net: dsa: lantiq_gswip: support bridge FDB entries on the CPU port

Currently, the driver takes the bridge from dsa_port_bridge_dev_get(),
which only works for user ports. This is why it has to ignore FDB
entries installed on the CPU port.

Commit c269336 ("net: dsa: request drivers to perform FDB
isolation") introduced the possibility of getting the originating bridge
from the passed dsa_db argument, so let's do that instead. This way, we
can act on the local FDB entries coming from the bridge.

Note that we do not expect FDB events for the DSA_DB_PORT database,
because this driver doesn't fulfill the dsa_switch_supports_uc_filtering()
requirements. So we can just return -EOPNOTSUPP and expect it will never
be triggered.

Signed-off-by: Vladimir Oltean <[email protected]>
Signed-off-by: Daniel Golle <[email protected]>
Link: https://patch.msgid.link/ed9d847c0356f0fec81422bdad9ebdcc6a59da79.1760566491.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <[email protected]>

Author: vladimiroltean

drivers/net/dsa/lantiq/lantiq_gswip.c

@@ -1140,20 +1140,16 @@ static void gswip_port_stp_state_set(struct dsa_switch *ds, int port, u8 state)
 }
 
 static int gswip_port_fdb(struct dsa_switch *ds, int port,
-			  const unsigned char *addr, u16 vid, bool add)
+			  struct net_device *bridge, const unsigned char *addr,
+			  u16 vid, bool add)
 {
-	struct net_device *bridge = dsa_port_bridge_dev_get(dsa_to_port(ds, port));
 	struct gswip_priv *priv = ds->priv;
 	struct gswip_pce_table_entry mac_bridge = {0,};
 	unsigned int max_ports = priv->hw_info->max_ports;
 	int fid = -1;
 	int i;
 	int err;
 
-	/* Operation not supported on the CPU port, don't throw errors */
-	if (!bridge)
-		return 0;
-
 	for (i = max_ports; i < ARRAY_SIZE(priv->vlans); i++) {
 		if (priv->vlans[i].bridge == bridge) {
 			fid = priv->vlans[i].fid;
@@ -1188,14 +1184,20 @@ static int gswip_port_fdb_add(struct dsa_switch *ds, int port,
 			      const unsigned char *addr, u16 vid,
 			      struct dsa_db db)
 {
-	return gswip_port_fdb(ds, port, addr, vid, true);
+	if (db.type != DSA_DB_BRIDGE)
+		return -EOPNOTSUPP;
+
+	return gswip_port_fdb(ds, port, db.bridge.dev, addr, vid, true);
 }
 
 static int gswip_port_fdb_del(struct dsa_switch *ds, int port,
 			      const unsigned char *addr, u16 vid,
 			      struct dsa_db db)
 {
-	return gswip_port_fdb(ds, port, addr, vid, false);
+	if (db.type != DSA_DB_BRIDGE)
+		return -EOPNOTSUPP;
+
+	return gswip_port_fdb(ds, port, db.bridge.dev, addr, vid, false);
 }
 
 static int gswip_port_fdb_dump(struct dsa_switch *ds, int port,