When CONFIG_PCC is disabled, pcc_mbox_request_channel() needs to
return ERR_PTR(-ENODEV), not a NULL pointer, as the callers of
this function use IS_ERR() to check for error code.
Signed-off-by: Duc Dang <dhdang@apm.com>
Signed-off-by: Hoan Tran <hotran@apm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

For PCC mailbox with interrupt flag, CPPC should call mbox_chan_txdone()
function to notify the mailbox framework about TX completion.
Signed-off-by: Hoan Tran <hotran@apm.com>
Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Since struct cpudata is defined in a header file, add prefix cppc_ to
make it not a generic name. Otherwise it causes compile issue in locally
define structure with the same name.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The CPPC registers can also be accessed via functional fixed hardware
addresse(FFH) in X86. Add support by modifying cpc_read and cpc_write to
be able to read/write MSRs on x86 platform on per cpu basis.
Also with this change, acpi_cppc_processor_probe doesn't bail out if
address space id is not equal to PCC or memory address space and FFH
is supported on the system.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

It is still possible to continue even CPPC data is invalid or missing.
Suggested-by: Alexey Klimov <alexey.klimov@arm.com>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Some newer x86 platforms have support for both _CPC and _PSS object. So
kernel config can have both ACPI_CPU_FREQ_PSS and ACPI_CPPC_LIB. So remove
restriction for ACPI_CPPC_LIB to build only when ACPI_CPU_FREQ_PSS is not
defined.
Also for legacy systems with only _PSS, we shouldn't bail out if
acpi_cppc_processor_probe() fails, if ACPI_CPU_FREQ_PSS is also defined.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCC status field exposes an error bit(2) to indicate any errors during
the execution of last comamnd. This patch checks the error bit before
notifying success/failure to the cpufreq driver.
Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

There are several global variables in cppc driver that are related
to PCC channel used for CPPC. This patch collects all such
information into a single consolidated structure(cppc_pcc_data).
Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The CPPC tables contain entries for per CPU feedback counters which
allows us to compute the delivered performance over a given interval
of time.

The math for delivered performance per the CPPCv5.0+ spec is:
  reference perf * delta(delivered perf ctr)/delta(ref perf ctr)

Maintaining deltas of the counters in the kernel is messy, as it
depends on when the reads are triggered. (e.g. via the cpufreq
->get() interface). Also the ->get() interace only returns one
value, so cant return raw values. So instead, leave it to userspace
to keep track of raw values and do its math for CPUs it cares about.

delivered and reference perf counters are exposed via the same
sysfs file to avoid the potential "skid", if these values are read
individually from userspace.
Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org>
Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Compute the expected transition latency for frequency transitions
using the values from the PCCT tables when the desired perf
register is in PCC.
Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org>
Reviewed-by: Alexey Klimov <alexey.klimov@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

CPPC defined in section 8.4.7 of ACPI 6.0 specification suggests
"To amortize the cost of PCC transactions, OSPM should read or write
all PCC registers via a single read or write command when possible"
This patch enables opportunistic batching of frequency transition
requests whenever the request happen to overlap in time.

Currently the access to pcc is serialized by a spin lock which does
not scale well as we increase the number of cores in the system. This
patch improves the scalability by allowing the differnt CPU cores to
update PCC subspace in parallel and by batching requests which will
reduce the certain types of operation(checking command completion bit,
ringing doorbell) by a significant margin.

Profiling shows significant improvement in the overall effeciency
to service freq. transition requests. With this patch we observe close
to 30% of the frequency transition requests being batched with other
requests while running apache bench on a ARM platform with 6
independent domains(or sets of related cpus).
Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

We need to acquire pcc_lock only when we are accessing registers
that are in the PCC subspsace.
Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

For cases where sys mapped CPC registers need to be accessed
frequently, it helps immensly to pre-map them rather than map
and unmap for each operation. e.g. case where feedback counters
are sys mem map registers.

