Currently the msm platform driver is a multiplex handling several cases:
- headless GPU-only driver,
- MDP4 with flat device nodes,
- MDP5/DPU MDSS with all the nodes being children of MDSS node.

This results in not-so-perfect code, checking the hardware version
(MDP4/MDP5/DPU) in several places, checking for mdss even when it can
not exist, etc. Split the code into three handling subdrivers (mdp4,
mdss and headless msm).
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/482507/
Link: https://lore.kernel.org/r/20220419155346.1272627-4-dmitry.baryshkov@linaro.orgSigned-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

Since now there is just one mdss subdriver, drop all the indirection,
make msm_mdss struct completely opaque (and defined inside msm_mdss.c)
and call mdss functions directly.
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/482505/
Link: https://lore.kernel.org/r/20220419155346.1272627-3-dmitry.baryshkov@linaro.orgSigned-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

MDP5 and DPU1 both provide the driver handling the MDSS region, which
handles the irq domain and (incase of DPU1) adds some init for the UBWC
controller. Unify those two pieces of code into a common driver.
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/482506/
Link: https://lore.kernel.org/r/20220419155346.1272627-2-dmitry.baryshkov@linaro.orgSigned-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

simple_ondemand interacts poorly with clamp_to_idle.  It only looks at
the load since the last get_dev_status call, while it should really look
at the load over polling_ms.  When clamp_to_idle true, it almost always
picks the lowest frequency on active because the gpu is idle between
msm_devfreq_idle/msm_devfreq_active.

This logic could potentially be moved into devfreq core.

Fixes: 7c0ffcd4 ("drm/msm/gpu: Respect PM QoS constraints")
Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
Cc: Rob Clark <robdclark@chromium.org>
Link: https://lore.kernel.org/r/20220416003314.59211-3-olvaffe@gmail.comSigned-off-by: Rob Clark <robdclark@chromium.org>

Move tracking and busy time calculation to msm_devfreq_get_dev_status.
Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
Cc: Rob Clark <robdclark@chromium.org>
Link: https://lore.kernel.org/r/20220416003314.59211-2-olvaffe@gmail.comSigned-off-by: Rob Clark <robdclark@chromium.org>

It is redundant since commit 7c0ffcd4 ("drm/msm/gpu: Respect PM QoS
constraints") because dev_pm_qos_update_request triggers get_dev_status.
Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
Cc: Rob Clark <robdclark@chromium.org>
Link: https://lore.kernel.org/r/20220416003314.59211-1-olvaffe@gmail.comSigned-off-by: Rob Clark <robdclark@chromium.org>

The motivation at this point is mainly native userspace mesa driver in a
VM guest.  The one remaining synchronous "hotpath" is buffer allocation,
because guest needs to wait to know the bo's iova before it can start
emitting cmdstream/state that references the new bo.  By allocating the
iova in the guest userspace, we no longer need to wait for a response
from the host, but can just rely on the allocation request being
processed before the cmdstream submission.  Allocation failures (OoM,
etc) would just be treated as context-lost (ie. GL_GUILTY_CONTEXT_RESET)
or subsequent allocations (or readpix, etc) can raise GL_OUT_OF_MEMORY.

v2: Fix inuse check
v3: Change mismatched iova case to -EBUSY
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Link: https://lore.kernel.org/r/20220411215849.297838-11-robdclark@gmail.comSigned-off-by: Rob Clark <robdclark@chromium.org>

With userspace allocated iova (next patch), we can have a race condition
where userspace observes the fence completion and deletes the vma before
retire_submit() gets around to unpinning the vma.  To handle this, add a
fenced unpin which drops the refcount but tracks the fence, and update
msm_gem_vma_inuse() to check any previously unsignaled fences.

v2: Fix inuse underflow (duplicate unpin)
v3: Fix msm_job_run() vs submit_cleanup() race condition
Signed-off-by: Rob Clark <robdclark@chromium.org>
Link: https://lore.kernel.org/r/20220411215849.297838-10-robdclark@gmail.comSigned-off-by: Rob Clark <robdclark@chromium.org>

