btrfs sets ->submit_io(), and we failed to set the block dev for
that path. That resulted in a potential NULL dereference when
we later wait for IO in dio_await_one().
Reported-by: kernel test robot <ying.huang@linux.intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

This adds support for sync O_DIRECT read/write poll support.
Signed-off-by: Jens Axboe <axboe@fb.com>
[hch: split from a larger patch, minor updates]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>

Add nvme_poll(), which will check a specific completion queue for
command completions. Wire that up to the new block layer poll
mechanism.
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>

Add basic support for polling for specific IO to complete. This uses
the cookie that blk-mq passes back, which enables the block layer
to pass this cookie to the driver to spin for a specific request.

This will be combined with request latency tracking, so we can make
qualified decisions about when to poll and when not to. For now, for
benchmark purposes, we add a sysfs file that controls whether polling
is enabled or not.
Signed-off-by: Jens Axboe <axboe@fb.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>

Return a cookie, blk_qc_t, from the blk-mq make request functions, that
allows a later caller to uniquely identify a specific IO. The cookie
doesn't mean anything to the caller, but the caller can use it to later
pass back to the block layer. The block layer can then identify the
hardware queue and request from that cookie.
Signed-off-by: Jens Axboe <axboe@fb.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>

No functional changes in this patch, but it prepares us for returning
a more useful cookie related to the IO that was queued up.
Signed-off-by: Jens Axboe <axboe@fb.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>

Pull char/misc driver updates from Greg KH:
 "Here is the big char/misc driver update for 4.4-rc1.  Lots of
  different driver and subsystem updates, hwtracing being the largest
  with the addition of some new platforms that are now supported.  Full
  details in the shortlog.

  All of these have been in linux-next for a long time with no reported
  issues"

* tag 'char-misc-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (181 commits)
  fpga: socfpga: Fix check of return value of devm_request_irq
  lkdtm: fix ACCESS_USERSPACE test
  mcb: Destroy IDA on module unload
  mcb: Do not return zero on error path in mcb_pci_probe()
  mei: bus: set the device name before running fixup
  mei: bus: use correct lock ordering
  mei: Fix debugfs filename in error output
  char: ipmi: ipmi_ssif: Replace timeval with timespec64
  fpga: zynq-fpga: Fix issue with drvdata being overwritten.
  fpga manager: remove unnecessary null pointer checks
  fpga manager: ensure lifetime with of_fpga_mgr_get
  fpga: zynq-fpga: Change fw format to handle bin instead of bit.
  fpga: zynq-fpga: Fix unbalanced clock handling
  misc: sram: partition base address belongs to __iomem space
  coresight: etm3x: adding documentation for sysFS's cpu interface
  vme: 8-bit status/id takes 256 values, not 255
  fpga manager: Adding FPGA Manager support for Xilinx Zynq 7000
  ARM: zynq: dt: Updated devicetree for Zynq 7000 platform.
  ARM: dt: fpga: Added binding docs for Xilinx Zynq FPGA manager.
  ver_linux: proc/modules, limit text processing to 'sed'
  ...

Pull driver core updates from Greg KH:
 "Here's the "big" driver core updates for 4.4-rc1.  Primarily a bunch
  of debugfs updates, with a smattering of minor driver core fixes and
  updates as well.

  All have been in linux-next for a long time"

* tag 'driver-core-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  debugfs: Add debugfs_create_ulong()
  of: to support binding numa node to specified device in devicetree
  debugfs: Add read-only/write-only bool file ops
  debugfs: Add read-only/write-only size_t file ops
  debugfs: Add read-only/write-only x64 file ops
  debugfs: Consolidate file mode checks in debugfs_create_*()
  Revert "mm: Check if section present during memory block (un)registering"
  driver-core: platform: Provide helpers for multi-driver modules
  mm: Check if section present during memory block (un)registering
  devres: fix a for loop bounds check
  CMA: fix CONFIG_CMA_SIZE_MBYTES overflow in 64bit
  base/platform: assert that dev_pm_domain callbacks are called unconditionally
  sysfs: correctly handle short reads on PREALLOC attrs.
  base: soc: siplify ida usage
  kobject: move EXPORT_SYMBOL() macros next to corresponding definitions
  kobject: explain what kobject's sd field is
  debugfs: document that debugfs_remove*() accepts NULL and error values
  debugfs: Pass bool pointer to debugfs_create_bool()
  ACPI / EC: Fix broken 64bit big-endian users of 'global_lock'

Pull staging driver updates from Greg KH:
 "Here's the big staging driver update for 4.4-rc1.  If you were
  disappointed for 4.3-rc1 that we didn't contribute enough changesets,
  you should be happy with this pull request of over 2400 patches.

  But overall we removed more lines of code than we added, which is nice
  to see.  Full details in the shortlog.

  All of these have been in linux-next for a while"

Greg, I've never been disappointed in how few commits Staging
contributes to the kernel..  Never.

* tag 'staging-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (2431 commits)
  Staging: rtl8192u: ieee80211: added missing blank lines
  Staging: rtl8192u: ieee80211: removed unnecessary braces
  Staging: rtl8192u: ieee80211: corrected block comments
  Staging: rtl8192u: ieee80211: corrected indent
  Staging: rtl8192u: ieee80211: added missing spaces after if
  Staging: rtl8192u: ieee80211: added missing space around '='
  Staging: rtl8192u: ieee80211: fixed position of else statements
  Staging: rtl8192u: ieee80211: fixed open brace positions
  staging: rdma: ipath: Remove unneeded vairable.
  staging: rtl8188eu: pwrGrpCnt variable removed in store_pwrindex_offset function
  staging: rtl8188eu: new variable for hal_data->MCSTxPowerLevelOriginalOffset[pwrGrpCnt] in store_pwrindex_offset function
  staging: rtl8188eu: checkpatch fixes: 'Avoid CamelCase' in hal/bb_cfg.c
  staging: rtl8188eu: checkpatch fixes: line over 80 characters splited into two parts
  staging: rtl8188eu: checkpatch fixes: alignment should match open parenthesis
  staging: rtl8188eu: checkpatch fixes: unnecessary parentheses removed in hal/bb_cfg.c
  staging: rtl8188eu: checkpatch fixes: spaces preferred around that '|' in hal/bb_cfg.c
  staging: rtl8188eu: operator = replaced by += in loop increment
  staging: rtl8188eu: occurrence of the 5 GHz code marked
  staging: rtl8188eu: increment placed into for loop header
  staging: rtl8188eu: while loop replaced by for loop in rtw_restruct_wmm_ie
  ...

Pull tty/serial driver updates from Greg KH:
 "Here is the big tty and serial driver update for 4.4-rc1.

  Lots of serial driver updates and a few small tty core changes.  Full
  details in the shortlog.

  All of these have been in linux-next for a while"

* tag 'tty-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (148 commits)
  tty: Use unbound workqueue for all input workers
  tty: Abstract tty buffer work
  tty: Prevent tty teardown during tty_write_message()
  tty: core: Use correct spinlock flavor in tiocspgrp()
  tty: Combine SIGTTOU/SIGTTIN handling
  serial: amba-pl011: fix incorrect integer size in pl011_fifo_to_tty()
  ttyFDC: Fix build problems due to use of module_{init,exit}
  tty: remove unneeded return statement
  serial: 8250_mid: add support for DMA engine handling from UART MMIO
  dmaengine: hsu: remove platform data
  dmaengine: hsu: introduce stubs for the exported functions
  dmaengine: hsu: make the UART driver in control of selecting this driver
  serial: fix mctrl helper functions
  serial: 8250_pci: Intel MID UART support to its own driver
  serial: fsl_lpuart: add earlycon support
  tty: disable unbind for old 74xx based serial/mpsc console port
  serial: pl011: Spelling s/clocks-names/clock-names/
  n_tty: Remove reader wakeups for TTY_BREAK/TTY_PARITY chars
  tty: synclink, fix indentation
  serial: at91, fix rs485 properties
  ...

Pull USB updates from Greg KH:
 "Here is the big USB patchset for 4.4-rc1.

