Merge branch 'configuring-congestion-watermarks-on-ocelot-switch-using-devlink-sb'

Merge branch 'configuring-congestion-watermarks-on-ocelot-switch-using-devlink-sb'

Vladimir Oltean says:

====================
Configuring congestion watermarks on ocelot switch using devlink-sb

In some applications, it is important to create resource reservations in
the Ethernet switches, to prevent background traffic, or deliberate
attacks, from inducing denial of service into the high-priority traffic.

These patches give the user some knobs to turn. The ocelot switches
support per-port and per-port-tc reservations, on ingress and on egress.
The resources that are monitored are packet buffers (in cells of 60
bytes each) and frame references.

The frames that exceed the reservations can optionally consume from
sharing watermarks which are not per-port but global across the switch.
There are 10 sharing watermarks, 8 of them are per traffic class and 2
are per drop priority.

I am configuring the hardware using the best of my knowledge, and mostly
through trial and error. Same goes for devlink-sb integration. Feedback
is welcome.
====================

Link: https://lore.kernel.org/r/20210115021120.3055988-1-olteanv@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>