Commit b7e92948 authored by Sean Anderson's avatar Sean Anderson Committed by David S. Miller
Browse files

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: default avatarSean Anderson <sean.anderson@seco.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ae0e4bb2

drivers/net/phy/phylink.c

+103 −3
Original line number Diff line number Diff line
@@ -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) {

include/linux/phylink.h

+2 −1
Original line number Diff line number Diff line
@@ -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);