This way we only lookup vma once per object per submit, for both the
submit and retire path.
Signed-off-by: Rob Clark <robdclark@chromium.org>
Link: https://lore.kernel.org/r/20220411215849.297838-9-robdclark@gmail.comSigned-off-by: Rob Clark <robdclark@chromium.org>

Combines duplicate vma lookup in the get_and_pin path.
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Link: https://lore.kernel.org/r/20220411215849.297838-8-robdclark@gmail.comSigned-off-by: Rob Clark <robdclark@chromium.org>

There was only a single user, which could just as easily stash the iova
when pinning.

v2: fix prepare->prepare->cleanup->cleanup sequences
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20220411215849.297838-7-robdclark@gmail.comSigned-off-by: Rob Clark <robdclark@chromium.org>

Get rid of all the unnecessary conversion between address/size and page
offsets.  It just confuses things.
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20220411215849.297838-6-robdclark@gmail.comSigned-off-by: Rob Clark <robdclark@chromium.org>

Prep for a following patch, where it gets a bit more complicated.
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20220411215849.297838-5-robdclark@gmail.comSigned-off-by: Rob Clark <robdclark@chromium.org>

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20220411215849.297838-4-robdclark@gmail.comSigned-off-by: Rob Clark <robdclark@chromium.org>

The ring seqno counter duplicates the fence-context last_fence counter.
They end up getting incremented in lock-step, on the same scheduler
thread, but the split just makes things less obvious.
Signed-off-by: Rob Clark <robdclark@chromium.org>
Link: https://lore.kernel.org/r/20220411215849.297838-3-robdclark@gmail.comSigned-off-by: Rob Clark <robdclark@chromium.org>

These belong more cleanly in the gem header.
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20220411215849.297838-2-robdclark@gmail.comSigned-off-by: Rob Clark <robdclark@chromium.org>

In the cause of using the GPU via virtgpu, the host side process is
really a sort of proxy, and not terribly interesting from the PoV of
crash/fault logging.  Add a way to override these per process so that
we can see the guest process's name.

v2: Handle kmalloc failure, add comment to explain kstrdup returns
    NULL if passed NULL [Dan Carpenter]
Signed-off-by: Rob Clark <robdclark@chromium.org>
Link: https://lore.kernel.org/r/20220317165144.222101-4-robdclark@gmail.comSigned-off-by: Rob Clark <robdclark@chromium.org>

Deduplicate this from fault_worker and recover_worker.
Signed-off-by: Rob Clark <robdclark@chromium.org>
Link: https://lore.kernel.org/r/20220317165144.222101-3-robdclark@gmail.comSigned-off-by: Rob Clark <robdclark@chromium.org>

The 64b value field is already suffient to hold a pointer instead of
immediate, but we also need a length field.
Signed-off-by: Rob Clark <robdclark@chromium.org>
Link: https://lore.kernel.org/r/20220317165144.222101-2-robdclark@gmail.comSigned-off-by: Rob Clark <robdclark@chromium.org>

Noticed this was unused and never set.
Signed-off-by: Rob Clark <robdclark@chromium.org>
Link: https://lore.kernel.org/r/20220225202614.225197-2-robdclark@gmail.comSigned-off-by: Rob Clark <robdclark@chromium.org>

These are mainly used internally in mesa, although I believe the display
should be able to scan out the TILED3 format.  Currently we define this
modifier internally in mesa for use with modifier based allocation.  But
we can get rid of that hack if we define the modfiers properly.
Signed-off-by: Rob Clark <robdclark@chromium.org>
Link: https://lore.kernel.org/r/20210904170603.1739137-1-robdclark@gmail.comSigned-off-by: Rob Clark <robdclark@chromium.org>

Pull serial driver fix from Greg KH:
 "This is a single serial driver fix for a build issue that showed up
  due to changes that came in through the tty tree in 5.18-rc1 that were
  missed previously. It resolves a build error with the mpc52xx_uart
  driver.

