Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

MFC r256231:

Improve logging around some of the isci(4) reset and recovery paths.

Sponsored by: Intel

MFC r248825, 248775

Add unmapped i/o support for the mps and isci drivers.

Submitted by: mav, jimharris
Obtained from: Netflix

Big MFC of the physbio changes necessary for unmapped I/O. These changes
have been in production at Netflix for several months with significant
success.

MFC r246713:

Reform the busdma API so that new types may be added without modifying
every architecture's busdma_machdep.c. It is done by unifying the
bus_dmamap_load_buffer() routines so that they may be called from MI
code. The MD busdma is then given a chance to do any final processing
in the complete() callback.

MFC r249538:
Some compilers issue a warning when wider integer is casted to narrow
pointer. Supposedly shut down the warning by casting through
uintptr_t.

MFC r251479:
Simplify the checking of flags for cam_periph_mapmem(). This gets rid of
a lot of code redundancy and grossness at very minor expense.

MFC r251837:
MFC r251842:
Add infrastructure for doing compatibility shims, as has been sorely
needed for the last 10 years. Far too much of the internal API is
exposed, and every small adjustment causes applications to stop working.
To kick this off, bump the API version to 0x17 as should have been done
with r246713, but add shims to compensate. Thanks to the shims, there
should be no visible change in application behavior.

Submitted by: kib, jeffr
Approved by: kib
Obtained from: Netflix

MFC r243904:

Don't call bus_dmamap_load in CAM_DIR_NONE case, since there is nothing
to map, and technically this isn't allowed.

Functionally, it works OK (at least on x86) to call bus_dmamap_load with
a NULL data pointer and zero length, so this is primarily for correctness
and consistency with other drivers.

While here, remove check in isci_io_request_construct for nseg==0.
Previously, bus_dmamap_load would pass nseg==1, even for case where
buffer is NULL and length = 0, which allowed CAM_DIR_NONE CCBs
to get processed. This check is not correct though, and needed to be
removed both for the changes elsewhere in this patch, as well as jeff's
preliminary bus_dmamap_load_ccb patch (which uncovered all of this in
the first place).

MFC r234106, r235751:

Queue CCBs internally instead of using CAM_REQUEUE_REQ status. This fixes
problem where userspace apps such as smartctl fail due to CAM_REQUEUE_REQ
status getting returned when tagged commands are outstanding when smartctl
sends its I/O using the pass(4) interface.

Sponsored by: Intel

MFC r230843, r231134, r231136, r231137, r231296

Add isci(4) driver for amd64 and i386 targets.

The isci driver is for the integrated SAS controller in the Intel C600
(Patsburg) chipset. Source files in sys/dev/isci directory are
FreeBSD-specific, and sys/dev/isci/scil subdirectory contains
an OS-agnostic library (SCIL) published by Intel to control the SAS
controller. This library is used primarily as-is in this driver, with
some post-processing to better integrate into the kernel build
environment.

isci.4 and a README in the sys/dev/isci directory contain a few
additional details.

This driver is only built for amd64 and i386 targets.

Sponsored by: Intel
Reviewed by: scottl
Approved by: scottl

Add isci(4) driver for amd64 and i386 targets.

The isci driver is for the integrated SAS controller in the Intel C600
(Patsburg) chipset. Source files in sys/dev/isci directory are
FreeBSD-specific, and sys/dev/isci/scil subdirectory contains
an OS-agnostic library (SCIL) published by Intel to control the SAS
controller. This library is used primarily as-is in this driver, with
some post-processing to better integrate into the kernel build
environment.

isci.4 and a README in the sys/dev/isci directory contain a few
additional details.

This driver is only built for amd64 and i386 targets.

Sponsored by: Intel
Reviewed by: scottl
Approved by: scottl

Add all isci driver source code to sys/dev/isci for the Intel C600
(Patsburg) integrated SAS controller.

sys/dev/isci contains all files specific to FreeBSD.
sys/dev/isci/scil contains OS-agnostic library maintained by Intel and
modified to best integrate into FreeBSD kernel build environment.

Sponsored by: Intel
Reviewed by: scottl