net: dsa: Handle SWITCHDEV_PORT_ATTR_SET

Following patches will change the way we communicate setting a port's
attribute and use notifiers towards that goal.

Prepare DSA to support receiving notifier events targeting
SWITCHDEV_PORT_ATTR_SET from both atomic and process context and use a
small helper to translate the event notifier into something that
dsa_slave_port_attr_set() can process.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/dsa/slave.c

@@ -1524,6 +1524,19 @@ static int dsa_slave_netdevice_event(struct notifier_block *nb,
 	return NOTIFY_DONE;
 }
 
+static int
+dsa_slave_switchdev_port_attr_set_event(struct net_device *netdev,
+		struct switchdev_notifier_port_attr_info *port_attr_info)
+{
+	int err;
+
+	err = dsa_slave_port_attr_set(netdev, port_attr_info->attr,
+				      port_attr_info->trans);
+
+	port_attr_info->handled = true;
+	return notifier_from_errno(err);
+}
+
 struct dsa_switchdev_event_work {
 	struct work_struct work;
 	struct switchdev_notifier_fdb_info fdb_info;
@@ -1602,6 +1615,9 @@ static int dsa_slave_switchdev_event(struct notifier_block *unused,
 	if (!dsa_slave_dev_check(dev))
 		return NOTIFY_DONE;
 
+	if (event == SWITCHDEV_PORT_ATTR_SET)
+		return dsa_slave_switchdev_port_attr_set_event(dev, ptr);
+
 	switchdev_work = kzalloc(sizeof(*switchdev_work), GFP_ATOMIC);
 	if (!switchdev_work)
 		return NOTIFY_BAD;
@@ -1664,6 +1680,8 @@ static int dsa_slave_switchdev_blocking_event(struct notifier_block *unused,
 	case SWITCHDEV_PORT_OBJ_ADD: /* fall through */
 	case SWITCHDEV_PORT_OBJ_DEL:
 		return dsa_slave_switchdev_port_obj_event(event, dev, ptr);
+	case SWITCHDEV_PORT_ATTR_SET:
+		return dsa_slave_switchdev_port_attr_set_event(dev, ptr);
 	}
 
 	return NOTIFY_DONE;