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 r253958:
Change CCB queue resize logic to be able safely handle overallocations:
- (re)allocate queue space in power of 2 chunks with 64 elements minimum
and never shrink it; with only 4/8 bytes per element size is insignificant.
- automatically reallocate the queue to double size if it is overflowed.
- if queue reallocation failed, store extra CCBs in unsorted TAILQ,
fetching them back as soon as some queue element is freed.

To free space in CCB for TAILQ linking, change highpowerq from keeping
high-power CCBs to keeping devices frozen due to high-power CCBs.

This encloses all pieces of queue resize logic inside of cam_queue.[ch],
removing some not obvious duties from xpt_release_ccb().

MFC r249466, r249481, r250025:
Remove multilevel freezing mechanism, implemented to handle specifics of
the ATA/SATA error recovery, when post-reset recovery commands should be
allocated when queues are already full of payload requests. Instead of
removing frozen CCBs with specified range of priorities from the queue
to provide free openings, use simple hack, allowing explicit CCBs over-
allocation for requests with priority higher (numerically lower) then
CAM_PRIORITY_OOB threshold.

Simplify CCB allocation logic by removing SIM-level allocation queue.
After that SIM-level queue manages only CCBs execution, while allocation
logic is localized within each single device.

MFC r227293 (by ed):
Mark MALLOC_DEFINEs static that have no corresponding MALLOC_DECLAREs.

This means that their use is restricted to a single C file.

MFC r241028:
Change queue overflow checks from DIAGNOSTIC+panic() to KASSERT() to make
them enabled on HEAD by default. It is probably better to do single compare
then hunt for unexpected memory corruption.

MFC r241444:
Increase device CCB queue array size by CAM_RL_VALUES - 1 (4) elements.
It is required to store extra recovery requests in case of bus resets.
On ATA/SATA this fixes assertion panics on HEAD with INVARIANTS enabled or
possible memory corruptions otherwise if timeout/reset happens when device
CCB queue is already full.

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

MFp4:
Some more missed parts from previous commits.

After thinking again, implement cam_ccbq_fini().
This is effectively NULL change, but makes this API a bit more consistent.

- Providing fine-grained malloc statistic by replacing M_DEVBUF with
module-specific malloc types. These should help us to pinpoint the
possible memory leakage in the future.
- Implementing xpt_alloc_ccb_nowait() and replacing all malloc/free based
CCB memory management with xpt_alloc_ccb[_nowait]/xpt_free_ccb. Hopefully
this would be helpful if someday we move the CCB allocator to use UMA
instead of malloc().

Encouraged by: jeffr, rwatson
Reviewed by: gibbs, scottl
Approved by: re (scottl)

Start each of the license/copyright comments with /*-

Use __FBSDID().

Fix typos, mostly s/ an / a / where appropriate and a few s/an/and/
Add FreeBSD Id tag where missing.

$Id$ -> $FreeBSD$

Fix a long standing bug in the camq teardown code.

cam_periph.c:
Move handling of CAM_AUTOSENSE_FAIL into block dealing with
all other scsi status errors.

cam_queue.c:
cam_queue.h:
Fix 'off by one' heap bug in a more efficient manner. Since
heap algorithms like to deal with indexes started from 1,
offset our heap array pointer at allocation time to make this
so for a C environment. This makes the implementation of the
algorithm a bit more efficient.

cam_xpt.c:
Use macros for accessing the head of the heap so that code
is isolated from implementation details of the heap.

Remove camq_regen(). We already perform modular comparisons
for generation counts, so no further steps to deal with generation
count wrap are required.

Fix an off by one problem in the camq heap code.

CAM Transport Layer (XPT).

Submitted by: The CAM Team