MFC r352976:
Unify prints in mlx5en(4).

All prints in mlx5en(4) should use on of the macros:
mlx5_en_err/dbg/warn

Submitted by: slavash@
Sponsored by: Mellanox Technologies

MFC r330659:
Avoid more LFENCE/SFENCe on x86 in mlx5en(4),
by using the FreeBSD native fences.

Submitted by: kib@
Sponsored by: Mellanox Technologies

MFC r305868:
mlx5en: Separate the sendqueue from using the mlx5e_channel structure.

This change allows for reusing the transmit path for so called
rate limited senqueues. While at it optimise some pointer lookups
in the fast path.

Sponsored by: Mellanox Technologies

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

Add support for CQE zipping. CQE zipping reduces PCI overhead by
coalescing and zipping multiple CQEs into a single merged CQE. The
feature is enabled by default and can be disabled by a sysctl.

Implementing this feature mlx5_cqwq_pop() has been separated from
mlx5e_get_cqe().

MFC after: 1 week
Submitted by: Mark Bloch <markb@mellanox.com>
Differential Revision: https://reviews.freebsd.org/D4598
Sponsored by: Mellanox Technologies

Add mlx5 and mlx5en driver(s) for ConnectX-4 and ConnectX-4LX cards
from Mellanox Technologies. The current driver supports ethernet
speeds up to and including 100 GBit/s. Infiniband support will be
done later.

The code added is not compiled by default, which will be done by a
separate commit.

Sponsored by: Mellanox Technologies
MFC after: 2 weeks