net: phylink: add PCS negotiation mode

PCS have to work out whether they should enable PCS negotiation by
looking at the "mode" and "interface" arguments, and the Autoneg bit
in the advertising mask.

This leads to some complex logic, so lets pull that out into phylink
and instead pass a "neg_mode" argument to the PCS configuration and
link up methods, instead of the "mode" argument.

In order to transition drivers, add a "neg_mode" flag to the phylink
PCS structure to PCS can indicate whether they want to be passed the
neg_mode or the old mode argument.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://lore.kernel.org/r/E1qA8De-00EaFA-Ht@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 34 insertions, 11 deletions

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 97c15e1f81de..5d8f8b84908c 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -71,6 +71,7 @@ struct phylink {
 	struct mutex state_mutex;
 	struct phylink_link_state phy_state;
 	struct work_struct resolve;
+	unsigned int pcs_neg_mode;
 
 	bool mac_link_dropped;
 	bool using_mac_select_pcs;
@@ -992,23 +993,23 @@ static void phylink_resolve_an_pause(struct phylink_link_state *state)
 	}
 }
 
-static int phylink_pcs_config(struct phylink_pcs *pcs, unsigned int mode,
+static int phylink_pcs_config(struct phylink_pcs *pcs, unsigned int neg_mode,
 			      const struct phylink_link_state *state,
 			      bool permit_pause_to_mac)
 {
 	if (!pcs)
 		return 0;
 
-	return pcs->ops->pcs_config(pcs, mode, state->interface,
+	return pcs->ops->pcs_config(pcs, neg_mode, state->interface,
 				    state->advertising, permit_pause_to_mac);
 }
 
-static void phylink_pcs_link_up(struct phylink_pcs *pcs, unsigned int mode,
+static void phylink_pcs_link_up(struct phylink_pcs *pcs, unsigned int neg_mode,
 				phy_interface_t interface, int speed,
 				int duplex)
 {
 	if (pcs && pcs->ops->pcs_link_up)
-		pcs->ops->pcs_link_up(pcs, mode, interface, speed, duplex);
+		pcs->ops->pcs_link_up(pcs, neg_mode, interface, speed, duplex);
 }
 
 static void phylink_pcs_poll_stop(struct phylink *pl)
@@ -1058,10 +1059,15 @@ static void phylink_major_config(struct phylink *pl, bool restart,
 	struct phylink_pcs *pcs = NULL;
 	bool pcs_changed = false;
 	unsigned int rate_kbd;
+	unsigned int neg_mode;
 	int err;
 
 	phylink_dbg(pl, "major config %s\n", phy_modes(state->interface));
 
+	pl->pcs_neg_mode = phylink_pcs_neg_mode(pl->cur_link_an_mode,
+						state->interface,
+						state->advertising);
+
 	if (pl->using_mac_select_pcs) {
 		pcs = pl->mac_ops->mac_select_pcs(pl->config, state->interface);
 		if (IS_ERR(pcs)) {
@@ -1094,9 +1100,12 @@ static void phylink_major_config(struct phylink *pl, bool restart,
 
 	phylink_mac_config(pl, state);
 
-	err = phylink_pcs_config(pl->pcs, pl->cur_link_an_mode, state,
-				 !!(pl->link_config.pause &
-				    MLO_PAUSE_AN));
+	neg_mode = pl->cur_link_an_mode;
+	if (pl->pcs && pl->pcs->neg_mode)
+		neg_mode = pl->pcs_neg_mode;
+
+	err = phylink_pcs_config(pl->pcs, neg_mode, state,
+				 !!(pl->link_config.pause & MLO_PAUSE_AN));
 	if (err < 0)
 		phylink_err(pl, "pcs_config failed: %pe\n",
 			    ERR_PTR(err));
@@ -1131,6 +1140,7 @@ static void phylink_major_config(struct phylink *pl, bool restart,
  */
 static int phylink_change_inband_advert(struct phylink *pl)
 {
+	unsigned int neg_mode;
 	int ret;
 
 	if (test_bit(PHYLINK_DISABLE_STOPPED, &pl->phylink_disable_state))
@@ -1149,12 +1159,20 @@ static int phylink_change_inband_advert(struct phylink *pl)
 		    __ETHTOOL_LINK_MODE_MASK_NBITS, pl->link_config.advertising,
 		    pl->link_config.pause);
 
+	/* Recompute the PCS neg mode */
+	pl->pcs_neg_mode = phylink_pcs_neg_mode(pl->cur_link_an_mode,
+					pl->link_config.interface,
+					pl->link_config.advertising);
+
+	neg_mode = pl->cur_link_an_mode;
+	if (pl->pcs->neg_mode)
+		neg_mode = pl->pcs_neg_mode;
+
 	/* Modern PCS-based method; update the advert at the PCS, and
 	 * restart negotiation if the pcs_config() helper indicates that
 	 * the programmed advertisement has changed.
 	 */
-	ret = phylink_pcs_config(pl->pcs, pl->cur_link_an_mode,
-				 &pl->link_config,
+	ret = phylink_pcs_config(pl->pcs, neg_mode, &pl->link_config,
 				 !!(pl->link_config.pause & MLO_PAUSE_AN));
 	if (ret < 0)
 		return ret;
@@ -1257,6 +1275,7 @@ static void phylink_link_up(struct phylink *pl,
 			    struct phylink_link_state link_state)
 {
 	struct net_device *ndev = pl->netdev;
+	unsigned int neg_mode;
 	int speed, duplex;
 	bool rx_pause;
 
@@ -1287,8 +1306,12 @@ static void phylink_link_up(struct phylink *pl,
 
 	pl->cur_interface = link_state.interface;
 
-	phylink_pcs_link_up(pl->pcs, pl->cur_link_an_mode, pl->cur_interface,
-			    speed, duplex);
+	neg_mode = pl->cur_link_an_mode;
+	if (pl->pcs && pl->pcs->neg_mode)
+		neg_mode = pl->pcs_neg_mode;
+
+	phylink_pcs_link_up(pl->pcs, neg_mode, pl->cur_interface, speed,
+			    duplex);
 
 	pl->mac_ops->mac_link_up(pl->config, pl->phydev, pl->cur_link_an_mode,
 				 pl->cur_interface, speed, duplex,