There are at least 3 advantages to use direct I/O and AIO on
read/write loop's backing file:

1) double cache can be avoided, then memory usage gets
decreased a lot

2) not like user space direct I/O, there isn't cost of
pinning pages

3) avoid context switch for obtaining good throughput
- in buffered file read, random I/O top throughput is often obtained
only if they are submitted concurrently from lots of tasks; but for
sequential I/O, most of times they can be hit from page cache, so
concurrent submissions often introduce unnecessary context switch
and can't improve throughput much. There was such discussion[1]
to use non-blocking I/O to improve the problem for application.
- with direct I/O and AIO, concurrent submissions can be
avoided and random read throughput can't be affected meantime

xfstests(-g auto, ext4) is basically passed when running with
direct I/O(aio), one exception is generic/232, but it failed in
loop buffered I/O(4.2-rc6-next-20150814) too.

Follows the fio test result for performance purpose:
	4 jobs fio test inside ext4 file system over loop block

1) How to run
	- KVM: 4 VCPUs, 2G RAM
	- linux kernel: 4.2-rc6-next-20150814(base) with the patchset
	- the loop block is over one image on SSD.
	- linux psync, 4 jobs, size 1500M, ext4 over loop block
	- test result: IOPS from fio output

2) Throughput(IOPS) becomes a bit better with direct I/O(aio)
        -------------------------------------------------------------
        test cases          |randread   |read   |randwrite  |write  |
        -------------------------------------------------------------
        base                |8015       |113811 |67442      |106978
        -------------------------------------------------------------
        base+loop aio       |8136       |125040 |67811      |111376
        -------------------------------------------------------------

- somehow, it should be caused by more page cache avaiable for
application or one extra page copy is avoided in case of direct I/O

3) context switch
        - context switch decreased by ~50% with loop direct I/O(aio)
	compared with loop buffered I/O(4.2-rc6-next-20150814)

4) memory usage from /proc/meminfo
        -------------------------------------------------------------
                                   | Buffers       | Cached
        -------------------------------------------------------------
        base                       | > 760MB       | ~950MB
        -------------------------------------------------------------
        base+loop direct I/O(aio)  | < 5MB         | ~1.6GB
        -------------------------------------------------------------

- so there are much more page caches available for application with
direct I/O

[1] https://lwn.net/Articles/612483/Signed-off-by: Ming Lei <ming.lei@canonical.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

If loop block is mounted via 'mount -o loop', it isn't easy
to pass file descriptor opened as O_DIRECT, so this patch
introduces a new command to support direct IO for this case.

Cc: linux-api@vger.kernel.org
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

This patches provides one interface for enabling direct IO
from user space:

	- userspace(such as losetup) can pass 'file' which is
	opened/fcntl as O_DIRECT

Also __loop_update_dio() is introduced to check if direct I/O
can be used on current loop setting.

The last big change is to introduce LO_FLAGS_DIRECT_IO flag
for userspace to know if direct IO is used to access backing
file.

Cc: linux-api@vger.kernel.org
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

The following patch will use dio/aio to submit IO to backing file,
then it needn't to schedule IO concurrently from work, so
use kthread_work for decreasing context switch cost a lot.

For non-AIO case, single thread has been used for long long time,
and it was just converted to work in v4.0, which has caused performance
regression for fedora live booting already. In discussion[1], even
though submitting I/O via work concurrently can improve random read IO
throughput, meantime it might hurt sequential read IO performance, so
better to restore to single thread behaviour.

For the following AIO support, it is better to use multi hw-queue
with per-hwq kthread than current work approach suppose there is so
high performance requirement for loop.

[1] http://marc.info/?t=143082678400002&r=1&w=2Signed-off-by: Ming Lei <ming.lei@canonical.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

It doesn't make sense to enable merge because the I/O
submitted to backing file is handled page by page.
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

When direct read IO is submitted from kernel, it is often
unnecessary to dirty pages, for example of loop, dirtying pages
have been considered in the upper filesystem(over loop) side
already, and they don't need to be dirtied again.

So this patch doesn't dirtying pages for ITER_BVEC/ITER_KVEC
direct read, and loop should be the 1st case to use ITER_BVEC/ITER_KVEC
for direct read I/O.

