[PATCH v3 net-next 04/14] net: bridge: mst: Notify switchdev drivers of MST mode changes

[Tobias Waldekranz]

Trigger a switchdev event whenever the bridge's MST mode is
enabled/disabled. This allows constituent ports to either perform any
required hardware config, or refuse the change if it not supported.

Signed-off-by: Tobias Waldekranz <tobias@xxxxxxxxxxxxxx>
---
 include/net/switchdev.h |  2 ++
 net/bridge/br_mst.c     | 10 ++++++++++
 2 files changed, 12 insertions(+)

diff --git a/include/net/switchdev.h b/include/net/switchdev.h
index 3e424d40fae3..85dd004dc9ad 100644
--- a/include/net/switchdev.h
+++ b/include/net/switchdev.h
@@ -27,6 +27,7 @@ enum switchdev_attr_id {
 	SWITCHDEV_ATTR_ID_BRIDGE_VLAN_PROTOCOL,
 	SWITCHDEV_ATTR_ID_BRIDGE_MC_DISABLED,
 	SWITCHDEV_ATTR_ID_BRIDGE_MROUTER,
+	SWITCHDEV_ATTR_ID_BRIDGE_MST,
 	SWITCHDEV_ATTR_ID_MRP_PORT_ROLE,
 };
 
@@ -48,6 +49,7 @@ struct switchdev_attr {
 		clock_t ageing_time;			/* BRIDGE_AGEING_TIME */
 		bool vlan_filtering;			/* BRIDGE_VLAN_FILTERING */
 		u16 vlan_protocol;			/* BRIDGE_VLAN_PROTOCOL */
+		bool mst;				/* BRIDGE_MST */
 		bool mc_disabled;			/* MC_DISABLED */
 		u8 mrp_port_role;			/* MRP_PORT_ROLE */
 	} u;
diff --git a/net/bridge/br_mst.c b/net/bridge/br_mst.c
index df65aa7701c1..39057585c302 100644
--- a/net/bridge/br_mst.c
+++ b/net/bridge/br_mst.c
@@ -99,8 +99,14 @@ void br_mst_vlan_init_state(struct net_bridge_vlan *v)
 int br_mst_set_enabled(struct net_bridge *br, bool on,
 		       struct netlink_ext_ack *extack)
 {
+	struct switchdev_attr attr = {
+		.id = SWITCHDEV_ATTR_ID_BRIDGE_MST,
+		.orig_dev = br->dev,
+		.u.mst = on,
+	};
 	struct net_bridge_vlan_group *vg;
 	struct net_bridge_port *p;
+	int err;
 
 	list_for_each_entry(p, &br->port_list, list) {
 		vg = nbp_vlan_group(p);
@@ -116,6 +122,10 @@ int br_mst_set_enabled(struct net_bridge *br, bool on,
 	if (br_opt_get(br, BROPT_MST_ENABLED) == on)
 		return 0;
 
+	err = switchdev_port_attr_set(br->dev, &attr, extack);
+	if (err && err != -EOPNOTSUPP)
+		return err;
+
 	if (on)
 		static_branch_enable(&br_mst_used);
 	else
-- 
2.25.1