sys: Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

cam: Remove non-sbuf announce/denounce proto and xport ops

Reviewed by: mav, imp
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D41264

cam: Migrate to modern uintXX_t from u_intXX_t

As per https://lists.freebsd.org/archives/freebsd-scsi/2023-July/000257.html
move to the modern uintXX_t.

MFC After: 3 days
Sponsored by: Netflix

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

cam: clean up empty lines in .c and .h files

Fix tiny style nit.

Refactor NVMe CAM integration.

- Remove layering violation, when NVMe SIM code accessed CAM internal
device structures to set pointers on controller and namespace data.
Instead make NVMe XPT probe fetch the data directly from hardware.
- Cleanup NVMe SIM code, fixing support for multiple namespaces per
controller (reporting them as LUNs) and adding controller detach support
and run-time namespace change notifications.
- Add initial support for namespace change async events. So far only
in CAM mode, but it allows run-time namespace arrival and departure.
- Add missing nvme_notify_fail_consumers() call on controller detach.
Together with previous changes this allows NVMe device detach/unplug.

Non-CAM mode still requires a lot of love to stay on par, but at least
CAM mode code should not stay in the way so much, becoming much more
self-sufficient.

Reviewed by: imp
MFC after: 1 month
Sponsored by: iXsystems, Inc.

sys/cam: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

An MMC/SD/SDIO stack using CAM

Implement the MMC/SD/SDIO protocol within a CAM framework. CAM's
flexible queueing will make it easier to write non-storage drivers
than the legacy stack. SDIO drivers from both the kernel and as
userland daemons are possible, though much of that functionality will
come later.

Some of the CAM integration isn't complete (there are sleeps in the
device probe state machine, for example), but those minor issues can
be improved in-tree more easily than out of tree and shouldn't gate
progress on other fronts. Appologies to reviews if specific items
have been overlooked.

Submitted by: Ilya Bakulin
Reviewed by: emaste, imp, mav, adrian, ian
Differential Review: https://reviews.freebsd.org/D4761

merge with first commit, various compile hacks.

Add infrastructure to the ATA and SCSI transports that supports
using a driver-supplied sbuf for printing device discovery
announcements. This helps ensure that messages to the console
will be properly serialized (through sbuf_putbuf) and not be
truncated and interleaved with other messages. The
infrastructure mirrors the existing xpt_announce_periph()
entry point and is opt-in for now. No content or formatting
changes are visible to the operator other than the new coherency.

While here, eliminate the stack usage of the temporary
announcement buffer in some of the drivers. It's moved to the
softc for now, but future work will eliminate it entirely by
making the code flow more linear. Future work will also address
locking so that the sbufs can be dynamically sized.

The scsi_da, scs_cd, scsi_ses, and ata_da drivers are converted
at this point, other drivers can be converted at a later date.
A tunable+sysctl, kern.cam.announce_nosbuf, exists for testing
purposes but will be removed later.

TODO:
Eliminate all of the code duplication and temporary buffers. The
old printf-based methods will be retired, and xpt_announce_periph()
will just be a wrapper that uses a dynamically sized sbuf. This
requires that the register and deregister paths be made malloc-safe,
which they aren't currently.

Sponsored by: Netflix

"Buses" is the preferred plural of "bus"

Replace archaic "busses" with modern form "buses."

Intentionally excluded:
* Old/random drivers I didn't recognize
* Old hardware in general
* Use of "busses" in code as identifiers

No functional change.

http://grammarist.com/spelling/buses-busses/

PR: 216099
Reported by: bltsrc at mail.ru
Sponsored by: Dell EMC Isilon

Move protocol specific stuff into a linker set object that's
per-protocol. This reduces the number scsi symbols references by
cam_xpt significantly, and eliminates all ata / nvme symbols. There's
still some NVME / ATA specific code for dealing with XPT_NVME_IO and
XPT_ATA_IO respectively, and a bunch of scsi-specific code, but this
is progress.

Differential Revision: https://reviews.freebsd.org/D7289

Switch to linker sets to find the xport callback object. This
eliminates the need to special case everything in cam_xpt for new
transports. It is now a failure to not have a transport object when
registering the bus as well. You can still, however, create a
transport that's unspecified (XPT_)

Differential Revision: https://reviews.freebsd.org/D7289

New NVMe front end (nda).

Add support for probing the SCSI VPD Extended Inquiry page (0x86).

