net: dsa: introduce dsa_phylink_to_port()

We convert from a phylink_config struct to a dsa_port struct in many
places, let's provide a helper for this.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://lore.kernel.org/r/E1rudqA-006K9B-85@rmk-PC.armlinux.org.ukSigned-off-by: Jakub Kicinski <kuba@kernel.org>

include/net/dsa.h

@@ -327,6 +327,12 @@ struct dsa_port {
 	};
 };
 
+static inline struct dsa_port *
+dsa_phylink_to_port(struct phylink_config *config)
+{
+	return container_of(config, struct dsa_port, pl_config);
+}
+
 /* TODO: ideally DSA ports would have a single dp->link_dp member,
  * and no dst->rtable nor this struct dsa_link would be needed,
  * but this would require some more complex tree walking,

net/dsa/port.c

@@ -1558,7 +1558,7 @@ static struct phylink_pcs *
 dsa_port_phylink_mac_select_pcs(struct phylink_config *config,
 				phy_interface_t interface)
 {
-	struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);
+	struct dsa_port *dp = dsa_phylink_to_port(config);
 	struct phylink_pcs *pcs = ERR_PTR(-EOPNOTSUPP);
 	struct dsa_switch *ds = dp->ds;
 
@@ -1572,7 +1572,7 @@ static int dsa_port_phylink_mac_prepare(struct phylink_config *config,
 					unsigned int mode,
 					phy_interface_t interface)
 {
-	struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);
+	struct dsa_port *dp = dsa_phylink_to_port(config);
 	struct dsa_switch *ds = dp->ds;
 	int err = 0;
 
@@ -1587,7 +1587,7 @@ static void dsa_port_phylink_mac_config(struct phylink_config *config,
 					unsigned int mode,
 					const struct phylink_link_state *state)
 {
-	struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);
+	struct dsa_port *dp = dsa_phylink_to_port(config);
 	struct dsa_switch *ds = dp->ds;
 
 	if (!ds->ops->phylink_mac_config)
@@ -1600,7 +1600,7 @@ static int dsa_port_phylink_mac_finish(struct phylink_config *config,
 				       unsigned int mode,
 				       phy_interface_t interface)
 {
-	struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);
+	struct dsa_port *dp = dsa_phylink_to_port(config);
 	struct dsa_switch *ds = dp->ds;
 	int err = 0;
 
@@ -1615,7 +1615,7 @@ static void dsa_port_phylink_mac_link_down(struct phylink_config *config,
 					   unsigned int mode,
 					   phy_interface_t interface)
 {
-	struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);
+	struct dsa_port *dp = dsa_phylink_to_port(config);
 	struct phy_device *phydev = NULL;
 	struct dsa_switch *ds = dp->ds;
 
@@ -1638,7 +1638,7 @@ static void dsa_port_phylink_mac_link_up(struct phylink_config *config,
 					 int speed, int duplex,
 					 bool tx_pause, bool rx_pause)
 {
-	struct dsa_port *dp = container_of(config, struct dsa_port, pl_config);
+	struct dsa_port *dp = dsa_phylink_to_port(config);
 	struct dsa_switch *ds = dp->ds;
 
 	if (!ds->ops->phylink_mac_link_up) {