From b7e9294885b610791fcebc799bf2a9e219446fd6 Mon Sep 17 00:00:00 2001 From: Sean Anderson Date: Tue, 20 Sep 2022 18:12:33 -0400 Subject: [PATCH] net: phylink: Adjust advertisement based on rate matching This adds support for adjusting the advertisement for pause-based rate matching. This may result in a lossy link, since the final link settings are not adjusted. Asymmetric pause support is necessary. It would be possible for a MAC supporting only symmetric pause to use pause-based rate adaptation, but only if pause reception was enabled as well. Signed-off-by: Sean Anderson Signed-off-by: David S. Miller --- drivers/net/phy/phylink.c | 106 ++++++++++++++++++++++++++++++++++++++++++++-- include/linux/phylink.h | 3 +- 2 files changed, 105 insertions(+), 4 deletions(-) diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c index 4576395..d0af026 100644 --- a/drivers/net/phy/phylink.c +++ b/drivers/net/phy/phylink.c @@ -373,18 +373,70 @@ void phylink_caps_to_linkmodes(unsigned long *linkmodes, unsigned long caps) } EXPORT_SYMBOL_GPL(phylink_caps_to_linkmodes); +static struct { + unsigned long mask; + int speed; + unsigned int duplex; +} phylink_caps_params[] = { + { MAC_400000FD, SPEED_400000, DUPLEX_FULL }, + { MAC_200000FD, SPEED_200000, DUPLEX_FULL }, + { MAC_100000FD, SPEED_100000, DUPLEX_FULL }, + { MAC_56000FD, SPEED_56000, DUPLEX_FULL }, + { MAC_50000FD, SPEED_50000, DUPLEX_FULL }, + { MAC_40000FD, SPEED_40000, DUPLEX_FULL }, + { MAC_25000FD, SPEED_25000, DUPLEX_FULL }, + { MAC_20000FD, SPEED_20000, DUPLEX_FULL }, + { MAC_10000FD, SPEED_10000, DUPLEX_FULL }, + { MAC_5000FD, SPEED_5000, DUPLEX_FULL }, + { MAC_2500FD, SPEED_2500, DUPLEX_FULL }, + { MAC_1000FD, SPEED_1000, DUPLEX_FULL }, + { MAC_1000HD, SPEED_1000, DUPLEX_HALF }, + { MAC_100FD, SPEED_100, DUPLEX_FULL }, + { MAC_100HD, SPEED_100, DUPLEX_HALF }, + { MAC_10FD, SPEED_10, DUPLEX_FULL }, + { MAC_10HD, SPEED_10, DUPLEX_HALF }, +}; + +/** + * phylink_cap_from_speed_duplex - Get mac capability from speed/duplex + * @speed: the speed to search for + * @duplex: the duplex to search for + * + * Find the mac capability for a given speed and duplex. + * + * Return: A mask with the mac capability patching @speed and @duplex, or 0 if + * there were no matches. + */ +static unsigned long phylink_cap_from_speed_duplex(int speed, + unsigned int duplex) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(phylink_caps_params); i++) { + if (speed == phylink_caps_params[i].speed && + duplex == phylink_caps_params[i].duplex) + return phylink_caps_params[i].mask; + } + + return 0; +} + /** * phylink_get_capabilities() - get capabilities for a given MAC * @interface: phy interface mode defined by &typedef phy_interface_t * @mac_capabilities: bitmask of MAC capabilities + * @rate_matching: type of rate matching being performed * * Get the MAC capabilities that are supported by the @interface mode and * @mac_capabilities. */ unsigned long phylink_get_capabilities(phy_interface_t interface, - unsigned long mac_capabilities) + unsigned long mac_capabilities, + int rate_matching) { + int max_speed = phylink_interface_max_speed(interface); unsigned long caps = MAC_SYM_PAUSE | MAC_ASYM_PAUSE; + unsigned long matched_caps = 0; switch (interface) { case PHY_INTERFACE_MODE_USXGMII: @@ -458,7 +510,53 @@ unsigned long phylink_get_capabilities(phy_interface_t interface, break; } - return caps & mac_capabilities; + switch (rate_matching) { + case RATE_MATCH_OPEN_LOOP: + /* TODO */ + fallthrough; + case RATE_MATCH_NONE: + matched_caps = 0; + break; + case RATE_MATCH_PAUSE: { + /* The MAC must support asymmetric pause towards the local + * device for this. We could allow just symmetric pause, but + * then we might have to renegotiate if the link partner + * doesn't support pause. This is because there's no way to + * accept pause frames without transmitting them if we only + * support symmetric pause. + */ + if (!(mac_capabilities & MAC_SYM_PAUSE) || + !(mac_capabilities & MAC_ASYM_PAUSE)) + break; + + /* We can't adapt if the MAC doesn't support the interface's + * max speed at full duplex. + */ + if (mac_capabilities & + phylink_cap_from_speed_duplex(max_speed, DUPLEX_FULL)) { + /* Although a duplex-matching phy might exist, we + * conservatively remove these modes because the MAC + * will not be aware of the half-duplex nature of the + * link. + */ + matched_caps = GENMASK(__fls(caps), __fls(MAC_10HD)); + matched_caps &= ~(MAC_1000HD | MAC_100HD | MAC_10HD); + } + break; + } + case RATE_MATCH_CRS: + /* The MAC must support half duplex at the interface's max + * speed. + */ + if (mac_capabilities & + phylink_cap_from_speed_duplex(max_speed, DUPLEX_HALF)) { + matched_caps = GENMASK(__fls(caps), __fls(MAC_10HD)); + matched_caps &= mac_capabilities; + } + break; + } + + return (caps & mac_capabilities) | matched_caps; } EXPORT_SYMBOL_GPL(phylink_get_capabilities); @@ -482,7 +580,8 @@ void phylink_generic_validate(struct phylink_config *config, phylink_set_port_modes(mask); phylink_set(mask, Autoneg); caps = phylink_get_capabilities(state->interface, - config->mac_capabilities); + config->mac_capabilities, + state->rate_matching); phylink_caps_to_linkmodes(mask, caps); linkmode_and(supported, supported, mask); @@ -1512,6 +1611,7 @@ static int phylink_bringup_phy(struct phylink *pl, struct phy_device *phy, config.interface = PHY_INTERFACE_MODE_NA; else config.interface = interface; + config.rate_matching = phy_get_rate_matching(phy, config.interface); ret = phylink_validate(pl, supported, &config); if (ret) { diff --git a/include/linux/phylink.h b/include/linux/phylink.h index 5c99c21..664dd40 100644 --- a/include/linux/phylink.h +++ b/include/linux/phylink.h @@ -554,7 +554,8 @@ void pcs_link_up(struct phylink_pcs *pcs, unsigned int mode, void phylink_caps_to_linkmodes(unsigned long *linkmodes, unsigned long caps); unsigned long phylink_get_capabilities(phy_interface_t interface, - unsigned long mac_capabilities); + unsigned long mac_capabilities, + int rate_matching); void phylink_generic_validate(struct phylink_config *config, unsigned long *supported, struct phylink_link_state *state); -- 2.7.4