From: Anshuman Khandual <anshuman.khandual@arm.com>
To: James Clark <james.clark@arm.com>
Cc: Mark Brown <broonie@kernel.org>, Rob Herring <robh@kernel.org>,
Marc Zyngier <maz@kernel.org>,
Suzuki Poulose <suzuki.poulose@arm.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
linux-perf-users@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, will@kernel.org,
catalin.marinas@arm.com, mark.rutland@arm.com
Subject: Re: [V14 3/8] drivers: perf: arm_pmuv3: Enable branch stack sampling framework
Date: Wed, 15 Nov 2023 11:14:12 +0530 [thread overview]
Message-ID: <5bf73672-4094-490b-b0a9-b983d512c904@arm.com> (raw)
In-Reply-To: <0020aa0d-e9a5-aef6-f33d-817da56411a3@arm.com>
On 11/14/23 15:28, James Clark wrote:
>
>
> On 14/11/2023 05:13, Anshuman Khandual wrote:
>> Branch stack sampling support i.e capturing branch records during execution
>> in core perf, rides along with normal HW events being scheduled on the PMU.
>> This prepares ARMV8 PMU framework for branch stack support on relevant PMUs
>> with required HW implementation.
>>
>
> [...]
>
>> - All armv8pmu_branch_xxxx() stub definitions have been moved inside
>> include/linux/perf/arm_pmuv3.h for easy access from both arm32 and
>> arm64 platforms
>>
>
> This causes lots of W=1 build errors because the prototypes are in
> arm_pmuv3.h, but arm_brbe.c doesn't include it.
I guess these are the W=1 warnings you mentioned above.
drivers/perf/arm_brbe.c:11:6: warning: no previous prototype for ‘armv8pmu_branch_reset’ [-Wmissing-prototypes]
11 | void armv8pmu_branch_reset(void)
| ^~~~~~~~~~~~~~~~~~~~~
drivers/perf/arm_brbe.c:190:6: warning: no previous prototype for ‘armv8pmu_branch_save’ [-Wmissing-prototypes]
190 | void armv8pmu_branch_save(struct arm_pmu *arm_pmu, void *ctx)
| ^~~~~~~~~~~~~~~~~~~~
drivers/perf/arm_brbe.c:236:6: warning: no previous prototype for ‘armv8pmu_branch_attr_valid’ [-Wmissing-prototypes]
236 | bool armv8pmu_branch_attr_valid(struct perf_event *event)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/perf/arm_brbe.c:269:5: warning: no previous prototype for ‘armv8pmu_task_ctx_cache_alloc’ [-Wmissing-prototypes]
269 | int armv8pmu_task_ctx_cache_alloc(struct arm_pmu *arm_pmu)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/perf/arm_brbe.c:279:6: warning: no previous prototype for ‘armv8pmu_task_ctx_cache_free’ [-Wmissing-prototypes]
279 | void armv8pmu_task_ctx_cache_free(struct arm_pmu *arm_pmu)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/perf/arm_brbe.c:303:6: warning: no previous prototype for ‘armv8pmu_branch_probe’ [-Wmissing-prototypes]
303 | void armv8pmu_branch_probe(struct arm_pmu *armpmu)
| ^~~~~~~~~~~~~~~~~~~~~
drivers/perf/arm_brbe.c:449:6: warning: no previous prototype for ‘armv8pmu_branch_enable’ [-Wmissing-prototypes]
449 | void armv8pmu_branch_enable(struct arm_pmu *arm_pmu)
| ^~~~~~~~~~~~~~~~~~~~~~
drivers/perf/arm_brbe.c:474:6: warning: no previous prototype for ‘armv8pmu_branch_disable’ [-Wmissing-prototypes]
474 | void armv8pmu_branch_disable(void)
| ^~~~~~~~~~~~~~~~~~~~~~~
drivers/perf/arm_brbe.c:717:6: warning: no previous prototype for ‘armv8pmu_branch_read’ [-Wmissing-prototypes]
717 | void armv8pmu_branch_read(struct pmu_hw_events *cpuc, struct perf_event *event)
Branch helpers are used in ARM PMU V3 driver i.e drivers/perf/arm_pmuv3.c.
