mlxsw: spectrum_switchdev: Ban PVID change if bridge has a RIF

When traffic passes through a router port, it needs to be assigned a FID
for ASIC to forward correctly. For bridges, this FID used to be the one
corresponding to VLAN 1. In a previous patch, this was changed to
instead use the PVID at the time that the RIF is created. This patch
guards PVID changes after the RIF was introduced.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -1135,6 +1135,39 @@ mlxsw_sp_bridge_port_vlan_add(struct mlxsw_sp_port *mlxsw_sp_port,
 	return err;
 }
 
+static int
+mlxsw_sp_br_ban_rif_pvid_change(struct mlxsw_sp *mlxsw_sp,
+				const struct net_device *br_dev,
+				const struct switchdev_obj_port_vlan *vlan)
+{
+	struct mlxsw_sp_rif *rif;
+	struct mlxsw_sp_fid *fid;
+	u16 pvid;
+	u16 vid;
+
+	rif = mlxsw_sp_rif_find_by_dev(mlxsw_sp, br_dev);
+	if (!rif)
+		return 0;
+	fid = mlxsw_sp_rif_fid(rif);
+	pvid = mlxsw_sp_fid_8021q_vid(fid);
+
+	for (vid = vlan->vid_begin; vid <= vlan->vid_end; ++vid) {
+		if (vlan->flags & BRIDGE_VLAN_INFO_PVID) {
+			if (vid != pvid) {
+				netdev_err(br_dev, "Can't change PVID, it's used by router interface\n");
+				return -EBUSY;
+			}
+		} else {
+			if (vid == pvid) {
+				netdev_err(br_dev, "Can't remove PVID, it's used by router interface\n");
+				return -EBUSY;
+			}
+		}
+	}
+
+	return 0;
+}
+
 static int mlxsw_sp_port_vlans_add(struct mlxsw_sp_port *mlxsw_sp_port,
 				   const struct switchdev_obj_port_vlan *vlan,
 				   struct switchdev_trans *trans)
@@ -1146,8 +1179,18 @@ static int mlxsw_sp_port_vlans_add(struct mlxsw_sp_port *mlxsw_sp_port,
 	struct mlxsw_sp_bridge_port *bridge_port;
 	u16 vid;
 
-	if (netif_is_bridge_master(orig_dev))
-		return -EOPNOTSUPP;
+	if (netif_is_bridge_master(orig_dev)) {
+		int err = 0;
+
+		if ((vlan->flags & BRIDGE_VLAN_INFO_BRENTRY) &&
+		    br_vlan_enabled(orig_dev) &&
+		    switchdev_trans_ph_prepare(trans))
+			err = mlxsw_sp_br_ban_rif_pvid_change(mlxsw_sp,
+							      orig_dev, vlan);
+		if (!err)
+			err = -EOPNOTSUPP;
+		return err;
+	}
 
 	if (switchdev_trans_ph_prepare(trans))
 		return 0;