Version 2 of the firmware file format includes length fields for the
various strings associated with control creation, to reduce file size.
However this does increase the parsing complexity slightly. This patch
adds support for the revision of the file format.

This patch also adds a new naming scheme for controls created from rev 2
firmware files. This version of the file format is commonly used to
add multiple controls per algorithm per memory region and the old
control naming scheme would cause multiple controls to have the same
name in this case.. Note that the naming scheme for older firmware
versions is left intact to ensure backwards compatibility.
Signed-off-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Revision one of the file format includes new algorithm and coefficient
blocks which provide additional information about the controls exported
by the firmware. This patch updates the processing to handle this
version of the file format. Note that whilst this version of the format
adds support for specifying a name for the control through the firmware
file this has not been used and to keep compatibility with existing
deployments no changes to the firmware control naming are made by this
patch.
Signed-off-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

This is slightly logically better and avoids some unnecessary forward
declarations in the following refactoring.
Signed-off-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

The private field in wm_coeff_ctl is currently unused and given the
controls are entirely handled within the ADSP code it is not clear what
it would be used for in the future. Remove the field for now it can be
readded if it is ever required.
Signed-off-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Tidy up the code a little by factoring out the creation of the algorithm
regions.
Signed-off-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Physically reading and writing controls to/from the DSP are handled by
two low level functions (wm_coeff_{write|read}_control, these currently
take in a snd_kcontrol pointer but immediately pull out a wm_coeff_ctl
pointer from the private data. These functions don't handle the kcontrols
at all they just shuttle data to and from the chip and all the call
sites have a wm_coeff_ctl pointer available. This patch just passes the
wm_coeff_ctl pointer straight into these functions.
Signed-off-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Now we only allocate 44 bytes for the control name keep it on the stack
to avoid a lot of pointless memory allocation.
Signed-off-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

ALSA only supports control names up to 44 bytes, so there is no point
allocating a whole page of memory to hold the control name, just limit
the control name to 44 bytes.
Signed-off-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

The algorithm region information in the firmware doesn't contain a
length field, explicitly pass this to the create_control function rather
than bundling into wm_adsp_alg_region.
Signed-off-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

We have wm_adsp_region, wm_adsp_alg_region, and wmfw_region, the
variables for which are all frequently called region, this can get quite
confusing when reviewing the code especially given some functions are
quite long. Consistently use mem for wm_adsp_regions, alg_region for
wm_adsp_alg_region and region for wmfw_region.

Additionally, we use a mix of adsp and dsp for pointers to the wm_adsp
structure standardise this on dsp.

Finally, we use algs to refer to the number of algorithms quite
frequently, change this to the more descriptive n_algs.
Signed-off-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

The vast majority of the wm_adsp_setup_algs function is case statements
for ADSP1 or ADSP2, this patch splits this out into two separate
functions wm_adsp1_setup_algs and wm_adsp2_setup_algs. The small amount
of shared code between them is factored out into an extra helper
function. This makes the code a lot cleaner.
Signed-off-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

AMD CPUs don't reinitialize the SS descriptor on SYSRET, so SYSRET with
SS == 0 results in an invalid usermode state in which SS is apparently
equal to __USER_DS but causes #SS if used.

Work around the issue by setting SS to __KERNEL_DS __switch_to, thus
ensuring that SYSRET never happens with SS set to NULL.

This was exposed by a recent vDSO cleanup.

Fixes: e7d6eefa x86/vdso32/syscall.S: Do not load __USER32_DS to %ss
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Brian Gerst <brgerst@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull intel drm fixes from Dave Airlie.

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/i915: vlv: fix save/restore of GFX_MAX_REQ_COUNT reg
  drm/i915: Workaround to avoid lite restore with HEAD==TAIL
  drm/i915: cope with large i2c transfers

Pull intel iommu updates from David Woodhouse:
 "This lays a little of the groundwork for upcoming Shared Virtual
  Memory support — fixing some bogus #defines for capability bits and
  adding the new ones, and starting to use the new wider page tables
  where we can, in anticipation of actually filling in the new fields
  therein.