The patch is based on previous Dave's patch.
Reviewed-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

In case of wbc->sync_mode == WB_SYNC_ALL we need to do data integrity
write, thus mark request as WRITE_SYNC.

akpm: afaict this change will cause the data integrity write bios to be
placed onto the second queue in cfq_io_cq.cfqq[], which presumably results
in special treatment.  The documentation for REQ_SYNC is horrid.
Signed-off-by: Roman Pen <r.peniaev@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>

The pages allocated for struct request contain pointers to other slab
allocations (via ops->init_request). Since kmemleak does not track/scan
page allocations, the slab objects will be reported as leaks (false
positives). This patch adds kmemleak callbacks to allow tracking of such
pages.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Bart Van Assche <bart.vanassche@sandisk.com>
Tested-by: Bart Van Assche<bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jens Axboe <axboe@fb.com>

Pull cgroup fixes from Tejun Heo:
 "The threadgroup locking changes which went in during 4.2 devel cycle
  added write locking of a percpu_rwsem in cgroup task migration path;
  unfortunately, that involved expedited rcu syncing which turned out to
  be too slow and heavy for certain workloads.  The patchset which is
  dependent on this one didn't get committed during that devel cycle, so
  these two patches can be reverted safely.

  Oleg reworked percpu_rwsem for 4.4 so that the writer path is a lot
  lighter.  The reported issue goes away with Oleg's reworked
  percpu_rwsem and I'll reapply these patches on the for-4.4 branch so
  that they can land together with Oleg's changes"

* 'for-4.3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  Revert "sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem"
  Revert "cgroup: simplify threadgroup locking"

Merge tag 'renesas-sh-drivers-for-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas

Pull SH drivers updates from Simon Horman:
 "I am sending this change after v4.3-rc1 has been released as it
  depends on SoC changes which are present in that rc release.

  Summary:

   - disable PM runtime for multi-platform ARM with genpd

   - disable legacy default PM Domain on emev2"

* tag 'renesas-sh-drivers-for-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas:
  drivers: sh: Disable PM runtime for multi-platform ARM with genpd
  drivers: sh: Disable legacy default PM Domain on emev2

Pull s390 fixes from Martin Schwidefsky:
 "A couple of system call updates.  The two new system calls userfaultfd
  and membarrier have been added, as well as the 17 direct calls for the
  multiplexed socket system calls.

  In addition the system call compat wrappers have been flagged as
  notrace functions and a few wrappers could be removed.

  And bug fixes for the vector register handling, cpu_mf, suspend/resume,
  compat signals, SMT cputime accounting and the zfcp dumper"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390: wire up separate socketcalls system calls
  s390/compat: remove superfluous compat wrappers
  s390/compat: do not trace compat wrapper functions
  s390/s390x: allocate sys_membarrier system call number
  s390/configs//zfcpdump_defconfig: Remove CONFIG_MEMSTICK
  s390: wire up userfaultfd system call
  s390/vtime: correct scaled cputime for SMT
  s390/cpum_cf: Corrected return code for unauthorized counter sets
  s390/compat: correct uc_sigmask of the compat signal frame
  s390: fix floating point register corruption
  s390/hibernate: fix save and restore of vector registers

Signed-off-by: Jann Horn <jann@thejh.net>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull ARM fixes from Russell King:
 "Three fixes and a resulting cleanup for -rc2:

   - Andre Przywara reported that he was seeing a warning with the new
     cast inside DMA_ERROR_CODE's definition, and fixed the incorrect
     use.

   - Doug Anderson noticed that kgdb causes a "scheduling while atomic"
     bug.

   - OMAP5 folk noticed that their Thumb-2 compiled X servers crashed
     when enabling support to cover ARMv6 CPUs due to a kernel bug
     leaking some conditional context into the signal handler"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: 8425/1: kgdb: Don't try to stop the machine when setting breakpoints
  ARM: 8437/1: dma-mapping: fix build warning with new DMA_ERROR_CODE definition
  ARM: get rid of needless #if in signal handling code
  ARM: fix Thumb2 signal handling when ARMv6 is enabled

Merge tag 'linux-kselftest-4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kselftest fixes from Shuah Khan:
 "This update contains 7 fixes for problems ranging from build failurs
  to incorrect error reporting"

* tag 'linux-kselftest-4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests: exec: revert to default emit rule
  selftests: change install command to rsync
  selftests: mqueue: simplify the Makefile
  selftests: mqueue: allow extra cflags
  selftests: rename jump label to static_keys
  selftests/seccomp: add support for s390
  seltests/zram: fix syntax error

Pull power management and ACPI updates from Rafael Wysocki:
 "Included are: a somewhat late devfreq update which however is mostly
  fixes and cleanups with one new thing only (the PPMUv2 support on
  Exynos5433), an ACPI cpufreq driver fixup and two ACPI core cleanups
  related to preprocessor directives.

