Merge branch 'devlink-dump-selector' into next

Jiri Pirko  says:

====================

From: Jiri Pirko <jiri@nvidia.com>

First 5 patches are preparations for the last one.

Motivation:

For SFs, one devlink instance per SF is created. There might be
thousands of these on a single host. When a user needs to know port
handle for specific SF, he needs to dump all devlink ports on the host
which does not scale good.

Solution:

Allow user to pass devlink handle (and possibly other attributes)
alongside the dump command and dump only objects which are matching
the selection.

Example:
$ devlink port show
auxiliary/mlx5_core.eth.0/65535: type eth netdev eth2 flavour physical port 0 splittable false
auxiliary/mlx5_core.eth.1/131071: type eth netdev eth3 flavour physical port 1 splittable false

$ devlink port show auxiliary/mlx5_core.eth.0
auxiliary/mlx5_core.eth.0/65535: type eth netdev eth2 flavour physical port 0 splittable false

$ devlink port show auxiliary/mlx5_core.eth.1
auxiliary/mlx5_core.eth.1/131071: type eth netdev eth3 flavour physical port 1 splittable false

====================

Signed-off-by: David Ahern <dsahern@kernel.org>