Pull LTO fix from Kees Cook:
 "It seems that there is a bug in ld.bfd when doing module section
  merging.

  As explicit merging is only needed for LTO, the work-around is to only
  do it under LTO, leaving the original section layout choices alone
  under normal builds:

   - Only perform explicit module section merges under LTO (Sean
     Christopherson)"

* tag 'lto-v5.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  kbuild: lto: Merge module sections if and only if CONFIG_LTO_CLANG is enabled

Merge module sections only when using Clang LTO. With ld.bfd, merging
sections does not appear to update the symbol tables for the module,
e.g. 'readelf -s' shows the value that a symbol would have had, if
sections were not merged. ld.lld does not show this problem.

The stale symbol table breaks gdb's function disassembler, and presumably
other things, e.g.

  gdb -batch -ex "file arch/x86/kvm/kvm.ko" -ex "disassemble kvm_init"

reads the wrong bytes and dumps garbage.

Fixes: dd277622 ("kbuild: lto: merge module sections")
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210322234438.502582-1-seanjc@google.com

Pull kvm fixes from Paolo Bonzini:
 "It's a bit larger than I (and probably you) would like by the time we
  get to -rc6, but perhaps not entirely unexpected since the changes in
  the last merge window were larger than usual.

  x86:
   - Fixes for missing TLB flushes with TDP MMU

   - Fixes for race conditions in nested SVM

   - Fixes for lockdep splat with Xen emulation

   - Fix for kvmclock underflow

   - Fix srcdir != builddir builds

   - Other small cleanups

  ARM:
   - Fix GICv3 MMIO compatibility probing

   - Prevent guests from using the ARMv8.4 self-hosted tracing
     extension"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  selftests: kvm: Check that TSC page value is small after KVM_SET_CLOCK(0)
  KVM: x86: Prevent 'hv_clock->system_time' from going negative in kvm_guest_time_update()
  KVM: x86: disable interrupts while pvclock_gtod_sync_lock is taken
  KVM: x86: reduce pvclock_gtod_sync_lock critical sections
  KVM: SVM: ensure that EFER.SVME is set when running nested guest or on nested vmexit
  KVM: SVM: load control fields from VMCB12 before checking them
  KVM: x86/mmu: Don't allow TDP MMU to yield when recovering NX pages
  KVM: x86/mmu: Ensure TLBs are flushed for TDP MMU during NX zapping
  KVM: x86/mmu: Ensure TLBs are flushed when yielding during GFN range zap
  KVM: make: Fix out-of-source module builds
  selftests: kvm: make hardware_disable_test less verbose
  KVM: x86/vPMU: Forbid writing to MSR_F15H_PERF MSRs when guest doesn't have X86_FEATURE_PERFCTR_CORE
  KVM: x86: remove unused declaration of kvm_write_tsc()
  KVM: clean up the unused argument
  tools/kvm_stat: Add restart delay
  KVM: arm64: Fix CPU interface MMIO compatibility detection
  KVM: arm64: Disable guest access to trace filter controls
  KVM: arm64: Hide system instruction access to Trace registers

Pull drm fixes from Dave Airlie:
 "Things have settled down in time for Easter, a random smattering of
  small fixes across a few drivers.

  I'm guessing though there might be some i915 and misc fixes out there
  I haven't gotten yet, but since today is a public holiday here, I'm
  sending this early so I can have the day off, I'll see if more
  requests come in and decide what to do with them later.

  amdgpu:
   - Polaris idle power fix
   - VM fix
   - Vangogh S3 fix
   - Fixes for non-4K page sizes

  amdkfd:
   - dqm fence memory corruption fix

  tegra:
   - lockdep warning fix
   - runtine PM reference fix
   - display controller fix
   - PLL Fix

  imx:
   - memory leak in error path fix
   - LDB driver channel registration fix
   - oob array warning in LDB driver

  exynos
   - unused header file removal"