Restructure cpc_read/write and the cpc_regs structure to allow
pre-mapping the system addresses and unmap them when the CPU exits.
Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI 6.1 has a PCC HW-Reduced Communication Subspace type 2 intended for
use on HW-Reduce ACPI Platform, which requires read-modify-write sequence
to acknowledge doorbell interrupt. This patch provides the implementation
for the Communication Subspace Type 2.
Signed-off-by: Hoan Tran <hotran@apm.com>
Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Pull drm fixes from Dave Airlie:
 "A bunch of fixes covering i915, amdgpu, one tegra and some core DRM
  ones.  Nothing too strange at this point"

* tag 'drm-fixes-for-4.8-rc4' of git://people.freedesktop.org/~airlied/linux: (21 commits)
  drm/atomic: Don't potentially reset color_mgmt_changed on successive property updates.
  drm: Protect fb_defio in drivers with CONFIG_KMS_FBDEV_EMULATION
  drm/amdgpu: skip TV/CV in display parsing
  drm/amdgpu: avoid a possible array overflow
  drm/amdgpu: fix lru size grouping v2
  drm/tegra: dsi: Enhance runtime power management
  drm/i915: Fix botched merge that downgrades CSR versions.
  drm/i915/skl: Ensure pipes with changed wms get added to the state
  drm/i915/gen9: Only copy WM results for changed pipes to skl_hw
  drm/i915/skl: Add support for the SAGV, fix underrun hangs
  drm/i915/gen6+: Interpret mailbox error flags
  drm/i915: Reattach comment, complete type specification
  drm/i915: Unconditionally flush any chipset buffers before execbuf
  drm/i915/gen9: Drop invalid WARN() during data rate calculation
  drm/i915/gen9: Initialize intel_state->active_crtcs during WM sanitization (v2)
  drm: Reject page_flip for !DRIVER_MODESET
  drm/amdgpu: fix timeout value check in amd_sched_job_recovery
  drm/amdgpu: fix sdma_v2_4_ring_test_ib
  drm/amdgpu: fix amdgpu_move_blit on 32bit systems
  drm/radeon: fix radeon_move_blit on 32bit systems
  ...

Due to assigning the 'replaced' value instead of or'ing it,
if drm_atomic_crtc_set_property() gets called multiple times,
the last call will define the color_mgmt_changed flag, so
a non-updating call to a property can reset the flag and
prevent actual hw state updates required by preceding
property updates.
Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: <stable@vger.kernel.org> # v4.6+
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Pull perf fixes from Thomas Gleixner:
 "A few fixes from the perf departement

   - prevent a imbalanced preemption disable in the events teardown code
   - prevent out of bound acces in perf userspace
   - make perf tools compile with UCLIBC again
   - a fix for the userspace unwinder utility"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Use this_cpu_ptr() when stopping AUX events
  perf evsel: Do not access outside hw cache name arrays
  tools lib: Reinstate strlcpy() header guard with __UCLIBC__
  perf unwind: Use addr_location::addr instead of ip for entries

Pull x86 fix from Thomas Gleixner:
 "A single bugfix to prevent irq remapping when the ioapic is disabled"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/apic: Do not init irq remapping if ioapic is disabled

Pull irq fixes from Thomas Gleixner:
 "This lot provides:

   - plug a hotplug race in the new affinity infrastructure
   - a fix for the trigger type of chained interrupts
   - plug a potential memory leak in the core code
   - a few fixes for ARM and MIPS GICs"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/mips-gic: Implement activate op for device domain
  irqchip/mips-gic: Cleanup chip and handler setup
  genirq/affinity: Use get/put_online_cpus around cpumask operations
  genirq: Fix potential memleak when failing to get irq pm
  irqchip/gicv3-its: Disable the ITS before initializing it
  irqchip/gicv3: Remove disabling redistributor and group1 non-secure interrupts
  irqchip/gic: Allow self-SGIs for SMP on UP configurations
  genirq: Correctly configure the trigger on chained interrupts

Pull timer fixes from Thomas Gleixner:
 "A few updates for timers & co:

