,7 @@ static void sifive_serial_console_write(struct console *co, const char *s,
 	__ssp_writel(ier, SIFIVE_SERIAL_IE_OFFS, ssp);
 
 	if (locked)
-		spin_unlock(&ssp->port.lock);
+		uart_port_unlock(&ssp->port);
 	local_irq_restore(flags);
 }
 
diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c
index f328fa57231f..f257525f9299 100644
--- a/drivers/tty/serial/sprd_serial.c
+++ b/drivers/tty/serial/sprd_serial.c
@@ -247,7 +247,7 @@ static void sprd_complete_tx_dma(void *data)
 	struct circ_buf *xmit = &port->state->xmit;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	dma_unmap_single(port->dev, sp->tx_dma.phys_addr,
 			 sp->tx_dma.trans_len, DMA_TO_DEVICE);
 
@@ -260,7 +260,7 @@ static void sprd_complete_tx_dma(void *data)
 	    sprd_tx_dma_config(port))
 		sp->tx_dma.trans_len = 0;
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static int sprd_uart_dma_submit(struct uart_port *port,
@@ -429,13 +429,13 @@ static void sprd_complete_rx_dma(void *data)
 	enum dma_status status;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	status = dmaengine_tx_status(sp->rx_dma.chn,
 				     sp->rx_dma.cookie, &state);
 	if (status != DMA_COMPLETE) {
 		sprd_stop_rx(port);
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 		return;
 	}
 
@@ -449,7 +449,7 @@ static void sprd_complete_rx_dma(void *data)
 	if (sprd_start_dma_rx(port))
 		sprd_stop_rx(port);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static int sprd_start_dma_rx(struct uart_port *port)
@@ -638,12 +638,12 @@ static irqreturn_t sprd_handle_irq(int irq, void *dev_id)
 	struct uart_port *port = dev_id;
 	unsigned int ims;
 
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 
 	ims = serial_in(port, SPRD_IMSR);
 
 	if (!ims) {
-		spin_unlock(&port->lock);
+		uart_port_unlock(port);
 		return IRQ_NONE;
 	}
 
@@ -660,7 +660,7 @@ static irqreturn_t sprd_handle_irq(int irq, void *dev_id)
 	if (ims & SPRD_IMSR_TX_FIFO_EMPTY)
 		sprd_tx(port);
 
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 
 	return IRQ_HANDLED;
 }
@@ -727,13 +727,13 @@ static int sprd_startup(struct uart_port *port)
 	serial_out(port, SPRD_CTL1, fc);
 
 	/* enable interrupt */
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	ien = serial_in(port, SPRD_IEN);
 	ien |= SPRD_IEN_BREAK_DETECT | SPRD_IEN_TIMEOUT;
 	if (!sp->rx_dma.enable)
 		ien |= SPRD_IEN_RX_FULL;
 	serial_out(port, SPRD_IEN, ien);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return 0;
 }
@@ -793,7 +793,7 @@ static void sprd_set_termios(struct uart_port *port, struct ktermios *termios,
 			lcr |= SPRD_LCR_EVEN_PAR;
 	}
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* update the per-port timeout */
 	uart_update_timeout(port, termios->c_cflag, baud);
@@ -837,7 +837,7 @@ static void sprd_set_termios(struct uart_port *port, struct ktermios *termios,
 	fc |= RX_TOUT_THLD_DEF | RX_HFC_THLD_DEF;
 	serial_out(port, SPRD_CTL1, fc);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	/* Don't rewrite B0 */
 	if (tty_termios_baud_rate(termios))
@@ -974,9 +974,9 @@ static void sprd_console_write(struct console *co, const char *s,
 	if (port->sysrq)
 		locked = 0;
 	else if (oops_in_progress)
-		locked = spin_trylock_irqsave(&port->lock, flags);
+		locked = uart_port_trylock_irqsave(port, &flags);
 	else
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 
 	uart_console_write(port, s, count, sprd_console_putchar);
 
@@ -984,7 +984,7 @@ static void sprd_console_write(struct console *co, const char *s,
 	wait_for_xmitr(port);
 
 	if (locked)
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 }
 
 static int sprd_console_setup(struct console *co, char *options)
diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
index 941695e0c79f..a821f5d76a26 100644
--- a/drivers/tty/serial/st-asc.c
+++ b/drivers/tty/serial/st-asc.c
@@ -319,7 +319,7 @@ static irqreturn_t asc_interrupt(int irq, void *ptr)
 	struct uart_port *port = ptr;
 	u32 status;
 
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 
 	status = asc_in(port, ASC_STA);
 
@@ -334,7 +334,7 @@ static irqreturn_t asc_interrupt(int irq, void *ptr)
 		asc_transmit_chars(port);
 	}
 
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 
 	return IRQ_HANDLED;
 }
@@ -452,10 +452,10 @@ static void asc_pm(struct uart_port *port, unsigned int state,
 		 * we can come to turning it off. Note this is not called with
 		 * the port spinlock held.
 		 */
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 		ctl = asc_in(port, ASC_CTL) & ~ASC_CTL_RUN;
 		asc_out(port, ASC_CTL, ctl);
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 		clk_disable_unprepare(ascport->clk);
 		break;
 	}
@@ -480,7 +480,7 @@ static void asc_set_termios(struct uart_port *port, struct ktermios *termios,
 	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
 	cflag = termios->c_cflag;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* read control register */
 	ctrl_val = asc_in(port, ASC_CTL);
@@ -594,7 +594,7 @@ static void asc_set_termios(struct uart_port *port, struct ktermios *termios,
 	/* write final value and enable port */
 	asc_out(port, ASC_CTL, (ctrl_val | ASC_CTL_RUN));
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static const char *asc_type(struct uart_port *port)
@@ -703,7 +703,9 @@ static int asc_init_port(struct asc_port *ascport,
 	if (WARN_ON(IS_ERR(ascport->clk)))
 		return -EINVAL;
 	/* ensure that clk rate is correct by enabling the clk */
-	clk_prepare_enable(ascport->clk);
+	ret = clk_prepare_enable(ascport->clk);
+	if (ret)
+		return ret;
 	ascport->port.uartclk = clk_get_rate(ascport->clk);
 	WARN_ON(ascport->port.uartclk == 0);
 	clk_disable_unprepare(ascport->clk);
@@ -753,7 +755,7 @@ static struct asc_port *asc_of_get_asc_port(struct platform_device *pdev)
 
 	asc_ports[id].hw_flow_control = of_property_read_bool(np,
 							"uart-has-rtscts");
-	asc_ports[id].force_m1 =  of_property_read_bool(np, "st,force_m1");
+	asc_ports[id].force_m1 =  of_property_read_bool(np, "st,force-m1");
 	asc_ports[id].port.line = id;
 	asc_ports[id].rts = NULL;
 
@@ -847,9 +849,9 @@ static void asc_console_write(struct console *co, const char *s, unsigned count)
 	if (port->sysrq)
 		locked = 0; /* asc_interrupt has already claimed the lock */
 	else if (oops_in_progress)
-		locked = spin_trylock_irqsave(&port->lock, flags);
+		locked = uart_port_trylock_irqsave(port, &flags);
 	else
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 
 	/*
 	 * Disable interrupts so we don't get the IRQ line bouncing
@@ -867,7 +869,7 @@ static void asc_console_write(struct console *co, const char *s, unsigned count)
 	asc_out(port, ASC_INTEN, intenable);
 
 	if (locked)
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 }
 
 static int asc_console_setup(struct console *co, char *options)
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index e5f933beb6c0..f0901bedcc28 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -251,9 +251,7 @@ static int stm32_usart_config_rs485(struct uart_port *port, struct ktermios *ter
 		writel_relaxed(cr3, port->membase + ofs->cr3);
 		writel_relaxed(cr1, port->membase + ofs->cr1);
 
-		if (!port->rs485_rx_during_tx_gpio)
-			rs485conf->flags |= SER_RS485_RX_DURING_TX;
-
+		rs485conf->flags |= SER_RS485_RX_DURING_TX;
 	} else {
 		stm32_usart_clr_bits(port, ofs->cr3,
 				     USART_CR3_DEM | USART_CR3_DEP);
@@ -535,7 +533,7 @@ static void stm32_usart_rx_dma_complete(void *arg)
 	unsigned int size;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	size = stm32_usart_receive_chars(port, false);
 	uart_unlock_and_check_sysrq_irqrestore(port, flags);
 	if (size)
@@ -641,9 +639,9 @@ static void stm32_usart_tx_dma_complete(void *arg)
 	stm32_usart_tx_dma_terminate(stm32port);
 
 	/* Let's see if we have pending data to send */
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	stm32_usart_transmit_chars(port);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void stm32_usart_tx_interrupt_enable(struct uart_port *port)
@@ -887,7 +885,7 @@ static irqreturn_t stm32_usart_interrupt(int irq, void *ptr)
 	if (!stm32_port->throttled) {
 		if (((sr & USART_SR_RXNE) && !stm32_usart_rx_dma_started(stm32_port)) ||
 		    ((sr & USART_SR_ERR_MASK) && stm32_usart_rx_dma_started(stm32_port))) {
-			spin_lock(&port->lock);
+			uart_port_lock(port);
 			size = stm32_usart_receive_chars(port, false);
 			uart_unlock_and_check_sysrq(port);
 			if (size)
@@ -896,14 +894,14 @@ static irqreturn_t stm32_usart_interrupt(int irq, void *ptr)
 	}
 
 	if ((sr & USART_SR_TXE) && !(stm32_port->tx_ch)) {
-		spin_lock(&port->lock);
+		uart_port_lock(port);
 		stm32_usart_transmit_chars(port);
-		spin_unlock(&port->lock);
+		uart_port_unlock(port);
 	}
 
 	/* Receiver timeout irq for DMA RX */
 	if (stm32_usart_rx_dma_started(stm32_port) && !stm32_port->throttled) {
-		spin_lock(&port->lock);
+		uart_port_lock(port);
 		size = stm32_usart_receive_chars(port, false);
 		uart_unlock_and_check_sysrq(port);
 		if (size)
@@ -991,7 +989,7 @@ static void stm32_usart_throttle(struct uart_port *port)
 	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/*
 	 * Pause DMA transfer, so the RX data gets queued into the FIFO.
@@ -1004,7 +1002,7 @@ static void stm32_usart_throttle(struct uart_port *port)
 		stm32_usart_clr_bits(port, ofs->cr3, stm32_port->cr3_irq);
 
 	stm32_port->throttled = true;
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 /* Unthrottle the remote, the input buffer can now accept data. */
@@ -1014,7 +1012,7 @@ static void stm32_usart_unthrottle(struct uart_port *port)
 	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	stm32_usart_set_bits(port, ofs->cr1, stm32_port->cr1_irq);
 	if (stm32_port->cr3_irq)
 		stm32_usart_set_bits(port, ofs->cr3, stm32_port->cr3_irq);
@@ -1028,7 +1026,7 @@ static void stm32_usart_unthrottle(struct uart_port *port)
 	if (stm32_port->rx_ch)
 		stm32_usart_rx_dma_start_or_resume(port);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 /* Receive stop */
@@ -1156,7 +1154,7 @@ static void stm32_usart_set_termios(struct uart_port *port,
 
 	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 8);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	ret = readl_relaxed_poll_timeout_atomic(port->membase + ofs->isr,
 						isr,
@@ -1347,7 +1345,7 @@ static void stm32_usart_set_termios(struct uart_port *port,
 	writel_relaxed(cr1, port->membase + ofs->cr1);
 
 	stm32_usart_set_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	/* Handle modem control interrupts */
 	if (UART_ENABLE_MS(port, termios->c_cflag))
@@ -1397,9 +1395,9 @@ static void stm32_usart_pm(struct uart_port *port, unsigned int state,
 		pm_runtime_get_sync(port->dev);
 		break;
 	case UART_PM_STATE_OFF:
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 		stm32_usart_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 		pm_runtime_put_sync(port->dev);
 		break;
 	}
@@ -1882,9 +1880,9 @@ static void stm32_usart_console_write(struct console *co, const char *s,
 	int locked = 1;
 
 	if (oops_in_progress)
-		locked = spin_trylock_irqsave(&port->lock, flags);
+		locked = uart_port_trylock_irqsave(port, &flags);
 	else
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 
 	/* Save and disable interrupts, enable the transmitter */
 	old_cr1 = readl_relaxed(port->membase + ofs->cr1);
@@ -1898,7 +1896,7 @@ static void stm32_usart_console_write(struct console *co, const char *s,
 	writel_relaxed(old_cr1, port->membase + ofs->cr1);
 
 	if (locked)
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 }
 
 static int stm32_usart_console_setup(struct console *co, char *options)
@@ -2033,7 +2031,7 @@ static int __maybe_unused stm32_usart_serial_en_wakeup(struct uart_port *port,
 		 * low-power mode.
 		 */
 		if (stm32_port->rx_ch) {
-			spin_lock_irqsave(&port->lock, flags);
+			uart_port_lock_irqsave(port, &flags);
 			/* Poll data from DMA RX buffer if any */
 			if (!stm32_usart_rx_dma_pause(stm32_port))
 				size += stm32_usart_receive_chars(port, true);
diff --git a/drivers/tty/serial/sunhv.c b/drivers/tty/serial/sunhv.c
index c671d674bce4..5bfc0040f17b 100644
--- a/drivers/tty/serial/sunhv.c
+++ b/drivers/tty/serial/sunhv.c
@@ -217,10 +217,10 @@ static irqreturn_t sunhv_interrupt(int irq, void *dev_id)
 	struct tty_port *tport;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	tport = receive_chars(port);
 	transmit_chars(port);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	if (tport)
 		tty_flip_buffer_push(tport);
@@ -271,7 +271,7 @@ static void sunhv_send_xchar(struct uart_port *port, char ch)
 	if (ch == __DISABLED_CHAR)
 		return;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	while (limit-- > 0) {
 		long status = sun4v_con_putchar(ch);
@@ -280,7 +280,7 @@ static void sunhv_send_xchar(struct uart_port *port, char ch)
 		udelay(1);
 	}
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 /* port->lock held by caller.  */
@@ -295,7 +295,7 @@ static void sunhv_break_ctl(struct uart_port *port, int break_state)
 		unsigned long flags;
 		int limit = 10000;
 
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 
 		while (limit-- > 0) {
 			long status = sun4v_con_putchar(CON_BREAK);
@@ -304,7 +304,7 @@ static void sunhv_break_ctl(struct uart_port *port, int break_state)
 			udelay(1);
 		}
 
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 	}
 }
 
@@ -328,7 +328,7 @@ static void sunhv_set_termios(struct uart_port *port, struct ktermios *termios,
 	unsigned int iflag, cflag;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	iflag = termios->c_iflag;
 	cflag = termios->c_cflag;
@@ -343,7 +343,7 @@ static void sunhv_set_termios(struct uart_port *port, struct ktermios *termios,
 	uart_update_timeout(port, cflag,
 			    (port->uartclk / (16 * quot)));
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static const char *sunhv_type(struct uart_port *port)
@@ -437,9 +437,9 @@ static void sunhv_console_write_paged(struct console *con, const char *s, unsign
 	int locked = 1;
 
 	if (port->sysrq || oops_in_progress)
-		locked = spin_trylock_irqsave(&port->lock, flags);
+		locked = uart_port_trylock_irqsave(port, &flags);
 	else
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 
 	while (n > 0) {
 		unsigned long ra = __pa(con_write_page);
@@ -470,7 +470,7 @@ static void sunhv_console_write_paged(struct console *con, const char *s, unsign
 	}
 
 	if (locked)
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 }
 
 static inline void sunhv_console_putchar(struct uart_port *port, char c)
@@ -492,9 +492,9 @@ static void sunhv_console_write_bychar(struct console *con, const char *s, unsig
 	int i, locked = 1;
 
 	if (port->sysrq || oops_in_progress)
-		locked = spin_trylock_irqsave(&port->lock, flags);
+		locked = uart_port_trylock_irqsave(port, &flags);
 	else
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 
 	for (i = 0; i < n; i++) {
 		if (*s == '\n')
@@ -503,7 +503,7 @@ static void sunhv_console_write_bychar(struct console *con, const char *s, unsig
 	}
 
 	if (locked)
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 }
 
 static struct console sunhv_console = {
diff --git a/drivers/tty/serial/sunplus-uart.c b/drivers/tty/serial/sunplus-uart.c
index 3aacd5eb414c..4251f4e1ba99 100644
--- a/drivers/tty/serial/sunplus-uart.c
+++ b/drivers/tty/serial/sunplus-uart.c
@@ -184,7 +184,7 @@ static void sunplus_break_ctl(struct uart_port *port, int ctl)
 	unsigned long flags;
 	unsigned int lcr;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	lcr = readl(port->membase + SUP_UART_LCR);
 
@@ -195,7 +195,7 @@ static void sunplus_break_ctl(struct uart_port *port, int ctl)
 
 	writel(lcr, port->membase + SUP_UART_LCR);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void transmit_chars(struct uart_port *port)
@@ -277,7 +277,7 @@ static irqreturn_t sunplus_uart_irq(int irq, void *args)
 	struct uart_port *port = args;
 	unsigned int isc;
 
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 
 	isc = readl(port->membase + SUP_UART_ISC);
 
@@ -287,7 +287,7 @@ static irqreturn_t sunplus_uart_irq(int irq, void *args)
 	if (isc & SUP_UART_ISC_TX)
 		transmit_chars(port);
 
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 
 	return IRQ_HANDLED;
 }
@@ -302,14 +302,14 @@ static int sunplus_startup(struct uart_port *port)
 	if (ret)
 		return ret;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	/* isc define Bit[7:4] int setting, Bit[3:0] int status
 	 * isc register will clean Bit[3:0] int status after read
 	 * only do a write to Bit[7:4] int setting
 	 */
 	isc |= SUP_UART_ISC_RXM;
 	writel(isc, port->membase + SUP_UART_ISC);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return 0;
 }
@@ -318,13 +318,13 @@ static void sunplus_shutdown(struct uart_port *port)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	/* isc define Bit[7:4] int setting, Bit[3:0] int status
 	 * isc register will clean Bit[3:0] int status after read
 	 * only do a write to Bit[7:4] int setting
 	 */
 	writel(0, port->membase + SUP_UART_ISC); /* disable all interrupt */
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	free_irq(port->irq, port);
 }
@@ -372,7 +372,7 @@ static void sunplus_set_termios(struct uart_port *port,
 			lcr |= UART_LCR_EPAR;
 	}
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	uart_update_timeout(port, termios->c_cflag, baud);
 
@@ -407,7 +407,7 @@ static void sunplus_set_termios(struct uart_port *port,
 	writel(div_l, port->membase + SUP_UART_DIV_L);
 	writel(lcr, port->membase + SUP_UART_LCR);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void sunplus_set_ldisc(struct uart_port *port, struct ktermios *termios)
@@ -517,15 +517,15 @@ static void sunplus_console_write(struct console *co,
 	if (sunplus_console_ports[co->index]->port.sysrq)
 		locked = 0;
 	else if (oops_in_progress)
-		locked = spin_trylock(&sunplus_console_ports[co->index]->port.lock);
+		locked = uart_port_trylock(&sunplus_console_ports[co->index]->port);
 	else
-		spin_lock(&sunplus_console_ports[co->index]->port.lock);
+		uart_port_lock(&sunplus_console_ports[co->index]->port);
 
 	uart_console_write(&sunplus_console_ports[co->index]->port, s, count,
 			   sunplus_uart_console_putchar);
 
 	if (locked)
-		spin_unlock(&sunplus_console_ports[co->index]->port.lock);
+		uart_port_unlock(&sunplus_console_ports[co->index]->port);
 
 	local_irq_restore(flags);
 }
diff --git a/drivers/tty/serial/sunsab.c b/drivers/tty/serial/sunsab.c
index 40eeaf835bba..6aa51a6f8063 100644
--- a/drivers/tty/serial/sunsab.c
+++ b/drivers/tty/serial/sunsab.c
@@ -310,7 +310,7 @@ static irqreturn_t sunsab_interrupt(int irq, void *dev_id)
 	unsigned long flags;
 	unsigned char gis;
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 
 	status.stat = 0;
 	gis = readb(&up->regs->r.gis) >> up->gis_shift;
@@ -331,7 +331,7 @@ static irqreturn_t sunsab_interrupt(int irq, void *dev_id)
 			transmit_chars(up, &status);
 	}
 
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 
 	if (port)
 		tty_flip_buffer_push(port);
@@ -473,12 +473,12 @@ static void sunsab_send_xchar(struct uart_port *port, char ch)
 	if (ch == __DISABLED_CHAR)
 		return;
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 
 	sunsab_tec_wait(up);
 	writeb(ch, &up->regs->w.tic);
 
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 }
 
 /* port->lock held by caller.  */
@@ -499,7 +499,7 @@ static void sunsab_break_ctl(struct uart_port *port, int break_state)
 	unsigned long flags;
 	unsigned char val;
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 
 	val = up->cached_dafo;
 	if (break_state)
@@ -512,7 +512,7 @@ static void sunsab_break_ctl(struct uart_port *port, int break_state)
 	if (test_bit(SAB82532_XPR, &up->irqflags))
 		sunsab_tx_idle(up);
 
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 }
 
 /* port->lock is not held.  */
@@ -527,7 +527,7 @@ static int sunsab_startup(struct uart_port *port)
 	if (err)
 		return err;
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 
 	/*
 	 * Wait for any commands or immediate characters
@@ -582,7 +582,7 @@ static int sunsab_startup(struct uart_port *port)
 	set_bit(SAB82532_ALLS, &up->irqflags);
 	set_bit(SAB82532_XPR, &up->irqflags);
 
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 
 	return 0;
 }
@@ -594,7 +594,7 @@ static void sunsab_shutdown(struct uart_port *port)
 		container_of(port, struct uart_sunsab_port, port);
 	unsigned long flags;
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 
 	/* Disable Interrupts */
 	up->interrupt_mask0 = 0xff;
@@ -628,7 +628,7 @@ static void sunsab_shutdown(struct uart_port *port)
 	writeb(tmp, &up->regs->rw.ccr0);
 #endif
 
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 	free_irq(up->port.irq, up);
 }
 
@@ -779,9 +779,9 @@ static void sunsab_set_termios(struct uart_port *port, struct ktermios *termios,
 	unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
 	unsigned int quot = uart_get_divisor(port, baud);
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 	sunsab_convert_to_sab(up, termios->c_cflag, termios->c_iflag, baud, quot);
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 }
 
 static const char *sunsab_type(struct uart_port *port)
@@ -857,15 +857,15 @@ static void sunsab_console_write(struct console *con, const char *s, unsigned n)
 	int locked = 1;
 
 	if (up->port.sysrq || oops_in_progress)
-		locked = spin_trylock_irqsave(&up->port.lock, flags);
+		locked = uart_port_trylock_irqsave(&up->port, &flags);
 	else
-		spin_lock_irqsave(&up->port.lock, flags);
+		uart_port_lock_irqsave(&up->port, &flags);
 
 	uart_console_write(&up->port, s, n, sunsab_console_putchar);
 	sunsab_tec_wait(up);
 
 	if (locked)
-		spin_unlock_irqrestore(&up->port.lock, flags);
+		uart_port_unlock_irqrestore(&up->port, flags);
 }
 
 static int sunsab_console_setup(struct console *con, char *options)
@@ -914,7 +914,7 @@ static int sunsab_console_setup(struct console *con, char *options)
 	 */
 	sunsab_startup(&up->port);
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 
 	/*
 	 * Finally, enable interrupts
@@ -932,7 +932,7 @@ static int sunsab_console_setup(struct console *con, char *options)
 	sunsab_convert_to_sab(up, con->cflag, 0, baud, quot);
 	sunsab_set_mctrl(&up->port, TIOCM_DTR | TIOCM_RTS);
 
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 	
 	return 0;
 }
diff --git a/drivers/tty/serial/sunsu.c b/drivers/tty/serial/sunsu.c
index 58a4342ad0f9..1e051cc2591c 100644
--- a/drivers/tty/serial/sunsu.c
+++ b/drivers/tty/serial/sunsu.c
@@ -212,9 +212,9 @@ static void enable_rsa(struct uart_sunsu_port *up)
 {
 	if (up->port.type == PORT_RSA) {
 		if (up->port.uartclk != SERIAL_RSA_BAUD_BASE * 16) {
-			spin_lock_irq(&up->port.lock);
+			uart_port_lock_irq(&up->port);
 			__enable_rsa(up);
-			spin_unlock_irq(&up->port.lock);
+			uart_port_unlock_irq(&up->port);
 		}
 		if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16)
 			serial_outp(up, UART_RSA_FRR, 0);
@@ -234,7 +234,7 @@ static void disable_rsa(struct uart_sunsu_port *up)
 
 	if (up->port.type == PORT_RSA &&
 	    up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) {
-		spin_lock_irq(&up->port.lock);
+		uart_port_lock_irq(&up->port);
 
 		mode = serial_inp(up, UART_RSA_MSR);
 		result = !(mode & UART_RSA_MSR_FIFO);
@@ -247,7 +247,7 @@ static void disable_rsa(struct uart_sunsu_port *up)
 
 		if (result)
 			up->port.uartclk = SERIAL_RSA_BAUD_BASE_LO * 16;
-		spin_unlock_irq(&up->port.lock);
+		uart_port_unlock_irq(&up->port);
 	}
 }
 #endif /* CONFIG_SERIAL_8250_RSA */
@@ -311,10 +311,10 @@ static void sunsu_enable_ms(struct uart_port *port)
 		container_of(port, struct uart_sunsu_port, port);
 	unsigned long flags;
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 	up->ier |= UART_IER_MSI;
 	serial_out(up, UART_IER, up->ier);
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 }
 
 static void
@@ -456,7 +456,7 @@ static irqreturn_t sunsu_serial_interrupt(int irq, void *dev_id)
 	unsigned long flags;
 	unsigned char status;
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 
 	do {
 		status = serial_inp(up, UART_LSR);
@@ -470,7 +470,7 @@ static irqreturn_t sunsu_serial_interrupt(int irq, void *dev_id)
 
 	} while (!(serial_in(up, UART_IIR) & UART_IIR_NO_INT));
 
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 
 	return IRQ_HANDLED;
 }
@@ -545,9 +545,9 @@ static unsigned int sunsu_tx_empty(struct uart_port *port)
 	unsigned long flags;
 	unsigned int ret;
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 
 	return ret;
 }
@@ -599,13 +599,13 @@ static void sunsu_break_ctl(struct uart_port *port, int break_state)
 		container_of(port, struct uart_sunsu_port, port);
 	unsigned long flags;
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 	if (break_state == -1)
 		up->lcr |= UART_LCR_SBC;
 	else
 		up->lcr &= ~UART_LCR_SBC;
 	serial_out(up, UART_LCR, up->lcr);
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 }
 
 static int sunsu_startup(struct uart_port *port)
@@ -683,12 +683,12 @@ static int sunsu_startup(struct uart_port *port)
 	 */
 	serial_outp(up, UART_LCR, UART_LCR_WLEN8);
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 
 	up->port.mctrl |= TIOCM_OUT2;
 
 	sunsu_set_mctrl(&up->port, up->port.mctrl);
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 
 	/*
 	 * Finally, enable interrupts.  Note: Modem status interrupts
@@ -731,7 +731,7 @@ static void sunsu_shutdown(struct uart_port *port)
 	up->ier = 0;
 	serial_outp(up, UART_IER, 0);
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 	if (up->port.flags & UPF_FOURPORT) {
 		/* reset interrupts on the AST Fourport board */
 		inb((up->port.iobase & 0xfe0) | 0x1f);
@@ -740,7 +740,7 @@ static void sunsu_shutdown(struct uart_port *port)
 		up->port.mctrl &= ~TIOCM_OUT2;
 
 	sunsu_set_mctrl(&up->port, up->port.mctrl);
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 
 	/*
 	 * Disable break condition and FIFOs
@@ -826,7 +826,7 @@ sunsu_change_speed(struct uart_port *port, unsigned int cflag,
 	 * Ok, we're now changing the port state.  Do it with
 	 * interrupts disabled.
 	 */
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 
 	/*
 	 * Update the per-port timeout.
@@ -891,7 +891,7 @@ sunsu_change_speed(struct uart_port *port, unsigned int cflag,
 
 	up->cflag = cflag;
 
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 }
 
 static void
@@ -1038,7 +1038,7 @@ static void sunsu_autoconfig(struct uart_sunsu_port *up)
 	up->type_probed = PORT_UNKNOWN;
 	up->port.iotype = UPIO_MEM;
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 
 	if (!(up->port.flags & UPF_BUGGY_UART)) {
 		/*
@@ -1173,7 +1173,7 @@ static void sunsu_autoconfig(struct uart_sunsu_port *up)
 	serial_outp(up, UART_IER, 0);
 
 out:
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 }
 
 static struct uart_driver sunsu_reg = {
@@ -1298,9 +1298,9 @@ static void sunsu_console_write(struct console *co, const char *s,
 	int locked = 1;
 
 	if (up->port.sysrq || oops_in_progress)
-		locked = spin_trylock_irqsave(&up->port.lock, flags);
+		locked = uart_port_trylock_irqsave(&up->port, &flags);
 	else
-		spin_lock_irqsave(&up->port.lock, flags);
+		uart_port_lock_irqsave(&up->port, &flags);
 
 	/*
 	 *	First save the UER then disable the interrupts
@@ -1318,7 +1318,7 @@ static void sunsu_console_write(struct console *co, const char *s,
 	serial_out(up, UART_IER, ier);
 
 	if (locked)
-		spin_unlock_irqrestore(&up->port.lock, flags);
+		uart_port_unlock_irqrestore(&up->port, flags);
 }
 
 /*
diff --git a/drivers/tty/serial/sunzilog.c b/drivers/tty/serial/sunzilog.c
index c8c71c56264c..d3b5e864b727 100644
--- a/drivers/tty/serial/sunzilog.c
+++ b/drivers/tty/serial/sunzilog.c
@@ -531,7 +531,7 @@ static irqreturn_t sunzilog_interrupt(int irq, void *dev_id)
 		struct tty_port *port;
 		unsigned char r3;
 
-		spin_lock(&up->port.lock);
+		uart_port_lock(&up->port);
 		r3 = read_zsreg(channel, R3);
 
 		/* Channel A */
@@ -548,7 +548,7 @@ static irqreturn_t sunzilog_interrupt(int irq, void *dev_id)
 			if (r3 & CHATxIP)
 				sunzilog_transmit_chars(up, channel);
 		}
-		spin_unlock(&up->port.lock);
+		uart_port_unlock(&up->port);
 
 		if (port)
 			tty_flip_buffer_push(port);
@@ -557,7 +557,7 @@ static irqreturn_t sunzilog_interrupt(int irq, void *dev_id)
 		up = up->next;
 		channel = ZILOG_CHANNEL_FROM_PORT(&up->port);
 
-		spin_lock(&up->port.lock);
+		uart_port_lock(&up->port);
 		port = NULL;
 		if (r3 & (CHBEXT | CHBTxIP | CHBRxIP)) {
 			writeb(RES_H_IUS, &channel->control);
@@ -571,7 +571,7 @@ static irqreturn_t sunzilog_interrupt(int irq, void *dev_id)
 			if (r3 & CHBTxIP)
 				sunzilog_transmit_chars(up, channel);
 		}
-		spin_unlock(&up->port.lock);
+		uart_port_unlock(&up->port);
 
 		if (port)
 			tty_flip_buffer_push(port);
@@ -604,11 +604,11 @@ static unsigned int sunzilog_tx_empty(struct uart_port *port)
 	unsigned char status;
 	unsigned int ret;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	status = sunzilog_read_channel_status(port);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	if (status & Tx_BUF_EMP)
 		ret = TIOCSER_TEMT;
@@ -764,7 +764,7 @@ static void sunzilog_break_ctl(struct uart_port *port, int break_state)
 	else
 		clear_bits |= SND_BRK;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	new_reg = (up->curregs[R5] | set_bits) & ~clear_bits;
 	if (new_reg != up->curregs[R5]) {
@@ -774,7 +774,7 @@ static void sunzilog_break_ctl(struct uart_port *port, int break_state)
 		write_zsreg(channel, R5, up->curregs[R5]);
 	}
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static void __sunzilog_startup(struct uart_sunzilog_port *up)
@@ -800,9 +800,9 @@ static int sunzilog_startup(struct uart_port *port)
 	if (ZS_IS_CONS(up))
 		return 0;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	__sunzilog_startup(up);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 	return 0;
 }
 
@@ -840,7 +840,7 @@ static void sunzilog_shutdown(struct uart_port *port)
 	if (ZS_IS_CONS(up))
 		return;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	channel = ZILOG_CHANNEL_FROM_PORT(port);
 
@@ -853,7 +853,7 @@ static void sunzilog_shutdown(struct uart_port *port)
 	up->curregs[R5] &= ~SND_BRK;
 	sunzilog_maybe_update_regs(up, channel);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 /* Shared by TTY driver and serial console setup.  The port lock is held
@@ -945,7 +945,7 @@ sunzilog_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	baud = uart_get_baud_rate(port, termios, old, 1200, 76800);
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 
 	brg = BPS_TO_BRG(baud, ZS_CLOCK / ZS_CLOCK_DIVISOR);
 
@@ -962,7 +962,7 @@ sunzilog_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	uart_update_timeout(port, termios->c_cflag, baud);
 
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 }
 
 static const char *sunzilog_type(struct uart_port *port)
@@ -1201,15 +1201,15 @@ sunzilog_console_write(struct console *con, const char *s, unsigned int count)
 	int locked = 1;
 
 	if (up->port.sysrq || oops_in_progress)
-		locked = spin_trylock_irqsave(&up->port.lock, flags);
+		locked = uart_port_trylock_irqsave(&up->port, &flags);
 	else
-		spin_lock_irqsave(&up->port.lock, flags);
+		uart_port_lock_irqsave(&up->port, &flags);
 
 	uart_console_write(&up->port, s, count, sunzilog_putchar);
 	udelay(2);
 
 	if (locked)
-		spin_unlock_irqrestore(&up->port.lock, flags);
+		uart_port_unlock_irqrestore(&up->port, flags);
 }
 
 static int __init sunzilog_console_setup(struct console *con, char *options)
@@ -1244,7 +1244,7 @@ static int __init sunzilog_console_setup(struct console *con, char *options)
 
 	brg = BPS_TO_BRG(baud, ZS_CLOCK / ZS_CLOCK_DIVISOR);
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 
 	up->curregs[R15] |= BRKIE;
 	sunzilog_convert_to_zs(up, con->cflag, 0, brg);
@@ -1252,7 +1252,7 @@ static int __init sunzilog_console_setup(struct console *con, char *options)
 	sunzilog_set_mctrl(&up->port, TIOCM_DTR | TIOCM_RTS);
 	__sunzilog_startup(up);
 