  It also allows graphics devices to be assigned to VM guests again.
  This got broken in 3.17 by disallowing assignment of RMRR-afflicted
  devices.  Like USB, we do understand why there's an RMRR for graphics
  devices — and unlike USB, it's actually sane.  So we can make an
  exception for graphics devices, just as we do USB controllers.

  Finally, tone down the warning about the X2APIC_OPT_OUT bit, due to
  persistent requests.  X2APIC_OPT_OUT was added to the spec as a nasty
  hack to allow broken BIOSes to forbid us from using X2APIC when they
  do stupid and invasive things and would break if we did.

  Someone noticed that since Windows doesn't have full IOMMU support for
  DMA protection, setting the X2APIC_OPT_OUT bit made Windows avoid
  initialising the IOMMU on the graphics unit altogether.

  This means that it would be available for use in "driver mode", where
  the IOMMU registers are made available through a BAR of the graphics
  device and the graphics driver can do SVM all for itself.

  So they started setting the X2APIC_OPT_OUT bit on *all* platforms with
  SVM capabilities.  And even the platforms which *might*, if the
  planets had been aligned correctly, possibly have had SVM capability
  but which in practice actually don't"

* git://git.infradead.org/intel-iommu:
  iommu/vt-d: support extended root and context entries
  iommu/vt-d: Add new extended capabilities from v2.3 VT-d specification
  iommu/vt-d: Allow RMRR on graphics devices too
  iommu/vt-d: Print x2apic opt out info instead of printing a warning
  iommu/vt-d: kill bogus ecap_niotlb_iunits()

Pull i2c fixes from Wolfram Sang:
 "This has a mixture of merge window cleanups and bugfixes"

* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: st: add include for pinctrl
  i2c: mux: use proper dev when removing "channel-X" symlinks
  i2c: digicolor: remove duplicate include
  i2c: Mark adapter devices with pm_runtime_no_callbacks
  i2c: pca-platform: fix broken email address
  i2c: mxs: fix broken email address
  i2c: rk3x: report number of messages transmitted

Pull btrfs fixes from Chris Mason:
 "Filipe hit two problems in my block group cache patches.  We finalized
  the fixes last week and ran through more tests"

* 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: prevent list corruption during free space cache processing
  Btrfs: fix inode cache writeout

Merge tag 'drm-intel-next-fixes-2015-04-25' of git://anongit.freedesktop.org/drm-intel into drm-fixes

three fixes for i915.

* tag 'drm-intel-next-fixes-2015-04-25' of git://anongit.freedesktop.org/drm-intel:
  drm/i915: vlv: fix save/restore of GFX_MAX_REQ_COUNT reg
  drm/i915: Workaround to avoid lite restore with HEAD==TAIL
  drm/i915: cope with large i2c transfers

Pull NFS client updates from Trond Myklebust:
 "Another set of mainly bugfixes and a couple of cleanups.  No new
  functionality in this round.

  Highlights include:

  Stable patches:
   - Fix a regression in /proc/self/mountstats
   - Fix the pNFS flexfiles O_DIRECT support
   - Fix high load average due to callback thread sleeping

  Bugfixes:
   - Various patches to fix the pNFS layoutcommit support
   - Do not cache pNFS deviceids unless server notifications are enabled
   - Fix a SUNRPC transport reconnection regression
   - make debugfs file creation failure non-fatal in SUNRPC
   - Another fix for circular directory warnings on NFSv4 "junctioned"
     mountpoints
   - Fix locking around NFSv4.2 fallocate() support
   - Truncating NFSv4 file opens should also sync O_DIRECT writes
   - Prevent infinite loop in rpcrdma_ep_create()

  Features:
   - Various improvements to the RDMA transport code's handling of
     memory registration
   - Various code cleanups"

