perf: arm_spe: Convert to platform remove callback returning void

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/abfedc224eca7f4960b7ddfb6daedd47a3699ca5.1702648125.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Will Deacon <will@kernel.org>

arm: pmu: Share user ABI format mechanism with SPE

This mechanism makes it much easier to define and read new attributes
so move it to the arm_pmu.h header so that it can be shared. At the same
time update the existing format attributes to use it.

GENMASK has to be changed to GENMASK_ULL because the config fields are
64 bits even on arm32 where this will also be used now.

Signed-off-by: James Clark <james.clark@arm.com>
Link: https://lore.kernel.org/r/20231211161331.1277825-7-james.clark@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

drivers/perf: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230714174832.4061752-1-robh@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

perf: arm_spe: Print the version of SPE detected

There's up to 4 versions of SPE now. Let's add the version that's been
detected to the driver's informational print out.

Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230206204746.1452942-1-robh@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

perf: arm_spe: Add support for SPEv1.2 inverted event filtering

Arm SPEv1.2 (Arm v8.7/v9.2) adds a new feature called Inverted Event
Filter which excludes samples matching the event filter. The feature
mirrors the existing event filter in PMSEVFR_EL1 adding a new register,
PMSNEVFR_EL1, which has the same event bit assignments.

Tested-by: James Clark <james.clark@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220825-arm-spe-v8-7-v4-8-327f860daf28@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

perf: arm_spe: Support new SPEv1.2/v8.7 'not taken' event

Arm SPEv1.2 (Armv8.7/v9.2) adds a new event, 'not taken', in bit 6 of
the PMSEVFR_EL1 register. Update arm_spe_pmsevfr_res0() to support the
additional event.

Tested-by: James Clark <james.clark@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20220825-arm-spe-v8-7-v4-6-327f860daf28@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

perf: arm_spe: Use new PMSIDR_EL1 register enums

Now that the SPE register definitions include enums for some PMSIDR_EL1
fields, use them in the driver in place of magic values.

Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20220825-arm-spe-v8-7-v4-5-327f860daf28@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

perf: arm_spe: Drop BIT() and use FIELD_GET/PREP accessors

Now that generated sysregs are in place, update the register field
accesses. The use of BIT() is no longer needed with the new defines. Use
FIELD_GET and FIELD_PREP instead of open coding masking and shifting.

No functional change.

Tested-by: James Clark <james.clark@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20220825-arm-spe-v8-7-v4-4-327f860daf28@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

arm64: Drop SYS_ from SPE register defines

We currently have a non-standard SYS_ prefix in the constants generated
for the SPE register bitfields. Drop this in preparation for automatic
register definition generation.

The SPE mask defines were unshifted, and the SPE register field
enumerations were shifted. The autogenerated defines are the opposite,
so make the necessary adjustments.

No functional changes.

Tested-by: James Clark <james.clark@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20220825-arm-spe-v8-7-v4-2-327f860daf28@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

perf: arm_spe: Use feature numbering for PMSEVFR_EL1 defines

Similar to commit 121a8fc088f1 ("arm64/sysreg: Use feature numbering for
PMU and SPE revisions") use feature numbering instead of architecture
versions for the PMSEVFR_EL1 Res0 defines.

Tested-by: James Clark <james.clark@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20220825-arm-spe-v8-7-v4-1-327f860daf28@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

arm64/perf: Assert all platform event flags are within PERF_EVENT_FLAG_ARCH

Ensure all platform specific event flags are within PERF_EVENT_FLAG_ARCH.

Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: James Clark <james.clark@arm.com>
Link: https://lkml.kernel.org/r/20220907091924.439193-4-anshuman.khandual@arm.com

arm64/sysreg: Fix a few missed conversions

After the conversion to automatically generating the ID_AA64DFR0_EL1
definition names, the build fails in a few different places because some
of the definitions were not changed to their new names along the way.
Update the names to resolve the build errors.

Fixes: c0357a73fa4a ("arm64/sysreg: Align field names in ID_AA64DFR0_EL1 with architecture")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220919160928.3905780-1-nathan@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

drivers/perf: arm_spe: Fix consistency of SYS_PMSCR_EL1.CX

The arm_spe_pmu driver will enable SYS_PMSCR_EL1.CX in order to add CONTEXT
packets into the traces, if the owner of the perf event runs with required
capabilities i.e CAP_PERFMON or CAP_SYS_ADMIN via perfmon_capable() helper.

The value of this bit is computed in the arm_spe_event_to_pmscr() function
but the check for capabilities happens in the pmu event init callback i.e
arm_spe_pmu_event_init(). This suggests that the value of the CX bit should
remain consistent for the duration of the perf session.