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 
 	return 0;
 }
@@ -1333,7 +1333,7 @@ static void sunzilog_init_hw(struct uart_sunzilog_port *up)
 
 	channel = ZILOG_CHANNEL_FROM_PORT(&up->port);
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 	if (ZS_IS_CHANNEL_A(up)) {
 		write_zsreg(channel, R9, FHWRES);
 		ZSDELAY_LONG();
@@ -1383,7 +1383,7 @@ static void sunzilog_init_hw(struct uart_sunzilog_port *up)
 		write_zsreg(channel, R9, up->curregs[R9]);
 	}
 
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 
 #ifdef CONFIG_SERIO
 	if (up->flags & (SUNZILOG_FLAG_CONS_KEYB |
diff --git a/drivers/tty/serial/timbuart.c b/drivers/tty/serial/timbuart.c
index 0859394a78cd..0cc6524f5e8b 100644
--- a/drivers/tty/serial/timbuart.c
+++ b/drivers/tty/serial/timbuart.c
@@ -174,7 +174,7 @@ static void timbuart_tasklet(struct tasklet_struct *t)
 	struct timbuart_port *uart = from_tasklet(uart, t, tasklet);
 	u32 isr, ier = 0;
 
-	spin_lock(&uart->port.lock);
+	uart_port_lock(&uart->port);
 
 	isr = ioread32(uart->port.membase + TIMBUART_ISR);
 	dev_dbg(uart->port.dev, "%s ISR: %x\n", __func__, isr);
@@ -189,7 +189,7 @@ static void timbuart_tasklet(struct tasklet_struct *t)
 
 	iowrite32(ier, uart->port.membase + TIMBUART_IER);
 
-	spin_unlock(&uart->port.lock);
+	uart_port_unlock(&uart->port);
 	dev_dbg(uart->port.dev, "%s leaving\n", __func__);
 }
 
@@ -295,10 +295,10 @@ static void timbuart_set_termios(struct uart_port *port,
 		tty_termios_copy_hw(termios, old);
 	tty_termios_encode_baud_rate(termios, baud, baud);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	iowrite8((u8)bindex, port->membase + TIMBUART_BAUDRATE);
 	uart_update_timeout(port, termios->c_cflag, baud);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static const char *timbuart_type(struct uart_port *port)
diff --git a/drivers/tty/serial/uartlite.c b/drivers/tty/serial/uartlite.c
index b225a78f6175..404c14acafa5 100644
--- a/drivers/tty/serial/uartlite.c
+++ b/drivers/tty/serial/uartlite.c
@@ -216,11 +216,11 @@ static irqreturn_t ulite_isr(int irq, void *dev_id)
 	unsigned long flags;
 
 	do {
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 		stat = uart_in32(ULITE_STATUS, port);
 		busy  = ulite_receive(port, stat);
 		busy |= ulite_transmit(port, stat);
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 		n++;
 	} while (busy);
 
@@ -238,9 +238,9 @@ static unsigned int ulite_tx_empty(struct uart_port *port)
 	unsigned long flags;
 	unsigned int ret;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 	ret = uart_in32(ULITE_STATUS, port);
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return ret & ULITE_STATUS_TXEMPTY ? TIOCSER_TEMT : 0;
 }
@@ -323,7 +323,7 @@ static void ulite_set_termios(struct uart_port *port,
 	termios->c_cflag |= pdata->cflags & (PARENB | PARODD | CSIZE);
 	tty_termios_encode_baud_rate(termios, pdata->baud, pdata->baud);
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	port->read_status_mask = ULITE_STATUS_RXVALID | ULITE_STATUS_OVERRUN
 		| ULITE_STATUS_TXFULL;
@@ -346,7 +346,7 @@ static void ulite_set_termios(struct uart_port *port,
 	/* update timeout */
 	uart_update_timeout(port, termios->c_cflag, pdata->baud);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static const char *ulite_type(struct uart_port *port)
@@ -495,9 +495,9 @@ static void ulite_console_write(struct console *co, const char *s,
 	int locked = 1;
 
 	if (oops_in_progress) {
-		locked = spin_trylock_irqsave(&port->lock, flags);
+		locked = uart_port_trylock_irqsave(port, &flags);
 	} else
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 
 	/* save and disable interrupt */
 	ier = uart_in32(ULITE_STATUS, port) & ULITE_STATUS_IE;
@@ -512,7 +512,7 @@ static void ulite_console_write(struct console *co, const char *s,
 		uart_out32(ULITE_CONTROL_IE, ULITE_CONTROL, port);
 
 	if (locked)
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 }
 
 static int ulite_console_setup(struct console *co, char *options)
diff --git a/drivers/tty/serial/ucc_uart.c b/drivers/tty/serial/ucc_uart.c
index 49457be37b3f..ed7a6bb5596a 100644
--- a/drivers/tty/serial/ucc_uart.c
+++ b/drivers/tty/serial/ucc_uart.c
@@ -29,7 +29,6 @@
 #include <linux/of_irq.h>
 #include <linux/dma-mapping.h>
 
-#include <linux/fs_uart_pd.h>
 #include <soc/fsl/qe/ucc_slow.h>
 
 #include <linux/firmware.h>
@@ -932,7 +931,7 @@ static void qe_uart_set_termios(struct uart_port *port,
 	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
 
 	/* Do we really need a spinlock here? */
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* Update the per-port timeout. */
 	uart_update_timeout(port, termios->c_cflag, baud);
@@ -950,7 +949,7 @@ static void qe_uart_set_termios(struct uart_port *port,
 		qe_setbrg(qe_port->us_info.tx_clock, baud, 16);
 	}
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 /*
diff --git a/drivers/tty/serial/vt8500_serial.c b/drivers/tty/serial/vt8500_serial.c
index c5d5c2765119..78a1c1eea11b 100644
--- a/drivers/tty/serial/vt8500_serial.c
+++ b/drivers/tty/serial/vt8500_serial.c
@@ -227,7 +227,7 @@ static irqreturn_t vt8500_irq(int irq, void *dev_id)
 	struct uart_port *port = dev_id;
 	unsigned long isr;
 
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 	isr = vt8500_read(port, VT8500_URISR);
 
 	/* Acknowledge active status bits */
@@ -240,7 +240,7 @@ static irqreturn_t vt8500_irq(int irq, void *dev_id)
 	if (isr & TCTS)
 		handle_delta_cts(port);
 
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 
 	return IRQ_HANDLED;
 }
@@ -342,7 +342,7 @@ static void vt8500_set_termios(struct uart_port *port,
 	unsigned int baud, lcr;
 	unsigned int loops = 1000;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* calculate and set baud rate */
 	baud = uart_get_baud_rate(port, termios, old, 900, 921600);
@@ -410,7 +410,7 @@ static void vt8500_set_termios(struct uart_port *port,
 	vt8500_write(&vt8500_port->uart, 0x881, VT8500_URFCR);
 	vt8500_write(&vt8500_port->uart, vt8500_port->ier, VT8500_URIER);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 static const char *vt8500_type(struct uart_port *port)
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index 2e5e86a00a77..9c13dac1d4d1 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -346,7 +346,7 @@ static irqreturn_t cdns_uart_isr(int irq, void *dev_id)
 	struct uart_port *port = (struct uart_port *)dev_id;
 	unsigned int isrstatus;
 
-	spin_lock(&port->lock);
+	uart_port_lock(port);
 
 	/* Read the interrupt status register to determine which
 	 * interrupt(s) is/are active and clear them.
@@ -369,7 +369,7 @@ static irqreturn_t cdns_uart_isr(int irq, void *dev_id)
 	    !(readl(port->membase + CDNS_UART_CR) & CDNS_UART_CR_RX_DIS))
 		cdns_uart_handle_rx(dev_id, isrstatus);
 
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 	return IRQ_HANDLED;
 }
 
@@ -506,14 +506,14 @@ static int cdns_uart_clk_notifier_cb(struct notifier_block *nb,
 			return NOTIFY_BAD;
 		}
 
-		spin_lock_irqsave(&cdns_uart->port->lock, flags);
+		uart_port_lock_irqsave(cdns_uart->port, &flags);
 
 		/* Disable the TX and RX to set baud rate */
 		ctrl_reg = readl(port->membase + CDNS_UART_CR);
 		ctrl_reg |= CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS;
 		writel(ctrl_reg, port->membase + CDNS_UART_CR);
 
-		spin_unlock_irqrestore(&cdns_uart->port->lock, flags);
+		uart_port_unlock_irqrestore(cdns_uart->port, flags);
 
 		return NOTIFY_OK;
 	}
@@ -523,7 +523,7 @@ static int cdns_uart_clk_notifier_cb(struct notifier_block *nb,
 		 * frequency.
 		 */
 
-		spin_lock_irqsave(&cdns_uart->port->lock, flags);
+		uart_port_lock_irqsave(cdns_uart->port, &flags);
 
 		locked = 1;
 		port->uartclk = ndata->new_rate;
@@ -533,7 +533,7 @@ static int cdns_uart_clk_notifier_cb(struct notifier_block *nb,
 		fallthrough;
 	case ABORT_RATE_CHANGE:
 		if (!locked)
-			spin_lock_irqsave(&cdns_uart->port->lock, flags);
+			uart_port_lock_irqsave(cdns_uart->port, &flags);
 
 		/* Set TX/RX Reset */
 		ctrl_reg = readl(port->membase + CDNS_UART_CR);
@@ -555,7 +555,7 @@ static int cdns_uart_clk_notifier_cb(struct notifier_block *nb,
 		ctrl_reg |= CDNS_UART_CR_TX_EN | CDNS_UART_CR_RX_EN;
 		writel(ctrl_reg, port->membase + CDNS_UART_CR);
 
-		spin_unlock_irqrestore(&cdns_uart->port->lock, flags);
+		uart_port_unlock_irqrestore(cdns_uart->port, flags);
 
 		return NOTIFY_OK;
 	default:
@@ -652,7 +652,7 @@ static void cdns_uart_break_ctl(struct uart_port *port, int ctl)
 	unsigned int status;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	status = readl(port->membase + CDNS_UART_CR);
 
@@ -664,7 +664,7 @@ static void cdns_uart_break_ctl(struct uart_port *port, int ctl)
 			writel(CDNS_UART_CR_STOPBRK | status,
 					port->membase + CDNS_UART_CR);
 	}
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 /**
@@ -683,7 +683,7 @@ static void cdns_uart_set_termios(struct uart_port *port,
 	unsigned long flags;
 	unsigned int ctrl_reg, mode_reg;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* Disable the TX and RX to set baud rate */
 	ctrl_reg = readl(port->membase + CDNS_UART_CR);
@@ -794,7 +794,7 @@ static void cdns_uart_set_termios(struct uart_port *port,
 		cval &= ~CDNS_UART_MODEMCR_FCM;
 	writel(cval, port->membase + CDNS_UART_MODEMCR);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 /**
@@ -813,7 +813,7 @@ static int cdns_uart_startup(struct uart_port *port)
 
 	is_brk_support = cdns_uart->quirks & CDNS_UART_RXBS_SUPPORT;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* Disable the TX and RX */
 	writel(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS,
@@ -861,7 +861,7 @@ static int cdns_uart_startup(struct uart_port *port)
 	writel(readl(port->membase + CDNS_UART_ISR),
 			port->membase + CDNS_UART_ISR);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	ret = request_irq(port->irq, cdns_uart_isr, 0, CDNS_UART_NAME, port);
 	if (ret) {
@@ -889,7 +889,7 @@ static void cdns_uart_shutdown(struct uart_port *port)
 	int status;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* Disable interrupts */
 	status = readl(port->membase + CDNS_UART_IMR);
@@ -900,7 +900,7 @@ static void cdns_uart_shutdown(struct uart_port *port)
 	writel(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS,
 			port->membase + CDNS_UART_CR);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	free_irq(port->irq, port);
 }
@@ -1050,7 +1050,7 @@ static int cdns_uart_poll_get_char(struct uart_port *port)
 	int c;
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* Check if FIFO is empty */
 	if (readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_RXEMPTY)
@@ -1058,7 +1058,7 @@ static int cdns_uart_poll_get_char(struct uart_port *port)
 	else /* Read a character */
 		c = (unsigned char) readl(port->membase + CDNS_UART_FIFO);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return c;
 }
@@ -1067,7 +1067,7 @@ static void cdns_uart_poll_put_char(struct uart_port *port, unsigned char c)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	/* Wait until FIFO is empty */
 	while (!(readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXEMPTY))
@@ -1080,7 +1080,7 @@ static void cdns_uart_poll_put_char(struct uart_port *port, unsigned char c)
 	while (!(readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXEMPTY))
 		cpu_relax();
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 #endif
 
@@ -1232,9 +1232,9 @@ static void cdns_uart_console_write(struct console *co, const char *s,
 	if (port->sysrq)
 		locked = 0;
 	else if (oops_in_progress)
-		locked = spin_trylock_irqsave(&port->lock, flags);
+		locked = uart_port_trylock_irqsave(port, &flags);
 	else
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 
 	/* save and disable interrupt */
 	imr = readl(port->membase + CDNS_UART_IMR);
@@ -1257,7 +1257,7 @@ static void cdns_uart_console_write(struct console *co, const char *s,
 	writel(imr, port->membase + CDNS_UART_IER);
 
 	if (locked)
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 }
 
 /**
@@ -1325,7 +1325,7 @@ static int cdns_uart_suspend(struct device *device)
 	if (console_suspend_enabled && uart_console(port) && may_wake) {
 		unsigned long flags;
 
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 		/* Empty the receive FIFO 1st before making changes */
 		while (!(readl(port->membase + CDNS_UART_SR) &
 					CDNS_UART_SR_RXEMPTY))
@@ -1334,7 +1334,7 @@ static int cdns_uart_suspend(struct device *device)
 		writel(1, port->membase + CDNS_UART_RXWM);
 		/* disable RX timeout interrups */
 		writel(CDNS_UART_IXR_TOUT, port->membase + CDNS_UART_IDR);
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 	}
 
 	/*
@@ -1372,7 +1372,7 @@ static int cdns_uart_resume(struct device *device)
 			return ret;
 		}
 
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 
 		/* Set TX/RX Reset */
 		ctrl_reg = readl(port->membase + CDNS_UART_CR);
@@ -1392,14 +1392,14 @@ static int cdns_uart_resume(struct device *device)
 
 		clk_disable(cdns_uart->uartclk);
 		clk_disable(cdns_uart->pclk);
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 	} else {
-		spin_lock_irqsave(&port->lock, flags);
+		uart_port_lock_irqsave(port, &flags);
 		/* restore original rx trigger level */
 		writel(rx_trigger_level, port->membase + CDNS_UART_RXWM);
 		/* enable RX timeout interrupt */
 		writel(CDNS_UART_IXR_TOUT, port->membase + CDNS_UART_IER);
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 	}
 
 	return uart_resume_port(cdns_uart->cdns_uart_driver, port);
diff --git a/drivers/tty/tty.h b/drivers/tty/tty.h
index db7f3f87772f..50862f98273e 100644
--- a/drivers/tty/tty.h
+++ b/drivers/tty/tty.h
@@ -99,14 +99,15 @@ extern int tty_ldisc_autoload;
 
 /* tty_audit.c */
 #ifdef CONFIG_AUDIT
-void tty_audit_add_data(struct tty_struct *tty, const void *data, size_t size);
-void tty_audit_tiocsti(struct tty_struct *tty, char ch);
+void tty_audit_add_data(const struct tty_struct *tty, const void *data,
+			size_t size);
+void tty_audit_tiocsti(const struct tty_struct *tty, u8 ch);
 #else
-static inline void tty_audit_add_data(struct tty_struct *tty, const void *data,
-				      size_t size)
+static inline void tty_audit_add_data(const struct tty_struct *tty,
+				      const void *data, size_t size)
 {
 }
-static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
+static inline void tty_audit_tiocsti(const struct tty_struct *tty, u8 ch)
 {
 }
 #endif
@@ -114,6 +115,6 @@ static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
 ssize_t redirected_tty_write(struct kiocb *, struct iov_iter *);
 
 int tty_insert_flip_string_and_push_buffer(struct tty_port *port,
-		const unsigned char *chars, size_t cnt);
+					   const u8 *chars, size_t cnt);
 
 #endif
diff --git a/drivers/tty/tty_audit.c b/drivers/tty/tty_audit.c
index 3a50236f7e5e..67dc317161c8 100644
--- a/drivers/tty/tty_audit.c
+++ b/drivers/tty/tty_audit.c
@@ -17,7 +17,7 @@ struct tty_audit_buf {
 	dev_t dev;		/* The TTY which the data is from */
 	bool icanon;
 	size_t valid;
-	unsigned char *data;	/* Allocated size N_TTY_BUF_SIZE */
+	u8 *data;		/* Allocated size N_TTY_BUF_SIZE */
 };
 
 static struct tty_audit_buf *tty_audit_buf_ref(void)
@@ -134,7 +134,7 @@ void tty_audit_fork(struct signal_struct *sig)
 /*
  *	tty_audit_tiocsti	-	Log TIOCSTI
  */
-void tty_audit_tiocsti(struct tty_struct *tty, char ch)
+void tty_audit_tiocsti(const struct tty_struct *tty, u8 ch)
 {
 	dev_t dev;
 
@@ -199,7 +199,8 @@ static struct tty_audit_buf *tty_audit_buf_get(void)
  *
  *	Audit @data of @size from @tty, if necessary.
  */
-void tty_audit_add_data(struct tty_struct *tty, const void *data, size_t size)
+void tty_audit_add_data(const struct tty_struct *tty, const void *data,
+			size_t size)
 {
 	struct tty_audit_buf *buf;
 	unsigned int audit_tty;
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 0b7dc62a32c8..383159639f65 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -3540,9 +3540,11 @@ static ssize_t show_cons_active(struct device *dev,
 	for_each_console(c) {
 		if (!c->device)
 			continue;
-		if (c->flags & CON_NO_BKL) {
-			if (!(c->write_thread || c->write_atomic))
+		if (c->flags & CON_NBCON) {
+			if (!c->write_atomic &&
+			    !(c->write_thread && c->kthread)) {
 				continue;
+			}
 		} else {
 			if (!c->write)
 				continue;
diff --git a/fs/proc/consoles.c b/fs/proc/consoles.c
index ab9f42d478c8..2703676549f5 100644
--- a/fs/proc/consoles.c
+++ b/fs/proc/consoles.c
@@ -21,7 +21,7 @@ static int show_console_dev(struct seq_file *m, void *v)
 		{ CON_ENABLED,		'E' },
 		{ CON_CONSDEV,		'C' },
 		{ CON_BOOT,		'B' },
-		{ CON_NO_BKL,		'N' },
+		{ CON_NBCON,		'N' },
 		{ CON_PRINTBUFFER,	'p' },
 		{ CON_BRL,		'b' },
 		{ CON_ANYTIME,		'a' },
@@ -59,8 +59,8 @@ static int show_console_dev(struct seq_file *m, void *v)
 	seq_setwidth(m, 21 - 1);
 	seq_printf(m, "%s%d", con->name, con->index);
 	seq_pad(m, ' ');
-	if (con->flags & CON_NO_BKL) {
-		if (con->write_thread || con->write_atomic)
+	if (con->flags & CON_NBCON) {
+		if (con->write_atomic || con->write_thread)
 			con_write = 'W';
 	} else {
 		if (con->write)
diff --git a/include/linux/console.h b/include/linux/console.h
index 837af1471dab..266b47d585ce 100644
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -165,7 +165,7 @@ static inline int con_debug_leave(void)
  *			/dev/kmesg which requires a larger output buffer.
  * @CON_SUSPENDED:	Indicates if a console is suspended. If true, the
  *			printing callbacks must not be called.
- * @CON_NO_BKL:		Console can operate outside of the BKL style console_lock
+ * @CON_NBCON:		Console can operate outside of the legacy style console_lock
  *			constraints.
  */
 enum cons_flags {
@@ -177,132 +177,113 @@ enum cons_flags {
 	CON_BRL			= BIT(5),
 	CON_EXTENDED		= BIT(6),
 	CON_SUSPENDED		= BIT(7),
-	CON_NO_BKL		= BIT(8),
+	CON_NBCON		= BIT(8),
 };
 
 /**
- * struct cons_state - console state for NOBKL consoles
+ * struct nbcon_state - console state for nbcon consoles
  * @atom:	Compound of the state fields for atomic operations
- * @seq:	Sequence for record tracking (64bit only)
- * @bits:	Compound of the state bits below
  *
- * @locked:	Console is locked by a writer
- * @unsafe:	Console is busy in a non takeover region
- * @thread:	Current owner is the printk thread
- * @cur_prio:	The priority of the current output
- * @req_prio:	The priority of a handover request
- * @cpu:	The CPU on which the writer runs
+ * @req_prio:		The priority of a handover request
+ * @prio:		The priority of the current owner
+ * @unsafe:		Console is busy in a non takeover region
+ * @unsafe_takeover:	A hostile takeover in an unsafe state happened in the
+ *			past. The console cannot be safe until re-initialized.
+ * @cpu:		The CPU on which the owner runs
  *
- * To be used for state read and preparation of atomic_long_cmpxchg()
- * operations.
+ * To be used for reading and preparing of the value stored in the nbcon
+ * state variable @console::nbcon_state.
  *
- * The @req_prio field is particularly important to allow spin-waiting to
- * timeout and give up without the risk of it being assigned the lock
- * after giving up. The @req_prio field has a nice side-effect that it
- * also makes it possible for a single read+cmpxchg in the common case of
- * acquire and release.
+ * The @prio and @req_prio fields are particularly important to allow
+ * spin-waiting to timeout and give up without the risk of a waiter being
+ * assigned the lock after giving up.
  */
-struct cons_state {
+struct nbcon_state {
 	union {
-		unsigned long	atom;
+		unsigned int	atom;
 		struct {
-#ifdef CONFIG_64BIT
-			u32	seq;
-#endif
-			union {
-				u32	bits;
-				struct {
-					u32 locked	:  1;
-					u32 unsafe	:  1;
-					u32 thread	:  1;
-					u32 cur_prio	:  2;
-					u32 req_prio	:  2;
-					u32 cpu		: 18;
-				};
-			};
+			unsigned int prio		:  2;
+			unsigned int req_prio		:  2;
+			unsigned int unsafe		:  1;
+			unsigned int unsafe_takeover	:  1;
+			unsigned int cpu		: 24;
 		};
 	};
 };
 
+/*
+ * The nbcon_state struct is used to easily create and interpret values that
+ * are stored in the @console::nbcon_state variable. Ensure this struct stays
+ * within the size boundaries of the atomic variable's underlying type in
+ * order to avoid any accidental truncation.
+ */
+static_assert(sizeof(struct nbcon_state) <= sizeof(int));
+
 /**
- * cons_prio - console writer priority for NOBKL consoles
- * @CONS_PRIO_NONE:		Unused
- * @CONS_PRIO_NORMAL:		Regular printk
- * @CONS_PRIO_EMERGENCY:	Emergency output (WARN/OOPS...)
- * @CONS_PRIO_PANIC:		Panic output
- * @CONS_PRIO_MAX:		The number of priority levels
+ * nbcon_prio - console owner priority for nbcon consoles
+ * @NBCON_PRIO_NONE:		Unused
+ * @NBCON_PRIO_NORMAL:		Normal (non-emergency) usage
+ * @NBCON_PRIO_EMERGENCY:	Emergency output (WARN/OOPS...)
+ * @NBCON_PRIO_PANIC:		Panic output
+ * @NBCON_PRIO_MAX:		The number of priority levels
  *
- * Emergency output can carefully takeover the console even without consent
- * of the owner, ideally only when @cons_state::unsafe is not set. Panic
- * output can ignore the unsafe flag as a last resort. If panic output is
- * active no takeover is possible until the panic output releases the
- * console.
+ * A higher priority context can takeover the console when it is
+ * in the safe state. The final attempt to flush consoles in panic()
+ * can be allowed to do so even in an unsafe state (Hope and pray).
  */
-enum cons_prio {
-	CONS_PRIO_NONE = 0,
-	CONS_PRIO_NORMAL,
-	CONS_PRIO_EMERGENCY,
-	CONS_PRIO_PANIC,
-	CONS_PRIO_MAX,
+enum nbcon_prio {
+	NBCON_PRIO_NONE = 0,
+	NBCON_PRIO_NORMAL,
+	NBCON_PRIO_EMERGENCY,
+	NBCON_PRIO_PANIC,
+	NBCON_PRIO_MAX,
 };
 
 struct console;
 struct printk_buffers;
 
 /**
- * struct cons_context - Context for console acquire/release
- * @console:		The associated console
- * @state:		The state at acquire time
- * @old_state:		The old state when try_acquire() failed for analysis
- *			by the caller
- * @hov_state:		The handover state for spin and cleanup
- * @req_state:		The request state for spin and cleanup
- * @spinwait_max_us:	Limit for spinwait acquire
- * @oldseq:		The sequence number at acquire()
- * @newseq:		The sequence number for progress
- * @prio:		Priority of the context
- * @pbufs:		Pointer to the text buffer for this context
- * @dropped:		Dropped counter for the current context
- * @thread:		The acquire is printk thread context
- * @hostile:		Hostile takeover requested. Cleared on normal
- *			acquire or friendly handover
- * @spinwait:		Spinwait on acquire if possible
- * @backlog:		Ringbuffer has pending records
+ * struct nbcon_context - Context for console acquire/release
+ * @console:			The associated console
+ * @spinwait_max_us:		Limit for spin-wait acquire
+ * @prio:			Priority of the context
+ * @allow_unsafe_takeover:	Allow performing takeover even if unsafe. Can
+ *				be used only with NBCON_PRIO_PANIC @prio. It
+ *				might cause a system freeze when the console
+ *				is used later.
+ * @backlog:			Ringbuffer has pending records
+ * @pbufs:			Pointer to the text buffer for this context
+ * @seq:			The sequence number to print for this context
  */
-struct cons_context {
+struct nbcon_context {
+	/* members set by caller */
 	struct console		*console;
-	struct cons_state	state;
-	struct cons_state	old_state;
-	struct cons_state	hov_state;
-	struct cons_state	req_state;
-	u64			oldseq;
-	u64			newseq;
 	unsigned int		spinwait_max_us;
-	enum cons_prio		prio;
+	enum nbcon_prio		prio;
+	unsigned int		allow_unsafe_takeover	: 1;
+
+	/* members set by emit */
+	unsigned int		backlog			: 1;
+
+	/* members set by acquire */
 	struct printk_buffers	*pbufs;
-	unsigned long		dropped;
-	unsigned int		thread		: 1;
-	unsigned int		hostile		: 1;
-	unsigned int		spinwait	: 1;
-	unsigned int		backlog		: 1;
+	u64			seq;
 };
 
 /**
- * struct cons_write_context - Context handed to the write callbacks
- * @ctxt:	The core console context
- * @outbuf:	Pointer to the text buffer for output
- * @len:	Length to write
- * @unsafe:	Invoked in unsafe state due to force takeover
+ * struct nbcon_write_context - Context handed to the nbcon write callbacks
+ * @ctxt:		The core console context
+ * @outbuf:		Pointer to the text buffer for output
+ * @len:		Length to write
+ * @unsafe_takeover:	If a hostile takeover in an unsafe state has occurred
  */
-struct cons_write_context {
-	struct cons_context	__private ctxt;
+struct nbcon_write_context {
+	struct nbcon_context	__private ctxt;
 	char			*outbuf;
 	unsigned int		len;
-	bool			unsafe;
+	bool			unsafe_takeover;
 };
 
-struct cons_context_data;
-
 /**
  * struct console - The console descriptor structure
  * @name:		The name of the console driver
@@ -323,17 +304,17 @@ struct cons_context_data;
  * @data:		Driver private data
  * @node:		hlist node for the console list
  *
- * @atomic_state:	State array for NOBKL consoles; real and handover
- * @atomic_seq:		Sequence for record tracking (32bit only)
- * @thread_pbufs:	Pointer to thread private buffer
- * @kthread:		Pointer to kernel thread
- * @rcuwait:		RCU wait for the kernel thread
- * @irq_work:		IRQ work for thread wakeup
- * @kthread_waiting:	Indicator whether the kthread is waiting to be woken
  * @write_atomic:	Write callback for atomic context
- * @write_thread:	Write callback for printk threaded printing
- * @port_lock:		Callback to lock/unlock the port lock
- * @pcpu_data:		Pointer to percpu context data
+ * @write_thread:	Write callback for non-atomic context
+ * @driver_enter:	Callback to begin synchronization with driver code
+ * @driver_exit:	Callback to finish synchronization with driver code
+ * @nbcon_state:	State for nbcon consoles
+ * @nbcon_seq:		Sequence number of the next record for nbcon to print
+ * @pbufs:		Pointer to nbcon private buffer
+ * @locked_port:	True, if the port lock is locked by nbcon
+ * @kthread:		Printer kthread for this console
+ * @rcuwait:		RCU-safe wait object for @kthread waking
+ * @irq_work:		Defer @kthread waking to IRQ work context
  */
 struct console {
 	char			name[16];
@@ -354,22 +335,20 @@ struct console {
 	void			*data;
 	struct hlist_node	node;
 
-	/* NOBKL console specific members */
-	atomic_long_t		__private atomic_state[2];
-#ifndef CONFIG_64BIT
-	atomic_t		__private atomic_seq;
-#endif
-	struct printk_buffers	*thread_pbufs;
+	/* nbcon console specific members */
+	bool			(*write_atomic)(struct console *con,
+						struct nbcon_write_context *wctxt);
+	bool			(*write_thread)(struct console *con,
+						struct nbcon_write_context *wctxt);
+	void			(*driver_enter)(struct console *con, unsigned long *flags);
+	void			(*driver_exit)(struct console *con, unsigned long flags);
+	atomic_t		__private nbcon_state;
+	atomic_long_t		__private nbcon_seq;
+	struct printk_buffers	*pbufs;
+	bool			locked_port;
 	struct task_struct	*kthread;
 	struct rcuwait		rcuwait;
 	struct irq_work		irq_work;
-	atomic_t		kthread_waiting;
-
-	bool (*write_atomic)(struct console *con, struct cons_write_context *wctxt);
-	bool (*write_thread)(struct console *con, struct cons_write_context *wctxt);
-	void (*port_lock)(struct console *con, bool do_lock, unsigned long *flags);
-
-	struct cons_context_data	__percpu *pcpu_data;
 };
 
 #ifdef CONFIG_LOCKDEP
@@ -497,21 +476,19 @@ static inline bool console_is_registered(const struct console *con)
 	hlist_for_each_entry(con, &console_list, node)
 
 #ifdef CONFIG_PRINTK
-extern enum cons_prio cons_atomic_enter(enum cons_prio prio);
-extern void cons_atomic_exit(enum cons_prio prio, enum cons_prio prev_prio);
-extern bool console_can_proceed(struct cons_write_context *wctxt);
-extern bool console_enter_unsafe(struct cons_write_context *wctxt);
-extern bool console_exit_unsafe(struct cons_write_context *wctxt);
-extern bool console_try_acquire(struct cons_write_context *wctxt);
-extern bool console_release(struct cons_write_context *wctxt);
+extern void nbcon_cpu_emergency_enter(void);
+extern void nbcon_cpu_emergency_exit(void);
+extern bool nbcon_can_proceed(struct nbcon_write_context *wctxt);
+extern bool nbcon_enter_unsafe(struct nbcon_write_context *wctxt);
+extern bool nbcon_exit_unsafe(struct nbcon_write_context *wctxt);
+extern void nbcon_reacquire(struct nbcon_write_context *wctxt);
 #else
-static inline enum cons_prio cons_atomic_enter(enum cons_prio prio) { return CONS_PRIO_NONE; }
-static inline void cons_atomic_exit(enum cons_prio prio, enum cons_prio prev_prio) { }
-static inline bool console_can_proceed(struct cons_write_context *wctxt) { return false; }
-static inline bool console_enter_unsafe(struct cons_write_context *wctxt) { return false; }
-static inline bool console_exit_unsafe(struct cons_write_context *wctxt) { return false; }
-static inline bool console_try_acquire(struct cons_write_context *wctxt) { return false; }
-static inline bool console_release(struct cons_write_context *wctxt) { return false; }
+static inline void nbcon_cpu_emergency_enter(void) { }
+static inline void nbcon_cpu_emergency_exit(void) { }
+static inline bool nbcon_can_proceed(struct nbcon_write_context *wctxt) { return false; }
+static inline bool nbcon_enter_unsafe(struct nbcon_write_context *wctxt) { return false; }
+static inline bool nbcon_exit_unsafe(struct nbcon_write_context *wctxt) { return false; }
+static inline void nbcon_reacquire(struct nbcon_write_context *wctxt) { }
 #endif
 
 extern int console_set_on_cmdline;
diff --git a/include/linux/printk.h b/include/linux/printk.h
index b55662624ff8..7a942e987b16 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -9,6 +9,8 @@
 #include <linux/ratelimit_types.h>
 #include <linux/once_lite.h>
 
+struct uart_port;
+
 extern const char linux_banner[];
 extern const char linux_proc_banner[];
 
@@ -139,7 +141,6 @@ void early_printk(const char *s, ...) { }
 #endif
 
 struct dev_printk_info;
-struct cons_write_context;
 
 #ifdef CONFIG_PRINTK
 asmlinkage __printf(4, 0)
@@ -158,10 +159,11 @@ int _printk(const char *fmt, ...);
  */
 __printf(1, 2) __cold int _printk_deferred(const char *fmt, ...);
 
-extern void __printk_safe_enter(unsigned long *flags);
-extern void __printk_safe_exit(unsigned long *flags);
+extern void __printk_safe_enter(void);
+extern void __printk_safe_exit(void);
 extern void __printk_deferred_enter(void);
 extern void __printk_deferred_exit(void);
+
 /*
  * The printk_deferred_enter/exit macros are available only as a hack for
  * some code paths that need to defer all printk console printing. Interrupts
@@ -195,8 +197,10 @@ void show_regs_print_info(const char *log_lvl);
 extern asmlinkage void dump_stack_lvl(const char *log_lvl) __cold;
 extern asmlinkage void dump_stack(void) __cold;
 void printk_trigger_flush(void);
-extern void cons_atomic_flush(struct cons_write_context *printk_caller_wctxt,
-			      bool skip_unsafe);
+void printk_legacy_allow_panic_sync(void);
+extern void nbcon_acquire(struct uart_port *up);
+extern void nbcon_release(struct uart_port *up);
+void nbcon_atomic_flush_unsafe(void);
 #else
 static inline __printf(1, 0)
 int vprintk(const char *s, va_list args)
@@ -277,8 +281,19 @@ static inline void printk_trigger_flush(void)
 {
 }
 
-static inline void cons_atomic_flush(struct cons_write_context *printk_caller_wctxt,
-				     bool skip_unsafe)
+static inline void printk_legacy_allow_panic_sync(void)
+{
+}
+
+static inline void nbcon_acquire(struct uart_port *up)
+{
+}
+
+static inline void nbcon_release(struct uart_port *up)
+{
+}
+
+static inline void nbcon_atomic_flush_unsafe(void)
 {
 }
 