  Specifics:

   - Fix a memory allocation size in the devfreq core (Xiaolong Ye).

   - Fix a mistake in the exynos-ppmu DT binding (Javier Martinez
     Canillas).

   - Add support for PPMUv2 ((Platform Performance Monitoring Unit
     version 2.0) on the Exynos5433 SoCs (Chanwoo Choi).

   - Fix a type casting bug in the Exynos PPMU code (MyungJoo Ham).

   - Assorted devfreq code cleanups and optimizations (Javi Merino,
     MyungJoo Ham, Viresh Kumar).

   - Fix up the ACPI cpufreq driver to use a more lightweight way to get
     to its private data in the ->get() callback (Rafael J Wysocki).

   - Fix a CONFIG_ prefix bug in one of the ACPI drivers and make the
     ACPI subsystem use IS_ENABLED() instead of #ifdefs in function
     bodies (Sudeep Holla)"

* tag 'pm+acpi-4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: acpi-cpufreq: Use cpufreq_cpu_get_raw() in ->get()
  ACPI: Eliminate CONFIG_.*{, _MODULE} #ifdef in favor of IS_ENABLED()
  ACPI: int340x_thermal: add missing CONFIG_ prefix
  PM / devfreq: Fix incorrect type issue.
  PM / devfreq: tegra: Update governor to use devfreq_update_stats()
  PM / devfreq: comments for get_dev_status usage updated
  PM / devfreq: drop comment about thermal setting max_freq
  PM / devfreq: cache the last call to get_dev_status()
  PM / devfreq: Drop unlikely before IS_ERR(_OR_NULL)
  PM / devfreq: exynos-ppmu: bit-wise operation bugfix.
  PM / devfreq: exynos-ppmu: Update documentation to support PPMUv2
  PM / devfreq: exynos-ppmu: Add the support of PPMUv2 for Exynos5433
  PM / devfreq: event: Remove incorrect property in exynos-ppmu DT binding

Pull clk fixes from Stephen Boyd:
 "A few driver fixes for tegra, rockchip, and st SoCs and a two-liner in
  the framework to avoid oops when get_parent ops return out of range
  values on tegra platforms"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  drivers: clk: st: Rename st_pll3200c32_407_c0_x into st_pll3200c32_cx_x
  clk: check for invalid parent index of orphans in __clk_init()
  clk: tegra: dfll: Properly protect OPP list
  clk: rockchip: add critical clock for rk3368

Merge tag 'led-fixes-for-v4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds

Pull LED fixes from Jacek Anaszewski:
 - fix module autoload for six OF platform drivers (aat1290, bcm6328,
   bcm6358, ktd2692, max77693, ns2)
 - aat1290: add missing static modifier
 - ipaq-micro: add missing LEDS_CLASS dependency
 - lp55xx: correct Kconfig dependecy for f/w user helper

* tag 'led-fixes-for-v4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds:
  leds:lp55xx: Correct Kconfig dependency for f/w user helper
  leds: leds-ipaq-micro: Add LEDS_CLASS dependency
  leds: aat1290: add 'static' modifier to init_mm_current_scale
  leds: leds-ns2: Fix module autoload for OF platform driver
  leds: max77693: Fix module autoload for OF platform driver
  leds: ktd2692: Fix module autoload for OF platform driver
  leds: bcm6358: Fix module autoload for OF platform driver
  leds: bcm6328: Fix module autoload for OF platform driver
  leds: aat1290: Fix module autoload for OF platform driver

Pull rdma fixes from Doug Ledford:
 "The new hfi1 driver in staging/rdma has had a number of fixup patches
  since being added to the tree.  This is the first batch of those fixes"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma:
  IB/hfi: Properly set permissions for user device files
  IB/hfi1: mask vs shift confusion
  IB/hfi1: clean up some defines
  IB/hfi1: info leak in get_ctxt_info()
  IB/hfi1: fix a locking bug
  IB/hfi1: checking for NULL instead of IS_ERR
  IB/hfi1: fix sdma_descq_cnt parameter parsing
  IB/hfi1: fix copy_to/from_user() error handling
  IB/hfi1: fix pstateinfo from returning improperly byteswapped value

Pull libnvdimm fixes from Dan Williams:

 - a boot regression (since v4.2) fix for some ARM configurations from
   Tyler

 - regression (since v4.1) fixes for mkfs.xfs on a DAX enabled device
   from Jeff.  These are tagged for -stable.

