net: bridge: switchdev: differentiate new VLANs from changed ones

br_switchdev_port_vlan_add() currently emits a SWITCHDEV_PORT_OBJ_ADD
event with a SWITCHDEV_OBJ_ID_PORT_VLAN for 2 distinct cases:

- a struct net_bridge_vlan got created
- an existing struct net_bridge_vlan was modified

This makes it impossible for switchdev drivers to properly balance
PORT_OBJ_ADD with PORT_OBJ_DEL events, so if we want to allow that to
happen, we must provide a way for drivers to distinguish between a
VLAN with changed flags and a new one.

Annotate struct switchdev_obj_port_vlan with a "bool changed" that
distinguishes the 2 cases above.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br_switchdev.c

@@ -160,13 +160,14 @@ br_switchdev_fdb_notify(struct net_bridge *br,
 }
 
 int br_switchdev_port_vlan_add(struct net_device *dev, u16 vid, u16 flags,
-			       struct netlink_ext_ack *extack)
+			       bool changed, struct netlink_ext_ack *extack)
 {
 	struct switchdev_obj_port_vlan v = {
 		.obj.orig_dev = dev,
 		.obj.id = SWITCHDEV_OBJ_ID_PORT_VLAN,
 		.flags = flags,
 		.vid = vid,
+		.changed = changed,
 	};
 
 	return switchdev_port_obj_add(dev, &v.obj, extack);