net: bridge: mst: Notify switchdev drivers of VLAN MSTI migrations

Whenever a VLAN moves to a new MSTI, send a switchdev notification so
that switchdevs can track a bridge's VID to MSTI mappings.
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

include/net/switchdev.h

@@ -29,6 +29,7 @@ enum switchdev_attr_id {
 	SWITCHDEV_ATTR_ID_BRIDGE_MROUTER,
 	SWITCHDEV_ATTR_ID_BRIDGE_MST,
 	SWITCHDEV_ATTR_ID_MRP_PORT_ROLE,
+	SWITCHDEV_ATTR_ID_VLAN_MSTI,
 };
 
 struct switchdev_brport_flags {
@@ -36,6 +37,11 @@ struct switchdev_brport_flags {
 	unsigned long mask;
 };
 
+struct switchdev_vlan_msti {
+	u16 vid;
+	u16 msti;
+};
+
 struct switchdev_attr {
 	struct net_device *orig_dev;
 	enum switchdev_attr_id id;
@@ -52,6 +58,7 @@ struct switchdev_attr {
 		bool mst;				/* BRIDGE_MST */
 		bool mc_disabled;			/* MC_DISABLED */
 		u8 mrp_port_role;			/* MRP_PORT_ROLE */
+		struct switchdev_vlan_msti vlan_msti;	/* VLAN_MSTI */
 	} u;
 };
 

net/bridge/br_mst.c

@@ -69,13 +69,26 @@ static void br_mst_vlan_sync_state(struct net_bridge_vlan *pv, u16 msti)
 
 int br_mst_vlan_set_msti(struct net_bridge_vlan *mv, u16 msti)
 {
+	struct switchdev_attr attr = {
+		.id = SWITCHDEV_ATTR_ID_VLAN_MSTI,
+		.orig_dev = mv->br->dev,
+		.u.vlan_msti = {
+			.vid = mv->vid,
+			.msti = msti,
+		},
+	};
 	struct net_bridge_vlan_group *vg;
 	struct net_bridge_vlan *pv;
 	struct net_bridge_port *p;
+	int err;
 
 	if (mv->msti == msti)
 		return 0;
 
+	err = switchdev_port_attr_set(mv->br->dev, &attr, NULL);
+	if (err && err != -EOPNOTSUPP)
+		return err;
+
 	mv->msti = msti;
 
 	list_for_each_entry(p, &mv->br->port_list, list) {

net/bridge/br_switchdev.c

@@ -331,6 +331,46 @@ br_switchdev_fdb_replay(const struct net_device *br_dev, const void *ctx,
 	return err;
 }
 
+static int br_switchdev_vlan_attr_replay(struct net_device *br_dev,
+					 const void *ctx,
+					 struct notifier_block *nb,
+					 struct netlink_ext_ack *extack)
+{
+	struct switchdev_notifier_port_attr_info attr_info = {
+		.info = {
+			.dev = br_dev,
+			.extack = extack,
+			.ctx = ctx,
+		},
+	};
+	struct net_bridge *br = netdev_priv(br_dev);
+	struct net_bridge_vlan_group *vg;
+	struct switchdev_attr attr;
+	struct net_bridge_vlan *v;
+	int err;
+
+	attr_info.attr = &attr;
+	attr.orig_dev = br_dev;
+
+	vg = br_vlan_group(br);
+
+	list_for_each_entry(v, &vg->vlan_list, vlist) {
+		if (v->msti) {
+			attr.id = SWITCHDEV_ATTR_ID_VLAN_MSTI;
+			attr.u.vlan_msti.vid = v->vid;
+			attr.u.vlan_msti.msti = v->msti;
+
+			err = nb->notifier_call(nb, SWITCHDEV_PORT_ATTR_SET,
+						&attr_info);
+			err = notifier_to_errno(err);
+			if (err)
+				return err;
+		}
+	}
+
+	return 0;
+}
+
 static int
 br_switchdev_vlan_replay_one(struct notifier_block *nb,
 			     struct net_device *dev,
@@ -425,6 +465,12 @@ static int br_switchdev_vlan_replay(struct net_device *br_dev,
 			return err;
 	}
 
+	if (adding) {
+		err = br_switchdev_vlan_attr_replay(br_dev, ctx, nb, extack);
+		if (err)
+			return err;
+	}
+
 	return 0;
 }