Originally, libata required the illusion that it could access the sata
control register.  Now, however, it can run perfectly well without
them, so remove the dummy routines from libsas which tried to emulate
them (but only ended up causing confusion).
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

ATAPI check condition needs to be treated the same as a success or
protocol return.  The register returns from the PACKET command are all
correctly positioned in the device to host register FIS and so we
should collect them properly.  Right at the moment this doesn't matter
because libata sends a request sense always for ATAPI errors, but if
it ever checked the registers, we should have the correct contents
just in case.
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

sd will get hung up issuing commands to flush write cache if a SAS
device behind the expander is unplugged without warning.  Change libsas
to reject commands to domain devices that have already gone away.

[maciej.trela@intel.com: removed setting ->gone in sas_deform_port() to
 permit sync cache commands at module removal]
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Tested-by: NHaipao Fan <haipao.fan@intel.com>
Signed-off-by: NMaciej Trela <maciej.trela@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Some cards (like mvsas) have issue troubles if non-NCQ commands are
mixed with NCQ ones.  Fix this by using the libata default NCQ check
routine which waits until all NCQ commands are complete before issuing
a non-NCQ one.  The impact to cards (like aic94xx) which don't need
this logic should be minimal

Cc: Stable Tree <stable@kernel.org>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

We have two separate definitions for identical constants with nearly the
same name.  One comes from the generic headers in scsi.h; the other is
an enum in libsas.h ... it's causing confusion about which one is
correct (fortunately they both are).

Fix this by eliminating the libsas.h duplicate
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

commit 70b25f89
Author: Tejun Heo <tj@kernel.org>
Date:   Thu Apr 15 09:00:08 2010 +0900

    [SCSI] fix locking around blk_abort_request()

Introduced a reference before check problem, fix this by moving the
lock shorthand code to be right at the point of actual use.
Reported-by: NDan Carpenter <error27@gmail.com>
Acked-by: NTejun Heo <tj@kernel.org>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

blk_abort_request() expects queue lock to be held by the caller.
Grab it before calling the function.

Lack of this synchronization led to infinite loop on corrupt
q->timeout_list.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: stable@kernel.org
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

Right now SCSI and others do their own command timeout handling.
Move those bits to the block layer.

Instead of having a timer per command, we try to be a bit more clever
and simply have one per-queue. This avoids the overhead of having to
tear down and setup a timer for each command, so it will result in a lot
less timer fiddling.
Signed-off-by: NMike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Logically, SCR access ops should take @link; however, there was no
compelling reason to convert all SCR access ops when adding @link
abstraction as there's one-to-one mapping between a port and a non-PMP
link.  However, that assumption won't hold anymore with the scheduled
addition of slave link.

Make SCR access ops per-link.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

[jejb: fixed up a ton of missed conversions.

 All of you are on notice this has happened, driver trees will now
 need to be rebased]
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Cc: SCSI List <linux-scsi@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Now that SFF assumptions are separated out from non-SFF reset
sequence, port_ops->sff_dev_select() is no longer necessary for
non-SFF controllers.  Kill ata_noop_dev_select() and ->sff_dev_select
initialization from base and other non-SFF port_ops.
Signed-off-by: NTejun Heo <htejun@gmail.com>

Now that all SFF stuff is separated out of core layer, core layer
doesn't call ops->[alt_]check_status().  In fact, no one calls them
for non-SFF drivers anymore.  Kill them.
Signed-off-by: NTejun Heo <htejun@gmail.com>

Now that all SFF stuff is separated out of core layer, core layer
doesn't call ops->tf_read directly.  It gets called only via
ops->qc_fill_rtf() for non-SFF drivers.  This patch directly
implements private ops->qc_fill_rtf() for non-SFF controllers and kill
ops->tf_read().

This is much cleaner for non-SFF controllers as some of them have to
cache SFF register values in private data structure and report the
cached values via ops->tf_read().  Also, ops->tf_read() gets nasty for
controllers which don't have clear notion of TF registers when
operation is not in progress.