* tag 'nfs-for-4.1-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (55 commits)
  fs/nfs: fix new compiler warning about boolean in switch
  nfs: Remove unneeded casts in nfs
  NFS: Don't attempt to decode missing directory entries
  Revert "nfs: replace nfs_add_stats with nfs_inc_stats when add one"
  NFS: Rename idmap.c to nfs4idmap.c
  NFS: Move nfs_idmap.h into fs/nfs/
  NFS: Remove CONFIG_NFS_V4 checks from nfs_idmap.h
  NFS: Add a stub for GETDEVICELIST
  nfs: remove WARN_ON_ONCE from nfs_direct_good_bytes
  nfs: fix DIO good bytes calculation
  nfs: Fetch MOUNTED_ON_FILEID when updating an inode
  sunrpc: make debugfs file creation failure non-fatal
  nfs: fix high load average due to callback thread sleeping
  NFS: Reduce time spent holding the i_mutex during fallocate()
  NFS: Don't zap caches on fallocate()
  xprtrdma: Make rpcrdma_{un}map_one() into inline functions
  xprtrdma: Handle non-SEND completions via a callout
  xprtrdma: Add "open" memreg op
  xprtrdma: Add "destroy MRs" memreg op
  xprtrdma: Add "reset MRs" memreg op
  ...

Pull fourth vfs update from Al Viro:
 "d_inode() annotations from David Howells (sat in for-next since before
  the beginning of merge window) + four assorted fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  RCU pathwalk breakage when running into a symlink overmounting something
  fix I_DIO_WAKEUP definition
  direct-io: only inc/dec inode->i_dio_count for file systems
  fs/9p: fix readdir()
  VFS: assorted d_backing_inode() annotations
  VFS: fs/inode.c helpers: d_inode() annotations
  VFS: fs/cachefiles: d_backing_inode() annotations
  VFS: fs library helpers: d_inode() annotations
  VFS: assorted weird filesystems: d_inode() annotations
  VFS: normal filesystems (and lustre): d_inode() annotations
  VFS: security/: d_inode() annotations
  VFS: security/: d_backing_inode() annotations
  VFS: net/: d_inode() annotations
  VFS: net/unix: d_backing_inode() annotations
  VFS: kernel/: d_inode() annotations
  VFS: audit: d_backing_inode() annotations
  VFS: Fix up some ->d_inode accesses in the chelsio driver
  VFS: Cachefiles should perform fs modifications on the top layer only
  VFS: AF_UNIX sockets should call mknod on the top layer only

Pull more power management and ACPI updates from Rafael Wysocki:
 "These are fixes mostly (intel_pstate, ACPI core, ACPI EC driver,
  cpupower tool), a new CPU ID for the Intel RAPL driver and one
  intel_pstate driver improvement that didn't make it to my previous
  pull requests due to timing.

  Specifics:

   - Fix a build warning in the intel_pstate driver showing up in
     non-SMP builds (Borislav Petkov)

   - Change one of the intel_pstate's P-state selection parameters for
     Baytrail and Cherrytrail CPUs to significantly improve performance
     at the cost of a small increase in energy consumption (Kristen
     Carlson Accardi)

   - Fix a NULL pointer dereference in the ACPI EC driver due to an
     unsafe list walk in the query handler removal routine (Chris
     Bainbridge)

   - Get rid of a false-positive lockdep warning in the ACPI container
     hot-remove code (Rafael J Wysocki)

   - Prevent the ACPI device enumeration code from creating device
     objects of a wrong type in some cases (Rafael J Wysocki)

   - Add Skylake processors support to the Intel RAPL power capping
     driver (Brian Bian)

   - Drop the stale MAINTAINERS entry for the ACPI dock driver that is
     regarded as part of the ACPI core and maintained along with it now
     (Chao Yu)

   - Fix cpupower tool breakage caused by a library API change in libpci
     3.3.0 (Lucas Stach)"

* tag 'pm+acpi-4.1-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / scan: Add a scan handler for PRP0001
  ACPI / scan: Annotate physical_node_lock in acpi_scan_is_offline()
  ACPI / EC: fix NULL pointer dereference in acpi_ec_remove_query_handler()
  MAINTAINERS: remove maintainship entry of docking station driver
  powercap / RAPL: Add support for Intel Skylake processors
  cpufreq: intel_pstate: Fix an annoying !CONFIG_SMP warning
  intel_pstate: Change the setpoint for Atom params
  cpupower: fix breakage from libpci API change