  It has been in linux-next this week with no reported problems"

* tag 'tty-5.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty: serial: mpc52xx_uart: make rx/tx hooks return unsigned, part II.

Pull staging driver fix from Greg KH:
 "Here is a single staging driver fix for 5.18-rc2 that resolves an
  endian issue for the r8188eu driver. It has been in linux-next all
  this week with no reported problems"

* tag 'staging-5.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: r8188eu: Fix PPPoE tag insertion on little endian systems

Merge tag 'driver-core-5.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here are two small driver core changes for 5.18-rc2.

  They are the final bits in the removal of the default_attrs field in
  struct kobj_type. I had to wait until after 5.18-rc1 for all of the
  changes to do this came in through different development trees, and
  then one new user snuck in. So this series has two changes:

   - removal of the default_attrs field in the powerpc/pseries/vas code.

     The change has been acked by the PPC maintainers to come through
     this tree

   - removal of default_attrs from struct kobj_type now that all
     in-kernel users are removed.

     This cleans up the kobject code a little bit and removes some
     duplicated functionality that confused people (now there is only
     one way to do default groups)

  Both of these have been in linux-next for all of this week with no
  reported problems"

* tag 'driver-core-5.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  kobject: kobj_type: remove default_attrs
  powerpc/pseries/vas: use default_groups in kobj_type

Pull char/misc driver fix from Greg KH:
 "A single driver fix. It resolves the build warning issue on 32bit
  systems in the habannalabs driver that came in during the 5.18-rc1
  merge cycle.

  It has been in linux-next for all this week with no reported problems"

* tag 'char-misc-5.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  habanalabs: Fix test build failures

Pull powerpc fixes from Michael Ellerman:

 - Fix KVM "lost kick" race, where an attempt to pull a vcpu out of the
   guest could be lost (or delayed until the next guest exit).

 - Disable SCV (system call vectored) when PR KVM guests could be run.

 - Fix KVM PR guests using SCV, by disallowing AIL != 0 for KVM PR
   guests.

 - Add a new KVM CAP to indicate if AIL == 3 is supported.

 - Fix a regression when hotplugging a CPU to a memoryless/cpuless node.

 - Make virt_addr_valid() stricter for 64-bit Book3E & 32-bit, which
   fixes crashes seen due to hardened usercopy.

 - Revert a change to max_mapnr which broke HIGHMEM.

Thanks to Christophe Leroy, Fabiano Rosas, Kefeng Wang, Nicholas Piggin,
and Srikar Dronamraju.

* tag 'powerpc-5.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  Revert "powerpc: Set max_mapnr correctly"
  powerpc: Fix virt_addr_valid() for 64-bit Book3E & 32-bit
  KVM: PPC: Move kvmhv_on_pseries() into kvm_ppc.h
  powerpc/numa: Handle partially initialized numa nodes
  powerpc/64: Fix build failure with allyesconfig in book3s_64_entry.S
  KVM: PPC: Use KVM_CAP_PPC_AIL_MODE_3
  KVM: PPC: Book3S PR: Disallow AIL != 0
  KVM: PPC: Book3S PR: Disable SCV when AIL could be disabled
  KVM: PPC: Book3S HV P9: Fix "lost kick" race

Pull irq fixes from Thomas Gleixner:
 "A set of interrupt chip driver fixes:

   - A fix for a long standing bug in the ARM GICv3 redistributor
     polling which uses the wrong bit number to test.

   - Prevent translation of bogus ACPI table entries which map device
     interrupts into the IPI space on ARM GICs.

   - Don't write into the pending register of ARM GICV4 before the scan
     in hardware has completed.

