Host prints lots of untracked MMIO at 0x4653c when creating linux guest.
"gvt: vgpu 2: untracked MMIO 0004653c len 4"

GEN9_CLKGATE_DIS_4 (0x4653c) is accessed by i915 for gmbus clockgating.
However vgpu doesn't support any clockgating powergating operations
on related mmio access trap so need add it to default handler.
GEN9_CLKGATE_DIS_4 is accessed in bxt_gmbus_clock_gating() which only
applies to GEN9_LP so doens't show the warning on other platforms.

The solution is to add it to default handler init_bxt_mmio_info().
Reviewed-by: He, Min <min.he@intel.com>
Signed-off-by: Colin Xu <colin.xu@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

Recent patch fixed the call trace
"ERROR Port B enabled but PHY powered down? (PHY_CTL 00000000)".
but introduced another similar call trace shown as:
"ERROR Port C enabled but PHY powered down? (PHY_CTL 00000200)".
The call trace will appear when host and guest enabled different ports,
i.e. host using PORT C or neither PORT is enabled, while guest is always
using PORT B as simulated by gvt. The issue is actually covered previously
before the commit and reverals now when the commit do the right thing.

On BXT, some PHY registers are initialized by vbios, before i915 loaded.
Later i915 will re-program some, or skip some based on the implementation.
The initialized mmio for guest i915 is done by gvt, based on the snapshot
taken from host. If host and guest have different PORT enabled, some
DPIO PHY mmios that gvt initialized for guest i915 will not match the
simualted monitor for guest, which leads to guest i915 print the calltrace
when it's trying to enable PHY and PORT.

The solution is to init these DPIO PHY registers to default value, then
guest i915 will program them to reasonable value based on the default
powerwell table and enabled PORT. Together with the old patch, all similar
call trace in guest kernel on BXT can be resolved.

v2: Move PHY register init to intel_vgpu_reset_mmio (Min)
v3: Do not delete empty line in issue fix patch. (zhenyu)

Fixes: c8ab5ac3 ("drm/i915/gvt: Make correct handling to vreg
BXT_PHY_CTL_FAMILY")
Reviewed-by: He, Min <min.he@intel.com>
Signed-off-by: Colin Xu <colin.xu@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

GVT-g emualte the opregion for guest with bdb version as '186' which
child_device_config length should be '33'.

v2: split into 2 patch. 1st for issue fix, 2nd for code clean up.(Zhenyu)
v3: add fixes tag.(Zhenyu)

Fixes: 4023f301 ("drm/i915/gvt: opregion virtualization for win")
CC: Xiaolin Zhang <xiaolin.zhang@intel.com>
Reviewed-by: Xiaolin Zhang <xiaolin.zhang@intel.com>
Signed-off-by: Weinan Li <weinan.z.li@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

Handle guest mm access life cycle properly with mmget()/mmput().
As noted by Linus, use_mm() depends on valid live page table but
KVM's mmgrab() doesn't guarantee that. As vGPU usage depends on
guest VM life cycle, need to make sure to use mmget()/mmput() to
guarantee VM address access.

v3: fix build

v2: v1 caused a weird dependence issue which failed for vfio
device release, which result invalid mdev vgpu and kvm state
without proper release taken. This trys to put right reference
around VM address space access instead.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Reviewed-by: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

This trys to give new born vGPU with higher scheduling chance
not only with adding to sched list head and also have higher
priority for workload sched for 2 seconds after starting to
schedule it. In order for fast GPU execution during VM boot,
and ensure guest driver setup with required state given in time.

This fixes recent failure seen on one VM with multiple linux VMs
running on kernel with commit 2621cefa("drm/i915: Provide a timeout to i915_gem_wait_for_idle() on setup"),
which had shorter setup timeout that caused context state init failed.

v2: change to 2s for higher scheduling period

Cc: Yuan Hang <hang.yuan@intel.com>
Reviewed-by: Hang Yuan <hang.yuan@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

Physical plane's tiling mode value is given directly as
drm_format_mod for plane query, which is not correct fourcc
code. Fix it by using correct intel tiling fourcc mod definition.

Current qemu seems also doesn't correctly utilize drm_format_mod
for plane object setting. Anyway this is required to fix the usage.

v3: use DRM_FORMAT_MOD_LINEAR, fix comment

v2: Fix missed old 'tiled' use for stride calculation

Fixes: e546e281 ("drm/i915/gvt: Dmabuf support for GVT-g")
Cc: Tina Zhang <tina.zhang@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Colin Xu <Colin.Xu@intel.com>
Reviewed-by: Colin Xu <Colin.Xu@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

pm_runtime_get_sync in intel_runtime_pm_get might sleep if i915
device is not active. When stop vgpu schedule, the device may be
inactive. So need to move runtime_pm_get out of spin_lock/unlock.