  As usual, most of the changes are in the gadget subsystem, and we
  removed a host controller for a device that is no longer in existance,
  and probably never was even made public.  There is also other minor
  driver updates and new device ids, full details in the changelog.

  All of these have been in linux-next for a while"

* tag 'usb-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (233 commits)
  USB: core: Codestyle fix in urb.c
  usb: misc: usb3503: Use i2c_add_driver helper macro
  usb: host: lpc32xx: don't unregister phy device
  usb: host: lpc32xx: balance clk enable/disable on removal
  usb: host: lpc32xx: fix warnings caused by enabling unprepared clock
  uwb: drp: Use setup_timer
  uwb: neh: Use setup_timer
  uwb: rsv: Use setup_timer
  USB: qcserial: add Sierra Wireless MC74xx/EM74xx
  usb: chipidea: otg: don't wait vbus drops below BSV when starts host
  chipidea: ci_hdrc_pci: use PCI_VDEVICE() instead of PCI_DEVICE()
  doc: dt-binding: ci-hdrc-usb2: split vendor specific properties
  usb: chipidea: imx: add imx6ul usb support
  doc: dt-binding: ci-hdrc-usb2: improve property description
  usb: chipidea: imx: add usb support for imx7d
  Doc: usb: ci-hdrc-usb2: Add phy-clkgate-delay-us entry
  usb: chipidea: Add support for 'phy-clkgate-delay-us' property
  usb: chipidea: Use extcon framework for VBUS and ID detect
  usb: gadget: net2280: restore ep_cfg after defect7374 workaround
  usb: dwc2: host: Fix use after free w/ simultaneous irqs
  ...

Pull device mapper updates from Mike Snitzer:
 "Smaller set of DM changes for this merge.  I've based these changes on
  Jens' for-4.4/reservations branch because the associated DM changes
  required it.

   - Revert a dm-multipath change that caused a regression for
     unprivledged users (e.g. kvm guests) that issued ioctls when a
     multipath device had no available paths.

   - Include Christoph's refactoring of DM's ioctl handling and add
     support for passing through persistent reservations with DM
     multipath.

   - All other changes are very simple cleanups"

* tag 'dm-4.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm switch: simplify conditional in alloc_region_table()
  dm delay: document that offsets are specified in sectors
  dm delay: capitalize the start of an delay_ctr() error message
  dm delay: Use DM_MAPIO macros instead of open-coded equivalents
  dm linear: remove redundant target name from error messages
  dm persistent data: eliminate unnecessary return values
  dm: eliminate unused "bioset" process for each bio-based DM device
  dm: convert ffs to __ffs
  dm: drop NULL test before kmem_cache_destroy() and mempool_destroy()
  dm: add support for passing through persistent reservations
  dm: refactor ioctl handling
  Revert "dm mpath: fix stalls when handling invalid ioctls"
  dm: initialize non-blk-mq queue data before queue is used

Pull md updates from Neil Brown:
 "Two major components to this update.

   1) The clustered-raid1 support from SUSE is nearly complete.  There
      are a few outstanding issues being worked on.  Maybe half a dozen
      patches will bring this to a usable state.

   2) The first stage of journalled-raid5 support from Facebook makes an
      appearance.  With a journal device configured (typically NVRAM or
      SSD), the "RAID5 write hole" should be closed - a crash during
      degraded operations cannot result in data corruption.

      The next stage will be to use the journal as a write-behind cache
      so that latency can be reduced and in some cases throughput
      increased by performing more full-stripe writes.

* tag 'md/4.4' of git://neil.brown.name/md: (66 commits)
  MD: when RAID journal is missing/faulty, block RESTART_ARRAY_RW
  MD: set journal disk ->raid_disk
  MD: kick out journal disk if it's not fresh
  raid5-cache: start raid5 readonly if journal is missing
  MD: add new bit to indicate raid array with journal
  raid5-cache: IO error handling
  raid5: journal disk can't be removed
  raid5-cache: add trim support for log
  MD: fix info output for journal disk
  raid5-cache: use bio chaining
  raid5-cache: small log->seq cleanup
  raid5-cache: new helper: r5_reserve_log_entry
  raid5-cache: inline r5l_alloc_io_unit into r5l_new_meta
  raid5-cache: take rdev->data_offset into account early on
  raid5-cache: refactor bio allocation
  raid5-cache: clean up r5l_get_meta
  raid5-cache: simplify state machine when caches flushes are not needed
  raid5-cache: factor out a helper to run all stripes for an I/O unit
  raid5-cache: rename flushed_ios to finished_ios
  raid5-cache: free I/O units earlier
  ...

Pull block reservation support from Jens Axboe:
 "This adds support for persistent reservations, both at the core level,
  as well as for sd and NVMe"

[ Background from the docs: "Persistent Reservations allow restricting
  access to block devices to specific initiators in a shared storage
  setup.  All implementations are expected to ensure the reservations
  survive a power loss and cover all connections in a multi path
  environment" ]

* 'for-4.4/reservations' of git://git.kernel.dk/linux-block:
  NVMe: Precedence error in nvme_pr_clear()
  nvme: add missing endianess annotations in nvme_pr_command
  NVMe: Add persistent reservation ops
  sd: implement the Persistent Reservation API
  block: add an API for Persistent Reservations
  block: cleanup blkdev_ioctl

Pull block integrity updates from Jens Axboe:
 ""This is the joint work of Dan and Martin, cleaning up and improving
  the support for block data integrity"

* 'for-4.4/integrity' of git://git.kernel.dk/linux-block:
  block, libnvdimm, nvme: provide a built-in blk_integrity nop profile
  block: blk_flush_integrity() for bio-based drivers
  block: move blk_integrity to request_queue
  block: generic request_queue reference counting
  nvme: suspend i/o during runtime blk_integrity_unregister
  md: suspend i/o during runtime blk_integrity_unregister
  md, dm, scsi, nvme, libnvdimm: drop blk_integrity_unregister() at shutdown
  block: Inline blk_integrity in struct gendisk
  block: Export integrity data interval size in sysfs
  block: Reduce the size of struct blk_integrity
  block: Consolidate static integrity profile properties
  block: Move integrity kobject to struct gendisk

Pull lightnvm support from Jens Axboe:
 "This adds support for lightnvm, and adds support to NVMe as well.
  This is pretty exciting, in that it enables new and interesting use
  cases for compatible flash devices.  There's a LWN writeup about an
  earlier posting here:

      https://lwn.net/Articles/641247/

  This has been underway for a while, and should be ready for merging at
  this point"

* 'for-4.4/lightnvm' of git://git.kernel.dk/linux-block:
  nvme: lightnvm: clean up a data type
  lightnvm: refactor phys addrs type to u64
  nvme: LightNVM support
  rrpc: Round-robin sector target with cost-based gc
  gennvm: Generic NVM manager
  lightnvm: Support for Open-Channel SSDs

Pull block driver updates from Jens Axboe:
 "Here are the block driver changes for 4.4.  This pull request
  contains:

   - NVMe:
        - Refactor and moving of code to prepare for proper target
          support. From Christoph and Jay.

        - 32-bit nvme warning fix from Arnd.

        - Error initialization fix from me.

        - Proper namespace removal and reference counting support from
          Keith.

        - Device resume fix on IO failure, also from Keith.

        - Dependency fix from Keith, now that nvme isn't under the
          umbrella of the block anymore.

        - Target location and maintainers update from Jay.

   - From Ming Lei, the long awaited DIO/AIO support for loop.

   - Enable BD-RE writeable opens, from Georgios"

* 'for-4.4/drivers' of git://git.kernel.dk/linux-block: (24 commits)
  Update target repo for nvme patch contributions
  NVMe: initialize error to '0'
  nvme: use an integer value to Linux errno values
  nvme: fix 32-bit build warning
  NVMe: Add explicit block config dependency
  nvme: include <linux/types.ĥ> in <linux/nvme.h>
  nvme: move to a new drivers/nvme/host directory
  nvme.h: add missing nvme_id_ctrl endianess annotations
  nvme: move hardware structures out of the uapi version of nvme.h
  nvme: add a local nvme.h header
  nvme: properly handle partially initialized queues in nvme_create_io_queues
  nvme: merge nvme_dev_start, nvme_dev_resume and nvme_async_probe
  nvme: factor reset code into a common helper
  nvme: merge nvme_dev_reset into nvme_reset_failed_dev
  nvme: delete dev from dev_list in nvme_reset
  NVMe: Simplify device resume on io queue failure
  NVMe: Namespace removal simplifications
  NVMe: Reference count open namespaces
  cdrom: Random writing support for BD-RE media
  block: loop: support DIO & AIO
  ...

