Annotate sas_queuecommand with locking details, and clean up a few
more sparse warnings about static/non-static declarations.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

ATA devices need special handling for sas_task_abort.  If the ATA command
came from SCSI, then we merely need to tell SCSI to abort the scsi_cmnd.
However, internal commands require a bit more work--we need to fill the qc
with the appropriate error status and complete the command, and eventually
post_internal will issue the actual ABORT TASK.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

ata_qc_complete and ata_sas_queuecmd require that the port lock be held
when they are called.  sas_ata doesn't do this, leading to BUG messages
about qc tags newly allocated qc tags already being in use.  This patch
fixes the locking, which should clean up the rest of those messages.

So far I've tested this against an IBM x206m with two SATA disks with no
BUG messages and no other signs of things going wrong, and the machine
finally passed the pounder stress test.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This is a respin of my earlier patch that migrates the ATA support code
into a separate file.  For now, the controversial linking bits have
been removed per James Bottomley's request for a patch that contains
only the migration diffs, which means that libsas continues to require
libata.  I intend to address that problem in a separate patch.

This patch is against the aic94xx-sas-2.6 git tree, and it has been
sanity tested on my x206m with Seagate SATA and SAS disks without
uncovering any new problems.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

We actually had two problems: the one with the tag (which is fixed by
zeroing the tag before sending the taskfile to the sequencer) but the
other with the fact that we sent our first NCQ command to the device
before the sequencer had been informed of the NCQ tagging
capabilities.  I fixed the latter by moving the rphy_add() to the
correct point in the code after the NCQ capabilities are set up.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

It turns out this is fairly easy to plumb in by recognising the three
command types and copying the CDB.  The protocol response path needs to
be amended to cope with SAS_PROTO_RESPONSE.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This patch adds SATAII NCQ support to libsas.  Both the use_ncq and the
dma_xfer flags in ata_task must be set for NCQ to work correctly on the
Adaptec SAS controller.  The rest of the patch adds ATA_FLAG_NCQ to
sata_port_info and sets up ap->scsi_host so that ata_setup_ncq doesn't
crash.  Please note that this patch is against the aic94xx-sas git tree,
not scsi-misc.  Thanks also to James Bottomley for providing an earlier
version of this patch from which to work.

I've tested this patch on a x206m with a ST380819AS SATA2 disk plugged
into the Adaptec SAS controller.  The drive came up with a queue depth
of 31, and I successfully ran an I/O flood test to coerce libata into
sending multiple commands simultaneously.  A kernel probe recorded the
maximum tag number that had been seen before and after the flood test;
before the test it was 2 and after it was 30, as I expected.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Hook the scsi_host_template functions in libsas to delegate
functionality to libata when appropriate.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>

Misc code changes and merge fixes and update for libata->drivers/ata
move
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Currently, the freezer treats all tasks as freezable, except for the kernel
threads that explicitly set the PF_NOFREEZE flag for themselves.  This
approach is problematic, since it requires every kernel thread to either
set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't
care for the freezing of tasks at all.

It seems better to only require the kernel threads that want to or need to
be frozen to use some freezer-related code and to remove any
freezer-related code from the other (nonfreezable) kernel threads, which is
done in this patch.

The patch causes all kernel threads to be nonfreezable by default (ie.  to
have PF_NOFREEZE set by default) and introduces the set_freezable()
function that should be called by the freezable kernel threads in order to
unset PF_NOFREEZE.  It also makes all of the currently freezable kernel
threads call set_freezable(), so it shouldn't cause any (intentional)
change of behaviour to appear.  Additionally, it updates documentation to
describe the freezing of tasks more accurately.

[akpm@linux-foundation.org: build fixes]
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NNigel Cunningham <nigel@nigel.suspend2.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

- convert to use the new accessors for the sg lists and the
parameters.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

After discussion with andmike and dougg, it seems that the purpose of
eh_device_reset_handler is to issue LU resets, and that
eh_bus_reset_handler would be a more appropriate place for a phy reset.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Why TASK_ATTR_HOQ?
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Set allow_restart=1 for all SAS disks so that they are spun up when needed.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This patch moves the code that handles SAS failures out of the main EH
function and into a separate function.  It also detects commands that have
no sas_task (i.e. they completed, but with error data) and sends them into
scsi_error for processing.  This allows us to handle SCSI errors (and
enables auto-spinup as a side effect) instead of dropping them on the
floor and falling into an infinite loop.  It also requires the
implementation of a device reset function, which the SAS failure code has
been modified to employ for REQ_DEVICE_RESET.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

The EH should fall into I_T recovery (and potentially stronger
remedies) if ABORT TASK fails.
Signed-off-by: NAlexis Bruemmer <alexisb@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Convert the phy port locks to use irq spinlocks.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

sas_task_abort() should simply abort the upper-level SCSI command and wait
until the error handler to send the actual ABORT TASK command.  By
deferring things to the EH we simplify the concurrency coordination and
eliminate some race conditions.  Note that sas_task_abort has a few hooks
to handle libsas internal commands properly too.