This VPD page is effectively an extension of the standard Inquiry
data page, and includes lots of additional bits.

This commit includes support for probing the page in the SCSI probe code,
and an additional request type for the XPT_DEV_ADVINFO CCB. CTL already
supports the Extended Inquiry page.

Support for querying this page in the sa(4) driver will come later.

sys/cam/scsi/scsi_xpt.c:
Probe the Extended Inquiry page, if the device supports it, and
return it in response to a XPT_DEV_ADVINFO CCB if it is requested.

sys/cam/scsi/cam_ccb.h:
Define a new advanced information CCB data type, CDAI_TYPE_EXT_INQ.

sys/cam/cam_xpt.c:
Free the extended inquiry data in a device when the device goes
away.

sys/cam/cam_xpt_internal.h:
Add an extended inquiry data pointer and length to struct cam_ed.

sys/sys/param.h
Bump __FreeBSD_version for the addition of the new
CDAI_TYPE_EXT_INQ advanced information type.

Sponsored by: Spectra Logic
MFC after: 1 week

Merge CAM locking changes from the projects/camlock branch to radically
reduce lock congestion and improve SMP scalability of the SCSI/ATA stack,
preparing the ground for the coming next GEOM direct dispatch support.

Replace big per-SIM locks with bunch of smaller ones:
- per-LUN locks to protect device and peripheral drivers state;
- per-target locks to protect list of LUNs on target;
- per-bus locks to protect reference counting;
- per-send queue locks to protect queue of CCBs to be sent;
- per-done queue locks to protect queue of completed CCBs;
- remaining per-SIM locks now protect only HBA driver internals.

While holding LUN lock it is allowed (while not recommended for performance
reasons) to take SIM lock. The opposite acquisition order is forbidden.
All the other locks are leaf locks, that can be taken anywhere, but should
not be cascaded. Many functions, such as: xpt_action(), xpt_done(),
xpt_async(), xpt_create_path(), etc. are no longer require (but allow) SIM
lock to be held.

To keep compatibility and solve cases where SIM lock can't be dropped, all
xpt_async() calls in addition to xpt_done() calls are queued to completion
threads for async processing in clean environment without SIM lock held.

Instead of single CAM SWI thread, used for commands completion processing
before, use multiple (depending on number of CPUs) threads. Load balanced
between them using "hash" of the device B:T:L address.

HBA drivers that can drop SIM lock during completion processing and have
sufficient number of completion threads to efficiently scale to multiple
CPUs can use new function xpt_done_direct() to avoid extra context switch.
Make ahci(4) driver to use this mechanism depending on hardware setup.

Sponsored by: iXsystems, Inc.
MFC after: 2 months

MFprojects/camlock r249505:
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().

Remove owner field from struct cam_ed, unused at least since FreeBSD 7.

MFprojects/camlock r248890, r248897, r248898, r248900, r248903, r248905,
r248917, r248918, r248978, r249001, r249014, r249030:

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.

Suggested by: gibbs

Add CAM infrastructure to allow reporting when a drive's long read capacity
data changes.

cam_ccb.h: Add a new advanced information type, CDAI_TYPE_RCAPLONG,
for long read capacity data.

cam_xpt_internal.h:
Add a read capacity data pointer and length to struct cam_ed.

cam_xpt.c: Free the read capacity buffer when a device goes away.
While we're here, make sure we don't leak memory for other
malloced fields in struct cam_ed.

scsi_all.c: Update the scsi_read_capacity_16() to take a uint8_t * and
a length instead of just a pointer to the parameter data
structure. This will hopefully make this function somewhat
immune to future changes in the parameter data.

scsi_all.h: Add some extra bit definitions to struct
scsi_read_capacity_data_long, and bump up the structure
size to the full size specified by SBC-3.

Change the prototype for scsi_read_capacity_16().

scsi_da.c: Register changes in read capacity data with the transport
layer. This allows the transport layer to send out an
async notification to interested parties. Update the
dasetgeom() API.

Use scsi_extract_sense_len() instead of
scsi_extract_sense().

scsi_xpt.c: Add support for the new CDAI_TYPE_RCAPLONG advanced
information type.

Make sure we set the physpath pointer to NULL after freeing
it. This allows blindly freeing it in the struct cam_ed
destructor.

sys/param.h: Bump __FreeBSD_version from 1000005 to 1000006 to make it
easier for third party drivers to determine that the read
capacity data async notification is available.

camcontrol.c,
mptutil/mpt_cam.c:
Update these for the new scsi_read_capacity_16() argument
structure.

