-From 027586ae8ecacff49757ed854c020f35d24a599c Mon Sep 17 00:00:00 2001
-From: Daniel Golle <daniel@makrotopia.org>
-Date: Sat, 11 Mar 2023 03:44:41 +0000
-Subject: [PATCH] generic: backport some phylink helper functions
-
-It isn't feasible to literally backport all upstream phylink_pcs changes
-down to Linux 5.15: It's just too many patches, and many downstream
-drivers and hacks are likely to break. We are too close to branching off
-to risk this, and it's also just too much work.
-Instead just add helper functions used by modern PCS drivers while keeping
-the original functions instact as well. While this may add a kilobyte or
-two of extra kernel size, it has the advantage that we get the best of both
-worlds: None of the existing codepaths are touched, but yet we have the
-option to backport singular improvements to Ethernet drivers where needed.
-
-Signed-off-by: Daniel Golle <daniel@makrotopia.org>
-
---- a/include/linux/phylink.h
-+++ b/include/linux/phylink.h
-@@ -584,10 +584,37 @@ int phylink_speed_up(struct phylink *pl)
- #define phylink_test(bm, mode) __phylink_do_bit(test_bit, bm, mode)
-
- void phylink_set_port_modes(unsigned long *bits);
-+
-+/**
-+ * phylink_get_link_timer_ns - return the PCS link timer value
-+ * @interface: link &typedef phy_interface_t mode
-+ *
-+ * Return the PCS link timer setting in nanoseconds for the PHY @interface
-+ * mode, or -EINVAL if not appropriate.
-+ */
-+static inline int phylink_get_link_timer_ns(phy_interface_t interface)
-+{
-+ switch (interface) {
-+ case PHY_INTERFACE_MODE_SGMII:
-+ return 1600000;
-+
-+ case PHY_INTERFACE_MODE_1000BASEX:
-+ case PHY_INTERFACE_MODE_2500BASEX:
-+ return 10000000;
-+
-+ default:
-+ return -EINVAL;
-+ }
-+}
-+
- void phylink_helper_basex_speed(struct phylink_link_state *state);
-
-+void phylink_mii_c22_pcs_decode_state(struct phylink_link_state *state,
-+ u16 bmsr, u16 lpa);
- void phylink_mii_c22_pcs_get_state(struct mdio_device *pcs,
- struct phylink_link_state *state);
-+int phylink_mii_c22_pcs_encode_advertisement(phy_interface_t interface,
-+ const unsigned long *advertising);
- int phylink_mii_c22_pcs_set_advertisement(struct mdio_device *pcs,
- phy_interface_t interface,
- const unsigned long *advertising);
---- a/drivers/net/phy/phylink.c
-+++ b/drivers/net/phy/phylink.c
-@@ -885,7 +885,6 @@ static int phylink_change_inband_advert(
-
- return 0;
- }
--
- static void phylink_mac_pcs_get_state(struct phylink *pl,
- struct phylink_link_state *state)
- {
-@@ -2966,6 +2965,52 @@ void phylink_mii_c22_pcs_get_state(struc
- EXPORT_SYMBOL_GPL(phylink_mii_c22_pcs_get_state);
-
- /**
-+ * phylink_mii_c22_pcs_decode_state() - Decode MAC PCS state from MII registers
-+ * @state: a pointer to a &struct phylink_link_state.
-+ * @bmsr: The value of the %MII_BMSR register
-+ * @lpa: The value of the %MII_LPA register
-+ *
-+ * Helper for MAC PCS supporting the 802.3 clause 22 register set for
-+ * clause 37 negotiation and/or SGMII control.
-+ *
-+ * Parse the Clause 37 or Cisco SGMII link partner negotiation word into
-+ * the phylink @state structure. This is suitable to be used for implementing
-+ * the mac_pcs_get_state() member of the struct phylink_mac_ops structure if
-+ * accessing @bmsr and @lpa cannot be done with MDIO directly.
-+ */
-+void phylink_mii_c22_pcs_decode_state(struct phylink_link_state *state,
-+ u16 bmsr, u16 lpa)
-+{
-+ state->link = !!(bmsr & BMSR_LSTATUS);
-+ state->an_complete = !!(bmsr & BMSR_ANEGCOMPLETE);
-+ /* If there is no link or autonegotiation is disabled, the LP advertisement
-+ * data is not meaningful, so don't go any further.
-+ */
-+ if (!state->link || !state->an_enabled)
-+ return;
-+
-+ switch (state->interface) {
-+ case PHY_INTERFACE_MODE_1000BASEX:
-+ phylink_decode_c37_word(state, lpa, SPEED_1000);
-+ break;
-+
-+ case PHY_INTERFACE_MODE_2500BASEX:
-+ phylink_decode_c37_word(state, lpa, SPEED_2500);
-+ break;
-+
-+ case PHY_INTERFACE_MODE_SGMII:
-+ case PHY_INTERFACE_MODE_QSGMII:
-+ phylink_decode_sgmii_word(state, lpa);
-+ break;
-+
-+ default:
-+ state->link = false;
-+ break;
-+ }
-+}
-+EXPORT_SYMBOL_GPL(phylink_mii_c22_pcs_decode_state);
-+
-+/**
- * phylink_mii_c22_pcs_set_advertisement() - configure the clause 37 PCS
- * advertisement
- * @pcs: a pointer to a &struct mdio_device.
-@@ -3037,6 +3082,46 @@ int phylink_mii_c22_pcs_set_advertisemen
- EXPORT_SYMBOL_GPL(phylink_mii_c22_pcs_set_advertisement);
-
- /**
-+ * phylink_mii_c22_pcs_encode_advertisement() - configure the clause 37 PCS
-+ * advertisement
-+ * @interface: the PHY interface mode being configured
-+ * @advertising: the ethtool advertisement mask
-+ *
-+ * Helper for MAC PCS supporting the 802.3 clause 22 register set for
-+ * clause 37 negotiation and/or SGMII control.
-+ *
-+ * Encode the clause 37 PCS advertisement as specified by @interface and
-+ * @advertising.
-+ *
-+ * Return: The new value for @adv, or ``-EINVAL`` if it should not be changed.
-+ */
-+int phylink_mii_c22_pcs_encode_advertisement(phy_interface_t interface,
-+ const unsigned long *advertising)
-+{
-+ u16 adv;
-+
-+ switch (interface) {
-+ case PHY_INTERFACE_MODE_1000BASEX:
-+ case PHY_INTERFACE_MODE_2500BASEX:
-+ adv = ADVERTISE_1000XFULL;
-+ if (linkmode_test_bit(ETHTOOL_LINK_MODE_Pause_BIT,
-+ advertising))
-+ adv |= ADVERTISE_1000XPAUSE;
-+ if (linkmode_test_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT,
-+ advertising))
-+ adv |= ADVERTISE_1000XPSE_ASYM;
-+ return adv;
-+ case PHY_INTERFACE_MODE_SGMII:
-+ case PHY_INTERFACE_MODE_QSGMII:
-+ return 0x0001;
-+ default:
-+ /* Nothing to do for other modes */
-+ return -EINVAL;
-+ }
-+}
-+EXPORT_SYMBOL_GPL(phylink_mii_c22_pcs_encode_advertisement);
-+
-+/**
- * phylink_mii_c22_pcs_config() - configure clause 22 PCS
- * @pcs: a pointer to a &struct mdio_device.
- * @mode: link autonegotiation mode