Merge branch 'hv_netvsc-less-headroom'

Merge branch 'hv_netvsc-less-headroom'

Merge branch 'hv_netvsc-less-headroom'

K. Y. Srinivasan says:

====================
hv_netvsc: Eliminate the additional head room

In an attempt to avoid having to allocate memory on the send path, the netvsc
driver was requesting additional head room so that both rndis header and the
netvsc packet (the state that had to persist) could be placed in the skb.
Since the amount of head room requested was exceeding the default head room
as set in LL_MAX_HEADER, we were forcing a reallocation of skb.

With this patch-set, I have reduced the size of the netvsc packet to less
than 20 bytes and with this reduction we don't need to ask for any additional
headroom. We place the rndis header in the skb head room and we place the
netvsc packet in control buffer area in the skb.

V2:  - Addressed  review comments:
     - Eliminated more fields from netvsc packet structure.

V3:  - Fixed a typo in patch: hv_netvsc: Don't ask for additional head room in the skb.
====================

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