Merge branch 'devlink-introduce-selective-dumps'

Jiri Pirko says:

====================
devlink: introduce selective dumps

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.

Use split ops to generate policies for dump callbacks acccording to
the attributes used for selection.

The userspace can use ctrl genetlink GET_POLICY command to find out if
the selective dumps are supported by kernel for particular command.

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

Extension:

patches #12 and #13 extends selection attributes by port index
for health reporter dumping.
====================

Link: https://lore.kernel.org/r/20230811155714.1736405-1-jiri@resnulli.us
Signed-off-by: Jakub Kicinski <kuba@kernel.org>