Fixes: b24881e0("drm/i915/gvt: Add runtime_pm_get/put into gvt_switch_mmio
Cc: <stable@vger.kernel.org>
Signed-off-by: Hang Yuan <hang.yuan@linux.intel.com>
Signed-off-by: Xiong Zhang <xiong.y.zhang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

Recent patch introduce strict check on scanning cmd:
Commit 8d458ea0 ("drm/i915/gvt: return error on cmd access")

Before 8d458ea0, if cmd_reg_handler() checks that a cmd access a mmio
that not marked as F_CMD_ACCESS, it simply returns 0 and log an error.
Now it will return -EBADRQC which will cause the workload fail to submit.

On BXT, i915 applies WaClearHIZ_WM_CHICKEN3 which will program
GEN9_WM_CHICKEN3 by LRI when init wa ctx. If it has no F_CMD_ACCESS flag,
vgpu will fail to start. Also add F_MODE_MASK since it's mode mask reg.

v2: Refresh commit message to elaborate issue symptom in detail.
v3: Make SKL_PLUS share same handling since GEN9_WM_CHICKEN3 should be
    F_CMD_ACCESS from HW aspect. (yan, zhenyu)
Signed-off-by: Colin Xu <colin.xu@intel.com>
Acked-by: Zhao Yan <yan.y.zhao@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

Guest kernel will write to BXT_PHY_CTL_FAMILY to reset DDI PHY
and pull BXT_PHY_CTL to check PHY status. Previous handling will
set/reset BXT_PHY_CTL of all PHYs at same time on receiving vreg
write to some BXT_PHY_CTL_FAMILY. If some BXT_PHY_CTL is already
enabled, following reset to another BXT_PHY_CTL_FAMILY will clear
the enabled BXT_PHY_CTL, which result in guest kernel print:

-----------------------------------
[drm:intel_ddi_get_hw_state [i915]]
*ERROR* Port B enabled but PHY powered down? (PHY_CTL 00000000)
-----------------------------------

The correct handling should operate BXT_PHY_CTL_FAMILY and
BXT_PHY_CTL on the same DDI.

v2: Use correct reg define. The naming looks confusing, however
    current i915_reg.h bind DPIO_PHY0 to _PHY_CTL_FAMILY_DDI and
    bind DPIO_PHY1 to _PHY_CTL_FAMILY_EDP, pairing to
    _BXT_PHY_CTL_DDI_A and _BXT_PHY_CTL_DDI_B respectively.
v3: v2 incorrectly map _PHY_CTL_FAMILY_EDP to _BXT_PHY_CTL_DDI_A.
    BXT_PHY_CTL() looks up DDI using PORTx but not PHYx. Based on
    DPIO_PHY to DDI mapping, make correct vreg handle to BXT_PHY_CTL
    on receiving vreg write to BXT_PHY_CTL_FAMILY. (He, Min)

Current mapping according to bxt_power_wells:
dpio-common-a:
    >>> DPIO_PHY1
    >>> BXT_DPIO_CMN_A_POWER_DOMAINS
    >>> POWER_DOMAIN_PORT_DDI_A_LANES
    >>> PORT_A

dpio-common-bc:
    >>> DPIO_PHY0
    >>> BXT_DPIO_CMN_BC_POWER_DOMAINS
    >>> POWER_DOMAIN_PORT_DDI_B_LANES | POWER_DOMAIN_PORT_DDI_C_LANES
    >>> PORT_B or PORT_C
Signed-off-by: Colin Xu <colin.xu@intel.com>
Reviewed-by: He, Min <min.he@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

there is below call track at boot time when booting guest
with kabylake vgpu with specifal configuration and this try to fix it.

