* netdev_upper_dev_link - Add a link to the upper device
* @dev: device
* @upper_dev: new upper device
+ * @extack: netlink extended ack
*
* Adds a link to device which is upper to this one. The caller must hold
* the RTNL lock. On a failure a negative errno code is returned.
* @upper_dev: new upper device
* @upper_priv: upper device private
* @upper_info: upper info to be passed down via notifier
+ * @extack: netlink extended ack
*
* Adds a link to device which is upper to this one. In this case, only
* one master upper device can be linked, although other non-master devices