Merge branch 'bonding-initial-support-for-hardware-crypto-offload'

Merge branch 'bonding-initial-support-for-hardware-crypto-offload'

Jarod Wilson says:

====================
bonding: initial support for hardware crypto offload

This is an initial functional implementation for doing pass-through of
hardware encryption from bonding device to capable slaves, in active-backup
bond setups. This was developed and tested using ixgbe-driven Intel x520
interfaces with libreswan and a transport mode connection, primarily using
netperf, with assorted connection failures forced during transmission. The
failover works quite well in my testing, and overall performance is right
on par with offload when running on a bare interface, no bond involved.

Caveats: this is ONLY enabled for active-backup, because I'm not sure
how one would manage multiple offload handles for different devices all
running at the same time in the same xfrm, and it relies on some minor
changes to both the xfrm code and slave device driver code to get things
to behave, and I don't have immediate access to any other hardware that
could function similarly, but the NIC driver changes are minimal and
straight-forward enough that I've included what I think ought to be
enough for mlx5 devices too.

v2: reordered patches, switched (back) to using CONFIG_XFRM_OFFLOAD
to wrap the code additions and wrapped overlooked additions.
v3: rebase w/net-next open, add proper cc list to cover letter
====================

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