Merge branch 'dsa-fdb-isolation'

Merge branch 'dsa-fdb-isolation'

Vladimir Oltean says:

====================
DSA FDB isolation

There are use cases which need FDB isolation between standalone ports
and bridged ports, as well as isolation between ports of different
bridges. Most of these use cases are a result of the fact that packets
can now be partially forwarded by the software bridge, so one port might
need to send a packet to the CPU but its FDB lookup will see that it can
forward it directly to a bridge port where that packet was autonomously
learned. So the source port will attempt to shortcircuit the CPU and
forward autonomously, which it can't due to the forwarding isolation we
have in place. So we will have packet drops instead of proper operation.

Additionally, before DSA can implement IFF_UNICAST_FLT for standalone
ports, we must have control over which database we install FDB entries
corresponding to port MAC addresses in. We don't want to hinder the
operation of the bridging layer.

DSA does not have a driver API that encourages FDB isolation, so this
needs to be created. The basis for this is a new struct dsa_db which
annotates each FDB and MDB entry with the database it belongs to.

The sja1105 and felix drivers are modified to observe the dsa_db
argument, and therefore, enforce the FDB isolation.

Compared to the previous RFC patch series from August:
https://patchwork.kernel.org/project/netdevbpf/cover/20210818120150.892647-1-vladimir.oltean@nxp.com/

what is different is that I stopped trying to make SWITCHDEV_FDB_{ADD,DEL}_TO_DEVICE
blocking, instead I'm making use of the fact that DSA waits for switchdev FDB work
items to finish before a port leaves the bridge. This is possible since:
https://patchwork.kernel.org/project/netdevbpf/patch/20211024171757.3753288-7-vladimir.oltean@nxp.com/

Additionally, v2 is also rebased over the DSA LAG FDB work.
====================

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