* tag 'drm-fixes-2021-04-02' of git://anongit.freedesktop.org/drm/drm:
  drm/amdgpu: check alignment on CPU page for bo map
  drm/amdgpu: Set a suitable dev_info.gart_page_size
  drm/amdgpu/vangogh: don't check for dpm in is_dpm_running when in suspend
  drm/amdkfd: dqm fence memory corruption
  drm/tegra: sor: Grab runtime PM reference across reset
  drm/tegra: dc: Restore coupling of display controllers
  gpu: host1x: Use different lock classes for each client
  drm/tegra: dc: Don't set PLL clock to 0Hz
  drm/amdgpu: fix offset calculation in amdgpu_vm_bo_clear_mappings()
  drm/amd/pm: no need to force MCLK to highest when no display connected
  drm/exynos/decon5433: Remove the unused include statements
  drm/imx: imx-ldb: fix out of bounds array access warning
  drm/imx: imx-ldb: Register LDB channel1 when it is the only channel to be used
  drm/imx: fix memory leak when fails to init

drm/imx: imx-drm-core and imx-ldb fixes

Fix a memory leak in an error path during DRM device initialization,
fix the LDB driver to register channel 1 even if channel 0 is unused,
and fix an out of bounds array access warning in the LDB driver.
Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Philipp Zabel <p.zabel@pengutronix.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210401092235.GA13586@pengutronix.de

drm/tegra: Fixes for v5.12-rc6

This contains a couple of fixes for various issues such as lockdep
warnings, runtime PM references, coupled display controllers and
misconfigured PLLs.
Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Thierry Reding <thierry.reding@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210401163352.3348296-1-thierry.reding@gmail.com

Pull sound fixes from Takashi Iwai:
 "Things seem calming down, only usual device-specific fixes for
  HD-audio and USB-audio at this time"

* tag 'sound-5.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda/realtek: fix mute/micmute LEDs for HP 640 G8
  ALSA: hda: Add missing sanity checks in PM prepare/complete callbacks
  ALSA: hda: Re-add dropped snd_poewr_change_state() calls
  ALSA: usb-audio: Apply sample rate quirk to Logitech Connect
  ALSA: hda/realtek: call alc_update_headset_mode() in hp_automute_hook
  ALSA: hda/realtek: fix a determine_headset_type issue for a Dell AIO

Pull tomory fix from Tetsuo Handa:
 "An update on 'tomoyo: recognize kernel threads correctly' from Jens
  Axboe to not special case PF_IO_WORKER for PF_KTHREAD"

* tag 'tomoyo-pr-20210401' of git://git.osdn.net/gitroot/tomoyo/tomoyo-test1:
  tomoyo: don't special case PF_IO_WORKER for PF_KTHREAD

Pull XArray fixes from Matthew Wilcox:
 "My apologies for the lateness of this. I had a bug reported in the
  test suite, and when I started working on it, I realised I had two
  fixes sitting in the xarray tree since last November. Anyway,
  everything here is fixes, apart from adding xa_limit_16b. The test
  suite passes.

  Summary:

   - Fix a bug when splitting to a non-zero order

   - Documentation fix

   - Add a predefined 16-bit allocation limit

   - Various test suite fixes"

* tag 'xarray-5.12' of git://git.infradead.org/users/willy/xarray:
  idr test suite: Improve reporting from idr_find_test_1
  idr test suite: Create anchor before launching throbber
  idr test suite: Take RCU read lock in idr_find_test_1
  radix tree test suite: Register the main thread with the RCU library
  radix tree test suite: Fix compilation
  XArray: Add xa_limit_16b
  XArray: Fix splitting to non-zero orders
  XArray: Fix split documentation

Instead of just reporting an assertion failure, report enough information
that we can start diagnosing exactly went wrong.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

The throbber could race with creation of the anchor entry and cause the
IDR to have zero entries in it, which would cause the test to fail.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

When run on a single CPU, this test would frequently access already-freed
memory.  Due to timing, this bug never showed up on multi-CPU tests.
Reported-by: Chris von Recklinghausen <crecklin@redhat.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Several test runners register individual worker threads with the
RCU library, but neglect to register the main thread, which can lead
to objects being freed while the main thread is in what appears to be
an RCU critical section.
Reported-by: Chris von Recklinghausen <crecklin@redhat.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Add a test for the issue when KVM_SET_CLOCK(0) call could cause
TSC page value to go very big because of a signedness issue around
hv_clock->system_time.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210326155551.17446-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

When guest time is reset with KVM_SET_CLOCK(0), it is possible for
'hv_clock->system_time' to become a small negative number. This happens
because in KVM_SET_CLOCK handling we set 'kvm->arch.kvmclock_offset' based
on get_kvmclock_ns(kvm) but when KVM_REQ_CLOCK_UPDATE is handled,
kvm_guest_time_update() does (masterclock in use case):

hv_clock.system_time = ka->master_kernel_ns + v->kvm->arch.kvmclock_offset;

And 'master_kernel_ns' represents the last time when masterclock
got updated, it can precede KVM_SET_CLOCK() call. Normally, this is not a
problem, the difference is very small, e.g. I'm observing
hv_clock.system_time = -70 ns. The issue comes from the fact that
'hv_clock.system_time' is stored as unsigned and 'system_time / 100' in
compute_tsc_page_parameters() becomes a very big number.

