* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: remove in_workqueue_context()
  workqueue: Clarify that schedule_on_each_cpu is synchronous
  memory_hotplug: drop spurious calls to flush_scheduled_work()
  shpchp: update workqueue usage
  pciehp: update workqueue usage
  isdn/eicon: don't call flush_scheduled_work() from diva_os_remove_soft_isr()
  workqueue: add and use WQ_MEM_RECLAIM flag
  workqueue: fix HIGHPRI handling in keep_working()
  workqueue: add queue_work and activate_work trace points
  workqueue: prepare for more tracepoints
  workqueue: implement flush[_delayed]_work_sync()
  workqueue: factor out start_flush_work()
  workqueue: cleanup flush/cancel functions
  workqueue: implement alloc_ordered_workqueue()

Fix up trivial conflict in fs/gfs2/main.c as per Tejun

* 'for-2.6.37/misc' of git://git.kernel.dk/linux-2.6-block:
  pipe: fix failure to return error code on ->confirm()

* 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block: (46 commits)
  xen-blkfront: disable barrier/flush write support
  Added blk-lib.c and blk-barrier.c was renamed to blk-flush.c
  block: remove BLKDEV_IFL_WAIT
  aic7xxx_old: removed unused 'req' variable
  block: remove the BH_Eopnotsupp flag
  block: remove the BLKDEV_IFL_BARRIER flag
  block: remove the WRITE_BARRIER flag
  swap: do not send discards as barriers
  fat: do not send discards as barriers
  ext4: do not send discards as barriers
  jbd2: replace barriers with explicit flush / FUA usage
  jbd2: Modify ASYNC_COMMIT code to not rely on queue draining on barrier
  jbd: replace barriers with explicit flush / FUA usage
  nilfs2: replace barriers with explicit flush / FUA usage
  reiserfs: replace barriers with explicit flush / FUA usage
  gfs2: replace barriers with explicit flush / FUA usage
  btrfs: replace barriers with explicit flush / FUA usage
  xfs: replace barriers with explicit flush / FUA usage
  block: pass gfp_mask and flags to sb_issue_discard
  dm: convey that all flushes are processed as empty
  ...

* 'for-2.6.37/drivers' of git://git.kernel.dk/linux-2.6-block: (95 commits)
  cciss: fix PCI IDs for new Smart Array controllers
  drbd: add race-breaker to drbd_go_diskless
  drbd: use dynamic_dev_dbg to optionally log uuid changes
  dynamic_debug.h: Fix dynamic_dev_dbg() macro if CONFIG_DYNAMIC_DEBUG not set
  drbd: cleanup: change "<= 0" to "== 0"
  drbd: relax the grace period of the md_sync timer again
  drbd: add some more explicit drbd_md_sync
  drbd: drop wrong debug asserts, fix recently introduced race
  drbd: cleanup useless leftover warn/error printk's
  drbd: add explicit drbd_md_sync to drbd_resync_finished
  drbd: Do not log an ASSERT for P_OV_REQUEST packets while C_CONNECTED
  drbd: fix for possible deadlock on IO error during resync
  drbd: fix unlikely access after free and list corruption
  drbd: fix for spurious fullsync (uuids rotated too fast)
  drbd: allow for explicit resync-finished notifications
  drbd: preparation commit, using full state in receive_state()
  drbd: drbd_send_ack_dp must not rely on header information
  drbd: Fix regression in recv_bm_rle_bits (compressed bitmap)
  drbd: Fixed a stupid copy and paste error
  drbd: Allow larger values for c-fill-target.
  ...

Fix up trivial conflict in drivers/block/ataflop.c due to BKL removal

* 'for-2.6.37/core' of git://git.kernel.dk/linux-2.6-block: (39 commits)
  cfq-iosched: Fix a gcc 4.5 warning and put some comments
  block: Turn bvec_k{un,}map_irq() into static inline functions
  block: fix accounting bug on cross partition merges
  block: Make the integrity mapped property a bio flag
  block: Fix double free in blk_integrity_unregister
  block: Ensure physical block size is unsigned int
  blkio-throttle: Fix possible multiplication overflow in iops calculations
  blkio-throttle: limit max iops value to UINT_MAX
  blkio-throttle: There is no need to convert jiffies to milli seconds
  blkio-throttle: Fix link failure failure on i386
  blkio: Recalculate the throttled bio dispatch time upon throttle limit change
  blkio: Add root group to td->tg_list
  blkio: deletion of a cgroup was causes oops
  blkio: Do not export throttle files if CONFIG_BLK_DEV_THROTTLING=n
  block: set the bounce_pfn to the actual DMA limit rather than to max memory
  block: revert bad fix for memory hotplug causing bounces
  Fix compile error in blk-exec.c for !CONFIG_DETECT_HUNG_TASK
  block: set the bounce_pfn to the actual DMA limit rather than to max memory
  block: Prevent hang_check firing during long I/O
  cfq: improve fsync performance for small files
  ...

