In most cases percpu reference counters are not switched to the
percpu mode after they reach the atomic mode. Some obvious exceptions
are reference counters which are initialized into the atomic
mode (using PERCPU_REF_INIT_ATOMIC and PERCPU_REF_INIT_DEAD flags),
and there are few other exceptions.

But in most cases there is no way back, and once the reference counter
is switched to the atomic mode, there is no reason to wait for
percpu_ref_exit() to release the percpu memory. Of course, the size
of a single counter is not so big, but because it can pin the whole
percpu block in memory, the memory footprint can be noticeable
(e.g. on my 32 CPUs machine a percpu block is 8Mb large).

To make releasing of the percpu memory as early as possible, let's
introduce the PERCPU_REF_ALLOW_REINIT flag with the following semantics:
it has to be set in order to switch a percpu reference counter to the
percpu mode after the initialization. PERCPU_REF_INIT_ATOMIC and
PERCPU_REF_INIT_DEAD flags will implicitly assume PERCPU_REF_ALLOW_REINIT.

This patch doesn't introduce any functional change to avoid any
regressions. It will be done later in the patchset after adjusting
all call sites, which are reviving percpu counters.
Signed-off-by: NRoman Gushchin <guro@fb.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NDennis Zhou <dennis@kernel.org>

Pull perf fixes from Ingo Molnar:
 "I'd like to apologize for this very late pull request: I was dithering
  through the week whether to send the fixes, and then yesterday Jiri's
  crash fix for a regression introduced in this cycle clearly marked
  perf/urgent as 'must merge now'.

  Most of the commits are tooling fixes, plus there's three kernel fixes
  via four commits:

    - race fix in the Intel PEBS code

    - fix an AUX bug and roll back a previous attempt

    - fix AMD family 17h generic HW cache-event perf counters

  The largest diffstat contribution comes from the AMD fix - a new event
  table is introduced, which is a fairly low risk change but has a large
  linecount"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Fix race in intel_pmu_disable_event()
  perf/x86/intel/pt: Remove software double buffering PMU capability
  perf/ring_buffer: Fix AUX software double buffering
  perf tools: Remove needless asm/unistd.h include fixing build in some places
  tools arch uapi: Copy missing unistd.h headers for arc, hexagon and riscv
  tools build: Add -ldl to the disassembler-four-args feature test
  perf cs-etm: Always allocate memory for cs_etm_queue::prev_packet
  perf cs-etm: Don't check cs_etm_queue::prev_packet validity
  perf report: Report OOM in status line in the GTK UI
  perf bench numa: Add define for RUSAGE_THREAD if not present
  tools lib traceevent: Change tag string for error
  perf annotate: Fix build on 32 bit for BPF annotation
  tools uapi x86: Sync vmx.h with the kernel
  perf bpf: Return value with unlocking in perf_env__find_btf()
  MAINTAINERS: Include vendor specific files under arch/*/events/*
  perf/x86/amd: Update generic hardware cache events for Family 17h

Pull scheduler fix from Ingo Molnar:
 "Fix a kobject memory leak in the cpufreq code"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/cpufreq: Fix kobject memleak

Pull x86 fix from Ingo Molnar:
 "Disable function tracing during early SME setup to fix a boot crash on
  SME-enabled kernels running distro kernels (some of which have
  function tracing enabled)"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm/mem_encrypt: Disable all instrumentation for early SME setup

Pull vfs fixes from Al Viro:

 - a couple of ->i_link use-after-free fixes

 - regression fix for wrong errno on absent device name in mount(2)
   (this cycle stuff)

 - ancient UFS braino in large GID handling on Solaris UFS images (bogus
   cut'n'paste from large UID handling; wrong field checked to decide
   whether we should look at old (16bit) or new (32bit) field)

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  ufs: fix braino in ufs_get_inode_gid() for solaris UFS flavour
  Abort file_remove_privs() for non-reg. files
  [fix] get rid of checking for absent device name in vfs_get_tree()
  apparmorfs: fix use-after-free on symlink traversal
  securityfs: fix use-after-free on symlink traversal

New race in x86_pmu_stop() was introduced by replacing the
atomic __test_and_clear_bit() of cpuc->active_mask by separate
test_bit() and __clear_bit() calls in the following commit:

  3966c3fe ("x86/perf/amd: Remove need to check "running" bit in NMI handler")

The race causes panic for PEBS events with enabled callchains:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
  ...
  RIP: 0010:perf_prepare_sample+0x8c/0x530
  Call Trace:
   <NMI>
   perf_event_output_forward+0x2a/0x80
   __perf_event_overflow+0x51/0xe0
   handle_pmi_common+0x19e/0x240
   intel_pmu_handle_irq+0xad/0x170
   perf_event_nmi_handler+0x2e/0x50
   nmi_handle+0x69/0x110
   default_do_nmi+0x3e/0x100
   do_nmi+0x11a/0x180
   end_repeat_nmi+0x16/0x1a
  RIP: 0010:native_write_msr+0x6/0x20
  ...
   </NMI>
   intel_pmu_disable_event+0x98/0xf0
   x86_pmu_stop+0x6e/0xb0
   x86_pmu_del+0x46/0x140
   event_sched_out.isra.97+0x7e/0x160
  ...