   - prevent a livelock in the timekeeping code when debugging is
     enabled

   - prevent out of bounds access in the timekeeping debug code

   - various fixes in clocksource drivers

   - a new maintainers entry"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource/drivers/sun4i: Clear interrupts after stopping timer in probe function
  drivers/clocksource/pistachio: Fix memory corruption in init
  clocksource/drivers/timer-atmel-pit: Enable mck clock
  clocksource/drivers/pxa: Fix include files for compilation
  MAINTAINERS: Add ARM ARCHITECTED TIMER entry
  timekeeping: Cap array access in timekeeping_debug
  timekeeping: Avoid taking lock in NMI path with CONFIG_DEBUG_TIMEKEEPING

Pull KVM fixes from Paolo Bonzini:
 "ARM:
   - fixes for ITS init issues, error handling, IRQ leakage, race
     conditions
   - an erratum workaround for timers
   - some removal of misleading use of errors and comments
   - a fix for GICv3 on 32-bit guests

  MIPS:
   - fix for where the guest could wrongly map the first page of
     physical memory

  x86:
   - nested virtualization fixes"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  MIPS: KVM: Check for pfn noslot case
  kvm: nVMX: fix nested tsc scaling
  KVM: nVMX: postpone VMCS changes on MSR_IA32_APICBASE write
  KVM: nVMX: fix msr bitmaps to prevent L2 from accessing L0 x2APIC
  arm64: KVM: report configured SRE value to 32-bit world
  arm64: KVM: remove misleading comment on pmu status
  KVM: arm/arm64: timer: Workaround misconfigured timer interrupt
  arm64: Document workaround for Cortex-A72 erratum #853709
  KVM: arm/arm64: Change misleading use of is_error_pfn
  KVM: arm64: ITS: avoid re-mapping LPIs
  KVM: arm64: check for ITS device on MSI injection
  KVM: arm64: ITS: move ITS registration into first VCPU run
  KVM: arm64: vgic-its: Make updates to propbaser/pendbaser atomic
  KVM: arm64: vgic-its: Plug race in vgic_put_irq
  KVM: arm64: vgic-its: Handle errors from vgic_add_lpi
  KVM: arm64: ITS: return 1 on successful MSI injection

Merge fixes from Andrew Morton:
 "11 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm: silently skip readahead for DAX inodes
  dax: fix device-dax region base
  fs/seq_file: fix out-of-bounds read
  mm: memcontrol: avoid unused function warning
  mm: clarify COMPACTION Kconfig text
  treewide: replace config_enabled() with IS_ENABLED() (2nd round)
  printk: fix parsing of "brl=" option
  soft_dirty: fix soft_dirty during THP split
  sysctl: handle error writing UINT_MAX to u32 fields
  get_maintainer: quiet noisy implicit -f vcs_file_exists checking
  byteswap: don't use __builtin_bswap*() with sparse

Pull ARM64 fix from Catalin Marinas:
 "ARM64 fix to avoid potential TLB conflict when CONFIG_RANDOMIZE_BASE
  is enabled"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: avoid TLB conflict with CONFIG_RANDOMIZE_BASE

Pull rdma fixes from Doug Ledford:
 "Round one of 4.8 rc fixes.

  This should be the bulk of the -rc fixes for 4.8.  I only have a few
  things that are still outstanding (two ipoib bugs for which the
  solution is not yet fully known, and a few queued items that came in
  after my last push and I didn't want to delay this pull request for
  late comers again).

  Even though the patch count is kind of high, everything is minor fixes
  so the overall churn is pretty low.

  Summary:

