From: Jonathan Cooper <jonathan.s.cooper@amd.com>
Date: Tue, 28 Jun 2022 14:58:55 +0100
Subject: sfc: Split STATE_READY in to STATE_NET_DOWN and STATE_NET_UP.
Patch-mainline: v6.0-rc1
Git-commit: 813cf9d1e753e1e0a247d3d685212a06141b483e
References: jsc#PED-1565

This patch splits the READY state in to NET_UP and NET_DOWN. This
is to prepare for future work to delay resource allocation until
interface up so that we can use resources more efficiently in
SRIOV environments, and also to lay the ground work for an extra
PROBED state where we don't create a network interface,
for VDPA operation.

Signed-off-by: Jonathan Cooper <jonathan.s.cooper@amd.com>
Acked-by: Martin Habets <habetsm.xilinx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/sfc/ef100_netdev.c   |    6 +++
 drivers/net/ethernet/sfc/efx.c            |   29 +++++++----------
 drivers/net/ethernet/sfc/efx_common.c     |   10 +++---
 drivers/net/ethernet/sfc/efx_common.h     |    6 +--
 drivers/net/ethernet/sfc/ethtool_common.c |    2 -
 drivers/net/ethernet/sfc/net_driver.h     |   50 +++++++++++++++++++++++++++---
 6 files changed, 72 insertions(+), 31 deletions(-)

--- a/drivers/net/ethernet/sfc/ef100_netdev.c
+++ b/drivers/net/ethernet/sfc/ef100_netdev.c
@@ -96,6 +96,8 @@ static int ef100_net_stop(struct net_dev
 	efx_mcdi_free_vis(efx);
 	efx_remove_interrupts(efx);
 
+	efx->state = STATE_NET_DOWN;
+
 	return 0;
 }
 
@@ -172,6 +174,8 @@ static int ef100_net_open(struct net_dev
 		efx_link_status_changed(efx);
 	mutex_unlock(&efx->mac_lock);
 
+	efx->state = STATE_NET_UP;
+
 	return 0;
 
 fail:
@@ -271,7 +275,7 @@ int ef100_register_netdev(struct efx_nic
 	/* Always start with carrier off; PHY events will detect the link */
 	netif_carrier_off(net_dev);
 
-	efx->state = STATE_READY;
+	efx->state = STATE_NET_DOWN;
 	rtnl_unlock();
 	efx_init_mcdi_logging(efx);
 
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -106,14 +106,6 @@ static int efx_xdp(struct net_device *de
 static int efx_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **xdpfs,
 			u32 flags);
 
-#define EFX_ASSERT_RESET_SERIALISED(efx)		\
-	do {						\
-		if ((efx->state == STATE_READY) ||	\
-		    (efx->state == STATE_RECOVERY) ||	\
-		    (efx->state == STATE_DISABLED))	\
-			ASSERT_RTNL();			\
-	} while (0)
-
 /**************************************************************************
  *
  * Port handling
@@ -378,6 +370,8 @@ static int efx_probe_all(struct efx_nic
 	if (rc)
 		goto fail5;
 
+	efx->state = STATE_NET_DOWN;
+
 	return 0;
 
  fail5:
@@ -544,6 +538,9 @@ int efx_net_open(struct net_device *net_
 	efx_start_all(efx);
 	if (efx->state == STATE_DISABLED || efx->reset_pending)
 		netif_device_detach(efx->net_dev);
+	else
+		efx->state = STATE_NET_UP;
+
 	efx_selftest_async_start(efx);
 	return 0;
 }
@@ -720,8 +717,6 @@ static int efx_register_netdev(struct ef
 	 * already requested.  If so, the NIC is probably hosed so we
 	 * abort.
 	 */
-	efx->state = STATE_READY;
-	smp_mb(); /* ensure we change state before checking reset_pending */
 	if (efx->reset_pending) {
 		pci_err(efx->pci_dev, "aborting probe due to scheduled reset\n");
 		rc = -EIO;
@@ -748,6 +743,8 @@ static int efx_register_netdev(struct ef
 
 	efx_associate(efx);
 
+	efx->state = STATE_NET_DOWN;
+
 	rtnl_unlock();
 
 	rc = device_create_file(&efx->pci_dev->dev, &dev_attr_phy_type);
@@ -845,7 +842,7 @@ static void efx_pci_remove_main(struct e
 	/* Flush reset_work. It can no longer be scheduled since we
 	 * are not READY.
 	 */
-	BUG_ON(efx->state == STATE_READY);
+	WARN_ON(efx_net_active(efx->state));
 	efx_flush_reset_workqueue(efx);
 
 	efx_disable_interrupts(efx);
@@ -1150,13 +1147,13 @@ static int efx_pm_freeze(struct device *
 
 	rtnl_lock();
 
-	if (efx->state != STATE_DISABLED) {
-		efx->state = STATE_UNINIT;
-
+	if (efx_net_active(efx->state)) {
 		efx_device_detach_sync(efx);
 
 		efx_stop_all(efx);
 		efx_disable_interrupts(efx);
+
+		efx->state = efx_freeze(efx->state);
 	}
 
 	rtnl_unlock();
@@ -1171,7 +1168,7 @@ static int efx_pm_thaw(struct device *de
 
 	rtnl_lock();
 
-	if (efx->state != STATE_DISABLED) {
+	if (efx_frozen(efx->state)) {
 		rc = efx_enable_interrupts(efx);
 		if (rc)
 			goto fail;
@@ -1184,7 +1181,7 @@ static int efx_pm_thaw(struct device *de
 
 		efx_device_attach_if_not_resetting(efx);
 