[drm:gen9_dbuf_enable [i915]] *ERROR* DBuf power enable timeout
------------[ cut here ]------------
WARNING: gen9_dc_off_power_well_enable+0x224/0x230 [i915]
Unexpected DBuf power power state (0x8000000a)
Hardware name: Red Hat KVM, BIOS 1.11.0-2.el7 04/01/2014
Call Trace:
 [<ffffffff99d24408>] dump_stack+0x19/0x1b
 [<ffffffff996926d8>] __warn+0xd8/0x100
 [<ffffffff9969275f>] warn_slowpath_fmt+0x5f/0x80
 [<ffffffffc07bbae4>] gen9_dc_off_power_well_enable+0x224/0x230 [i915]
 [<ffffffffc07ba9d2>] intel_power_well_enable+0x42/0x50 [i915]
 [<ffffffffc07baa6a>] __intel_display_power_get_domain+0x8a/0xb0 [i915]
 [<ffffffffc07bdb93>] intel_display_power_get+0x33/0x50 [i915]
 [<ffffffffc07bdf95>] intel_display_set_init_power+0x45/0x50 [i915]
 [<ffffffffc07be003>] intel_power_domains_init_hw+0x63/0x8a0 [i915]
 [<ffffffffc07995c3>] i915_driver_load+0xae3/0x1760 [i915]
 [<ffffffff99bd6580>] ? nvmem_register+0x500/0x500
 [<ffffffffc07a476c>] i915_pci_probe+0x2c/0x50 [i915]
 [<ffffffff9999cfea>] local_pci_probe+0x4a/0xb0
 [<ffffffff9999e729>] pci_device_probe+0x109/0x160
 [<ffffffff99a79aa5>] driver_probe_device+0xc5/0x3e0
 [<ffffffff99a79ea3>] __driver_attach+0x93/0xa0
 [<ffffffff99a79e10>] ? __device_attach+0x50/0x50
 [<ffffffff99a77645>] bus_for_each_dev+0x75/0xc0
 [<ffffffff99a7941e>] driver_attach+0x1e/0x20
 [<ffffffff99a78ec0>] bus_add_driver+0x200/0x2d0
 [<ffffffff99a7a534>] driver_register+0x64/0xf0
 [<ffffffff9999df65>] __pci_register_driver+0xa5/0xc0
 [<ffffffffc0929000>] ? 0xffffffffc0928fff
 [<ffffffffc0929059>] i915_init+0x59/0x5c [i915]
 [<ffffffff9960210a>] do_one_initcall+0xba/0x240
 [<ffffffff9971108c>] load_module+0x272c/0x2bc0
 [<ffffffff9997b990>] ? ddebug_proc_write+0xf0/0xf0
 [<ffffffff997115e5>] SyS_init_module+0xc5/0x110
 [<ffffffff99d36795>] system_call_fastpath+0x1c/0x21
Signed-off-by: Xiaolin Zhang <xiaolin.zhang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

If the display has been disabled by modparam, we still want to connect
together the HW bits and bobs with the associated drivers so that we can
continue to manage their runtime power gating.

Fixes: 10810944 ("drm/i915: Check num_pipes before initializing audio component")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Elaine Wang <elaine.wang@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180817100241.4628-1-chris@chris-wilson.co.uk
(cherry picked from commit 35a5fd9e)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

100 ms is not enough time for the LSPCON adapter on Intel NUC devices to
settle. This causes dropped display modes at boot or screen reconfiguration.
Empirical testing can reproduce the error up to a timeout of 190 ms. Basic
boot and stress testing at 200 ms has not (yet) failed.

Increase timeout to 400 ms to get some margin of error.

Changes from v1:
The initial suggestion of 1000 ms was lowered due to concerns about delaying
valid timeout cases.
Update patch metadata.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107503
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1570392
Fixes: 357c0ae9 ("drm/i915/lspcon: Wait for expected LSPCON mode to settle")
Cc: Shashank Sharma <shashank.sharma@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: <stable@vger.kernel.org> # v4.11+
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Fredrik Schön <fredrik.schon@gmail.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180817200728.8154-1-fredrik.schon@gmail.com
(cherry picked from commit 59f1c8ab)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

The context owns both the ppgtt and the vma within it, and our activity
tracking on the context ensures that we do not release active ppgtt. As
the context fulfils our obligations for active memory tracking, we can
relinquish the reference from the vma.

This fixes a silly transient refleak from closed vma being kept alive
until the entire system was idle, keeping all vm alive as well.
Reported-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Testcase: igt/gem_ctx_create/files
Fixes: 3365e226 ("drm/i915: Lazily unbind vma on close")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Tested-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180816073448.19396-1-chris@chris-wilson.co.uk
(cherry picked from commit a4417b7b)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

We use kzalloc to allocate the write_buf that we use for
i2c transfer on hdcp write. But it seems that we are forgetting
to free the memory that is not needed after i2c transfer is
completed.
Reported-by: Brian J Wood <brian.j.wood@intel.com>
Fixes: 2320175f ("drm/i915: Implement HDCP for HDMI")
Cc: Ramalingam C <ramalingam.c@intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: <stable@vger.kernel.org> # v4.17+
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180823205136.31310-1-rodrigo.vivi@intel.com
(cherry picked from commit 62d3a8de)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

The workaround was supposed to look at the plane destination
coordinates. Currently it's looking at some mixture of src
and dst coordinates that doesn't make sense. Fix it up.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180719182214.4323-2-ville.syrjala@linux.intel.com
Fixes: 394676f0 (drm/i915: Add WA for planes ending close to left screen edge)
Reviewed-by: Imre Deak <imre.deak@intel.com>
(cherry picked from commit b1f1c2c1)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Pull timer update from Thomas Gleixner:
 "New defines for the compat time* types so they can be shared between
  32bit and 64bit builds. Not used yet, but merging them now allows the
  actual conversions to be merged through different maintainer trees
  without dependencies

  We still have compat interfaces for 32bit on 64bit even with the new
  2038 safe timespec/val variants because pointer size is different. And
  for the old style timespec/val interfaces we need yet another 'compat'
  interface for both 32bit native and 32bit on 64bit"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  y2038: Provide aliases for compat helpers

Pull IDA updates from Matthew Wilcox:
 "A better IDA API:

      id = ida_alloc(ida, GFP_xxx);
      ida_free(ida, id);

  rather than the cumbersome ida_simple_get(), ida_simple_remove().

