libsas fails to discover all sata devices in the domain.  If a device fails
negotiation and does not transmit a signature fis the link needs recovery.
libata already understands how to manage slow to come up links, so treat these
conditions as ata device attach events for the purposes of creating an
ata_port.  This allows libata to manage retrying link bring up.

Rediscovery is modified to be careful about checking changes in dev_type.  It
looks like libsas leaks old devices if the sas address changes, but that's a
fix for another patch.
Acked-by: NJack Wang <jack_wang@usish.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Holdover from a patch rework, prior to the addition of SAS_DEV_DESTROY
we were holding a reference while the destruct was pending in case the
domain was torn down before the desctruct event ran.  That case is
covered by SAS_DEV_DESTROY, and the sas_put_device() just corrupts freed
memory, or worse frees the memory while another agent holds a reference.
Signed-off-by: NMaciej Trela <maciej.trela@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

ata_port lifetime in libata follows the host.  In libsas it follows the
scsi_target.  Once scsi_remove_device() has caused all commands to be
completed it allows scsi_remove_target() to immediately proceed to
freeing the ata_port causing bug reports like:

[  848.393333] BUG: spinlock bad magic on CPU#4, kworker/u:2/5107
[  848.400262] general protection fault: 0000 [#1] SMP
[  848.406244] CPU 4
[  848.408310] Modules linked in: nls_utf8 ipv6 uinput i2c_i801 i2c_core iTCO_wdt iTCO_vendor_support ioatdma dca sg sd_mod sr_mod cdrom ahci libahci isci libsas libata scsi_transport_sas [last unloaded: scsi_wait_scan]
[  848.432060]
[  848.434137] Pid: 5107, comm: kworker/u:2 Not tainted 3.2.0-isci+ #8 Intel Corporation S2600CP/S2600CP
[  848.445310] RIP: 0010:[<ffffffff8126a68c>]  [<ffffffff8126a68c>] spin_dump+0x5e/0x8c
[  848.454787] RSP: 0018:ffff8807f868dca0  EFLAGS: 00010002
[  848.461137] RAX: 0000000000000048 RBX: ffff8807fe86a630 RCX: ffffffff817d0be0
[  848.469520] RDX: 0000000000000000 RSI: ffffffff814af1cf RDI: 0000000000000002
[  848.477959] RBP: ffff8807f868dcb0 R08: 00000000ffffffff R09: 000000006b6b6b6b
[  848.486327] R10: 000000000003fb8c R11: ffffffff81a19448 R12: 6b6b6b6b6b6b6b6b
[  848.494699] R13: ffff8808027dc520 R14: 0000000000000000 R15: 000000000000001e
[  848.503067] FS:  0000000000000000(0000) GS:ffff88083fd00000(0000) knlGS:0000000000000000
[  848.512899] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  848.519710] CR2: 00007ff77d001000 CR3: 00000007f7a5d000 CR4: 00000000000406e0
[  848.528072] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  848.536446] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  848.544831] Process kworker/u:2 (pid: 5107, threadinfo ffff8807f868c000, task ffff8807ff348000)
[  848.555327] Stack:
[  848.557959]  ffff8807fe86a630 ffff8807fe86a630 ffff8807f868dcd0 ffffffff8126a6e0
[  848.567072]  ffffffff817c142f ffff8807fe86a630 ffff8807f868dcf0 ffffffff8126a703
[  848.576190]  ffff8808027dc520 0000000000000286 ffff8807f868dd10 ffffffff814af1bb
[  848.585281] Call Trace:
[  848.588409]  [<ffffffff8126a6e0>] spin_bug+0x26/0x28
[  848.594357]  [<ffffffff8126a703>] do_raw_spin_unlock+0x21/0x88
[  848.601283]  [<ffffffff814af1bb>] _raw_spin_unlock_irqrestore+0x2c/0x65
[  848.609089]  [<ffffffffa001c103>] ata_scsi_port_error_handler+0x548/0x557 [libata]
[  848.618331]  [<ffffffff81061813>] ? async_schedule+0x17/0x17
[  848.625060]  [<ffffffffa004f30f>] async_sas_ata_eh+0x45/0x69 [libsas]
[  848.632655]  [<ffffffff810618aa>] async_run_entry_fn+0x97/0x125
[  848.639670]  [<ffffffff81057439>] process_one_work+0x207/0x38d
[  848.646577]  [<ffffffff8105738c>] ? process_one_work+0x15a/0x38d
[  848.653681]  [<ffffffff810576f7>] worker_thread+0x138/0x21c
[  848.660305]  [<ffffffff810575bf>] ? process_one_work+0x38d/0x38d
[  848.667493]  [<ffffffff8105b098>] kthread+0x9d/0xa5
[  848.673382]  [<ffffffff8106e1bd>] ? trace_hardirqs_on_caller+0x12f/0x166
[  848.681304]  [<ffffffff814b7704>] kernel_thread_helper+0x4/0x10
[  848.688324]  [<ffffffff814af534>] ? retint_restore_args+0x13/0x13
[  848.695530]  [<ffffffff8105affb>] ? __init_kthread_worker+0x5b/0x5b
[  848.702929]  [<ffffffff814b7700>] ? gs_change+0x13/0x13
[  848.709155] Code: 00 00 48 8d 88 38 04 00 00 44 8b 80 84 02 00 00 31 c0 e8 cf 1b 24 00 41 83 c8 ff 44 8b 4b 08 48 c7 c1 e0 0b 7d 81 4d 85 e4 74 10 <45> 8b 84 24 84 02 00 00 49 8d 8c 24 38 04 00 00 8b 53 04 48 89
[  848.732467] RIP  [<ffffffff8126a68c>] spin_dump+0x5e/0x8c
[  848.738905]  RSP <ffff8807f868dca0>
[  848.743743] ---[ end trace 143161646eee8caa ]---

