[PATCH net-next 10/13] net: phy: phy_caps: Allow looking-up link caps based on speed and duplex

From: Maxime Chevallier
Date: Sat Feb 22 2025 - 09:32:19 EST


As the link_caps array is efficient for <speed,duplex> lookups,
implement a function for speed/duplex lookups that matches a given
mask. This replicates to some extent the phy_lookup_settings()
behaviour, matching full link_capabilities instead of a single linkmode.

phy.c's phy_santize_settings() and phylink's
phylink_ethtool_ksettings_set() performs such lookup using the
phy_settings table, but are only interested in the actual speed/duplex
that were matched, rathet than the individual linkmode.

Similar to phy_lookup_settings(), the newly introduced phy_caps_lookup()
will run through the link_caps[] array by descending speed/duplex order.

If the link_capabilities for a given <speed/duplex> tuple intersects the
passed linkmodes, we consider that a match.

Similar to phy_lookup_settings(), we also allow passing an 'exact'
boolean, allowing non-exact match. Here, we MUST always match the
linkmodes mask, but we allow matching on lower speed settings.

Signed-off-by: Maxime Chevallier <maxime.chevallier@xxxxxxxxxxx>
---
drivers/net/phy/phy-caps.h | 4 ++++
drivers/net/phy/phy.c | 32 ++++++--------------------
drivers/net/phy/phy_caps.c | 46 ++++++++++++++++++++++++++++++++++++++
drivers/net/phy/phylink.c | 16 ++++++-------
4 files changed, 65 insertions(+), 33 deletions(-)

diff --git a/drivers/net/phy/phy-caps.h b/drivers/net/phy/phy-caps.h
index b4b476495f6c..337e682aa754 100644
--- a/drivers/net/phy/phy-caps.h
+++ b/drivers/net/phy/phy-caps.h
@@ -32,4 +32,8 @@ phy_caps_lookup_by_linkmode(const unsigned long *linkmodes);
const struct link_capabilities *
phy_caps_lookup_by_linkmode_rev(const unsigned long *linkmodes, bool fdx_only);

+const struct link_capabilities *
+phy_caps_lookup(int speed, unsigned int duplex, const unsigned long *supported,
+ bool exact);
+
#endif /* __PHY_CAPS_H */
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index cb73293f7bce..63ddd27ec91b 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -212,25 +212,6 @@ int phy_aneg_done(struct phy_device *phydev)
}
EXPORT_SYMBOL(phy_aneg_done);

-/**
- * phy_find_valid - find a PHY setting that matches the requested parameters
- * @speed: desired speed
- * @duplex: desired duplex
- * @supported: mask of supported link modes
- *
- * Locate a supported phy setting that is, in priority order:
- * - an exact match for the specified speed and duplex mode
- * - a match for the specified speed, or slower speed
- * - the slowest supported speed
- * Returns the matched phy_setting entry, or %NULL if no supported phy
- * settings were found.
- */
-static const struct phy_setting *
-phy_find_valid(int speed, int duplex, unsigned long *supported)
-{
- return phy_lookup_setting(speed, duplex, supported, false);
-}
-
/**
* phy_supported_speeds - return all speeds currently supported by a phy device
* @phy: The phy device to return supported speeds of.
@@ -273,13 +254,14 @@ EXPORT_SYMBOL(phy_check_valid);
*/
static void phy_sanitize_settings(struct phy_device *phydev)
{
- const struct phy_setting *setting;
+ const struct link_capabilities *c;
+
+ c = phy_caps_lookup(phydev->speed, phydev->duplex, phydev->supported,
+ false);

- setting = phy_find_valid(phydev->speed, phydev->duplex,
- phydev->supported);
- if (setting) {
- phydev->speed = setting->speed;
- phydev->duplex = setting->duplex;
+ if (c) {
+ phydev->speed = c->speed;
+ phydev->duplex = c->duplex;
} else {
/* We failed to find anything (no supported speeds?) */
phydev->speed = SPEED_UNKNOWN;
diff --git a/drivers/net/phy/phy_caps.c b/drivers/net/phy/phy_caps.c
index 9faa7113a22f..ee03ecedd522 100644
--- a/drivers/net/phy/phy_caps.c
+++ b/drivers/net/phy/phy_caps.c
@@ -174,6 +174,52 @@ phy_caps_lookup_by_linkmode_rev(const unsigned long *linkmodes, bool fdx_only)
return NULL;
}

+/**
+ * phy_caps_lookup() - Lookup capabilities by speed/duplex that matches a mask
+ * @speed: Speed to match
+ * @duplex: Duplex to match
+ * @supported: Mask of linkmodes to match
+ * @exact: Perform an exact match or not.
+ *
+ * Lookup a link_capabilities entry that intersect the supported linkmodes mask,
+ * and that matches the passed speed and duplex.
+ *
+ * When @exact is set, an exact match is performed on speed and duplex, meaning
+ * that if the linkmodes for the given speed and duplex intersect the supported
+ * mask, this capability is returned, otherwise we don't have a match and return
+ * NULL.
+ *
+ * When @exact is not set, we return either an exact match, or matching capabilities
+ * at lower speed, or the lowest matching speed, or NULL.
+ */
+const struct link_capabilities *
+phy_caps_lookup(int speed, unsigned int duplex, const unsigned long *supported,
+ bool exact)
+{
+ const struct link_capabilities *c, *last = NULL;
+ int capa;
+
+ for (capa = __LINK_CAPA_LAST; capa >= 0; capa--) {
+ c = &link_caps[capa];
+ if (linkmode_intersects(c->linkmodes, supported)) {
+ last = c;
+ /* exact match on speed and duplex*/
+ if (c->speed == speed && c->duplex == duplex) {
+ return c;
+ } else if (!exact) {
+ if (c->speed <= speed)
+ return c;
+ }
+ }
+ }
+
+ if (!exact)
+ return last;
+
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(phy_caps_lookup);
+
/**
* phy_caps_linkmode_max_speed() - Clamp a linkmodes set to a max speed
* @max_speed: Speed limit for the linkmode set
diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index af04be1d23c5..da7b159702c5 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -2552,8 +2552,8 @@ int phylink_ethtool_ksettings_set(struct phylink *pl,
const struct ethtool_link_ksettings *kset)
{
__ETHTOOL_DECLARE_LINK_MODE_MASK(support);
+ const struct link_capabilities *c;
struct phylink_link_state config;
- const struct phy_setting *s;

ASSERT_RTNL();

@@ -2596,23 +2596,23 @@ int phylink_ethtool_ksettings_set(struct phylink *pl,
/* Autonegotiation disabled, select a suitable speed and
* duplex.
*/
- s = phy_lookup_setting(kset->base.speed, kset->base.duplex,
- pl->supported, false);
- if (!s)
+ c = phy_caps_lookup(kset->base.speed, kset->base.duplex,
+ pl->supported, false);
+ if (!c)
return -EINVAL;

/* If we have a fixed link, refuse to change link parameters.
* If the link parameters match, accept them but do nothing.
*/
if (pl->req_link_an_mode == MLO_AN_FIXED) {
- if (s->speed != pl->link_config.speed ||
- s->duplex != pl->link_config.duplex)
+ if (c->speed != pl->link_config.speed ||
+ c->duplex != pl->link_config.duplex)
return -EINVAL;
return 0;
}

- config.speed = s->speed;
- config.duplex = s->duplex;
+ config.speed = c->speed;
+ config.duplex = c->duplex;
break;

case AUTONEG_ENABLE:
--
2.48.1