[PATCH v2 net-next 05/10] net: bridge: mst: Notify switchdev drivers of MST state changes

[Tobias Waldekranz]

Generate a switchdev notification whenever an MST state changes. This
notification is keyed by the VLANs MSTI rather than the VID, since
multiple VLANs may share the same MST instance.

Signed-off-by: Tobias Waldekranz <tobias@xxxxxxxxxxxxxx>
---
 include/net/switchdev.h |  7 +++++++
 net/bridge/br_mst.c     | 21 +++++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/include/net/switchdev.h b/include/net/switchdev.h
index 39e57aa5005a..441beeb2fda5 100644
--- a/include/net/switchdev.h
+++ b/include/net/switchdev.h
@@ -19,6 +19,7 @@
 enum switchdev_attr_id {
 	SWITCHDEV_ATTR_ID_UNDEFINED,
 	SWITCHDEV_ATTR_ID_PORT_STP_STATE,
+	SWITCHDEV_ATTR_ID_PORT_MST_STATE,
 	SWITCHDEV_ATTR_ID_PORT_BRIDGE_FLAGS,
 	SWITCHDEV_ATTR_ID_PORT_PRE_BRIDGE_FLAGS,
 	SWITCHDEV_ATTR_ID_PORT_MROUTER,
@@ -31,6 +32,11 @@ enum switchdev_attr_id {
 	SWITCHDEV_ATTR_ID_VLAN_MSTI,
 };
 
+struct switchdev_mst_state {
+	u16 msti;
+	u8 state;
+};
+
 struct switchdev_brport_flags {
 	unsigned long val;
 	unsigned long mask;
@@ -52,6 +58,7 @@ struct switchdev_attr {
 	void (*complete)(struct net_device *dev, int err, void *priv);
 	union {
 		u8 stp_state;				/* PORT_STP_STATE */
+		struct switchdev_mst_state mst_state;	/* PORT_MST_STATE */
 		struct switchdev_brport_flags brport_flags; /* PORT_BRIDGE_FLAGS */
 		bool mrouter;				/* PORT_MROUTER */
 		clock_t ageing_time;			/* BRIDGE_AGEING_TIME */
diff --git a/net/bridge/br_mst.c b/net/bridge/br_mst.c
index aba603675165..9cdd7d9e07c6 100644
--- a/net/bridge/br_mst.c
+++ b/net/bridge/br_mst.c
@@ -29,8 +29,18 @@ void br_mst_vlan_set_state(struct net_bridge_port *p, struct net_bridge_vlan *v,
 
 void br_mst_set_state(struct net_bridge_port *p, u16 msti, u8 state)
 {
+	struct switchdev_attr attr = {
+		.id = SWITCHDEV_ATTR_ID_PORT_MST_STATE,
+		.flags = SWITCHDEV_F_DEFER,
+		.orig_dev = p->dev,
+		.u.mst_state = {
+			.msti = msti,
+			.state = state,
+		},
+	};
 	struct net_bridge_vlan_group *vg;
 	struct net_bridge_vlan *v;
+	int err;
 
 	vg = nbp_vlan_group(p);
 	if (!vg)
@@ -42,6 +52,17 @@ void br_mst_set_state(struct net_bridge_port *p, u16 msti, u8 state)
 
 		br_mst_vlan_set_state(p, v, state);
 	}
+
+	if (!msti)
+		/* MSTI 0 (CST) state changes are notified via the
+		 * regular SWITCHDEV_ATTR_ID_PORT_STP_STATE.
+		 */
+		return;
+
+	err = switchdev_port_attr_set(p->dev, &attr, NULL);
+	if (err && err != -EOPNOTSUPP)
+		br_warn(p->br, "unable to offload MST state on %s in MSTI %u",
+			netdev_name(p->dev), msti);
 }
 
 static void br_mst_vlan_sync_state(struct net_bridge_vlan *pv, u16 msti)
-- 
2.25.1