   - minor fixes to cxgb4
   - minor fixes to mlx4
   - one minor fix each to core, rxe, isert, srpt, mlx5, ocrdma, and usnic
   - six or so fixes to i40iw fixes
   - the rest are hfi1 fixes"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma: (34 commits)
  i40iw: Send last streaming mode message for loopback connections
  IB/srpt: Update sport->port_guid with each port refresh
  RDMA/ocrdma: Fix the max_sge reported from FW
  i40iw: Avoid writing to freed memory
  i40iw: Fix double free of allocated_buffer
  IB/mlx5: Remove superfluous include of io-mapping.h
  i40iw: Do not set self-referencing pointer to NULL after kfree
  i40iw: Add missing NULL check for MPA private data
  iw_cxgb4: Fix cxgb4 arm CQ logic w/IB_CQ_REPORT_MISSED_EVENTS
  i40iw: Add missing check for interface already open
  i40iw: Protect req_resource_num update
  i40iw: Change mem_resources pointer to a u8
  IB/core: Use memdup_user() rather than duplicating its implementation
  IB/qib: Use memdup_user() rather than duplicating its implementation
  iw_cxgb4: use the MPA initiator's IRD if < our ORD
  iw_cxgb4: limit IRD/ORD advertised to ULP by device max.
  IB/hfi1: Fix mm_struct use after free
  IB/rdmvat: Fix double vfree() in rvt_create_qp() error path
  IB/hfi1: Improve J_KEY generation
  IB/hfi1: Return invalid field for non-QSFP CableInfo queries
  ...

Pull sound fixes from Takashi Iwai:
 "Here are a bunch of fixes as you can see in diffstat.

  One core change in ASoC is about the unexpected unbinding error, and
  another about debugfs cleanup.

  The rest are wide-spread driver-specific fixes: a series of LINE6 USB
  fixes, a HD-audio quirk, and various ASoC fixes including OMAP boot
  fixes and Intel SKL fixes"

* tag 'sound-4.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (22 commits)
  ALSA: hda/realtek - fix headset mic detection for MSI MS-B120
  ASoC: omap-mcpdm: Fix irq resource handling
  ASoC: max98371: Add terminate entry for i2c_device_id tables
  ALSA: line6: Fix POD sysfs attributes segfault
  ALSA: line6: Give up on the lock while URBs are released.
  ALSA: line6: Remove double line6_pcm_release() after failed acquire.
  ASoC: omap-abe-twl6040: Correct dmic-codec device registration
  ASoC: core: Clean up DAPM before the card debugfs
  ASoC: omap-mcpdm: Drop pdmclk clock handling
  ASoC: atmel_ssc_dai: Don't unconditionally reset SSC on stream startup
  ASoC: compress: Fix leak of a widget list in soc_compr_open_fe
  ASoC: Intel: Skylake: Fix error return code in skl_probe()
  ASoC: wm2000: Fix return of uninitialised varible
  ASoC: Fix leak of rtd in soc_bind_dai_link
  ASoC: da7213: Default to 64 BCLKs per WCLK to support all formats
  ASoC: nau8825: fix static check error about semaphone control
  ASoC: nau8825: fix bug in playback when suspend
  ASoC: samsung: Fix clock handling in S3C24XX_UDA134X card
  ASoC: simple-card-utils: add missing MODULE_xxx()
  ASoC: Intel: Skylake: Check list empty while getting module info
  ...

Pull btrfs fixes from Chris Mason:
 "We've queued up a few different fixes in here.  These range from
  enospc corners to fsync and quota fixes, and a few targeted at error
  handling for corrupt metadata/fuzzing"

* 'for-linus-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix lockdep warning on deadlock against an inode's log mutex
  Btrfs: detect corruption when non-root leaf has zero item
  Btrfs: check btree node's nritems
  btrfs: don't create or leak aliased root while cleaning up orphans
  Btrfs: fix em leak in find_first_block_group
  btrfs: do not background blkdev_put()
  Btrfs: clarify do_chunk_alloc()'s return value
  btrfs: fix fsfreeze hang caused by delayed iputs deal
  btrfs: update btrfs_space_info's bytes_may_use timely
  btrfs: divide btrfs_update_reserved_bytes() into two functions
  btrfs: use correct offset for reloc_inode in prealloc_file_extent_cluster()
  btrfs: qgroup: Fix qgroup incorrectness caused by log replay
  btrfs: relocation: Fix leaking qgroups numbers on data extents
  btrfs: qgroup: Refactor btrfs_qgroup_insert_dirty_extent()
  btrfs: waiting on qgroup rescan should not always be interruptible
  btrfs: properly track when rescan worker is running
  btrfs: flush_space: treat return value of do_chunk_alloc properly
  Btrfs: add ASSERT for block group's memory leak
  btrfs: backref: Fix soft lockup in __merge_refs function
  Btrfs: fix memory leak of reloc_root

Pull dlm fix from David Teigland:
 "This fixes a bug introduced by recent debugfs cleanup"

* tag 'dlm-4.8-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/linux-dlm:
  dlm: fix malfunction of dlm_tool caused by debugfs changes

Pull device mapper fixes from Mike Snitzer:

 - another stable fix for DM flakey (that tweaks the previous fix that
   didn't factor in expected 'drop_writes' behavior for read IO).

