net: dsa: add VLAN notifier

Add two new DSA_NOTIFIER_VLAN_ADD and DSA_NOTIFIER_VLAN_DEL events to
notify not only a single switch, but all switches of a the fabric when
an VLAN entry is added or removed.

For the moment, keep the current behavior and ignore other switches.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dsa/port.c b/net/dsa/port.c
index c7c4920..c88c0ce 100644
--- a/net/dsa/port.c
+++ b/net/dsa/port.c
@@ -225,29 +225,26 @@ int dsa_port_vlan_add(struct dsa_port *dp,
 		      const struct switchdev_obj_port_vlan *vlan,
 		      struct switchdev_trans *trans)
 {
-	struct dsa_switch *ds = dp->ds;
+	struct dsa_notifier_vlan_info info = {
+		.sw_index = dp->ds->index,
+		.port = dp->index,
+		.trans = trans,
+		.vlan = vlan,
+	};
 
-	if (switchdev_trans_ph_prepare(trans)) {
-		if (!ds->ops->port_vlan_prepare || !ds->ops->port_vlan_add)
-			return -EOPNOTSUPP;
-
-		return ds->ops->port_vlan_prepare(ds, dp->index, vlan, trans);
-	}
-
-	ds->ops->port_vlan_add(ds, dp->index, vlan, trans);
-
-	return 0;
+	return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_ADD, &info);
 }
 
 int dsa_port_vlan_del(struct dsa_port *dp,
 		      const struct switchdev_obj_port_vlan *vlan)
 {
-	struct dsa_switch *ds = dp->ds;
+	struct dsa_notifier_vlan_info info = {
+		.sw_index = dp->ds->index,
+		.port = dp->index,
+		.vlan = vlan,
+	};
 
-	if (!ds->ops->port_vlan_del)
-		return -EOPNOTSUPP;
-
-	return ds->ops->port_vlan_del(ds, dp->index, vlan);
+	return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_DEL, &info);
 }
 
 int dsa_port_vlan_dump(struct dsa_port *dp,