mlxsw: spectrum_router: Allocate FID according to PVID

For bridge netdevices, instead of assuming that the router traffic is on
VLAN 1, look at the bridge PVID.

This patch assumes that the PVID doesn't change after the router
interface is created (i.e. after the IP address is assigned).
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c

@@ -6870,7 +6870,20 @@ static struct mlxsw_sp_fid *
 mlxsw_sp_rif_vlan_fid_get(struct mlxsw_sp_rif *rif,
 			  struct netlink_ext_ack *extack)
 {
-	u16 vid = is_vlan_dev(rif->dev) ? vlan_dev_vlan_id(rif->dev) : 1;
+	u16 vid;
+	int err;
+
+	if (is_vlan_dev(rif->dev)) {
+		vid = vlan_dev_vlan_id(rif->dev);
+	} else {
+		err = br_vlan_get_pvid(rif->dev, &vid);
+		if (!vid)
+			err = -EINVAL;
+		if (err) {
+			NL_SET_ERR_MSG_MOD(extack, "Couldn't determine bridge PVID");
+			return ERR_PTR(err);
+		}
+	}
 
 	return mlxsw_sp_fid_8021q_get(rif->mlxsw_sp, vid);
 }