Use 'master_kernel_ns' instead of get_kvmclock_ns() when masterclock is in
use and get_kvmclock_base_ns() when it's not to prevent 'system_time' from
going negative.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210331124130.337992-2-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

pvclock_gtod_sync_lock can be taken with interrupts disabled if the
preempt notifier calls get_kvmclock_ns to update the Xen
runstate information:

   spin_lock include/linux/spinlock.h:354 [inline]
   get_kvmclock_ns+0x25/0x390 arch/x86/kvm/x86.c:2587
   kvm_xen_update_runstate+0x3d/0x2c0 arch/x86/kvm/xen.c:69
   kvm_xen_update_runstate_guest+0x74/0x320 arch/x86/kvm/xen.c:100
   kvm_xen_runstate_set_preempted arch/x86/kvm/xen.h:96 [inline]
   kvm_arch_vcpu_put+0x2d8/0x5a0 arch/x86/kvm/x86.c:4062

So change the users of the spinlock to spin_lock_irqsave and
spin_unlock_irqrestore.

Reported-by: syzbot+b282b65c2c68492df769@syzkaller.appspotmail.com
Fixes: 30b5c851 ("KVM: x86/xen: Add support for vCPU runstate information")
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

There is no need to include changes to vcpu->requests into
the pvclock_gtod_sync_lock critical section.  The changes to
the shared data structures (in pvclock_update_vm_gtod_copy)
already occur under the lock.

Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Fixing nested_vmcb_check_save to avoid all TOC/TOU races
is a bit harder in released kernels, so do the bare minimum
by avoiding that EFER.SVME is cleared.  This is problematic
because svm_set_efer frees the data structures for nested
virtualization if EFER.SVME is cleared.

Also check that EFER.SVME remains set after a nested vmexit;
clearing it could happen if the bit is zero in the save area
that is passed to KVM_SET_NESTED_STATE (the save area of the
nested state corresponds to the nested hypervisor's state
and is restored on the next nested vmexit).

Cc: stable@vger.kernel.org
Fixes: 2fcf4876 ("KVM: nSVM: implement on demand allocation of the nested state")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Avoid races between check and use of the nested VMCB controls.  This
for example ensures that the VMRUN intercept is always reflected to the
nested hypervisor, instead of being processed by the host.  Without this
patch, it is possible to end up with svm->nested.hsave pointing to
the MSR permission bitmap for nested guests.

This bug is CVE-2021-29657.
Reported-by: Felix Wilhelm <fwilhelm@google.com>
Cc: stable@vger.kernel.org
Fixes: 2fcf4876 ("KVM: nSVM: implement on demand allocation of the nested state")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Merge tag 'amd-drm-fixes-5.12-2021-03-31' of https://gitlab.freedesktop.org/agd5f/linux into drm-fixes

amd-drm-fixes-5.12-2021-03-31:

amdgpu:
- Polaris idle power fix
- VM fix
- Vangogh S3 fix
- Fixes for non-4K page sizes

amdkfd:
- dqm fence memory corruption fix
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210401020057.17831-1-alexander.deucher@amd.com

Merge tag 'exynos-drm-fixes-for-v5.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos into drm-fixes

Just one cleanup which drops of_gpio.h inclusion.
- This header file isn't used anymore so drop it.
Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Inki Dae <inki.dae@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1617016858-14081-1-git-send-email-inki.dae@samsung.com

The page table of AMDGPU requires an alignment to CPU page so we should
check ioctl parameters for it.  Return -EINVAL if some parameter is
unaligned to CPU page, instead of corrupt the page table sliently.
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Xi Ruoyao <xry111@mengyan1223.wang>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

In Mesa, dev_info.gart_page_size is used for alignment and it was
set to AMDGPU_GPU_PAGE_SIZE(4KB). However, the page table of AMDGPU
driver requires an alignment on CPU pages.  So, for non-4KB page system,
gart_page_size should be max_t(u32, PAGE_SIZE, AMDGPU_GPU_PAGE_SIZE).
Signed-off-by: Rui Wang <wangr@lemote.com>
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Link: https://github.com/loongson-community/linux-stable/commit/caa9c0a1
[Xi: rebased for drm-next, use max_t for checkpatch,
     and reworded commit message.]
Signed-off-by: Xi Ruoyao <xry111@mengyan1223.wang>
BugLink: https://gitlab.freedesktop.org/drm/amd/-/issues/1549Tested-by: Dan Horák <dan@danny.cz>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