The event is configured to make samples from PEBS drain code,
but when it's disabled, we'll go through NMI path instead,
where data->callchain will not get allocated and we'll crash:

          x86_pmu_stop
            test_bit(hwc->idx, cpuc->active_mask)
            intel_pmu_disable_event(event)
            {
              ...
              intel_pmu_pebs_disable(event);
              ...

EVENT OVERFLOW ->  <NMI>
                     intel_pmu_handle_irq
                       handle_pmi_common
   TEST PASSES ->        test_bit(bit, cpuc->active_mask))
                           perf_event_overflow
                             perf_prepare_sample
                             {
                               ...
                               if (!(sample_type & __PERF_SAMPLE_CALLCHAIN_EARLY))
                                     data->callchain = perf_callchain(event, regs);

         CRASH ->              size += data->callchain->nr;
                             }
                   </NMI>
              ...
              x86_pmu_disable_event(event)
            }

            __clear_bit(hwc->idx, cpuc->active_mask);

Fixing this by disabling the event itself before setting
off the PEBS bit.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Arcari <darcari@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Lendacky Thomas <Thomas.Lendacky@amd.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 3966c3fe ("x86/perf/amd: Remove need to check "running" bit in NMI handler")
Link: http://lkml.kernel.org/r/20190504151556.31031-1-jolsa@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Pull powerpc fix from Michael Ellerman:
 "One regression fix.

  Changes we merged to STRICT_KERNEL_RWX on 32-bit were causing crashes
  under load on some machines depending on memory layout.

  Thanks to Christophe Leroy"

* tag 'powerpc-5.1-7' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/32s: Fix BATs setting with CONFIG_STRICT_KERNEL_RWX

Pull KVM fixes from Paolo Bonzini:

 - PPC and ARM bugfixes from submaintainers

 - Fix old Windows versions on AMD (recent regression)

 - Fix old Linux versions on processors without EPT

 - Fixes for LAPIC timer optimizations

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (21 commits)
  KVM: nVMX: Fix size checks in vmx_set_nested_state
  KVM: selftests: make hyperv_cpuid test pass on AMD
  KVM: lapic: Check for in-kernel LAPIC before deferencing apic pointer
  KVM: fix KVM_CLEAR_DIRTY_LOG for memory slots of unaligned size
  x86/kvm/mmu: reset MMU context when 32-bit guest switches PAE
  KVM: x86: Whitelist port 0x7e for pre-incrementing %rip
  Documentation: kvm: fix dirty log ioctl arch lists
  KVM: VMX: Move RSB stuffing to before the first RET after VM-Exit
  KVM: arm/arm64: Don't emulate virtual timers on userspace ioctls
  kvm: arm: Skip stage2 huge mappings for unaligned ipa backed by THP
  KVM: arm/arm64: Ensure vcpu target is unset on reset failure
  KVM: lapic: Convert guest TSC to host time domain if necessary
  KVM: lapic: Allow user to disable adaptive tuning of timer advancement
  KVM: lapic: Track lapic timer advance per vCPU
  KVM: lapic: Disable timer advancement if adaptive tuning goes haywire
  x86: kvm: hyper-v: deal with buggy TLB flush requests from WS2012
  KVM: x86: Consider LAPIC TSC-Deadline timer expired if deadline too short
  KVM: PPC: Book3S: Protect memslots while validating user address
  KVM: PPC: Book3S HV: Perserve PSSCR FAKE_SUSPEND bit on guest exit
  KVM: arm/arm64: vgic-v3: Retire pending interrupts on disabling LPIs
  ...

Merge branch 'i2c/for-current-fixed' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c fixes from Wolfram Sang:
 "I2C driver bugfixes and a MAINTAINERS update for you"

* 'i2c/for-current-fixed' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: Prevent runtime suspend of adapter when Host Notify is required
  i2c: synquacer: fix enumeration of slave devices
  MAINTAINERS: friendly takeover of i2c-gpio driver
  i2c: designware: ratelimit 'transfer when suspended' errors
  i2c: imx: correct the method of getting private data in notifier_call

Pull drm fix from Dave Airlie:
 "Just a single qxl revert"

* tag 'drm-fixes-2019-05-03' of git://anongit.freedesktop.org/drm/drm:
  Revert "drm/qxl: drop prime import/export callbacks"

Pull clk fixes from Stephen Boyd:
 "Two fixes for the NKMP clks on Allwinner SoCs, a locking fix for
  clkdev where we forgot to hold a lock while iterating a list that can
  change, and finally a build fix that adds some stubs for clk APIs that
  are used by devfreq drivers on platforms without the clk APIs"

* tag 'clk-fixes-for-linus' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: Add missing stubs for a few functions
  clkdev: Hold clocks_mutex while iterating clocks list
  clk: sunxi-ng: nkmp: Explain why zero width check is needed
  clk: sunxi-ng: nkmp: Avoid GENMASK(-1, 0)

Pull sound fixes from Takashi Iwai:
 "A few stable fixes at this round.