However, the function arm_spe_event_to_pmscr() may be called later during
the event start callback i.e arm_spe_pmu_start() when the "current" process
is not the owner of the perf session, hence the CX bit setting is currently
not consistent.

One way to fix this, is by caching the required value of the CX bit during
the initialization of the PMU event, so that it remains consistent for the
duration of the session. It uses currently unused 'event->hw.flags' element
to cache perfmon_capable() value, which can be referred during event start
callback to compute SYS_PMSCR_EL1.CX. This ensures consistent availability
of context packets in the trace as per event owner capabilities.

Drop BIT(SYS_PMSCR_EL1_CX_SHIFT) check in arm_spe_pmu_event_init(), because
now CX bit cannot be set in arm_spe_event_to_pmscr() with perfmon_capable()
disabled.

Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Fixes: d5d9696b0380 ("drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension")
Reported-by: German Gomez <german.gomez@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20220714061302.2715102-1-anshuman.khandual@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

drivers/perf: arm_spe: Expose saturating counter to 16-bit

In order to acquire more accurate latency, Armv8.8[1] has defined the
CountSize field to 16-bit saturating counters when it's 0b0011.

Let's support this new feature and expose its to user under sysfs.

[1] https://developer.arm.com/documentation/ddi0487/latest

Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Link: https://lore.kernel.org/r/20220429063307.63251-1-zhangshaokun@hisilicon.com
Signed-off-by: Will Deacon <will@kernel.org>

perf: arm_spe: use DEVICE_ATTR_RO macro

Use DEVICE_ATTR_RO() helper instead of plain DEVICE_ATTR(),
which makes the code a bit shorter and easier to read.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20210528061738.23392-1-yuehaibing@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>

drivers/perf: arm_spe_pmu: Fix some coding style issues

Fix some coding style issues reported by checkpatch.pl, including
following types:

WARNING: void function return statements are not generally useful
WARNING: Possible unnecessary 'out of memory' message

Signed-off-by: Junhao He <hejunhao2@hisilicon.com>
Signed-off-by: Jay Fang <f.fangjian@huawei.com>
Link: https://lore.kernel.org/r/1620736054-58412-2-git-send-email-f.fangjian@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>

drivers/perf: convert sysfs snprintf family to sysfs_emit

Fix the following coccicheck warning:

./drivers/perf/hisilicon/hisi_uncore_pmu.c:128:8-16: WARNING: use scnprintf or sprintf.
./drivers/perf/fsl_imx8_ddr_perf.c:173:8-16: WARNING: use scnprintf or sprintf.
./drivers/perf/arm_spe_pmu.c:129:8-16: WARNING: use scnprintf or sprintf.
./drivers/perf/arm_smmu_pmu.c:563:8-16: WARNING: use scnprintf or sprintf.
./drivers/perf/arm_dsu_pmu.c:149:8-16: WARNING: use scnprintf or sprintf.
./drivers/perf/arm_dsu_pmu.c:139:8-16: WARNING: use scnprintf or sprintf.
./drivers/perf/arm-cmn.c:563:8-16: WARNING: use scnprintf or sprintf.
./drivers/perf/arm-cmn.c:351:8-16: WARNING: use scnprintf or sprintf.
./drivers/perf/arm-ccn.c:224:8-16: WARNING: use scnprintf or sprintf.
./drivers/perf/arm-cci.c:708:8-16: WARNING: use scnprintf or sprintf.
./drivers/perf/arm-cci.c:699:8-16: WARNING: use scnprintf or sprintf.
./drivers/perf/arm-cci.c:528:8-16: WARNING: use scnprintf or sprintf.
./drivers/perf/arm-cci.c:309:8-16: WARNING: use scnprintf or sprintf.

Signed-off-by: Zihao Tang <tangzihao1@hisilicon.com>
Signed-off-by: Qi Liu <liuqi115@huawei.com>
Link: https://lore.kernel.org/r/1616148273-16374-2-git-send-email-liuqi115@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>

perf: Constify static struct attribute_group

The only usage is to put their addresses in an array of pointers to
const struct attribute group. Make them const to allow the compiler
to put them in read-only memory.

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Link: https://lore.kernel.org/r/20210117212847.21319-5-rikard.falkeborn@gmail.com
Signed-off-by: Will Deacon <will@kernel.org>

drivers/perf: Add support for ARMv8.3-SPE

Armv8.3 extends the SPE by adding:
- Alignment field in the Events packet, and filtering on this event
using PMSEVFR_EL1.
- Support for the Scalable Vector Extension (SVE).

The main additions for SVE are:
- Recording the vector length for SVE operations in the Operation Type
packet. It is not possible to filter on vector length.
- Incomplete predicate and empty predicate fields in the Events packet,
and filtering on these events using PMSEVFR_EL1.