  The new IDA API is similar to ida_simple_get() but better named.  The
  internal restructuring of the IDA code removes the bitmap
  preallocation nonsense.

  I hope the net -200 lines of code is convincing"

* 'ida-4.19' of git://git.infradead.org/users/willy/linux-dax: (29 commits)
  ida: Change ida_get_new_above to return the id
  ida: Remove old API
  test_ida: check_ida_destroy and check_ida_alloc
  test_ida: Convert check_ida_conv to new API
  test_ida: Move ida_check_max
  test_ida: Move ida_check_leaf
  idr-test: Convert ida_check_nomem to new API
  ida: Start new test_ida module
  target/iscsi: Allocate session IDs from an IDA
  iscsi target: fix session creation failure handling
  drm/vmwgfx: Convert to new IDA API
  dmaengine: Convert to new IDA API
  ppc: Convert vas ID allocation to new IDA API
  media: Convert entity ID allocation to new IDA API
  ppc: Convert mmu context allocation to new IDA API
  Convert net_namespace to new IDA API
  cb710: Convert to new IDA API
  rsxx: Convert to new IDA API
  osd: Convert to new IDA API
  sd: Convert to new IDA API
  ...

Pull gcc plugin fix from Kees Cook:
 "Lift gcc test into Kconfig. This is for better behavior when the
  kernel is built with Clang, reported by Stefan Agner"

* tag 'gcc-plugins-v4.19-rc1-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  gcc-plugins: Disable when building under Clang

Pull perf updates from Thomas Gleixner:
 "Kernel:
   - Improve kallsyms coverage
   - Add x86 entry trampolines to kcore
   - Fix ARM SPE handling
   - Correct PPC event post processing

  Tools:
   - Make the build system more robust
   - Small fixes and enhancements all over the place
   - Update kernel ABI header copies
   - Preparatory work for converting libtraceevnt to a shared library
   - License cleanups"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (100 commits)
  tools arch: Update arch/x86/lib/memcpy_64.S copy used in 'perf bench mem memcpy'
  tools arch x86: Update tools's copy of cpufeatures.h
  perf python: Fix pyrf_evlist__read_on_cpu() interface
  perf mmap: Store real cpu number in 'struct perf_mmap'
  perf tools: Remove ext from struct kmod_path
  perf tools: Add gzip_is_compressed function
  perf tools: Add lzma_is_compressed function
  perf tools: Add is_compressed callback to compressions array
  perf tools: Move the temp file processing into decompress_kmodule
  perf tools: Use compression id in decompress_kmodule()
  perf tools: Store compression id into struct dso
  perf tools: Add compression id into 'struct kmod_path'
  perf tools: Make is_supported_compression() static
  perf tools: Make decompress_to_file() function static
  perf tools: Get rid of dso__needs_decompress() call in __open_dso()
  perf tools: Get rid of dso__needs_decompress() call in symbol__disassemble()
  perf tools: Get rid of dso__needs_decompress() call in read_object_code()
  tools lib traceevent: Change to SPDX License format
  perf llvm: Allow passing options to llc in addition to clang
  perf parser: Improve error message for PMU address filters
  ...

Pull x86 fixes from Thomas Gleixner:

 - Correct the L1TF fallout on 32bit and the off by one in the 'too much
   RAM for protection' calculation.

 - Add a helpful kernel message for the 'too much RAM' case

 - Unbreak the VDSO in case that the compiler desides to use indirect
   jumps/calls and emits retpolines which cannot be resolved because the
   kernel uses its own thunks, which does not work for the VDSO. Make it
   use the builtin thunks.

 - Re-export start_thread() which was unexported when the 32/64bit
   implementation was unified. start_thread() is required by modular
   binfmt handlers.

