| Message ID | 20200218125631.19692-2-maddy@linux.ibm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [1/2] powerpc/perf: Add mtmmcr0(FC) after ppc_set_pmu_inuse(1) | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | Successfully applied on branch powerpc/merge (a5bc6e124219546a81ce334dc9b16483d55e9abf) |
| snowpatch_ozlabs/build-ppc64le | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64be | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64e | success | Build succeeded |
| snowpatch_ozlabs/build-pmac32 | success | Build succeeded |
| snowpatch_ozlabs/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 41 lines checked |
| snowpatch_ozlabs/needsstable | success | Patch has no Fixes tags |
diff --git a/arch/powerpc/include/asm/pmc.h b/arch/powerpc/include/asm/pmc.h index c6bbe9778d3c..600c133b49cd 100644 --- a/arch/powerpc/include/asm/pmc.h +++ b/arch/powerpc/include/asm/pmc.h @@ -34,11 +34,26 @@ static inline void ppc_set_pmu_inuse(int inuse) #endif } +static inline u8 ppc_get_pmu_inuse(void) +{ +#if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) + if (firmware_has_feature(FW_FEATURE_LPAR)) { +#ifdef CONFIG_PPC_PSERIES + return get_lppaca()->pmcregs_in_use; +#endif + } +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE + return get_paca()->pmcregs_in_use; +#endif +#endif +} + extern void power4_enable_pmcs(void); #else /* CONFIG_PPC64 */ static inline void ppc_set_pmu_inuse(int inuse) { } +static inline u8 ppc_get_pmu_inuse(void) { return 0; } #endif diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index 6e35bf9ff80a..61d4a290b336 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -808,6 +808,15 @@ void perf_event_print_debug(void) if (!ppmu->n_counter) return; + /* + * Check pmu_inuse flag. As per PAPR spec, hypersivor + * will save/restore the PMU regs only if pmu_inuse is + * set. If its not enable, values dumped from these SPRs + * may not be valid or useful. + */ + if (!ppc_get_pmu_inuse()) + return; + local_irq_save(flags); pr_info("CPU: %d PMU registers, ppmu = %s n_counters = %d",
pmu_inuse flag is part of lppaca struct which notifies the hypervisor whether guest/partition is using PMUs. This provides a hint for save/restore of PMU registers. Currently perf_event_print_debug() does not check for pmu_inuse flag and it is not safe to use it to dump PMU SPRs in a CONFIG_PSERIES. Patch adds two things here. 1) An inline ppc_get_pmu_inuse() to get the pmu_inuse value and 2)check in perf_event_print_debug() before dumping the PMU SPRs. ppc_get_pmu_inuse() is based on ppc_set_pmu_inuse() and includes same CONFIG_ checks. Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> --- Changelog v1: - Fixed pmac32_deconfig build break - Fixed errors reported by checkpatch.pl arch/powerpc/include/asm/pmc.h | 15 +++++++++++++++ arch/powerpc/perf/core-book3s.c | 9 +++++++++ 2 files changed, 24 insertions(+)