Sponsored by: Spectra Logic

Lay groundwork in CAM for recording and reporting physical path and
other device attributes stored in the CAM Existing Device Table (EDT).
This includes some infrastructure requried by the enclosure services
driver to export physical path information.

Make the CAM device advanced info interface accept store requests.

sys/cam/scsi/scsi_all.c:
sys/cam/scsi/scsi_all.h:
- Replace scsi_get_sas_addr() with a scsi_get_devid() which takes
a callback that decides whether to accept a particular descriptor.
Provide callbacks for NAA IEEE Registered addresses and for SAS
addresses, replacing the old function. This is needed because
the old function doesn't work for an enclosure address for a SAS
device, which is not flagged as a SAS address, but is NAA IEEE
Registered. It may be worthwhile merging this interface with the
devid match interface.
- Add a few more defines for some device ID fields.

sbin/camcontrol/camcontrol.c:
- Update for the CCB_DEV_ADVINFO interface change.

cam/cam_xpt_internal.h:
- Add the new fields for the physical path string to the CAM EDT.
cam/cam_ccb.h:
- Rename CCB_GDEV_ADVINFO to simply CCB_DEV_ADVINFO, and the ccb
structure to ccb_dev_advinfo.
- Add a flag that changes this CCB's action to store, rather than
the default, retrieve.
- Add a new buffer type, CDAI_TYPE_PHYS_PATH, for the new CAM EDT
physpath field.
- Remove the never-implemented transport & proto flags.
cam/cam_xpt.c:
cam/cam_xpt.h:
- Add xpt_getattr(), which provides a wrapper for fetching a device's
attribute using the GEOM strings as key. This method currently
supports "GEOM::ident" and "GEOM::physpath".

Submitted by: will
Reviewed by : gibbs

Extend the XPT_DEV_MATCH api to allow a device search by device ID.
As far as the API is concerned, device ID is a binary blob to be
interpreted by the transport layer. The SCSI implementation assumes
it is an array of VPD device ID descriptors.

sys/cam/cam_ccb.h:
Create a new structure, device_id_match_pattern, and
update the XPT_DEV_MATCH datastructures and flags so
that this pattern type can be used.

sys/cam/cam_xpt.c:
- A single pattern matching on both inquiry data and device
ID is invalid. Report any violators.
- Pass device ID match requests through to the new routine
scsi_devid_match(). The direct call of a SCSI routine is
a layering violation, but no worse than the one a few
lines up that checks inquiry data. Defer cleaning this
up until our future, larger, rototilling of CAM.
- Zero out cam_ed and cam_et nodes on allocation. Prior to
this change, device_id_len and device_id were not inialized,
preventing proper detection of the presence of this
information.

sys/cam/scsi/scsi_all.c:
sys/cam/scsi/scsi_all.h:
Add the scsi_match_devid() routine.

Add a helper function for extracting peripherial driver names

sys/cam/cam_periph.c:
sys/cam/cam_periph.h:
Add the cam_periph_list() method which fills an sbuf
with a comma delimited list of the peripheral instances
associated with a given CAM path.

Add a helper functions for SCSI commands used by the SES driver.

sys/cam/scsi/scsi_all.c:
sys/cam/scsi/scsi_all.h:
Add structure definitions and csio filling functions for
the receive diagnostic results and send diagnostic commands.

Misc CAM XPT cleanups.

sys/cam/cam_xpt.c:
Broadcast AC_FOUND_DEVICE and AC_PATH_REGISTERED
events at the time async event handlers are attached
even when registering just for events on a partitular
SIM. Previously, you had to register for these
events on all SIMs in the system in order to get
the initial broadcast even though subsequent device
and path arrivals would be delivered.

sys/cam/cam_xpt.c:
Remove SIM mutex held asserts from path accessors.
CAM paths are reference counted and it is this
reference count, not the sim mutex, that garantees
they are stable.

Sponsored by: Spectra Logic Corporation

Add Serial Management Protocol (SMP) passthrough support to CAM.

This includes support in the kernel, camcontrol(8), libcam and the mps(4)
driver for SMP passthrough.

The CAM SCSI probe code has been modified to fetch Inquiry VPD page 0x00
to determine supported pages, and will now fetch page 0x83 in addition to
page 0x80 if supported.

