Add documentation for Coresight Dummy Trace under trace/coresight.

Signed-off-by: Hao Zhang <quic_hazha@quicinc.com>

This patch add support for Coresight dummy source and dummy sink trace.

Signed-off-by: Hao Zhang <quic_hazha@quicinc.com>

Some Coresight devices that kernel don't have permission to access or
configure. For these devices, a dummy driver is needed to register them as
Coresight devices. The module may also be used to define components that may
not have any programming interfaces (e.g, static links), so that paths can be
created in the driver. It provides Coresight API for operations on dummy
devices, such as enabling and disabling them. It also provides the Coresight
dummy sink/source paths for debugging.

Signed-off-by: Hao Zhang <quic_hazha@quicinc.com>

If TMC ETR is enabled without being ready, in later use we may
see AXI bus errors caused by accessing invalid addresses.

Signed-off-by: Yabin Cui <yabinc@google.com>
[ Tweak error message ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230127231001.1920947-1-yabinc@google.com

devm_ioremap_resource() never returns NULL pointer, it
will return ERR_PTR() when it fails, so replace the check
with IS_ERR().

Fixes: 5b791662 ("Coresight: Add TPDA link driver")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
[ Fix return value to the PTR_ERR(base) ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230129084246.537694-1-yangyingliang@huawei.com

'remove' callbacks get called whenever a device is unbound from
the driver, which can get triggered from user space.

Putting it into the __exit section means that the function gets
dropped in for built-in drivers, as pointed out by this build
warning:

`tpda_remove' referenced in section `.data' of drivers/hwtracing/coresight/coresight-tpda.o: defined in discarded section `.exit.text' of drivers/hwtracing/coresight/coresight-tpda.o
`tpdm_remove' referenced in section `.data' of drivers/hwtracing/coresight/coresight-tpdm.o: defined in discarded section `.exit.text' of drivers/hwtracing/coresight/coresight-tpdm.o

Fixes: 5b791662 ("Coresight: Add TPDA link driver")
Fixes: b3c71626 ("Coresight: Add coresight TPDM source driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230126163530.3495413-1-arnd@kernel.org

With the dynamic traceid allocation scheme in, we output the
AUX_OUTPUT_HWID packet every time event->start() is called.
This could cause too many such records in the perf.data,
while only one per CPU throughout the life time of
the event is required. Make sure we only output it once.

Before this patch:
  $ perf report -D | grep OUTPUT_HW_ID
  ...
  AUX_OUTPUT_HW_ID events:         55  (18.3%)

After this patch:

 $ perf report -D | grep OUTPUT_HW_ID
 ...
 AUX_OUTPUT_HW_ID events:          5  ( 1.9%)

Cc: Mike Leach <mike.leach@linaro.org>
Cc: James Clark <james.clark@arm.com>
Cc: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: James Clark <james.clark@arm.com>
Link: https://lore.kernel.org/r/20230120103434.864318-1-suzuki.poulose@arm.com

Kernel test robot reports:

 drivers/hwtracing/coresight/coresight-core.c:1176:7: warning: variable
 'hash' is used uninitialized whenever switch case is taken
 [-Wsometimes-uninitialized]

	case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
	      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 drivers/hwtracing/coresight/coresight-core.c:1195:24: note: uninitialized
 use occurs here
		idr_remove(&path_idr, hash);
		                      ^~~~
Fix this by moving the usage of the hash variable to where it actually
should have been.

Cc: Mao Jinlong <quic_jinlmao@quicinc.com>
Link: https://lkml.kernel.org/r/202301211339.9mU0dccO-lkp@intel.com


Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: James Clark <james.clark@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lkml.kernel.org/r/20230123164700.1074064-1-suzuki.poulose@arm.com

kernel test robot reported htmldocs warning:

Documentation/trace/coresight/coresight-tpdm.rst:43: WARNING: Document may not end with a transition.

Since there is no more documentation left for TPDM, fix the warning by adding
dummy comment, thus creating the required text transition.

