switchdev: Add SWITCHDEV_PORT_ATTR_SET

In preparation for allowing switchdev enabled drivers to veto specific
attribute settings from within the context of the caller, introduce a
new switchdev notifier type for port attributes.

Suggested-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 51 insertions, 0 deletions

diff --git a/net/switchdev/switchdev.c b/net/switchdev/switchdev.c
index 362413c9b389..3560c19aa7e2 100644
--- a/net/switchdev/switchdev.c
+++ b/net/switchdev/switchdev.c
@@ -655,3 +655,54 @@ int switchdev_handle_port_obj_del(struct net_device *dev,
 	return err;
 }
 EXPORT_SYMBOL_GPL(switchdev_handle_port_obj_del);
+
+static int __switchdev_handle_port_attr_set(struct net_device *dev,
+			struct switchdev_notifier_port_attr_info *port_attr_info,
+			bool (*check_cb)(const struct net_device *dev),
+			int (*set_cb)(struct net_device *dev,
+				      const struct switchdev_attr *attr,
+				      struct switchdev_trans *trans))
+{
+	struct net_device *lower_dev;
+	struct list_head *iter;
+	int err = -EOPNOTSUPP;
+
+	if (check_cb(dev)) {
+		port_attr_info->handled = true;
+		return set_cb(dev, port_attr_info->attr,
+			      port_attr_info->trans);
+	}
+
+	/* Switch ports might be stacked under e.g. a LAG. Ignore the
+	 * unsupported devices, another driver might be able to handle them. But
+	 * propagate to the callers any hard errors.
+	 *
+	 * If the driver does its own bookkeeping of stacked ports, it's not
+	 * necessary to go through this helper.
+	 */
+	netdev_for_each_lower_dev(dev, lower_dev, iter) {
+		err = __switchdev_handle_port_attr_set(lower_dev, port_attr_info,
+						       check_cb, set_cb);
+		if (err && err != -EOPNOTSUPP)
+			return err;
+	}
+
+	return err;
+}
+
+int switchdev_handle_port_attr_set(struct net_device *dev,
+			struct switchdev_notifier_port_attr_info *port_attr_info,
+			bool (*check_cb)(const struct net_device *dev),
+			int (*set_cb)(struct net_device *dev,
+				      const struct switchdev_attr *attr,
+				      struct switchdev_trans *trans))
+{
+	int err;
+
+	err = __switchdev_handle_port_attr_set(dev, port_attr_info, check_cb,
+					       set_cb);
+	if (err == -EOPNOTSUPP)
+		err = 0;
+	return err;
+}
+EXPORT_SYMBOL_GPL(switchdev_handle_port_attr_set);