Fix up trivial conflicts due to __rcu sparse annotation in include/linux/genhd.h

* 'linux-next' of git://git.infradead.org/ubi-2.6:
  UBI: tighten the corrupted PEB criteria
  UBI: fix check_data_ff return code
  UBI: remember copy_flag while scanning
  UBI: preserve corrupted PEBs
  UBI: add truly corrupted PEBs to corrupted list
  UBI: introduce debugging helper function
  UBI: make check_pattern function non-static
  UBI: do not put eraseblocks to the corrupted list unnecessarily
  UBI: separate out corrupted list
  UBI: change cascade of ifs to switch statements
  UBI: rename a local variable
  UBI: handle bit-flips when no header found
  UBI: remove duplicate IO error codes
  UBI: rename IO error code
  UBI: fix small 80 characters limit style issue
  UBI: cleanup and simplify Kconfig

* 'linux-next' of git://git.infradead.org/ubifs-2.6:
  UBIFS: do not allocate unneeded scan buffer
  UBIFS: do not forget to cancel timers
  UBIFS: remove a bit of unneeded code
  UBIFS: add a commentary about log recovery
  UBIFS: avoid kernel error if ubifs superblock read fails
  UBIFS: introduce new flags for RO mounts
  UBIFS: introduce new flag for RO due to errors
  UBIFS: check return code of pnode_lookup
  UBIFS: check return code of ubifs_lpt_lookup
  UBIFS: improve error reporting when reading bad node
  UBIFS: introduce list sorting debugging checks
  UBIFS: fix assertion warnings in comparison function
  UBIFS: mark unused key objects as invalid
  UBIFS: do not write rubbish into truncation scanning node
  UBIFS: improve assertion in node comparison functions
  UBIFS: do not use key type in list_sort
  UBIFS: do not look up truncation nodes
  UBIFS: fix assertion warning
  UBIFS: do not treat ENOSPC specially
  UBIFS: switch to RO mode after synchronizing

* 'urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/brodo/pcmcia-2.6:
  pcmcia: fix ni_daq_700 compilation
  pcmcia: IOCARD is also required for using IRQs

* git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  asm-generic/io.h: allow people to override individual funcs
  bitops: remove duplicated extern declarations
  bitops: make asm-generic/bitops/find.h more generic
  asm-generic: kdebug.h: Checkpatch cleanup
  asm-generic: fcntl: make exported headers use strict posix types
  asm-generic: cmpxchg does not handle non-long arguments
  asm-generic: make atomic_add_unless a function

* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
  vfs: make no_llseek the default
  vfs: don't use BKL in default_llseek
  llseek: automatically add .llseek fop
  libfs: use generic_file_llseek for simple_attr
  mac80211: disallow seeks in minstrel debug code
  lirc: make chardev nonseekable
  viotape: use noop_llseek
  raw: use explicit llseek file operations
  ibmasmfs: use generic_file_llseek
  spufs: use llseek in all file operations
  arm/omap: use generic_file_llseek in iommu_debug
  lkdtm: use generic_file_llseek in debugfs
  net/wireless: use generic_file_llseek in debugfs
  drm: use noop_llseek

* 'vfs' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl: (30 commits)
  BKL: remove BKL from freevxfs
  BKL: remove BKL from qnx4
  autofs4: Only declare function when CONFIG_COMPAT is defined
  autofs: Only declare function when CONFIG_COMPAT is defined
  ncpfs: Lock socket in ncpfs while setting its callbacks
  fs/locks.c: prepare for BKL removal
  BKL: Remove BKL from ncpfs
  BKL: Remove BKL from OCFS2
  BKL: Remove BKL from squashfs
  BKL: Remove BKL from jffs2
  BKL: Remove BKL from ecryptfs
  BKL: Remove BKL from afs
  BKL: Remove BKL from USB gadgetfs
  BKL: Remove BKL from autofs4
  BKL: Remove BKL from isofs
  BKL: Remove BKL from fat
  BKL: Remove BKL from ext2 filesystem
  BKL: Remove BKL from do_new_mount()
  BKL: Remove BKL from cgroup
  BKL: Remove BKL from NTFS
  ...