 - Trivial cleanups

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/speculation/l1tf: Suggest what to do on systems with too much RAM
  x86/speculation/l1tf: Fix off-by-one error when warning that system has too much RAM
  x86/kvm/vmx: Remove duplicate l1d flush definitions
  x86/speculation/l1tf: Fix overflow in l1tf_pfn_limit() on 32bit
  x86/process: Re-export start_thread()
  x86/mce: Add notifier_block forward declaration
  x86/vdso: Fix vDSO build if a retpoline is emitted

Pull irq update from Thomas Gleixner:
 "A small set of updats/fixes for the irq subsystem:

   - Allow GICv3 interrupts to be configured as wake-up sources to
     enable wakeup from suspend

   - Make the error handling of the STM32 irqchip init function work

   - A set of small cleanups and improvements"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/gic-v3: Allow interrupt to be configured as wake-up sources
  irqchip/tango: Set irq handler and data in one go
  dt-bindings: irqchip: renesas-irqc: Document r8a774a1 support
  irqchip/s3c24xx: Remove unneeded comparison of unsigned long to 0
  irqchip/stm32: Fix init error handling
  irqchip/bcm7038-l1: Hide cpu offline callback when building for !SMP

Pull licking update from Thomas Gleixner:
 "Mark the switch cases which fall through to the next case with the
  proper comment so the fallthrough compiler checks can be enabled"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Mark expected switch fall-throughs

Merge tag 'libnvdimm-for-4.19_dax-memory-failure' of gitolite.kernel.org:pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm memory-failure update from Dave Jiang:
 "As it stands, memory_failure() gets thoroughly confused by dev_pagemap
  backed mappings. The recovery code has specific enabling for several
  possible page states and needs new enabling to handle poison in dax
  mappings.

  In order to support reliable reverse mapping of user space addresses:

   1/ Add new locking in the memory_failure() rmap path to prevent races
      that would typically be handled by the page lock.

   2/ Since dev_pagemap pages are hidden from the page allocator and the
      "compound page" accounting machinery, add a mechanism to determine
      the size of the mapping that encompasses a given poisoned pfn.

   3/ Given pmem errors can be repaired, change the speculatively
      accessed poison protection, mce_unmap_kpfn(), to be reversible and
      otherwise allow ongoing access from the kernel.

  A side effect of this enabling is that MADV_HWPOISON becomes usable
  for dax mappings, however the primary motivation is to allow the
  system to survive userspace consumption of hardware-poison via dax.
  Specifically the current behavior is:

     mce: Uncorrected hardware memory error in user-access at af34214200
     {1}[Hardware Error]: It has been corrected by h/w and requires no further action
     mce: [Hardware Error]: Machine check events logged
     {1}[Hardware Error]: event severity: corrected
     Memory failure: 0xaf34214: reserved kernel page still referenced by 1 users
     [..]
     Memory failure: 0xaf34214: recovery action for reserved kernel page: Failed
     mce: Memory error not recovered
     <reboot>

  ...and with these changes:

     Injecting memory failure for pfn 0x20cb00 at process virtual address 0x7f763dd00000
     Memory failure: 0x20cb00: Killing dax-pmd:5421 due to hardware memory corruption
     Memory failure: 0x20cb00: recovery action for dax page: Recovered

  Given all the cross dependencies I propose taking this through
  nvdimm.git with acks from Naoya, x86/core, x86/RAS, and of course dax
  folks"

* tag 'libnvdimm-for-4.19_dax-memory-failure' of gitolite.kernel.org:pub/scm/linux/kernel/git/nvdimm/nvdimm:
  libnvdimm, pmem: Restore page attributes when clearing errors
  x86/memory_failure: Introduce {set, clear}_mce_nospec()
  x86/mm/pat: Prepare {reserve, free}_memtype() for "decoy" addresses
  mm, memory_failure: Teach memory_failure() about dev_pagemap pages
  filesystem-dax: Introduce dax_lock_mapping_entry()
  mm, memory_failure: Collect mapping size in collect_procs()
  mm, madvise_inject_error: Let memory_failure() optionally take a page reference
  mm, dev_pagemap: Do not clear ->mapping on final put
  mm, madvise_inject_error: Disable MADV_SOFT_OFFLINE for ZONE_DEVICE pages
  filesystem-dax: Set page->index
  device-dax: Set page->index
  device-dax: Enable page_mapping()
  device-dax: Convert to vmf_insert_mixed and vm_fault_t

Pull libnvdimm updates from Dave Jiang:
 "Collection of misc libnvdimm patches for 4.19 submission:

   - Adding support to read locked nvdimm capacity.

   - Change test code to make DSM failure code injection an override.

   - Add support for calculate maximum contiguous area for namespace.

   - Add support for queueing a short ARS when there is on going ARS for
     nvdimm.

   - Allow NULL to be passed in to ->direct_access() for kaddr and pfn
     params.

   - Improve smart injection support for nvdimm emulation testing.

   - Fix test code that supports for emulating controller temperature.

   - Fix hang on error before devm_memremap_pages()

   - Fix a bug that causes user memory corruption when data returned to
     user for ars_status.