  The USB Line6 audio fixes are a bit large, but they are rather trivial
  and pretty much device-specific, so should be safe to apply at this
  late stage. Ditto for other HD-audio quirks"

* tag 'sound-5.1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda/realtek - Apply the fixup for ASUS Q325UAR
  ALSA: line6: use dynamic buffers
  ALSA: hda/realtek - Fixed Dell AIO speaker noise
  ALSA: hda/realtek - Add new Dell platform for headset mode

Now that all AUX allocations are high-order by default, the software
double buffering PMU capability doesn't make sense any more, get rid
of it. In case some PMUs choose to opt out, we can re-introduce it.
Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: adrian.hunter@intel.com
Link: http://lkml.kernel.org/r/20190503085536.24119-3-alexander.shishkin@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

This recent commit:

  5768402f ("perf/ring_buffer: Use high order allocations for AUX buffers optimistically")

overlooked the fact that the previous one page granularity of the AUX buffer
provided an implicit double buffering capability to the PMU driver, which
went away when the entire buffer became one high-order page.

Always make the full-trace mode AUX allocation at least two-part to preserve
the previous behavior and allow the implicit double buffering to continue.
Reported-by: NAmmy Yi <ammy.yi@intel.com>
Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: adrian.hunter@intel.com
Fixes: 5768402f ("perf/ring_buffer: Use high order allocations for AUX buffers optimistically")
Link: http://lkml.kernel.org/r/20190503085536.24119-2-alexander.shishkin@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Merge tag 'perf-urgent-for-mingo-5.1-20190502' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/urgent fixes from Arnaldo Carvalho de Melo:

tools UAPI:

  Arnaldo Carvalho de Melo:

  - Sync x86's vmx.h with the kernel.

  - Copy missing unistd.h headers for arc, hexagon and riscv, fixing
    a reported build regression on the ARC 32-bit architecture.

perf bench numa:

  Arnaldo Carvalho de Melo:

  - Add define for RUSAGE_THREAD if not present, fixing the build on the
    ARC architecture when only zlib and libnuma are present.

perf BPF:

  Arnaldo Carvalho de Melo:

  - The disassembler-four-args feature test needs -ldl on distros such as
    Mageia 7.

  Bo YU:

  - Fix unlocking on success in perf_env__find_btf(), detected with
    the coverity tool.

libtraceevent:

  Leo Yan:

  - Change misleading hard coded 'trace-cmd' string in error messages.

ARM hardware tracing:

  Leo Yan:

  - Always allocate memory for cs_etm_queue::prev_packet, fixing a segfault
    when processing CoreSight perf data.

perf annotate:

  Thadeu Lima de Souza Cascardo:

  - Fix build on 32 bit for BPF.

perf report:

  Thomas Richter:

  - Report OOM in status line in the GTK UI.

core libs:

  - Remove needless asm/unistd.h that, used with sys/syscall.h ended
    up redefining the syscalls defines in environments such as the
    ARC arch when using uClibc.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

- One revert for QXL for a DRI3 breakage
Signed-off-by: NDave Airlie <airlied@redhat.com>

From: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190502122529.hguztj3kncaixe3d@flea

We were including sys/syscall.h and asm/unistd.h, since sys/syscall.h
includes asm/unistd.h, sometimes this leads to the redefinition of
defines, breaking the build.

Noticed on ARC with uCLibc.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Link: https://lkml.kernel.org/n/tip-xjpf80o64i2ko74aj2jih0qg@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Since those were introduced in:

  c8ce48f0 ("asm-generic: Make time32 syscall numbers optional")

But when the asm-generic/unistd.h was sync'ed with tools/ in:

  1a787fc5 ("tools headers uapi: Sync copy of asm-generic/unistd.h with the kernel sources")

I forgot to copy the files for the architectures that define
__ARCH_WANT_TIME32_SYSCALLS, so the perf build was breaking there, as
reported by Vineet Gupta for the ARC architecture.

After updating my ARC container to use the glibc based toolchain + cross
building libnuma, zlib and elfutils, I finally managed to reproduce the
problem and verify that this now is fixed and will not regress as will
be tested before each pull req sent upstream.
Reported-by: NVineet Gupta <Vineet.Gupta1@synopsys.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jiri Olsa <jolsa@kernel.org>
CC: linux-snps-arc@lists.infradead.org
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/r/20190426193531.GC28586@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Thomas Backlund reported that the perf build was failing on the Mageia 7
distro, that is because it uses:

  cat /tmp/build/perf/feature/test-disassembler-four-args.make.output
  /usr/bin/ld: /usr/lib64/libbfd.a(plugin.o): in function `try_load_plugin':
  /home/iurt/rpmbuild/BUILD/binutils-2.32/objs/bfd/../../bfd/plugin.c:243:
  undefined reference to `dlopen'
  /usr/bin/ld:
  /home/iurt/rpmbuild/BUILD/binutils-2.32/objs/bfd/../../bfd/plugin.c:271:
  undefined reference to `dlsym'
  /usr/bin/ld:
  /home/iurt/rpmbuild/BUILD/binutils-2.32/objs/bfd/../../bfd/plugin.c:256:
  undefined reference to `dlclose'
  /usr/bin/ld:
  /home/iurt/rpmbuild/BUILD/binutils-2.32/objs/bfd/../../bfd/plugin.c:246:
  undefined reference to `dlerror'
  as we allow dynamic linking and loading