Add two new CAM CCBs, XPT_SMP_IO, and XPT_GDEV_ADVINFO. The SMP CCB is
intended for SMP requests and responses. The ADVINFO is currently used to
fetch cached VPD page 0x83 data from the transport layer, but is intended
to be extensible to fetch other types of device-specific data.

SMP-only devices are not currently represented in the CAM topology, and so
the current semantics are that the SIM will route SMP CCBs to either the
addressed device, if it contains an SMP target, or its parent, if it
contains an SMP target. (This is noted in cam_ccb.h, since it will change
later once we have the ability to have SMP-only devices in CAM's topology.)

smp_all.c,
smp_all.h: New helper routines for SMP. This includes
SMP request building routines, response parsing
routines, error decoding routines, and structure
definitions for a number of SMP commands.

libcam/Makefile: Add smp_all.c to libcam, so that SMP functionality
is available to userland applications.

camcontrol.8,
camcontrol.c: Add smp passthrough support to camcontrol. Several
new subcommands are now available:

'smpcmd' functions much like 'cmd', except that it
allows the user to send generic SMP commands.

'smprg' sends the SMP report general command, and
displays the decoded output. It will automatically
fetch extended output if it is available.

'smppc' sends the SMP phy control command, with any
number of potential options. Among other things,
this allows the user to reset a phy on a SAS
expander, or disable a phy on an expander.

'smpmaninfo' sends the SMP report manufacturer
information and displays the decoded output.

'smpphylist' displays a list of phys on an
expander, and the CAM devices attached to those
phys, if any.

cam.h,
cam.c: Add a status value for SMP errors
(CAM_SMP_STATUS_ERROR).

Add a missing description for CAM_SCSI_IT_NEXUS_LOST.

Add support for SMP commands to cam_error_string().

cam_ccb.h: Rename the CAM_DIR_RESV flag to CAM_DIR_BOTH. SMP
commands are by nature bi-directional, and we may
need to support bi-directional SCSI commands later.

Add the XPT_SMP_IO CCB. Since SMP commands are
bi-directional, there are pointers for both the
request and response.

Add a fill routine for SMP CCBs.

Add the XPT_GDEV_ADVINFO CCB. This is currently
used to fetch cached page 0x83 data from the
transport later, but is extensible to fetch many
other types of data.

cam_periph.c: Add support in cam_periph_mapmem() for XPT_SMP_IO
and XPT_GDEV_ADVINFO CCBs.

cam_xpt.c: Add support for executing XPT_SMP_IO CCBs.

cam_xpt_internal.h: Add fields for VPD pages 0x00 and 0x83 in struct
cam_ed.

scsi_all.c: Add scsi_get_sas_addr(), a function that parses
VPD page 0x83 data and pulls out a SAS address.

scsi_all.h: Add VPD page 0x00 and 0x83 structures, and a
prototype for scsi_get_sas_addr().

scsi_pass.c: Add support for mapping buffers in XPT_SMP_IO and
XPT_GDEV_ADVINFO CCBs.

scsi_xpt.c: In the SCSI probe code, first ask the device for
VPD page 0x00. If any VPD pages are supported,
that page is required to be implemented. Based on
the response, we may probe for the serial number
(page 0x80) or device id (page 0x83).

Add support for the XPT_GDEV_ADVINFO CCB.

sys/conf/files: Add smp_all.c.

mps.c: Add support for passing in a uio in mps_map_command(),
so we can map a S/G list at once.

Add support for SMP passthrough commands in
mps_data_cb(). SMP is a special case, because the
first buffer in the S/G list is outbound and the
second buffer is inbound.

Add support for warning the user if the busdma code
comes back with more buffers than will work for the
command. This will, for example, help the user
determine why an SMP command failed if busdma comes
back with three buffers.

mps_pci.c: Add sys/uio.h.

mps_sas.c: Add the SAS address and the parent handle to the
list of fields we pull from device page 0 and cache
in struct mpssas_target. These are needed for SMP
passthrough.

Add support for the XPT_SMP_IO CCB. For now, this
CCB is routed to the addressed device if it supports
SMP, or to its parent if it does not and the parent
does. This is necessary because CAM does not
currently support SMP-only nodes in the topology.

