With ARCH=x86, make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/perf/arm-ccn.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/perf/fsl_imx8_ddr_perf.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/perf/marvell_cn10k_ddr_pmu.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/perf/arm_cspmu/arm_cspmu_module.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/perf/arm_cspmu/nvidia_cspmu.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/perf/arm_cspmu/ampere_cspmu.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/perf/cxl_pmu.o

Add the missing invocation of the MODULE_DESCRIPTION() macro to all
files which have a MODULE_LICENSE().

This includes drivers/perf/hisilicon/hisi_uncore_pmu.c which, although
it did not produce a warning with the x86 allmodconfig configuration,
may cause this warning with arm64 configurations.

Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Link: https://lore.kernel.org/r/20240709-md-drivers-perf-v3-1-513275b75ed0@quicinc.com
Signed-off-by: Will Deacon <will@kernel.org>

Pull driver core updates from Greg KH:
 "Here is the small set of driver core and kernfs changes for 6.10-rc1.

  Nothing major here at all, just a small set of changes for some driver
  core apis, and minor fixups. Included in here are:

   - sysfs_bin_attr_simple_read() helper added and used

   - device_show_string() helper added and used

  All usages of these were acked by the various maintainers. Also in
  here are:

   - kernfs minor cleanup

   - removed unused functions

   - typo fix in documentation

   - pay attention to sysfs_create_link() failures in module.c finally

  All of these have been in linux-next for a very long time with no
  reported problems"

* tag 'driver-core-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  device property: Fix a typo in the description of device_get_child_node_count()
  kernfs: mount: Remove unnecessary ‘NULL’ values from knparent
  scsi: Use device_show_string() helper for sysfs attributes
  platform/x86: Use device_show_string() helper for sysfs attributes
  perf: Use device_show_string() helper for sysfs attributes
  IB/qib: Use device_show_string() helper for sysfs attributes
  hwmon: Use device_show_string() helper for sysfs attributes
  driver core: Add device_show_string() helper for sysfs attributes
  treewide: Use sysfs_bin_attr_simple_read() helper
  sysfs: Add sysfs_bin_attr_simple_read() helper
  module: don't ignore sysfs_create_link() failures
  driver core: Remove unused platform_notify, platform_notify_remove

Deduplicate sysfs ->show() callbacks which expose a string at a static
memory location.  Use the newly introduced device_show_string() helper
in the driver core instead by declaring those sysfs attributes with
DEVICE_STRING_ATTR_RO().

No functional change intended.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/3a297850312b4ecb62d6872121de04496900f502.1713608122.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Currently all these devices appear directly under /sys/devices/
Only root busses should appear there, so instead assign the pmu->dev
parents to be the platform device.

Link: https://lore.kernel.org/linux-cxl/ZCLI9A40PJsyqAmq@kroah.com/
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20240412161057.14099-8-Jonathan.Cameron@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>

In general it's preferable to avoid placing cpumasks on the stack, as
for large values of NR_CPUS these can consume significant amounts of
stack space and make stack overflows more likely.

Use cpumask_any_and_but() to avoid the need for a temporary cpumask on
the stack.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Dawei Li <dawei.li@shingroup.cn>
Link: https://lore.kernel.org/r/20240403155950.2068109-5-dawei.li@shingroup.cn
Signed-off-by: Will Deacon <will@kernel.org>

Hook up devicetree probing support. For now let's hope that people
implement PMIIDR properly and we don't need an override property or
match data mechanism.

Reviewed-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Besar Wicaksono <bwicaksono@nvidia.com>
Tested-by: Besar Wicaksono <bwicaksono@nvidia.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/836722034302ff62f2df56aaeb0036e71945a5d1.1706718007.git.robin.murphy@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

arm_cspmu_reset_counters() inherently also stops them since it is
writing 0 to PMCR.E, so there should be no need to do that twice.
Also tidy up the reset routine itself for consistency with the start
and stop routines, and to be clear at first glance that it is simply
writing a constant value.

Reviewed-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/3105815327989f6bb7bb068994d0eb4096b4ef64.1706718007.git.robin.murphy@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

The attribute group array itself is always the same, so there's no
need to allocate it separately. Storing it directly in our instance
data saves memory and gives us one less point of failure.

Reviewed-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/cf12b803114b0815438833fcb2495f20f2007761.1706718007.git.robin.murphy@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

It's far simpler for implementations to literally override whichever
default ops they want to, by initialising to the default ops first. This
saves all the bother of checking what the impl_init_ops call has or
hasn't touched. Make the same clear distinction for the PMIIDR override
as well, in case we gain more sources for overriding that in future.

Reviewed-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/dd39718ee4890fd46a8e443c25303e87ae23f422.1706718007.git.robin.murphy@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/9ff5a467569dd51b2fc44e11594ad5db7ea15f57.1702648125.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Will Deacon <will@kernel.org>