[PATCH net-next 0/4] Software fallback for bridging in DSA

[Vladimir Oltean <olteanv@gmail.com>]

From: Vladimir Oltean <vladimir.oltean@nxp.com>

As was discussed here:
https://patchwork.kernel.org/project/netdevbpf/patch/20201202091356.24075-3-tobias@waldekranz.com/

it is desirable to not reject a LAG interface (bonding, team) even if
the switch isn't able to offload bridging towards that link aggregation
group. At least the DSA setups I have are not that unbalanced between
the horsepower of the CPU and the horsepower of the switch such that
software forwarding to be completely impractical.

This series makes all switch drivers theoretically able to do the right
thing when they are configured in a way similar to this (credits to
Tobias Waldekranz for the drawing):

      br0
     /   \
  team0   \
   / \     \
swp0 swp1  swp2

although in practice there is one more prerequisite: for software
fallback mode, they need to disable address learning. It is preferable
that they do this by implementing the .port_pre_bridge_join and
.port_bridge_join methods.

Vladimir Oltean (4):
  net: dsa: don't offload switchdev objects on ports that don't offload
    the bridge
  net: dsa: reject switchdev objects centrally from
    dsa_slave_port_obj_{add,del}
  net: dsa: return -EOPNOTSUPP if .port_lag_join is not implemented
  net: dsa: don't set skb->offload_fwd_mark when not offloading the
    bridge

 net/dsa/dsa_priv.h         | 16 ++++++++++++++++
 net/dsa/slave.c            | 21 +++++++++++----------
 net/dsa/switch.c           | 13 ++++++++++---
 net/dsa/tag_brcm.c         |  2 +-
 net/dsa/tag_dsa.c          |  9 +++++----
 net/dsa/tag_hellcreek.c    |  2 +-
 net/dsa/tag_ksz.c          |  2 +-
 net/dsa/tag_lan9303.c      |  4 +++-
 net/dsa/tag_mtk.c          |  2 +-
 net/dsa/tag_ocelot.c       |  2 +-
 net/dsa/tag_ocelot_8021q.c |  2 +-
 net/dsa/tag_rtl4_a.c       |  2 +-
 net/dsa/tag_sja1105.c      |  4 ++--
 net/dsa/tag_xrs700x.c      |  3 +--
 14 files changed, 55 insertions(+), 29 deletions(-)

-- 
2.25.1