MFC r286567, r286568, r289426, r289429, r295113, r295286, r299367, r299369,

r308217, r308301, r311958, r312437, r318188, r318427, r318679

r286567:
Remove some unused code.

Obtained from: Netflix, Inx.

r286568:
Remove mps_request_polled(), it's redundant to mps_wait_command()

Obtained from: Netflix, Inc.

r289426:
Remove _FreeBSD_version check for something that was only an issue with
9-CURRENT.

Obtained from: Netlfix, Inc
MFC after: 3 days

r289429:
Revert an extra hunk that crept into the last commit.

Submitted by: emax
Obtained from: Netflix, Inc.
MFC after: 3 days

r295113:
Clean up unused-but-set-variable spotted by gcc-4.9.

Reviewed by: mav, slm
Approved by: rodrigc (mentor)
MFC after: 2 weeks
Sponsored by: gandi.net

r295286:
Add sysctls for dumping out the device mapping tables. I'm finding this
useful for debugging device-target translation bugs.

MFC after: 3 days
Sponsored by: Netflix

r299367:
Remove NULL checks after M_WAITOK allocations from mps(4).

Reviewed by: asomers@
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D6296

r299369:
Remove NULL checks after M_WAITOK allocations from mpr(4).

Reviewed by: asomers@
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D6297

r308217:
Add a fallback to the device mapper logic. We've seen systems in the field
that are apparently misconfigured by the manufacturer and cause the mapping
logic to fail. The fallback allows drive numbers to be assigned based on the
PHY number that they're attached to. Add sysctls and tunables to overrid
this new behavior, but they should be considered only necessary for debugging.

Reviewed by: imp, smh
Obtained from: Netflix
MFC after: 3 days
Sponsored by: D8403

r308301:
Record the LogInfo field when reporting the IOCStatus. Helps in
debugging errors.

Submitted by: slm
Obtained from: Netflix
MFC after: 3 days

r311958:
Print out the number of queues/MSIx vectors.

Sponsored by: Netflix

r312437:
Rework the debug print API. Event printing no longer gets special handling.
All of the printing from the tables file now has wrappers so that the
handling is cleaner and it's possible to print something out (say, during
development) without having to fight the global debug flags. This re-org
will also make it easier to have the tables be compiled out at build time
if desired.

Other than fixing some minor bugs, there are no user-visible changes from
this change

Sponsored by: Netflix, Inc.
Differential Revision: D9238

r318188:
Improve error messages during command timeout for the mpr and mps
drivers.

Sponsored by: Netflix

r318427:
Add tri-mode support (SAS/SATA/PCIe).

This includes NVMe device support and adds support for the following adapters:

SAS 3408
SAS 3416
SAS 3508
SAS 3516
SAS 3616
SAS 3708
SAS 3716

Reviewed by: ken, scottl, asomers, mav
Approved by: ken, scottl, mav
MFC after: 2 weeks
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D10095

r318679:
Fix powerpc compiler error.

Approved by: ken