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index ceb7a1ce9a4e..ec46e3b49ee9 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -169,9 +169,6 @@ struct uart_8250_port {
 	/* Serial port overrun backoff */
 	struct delayed_work overrun_backoff;
 	u32 overrun_backoff_time_ms;
-
-	struct cons_write_context wctxt;
-	int cookie;
 };
 
 static inline struct uart_8250_port *up_to_u8250p(struct uart_port *up)
@@ -207,10 +204,12 @@ void serial8250_tx_chars(struct uart_8250_port *up);
 unsigned int serial8250_modem_status(struct uart_8250_port *up);
 void serial8250_init_port(struct uart_8250_port *up);
 void serial8250_set_defaults(struct uart_8250_port *up);
+void serial8250_console_write(struct uart_8250_port *up, const char *s,
+			      unsigned int count);
 bool serial8250_console_write_atomic(struct uart_8250_port *up,
-				     struct cons_write_context *wctxt);
+				     struct nbcon_write_context *wctxt);
 bool serial8250_console_write_thread(struct uart_8250_port *up,
-				     struct cons_write_context *wctxt);
+				     struct nbcon_write_context *wctxt);
 int serial8250_console_setup(struct uart_port *port, char *options, bool probe);
 int serial8250_console_exit(struct uart_port *port);
 
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index e9f16ec252a0..367091bbf11a 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -459,7 +459,8 @@ struct uart_port {
 						struct serial_rs485 *rs485);
 	int			(*iso7816_config)(struct uart_port *,
 						  struct serial_iso7816 *iso7816);
-	int			ctrl_id;		/* optional serial core controller id */
+	unsigned int		ctrl_id;		/* optional serial core controller id */
+	unsigned int		port_id;		/* optional serial core port id */
 	unsigned int		irq;			/* irq number */
 	unsigned long		irqflags;		/* irq flags  */
 	unsigned int		uartclk;		/* base uart clock */
@@ -569,7 +570,7 @@ struct uart_port {
 	struct serial_port_device *port_dev;		/* serial core port device */
 
 	unsigned long		sysrq;			/* sysrq timeout */
-	unsigned int		sysrq_ch;		/* char for sysrq */
+	u8			sysrq_ch;		/* char for sysrq */
 	unsigned char		has_sysrq;
 	unsigned char		sysrq_seq;		/* index in sysrq_toggle_seq */
 
@@ -594,6 +595,7 @@ struct uart_port {
 static inline void uart_port_lock(struct uart_port *up)
 {
 	spin_lock(&up->lock);
+	nbcon_acquire(up);
 }
 
 /**
@@ -603,6 +605,7 @@ static inline void uart_port_lock(struct uart_port *up)
 static inline void uart_port_lock_irq(struct uart_port *up)
 {
 	spin_lock_irq(&up->lock);
+	nbcon_acquire(up);
 }
 
 /**
@@ -613,6 +616,7 @@ static inline void uart_port_lock_irq(struct uart_port *up)
 static inline void uart_port_lock_irqsave(struct uart_port *up, unsigned long *flags)
 {
 	spin_lock_irqsave(&up->lock, *flags);
+	nbcon_acquire(up);
 }
 
 /**
@@ -623,7 +627,11 @@ static inline void uart_port_lock_irqsave(struct uart_port *up, unsigned long *f
  */
 static inline bool uart_port_trylock(struct uart_port *up)
 {
-	return spin_trylock(&up->lock);
+	if (!spin_trylock(&up->lock))
+		return false;
+
+	nbcon_acquire(up);
+	return true;
 }
 
 /**
@@ -635,7 +643,11 @@ static inline bool uart_port_trylock(struct uart_port *up)
  */
 static inline bool uart_port_trylock_irqsave(struct uart_port *up, unsigned long *flags)
 {
-	return spin_trylock_irqsave(&up->lock, *flags);
+	if (!spin_trylock_irqsave(&up->lock, *flags))
+		return false;
+
+	nbcon_acquire(up);
+	return true;
 }
 
 /**
@@ -644,6 +656,7 @@ static inline bool uart_port_trylock_irqsave(struct uart_port *up, unsigned long
  */
 static inline void uart_port_unlock(struct uart_port *up)
 {
+	nbcon_release(up);
 	spin_unlock(&up->lock);
 }
 
@@ -653,15 +666,29 @@ static inline void uart_port_unlock(struct uart_port *up)
  */
 static inline void uart_port_unlock_irq(struct uart_port *up)
 {
+	nbcon_release(up);
 	spin_unlock_irq(&up->lock);
 }
 
 /**
- * uart_port_unlock_irqrestore - Unlock the UART port, restore interrupts
+ * uart_port_lock_irqrestore - Unlock the UART port, restore interrupts
  * @up:		Pointer to UART port structure
  * @flags:	The saved interrupt flags for restore
  */
 static inline void uart_port_unlock_irqrestore(struct uart_port *up, unsigned long flags)
+{
+	nbcon_release(up);
+	spin_unlock_irqrestore(&up->lock, flags);
+}
+
+/* Only for use in the console->driver_enter() callback. */
+static inline void __uart_port_lock_irqsave(struct uart_port *up, unsigned long *flags)
+{
+	spin_lock_irqsave(&up->lock, *flags);
+}
+
+/* Only for use in the console->driver_exit() callback. */
+static inline void __uart_port_unlock_irqrestore(struct uart_port *up, unsigned long flags)
 {
 	spin_unlock_irqrestore(&up->lock, flags);
 }
@@ -747,17 +774,8 @@ struct uart_driver {
 
 void uart_write_wakeup(struct uart_port *port);
 
-/**
- * enum UART_TX_FLAGS -- flags for uart_port_tx_flags()
- *
- * @UART_TX_NOSTOP: don't call port->ops->stop_tx() on empty buffer
- */
-enum UART_TX_FLAGS {
-	UART_TX_NOSTOP = BIT(0),
-};
-
-#define __uart_port_tx(uport, ch, flags, tx_ready, put_char, tx_done,	      \
-		       for_test, for_post)				      \
+#define __uart_port_tx(uport, ch, tx_ready, put_char, tx_done, for_test,      \
+		for_post)						      \
 ({									      \
 	struct uart_port *__port = (uport);				      \
 	struct circ_buf *xmit = &__port->state->xmit;			      \
@@ -785,7 +803,7 @@ enum UART_TX_FLAGS {
 	if (pending < WAKEUP_CHARS) {					      \
 		uart_write_wakeup(__port);				      \
 									      \
-		if (!((flags) & UART_TX_NOSTOP) && pending == 0)	      \
+		if (pending == 0)					      \
 			__port->ops->stop_tx(__port);			      \
 	}								      \
 									      \
@@ -820,7 +838,7 @@ enum UART_TX_FLAGS {
  */
 #define uart_port_tx_limited(port, ch, count, tx_ready, put_char, tx_done) ({ \
 	unsigned int __count = (count);					      \
-	__uart_port_tx(port, ch, 0, tx_ready, put_char, tx_done, __count,     \
+	__uart_port_tx(port, ch, tx_ready, put_char, tx_done, __count,	      \
 			__count--);					      \
 })
 
@@ -834,21 +852,8 @@ enum UART_TX_FLAGS {
  * See uart_port_tx_limited() for more details.
  */
 #define uart_port_tx(port, ch, tx_ready, put_char)			\
-	__uart_port_tx(port, ch, 0, tx_ready, put_char, ({}), true, ({}))
+	__uart_port_tx(port, ch, tx_ready, put_char, ({}), true, ({}))
 
-
-/**
- * uart_port_tx_flags -- transmit helper for uart_port with flags
- * @port: uart port
- * @ch: variable to store a character to be written to the HW
- * @flags: %UART_TX_NOSTOP or similar
- * @tx_ready: can HW accept more data function
- * @put_char: function to write a character
- *
- * See uart_port_tx_limited() for more details.
- */
-#define uart_port_tx_flags(port, ch, flags, tx_ready, put_char)		\
-	__uart_port_tx(port, ch, flags, tx_ready, put_char, ({}), true, ({}))
 /*
  * Baud rate helpers.
  */
@@ -1004,7 +1009,7 @@ void uart_handle_dcd_change(struct uart_port *uport, bool active);
 void uart_handle_cts_change(struct uart_port *uport, bool active);
 
 void uart_insert_char(struct uart_port *port, unsigned int status,
-		      unsigned int overrun, unsigned int ch, unsigned int flag);
+		      unsigned int overrun, u8 ch, u8 flag);
 
 void uart_xchar_out(struct uart_port *uport, int offset);
 
@@ -1013,7 +1018,7 @@ void uart_xchar_out(struct uart_port *uport, int offset);
 
 bool uart_try_toggle_sysrq(struct uart_port *port, unsigned int ch);
 
-static inline int uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
+static inline int uart_handle_sysrq_char(struct uart_port *port, u8 ch)
 {
 	if (!port->sysrq)
 		return 0;
@@ -1032,7 +1037,7 @@ static inline int uart_handle_sysrq_char(struct uart_port *port, unsigned int ch
 	return 0;
 }
 
-static inline int uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch)
+static inline int uart_prepare_sysrq_char(struct uart_port *port, u8 ch)
 {
 	if (!port->sysrq)
 		return 0;
@@ -1053,17 +1058,17 @@ static inline int uart_prepare_sysrq_char(struct uart_port *port, unsigned int c
 
 static inline void uart_unlock_and_check_sysrq(struct uart_port *port)
 {
-	int sysrq_ch;
+	u8 sysrq_ch;
 
 	if (!port->has_sysrq) {
-		spin_unlock(&port->lock);
+		uart_port_unlock(port);
 		return;
 	}
 
 	sysrq_ch = port->sysrq_ch;
 	port->sysrq_ch = 0;
 
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 
 	if (sysrq_ch)
 		handle_sysrq(sysrq_ch);
@@ -1072,38 +1077,38 @@ static inline void uart_unlock_and_check_sysrq(struct uart_port *port)
 static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port,
 		unsigned long flags)
 {
-	int sysrq_ch;
+	u8 sysrq_ch;
 
 	if (!port->has_sysrq) {
-		spin_unlock_irqrestore(&port->lock, flags);
+		uart_port_unlock_irqrestore(port, flags);
 		return;
 	}
 
 	sysrq_ch = port->sysrq_ch;
 	port->sysrq_ch = 0;
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	if (sysrq_ch)
 		handle_sysrq(sysrq_ch);
 }
 #else	/* CONFIG_MAGIC_SYSRQ_SERIAL */
-static inline int uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
+static inline int uart_handle_sysrq_char(struct uart_port *port, u8 ch)
 {
 	return 0;
 }
-static inline int uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch)
+static inline int uart_prepare_sysrq_char(struct uart_port *port, u8 ch)
 {
 	return 0;
 }
 static inline void uart_unlock_and_check_sysrq(struct uart_port *port)
 {
-	spin_unlock(&port->lock);
+	uart_port_unlock(port);
 }
 static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port,
 		unsigned long flags)
 {
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 #endif	/* CONFIG_MAGIC_SYSRQ_SERIAL */
 
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 151bd3de5936..5c21ba41e308 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -56,6 +56,7 @@
 #include <linux/kprobes.h>
 #include <linux/lockdep.h>
 #include <linux/context_tracking.h>
+#include <linux/console.h>
 
 #include <asm/sections.h>
 
@@ -3971,6 +3972,8 @@ print_usage_bug(struct task_struct *curr, struct held_lock *this,
 	if (!debug_locks_off() || debug_locks_silent)
 		return;
 
+	nbcon_cpu_emergency_enter();
+
 	pr_warn("\n");
 	pr_warn("================================\n");
 	pr_warn("WARNING: inconsistent lock state\n");
@@ -3999,6 +4002,8 @@ print_usage_bug(struct task_struct *curr, struct held_lock *this,
 
 	pr_warn("\nstack backtrace:\n");
 	dump_stack();
+
+	nbcon_cpu_emergency_exit();
 }
 
 /*
diff --git a/kernel/panic.c b/kernel/panic.c
index 68c028c7790b..63b5d2f7eb72 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -275,7 +275,6 @@ static void panic_other_cpus_shutdown(bool crash_kexec)
  */
 void panic(const char *fmt, ...)
 {
-	enum cons_prio prev_prio;
 	static char buf[1024];
 	va_list args;
 	long i, i_next = 0, len;
@@ -323,8 +322,6 @@ void panic(const char *fmt, ...)
 	if (old_cpu != PANIC_CPU_INVALID && old_cpu != this_cpu)
 		panic_smp_self_stop();
 
-	prev_prio = cons_atomic_enter(CONS_PRIO_PANIC);
-
 	console_verbose();
 	bust_spinlocks(1);
 	va_start(args, fmt);
@@ -369,6 +366,8 @@ void panic(const char *fmt, ...)
 	 */
 	atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
 
+	printk_legacy_allow_panic_sync();
+
 	panic_print_sys_info(false);
 
 	kmsg_dump(KMSG_DUMP_PANIC);
@@ -385,8 +384,6 @@ void panic(const char *fmt, ...)
 	if (_crash_kexec_post_notifiers)
 		__crash_kexec(NULL);
 
-	cons_atomic_flush(NULL, true);
-
 	console_unblank();
 
 	/*
@@ -411,7 +408,6 @@ void panic(const char *fmt, ...)
 		 * We can't use the "normal" timers since we just panicked.
 		 */
 		pr_emerg("Rebooting in %d seconds..\n", panic_timeout);
-		cons_atomic_flush(NULL, true);
 
 		for (i = 0; i < panic_timeout * 1000; i += PANIC_TIMER_STEP) {
 			touch_nmi_watchdog();
@@ -430,7 +426,6 @@ void panic(const char *fmt, ...)
 		 */
 		if (panic_reboot_mode != REBOOT_UNDEFINED)
 			reboot_mode = panic_reboot_mode;
-		cons_atomic_flush(NULL, true);
 		emergency_restart();
 	}
 #ifdef __sparc__
@@ -443,7 +438,6 @@ void panic(const char *fmt, ...)
 	}
 #endif
 #if defined(CONFIG_S390)
-	cons_atomic_flush(NULL, true);
 	disabled_wait();
 #endif
 	pr_emerg("---[ end Kernel panic - not syncing: %s ]---\n", buf);
@@ -451,7 +445,13 @@ void panic(const char *fmt, ...)
 	/* Do not scroll important messages printed above */
 	suppress_printk = 1;
 
-	cons_atomic_exit(CONS_PRIO_PANIC, prev_prio);
+	/*
+	 * The final messages may not have been printed if in a context that
+	 * defers printing (such as NMI) and irq_work is not available.
+	 * Explicitly flush the kernel log buffer one last time.
+	 */
+	console_flush_on_panic(CONSOLE_FLUSH_PENDING);
+	nbcon_atomic_flush_unsafe();
 
 	local_irq_enable();
 	for (i = 0; ; i += PANIC_TIMER_STEP) {
@@ -490,10 +490,6 @@ const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = {
 	[ TAINT_AUX ]			= { 'X', ' ', true },
 	[ TAINT_RANDSTRUCT ]		= { 'T', ' ', true },
 	[ TAINT_TEST ]			= { 'N', ' ', true },
-	[ TAINT_UNSAFE_HIBERNATE ]	= { 'H', ' ', false },
-#ifdef CONFIG_SUSE_KERNEL_SUPPORTED
-	[ TAINT_NO_SUPPORT ]		= { 'n', ' ', true },
-#endif
 };
 
 /**
@@ -517,9 +513,6 @@ const char *print_tainted(void)
 		s = buf + sprintf(buf, "Tainted: ");
 		for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
 			const struct taint_flag *t = &taint_flags[i];
-
-			if (!t->c_true)
-				continue;
 			*s++ = test_bit(i, &tainted_mask) ?
 					t->c_true : t->c_false;
 		}
@@ -637,6 +630,7 @@ bool oops_may_print(void)
  */
 void oops_enter(void)
 {
+	nbcon_cpu_emergency_enter();
 	tracing_off();
 	/* can't trust the integrity of the kernel anymore: */
 	debug_locks_off();
@@ -659,6 +653,7 @@ void oops_exit(void)
 {
 	do_oops_enter_exit();
 	print_oops_end_marker();
+	nbcon_cpu_emergency_exit();
 	kmsg_dump(KMSG_DUMP_OOPS);
 }
 
@@ -670,9 +665,7 @@ struct warn_args {
 void __warn(const char *file, int line, void *caller, unsigned taint,
 	    struct pt_regs *regs, struct warn_args *args)
 {
-	enum cons_prio prev_prio;
-
-	prev_prio = cons_atomic_enter(CONS_PRIO_EMERGENCY);
+	nbcon_cpu_emergency_enter();
 
 	disable_trace_on_warning();
 
@@ -705,7 +698,7 @@ void __warn(const char *file, int line, void *caller, unsigned taint,
 	/* Just a warning, don't kill lockdep. */
 	add_taint(taint, LOCKDEP_STILL_OK);
 
-	cons_atomic_exit(CONS_PRIO_EMERGENCY, prev_prio);
+	nbcon_cpu_emergency_exit();
 }
 
 #ifdef CONFIG_BUG
diff --git a/kernel/printk/Makefile b/kernel/printk/Makefile
index b36683bd2f82..39a2b61c7232 100644
--- a/kernel/printk/Makefile
+++ b/kernel/printk/Makefile
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0-only
 obj-y	= printk.o
-obj-$(CONFIG_PRINTK)	+= printk_safe.o printk_nobkl.o
+obj-$(CONFIG_PRINTK)	+= printk_safe.o nbcon.o
 obj-$(CONFIG_A11Y_BRAILLE_CONSOLE)	+= braille.o
 obj-$(CONFIG_PRINTK_INDEX)	+= index.o
 
diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h
index 2d47a69849e2..7db6992c54f3 100644
--- a/kernel/printk/internal.h
+++ b/kernel/printk/internal.h
@@ -16,11 +16,12 @@ int devkmsg_sysctl_set_loglvl(struct ctl_table *table, int write,
 
 #define con_printk(lvl, con, fmt, ...)				\
 	printk(lvl pr_fmt("%s%sconsole [%s%d] " fmt),		\
-	       (con->flags & CON_NO_BKL) ? "" : "legacy ",	\
-	       (con->flags & CON_BOOT) ? "boot" : "",		\
-	       con->name, con->index, ##__VA_ARGS__)
+		(con->flags & CON_NBCON) ? "" : "legacy ",	\
+		(con->flags & CON_BOOT) ? "boot" : "",		\
+		con->name, con->index, ##__VA_ARGS__)
 
 #ifdef CONFIG_PRINTK
+
 #ifdef CONFIG_PRINTK_CALLER
 #define PRINTK_PREFIX_MAX	48
 #else
@@ -43,11 +44,18 @@ enum printk_info_flags {
 };
 
 extern struct printk_ringbuffer *prb;
-extern bool have_bkl_console;
 extern bool printk_threads_enabled;
-
+extern bool have_legacy_console;
 extern bool have_boot_console;
 
+/*
+ * Specifies if the console lock/unlock dance is needed for console
+ * printing. If @have_boot_console is true, the nbcon consoles will
+ * be printed serially along with the legacy consoles because nbcon
+ * consoles cannot print simultaneously with boot consoles.
+ */
+#define printing_via_unlock (have_legacy_console || have_boot_console)
+
 __printf(4, 0)
 int vprintk_store(int facility, int level,
 		  const struct dev_printk_info *dev_info,
@@ -58,47 +66,44 @@ __printf(1, 0) int vprintk_deferred(const char *fmt, va_list args);
 
 bool printk_percpu_data_ready(void);
 
-/*
- * The printk_safe_enter()/_exit() macros mark code blocks using locks that
- * would lead to deadlock if an interrupting context were to call printk()
- * while the interrupted context was within such code blocks.
- *
- * When a CPU is in such a code block, an interrupting context calling
- * printk() will only log the new message to the lockless ringbuffer and
- * then trigger console printing using irqwork.
- */
-
 #define printk_safe_enter_irqsave(flags)	\
 	do {					\
-		__printk_safe_enter(&flags);	\
+		local_irq_save(flags);		\
+		__printk_safe_enter();		\
 	} while (0)
 
 #define printk_safe_exit_irqrestore(flags)	\
 	do {					\
-		__printk_safe_exit(&flags);	\
+		__printk_safe_exit();		\
+		local_irq_restore(flags);	\
 	} while (0)
 
 void defer_console_output(void);
 
 u16 printk_parse_prefix(const char *text, int *level,
 			enum printk_info_flags *flags);
-
-u64 cons_read_seq(struct console *con);
-void cons_nobkl_cleanup(struct console *con);
-bool cons_nobkl_init(struct console *con);
-bool cons_alloc_percpu_data(struct console *con);
-void cons_kthread_create(struct console *con);
-void cons_wake_threads(void);
-void cons_force_seq(struct console *con, u64 seq);
-void console_bkl_kthread_create(void);
+void console_lock_spinning_enable(void);
+int console_lock_spinning_disable_and_check(int cookie);
+
+u64 nbcon_seq_read(struct console *con);
+void nbcon_seq_force(struct console *con, u64 seq);
+bool nbcon_alloc(struct console *con);
+void nbcon_init(struct console *con);
+void nbcon_free(struct console *con);
+enum nbcon_prio nbcon_get_default_prio(void);
+void nbcon_atomic_flush_all(void);
+bool nbcon_atomic_emit_next_record(struct console *con, bool *handover, int cookie);
+void nbcon_kthread_create(struct console *con);
+void nbcon_wake_threads(void);
+void nbcon_legacy_kthread_create(void);
 
 /*
  * Check if the given console is currently capable and allowed to print
- * records. If the caller only works with certain types of consoles, the
- * caller is responsible for checking the console type before calling
- * this function.
+ * records. Note that this function does not consider the current context,
+ * which can also play a role in deciding if @con can be used to print
+ * records.
  */
-static inline bool console_is_usable(struct console *con, short flags)
+static inline bool console_is_usable(struct console *con, short flags, bool use_atomic)
 {
 	if (!(flags & CON_ENABLED))
 		return false;
@@ -106,38 +111,48 @@ static inline bool console_is_usable(struct console *con, short flags)
 	if ((flags & CON_SUSPENDED))
 		return false;
 
-	/*
-	 * The usability of a console varies depending on whether
-	 * it is a NOBKL console or not.
-	 */
-
-	if (flags & CON_NO_BKL) {
-		if (have_boot_console)
-			return false;
-
+	if (flags & CON_NBCON) {
+		if (use_atomic) {
+			if (!con->write_atomic)
+				return false;
+		} else {
+			if (!con->write_thread || !con->kthread)
+				return false;
+		}
 	} else {
 		if (!con->write)
 			return false;
-		/*
-		 * Console drivers may assume that per-cpu resources have
-		 * been allocated. So unless they're explicitly marked as
-		 * being able to cope (CON_ANYTIME) don't call them until
-		 * this CPU is officially up.
-		 */
-		if (!cpu_online(raw_smp_processor_id()) && !(flags & CON_ANYTIME))
-			return false;
 	}
 
+	/*
+	 * Console drivers may assume that per-cpu resources have been
+	 * allocated. So unless they're explicitly marked as being able to
+	 * cope (CON_ANYTIME) don't call them until this CPU is officially up.
+	 */
+	if (!cpu_online(raw_smp_processor_id()) && !(flags & CON_ANYTIME))
+		return false;
+
 	return true;
 }
 
 /**
- * cons_kthread_wake - Wake up a printk thread
+ * nbcon_kthread_wake - Wake up a printk thread
  * @con:        Console to operate on
  */
-static inline void cons_kthread_wake(struct console *con)
+static inline void nbcon_kthread_wake(struct console *con)
 {
-	rcuwait_wake_up(&con->rcuwait);
+	/*
+	 * Guarantee any new records can be seen by tasks preparing to wait
+	 * before this context checks if the rcuwait is empty.
+	 *
+	 * The full memory barrier in rcuwait_wake_up() pairs with the full
+	 * memory barrier within set_current_state() of
+	 * ___rcuwait_wait_event(), which is called after prepare_to_rcuwait()
+	 * adds the waiter but before it has checked the wait condition.
+	 *
+	 * This pairs with nbcon_kthread_func:A.
+	 */
+	rcuwait_wake_up(&con->rcuwait); /* LMM(nbcon_kthread_wake:A) */
 }
 
 #else
@@ -146,9 +161,10 @@ static inline void cons_kthread_wake(struct console *con)
 #define PRINTK_MESSAGE_MAX	0
 #define PRINTKRB_RECORD_MAX	0
 
-static inline void cons_kthread_wake(struct console *con) { }
-static inline void cons_kthread_create(struct console *con) { }
-#define printk_threads_enabled	(false)
+static inline void nbcon_kthread_wake(struct console *con) { }
+static inline void nbcon_kthread_create(struct console *con) { }
+#define printk_threads_enabled (false)
+#define printing_via_unlock (false)
 
 /*
  * In !PRINTK builds we still export console_sem
@@ -159,14 +175,22 @@ static inline void cons_kthread_create(struct console *con) { }
 #define printk_safe_exit_irqrestore(flags) local_irq_restore(flags)
 
 static inline bool printk_percpu_data_ready(void) { return false; }
-static inline bool cons_nobkl_init(struct console *con) { return true; }
-static inline void cons_nobkl_cleanup(struct console *con) { }
-static inline bool console_is_usable(struct console *con, short flags) { return false; }
-static inline void cons_force_seq(struct console *con, u64 seq) { }
+static inline u64 nbcon_seq_read(struct console *con) { return 0; }
+static inline void nbcon_seq_force(struct console *con, u64 seq) { }
+static inline bool nbcon_alloc(struct console *con) { return false; }
+static inline void nbcon_init(struct console *con) { }
+static inline void nbcon_free(struct console *con) { }
+static inline enum nbcon_prio nbcon_get_default_prio(void) { return NBCON_PRIO_NONE; }
+static inline void nbcon_atomic_flush_all(void) { }
+static inline bool nbcon_atomic_emit_next_record(struct console *con, bool *handover,
+						 int cookie) { return false; }
+
+static inline bool console_is_usable(struct console *con, short flags,
+				     bool use_atomic) { return false; }
 
 #endif /* CONFIG_PRINTK */
 
-extern bool have_boot_console;
+extern struct printk_buffers printk_shared_pbufs;
 
 /**
  * struct printk_buffers - Buffers to read/format/output printk messages.
@@ -194,29 +218,11 @@ struct printk_message {
 	unsigned long		dropped;
 };
 
-/**
- * struct cons_context_data - console context data
- * @wctxt:		Write context per priority level
- * @pbufs:		Buffer for storing the text
- *
- * Used for early boot and for per CPU data.
- *
- * The write contexts are allocated to avoid having them on stack, e.g. in
- * warn() or panic().
- */
-struct cons_context_data {
-	struct cons_write_context	wctxt[CONS_PRIO_MAX];
-	struct printk_buffers	pbufs;
-};
-
+bool other_cpu_in_panic(void);
+bool this_cpu_in_panic(void);
 bool printk_get_next_message(struct printk_message *pmsg, u64 seq,
 			     bool is_extended, bool may_supress);
 
