MFC r316541, r316544, and r320688 from HEAD to stable/11.

r316541:
Fix a double free in ixgbe_rxeof()

r316544:
Don't overwrite vf->flags variable at the end of ixgbe(4) ixgbe_add_vf()

r320688:
ixgbe(4): Update HEAD (p3) to 3.2.12-k

Includes:

- Support for X550EM devices.
- Support for Bypass adapters.
- Flow Director code moved to separate files
- SR-IOV code moved to separate files
- Netmap code moved to separate files

Sponsored by: Intel Corporation

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

ixgbe(4): Update to version 3.1.13-k

Add support for two new devices: X552 SFP+ 10 GbE, and the single port
version of X550T.

Submitted by: erj
Reviewed by: gnn
Sponsored by: Intel Corporation
Differential Revision: https://reviews.freebsd.org/D4186

Update to the Intel ixgbe driver:
- Split the driver into independent pf and vf loadables. This is
in preparation for SRIOV support which will be following shortly.
This also allows us to keep a seperate revision control over the
two parts, making for easier sustaining.
- Make the TX/RX code a shared/seperated file, in the old code base
the ixv code would miss fixes that went into ixgbe, this model
will eliminate that problem.
- The driver loadables will now match the device names, something that
has been requested for some time.
- Rather than a modules/ixgbe there is now modules/ix and modules/ixv
- It will also be possible to make your static kernel with only one
or the other for streamlined installs, or both.

Enjoy!

Submitted by: jfv and erj

First, sync to internal shared code, and then

Fixes:
- flow control - don't override user value on re-init
- fix to make 1G optics work correctly
- change to interrupt enabling - some bits were incorrect
for certain hardware.
- certain stats fixes, remove a duplicate increment of
ierror, thanks to Scott Long for pointing these out.
- shared code link interface changed, requiring some
core code changes to accomodate this.
- add an m_adj() to ETHER_ALIGN on the recieve side, this
was requested by Mike Karels, thanks Mike.
- Multicast code corrections also thanks to Mike Karels.

First off: update the driver README, the old one was horribly
crusty, and this still isn't perfect, but its at least a bit
more recent.

Secondly, a few improvements to the driver from Andrew Boyer,
support hint to allow devices to not attach, add VLAN_HWTSO
capability so vlans can use TSO, fix in the interrupt handler
to make sure the stack TX queue is processed. Oh, and also
make sure IPv6 does not cause a re-init in the ioctl routine.
Thanks for your efforts Andrew!

Thanks to Claudio Jeker for noticing the ixgbe_xmit() routine
was not correctly swapping the dma map from the first to the
last descriptor in a multi-descriptor transmission, corrected
this.

Update the driver to Intel version 2.1.6
- add some new hardware support for 82599
- Big change to interrupt architecture, it now
uses a queue which contains an RX/TX pair as
the recipient of the interrupt. This will reduce
overall system interrupts/msix usage.
- Improved RX mbuf handling: the old get_buf routine
is no longer synchronized with rxeof, this allows
the elimination of packet discards due to mbuf
allocation failure.
- Much simplified and improved AIM code, it now
happens in the queue interrupt context and takes
into account both the traffic on the RX AND TX
side.
- variety of small tweaks, like ring size, that have
been seen as performance improvements.
- Thanks to those that provided feedback or suggested
changes, I hope I've caught all of them.

Update the ixgbe driver to 1.7.4, this includes support
for the new 82599 adapter family, adds header split, and
many small fixes. The driver should now be added to the
GENERIC kernel.

MFC after: 2 weeks

This is driver version 1.4.4 of the Intel ixgbe driver.
-It has new hardware support
-It uses a new method of TX cleanup called Head Write Back
-It includes the provisional generic TCP LRO feature contributed
by Myricom and made general purpose by me. This should move into
the stack upon approval but for this driver drop its in here.
-Also bug fixes and etc...

MFC in a week if no serious issues arise.

Add the actual source too :)

Approved by: re