Mageia 7 uses these linker flags:
  $ rpm --eval %ldflags
    -Wl,--as-needed -Wl,--no-undefined -Wl,-z,relro -Wl,-O1 -Wl,--build-id -Wl,--enable-new-dtags

So add -ldl to this feature LDFLAGS.
Reported-by: NThomas Backlund <tmb@mageia.org>
Tested-by: NThomas Backlund <tmb@mageia.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Link: https://lkml.kernel.org/r/20190501173158.GC21436@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Robert Walker reported a segmentation fault is observed when process
CoreSight trace data; this issue can be easily reproduced by the command
'perf report --itrace=i1000i' for decoding tracing data.

If neither the 'b' flag (synthesize branches events) nor 'l' flag
(synthesize last branch entries) are specified to option '--itrace',
cs_etm_queue::prev_packet will not been initialised.  After merging the
code to support exception packets and sample flags, there introduced a
number of uses of cs_etm_queue::prev_packet without checking whether it
is valid, for these cases any accessing to uninitialised prev_packet
will cause crash.

As cs_etm_queue::prev_packet is used more widely now and it's already
hard to follow which functions have been called in a context where the
validity of cs_etm_queue::prev_packet has been checked, this patch
always allocates memory for cs_etm_queue::prev_packet.
Reported-by: NRobert Walker <robert.walker@arm.com>
Suggested-by: NRobert Walker <robert.walker@arm.com>
Signed-off-by: NLeo Yan <leo.yan@linaro.org>
Tested-by: NRobert Walker <robert.walker@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Suzuki K Poulouse <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Fixes: 7100b12c ("perf cs-etm: Generate branch sample for exception packet")
Fixes: 24fff5eb ("perf cs-etm: Avoid stale branch samples when flush packet")
Link: http://lkml.kernel.org/r/20190428083228.20246-1-leo.yan@linaro.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Since cs_etm_queue::prev_packet is allocated for all cases, it will
never be NULL pointer; now validity checking prev_packet is pointless,
remove all of them.
Signed-off-by: NLeo Yan <leo.yan@linaro.org>
Tested-by: NRobert Walker <robert.walker@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Suzuki K Poulouse <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20190428083228.20246-2-leo.yan@linaro.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

An -ENOMEM error is not reported in the GTK GUI.  Instead this error
message pops up on the screen:

[root@m35lp76 perf]# ./perf  report -i perf.data.error68-1

	Processing events... [974K/3M]
	Error:failed to process sample

	0xf4198 [0x8]: failed to process type: 68

However when I use the same perf.data file with --stdio it works:

[root@m35lp76 perf]# ./perf  report -i perf.data.error68-1 --stdio \
		| head -12

  # Total Lost Samples: 0
  #
  # Samples: 76K of event 'cycles'
  # Event count (approx.): 99056160000
  #
  # Overhead  Command          Shared Object      Symbol
  # ........  ...............  .................  .........
  #
     8.81%  find             [kernel.kallsyms]  [k] ftrace_likely_update
     8.74%  swapper          [kernel.kallsyms]  [k] ftrace_likely_update
     8.34%  sshd             [kernel.kallsyms]  [k] ftrace_likely_update
     2.19%  kworker/u512:1-  [kernel.kallsyms]  [k] ftrace_likely_update

The sample precentage is a bit low.....

The GUI always fails in the FINISHED_ROUND event (68) and does not
indicate the reason why.

When happened is the following. Perf report calls a lot of functions and
down deep when a FINISHED_ROUND event is processed, these functions are
called:

  perf_session__process_event()
  + perf_session__process_user_event()
    + process_finished_round()
      + ordered_events__flush()
        + __ordered_events__flush()
	  + do_flush()
	    + ordered_events__deliver_event()
	      + perf_session__deliver_event()
	        + machine__deliver_event()
	          + perf_evlist__deliver_event()
	            + process_sample_event()
	              + hist_entry_iter_add() --> only called in GUI case!!!
	                + hist_iter__report__callback()
	                  + symbol__inc_addr_sample()

	                    Now this functions runs out of memory and
			    returns -ENOMEM. This is reported all the way up
			    until function

perf_session__process_event() returns to its caller, where -ENOMEM is
changed to -EINVAL and processing stops:

 if ((skip = perf_session__process_event(session, event, head)) < 0) {
      pr_err("%#" PRIx64 " [%#x]: failed to process type: %d\n",
	     head, event->header.size, event->header.type);
      err = -EINVAL;
      goto out_err;
 }

This occurred in the FINISHED_ROUND event when it has to process some
10000 entries and ran out of memory.