 - a dm-log bio operation flags fix for the broader block changes that
   were merged during the 4.8 merge window.

* tag 'dm-4.8-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm log: fix unitialized bio operation flags
  dm flakey: fix reads to be issued if drop_writes configured

Pull IOMMU fixes from Joerg Roedel:
 "Fixes from Will Deacon:

   - fix a couple of thinkos in the CMDQ error handling and
     short-descriptor page table code that have been there since day one

   - disable stalling faults, since they may result in hardware deadlock

   - fix an accidental BUG() when passing disable_bypass=1 on the
     cmdline"

* tag 'iommu-fixes-v4.8-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/arm-smmu: Don't BUG() if we find aborting STEs with disable_bypass
  iommu/arm-smmu: Disable stalling faults for all endpoints
  iommu/arm-smmu: Fix CMDQ error handling
  iommu/io-pgtable-arm-v7s: Fix attributes when splitting blocks

Pull block fixes from Jens Axboe:
 "Here's a set of block fixes for the current 4.8-rc release.  This
  contains:

   - a fix for a secure erase regression, from Adrian.

   - a fix for an mmc use-after-free bug regression, also from Adrian.

   - potential zero pointer deference in bdev freezing, from Andrey.

   - a race fix for blk_set_queue_dying() from Bart.

   - a set of xen blkfront fixes from Bob Liu.

   - three small fixes for bcache, from Eric and Kent.

   - a fix for a potential invalid NVMe state transition, from Gabriel.

   - blk-mq CPU offline fix, preventing us from issuing and completing a
     request on the wrong queue.  From me.

   - revert two previous floppy changes, since they caused a user
     visibile regression.  A better fix is in the works.

   - ensure that we don't send down bios that have more than 256
     elements in them.  Fixes a crash with bcache, for example.  From
     Ming.

   - a fix for deferencing an error pointer with cgroup writeback.
     Fixes a regression.  From Vegard"

* 'for-linus' of git://git.kernel.dk/linux-block:
  mmc: fix use-after-free of struct request
  Revert "floppy: refactor open() flags handling"
  Revert "floppy: fix open(O_ACCMODE) for ioctl-only open"
  fs/block_dev: fix potential NULL ptr deref in freeze_bdev()
  blk-mq: improve warning for running a queue on the wrong CPU
  blk-mq: don't overwrite rq->mq_ctx
  block: make sure a big bio is split into at most 256 bvecs
  nvme: Fix nvme_get/set_features() with a NULL result pointer
  bdev: fix NULL pointer dereference
  xen-blkfront: free resources if xlvbd_alloc_gendisk fails
  xen-blkfront: introduce blkif_set_queue_limits()
  xen-blkfront: fix places not updated after introducing 64KB page granularity
  bcache: pr_err: more meaningful error message when nr_stripes is invalid
  bcache: RESERVE_PRIO is too small by one when prio_buckets() is a power of two.
  bcache: register_bcache(): call blkdev_put() when cache_alloc() fails
  block: Fix race triggered by blk_set_queue_dying()
  block: Fix secure erase
  nvme: Prevent controller state invalid transition

Pull input subsystem fixes from Dmitry Torokhov:
 "Simply small driver fixups"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: ads7846 - remove redundant regulator_disable call
  Input: synaptics-rmi4 - fix register descriptor subpacket map construction
  Input: tegra-kbc - fix inverted reset logic
  Input: silead - use devm_gpiod_get
  Input: i8042 - set up shared ps2_cmd_mutex for AUX ports

Pull PCI fixes from Bjorn Helgaas:
 "Resource management:
   - Update "pci=resource_alignment" documentation (Mathias Koehrer)