Pull core block updates from Jens Axboe:
 "This is the core block pull request for 4.4.  I've got a few more
  topic branches this time around, some of them will layer on top of the
  core+drivers changes and will come in a separate round.  So not a huge
  chunk of changes in this round.

  This pull request contains:

   - Enable blk-mq page allocation tracking with kmemleak, from Catalin.

   - Unused prototype removal in blk-mq from Christoph.

   - Cleanup of the q->blk_trace exchange, using cmpxchg instead of two
     xchg()'s, from Davidlohr.

   - A plug flush fix from Jeff.

   - Also from Jeff, a fix that means we don't have to update shared tag
     sets at init time unless we do a state change.  This cuts down boot
     times on thousands of devices a lot with scsi/blk-mq.

   - blk-mq waitqueue barrier fix from Kosuke.

   - Various fixes from Ming:

        - Fixes for segment merging and splitting, and checks, for
          the old core and blk-mq.

        - Potential blk-mq speedup by marking ctx pending at the end
          of a plug insertion batch in blk-mq.

        - direct-io no page dirty on kernel direct reads.

   - A WRITE_SYNC fix for mpage from Roman"

* 'for-4.4/core' of git://git.kernel.dk/linux-block:
  blk-mq: avoid excessive boot delays with large lun counts
  blktrace: re-write setting q->blk_trace
  blk-mq: mark ctx as pending at batch in flush plug path
  blk-mq: fix for trace_block_plug()
  block: check bio_mergeable() early before merging
  blk-mq: check bio_mergeable() early before merging
  block: avoid to merge splitted bio
  block: setup bi_phys_segments after splitting
  block: fix plug list flushing for nomerge queues
  blk-mq: remove unused blk_mq_clone_flush_request prototype
  blk-mq: fix waitqueue_active without memory barrier in block/blk-mq-tag.c
  fs: direct-io: don't dirtying pages for ITER_BVEC/ITER_KVEC direct read
  fs/mpage.c: forgotten WRITE_SYNC in case of data integrity write
  block: kmemleak: Track the page allocations for struct request

Pull power management and ACPI updates from Rafael Wysocki:
 "Quite a new features are included this time.

  First off, the Collaborative Processor Performance Control interface
  (version 2) defined by ACPI will now be supported on ARM64 along with
  a cpufreq frontend for CPU performance scaling.

  Second, ACPI gets a new infrastructure for the early probing of IRQ
  chips and clock sources (along the lines of the existing similar
  mechanism for DT).

  Next, the ACPI core and the generic device properties API will now
  support a recently introduced hierarchical properties extension of the
  _DSD (Device Specific Data) ACPI device configuration object.  If the
  ACPI platform firmware uses that extension to organize device
  properties in a hierarchical way, the kernel will automatically handle
  it and make those properties available to device drivers via the
  generic device properties API.

  It also will be possible to build the ACPICA's AML interpreter
  debugger into the kernel now and use that to diagnose AML-related
  problems more efficiently.  In the future, this should make it
  possible to single-step AML execution and do similar things.
  Interesting stuff, although somewhat experimental at this point.

  Finally, the PM core gets a new mechanism that can be used by device
  drivers to distinguish between suspend-to-RAM (based on platform
  firmware support) and suspend-to-idle (or other variants of system
  suspend the platform firmware is not involved in) and possibly
  optimize their device suspend/resume handling accordingly.

  In addition to that, some existing features are re-organized quite
  substantially.

  First, the ACPI-based handling of PCI host bridges on x86 and ia64 is
  unified and the common code goes into the ACPI core (so as to reduce
  code duplication and eliminate non-essential differences between the
  two architectures in that area).

  Second, the Operating Performance Points (OPP) framework is
  reorganized to make the code easier to find and follow.

  Next, the cpufreq core's sysfs interface is reorganized to get rid of
  the "primary CPU" concept for configurations in which the same
  performance scaling settings are shared between multiple CPUs.

  Finally, some interfaces that aren't necessary any more are dropped
  from the generic power domains framework.

  On top of the above we have some minor extensions, cleanups and bug
  fixes in multiple places, as usual.

  Specifics:

   - ACPICA update to upstream revision 20150930 (Bob Moore, Lv Zheng).

     The most significant change is to allow the AML debugger to be
     built into the kernel.  On top of that there is an update related
     to the NFIT table (the ACPI persistent memory interface) and a few
     fixes and cleanups.

   - ACPI CPPC2 (Collaborative Processor Performance Control v2) support
     along with a cpufreq frontend (Ashwin Chaugule).

     This can only be enabled on ARM64 at this point.

   - New ACPI infrastructure for the early probing of IRQ chips and
     clock sources (Marc Zyngier).

   - Support for a new hierarchical properties extension of the ACPI
     _DSD (Device Specific Data) device configuration object allowing
     the kernel to handle hierarchical properties (provided by the
     platform firmware this way) automatically and make them available
     to device drivers via the generic device properties interface
     (Rafael Wysocki).

   - Generic device properties API extension to obtain an index of
     certain string value in an array of strings, along the lines of
     of_property_match_string(), but working for all of the supported
     firmware node types, and support for the "dma-names" device
     property based on it (Mika Westerberg).

   - ACPI core fix to parse the MADT (Multiple APIC Description Table)
     entries in the order expected by platform firmware (and mandated by
     the specification) to avoid confusion on systems with more than 255
     logical CPUs (Lukasz Anaczkowski).

   - Consolidation of the ACPI-based handling of PCI host bridges on x86
     and ia64 (Jiang Liu).

   - ACPI core fixes to ensure that the correct IRQ number is used to
     represent the SCI (System Control Interrupt) in the cases when it
     has been re-mapped (Chen Yu).

   - New ACPI backlight quirk for Lenovo IdeaPad S405 (Hans de Goede).

   - ACPI EC driver fixes (Lv Zheng).

   - Assorted ACPI fixes and cleanups (Dan Carpenter, Insu Yun, Jiri
     Kosina, Rami Rosen, Rasmus Villemoes).

   - New mechanism in the PM core allowing drivers to check if the
     platform firmware is going to be involved in the upcoming system
     suspend or if it has been involved in the suspend the system is
     resuming from at the moment (Rafael Wysocki).

     This should allow drivers to optimize their suspend/resume handling
     in some cases and the changes include a couple of users of it (the
     i8042 input driver, PCI PM).

   - PCI PM fix to prevent runtime-suspended devices with PME enabled
     from being resumed during system suspend even if they aren't
     configured to wake up the system from sleep (Rafael Wysocki).

   - New mechanism to report the number of a wakeup IRQ that woke up the
     system from sleep last time (Alexandra Yates).

   - Removal of unused interfaces from the generic power domains
     framework and fixes related to latency measurements in that code
     (Ulf Hansson, Daniel Lezcano).

   - cpufreq core sysfs interface rework to make it handle CPUs that
     share performance scaling settings (represented by a common cpufreq
     policy object) more symmetrically (Viresh Kumar).

     This should help to simplify the CPU offline/online handling among
     other things.

   - cpufreq core fixes and cleanups (Viresh Kumar).

   - intel_pstate fixes related to the Turbo Activation Ratio (TAR)
     mechanism on client platforms which causes the turbo P-states range
     to vary depending on platform firmware settings (Srinivas
     Pandruvada).

   - intel_pstate sysfs interface fix (Prarit Bhargava).

   - Assorted cpufreq driver (imx, tegra20, powernv, integrator) fixes
     and cleanups (Bai Ping, Bartlomiej Zolnierkiewicz, Shilpasri G
     Bhat, Luis de Bethencourt).

