From: Russell King <rmk+kernel@armlinux.org.uk>
Date: Sat, 15 Feb 2020 15:49:27 +0000
Subject: net: add helpers to resolve negotiated flow control
Patch-mainline: v5.7-rc1
Git-commit: a87ae8a963bde755b0962bcc18db83d611f63e7a
References: bsc#1176447
Add a couple of helpers to resolve negotiated flow control. Two helpers
are provided:
- linkmode_resolve_pause() which takes the link partner and local
advertisements, and decodes whether we should enable TX or RX pause
at the MAC. This is useful outside of phylib, e.g. in phylink.
- phy_get_pause(), which returns the TX/RX enablement status for the
current negotiation results of the PHY.
This allows us to centralise the flow control resolution, rather than
spreading it around.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/phy/Makefile | 3 +-
drivers/net/phy/linkmode.c | 44 +++++++++++++++++++++++++++++++++++++++++++
drivers/net/phy/phy_device.c | 26 +++++++++++++++++++++++++
include/linux/linkmode.h | 4 +++
include/linux/phy.h | 3 ++
5 files changed, 79 insertions(+), 1 deletion(-)
create mode 100644 drivers/net/phy/linkmode.c
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -1,7 +1,8 @@
# SPDX-License-Identifier: GPL-2.0
# Makefile for Linux PHY drivers and MDIO bus drivers
-libphy-y := phy.o phy-c45.o phy-core.o phy_device.o
+libphy-y := phy.o phy-c45.o phy-core.o phy_device.o \
+ linkmode.o
mdio-bus-y += mdio_bus.o mdio_device.o
ifdef CONFIG_MDIO_DEVICE
--- /dev/null
+++ b/drivers/net/phy/linkmode.c
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0+
+#include <linux/linkmode.h>
+
+/**
+ * linkmode_resolve_pause - resolve the allowable pause modes
+ * @local_adv: local advertisement in ethtool format
+ * @partner_adv: partner advertisement in ethtool format
+ * @tx_pause: pointer to bool to indicate whether transmit pause should be
+ * enabled.
+ * @rx_pause: pointer to bool to indicate whether receive pause should be
+ * enabled.
+ *
+ * Flow control is resolved according to our and the link partners
+ * advertisements using the following drawn from the 802.3 specs:
+ * Local device Link partner
+ * Pause AsymDir Pause AsymDir Result
+ * 0 X 0 X Disabled
+ * 0 1 1 0 Disabled
+ * 0 1 1 1 TX
+ * 1 0 0 X Disabled
+ * 1 X 1 X TX+RX
+ * 1 1 0 1 RX
+ */
+void linkmode_resolve_pause(const unsigned long *local_adv,
+ const unsigned long *partner_adv,
+ bool *tx_pause, bool *rx_pause)
+{
+ __ETHTOOL_DECLARE_LINK_MODE_MASK(m);
+
+ linkmode_and(m, local_adv, partner_adv);
+ if (linkmode_test_bit(ETHTOOL_LINK_MODE_Pause_BIT, m)) {
+ *tx_pause = true;
+ *rx_pause = true;
+ } else if (linkmode_test_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT, m)) {
+ *tx_pause = linkmode_test_bit(ETHTOOL_LINK_MODE_Pause_BIT,
+ partner_adv);
+ *rx_pause = linkmode_test_bit(ETHTOOL_LINK_MODE_Pause_BIT,
+ local_adv);
+ } else {
+ *tx_pause = false;
+ *rx_pause = false;
+ }
+}
+EXPORT_SYMBOL_GPL(linkmode_resolve_pause);
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -2401,6 +2401,32 @@ bool phy_validate_pause(struct phy_devic
}
EXPORT_SYMBOL(phy_validate_pause);
+/**
+ * phy_get_pause - resolve negotiated pause modes
+ * @phydev: phy_device struct
+ * @tx_pause: pointer to bool to indicate whether transmit pause should be
+ * enabled.
+ * @rx_pause: pointer to bool to indicate whether receive pause should be
+ * enabled.
+ *
+ * Resolve and return the flow control modes according to the negotiation
+ * result. This includes checking that we are operating in full duplex mode.
+ * See linkmode_resolve_pause() for further details.
+ */
+void phy_get_pause(struct phy_device *phydev, bool *tx_pause, bool *rx_pause)
+{
+ if (phydev->duplex != DUPLEX_FULL) {
+ *tx_pause = false;
+ *rx_pause = false;
+ return;
+ }
+
+ return linkmode_resolve_pause(phydev->advertising,
+ phydev->lp_advertising,
+ tx_pause, rx_pause);
+}
+EXPORT_SYMBOL(phy_get_pause);
+
static bool phy_drv_supports_irq(struct phy_driver *phydrv)
{
return phydrv->config_intr && phydrv->ack_interrupt;
--- a/include/linux/linkmode.h
+++ b/include/linux/linkmode.h
@@ -88,4 +88,8 @@ static inline int linkmode_subset(const
return bitmap_subset(src1, src2, __ETHTOOL_LINK_MODE_MASK_NBITS);
}
+void linkmode_resolve_pause(const unsigned long *local_adv,
+ const unsigned long *partner_adv,
+ bool *tx_pause, bool *rx_pause);
+
#endif /* __LINKMODE_H */
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -1234,6 +1234,9 @@ void phy_set_sym_pause(struct phy_device
void phy_set_asym_pause(struct phy_device *phydev, bool rx, bool tx);
bool phy_validate_pause(struct phy_device *phydev,
struct ethtool_pauseparam *pp);
+void phy_get_pause(struct phy_device *phydev, bool *tx_pause, bool *rx_pause);
+void phy_resolve_pause(unsigned long *local_adv, unsigned long *partner_adv,
+ bool *tx_pause, bool *rx_pause);
int phy_register_fixup(const char *bus_id, u32 phy_uid, u32 phy_uid_mask,
int (*run)(struct phy_device *));