...so arrange for the ata_port to have the same end of life as the domain
device.
Reported-by: NMarcin Tomczak <marcin.tomczak@intel.com>
Acked-by: NJeff Garzik <jgarzik@redhat.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

If the top level expander is hot removed, mark all child devices as gone
before unregistration to short circuit futile recovery.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

In the direct-attached case this routine returns the phy on which this
device was first discovered.  Which is broken if we want to support
wide-targets, as this phy reference can become stale even though the
port is still active.

In the expander-attached case this routine tries to lookup the phy by
scanning the attached sas addresses of the parent expander, and BUG_ONs
if it can't find it.  However since eh and the libsas workqueue run
independently we can still be attempting device recovery via eh after
libsas has recorded the device as detached.  This is even easier to hit
now that eh is blocked while device domain rediscovery takes place, and
that libata is fed more timed out commands increasing the chances that
it will try to recover the ata device.

Arrange for dev->phy to always point to a last known good phy, it may be
stale after the port is torn down, but it will catch up for wide port
reconfigurations, and never be NULL.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

SAS does not tag SMP requests, and at least one lldd (isci) does not permit
more than one in-flight request at a time.

[jejb: fix sas_init_dev tab issues while we're at it]
Signed-off-by: NJeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

sas_discover_sata() notifies lldds of sata devices twice.  Once to allow
the 'identify' to be sent, and a second time to allow aic94xx (the only
libsas driver that cares about sata_dev.identify) to setup NCQ
parameters before the device becomes known to the midlayer.  Replace
this double notification and intervening 'identify' with an explicit
->lldd_ata_set_dmamode notification.  With this change all ata internal
commands are issued by libata, so we no longer need sas_issue_ata_cmd().

The data from the identify command only needs to be cached in one
location so ata_device.id replaces domain_device.sata_dev.identify.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

libata error handling provides for a timeout for link recovery.  libsas
must not rescan for previously known devices in this interval otherwise
it may remove a device that is simply waiting for its link to recover.
Let libata-eh make the determination of when the link is stable and
prevent libsas (host workqueue) from taking action while this
determination is pending.

Using a mutex (ha->disco_mutex) to flush and disable revalidation while
eh is running requires any discovery action that may block on eh be
moved to its own context outside the lock.  Probing ATA devices
explicitly waits on ata-eh and the cache-flush-io issued during device
removal may also pend awaiting eh completion.  Essentially any rphy
add/remove activity needs to run outside the lock.

This adds two new cleanup states for sas_unregister_domain_devices()
'allocated-but-not-probed', and 'flagged-for-destruction'.  In the
'allocated-but-not-probed' state  dev->rphy points to a rphy that is
known to have not been through a sas_rphy_add() event.  At domain
teardown check if this device is still pending probe and cleanup
accordingly.  Similarly if a device has already been queued for removal
then sas_unregister_domain_devices has nothing to do.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

When an lldd invokes ->notify_port_event() it can trigger a chain of libsas
events to:

  1/ form the port and find the direct attached device

  2/ if the attached device is an expander perform domain discovery

A call to flush_workqueue() will only flush the initial port formation work.
Currently libsas users need to call scsi_flush_work() up to the max depth of
chain (which will grow from 2 to 3 when ata discovery is moved to its own
discovery event).  Instead of open coding multiple calls switch to use
drain_workqueue() to flush sas work.

