Merge branch 'mlxsw-Shared-buffer-improvements'

Ido Schimmel says:

====================
mlxsw: Shared buffer improvements

This patchset includes two improvements with regards to shared buffer
configuration in mlxsw.

The first part of this patchset forbids the user from performing illegal
shared buffer configuration that can result in unnecessary packet loss.
In order to better communicate these configuration failures to the user,
extack is propagated from devlink towards drivers. This is done in
patches #1-#8.

The second part of the patchset deals with the shared buffer
configuration of the CPU port. When a packet is trapped by the device,
it is sent across the PCI bus to the attached host CPU. From the
device's perspective, it is as if the packet is transmitted through the
CPU port.

While testing traffic directed at the CPU it became apparent that for
certain packet sizes and certain burst sizes, the current shared buffer
configuration of the CPU port is inadequate and results in packet drops.
The configuration is adjusted by patches #9-#14 that create two new pools
- ingress & egress - which are dedicated for CPU traffic.
====================

Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>