mlxsw: spectrum_switchdev: Add support for learning FDB through notification

Add support for learning FDB through notification. The driver defers
the hardware update via ordered work queue. Support for stacked devices
is also provided. In case of a successful FDB add a notification is
sent back to bridge.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum.c

@@ -3706,7 +3706,7 @@ struct mlxsw_sp *mlxsw_sp_lower_get(struct net_device *dev)
 	return mlxsw_sp_port ? mlxsw_sp_port->mlxsw_sp : NULL;
 }
 
-static struct mlxsw_sp_port *mlxsw_sp_port_dev_lower_find_rcu(struct net_device *dev)
+struct mlxsw_sp_port *mlxsw_sp_port_dev_lower_find_rcu(struct net_device *dev)
 {
 	struct mlxsw_sp_port *mlxsw_sp_port;
 

drivers/net/ethernet/mellanox/mlxsw/spectrum.h

@@ -361,6 +361,7 @@ struct mlxsw_sp *mlxsw_sp_lower_get(struct net_device *dev);
 struct mlxsw_sp_port *mlxsw_sp_port_dev_lower_find(struct net_device *dev);
 struct mlxsw_sp_port *mlxsw_sp_port_lower_dev_hold(struct net_device *dev);
 void mlxsw_sp_port_dev_put(struct mlxsw_sp_port *mlxsw_sp_port);
+struct mlxsw_sp_port *mlxsw_sp_port_dev_lower_find_rcu(struct net_device *dev);
 
 /* spectrum_dcb.c */
 #ifdef CONFIG_MLXSW_SPECTRUM_DCB

drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c

@@ -1181,6 +1181,43 @@ mlxsw_sp_port_fdb_static_add(struct mlxsw_sp_port *mlxsw_sp_port,
 						   true, false);
 }
 
+static int
+mlxsw_sp_port_fdb_set(struct mlxsw_sp_port *mlxsw_sp_port,
+		      struct switchdev_notifier_fdb_info *fdb_info, bool adding)
+{
+	struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
+	struct net_device *orig_dev = fdb_info->info.dev;
+	struct mlxsw_sp_port_vlan *mlxsw_sp_port_vlan;
+	struct mlxsw_sp_bridge_device *bridge_device;
+	struct mlxsw_sp_bridge_port *bridge_port;
+	u16 fid_index, vid;
+
+	bridge_port = mlxsw_sp_bridge_port_find(mlxsw_sp->bridge, orig_dev);
+	if (!bridge_port)
+		return -EINVAL;
+
+	bridge_device = bridge_port->bridge_device;
+	mlxsw_sp_port_vlan = mlxsw_sp_port_vlan_find_by_bridge(mlxsw_sp_port,
+							       bridge_device,
+							       fdb_info->vid);
+	if (!mlxsw_sp_port_vlan)
+		return 0;
+
+	fid_index = mlxsw_sp_fid_index(mlxsw_sp_port_vlan->fid);
+	vid = mlxsw_sp_port_vlan->vid;
+
+	if (!bridge_port->lagged)
+		return mlxsw_sp_port_fdb_uc_op(mlxsw_sp,
+					       bridge_port->system_port,
+					       fdb_info->addr, fid_index,
+					       adding, false);
+	else
+		return mlxsw_sp_port_fdb_uc_lag_op(mlxsw_sp,
+						   bridge_port->lag_id,
+						   fdb_info->addr, fid_index,
+						   vid, adding, false);
+}
+
 static int mlxsw_sp_port_mdb_op(struct mlxsw_sp *mlxsw_sp, const char *addr,
 				u16 fid, u16 mid, bool adding)
 {
@@ -2013,6 +2050,97 @@ static void mlxsw_sp_fdb_notify_work(struct work_struct *work)
 	mlxsw_sp_fdb_notify_work_schedule(mlxsw_sp);
 }
 