   - cpuidle mvebu driver cleanups (Russell King).

   - OPP (Operating Performance Points) framework code reorganization to
     make it more maintainable (Viresh Kumar).

   - Intel Broxton support for the RAPL (Running Average Power Limits)
     power capping driver (Amy Wiles).

   - Assorted power management code fixes and cleanups (Dan Carpenter,
     Geert Uytterhoeven, Geliang Tang, Luis de Bethencourt, Rasmus
     Villemoes)"

* tag 'pm+acpi-4.4-rc1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (108 commits)
  cpufreq: postfix policy directory with the first CPU in related_cpus
  cpufreq: create cpu/cpufreq/policyX directories
  cpufreq: remove cpufreq_sysfs_{create|remove}_file()
  cpufreq: create cpu/cpufreq at boot time
  cpufreq: Use cpumask_copy instead of cpumask_or to copy a mask
  cpufreq: ondemand: Drop unnecessary locks from update_sampling_rate()
  PM / Domains: Merge measurements for PM QoS device latencies
  PM / Domains: Don't measure ->start|stop() latency in system PM callbacks
  PM / clk: Fix broken build due to non-matching code and header #ifdefs
  ACPI / Documentation: add copy_dsdt to ACPI format options
  ACPI / sysfs: correctly check failing memory allocation
  ACPI / video: Add a quirk to force native backlight on Lenovo IdeaPad S405
  ACPI / CPPC: Fix potential memory leak
  ACPI / CPPC: signedness bug in register_pcc_channel()
  ACPI / PAD: power_saving_thread() is not freezable
  ACPI / PM: Fix incorrect wakeup IRQ setting during suspend-to-idle
  ACPI: Using correct irq when waiting for events
  ACPI: Use correct IRQ when uninstalling ACPI interrupt handler
  cpuidle: mvebu: disable the bind/unbind attributes and use builtin_platform_driver
  cpuidle: mvebu: clean up multiple platform drivers
  ...

Pull xen updates from David Vrabel:

 - Improve balloon driver memory hotplug placement.

 - Use unpopulated hotplugged memory for foreign pages (if
   supported/enabled).

 - Support 64 KiB guest pages on arm64.

 - CPU hotplug support on arm/arm64.

* tag 'for-linus-4.4-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (44 commits)
  xen: fix the check of e_pfn in xen_find_pfn_range
  x86/xen: add reschedule point when mapping foreign GFNs
  xen/arm: don't try to re-register vcpu_info on cpu_hotplug.
  xen, cpu_hotplug: call device_offline instead of cpu_down
  xen/arm: Enable cpu_hotplug.c
  xenbus: Support multiple grants ring with 64KB
  xen/grant-table: Add an helper to iterate over a specific number of grants
  xen/xenbus: Rename *RING_PAGE* to *RING_GRANT*
  xen/arm: correct comment in enlighten.c
  xen/gntdev: use types from linux/types.h in userspace headers
  xen/gntalloc: use types from linux/types.h in userspace headers
  xen/balloon: Use the correct sizeof when declaring frame_list
  xen/swiotlb: Add support for 64KB page granularity
  xen/swiotlb: Pass addresses rather than frame numbers to xen_arch_need_swiotlb
  arm/xen: Add support for 64KB page granularity
  xen/privcmd: Add support for Linux 64KB page granularity
  net/xen-netback: Make it running on 64KB page granularity
  net/xen-netfront: Make it running on 64KB page granularity
  block/xen-blkback: Make it running on 64KB page granularity
  block/xen-blkfront: Make it running on 64KB page granularity
  ...

Pull arm64 updates from Catalin Marinas:

 - "genirq: Introduce generic irq migration for cpu hotunplugged" patch
   merged from tip/irq/for-arm to allow the arm64-specific part to be
   upstreamed via the arm64 tree

 - CPU feature detection reworked to cope with heterogeneous systems
   where CPUs may not have exactly the same features.  The features
   reported by the kernel via internal data structures or ELF_HWCAP are
   delayed until all the CPUs are up (and before user space starts)

 - Support for 16KB pages, with the additional bonus of a 36-bit VA
   space, though the latter only depending on EXPERT

 - Implement native {relaxed, acquire, release} atomics for arm64

 - New ASID allocation algorithm which avoids IPI on roll-over, together
   with TLB invalidation optimisations (using local vs global where
   feasible)

 - KASan support for arm64

 - EFI_STUB clean-up and isolation for the kernel proper (required by
   KASan)

 - copy_{to,from,in}_user optimisations (sharing the memcpy template)

 - perf: moving arm64 to the arm32/64 shared PMU framework

 - L1_CACHE_BYTES increased to 128 to accommodate Cavium hardware

 - Support for the contiguous PTE hint on kernel mapping (16 consecutive
   entries may be able to use a single TLB entry)

 - Generic CONFIG_HZ now used on arm64

 - defconfig updates

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (91 commits)
  arm64/efi: fix libstub build under CONFIG_MODVERSIONS
  ARM64: Enable multi-core scheduler support by default
  arm64/efi: move arm64 specific stub C code to libstub
  arm64: page-align sections for DEBUG_RODATA
  arm64: Fix build with CONFIG_ZONE_DMA=n
  arm64: Fix compat register mappings
  arm64: Increase the max granular size
  arm64: remove bogus TASK_SIZE_64 check
  arm64: make Timer Interrupt Frequency selectable
  arm64/mm: use PAGE_ALIGNED instead of IS_ALIGNED
  arm64: cachetype: fix definitions of ICACHEF_* flags
  arm64: cpufeature: declare enable_cpu_capabilities as static
  genirq: Make the cpuhotplug migration code less noisy
  arm64: Constify hwcap name string arrays
  arm64/kvm: Make use of the system wide safe values
  arm64/debug: Make use of the system wide safe value
  arm64: Move FP/ASIMD hwcap handling to common code
  arm64/HWCAP: Use system wide safe values
  arm64/capabilities: Make use of system wide safe value
  arm64: Delay cpu feature capability checks
  ...

Pull s390 updates from Martin Schwidefsky:
 "There is only one new feature in this pull for the 4.4 merge window,
  most of it is small enhancements, cleanup and bug fixes:

   - Add the s390 backend for the software dirty bit tracking.  This
     adds two new pgtable functions pte_clear_soft_dirty and
     pmd_clear_soft_dirty which is why there is a hit to
     arch/x86/include/asm/pgtable.h in this pull request.

   - A series of cleanup patches for the AP bus, this includes the
     removal of the support for two outdated crypto cards (PCICC and
     PCICA).

   - The irq handling / signaling on buffer full in the runtime
     instrumentation code is dropped.

   - Some micro optimizations: remove unnecessary memory barriers for a
     couple of functions: [smb_]rmb, [smb_]wmb, atomics, bitops, and for
     spin_unlock.  Use the builtin bswap if available and make
     test_and_set_bit_lock more cache friendly.

   - Statistics and a tracepoint for the diagnose calls to the
     hypervisor.

   - The CPU measurement facility support to sample KVM guests is
     improved.

   - The vector instructions are now always enabled for user space
     processes if the hardware has the vector facility.  This simplifies
     the FPU handling code.  The fpu-internal.h header is split into fpu
     internals, api and types just like x86.

   - Cleanup and improvements for the common I/O layer.

   - Rework udelay to solve a problem with kprobe.  udelay has busy loop
     semantics but still uses an idle processor state for the wait"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (66 commits)
  s390: remove runtime instrumentation interrupts
  s390/cio: de-duplicate subchannel validation
  s390/css: unneeded initialization in for_each_subchannel
  s390/Kconfig: use builtin bswap
  s390/dasd: fix disconnected device with valid path mask
  s390/dasd: fix invalid PAV assignment after suspend/resume
  s390/dasd: fix double free in dasd_eckd_read_conf
  s390/kernel: fix ptrace peek/poke for floating point registers
  s390/cio: move ccw_device_stlck functions
  s390/cio: move ccw_device_call_handler
  s390/topology: reduce per_cpu() invocations
  s390/nmi: reduce size of percpu variable
  s390/nmi: fix terminology
  s390/nmi: remove casts
  s390/nmi: remove pointless error strings
  s390: don't store registers on disabled wait anymore
  s390: get rid of __set_psw_mask()
  s390/fpu: split fpu-internal.h into fpu internals, api, and type headers
  s390/dasd: fix list_del corruption after lcu changes
  s390/spinlock: remove unneeded serializations at unlock
  ...