drain_workqueue() does not handle new work submitted during the drain so
libsas needs a bit of infrastructure to hold off unchained work submissions
while a drain is in flight.  A lldd ->notify() event is considered 'unchained'
while a sas_discover_event() is 'chained'.  As Tejun notes:

  "For now, I think it would be best to add private wrapper in libsas to
   support deferring unchained work items while draining."
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

The locks only served to make sure the pending event bitmask was updated
consistently.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

These are never freed in the nominal path.  A domain_device has a
different lifetime than a sas_rphy we need a dev->rphy independent way
of identifying sata devices.
Reviewed-by: NJack Wang <jack_wang@usish.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Arrange for the deallocation of a struct domain_device object when it no
longer has:
1/ any children
2/ references by any scsi_targets
3/ references by a lldd

The comment about domain_device lifetime in
Documentation/scsi/libsas.txt is stale as it appears mainline never had
a version of a struct domain_device that was registered as a kobject.
We now manage domain_device reference counts on behalf of external
agents.
Reviewed-by: NJack Wang <jack_wang@usish.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

port->dev_list maintains a list of devices attached to a given sas root port.
It needs to be mutated under a lock as contexts outside of the
single-threaded-libsas-workqueue access the list via sas_find_dev_by_rphy().
Fixup locations where the list was being mutated without a lock.

This is a follow-up to commit 5911e963 "[SCSI] libsas: remove expander
from dev list on error", where Luben noted [1]:

    > 2/ We have unlocked list manipulations in sas_ex_discover_end_dev(),
    > sas_unregister_common_dev(), and sas_ex_discover_end_dev()

    Yes, I can see that and that is very unfortunate.

[1]: http://marc.info/?l=linux-scsi&m=131480962006471&w=2Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

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>

[jejb: limit ioctl to returning 20 characters to avoid overrun
       on long device names and add a few more conversions]
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

We give a very cryptic error if an ATA device is seen on a SAS port
but libsas isn't compiled to include libata to handle them.  Add an
extra warning to explain specifically what the problem is.
Acked-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

sparse complains about the mixing of enums in libsas.  Since the
underlying numeric values of both enums are the same, combine them
to get rid of the warning.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The task_struct->pid member is going to be deprecated, so start
using the helpers (task_pid_nr/task_pid_vnr/task_pid_nr_ns) in
the kernel.

The first thing to start with is the pid, printed to dmesg - in
this case we may safely use task_pid_nr(). Besides, printks produce
more (much more) than a half of all the explicit pid usage.

[akpm@linux-foundation.org: git-drm went and changed lots of stuff]
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Cc: Dave Airlie <airlied@linux.ie>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.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>

lockdep noticed that with ATA support the port->dev_list_lock was
entangled at irq context, so it now needs to become IRQ safe
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This one was noticed by Gilbert Wu of Adaptec:

The libata core actually does the DMA mapping for you, so there has to
be an exception in the device drivers that *don't* do dma mapping for
ATA commands.  However, since we've already done this, libsas must now
dma map any ATA commands that it wishes to issue ... and yes, this is a
horrible mess.

Additionally, the test in aic94xx for ATA protocols isn't quite right.
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>

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>

sas_rphy_delete does two things: it removes the sas_rphy from the transport
layer and frees the sas_rphy.  This can be broken down into two functions,
sas_rphy_remove and sas_rphy_free; sas_rphy_remove is of interest to
sas_discover_root_expander because it calls functions that require
sas_rphy_add as a prerequisite and can fail (namely sas_discover_expander).
In that case, sas_discover_root_expander needs to be able to undo the effects
of sas_rphy_add yet leave the job of freeing the sas_rphy to the caller of
sas_discover_root_expander.

This patch also removes some unnecessary code from sas_discover_end_dev
to eliminate an unnecessary cycle of sas_notify_lldd_gone/found for SAS
devices, thus eliminating a sas_rphy_remove call (and fixing a race condition
where a SCSI target scan can come in between the gone and found call).
It also moves the sas_rphy_free calls into sas_discover_domain and
sas_ex_discover_end_dev to complement the sas_rphy_allocation via
sas_get_port_device.

This patch does not change the semantics of sas_rphy_delete.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Track sas_ha_struct state so that we ignore events that come in while
we're shutting things down.
Signed-off-by: NMalahal Naineni <malahal@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

sas_get_port_device assigns a rphy to a domain device in anticipation
of finding a disk.  When a discovery error occurs in
sas_discover_{sata,sas,expander}*, however, we need to clean up that
rphy and the port device list so that we don't GPF.  In addition, we
need to check the result of the second sas_notify_lldd_dev_found.
This patch seems ok on a x260, x366 and x206m.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Fix up for make allyesconfig.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>

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>