Link: https://lore.kernel.org/linux-doc/202301210955.zYxDrLgv-lkp@intel.com/


Fixes: 758d6386 ("Documentation: trace: Add documentation for TPDM and TPDA")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230121040015.28139-3-bagasdotme@gmail.com

kernel test robot reported htmldocs warnings:

Documentation/trace/coresight/coresight-tpda.rst:3: WARNING: Title overline too short.
Documentation/trace/coresight/coresight-tpdm.rst:3: WARNING: Title overline too short.

Extend title heading syntax (overline and underline) to match title text to
fix these warnings.

While at it, trim unneeded period in the title text.

Link: https://lore.kernel.org/linux-doc/202301210955.zYxDrLgv-lkp@intel.com/


Fixes: 758d6386 ("Documentation: trace: Add documentation for TPDM and TPDA")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230121040015.28139-2-bagasdotme@gmail.com

Add documentation for the TPDM and TPDA under trace/coresight.

Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230117145708.16739-9-quic_jinlmao@quicinc.com

Adds new coresight-tpda.yaml file describing the bindings required
to define tpda in the device trees.

Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230117145708.16739-8-quic_jinlmao@quicinc.com

TPDA(Trace, Profiling and Diagnostics Aggregator) is
to provide packetization, funneling and timestamping of
TPDM data. Multiple monitors are connected to different
input ports of TPDA.This change is to add tpda
enable/disable/probe functions for coresight tpda driver.

 - - - -         - - - -        - - - -
| TPDM 0|      | TPDM 1 |     | TPDM 2|
 - - - -         - - - -        - - - -
    |               |             |
    |_ _ _ _ _ _    |     _ _ _ _ |
                |   |    |
                |   |    |
           ------------------
          |        TPDA      |
           ------------------

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230120095301.30792-2-quic_jinlmao@quicinc.com

Integration test for tpdm can help to generate the data for
verification of the topology during TPDM software bring up.

Sample:
echo 1 > /sys/bus/coresight/devices/tmc_etf0/enable_sink
echo 1 > /sys/bus/coresight/devices/tpdm0/enable_source
echo 1 > /sys/bus/coresight/devices/tpdm0/integration_test
echo 2 > /sys/bus/coresight/devices/tpdm0/integration_test
cat /dev/tmc_etf0 > /data/etf-tpdm0.bin

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230117145708.16739-6-quic_jinlmao@quicinc.com

TPDM serves as data collection component for various dataset types.
DSB(Discrete Single Bit) is one of the dataset types. DSB subunit
can be enabled for data collection by writing 1 to the first bit of
DSB_CR register. This change is to add enable/disable function for
DSB dataset by writing DSB_CR register.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230117145708.16739-5-quic_jinlmao@quicinc.com

Add new coresight-tpdm.yaml file describing the bindings required
to define tpdm in the device trees.

Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230117145708.16739-4-quic_jinlmao@quicinc.com

Add driver to support Coresight device TPDM (Trace, Profiling and
Diagnostics Monitor). TPDM is a monitor to collect data from
different datasets. This change is to add probe/enable/disable
functions for tpdm source.

Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230120095301.30792-1-quic_jinlmao@quicinc.com

Except stm, there could be other sources which are not associated
with cpus. Use IDR to store and search these sources' paths.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230117145708.16739-2-quic_jinlmao@quicinc.com

Adds in a number of pr_debug macros to allow the debugging and test of
the trace ID allocation system.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230116124928.5440-15-mike.leach@linaro.org

Use the perf_report_aux_output_id() call to output the CoreSight trace ID
and associated CPU as a PERF_RECORD_AUX_OUTPUT_HW_ID record in the
perf.data file.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230116124928.5440-14-mike.leach@linaro.org

CoreSight trace being updated to use the perf_report_aux_output_id()
in a similar way to intel-pt.

