Merge branch 'bridge-port-offload'

Vladimir Oltean says:

====================
Let switchdev drivers offload and unoffload bridge ports at their own convenience

This series introduces an explicit API through which switchdev drivers
mark a bridge port as offloaded or not:
- switchdev_bridge_port_offload()
- switchdev_bridge_port_unoffload()

Currently, the bridge assumes that a port is offloaded if
dev_get_port_parent_id(dev, &ppid, recurse=true) returns something, but
that is just an assumption that breaks some use cases (like a
non-offloaded LAG interface on top of a switchdev port, bridged with
other switchdev ports).

Along with some consolidation of the bridge logic to assign a "switchdev
offloading mark" to a port (now better called a "hardware domain"), this
series allows the bridge driver side to no longer impose restrictions on
that configuration.

Right now, all switchdev drivers must be modified to use the explicit
API, but more and more logic can then be placed centrally in the bridge
and therefore ease the job of a switchdev driver writer in the future.

For example, the first thing we can hook into the explicit switchdev
offloading API calls are the switchdev object and FDB replay helpers.
So far, these have only been used by DSA in "pull" mode (where the
driver must ask for them). Adding the replay helpers to other drivers
involves a lot of repetition. But by moving the helpers inside the
bridge port offload/unoffload hook points, we can move the entire replay
process to "push" mode (where the bridge provides them automatically).

The explicit switchdev offloading API will see further extensions in the
future.

The patches were split from a larger series for easier review:
https://patchwork.kernel.org/project/netdevbpf/cover/20210718214434.3938850-1-vladimir.oltean@nxp.com/

Changes in v6:
- Make the switchdev replay helpers opt-in
- Opt out of the replay helpers for mlxsw, rocker, prestera, sparx5,
  cpsw, am65-cpsw
====================

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