Pull parisc updates from Helge Deller:
 "The most important change is that we reduce L1_CACHE_BYTES to 16
  bytes, for which a trivial patch for XPS in the network layer was
  needed.  Then we wire up the sys_membarrier and userfaultfd syscalls
  and added two other small cleanups"

* 'parisc-4.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Change L1_CACHE_BYTES to 16
  net/xps: Fix calculation of initial number of xps queues
  parisc: reduce syslog debug output
  parisc: serial/mux: Convert to uart_console_device instead of open-coded
  parisc: Wire up userfaultfd syscall
  parisc: allocate sys_membarrier system call number

Pull IDE fixlet from David Miller:
 "Just a y2038 fix to the pdc202xx_new IDE driver"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide:
  ide: pdc202xx_new: Replace timeval with ktime_t

Pull networking updates from David Miller:

Changes of note:

 1) Allow to schedule ICMP packets in IPVS, from Alex Gartrell.

 2) Provide FIB table ID in ipv4 route dumps just as ipv6 does, from
    David Ahern.

 3) Allow the user to ask for the statistics to be filtered out of
    ipv4/ipv6 address netlink dumps.  From Sowmini Varadhan.

 4) More work to pass the network namespace context around deep into
    various packet path APIs, starting with the netfilter hooks.  From
    Eric W Biederman.

 5) Add layer 2 TX/RX checksum offloading to qeth driver, from Thomas
    Richter.

 6) Use usec resolution for SYN/ACK RTTs in TCP, from Yuchung Cheng.

 7) Support Very High Throughput in wireless MESH code, from Bob
    Copeland.

 8) Allow setting the ageing_time in switchdev/rocker.  From Scott
    Feldman.

 9) Properly autoload L2TP type modules, from Stephen Hemminger.

10) Fix and enable offload features by default in 8139cp driver, from
    David Woodhouse.

11) Support both ipv4 and ipv6 sockets in a single vxlan device, from
    Jiri Benc.

12) Fix CWND limiting of thin streams in TCP, from Bendik Rønning
    Opstad.

13) Fix IPSEC flowcache overflows on large systems, from Steffen
    Klassert.

14) Convert bridging to track VLANs using rhashtable entries rather than
    a bitmap.  From Nikolay Aleksandrov.

15) Make TCP listener handling completely lockless, this is a major
    accomplishment.  Incoming request sockets now live in the
    established hash table just like any other socket too.

    From Eric Dumazet.

15) Provide more bridging attributes to netlink, from Nikolay
    Aleksandrov.

16) Use hash based algorithm for ipv4 multipath routing, this was very
    long overdue.  From Peter Nørlund.

17) Several y2038 cures, mostly avoiding timespec.  From Arnd Bergmann.

18) Allow non-root execution of EBPF programs, from Alexei Starovoitov.

19) Support SO_INCOMING_CPU as setsockopt, from Eric Dumazet.  This
    influences the port binding selection logic used by SO_REUSEPORT.

20) Add ipv6 support to VRF, from David Ahern.

21) Add support for Mellanox Spectrum switch ASIC, from Jiri Pirko.

22) Add rtl8xxxu Realtek wireless driver, from Jes Sorensen.

23) Implement RACK loss recovery in TCP, from Yuchung Cheng.

24) Support multipath routes in MPLS, from Roopa Prabhu.

25) Fix POLLOUT notification for listening sockets in AF_UNIX, from Eric
    Dumazet.

26) Add new QED Qlogic river, from Yuval Mintz, Manish Chopra, and
    Sudarsana Kalluru.

27) Don't fetch timestamps on AF_UNIX sockets, from Hannes Frederic
    Sowa.

28) Support ipv6 geneve tunnels, from John W Linville.

29) Add flood control support to switchdev layer, from Ido Schimmel.

30) Fix CHECKSUM_PARTIAL handling of potentially fragmented frames, from
    Hannes Frederic Sowa.

31) Support persistent maps and progs in bpf, from Daniel Borkmann.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1790 commits)
  sh_eth: use DMA barriers
  switchdev: respect SKIP_EOPNOTSUPP flag in case there is no recursion
  net: sched: kill dead code in sch_choke.c
  irda: Delete an unnecessary check before the function call "irlmp_unregister_service"
  net: dsa: mv88e6xxx: include DSA ports in VLANs
  net: dsa: mv88e6xxx: disable SA learning for DSA and CPU ports
  net/core: fix for_each_netdev_feature
  vlan: Invoke driver vlan hooks only if device is present
  arcnet/com20020: add LEDS_CLASS dependency
  bpf, verifier: annotate verbose printer with __printf
  dp83640: Only wait for timestamps for packets with timestamping enabled.
  ptp: Change ptp_class to a proper bitmask
  dp83640: Prune rx timestamp list before reading from it
  dp83640: Delay scheduled work.
  dp83640: Include hash in timestamp/packet matching
  ipv6: fix tunnel error handling
  net/mlx5e: Fix LSO vlan insertion
  net/mlx5e: Re-eanble client vlan TX acceleration
  net/mlx5e: Return error in case mlx5e_set_features() fails
  net/mlx5e: Don't allow more than max supported channels
  ...

Pull crypto update from Herbert Xu:
 "API:

   - Add support for cipher output IVs in testmgr
   - Add missing crypto_ahash_blocksize helper
   - Mark authenc and des ciphers as not allowed under FIPS.

Algorithms:

   - Add CRC support to 842 compression
   - Add keywrap algorithm
   - A number of changes to the akcipher interface:
      + Separate functions for setting public/private keys.
      + Use SG lists.

Drivers:

   - Add Intel SHA Extension optimised SHA1 and SHA256
   - Use dma_map_sg instead of custom functions in crypto drivers
   - Add support for STM32 RNG
   - Add support for ST RNG
   - Add Device Tree support to exynos RNG driver
   - Add support for mxs-dcp crypto device on MX6SL
   - Add xts(aes) support to caam
   - Add ctr(aes) and xts(aes) support to qat
   - A large set of fixes from Russell King for the marvell/cesa driver"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (115 commits)
  crypto: asymmetric_keys - Fix unaligned access in x509_get_sig_params()
  crypto: akcipher - Don't #include crypto/public_key.h as the contents aren't used
  hwrng: exynos - Add Device Tree support
  hwrng: exynos - Fix missing configuration after suspend to RAM
  hwrng: exynos - Add timeout for waiting on init done
  dt-bindings: rng: Describe Exynos4 PRNG bindings
  crypto: marvell/cesa - use __le32 for hardware descriptors
  crypto: marvell/cesa - fix missing cpu_to_le32() in mv_cesa_dma_add_op()
  crypto: marvell/cesa - use memcpy_fromio()/memcpy_toio()
  crypto: marvell/cesa - use gfp_t for gfp flags
  crypto: marvell/cesa - use dma_addr_t for cur_dma
  crypto: marvell/cesa - use readl_relaxed()/writel_relaxed()
  crypto: caam - fix indentation of close braces
  crypto: caam - only export the state we really need to export
  crypto: caam - fix non-block aligned hash calculation
  crypto: caam - avoid needlessly saving and restoring caam_hash_ctx
  crypto: caam - print errno code when hash registration fails
  crypto: marvell/cesa - fix memory leak
  crypto: marvell/cesa - fix first-fragment handling in mv_cesa_ahash_dma_last_req()
  crypto: marvell/cesa - rearrange handling for sw padded hashes
  ...