This function in needs export visibility to allow it to be called from
kernel loadable modules, which CoreSight may configured to be built as.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230116124928.5440-12-mike.leach@linaro.org

Removes legacy coresight_get_trace_id() function now its use has been
removed from the ETM code.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230116124928.5440-9-mike.leach@linaro.org

CoreSight sources provide a callback (.trace_id) in the standard source
ops which returns the ID to the core code. This was used to check that
sources all had a unique Trace ID.

Uniqueness is now gauranteed by the Trace ID allocation system, and the
check code has been removed from the core.

This patch removes the unneeded and unused .trace_id source ops
from the ops structure and implementations in etm3x, etm4x and stm.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230116124928.5440-8-mike.leach@linaro.org

Use the TraceID API to allocate ETM trace IDs dynamically.

As with the etm4x we allocate on enable / disable for perf,
allocate on enable / reset for sysfs.

Additionally we allocate on sysfs file read as both perf and sysfs
can read the ID before enabling the hardware.

Remove sysfs option to write trace ID - which is inconsistent with
both the dynamic allocation method and the fixed allocation method
previously used.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230116124928.5440-7-mike.leach@linaro.org

The trace ID API is now used to allocate trace IDs for ETM4.x / ETE
devices.

For perf sessions, these will be allocated on enable, and released on
disable.

For sysfs sessions, these will be allocated on enable, but only released
on reset. This allows the sysfs session to interrogate the Trace ID used
after the session is over - maintaining functional consistency with the
previous allocation scheme.

The trace ID will also be allocated on read of the mgmt/trctraceid file.
This ensures that if perf or sysfs read this before enabling trace, the
value will be the one used for the trace session.

Trace ID initialisation is removed from the _probe() function.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230116124928.5440-6-mike.leach@linaro.org

Updates the STM driver to use the trace ID allocation API.
This uses the _system_id calls to allocate an ID on device poll,
and release on device remove.

The sysfs access to the STMTRACEIDR register has been changed from RW
to RO. Having this value as writable is not appropriate for the new
Trace ID scheme - and had potential to cause errors in the previous
scheme if values clashed with other sources.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230116124928.5440-5-mike.leach@linaro.org

Adds in calls to allocate and release Trace ID for the CPUs in use
by the perf session.

Adds in notifier calls to the trace ID allocator that perf
events are starting and stopping.

This ensures that Trace IDs associated with CPUs remain the same
throughout the perf session, and are only released when all perf
sessions are complete.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230116124928.5440-4-mike.leach@linaro.org

The checks for sources to have unique IDs has been removed - this is now
guaranteed by the ID allocation mechanisms, and inappropriate where
multiple ID maps are in use in larger systems

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230116124928.5440-3-mike.leach@linaro.org

The existing mechanism to assign Trace ID values to sources is limited
and does not scale for larger multicore / multi trace source systems.

The API introduces functions that reserve IDs based on availabilty
represented by a coresight_trace_id_map structure. This records the
used and free IDs in a bitmap.

CPU bound sources such as ETMs use the coresight_trace_id_get_cpu_id
coresight_trace_id_put_cpu_id pair of functions. The API will record
the ID associated with the CPU. This ensures that the same ID will be
re-used while perf events are active on the CPU. The put_cpu_id function
will pend release of the ID until all perf cs_etm sessions are complete.

For backward compatibility the functions will attempt to use the same
CPU IDs as the legacy system would have used if these are still available.

Non-cpu sources, such as the STM can use coresight_trace_id_get_system_id /
coresight_trace_id_put_system_id.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
[ Fix checkpatch warning in drivers/hwtracing/coresight/coresight-trace-id.c ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230116124928.5440-2-mike.leach@linaro.org

Add missing entries for the perf userspace part of this driver.
Also add Jonathan as the maintainer for his expertise on this
driver and PCIe stuffs.

Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230112112201.16283-2-yangyicong@huawei.com

The PTT device can only support the devices on the same PCIe core,
within BDF range [lower_bdf, upper_bdf]. It's not correct to assume
the devices on the root bus are from the same PCIe core, there are
cases that root ports from different PCIe core are sharing the same
bus. So check when initializing the filters list.

