Merge branch 'mlxsw-resilient-nh-groups'

Merge branch 'mlxsw-resilient-nh-groups'
Ido Schimmel says:

====================
mlxsw: Add support for resilient nexthop groups

This patchset adds support for resilient nexthop groups in mlxsw. As far
as the hardware is concerned, resilient groups are the same as regular
groups. The differences lie in how mlxsw manages the individual
adjacency entries (nexthop buckets) that make up the group.

The first difference is that unlike regular groups the driver needs to
periodically update the kernel about activity of nexthop buckets so that
the kernel will not treat the buckets as idle, given traffic is
offloaded from the CPU to the ASIC. This is similar to what mlxsw is
already doing with respect to neighbour entries. The update interval is
set to 1 second to allow for short idle timers.

The second difference is that nexthop buckets that correspond to an
unresolved neighbour must be programmed to the device, as the size of
the group must remain fixed. This is achieved by programming such
entries with trap action, in order to trigger neighbour resolution by
the kernel.

The third difference is atomic replacement of individual nexthop
buckets. While the driver periodically updates the kernel about activity
of nexthop buckets, it is possible for a bucket to become active just
before the kernel decides to replace it with a different nexthop. To
avoid such situations and connections being reset, the driver instructs
the device to only replace an adjacency entry if it is inactive.
Failures are propagated back to the nexthop code.

Patchset overview:

Patches #1-#7 gradually add support for resilient nexthop groups

Patch #8 finally enables such groups to be programmed to the device

Patches #9-#10 add mlxsw-specific selftests
====================

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