Also rename do_sas_task_abort to __sas_task_abort just in case we really
want to abort the task *right now* and we don't have a scsi_cmnd attached
to the command.  This is a hook for libata internal commands to abort.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

When a SAS LLDD needs to request a device port reset, it needs to have all
commands aborted before it can reset the port.  Since commands are put on
the EH's list in the order that they were queued, the LLDD can set a "need
reset" flag in the last task to be aborted so that the EH can reset the
port after all commands are aborted.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This flag is no longer necessary because we push tasks to be aborted into
the EH as soon as we possibly can, and let the SCSI EH code take care of
the coordination for which this flag was used.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Every so often, a scsi_cmnd will time out, and the libsas timeout handler
will discover that the scsi_cmnd does not have a sas_task attached to it.
This can happen in two cases: (1) the scsi_cmnd actually made it through
libsas to the HBA and is now going through scsi_done, or (2) the
scsi_cmnd has been held up (host lock, slab alloc, etc) and libsas has
not yet attached a sas_task.  In both cases, it is safe to ask SCSI for
more time to process the command via EH_RESET_TIMER; we cannot blindly
return EH_HANDLED because if (2) happens, we could end up calling
scsi_done while another CPU is heading towards sas_queuecommand, which
causes slab corruption when sas_task_done updates the freed scsi_cmnd.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This patch lets a user arbitrarily enable or disable a phy via sysfs.
Potential applications include shutting down a phy to replace one
lane of wide port, and (more importantly) providing a method for the
libata SATL to control the phy.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

[SCSI] libsas: Don't give scsi_cmnds to the EH if they never made it to the SAS LLDD or have already returned

On a system with many SAS targets, it appears possible that a scsi_cmnd
can time out without ever making it to the SAS LLDD or at the same time
that a completion is occurring.  In both of these cases, telling the
LLDD to abort the sas_task makes no sense because the LLDD won't know
about the sas_task; what we really want to do is to increase the timer.
Note that this involves creating another sas_task bit to indicate
whether or not the task has been sent to the LLDD; I could have
implemented this by slightly redefining SAS_TASK_STATE_PENDING, but
this way seems cleaner.

This second version amends the aic94xx portion to set the
TASK_AT_INITIATOR flag for all sas_tasks that were passed to
lldd_execute_task.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-Off-By: NDavid Howells <dhowells@redhat.com>

This patch implements a REQ_DEVICE_RESET handler for the aic94xx
driver.  Like the earlier REQ_TASK_ABORT patch, this patch defers the
device reset to the Scsi_Host's workqueue, which has the added benefit
of ensuring that the device reset does not happen at the same time
that the abort tmfs are being processed.  After the phy reset, the
busted drive should go away and be re-detected later, which is indeed
what I've seen on both a x260 and a x206m.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This patch adds an external function, sas_abort_task, to enable LLDDs
to abort sas_tasks.  It also adds a work_struct so that the actual
work of aborting a task can be shifted from tasklet context (in the
LLDD) onto the scsi_host's workqueue.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This patch adds an EH done queue to sas_ha, converts the error handling
strategy function and the sas_scsi_task_done functions in libsas to use
the scsi_eh_* commands for error'd commands, and adds checks for the
INITIATOR_ABORTED flag so that we do the right thing if a sas_task has
been aborted by the initiator.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

The ->flags in struct request was split into two variables, in a recent
changeset.  The merge of this change forgot to update SCSI's libsas,
probably because libsas was a very recent merge.
Signed-off-by: NJeff Garzik <jeff@garzik.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This is the end point of the separate aic94xx driver based on the
original driver and transport class from Luben Tuikov
<ltuikov@yahoo.com>

The log of the separate development is:

Alexis Bruemmer:
  o aic94xx: fix hotplug/unplug for expanderless systems
  o aic94xx: disable split completion timer/setting by default
  o aic94xx: wide port off expander support
  o aic94xx: remove various inline functions
  o aic94xx: use bitops
  o aic94xx: remove queue comment
  o aic94xx: remove sas_common.c
  o aic94xx: sas remove depot's
  o aic94xx: use available list_for_each_entry_safe_reverse()
  o aic94xx: sas header file merge

James Bottomley:
  o aic94xx: fix TF_TMF_NO_CTX processing
  o aic94xx: convert to request_firmware interface
  o aic94xx: fix hotplug/unplug
  o aic94xx: add link error counts to the expander phys
  o aic94xx: add transport class phy reset capability
  o aic94xx: remove local_attached flag
  o Remove README
  o Fixup Makefile variable for libsas rename
  o Rename sas->libsas
  o aic94xx: correct return code for sas_discover_event
  o aic94xx: use parent backlink port
  o aic94xx: remove channel abstraction
  o aic94xx: fix routing algorithms
  o aic94xx: add backlink port
  o aic94xx: fix cascaded expander properties
  o aic94xx: fix sleep under lock
  o aic94xx: fix panic on module removal in complex topology
  o aic94xx: make use of the new sas_port
  o rename sas_port to asd_sas_port
  o Fix for eh_strategy_handler move
  o aic94xx: move entirely over to correct transport class formulation
  o remove last vestages of sas_rphy_alloc()
  o update for eh_timed_out move
  o Preliminary expander support for aic94xx
  o sas: remove event thread
  o minor warning cleanups
  o remove last vestiges of id mapping arrays
  o Further updates
  o Convert aic94xx over entirely to the transport class end device and
  o update aic94xx/sas to use the new sas transport class end device
  o [PATCH] aic94xx: attaching to the sas transport class
  o Add missing completion removal from prior patch
  o [PATCH] aic94xx: attaching to the sas transport class
  o Build fixes from akpm

Jeff Garzik:
  o [scsi aic94xx] Remove ->owner from PCI info table

Luben Tuikov:
  o initial aic94xx driver

Mike Anderson:
  o aic94xx: fix panic on module insertion
  o aic94xx: stub out SATA_DEV case
  o aic94xx: compile warning cleanups
  o aic94xx: sas_alloc_task
  o aic94xx: ref count update
  o aic94xx nexus loss time value
  o [PATCH] aic94xx: driver assertion in non-x86 BIOS env

Randy Dunlap:
  o libsas: externs not needed

Robert Tarte:
  o aic94xx: sequence patch - fixes SATA support
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>