Pull x86 platform changes from Ingo Molnar:
 "Misc updates to the Intel MID and SGI UV platforms"

* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/intel-mid: Make intel_mid_ops static
  arch/x86/intel-mid: Use kmemdup rather than duplicating its implementation
  x86/platform/uv: Implement simple dump failover if kdump fails
  x86/platform/uv: Insert per_cpu accessor function on uv_hub_nmi

Pull x86 mm changes from Ingo Molnar:
 "The main changes are: continued PAT work by Toshi Kani, plus a new
  boot time warning about insecure RWX kernel mappings, by Stephen
  Smalley.

  The new CONFIG_DEBUG_WX=y warning is marked default-y if
  CONFIG_DEBUG_RODATA=y is already eanbled, as a special exception, as
  these bugs are hard to notice and this check already found several
  live bugs"

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Warn on W^X mappings
  x86/mm: Fix no-change case in try_preserve_large_page()
  x86/mm: Fix __split_large_page() to handle large PAT bit
  x86/mm: Fix try_preserve_large_page() to handle large PAT bit
  x86/mm: Fix gup_huge_p?d() to handle large PAT bit
  x86/mm: Fix slow_virt_to_phys() to handle large PAT bit
  x86/mm: Fix page table dump to show PAT bit
  x86/asm: Add pud_pgprot() and pmd_pgprot()
  x86/asm: Fix pud/pmd interfaces to handle large PAT bit
  x86/asm: Add pud/pmd mask interfaces to handle large PAT bit
  x86/asm: Move PUD_PAGE macros to page_types.h
  x86/vdso32: Define PGTABLE_LEVELS to 32bit VDSO

Pull x86 sigcontext header cleanups from Ingo Molnar:
 "This series reorganizes and cleans up various aspects of the main
  sigcontext UAPI headers, such as unifying the data structures and
  updating/adding lots of comments to explain all the ABI details and
  quirks.  The headers can now also be built in user-space standalone"

* 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/headers: Clean up too long lines
  x86/headers: Remove <asm/sigcontext.h> references on the kernel side
  x86/headers: Remove direct sigcontext32.h uses
  x86/headers: Convert sigcontext_ia32 uses to sigcontext_32
  x86/headers: Unify 'struct sigcontext_ia32' and 'struct sigcontext_32'
  x86/headers: Make sigcontext pointers bit independent
  x86/headers: Move the 'struct sigcontext' definitions into the UAPI header
  x86/headers: Clean up the kernel's struct sigcontext types to be ABI-clean
  x86/headers: Convert uses of _fpstate_ia32 to _fpstate_32
  x86/headers: Unify 'struct _fpstate_ia32' and i386 struct _fpstate
  x86/headers: Unify register type definitions between 32-bit compat and i386
  x86/headers: Use ABI types consistently in sigcontext*.h
  x86/headers: Separate out legacy user-space structure definitions
  x86/headers: Clean up and better document uapi/asm/sigcontext.h
  x86/headers: Clean up uapi/asm/sigcontext32.h
  x86/headers: Fix (old) header file dependency bug in uapi/asm/sigcontext32.h

Pull x86 fpu changes from Ingo Molnar:
 "There are two main areas of changes:

   - Rework of the extended FPU state code to robustify the kernel's
     usage of cpuid provided xstate sizes - and related changes (Dave
     Hansen)"

   - math emulation enhancements: new modern FPU instructions support,
     with testcases, plus cleanups (Denys Vlasnko)"

* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  x86/fpu: Fixup uninitialized feature_name warning
  x86/fpu/math-emu: Add support for FISTTP instructions
  x86/fpu/math-emu, selftests: Add test for FISTTP instructions
  x86/fpu/math-emu: Add support for FCMOVcc insns
  x86/fpu/math-emu: Add support for F[U]COMI[P] insns
  x86/fpu/math-emu: Remove define layer for undocumented opcodes
  x86/fpu/math-emu, selftests: Add tests for FCMOV and FCOMI insns
  x86/fpu/math-emu: Remove !NO_UNDOC_CODE
  x86/fpu: Check CPU-provided sizes against struct declarations
  x86/fpu: Check to ensure increasing-offset xstate offsets
  x86/fpu: Correct and check XSAVE xstate size calculations
  x86/fpu: Add C structures for AVX-512 state components
  x86/fpu: Rework YMM definition
  x86/fpu/mpx: Rework MPX 'xstate' types
  x86/fpu: Add xfeature_enabled() helper instead of test_bit()
  x86/fpu: Remove 'xfeature_nr'
  x86/fpu: Rework XSTATE_* macros to remove magic '2'
  x86/fpu: Rename XFEATURES_NR_MAX
  x86/fpu: Rename XSAVE macros
  x86/fpu: Remove partial LWP support definitions
  ...

Pull x86 kgdb fixlet from Ingo Molnar:
 "A single debugging related commit: compress the memory usage of a kgdb
  data structure"

* 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/kgdb: Replace bool_int_array[NR_CPUS] with bitmap

Pull x86 cpu changes from Ingo Molnar:
 "Two changes in this cycle: a Kconfig help text enhancement, and an AMD
  CLZERO instruction capability detection and enumeration"

* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Add CLZERO detection
  x86/Kconfig/cpus: Fix/complete CPU type help texts

Pull x86 cleanups from Ingo Molnar:
 "An early_printk cleanup plus deinlining enhancements"

* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/early_printk: Set __iomem address space for IO
  x86/signal: Deinline get_sigframe, save 240 bytes
  x86: Deinline early_console_register, save 403 bytes
  x86/e820: Deinline e820_type_to_string, save 126 bytes

Pull x86 boot cleanup from Ingo Molnar:
 "A single commit: remove an obsolete kcrash boot flag"

* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/kexec: Remove obsolete 'in_crash_kexec' flag

Pull x86 asm changes from Ingo Molnar:
 "The main change in this cycle is another step in the big x86 system
  call interface rework by Andy Lutomirski, which moves most of the low
  level x86 entry code from assembly to C, for all syscall entries
  except native 64-bit system calls:

    arch/x86/entry/entry_32.S        | 182 ++++------
    arch/x86/entry/entry_64_compat.S | 547 ++++++++-----------------------
    194 insertions(+), 535 deletions(-)

  ... our hope is that the final remaining step (converting native
  64-bit system calls) will be less painful as all the previous steps,
  given that most of the legacies and quirks are concentrated around
  native 32-bit and compat environments"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits)
  x86/entry/32: Fix FS and GS restore in opportunistic SYSEXIT
  x86/entry/32: Fix entry_INT80_32() to expect interrupts to be on
  um/x86: Fix build after x86 syscall changes
  x86/asm: Remove the xyz_cfi macros from dwarf2.h
  selftests/x86: Style fixes for the 'unwind_vdso' test
  x86/entry/64/compat: Document sysenter_fix_flags's reason for existence
  x86/entry: Split and inline syscall_return_slowpath()
  x86/entry: Split and inline prepare_exit_to_usermode()
  x86/entry: Use pt_regs_to_thread_info() in syscall entry tracing
  x86/entry: Hide two syscall entry assertions behind CONFIG_DEBUG_ENTRY
  x86/entry: Micro-optimize compat fast syscall arg fetch
  x86/entry: Force inlining of 32-bit syscall code
  x86/entry: Make irqs_disabled checks in exit code depend on lockdep
  x86/entry: Remove unnecessary IRQ twiddling in fast 32-bit syscalls
  x86/asm: Remove thread_info.sysenter_return
  x86/entry/32: Re-implement SYSENTER using the new C path
  x86/entry/32: Switch INT80 to the new C syscall path
  x86/entry/32: Open-code return tracking from fork and kthreads
  x86/entry/compat: Implement opportunistic SYSRETL for compat syscalls
  x86/vdso/compat: Wire up SYSENTER and SYSCSALL for compat userspace
  ...