Pull crypto fixes from Herbert Xu:
 "This push fixes a build problem with img-hash under non-standard
  configurations and a serious regression with sha512_ssse3 which can
  lead to boot failures"

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: img-hash - CRYPTO_DEV_IMGTEC_HASH should depend on HAS_DMA
  crypto: x86/sha512_ssse3 - fixup for asm function prototype change

Merge tag 'platform-drivers-x86-v4.1-1' of git://git.infradead.org/users/dvhart/linux-platform-drivers-x86

Pull x86 platform driver updates from Darren Hart:
 "This series includes significant updates to the toshiba_acpi driver
  and the reintroduction of the dell-laptop keyboard backlight additions
  I had to revert previously.  Also included are various fixes for
  typos, warnings, correctness, and minor bugs.

  Specifics:

  dell-laptop:
     - add support for keyboard backlight.

  toshiba_acpi:
     - adaptive keyboard, hotkey, USB sleep and charge, and backlight
       updates.  Update sysfs documentation.

  toshiba_bluetooth:
     - fix enabling/disabling loop on recent devices

  apple-gmux:
     - lock iGP IO to protect from vgaarb changes

  other:
     - Fix typos, clear gcc warnings, clarify pr_* messages, correct
       return types, update MAINTAINERS"

* tag 'platform-drivers-x86-v4.1-1' of git://git.infradead.org/users/dvhart/linux-platform-drivers-x86: (25 commits)
  toshiba_acpi: Do not register vendor backlight when acpi_video bl is available
  MAINTAINERS: Add me on list of Dell laptop drivers
  platform: x86: dell-laptop: Add support for keyboard backlight
  Documentation/ABI: Update sysfs-driver-toshiba_acpi entry
  toshiba_acpi: Fix pr_* messages from USB Sleep Functions
  toshiba_acpi: Update and fix USB Sleep and Charge modes
  wmi: Use bool function return values of true/false not 1/0
  toshiba_bluetooth: Fix enabling/disabling loop on recent devices
  toshiba_bluetooth: Clean up *_add function and disable BT device at removal
  toshiba_bluetooth: Add three new functions to the driver
  toshiba_acpi: Fix the enabling of the Special Functions
  toshiba_acpi: Use the Hotkey Event Type function for keymap choosing
  toshiba_acpi: Add Hotkey Event Type function and definitions
  x86/wmi: delete unused wmi_data_lock mutex causing gcc warning
  apple-gmux: lock iGP IO to protect from vgaarb changes
  MAINTAINERS: Add missing Toshiba devices and add myself as maintainer
  toshiba_acpi: Update events in toshiba_acpi_notify
  intel-oaktrail: Fix trivial typo in comment
  thinkpad_acpi: off by one in adaptive_keyboard_hotkey_notify_hotkey()
  thinkpad_acpi: signedness bugs getting current_mode
  ...

Pull chrome platform updates from Olof Johansson:
 "Here's a set of updates to the Chrome OS platform drivers for this
  merge window.

  Main new things this cycle is:

   - Driver changes to expose the lightbar to users.  With this, you can
     make your own blinkenlights on Chromebook Pixels.

   - Changes in the way that the atmel_mxt trackpads are probed.  The
     laptop driver is trying to be smart and not instantiate the devices
     that don't answer to probe.  For the trackpad that can come up in
     two modes (bootloader or regular), this gets complicated since the
     driver already knows how to handle the two modes including the
     actual addresses used.  So now the laptop driver needs to know more
     too, instantiating the regular address even if the bootloader one
     is the probe that passed.

