As a next step to complete the mxl862xx DSA driver, add support for
offloading forwarding between bridged ports to the switch hardware.

This works pretty much without any big surprises, apart from two
subtleties:
 * per-port control over flooding behavior has to be implemented by
   (ab)using a 0-rate QoS meters as stopper in lack of any better
   option.
 * STP state transition unconditionally enables learning on a port
   even if it was previously explicitely disabled (a firmware bug)

Note that as the driver is still lacking all VLAN features (which
are going to be added next), at this point some of the
bridge_vlan_aware.sh tests are failing after applying this series.

This is expected and cannot be avoided without implementing
port_vlan_filtering + port_vlan_add/del. And adding both bridge and
VLAN offloading at the same time would be too much for anyone to
review.

All other relevant selftests (including bridge_vlan_unaware.sh) are
still passing.

Changes since v1:
 * don't set dsa_default_offload_fwd_mark() on link-local frames
 * fix kernel-doc comments in API header
 * use bitfield helpers for compound tci field in fdb API
 * add missing endian conversion for mxl862xx_stp_port_cfg.port_state
   as well as mxl862xx_mac_table_read.tci (spotted by AI review)
 * drop manually resetting port learning state on bridge<->standalone
   transitions, DSA framework takes care of that
 * don't abort updating bridge ports on error, return error at the end
 * report error in mxl862xx_port_bridge_leave()
 * create mxl862xx_get_fid() helper and use it in
   mxl862xx_port_fdb_add() and mxl862xx_port_fdb_del()
 * propagete error of callback function in mxl862xx_port_fdb_dump()
 * manually mxl862xx_port_fast_age() in mxl862xx_port_stp_state_set()
   to avoid FDB poisoning due to race condition


Daniel Golle (2):
  dsa: tag_mxl862xx: set dsa_default_offload_fwd_mark()
  net: dsa: mxl862xx: implement bridge offloading

 drivers/net/dsa/mxl862xx/mxl862xx-api.h | 178 ++++++++
 drivers/net/dsa/mxl862xx/mxl862xx-cmd.h |  19 +-
 drivers/net/dsa/mxl862xx/mxl862xx.c     | 579 ++++++++++++++++++++++--
 drivers/net/dsa/mxl862xx/mxl862xx.h     |  21 +
 net/dsa/tag_mxl862xx.c                  |   3 +
 5 files changed, 767 insertions(+), 33 deletions(-)

-- 
2.53.0