From e278ad6a01dde557c391d0c4b34bd1f2d95e1dae Mon Sep 17 00:00:00 2001 From: Russell King Date: Fri, 3 Jan 2020 17:50:27 +0000 Subject: net: add linkmode helper for setting flow control advertisement Add a linkmode helper to set the flow control advertisement in an ethtool linkmode mask according to the tx/rx capabilities. This implementation is moved from phylib, and documented with an analysis of its shortcomings. Signed-off-by: Russell King --- drivers/net/phy/linkmode.c | 51 ++++++++++++++++++++++++++++++++++++++++++++ drivers/net/phy/phy_device.c | 17 +-------------- include/linux/linkmode.h | 2 ++ 3 files changed, 54 insertions(+), 16 deletions(-) diff --git a/drivers/net/phy/linkmode.c b/drivers/net/phy/linkmode.c index 969918795228..f60560fe3499 100644 --- a/drivers/net/phy/linkmode.c +++ b/drivers/net/phy/linkmode.c @@ -42,3 +42,54 @@ void linkmode_resolve_pause(const unsigned long *local_adv, } } EXPORT_SYMBOL_GPL(linkmode_resolve_pause); + +/** + * linkmode_set_pause - set the pause mode advertisement + * @advertisement: advertisement in ethtool format + * @tx: boolean from ethtool struct ethtool_pauseparam tx_pause member + * @rx: boolean from ethtool struct ethtool_pauseparam rx_pause member + * + * Configure the advertised Pause and Asym_Pause bits according to the + * capabilities of provided in @tx and @rx. + * + * We convert as follows: + * tx rx Pause AsymDir + * 0 0 0 0 + * 0 1 1 1 + * 1 0 0 1 + * 1 1 1 0 + * + * Note: this translation from ethtool tx/rx notation to the advertisement + * is actually very problematical. Here are some examples: + * + * For tx=0 rx=1, meaning transmit is unsupported, receive is supported: + * + * Local device Link partner + * Pause AsymDir Pause AsymDir Result + * 1 1 1 0 TX + RX - but we have no TX support. + * 1 1 0 1 Only this gives RX only + * + * For tx=1 rx=1, meaning we have the capability to transmit and receive + * pause frames: + * + * Local device Link partner + * Pause AsymDir Pause AsymDir Result + * 1 0 0 1 Disabled - but since we do support tx and rx, + * this should resolve to RX only. + * + * Hence, asking for: + * rx=1 tx=0 gives Pause+AsymDir advertisement, but we may end up + * resolving to tx+rx pause or only rx pause depending on + * the partners advertisement. + * rx=0 tx=1 gives AsymDir only, which will only give tx pause if + * the partners advertisement allows it. + * rx=1 tx=1 gives Pause only, which will only allow tx+rx pause + * if the other end also advertises Pause. + */ +void linkmode_set_pause(unsigned long *advertisement, bool tx, bool rx) +{ + linkmode_mod_bit(ETHTOOL_LINK_MODE_Pause_BIT, advertisement, rx); + linkmode_mod_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT, advertisement, + rx ^ tx); +} +EXPORT_SYMBOL_GPL(linkmode_set_pause); diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index a59bf4bd6cd3..67515916722b 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -2356,22 +2356,7 @@ void phy_set_asym_pause(struct phy_device *phydev, bool rx, bool tx) __ETHTOOL_DECLARE_LINK_MODE_MASK(oldadv); linkmode_copy(oldadv, phydev->advertising); - - linkmode_clear_bit(ETHTOOL_LINK_MODE_Pause_BIT, - phydev->advertising); - linkmode_clear_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT, - phydev->advertising); - - if (rx) { - linkmode_set_bit(ETHTOOL_LINK_MODE_Pause_BIT, - phydev->advertising); - linkmode_set_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT, - phydev->advertising); - } - - if (tx) - linkmode_change_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT, - phydev->advertising); + linkmode_set_pause(phydev->advertising, tx, rx); if (!linkmode_equal(oldadv, phydev->advertising) && phydev->autoneg) diff --git a/include/linux/linkmode.h b/include/linux/linkmode.h index 9ec210f31d06..c664c27a29a0 100644 --- a/include/linux/linkmode.h +++ b/include/linux/linkmode.h @@ -92,4 +92,6 @@ void linkmode_resolve_pause(const unsigned long *local_adv, const unsigned long *partner_adv, bool *tx_pause, bool *rx_pause); +void linkmode_set_pause(unsigned long *advertisement, bool tx, bool rx); + #endif /* __LINKMODE_H */ -- cgit