   - mfd driver improvements by Javier Martines Canillas, and a few
     bugfixes from him, kbuild and myself"

* tag 'chrome-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/olof/chrome-platform:
  platform/chrome: chromeos_laptop - instantiate Atmel at primary address
  platform/chrome: cros_ec_lpc - Depend on X86 || COMPILE_TEST
  platform/chrome: cros_ec_lpc - Include linux/io.h header file
  platform/chrome: fix platform_no_drv_owner.cocci warnings
  platform/chrome: cros_ec_lightbar - fix duplicate const warning
  platform/chrome: cros_ec_dev - fix Unknown escape '%' warning
  platform/chrome: Expose Chrome OS Lightbar to users
  platform/chrome: Create sysfs attributes for the ChromeOS EC
  mfd: cros_ec: Instantiate ChromeOS EC character device
  platform/chrome: Add Chrome OS EC userspace device interface
  platform/chrome: Add cros_ec_lpc driver for x86 devices
  mfd: cros_ec: Add char dev and virtual dev pointers
  mfd: cros_ec: Use fixed size arrays to transfer data with the EC

Pull arch/cris updates from Jesper Nilsson:
 "Some much needed love for the CRIS-port.

  There's a bunch of changes this time, giving the CRISv32 port a bit of
  modern makeover with device-tree, irq domain and gpiolib support, and
  more switchover to generic frameworks.

  Some small fixes and removal of the theoretical SMP support brings up
  the rear"

* tag 'cris-for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/jesper/cris:
  cris: fix integer overflow in ELF_ET_DYN_BASE
  CRISv32: use GENERIC_SCHED_CLOCK
  CRISv32: use MMIO clocksource
  CRISv32: use generic clockevents
  CRIS: use generic headers via Kbuild
  CRIS: use generic cmpxchg.h
  CRIS: use generic atomic.h
  CRIS: use generic atomic bitops
  CRISv10: remove redundant macros from system.h
  CRIS: remove SMP code
  CRISv32: don't enable irqs in INIT_THREAD
  CRISv32: handle multiple signals
  CRISv32: prevent bogus restarts on sigreturn
  CRISv32: don't attempt syscall restart on irq exit
  Add binding documentation for CRIS
  CRIS: add Axis 88 board device tree
  CRISv32: add device tree support
  CRISv32: add irq domains support
  CRIS: enable GPIOLIB

Pull powerpc fixes from Michael Ellerman:

 - fix for mm_dec_nr_pmds() from Scott.

 - fixes for oopses seen with KVM + THP from Aneesh.

 - build fixes from Aneesh & Shreyas.

* tag 'powerpc-4.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux:
  powerpc/mm: Fix build error with CONFIG_PPC_TRANSACTIONAL_MEM disabled
  powerpc/kvm: Fix ppc64_defconfig + PPC_POWERNV=n build error
  powerpc/mm/thp: Return pte address if we find trans_splitting.
  powerpc/mm/thp: Make page table walk safe against thp split/collapse
  KVM: PPC: Remove page table walk helpers
  KVM: PPC: Use READ_ONCE when dereferencing pte_t pointer
  powerpc/hugetlb: Call mm_dec_nr_pmds() in hugetlb_free_pmd_range()

Pull second batch of KVM changes from Paolo Bonzini:
 "This mostly includes the PPC changes for 4.1, which this time cover
  Book3S HV only (debugging aids, minor performance improvements and
  some cleanups).  But there are also bug fixes and small cleanups for
  ARM, x86 and s390.

  The task_migration_notifier revert and real fix is still pending
  review, but I'll send it as soon as possible after -rc1"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (29 commits)
  KVM: arm/arm64: check IRQ number on userland injection
  KVM: arm: irqfd: fix value returned by kvm_irq_map_gsi
  KVM: VMX: Preserve host CR4.MCE value while in guest mode.
  KVM: PPC: Book3S HV: Use msgsnd for signalling threads on POWER8
  KVM: PPC: Book3S HV: Translate kvmhv_commence_exit to C
  KVM: PPC: Book3S HV: Streamline guest entry and exit
  KVM: PPC: Book3S HV: Use bitmap of active threads rather than count
  KVM: PPC: Book3S HV: Use decrementer to wake napping threads
  KVM: PPC: Book3S HV: Don't wake thread with no vcpu on guest IPI
  KVM: PPC: Book3S HV: Get rid of vcore nap_count and n_woken
  KVM: PPC: Book3S HV: Move vcore preemption point up into kvmppc_run_vcpu
  KVM: PPC: Book3S HV: Minor cleanups
  KVM: PPC: Book3S HV: Simplify handling of VCPUs that need a VPA update
  KVM: PPC: Book3S HV: Accumulate timing information for real-mode code
  KVM: PPC: Book3S HV: Create debugfs file for each guest's HPT
  KVM: PPC: Book3S HV: Add ICP real mode counters
  KVM: PPC: Book3S HV: Move virtual mode ICP functions to real-mode
  KVM: PPC: Book3S HV: Convert ICS mutex lock to spin lock
  KVM: PPC: Book3S HV: Add guest->host real mode completion counters
  KVM: PPC: Book3S HV: Add helpers for lock/unlock hpte
  ...

Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The new Atmel MXT driver expects i2c client's address contain the
primary (main address) of the chip, and calculates the expected
bootloader address form the primary address. Unfortunately chrome_laptop
does probe the devices and if touchpad (or touchscreen, or both) comes
up in bootloader mode the i2c device gets instantiated with the
bootloader address which confuses the driver.

To work around this issue let's probe the primary address first. If the
device is not detected at the primary address we'll probe alternative
addresses as "dummy" devices. If any of them are found, destroy the
dummy client and instantiate client with proper name at primary address
still.
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NOlof Johansson <olof@lixom.net>

Calling unlazy_walk() in walk_component() and do_last() when we find
a symlink that needs to be followed doesn't acquire a reference to vfsmount.
That's fine when the symlink is on the same vfsmount as the parent directory
(which is almost always the case), but it's not always true - one _can_
manage to bind a symlink on top of something.  And in such cases we end up
with excessive mntput().

Cc: stable@vger.kernel.org # since 2.6.39
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

I_DIO_WAKEUP is never directly used, but fix it up anyway.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

do_blockdev_direct_IO() increments and decrements the inode
->i_dio_count for each IO operation. It does this to protect against
truncate of a file. Block devices don't need this sort of protection.

For a capable multiqueue setup, this atomic int is the only shared
state between applications accessing the device for O_DIRECT, and it
presents a scaling wall for that. In my testing, as much as 30% of
system time is spent incrementing and decrementing this value. A mixed
read/write workload improved from ~2.5M IOPS to ~9.6M IOPS, with
better latencies too. Before:

clat percentiles (usec):
 |  1.00th=[   33],  5.00th=[   34], 10.00th=[   34], 20.00th=[   34],
 | 30.00th=[   34], 40.00th=[   34], 50.00th=[   35], 60.00th=[   35],
 | 70.00th=[   35], 80.00th=[   35], 90.00th=[   37], 95.00th=[   80],
 | 99.00th=[   98], 99.50th=[  151], 99.90th=[  155], 99.95th=[  155],
 | 99.99th=[  165]

After:

clat percentiles (usec):
 |  1.00th=[   95],  5.00th=[  108], 10.00th=[  129], 20.00th=[  149],
 | 30.00th=[  155], 40.00th=[  161], 50.00th=[  167], 60.00th=[  171],
 | 70.00th=[  177], 80.00th=[  185], 90.00th=[  201], 95.00th=[  270],
 | 99.00th=[  390], 99.50th=[  398], 99.90th=[  418], 99.95th=[  422],
 | 99.99th=[  438]

In other setups, Robert Elliott reported seeing good performance
improvements:

https://lkml.org/lkml/2015/4/3/557

The more applications accessing the device, the worse it gets.

Add a new direct-io flags, DIO_SKIP_DIO_COUNT, which tells
do_blockdev_direct_IO() that it need not worry about incrementing
or decrementing the inode i_dio_count for this caller.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Elliott, Robert (Server Storage) <elliott@hp.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NJens Axboe <axboe@fb.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Al Viro's IOV changes broke 9p readdir() because the new code
didn't abort the read when it returned nothing. The original
code checked if the combined error/length was <= 0 but in the
new code that accidentally got changed to just an error check.