This patch indicates the root cause and displays it in the status line
of ther perf report GUI.

Output before (on GUI status line):

  0xf4198 [0x8]: failed to process type: 68

Output after:

  0xf4198 [0x8]: failed to process type: 68 [not enough memory]

Committer notes:

the 'skip' variable needs to be initialized to -EINVAL, so that when the
size is less than sizeof(struct perf_event_attr) we avoid this valid
compiler warning:

  util/session.c: In function ‘perf_session__process_events’:
  util/session.c:1936:7: error: ‘skip’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
     err = skip;
     ~~~~^~~~~~
  util/session.c:1874:6: note: ‘skip’ was declared here
    s64 skip;
        ^~~~
  cc1: all warnings being treated as errors
Signed-off-by: NThomas Richter <tmricht@linux.ibm.com>
Reviewed-by: NHendrik Brueckner <brueckner@linux.ibm.com>
Reviewed-by: NJiri Olsa <jolsa@redhat.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Link: http://lkml.kernel.org/r/20190423105303.61683-1-tmricht@linux.ibm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

While cross building perf to the ARC architecture on a fedora 30 host,
we were failing with:

      CC       /tmp/build/perf/bench/numa.o
  bench/numa.c: In function ‘worker_thread’:
  bench/numa.c:1261:12: error: ‘RUSAGE_THREAD’ undeclared (first use in this function); did you mean ‘SIGEV_THREAD’?
    getrusage(RUSAGE_THREAD, &rusage);
              ^~~~~~~~~~~~~
              SIGEV_THREAD
  bench/numa.c:1261:12: note: each undeclared identifier is reported only once for each function it appears in

[perfbuilder@60d5802468f6 perf]$ /arc_gnu_2019.03-rc1_prebuilt_uclibc_le_archs_linux_install/bin/arc-linux-gcc --version | head -1
arc-linux-gcc (ARCv2 ISA Linux uClibc toolchain 2019.03-rc1) 8.3.1 20190225
[perfbuilder@60d5802468f6 perf]$

Trying to reproduce a report by Vineet, I noticed that, with just
cross-built zlib and numactl libraries, I ended up with the above
failure.

So, since RUSAGE_THREAD is available as a define, check for that and
numactl libraries, I ended up with the above failure.

So, since RUSAGE_THREAD is available as a define in the system headers,
check if it is defined in the 'perf bench numa' sources and define it if
not.

Now it builds and I have to figure out if the problem reported by Vineet
only takes place if we have libelf or some other library available.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: linux-snps-arc@lists.infradead.org
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Link: https://lkml.kernel.org/n/tip-2wb4r1gir9xrevbpq7qp0amk@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The traceevent lib is used by the perf tool, and when executing

  perf test -v 6

it outputs error log on the ARM64 platform:

  running test 33 '*:*'trace-cmd: No such file or directory

  [...]

  trace-cmd: Invalid argument

The trace event parsing code originally came from trace-cmd so it keeps
the tag string "trace-cmd" for errors, this easily introduces the
impression that the perf tool launches trace-cmd command for trace event
parsing, but in fact the related parsing is accomplished by the
traceevent lib.

This patch changes the tag string to "libtraceevent" so that we can
avoid confusion and let users to more easily connect the error with
traceevent lib.
Signed-off-by: NLeo Yan <leo.yan@linaro.org>
Acked-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20190424013802.27569-1-leo.yan@linaro.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Commit 6987561c ("perf annotate: Enable annotation of BPF programs") adds
support for BPF programs annotations but the new code does not build on 32-bit.
Signed-off-by: NThadeu Lima de Souza Cascardo <cascardo@canonical.com>
Acked-by: NSong Liu <songliubraving@fb.com>
Fixes: 6987561c ("perf annotate: Enable annotation of BPF programs")
Link: http://lkml.kernel.org/r/20190403194452.10845-1-cascardo@canonical.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To pick up the changes from:

  2b27924b ("KVM: nVMX: always use early vmcs check when EPT is disabled")

That causes this object in the tools/perf build process to be rebuilt:

  CC       /tmp/build/perf/arch/x86/util/kvm-stat.o

But it isn't using VMX_ABORT_ prefixed constants, so no change in
behaviour.

This silences this perf build warning:

  Warning: Kernel ABI header at 'tools/arch/x86/include/uapi/asm/vmx.h' differs from latest version at 'arch/x86/include/uapi/asm/vmx.h'
  diff -u tools/arch/x86/include/uapi/asm/vmx.h arch/x86/include/uapi/asm/vmx.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lkml.kernel.org/n/tip-bjbo3zc0r8i8oa0udpvftya6@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

In perf_env__find_btf(), we're returning without unlocking
"env->bpf_progs.lock". There may be cause lockdep issue.

Detected by CoversityScan, CID# 1444762:(program hangs(LOCK))
Signed-off-by: NBo YU <tsu.yubo@gmail.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Fixes: 2db7b1e0: (perf bpf: Return NULL when RB tree lookup fails in perf_env__find_btf())
Link: http://lkml.kernel.org/r/20190422080138.10088-1-tsu.yubo@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Pull networking fixes from David Miller:

 1) Out of bounds access in xfrm IPSEC policy unlink, from Yue Haibing.