   - Maintainer updates for Ross Zwisler emails and adding Jan Kara to
     fsdax"

* tag 'libnvdimm-for-4.19_misc' of gitolite.kernel.org:pub/scm/linux/kernel/git/nvdimm/nvdimm:
  libnvdimm: fix ars_status output length calculation
  device-dax: avoid hang on error before devm_memremap_pages()
  tools/testing/nvdimm: improve emulation of smart injection
  filesystem-dax: Do not request kaddr and pfn when not required
  md/dm-writecache: Don't request pointer dummy_addr when not required
  dax/super: Do not request a pointer kaddr when not required
  tools/testing/nvdimm: kaddr and pfn can be NULL to ->direct_access()
  s390, dcssblk: kaddr and pfn can be NULL to ->direct_access()
  libnvdimm, pmem: kaddr and pfn can be NULL to ->direct_access()
  acpi/nfit: queue issuing of ars when an uc error notification comes in
  libnvdimm: Export max available extent
  libnvdimm: Use max contiguous area for namespace size
  MAINTAINERS: Add Jan Kara for filesystem DAX
  MAINTAINERS: update Ross Zwisler's email address
  tools/testing/nvdimm: Fix support for emulating controller temperature
  tools/testing/nvdimm: Make DSM failure code injection an override
  acpi, nfit: Prefer _DSM over _LSR for namespace label reads
  libnvdimm: Introduce locked DIMM capacity support

Pull ARM SoC late updates from Olof Johansson:
 "A couple of late-merged changes that would be useful to get in this
  merge window:

   - Driver support for reset of audio complex on Meson platforms. The
     audio driver went in this merge window, and these changes have been
     in -next for a while (just not in our tree).

   - Power management fixes for IOMMU on Rockchip platforms, getting
     closer to kexec working on them, including Chromebooks.

   - Another pass updating "arm,psci" -> "psci" for some properties that
     have snuck in since last time it was done"

* tag 'armsoc-late' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  iommu/rockchip: Move irq request past pm_runtime_enable
  iommu/rockchip: Handle errors returned from PM framework
  arm64: rockchip: Force CONFIG_PM on Rockchip systems
  ARM: rockchip: Force CONFIG_PM on Rockchip systems
  arm64: dts: Fix various entry-method properties to reflect documentation
  reset: imx7: Fix always writing bits as 0
  reset: meson: add meson audio arb driver
  reset: meson: add dt-bindings for meson-axg audio arb

Pull more Kbuild updates from Masahiro Yamada:

 - add build_{menu,n,g,x}config targets for compile-testing Kconfig

 - fix and improve recursive dependency detection in Kconfig

 - fix parallel building of menuconfig/nconfig

 - fix syntax error in clang-version.sh

 - suppress distracting log from syncconfig

 - remove obsolete "rpm" target

 - remove VMLINUX_SYMBOL(_STR) macro entirely

 - fix microblaze build with CONFIG_DYNAMIC_FTRACE

 - move compiler test for dead code/data elimination to Kconfig

 - rename well-known LDFLAGS variable to KBUILD_LDFLAGS

 - misc fixes and cleanups

* tag 'kbuild-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: rename LDFLAGS to KBUILD_LDFLAGS
  kbuild: pass LDFLAGS to recordmcount.pl
  kbuild: test dead code/data elimination support in Kconfig
  initramfs: move gen_initramfs_list.sh from scripts/ to usr/
  vmlinux.lds.h: remove stale <linux/export.h> include
  export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR()
  Coccinelle: remove pci_alloc_consistent semantic to detect in zalloc-simple.cocci
  kbuild: make sorting initramfs contents independent of locale
  kbuild: remove "rpm" target, which is alias of "rpm-pkg"
  kbuild: Fix LOADLIBES rename in Documentation/kbuild/makefiles.txt
  kconfig: suppress "configuration written to .config" for syncconfig
  kconfig: fix "Can't open ..." in parallel build
  kbuild: Add a space after `!` to prevent parsing as file pattern
  scripts: modpost: check memory allocation results
  kconfig: improve the recursive dependency report
  kconfig: report recursive dependency involving 'imply'
  kconfig: error out when seeing recursive dependency
  kconfig: add build-only configurator targets
  scripts/dtc: consolidate include path options in Makefile

Pull block fixes from Jens Axboe:
 "A few small fixes for this merge window:

   - Locking imbalance fix for bcache (Shan Hai)

   - A few small fixes for wbt. One is a cleanup/prep, one is a fix for
     an existing issue, and the last two are fixes for changes that went
     into this merge window (me)"

* tag 'for-linus-20180825' of git://git.kernel.dk/linux-block:
  blk-wbt: don't maintain inflight counts if disabled
  blk-wbt: fix has-sleeper queueing check
  blk-wbt: use wq_has_sleeper() for wq active check
  blk-wbt: move disable check into get_limit()
  bcache: release dc->writeback_lock properly in bch_writeback_thread()

Pull UBIFS fix from Richard Weinberger:
 "Remove an empty file from UBIFS source"

* tag 'upstream-4.19-rc1-fix' of git://git.infradead.org/linux-ubifs:
  ubifs: Remove empty file.h

Pull cifs fixes from Steve French:
 "Three small SMB3 fixes, one for stable"

* tag '4.19-rc-smb3' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: update internal module version number for cifs.ko to 2.12
  cifs: check kmalloc before use
  cifs: check if SMB2 PDU size has been padded and suppress the warning
  cifs: create a define for how many iovs we need for an SMB2_open()

This is not normally noticeable, but repeated forks are unnecessarily
expensive because they repeatedly dirty the parent page tables during
the page table copy operation.