Pull x86 apic changes from Ingo Molnar:
 "The main changes in this cycle were:

   - Numachip updates: new hardware support, fixes and cleanups.
     (Daniel J Blueman)

   - misc smaller cleanups and fixlets"

* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/io_apic: Make eoi_ioapic_pin() static
  x86/irq: Drop unlikely before IS_ERR_OR_NULL
  x86/x2apic: Make stub functions available even if !CONFIG_X86_LOCAL_APIC
  x86/apic: Deinline various functions
  x86/numachip: Fix timer build conflict
  x86/numachip: Introduce Numachip2 timer mechanisms
  x86/numachip: Add Numachip IPI optimisations
  x86/numachip: Add Numachip2 APIC support
  x86/numachip: Cleanup Numachip support

Pull scheduler changes from Ingo Molnar:
 "The main changes in this cycle were:

   - sched/fair load tracking fixes and cleanups (Byungchul Park)

   - Make load tracking frequency scale invariant (Dietmar Eggemann)

   - sched/deadline updates (Juri Lelli)

   - stop machine fixes, cleanups and enhancements for bugs triggered by
     CPU hotplug stress testing (Oleg Nesterov)

   - scheduler preemption code rework: remove PREEMPT_ACTIVE and related
     cleanups (Peter Zijlstra)

   - Rework the sched_info::run_delay code to fix races (Peter Zijlstra)

   - Optimize per entity utilization tracking (Peter Zijlstra)

   - ... misc other fixes, cleanups and smaller updates"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits)
  sched: Don't scan all-offline ->cpus_allowed twice if !CONFIG_CPUSETS
  sched: Move cpu_active() tests from stop_two_cpus() into migrate_swap_stop()
  sched: Start stopper early
  stop_machine: Kill cpu_stop_threads->setup() and cpu_stop_unpark()
  stop_machine: Kill smp_hotplug_thread->pre_unpark, introduce stop_machine_unpark()
  stop_machine: Change cpu_stop_queue_two_works() to rely on stopper->enabled
  stop_machine: Introduce __cpu_stop_queue_work() and cpu_stop_queue_two_works()
  stop_machine: Ensure that a queued callback will be called before cpu_stop_park()
  sched/x86: Fix typo in __switch_to() comments
  sched/core: Remove a parameter in the migrate_task_rq() function
  sched/core: Drop unlikely behind BUG_ON()
  sched/core: Fix task and run queue sched_info::run_delay inconsistencies
  sched/numa: Fix task_tick_fair() from disabling numa_balancing
  sched/core: Add preempt_count invariant check
  sched/core: More notrace annotations
  sched/core: Kill PREEMPT_ACTIVE
  sched/core, sched/x86: Kill thread_info::saved_preempt_count
  sched/core: Simplify preempt_count tests
  sched/core: Robustify preemption leak checks
  sched/core: Stop setting PREEMPT_ACTIVE
  ...

Pull RAS changes from Ingo Molnar:
 "The main system reliability related changes were from x86, but also
  some generic RAS changes:

   - AMD MCE error injection subsystem enhancements.  (Aravind
     Gopalakrishnan)

   - Fix MCE and CPU hotplug interaction bug.  (Ashok Raj)

   - kcrash bootup robustness fix.  (Baoquan He)

   - kcrash cleanups.  (Borislav Petkov)

   - x86 microcode driver rework: simplify it by unmodularizing it and
     other cleanups.  (Borislav Petkov)"

* 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  x86/mce: Add a default case to the switch in __mcheck_cpu_ancient_init()
  x86/mce: Add a Scalable MCA vendor flags bit
  MAINTAINERS: Unify the microcode driver section
  x86/microcode/intel: Move #ifdef DEBUG inside the function
  x86/microcode/amd: Remove maintainers from comments
  x86/microcode: Remove modularization leftovers
  x86/microcode: Merge the early microcode loader
  x86/microcode: Unmodularize the microcode driver
  x86/mce: Fix thermal throttling reporting after kexec
  kexec/crash: Say which char is the unrecognized
  x86/setup/crash: Check memblock_reserve() retval
  x86/setup/crash: Cleanup some more
  x86/setup/crash: Remove alignment variable
  x86/setup: Cleanup crashkernel reservation functions
  x86/amd_nb, EDAC: Rename amd_get_node_id()
  x86/setup: Do not reserve crashkernel high memory if low reservation failed
  x86/microcode/amd: Do not overwrite final patch levels
  x86/microcode/amd: Extract current patch level read to a function
  x86/ras/mce_amd_inj: Inject bank 4 errors on the NBC
  x86/ras/mce_amd_inj: Trigger deferred and thresholding errors interrupts
  ...

Pull perf updates from Ingo Molnar:
 "Kernel side changes:

   - Improve accuracy of perf/sched clock on x86.  (Adrian Hunter)

   - Intel DS and BTS updates.  (Alexander Shishkin)

   - Intel cstate PMU support.  (Kan Liang)

   - Add group read support to perf_event_read().  (Peter Zijlstra)

   - Branch call hardware sampling support, implemented on x86 and
     PowerPC.  (Stephane Eranian)

   - Event groups transactional interface enhancements.  (Sukadev
     Bhattiprolu)

   - Enable proper x86/intel/uncore PMU support on multi-segment PCI
     systems.  (Taku Izumi)

   - ... misc fixes and cleanups.

  The perf tooling team was very busy again with 200+ commits, the full
  diff doesn't fit into lkml size limits.  Here's an (incomplete) list
  of the tooling highlights:

  New features:

   - Change the default event used in all tools (record/top): use the
     most precise "cycles" hw counter available, i.e. when the user
     doesn't specify any event, it will try using cycles:ppp, cycles:pp,
     etc and fall back transparently until it finds a working counter.
     (Arnaldo Carvalho de Melo)

   - Integration of perf with eBPF that, given an eBPF .c source file
     (or .o file built for the 'bpf' target with clang), will get it
     automatically built, validated and loaded into the kernel via the
     sys_bpf syscall, which can then be used and seen using 'perf trace'
     and other tools.

     (Wang Nan)

  Various user interface improvements:

   - Automatic pager invocation on long help output.  (Namhyung Kim)

   - Search for more options when passing args to -h, e.g.: (Arnaldo
     Carvalho de Melo)

        $ perf report -h interface

        Usage: perf report [<options>]

         --gtk    Use the GTK2 interface
         --stdio  Use the stdio interface
         --tui    Use the TUI interface

   - Show ordered command line options when -h is used or when an
     unknown option is specified.  (Arnaldo Carvalho de Melo)

   - If options are passed after -h, show just its descriptions, not all
     options.  (Arnaldo Carvalho de Melo)

   - Implement column based horizontal scrolling in the hists browser
     (top, report), making it possible to use the TUI for things like
     'perf mem report' where there are many more columns than can fit in
     a terminal.  (Arnaldo Carvalho de Melo)

   - Enhance the error reporting of tracepoint event parsing, e.g.:

       $ oldperf record -e sched:sched_switc usleep 1
       event syntax error: 'sched:sched_switc'
                            \___ unknown tracepoint
       Run 'perf list' for a list of valid events

     Now we get the much nicer:

       $ perf record -e sched:sched_switc ls
       event syntax error: 'sched:sched_switc'
                            \___ can't access trace events

       Error: No permissions to read /sys/kernel/debug/tracing/events/sched/sched_switc
       Hint:  Try 'sudo mount -o remount,mode=755 /sys/kernel/debug'

     And after we have those mount point permissions fixed:

       $ perf record -e sched:sched_switc ls
       event syntax error: 'sched:sched_switc'
                            \___ unknown tracepoint

       Error: File /sys/kernel/debug/tracing/events/sched/sched_switc not found.
       Hint:  Perhaps this kernel misses some CONFIG_ setting to enable this feature?.