-		efx->state = STATE_READY;
+		efx->state = efx_thaw(efx->state);
 
 		efx->type->resume_wol(efx);
 	}
--- a/drivers/net/ethernet/sfc/efx_common.c
+++ b/drivers/net/ethernet/sfc/efx_common.c
@@ -898,7 +898,7 @@ static void efx_reset_work(struct work_s
 	 * have changed by now.  Now that we have the RTNL lock,
 	 * it cannot change again.
 	 */
-	if (efx->state == STATE_READY)
+	if (efx_net_active(efx->state))
 		(void)efx_reset(efx, method);
 
 	rtnl_unlock();
@@ -908,7 +908,7 @@ void efx_schedule_reset(struct efx_nic *
 {
 	enum reset_type method;
 
-	if (efx->state == STATE_RECOVERY) {
+	if (efx_recovering(efx->state)) {
 		netif_dbg(efx, drv, efx->net_dev,
 			  "recovering: skip scheduling %s reset\n",
 			  RESET_TYPE(type));
@@ -943,7 +943,7 @@ void efx_schedule_reset(struct efx_nic *
 	/* If we're not READY then just leave the flags set as the cue
 	 * to abort probing or reschedule the reset later.
 	 */
-	if (READ_ONCE(efx->state) != STATE_READY)
+	if (!efx_net_active(READ_ONCE(efx->state)))
 		return;
 
 	/* efx_process_channel() will no longer read events once a
@@ -1217,7 +1217,7 @@ static pci_ers_result_t efx_io_error_det
 	rtnl_lock();
 
 	if (efx->state != STATE_DISABLED) {
-		efx->state = STATE_RECOVERY;
+		efx->state = efx_recover(efx->state);
 		efx->reset_pending = 0;
 
 		efx_device_detach_sync(efx);
@@ -1271,7 +1271,7 @@ static void efx_io_resume(struct pci_dev
 		netif_err(efx, hw, efx->net_dev,
 			  "efx_reset failed after PCI error (%d)\n", rc);
 	} else {
-		efx->state = STATE_READY;
+		efx->state = efx_recovered(efx->state);
 		netif_dbg(efx, hw, efx->net_dev,
 			  "Done resetting and resuming IO after PCI error.\n");
 	}
--- a/drivers/net/ethernet/sfc/efx_common.h
+++ b/drivers/net/ethernet/sfc/efx_common.h
@@ -45,9 +45,7 @@ int efx_reconfigure_port(struct efx_nic
 
 #define EFX_ASSERT_RESET_SERIALISED(efx)		\
 	do {						\
-		if ((efx->state == STATE_READY) ||	\
-		    (efx->state == STATE_RECOVERY) ||	\
-		    (efx->state == STATE_DISABLED))	\
+		if (efx->state != STATE_UNINIT)		\
 			ASSERT_RTNL();			\
 	} while (0)
 
@@ -64,7 +62,7 @@ void efx_port_dummy_op_void(struct efx_n
 
 static inline int efx_check_disabled(struct efx_nic *efx)
 {
-	if (efx->state == STATE_DISABLED || efx->state == STATE_RECOVERY) {
+	if (efx->state == STATE_DISABLED || efx_recovering(efx->state)) {
 		netif_err(efx, drv, efx->net_dev,
 			  "device is disabled due to earlier errors\n");
 		return -EIO;
--- a/drivers/net/ethernet/sfc/ethtool_common.c
+++ b/drivers/net/ethernet/sfc/ethtool_common.c
@@ -137,7 +137,7 @@ void efx_ethtool_self_test(struct net_de
 	if (!efx_tests)
 		goto fail;
 
-	if (efx->state != STATE_READY) {
+	if (!efx_net_active(efx->state)) {
 		rc = -EBUSY;
 		goto out;
 	}
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -622,12 +622,54 @@ enum efx_int_mode {
 #define EFX_INT_MODE_USE_MSI(x) (((x)->interrupt_mode) <= EFX_INT_MODE_MSI)
 
 enum nic_state {
-	STATE_UNINIT = 0,	/* device being probed/removed or is frozen */
-	STATE_READY = 1,	/* hardware ready and netdev registered */
-	STATE_DISABLED = 2,	/* device disabled due to hardware errors */
-	STATE_RECOVERY = 3,	/* device recovering from PCI error */
+	STATE_UNINIT = 0,	/* device being probed/removed */
+	STATE_NET_DOWN,		/* hardware probed and netdev registered */
+	STATE_NET_UP,		/* ready for traffic */
+	STATE_DISABLED,		/* device disabled due to hardware errors */
+
+	STATE_RECOVERY = 0x100,/* recovering from PCI error */
+	STATE_FROZEN = 0x200,	/* frozen by power management */
 };
 
+static inline bool efx_net_active(enum nic_state state)
+{
+	return state == STATE_NET_DOWN || state == STATE_NET_UP;
+}
+
+static inline bool efx_frozen(enum nic_state state)
+{
+	return state & STATE_FROZEN;
+}
+
+static inline bool efx_recovering(enum nic_state state)
+{
+	return state & STATE_RECOVERY;
+}
+
+static inline enum nic_state efx_freeze(enum nic_state state)
+{
+	WARN_ON(!efx_net_active(state));
+	return state | STATE_FROZEN;
+}
+
+static inline enum nic_state efx_thaw(enum nic_state state)
+{
+	WARN_ON(!efx_frozen(state));
+	return state & ~STATE_FROZEN;
+}
+
+static inline enum nic_state efx_recover(enum nic_state state)
+{
+	WARN_ON(!efx_net_active(state));
+	return state | STATE_RECOVERY;
+}
+
+static inline enum nic_state efx_recovered(enum nic_state state)
+{
+	WARN_ON(!efx_recovering(state));
+	return state & ~STATE_RECOVERY;
+}
+
 /* Forward declaration */
 struct efx_nic;