* 'trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
  block: autoconvert trivial BKL users to private mutex
  drivers: autoconvert trivial BKL users to private mutex
  ipmi: autoconvert trivial BKL users to private mutex
  mac: autoconvert trivial BKL users to private mutex
  mtd: autoconvert trivial BKL users to private mutex
  scsi: autoconvert trivial BKL users to private mutex

Fix up trivial conflicts (due to addition of private mutex right next to
deletion of a version string) in drivers/char/pcmcia/cm40[04]0_cs.c

* 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
  BKL: introduce CONFIG_BKL.
  dabusb: remove the BKL
  sunrpc: remove the big kernel lock
  init/main.c: remove BKL notations
  blktrace: remove the big kernel lock
  rtmutex-tester: make it build without BKL
  dvb-core: kill the big kernel lock
  dvb/bt8xx: kill the big kernel lock
  tlclk: remove big kernel lock
  fix rawctl compat ioctls breakage on amd64 and itanic
  uml: kill big kernel lock
  parisc: remove big kernel lock
  cris: autoconvert trivial BKL users
  alpha: kill big kernel lock
  isapnp: BKL removal
  s390/block: kill the big kernel lock
  hpet: kill BKL, add compat_ioctl

Reported-by: Anca Emanuel <anca.emanuel@gmail.com>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

* 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, 32-bit: Align percpu area and irq stacks to THREAD_SIZE
  x86: Move alloc_desk_mask variables inside ifdef
  x86-32: Align IRQ stacks properly
  x86: Remove CONFIG_4KSTACKS
  x86: Always use irq stacks

Fixed up trivial conflicts in include/linux/{irq.h, percpu-defs.h}

Merge branch 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Hpet: Avoid the comparator readback penalty

Fortunately this is only exploitable on very unusual hardware.

[Reported a while ago but nothing happened so just fixing it]
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The driver doesn't handle empty flushes. Disable barrier/flush
write support until this is fixed up.
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

- Andi encountedred following warning with gcc 4.5

  linux/block/cfq-iosched.c: In function ‘cfq_dispatch_requests’:
  linux/block/cfq-iosched.c:2156:3: warning: array subscript is above array
  bounds

- Warning happens due to following code.

  slice = group_slice * count /
		max_t(unsigned, cfqg->busy_queues_avg[cfqd->serving_prio],
		cfq_group_busy_queues_wl(cfqd->serving_prio, cfqd, cfqg));

  gcc is complaining about cfqg->busy_queues_avg[] being indexed by CFQ
  prio classes (RT, BE and IDLE) while the array size is only 2.

- At run time, we never access cfqg->busy_queues_avg[IDLE] and return from
  function before this code hits.

- To fix warning increase the array size though it will remain unused. This
  patch also puts some comments to clarify some of the confusions.

- I have taken Jens's patch and modified it a bit.

- Compile tested with gcc 4.4 and boot tested. I don't have gcc 4.5
  running, Andi can you please test it with gcc 4.5 to make sure it
  worked.
Reported-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

Dave Hinds pointed out to me that 37979e15 will break b43 and
ray_cs, as IOCARD is not -- as the name would suggest -- only needed
for cards using IO ports. Instead, as it re-deines several pins, it
is also required for using interrupts.
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (71 commits)
  powerpc/44x: Update ppc44x_defconfig
  powerpc/watchdog: Make default timeout for Book-E watchdog a Kconfig option
  fsl_rio: Add comments for sRIO registers.
  powerpc/fsl-booke: Add e55xx (64-bit) smp defconfig
  powerpc/fsl-booke: Add p5020 DS board support
  powerpc/fsl-booke64: Use TLB CAMs to cover linear mapping on FSL 64-bit chips
  powerpc/fsl-booke: Add support for FSL Arch v1.0 MMU in setup_page_sizes
  powerpc/fsl-booke: Add support for FSL 64-bit e5500 core
  powerpc/85xx: add cache-sram support
  powerpc/85xx: add ngPIXIS FPGA device tree node to the P1022DS board
  powerpc: Fix compile error with paca code on ppc64e
  powerpc/fsl-booke: Add p3041 DS board support
  oprofile/fsl emb: Don't set MSR[PMM] until after clearing the interrupt.
  powerpc/fsl-booke: Add PCI device ids for P2040/P3041/P5010/P5020 QoirQ chips
  powerpc/mpc8xxx_gpio: Add support for 'qoriq-gpio' controllers
  powerpc/fsl_booke: Add support to boot from core other than 0
  powerpc/p1022: Add probing for individual DMA channels
  powerpc/fsl_soc: Search all global-utilities nodes for rstccr
  powerpc: Fix invalid page flags in create TLB CAM path for PTE_64BIT
  powerpc/mpc83xx: Support for MPC8308 P1M board
  ...