     I.e.  basically now the event parsing routing uses the strerror_open()
     routines introduced by and used in 'perf trace' work.  (Jiri Olsa)

   - Fail properly when pattern matching fails to find a tracepoint,
     i.e. '-e non:existent' was being correctly handled, with a proper
     error message about that not being a valid event, but '-e
     non:existent*' wasn't, fix it.  (Jiri Olsa)

   - Do event name substring search as last resort in 'perf list'.
     (Arnaldo Carvalho de Melo)

     E.g.:

       # perf list clock

       List of pre-defined events (to be used in -e):

        cpu-clock                                          [Software event]
        task-clock                                         [Software event]

        uncore_cbox_0/clockticks/                          [Kernel PMU event]
        uncore_cbox_1/clockticks/                          [Kernel PMU event]

        kvm:kvm_pvclock_update                             [Tracepoint event]
        kvm:kvm_update_master_clock                        [Tracepoint event]
        power:clock_disable                                [Tracepoint event]
        power:clock_enable                                 [Tracepoint event]
        power:clock_set_rate                               [Tracepoint event]
        syscalls:sys_enter_clock_adjtime                   [Tracepoint event]
        syscalls:sys_enter_clock_getres                    [Tracepoint event]
        syscalls:sys_enter_clock_gettime                   [Tracepoint event]
        syscalls:sys_enter_clock_nanosleep                 [Tracepoint event]
        syscalls:sys_enter_clock_settime                   [Tracepoint event]
        syscalls:sys_exit_clock_adjtime                    [Tracepoint event]
        syscalls:sys_exit_clock_getres                     [Tracepoint event]
        syscalls:sys_exit_clock_gettime                    [Tracepoint event]
        syscalls:sys_exit_clock_nanosleep                  [Tracepoint event]
        syscalls:sys_exit_clock_settime                    [Tracepoint event]

  Intel PT hardware tracing enhancements:

   - Accept a zero --itrace period, meaning "as often as possible".  In
     the case of Intel PT that is the same as a period of 1 and a unit
     of 'instructions' (i.e.  --itrace=i1i).  (Adrian Hunter)

   - Harmonize itrace's synthesized callchains with the existing
     --max-stack tool option.  (Adrian Hunter)

   - Allow time to be displayed in nanoseconds in 'perf script'.
     (Adrian Hunter)

   - Fix potential infinite loop when handling Intel PT timestamps.
     (Adrian Hunter)

   - Slighly improve Intel PT debug logging.  (Adrian Hunter)

   - Warn when AUX data has been lost, just like when processing
     PERF_RECORD_LOST.  (Adrian Hunter)

   - Further document export-to-postgresql.py script.  (Adrian Hunter)

   - Add option to synthesize branch stack from auxtrace data.  (Adrian
     Hunter)

  Misc notable changes:

   - Switch the default callchain output mode to 'graph,0.5,caller', to
     make it look like the default for other tools, reducing the
     learning curve for people used to 'caller' based viewing.  (Arnaldo
     Carvalho de Melo)

   - various call chain usability enhancements.  (Namhyung Kim)

   - Introduce the 'P' event modifier, meaning 'max precision level,
     please', i.e.:

        $ perf record -e cycles:P usleep 1

     Is now similar to:

        $ perf record usleep 1

     Useful, for instance, when specifying multiple events.  (Jiri Olsa)

   - Add 'socket' sort entry, to sort by the processor socket in 'perf
     top' and 'perf report'.  (Kan Liang)

   - Introduce --socket-filter to 'perf report', for filtering by
     processor socket.  (Kan Liang)

   - Add new "Zoom into Processor Socket" operation in the perf hists
     browser, used in 'perf top' and 'perf report'.  (Kan Liang)

   - Allow probing on kmodules without DWARF.  (Masami Hiramatsu)

   - Fix 'perf probe -l' for probes added to kernel module functions.
     (Masami Hiramatsu)

   - Preparatory work for the 'perf stat record' feature that will allow
     generating perf.data files with counting data in addition to the
     sampling mode we have now (Jiri Olsa)

   - Update libtraceevent KVM plugin.  (Paolo Bonzini)

   - ... plus lots of other enhancements that I failed to list properly,
     by: Adrian Hunter, Alexander Shishkin, Andi Kleen, Andrzej Hajda,
     Arnaldo Carvalho de Melo, Dima Kogan, Don Zickus, Geliang Tang, He
     Kuang, Huaitong Han, Ingo Molnar, Jan Stancek, Jiri Olsa, Kan
     Liang, Kirill Tkhai, Masami Hiramatsu, Matt Fleming, Namhyung Kim,
     Paolo Bonzini, Peter Zijlstra, Rabin Vincent, Scott Wood, Stephane
     Eranian, Sukadev Bhattiprolu, Taku Izumi, Vaishali Thakkar, Wang
     Nan, Yang Shi and Yunlong Song"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (260 commits)
  perf unwind: Pass symbol source to libunwind
  tools build: Fix libiberty feature detection
  perf tools: Compile scriptlets to BPF objects when passing '.c' to --event
  perf record: Add clang options for compiling BPF scripts
  perf bpf: Attach eBPF filter to perf event
  perf tools: Make sure fixdep is built before libbpf
  perf script: Enable printing of branch stack
  perf trace: Add cmd string table to decode sys_bpf first arg
  perf bpf: Collect perf_evsel in BPF object files
  perf tools: Load eBPF object into kernel
  perf tools: Create probe points for BPF programs
  perf tools: Enable passing bpf object file to --event
  perf ebpf: Add the libbpf glue
  perf tools: Make perf depend on libbpf
  perf symbols: Fix endless loop in dso__split_kallsyms_for_kcore
  perf tools: Enable pre-event inherit setting by config terms
  perf symbols: we can now read separate debug-info files based on a build ID
  perf symbols: Fix type error when reading a build-id
  perf tools: Search for more options when passing args to -h
  perf stat: Cache aggregated map entries in extra cpumap
  ...

This seems to be a mis-reading of how alpha memory ordering works, and
is not backed up by the alpha architecture manual.  The helper functions
don't do anything special on any other architectures, and the arguments
that support them being safe on other architectures also argue that they
are safe on alpha.

Basically, the "control dependency" is between a previous read and a
subsequent write that is dependent on the value read.  Even if the
subsequent write is actually done speculatively, there is no way that
such a speculative write could be made visible to other cpu's until it
has been committed, which requires validating the speculation.

Note that most weakely ordered architectures (very much including alpha)
do not guarantee any ordering relationship between two loads that depend
on each other on a control dependency:

    read A
    if (val == 1)
        read B

because the conditional may be predicted, and the "read B" may be
speculatively moved up to before reading the value A.  So we require the
user to insert a smp_rmb() between the two accesses to be correct:

    read A;
    if (A == 1)
        smp_rmb()
        read B

Alpha is further special in that it can break that ordering even if the
*address* of B depends on the read of A, because the cacheline that is
read later may be stale unless you have a memory barrier in between the
pointer read and the read of the value behind a pointer:

    read ptr
    read offset(ptr)

whereas all other weakly ordered architectures guarantee that the data
dependency (as opposed to just a control dependency) will order the two
accesses.  As a result, alpha needs a "smp_read_barrier_depends()" in
between those two reads for them to be ordered.

The coontrol dependency that "READ_ONCE_CTRL()" and "atomic_read_ctrl()"
had was a control dependency to a subsequent *write*, however, and
nobody can finalize such a subsequent write without having actually done
the read.  And were you to write such a value to a "stale" cacheline
(the way the unordered reads came to be), that would seem to lose the
write entirely.

So the things that make alpha able to re-order reads even more
aggressively than other weak architectures do not seem to be relevant
for a subsequent write.  Alpha memory ordering may be strange, but
there's no real indication that it is *that* strange.

Also, the alpha architecture reference manual very explicitly talks
about the definition of "Dependence Constraints" in section 5.6.1.7,
where a preceding read dominates a subsequent write.

Such a dependence constraint admittedly does not impose a BEFORE (alpha
architecture term for globally visible ordering), but it does guarantee
that there can be no "causal loop".  I don't see how you could avoid
such a loop if another cpu could see the stored value and then impact
the value of the first read.  Put another way: the read and the write
could not be seen as being out of order wrt other cpus.

So I do not see how these "x_ctrl()" functions can currently be necessary.

I may have to eat my words at some point, but in the absense of clear
proof that alpha actually needs this, or indeed even an explanation of
how alpha could _possibly_ need it, I do not believe these functions are
called for.

And if it turns out that alpha really _does_ need a barrier for this
case, that barrier still should not be "smp_read_barrier_depends()".
We'd have to make up some new speciality barrier just for alpha, along
with the documentation for why it really is necessary.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul E McKenney <paulmck@us.ibm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>