It's trivial to just avoid write protecting the page table entry if it
was already not writable.

This patch was inspired by

    https://bugzilla.kernel.org/show_bug.cgi?id=200447

which points to an ancient "waste time re-doing fork" issue in the
presence of lots of signals.

That bug was fixed by Eric Biederman's signal handling series
culminating in commit c3ad2c3b ("signal: Don't restart fork when
signals come in"), but the unnecessary work for repeated forks is still
work just fixing, particularly since the fix is trivial.

Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

At the point where r is being checked for different values, r is always
going to be equal to 2 as the previous if statements jump to end or end1
if r is not 2.  Hence the assignment to err can be simplified to just
err an assignment without any checks on the value or r.

Detected by CoverityScan, CID#1226737 ("Logically dead code")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Tejun Heo wrote:
>
> I asked Jens whether he could take care of the libata tree and he
> thankfully agreed, so, from now on, Jens will be the libata
> maintainer.
>
> Thanks a lot!

Thanks for your work in this area. I still remember the first linux
storage summit we did in Vancouver 2001, Tejun was invited to talk about
his libata error handling work. Before that, it was basically a crap
shoot if we recovered properly or not... A lot of water has flown under
the bridge since then!

Here's an "official" patch. Linus, can you apply it?
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull libata updates from Tejun Heo:
 "Nothing too interesting. Mostly ahci and ahci_platform changes, many
  around power management"

* 'for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata: (22 commits)
  ata: ahci_platform: enable to get and control reset
  ata: libahci_platform: add reset control support
  ata: add an extra argument to ahci_platform_get_resources()
  ata: sata_rcar: Add r8a77965 support
  ata: sata_rcar: exclude setting of PHY registers in Gen3
  ata: sata_rcar: really mask all interrupts on Gen2 and later
  Revert "ata: ahci_platform: allow disabling of hotplug to save power"
  ata: libahci: Allow reconfigure of DEVSLP register
  ata: libahci: Correct setting of DEVSLP register
  ata: ahci: Enable DEVSLP by default on x86 with SLP_S0
  ata: ahci: Support state with min power but Partial low power state
  Revert "ata: ahci_platform: convert kcalloc to devm_kcalloc"
  ata: sata_rcar: Add rudimentary Runtime PM support
  ata: sata_rcar: Provide a short-hand for &pdev->dev
  ata: Only output sg element mapped number in verbose debug
  ata: Guard ata_scsi_dump_cdb() by ATA_VERBOSE_DEBUG
  ata: ahci_platform: convert kcalloc to devm_kcalloc
  ata: ahci_platform: convert kzallloc to kcalloc
  ata: ahci_platform: correct parameter documentation for ahci_platform_shutdown
  libata: remove ata_sff_data_xfer_noirq()
  ...

Pull cgroup updates from Tejun Heo:
 "Just one commit from Steven to take out spin lock from trace event
  handlers"

* 'for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup/tracing: Move taking of spin lock out of trace event handlers

Pull workqueue updates from Tejun Heo:
 "Over the lockdep cross-release churn, workqueue lost some of the
  existing annotations. Johannes Berg restored it and also improved
  them"

* 'for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: re-add lockdep dependencies for flushing
  workqueue: skip lockdep wq dependency in cancel_work_sync()

Pull IOMMU updates from Joerg Roedel:

 - PASID table handling updates for the Intel VT-d driver. It implements
   a global PASID space now so that applications usings multiple devices
   will just have one PASID.

 - A new config option to make iommu passthroug mode the default.

 - New sysfs attribute for iommu groups to export the type of the
   default domain.

 - A debugfs interface (for debug only) usable by IOMMU drivers to
   export internals to user-space.

 - R-Car Gen3 SoCs support for the ipmmu-vmsa driver

 - The ARM-SMMU now aborts transactions from unknown devices and devices
   not attached to any domain.

 - Various cleanups and smaller fixes all over the place.

