From 429a64f6e91fbfe4912d17247c27d0d66767b1c2 Mon Sep 17 00:00:00 2001 From: Athira Rajeev Date: Fri, 14 Jan 2022 08:43:55 +0530 Subject: powerpc/perf: Only define power_pmu_wants_prompt_pmi() for CONFIG_PPC64 power_pmu_wants_prompt_pmi() is used to decide if PMIs should be taken promptly. This is valid only for ppc64 and is used only if CONFIG_PPC_BOOK3S_64=y. Hence include the function under config check for PPC64. Fixes warning for 32-bit compilation: arch/powerpc/perf/core-book3s.c:2455:6: warning: no previous prototype for 'power_pmu_wants_prompt_pmi' 2455 | bool power_pmu_wants_prompt_pmi(void) | ^~~~~~~~~~~~~~~~~~~~~~~~~~ Fixes: 5a7745b96f43 ("powerpc/64s/perf: add power_pmu_wants_prompt_pmi to say whether perf wants PMIs to be soft-NMI") Reported-by: kernel test robot Signed-off-by: Athira Rajeev Reviewed-by: Nicholas Piggin [mpe: Move inside existing CONFIG_PPC64 ifdef block] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220114031355.87480-1-atrajeev@linux.vnet.ibm.com --- arch/powerpc/perf/core-book3s.c | 58 ++++++++++++++++++++--------------------- 1 file changed, 28 insertions(+), 30 deletions(-) diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index a684901b6965..32b98b7a1f86 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -776,6 +776,34 @@ static void pmao_restore_workaround(bool ebb) mtspr(SPRN_PMC6, pmcs[5]); } +/* + * If the perf subsystem wants performance monitor interrupts as soon as + * possible (e.g., to sample the instruction address and stack chain), + * this should return true. The IRQ masking code can then enable MSR[EE] + * in some places (e.g., interrupt handlers) that allows PMI interrupts + * through to improve accuracy of profiles, at the cost of some performance. + * + * The PMU counters can be enabled by other means (e.g., sysfs raw SPR + * access), but in that case there is no need for prompt PMI handling. + * + * This currently returns true if any perf counter is being used. It + * could possibly return false if only events are being counted rather than + * samples being taken, but for now this is good enough. + */ +bool power_pmu_wants_prompt_pmi(void) +{ + struct cpu_hw_events *cpuhw; + + /* + * This could simply test local_paca->pmcregs_in_use if that were not + * under ifdef KVM. + */ + if (!ppmu) + return false; + + cpuhw = this_cpu_ptr(&cpu_hw_events); + return cpuhw->n_events; +} #endif /* CONFIG_PPC64 */ static void perf_event_interrupt(struct pt_regs *regs); @@ -2438,36 +2466,6 @@ static void perf_event_interrupt(struct pt_regs *regs) perf_sample_event_took(sched_clock() - start_clock); } -/* - * If the perf subsystem wants performance monitor interrupts as soon as - * possible (e.g., to sample the instruction address and stack chain), - * this should return true. The IRQ masking code can then enable MSR[EE] - * in some places (e.g., interrupt handlers) that allows PMI interrupts - * though to improve accuracy of profiles, at the cost of some performance. - * - * The PMU counters can be enabled by other means (e.g., sysfs raw SPR - * access), but in that case there is no need for prompt PMI handling. - * - * This currently returns true if any perf counter is being used. It - * could possibly return false if only events are being counted rather than - * samples being taken, but for now this is good enough. - */ -bool power_pmu_wants_prompt_pmi(void) -{ - struct cpu_hw_events *cpuhw; - - /* - * This could simply test local_paca->pmcregs_in_use if that were not - * under ifdef KVM. - */ - - if (!ppmu) - return false; - - cpuhw = this_cpu_ptr(&cpu_hw_events); - return cpuhw->n_events; -} - static int power_pmu_prepare_cpu(unsigned int cpu) { struct cpu_hw_events *cpuhw = &per_cpu(cpu_hw_events, cpu); -- cgit v1.2.3