   - A set of build and correctness fixes for the Qualcomm MPM driver"

* tag 'irq-urgent-2022-04-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/gic, gic-v3: Prevent GSI to SGI translations
  irqchip/gic-v3: Fix GICR_CTLR.RWP polling
  irqchip/gic-v4: Wait for GICR_VPENDBASER.Dirty to clear before descheduling
  irqchip/irq-qcom-mpm: fix return value check in qcom_mpm_init()
  irq/qcom-mpm: Fix build error without MAILBOX

Pull x86 fixes from Borislav Petkov:

 - Fix the MSI message data struct definition

 - Use local labels in the exception table macros to avoid symbol
   conflicts with clang LTO builds

 - A couple of fixes to objtool checking of the relatively newly added
   SLS and IBT code

 - Rename a local var in the WARN* macro machinery to prevent shadowing

* tag 'x86_urgent_for_v5.18_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/msi: Fix msi message data shadow struct
  x86/extable: Prefer local labels in .set directives
  x86,bpf: Avoid IBT objtool warning
  objtool: Fix SLS validation for kcov tail-call replacement
  objtool: Fix IBT tail-call detection
  x86/bug: Prevent shadowing in __WARN_FLAGS
  x86/mm/tlb: Revert retpoline avoidance approach

Pull perf fixes from Borislav Petkov:

 - A couple of fixes to cgroup-related handling of perf events

 - A couple of fixes to event encoding on Sapphire Rapids

 - Pass event caps of inherited events so that perf doesn't fail wrongly
   at fork()

 - Add support for a new Raptor Lake CPU

* tag 'perf_urgent_for_v5.18_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Always set cpuctx cgrp when enable cgroup event
  perf/core: Fix perf_cgroup_switch()
  perf/core: Use perf_cgroup_info->active to check if cgroup is active
  perf/core: Don't pass task around when ctx sched in
  perf/x86/intel: Update the FRONTEND MSR mask on Sapphire Rapids
  perf/x86/intel: Don't extend the pseudo-encoding to GP counters
  perf/core: Inherit event_caps
  perf/x86/uncore: Add Raptor Lake uncore support
  perf/x86/msr: Add Raptor Lake CPU support
  perf/x86/cstate: Add Raptor Lake support
  perf/x86: Add Intel Raptor Lake support

Pull locking fixes from Borislav Petkov:

 - Allow the compiler to optimize away unused percpu accesses and change
   the local_lock_* macros back to inline functions

 - A couple of fixes to static call insn patching

* tag 'locking_urgent_for_v5.18_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Revert "mm/page_alloc: mark pagesets as __maybe_unused"
  Revert "locking/local_lock: Make the empty local_lock_*() function a macro."
  x86/percpu: Remove volatile from arch_raw_cpu_ptr().
  static_call: Remove __DEFINE_STATIC_CALL macro
  static_call: Properly initialise DEFINE_STATIC_CALL_RET0()
  static_call: Don't make __static_call_return0 static
  x86,static_call: Fix __static_call_return0 for i386

Pull scheduler fixes from Borislav Petkov:

 - Use the correct static key checking primitive on the IRQ exit path

 - Two fixes for the new forceidle balancer

* tag 'sched_urgent_for_v5.18_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  entry: Fix compile error in dynamic_irqentry_exit_cond_resched()
  sched: Teach the forced-newidle balancer about CPU affinity limitation.
  sched/core: Fix forceidle balancing

Merge tag 'perf-tools-fixes-for-v5.18-2022-04-09' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

Pull perf tools fixes from Arnaldo Carvalho de Melo:

 - Fix the clang command line option probing and remove some options to
   filter out, fixing the build with the latest clang versions

 - Fix 'perf bench' futex and epoll benchmarks to deal with machines
   with more than 1K CPUs

 - Fix 'perf test tsc' error message when not supported

 - Remap perf ring buffer if there is no space for event, fixing perf
   usage in 32-bit ChromeOS

 - Drop objdump stderr to avoid getting stuck waiting for stdout output
   in 'perf annotate'

 - Fix up garbled output by now showing unwind error messages when
   augmenting frame in best effort mode

 - Fix perf's libperf_print callback, use the va_args eprintf() variant

 - Sync vhost and arm64 cputype headers with the kernel sources

 - Fix 'perf report --mem-mode' with ARM SPE

 - Add missing external commands ('iiostat', etc) to 'perf --list-cmds'

