Merge branch 'mlxsw-Reflect-nexthop-status-changes'

Jiri Pirko says:

====================
mlxsw: Reflect nexthop status changes

Ido says:

When the kernel forwards IPv4 packets via multipath routes it doesn't
consider nexthops that are dead or linkdown. For example, if the nexthop
netdev is administratively down or doesn't have a carrier.

Devices capable of offloading such multipath routes need to be made
aware of changes in the reflected nexthops' status. Otherwise, the
device might forward packets via non-functional nexthops, resulting in
packet loss. This patchset aims to fix that.

The first 11 patches deal with the necessary restructuring in the
mlxsw driver, so that it's able to correctly add and remove nexthops
from the device's adjacency table.

The 12th patch adds the NH_{ADD,DEL} events to the FIB notification
chain. These notifications are sent whenever the kernel decides to add
or remove a nexthop from the forwarding plane.

Finally, the last three patches add support for these events in the
mlxsw driver, which is currently the only driver capable of offloading
multipath routes.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>