Update the check of pmsevfr for empty/partial predicated SVE and
alignment event in SPE driver.

Signed-off-by: Wei Li <liwei391@huawei.com>
Link: https://lore.kernel.org/r/20201203141609.14148-1-liwei391@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

drivers/perf: Prevent forced unbinding of PMU drivers

Forcefully unbinding PMU drivers during perf sampling will lead to
a kernel panic, because the perf upper-layer framework call a NULL
pointer in this situation.

To solve this issue, "suppress_bind_attrs" should be set to true, so
that bind/unbind can be disabled via sysfs and prevent unbinding PMU
drivers during perf sampling.

Signed-off-by: Qi Liu <liuqi115@huawei.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/1594975763-32966-1-git-send-email-liuqi115@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>

drivers/perf: arm_spe_pmu: Avoid duplicate printouts

platform_get_irq() already screams on failure, so the redundant call to
dev_err() can be removed.

Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
Link: https://lore.kernel.org/r/20200402120330.19468-1-tangbin@cmss.chinamobile.com
Signed-off-by: Will Deacon <will@kernel.org>

drivers/perf: Open access for CAP_PERFMON privileged process

Open access to monitoring for CAP_PERFMON privileged process. Providing
the access under CAP_PERFMON capability singly, without the rest of
CAP_SYS_ADMIN credentials, excludes chances to misuse the credentials
and makes operation more secure.

CAP_PERFMON implements the principle of least privilege for performance
monitoring and observability operations (POSIX IEEE 1003.1e 2.2.2.39
principle of least privilege: A security design principle that states
that a process or program be granted only those privileges (e.g.,
capabilities) necessary to accomplish its legitimate function, and only
for the time that such privileges are actually required)

For backward compatibility reasons access to the monitoring remains open
for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for
secure monitoring is discouraged with respect to CAP_PERFMON capability.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Acked-by: Will Deacon <will@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Igor Lubashev <ilubashe@akamai.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: intel-gfx@lists.freedesktop.org
Cc: linux-doc@vger.kernel.org
Cc: linux-man@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Cc: selinux@vger.kernel.org
Link: http://lore.kernel.org/lkml/4ec1d6f7-548c-8d1c-f84a-cebeb9674e4e@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf: arm_spe: Remove unnecessary zero check on 'nr_pages'

We already check that the 'nr_pages' is > 2, so there's no need to check
that it's != 0 later on.

Signed-off-by: Liguang Zhang <zhangliguang@linux.alibaba.com>
Signed-off-by: Will Deacon <will@kernel.org>

perf: arm_spe: Enable ACPI/Platform automatic module loading

Lets add the MODULE_TABLE and platform id_table entries so that
the SPE driver can attach to the ACPI platform device created by
the core pmu code.

Tested-by: Hanjun Guo <hanjun.guo@linaro.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not see http www gnu org
licenses

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 503 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Enrico Weigelt <info@metux.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/perf: arm_spe: Don't error on high-order pages for aux buf

Since commit 5768402fd9c6 ("perf/ring_buffer: Use high order allocations
for AUX buffers optimistically"), the perf core tends to back aux buffer
allocations with high-order pages with the order encoded in the
PagePrivate data. The Arm SPE driver explicitly rejects such pages,
causing the perf tool to fail with:

| failed to mmap with 12 (Cannot allocate memory)

In actual fact, we can simply treat these pages just like any other
since the perf core takes care to populate the page array appropriately.
In theory we could try to map with PMDs where possible, but for now,
let's just get things working again.

Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Fixes: 5768402fd9c6 ("perf/ring_buffer: Use high order allocations for AUX buffers optimistically")
Reported-by: Hanjun Guo <guohanjun@huawei.com>
Tested-by: Hanjun Guo <guohanjun@huawei.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

perf/aux: Make perf_event accessible to setup_aux()

When pmu::setup_aux() is called the coresight PMU needs to know which
sink to use for the session by looking up the information in the
event's attr::config2 field.

As such simply replace the cpu information by the complete perf_event
structure and change all affected customers.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

perf/aux: Make perf_event accessible to setup_aux()

When pmu::setup_aux() is called the coresight PMU needs to know which
sink to use for the session by looking up the information in the
event's attr::config2 field.