 #ifdef CONFIG_PRINTK
-
-void console_prepend_dropped(struct printk_message *pmsg,
-			     unsigned long dropped);
-
+void console_prepend_dropped(struct printk_message *pmsg, unsigned long dropped);
 #endif
-
-bool other_cpu_in_panic(void);
diff --git a/kernel/printk/nbcon.c b/kernel/printk/nbcon.c
new file mode 100644
index 000000000000..1b1b585b1675
--- /dev/null
+++ b/kernel/printk/nbcon.c
@@ -0,0 +1,1664 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2022 Linutronix GmbH, John Ogness
+// Copyright (C) 2022 Intel, Thomas Gleixner
+
+#include <linux/kernel.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
+#include <linux/slab.h>
+#include <linux/serial_core.h>
+#include <linux/syscore_ops.h>
+#include "printk_ringbuffer.h"
+#include "internal.h"
+/*
+ * Printk console printing implementation for consoles which does not depend
+ * on the legacy style console_lock mechanism.
+ *
+ * The state of the console is maintained in the "nbcon_state" atomic
+ * variable.
+ *
+ * The console is locked when:
+ *
+ *   - The 'prio' field contains the priority of the context that owns the
+ *     console. Only higher priority contexts are allowed to take over the
+ *     lock. A value of 0 (NBCON_PRIO_NONE) means the console is not locked.
+ *
+ *   - The 'cpu' field denotes on which CPU the console is locked. It is used
+ *     to prevent busy waiting on the same CPU. Also it informs the lock owner
+ *     that it has lost the lock in a more complex scenario when the lock was
+ *     taken over by a higher priority context, released, and taken on another
+ *     CPU with the same priority as the interrupted owner.
+ *
+ * The acquire mechanism uses a few more fields:
+ *
+ *   - The 'req_prio' field is used by the handover approach to make the
+ *     current owner aware that there is a context with a higher priority
+ *     waiting for the friendly handover.
+ *
+ *   - The 'unsafe' field allows to take over the console in a safe way in the
+ *     middle of emitting a message. The field is set only when accessing some
+ *     shared resources or when the console device is manipulated. It can be
+ *     cleared, for example, after emitting one character when the console
+ *     device is in a consistent state.
+ *
+ *   - The 'unsafe_takeover' field is set when a hostile takeover took the
+ *     console in an unsafe state. The console will stay in the unsafe state
+ *     until re-initialized.
+ *
+ * The acquire mechanism uses three approaches:
+ *
+ *   1) Direct acquire when the console is not owned or is owned by a lower
+ *      priority context and is in a safe state.
+ *
+ *   2) Friendly handover mechanism uses a request/grant handshake. It is used
+ *      when the current owner has lower priority and the console is in an
+ *      unsafe state.
+ *
+ *      The requesting context:
+ *
+ *        a) Sets its priority into the 'req_prio' field.
+ *
+ *        b) Waits (with a timeout) for the owning context to unlock the
+ *           console.
+ *
+ *        c) Takes the lock and clears the 'req_prio' field.
+ *
+ *      The owning context:
+ *
+ *        a) Observes the 'req_prio' field set on exit from the unsafe
+ *           console state.
+ *
+ *        b) Gives up console ownership by clearing the 'prio' field.
+ *
+ *   3) Unsafe hostile takeover allows to take over the lock even when the
+ *      console is an unsafe state. It is used only in panic() by the final
+ *      attempt to flush consoles in a try and hope mode.
+ *
+ *      Note that separate record buffers are used in panic(). As a result,
+ *      the messages can be read and formatted without any risk even after
+ *      using the hostile takeover in unsafe state.
+ *
+ * The release function simply clears the 'prio' field.
+ *
+ * All operations on @console::nbcon_state are atomic cmpxchg based to
+ * handle concurrency.
+ *
+ * The acquire/release functions implement only minimal policies:
+ *
+ *   - Preference for higher priority contexts.
+ *   - Protection of the panic CPU.
+ *
+ * All other policy decisions must be made at the call sites:
+ *
+ *   - What is marked as an unsafe section.
+ *   - Whether to spin-wait if there is already an owner and the console is
+ *     in an unsafe state.
+ *   - Whether to attempt an unsafe hostile takeover.
+ *
+ * The design allows to implement the well known:
+ *
+ *     acquire()
+ *     output_one_printk_record()
+ *     release()
+ *
+ * The output of one printk record might be interrupted with a higher priority
+ * context. The new owner is supposed to reprint the entire interrupted record
+ * from scratch.
+ */
+
+/**
+ * nbcon_state_set - Helper function to set the console state
+ * @con:	Console to update
+ * @new:	The new state to write
+ *
+ * Only to be used when the console is not yet or no longer visible in the
+ * system. Otherwise use nbcon_state_try_cmpxchg().
+ */
+static inline void nbcon_state_set(struct console *con, struct nbcon_state *new)
+{
+	atomic_set(&ACCESS_PRIVATE(con, nbcon_state), new->atom);
+}
+
+/**
+ * nbcon_state_read - Helper function to read the console state
+ * @con:	Console to read
+ * @state:	The state to store the result
+ */
+static inline void nbcon_state_read(struct console *con, struct nbcon_state *state)
+{
+	state->atom = atomic_read(&ACCESS_PRIVATE(con, nbcon_state));
+}
+
+/**
+ * nbcon_state_try_cmpxchg() - Helper function for atomic_try_cmpxchg() on console state
+ * @con:	Console to update
+ * @cur:	Old/expected state
+ * @new:	New state
+ *
+ * Return: True on success. False on fail and @cur is updated.
+ */
+static inline bool nbcon_state_try_cmpxchg(struct console *con, struct nbcon_state *cur,
+					   struct nbcon_state *new)
+{
+	return atomic_try_cmpxchg(&ACCESS_PRIVATE(con, nbcon_state), &cur->atom, new->atom);
+}
+
+/**
+ * nbcon_seq_read - Read the current console sequence
+ * @con:	Console to read the sequence of
+ *
+ * Return:	Sequence number of the next record to print on @con.
+ */
+u64 nbcon_seq_read(struct console *con)
+{
+	unsigned long nbcon_seq = atomic_long_read(&ACCESS_PRIVATE(con, nbcon_seq));
+
+	return __ulseq_to_u64seq(prb, nbcon_seq);
+}
+
+/**
+ * nbcon_seq_force - Force console sequence to a specific value
+ * @con:	Console to work on
+ * @seq:	Sequence number value to set
+ *
+ * Only to be used during init (before registration) or in extreme situations
+ * (such as panic with CONSOLE_REPLAY_ALL).
+ */
+void nbcon_seq_force(struct console *con, u64 seq)
+{
+	/*
+	 * If the specified record no longer exists, the oldest available record
+	 * is chosen. This is especially important on 32bit systems because only
+	 * the lower 32 bits of the sequence number are stored. The upper 32 bits
+	 * are derived from the sequence numbers available in the ringbuffer.
+	 */
+	u64 valid_seq = max_t(u64, seq, prb_first_valid_seq(prb));
+
+	atomic_long_set(&ACCESS_PRIVATE(con, nbcon_seq), __u64seq_to_ulseq(valid_seq));
+
+	/* Clear con->seq since nbcon consoles use con->nbcon_seq instead. */
+	con->seq = 0;
+}
+
+/**
+ * nbcon_seq_try_update - Try to update the console sequence number
+ * @ctxt:	Pointer to an acquire context that contains
+ *		all information about the acquire mode
+ * @new_seq:	The new sequence number to set
+ *
+ * @ctxt->seq is updated to the new value of @con::nbcon_seq (expanded to
+ * the 64bit value). This could be a different value than @new_seq if
+ * nbcon_seq_force() was used or the current context no longer owns the
+ * console. In the later case, it will stop printing anyway.
+ */
+static void nbcon_seq_try_update(struct nbcon_context *ctxt, u64 new_seq)
+{
+	unsigned long nbcon_seq = __u64seq_to_ulseq(ctxt->seq);
+	struct console *con = ctxt->console;
+
+	if (atomic_long_try_cmpxchg(&ACCESS_PRIVATE(con, nbcon_seq), &nbcon_seq,
+				    __u64seq_to_ulseq(new_seq))) {
+		ctxt->seq = new_seq;
+	} else {
+		ctxt->seq = nbcon_seq_read(con);
+	}
+}
+
+bool printk_threads_enabled __ro_after_init;
+
+/**
+ * nbcon_context_try_acquire_direct - Try to acquire directly
+ * @ctxt:	The context of the caller
+ * @cur:	The current console state
+ *
+ * Acquire the console when it is released. Also acquire the console when
+ * the current owner has a lower priority and the console is in a safe state.
+ *
+ * Return:	0 on success. Otherwise, an error code on failure. Also @cur
+ *		is updated to the latest state when failed to modify it.
+ *
+ * Errors:
+ *
+ *	-EPERM:		A panic is in progress and this is not the panic CPU.
+ *			Or the current owner or waiter has the same or higher
+ *			priority. No acquire method can be successful in
+ *			this case.
+ *
+ *	-EBUSY:		The current owner has a lower priority but the console
+ *			in an unsafe state. The caller should try using
+ *			the handover acquire method.
+ */
+static int nbcon_context_try_acquire_direct(struct nbcon_context *ctxt,
+					    struct nbcon_state *cur)
+{
+	unsigned int cpu = smp_processor_id();
+	struct console *con = ctxt->console;
+	struct nbcon_state new;
+
+	do {
+		if (other_cpu_in_panic())
+			return -EPERM;
+
+		if (ctxt->prio <= cur->prio || ctxt->prio <= cur->req_prio)
+			return -EPERM;
+
+		if (cur->unsafe)
+			return -EBUSY;
+
+		/*
+		 * The console should never be safe for a direct acquire
+		 * if an unsafe hostile takeover has ever happened.
+		 */
+		WARN_ON_ONCE(cur->unsafe_takeover);
+
+		new.atom = cur->atom;
+		new.prio	= ctxt->prio;
+		new.req_prio	= NBCON_PRIO_NONE;
+		new.unsafe	= cur->unsafe_takeover;
+		new.cpu		= cpu;
+
+	} while (!nbcon_state_try_cmpxchg(con, cur, &new));
+
+	return 0;
+}
+
+static bool nbcon_waiter_matches(struct nbcon_state *cur, int expected_prio)
+{
+	/*
+	 * The request context is well defined by the @req_prio because:
+	 *
+	 * - Only a context with a higher priority can take over the request.
+	 * - There are only three priorities.
+	 * - Only one CPU is allowed to request PANIC priority.
+	 * - Lower priorities are ignored during panic() until reboot.
+	 *
+	 * As a result, the following scenario is *not* possible:
+	 *
+	 * 1. Another context with a higher priority directly takes ownership.
+	 * 2. The higher priority context releases the ownership.
+	 * 3. A lower priority context takes the ownership.
+	 * 4. Another context with the same priority as this context
+	 *    creates a request and starts waiting.
+	 */
+
+	return (cur->req_prio == expected_prio);
+}
+
+/**
+ * nbcon_context_try_acquire_requested - Try to acquire after having
+ *					 requested a handover
+ * @ctxt:	The context of the caller
+ * @cur:	The current console state
+ *
+ * This is a helper function for nbcon_context_try_acquire_handover().
+ * It is called when the console is in an unsafe state. The current
+ * owner will release the console on exit from the unsafe region.
+ *
+ * Return:	0 on success and @cur is updated to the new console state.
+ *		Otherwise an error code on failure.
+ *
+ * Errors:
+ *
+ *	-EPERM:		A panic is in progress and this is not the panic CPU
+ *			or this context is no longer the waiter.
+ *
+ *	-EBUSY:		The console is still locked. The caller should
+ *			continue waiting.
+ *
+ * Note: The caller must still remove the request when an error has occurred
+ *       except when this context is no longer the waiter.
+ */
+static int nbcon_context_try_acquire_requested(struct nbcon_context *ctxt,
+					       struct nbcon_state *cur)
+{
+	unsigned int cpu = smp_processor_id();
+	struct console *con = ctxt->console;
+	struct nbcon_state new;
+
+	/* Note that the caller must still remove the request! */
+	if (other_cpu_in_panic())
+		return -EPERM;
+
+	/*
+	 * Note that the waiter will also change if there was an unsafe
+	 * hostile takeover.
+	 */
+	if (!nbcon_waiter_matches(cur, ctxt->prio))
+		return -EPERM;
+
+	/* If still locked, caller should continue waiting. */
+	if (cur->prio != NBCON_PRIO_NONE)
+		return -EBUSY;
+
+	/*
+	 * The previous owner should have never released ownership
+	 * in an unsafe region.
+	 */
+	WARN_ON_ONCE(cur->unsafe);
+
+	new.atom = cur->atom;
+	new.prio	= ctxt->prio;
+	new.req_prio	= NBCON_PRIO_NONE;
+	new.unsafe	= cur->unsafe_takeover;
+	new.cpu		= cpu;
+
+	if (!nbcon_state_try_cmpxchg(con, cur, &new)) {
+		/*
+		 * The acquire could fail only when it has been taken
+		 * over by a higher priority context.
+		 */
+		WARN_ON_ONCE(nbcon_waiter_matches(cur, ctxt->prio));
+		return -EPERM;
+	}
+
+	/* Handover success. This context now owns the console. */
+	return 0;
+}
+
+/**
+ * nbcon_context_try_acquire_handover - Try to acquire via handover
+ * @ctxt:	The context of the caller
+ * @cur:	The current console state
+ *
+ * The function must be called only when the context has higher priority
+ * than the current owner and the console is in an unsafe state.
+ * It is the case when nbcon_context_try_acquire_direct() returns -EBUSY.
+ *
+ * The function sets "req_prio" field to make the current owner aware of
+ * the request. Then it waits until the current owner releases the console,
+ * or an even higher context takes over the request, or timeout expires.
+ *
+ * The current owner checks the "req_prio" field on exit from the unsafe
+ * region and releases the console. It does not touch the "req_prio" field
+ * so that the console stays reserved for the waiter.
+ *
+ * Return:	0 on success. Otherwise, an error code on failure. Also @cur
+ *		is updated to the latest state when failed to modify it.
+ *
+ * Errors:
+ *
+ *	-EPERM:		A panic is in progress and this is not the panic CPU.
+ *			Or a higher priority context has taken over the
+ *			console or the handover request.
+ *
+ *	-EBUSY:		The current owner is on the same CPU so that the hand
+ *			shake could not work. Or the current owner is not
+ *			willing to wait (zero timeout). Or the console does
+ *			not enter the safe state before timeout passed. The
+ *			caller might still use the unsafe hostile takeover
+ *			when allowed.
+ *
+ *	-EAGAIN:	@cur has changed when creating the handover request.
+ *			The caller should retry with direct acquire.
+ */
+static int nbcon_context_try_acquire_handover(struct nbcon_context *ctxt,
+					      struct nbcon_state *cur)
+{
+	unsigned int cpu = smp_processor_id();
+	struct console *con = ctxt->console;
+	struct nbcon_state new;
+	int timeout;
+	int request_err = -EBUSY;
+
+	/*
+	 * Check that the handover is called when the direct acquire failed
+	 * with -EBUSY.
+	 */
+	WARN_ON_ONCE(ctxt->prio <= cur->prio || ctxt->prio <= cur->req_prio);
+	WARN_ON_ONCE(!cur->unsafe);
+
+	/* Handover is not possible on the same CPU. */
+	if (cur->cpu == cpu)
+		return -EBUSY;
+
+	/*
+	 * Console stays unsafe after an unsafe takeover until re-initialized.
+	 * Waiting is not going to help in this case.
+	 */
+	if (cur->unsafe_takeover)
+		return -EBUSY;
+
+	/* Is the caller willing to wait? */
+	if (ctxt->spinwait_max_us == 0)
+		return -EBUSY;
+
+	/*
+	 * Setup a request for the handover. The caller should try to acquire
+	 * the console directly when the current state has been modified.
+	 */
+	new.atom = cur->atom;
+	new.req_prio = ctxt->prio;
+	if (!nbcon_state_try_cmpxchg(con, cur, &new))
+		return -EAGAIN;
+
+	cur->atom = new.atom;
+
+	/* Wait until there is no owner and then acquire the console. */
+	for (timeout = ctxt->spinwait_max_us; timeout >= 0; timeout--) {
+		/* On successful acquire, this request is cleared. */
+		request_err = nbcon_context_try_acquire_requested(ctxt, cur);
+		if (!request_err)
+			return 0;
+
+		/*
+		 * If the acquire should be aborted, it must be ensured
+		 * that the request is removed before returning to caller.
+		 */
+		if (request_err == -EPERM)
+			break;
+
+		udelay(1);
+
+		/* Re-read the state because some time has passed. */
+		nbcon_state_read(con, cur);
+	}
+
+	/* Timed out or aborted. Carefully remove handover request. */
+	do {
+		/*
+		 * No need to remove request if there is a new waiter. This
+		 * can only happen if a higher priority context has taken over
+		 * the console or the handover request.
+		 */
+		if (!nbcon_waiter_matches(cur, ctxt->prio))
+			return -EPERM;
+
+		/* Unset request for handover. */
+		new.atom = cur->atom;
+		new.req_prio = NBCON_PRIO_NONE;
+		if (nbcon_state_try_cmpxchg(con, cur, &new)) {
+			/*
+			 * Request successfully unset. Report failure of
+			 * acquiring via handover.
+			 */
+			cur->atom = new.atom;
+			return request_err;
+		}
+
+		/*
+		 * Unable to remove request. Try to acquire in case
+		 * the owner has released the lock.
+		 */
+	} while (nbcon_context_try_acquire_requested(ctxt, cur));
+
+	/* Lucky timing. The acquire succeeded while removing the request. */
+	return 0;
+}
+
+/**
+ * nbcon_context_try_acquire_hostile - Acquire via unsafe hostile takeover
+ * @ctxt:	The context of the caller
+ * @cur:	The current console state
+ *
+ * Acquire the console even in the unsafe state.
+ *
+ * It can be permitted by setting the 'allow_unsafe_takeover' field only
+ * by the final attempt to flush messages in panic().
+ *
+ * Return:	0 on success. -EPERM when not allowed by the context.
+ */
+static int nbcon_context_try_acquire_hostile(struct nbcon_context *ctxt,
+					     struct nbcon_state *cur)
+{
+	unsigned int cpu = smp_processor_id();
+	struct console *con = ctxt->console;
+	struct nbcon_state new;
+
+	if (!ctxt->allow_unsafe_takeover)
+		return -EPERM;
+
+	/* Ensure caller is allowed to perform unsafe hostile takeovers. */
+	if (WARN_ON_ONCE(ctxt->prio != NBCON_PRIO_PANIC))
+		return -EPERM;
+
+	/*
+	 * Check that try_acquire_direct() and try_acquire_handover() returned
+	 * -EBUSY in the right situation.
+	 */
+	WARN_ON_ONCE(ctxt->prio <= cur->prio || ctxt->prio <= cur->req_prio);
+	WARN_ON_ONCE(cur->unsafe != true);
+
+	do {
+		new.atom = cur->atom;
+		new.cpu			= cpu;
+		new.prio		= ctxt->prio;
+		new.unsafe		|= cur->unsafe_takeover;
+		new.unsafe_takeover	|= cur->unsafe;
+
+	} while (!nbcon_state_try_cmpxchg(con, cur, &new));
+
+	return 0;
+}
+
+static struct printk_buffers panic_nbcon_pbufs;
+
+/**
+ * nbcon_context_try_acquire - Try to acquire nbcon console
+ * @ctxt:	The context of the caller
+ *
+ * Context:	Any context which could not be migrated to another CPU.
+ * Return:	True if the console was acquired. False otherwise.
+ *
+ * If the caller allowed an unsafe hostile takeover, on success the
+ * caller should check the current console state to see if it is
+ * in an unsafe state. Otherwise, on success the caller may assume
+ * the console is not in an unsafe state.
+ */
+static bool nbcon_context_try_acquire(struct nbcon_context *ctxt)
+{
+	unsigned int cpu = smp_processor_id();
+	struct console *con = ctxt->console;
+	struct nbcon_state cur;
+	int err;
+
+	nbcon_state_read(con, &cur);
+try_again:
+	err = nbcon_context_try_acquire_direct(ctxt, &cur);
+	if (err != -EBUSY)
+		goto out;
+
+	err = nbcon_context_try_acquire_handover(ctxt, &cur);
+	if (err == -EAGAIN)
+		goto try_again;
+	if (err != -EBUSY)
+		goto out;
+
+	err = nbcon_context_try_acquire_hostile(ctxt, &cur);
+out:
+	if (err)
+		return false;
+
+	/* Acquire succeeded. */
+
+	/* Assign the appropriate buffer for this context. */
+	if (atomic_read(&panic_cpu) == cpu)
+		ctxt->pbufs = &panic_nbcon_pbufs;
+	else
+		ctxt->pbufs = con->pbufs;
+
+	/* Set the record sequence for this context to print. */
+	ctxt->seq = nbcon_seq_read(ctxt->console);
+
+	return true;
+}
+
+static bool nbcon_owner_matches(struct nbcon_state *cur, int expected_cpu,
+				int expected_prio)
+{
+	/*
+	 * Since consoles can only be acquired by higher priorities,
+	 * owning contexts are uniquely identified by @prio. However,
+	 * since contexts can unexpectedly lose ownership, it is
+	 * possible that later another owner appears with the same
+	 * priority. For this reason @cpu is also needed.
+	 */
+
+	if (cur->prio != expected_prio)
+		return false;
+
+	if (cur->cpu != expected_cpu)
+		return false;
+
+	return true;
+}
+
+/**
+ * nbcon_context_release - Release the console
+ * @ctxt:	The nbcon context from nbcon_context_try_acquire()
+ */
+static void nbcon_context_release(struct nbcon_context *ctxt)
+{
+	unsigned int cpu = smp_processor_id();
+	struct console *con = ctxt->console;
+	struct nbcon_state cur;
+	struct nbcon_state new;
+
+	nbcon_state_read(con, &cur);
+
+	do {
+		if (!nbcon_owner_matches(&cur, cpu, ctxt->prio))
+			break;
+
+		new.atom = cur.atom;
+		new.prio = NBCON_PRIO_NONE;
+
+		/*
+		 * If @unsafe_takeover is set, it is kept set so that
+		 * the state remains permanently unsafe.
+		 */
+		new.unsafe |= cur.unsafe_takeover;
+
+	} while (!nbcon_state_try_cmpxchg(con, &cur, &new));
+
+	ctxt->pbufs = NULL;
+}
+
+/**
+ * nbcon_context_can_proceed - Check whether ownership can proceed
+ * @ctxt:	The nbcon context from nbcon_context_try_acquire()
+ * @cur:	The current console state
+ *
+ * Return:	True if this context still owns the console. False if
+ *		ownership was handed over or taken.
+ *
+ * Must be invoked when entering the unsafe state to make sure that it still
+ * owns the lock. Also must be invoked when exiting the unsafe context
+ * to eventually free the lock for a higher priority context which asked
+ * for the friendly handover.
+ *
+ * It can be called inside an unsafe section when the console is just
+ * temporary in safe state instead of exiting and entering the unsafe
+ * state.
+ *
+ * Also it can be called in the safe context before doing an expensive
+ * safe operation. It does not make sense to do the operation when
+ * a higher priority context took the lock.
+ *
+ * When this function returns false then the calling context no longer owns
+ * the console and is no longer allowed to go forward. In this case it must
+ * back out immediately and carefully. The buffer content is also no longer
+ * trusted since it no longer belongs to the calling context.
+ */
+static bool nbcon_context_can_proceed(struct nbcon_context *ctxt, struct nbcon_state *cur)
+{
+	unsigned int cpu = smp_processor_id();
+
+	/* Make sure this context still owns the console. */
+	if (!nbcon_owner_matches(cur, cpu, ctxt->prio))
+		return false;
+
+	/* The console owner can proceed if there is no waiter. */
+	if (cur->req_prio == NBCON_PRIO_NONE)
+		return true;
+
+	/*
+	 * A console owner within an unsafe region is always allowed to
+	 * proceed, even if there are waiters. It can perform a handover
+	 * when exiting the unsafe region. Otherwise the waiter will
+	 * need to perform an unsafe hostile takeover.
+	 */
+	if (cur->unsafe)
+		return true;
+
+	/* Waiters always have higher priorities than owners. */
+	WARN_ON_ONCE(cur->req_prio <= cur->prio);
+
+	/*
+	 * Having a safe point for take over and eventually a few
+	 * duplicated characters or a full line is way better than a
+	 * hostile takeover. Post processing can take care of the garbage.
+	 * Release and hand over.
+	 */
+	nbcon_context_release(ctxt);
+
+	/*
+	 * It is not clear whether the waiter really took over ownership. The
+	 * outermost callsite must make the final decision whether console
+	 * ownership is needed for it to proceed. If yes, it must reacquire
+	 * ownership (possibly hostile) before carefully proceeding.
+	 *
+	 * The calling context no longer owns the console so go back all the
+	 * way instead of trying to implement reacquire heuristics in tons of
+	 * places.
+	 */
+	return false;
+}
+
+/**
+ * nbcon_can_proceed - Check whether ownership can proceed
+ * @wctxt:	The write context that was handed to the write function
+ *
+ * Return:	True if this context still owns the console. False if
+ *		ownership was handed over or taken.
+ *
+ * It is used in nbcon_enter_unsafe() to make sure that it still owns the
+ * lock. Also it is used in nbcon_exit_unsafe() to eventually free the lock
+ * for a higher priority context which asked for the friendly handover.
+ *
+ * It can be called inside an unsafe section when the console is just
+ * temporary in safe state instead of exiting and entering the unsafe state.
+ *
+ * Also it can be called in the safe context before doing an expensive safe
+ * operation. It does not make sense to do the operation when a higher
+ * priority context took the lock.
+ *
+ * When this function returns false then the calling context no longer owns
+ * the console and is no longer allowed to go forward. In this case it must
+ * back out immediately and carefully. The buffer content is also no longer
+ * trusted since it no longer belongs to the calling context.
+ */
+bool nbcon_can_proceed(struct nbcon_write_context *wctxt)
+{
+	struct nbcon_context *ctxt = &ACCESS_PRIVATE(wctxt, ctxt);
+	struct console *con = ctxt->console;
+	struct nbcon_state cur;
+
+	nbcon_state_read(con, &cur);
+
+	return nbcon_context_can_proceed(ctxt, &cur);
+}
+EXPORT_SYMBOL_GPL(nbcon_can_proceed);
+
+#define nbcon_context_enter_unsafe(c)	__nbcon_context_update_unsafe(c, true)
+#define nbcon_context_exit_unsafe(c)	__nbcon_context_update_unsafe(c, false)
+
+/**
+ * __nbcon_context_update_unsafe - Update the unsafe bit in @con->nbcon_state
+ * @ctxt:	The nbcon context from nbcon_context_try_acquire()
+ * @unsafe:	The new value for the unsafe bit
+ *
+ * Return:	True if the unsafe state was updated and this context still
+ *		owns the console. Otherwise false if ownership was handed
+ *		over or taken.
+ *
+ * This function allows console owners to modify the unsafe status of the
+ * console.
+ *
+ * When this function returns false then the calling context no longer owns
+ * the console and is no longer allowed to go forward. In this case it must
+ * back out immediately and carefully. The buffer content is also no longer
+ * trusted since it no longer belongs to the calling context.
+ *
+ * Internal helper to avoid duplicated code.
+ */
+static bool __nbcon_context_update_unsafe(struct nbcon_context *ctxt, bool unsafe)
+{
+	struct console *con = ctxt->console;
+	struct nbcon_state cur;
+	struct nbcon_state new;
+
+	nbcon_state_read(con, &cur);
+
+	do {
+		/*
+		 * The unsafe bit must not be cleared if an
+		 * unsafe hostile takeover has occurred.
+		 */
+		if (!unsafe && cur.unsafe_takeover)
+			goto out;
+
+		if (!nbcon_context_can_proceed(ctxt, &cur))
+			return false;
+
+		new.atom = cur.atom;
+		new.unsafe = unsafe;
+	} while (!nbcon_state_try_cmpxchg(con, &cur, &new));
+
+	cur.atom = new.atom;
+out:
+	return nbcon_context_can_proceed(ctxt, &cur);
+}
+
+/**
+ * nbcon_enter_unsafe - Enter an unsafe region in the driver
+ * @wctxt:	The write context that was handed to the write function
+ *
+ * Return:	True if this context still owns the console. False if
+ *		ownership was handed over or taken.
+ *
+ * When this function returns false then the calling context no longer owns
+ * the console and is no longer allowed to go forward. In this case it must
+ * back out immediately and carefully. The buffer content is also no longer
+ * trusted since it no longer belongs to the calling context.
+ */
+bool nbcon_enter_unsafe(struct nbcon_write_context *wctxt)
+{
+	struct nbcon_context *ctxt = &ACCESS_PRIVATE(wctxt, ctxt);
+
+	return nbcon_context_enter_unsafe(ctxt);
+}
+EXPORT_SYMBOL_GPL(nbcon_enter_unsafe);
+
+/**
+ * nbcon_exit_unsafe - Exit an unsafe region in the driver
+ * @wctxt:	The write context that was handed to the write function
+ *
+ * Return:	True if this context still owns the console. False if
+ *		ownership was handed over or taken.
+ *
+ * When this function returns false then the calling context no longer owns
+ * the console and is no longer allowed to go forward. In this case it must
+ * back out immediately and carefully. The buffer content is also no longer
+ * trusted since it no longer belongs to the calling context.
+ */
+bool nbcon_exit_unsafe(struct nbcon_write_context *wctxt)
+{
+	struct nbcon_context *ctxt = &ACCESS_PRIVATE(wctxt, ctxt);
+
+	return nbcon_context_exit_unsafe(ctxt);
+}
+EXPORT_SYMBOL_GPL(nbcon_exit_unsafe);
+
+/**
+ * nbcon_reacquire - Reacquire a console after losing ownership
+ * @wctxt:	The write context that was handed to the write function
+ *
+ * Since ownership can be lost at any time due to handover or takeover, a
+ * printing context _should_ be prepared to back out immediately and
+ * carefully. However, there are many scenarios where the context _must_
+ * reacquire ownership in order to finalize or revert hardware changes.
+ *
+ * This function allows a context to reacquire ownership using the same
+ * priority as its previous ownership.
+ *
+ * Note that for printing contexts, after a successful reacquire the
+ * context will have no output buffer because that has been lost. This
+ * function cannot be used to resume printing.
+ */
+void nbcon_reacquire(struct nbcon_write_context *wctxt)
+{
+	struct nbcon_context *ctxt = &ACCESS_PRIVATE(wctxt, ctxt);
+	struct console *con = ctxt->console;
+	struct nbcon_state cur;
+
+	while (!nbcon_context_try_acquire(ctxt))
+		cpu_relax();
+
+	wctxt->outbuf = NULL;
+	wctxt->len = 0;
+	nbcon_state_read(con, &cur);
+	wctxt->unsafe_takeover = cur.unsafe_takeover;
+}
+EXPORT_SYMBOL_GPL(nbcon_reacquire);
+
+/**
+ * nbcon_emit_next_record - Emit a record in the acquired context
+ * @wctxt:	The write context that will be handed to the write function
+ * @use_atomic:	True if the write_atomic callback is to be used
+ *
+ * Return:	True if this context still owns the console. False if
+ *		ownership was handed over or taken.
+ *
+ * When this function returns false then the calling context no longer owns
+ * the console and is no longer allowed to go forward. In this case it must
+ * back out immediately and carefully. The buffer content is also no longer
+ * trusted since it no longer belongs to the calling context. If the caller
+ * wants to do more it must reacquire the console first.
+ *
+ * When true is returned, @wctxt->ctxt.backlog indicates whether there are
+ * still records pending in the ringbuffer,
+ */
+static bool nbcon_emit_next_record(struct nbcon_write_context *wctxt, bool use_atomic)
+{
+	struct nbcon_context *ctxt = &ACCESS_PRIVATE(wctxt, ctxt);
+	struct console *con = ctxt->console;
+	bool is_extended = console_srcu_read_flags(con) & CON_EXTENDED;
+	struct printk_message pmsg = {
+		.pbufs = ctxt->pbufs,
+	};
+	unsigned long con_dropped;
+	struct nbcon_state cur;
+	unsigned long dropped;
+	bool done = false;
+
+	/*
+	 * The printk buffers are filled within an unsafe section. This
+	 * prevents NBCON_PRIO_NORMAL and NBCON_PRIO_EMERGENCY from
+	 * clobbering each other.
+	 */
+
+	if (!nbcon_context_enter_unsafe(ctxt))
+		return false;
+
+	ctxt->backlog = printk_get_next_message(&pmsg, ctxt->seq, is_extended, true);
+	if (!ctxt->backlog)
+		return nbcon_context_exit_unsafe(ctxt);
+
+	/*
+	 * @con->dropped is not protected in case of an unsafe hostile
+	 * takeover. In that situation the update can be racy so
+	 * annotate it accordingly.
+	 */
+	con_dropped = data_race(READ_ONCE(con->dropped));
+
+	dropped = con_dropped + pmsg.dropped;
+	if (dropped && !is_extended)
+		console_prepend_dropped(&pmsg, dropped);
+
+	if (!nbcon_context_exit_unsafe(ctxt))
+		return false;
+
+	/* For skipped records just update seq/dropped in @con. */
+	if (pmsg.outbuf_len == 0)
+		goto update_con;
+
+	/* Initialize the write context for driver callbacks. */
+	wctxt->outbuf = &pmsg.pbufs->outbuf[0];
+	wctxt->len = pmsg.outbuf_len;
+	nbcon_state_read(con, &cur);
+	wctxt->unsafe_takeover = cur.unsafe_takeover;
+
+	if (use_atomic &&
+	    con->write_atomic) {
+		done = con->write_atomic(con, wctxt);
+
+	} else if (!use_atomic &&
+		   con->write_thread &&
+		   con->kthread) {
+		WARN_ON_ONCE(con->kthread != current);
+		done = con->write_thread(con, wctxt);
+	}
+
+	if (!done) {
+		/*
+		 * The emit was aborted, probably due to a loss of ownership.
+		 * Ensure ownership was lost or released before reporting the
+		 * loss.
+		 */
+		nbcon_context_release(ctxt);
+		return false;
+	}
+
+	/*
+	 * Since any dropped message was successfully output, reset the
+	 * dropped count for the console.
+	 */
+	dropped = 0;
+update_con:
+	/*
+	 * The dropped count and the sequence number are updated within an
+	 * unsafe section. This limits update races to the panic context and
+	 * allows the panic context to win.
+	 */
+
+	if (!nbcon_context_enter_unsafe(ctxt))
+		return false;
+
+	if (dropped != con_dropped) {
+		/* Counterpart to the READ_ONCE() above. */
+		WRITE_ONCE(con->dropped, dropped);
+	}
+
+	nbcon_seq_try_update(ctxt, pmsg.seq + 1);
+
+	return nbcon_context_exit_unsafe(ctxt);
+}
+
+/**
+ * nbcon_kthread_should_wakeup - Check whether a printer thread should wakeup
+ * @con:	Console to operate on
+ * @ctxt:	The acquire context that contains the state
+ *		at console_acquire()
+ *
+ * Return:	True if the thread should shutdown or if the console is
+ *		allowed to print and a record is available. False otherwise.
+ *
+ * After the thread wakes up, it must first check if it should shutdown before
+ * attempting any printing.
+ */
+static bool nbcon_kthread_should_wakeup(struct console *con, struct nbcon_context *ctxt)
+{
+	bool is_usable;
+	short flags;
+	int cookie;
+
+	if (kthread_should_stop())
+		return true;
+
+	cookie = console_srcu_read_lock();
+	flags = console_srcu_read_flags(con);
+	is_usable = console_is_usable(con, flags, false);
+	console_srcu_read_unlock(cookie);
+
+	if (!is_usable)
+		return false;
+
+	/* Bring the sequence in @ctxt up to date */
+	ctxt->seq = nbcon_seq_read(con);
+
+	return prb_read_valid(prb, ctxt->seq, NULL);
+}
+
+/**
+ * nbcon_kthread_func - The printer thread function
+ * @__console:	Console to operate on
+ */
+static int nbcon_kthread_func(void *__console)
+{
+	struct console *con = __console;
+	struct nbcon_write_context wctxt = {
+		.ctxt.console	= con,
+		.ctxt.prio	= NBCON_PRIO_NORMAL,
+	};
+	struct nbcon_context *ctxt = &ACCESS_PRIVATE(&wctxt, ctxt);
+	unsigned long flags;
+	short con_flags;
+	bool backlog;
+	int cookie;
+	int ret;
+
+wait_for_event:
+	/*
+	 * Guarantee this task is visible on the rcuwait before
+	 * checking the wake condition.
+	 *
+	 * The full memory barrier within set_current_state() of
+	 * ___rcuwait_wait_event() pairs with the full memory
+	 * barrier within rcuwait_has_sleeper().
+	 *
+	 * This pairs with rcuwait_has_sleeper:A and nbcon_kthread_wake:A.
+	 */
+	ret = rcuwait_wait_event(&con->rcuwait,
+				 nbcon_kthread_should_wakeup(con, ctxt),
+				 TASK_INTERRUPTIBLE); /* LMM(nbcon_kthread_func:A) */
+
+	if (kthread_should_stop())
+		return 0;
+
+	/* Wait was interrupted by a spurious signal, go back to sleep. */
+	if (ret)
+		goto wait_for_event;
+
+	do {
+		backlog = false;
+
+		cookie = console_srcu_read_lock();
+
+		con_flags = console_srcu_read_flags(con);
+
+		if (console_is_usable(con, con_flags, false)) {
+			con->driver_enter(con, &flags);
+
+			/*
+			 * Ensure this stays on the CPU to make handover and
+			 * takeover possible.
+			 */
+			cant_migrate();
+
+			if (nbcon_context_try_acquire(ctxt)) {
+				/*
+				 * If the emit fails, this context is no
+				 * longer the owner.
+				 */
+				if (nbcon_emit_next_record(&wctxt, false)) {
+					nbcon_context_release(ctxt);
+					backlog = ctxt->backlog;
+				}
+			}
+
+			con->driver_exit(con, flags);
+		}
+
+		console_srcu_read_unlock(cookie);
+
+	} while (backlog);
+
+	goto wait_for_event;
+}
+
+/**
+ * nbcon_irq_work - irq work to wake printk thread
+ * @irq_work:	The irq work to operate on
+ */
+static void nbcon_irq_work(struct irq_work *irq_work)
+{
+	struct console *con = container_of(irq_work, struct console, irq_work);
+
+	nbcon_kthread_wake(con);
+}
+
+static inline bool rcuwait_has_sleeper(struct rcuwait *w)
+{
+	bool has_sleeper;
+
+	rcu_read_lock();
+	/*
+	 * Guarantee any new records can be seen by tasks preparing to wait
+	 * before this context checks if the rcuwait is empty.
+	 *
+	 * This full memory barrier pairs with the full memory barrier within
+	 * set_current_state() of ___rcuwait_wait_event(), which is called
+	 * after prepare_to_rcuwait() adds the waiter but before it has
+	 * checked the wait condition.
+	 *
+	 * This pairs with nbcon_kthread_func:A.
+	 */
+	smp_mb(); /* LMM(rcuwait_has_sleeper:A) */
+	has_sleeper = !!rcu_dereference(w->task);
+	rcu_read_unlock();
+
+	return has_sleeper;
+}
+
+/**
+ * nbcon_wake_threads - Wake up printing threads using irq_work
+ */
+void nbcon_wake_threads(void)
+{
+	struct console *con;
+	int cookie;
+
+	cookie = console_srcu_read_lock();
+	for_each_console_srcu(con) {
+		/*
+		 * Only schedule irq_work if the printing thread is
+		 * actively waiting. If not waiting, the thread will
+		 * notice by itself that it has work to do.
+		 */
+		if (con->kthread && rcuwait_has_sleeper(&con->rcuwait))
+			irq_work_queue(&con->irq_work);
+	}
+	console_srcu_read_unlock(cookie);
+}
+
+/* Track the nbcon emergency nesting per CPU. */
+static DEFINE_PER_CPU(unsigned int, nbcon_pcpu_emergency_nesting);
+static unsigned int early_nbcon_pcpu_emergency_nesting __initdata;
+
+/**
+ * nbcon_get_cpu_emergency_nesting - Get the per CPU emergency nesting pointer
+ *
+ * Return:	Either a pointer to the per CPU emergency nesting counter of
+ *		the current CPU or to the init data during early boot.
+ */
+static __ref unsigned int *nbcon_get_cpu_emergency_nesting(void)
+{
+	/*
+	 * The value of __printk_percpu_data_ready gets set in normal
+	 * context and before SMP initialization. As a result it could
+	 * never change while inside an nbcon emergency section.
+	 */
+	if (!printk_percpu_data_ready())
+		return &early_nbcon_pcpu_emergency_nesting;
+
+	return this_cpu_ptr(&nbcon_pcpu_emergency_nesting);
+}
+
+/**
+ * nbcon_atomic_emit_one - Print one record for an nbcon console using the
+ *				write_atomic() callback
+ * @wctxt:	An initialized write context struct to use
+ *		for this context
+ *
+ * Return:	False if the given console could not print a record or there
+ *		are no more records to print, otherwise true.
+ *
+ * This is an internal helper to handle the locking of the console before
+ * calling nbcon_emit_next_record().
+ */
+static bool nbcon_atomic_emit_one(struct nbcon_write_context *wctxt)
+{
+	struct nbcon_context *ctxt = &ACCESS_PRIVATE(wctxt, ctxt);
+
+	if (!nbcon_context_try_acquire(ctxt))
+		return false;
+
+	/*
+	 * nbcon_emit_next_record() returns false when the console was
+	 * handed over or taken over. In both cases the context is no
+	 * longer valid.
+	 */
+	if (!nbcon_emit_next_record(wctxt, true))
+		return false;
+
+	nbcon_context_release(ctxt);
+
+	return ctxt->backlog;
+}
+
+/**
+ * nbcon_get_default_prio - The appropriate nbcon priority to use for nbcon
+ *				printing on the current CPU
+ *
+ * Context:	Any context which could not be migrated to another CPU.
+ * Return:	The nbcon_prio to use for acquiring an nbcon console in this
+ *		context for printing.
+ */
+enum nbcon_prio nbcon_get_default_prio(void)
+{
+	unsigned int *cpu_emergency_nesting;
+
+	if (this_cpu_in_panic())
+		return NBCON_PRIO_PANIC;
+
+	cpu_emergency_nesting = nbcon_get_cpu_emergency_nesting();
+	if (*cpu_emergency_nesting)
+		return NBCON_PRIO_EMERGENCY;
+
+	return NBCON_PRIO_NORMAL;
+}
+
+/**
+ * nbcon_atomic_emit_next_record - Print one record for an nbcon console
+ *					using the write_atomic() callback
+ * @con:	The console to print on
+ * @handover:	Will be set to true if a printk waiter has taken over the
+ *		console_lock, in which case the caller is no longer holding
+ *		both the console_lock and the SRCU read lock. Otherwise it
+ *		is set to false.
+ * @cookie:	The cookie from the SRCU read lock.
+ *
+ * Context:	Any context which could not be migrated to another CPU.
+ * Return:	True if a record could be printed, otherwise false.
+ *
+ * This function is meant to be called by console_flush_all() to print records
+ * on nbcon consoles using the write_atomic() callback. Essentially it is the
+ * nbcon version of console_emit_next_record().
+ */
+bool nbcon_atomic_emit_next_record(struct console *con, bool *handover, int cookie)
+{
+	struct nbcon_write_context wctxt = { };
+	struct nbcon_context *ctxt = &ACCESS_PRIVATE(&wctxt, ctxt);
+	unsigned long driver_flags;
+	bool progress = false;
+	unsigned long flags;
+
+	*handover = false;
+
+	/* Use the same locking order as console_emit_next_record(). */
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
+		printk_safe_enter_irqsave(flags);
+		console_lock_spinning_enable();
+		stop_critical_timings();
+	}
+
+	con->driver_enter(con, &driver_flags);
+	cant_migrate();
+
+	ctxt->console	= con;
+	ctxt->prio	= nbcon_get_default_prio();
+
+	progress = nbcon_atomic_emit_one(&wctxt);
+
+	con->driver_exit(con, driver_flags);
+
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
+		start_critical_timings();
+		*handover = console_lock_spinning_disable_and_check(cookie);
+		printk_safe_exit_irqrestore(flags);
+	}
+
+	return progress;
+}
+
+/**
+ * __nbcon_atomic_flush_all - Flush all nbcon consoles using their
+ *					write_atomic() callback
+ * @stop_seq:			Flush up until this record
+ * @allow_unsafe_takeover:	True, to allow unsafe hostile takeovers
+ */
+static void __nbcon_atomic_flush_all(u64 stop_seq, bool allow_unsafe_takeover)
+{
+	struct nbcon_write_context wctxt = { };
+	struct nbcon_context *ctxt = &ACCESS_PRIVATE(&wctxt, ctxt);
+	struct console *con;
+	bool any_progress;
+	int cookie;
+
+	do {
+		any_progress = false;
+
+		cookie = console_srcu_read_lock();
+		for_each_console_srcu(con) {
+			short flags = console_srcu_read_flags(con);
+			unsigned long irq_flags;
+
+			if (!(flags & CON_NBCON))
+				continue;
+
+			if (!console_is_usable(con, flags, true))
+				continue;
+
+			if (nbcon_seq_read(con) >= stop_seq)
+				continue;
+
+			memset(ctxt, 0, sizeof(*ctxt));
+			ctxt->console			= con;
+			ctxt->spinwait_max_us		= 2000;
+			ctxt->allow_unsafe_takeover	= allow_unsafe_takeover;
+
+			/*
+			 * Atomic flushing does not use console driver
+			 * synchronization (i.e. it does not hold the port
+			 * lock for uart consoles). Therefore IRQs must be
+			 * disabled to avoid being interrupted and then
+			 * calling into a driver that will deadlock trying
+			 * acquire console ownership.
+			 *
+			 * This also disables migration in order to get the
+			 * current CPU priority.
+			 */
+			local_irq_save(irq_flags);
+
+			ctxt->prio = nbcon_get_default_prio();
+
+			any_progress |= nbcon_atomic_emit_one(&wctxt);
+
+			local_irq_restore(irq_flags);
+		}
+		console_srcu_read_unlock(cookie);
+	} while (any_progress);
+}
+
+/**
+ * nbcon_atomic_flush_all - Flush all nbcon consoles using their
+ *				write_atomic() callback
+ *
+ * Flush the backlog up through the currently newest record. Any new
+ * records added while flushing will not be flushed. This is to avoid
+ * one CPU printing unbounded because other CPUs continue to add records.
+ */
+void nbcon_atomic_flush_all(void)
+{
+	__nbcon_atomic_flush_all(prb_next_reserve_seq(prb), false);
+}
+
+/**
+ * nbcon_atomic_flush_unsafe - Flush all nbcon consoles using their
+ *	write_atomic() callback and allowing unsafe hostile takeovers
+ *
+ * Flush the backlog up through the currently newest record. Unsafe hostile
+ * takeovers will be performed, if necessary.
+ */
+void nbcon_atomic_flush_unsafe(void)
+{
+	__nbcon_atomic_flush_all(prb_next_reserve_seq(prb), true);
+}
+
+/**
+ * nbcon_cpu_emergency_enter - Enter an emergency section where printk()
+ *	messages for that CPU are only stored
+ *
+ * Upon exiting the emergency section, all stored messages are flushed.
+ *
+ * Context:	Any context. Disables preemption.
+ *
+ * When within an emergency section, no printing occurs on that CPU. This
+ * is to allow all emergency messages to be dumped into the ringbuffer before
+ * flushing the ringbuffer. The actual printing occurs when exiting the
+ * outermost emergency section.
+ */
+void nbcon_cpu_emergency_enter(void)
+{
+	unsigned int *cpu_emergency_nesting;
+
+	preempt_disable();
+
+	cpu_emergency_nesting = nbcon_get_cpu_emergency_nesting();
+	(*cpu_emergency_nesting)++;
+}
+
+/**
+ * nbcon_cpu_emergency_exit - Exit an emergency section and flush the
+ *	stored messages
+ *
+ * Flushing only occurs when exiting all nesting for the CPU.
+ *
+ * Context:	Any context. Enables preemption.
+ */
+void nbcon_cpu_emergency_exit(void)
+{
+	unsigned int *cpu_emergency_nesting;
+	bool do_trigger_flush = false;
+
+	cpu_emergency_nesting = nbcon_get_cpu_emergency_nesting();
+
+	WARN_ON_ONCE(*cpu_emergency_nesting == 0);
+
+	if (*cpu_emergency_nesting == 1)
+		do_trigger_flush = true;
+
+	/* Undo the nesting count of nbcon_cpu_emergency_enter(). */
+	(*cpu_emergency_nesting)--;
+
+	preempt_enable();
+
+	if (do_trigger_flush)
+		printk_trigger_flush();
+}
+
+/**
+ * nbcon_kthread_stop - Stop a printer thread
+ * @con:	Console to operate on
+ */
+static void nbcon_kthread_stop(struct console *con)
+{
+	lockdep_assert_console_list_lock_held();
+
+	if (!con->kthread)
+		return;
+
+	kthread_stop(con->kthread);
+	con->kthread = NULL;
+}
+
+/**
+ * nbcon_kthread_create - Create a printer thread
+ * @con:	Console to operate on
+ *
+ * If it fails, let the console proceed. The atomic part might
+ * be usable and useful.
+ */
+void nbcon_kthread_create(struct console *con)
+{
+	struct task_struct *kt;
+
+	lockdep_assert_console_list_lock_held();
+
+	if (!(con->flags & CON_NBCON) || !con->write_thread)
+		return;
+
+	if (!printk_threads_enabled || con->kthread)
+		return;
+
+	/*
+	 * Printer threads cannot be started as long as any boot console is
+	 * registered because there is no way to synchronize the hardware
+	 * registers between boot console code and regular console code.
+	 */
+	if (have_boot_console)
+		return;
+
+	kt = kthread_run(nbcon_kthread_func, con, "pr/%s%d", con->name, con->index);
+	if (IS_ERR(kt)) {
+		con_printk(KERN_ERR, con, "failed to start printing thread\n");
+		return;
+	}
+
+	con->kthread = kt;
+
+	/*
+	 * It is important that console printing threads are scheduled
+	 * shortly after a printk call and with generous runtime budgets.
+	 */
+	sched_set_normal(con->kthread, -20);
+}
+
+static int __init printk_setup_threads(void)
+{
+	struct console *con;
+
+	console_list_lock();
+	printk_threads_enabled = true;
+	for_each_console(con)
+		nbcon_kthread_create(con);
+	if (IS_ENABLED(CONFIG_PREEMPT_RT) && printing_via_unlock)
+		nbcon_legacy_kthread_create();
+	console_list_unlock();
+	return 0;
+}
+early_initcall(printk_setup_threads);
+
+/**
+ * nbcon_alloc - Allocate buffers needed by the nbcon console
+ * @con:	Console to allocate buffers for
+ *
+ * Return:	True on success. False otherwise and the console cannot
+ *		be used.
+ *
+ * This is not part of nbcon_init() because buffer allocation must
+ * be performed earlier in the console registration process.
+ */
+bool nbcon_alloc(struct console *con)
+{
+	if (con->flags & CON_BOOT) {
+		/*
+		 * Boot console printing is synchronized with legacy console
+		 * printing, so boot consoles can share the same global printk
+		 * buffers.
+		 */
+		con->pbufs = &printk_shared_pbufs;
+	} else {
+		con->pbufs = kmalloc(sizeof(*con->pbufs), GFP_KERNEL);
+		if (!con->pbufs) {
+			con_printk(KERN_ERR, con, "failed to allocate printing buffer\n");
+			return false;
+		}
+	}
+
+	return true;
+}
+
+/**
+ * nbcon_init - Initialize the nbcon console specific data
+ * @con:	Console to initialize
+ *
+ * nbcon_alloc() *must* be called and succeed before this function
+ * is called.
+ *
+ * This function expects that the legacy @con->seq has been set.
+ */
+void nbcon_init(struct console *con)
+{
+	struct nbcon_state state = { };
+
+	/* nbcon_alloc() must have been called and successful! */
+	BUG_ON(!con->pbufs);
+
+	rcuwait_init(&con->rcuwait);
+	init_irq_work(&con->irq_work, nbcon_irq_work);
+	nbcon_seq_force(con, con->seq);
+	nbcon_state_set(con, &state);
+	nbcon_kthread_create(con);
+}
+
+/**
+ * nbcon_free - Free and cleanup the nbcon console specific data
+ * @con:	Console to free/cleanup nbcon data
+ */
+void nbcon_free(struct console *con)
+{
+	struct nbcon_state state = { };
+
+	nbcon_kthread_stop(con);
+	nbcon_state_set(con, &state);
+
+	/* Boot consoles share global printk buffers. */
+	if (!(con->flags & CON_BOOT))
+		kfree(con->pbufs);
+
+	con->pbufs = NULL;
+}
+
+static inline bool uart_is_nbcon(struct uart_port *up)
+{
+	int cookie;
+	bool ret;
+
+	if (!uart_console(up))
+		return false;
+
+	cookie = console_srcu_read_lock();
+	ret = (console_srcu_read_flags(up->cons) & CON_NBCON);
+	console_srcu_read_unlock(cookie);
+	return ret;
+}
+
+/**
+ * nbcon_acquire - The second half of the port locking wrapper
+ * @up:		The uart port whose @lock was locked
+ *
+ * The uart_port_lock() wrappers will first lock the spin_lock @up->lock.
+ * Then this function is called to implement nbcon-specific processing.
+ *
+ * If @up is an nbcon console, this console will be acquired and marked as
+ * unsafe. Otherwise this function does nothing.
+ *
+ * nbcon consoles acquired via the port lock wrapper always use priority
+ * NBCON_PRIO_NORMAL.
+ */
+void nbcon_acquire(struct uart_port *up)
+{
+	struct console *con = up->cons;
+	struct nbcon_context ctxt;
+
+	if (!uart_is_nbcon(up))
+		return;
+
+	WARN_ON_ONCE(con->locked_port);
+
+	do {
+		do {
+			memset(&ctxt, 0, sizeof(ctxt));
+			ctxt.console	= con;
+			ctxt.prio	= NBCON_PRIO_NORMAL;
+		} while (!nbcon_context_try_acquire(&ctxt));
+
+	} while (!nbcon_context_enter_unsafe(&ctxt));
+
+	con->locked_port = true;
+}
+EXPORT_SYMBOL_GPL(nbcon_acquire);
+
+/**
+ * nbcon_release - The first half of the port unlocking wrapper
+ * @up:		The uart port whose @lock is about to be unlocked
+ *
+ * The uart_port_unlock() wrappers will first call this function to implement
+ * nbcon-specific processing. Then afterwards the uart_port_unlock() wrappers
+ * will unlock the spin_lock @up->lock.
+ *
+ * If @up is an nbcon console, the console will be marked as safe and
+ * released. Otherwise this function does nothing.
+ *
+ * nbcon consoles acquired via the port lock wrapper always use priority
+ * NBCON_PRIO_NORMAL.
+ */
+void nbcon_release(struct uart_port *up)
+{
+	struct console *con = up->cons;
+	struct nbcon_context ctxt = {
+		.console	= con,
+		.prio		= NBCON_PRIO_NORMAL,
+	};
+
+	if (!con->locked_port)
+		return;
+
+	if (nbcon_context_exit_unsafe(&ctxt))
+		nbcon_context_release(&ctxt);
+
+	con->locked_port = false;
+}
+EXPORT_SYMBOL_GPL(nbcon_release);
+
+/**
+ * printk_kthread_shutdown - shutdown all threaded printers
+ *
+ * On system shutdown all threaded printers are stopped. This allows printk
+ * to transition back to atomic printing, thus providing a robust mechanism
+ * for the final shutdown/reboot messages to be output.
+ */
+static void printk_kthread_shutdown(void)
+{
+	struct console *con;
+
+	console_list_lock();
+	for_each_console(con) {
+		if (con->flags & CON_NBCON)
+			nbcon_kthread_stop(con);
+	}
+	console_list_unlock();
+}
+
+static struct syscore_ops printk_syscore_ops = {
+	.shutdown = printk_kthread_shutdown,
+};
+
+static int __init printk_init_ops(void)
+{
+	register_syscore_ops(&printk_syscore_ops);
+	return 0;
+}
+device_initcall(printk_init_ops);
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index c3aff0ba526d..ddf79752c80c 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -102,12 +102,6 @@ DEFINE_STATIC_SRCU(console_srcu);
  */
 int __read_mostly suppress_printk;
 