 - a pair of locking fixes from Axel that are hidden from lockdep since
   they involve device_lock().  The "btt" one is tagged for -stable, the
   other only applies to the new "pfn" mechanism in v4.3.

 - a fix for the pmem ->rw_page() path to use wmb_pmem() from Ross.

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  mm: fix type cast in __pfn_to_phys()
  pmem: add proper fencing to pmem_rw_page()
  libnvdimm: pfn_devs: Fix locking in namespace_store
  libnvdimm: btt_devs: Fix locking in namespace_store
  blockdev: don't set S_DAX for misaligned partitions
  dax: fix O_DIRECT I/O to the last block of a blockdev

Pull block updates from Jens Axboe:
 "This is a bit bigger than it should be, but I could (did) not want to
  send it off last week due to both wanting extra testing, and expecting
  a fix for the bounce regression as well.  In any case, this contains:

   - Fix for the blk-merge.c compilation warning on gcc 5.x from me.

   - A set of back/front SG gap merge fixes, from me and from Sagi.
     This ensures that we honor SG gapping for integrity payloads as
     well.

   - Two small fixes for null_blk from Matias, fixing a leak and a
     capacity propagation issue.

   - A blkcg fix from Tejun, fixing a NULL dereference.

   - A fast clone optimization from Ming, fixing a performance
     regression since the arbitrarily sized bio's were introduced.

   - Also from Ming, a regression fix for bouncing IOs"

* 'for-linus' of git://git.kernel.dk/linux-block:
  block: fix bounce_end_io
  block: blk-merge: fast-clone bio when splitting rw bios
  block: blkg_destroy_all() should clear q->root_blkg and ->root_rl.blkg
  block: Copy a user iovec if it includes gaps
  block: Refuse adding appending a gapped integrity page to a bio
  block: Refuse request/bio merges with gaps in the integrity payload
  block: Check for gaps on front and back merges
  null_blk: fix wrong capacity when bs is not 512 bytes
  null_blk: fix memory leak on cleanup
  block: fix bogus compiler warnings in blk-merge.c

Commit 505a666e ("writeback: plug writeback in wb_writeback() and
writeback_inodes_wb()") has us holding a plug during writeback_sb_inodes,
which increases the merge rate when relatively contiguous small files
are written by the filesystem.  It helps both on flash and spindles.

For an fs_mark workload creating 4K files in parallel across 8 drives,
this commit improves performance ~9% more by unplugging before calling
cond_resched().  cond_resched() doesn't trigger an implicit unplug, so
explicitly getting the IO down to the device before scheduling reduces
latencies for anyone waiting on clean pages.

It also cuts down on how often we use kblockd to unplug, which means
less work bouncing from one workqueue to another.

Many more details about how we got here:

  https://lkml.org/lkml/2015/9/11/570Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The various definitions of __pfn_to_phys() have been consolidated to
use a generic macro in include/asm-generic/memory_model.h. This hit
mainline in the form of 012dcef3 "mm: move __phys_to_pfn and
__pfn_to_phys to asm/generic/memory_model.h". When the generic macro
was implemented the type cast to phys_addr_t was dropped which caused
boot regressions on ARM platforms with more than 4GB of memory and
LPAE enabled.

It was suggested to use PFN_PHYS() defined in include/linux/pfn.h
as provides the correct logic and avoids further duplication.
Reported-by: kernelci.org bot <bot@kernelci.org>
Suggested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Tyler Baker <tyler.baker@linaro.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

* acpi-bus:
  ACPI: Eliminate CONFIG_.*{, _MODULE} #ifdef in favor of IS_ENABLED()
  ACPI: int340x_thermal: add missing CONFIG_ prefix

* pm-cpufreq:
  cpufreq: acpi-cpufreq: Use cpufreq_cpu_get_raw() in ->get()