As this change makes default ops->qc_fill_rtf unnecessary, move
ata_sff_qc_fill_rtf() form ata_base_port_ops to ata_sff_port_ops where
it belongs.
Signed-off-by: NTejun Heo <htejun@gmail.com>

On command completion, ata_qc_complete() directly called ops->tf_read
to fill qc->result_tf.  This patch adds ops->qc_fill_rtf to replace
hardcoded ops->tf_read usage.

ata_sff_qc_fill_rtf() which uses ops->tf_read to fill result_tf is
implemented and set in ata_base_port_ops and other ops tables which
don't inherit from ata_base_port_ops, so this patch doesn't introduce
any behavior change.

ops->qc_fill_rtf() is similar to ops->sff_tf_read() but can only be
called when a command finishes.  As some non-SFF controllers don't
have TF registers defined unless they're associated with in-flight
commands, this limited operation makes life easier for those drivers
and help lifting SFF assumptions from libata core layer.
Signed-off-by: NTejun Heo <htejun@gmail.com>

Add sff_ prefix to SFF specific port ops.

This rename is in preparation of separating SFF support out of libata
core layer.  This patch strictly renames ops and doesn't introduce any
behavior difference.
Signed-off-by: NTejun Heo <htejun@gmail.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Once the phy reset is plumbed in properly, SATA error handling fails
nastily because we change the port attached_sas_address using the WWN
field of the IDENTIFY message.  This is a nice thing to do in theory,
but it really destroys hotplug because any event on the port causes an
automatic mismatch between the sas_address the phy just picked up and
the one we propagate into the port.  However ugly they are, we have to
stick with the sas addresses made up by the phys and expanders.

Also does a few cosmetic changes to the way port printing is done to
make it clearer how a port is formed.
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

that provided by the block layer

ATA requires that all DMA transfers begin and end on word boundaries.
Because of this, a large amount of machinery grew up in ide to adjust
scatterlists on this basis.  However, as of 2.5, the block layer has a
dma_alignment variable which ensures both the beginning and length of a
DMA transfer are aligned on the dma_alignment boundary.  Although the
block layer does adjust the beginning of the transfer to ensure this
happens, it doesn't actually adjust the length, it merely makes sure
that space is allocated for transfers beyond the declared length.  The
upshot of this is that scatterlists may be padded to any size between
the actual length and the length adjusted to the dma_alignment safely
knowing that memory is allocated in this region.

Right at the moment, SCSI takes the default dma_aligment which is on a
512 byte boundary.  Note that this aligment only applies to transfers
coming in from user space.  However, since all kernel allocations are
automatically aligned on a minimum of 32 byte boundaries, it is safe to
adjust them in this manner as well.

tj: * Adjusting sg after padding is done in block layer.  Make libata
      set queue alignment correctly for ATAPI devices and drop broken
      sg mangling from ata_sg_setup().
    * Use request->raw_data_len for ATAPI transfer chunk size.
    * Killed qc->raw_nbytes.
    * Separated out killing qc->n_iter.
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

libata used private sg iterator to handle padding sg.  Now that sg can
be chained, padding can be handled using standard sg ops.  Convert to
chained sg.

* s/qc->__sg/qc->sg/

* s/qc->pad_sgent/qc->extra_sg[]/.  Because chaining consumes one sg
  entry.  There need to be two extra sg entries.  The renaming is also
  for future addition of other extra sg entries.

* Padding setup is moved into ata_sg_setup_extra() which is organized
  in a way that future addition of other extra sg entries is easy.

* qc->orig_n_elem is unused and removed.

* qc->n_elem now contains the number of sg entries that LLDs should
  map.  qc->mapped_n_elem is added to carry the original number of
  mapped sgs for unmapping.

* The last sg of the original sg list is used to chain to extra sg
  list.  The original last sg is pointed to by qc->last_sg and the
  content is stored in qc->saved_last_sg.  It's restored during
  ata_sg_clean().