-/*
- * During panic, heavy printk by other CPUs can delay the
- * panic and risk deadlock on console resources.
- */
-static int __read_mostly suppress_panic_printk;
-
 #ifdef CONFIG_LOCKDEP
 static struct lockdep_map console_lock_dep_map = {
 	.name = "console_lock"
@@ -288,6 +282,7 @@ EXPORT_SYMBOL(console_list_unlock);
  * Return: A cookie to pass to console_srcu_read_unlock().
  */
 int console_srcu_read_lock(void)
+	__acquires(&console_srcu)
 {
 	return srcu_read_lock_nmisafe(&console_srcu);
 }
@@ -301,6 +296,7 @@ EXPORT_SYMBOL(console_srcu_read_lock);
  * Counterpart to console_srcu_read_lock()
  */
 void console_srcu_read_unlock(int cookie)
+	__releases(&console_srcu)
 {
 	srcu_read_unlock_nmisafe(&console_srcu, cookie);
 }
@@ -353,6 +349,29 @@ static bool panic_in_progress(void)
 	return unlikely(atomic_read(&panic_cpu) != PANIC_CPU_INVALID);
 }
 
+/* Return true if a panic is in progress on the current CPU. */
+bool this_cpu_in_panic(void)
+{
+	/*
+	 * We can use raw_smp_processor_id() here because it is impossible for
+	 * the task to be migrated to the panic_cpu, or away from it. If
+	 * panic_cpu has already been set, and we're not currently executing on
+	 * that CPU, then we never will be.
+	 */
+	return unlikely(atomic_read(&panic_cpu) == raw_smp_processor_id());
+}
+
+/*
+ * Return true if a panic is in progress on a remote CPU.
+ *
+ * On true, the local CPU should immediately release any printing resources
+ * that may be needed by the panic CPU.
+ */
+bool other_cpu_in_panic(void)
+{
+	return (panic_in_progress() && !this_cpu_in_panic());
+}
+
 /*
  * This is used for debugging the mess that is the VT code by
  * keeping track if we have the console semaphore held. It's
@@ -445,22 +464,32 @@ static int console_msg_format = MSG_FORMAT_DEFAULT;
 static DEFINE_MUTEX(syslog_lock);
 
 /*
- * Specifies if a BKL console was ever registered. Used to determine if the
- * console lock/unlock dance is needed for console printing.
+ * Specifies if a legacy console is registered. If legacy consoles are
+ * present, it is necessary to perform the console_lock/console_unlock dance
+ * whenever console flushing should occur.
  */
-bool have_bkl_console;
+bool have_legacy_console;
 
 /*
- * Specifies if a boot console is registered. Used to determine if NOBKL
- * consoles may be used since NOBKL consoles cannot synchronize with boot
- * consoles.
+ * Specifies if an nbcon console is registered. If nbcon consoles are present,
+ * synchronous printing of legacy consoles will not occur during panic until
+ * the backtrace has been stored to the ringbuffer.
  */
-bool have_boot_console;
+bool have_nbcon_console;
 
-static int unregister_console_locked(struct console *console);
+/*
+ * Specifies if a boot console is registered. If boot consoles are present,
+ * nbcon consoles cannot print simultaneously and must be synchronized by
+ * the console lock. This is because boot consoles and nbcon consoles may
+ * have mapped the same hardware.
+ */
+bool have_boot_console;
 
 #ifdef CONFIG_PRINTK
 DECLARE_WAIT_QUEUE_HEAD(log_wait);
+
+static DECLARE_WAIT_QUEUE_HEAD(legacy_wait);
+
 /* All 3 protected by @syslog_lock. */
 /* the next printk record to read by syslog(READ) or /proc/kmsg */
 static u64 syslog_seq;
@@ -1103,19 +1132,7 @@ static inline void log_buf_add_cpu(void) {}
 
 static void __init set_percpu_data_ready(void)
 {
-	struct hlist_node *tmp;
-	struct console *con;
-
-	console_list_lock();
-
-	hlist_for_each_entry_safe(con, tmp, &console_list, node) {
-		if (!cons_alloc_percpu_data(con))
-			unregister_console_locked(con);
-	}
-
 	__printk_percpu_data_ready = true;
-
-	console_list_unlock();
 }
 
 static unsigned int __init add_to_rb(struct printk_ringbuffer *rb,
@@ -1872,12 +1889,25 @@ static bool console_waiter;
  * there may be a waiter spinning (like a spinlock). Also it must be
  * ready to hand over the lock at the end of the section.
  */
-static void console_lock_spinning_enable(void)
+void console_lock_spinning_enable(void)
 {
+	/*
+	 * Do not use spinning in panic(). The panic CPU wants to keep the lock.
+	 * Non-panic CPUs abandon the flush anyway.
+	 *
+	 * Just keep the lockdep annotation. The panic-CPU should avoid
+	 * taking console_owner_lock because it might cause a deadlock.
+	 * This looks like the easiest way how to prevent false lockdep
+	 * reports without handling races a lockless way.
+	 */
+	if (panic_in_progress())
+		goto lockdep;
+
 	raw_spin_lock(&console_owner_lock);
 	console_owner = current;
 	raw_spin_unlock(&console_owner_lock);
 
+lockdep:
 	/* The waiter may spin on us after setting console_owner */
 	spin_acquire(&console_owner_dep_map, 0, 0, _THIS_IP_);
 }
@@ -1898,10 +1928,26 @@ static void console_lock_spinning_enable(void)
  *
  * Return: 1 if the lock rights were passed, 0 otherwise.
  */
-static int console_lock_spinning_disable_and_check(int cookie)
+int console_lock_spinning_disable_and_check(int cookie)
 {
 	int waiter;
 
+	/*
+	 * Ignore spinning waiters during panic() because they might get stopped
+	 * or blocked at any time,
+	 *
+	 * It is safe because nobody is allowed to start spinning during panic
+	 * in the first place. If there has been a waiter then non panic CPUs
+	 * might stay spinning. They would get stopped anyway. The panic context
+	 * will never start spinning and an interrupted spin on panic CPU will
+	 * never continue.
+	 */
+	if (panic_in_progress()) {
+		/* Keep lockdep happy. */
+		spin_release(&console_owner_dep_map, _THIS_IP_);
+		return 0;
+	}
+
 	raw_spin_lock(&console_owner_lock);
 	waiter = READ_ONCE(console_waiter);
 	console_owner = NULL;
@@ -2287,67 +2333,123 @@ int vprintk_store(int facility, int level,
 	return ret;
 }
 
+static bool legacy_allow_panic_sync;
+
+/*
+ * This acts as a one-way switch to allow legacy consoles to print from
+ * the printk() caller context on a panic CPU.
+ */
+void printk_legacy_allow_panic_sync(void)
+{
+	legacy_allow_panic_sync = true;
+}
+
 asmlinkage int vprintk_emit(int facility, int level,
 			    const struct dev_printk_info *dev_info,
 			    const char *fmt, va_list args)
 {
-	struct cons_write_context wctxt = { };
+	bool do_trylock_unlock = printing_via_unlock &&
+				 !IS_ENABLED(CONFIG_PREEMPT_RT);
 	int printed_len;
-	bool in_sched = false;
 
 	/* Suppress unimportant messages after panic happens */
 	if (unlikely(suppress_printk))
 		return 0;
 
-	if (unlikely(suppress_panic_printk) &&
-	    atomic_read(&panic_cpu) != raw_smp_processor_id())
+	/*
+	 * The messages on the panic CPU are the most important. If
+	 * non-panic CPUs are generating any messages, they will be
+	 * silently dropped.
+	 */
+	if (other_cpu_in_panic())
 		return 0;
 
 	if (level == LOGLEVEL_SCHED) {
 		level = LOGLEVEL_DEFAULT;
-		in_sched = true;
+		/* If called from the scheduler, we can not call up(). */
+		do_trylock_unlock = false;
 	}
 
 	printk_delay(level);
 
 	printed_len = vprintk_store(facility, level, dev_info, fmt, args);
 
-	/*
-	 * The caller may be holding system-critical or
-	 * timing-sensitive locks. Disable preemption during
-	 * printing of all remaining records to all consoles so that
-	 * this context can return as soon as possible. Hopefully
-	 * another printk() caller will take over the printing.
-	 */
-	preempt_disable();
+	if (!have_boot_console && have_nbcon_console) {
+		bool is_panic_context = this_cpu_in_panic();
 
-	/*
-	 * Flush the non-BKL consoles. This only leads to direct atomic
-	 * printing for non-BKL consoles that do not have a printer
-	 * thread available. Otherwise the printer thread will perform
-	 * the printing.
-	 */
-	cons_atomic_flush(&wctxt, true);
+		/*
+		 * In panic, the legacy consoles are not allowed to print from
+		 * the printk calling context unless explicitly allowed. This
+		 * gives the safe nbcon consoles a chance to print out all the
+		 * panic messages first. This restriction only applies if
+		 * there are nbcon consoles registered.
+		 */
+		if (is_panic_context)
+			do_trylock_unlock &= legacy_allow_panic_sync;
 
-	/* If called from the scheduler, we can not call up(). */
-	if (!in_sched && have_bkl_console && !IS_ENABLED(CONFIG_PREEMPT_RT)) {
 		/*
-		 * Try to acquire and then immediately release the console
-		 * semaphore. The release will print out buffers. With the
-		 * spinning variant, this context tries to take over the
-		 * printing from another printing context.
+		 * There are situations where nbcon atomic printing should
+		 * happen in the printk() caller context:
+		 *
+		 * - When this CPU is in panic.
+		 *
+		 * - When booting, before the printing threads have been
+		 *   started.
+		 *
+		 * - During shutdown, since the printing threads may not get
+		 *   a chance to print the final messages.
+		 *
+		 * Note that if boot consoles are registered, the
+		 * console_lock/console_unlock dance must be relied upon
+		 * instead because nbcon consoles cannot print simultaneously
+		 * with boot consoles.
 		 */
-		if (console_trylock_spinning())
-			console_unlock();
+		if (is_panic_context ||
+		    !printk_threads_enabled ||
+		    (system_state > SYSTEM_RUNNING)) {
+			nbcon_atomic_flush_all();
+		}
 	}
 
-	preempt_enable();
+	nbcon_wake_threads();
 
-	cons_wake_threads();
-	if (in_sched)
-		defer_console_output();
-	else
+	if (do_trylock_unlock) {
+		/*
+		 * The caller may be holding system-critical or
+		 * timing-sensitive locks. Disable preemption during
+		 * printing of all remaining records to all consoles so that
+		 * this context can return as soon as possible. Hopefully
+		 * another printk() caller will take over the printing.
+		 *
+		 * Also, nbcon_get_default_prio() requires migration disabled.
+		 */
+		preempt_disable();
+
+		/*
+		 * Do not emit for EMERGENCY priority. The console will be
+		 * explicitly flushed when exiting the emergency section.
+		 */
+		if (nbcon_get_default_prio() == NBCON_PRIO_EMERGENCY) {
+			do_trylock_unlock = false;
+		} else {
+			/*
+			 * Try to acquire and then immediately release the
+			 * console semaphore. The release will print out
+			 * buffers. With the spinning variant, this context
+			 * tries to take over the printing from another
+			 * printing context.
+			 */
+			if (console_trylock_spinning())
+				console_unlock();
+		}
+
+		preempt_enable();
+	}
+
+	if (do_trylock_unlock)
 		wake_up_klogd();
+	else
+		defer_console_output();
 
 	return printed_len;
 }
@@ -2375,6 +2477,14 @@ EXPORT_SYMBOL(_printk);
 static bool pr_flush(int timeout_ms, bool reset_on_progress);
 static bool __pr_flush(struct console *con, int timeout_ms, bool reset_on_progress);
 
+static struct task_struct *nbcon_legacy_kthread;
+
+static inline void wake_up_legacy_kthread(void)
+{
+	if (nbcon_legacy_kthread)
+		wake_up_interruptible(&legacy_wait);
+}
+
 #else /* CONFIG_PRINTK */
 
 #define printk_time		false
@@ -2385,25 +2495,11 @@ static bool __pr_flush(struct console *con, int timeout_ms, bool reset_on_progre
 
 static u64 syslog_seq;
 
-static size_t record_print_text(const struct printk_record *r,
-				bool syslog, bool time)
-{
-	return 0;
-}
-static ssize_t info_print_ext_header(char *buf, size_t size,
-				     struct printk_info *info)
-{
-	return 0;
-}
-static ssize_t msg_print_ext_body(char *buf, size_t size,
-				  char *text, size_t text_len,
-				  struct dev_printk_info *dev_info) { return 0; }
-static void console_lock_spinning_enable(void) { }
-static int console_lock_spinning_disable_and_check(int cookie) { return 0; }
-static bool suppress_message_printing(int level) { return false; }
 static bool pr_flush(int timeout_ms, bool reset_on_progress) { return true; }
 static bool __pr_flush(struct console *con, int timeout_ms, bool reset_on_progress) { return true; }
 
+static inline void nbcon_legacy_kthread_create(void) { }
+static inline void wake_up_legacy_kthread(void) { }
 #endif /* CONFIG_PRINTK */
 
 #ifdef CONFIG_EARLY_PRINTK
@@ -2629,16 +2725,19 @@ void resume_console(void)
 	 */
 	synchronize_srcu(&console_srcu);
 
+	/*
+	 * Since this runs in task context, wake the threaded printers
+	 * directly rather than scheduling irq_work to do it.
+	 */
 	cookie = console_srcu_read_lock();
 	for_each_console_srcu(con) {
 		flags = console_srcu_read_flags(con);
-		if (flags & CON_NO_BKL)
-			cons_kthread_wake(con);
+		if (flags & CON_NBCON)
+			nbcon_kthread_wake(con);
 	}
 	console_srcu_read_unlock(cookie);
 
-	if (IS_ENABLED(CONFIG_PREEMPT_RT) && have_bkl_console)
-		wake_up_interruptible(&log_wait);
+	wake_up_legacy_kthread();
 
 	pr_flush(1000, true);
 }
@@ -2654,7 +2753,8 @@ void resume_console(void)
  */
 static int console_cpu_notify(unsigned int cpu)
 {
-	if (!cpuhp_tasks_frozen && have_bkl_console) {
+	if (!cpuhp_tasks_frozen && printing_via_unlock &&
+	    !IS_ENABLED(CONFIG_PREEMPT_RT)) {
 		/* If trylock fails, someone else is doing the printing */
 		if (console_trylock())
 			console_unlock();
@@ -2662,26 +2762,6 @@ static int console_cpu_notify(unsigned int cpu)
 	return 0;
 }
 
-/*
- * Return true if a panic is in progress on a remote CPU.
- *
- * On true, the local CPU should immediately release any printing resources
- * that may be needed by the panic CPU.
- */
-bool other_cpu_in_panic(void)
-{
-	if (!panic_in_progress())
-		return false;
-
-	/*
-	 * We can use raw_smp_processor_id() here because it is impossible for
-	 * the task to be migrated to the panic_cpu, or away from it. If
-	 * panic_cpu has already been set, and we're not currently executing on
-	 * that CPU, then we never will be.
-	 */
-	return atomic_read(&panic_cpu) != raw_smp_processor_id();
-}
-
 /**
  * console_lock - block the console subsystem from printing
  *
@@ -2737,6 +2817,10 @@ static void __console_unlock(void)
 	up_console_sem();
 }
 
+static DEFINE_WAIT_OVERRIDE_MAP(printk_legacy_map, LD_WAIT_SLEEP);
+
+#ifdef CONFIG_PRINTK
+
 /*
  * Prepend the message in @pmsg->pbufs->outbuf with a "dropped message". This
  * is achieved by shifting the existing message over and inserting the dropped
@@ -2751,7 +2835,6 @@ static void __console_unlock(void)
  *
  * If @pmsg->pbufs->outbuf is modified, @pmsg->outbuf_len is updated.
  */
-#ifdef CONFIG_PRINTK
 void console_prepend_dropped(struct printk_message *pmsg, unsigned long dropped)
 {
 	struct printk_buffers *pbufs = pmsg->pbufs;
@@ -2783,10 +2866,6 @@ void console_prepend_dropped(struct printk_message *pmsg, unsigned long dropped)
 	memcpy(outbuf, scratchbuf, len);
 	pmsg->outbuf_len += len;
 }
-#else
-static inline void console_prepend_dropped(struct printk_message *pmsg,
-					   unsigned long dropped) { }
-#endif /* CONFIG_PRINTK */
 
 /*
  * Read and format the specified record (or a later record if the specified
@@ -2810,8 +2889,6 @@ static inline void console_prepend_dropped(struct printk_message *pmsg,
 bool printk_get_next_message(struct printk_message *pmsg, u64 seq,
 			     bool is_extended, bool may_suppress)
 {
-	static int panic_console_dropped;
-
 	struct printk_buffers *pbufs = pmsg->pbufs;
 	const size_t scratchbuf_sz = sizeof(pbufs->scratchbuf);
 	const size_t outbuf_sz = sizeof(pbufs->outbuf);
@@ -2839,17 +2916,6 @@ bool printk_get_next_message(struct printk_message *pmsg, u64 seq,
 	pmsg->seq = r.info->seq;
 	pmsg->dropped = r.info->seq - seq;
 
-	/*
-	 * Check for dropped messages in panic here so that printk
-	 * suppression can occur as early as possible if necessary.
-	 */
-	if (pmsg->dropped &&
-	    panic_in_progress() &&
-	    panic_console_dropped++ > 10) {
-		suppress_panic_printk = 1;
-		pr_warn_once("Too many dropped messages. Suppress messages on non-panic CPUs to prevent livelock.\n");
-	}
-
 	/* Skip record that has level above the console loglevel. */
 	if (may_suppress && suppress_message_printing(r.info->level))
 		goto out;
@@ -2866,6 +2932,13 @@ bool printk_get_next_message(struct printk_message *pmsg, u64 seq,
 	return true;
 }
 
+/*
+ * Used as the printk buffers for non-panic, serialized console printing.
+ * This is for legacy (!CON_NBCON) as well as all boot (CON_BOOT) consoles.
+ * Its usage requires the console_lock held.
+ */
+struct printk_buffers printk_shared_pbufs;
+
 /*
  * Print one record for the given console. The record printed is whatever
  * record is the next available record for the given console.
@@ -2883,12 +2956,10 @@ bool printk_get_next_message(struct printk_message *pmsg, u64 seq,
  */
 static bool console_emit_next_record(struct console *con, bool *handover, int cookie)
 {
-	static struct printk_buffers pbufs;
-
 	bool is_extended = console_srcu_read_flags(con) & CON_EXTENDED;
-	char *outbuf = &pbufs.outbuf[0];
+	char *outbuf = &printk_shared_pbufs.outbuf[0];
 	struct printk_message pmsg = {
-		.pbufs = &pbufs,
+		.pbufs = &printk_shared_pbufs,
 	};
 	unsigned long flags;
 
@@ -2910,35 +2981,59 @@ static bool console_emit_next_record(struct console *con, bool *handover, int co
 		con->dropped = 0;
 	}
 
-	/*
-	 * While actively printing out messages, if another printk()
-	 * were to occur on another CPU, it may wait for this one to
-	 * finish. This task can not be preempted if there is a
-	 * waiter waiting to take over.
-	 *
-	 * Interrupts are disabled because the hand over to a waiter
-	 * must not be interrupted until the hand over is completed
-	 * (@console_waiter is cleared).
-	 */
-	printk_safe_enter_irqsave(flags);
-	console_lock_spinning_enable();
+	/* Write everything out to the hardware. */
 
-	/* Do not trace print latency. */
-	stop_critical_timings();
+	if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
+		/*
+		 * On PREEMPT_RT this function is either in a thread or
+		 * panic context. So there is no need for concern about
+		 * printk reentrance, handovers, or lockdep complaints.
+		 */
 
-	/* Write everything out to the hardware. */
-	con->write(con, outbuf, pmsg.outbuf_len);
+		con->write(con, outbuf, pmsg.outbuf_len);
+		con->seq = pmsg.seq + 1;
+	} else {
+		/*
+		 * While actively printing out messages, if another printk()
+		 * were to occur on another CPU, it may wait for this one to
+		 * finish. This task can not be preempted if there is a
+		 * waiter waiting to take over.
+		 *
+		 * Interrupts are disabled because the hand over to a waiter
+		 * must not be interrupted until the hand over is completed
+		 * (@console_waiter is cleared).
+		 */
+		printk_safe_enter_irqsave(flags);
+		console_lock_spinning_enable();
 
-	start_critical_timings();
+		/* Do not trace print latency. */
+		stop_critical_timings();
 
-	con->seq = pmsg.seq + 1;
+		lock_map_acquire_try(&printk_legacy_map);
+		con->write(con, outbuf, pmsg.outbuf_len);
+		lock_map_release(&printk_legacy_map);
 
-	*handover = console_lock_spinning_disable_and_check(cookie);
-	printk_safe_exit_irqrestore(flags);
+		start_critical_timings();
+
+		con->seq = pmsg.seq + 1;
+
+		*handover = console_lock_spinning_disable_and_check(cookie);
+		printk_safe_exit_irqrestore(flags);
+	}
 skip:
 	return true;
 }
 
