Commit a87ae8a9 authored by Russell King's avatar Russell King Committed by David S. Miller
Browse files

net: add helpers to resolve negotiated flow control 



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: default avatarRussell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8062e233

drivers/net/phy/Makefile

+2 −1
Original line number Diff line number Diff line 
# 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

drivers/net/phy/linkmode.c

0 → 100644
+44 −0
Original line number Diff line number Diff line 
// 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);

drivers/net/phy/phy_device.c

+26 −0
Original line number Diff line number Diff line
@@ -2409,6 +2409,32 @@ bool phy_validate_pause(struct phy_device *phydev, 
}

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;

include/linux/linkmode.h

+4 −0
Original line number Diff line number Diff line
@@ -88,4 +88,8 @@ static inline int linkmode_subset(const unsigned long *src1, 
	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 */

include/linux/phy.h

+3 −0
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@@ -1257,6 +1257,9 @@ void phy_set_sym_pause(struct phy_device *phydev, bool rx, bool tx, 
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 *));

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