 2) Missing length check for esp4 UDP encap, from Sabrina Dubroca.

 3) Fix byte order of RX STBC access in mac80211, from Johannes Berg.

 4) Inifnite loop in bpftool map create, from Alban Crequy.

 5) Register mark fix in ebpf verifier after pkt/null checks, from Paul
    Chaignon.

 6) Properly use rcu_dereference_sk_user_data in L2TP code, from Eric
    Dumazet.

 7) Buffer overrun in marvell phy driver, from Andrew Lunn.

 8) Several crash and statistics handling fixes to bnxt_en driver, from
    Michael Chan and Vasundhara Volam.

 9) Several fixes to the TLS layer from Jakub Kicinski (copying negative
    amounts of data in reencrypt, reencrypt frag copying, blind nskb->sk
    NULL deref, etc).

10) Several UDP GRO fixes, from Paolo Abeni and Eric Dumazet.

11) PID/UID checks on ipv6 flow labels are inverted, from Willem de
    Bruijn.

12) Use after free in l2tp, from Eric Dumazet.

13) IPV6 route destroy races, also from Eric Dumazet.

14) SCTP state machine can erroneously run recursively, fix from Xin
    Long.

15) Adjust AF_PACKET msg_name length checks, add padding bytes if
    necessary. From Willem de Bruijn.

16) Preserve skb_iif, so that forwarded packets have consistent values
    even if fragmentation is involved. From Shmulik Ladkani.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (69 commits)
  udp: fix GRO packet of death
  ipv6: A few fixes on dereferencing rt->from
  rds: ib: force endiannes annotation
  selftests: fib_rule_tests: print the result and return 1 if any tests failed
  ipv4: ip_do_fragment: Preserve skb_iif during fragmentation
  net/tls: avoid NULL pointer deref on nskb->sk in fallback
  selftests: fib_rule_tests: Fix icmp proto with ipv6
  packet: validate msg_namelen in send directly
  packet: in recvmsg msg_name return at least sizeof sockaddr_ll
  sctp: avoid running the sctp state machine recursively
  stmmac: pci: Fix typo in IOT2000 comment
  Documentation: fix netdev-FAQ.rst markup warning
  ipv6: fix races in ip6_dst_destroy()
  l2ip: fix possible use-after-free
  appletalk: Set error code if register_snap_client failed
  net: dsa: bcm_sf2: fix buffer overflow doing set_rxnfc
  rxrpc: Fix net namespace cleanup
  ipv6/flowlabel: wait rcu grace period before put_pid()
  vrf: Use orig netdev to count Ip6InNoRoutes and a fresh route lookup when sending dest unreach
  tcp: add sanity tests in tcp_add_backlog()
  ...

Pull io_uring fixes from Jens Axboe:
 "This is mostly io_uring fixes/tweaks. Most of these were actually done
  in time for the last -rc, but I wanted to ensure that everything
  tested out great before including them. The code delta looks larger
  than it really is, as it's mostly just comment additions/changes.

  Outside of the comment additions/changes, this is mostly removal of
  unnecessary barriers. In all, this pull request contains:

   - Tweak to how we handle errors at submission time. We now post a
     completion event if the error occurs on behalf of an sqe, instead
     of returning it through the system call. If the error happens
     outside of a specific sqe, we return the error through the system
     call. This makes it nicer to use and makes the "normal" use case
     behave the same as the offload cases. (me)

   - Fix for a missing req reference drop from async context (me)

   - If an sqe is submitted with RWF_NOWAIT, don't punt it to async
     context. Return -EAGAIN directly, instead of using it as a hint to
     do async punt. (Stefan)

   - Fix notes on barriers (Stefan)

   - Remove unnecessary barriers (Stefan)

   - Fix potential double free of memory in setup error (Mark)

   - Further improve sq poll CPU validation (Mark)

   - Fix page allocation warning and leak on buffer registration error
     (Mark)

   - Fix iov_iter_type() for new no-ref flag (Ming)

   - Fix a case where dio doesn't honor bio no-page-ref (Ming)"

* tag 'for-linus-20190502' of git://git.kernel.dk/linux-block:
  io_uring: avoid page allocation warnings
  iov_iter: fix iov_iter_type
  block: fix handling for BIO_NO_PAGE_REF
  io_uring: drop req submit reference always in async punt
  io_uring: free allocated io_memory once
  io_uring: fix SQPOLL cpu validation
  io_uring: have submission side sqe errors post a cqe
  io_uring: remove unnecessary barrier after unsetting IORING_SQ_NEED_WAKEUP
  io_uring: remove unnecessary barrier after incrementing dropped counter
  io_uring: remove unnecessary barrier before reading SQ tail
  io_uring: remove unnecessary barrier after updating SQ head
  io_uring: remove unnecessary barrier before reading cq head
  io_uring: remove unnecessary barrier before wq_has_sleeper
  io_uring: fix notes on barriers
  io_uring: fix handling SQEs requesting NOWAIT

Multiple users have reported their Synaptics touchpad has stopped
working between v4.20.1 and v4.20.2 when using SMBus interface.