Fix up conflict with the generic irq_work changes in arch/powerpc/kernel/time.c

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev: (26 commits)
  include/linux/libata.h: fix typo
  pata_bf54x: fix return type of bfin_set_devctl
  Drivers: ata: Makefile: replace the use of <module>-objs with <module>-y
  libahci: fix result_tf handling after an ATA PIO data-in command
  pata_sl82c105: implement sff_irq_check() method
  pata_sil680: implement sff_irq_check() method
  pata_pdc202xx_old: implement sff_irq_check() method
  pata_cmd640: implement sff_irq_check() method
  ata_piix: Add device ID for ICH4-L
  pata_sil680: make sil680_sff_exec_command() 'static'
  ata: Intel IDE-R support
  libata: reorder ata_queued_cmd to remove alignment padding on 64 bit builds
  libata: Signal that our SATL supports WRITE SAME(16) with UNMAP
  ata_piix: remove SIDPR locking
  libata: implement cross-port EH exclusion
  libata: add @ap to ata_wait_register() and introduce ata_msleep()
  ata_piix: implement LPM support
  libata: implement LPM support for port multipliers
  libata: reimplement link power management
  libata: implement sata_link_scr_lpm() and make ata_dev_set_feature() global
  ...

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2: (48 commits)
  ocfs2: Avoid to evaluate xattr block flags again.
  ocfs2/cluster: Release debugfs file elapsed_time_in_ms
  ocfs2: Add a mount option "coherency=*" to handle cluster coherency for O_DIRECT writes.
  Initialize max_slots early
  When I tried to compile I got the following warning: fs/ocfs2/slot_map.c: In function ‘ocfs2_init_slot_info’: fs/ocfs2/slot_map.c:360: warning: ‘bytes’ may be used uninitialized in this function fs/ocfs2/slot_map.c:360: note: ‘bytes’ was declared here Compiler: gcc version 4.4.3 (GCC) on Mandriva I'm not sure why this warning occurs, I think compiler don't know that variable "bytes" is initialized when it is sent by reference to ocfs2_slot_map_physical_size and it throws that ugly warning. However, a simple initialization of "bytes" variable with 0 will fix it.
  ocfs2: validate bg_free_bits_count after update
  ocfs2/cluster: Bump up dlm protocol to version 1.1
  ocfs2/cluster: Show per region heartbeat elapsed time
  ocfs2/cluster: Add mlogs for heartbeat up/down events
  ocfs2/cluster: Create debugfs dir/files for each region
  ocfs2/cluster: Create debugfs files for live, quorum and failed region bitmaps
  ocfs2/cluster: Maintain bitmap of failed regions
  ocfs2/cluster: Maintain bitmap of quorum regions
  ocfs2/cluster: Track bitmap of live heartbeat regions
  ocfs2/cluster: Track number of global heartbeat regions
  ocfs2/cluster: Maintain live node bitmap per heartbeat region
  ocfs2/cluster: Reorganize o2hb debugfs init
  ocfs2/cluster: Check slots for unconfigured live nodes
  ocfs2/cluster: Print messages when adding/removing nodes
  ocfs2/cluster: Print messages when adding/removing heartbeat regions
  ...

Merge branch 'core-memblock-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-memblock-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (74 commits)
  x86-64: Only set max_pfn_mapped to 512 MiB if we enter via head_64.S
  xen: Cope with unmapped pages when initializing kernel pagetable
  memblock, bootmem: Round pfn properly for memory and reserved regions
  memblock: Annotate memblock functions with __init_memblock
  memblock: Allow memblock_init to be called early
  memblock/arm: Fix memblock_region_is_memory() typo
  x86, memblock: Remove __memblock_x86_find_in_range_size()
  memblock: Fix wraparound in find_region()
  x86-32, memblock: Make add_highpages honor early reserved ranges
  x86, memblock: Fix crashkernel allocation
  arm, memblock: Fix the sparsemem build
  memblock: Fix section mismatch warnings
  powerpc, memblock: Fix memblock API change fallout
  memblock, microblaze: Fix memblock API change fallout
  x86: Remove old bootmem code
  x86, memblock: Use memblock_memory_size()/memblock_free_memory_size() to get correct dma_reserve
  x86: Remove not used early_res code
  x86, memblock: Replace e820_/_early string with memblock_
  x86: Use memblock to replace early_res
  x86, memblock: Use memblock_debug to control debug message print out
  ...