* All sg walking code has been updated.  Unnecessary assertions and
  checks for conditions the core layer already guarantees are removed.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

ATA_PROT_ATAPI_* are ugly and naming schemes between ATA_PROT_* and
ATA_PROT_ATAPI_* are inconsistent causing confusion.  Rename them to
ATAPI_PROT_* and make them consistent with ATA counterpart.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Implement protocol tests - ata_is_atapi(), ata_is_nodata(),
ata_is_pio(), ata_is_dma(), ata_is_ncq() and ata_is_data() and use
them to replace is_atapi_taskfile() and hard coded protocol tests.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

This is bad for two reasons:

     1. If they're returned to outside applications, no-one knows what
        they mean.
     2. Eventually they'll clash with the ever expanding standard error
        codes.

The problem error code in question is ETASK.  I've replaced this by
ECOMM (communications error on send) a network error code that seems to
most closely relay what ETASK meant.
Acked-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

It was always set to ata_port_disable().  Removed the hook, and replaced
the very few ap->ops->port_disable() callsites with direct calls to
ata_port_disable().
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Introduce ata_link.  It abstracts PHY and sits between ata_port and
ata_device.  This new level of abstraction is necessary to support
SATA Port Multiplier, which basically adds a bunch of links (PHYs) to
a ATA host port.  Fields related to command execution, spd_limit and
EH are per-link and thus moved to ata_link.

This patch only defines the host link.  Multiple link handling will be
added later.  Also, a lot of ap->link derefences are added but many of
them will be removed as each part is converted to deal directly with
ata_link instead of ata_port.

This patch introduces no behavior change.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Eliminate unnecessary PCI dependencies in libsas.  It should use generic
DMA and struct device like other subsystems.
Signed-off-by: NJeff Garzik <jeff@garzik.org>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Not everyone wants libsas automatically to pull in libata.  This patch
makes the behaviour configurable, so you can build libsas with or
without ATA support.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This fixes up the usage in libsas (which are easy to miss, since they're
only in the scsi-misc tree) ... and also corrects the documentation on
the point of what these two function pointers actually return.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.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>

The SATL should connect the scsi_cmnd to the sas_task (despite the presence
of libata) so that requests to abort scsi_cmnds headed to the ATA device
can be processed by the EH and aborted correctly.  The abort status should
still be propagated from sas -> ata -> scsi.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

When libsas encounters a STP device whose protocol isn't recognized (i.e.
not ATA or ATAPI), we should set the ata_device's class to ATA_DEV_UNKNOWN
instead of ATA_DEV_ATA.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

A sas_task sent to an ATAPI devices returns SAM_GOOD if successful.
Therefore, we should treat this the same way we treat ATA commands
that succeed.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Since the aic94xx sequencer assigns its own NCQ tags to ATA commands, it
no longer makes any sense to copy the sactive field in the STP response
to ata_port->sactive, as that will confuse libata.  Also, libata seems
to be capable of managing sactive on its own.

The attached patch gets rid of one of the causes of the BUG messages in
ata_qc_new, and seems to work without problems on an IBM x206m.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This patch adds a new field, lldd_task, to ata_queued_cmd so that libata
users such as libsas can associate some data with a qc.  The particular
ambition with this patch is to associate a sas_task with a qc; that way,
if libata decides to timeout a command, we can come back (in
sas_ata_post_internal) and abort the sas task.

One question remains: Is it necessary to reset the phy on error, or will
the libata error handler take care of it?  (Assuming that one is written,
of course.)  This patch, as it is today, works well enough to clean
things up when an ATA device probe attempt fails halfway through the probe,
though I'm not sure this is always the right thing to do.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

The sas_ata_qc_issue function was incorrectly written to return error
codes such as -ENOMEM.  Since libata OR's qc->err_mask with the
return value, It is necessary to make my code return one of the
AC_ERR_ codes instead.  For now, use AC_ERR_SYSTEM because an error
here means that the OS couldn't send the command to the controller.

If anybody has a suggestion for a better AC_ERR_ code to use, please
suggest it.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
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>