Add back the return from the function when nothing is read.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Fixes: e1200fe6 ("9p: switch p9_client_read() to passing struct iov_iter *")
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

__btrfs_write_out_cache is holding the ctl->tree_lock while it prepares
a list of bitmaps to record in the free space cache.  It was dropping
the lock while it worked on other components, which made a window for
free_bitmap() to free the bitmap struct without removing it from the
list.

This changes things to hold the lock the whole time, and also makes sure
we hold the lock during enospc cleanup.
Reported-by: NFilipe Manana <fdmanana@suse.com>
Signed-off-by: NChris Mason <clm@fb.com>

commit a39f46df ("toshiba_acpi: Fix regression caused by backlight extra
check code") causes the backlight to no longer work on the Toshiba Z30,
reverting that commit fixes this but restores the original issue fixed
by that commit.

Looking at the toshiba_acpi backlight code for a fix for this I noticed that
the toshiba code is the only code under platform/x86 which unconditionally
registers a vendor acpi backlight interface, without checking for acpi_video
backlight support first.

This commit adds the necessary checks bringing toshiba_acpi in line with the
other drivers, and fixing the Z30 regression without needing to revert the
commit causing it.

Chances are that there will be some Toshiba models which have a non working
acpi-video implementation while the toshiba vendor backlight interface does
work, this commit adds an empty dmi_id table where such systems can be added,
this is identical to how other drivers handle such systems.

BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1206036
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=86521Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Reviewed-and-tested-by: NAzael Avalos <coproscefalo@gmail.com>
Signed-off-by: NDarren Hart <dvhart@linux.intel.com>

Pull sound fixes from Takashi Iwai:
 "Here are a few fixes that have been pending since the previous pull
  request: a regression fix for HD-audio multiple SPDIF / HDMI devices,
  several ALC256 codec fixes, a couple of i915 HDMI audio fixes, and
  various small fixes.

  Nothing exciting, just boring, but things good to have"

* tag 'sound-fix-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda - fix headset mic detection problem for one more machine
  ALSA: hda/realtek - Fix Headphone Mic doesn't recording for ALC256
  ALSA: hda - fix "num_steps = 0" error on ALC256
  ALSA: usb-audio: Fix audio output on Roland SC-D70 sound module
  ALSA: hda - add AZX_DCAPS_I915_POWERWELL to Baytrail
  ALSA: hda - only sync BCLK to the display clock for Haswell & Broadwell
  ALSA: hda - Mute headphone pin on suspend on XPS13 9333
  sound/oss: fix deadlock in sequencer_ioctl(SNDCTL_SEQ_OUTOFBAND)
  ALSA: asound.h - use SNDRV_CTL_ELEM_ID_NAME_MAXLEN
  ALSA: hda - potential (but unlikely) uninitialized variable
  ALSA: hda - Fix regression for slave SPDIF setups
  ALSA: intel8x0: Check pci_iomap() success for DEVICE_ALI
  ALSA: hda - simplify azx_has_pm_runtime

Pull SCSI target updates from Nicholas Bellinger:
 "Lots of activity in target land the last months.

  The highlights include:

   - Convert fabric drivers tree-wide to target_register_template() (hch
     + bart)

   - iser-target hardening fixes + v1.0 improvements (sagi)

   - Convert iscsi_thread_set usage to kthread.h + kill
     iscsi_target_tq.c (sagi + nab)

   - Add support for T10-PI WRITE_STRIP + READ_INSERT operation (mkp +
     sagi + nab)

   - DIF fixes for CONFIG_DEBUG_SG=y + UNMAP file emulation (akinobu +
     sagi + mkp)

   - Extended TCMU ABI v2 for future BIDI + DIF support (andy + ilias)

   - Fix COMPARE_AND_WRITE handling for NO_ALLLOC drivers (hch + nab)

  Thanks to everyone who contributed this round with new features,
  bug-reports, fixes, cleanups and improvements.