As such simply replace the cpu information by the complete perf_event
structure and change all affected customers.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki Poulouse <suzuki.poulose@arm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-s390@vger.kernel.org
Link: http://lkml.kernel.org/r/20190131184714.20388-2-mathieu.poirier@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf: arm_spe: handle devm_kasprintf() failure

devm_kasprintf() may return NULL on failure of internal allocation
thus the assignment to 'name' is not safe if unchecked. If NULL
is passed in for name then perf_pmu_register() would not fail
but rather silently jump to skip_type which is not the intent
here. As perf_pmu_register() may also return -ENOMEM returning
-ENOMEM in the (unlikely) failure case of devm_kasprintf() should
be fine here as well.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Fixes: d5d9696b0380 ("drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension")
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
[will: reworded error message]
Signed-off-by: Will Deacon <will.deacon@arm.com>

perf: arm_spe: Enable automatic DT loading

When built as a module, the spe driver isn't automatically
loaded on DT systems. Add the MODULE_DEVICE_TABLE entry.

Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

perf: simplify getting .drvdata

We should get drvdata from struct device directly. Going via
platform_device is an unneeded step back and forth.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

perf: arm_spe: include linux/vmalloc.h for vmap()

On linux-next, I get a build failure in some configurations:

drivers/perf/arm_spe_pmu.c: In function 'arm_spe_pmu_setup_aux':
drivers/perf/arm_spe_pmu.c:857:14: error: implicit declaration of function 'vmap'; did you mean 'swap'? [-Werror=implicit-function-declaration]
buf->base = vmap(pglist, nr_pages, VM_MAP, PAGE_KERNEL);
^~~~
swap
drivers/perf/arm_spe_pmu.c:857:37: error: 'VM_MAP' undeclared (first use in this function); did you mean 'VM_MPX'?
buf->base = vmap(pglist, nr_pages, VM_MAP, PAGE_KERNEL);
^~~~~~
VM_MPX
drivers/perf/arm_spe_pmu.c:857:37: note: each undeclared identifier is reported only once for each function it appears in
drivers/perf/arm_spe_pmu.c: In function 'arm_spe_pmu_free_aux':
drivers/perf/arm_spe_pmu.c:878:2: error: implicit declaration of function 'vunmap'; did you mean 'iounmap'? [-Werror=implicit-function-declaration]

vmap() is declared in linux/vmalloc.h, so we should include that header file.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[will: add additional missing #includes reported by Mark]
Signed-off-by: Will Deacon <will.deacon@arm.com>

perf: arm_spe: Fail device probe when arm64_kernel_unmapped_at_el0()

When running with the kernel unmapped whilst at EL0, the virtually-addressed
SPE buffer is also unmapped, which can lead to buffer faults if userspace
profiling is enabled and potentially also when writing back kernel samples
unless an expensive drain operation is performed on exception return.

For now, fail the SPE driver probe when arm64_kernel_unmapped_at_el0().

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

perf: arm_spe: Prevent module unload while the PMU is in use

When the PMU driver is built as a module, the perf expects the
pmu->module to be valid, so that the driver is prevented from
being unloaded while it is in use. Fix the SPE pmu driver to
fill in this field.

Cc: Will Deacon <will.deacon@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension

The ARMv8.2 architecture introduces the optional Statistical Profiling
Extension (SPE).

SPE can be used to profile a population of operations in the CPU pipeline
after instruction decode. These are either architected instructions (i.e.
a dynamic instruction trace) or CPU-specific uops and the choice is fixed
statically in the hardware and advertised to userspace via caps/. Sampling
is controlled using a sampling interval, similar to a regular PMU counter,
but also with an optional random perturbation to avoid falling into patterns
where you continuously profile the same instruction in a hot loop.

After each operation is decoded, the interval counter is decremented. When
it hits zero, an operation is chosen for profiling and tracked within the
pipeline until it retires. Along the way, information such as TLB lookups,
cache misses, time spent to issue etc is captured in the form of a sample.
The sample is then filtered according to certain criteria (e.g. load
latency) that can be specified in the event config (described under
format/) and, if the sample satisfies the filter, it is written out to
memory as a record, otherwise it is discarded. Only one operation can
be sampled at a time.

The in-memory buffer is linear and virtually addressed, raising an
interrupt when it fills up. The PMU driver handles these interrupts to
give the appearance of a ring buffer, as expected by the AUX code.

The in-memory trace-like format is self-describing (though not parseable
in reverse) and written as a series of records, with each record
corresponding to a sample and consisting of a sequence of packets. These
packets are defined by the architecture, although some have CPU-specific
fields for recording information specific to the microarchitecture.

As a simple example, a record generated for a branch instruction may
consist of the following packets:

0 (Address) : Virtual PC of the branch instruction
1 (Type) : Conditional direct branch
2 (Counter) : Number of cycles taken from Dispatch to Issue
3 (Address) : Virtual branch target + condition flags
4 (Counter) : Number of cycles taken from Dispatch to Complete
5 (Events) : Mispredicted as not-taken
6 (END) : End of record

It is also possible to toggle properties such as timestamp packets in
each record.

This patch adds support for SPE in the form of a new perf driver.

Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>