+#else
+
+static bool console_emit_next_record(struct console *con, bool *handover, int cookie)
+{
+	*handover = false;
+	return false;
+}
+
+#endif /* CONFIG_PRINTK */
+
 /*
  * Print out all remaining records to all consoles.
  *
@@ -2978,17 +3073,32 @@ static bool console_flush_all(bool do_cond_resched, u64 *next_seq, bool *handove
 		cookie = console_srcu_read_lock();
 		for_each_console_srcu(con) {
 			short flags = console_srcu_read_flags(con);
+			u64 printk_seq;
 			bool progress;
 
-			/* console_flush_all() is only for legacy consoles. */
-			if (flags & CON_NO_BKL)
+			/*
+			 * console_flush_all() is only for legacy consoles,
+			 * unless the nbcon console has no kthread printer.
+			 */
+			if ((flags & CON_NBCON) && con->kthread)
 				continue;
 
-			if (!console_is_usable(con, flags))
+			if (!console_is_usable(con, flags, true))
 				continue;
 			any_usable = true;
 
-			progress = console_emit_next_record(con, handover, cookie);
+			if (flags & CON_NBCON) {
+
+				lock_map_acquire_try(&printk_legacy_map);
+				progress = nbcon_atomic_emit_next_record(con, handover, cookie);
+				lock_map_release(&printk_legacy_map);
+
+				printk_seq = nbcon_seq_read(con);
+			} else {
+				progress = console_emit_next_record(con, handover, cookie);
+
+				printk_seq = con->seq;
+			}
 
 			/*
 			 * If a handover has occurred, the SRCU read lock
@@ -2998,8 +3108,8 @@ static bool console_flush_all(bool do_cond_resched, u64 *next_seq, bool *handove
 				return false;
 
 			/* Track the next of the highest seq flushed. */
-			if (con->seq > *next_seq)
-				*next_seq = con->seq;
+			if (printk_seq > *next_seq)
+				*next_seq = printk_seq;
 
 			if (!progress)
 				continue;
@@ -3022,7 +3132,7 @@ static bool console_flush_all(bool do_cond_resched, u64 *next_seq, bool *handove
 	return false;
 }
 
-static u64 console_flush_and_unlock(void)
+static void console_flush_and_unlock(void)
 {
 	bool do_cond_resched;
 	bool handover;
@@ -3065,8 +3175,6 @@ static u64 console_flush_and_unlock(void)
 		 * fails, another context is already handling the printing.
 		 */
 	} while (prb_read_valid(prb, next_seq, NULL) && console_trylock());
-
-	return next_seq;
 }
 
 /**
@@ -3118,9 +3226,6 @@ void console_unblank(void)
 	struct console *c;
 	int cookie;
 
-	if (!have_bkl_console)
-		return;
-
 	/*
 	 * First check if there are any consoles implementing the unblank()
 	 * callback. If not, there is no reason to continue and take the
@@ -3185,32 +3290,8 @@ void console_unblank(void)
  */
 void console_flush_on_panic(enum con_flush_mode mode)
 {
-	struct console *c;
 	bool handover;
 	u64 next_seq;
-	short flags;
-	int cookie;
-	u64 seq;
-
-	seq = prb_first_valid_seq(prb);
-
-	/*
-	 * Safely flush the atomic consoles before trying to flush any
-	 * BKL/legacy consoles.
-	 */
-	if (mode == CONSOLE_REPLAY_ALL) {
-		cookie = console_srcu_read_lock();
-		for_each_console_srcu(c) {
-			flags = console_srcu_read_flags(c);
-			if (flags & CON_NO_BKL)
-				cons_force_seq(c, seq);
-		}
-		console_srcu_read_unlock(cookie);
-	}
-	cons_atomic_flush(NULL, true);
-
-	if (!have_bkl_console)
-		return;
 
 	/*
 	 * Ignore the console lock and flush out the messages. Attempting a
@@ -3230,18 +3311,34 @@ void console_flush_on_panic(enum con_flush_mode mode)
 	console_may_schedule = 0;
 
 	if (mode == CONSOLE_REPLAY_ALL) {
+		struct console *c;
+		short flags;
+		int cookie;
+		u64 seq;
+
+		seq = prb_first_valid_seq(prb);
+
 		cookie = console_srcu_read_lock();
 		for_each_console_srcu(c) {
-			/*
-			 * This is an unsynchronized assignment, but the
-			 * kernel is in "hope and pray" mode anyway.
-			 */
-			c->seq = seq;
+			flags = console_srcu_read_flags(c);
+
+			if (flags & CON_NBCON) {
+				nbcon_seq_force(c, seq);
+			} else {
+				/*
+				 * This is an unsynchronized assignment. On
+				 * panic legacy consoles are only best effort.
+				 */
+				c->seq = seq;
+			}
 		}
 		console_srcu_read_unlock(cookie);
 	}
 
-	console_flush_all(false, &next_seq, &handover);
+	nbcon_atomic_flush_all();
+
+	if (printing_via_unlock)
+		console_flush_all(false, &next_seq, &handover);
 }
 
 /*
@@ -3312,18 +3409,17 @@ void console_start(struct console *console)
 	 */
 	synchronize_srcu(&console_srcu);
 
-	if (flags & CON_NO_BKL)
-		cons_kthread_wake(console);
-	else if (IS_ENABLED(CONFIG_PREEMPT_RT))
-		wake_up_interruptible(&log_wait);
+	if (flags & CON_NBCON)
+		nbcon_kthread_wake(console);
+	else
+		wake_up_legacy_kthread();
 
 	__pr_flush(console, 1000, true);
 }
 EXPORT_SYMBOL(console_start);
 
-static struct task_struct *console_bkl_kthread;
-
-static bool printer_should_wake(u64 seq)
+#ifdef CONFIG_PRINTK
+static bool printer_should_wake(void)
 {
 	bool available = false;
 	struct console *con;
@@ -3335,16 +3431,29 @@ static bool printer_should_wake(u64 seq)
 	cookie = console_srcu_read_lock();
 	for_each_console_srcu(con) {
 		short flags = console_srcu_read_flags(con);
+		u64 printk_seq;
 
-		if (flags & CON_NO_BKL)
-			continue;
-		if (!console_is_usable(con, flags))
-			continue;
 		/*
-		 * It is safe to read @seq because only this
-		 * thread context updates @seq.
+		 * The legacy printer thread is only for legacy consoles,
+		 * unless the nbcon console has no kthread printer.
 		 */
-		if (prb_read_valid(prb, con->seq, NULL)) {
+		if ((flags & CON_NBCON) && con->kthread)
+			continue;
+
+		if (!console_is_usable(con, flags, true))
+			continue;
+
+		if (flags & CON_NBCON) {
+			printk_seq = nbcon_seq_read(con);
+		} else {
+			/*
+			 * It is safe to read @seq because only this
+			 * thread context updates @seq.
+			 */
+			printk_seq = con->seq;
+		}
+
+		if (prb_read_valid(prb, printk_seq, NULL)) {
 			available = true;
 			break;
 		}
@@ -3354,13 +3463,12 @@ static bool printer_should_wake(u64 seq)
 	return available;
 }
 
-static int console_bkl_kthread_func(void *unused)
+static int nbcon_legacy_kthread_func(void *unused)
 {
-	u64 seq = 0;
 	int error;
 
 	for (;;) {
-		error = wait_event_interruptible(log_wait, printer_should_wake(seq));
+		error = wait_event_interruptible(legacy_wait, printer_should_wake());
 
 		if (kthread_should_stop())
 			break;
@@ -3369,43 +3477,39 @@ static int console_bkl_kthread_func(void *unused)
 			continue;
 
 		console_lock();
-		seq = console_flush_and_unlock();
+		console_flush_and_unlock();
 	}
+
 	return 0;
 }
 
-void console_bkl_kthread_create(void)
+void nbcon_legacy_kthread_create(void)
 {
 	struct task_struct *kt;
-	struct console *c;
 
 	lockdep_assert_held(&console_mutex);
 
 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 		return;
 
-	if (!printk_threads_enabled || console_bkl_kthread)
+	if (!printk_threads_enabled || nbcon_legacy_kthread)
 		return;
 
-	for_each_console(c) {
-		if (c->flags & CON_BOOT)
-			return;
-	}
-
-	kt = kthread_run(console_bkl_kthread_func, NULL, "pr/bkl");
+	kt = kthread_run(nbcon_legacy_kthread_func, NULL, "pr/legacy");
 	if (IS_ERR(kt)) {
-		pr_err("unable to start BKL printing thread\n");
+		pr_err("unable to start legacy printing thread\n");
 		return;
 	}
 
-	console_bkl_kthread = kt;
+	nbcon_legacy_kthread = kt;
 
 	/*
 	 * It is important that console printing threads are scheduled
 	 * shortly after a printk call and with generous runtime budgets.
 	 */
-	sched_set_normal(console_bkl_kthread, -20);
+	sched_set_normal(nbcon_legacy_kthread, -20);
 }
+#endif /* CONFIG_PRINTK */
 
 static int __read_mostly keep_bootcon;
 
@@ -3538,11 +3642,20 @@ static void console_init_seq(struct console *newcon, bool bootcon_registered)
 
 				newcon->seq = prb_next_seq(prb);
 				for_each_console(con) {
-					if ((con->flags & CON_BOOT) &&
-					    (con->flags & CON_ENABLED) &&
-					    con->seq < newcon->seq) {
-						newcon->seq = con->seq;
+					u64 seq;
+
+					if (!((con->flags & CON_BOOT) &&
+					      (con->flags & CON_ENABLED))) {
+						continue;
 					}
+
+					if (con->flags & CON_NBCON)
+						seq = nbcon_seq_read(con);
+					else
+						seq = con->seq;
+
+					if (seq < newcon->seq)
+						newcon->seq = seq;
 				}
 			}
 
@@ -3554,6 +3667,8 @@ static void console_init_seq(struct console *newcon, bool bootcon_registered)
 #define console_first()				\
 	hlist_entry(console_list.first, struct console, node)
 
+static int unregister_console_locked(struct console *console);
+
 /*
  * The console driver calls this routine during kernel initialization
  * to register the console printing procedure with printk() and to
@@ -3601,6 +3716,15 @@ void register_console(struct console *newcon)
 		goto unlock;
 	}
 
+	if (newcon->flags & CON_NBCON) {
+		/*
+		 * Ensure the nbcon console buffers can be allocated
+		 * before modifying any global data.
+		 */
+		if (!nbcon_alloc(newcon))
+			goto unlock;
+	}
+
 	/*
 	 * See if we want to enable this console driver by default.
 	 *
@@ -3628,8 +3752,11 @@ void register_console(struct console *newcon)
 		err = try_enable_preferred_console(newcon, false);
 
 	/* printk() messages are not printed to the Braille console. */
-	if (err || newcon->flags & CON_BRL)
+	if (err || newcon->flags & CON_BRL) {
+		if (newcon->flags & CON_NBCON)
+			nbcon_free(newcon);
 		goto unlock;
+	}
 
 	/*
 	 * If we have a bootconsole, and are switching to a real console,
@@ -3645,11 +3772,12 @@ void register_console(struct console *newcon)
 	newcon->dropped = 0;
 	console_init_seq(newcon, bootcon_registered);
 
-	if (!(newcon->flags & CON_NO_BKL)) {
-		have_bkl_console = true;
-		console_bkl_kthread_create();
-	} else if (!cons_nobkl_init(newcon)) {
-		goto unlock;
+	if (newcon->flags & CON_NBCON) {
+		have_nbcon_console = true;
+		nbcon_init(newcon);
+	} else {
+		have_legacy_console = true;
+		nbcon_legacy_kthread_create();
 	}
 
 	if (newcon->flags & CON_BOOT)
@@ -3698,9 +3826,6 @@ void register_console(struct console *newcon)
 			if (con->flags & CON_BOOT)
 				unregister_console_locked(con);
 		}
-
-		/* All boot consoles have been unregistered. */
-		have_boot_console = false;
 	}
 unlock:
 	console_list_unlock();
@@ -3710,13 +3835,16 @@ EXPORT_SYMBOL(register_console);
 /* Must be called under console_list_lock(). */
 static int unregister_console_locked(struct console *console)
 {
+	bool is_boot_con = (console->flags & CON_BOOT);
+	bool found_legacy_con = false;
+	bool found_nbcon_con = false;
+	bool found_boot_con = false;
 	struct console *c;
-	bool is_boot_con;
 	int res;
 
 	lockdep_assert_console_list_lock_held();
 
-	is_boot_con = console->flags & CON_BOOT;
+	con_printk(KERN_INFO, console, "disabled\n");
 
 	res = _braille_unregister_console(console);
 	if (res < 0)
@@ -3724,12 +3852,11 @@ static int unregister_console_locked(struct console *console)
 	if (res > 0)
 		return 0;
 
-	if (!console_is_registered_locked(console))
-		return -ENODEV;
-
+	/* Disable it unconditionally */
 	console_srcu_write_flags(console, console->flags & ~CON_ENABLED);
 
-	con_printk(KERN_INFO, console, "disabled\n");
+	if (!console_is_registered_locked(console))
+		return -ENODEV;
 
 	hlist_del_init_rcu(&console->node);
 
@@ -3752,8 +3879,8 @@ static int unregister_console_locked(struct console *console)
 	 */
 	synchronize_srcu(&console_srcu);
 
-	if (console->flags & CON_NO_BKL)
-		cons_nobkl_cleanup(console);
+	if (console->flags & CON_NBCON)
+		nbcon_free(console);
 
 	console_sysfs_notify();
 
@@ -3761,14 +3888,41 @@ static int unregister_console_locked(struct console *console)
 		res = console->exit(console);
 
 	/*
-	 * Each time a boot console unregisters, try to start up the printing
-	 * threads. They will only start if this was the last boot console.
+	 * With this console gone, the global flags tracking registered
+	 * console types may have changed. Update them.
 	 */
-	if (is_boot_con) {
+	for_each_console(c) {
+		if (c->flags & CON_BOOT)
+			found_boot_con = true;
+
+		if (c->flags & CON_NBCON)
+			found_nbcon_con = true;
+		else
+			found_legacy_con = true;
+	}
+	if (!found_boot_con)
+		have_boot_console = false;
+	if (!found_legacy_con)
+		have_legacy_console = false;
+	if (!found_nbcon_con)
+		have_nbcon_console = false;
+
+	/*
+	 * When the last boot console unregisters, start up the
+	 * printing threads.
+	 */
+	if (is_boot_con && !have_boot_console) {
 		for_each_console(c)
-			cons_kthread_create(c);
+			nbcon_kthread_create(c);
 	}
 
+#ifdef CONFIG_PRINTK
+	if (!printing_via_unlock && nbcon_legacy_kthread) {
+		kthread_stop(nbcon_legacy_kthread);
+		nbcon_legacy_kthread = NULL;
+	}
+#endif
+
 	return res;
 }
 
@@ -3913,76 +4067,94 @@ late_initcall(printk_late_init);
 /* If @con is specified, only wait for that console. Otherwise wait for all. */
 static bool __pr_flush(struct console *con, int timeout_ms, bool reset_on_progress)
 {
-	int remaining = timeout_ms;
+	unsigned long timeout_jiffies = msecs_to_jiffies(timeout_ms);
+	unsigned long remaining_jiffies = timeout_jiffies;
 	struct console *c;
 	u64 last_diff = 0;
 	u64 printk_seq;
+	short flags;
+	bool locked;
 	int cookie;
 	u64 diff;
 	u64 seq;
 
 	might_sleep();
 
-	seq = prb_next_seq(prb);
+	seq = prb_next_reserve_seq(prb);
+
+	/*
+	 * Flush the consoles so that records up to @seq are printed.
+	 * Otherwise this function will just wait for the threaded printers
+	 * to print up to @seq.
+	 */
+	if (printing_via_unlock && !IS_ENABLED(CONFIG_PREEMPT_RT)) {
+		console_lock();
+		console_unlock();
+	}
 
 	for (;;) {
+		unsigned long begin_jiffies;
+		unsigned long slept_jiffies;
+
+		locked = false;
 		diff = 0;
 
-		/*
-		 * Hold the console_lock to guarantee safe access to
-		 * console->seq.
-		 */
-		console_lock();
+		if (printing_via_unlock) {
+			/*
+			 * Hold the console_lock to guarantee safe access to
+			 * console->seq. Releasing console_lock flushes more
+			 * records in case @seq is still not printed on all
+			 * usable consoles.
+			 */
+			console_lock();
+			locked = true;
+		}
 
 		cookie = console_srcu_read_lock();
 		for_each_console_srcu(c) {
-			short flags;
-
 			if (con && con != c)
 				continue;
+
+			flags = console_srcu_read_flags(c);
+
 			/*
 			 * If consoles are not usable, it cannot be expected
 			 * that they make forward progress, so only increment
 			 * @diff for usable consoles.
 			 */
-
-			flags = console_srcu_read_flags(c);
-
-			if (!console_is_usable(c, flags))
+			if (!console_is_usable(c, flags, true) &&
+			    !console_is_usable(c, flags, false)) {
 				continue;
+			}
 
-			/*
-			 * Since the console is locked, use this opportunity
-			 * to update console->seq for NOBKL consoles.
-			 */
-			if (flags & CON_NO_BKL)
-				c->seq = cons_read_seq(c);
+			if (flags & CON_NBCON) {
+				printk_seq = nbcon_seq_read(c);
+			} else {
+				WARN_ON_ONCE(!locked);
+				printk_seq = c->seq;
+			}
 
-			printk_seq = c->seq;
 			if (printk_seq < seq)
 				diff += seq - printk_seq;
 		}
 		console_srcu_read_unlock(cookie);
 
 		if (diff != last_diff && reset_on_progress)
-			remaining = timeout_ms;
+			remaining_jiffies = timeout_jiffies;
 
-		console_unlock();
+		if (locked)
+			console_unlock();
 
 		/* Note: @diff is 0 if there are no usable consoles. */
-		if (diff == 0 || remaining == 0)
+		if (diff == 0 || remaining_jiffies == 0)
 			break;
 
-		if (remaining < 0) {
-			/* no timeout limit */
-			msleep(100);
-		} else if (remaining < 100) {
-			msleep(remaining);
-			remaining = 0;
-		} else {
-			msleep(100);
-			remaining -= 100;
-		}
+		/* msleep(1) might sleep much longer. Check time by jiffies. */
+		begin_jiffies = jiffies;
+		msleep(1);
+		slept_jiffies = jiffies - begin_jiffies;
+
+		remaining_jiffies -= min(slept_jiffies, remaining_jiffies);
 
 		last_diff = diff;
 	}
@@ -4024,8 +4196,7 @@ static void wake_up_klogd_work_func(struct irq_work *irq_work)
 
 	if (pending & PRINTK_PENDING_OUTPUT) {
 		if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
-			/* The BKL thread waits on @log_wait. */
-			pending |= PRINTK_PENDING_WAKEUP;
+			wake_up_interruptible(&legacy_wait);
 		} else {
 			/*
 			 * If trylock fails, some other context
@@ -4097,26 +4268,20 @@ void wake_up_klogd(void)
  */
 void defer_console_output(void)
 {
-	int val = PRINTK_PENDING_WAKEUP;
-
 	/*
 	 * New messages may have been added directly to the ringbuffer
 	 * using vprintk_store(), so wake any waiters as well.
 	 */
-	if (have_bkl_console)
+	int val = PRINTK_PENDING_WAKEUP;
+
+	if (printing_via_unlock)
 		val |= PRINTK_PENDING_OUTPUT;
 	__wake_up_klogd(val);
 }
 
 void printk_trigger_flush(void)
 {
-	struct cons_write_context wctxt = { };
-
-	preempt_disable();
-	cons_atomic_flush(&wctxt, true);
-	preempt_enable();
-
-	cons_wake_threads();
+	nbcon_wake_threads();
 	defer_console_output();
 }
 