Do the same thing we do for Renoir.  We can check, but since
the sbios has started DPM, it will always return true which
causes the driver to skip some of the SMU init when it shouldn't.
Reviewed-by: Zhan Liu <zhan.liu@amd.com>
Acked-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

Amdgpu driver uses 4-byte data type as DQM fence memory,
and transmits GPU address of fence memory to microcode
through query status PM4 message. However, query status
PM4 message definition and microcode processing are all
processed according to 8 bytes. Fence memory only allocates
4 bytes of memory, but microcode does write 8 bytes of memory,
so there is a memory corruption.

Changes since v1:
  * Change dqm->fence_addr as a u64 pointer to fix this issue,
also fix up query_status and amdkfd_fence_wait_timeout function
uses 64 bit fence value to make them consistent.
Signed-off-by: Qu Huang <jinsdb@126.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

Pull ftrace fix from Steven Rostedt:
 "Add check of order < 0 before calling free_pages()

  The function addresses that are traced by ftrace are stored in pages,
  and the size is held in a variable. If there's some error in creating
  them, the allocate ones will be freed. In this case, it is possible
  that the order of pages to be freed may end up being negative due to a
  size of zero passed to get_count_order(), and then that negative
  number will cause free_pages() to free a very large section.

  Make sure that does not happen"

* tag 'trace-v5.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Check if pages were allocated before calling free_pages()

Pull pin control fixes from Linus Walleij:
 "Some overly ripe fixes for the v5.12 kernel. I should have sent
  earlier but had my head stuck in GDB.

  All are driver fixes:

   - Fix up some Intel GPIO base calculations.

   - Fix a register offset in the Microchip driver.

   - Fix suspend/resume bug in the Rockchip driver.

   - Default pull up strength in the Qualcomm LPASS driver.

   - Fix two pingroup offsets in the Qualcomm SC7280 driver.

   - Fix SDC1 register offset in the Qualcomm SC7280 driver.

   - Fix a nasty string concatenation in the Qualcomm SDX55 driver.

   - Check the REVID register to see if the device is real or
     virtualized during virtualization in the Intel driver"

* tag 'pinctrl-v5.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
  pinctrl: intel: check REVID register value for device presence
  pinctrl: qcom: fix unintentional string concatenation
  pinctrl: qcom: sc7280: Fix SDC1_RCLK configurations
  pinctrl: qcom: sc7280: Fix SDC_QDSD_PINGROUP and UFS_RESET offsets
  pinctrl: qcom: lpass lpi: use default pullup/strength values
  pinctrl: rockchip: fix restore error in resume
  pinctrl: microchip-sgpio: Fix wrong register offset for IRQ trigger
  pinctrl: intel: Show the GPIO base calculation explicitly

syzbot is reporting NULL pointer dereference at reiserfs_security_init()
[1], for commit ab17c4f0 ("reiserfs: fixup xattr_root caching")
is assuming that REISERFS_SB(s)->xattr_root != NULL in
reiserfs_xattr_jcreate_nblocks() despite that commit made
REISERFS_SB(sb)->priv_root != NULL && REISERFS_SB(s)->xattr_root == NULL
case possible.

I guess that commit 6cb4aff0 ("reiserfs: fix oops while creating
privroot with selinux enabled") wanted to check xattr_root != NULL
before reiserfs_xattr_jcreate_nblocks(), for the changelog is talking
about the xattr root.

  The issue is that while creating the privroot during mount
  reiserfs_security_init calls reiserfs_xattr_jcreate_nblocks which
  dereferences the xattr root. The xattr root doesn't exist, so we get
  an oops.

Therefore, update reiserfs_xattrs_initialized() to check both the
privroot and the xattr root.

Link: https://syzkaller.appspot.com/bug?id=8abaedbdeb32c861dc5340544284167dd0e46cde # [1]
Reported-and-tested-by: syzbot <syzbot+690cb1e51970435f9775@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: 6cb4aff0 ("reiserfs: fix oops while creating privroot with selinux enabled")
Acked-by: Jeff Mahoney <jeffm@suse.com>
Acked-by: Jan Kara <jack@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull s390 updates from Heiko Carstens:

 - fix incorrect initialization and update of vdso data pages, which
   results in incorrect tod clock steering, and that
   clock_gettime(CLOCK_MONOTONIC_RAW, ...) returns incorrect values.