  MSI:
   - Use positive flags in pci_alloc_irq_vectors() (Christoph Hellwig)
   - Call pci_intx() when using legacy interrupts in pci_alloc_irq_vectors() (Christoph Hellwig)

  Intel VMD host bridge driver:
   - Fix infinite loop executing irq's (Keith Busch)"

* tag 'pci-v4.8-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  x86/PCI: VMD: Fix infinite loop executing irq's
  PCI: Call pci_intx() when using legacy interrupts in pci_alloc_irq_vectors()
  PCI: Use positive flags in pci_alloc_irq_vectors()
  PCI: Update "pci=resource_alignment" documentation

For DAX inodes we need to be careful to never have page cache pages in
the mapping->page_tree.  This radix tree should be composed only of DAX
exceptional entries and zero pages.

ltp's readahead02 test was triggering a warning because we were trying
to insert a DAX exceptional entry but found that a page cache page had
already been inserted into the tree.  This page was being inserted into
the radix tree in response to a readahead(2) call.

Readahead doesn't make sense for DAX inodes, but we don't want it to
report a failure either.  Instead, we just return success and don't do
any work.

Link: http://lkml.kernel.org/r/20160824221429.21158-1-ross.zwisler@linux.intel.comSigned-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reported-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jan Kara <jack@suse.com>
Cc: <stable@vger.kernel.org>	[4.5+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The data offset for a dax region needs to account for a reservation in
the resource range.  Otherwise, device-dax is allowing mappings directly
into the memmap or device-info-block area with crash signatures like the
following:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
 IP: get_zone_device_page+0x11/0x30
 Call Trace:
   follow_devmap_pmd+0x298/0x2c0
   follow_page_mask+0x275/0x530
   __get_user_pages+0xe3/0x750
   __gfn_to_pfn_memslot+0x1b2/0x450 [kvm]
   tdp_page_fault+0x130/0x280 [kvm]
   kvm_mmu_page_fault+0x5f/0xf0 [kvm]
   handle_ept_violation+0x94/0x180 [kvm_intel]
   vmx_handle_exit+0x1d3/0x1440 [kvm_intel]
   kvm_arch_vcpu_ioctl_run+0x81d/0x16a0 [kvm]
   kvm_vcpu_ioctl+0x33c/0x620 [kvm]
   do_vfs_ioctl+0xa2/0x5d0
   SyS_ioctl+0x79/0x90
   entry_SYSCALL_64_fastpath+0x1a/0xa4

Fixes: ab68f262 ("/dev/dax, pmem: direct access to persistent memory")
Link: http://lkml.kernel.org/r/147205536732.1606.8994275381938837346.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Abhilash Kumar Mulumudi <m.abhilash-kumar@hpe.com>
Reported-by: Toshi Kani <toshi.kani@hpe.com>
Tested-by: Toshi Kani <toshi.kani@hpe.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

seq_read() is a nasty piece of work, not to mention buggy.

It has (I think) an old bug which allows unprivileged userspace to read
beyond the end of m->buf.

I was getting these:

    BUG: KASAN: slab-out-of-bounds in seq_read+0xcd2/0x1480 at addr ffff880116889880
    Read of size 2713 by task trinity-c2/1329
    CPU: 2 PID: 1329 Comm: trinity-c2 Not tainted 4.8.0-rc1+ #96
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014
    Call Trace:
      kasan_object_err+0x1c/0x80
      kasan_report_error+0x2cb/0x7e0
      kasan_report+0x4e/0x80
      check_memory_region+0x13e/0x1a0
      kasan_check_read+0x11/0x20
      seq_read+0xcd2/0x1480
      proc_reg_read+0x10b/0x260
      do_loop_readv_writev.part.5+0x140/0x2c0
      do_readv_writev+0x589/0x860
      vfs_readv+0x7b/0xd0
      do_readv+0xd8/0x2c0
      SyS_readv+0xb/0x10
      do_syscall_64+0x1b3/0x4b0
      entry_SYSCALL64_slow_path+0x25/0x25
    Object at ffff880116889100, in cache kmalloc-4096 size: 4096
    Allocated:
    PID = 1329
      save_stack_trace+0x26/0x80
      save_stack+0x46/0xd0
      kasan_kmalloc+0xad/0xe0
      __kmalloc+0x1aa/0x4a0
      seq_buf_alloc+0x35/0x40
      seq_read+0x7d8/0x1480
      proc_reg_read+0x10b/0x260
      do_loop_readv_writev.part.5+0x140/0x2c0
      do_readv_writev+0x589/0x860
      vfs_readv+0x7b/0xd0
      do_readv+0xd8/0x2c0
      SyS_readv+0xb/0x10
      do_syscall_64+0x1b3/0x4b0
      return_from_SYSCALL_64+0x0/0x6a
    Freed:
    PID = 0
    (stack is not available)
    Memory state around the buggy address:
     ffff88011688a000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
     ffff88011688a080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    >ffff88011688a100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
		       ^
     ffff88011688a180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
     ffff88011688a200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
    ==================================================================
    Disabling lock debugging due to kernel taint

This seems to be the same thing that Dave Jones was seeing here:

  https://lkml.org/lkml/2016/8/12/334

There are multiple issues here:

  1) If we enter the function with a non-empty buffer, there is an attempt
     to flush it. But it was not clearing m->from after doing so, which
     means that if we try to do this flush twice in a row without any call
     to traverse() in between, we are going to be reading from the wrong
     place -- the splat above, fixed by this patch.

  2) If there's a short write to userspace because of page faults, the
     buffer may already contain multiple lines (i.e. pos has advanced by
     more than 1), but we don't save the progress that was made so the
     next call will output what we've already returned previously. Since
     that is a much less serious issue (and I have a headache after
     staring at seq_read() for the past 8 hours), I'll leave that for now.

Link: http://lkml.kernel.org/r/1471447270-32093-1-git-send-email-vegard.nossum@oracle.comSigned-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

A bugfix in v4.8-rc2 introduced a harmless warning when
CONFIG_MEMCG_SWAP is disabled but CONFIG_MEMCG is enabled:

  mm/memcontrol.c:4085:27: error: 'mem_cgroup_id_get_online' defined but not used [-Werror=unused-function]
   static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg)

This moves the function inside of the #ifdef block that hides the
calling function, to avoid the warning.

Fixes: 1f47b61f ("mm: memcontrol: fix swap counter leak on swapout from offline cgroup")
Link: http://lkml.kernel.org/r/20160824113733.2776701-1-arnd@arndb.deSigned-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The current wording of the COMPACTION Kconfig help text doesn't
emphasise that disabling COMPACTION might cripple the page allocator
which relies on the compaction quite heavily for high order requests and
an unexpected OOM can happen with the lack of compaction.  Make sure we
are vocal about that.

Link: http://lkml.kernel.org/r/20160823091726.GK23577@dhcp22.suse.czSigned-off-by: Michal Hocko <mhocko@suse.com>
Cc: Markus Trippelsdorf <markus@trippelsdorf.de>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 97f2645f ("tree-wide: replace config_enabled() with
IS_ENABLED()") mostly killed config_enabled(), but some new users have
appeared for v4.8-rc1.  They are all used for a boolean option, so can
be replaced with IS_ENABLED() safely.

Link: http://lkml.kernel.org/r/1471970749-24867-1-git-send-email-yamada.masahiro@socionext.comSigned-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit bbeddf52 ("printk: move braille console support into separate
braille.[ch] files") moved the parsing of braille-related options into
_braille_console_setup(), changing the type of variable str from char*
to char**.  In this commit, memcmp(str, "brl,", 4) was correctly updated
to memcmp(*str, "brl,", 4) but not memcmp(str, "brl=", 4).

Update the code to make "brl=" option work again and replace memcmp()
with strncmp() to make the compiler able to detect such an issue.

Fixes: bbeddf52 ("printk: move braille console support into separate braille.[ch] files")
Link: http://lkml.kernel.org/r/20160823165700.28952-1-nicolas.iooss_linux@m4x.orgSigned-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>