netmap support for the Intel 40G card in head

Thanks to Jack Vogel who made available some hardware,
I have been able to implement native netmap support for the
Intel "ixl" driver, aka xl710, the 40G card.

I have committed the code to 'head', and the same works in stable/10
where it will land soon.

Testers welcome. I have seen 32 Mpps on tx, 24 Mpps on rx
with two ports on the same card connected to each other.

This is our second 40G device for which we have native
netmap support, which makes FreeBSD quite unique.

cheers
luigi

Date: Tue, 24 Feb 2015 06:20:51 +0000 (UTC)
From: Luigi Rizzo <luigi_at_FreeBSD.org>
Subject: svn commit: r279232 - in head/sys/dev: ixl netmap
To: src-committers_at_freebsd.org, svn-src-all_at_freebsd.org,
	svn-src-head_at_freebsd.org

Author: luigi
Date: Tue Feb 24 06:20:50 2015
New Revision: 279232
URL: https://svnweb.freebsd.org/changeset/base/279232

Log:
  Add native netmap support to ixl.
  Preliminary tests indicate 32 Mpps on tx, 24 Mpps on rx
  with source and receiver on two different ports of the same 40G card.
  Optimizations are likely possible.
  The code follows closely the one for ixgbe so i do not
  expect stability issues.
  
  Hardware kindly supplied by Intel.
  
  Reviewed by:	Jack Vogel
  MFC after:	1 week

Added:
  head/sys/dev/netmap/if_ixl_netmap.h   (contents, props changed)
Modified:
  head/sys/dev/ixl/if_ixl.c
  head/sys/dev/ixl/ixl_txrx.c