* pm-devfreq:
  PM / devfreq: Fix incorrect type issue.
  PM / devfreq: tegra: Update governor to use devfreq_update_stats()
  PM / devfreq: comments for get_dev_status usage updated
  PM / devfreq: drop comment about thermal setting max_freq
  PM / devfreq: cache the last call to get_dev_status()
  PM / devfreq: Drop unlikely before IS_ERR(_OR_NULL)
  PM / devfreq: exynos-ppmu: bit-wise operation bugfix.
  PM / devfreq: exynos-ppmu: Update documentation to support PPMUv2
  PM / devfreq: exynos-ppmu: Add the support of PPMUv2 for Exynos5433
  PM / devfreq: event: Remove incorrect property in exynos-ppmu DT binding

Pull virtio fixes and cleanups from Michael Tsirkin:
 "This fixes the virtio-test tool, and improves the error handling for
  virtio-ccw"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio/s390: handle failures of READ_VQ_CONF ccw
  tools/virtio: propagate V=X to kernel build
  vhost: move features to core
  tools/virtio: fix build after 4.2 changes

Pull KVM fixes from Paolo Bonzini:
 "Mostly stable material, a lot of ARM fixes"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (22 commits)
  sched: access local runqueue directly in single_task_running
  arm/arm64: KVM: Remove 'config KVM_ARM_MAX_VCPUS'
  arm64: KVM: Remove all traces of the ThumbEE registers
  arm: KVM: Disable virtual timer even if the guest is not using it
  arm64: KVM: Disable virtual timer even if the guest is not using it
  arm/arm64: KVM: vgic: Check for !irqchip_in_kernel() when mapping resources
  KVM: s390: Replace incorrect atomic_or with atomic_andnot
  arm: KVM: Fix incorrect device to IPA mapping
  arm64: KVM: Fix user access for debug registers
  KVM: vmx: fix VPID is 0000H in non-root operation
  KVM: add halt_attempted_poll to VCPU stats
  kvm: fix zero length mmio searching
  kvm: fix double free for fast mmio eventfd
  kvm: factor out core eventfd assign/deassign logic
  kvm: don't try to register to KVM_FAST_MMIO_BUS for non mmio eventfd
  KVM: make the declaration of functions within 80 characters
  KVM: arm64: add workaround for Cortex-A57 erratum #852523
  KVM: fix polling for guest halt continued even if disable it
  arm/arm64: KVM: Fix PSCI affinity info return value for non valid cores
  arm64: KVM: set {v,}TCR_EL2 RES1 bits
  ...

Some of the device files are required to be user accessible for PSM while
most should remain accessible only by root.

Add a parameter to hfi1_cdev_init which controls if the user should have access
to this device which places it in a different class with the appropriate
devnode callback.

In addition set the devnode call back for the existing class to be a bit more
explicit for those permissions.

Finally remove the unnecessary null check before class_destroy
Tested-by: Donald Dutile <ddutile@redhat.com>
Signed-off-by: Haralanov, Mitko (mitko.haralanov@intel.com)
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

We are shifting by the _MASK macros instead of the _SHIFT ones.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

I added spaces around operators so it matches kernel style because
normally "-1ULL" is a number and " - 1" is a subtract operation.  Also
removed some superflous "ULL" types so "1ULL" becomes "1".
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

The cinfo struct has a hole after the last struct member so we need to
zero it out.  Otherwise we disclose some uninitialized stack data.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

mutex_trylock() returns zero on failure, not EBUSY.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

__get_txreq() returns an ERR_PTR() but this checks for NULL so it would
oops on failure.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

The boolean tests should have been or-ed.
Reported-by: David Binderman <dcb314@hotmail.com>
Reviewed-by: Jubin John <jubin.john@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

copy_to/from_user() returns the number of bytes which we were not able
to copy.  It doesn't return an error code.

Also a couple places had a printk() on error and I removed that because
people can take advantage of it to fill /var/log/messages with spam.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

Byteswap link_width_downgrade_*_active values before sending on the wire.  In
addition properly define the Port State Info structure.
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Reviewed-by: Christian Gomez <christian.gomez@intel.com>
Signed-off-by: Rimmer, Todd <todd.rimmer@intel.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Acked-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

Pull irq updates from Thomas Gleixner:
 "This is a rather large update post rc1 due to the final steps of
  cleanups and API changes which had to wait for the preparatory patches
  to hit your tree.

   - Regression fixes for ARM GIC irqchips

   - Regression fixes and lockdep anotations for renesas irq chips

   - The leftovers of the cleanup and preparatory patches which have
     been ignored by maintainers

   - Final conversions of the newly merged users of obsolete APIs

   - Final removal of obsolete APIs

   - Final removal of ARM artifacts which had been introduced during the
     conversion of ARM to the generic interrupt code.