Make SMP passthrough support conditional on
__FreeBSD_version >= 900026. This will make it
easier to MFC this change to the driver without
MFCing the CAM changes as well.

mps_user.c: Un-staticize mpi_init_sge() so we can use it for
the SMP passthrough code.

mpsvar.h: Add a uio and iovecs into struct mps_command for
SMP passthrough commands.

Add a cm_max_segs field to struct mps_command so
that we can warn the user if busdma comes back with
too many segments.

Clear the cm_reply when a command gets freed. If
it is not cleared, reply frames will eventually get
freed into the pool multiple times and corrupt the
pool. (This fix is from scottl.)

Add a prototype for mpi_init_sge().

sys/param.h: Bump __FreeBSD_version to 900026 for the for the
inclusion of the XPT_GDEV_ADVINFO and XPT_SMP_IO
CAM CCBs.

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Implement the usage of Report Luns as part of SCSI probing for SCP3 or
better devices. This can be disabled on a per-device basis using quirks as
well.

This also handles the case where there is actually no connected LUN 0
(which can definitely be the case for storage arrays).

Reviewed by: scsi@
MFC after: 1 month

MFC r204220, r204353:
Virtualize transport part of periph announcement.

Virtualize transport part of periph announcement.

MFC r203108:
Large set of CAM improvements:
- Unify bus reset/probe sequence. Whenever bus attached at boot or later,
CAM will automatically reset and scan it. It allows to remove duplicate
code from many drivers.
- Any bus, attached before CAM completed it's boot-time initialization,
will equally join to the process, delaying boot if needed.
- New kern.cam.boot_delay loader tunable should help controllers that
are still unable to register their buses in time (such as slow USB/
PCCard/ CardBus devices), by adding one more event to wait on boot.
- To allow synchronization between different CAM levels, concept of
requests priorities was extended. Priorities now split between several
"run levels". Device can be freezed at specified level, allowing higher
priority requests to pass. For example, no payload requests allowed,
until PMP driver enable port. ATA XPT negotiate transfer parameters,
periph driver configure caching and so on.
- Frozen requests are no more counted by request allocation scheduler.
It fixes deadlocks, when frozen low priority payload requests occupying
slots, required by higher levels to manage theit execution.
- Two last changes were holding proper ATA reinitialization and error
recovery implementation. Now it is done: SATA controllers and Port
Multipliers now implement automatic hot-plug and should correctly
recover from timeouts and bus resets.
- Improve SCSI error recovery for devices on buses without automatic sense
reporting, such as ATAPI or USB. For example, it allows CAM to wait, while
CD drive loads disk, instead of immediately return error status.
- Decapitalize diagnostic messages and make them more readable and sensible.
- Teach PMP driver to limit maximum speed on fan-out ports.
- Make boot wait for PMP scan completes, and make rescan more reliable.
- Fix pass driver, to return CCB to user level in case of error.
- Increase number of retries in cd driver, as device may return several UAs.

MFp4: Large set of CAM inprovements.

- Unify bus reset/probe sequence. Whenever bus attached at boot or later,
CAM will automatically reset and scan it. It allows to remove duplicate
code from many drivers.
- Any bus, attached before CAM completed it's boot-time initialization,
will equally join to the process, delaying boot if needed.
- New kern.cam.boot_delay loader tunable should help controllers that
are still unable to register their buses in time (such as slow USB/
PCCard/ CardBus devices), by adding one more event to wait on boot.
- To allow synchronization between different CAM levels, concept of
requests priorities was extended. Priorities now split between several
"run levels". Device can be freezed at specified level, allowing higher
priority requests to pass. For example, no payload requests allowed,
until PMP driver enable port. ATA XPT negotiate transfer parameters,
periph driver configure caching and so on.
- Frozen requests are no more counted by request allocation scheduler.
It fixes deadlocks, when frozen low priority payload requests occupying
slots, required by higher levels to manage theit execution.
- Two last changes were holding proper ATA reinitialization and error
recovery implementation. Now it is done: SATA controllers and Port
Multipliers now implement automatic hot-plug and should correctly
recover from timeouts and bus resets.
- Improve SCSI error recovery for devices on buses without automatic sense
reporting, such as ATAPI or USB. For example, it allows CAM to wait, while
CD drive loads disk, instead of immediately return error status.
- Decapitalize diagnostic messages and make them more readable and sensible.
- Teach PMP driver to limit maximum speed on fan-out ports.
- Make boot wait for PMP scan completes, and make rescan more reliable.
- Fix pass driver, to return CCB to user level in case of error.
- Increase number of retries in cd driver, as device may return several UAs.