+struct mlxsw_sp_switchdev_event_work {
+	struct work_struct work;
+	struct switchdev_notifier_fdb_info fdb_info;
+	struct net_device *dev;
+	unsigned long event;
+};
+
+static void mlxsw_sp_switchdev_event_work(struct work_struct *work)
+{
+	struct mlxsw_sp_switchdev_event_work *switchdev_work =
+		container_of(work, struct mlxsw_sp_switchdev_event_work, work);
+	struct net_device *dev = switchdev_work->dev;
+	struct switchdev_notifier_fdb_info *fdb_info;
+	struct mlxsw_sp_port *mlxsw_sp_port;
+	int err;
+
+	rtnl_lock();
+	mlxsw_sp_port = mlxsw_sp_port_dev_lower_find(dev);
+	if (!mlxsw_sp_port)
+		goto out;
+
+	switch (switchdev_work->event) {
+	case SWITCHDEV_FDB_ADD_TO_DEVICE:
+		fdb_info = &switchdev_work->fdb_info;
+		err = mlxsw_sp_port_fdb_set(mlxsw_sp_port, fdb_info, true);
+		if (err)
+			break;
+		mlxsw_sp_fdb_call_notifiers(SWITCHDEV_FDB_OFFLOADED,
+					    fdb_info->addr,
+					    fdb_info->vid, dev);
+		break;
+	case SWITCHDEV_FDB_DEL_TO_DEVICE:
+		fdb_info = &switchdev_work->fdb_info;
+		mlxsw_sp_port_fdb_set(mlxsw_sp_port, fdb_info, false);
+		break;
+	}
+
+out:
+	rtnl_unlock();
+	kfree(switchdev_work->fdb_info.addr);
+	kfree(switchdev_work);
+	dev_put(dev);
+}
+
+/* Called under rcu_read_lock() */
+static int mlxsw_sp_switchdev_event(struct notifier_block *unused,
+				    unsigned long event, void *ptr)
+{
+	struct net_device *dev = switchdev_notifier_info_to_dev(ptr);
+	struct mlxsw_sp_switchdev_event_work *switchdev_work;
+	struct switchdev_notifier_fdb_info *fdb_info = ptr;
+
+	if (!mlxsw_sp_port_dev_lower_find_rcu(dev))
+		return NOTIFY_DONE;
+
+	switchdev_work = kzalloc(sizeof(*switchdev_work), GFP_ATOMIC);
+	if (!switchdev_work)
+		return NOTIFY_BAD;
+
+	INIT_WORK(&switchdev_work->work, mlxsw_sp_switchdev_event_work);
+	switchdev_work->dev = dev;
+	switchdev_work->event = event;
+
+	switch (event) {
+	case SWITCHDEV_FDB_ADD_TO_DEVICE: /* fall through */
+	case SWITCHDEV_FDB_DEL_TO_DEVICE:
+		memcpy(&switchdev_work->fdb_info, ptr,
+		       sizeof(switchdev_work->fdb_info));
+		switchdev_work->fdb_info.addr = kzalloc(ETH_ALEN, GFP_ATOMIC);
+		ether_addr_copy((u8 *)switchdev_work->fdb_info.addr,
+				fdb_info->addr);
+		/* Take a reference on the device. This can be either
+		 * upper device containig mlxsw_sp_port or just a
+		 * mlxsw_sp_port
+		 */
+		dev_hold(dev);
+		break;
+	default:
+		kfree(switchdev_work);
+		return NOTIFY_DONE;
+	}
+
+	mlxsw_core_schedule_work(&switchdev_work->work);
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block mlxsw_sp_switchdev_notifier = {
+	.notifier_call = mlxsw_sp_switchdev_event,
+};
+
 static int mlxsw_sp_fdb_init(struct mlxsw_sp *mlxsw_sp)
 {
 	struct mlxsw_sp_bridge *bridge = mlxsw_sp->bridge;
@@ -2023,6 +2151,13 @@ static int mlxsw_sp_fdb_init(struct mlxsw_sp *mlxsw_sp)
 		dev_err(mlxsw_sp->bus_info->dev, "Failed to set default ageing time\n");
 		return err;
 	}
+
+	err = register_switchdev_notifier(&mlxsw_sp_switchdev_notifier);
+	if (err) {
+		dev_err(mlxsw_sp->bus_info->dev, "Failed to register switchdev notifier\n");
+		return err;
+	}
+
 	INIT_DELAYED_WORK(&bridge->fdb_notify.dw, mlxsw_sp_fdb_notify_work);
 	bridge->fdb_notify.interval = MLXSW_SP_DEFAULT_LEARNING_INTERVAL;
 	mlxsw_sp_fdb_notify_work_schedule(mlxsw_sp);
@@ -2032,6 +2167,8 @@ static int mlxsw_sp_fdb_init(struct mlxsw_sp *mlxsw_sp)
 static void mlxsw_sp_fdb_fini(struct mlxsw_sp *mlxsw_sp)
 {
 	cancel_delayed_work_sync(&mlxsw_sp->bridge->fdb_notify.dw);
+	unregister_switchdev_notifier(&mlxsw_sp_switchdev_notifier);
+
 }
 
 int mlxsw_sp_switchdev_init(struct mlxsw_sp *mlxsw_sp)