The culprit for this appeared to be commit c5eb1190 ("PCI / PM: Allow
runtime PM without callback functions") that fixed the runtime PM for
i2c-i801 SMBus adapter. Those Synaptics touchpad are using i2c-i801
for SMBus communication and testing showed they are able to get back
working by preventing the runtime suspend of adapter.

Normally when i2c-i801 SMBus adapter transmits with the client it resumes
before operation and autosuspends after.

However, if client requires SMBus Host Notify protocol, what those
Synaptics touchpads do, then the host adapter must not go to runtime
suspend since then it cannot process incoming SMBus Host Notify commands
the client may send.

Fix this by keeping I2C/SMBus adapter active in case client requires
Host Notify.
Reported-by: NKeijo Vaara <ferdasyn@rocketmail.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=203297
Fixes: c5eb1190 ("PCI / PM: Allow runtime PM without callback functions")
Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: NKeijo Vaara <ferdasyn@rocketmail.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The I2C host driver for SynQuacer fails to populate the of_node and
ACPI companion fields of the struct i2c_adapter it instantiates,
resulting in enumeration of the subordinate I2C bus to fail.

Fixes: 0d676a6c ("i2c: add support for Socionext SynQuacer I2C controller")
Cc: <stable@vger.kernel.org> # v4.19+
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

I haven't heard from Haavard in years despite putting him to the CC list for
i2c-gpio related mails. Since I was doing the work on this driver for a while
now, let me take official maintainership, so it will be more clear to users.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: NHaavard Skinnemoen <hskinnemoen@gmail.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Add an explicit subdirectory specification for arch/x86/events/amd to
the MAINTAINERS file, to distinguish it from its parent. This will
produce the correct set of maintainers for the files found therein.
Signed-off-by: NKim Phillips <kim.phillips@amd.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Gary Hook <Gary.Hook@amd.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Liška <mliska@suse.cz>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pu Wen <puwen@hygon.cn>
Cc: Stephane Eranian <eranian@google.com>
Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Lendacky <Thomas.Lendacky@amd.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Fixes: 39b0332a ("perf/x86: Move perf_event_amd.c ........... => x86/events/amd/core.c")
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Add a new amd_hw_cache_event_ids_f17h assignment structure set
for AMD families 17h and above, since a lot has changed.  Specifically:

L1 Data Cache

The data cache access counter remains the same on Family 17h.

For DC misses, PMCx041's definition changes with Family 17h,
so instead we use the L2 cache accesses from L1 data cache
misses counter (PMCx060,umask=0xc8).

For DC hardware prefetch events, Family 17h breaks compatibility
for PMCx067 "Data Prefetcher", so instead, we use PMCx05a "Hardware
Prefetch DC Fills."

L1 Instruction Cache

PMCs 0x80 and 0x81 (32-byte IC fetches and misses) are backward
compatible on Family 17h.

For prefetches, we remove the erroneous PMCx04B assignment which
counts how many software data cache prefetch load instructions were
dispatched.

LL - Last Level Cache

Removing PMCs 7D, 7E, and 7F assignments, as they do not exist
on Family 17h, where the last level cache is L3.  L3 counters
can be accessed using the existing AMD Uncore driver.

Data TLB

On Intel machines, data TLB accesses ("dTLB-loads") are assigned
to counters that count load/store instructions retired.  This
is inconsistent with instruction TLB accesses, where Intel
implementations report iTLB misses that hit in the STLB.

Ideally, dTLB-loads would count higher level dTLB misses that hit
in lower level TLBs, and dTLB-load-misses would report those
that also missed in those lower-level TLBs, therefore causing
a page table walk.  That would be consistent with instruction
TLB operation, remove the redundancy between dTLB-loads and
L1-dcache-loads, and prevent perf from producing artificially
low percentage ratios, i.e. the "0.01%" below:

        42,550,869      L1-dcache-loads
        41,591,860      dTLB-loads
             4,802      dTLB-load-misses          #    0.01% of all dTLB cache hits
         7,283,682      L1-dcache-stores
         7,912,392      dTLB-stores
               310      dTLB-store-misses

On AMD Families prior to 17h, the "Data Cache Accesses" counter is
used, which is slightly better than load/store instructions retired,
but still counts in terms of individual load/store operations
instead of TLB operations.

So, for AMD Families 17h and higher, this patch assigns "dTLB-loads"
to a counter for L1 dTLB misses that hit in the L2 dTLB, and
"dTLB-load-misses" to a counter for L1 DTLB misses that caused
L2 DTLB misses and therefore also caused page table walks.  This
results in a much more accurate view of data TLB performance:

        60,961,781      L1-dcache-loads
             4,601      dTLB-loads
               963      dTLB-load-misses          #   20.93% of all dTLB cache hits

Note that for all AMD families, data loads and stores are combined
in a single accesses counter, so no 'L1-dcache-stores' are reported
separately, and stores are counted with loads in 'L1-dcache-loads'.