  Looking forward, it's currently shaping up to be a busy v4.2 as well"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (69 commits)
  target: Put TCMU under a new config option
  target: Version 2 of TCMU ABI
  target: fix tcm_mod_builder.py
  target/file: Fix UNMAP with DIF protection support
  target/file: Fix SG table for prot_buf initialization
  target/file: Fix BUG() when CONFIG_DEBUG_SG=y and DIF protection enabled
  target: Make core_tmr_abort_task() skip TMFs
  target/sbc: Update sbc_dif_generate pr_debug output
  target/sbc: Make internal DIF emulation honor ->prot_checks
  target/sbc: Return INVALID_CDB_FIELD if DIF + sess_prot_type disabled
  target: Ensure sess_prot_type is saved across session restart
  target/rd: Don't pass incomplete scatterlist entries to sbc_dif_verify_*
  target: Remove the unused flag SCF_ACK_KREF
  target: Fix two sparse warnings
  target: Fix COMPARE_AND_WRITE with SG_TO_MEM_NOALLOC handling
  target: simplify the target template registration API
  target: simplify target_xcopy_init_pt_lun
  target: remove the unused SCF_CMD_XCOPY_PASSTHROUGH flag
  target/rd: reduce code duplication in rd_execute_rw()
  tcm_loop: fixup tpgt string to integer conversion
  ...

Merge tag 'pwm/for-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm changes from Thierry Reding:
 "Not much has been happening in PWM land lately, so this contains
  mostly minor fixes that didn't seem urgent enough for a late
  pull-request last cycle"

* tag 'pwm/for-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm:
  pwm: Remove __init initializer for pwm_add_table()
  pwm: samsung: Fix output race on disabling
  pwm: mxs: Fix period divider computation
  pwm: atmel-hlcdc: Add errata handling for sama5d4
  pwm: pca9685: Constify struct regmap_config
  pwm: imx-pwm: add explicit compatible strings and required clock properties

Pull dma-buf updates from Sumit Semwal:
 "Minor cleanup only; this could've gone in for the 4.0 merge window,
  but for a copy-paste stupidity from me.

  It has been in the for-next since then, and no issues reported.

   - cleanup of dma_buf_export()

   - correction of copy-paste stupidity while doing the cleanup"

* tag 'dma-buf-for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/sumits/dma-buf:
  staging: android: ion: fix wrong init of dma_buf_export_info
  dma-buf: cleanup dma_buf_export() to make it easily extensible

Pull slave-dmaengine updates from Vinod Koul:

 - new drivers for:
        - Ingenic JZ4780 controller
        - APM X-Gene controller
        - Freescale RaidEngine device
        - Renesas USB Controller

  - remove device_alloc_chan_resources dummy handlers

  - sh driver cleanups for peri peri and related emmc and asoc patches
    as well

  - fixes and enhancements spread over the drivers

* 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma: (59 commits)
  dmaengine: dw: don't prompt for DW_DMAC_CORE
  dmaengine: shdmac: avoid unused variable warnings
  dmaengine: fix platform_no_drv_owner.cocci warnings
  dmaengine: pch_dma: fix memory leak on failure path in pch_dma_probe()
  dmaengine: at_xdmac: unlock spin lock before return
  dmaengine: xgene: devm_ioremap() returns NULL on error
  dmaengine: xgene: buffer overflow in xgene_dma_init_channels()
  dmaengine: usb-dmac: Fix dereferencing freed memory 'desc'
  dmaengine: sa11x0: report slave capabilities to upper layers
  dmaengine: vdma: Fix compilation warnings
  dmaengine: fsl_raid: statify fsl_re_chan_probe
  dmaengine: Driver support for FSL RaidEngine device.
  dmaengine: xgene_dma_init_ring_mngr() can be static
  Documentation: dma: Add documentation for the APM X-Gene SoC DMA device DTS binding
  arm64: dts: Add APM X-Gene SoC DMA device and DMA clock DTS nodes
  dmaengine: Add support for APM X-Gene SoC DMA engine driver
  dmaengine: usb-dmac: Add Renesas USB DMA Controller (USB-DMAC) driver
  dmaengine: renesas,usb-dmac: Add device tree bindings documentation
  dmaengine: edma: fixed wrongly initialized data parameter to the edma callback
  dmaengine: ste_dma40: fix implicit conversion
  ...