net/core: Add VF link state control

Add netlink directives and ndo entry to allow for controling
VF link, which can be in one of three states:

Auto - VF link state reflects the PF link state (default)

Up - VF link state is up, traffic from VF to VF works even if
the actual PF link is down

Down - VF link state is down, no traffic from/to this VF, can be of
use while configuring the VF

Signed-off-by: Rony Efraim <ronye@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 8c9fcc4..09b4188 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -829,6 +829,7 @@
  * int (*ndo_set_vf_spoofchk)(struct net_device *dev, int vf, bool setting);
  * int (*ndo_get_vf_config)(struct net_device *dev,
  *			    int vf, struct ifla_vf_info *ivf);
+ * int (*ndo_set_vf_link_state)(struct net_device *dev, int vf, int link_state);
  * int (*ndo_set_vf_port)(struct net_device *dev, int vf,
  *			  struct nlattr *port[]);
  * int (*ndo_get_vf_port)(struct net_device *dev, int vf, struct sk_buff *skb);
@@ -986,6 +987,8 @@
 	int			(*ndo_get_vf_config)(struct net_device *dev,
 						     int vf,
 						     struct ifla_vf_info *ivf);
+	int			(*ndo_set_vf_link_state)(struct net_device *dev,
+							 int vf, int link_state);
 	int			(*ndo_set_vf_port)(struct net_device *dev,
 						   int vf,
 						   struct nlattr *port[]);