 - update MAINTAINERS for s390 vfio drivers

* tag 's390-5.12-5' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  MAINTAINERS: add backups for s390 vfio drivers
  s390/vdso: fix initializing and updating of vdso_data
  s390/vdso: fix tod_steering_delta type
  s390/vdso: copy tod_steering_delta value to vdso_data page

The SOR resets are exclusively shared with the SOR power domain. This
means that exclusive access can only be granted temporarily and in order
for that to work, a rigorous sequence must be observed. To ensure that a
single consumer gets exclusive access to a reset, each consumer must
implement a rigorous protocol using the reset_control_acquire() and
reset_control_release() functions.

However, these functions alone don't provide any guarantees at the
system level. Drivers need to ensure that the only a single consumer has
access to the reset at the same time. In order for the SOR to be able to
exclusively access its reset, it must therefore ensure that the SOR
power domain is not powered off by holding on to a runtime PM reference
to that power domain across the reset assert/deassert operation.

This used to work fine by accident, but was revealed when recently more
devices started to rely on the SOR power domain.

Fixes: 11c632e1 ("drm/tegra: sor: Implement acquire/release for reset")
Reported-by: Jonathan Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Commit 4bba4c4b added tools/include/linux/compiler_types.h which
includes linux/compiler-gcc.h.  Unfortunately, we had our own (empty)
compiler_types.h which overrode the one added by that commit, and
so we lost the definition of __must_be_array().  Removing our empty
compiler_types.h fixes the problem and reduces our divergence from the
rest of the tools.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

A 16-bit limit is a more common limit than I had realised.  Make it
generally available.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Splitting an order-4 entry into order-2 entries would leave the array
containing pointers to 000040008000c000 instead of 000044448888cccc.
This is a one-character fix, but enhance the test suite to check this
case.
Reported-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

I wrote the documentation backwards; the new order of the entry is stored
in the xas and the caller passes the old entry.
Reported-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Coupling of display controllers used to rely on runtime PM to take the
companion controller out of reset. Commit fd67e9c6 ("drm/tegra: Do
not implement runtime PM") accidentally broke this when runtime PM was
removed.

Restore this functionality by reusing the hierarchical host1x client
suspend/resume infrastructure that's similar to runtime PM and which
perfectly fits this use-case.

Fixes: fd67e9c6 ("drm/tegra: Do not implement runtime PM")
Reported-by: Dmitry Osipenko <digetx@gmail.com>
Reported-by: Paul Fertser <fercerpav@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

To avoid false lockdep warnings, give each client lock a different
lock class, passed from the initialization site by macro.
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

RGB output doesn't allow to change parent clock rate of the display and
PCLK rate is set to 0Hz in this case. The tegra_dc_commit_state() shall
not set the display clock to 0Hz since this change propagates to the
parent clock. The DISP clock is defined as a NODIV clock by the tegra-clk
driver and all NODIV clocks use the CLK_SET_RATE_PARENT flag.

This bug stayed unnoticed because by default PLLP is used as the parent
clock for the display controller and PLLP silently skips the erroneous 0Hz
rate changes because it always has active child clocks that don't permit
rate changes. The PLLP isn't acceptable for some devices that we want to
upstream (like Samsung Galaxy Tab and ASUS TF700T) due to a display panel
clock rate requirements that can't be fulfilled by using PLLP and then the
bug pops up in this case since parent clock is set to 0Hz, killing the
display output.

Don't touch DC clock if pclk=0 in order to fix the problem.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Prevent the TDP MMU from yielding when zapping a gfn range during NX
page recovery.  If a flush is pending from a previous invocation of the
zapping helper, either in the TDP MMU or the legacy MMU, but the TDP MMU
has not accumulated a flush for the current invocation, then yielding
will release mmu_lock with stale TLB entries.

That being said, this isn't technically a bug fix in the current code, as
the TDP MMU will never yield in this case.  tdp_mmu_iter_cond_resched()
will yield if and only if it has made forward progress, as defined by the
current gfn vs. the last yielded (or starting) gfn.  Because zapping a
single shadow page is guaranteed to (a) find that page and (b) step
sideways at the level of the shadow page, the TDP iter will break its loop
before getting a chance to yield.

But that is all very, very subtle, and will break at the slightest sneeze,
e.g. zapping while holding mmu_lock for read would break as the TDP MMU
wouldn't be guaranteed to see the present shadow page, and thus could step
sideways at a lower level.

Cc: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210325200119.1359384-4-seanjc@google.com>
[Add lockdep assertion. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>