diff --git a/kernel/printk/printk_nobkl.c b/kernel/printk/printk_nobkl.c
deleted file mode 100644
index e0b818a4f8b3..000000000000
--- a/kernel/printk/printk_nobkl.c
+++ /dev/null
@@ -1,1825 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-// Copyright (C) 2022 Linutronix GmbH, John Ogness
-// Copyright (C) 2022 Intel, Thomas Gleixner
-
-#include <linux/kernel.h>
-#include <linux/console.h>
-#include <linux/delay.h>
-#include <linux/kthread.h>
-#include <linux/slab.h>
-#include <linux/syscore_ops.h>
-#include "printk_ringbuffer.h"
-#include "internal.h"
-/*
- * Printk implementation for consoles that do not depend on the BKL style
- * console_lock mechanism.
- *
- * Console is locked on a CPU when state::locked is set and state:cpu ==
- * current CPU. This is valid for the current execution context.
- *
- * Nesting execution contexts on the same CPU can carefully take over
- * if the driver allows reentrancy via state::unsafe = false. When the
- * interrupted context resumes it checks the state before entering
- * an unsafe region and aborts the operation if it detects a takeover.
- *
- * In case of panic or emergency the nesting context can take over the
- * console forcefully. The write callback is then invoked with the unsafe
- * flag set in the write context data, which allows the driver side to avoid
- * locks and to evaluate the driver state so it can use an emergency path
- * or repair the state instead of blindly assuming that it works.
- *
- * If the interrupted context touches the assigned record buffer after
- * takeover, it does not cause harm because at the same execution level
- * there is no concurrency on the same CPU. A threaded printer always has
- * its own record buffer so it can never interfere with any of the per CPU
- * record buffers.
- *
- * A concurrent writer on a different CPU can request to take over the
- * console by:
- *
- *	1) Carefully writing the desired state into state[REQ]
- *	   if there is no same or higher priority request pending.
- *	   This locks state[REQ] except for higher priority
- *	   waiters.
- *
- *	2) Setting state[CUR].req_prio unless a same or higher
- *	   priority waiter won the race.
- *
- *	3) Carefully spin on state[CUR] until that is locked with the
- *	   expected state. When the state is not the expected one then it
- *	   has to verify that state[REQ] is still the same and that
- *	   state[CUR] has not been taken over or unlocked.
- *
- *      The unlocker hands over to state[REQ], but only if state[CUR]
- *	matches.
- *
- * In case that the owner does not react on the request and does not make
- * observable progress, the waiter will timeout and can then decide to do
- * a hostile takeover.
- */
-
-#define copy_full_state(_dst, _src)	do { _dst = _src; } while (0)
-#define copy_bit_state(_dst, _src)	do { _dst.bits = _src.bits; } while (0)
-
-#ifdef CONFIG_64BIT
-#define copy_seq_state64(_dst, _src)	do { _dst.seq = _src.seq; } while (0)
-#else
-#define copy_seq_state64(_dst, _src)	do { } while (0)
-#endif
-
-enum state_selector {
-	CON_STATE_CUR,
-	CON_STATE_REQ,
-};
-
-/**
- * cons_state_set - Helper function to set the console state
- * @con:	Console to update
- * @which:	Selects real state or handover state
- * @new:	The new state to write
- *
- * Only to be used when the console is not yet or no longer visible in the
- * system. Otherwise use cons_state_try_cmpxchg().
- */
-static inline void cons_state_set(struct console *con, enum state_selector which,
-				  struct cons_state *new)
-{
-	atomic_long_set(&ACCESS_PRIVATE(con, atomic_state[which]), new->atom);
-}
-
-/**
- * cons_state_read - Helper function to read the console state
- * @con:	Console to update
- * @which:	Selects real state or handover state
- * @state:	The state to store the result
- */
-static inline void cons_state_read(struct console *con, enum state_selector which,
-				   struct cons_state *state)
-{
-	state->atom = atomic_long_read(&ACCESS_PRIVATE(con, atomic_state[which]));
-}
-
-/**
- * cons_state_try_cmpxchg() - Helper function for atomic_long_try_cmpxchg() on console state
- * @con:	Console to update
- * @which:	Selects real state or handover state
- * @old:	Old/expected state
- * @new:	New state
- *
- * Returns: True on success, false on fail
- */
-static inline bool cons_state_try_cmpxchg(struct console *con,
-					  enum state_selector which,
-					  struct cons_state *old,
-					  struct cons_state *new)
-{
-	return atomic_long_try_cmpxchg(&ACCESS_PRIVATE(con, atomic_state[which]),
-				       &old->atom, new->atom);
-}
-
-/**
- * cons_state_full_match - Check whether the full state matches
- * @cur:	The state to check
- * @prev:	The previous state
- *
- * Returns: True if matching, false otherwise.
- *
- * Check the full state including state::seq on 64bit. For take over
- * detection.
- */
-static inline bool cons_state_full_match(struct cons_state cur,
-					 struct cons_state prev)
-{
-	/*
-	 * req_prio can be set by a concurrent writer for friendly
-	 * handover. Ignore it in the comparison.
-	 */
-	cur.req_prio = prev.req_prio;
-	return cur.atom == prev.atom;
-}
-
-/**
- * cons_state_bits_match - Check for matching state bits
- * @cur:	The state to check
- * @prev:	The previous state
- *
- * Returns: True if state matches, false otherwise.
- *
- * Contrary to cons_state_full_match this checks only the bits and ignores
- * a sequence change on 64bits. On 32bit the two functions are identical.
- */
-static inline bool cons_state_bits_match(struct cons_state cur, struct cons_state prev)
-{
-	/*
-	 * req_prio can be set by a concurrent writer for friendly
-	 * handover. Ignore it in the comparison.
-	 */
-	cur.req_prio = prev.req_prio;
-	return cur.bits == prev.bits;
-}
-
-/**
- * cons_check_panic - Check whether a remote CPU is in panic
- *
- * Returns: True if a remote CPU is in panic, false otherwise.
- */
-static inline bool cons_check_panic(void)
-{
-	unsigned int pcpu = atomic_read(&panic_cpu);
-
-	return pcpu != PANIC_CPU_INVALID && pcpu != smp_processor_id();
-}
-
-static struct cons_context_data early_cons_ctxt_data __initdata;
-
-/**
- * cons_context_set_pbufs - Set the output text buffer for the current context
- * @ctxt:	Pointer to the acquire context
- *
- * Buffer selection:
- *   1) Early boot uses the global (initdata) buffer
- *   2) Printer threads use the dynamically allocated per-console buffers
- *   3) All other contexts use the per CPU buffers
- *
- * This guarantees that there is no concurrency on the output records ever.
- * Early boot and per CPU nesting is not a problem. The takeover logic
- * tells the interrupted context that the buffer has been overwritten.
- *
- * There are two critical regions that matter:
- *
- * 1) Context is filling the buffer with a record. After interruption
- *    it continues to sprintf() the record and before it goes to
- *    write it out, it checks the state, notices the takeover, discards
- *    the content and backs out.
- *
- * 2) Context is in a unsafe critical region in the driver. After
- *    interruption it might read overwritten data from the output
- *    buffer. When it leaves the critical region it notices and backs
- *    out. Hostile takeovers in driver critical regions are best effort
- *    and there is not much that can be done about that.
- */
-static __ref void cons_context_set_pbufs(struct cons_context *ctxt)
-{
-	struct console *con = ctxt->console;
-
-	/* Thread context or early boot? */
-	if (ctxt->thread)
-		ctxt->pbufs = con->thread_pbufs;
-	else if (!con->pcpu_data)
-		ctxt->pbufs = &early_cons_ctxt_data.pbufs;
-	else
-		ctxt->pbufs = &(this_cpu_ptr(con->pcpu_data)->pbufs);
-}
-
-/**
- * cons_seq_init - Helper function to initialize the console sequence
- * @con:	Console to work on
- *
- * Set @con->atomic_seq to the starting record, or if that record no
- * longer exists, the oldest available record. For init only. Do not
- * use for runtime updates.
- */
-static void cons_seq_init(struct console *con)
-{
-	u32 seq = (u32)max_t(u64, con->seq, prb_first_valid_seq(prb));
-#ifdef CONFIG_64BIT
-	struct cons_state state;
-
-	cons_state_read(con, CON_STATE_CUR, &state);
-	state.seq = seq;
-	cons_state_set(con, CON_STATE_CUR, &state);
-#else
-	atomic_set(&ACCESS_PRIVATE(con, atomic_seq), seq);
-#endif
-}
-
-/**
- * cons_force_seq - Force a specified sequence number for a console
- * @con:	Console to work on
- * @seq:	Sequence number to force
- *
- * This function is only intended to be used in emergency situations. In
- * particular: console_flush_on_panic(CONSOLE_REPLAY_ALL)
- */
-void cons_force_seq(struct console *con, u64 seq)
-{
-#ifdef CONFIG_64BIT
-	struct cons_state old;
-	struct cons_state new;
-
-	do {
-		cons_state_read(con, CON_STATE_CUR, &old);
-		copy_bit_state(new, old);
-		new.seq = seq;
-	} while (!cons_state_try_cmpxchg(con, CON_STATE_CUR, &old, &new));
-#else
-	atomic_set(&ACCESS_PRIVATE(con, atomic_seq), seq);
-#endif
-}
-
-static inline u64 cons_expand_seq(u64 seq)
-{
-	u64 rbseq;
-
-	/*
-	 * The provided sequence is only the lower 32bits of the ringbuffer
-	 * sequence. It needs to be expanded to 64bit. Get the next sequence
-	 * number from the ringbuffer and fold it.
-	 */
-	rbseq = prb_next_seq(prb);
-	seq = rbseq - ((u32)rbseq - (u32)seq);
-
-	return seq;
-}
-
-/**
- * cons_read_seq - Read the current console sequence
- * @con:	Console to read the sequence of
- *
- * Returns:	Sequence number of the next record to print on @con.
- */
-u64 cons_read_seq(struct console *con)
-{
-	u64 seq;
-#ifdef CONFIG_64BIT
-	struct cons_state state;
-
-	cons_state_read(con, CON_STATE_CUR, &state);
-	seq = state.seq;
-#else
-	seq = atomic_read(&ACCESS_PRIVATE(con, atomic_seq));
-#endif
-	return cons_expand_seq(seq);
-}
-
-/**
- * cons_context_set_seq - Setup the context with the next sequence to print
- * @ctxt:	Pointer to an acquire context that contains
- *		all information about the acquire mode
- *
- * On return the retrieved sequence number is stored in ctxt->oldseq.
- *
- * The sequence number is safe in forceful takeover situations.
- *
- * Either the writer succeeded to update before it got interrupted
- * or it failed. In the latter case the takeover will print the
- * same line again.
- *
- * The sequence is only the lower 32bits of the ringbuffer sequence. The
- * ringbuffer must be 2^31 records ahead to get out of sync. This needs
- * some care when starting a console, i.e setting the sequence to 0 is
- * wrong. It has to be set to the oldest valid sequence in the ringbuffer
- * as that cannot be more than 2^31 records away
- *
- * On 64bit the 32bit sequence is part of console::state, which is saved
- * in @ctxt->state. This prevents the 32bit update race.
- */
-static void cons_context_set_seq(struct cons_context *ctxt)
-{
-#ifdef CONFIG_64BIT
-	ctxt->oldseq = ctxt->state.seq;
-#else
-	ctxt->oldseq = atomic_read(&ACCESS_PRIVATE(ctxt->console, atomic_seq));
-#endif
-	ctxt->oldseq = cons_expand_seq(ctxt->oldseq);
-	ctxt->newseq = ctxt->oldseq;
-}
-
-/**
- * cons_seq_try_update - Try to update the console sequence number
- * @ctxt:	Pointer to an acquire context that contains
- *		all information about the acquire mode
- *
- * Returns:	True if the console sequence was updated, false otherwise.
- *
- * Internal helper as the logic is different on 32bit and 64bit.
- *
- * On 32 bit the sequence is separate from state and therefore
- * subject to a subtle race in the case of hostile takeovers.
- *
- * On 64 bit the sequence is part of the state and therefore safe
- * vs. hostile takeovers.
- *
- * In case of fail the console has been taken over and @ctxt is
- * invalid. Caller has to reacquire the console.
- */
-#ifdef CONFIG_64BIT
-static bool cons_seq_try_update(struct cons_context *ctxt)
-{
-	struct console *con = ctxt->console;
-	struct cons_state old;
-	struct cons_state new;
-
-	cons_state_read(con, CON_STATE_CUR, &old);
-	do {
-		/* Make sure this context is still the owner. */
-		if (!cons_state_bits_match(old, ctxt->state))
-			return false;
-
-		/* Preserve bit state */
-		copy_bit_state(new, old);
-		new.seq = ctxt->newseq;
-
-		/*
-		 * Can race with hostile takeover or with a handover
-		 * request.
-		 */
-	} while (!cons_state_try_cmpxchg(con, CON_STATE_CUR, &old, &new));
-
-	copy_full_state(ctxt->state, new);
-	ctxt->oldseq = ctxt->newseq;
-
-	return true;
-}
-#else
-static bool cons_release(struct cons_context *ctxt);
-static bool cons_seq_try_update(struct cons_context *ctxt)
-{
-	struct console *con = ctxt->console;
-	struct cons_state state;
-	int pcpu;
-	u32 old;
-	u32 new;
-
-	/*
-	 * There is a corner case that needs to be considered here:
-	 *
-	 * CPU0			CPU1
-	 * printk()
-	 *  acquire()		-> emergency
-	 *  write()		   acquire()
-	 *  update_seq()
-	 *    state == OK
-	 * --> NMI
-	 *			   takeover()
-	 * <---			     write()
-	 *  cmpxchg() succeeds	     update_seq()
-	 *			     cmpxchg() fails
-	 *
-	 * There is nothing that can be done about this other than having
-	 * yet another state bit that needs to be tracked and analyzed,
-	 * but fails to cover the problem completely.
-	 *
-	 * No other scenarios expose such a problem. On same CPU takeovers
-	 * the cmpxchg() always fails on the interrupted context after the
-	 * interrupting context finished printing, but that's fine as it
-	 * does not own the console anymore. The state check after the
-	 * failed cmpxchg prevents that.
-	 */
-	cons_state_read(con, CON_STATE_CUR, &state);
-	/* Make sure this context is still the owner. */
-	if (!cons_state_bits_match(state, ctxt->state))
-		return false;
-
-	/*
-	 * Get the original sequence number that was retrieved
-	 * from @con->atomic_seq. @con->atomic_seq should be still
-	 * the same. 32bit truncates. See cons_context_set_seq().
-	 */
-	old = (u32)ctxt->oldseq;
-	new = (u32)ctxt->newseq;
-	if (atomic_try_cmpxchg(&ACCESS_PRIVATE(con, atomic_seq), &old, new)) {
-		ctxt->oldseq = ctxt->newseq;
-		return true;
-	}
-
-	/*
-	 * Reread the state. If this context does not own the console anymore
-	 * then it cannot touch the sequence again.
-	 */
-	cons_state_read(con, CON_STATE_CUR, &state);
-	if (!cons_state_bits_match(state, ctxt->state))
-		return false;
-
-	pcpu = atomic_read(&panic_cpu);
-	if (pcpu == smp_processor_id()) {
-		/*
-		 * This is the panic CPU. Emitting a warning here does not
-		 * help at all. The callchain is clear and the priority is
-		 * to get the messages out. In the worst case duplicated
-		 * ones. That's a job for postprocessing.
-		 */
-		atomic_set(&ACCESS_PRIVATE(con, atomic_seq), new);
-		ctxt->oldseq = ctxt->newseq;
-		return true;
-	}
-
-	/*
-	 * Only emit a warning when this happens outside of a panic
-	 * situation as on panic it's neither useful nor helping to let the
-	 * panic CPU get the important stuff out.
-	 */
-	WARN_ON_ONCE(pcpu == PANIC_CPU_INVALID);
-
-	cons_release(ctxt);
-	return false;
-}
-#endif
-
-/**
- * cons_cleanup_handover - Cleanup a handover request
- * @ctxt:	Pointer to acquire context
- *
- * @ctxt->hov_state contains the state to clean up
- */
-static void cons_cleanup_handover(struct cons_context *ctxt)
-{
-	struct console *con = ctxt->console;
-	struct cons_state new;
-
-	/*
-	 * No loop required. Either hov_state is still the same or
-	 * not.
-	 */
-	new.atom = 0;
-	cons_state_try_cmpxchg(con, CON_STATE_REQ, &ctxt->hov_state, &new);
-}
-
-/**
- * cons_setup_handover - Setup a handover request
- * @ctxt:	Pointer to acquire context
- *
- * Returns: True if a handover request was setup, false otherwise.
- *
- * On success @ctxt->hov_state contains the requested handover state
- *
- * On failure this context is not allowed to request a handover from the
- * current owner. Reasons would be priority too low or a remote CPU in panic.
- * In both cases this context should give up trying to acquire the console.
- */
-static bool cons_setup_handover(struct cons_context *ctxt)
-{
-	unsigned int cpu = smp_processor_id();
-	struct console *con = ctxt->console;
-	struct cons_state old;
-	struct cons_state hstate = {
-		.locked		= 1,
-		.cur_prio	= ctxt->prio,
-		.cpu		= cpu,
-	};
-
-	/*
-	 * Try to store hstate in @con->atomic_state[REQ]. This might
-	 * race with a higher priority waiter.
-	 */
-	cons_state_read(con, CON_STATE_REQ, &old);
-	do {
-		if (cons_check_panic())
-			return false;
-
-		/* Same or higher priority waiter exists? */
-		if (old.cur_prio >= ctxt->prio)
-			return false;
-
-	} while (!cons_state_try_cmpxchg(con, CON_STATE_REQ, &old, &hstate));
-
-	/* Save that state for comparison in spinwait */
-	copy_full_state(ctxt->hov_state, hstate);
-	return true;
-}
-
-/**
- * cons_setup_request - Setup a handover request in state[CUR]
- * @ctxt:	Pointer to acquire context
- * @old:	The state that was used to make the decision to spin wait
- *
- * Returns: True if a handover request was setup in state[CUR], false
- * otherwise.
- *
- * On success @ctxt->req_state contains the request state that was set in
- * state[CUR]
- *
- * On failure this context encountered unexpected state values. This
- * context should retry the full handover request setup process (the
- * handover request setup by cons_setup_handover() is now invalidated
- * and must be performed again).
- */
-static bool cons_setup_request(struct cons_context *ctxt, struct cons_state old)
-{
-	struct console *con = ctxt->console;
-	struct cons_state cur;
-	struct cons_state new;
-
-	/* Now set the request in state[CUR] */
-	cons_state_read(con, CON_STATE_CUR, &cur);
-	do {
-		if (cons_check_panic())
-			goto cleanup;
-
-		/* Bit state changed vs. the decision to spinwait? */
-		if (!cons_state_bits_match(cur, old))
-			goto cleanup;
-
-		/*
-		 * A higher or equal priority context already setup a
-		 * request?
-		 */
-		if (cur.req_prio >= ctxt->prio)
-			goto cleanup;
-
-		/* Setup a request for handover. */
-		copy_full_state(new, cur);
-		new.req_prio = ctxt->prio;
-	} while (!cons_state_try_cmpxchg(con, CON_STATE_CUR, &cur, &new));
-
-	/* Save that state for comparison in spinwait */
-	copy_bit_state(ctxt->req_state, new);
-	return true;
-
-cleanup:
-	cons_cleanup_handover(ctxt);
-	return false;
-}
-
-/**
- * cons_try_acquire_spin - Complete the spinwait attempt
- * @ctxt:	Pointer to an acquire context that contains
- *		all information about the acquire mode
- *
- * @ctxt->hov_state contains the handover state that was set in
- * state[REQ]
- * @ctxt->req_state contains the request state that was set in
- * state[CUR]
- *
- * Returns: 0 if successfully locked. -EBUSY on timeout. -EAGAIN on
- * unexpected state values.
- *
- * On success @ctxt->state contains the new state that was set in
- * state[CUR]
- *
- * On -EBUSY failure this context timed out. This context should either
- * give up or attempt a hostile takeover.
- *
- * On -EAGAIN failure this context encountered unexpected state values.
- * This context should retry the full handover request setup process (the
- * handover request setup by cons_setup_handover() is now invalidated and
- * must be performed again).
- */
-static int cons_try_acquire_spin(struct cons_context *ctxt)
-{
-	struct console *con = ctxt->console;
-	struct cons_state cur;
-	struct cons_state new;
-	int err = -EAGAIN;
-	int timeout;
-
-	/* Now wait for the other side to hand over */
-	for (timeout = ctxt->spinwait_max_us; timeout >= 0; timeout--) {
-		/* Timeout immediately if a remote panic is detected. */
-		if (cons_check_panic())
-			break;
-
-		cons_state_read(con, CON_STATE_CUR, &cur);
-
-		/*
-		 * If the real state of the console matches the handover state
-		 * that this context setup, then the handover was a success
-		 * and this context is now the owner.
-		 *
-		 * Note that this might have raced with a new higher priority
-		 * requester coming in after the lock was handed over.
-		 * However, that requester will see that the owner changes and
-		 * setup a new request for the current owner (this context).
-		 */
-		if (cons_state_bits_match(cur, ctxt->hov_state))
-			goto success;
-
-		/*
-		 * If state changed since the request was made, give up as
-		 * it is no longer consistent. This must include
-		 * state::req_prio since there could be a higher priority
-		 * request available.
-		 */
-		if (cur.bits != ctxt->req_state.bits)
-			goto cleanup;
-
-		/*
-		 * Finally check whether the handover state is still
-		 * the same.
-		 */
-		cons_state_read(con, CON_STATE_REQ, &cur);
-		if (cur.atom != ctxt->hov_state.atom)
-			goto cleanup;
-
-		/* Account time */
-		if (timeout > 0)
-			udelay(1);
-	}
-
-	/*
-	 * Timeout. Cleanup the handover state and carefully try to reset
-	 * req_prio in the real state. The reset is important to ensure
-	 * that the owner does not hand over the lock after this context
-	 * has given up waiting.
-	 */
-	cons_cleanup_handover(ctxt);
-
-	cons_state_read(con, CON_STATE_CUR, &cur);
-	do {
-		/*
-		 * The timeout might have raced with the owner coming late
-		 * and handing it over gracefully.
-		 */
-		if (cons_state_bits_match(cur, ctxt->hov_state))
-			goto success;
-
-		/*
-		 * Validate that the state matches with the state at request
-		 * time. If this check fails, there is already a higher
-		 * priority context waiting or the owner has changed (either
-		 * by higher priority or by hostile takeover). In all fail
-		 * cases this context is no longer in line for a handover to
-		 * take place, so no reset is necessary.
-		 */
-		if (cur.bits != ctxt->req_state.bits)
-			goto cleanup;
-
-		copy_full_state(new, cur);
-		new.req_prio = 0;
-	} while (!cons_state_try_cmpxchg(con, CON_STATE_CUR, &cur, &new));
-	/* Reset worked. Report timeout. */
-	return -EBUSY;
-
-success:
-	/* Store the real state */
-	copy_full_state(ctxt->state, cur);
-	ctxt->hostile = false;
-	err = 0;
-
-cleanup:
-	cons_cleanup_handover(ctxt);
-	return err;
-}
-
-/**
- * __cons_try_acquire - Try to acquire the console for printk output
- * @ctxt:	Pointer to an acquire context that contains
- *		all information about the acquire mode
- *
- * Returns: True if the acquire was successful. False on fail.
- *
- * In case of success @ctxt->state contains the acquisition
- * state.
- *
- * In case of fail @ctxt->old_state contains the state
- * that was read from @con->state for analysis by the caller.
- */
-static bool __cons_try_acquire(struct cons_context *ctxt)
-{
-	unsigned int cpu = smp_processor_id();
-	struct console *con = ctxt->console;
-	short flags = console_srcu_read_flags(con);
-	struct cons_state old;
-	struct cons_state new;
-	int err;
-
-	if (WARN_ON_ONCE(!(flags & CON_NO_BKL)))
-		return false;
-again:
-	cons_state_read(con, CON_STATE_CUR, &old);
-
-	/* Preserve it for the caller and for spinwait */
-	copy_full_state(ctxt->old_state, old);
-
-	if (cons_check_panic())
-		return false;
-
-	/* Set up the new state for takeover */
-	copy_full_state(new, old);
-	new.locked = 1;
-	new.thread = ctxt->thread;
-	new.cur_prio = ctxt->prio;
-	new.req_prio = CONS_PRIO_NONE;
-	new.cpu = cpu;
-
-	/* Attempt to acquire it directly if unlocked */
-	if (!old.locked) {
-		if (!cons_state_try_cmpxchg(con, CON_STATE_CUR, &old, &new))
-			goto again;
-
-		ctxt->hostile = false;
-		copy_full_state(ctxt->state, new);
-		goto success;
-	}
-
-	/*
-	 * A threaded printer context will never spin or perform a
-	 * hostile takeover. The atomic writer will wake the thread
-	 * when it is done with the important output.
-	 */
-	if (ctxt->thread)
-		return false;
-
-	/*
-	 * If the active context is on the same CPU then there is
-	 * obviously no handshake possible.
-	 */
-	if (old.cpu == cpu)
-		goto check_hostile;
-
-	/*
-	 * If a handover request with same or higher priority is already
-	 * pending then this context cannot setup a handover request.
-	 */
-	if (old.req_prio >= ctxt->prio)
-		goto check_hostile;
-
-	/*
-	 * If the caller did not request spin-waiting then performing a
-	 * handover is not an option.
-	 */
-	if (!ctxt->spinwait)
-		goto check_hostile;
-
-	/*
-	 * Setup the request in state[REQ]. If this fails then this
-	 * context is not allowed to setup a handover request.
-	 */
-	if (!cons_setup_handover(ctxt))
-		goto check_hostile;
-
-	/*
-	 * Setup the request in state[CUR]. Hand in the state that was
-	 * used to make the decision to spinwait above, for comparison. If
-	 * this fails then unexpected state values were encountered and the
-	 * full request setup process is retried.
-	 */
-	if (!cons_setup_request(ctxt, old))
-		goto again;
-
-	/*
-	 * Spin-wait to acquire the console. If this fails then unexpected
-	 * state values were encountered (for example, a hostile takeover by
-	 * another context) and the full request setup process is retried.
-	 */
-	err = cons_try_acquire_spin(ctxt);
-	if (err) {
-		if (err == -EAGAIN)
-			goto again;
-		goto check_hostile;
-	}
-success:
-	/* Common updates on success */
-	cons_context_set_seq(ctxt);
-	cons_context_set_pbufs(ctxt);
-	return true;
-
-check_hostile:
-	if (!ctxt->hostile)
-		return false;
-
-	if (cons_check_panic())
-		return false;
-
-	if (!cons_state_try_cmpxchg(con, CON_STATE_CUR, &old, &new))
-		goto again;
-
-	copy_full_state(ctxt->state, new);
-	goto success;
-}
-
-/**
- * cons_try_acquire - Try to acquire the console for printk output
- * @ctxt:	Pointer to an acquire context that contains
- *		all information about the acquire mode
- *
- * Returns: True if the acquire was successful. False on fail.
- *
- * In case of success @ctxt->state contains the acquisition
- * state.
- *
- * In case of fail @ctxt->old_state contains the state
- * that was read from @con->state for analysis by the caller.
- */
-static bool cons_try_acquire(struct cons_context *ctxt)
-{
-	if (__cons_try_acquire(ctxt))
-		return true;
-
-	ctxt->state.atom = 0;
-	return false;
-}
-
-/**
- * __cons_release - Release the console after output is done
- * @ctxt:	The acquire context that contains the state
- *		at cons_try_acquire()
- *
- * Returns:	True if the release was regular
- *
- *		False if the console is in unusable state or was handed over
- *		with handshake or taken	over hostile without handshake.
- *
- * The return value tells the caller whether it needs to evaluate further
- * printing.
- */
-static bool __cons_release(struct cons_context *ctxt)
-{
-	struct console *con = ctxt->console;
-	short flags = console_srcu_read_flags(con);
-	struct cons_state hstate;
-	struct cons_state old;
-	struct cons_state new;
-
-	if (WARN_ON_ONCE(!(flags & CON_NO_BKL)))
-		return false;
-
-	cons_state_read(con, CON_STATE_CUR, &old);
-again:
-	if (!cons_state_bits_match(old, ctxt->state))
-		return false;
-
-	/* Release it directly when no handover request is pending. */
-	if (!old.req_prio)
-		goto unlock;
-
-	/* Read the handover target state */
-	cons_state_read(con, CON_STATE_REQ, &hstate);
-
-	/* If the waiter gave up hstate is 0 */
-	if (!hstate.atom)
-		goto unlock;
-
-	/*
-	 * If a higher priority waiter raced against a lower priority
-	 * waiter then unlock instead of handing over to either. The
-	 * higher priority waiter will notice the updated state and
-	 * retry.
-	 */
-	if (hstate.cur_prio != old.req_prio)
-		goto unlock;
-
-	/* Switch the state and preserve the sequence on 64bit */
-	copy_bit_state(new, hstate);
-	copy_seq_state64(new, old);
-	if (!cons_state_try_cmpxchg(con, CON_STATE_CUR, &old, &new))
-		goto again;
-
-	return true;
-
-unlock:
-	/* Clear the state and preserve the sequence on 64bit */
-	new.atom = 0;
-	copy_seq_state64(new, old);
-	if (!cons_state_try_cmpxchg(con, CON_STATE_CUR, &old, &new))
-		goto again;
-
-	return true;
-}
-
-bool printk_threads_enabled __ro_after_init;
-static bool printk_force_atomic __initdata;
-
-/**
- * cons_release - Release the console after output is done
- * @ctxt:	The acquire context that contains the state
- *		at cons_try_acquire()
- *
- * Returns:	True if the release was regular
- *
- *		False if the console is in unusable state or was handed over
- *		with handshake or taken	over hostile without handshake.
- *
- * The return value tells the caller whether it needs to evaluate further
- * printing.
- */
-static bool cons_release(struct cons_context *ctxt)
-{
-	bool ret = __cons_release(ctxt);
-
-	/* Invalidate the buffer pointer. It is no longer valid. */
-	ctxt->pbufs = NULL;
-
-	ctxt->state.atom = 0;
-	return ret;
-}
-
-bool console_try_acquire(struct cons_write_context *wctxt)
-{
-	struct cons_context *ctxt = &ACCESS_PRIVATE(wctxt, ctxt);
-
-	return cons_try_acquire(ctxt);
-}
-EXPORT_SYMBOL_GPL(console_try_acquire);
-
-bool console_release(struct cons_write_context *wctxt)
-{
-	struct cons_context *ctxt = &ACCESS_PRIVATE(wctxt, ctxt);
-
-	return cons_release(ctxt);
-}
-EXPORT_SYMBOL_GPL(console_release);
-
-/**
- * cons_alloc_percpu_data - Allocate percpu data for a console
- * @con:	Console to allocate for
- *
- * Returns: True on success. False otherwise and the console cannot be used.
- *
- * If it is not yet possible to allocate per CPU data, success is returned.
- * When per CPU data becomes possible, set_percpu_data_ready() will call
- * this function again for all registered consoles.
- */
-bool cons_alloc_percpu_data(struct console *con)
-{
-	if (!printk_percpu_data_ready())
-		return true;
-
-	con->pcpu_data = alloc_percpu(typeof(*con->pcpu_data));
-	if (con->pcpu_data)
-		return true;
-
-	con_printk(KERN_WARNING, con, "failed to allocate percpu buffers\n");
-	return false;
-}
-
-/**
- * cons_free_percpu_data - Free percpu data of a console on unregister
- * @con:	Console to clean up
- */
-static void cons_free_percpu_data(struct console *con)
-{
-	if (!con->pcpu_data)
-		return;
-
-	free_percpu(con->pcpu_data);
-	con->pcpu_data = NULL;
-}
-
-/**
- * console_can_proceed - Check whether printing can proceed
- * @wctxt:	The write context that was handed to the write function
- *
- * Returns:	True if the state is correct. False if a handover
- *		has been requested or if the console was taken
- *		over.
- *
- * Must be invoked after the record was dumped into the assigned record
- * buffer and at appropriate safe places in the driver.  For unsafe driver
- * sections see console_enter_unsafe().
- *
- * When this function returns false then the calling context is not allowed
- * to go forward and has to back out immediately and carefully. The buffer
- * content is no longer trusted either and the console lock is no longer
- * held.
- */
-bool console_can_proceed(struct cons_write_context *wctxt)
-{
-	struct cons_context *ctxt = &ACCESS_PRIVATE(wctxt, ctxt);
-	struct console *con = ctxt->console;
-	struct cons_state state;
-
-	cons_state_read(con, CON_STATE_CUR, &state);
-	/* Store it for analysis or reuse */
-	copy_full_state(ctxt->old_state, state);
-
-	/* Make sure this context is still the owner. */
-	if (!cons_state_full_match(state, ctxt->state))
-		return false;
-
-	/*
-	 * Having a safe point for take over and eventually a few
-	 * duplicated characters or a full line is way better than a
-	 * hostile takeover. Post processing can take care of the garbage.
-	 * Continue if the requested priority is not sufficient.
-	 */
-	if (state.req_prio <= state.cur_prio)
-		return true;
-
-	/*
-	 * A console printer within an unsafe region is allowed to continue.
-	 * It can perform the handover when exiting the safe region. Otherwise
-	 * a hostile takeover will be necessary.
-	 */
-	if (state.unsafe)
-		return true;
-
-	/* Release and hand over */
-	cons_release(ctxt);
-	/*
-	 * This does not check whether the handover succeeded. The
-	 * outermost callsite has to make the final decision whether printing
-	 * should continue or not (via reacquire, possibly hostile). The
-	 * console is unlocked already so go back all the way instead of
-	 * trying to implement heuristics in tons of places.
-	 */
-	return false;
-}
-EXPORT_SYMBOL_GPL(console_can_proceed);
-
-/**
- * __console_update_unsafe - Update the unsafe bit in @con->atomic_state
- * @wctxt:	The write context that was handed to the write function
- *
- * Returns:	True if the state is correct. False if a handover
- *		has been requested or if the console was taken
- *		over.
- *
- * Must be invoked before an unsafe driver section is entered.
- *
- * When this function returns false then the calling context is not allowed
- * to go forward and has to back out immediately and carefully. The buffer
- * content is no longer trusted either and the console lock is no longer
- * held.
- *
- * Internal helper to avoid duplicated code
- */
-static bool __console_update_unsafe(struct cons_write_context *wctxt, bool unsafe)
-{
-	struct cons_context *ctxt = &ACCESS_PRIVATE(wctxt, ctxt);
-	struct console *con = ctxt->console;
-	struct cons_state new;
-
-	do  {
-		if (!console_can_proceed(wctxt))
-			return false;
-		/*
-		 * console_can_proceed() saved the real state in
-		 * ctxt->old_state
-		 */
-		copy_full_state(new, ctxt->old_state);
-		new.unsafe = unsafe;
-
-	} while (!cons_state_try_cmpxchg(con, CON_STATE_CUR, &ctxt->old_state, &new));
-
-	copy_full_state(ctxt->state, new);
-	return true;
-}
-
-/**
- * console_enter_unsafe - Enter an unsafe region in the driver
- * @wctxt:	The write context that was handed to the write function
- *
- * Returns:	True if the state is correct. False if a handover
- *		has been requested or if the console was taken
- *		over.
- *
- * Must be invoked before an unsafe driver section is entered.
- *
- * When this function returns false then the calling context is not allowed
- * to go forward and has to back out immediately and carefully. The buffer
- * content is no longer trusted either and the console lock is no longer
- * held.
- */
-bool console_enter_unsafe(struct cons_write_context *wctxt)
-{
-	return __console_update_unsafe(wctxt, true);
-}
-EXPORT_SYMBOL_GPL(console_enter_unsafe);
-
-/**
- * console_exit_unsafe - Exit an unsafe region in the driver
- * @wctxt:	The write context that was handed to the write function
- *
- * Returns:	True if the state is correct. False if a handover
- *		has been requested or if the console was taken
- *		over.
- *
- * Must be invoked before an unsafe driver section is exited.
- *
- * When this function returns false then the calling context is not allowed
- * to go forward and has to back out immediately and carefully. The buffer
- * content is no longer trusted either and the console lock is no longer
- * held.
- */
-bool console_exit_unsafe(struct cons_write_context *wctxt)
-{
-	return __console_update_unsafe(wctxt, false);
-}
-EXPORT_SYMBOL_GPL(console_exit_unsafe);
-
-/**
- * cons_get_record - Fill the buffer with the next pending ringbuffer record
- * @wctxt:	The write context which will be handed to the write function
- *
- * Returns:	True if there are records available. If the next record should
- *		be printed, the output buffer is filled and @wctxt->outbuf
- *		points to the text to print. If @wctxt->outbuf is NULL after
- *		the call, the record should not be printed but the caller must
- *		still update the console sequence number.
- *
- *		False means that there are no pending records anymore and the
- *		printing can stop.
- */
-static bool cons_get_record(struct cons_write_context *wctxt)
-{
-	struct cons_context *ctxt = &ACCESS_PRIVATE(wctxt, ctxt);
-	struct console *con = ctxt->console;
-	bool is_extended = console_srcu_read_flags(con) & CON_EXTENDED;
-	struct printk_message pmsg = {
-		.pbufs = ctxt->pbufs,
-	};
-
-	if (!printk_get_next_message(&pmsg, ctxt->newseq, is_extended, true))
-		return false;
-
-	ctxt->newseq = pmsg.seq;
-	ctxt->dropped += pmsg.dropped;
-
-	if (pmsg.outbuf_len == 0) {
-		wctxt->outbuf = NULL;
-	} else {
-		if (ctxt->dropped && !is_extended)
-			console_prepend_dropped(&pmsg, ctxt->dropped);
-		wctxt->outbuf = &pmsg.pbufs->outbuf[0];
-	}
-
-	wctxt->len = pmsg.outbuf_len;
-
-	return true;
-}
-
-/**
- * cons_emit_record - Emit record in the acquired context
- * @wctxt:	The write context that will be handed to the write function
- *
- * Returns:	False if the operation was aborted (takeover or handover).
- *		True otherwise
- *
- * When false is returned, the caller is not allowed to touch console state.
- * The console is owned by someone else. If the caller wants to print more
- * it has to reacquire the console first.
- *
- * When true is returned, @wctxt->ctxt.backlog indicates whether there are
- * still records pending in the ringbuffer,
- */
-static bool cons_emit_record(struct cons_write_context *wctxt)
-{
-	struct cons_context *ctxt = &ACCESS_PRIVATE(wctxt, ctxt);
-	struct console *con = ctxt->console;
-	bool done = false;
-
-	/*
-	 * @con->dropped is not protected in case of hostile takeovers so
-	 * the update below is racy. Annotate it accordingly.
-	 */
-	ctxt->dropped = data_race(READ_ONCE(con->dropped));
-
-	/* Fill the output buffer with the next record */
-	ctxt->backlog = cons_get_record(wctxt);
-	if (!ctxt->backlog)
-		return true;
-
-	/* Safety point. Don't touch state in case of takeover */
-	if (!console_can_proceed(wctxt))
-		return false;
-
-	/* Counterpart to the read above */
-	WRITE_ONCE(con->dropped, ctxt->dropped);
-
-	/*
-	 * In case of skipped records, Update sequence state in @con.
-	 */
-	if (!wctxt->outbuf)
-		goto update;
-
-	/* Tell the driver about potential unsafe state */
-	wctxt->unsafe = ctxt->state.unsafe;
-
-	if (!ctxt->thread && con->write_atomic) {
-		done = con->write_atomic(con, wctxt);
-	} else if (ctxt->thread && con->write_thread) {
-		done = con->write_thread(con, wctxt);
-	} else {
-		cons_release(ctxt);
-		WARN_ON_ONCE(1);
-		return false;
-	}
-
-	/* If not done, the write was aborted due to takeover */
-	if (!done)
-		return false;
-
-	/* If there was a dropped message, it has now been output. */
-	if (ctxt->dropped) {
-		ctxt->dropped = 0;
-		/* Counterpart to the read above */
-		WRITE_ONCE(con->dropped, ctxt->dropped);
-	}
-update:
-	ctxt->newseq++;
-	/*
-	 * The sequence update attempt is not part of console_release()
-	 * because in panic situations the console is not released by
-	 * the panic CPU until all records are written. On 32bit the
-	 * sequence is separate from state anyway.
-	 */
-	return cons_seq_try_update(ctxt);
-}
-
-/**
- * cons_kthread_should_wakeup - Check whether the printk thread should wakeup
- * @con:	Console to operate on
- * @ctxt:	The acquire context that contains the state
- *		at console_acquire()
- *
- * Returns: True if the thread should shutdown or if the console is allowed to
- * print and a record is available. False otherwise
- *
- * After the thread wakes up, it must first check if it should shutdown before
- * attempting any printing.
- */
-static bool cons_kthread_should_wakeup(struct console *con, struct cons_context *ctxt)
-{
-	bool is_usable;
-	short flags;
-	int cookie;
-
-	if (kthread_should_stop())
-		return true;
-
-	cookie = console_srcu_read_lock();
-	flags = console_srcu_read_flags(con);
-	is_usable = console_is_usable(con, flags);
-	console_srcu_read_unlock(cookie);
-
-	if (!is_usable)
-		return false;
-
-	/* This reads state and sequence on 64bit. On 32bit only state */
-	cons_state_read(con, CON_STATE_CUR, &ctxt->state);
-
-	/*
-	 * Atomic printing is running on some other CPU. The owner
-	 * will wake the console thread on unlock if necessary.
-	 */
-	if (ctxt->state.locked)
-		return false;
-
-	/* Bring the sequence in @ctxt up to date */
-	cons_context_set_seq(ctxt);
-
-	return prb_read_valid(prb, ctxt->oldseq, NULL);
-}
-
-/**
- * cons_kthread_func - The printk thread function
- * @__console:	Console to operate on
- */
-static int cons_kthread_func(void *__console)
-{
-	struct console *con = __console;
-	struct cons_write_context wctxt = {
-		.ctxt.console	= con,
-		.ctxt.prio	= CONS_PRIO_NORMAL,
-		.ctxt.thread	= 1,
-	};
-	struct cons_context *ctxt = &ACCESS_PRIVATE(&wctxt, ctxt);
-	unsigned long flags;
-	short con_flags;
-	bool backlog;
-	int cookie;
-	int ret;
-
-	for (;;) {
-		atomic_inc(&con->kthread_waiting);
-
-		/*
-		 * Provides a full memory barrier vs. cons_kthread_wake().
-		 */
-		ret = rcuwait_wait_event(&con->rcuwait,
-					 cons_kthread_should_wakeup(con, ctxt),
-					 TASK_INTERRUPTIBLE);
-
-		atomic_dec(&con->kthread_waiting);
-
-		if (kthread_should_stop())
-			break;
-
-		/* Wait was interrupted by a spurious signal, go back to sleep */
-		if (ret)
-			continue;
-
-		for (;;) {
-			cookie = console_srcu_read_lock();
-
-			/*
-			 * Ensure this stays on the CPU to make handover and
-			 * takeover possible.
-			 */
-			if (con->port_lock)
-				con->port_lock(con, true, &flags);
-			else
-				migrate_disable();
-
-			/*
-			 * Try to acquire the console without attempting to
-			 * take over. If an atomic printer wants to hand
-			 * back to the thread it simply wakes it up.
-			 */
-			if (!cons_try_acquire(ctxt))
-				break;
-
-			con_flags = console_srcu_read_flags(con);
-
-			if (console_is_usable(con, con_flags)) {
-				/*
-				 * If the emit fails, this context is no
-				 * longer the owner. Abort the processing and
-				 * wait for new records to print.
-				 */
-				if (!cons_emit_record(&wctxt))
-					break;
-				backlog = ctxt->backlog;
-			} else {
-				backlog = false;
-			}
-
-			/*
-			 * If the release fails, this context was not the
-			 * owner. Abort the processing and wait for new
-			 * records to print.
-			 */
-			if (!cons_release(ctxt))
-				break;
-
-			/* Backlog done? */
-			if (!backlog)
-				break;
-
-			if (con->port_lock)
-				con->port_lock(con, false, &flags);
-			else
-				migrate_enable();
-
-			console_srcu_read_unlock(cookie);
-
-			cond_resched();
-		}
-		if (con->port_lock)
-			con->port_lock(con, false, &flags);
-		else
-			migrate_enable();
-
-		console_srcu_read_unlock(cookie);
-	}
-	return 0;
-}
-
-/**
- * cons_irq_work - irq work to wake printk thread
- * @irq_work:	The irq work to operate on
- */
-static void cons_irq_work(struct irq_work *irq_work)
-{
-	struct console *con = container_of(irq_work, struct console, irq_work);
-
-	cons_kthread_wake(con);
-}
-
-/**
- * cons_wake_threads - Wake up printing threads
- *
- * A printing thread is only woken if it is within the @kthread_waiting
- * block. If it is not within the block (or enters the block later), it
- * will see any new records and continue printing on its own.
- */
-void cons_wake_threads(void)
-{
-	struct console *con;
-	int cookie;
-
-	cookie = console_srcu_read_lock();
-	for_each_console_srcu(con) {
-		if (con->kthread && atomic_read(&con->kthread_waiting))
-			irq_work_queue(&con->irq_work);
-	}
-	console_srcu_read_unlock(cookie);
-}
-
-/**
- * struct cons_cpu_state - Per CPU printk context state
- * @prio:	The current context priority level
- * @nesting:	Per priority nest counter
- */
-struct cons_cpu_state {
-	enum cons_prio	prio;
-	int		nesting[CONS_PRIO_MAX];
-};
-
-static DEFINE_PER_CPU(struct cons_cpu_state, cons_pcpu_state);
-static struct cons_cpu_state early_cons_pcpu_state __initdata;
-
-/**
- * cons_get_cpu_state - Get the per CPU console state pointer
- *
- * Returns either a pointer to the per CPU state of the current CPU or to
- * the init data state during early boot.
- */
-static __ref struct cons_cpu_state *cons_get_cpu_state(void)
-{
-	if (!printk_percpu_data_ready())
-		return &early_cons_pcpu_state;
-
-	return this_cpu_ptr(&cons_pcpu_state);
-}
-
-/**
- * cons_get_wctxt - Get the write context for atomic printing
- * @con:	Console to operate on
- * @prio:	Priority of the context
- *
- * Returns either the per CPU context or the builtin context for
- * early boot.
- */
-static __ref struct cons_write_context *cons_get_wctxt(struct console *con,
-						       enum cons_prio prio)
-{
-	if (!con->pcpu_data)
-		return &early_cons_ctxt_data.wctxt[prio];
-
-	return &this_cpu_ptr(con->pcpu_data)->wctxt[prio];
-}
-
-/**
- * cons_atomic_try_acquire - Try to acquire the console for atomic printing
- * @con:	The console to acquire
- * @ctxt:	The console context instance to work on
- * @prio:	The priority of the current context
- */
-static bool cons_atomic_try_acquire(struct console *con, struct cons_context *ctxt,
-				    enum cons_prio prio, bool skip_unsafe)
-{
-	memset(ctxt, 0, sizeof(*ctxt));
-	ctxt->console		= con;
-	ctxt->spinwait_max_us	= 2000;
-	ctxt->prio		= prio;
-	ctxt->spinwait		= 1;
-
-	/* Try to acquire it directly or via a friendly handover */
-	if (cons_try_acquire(ctxt))
-		return true;
-
-	/* Investigate whether a hostile takeover is due */
-	if (ctxt->old_state.cur_prio >= prio)
-		return false;
-
-	if (!ctxt->old_state.unsafe || !skip_unsafe)
-		ctxt->hostile = 1;
-	return cons_try_acquire(ctxt);
-}
-
-/**
- * cons_atomic_flush_con - Flush one console in atomic mode
- * @wctxt:		The write context struct to use for this context
- * @con:		The console to flush
- * @prio:		The priority of the current context
- * @skip_unsafe:	True, to avoid unsafe hostile takeovers
- */
-static void cons_atomic_flush_con(struct cons_write_context *wctxt, struct console *con,
-				  enum cons_prio prio, bool skip_unsafe)
-{
-	struct cons_context *ctxt = &ACCESS_PRIVATE(wctxt, ctxt);
-	bool wake_thread = false;
-	short flags;
-
-	if (!cons_atomic_try_acquire(con, ctxt, prio, skip_unsafe))
-		return;
-
-	do {
-		flags = console_srcu_read_flags(con);
-
-		if (!console_is_usable(con, flags))
-			break;
-
-		/*
-		 * For normal prio messages let the printer thread handle
-		 * the printing if it is available.
-		 */
-		if (prio <= CONS_PRIO_NORMAL && con->kthread) {
-			wake_thread = true;
-			break;
-		}
-
-		/*
-		 * cons_emit_record() returns false when the console was
-		 * handed over or taken over. In both cases the context is
-		 * no longer valid.
-		 */
-		if (!cons_emit_record(wctxt))
-			return;
-	} while (ctxt->backlog);
-
-	cons_release(ctxt);
-
-	if (wake_thread && atomic_read(&con->kthread_waiting))
-		irq_work_queue(&con->irq_work);
-}
-
-/**
- * cons_atomic_flush - Flush consoles in atomic mode if required
- * @printk_caller_wctxt:	The write context struct to use for this
- *				context (for printk() context only)
- * @skip_unsafe:		True, to avoid unsafe hostile takeovers
- */
-void cons_atomic_flush(struct cons_write_context *printk_caller_wctxt, bool skip_unsafe)
-{
-	struct cons_write_context *wctxt;
-	struct cons_cpu_state *cpu_state;
-	struct console *con;
-	short flags;
-	int cookie;
-
-	cpu_state = cons_get_cpu_state();
-
-	/*
-	 * When in an elevated priority, the printk() calls are not
-	 * individually flushed. This is to allow the full output to
-	 * be dumped to the ringbuffer before starting with printing
-	 * the backlog.
-	 */
-	if (cpu_state->prio > CONS_PRIO_NORMAL && printk_caller_wctxt)
-		return;
-
-	/*
-	 * Let the outermost write of this priority print. This avoids
-	 * nasty hackery for nested WARN() where the printing itself
-	 * generates one.
-	 *
-	 * cpu_state->prio <= CONS_PRIO_NORMAL is not subject to nesting
-	 * and can proceed in order to allow atomic printing when consoles
-	 * do not have a printer thread.
-	 */
-	if (cpu_state->prio > CONS_PRIO_NORMAL &&
-	    cpu_state->nesting[cpu_state->prio] != 1)
-		return;
-
-	cookie = console_srcu_read_lock();
-	for_each_console_srcu(con) {
-		if (!con->write_atomic)
-			continue;
-
-		flags = console_srcu_read_flags(con);
-
-		if (!console_is_usable(con, flags))
-			continue;
-
-		if (cpu_state->prio > CONS_PRIO_NORMAL || !con->kthread) {
-			if (printk_caller_wctxt)
-				wctxt = printk_caller_wctxt;
-			else
-				wctxt = cons_get_wctxt(con, cpu_state->prio);
-			cons_atomic_flush_con(wctxt, con, cpu_state->prio, skip_unsafe);
-		}
-	}
-	console_srcu_read_unlock(cookie);
-}
-
-/**
- * cons_atomic_enter - Enter a context that enforces atomic printing
- * @prio:	Priority of the context
- *
- * Returns:	The previous priority that needs to be fed into
- *		the corresponding cons_atomic_exit()
- */
-enum cons_prio cons_atomic_enter(enum cons_prio prio)
-{
-	struct cons_cpu_state *cpu_state;
-	enum cons_prio prev_prio;
-
-	migrate_disable();
-	cpu_state = cons_get_cpu_state();
-
-	prev_prio = cpu_state->prio;
-	if (prev_prio < prio)
-		cpu_state->prio = prio;
-
-	/*
-	 * Increment the nesting on @cpu_state->prio so a WARN()
-	 * nested into a panic printout does not attempt to
-	 * scribble state.
-	 */
-	cpu_state->nesting[cpu_state->prio]++;
-
-	return prev_prio;
-}
-
-/**
- * cons_atomic_exit - Exit a context that enforces atomic printing
- * @prio:	Priority of the context to leave
- * @prev_prio:	Priority of the previous context for restore
- *
- * @prev_prio is the priority returned by the corresponding cons_atomic_enter().
- */
-void cons_atomic_exit(enum cons_prio prio, enum cons_prio prev_prio)
-{
-	struct cons_cpu_state *cpu_state;
-
-	cons_atomic_flush(NULL, true);
-
-	cpu_state = cons_get_cpu_state();
-
-	if (cpu_state->prio == CONS_PRIO_PANIC)
-		cons_atomic_flush(NULL, false);
-
-	/*
-	 * Undo the nesting of cons_atomic_enter() at the CPU state
-	 * priority.
-	 */
-	cpu_state->nesting[cpu_state->prio]--;
-
-	/*
-	 * Restore the previous priority, which was returned by
-	 * cons_atomic_enter().
-	 */
-	cpu_state->prio = prev_prio;
-
-	migrate_enable();
-}
-
-/**
- * cons_kthread_stop - Stop a printk thread
- * @con:	Console to operate on
- */
-static void cons_kthread_stop(struct console *con)
-{
-	lockdep_assert_console_list_lock_held();
-
-	if (!con->kthread)
-		return;
-
-	kthread_stop(con->kthread);
-	con->kthread = NULL;
-
-	kfree(con->thread_pbufs);
-	con->thread_pbufs = NULL;
-}
-
-/**
- * cons_kthread_create - Create a printk thread
- * @con:	Console to operate on
- *
- * If it fails, let the console proceed. The atomic part might
- * be usable and useful.
- */
-void cons_kthread_create(struct console *con)
-{
-	struct task_struct *kt;
-	struct console *c;
-
-	lockdep_assert_console_list_lock_held();
-
-	if (!(con->flags & CON_NO_BKL) || !con->write_thread)
-		return;
-
-	if (!printk_threads_enabled || con->kthread)
-		return;
-
-	/*
-	 * Printer threads cannot be started as long as any boot console is
-	 * registered because there is no way to synchronize the hardware
-	 * registers between boot console code and regular console code.
-	 */
-	for_each_console(c) {
-		if (c->flags & CON_BOOT)
-			return;
-	}
-	have_boot_console = false;
-
-	con->thread_pbufs = kmalloc(sizeof(*con->thread_pbufs), GFP_KERNEL);
-	if (!con->thread_pbufs) {
-		con_printk(KERN_ERR, con, "failed to allocate printing thread buffers\n");
-		return;
-	}
-
-	kt = kthread_run(cons_kthread_func, con, "pr/%s%d", con->name, con->index);
-	if (IS_ERR(kt)) {
-		con_printk(KERN_ERR, con, "failed to start printing thread\n");
-		kfree(con->thread_pbufs);
-		con->thread_pbufs = NULL;
-		return;
-	}
-
-	con->kthread = kt;
-
-	/*
-	 * It is important that console printing threads are scheduled
-	 * shortly after a printk call and with generous runtime budgets.
-	 */
-	sched_set_normal(con->kthread, -20);
-}
-
-static int __init printk_setup_threads(void)
-{
-	struct console *con;
-
-	if (printk_force_atomic)
-		return 0;
-
-	console_list_lock();
-	printk_threads_enabled = true;
-	for_each_console(con)
-		cons_kthread_create(con);
-	if (have_bkl_console)
-		console_bkl_kthread_create();
-	console_list_unlock();
-	return 0;
-}
-early_initcall(printk_setup_threads);
-
-/**
- * cons_nobkl_init - Initialize the NOBKL console specific data
- * @con:	Console to initialize
- *
- * Returns: True on success. False otherwise and the console cannot be used.
- */
-bool cons_nobkl_init(struct console *con)
-{
-	struct cons_state state = { };
-
-	if (!cons_alloc_percpu_data(con))
-		return false;
-
-	rcuwait_init(&con->rcuwait);
-	atomic_set(&con->kthread_waiting, 0);
-	init_irq_work(&con->irq_work, cons_irq_work);
-	cons_state_set(con, CON_STATE_CUR, &state);
-	cons_state_set(con, CON_STATE_REQ, &state);
-	cons_seq_init(con);
-	cons_kthread_create(con);
-	return true;
-}
-
-/**
- * cons_nobkl_cleanup - Cleanup the NOBKL console specific data
- * @con:	Console to cleanup
- */
-void cons_nobkl_cleanup(struct console *con)
-{
-	struct cons_state state = { };
-
-	cons_kthread_stop(con);
-	cons_state_set(con, CON_STATE_CUR, &state);
-	cons_state_set(con, CON_STATE_REQ, &state);
-	cons_free_percpu_data(con);
-}
-
-/**
- * printk_kthread_shutdown - shutdown all threaded printers
- *
- * On system shutdown all threaded printers are stopped. This allows printk
- * to transition back to atomic printing, thus providing a robust mechanism
- * for the final shutdown/reboot messages to be output.
- */
-static void printk_kthread_shutdown(void)
-{
-	struct console *con;
-
-	console_list_lock();
-	for_each_console(con) {
-		if (con->flags & CON_NO_BKL)
-			cons_kthread_stop(con);
-	}
-	console_list_unlock();
-}
-
-static struct syscore_ops printk_syscore_ops = {
-	.shutdown = printk_kthread_shutdown,
-};
-
-static int __init printk_init_ops(void)
-{
-	register_syscore_ops(&printk_syscore_ops);
-	return 0;
-}
-device_initcall(printk_init_ops);
diff --git a/kernel/printk/printk_ringbuffer.c b/kernel/printk/printk_ringbuffer.c
index fde338606ce8..e7b808b829a0 100644
--- a/kernel/printk/printk_ringbuffer.c
+++ b/kernel/printk/printk_ringbuffer.c
@@ -6,6 +6,7 @@
 #include <linux/errno.h>
 #include <linux/bug.h>
 #include "printk_ringbuffer.h"
+#include "internal.h"
 