Fix up trivial conflicts in arch/x86/kernel/setup.c and kernel/Makefile

Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

The new devctl func added for us to the driver has the wrong return
type.  Which is to say there shouldn't be any.  This fixes compile
time warnings as there shouldn't be any runtime difference.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Changed <module>-objs to <module>-y in Makefile.
Signed-off-by: Tracey Dent <tdent48227@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

ATA devices don't send D2H Reg FIS after an successful ATA PIO data-in
command.  The host is supposed to take the TF and E_Status of the
preceding PIO Setup FIS.  Update ahci_qc_fill_rtf() such that it takes
TF + E_Status from PIO Setup FIS after a successful ATA PIO data-in
command.

Without this patch, result_tf for such a command is filled with the
content of the previous D2H Reg FIS which belongs to a previous
command, which can make the command incorrectly seen as failed.

* Patch updated to grab the whole TF + E_Status from PIO Setup FIS
  instead of just E_Status as suggested by Robert Hancock.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Mark Lord <kernel@teksavvy.com>
Cc: Robert Hancock <hancockrwd@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

ICH4-L is a variant of ICH4 lacking USB2 functionality and with some
different device IDs.

It is documented in Intel specification update 290745-025, currently
at <http://www.intel.com/assets/pdf/specupdate/290745.pdf>, and is
included in the device ID table for piix.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

... since, of course, it's not used outside this driver.
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Intel IDE-R devices are part of the Intel AMT management setup. They don't
have any special configuration registers or settings so the ata_generic
driver will support them fully.

Rather than add a huge table of IDs for each chipset and keep sending in
new ones this patch autodetects them.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Reorder structure ata_queued_cmd to remove 8 bytes of alignment padding
on 64 bit builds & therefore reduce the size of structure ata_port by
256 bytes.

Overall this will have little impact, other than reducing the amount of
memory that is cleared when allocating ata_ports.
Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Until now identifying that a device supports WRITE SAME(16) with the
UNMAP bit set has been black magic.  Implement support for the SBC-3
Thin Provisioning VPD page and set the TPWS bit.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Now that libata provides proper cross-port EH exclusion.  The SIDPR
locking added by commit 213373cf (ata_piix: fix locking around SIDPR
access) is no longer necessary.  Remove it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

In libata, the non-EH code paths should always take and release
ap->lock explicitly when accessing hardware or shared data structures.
However, once EH is active, it's assumed that the port is owned by EH
and EH methods don't explicitly take ap->lock unless race from irq
handler or other code paths are expected.  However, libata EH didn't
guarantee exclusion among EHs for ports of the same host.  IOW,
multiple EHs may execute in parallel on multiple ports of the same
controller.

In many cases, especially in SATA, the ports are completely
independent of each other and this doesn't cause problems; however,
there are cases where different ports share the same resource, which
lead to obscure timing related bugs such as the one fixed by commit
213373cf (ata_piix: fix locking around SIDPR access).

This patch implements exclusion among EHs of the same host.  When EH
begins, it acquires per-host EH ownership by calling ata_eh_acquire().
When EH finishes, the ownership is released by calling
ata_eh_release().  EH ownership is also released whenever the EH
thread goes to sleep from ata_msleep() or explicitly and reacquired
after waking up.

This ensures that while EH is actively accessing the hardware, it has
exclusive access to it while allowing EHs to interleave and progress
in parallel as they hit waiting stages, which dominate the time spent
in EH.  This achieves cross-port EH exclusion without pervasive and
fragile changes while still allowing parallel EH for the most part.

This was first reported by yuanding02@gmail.com more than three years
ago in the following bugzilla.  :-)

  https://bugzilla.kernel.org/show_bug.cgi?id=8223Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Reported-by: yuanding02@gmail.com
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

Add optional @ap argument to ata_wait_register() and replace msleep()
calls with ata_msleep() which take optional @ap in addition to the
duration.  These will be used to implement EH exclusion.

This patch doesn't cause any behavior difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>