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Message-Id: <20220719235002.1944800-9-sean.anderson@seco.com>
Date: Tue, 19 Jul 2022 19:49:58 -0400
From: Sean Anderson <sean.anderson@...o.com>
To: netdev@...r.kernel.org, Andrew Lunn <andrew@...n.ch>,
Heiner Kallweit <hkallweit1@...il.com>,
Russell King <linux@...linux.org.uk>
Cc: Alexandru Marginean <alexandru.marginean@....com>,
Paolo Abeni <pabeni@...hat.com>,
"David S . Miller" <davem@...emloft.net>,
linux-kernel@...r.kernel.org, Vladimir Oltean <olteanv@...il.com>,
Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>,
Sean Anderson <sean.anderson@...o.com>
Subject: [PATCH v2 08/11] net: phylink: Adjust advertisement based on rate adaptation
This adds support for adjusting the advertisement for pause-based rate
adaptation. 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 <sean.anderson@...o.com>
---
Changes in v2:
- Determine the interface speed and max mac speed directly instead of
guessing based on the caps.
drivers/net/phy/phylink.c | 87 +++++++++++++++++++++++++++++++++++++--
include/linux/phylink.h | 5 ++-
2 files changed, 88 insertions(+), 4 deletions(-)
diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 619ef553476f..f61040c93f3c 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -398,18 +398,65 @@ void phylink_caps_to_linkmodes(unsigned long *linkmodes, unsigned long caps)
}
EXPORT_SYMBOL_GPL(phylink_caps_to_linkmodes);
+static int phylink_caps_to_speed(unsigned long caps)
+{
+ unsigned int max_cap = __fls(caps);
+
+ if (max_cap == __fls(MAC_10HD) || max_cap == __fls(MAC_10FD))
+ return SPEED_10;
+ if (max_cap == __fls(MAC_100HD) || max_cap == __fls(MAC_100FD))
+ return SPEED_100;
+ if (max_cap == __fls(MAC_1000HD) || max_cap == __fls(MAC_1000FD))
+ return SPEED_1000;
+ if (max_cap == __fls(MAC_2500FD))
+ return SPEED_2500;
+ if (max_cap == __fls(MAC_5000FD))
+ return SPEED_5000;
+ if (max_cap == __fls(MAC_10000FD))
+ return SPEED_10000;
+ if (max_cap == __fls(MAC_20000FD))
+ return SPEED_20000;
+ if (max_cap == __fls(MAC_25000FD))
+ return SPEED_25000;
+ if (max_cap == __fls(MAC_40000FD))
+ return SPEED_40000;
+ if (max_cap == __fls(MAC_50000FD))
+ return SPEED_50000;
+ if (max_cap == __fls(MAC_56000FD))
+ return SPEED_56000;
+ if (max_cap == __fls(MAC_100000FD))
+ return SPEED_100000;
+ if (max_cap == __fls(MAC_200000FD))
+ return SPEED_200000;
+ if (max_cap == __fls(MAC_400000FD))
+ return SPEED_400000;
+ return SPEED_UNKNOWN;
+}
+
/**
* 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_adaptation: type of rate adaptation 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_adaptation)
{
unsigned long caps = MAC_SYM_PAUSE | MAC_ASYM_PAUSE;
+ unsigned long adapted_caps = 0;
+ struct phylink_link_state state = {
+ .interface = interface,
+ .rate_adaptation = rate_adaptation,
+ .link_speed = SPEED_UNKNOWN,
+ .link_duplex = DUPLEX_UNKNOWN,
+ };
+
+ /* Look up the interface speed */
+ phylink_state_fill_speed_duplex(&state);
switch (interface) {
case PHY_INTERFACE_MODE_USXGMII:
@@ -482,7 +529,39 @@ unsigned long phylink_get_capabilities(phy_interface_t interface,
break;
}
- return caps & mac_capabilities;
+ switch (rate_adaptation) {
+ case RATE_ADAPT_NONE:
+ break;
+ case RATE_ADAPT_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.
+ */
+ if (!(mac_capabilities & MAC_SYM_PAUSE) ||
+ !(mac_capabilities & MAC_ASYM_PAUSE))
+ break;
+
+ /* Can't adapt if the MAC doesn't support the interface's max
+ * speed
+ */
+ if (state.speed != phylink_caps_to_speed(mac_capabilities))
+ break;
+
+ adapted_caps = GENMASK(__fls(caps), __fls(MAC_10HD));
+ /* We can't use pause frames in half-duplex mode */
+ adapted_caps &= ~(MAC_1000HD | MAC_100HD | MAC_10HD);
+ break;
+ }
+ case RATE_ADAPT_CRS:
+ /* TODO */
+ break;
+ case RATE_ADAPT_OPEN_LOOP:
+ /* TODO */
+ break;
+ }
+
+ return (caps & mac_capabilities) | adapted_caps;
}
EXPORT_SYMBOL_GPL(phylink_get_capabilities);
@@ -506,7 +585,8 @@ 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_adaptation);
phylink_caps_to_linkmodes(mask, caps);
linkmode_and(supported, supported, mask);
@@ -1529,6 +1609,7 @@ static int phylink_bringup_phy(struct phylink *pl, struct phy_device *phy,
config.interface = PHY_INTERFACE_MODE_NA;
else
config.interface = interface;
+ config.rate_adaptation = phy_get_rate_adaptation(phy, config.interface);
ret = phylink_validate(pl, supported, &config);
if (ret) {
diff --git a/include/linux/phylink.h b/include/linux/phylink.h
index f32b97f27ddc..73e1aa73e30f 100644
--- a/include/linux/phylink.h
+++ b/include/linux/phylink.h
@@ -70,6 +70,8 @@ static inline bool phylink_autoneg_inband(unsigned int mode)
* @link: true if the link is up.
* @an_enabled: true if autonegotiation is enabled/desired.
* @an_complete: true if autonegotiation has completed.
+ * @rate_adaptation: method of throttling @interface_speed to @speed, one of
+ * RATE_ADAPT_* constants.
*/
struct phylink_link_state {
__ETHTOOL_DECLARE_LINK_MODE_MASK(advertising);
@@ -531,7 +533,8 @@ 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_adaptation);
void phylink_generic_validate(struct phylink_config *config,
unsigned long *supported,
struct phylink_link_state *state);
--
2.35.1.1320.gc452695387.dirty
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