Merge branch 'net-hash-tx'

Tom Herbert says:

====================
net: Improvements and applications of packet flow hash in transmit path

This patch series includes some patches which improve and make use
of skb->hash in the transmit path.

What is included:

- Infrastructure to save a precomputed hash in the sock structure.
  For connected TCP and UDP sockets we only need to compute the
  flow hash once and not once for every packet.
- Call skb_get_hash in get_xps_queue and __skb_tx_hash. This eliminates
  the awkward access to skb->sk->sk_hash in the lower transmit path.
- Move UDP source port generation into a common function in udp.h This
  implementation is mostly based on vxlan_src_port.
- Use non-zero IPv6 flow labels in flow_dissector as port information
  for flow hash calculation.
- Implement automatic flow label generation on transmit (per RFC 6438).
- Don't repeatedly try to compute an L4 hash in skb_get_hash if we've
  already tried to find one in software stack calculation.
====================

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