   - Final split of the irq_data into chip specific and common data to
     reflect the needs of hierarchical irq domains.

   - Treewide removal of the first argument of interrupt flow handlers,
     i.e. the irq number, which is not used by the majority of handlers
     and simple to retrieve from the other argument the irq descriptor.

   - A few comment updates and build warning fixes"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
  arm64: Remove ununsed set_irq_flags
  ARM: Remove ununsed set_irq_flags
  sh: Kill off set_irq_flags usage
  irqchip: Kill off set_irq_flags usage
  gpu/drm: Kill off set_irq_flags usage
  genirq: Remove irq argument from irq flow handlers
  genirq: Move field 'msi_desc' from irq_data into irq_common_data
  genirq: Move field 'affinity' from irq_data into irq_common_data
  genirq: Move field 'handler_data' from irq_data into irq_common_data
  genirq: Move field 'node' from irq_data into irq_common_data
  irqchip/gic-v3: Use IRQD_FORWARDED_TO_VCPU flag
  irqchip/gic: Use IRQD_FORWARDED_TO_VCPU flag
  genirq: Provide IRQD_FORWARDED_TO_VCPU status flag
  genirq: Simplify irq_data_to_desc()
  genirq: Remove __irq_set_handler_locked()
  pinctrl/pistachio: Use irq_set_handler_locked
  gpio: vf610: Use irq_set_handler_locked
  powerpc/mpc8xx: Use irq_set_handler_locked()
  powerpc/ipic: Use irq_set_handler_locked()
  powerpc/cpm2: Use irq_set_handler_locked()
  ...

Pull x86 fix from Thomas Gleixner:
 "A single regression fix for the x86 dma allocator which got wreckaged
  in the merge window"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/pci/dma: Fix gfp flags for coherent DMA memory allocation

Pull powerpc fixes from Michael Ellerman:

 - Fix 32-bit TCE table init in kdump kernel from Nish

 - Fix kdump with non-power-of-2 crashkernel= from Nish

 - Abort cxl_pci_enable_device_hook() if PCI channel is offline from
   Andrew

 - Fix to release DRC when configure_connector() fails from Bharata

 - Wire up sys_userfaultfd()

 - Fix race condition in tearing down MSI interrupts from Paul

 - Fix unbalanced pci_dev_get() in cxl_probe() from Daniel

 - Fix cxl build failure due to -Wunused-variable gcc behaviour change
   from Ian

 - Tell the toolchain to use ABI v2 when building an LE boot wrapper
   from Benh

 - Fix THP to recompute hash value after a failed update from Aneesh

 - 32-bit memcpy/memset: only use dcbz once cache is enabled from
   Christophe

* tag 'powerpc-4.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc32: memset: only use dcbz once cache is enabled
  powerpc32: memcpy: only use dcbz once cache is enabled
  powerpc/mm: Recompute hash value after a failed update
  powerpc/boot: Specify ABI v2 when building an LE boot wrapper
  cxl: Fix build failure due to -Wunused-variable behaviour change
  cxl: Fix unbalanced pci_dev_get in cxl_probe
  powerpc/MSI: Fix race condition in tearing down MSI interrupts
  powerpc: Wire up sys_userfaultfd()
  powerpc/pseries: Release DRC when configure_connector fails
  cxl: abort cxl_pci_enable_device_hook() if PCI channel is offline
  powerpc/powernv/pci-ioda: fix kdump with non-power-of-2 crashkernel=
  powerpc/powernv/pci-ioda: fix 32-bit TCE table init in kdump kernel

Commit 2ee507c4 ("sched: Add function single_task_running to let a task
check if it is the only task running on a cpu") referenced the current
runqueue with the smp_processor_id.  When CONFIG_DEBUG_PREEMPT is enabled,
that is only allowed if preemption is disabled or the currrent task is
bound to the local cpu (e.g. kernel worker).

With commit f7819512 ("kvm: add halt_poll_ns module parameter") KVM
calls single_task_running. If CONFIG_DEBUG_PREEMPT is enabled that
generates a lot of kernel messages.

To avoid adding preemption in that cases, as it would limit the usefulness,
we change single_task_running to access directly the cpu local runqueue.

Cc: Tim Chen <tim.c.chen@linux.intel.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Fixes: 2ee507c4Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>