 /**
  * DOC: printk_ringbuffer overview
@@ -303,6 +304,9 @@
  *
  *   desc_push_tail:B / desc_reserve:D
  *     set descriptor reusable (state), then push descriptor tail (id)
+ *
+ *   desc_update_last_finalized:A / desc_last_finalized_seq:A
+ *     store finalized record, then set new highest finalized sequence number
  */
 
 #define DATA_SIZE(data_ring)		_DATA_SIZE((data_ring)->size_bits)
@@ -1030,9 +1034,13 @@ static char *data_alloc(struct printk_ringbuffer *rb, unsigned int size,
 	unsigned long next_lpos;
 
 	if (size == 0) {
-		/* Specify a data-less block. */
-		blk_lpos->begin = NO_LPOS;
-		blk_lpos->next = NO_LPOS;
+		/*
+		 * Data blocks are not created for empty lines. Instead, the
+		 * reader will recognize these special lpos values and handle
+		 * it appropriately.
+		 */
+		blk_lpos->begin = EMPTY_LINE_LPOS;
+		blk_lpos->next = EMPTY_LINE_LPOS;
 		return NULL;
 	}
 
@@ -1210,10 +1218,18 @@ static const char *get_data(struct prb_data_ring *data_ring,
 
 	/* Data-less data block description. */
 	if (BLK_DATALESS(blk_lpos)) {
-		if (blk_lpos->begin == NO_LPOS && blk_lpos->next == NO_LPOS) {
+		/*
+		 * Records that are just empty lines are also valid, even
+		 * though they do not have a data block. For such records
+		 * explicitly return empty string data to signify success.
+		 */
+		if (blk_lpos->begin == EMPTY_LINE_LPOS &&
+		    blk_lpos->next == EMPTY_LINE_LPOS) {
 			*data_size = 0;
 			return "";
 		}
+
+		/* Data lost, invalid, or otherwise unavailable. */
 		return NULL;
 	}
 
@@ -1441,20 +1457,118 @@ bool prb_reserve_in_last(struct prb_reserved_entry *e, struct printk_ringbuffer
 	return false;
 }
 
+/*
+ * @last_finalized_seq value guarantees that all records up to and including
+ * this sequence number are finalized and can be read. The only exception are
+ * too old records which have already been overwritten.
+ *
+ * It is also guaranteed that @last_finalized_seq only increases.
+ *
+ * Be aware that finalized records following non-finalized records are not
+ * reported because they are not yet available to the reader. For example,
+ * a new record stored via printk() will not be available to a printer if
+ * it follows a record that has not been finalized yet. However, once that
+ * non-finalized record becomes finalized, @last_finalized_seq will be
+ * appropriately updated and the full set of finalized records will be
+ * available to the printer. And since each printk() caller will either
+ * directly print or trigger deferred printing of all available unprinted
+ * records, all printk() messages will get printed.
+ */
+static u64 desc_last_finalized_seq(struct printk_ringbuffer *rb)
+{
+	struct prb_desc_ring *desc_ring = &rb->desc_ring;
+	unsigned long ulseq;
+
+	/*
+	 * Guarantee the sequence number is loaded before loading the
+	 * associated record in order to guarantee that the record can be
+	 * seen by this CPU. This pairs with desc_update_last_finalized:A.
+	 */
+	ulseq = atomic_long_read_acquire(&desc_ring->last_finalized_seq
+					); /* LMM(desc_last_finalized_seq:A) */
+
+	return __ulseq_to_u64seq(rb, ulseq);
+}
+
+static bool _prb_read_valid(struct printk_ringbuffer *rb, u64 *seq,
+			    struct printk_record *r, unsigned int *line_count);
+
+/*
+ * Check if there are records directly following @last_finalized_seq that are
+ * finalized. If so, update @last_finalized_seq to the latest of these
+ * records. It is not allowed to skip over records that are not yet finalized.
+ */
+static void desc_update_last_finalized(struct printk_ringbuffer *rb)
+{
+	struct prb_desc_ring *desc_ring = &rb->desc_ring;
+	u64 old_seq = desc_last_finalized_seq(rb);
+	unsigned long oldval;
+	unsigned long newval;
+	u64 finalized_seq;
+	u64 try_seq;
+
+try_again:
+	finalized_seq = old_seq;
+	try_seq = finalized_seq + 1;
+
+	/* Try to find later finalized records. */
+	while (_prb_read_valid(rb, &try_seq, NULL, NULL)) {
+		finalized_seq = try_seq;
+		try_seq++;
+	}
+
+	/* No update needed if no later finalized record was found. */
+	if (finalized_seq == old_seq)
+		return;
+
+	oldval = __u64seq_to_ulseq(old_seq);
+	newval = __u64seq_to_ulseq(finalized_seq);
+
+	/*
+	 * Set the sequence number of a later finalized record that has been
+	 * seen.
+	 *
+	 * Guarantee the record data is visible to other CPUs before storing
+	 * its sequence number. This pairs with desc_last_finalized_seq:A.
+	 *
+	 * Memory barrier involvement:
+	 *
+	 * If desc_last_finalized_seq:A reads from
+	 * desc_update_last_finalized:A, then desc_read:A reads from
+	 * _prb_commit:B.
+	 *
+	 * Relies on:
+	 *
+	 * RELEASE from _prb_commit:B to desc_update_last_finalized:A
+	 *    matching
+	 * ACQUIRE from desc_last_finalized_seq:A to desc_read:A
+	 *
+	 * Note: _prb_commit:B and desc_update_last_finalized:A can be
+	 *       different CPUs. However, the desc_update_last_finalized:A
+	 *       CPU (which performs the release) must have previously seen
+	 *       _prb_commit:B.
+	 */
+	if (!atomic_long_try_cmpxchg_release(&desc_ring->last_finalized_seq,
+				&oldval, newval)) { /* LMM(desc_update_last_finalized:A) */
+		old_seq = __ulseq_to_u64seq(rb, oldval);
+		goto try_again;
+	}
+}
+
 /*
  * Attempt to finalize a specified descriptor. If this fails, the descriptor
  * is either already final or it will finalize itself when the writer commits.
  */
-static void desc_make_final(struct prb_desc_ring *desc_ring, unsigned long id)
+static void desc_make_final(struct printk_ringbuffer *rb, unsigned long id)
 {
+	struct prb_desc_ring *desc_ring = &rb->desc_ring;
 	unsigned long prev_state_val = DESC_SV(id, desc_committed);
 	struct prb_desc *d = to_desc(desc_ring, id);
 
-	atomic_long_cmpxchg_relaxed(&d->state_var, prev_state_val,
-			DESC_SV(id, desc_finalized)); /* LMM(desc_make_final:A) */
-
-	/* Best effort to remember the last finalized @id. */
-	atomic_long_set(&desc_ring->last_finalized_id, id);
+	if (atomic_long_try_cmpxchg_relaxed(&d->state_var, &prev_state_val,
+			DESC_SV(id, desc_finalized))) { /* LMM(desc_make_final:A) */
+		desc_update_last_finalized(rb);
+	}
 }
 
 /**
@@ -1550,7 +1664,7 @@ bool prb_reserve(struct prb_reserved_entry *e, struct printk_ringbuffer *rb,
 	 * readers. (For seq==0 there is no previous descriptor.)
 	 */
 	if (info->seq > 0)
-		desc_make_final(desc_ring, DESC_ID(id - 1));
+		desc_make_final(rb, DESC_ID(id - 1));
 
 	r->text_buf = data_alloc(rb, r->text_buf_size, &d->text_blk_lpos, id);
 	/* If text data allocation fails, a data-less record is committed. */
@@ -1643,7 +1757,7 @@ void prb_commit(struct prb_reserved_entry *e)
 	 */
 	head_id = atomic_long_read(&desc_ring->head_id); /* LMM(prb_commit:A) */
 	if (head_id != e->id)
-		desc_make_final(desc_ring, e->id);
+		desc_make_final(e->rb, e->id);
 }
 
 /**
@@ -1663,12 +1777,9 @@ void prb_commit(struct prb_reserved_entry *e)
  */
 void prb_final_commit(struct prb_reserved_entry *e)
 {
-	struct prb_desc_ring *desc_ring = &e->rb->desc_ring;
-
 	_prb_commit(e, desc_finalized);
 
-	/* Best effort to remember the last finalized @id. */
-	atomic_long_set(&desc_ring->last_finalized_id, e->id);
+	desc_update_last_finalized(e->rb);
 }
 
 /*
@@ -1746,6 +1857,8 @@ static bool copy_data(struct prb_data_ring *data_ring,
  * descriptor. However, it also verifies that the record is finalized and has
  * the sequence number @seq. On success, 0 is returned.
  *
+ * For the panic CPU, committed descriptors are also considered finalized.
+ *
  * Error return values:
  * -EINVAL: A finalized record with sequence number @seq does not exist.
  * -ENOENT: A finalized record with sequence number @seq exists, but its data
@@ -1764,16 +1877,25 @@ static int desc_read_finalized_seq(struct prb_desc_ring *desc_ring,
 
 	/*
 	 * An unexpected @id (desc_miss) or @seq mismatch means the record
-	 * does not exist. A descriptor in the reserved or committed state
-	 * means the record does not yet exist for the reader.
+	 * does not exist. A descriptor in the reserved state means the
+	 * record does not yet exist for the reader.
 	 */
 	if (d_state == desc_miss ||
 	    d_state == desc_reserved ||
-	    d_state == desc_committed ||
 	    s != seq) {
 		return -EINVAL;
 	}
 
+	/*
+	 * A descriptor in the committed state means the record does not yet
+	 * exist for the reader. However, for the panic CPU, committed
+	 * records are also handled as finalized records since they contain
+	 * message data in a consistent state and may contain additional
+	 * hints as to the cause of the panic.
+	 */
+	if (d_state == desc_committed && !this_cpu_in_panic())
+		return -EINVAL;
+
 	/*
 	 * A descriptor in the reusable state may no longer have its data
 	 * available; report it as existing but with lost data. Or the record
@@ -1832,7 +1954,7 @@ static int prb_read(struct printk_ringbuffer *rb, u64 seq,
 }
 
 /* Get the sequence number of the tail descriptor. */
-static u64 prb_first_seq(struct printk_ringbuffer *rb)
+u64 prb_first_seq(struct printk_ringbuffer *rb)
 {
 	struct prb_desc_ring *desc_ring = &rb->desc_ring;
 	enum desc_state d_state;
@@ -1875,12 +1997,131 @@ static u64 prb_first_seq(struct printk_ringbuffer *rb)
 	return seq;
 }
 
+/**
+ * prb_next_reserve_seq() - Get the sequence number after the most recently
+ *                  reserved record.
+ *
+ * @rb:  The ringbuffer to get the sequence number from.
+ *
+ * This is the public function available to readers to see what sequence
+ * number will be assigned to the next reserved record.
+ *
+ * Note that depending on the situation, this value can be equal to or
+ * higher than the sequence number returned by prb_next_seq().
+ *
+ * Context: Any context.
+ * Return: The sequence number that will be assigned to the next record
+ *         reserved.
+ */
+u64 prb_next_reserve_seq(struct printk_ringbuffer *rb)
+{
+	struct prb_desc_ring *desc_ring = &rb->desc_ring;
+	unsigned long last_finalized_id;
+	atomic_long_t *state_var;
+	u64 last_finalized_seq;
+	unsigned long head_id;
+	struct prb_desc desc;
+	unsigned long diff;
+	struct prb_desc *d;
+	int err;
+
+	/*
+	 * It may not be possible to read a sequence number for @head_id.
+	 * So the ID of @last_finailzed_seq is used to calculate what the
+	 * sequence number of @head_id will be.
+	 */
+
+try_again:
+	last_finalized_seq = desc_last_finalized_seq(rb);
+
+	/*
+	 * @head_id is loaded after @last_finalized_seq to ensure that it is
+	 * at or beyond @last_finalized_seq.
+	 *
+	 * Memory barrier involvement:
+	 *
+	 * If desc_last_finalized_seq:A reads from
+	 * desc_update_last_finalized:A, then
+	 * prb_next_reserve_seq:A reads from desc_reserve:D.
+	 *
+	 * Relies on:
+	 *
+	 * RELEASE from desc_reserve:D to desc_update_last_finalized:A
+	 *    matching
+	 * ACQUIRE from desc_last_finalized_seq:A to prb_next_reserve_seq:A
+	 *
+	 * Note: desc_reserve:D and desc_update_last_finalized:A can be
+	 *       different CPUs. However, the desc_update_last_finalized:A CPU
+	 *       (which performs the release) must have previously seen
+	 *       desc_read:C, which implies desc_reserve:D can be seen.
+	 */
+	head_id = atomic_long_read(&desc_ring->head_id); /* LMM(prb_next_reserve_seq:A) */
+
+	d = to_desc(desc_ring, last_finalized_seq);
+	state_var = &d->state_var;
+
+	/* Extract the ID, used to specify the descriptor to read. */
+	last_finalized_id = DESC_ID(atomic_long_read(state_var));
+
+	/* Ensure @last_finalized_id is correct. */
+	err = desc_read_finalized_seq(desc_ring, last_finalized_id, last_finalized_seq, &desc);
+
+	if (err == -EINVAL) {
+		if (last_finalized_seq == 0) {
+			/*
+			 * @last_finalized_seq still contains its initial
+			 * value. Probably no record has been finalized yet.
+			 * This means the ringbuffer is not yet full and the
+			 * @head_id value can be used directly (subtracting
+			 * off the id value corresponding to seq=0).
+			 */
+
+			/*
+			 * Because of hack#2 of the bootstrapping phase, the
+			 * @head_id initial value must be handled separately.
+			 */
+			if (head_id == DESC0_ID(desc_ring->count_bits))
+				return 0;
+
+			/*
+			 * The @head_id is initialized such that the first
+			 * increment will yield the first record (seq=0).
+			 * Therefore use the initial value +1 as the base to
+			 * subtract from @head_id.
+			 */
+			last_finalized_id = DESC0_ID(desc_ring->count_bits) + 1;
+		} else {
+			/* Record must have been overwritten. Try again. */
+			goto try_again;
+		}
+	}
+
+	/*
+	 * @diff is the number of records beyond the last record available
+	 * to readers.
+	 */
+	diff = head_id - last_finalized_id;
+
+	/*
+	 * @head_id points to the most recently reserved record, but this
+	 * function returns the sequence number that will be assigned to the
+	 * next (not yet reserved) record. Thus +1 is needed.
+	 */
+	return (last_finalized_seq + diff + 1);
+}
+
 /*
- * Non-blocking read of a record. Updates @seq to the last finalized record
- * (which may have no data available).
+ * Non-blocking read of a record.
  *
- * See the description of prb_read_valid() and prb_read_valid_info()
- * for details.
+ * On success @seq is updated to the record that was read and (if provided)
+ * @r and @line_count will contain the read/calculated data.
+ *
+ * On failure @seq is updated to a record that is not yet available to the
+ * reader, but it will be the next record available to the reader.
+ *
+ * Note: When the current CPU is in panic, this function will skip over any
+ *       non-existent/non-finalized records in order to allow the panic CPU
+ *       to print any and all records that have been finalized.
  */
 static bool _prb_read_valid(struct printk_ringbuffer *rb, u64 *seq,
 			    struct printk_record *r, unsigned int *line_count)
@@ -1899,12 +2140,32 @@ static bool _prb_read_valid(struct printk_ringbuffer *rb, u64 *seq,
 			*seq = tail_seq;
 
 		} else if (err == -ENOENT) {
-			/* Record exists, but no data available. Skip. */
+			/* Record exists, but the data was lost. Skip. */
 			(*seq)++;
 
 		} else {
-			/* Non-existent/non-finalized record. Must stop. */
-			return false;
+			/*
+			 * Non-existent/non-finalized record. Must stop.
+			 *
+			 * For panic situations it cannot be expected that
+			 * non-finalized records will become finalized. But
+			 * there may be other finalized records beyond that
+			 * need to be printed for a panic situation. If this
+			 * is the panic CPU, skip this
+			 * non-existent/non-finalized record unless it is
+			 * at or beyond the head, in which case it is not
+			 * possible to continue.
+			 *
+			 * Note that new messages printed on panic CPU are
+			 * finalized when we are here. The only exception
+			 * might be the last message without trailing newline.
+			 * But it would have the sequence number returned
+			 * by "prb_next_reserve_seq() - 1".
+			 */
+			if (this_cpu_in_panic() && ((*seq + 1) < prb_next_reserve_seq(rb)))
+				(*seq)++;
+			else
+				return false;
 		}
 	}
 
@@ -1932,7 +2193,7 @@ static bool _prb_read_valid(struct printk_ringbuffer *rb, u64 *seq,
  * On success, the reader must check r->info.seq to see which record was
  * actually read. This allows the reader to detect dropped records.
  *
- * Failure means @seq refers to a not yet written record.
+ * Failure means @seq refers to a record not yet available to the reader.
  */
 bool prb_read_valid(struct printk_ringbuffer *rb, u64 seq,
 		    struct printk_record *r)
@@ -1962,7 +2223,7 @@ bool prb_read_valid(struct printk_ringbuffer *rb, u64 seq,
  * On success, the reader must check info->seq to see which record meta data
  * was actually read. This allows the reader to detect dropped records.
  *
- * Failure means @seq refers to a not yet written record.
+ * Failure means @seq refers to a record not yet available to the reader.
  */
 bool prb_read_valid_info(struct printk_ringbuffer *rb, u64 seq,
 			 struct printk_info *info, unsigned int *line_count)
@@ -2008,7 +2269,9 @@ u64 prb_first_valid_seq(struct printk_ringbuffer *rb)
  * newest sequence number available to readers will be.
  *
  * This provides readers a sequence number to jump to if all currently
- * available records should be skipped.
+ * available records should be skipped. It is guaranteed that all records
+ * previous to the returned value have been finalized and are (or were)
+ * available to the reader.
  *
  * Context: Any context.
  * Return: The sequence number of the next newest (not yet available) record
@@ -2016,34 +2279,19 @@ u64 prb_first_valid_seq(struct printk_ringbuffer *rb)
  */
 u64 prb_next_seq(struct printk_ringbuffer *rb)
 {
-	struct prb_desc_ring *desc_ring = &rb->desc_ring;
-	enum desc_state d_state;
-	unsigned long id;
 	u64 seq;
 
-	/* Check if the cached @id still points to a valid @seq. */
-	id = atomic_long_read(&desc_ring->last_finalized_id);
-	d_state = desc_read(desc_ring, id, NULL, &seq, NULL);
+	seq = desc_last_finalized_seq(rb);
 
-	if (d_state == desc_finalized || d_state == desc_reusable) {
-		/*
-		 * Begin searching after the last finalized record.
-		 *
-		 * On 0, the search must begin at 0 because of hack#2
-		 * of the bootstrapping phase it is not known if a
-		 * record at index 0 exists.
-		 */
-		if (seq != 0)
-			seq++;
-	} else {
-		/*
-		 * The information about the last finalized sequence number
-		 * has gone. It should happen only when there is a flood of
-		 * new messages and the ringbuffer is rapidly recycled.
-		 * Give up and start from the beginning.
-		 */
-		seq = 0;
-	}
+	/*
+	 * Begin searching after the last finalized record.
+	 *
+	 * On 0, the search must begin at 0 because of hack#2
+	 * of the bootstrapping phase it is not known if a
+	 * record at index 0 exists.
+	 */
+	if (seq != 0)
+		seq++;
 
 	/*
 	 * The information about the last finalized @seq might be inaccurate.
@@ -2085,7 +2333,7 @@ void prb_init(struct printk_ringbuffer *rb,
 	rb->desc_ring.infos = infos;
 	atomic_long_set(&rb->desc_ring.head_id, DESC0_ID(descbits));
 	atomic_long_set(&rb->desc_ring.tail_id, DESC0_ID(descbits));
-	atomic_long_set(&rb->desc_ring.last_finalized_id, DESC0_ID(descbits));
+	atomic_long_set(&rb->desc_ring.last_finalized_seq, 0);
 
 	rb->text_data_ring.size_bits = textbits;
 	rb->text_data_ring.data = text_buf;
diff --git a/kernel/printk/printk_ringbuffer.h b/kernel/printk/printk_ringbuffer.h
index 18cd25e489b8..52626d0f1fa3 100644
--- a/kernel/printk/printk_ringbuffer.h
+++ b/kernel/printk/printk_ringbuffer.h
@@ -75,7 +75,7 @@ struct prb_desc_ring {
 	struct printk_info	*infos;
 	atomic_long_t		head_id;
 	atomic_long_t		tail_id;
-	atomic_long_t		last_finalized_id;
+	atomic_long_t		last_finalized_seq;
 };
 
 /*
@@ -127,8 +127,22 @@ enum desc_state {
 #define DESC_SV(id, state)	(((unsigned long)state << DESC_FLAGS_SHIFT) | id)
 #define DESC_ID_MASK		(~DESC_FLAGS_MASK)
 #define DESC_ID(sv)		((sv) & DESC_ID_MASK)
+
+/*
+ * Special data block logical position values (for fields of
+ * @prb_desc.text_blk_lpos).
+ *
+ * - Bit0 is used to identify if the record has no data block. (Implemented in
+ *   the LPOS_DATALESS() macro.)
+ *
+ * - Bit1 specifies the reason for not having a data block.
+ *
+ * These special values could never be real lpos values because of the
+ * meta data and alignment padding of data blocks. (See to_blk_size() for
+ * details.)
+ */
 #define FAILED_LPOS		0x1
-#define NO_LPOS			0x3
+#define EMPTY_LINE_LPOS		0x3
 
 #define FAILED_BLK_LPOS	\
 {				\
@@ -259,7 +273,7 @@ static struct printk_ringbuffer name = {							\
 		.infos		= &_##name##_infos[0],						\
 		.head_id	= ATOMIC_INIT(DESC0_ID(descbits)),				\
 		.tail_id	= ATOMIC_INIT(DESC0_ID(descbits)),				\
-		.last_finalized_id = ATOMIC_INIT(DESC0_ID(descbits)),				\
+		.last_finalized_seq = ATOMIC_INIT(0),						\
 	},											\
 	.text_data_ring = {									\
 		.size_bits	= (avgtextbits) + (descbits),					\
@@ -378,7 +392,41 @@ bool prb_read_valid(struct printk_ringbuffer *rb, u64 seq,
 bool prb_read_valid_info(struct printk_ringbuffer *rb, u64 seq,
 			 struct printk_info *info, unsigned int *line_count);
 
+u64 prb_first_seq(struct printk_ringbuffer *rb);
 u64 prb_first_valid_seq(struct printk_ringbuffer *rb);
 u64 prb_next_seq(struct printk_ringbuffer *rb);
+u64 prb_next_reserve_seq(struct printk_ringbuffer *rb);
+
+#ifdef CONFIG_64BIT
+
+#define __u64seq_to_ulseq(u64seq) (u64seq)
+#define __ulseq_to_u64seq(rb, ulseq) (ulseq)
+
+#else /* CONFIG_64BIT */
+
+#define __u64seq_to_ulseq(u64seq) ((u32)u64seq)
+
+static inline u64 __ulseq_to_u64seq(struct printk_ringbuffer *rb, u32 ulseq)
+{
+	u64 rb_first_seq = prb_first_seq(rb);
+	u64 seq;
+
+	/*
+	 * The provided sequence is only the lower 32 bits of the ringbuffer
+	 * sequence. It needs to be expanded to 64bit. Get the first sequence
+	 * number from the ringbuffer and fold it.
+	 *
+	 * Having a 32bit representation in the console is sufficient.
+	 * If a console ever gets more than 2^31 records behind
+	 * the ringbuffer then this is the least of the problems.
+	 *
+	 * Also the access to the ring buffer is always safe.
+	 */
+	seq = rb_first_seq - (s32)((u32)rb_first_seq - ulseq);
+
+	return seq;
+}
+
+#endif /* CONFIG_64BIT */
 
 #endif /* _KERNEL_PRINTK_RINGBUFFER_H */
diff --git a/kernel/printk/printk_safe.c b/kernel/printk/printk_safe.c
index 5c1470bd60bc..8d9408d653de 100644
--- a/kernel/printk/printk_safe.c
+++ b/kernel/printk/printk_safe.c
@@ -12,41 +12,30 @@
 
 #include "internal.h"
 
-struct printk_context {
-	local_lock_t cpu;
-	int recursion;
-};
-
-static DEFINE_PER_CPU(struct printk_context, printk_context) = {
-	.cpu = INIT_LOCAL_LOCK(cpu),
-};
+static DEFINE_PER_CPU(int, printk_context);
 
 /* Can be preempted by NMI. */
-void __printk_safe_enter(unsigned long *flags)
+void __printk_safe_enter(void)
 {
-	WARN_ON_ONCE(in_nmi());
-	local_lock_irqsave(&printk_context.cpu, *flags);
-	this_cpu_inc(printk_context.recursion);
+	this_cpu_inc(printk_context);
 }
 
 /* Can be preempted by NMI. */
-void __printk_safe_exit(unsigned long *flags)
+void __printk_safe_exit(void)
 {
-	WARN_ON_ONCE(in_nmi());
-	this_cpu_dec(printk_context.recursion);
-	local_unlock_irqrestore(&printk_context.cpu, *flags);
+	this_cpu_dec(printk_context);
 }
 
 void __printk_deferred_enter(void)
 {
-	WARN_ON_ONCE(!in_atomic());
-	this_cpu_inc(printk_context.recursion);
+	cant_migrate();
+	this_cpu_inc(printk_context);
 }
 
 void __printk_deferred_exit(void)
 {
-	WARN_ON_ONCE(!in_atomic());
-	this_cpu_dec(printk_context.recursion);
+	cant_migrate();
+	this_cpu_dec(printk_context);
 }
 
 asmlinkage int vprintk(const char *fmt, va_list args)
@@ -61,7 +50,7 @@ asmlinkage int vprintk(const char *fmt, va_list args)
 	 * Use the main logbuf even in NMI. But avoid calling console
 	 * drivers that might have their own locks.
 	 */
-	if (this_cpu_read(printk_context.recursion) || in_nmi())
+	if (this_cpu_read(printk_context) || in_nmi())
 		return vprintk_deferred(fmt, args);
 
 	/* No obstacles. */
diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h
index 7322f5353861..ddd4005ce57a 100644
--- a/kernel/rcu/tree_stall.h
+++ b/kernel/rcu/tree_stall.h
@@ -583,7 +583,6 @@ static void rcu_check_gp_kthread_expired_fqs_timer(void)
 
 static void print_other_cpu_stall(unsigned long gp_seq, unsigned long gps)
 {
-	enum cons_prio prev_prio;
 	int cpu;
 	unsigned long flags;
 	unsigned long gpa;
@@ -599,7 +598,7 @@ static void print_other_cpu_stall(unsigned long gp_seq, unsigned long gps)
 	if (rcu_stall_is_suppressed())
 		return;
 
-	prev_prio = cons_atomic_enter(CONS_PRIO_EMERGENCY);
+	nbcon_cpu_emergency_enter();
 
 	/*
 	 * OK, time to rat on our buddy...
@@ -656,7 +655,7 @@ static void print_other_cpu_stall(unsigned long gp_seq, unsigned long gps)
 
 	rcu_force_quiescent_state();  /* Kick them all. */
 
-	cons_atomic_exit(CONS_PRIO_EMERGENCY, prev_prio);
+	nbcon_cpu_emergency_exit();
 }
 
 static void print_cpu_stall(unsigned long gps)