Also note that the "% of all dTLB cache hits" string is misleading
because (a) "dTLB cache": although TLBs can be considered caches for
page tables, in this context, it can be misinterpreted as data cache
hits because the figures are similar (at least on Intel), and (b) not
all those loads (technically accesses) technically "hit" at that
hardware level.  "% of all dTLB accesses" would be more clear/accurate.

Instruction TLB

On Intel machines, 'iTLB-loads' measure iTLB misses that hit in the
STLB, and 'iTLB-load-misses' measure iTLB misses that also missed in
the STLB and completed a page table walk.

For AMD Family 17h and above, for 'iTLB-loads' we replace the
erroneous instruction cache fetches counter with PMCx084
"L1 ITLB Miss, L2 ITLB Hit".

For 'iTLB-load-misses' we still use PMCx085 "L1 ITLB Miss,
L2 ITLB Miss", but set a 0xff umask because without it the event
does not get counted.

Branch Predictor (BPU)

PMCs 0xc2 and 0xc3 continue to be valid across all AMD Families.

Node Level Events

Family 17h does not have a PMCx0e9 counter, and corresponding counters
have not been made available publicly, so for now, we mark them as
unsupported for Families 17h and above.

Reference:

  "Open-Source Register Reference For AMD Family 17h Processors Models 00h-2Fh"
  Released 7/17/2018, Publication #56255, Revision 3.03:
  https://www.amd.com/system/files/TechDocs/56255_OSRR.pdf

[ mingo: tidied up the line breaks. ]
Signed-off-by: NKim Phillips <kim.phillips@amd.com>
Cc: <stable@vger.kernel.org> # v4.9+
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Liška <mliska@suse.cz>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pu Wen <puwen@hygon.cn>
Cc: Stephane Eranian <eranian@google.com>
Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Lendacky <Thomas.Lendacky@amd.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.kernel.org
Fixes: e40ed154 ("perf/x86: Add perf support for AMD family-17h processors")
Signed-off-by: NIngo Molnar <mingo@kernel.org>

There are two problems with dev_err() here. One: It is not ratelimited.
Two: We don't see which driver tried to transfer something with a
suspended adapter. Switch to dev_WARN_ONCE to fix both issues. Drawback
is that we don't see if multiple drivers are trying to transfer while
suspended. They need to be discovered one after the other now. This is
better than a high CPU load because a really broken driver might try to
resend endlessly.

Link: https://bugs.archlinux.org/task/62391
Fixes: 27515415 ("i2c: designware: Do not allow i2c_dw_xfer() calls while suspended")
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reported-by: Nskidnik <skidnik@gmail.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Nskidnik <skidnik@gmail.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Pull PCI fixes from Bjorn Helgaas:
 "I apologize for sending these so late in the cycle. We went back and
  forth about how to deal with the unexpected logging of intentional
  link state changes and finally decided to just config them off by
  default.

  PCI fixes:

   - Stop ignoring "pci=disable_acs_redir" parameter (Logan Gunthorpe)

   - Use shared MSI/MSI-X vector for Link Bandwidth Management (Alex
     Williamson)

   - Add Kconfig option for Link Bandwidth notification messages (Keith
     Busch)"

* tag 'pci-v5.1-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI/LINK: Add Kconfig option (default off)
  PCI/portdrv: Use shared MSI/MSI-X vector for Bandwidth Management
  PCI: Fix issue with "pci=disable_acs_redir" parameter being ignored

Pull MTD fix from Richard Weinberger:
 "A single regression fix for the marvell nand driver"

* tag 'mtd/fixes-for-5.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux:
  mtd: rawnand: marvell: Clean the controller state before each operation

e8303bb7 ("PCI/LINK: Report degraded links via link bandwidth
notification") added dmesg logging whenever a link changes speed or width
to a state that is considered degraded.  Unfortunately, it cannot
differentiate signal integrity-related link changes from those
intentionally initiated by an endpoint driver, including drivers that may
live in userspace or VMs when making use of vfio-pci.  Some GPU drivers
actively manage the link state to save power, which generates a stream of
messages like this:

  vfio-pci 0000:07:00.0: 32.000 Gb/s available PCIe bandwidth, limited by 2.5 GT/s x16 link at 0000:00:02.0 (capable of 64.000 Gb/s with 5 GT/s x16 link)

Since we can't distinguish the intentional changes from the signal
integrity issues, leave the reporting turned off by default.  Add a Kconfig
option to turn it on if desired.

Fixes: e8303bb7 ("PCI/LINK: Report degraded links via link bandwidth notification")
Link: https://lore.kernel.org/linux-pci/20190501142942.26972-1-keith.busch@intel.comSigned-off-by: NKeith Busch <keith.busch@intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

To choose whether to pick the GID from the old (16bit) or new (32bit)
field, we should check if the old gid field is set to 0xffff.  Mainline
checks the old *UID* field instead - cut'n'paste from the corresponding
code in ufs_get_inode_uid().

Fixes: 252e211eSigned-off-by: NAl Viro <viro@zeniv.linux.org.uk>