MFC r299182
If ALTQ is defined in the kern conf, switch to Legacy Mode.

PR: 208409

MFC r297187

Support checksum offloading for TCP/IPV6 and UDP/IPV6.
Support SCTP checksum offloading for SCTP/IPV6.
Support SCTP checksum offloading on all controllers except 82575.

Differential Revision: https://reviews.freebsd.org/D7215

MFC: r295906

Fix and clean up usage of DMA and TSO segments:
- At Intel it is believed that most of their products support "only"
40 DMA segments so lower {EM,IGB}_MAX_SCATTER accordingly. Actually,
40 is more than plenty to handle full size TSO packets so it doesn't
make sense to further distinguish between MAC variants that really
can do 64 DMA segments. Moreover, capping at 40 DMA segments limits
the stack usage of {em,igb}_xmit() that - given the rare use of more
than these - previously hardly was justifiable, while still being
sufficient to avoid the problems seen with em(4) and EM_MAX_SCATTER
set to 32.
- In igb(4), pass the actually supported TSO parameters up the stack.
Previously, the defaults set in if_attach_internal() were applied,
i. e. a maximum of 35 TSO segments, which made supporting more than
these in the driver pointless. However, this might explain why no
problems were seen with IGB_MAX_SCATTER at 64.
- In em(4), take the 5 m_pullup(9) invocations performed by em_xmit()
in the TSO case into account when reporting TSO parameters upwards.
In the worst case, each of these calls will add another mbuf and,
thus, the requirement for an additional DMA segment. So for best
performance, it doesn't make sense to advertize a maximum of TSO
segments that typically will require defragmentation in em_xmit().
Again, this leaves enough room to handle full size TSO packets.
- Drop TSO macros from if_lem.h given that corresponding MACS don't
support TSO in the first place.

Reviewed by: erj, sbruno, jeffrey.e.pieper_intel.com
Approved by: re (gjb)

MFC r295323:
Update em(4) to 7.6.1; update igb(4) to 2.5.3.

Major changes:

- Add i219/i219(2) hardware support. (Found on Skylake generation and newer
chipsets.)
- Further to the last Skylake support diff, this one also includes support for
the Lewisburg chipset (i219(3)).

- Add a workaround to an igb hardware errata.
All 1G server products need to have IPv6 extension header parsing turned off.
This should be listed in the specification updates for current 1G server
products, e.g. for i350 it's errata #37 in this document:
http://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/ethernet-controller-i350-spec-update.pdf

- Avoton (i354) PHY errata workaround added

And a bunch of minor fixes, as well as #defines for things that the current
em(4)/igb(4) drivers don't implement.

MFC r287465:

igb(4): Update and fix HW errata
- HW errata workaround for IPv6 offload w/ extension headers
- Edited start of if_igb.c (Device IDs / #includes) to match ixgbe/ixl

Approved by: re (gjb)
Sponsored by: Intel Corporation

Sync the e1000 drivers with what's in head as of r294327, modulo parts
that don't apply to stable/10 (driver API, if_inc_counter(), RSS changes
etc.) and modulo r287465 (which reportedly breaks igb(4)), i. e. assorted
fixes and improvements only:

o MFC r267385 (partial):
- Don't compare bus_dma map pointers for static DMA allocations against
NULL to determine if bus_dmamap_unload() or bus_dmamem_free() should be
called. Instead, check the associated bus and virtual addresses.
- Don't clear static DMA maps to NULL.
o MFC r284933:
Delete the refernce to VLAN handling being disabled by default. This is
no longer the case. [1]
o MFC r285639:
Add an adapter CORE lock in the DDB hook em_dump_queue to avoid WITNESS
panic in em_init_locked() while debugging.
o MFC r285879:
- Remove unused txd_saved.
- Intialize txd_upper, txd_lower and txd_used at declaration.
o MFC r286162:
Free mbufs when busdma loading fails.
o MFC r286829:
Add capability to disable CRC stripping as it breaks IPMI/BMC capabilities
on certain adatpers. [2]
o MFC r286831: [3]
- Increase EM_MAX_SCATTER to 64 such that the size of em_xmit()::
segs[EM_MAX_SCATTER] doesn't get overrun by things like NFS that can
and do shove more than 32 segs when being used with em(4) and TSO4.
- Update tso handling code in em_xmit() with update from jhb@
- Set if_hw_tsomax, if_hw_tsomaxsegcount and if_hw_tsomaxsegsize to
appropriate values.
- Define a TSO workaround "magic" number of 4 that is used to avoid an
alignment issue in hardware.
- Change a couple of integer values that were used as booleans to actual
bool types.
- Ensure that em_enable_intr() enables the appropriate mask of interrupts
and not just a hardcoded define of values.
o MFC r286832:
e1000/if_lem.c bump to 1.1.0
o MFC r286833:
Bump all copywrite dates to 2015.
o MFC r287112:
Style/whitespace cleanup in shared/common code.
o MFC r293331:
- Switch em(4) to the extended RX descriptor format.
- Split rxbuffer and txbuffer apart to support the new RX descriptor
format structures. Move rxbuffer manipulation to em_setup_rxdesc() to
unify the new behavior changes.
- Add a RSSKEYLEN macro for help in generating the RSSKEY data structures
in the card.
- Change em_receive_checksum() to process the new rxdescriptor format
status bit.
o MFC r293332:
Disable the reuse of checksum offload context descriptors in the case
of multiple queues in em(4). Document errata in the code.
o MFC r293854:
Given that em(4), lem(4) and igb(4) hardware doesn't require the
alignment guarantees provided by m_defrag(9), use m_collapse(9)
instead for performance reasons.
While at it, sanitize the statistics softc members, i. e. retire
unused ones and add SYSCTL nodes missing for actually used ones.

PR: 118693 [1], 161277 [2], 195078 [3], 199174 [3], 200221 [3]

MFC r292670

Add support for sysctl knobs to live tune the tx packet processing limits
in igb and fix a wrap-around bug.

Submitted by: Jason (j@nitrology.com)
Sponsored by: Limelight Networks

MFC r271784 - Fix the handling of EOP in status descriptors for if_igb(4)
and don't double-free mbufs.

Like ixgbe(4) chipsets, EOP is only set on the final descriptor
in a chain of descriptors. So, to free the whole list of descriptors,
we should free the current slot _and_ the assembled list of descriptors
that make up the fragment list.

The existing code was setting discard once it saw EOP + an error status;
it then freed all the subsequent descriptors until the next EOP. That's
totally the wrong order.

MFC r271784 - Fix the handling of EOP in status descriptors for if_igb(4)
and don't double-free mbufs.

Like ixgbe(4) chipsets, EOP is only set on the final descriptor
in a chain of descriptors. So, to free the whole list of descriptors,
we should free the current slot _and_ the assembled list of descriptors
that make up the fragment list.

The existing code was setting discard once it saw EOP + an error status;
it then freed all the subsequent descriptors until the next EOP. That's
totally the wrong order.