* tag 'iommu-updates-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (42 commits)
  iommu/omap: Fix cache flushes on L2 table entries
  iommu: Remove the ->map_sg indirection
  iommu/arm-smmu-v3: Abort all transactions if SMMU is enabled in kdump kernel
  iommu/arm-smmu-v3: Prevent any devices access to memory without registration
  iommu/ipmmu-vmsa: Don't register as BUS IOMMU if machine doesn't have IPMMU-VMSA
  iommu/ipmmu-vmsa: Clarify supported platforms
  iommu/ipmmu-vmsa: Fix allocation in atomic context
  iommu: Add config option to set passthrough as default
  iommu: Add sysfs attribyte for domain type
  iommu/arm-smmu-v3: sync the OVACKFLG to PRIQ consumer register
  iommu/arm-smmu: Error out only if not enough context interrupts
  iommu/io-pgtable-arm-v7s: Abort allocation when table address overflows the PTE
  iommu/io-pgtable-arm: Fix pgtable allocation in selftest
  iommu/vt-d: Remove the obsolete per iommu pasid tables
  iommu/vt-d: Apply per pci device pasid table in SVA
  iommu/vt-d: Allocate and free pasid table
  iommu/vt-d: Per PCI device pasid table interfaces
  iommu/vt-d: Add for_each_device_domain() helper
  iommu/vt-d: Move device_domain_info to header
  iommu/vt-d: Apply global PASID in SVA
  ...

Pull thermal management updates from Zhang Rui:

 - Add Daniel Lezcano as the reviewer of thermal framework and SoC
   driver changes (Daniel Lezcano).

 - Fix a bug in intel_dts_soc_thermal driver, which does not translate
   IO-APIC GSI (Global System Interrupt) into Linux irq number (Hans de
   Goede).

 - For device tree bindings, allow cooling devices sharing same trip
   point with same contribution value to share cooling map (Viresh
   Kumar).

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
  dt-bindings: thermal: Allow multiple devices to share cooling map
  MAINTAINERS: Add Daniel Lezcano as designated reviewer for thermal
  Thermal: Intel SoC DTS: Translate IO-APIC GSI number to linux irq number

Merge tag 'apparmor-pr-2018-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor

Pull apparmor updates from John Johansen:
 "There is nothing major this time just four bug fixes and a patch to
  remove some dead code:

  Cleanups:
   - remove no-op permission check in policy_unpack

  Bug fixes:
   - fix an error code in __aa_create_ns()
   - fix failure to audit context info in build_change_hat
   - check buffer bounds when mapping permissions mask
   - fully initialize aa_perms struct when answering userspace query"

* tag 'apparmor-pr-2018-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor:
  apparmor: remove no-op permission check in policy_unpack
  apparmor: fix an error code in __aa_create_ns()
  apparmor: Fix failure to audit context info in build_change_hat
  apparmor: Fully initialize aa_perms struct when answering userspace query
  apparmor: Check buffer bounds when mapping permissions mask

Pull powerpc fixes from Michael Ellerman:

 - An implementation for the newly added hv_ops->flush() for the OPAL
   hvc console driver backends, I forgot to apply this after merging the
   hvc driver changes before the merge window.

 - Enable all PCI bridges at boot on powernv, to avoid races when
   multiple children of a bridge try to enable it simultaneously. This
   is a workaround until the PCI core can be enhanced to fix the races.

 - A fix to query PowerVM for the correct system topology at boot before
   initialising sched domains, seen in some configurations to cause
   broken scheduling etc.

 - A fix for pte_access_permitted() on "nohash" platforms.

 - Two commits to fix SIGBUS when using remap_pfn_range() seen on Power9
   due to a workaround when using the nest MMU (GPUs, accelerators).

 - Another fix to the VFIO code used by KVM, the previous fix had some
   bugs which caused guests to not start in some configurations.

 - A handful of other minor fixes.

Thanks to: Aneesh Kumar K.V, Benjamin Herrenschmidt, Christophe Leroy,
Hari Bathini, Luke Dashjr, Mahesh Salgaonkar, Nicholas Piggin, Paul
Mackerras, Srikar Dronamraju.

* tag 'powerpc-4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/mce: Fix SLB rebolting during MCE recovery path.
  KVM: PPC: Book3S: Fix guest DMA when guest partially backed by THP pages
  powerpc/mm/radix: Only need the Nest MMU workaround for R -> RW transition
  powerpc/mm/books3s: Add new pte bit to mark pte temporarily invalid.
  powerpc/nohash: fix pte_access_permitted()
  powerpc/topology: Get topology for shared processors at boot
  powerpc64/ftrace: Include ftrace.h needed for enable/disable calls
  powerpc/powernv/pci: Work around races in PCI bridge enabling
  powerpc/fadump: cleanup crash memory ranges support
  powerpc/powernv: provide a console flush operation for opal hvc driver
  powerpc/traps: Avoid rate limit messages from show unhandled signals
  powerpc/64s: Fix PACA_IRQ_HARD_DIS accounting in idle_power4()