Whether the actual BRBE helper definitions, or their fallback stubs (when
CONFIG_ARM64_BRBE is not enabled), need to be accessible from arm_pmuv3.c
driver not from brbe.c implementations itself.
>
> It seems like the main reason you can't include arm_brbe.h in arm32 code
> is because there are a load of inline functions and references to
> registers in there. But these are only used in arm_brbe.c, so they don't
Right, arm32 should not be exposed to BRBE internals via arm_brbe.h header.
> need to be in the header anyway.
Right, these are only used in arm_brbe.c
>
> If you removed the code from the header and moved it to the source file
> you could move the brbe prototypes to the brbe header and it would be a
> bit cleaner and more idiomatic.
Alight, how about the following changes - build tested on arm32 and arm64.
- Move BRBE helpers from arm_brbe.h into arm_brbe.c
- Move armv8_pmu_xxx() declaration inside arm_brbe.h for arm64 (CONFIG_ARM64_BRBE)
- Move armv8_pmu_xxx() stub definitions inside arm_pmuv3.c for arm32 (!CONFIG_ARM64_BRBE)
- Include arm_brbe.h header both in arm_pmuv3.c and arm_brbe.c
next prev parent reply other threads:[~2023-11-15 5:44 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-14 5:13 [V14 0/8] arm64/perf: Enable branch stack sampling Anshuman Khandual
2023-11-14 5:13 ` [V14 1/8] arm64/sysreg: Add BRBE registers and fields Anshuman Khandual
2023-11-14 5:13 ` [V14 2/8] KVM: arm64: Prevent guest accesses into BRBE system registers/instructions Anshuman Khandual
2023-11-14 5:13 ` [V14 3/8] drivers: perf: arm_pmuv3: Enable branch stack sampling framework Anshuman Khandual
2023-11-14 9:58 ` James Clark
2023-11-15 5:44 ` Anshuman Khandual [this message]
2023-11-15 9:37 ` James Clark
2023-11-21 9:13 ` Anshuman Khandual
2023-11-14 12:14 ` James Clark
2023-11-15 7:22 ` Anshuman Khandual
2023-11-15 10:07 ` James Clark
2023-11-21 9:57 ` Anshuman Khandual
2023-11-23 12:35 ` James Clark
2023-11-27 8:06 ` Anshuman Khandual
2023-11-14 17:10 ` James Clark
2023-11-30 3:58 ` Anshuman Khandual
2023-11-14 5:13 ` [V14 4/8] drivers: perf: arm_pmuv3: Enable branch stack sampling via FEAT_BRBE Anshuman Khandual
2023-11-14 12:11 ` James Clark
2023-11-21 10:47 ` Anshuman Khandual
2023-11-14 5:13 ` [V14 5/8] KVM: arm64: nvhe: Disable branch generation in nVHE guests Anshuman Khandual
2023-11-14 9:16 ` James Clark
2023-11-21 11:12 ` Anshuman Khandual
2023-11-23 13:54 ` James Clark
2023-11-27 8:25 ` Anshuman Khandual
2023-11-14 5:13 ` [V14 6/8] perf: test: Speed up running brstack test on an Arm model Anshuman Khandual
2023-11-14 5:13 ` [V14 7/8] perf: test: Remove empty lines from branch filter test output Anshuman Khandual
2023-11-14 5:13 ` [V14 8/8] perf: test: Extend branch stack sampling test for Arm64 BRBE Anshuman Khandual
2023-11-14 17:17 ` [V14 0/8] arm64/perf: Enable branch stack sampling James Clark
2023-11-22 5:15 ` Anshuman Khandual
2023-11-23 16:23 ` James Clark
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