* tag 'perf-tools-fixes-for-v5.18-2022-04-09' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux:
  perf annotate: Drop objdump stderr to avoid getting stuck waiting for stdout output
  perf tools: Add external commands to list-cmds
  perf docs: Add perf-iostat link to manpages
  perf session: Remap buf if there is no space for event
  perf bench: Fix epoll bench to correct usage of affinity for machines with #CPUs > 1K
  perf bench: Fix futex bench to correct usage of affinity for machines with #CPUs > 1K
  perf tools: Fix perf's libperf_print callback
  perf: arm-spe: Fix perf report --mem-mode
  perf unwind: Don't show unwind error messages when augmenting frame pointer stack
  tools headers arm64: Sync arm64's cputype.h with the kernel sources
  perf test tsc: Fix error message when not supported
  perf build: Don't use -ffat-lto-objects in the python feature test when building with clang-13
  perf python: Fix probing for some clang command line options
  tools build: Filter out options and warnings not supported by clang
  tools build: Use $(shell ) instead of `` to get embedded libperl's ccopts
  tools include UAPI: Sync linux/vhost.h with the kernel sources

Pull cxl and nvdimm fixes from Dan Williams:

 - Fix a compile error in the nvdimm unit tests

 - Fix a shadowed variable warning in the CXL PCI driver

* tag 'cxl+nvdimm-for-5.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  cxl/pci: Drop shadowed variable
  tools/testing/nvdimm: Fix security_init() symbol collision

Pull gpio fix from Bartosz Golaszewski:

 - fix a race condition with consumers accessing the fields of GPIO IRQ
   chips before they're fully initialized

* tag 'gpio-fixes-for-v5.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
  gpio: Restrict usage of GPIO chip irq members before initialization

Merge tag 'irqchip-fixes-5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent

Pull irqchip fixes from Marc Zyngier:

 - Fix GICv3 polling for RWP in redistributors

 - Reject ACPI attempts to use SGIs on GIC/GICv3

 - Fix unpredictible behaviour when making a VPE non-resident
   with GICv4

 - A couple of fixes for the newly merged qcom-mpm driver

Link: https://lore.kernel.org/lkml/20220409094229.267649-1-maz@kernel.org

If objdump writes to stderr it can block waiting for it to be read. As
perf doesn't read stderr then progress stops with perf waiting for
stdout output.
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexandre Truong <alexandre.truong@arm.com>
Cc: Dave Marchevsky <davemarchevsky@fb.com>
Cc: Denis Nikitin <denik@chromium.org>
Cc: German Gomez <german.gomez@arm.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.garry@huawei.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Lexi Shao <shaolexi@huawei.com>
Cc: Li Huafei <lihuafei1@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin Liška <mliska@suse.cz>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Remi Bernon <rbernon@codeweavers.com>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: William Cohen <wcohen@redhat.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lore.kernel.org/lkml/20220407230503.1265036-2-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The `perf --list-cmds` output prints only internal commands, although
there is no reason for that from users' perspective.

Adding the external commands to commands array with NULL function
pointer allows printing all perf commands while not changing the logic
of command handler selection.
Signed-off-by: Michael Petlan <mpetlan@redhat.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220404221541.30312-2-mpetlan@redhat.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Signed-off-by: Michael Petlan <mpetlan@redhat.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220404221541.30312-1-mpetlan@redhat.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

If a perf event doesn't fit into remaining buffer space return NULL to
remap buf and fetch the event again.

Keep the logic to error out on inadequate input from fuzzing.

This fixes perf failing on ChromeOS (with 32b userspace):

  $ perf report -v -i perf.data
  ...
  prefetch_event: head=0x1fffff8 event->header_size=0x30, mmap_size=0x2000000: fuzzed or compressed perf.data?
  Error:
  failed to process sample

Fixes: 57fc032a ("perf session: Avoid infinite loop when seeing invalid header.size")
Reviewed-by: James Clark <james.clark@arm.com>
Signed-off-by: Denis Nikitin <denik@chromium.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20220330031130.2152327-1-denik@chromium.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>