Fixes: ff0de066 ("hwtracing: hisi_ptt: Add trace function support for HiSilicon PCIe Tune and Trace device")
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230112112201.16283-1-yangyicong@huawei.com

platform_get_resource() returns NULL pointer not PTR_ERR(), replace
the IS_ERR() check with NULL pointer check.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230118074920.1772141-1-yangyingliang@huawei.com

Bring in documentation for UltraSoc SMB driver.
It simply describes the device, sysfs interface and the
firmware bindings.

Signed-off-by: Qi Liu <liuqi115@huawei.com>
Signed-off-by: Junhao He <hejunhao3@huawei.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230114101302.62320-3-hejunhao3@huawei.com

Add driver for UltraSoc SMB(System Memory Buffer) device.
SMB provides a way to buffer messages from ETM, and store
these "CPU instructions trace" in system memory.
The SMB device is identifier as ACPI HID "HISI03A1". Device
system memory address resources are allocated using the _CRS
method and buffer modes is the circular buffer mode.

SMB is developed by UltraSoc technology, which is acquired by
Siemens, and we still use "UltraSoc" to name driver.

Signed-off-by: Qi Liu <liuqi115@huawei.com>
Signed-off-by: Junhao He <hejunhao3@huawei.com>
Tested-by: JunHao He <hejunhao3@huawei.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230114101302.62320-2-hejunhao3@huawei.com

enable_req_count is only ever accessed inside the spinlock, so to avoid
confusion that there are concurrent accesses and simplify the code,
change it to an int.

One access outside of the spinlock is in enable_show() which appears to
allow partially written data to be displayed between enable_req_count,
powered and enabled so move this one inside the spin lock too.

Signed-off-by: James Clark <james.clark@arm.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230110110736.2709917-4-james.clark@arm.com

In commit 6746eae4 ("coresight: cti: Fix hang in cti_disable_hw()")
PM runtime calls are removed from cti_enable_hw/cti_disable_hw. When
enabling CTI by writing enable sysfs node, clock for accessing CTI
register won't be enabled. Device will crash due to register access
issue. Add PM runtime call in enable_store to fix this issue.

Fixes: 6746eae4 ("coresight: cti: Fix hang in cti_disable_hw()")
Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
[Change to only call pm_runtime_put if a disable happened]
Tested-by: Jinlong Mao <quic_jinlmao@quicinc.com>
Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230110110736.2709917-3-james.clark@arm.com

Writing 0 to the enable control repeatedly results in a negative value
for enable_req_count. After this, writing 1 to the enable control
appears to not work until the count returns to positive.

Change it so that it's impossible for enable_req_count to be < 0.
Return an error to indicate that the disable request was invalid.

Fixes: 835d722b ("coresight: cti: Initial CoreSight CTI Driver")
Tested-by: Jinlong Mao <quic_jinlmao@quicinc.com>
Signed-off-by: James Clark <james.clark@arm.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230110110736.2709917-2-james.clark@arm.com

The TRCSEQRSTEVR and TRCSEQSTR registers are not implemented if the
TRCIDR5.NUMSEQSTATE == 0. Skip accessing the registers in such cases.

Fixes: 2e1cdfe1 ("coresight-etm4x: Adding CoreSight ETM4x driver")
Signed-off-by: Junhao He <hejunhao3@huawei.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230114091632.60095-1-hejunhao3@huawei.com

Pull perf fixes from Borislav Petkov:

 - Pass only an initialized perf event attribute to the LSM hook

 - Fix a use-after-free on the perf syscall's error path

 - A potential integer overflow fix in amd_core_pmu_init()

 - Fix the cgroup events tracking after the context handling rewrite

 - Return the proper value from the inherit_event() function on error

* tag 'perf_urgent_for_v6.2_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Call LSM hook after copying perf_event_attr
  perf: Fix use-after-free in error path
  perf/x86/amd: fix potential integer overflow on shift of a int
  perf/core: Fix cgroup events tracking
  perf core: Return error pointer if inherit_event() fails to find pmu_ctx