MFC r199178:
- Move tagged queueing control from ADA to ATA XPT. It allows to control
device command queue length correctly. First step to support < 32 tags.
- Limit queue for non-tagged devices by 2 slots for ahci(4) and siis(4).
- Implement quirk matching for ATA devices.
- Move xpt_schedule_dev_sendq() from header to source file.
- Move delayed queue shrinking to the more expected place - element freeing.
- Remove some SCSIsms in ATA.

MFC r198748, r198782:
Fix reference counting bug, when device unreferenced before
invalidated. To do it, do not handle validity flag as another
reference, but explicitly modify reference count each time flag is
modified.
The async callback could free the device. If it is a broadcast async,
it doesn't hold device reference, so take our own reference.

MFC r198331:
Separate CAM_DEV_IDENTIFY_DATA_VALID flag from CAM_DEV_INQUIRY_DATA_VALID.
Add workaround for very old devices without support for mode setting.
Add some PATA bus scanning support.
Remove some SCSIsms.

MFC r196903:
Remove duplicate qfrozen_cnt variable from struct cam_ed.
ccbq.queue.qfrozen_cnt should be used instead.

MFp4:
- Move tagged queueing control from ADA to ATA XPT. It allows to control
device command queue length correctly. First step to support < 32 tags.
- Limit queue for non-tagged devices by 2 slots for ahci(4) and siis(4).
- Implement quirk matching for ATA devices.
- Move xpt_schedule_dev_sendq() from header to source file.
- Move delayed queue shrinking to the more expected place - element freeing.
- Remove some SCSIsms in ATA.

MFp4:
Fix reference counting bug, when device unreferenced before then
invalidated. To do it, do not handle validity flag as another
reference, but explicitly modify reference count each time flag is
modified.

Discovered by: thompsa

MFp4:
Separate CAM_DEV_IDENTIFY_DATA_VALID flag from CAM_DEV_INQUIRY_DATA_VALID.
Add workaround for very old devices without support for mode setting.
Add some PATA bus scanning support.
Remove some SCSIsms.

MFp4:
Remove duplicate qfrozen_cnt variable from struct cam_ed.
ccbq.queue.qfrozen_cnt should be used instead.

Separate the parallel scsi knowledge out of the core of the XPT, and
modularize it so that new transports can be created.

Add a transport for SATA

Add a periph+protocol layer for ATA

Add a driver for AHCI-compliant hardware.

Add a maxio field to CAM so that drivers can advertise their max
I/O capability. Modify various drivers so that they are insulated
from the value of MAXPHYS.

The new ATA/SATA code supports AHCI-compliant hardware, and will override
the classic ATA driver if it is loaded as a module at boot time or compiled
into the kernel. The stack now support NCQ (tagged queueing) for increased
performance on modern SATA drives. It also supports port multipliers.

ATA drives are accessed via 'ada' device nodes. ATAPI drives are
accessed via 'cd' device nodes. They can all be enumerated and manipulated
via camcontrol, just like SCSI drives. SCSI commands are not translated to
their ATA equivalents; ATA native commands are used throughout the entire
stack, including camcontrol. See the camcontrol manpage for further
details. Testing this code may require that you update your fstab, and
possibly modify your BIOS to enable AHCI functionality, if available.

This code is very experimental at the moment. The userland ABI/API has
changed, so applications will need to be recompiled. It may change
further in the near future. The 'ada' device name may also change as
more infrastructure is completed in this project. The goal is to
eventually put all CAM busses and devices until newbus, allowing for
interesting topology and management options.

Few functional changes will be seen with existing SCSI/SAS/FC drivers,
though the userland ABI has still changed. In the future, transports
specific modules for SAS and FC may appear in order to better support
the topologies and capabilities of these technologies.

The modularization of CAM and the addition of the ATA/SATA modules is
meant to break CAM out of the mold of being specific to SCSI, letting it
grow to be a framework for arbitrary transports and protocols. It also
allows drivers to be written to support discrete hardware without
jeopardizing the stability of non-related hardware. While only an AHCI
driver is provided now, a Silicon Image driver is also in the works.
Drivers for ICH1-4, ICH5-6, PIIX, classic IDE, and any other hardware
is possible and encouraged. Help with new transports is also encouraged.

Submitted by: scottl, mav
Approved by: re