Merge branch 'mlxsw-Add-support-for-Q-in-VNI'

Ido Schimmel says:

====================
mlxsw: Add support for Q-in-VNI

This patch set adds support for Q-in-VNI over Spectrum-{2,3} ASICs.
Q-in-VNI is like regular VxLAN encapsulation with the sole difference
that overlay packets can contain a VLAN tag. In Linux, this is achieved
by adding the VxLAN device to a 802.1ad bridge instead of a 802.1q
bridge.

From mlxsw perspective, Q-in-VNI support entails two main changes:

1. An outer VLAN tag should always be pushed to the overlay packet
during decapsulation

2. The EtherType used during decapsulation should be 802.1ad (0x88a8)
instead of the default 802.1q (0x8100)

Patch set overview:

Patches #1-#3 add required device registers and fields

Patch #4 performs small refactoring to allow code re-use

Patches #5-#7 make the EtherType used during decapsulation a property of
the tunnel port (i.e., VxLAN). This leads to the driver vetoing
configurations in which VxLAN devices are member in both 802.1ad and
802.1q/802.1d bridges. Will be handled in the future by determining the
overlay EtherType on the egress port instead

Patch #8 adds support for Q-in-VNI for Spectrum-2 and newer ASICs

Patches #9-#10 veto Q-in-VNI for Spectrum-1 ASICs due to some hardware
limitations. Can be worked around, but decided not to support it for now

Patch #11 adjusts mlxsw to stop vetoing addition of VXLAN devices to
802.1ad bridges

Patch #12 adds a generic forwarding test that can be used with both veth
pairs and physical ports with a loopback

Patch #13 adds a test to make sure mlxsw vetoes unsupported Q-in-VNI
configurations
====================

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