diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 1515f6f153a0dc9a3ebc4220442686138a9f7859..7d3440770b148a4e0a8eb6f488d5663c18b5e4ae 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -170,6 +170,8 @@ config ARM64 select HAVE_NMI select HAVE_PATA_PLATFORM select HAVE_PERF_EVENTS + select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI + select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP select HAVE_REGS_AND_STACK_ACCESS_API diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c index 3605f77ad4df1796c52b01a2bb959569d5ea1a83..38bb07eff8720d238e1d03759f59fb76e8f5ee05 100644 --- a/arch/arm64/kernel/perf_event.c +++ b/arch/arm64/kernel/perf_event.c @@ -23,6 +23,8 @@ #include #include #include +#include +#include /* ARMv8 Cortex-A53 specific event types. */ #define ARMV8_A53_PERFCTR_PREF_LINEFILL 0xC2 @@ -1248,10 +1250,21 @@ static struct platform_driver armv8_pmu_driver = { static int __init armv8_pmu_driver_init(void) { + int ret; + if (acpi_disabled) - return platform_driver_register(&armv8_pmu_driver); + ret = platform_driver_register(&armv8_pmu_driver); else - return arm_pmu_acpi_probe(armv8_pmuv3_init); + ret = arm_pmu_acpi_probe(armv8_pmuv3_init); + + /* + * Try to re-initialize lockup detector after PMU init in + * case PMU events are triggered via NMIs. + */ + if (ret == 0 && arm_pmu_irq_is_nmi()) + lockup_detector_init(); + + return ret; } device_initcall(armv8_pmu_driver_init) @@ -1309,3 +1322,27 @@ void arch_perf_update_userpage(struct perf_event *event, userpg->cap_user_time_zero = 1; userpg->cap_user_time_short = 1; } + +#ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF +/* + * Safe maximum CPU frequency in case a particular platform doesn't implement + * cpufreq driver. Although, architecture doesn't put any restrictions on + * maximum frequency but 5 GHz seems to be safe maximum given the available + * Arm CPUs in the market which are clocked much less than 5 GHz. On the other + * hand, we can't make it much higher as it would lead to a large hard-lockup + * detection timeout on parts which are running slower (eg. 1GHz on + * Developerbox) and doesn't possess a cpufreq driver. + */ +#define SAFE_MAX_CPU_FREQ 5000000000UL // 5 GHz +u64 hw_nmi_get_sample_period(int watchdog_thresh) +{ + unsigned int cpu = smp_processor_id(); + unsigned long max_cpu_freq; + + max_cpu_freq = cpufreq_get_hw_max_freq(cpu) * 1000UL; + if (!max_cpu_freq) + max_cpu_freq = SAFE_MAX_CPU_FREQ; + + return (u64)max_cpu_freq * watchdog_thresh; +} +#endif diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c index cb2f55f450e4adf05a7b3d81e8b9a01230665584..794a37d5085376c54b571274f360f9c427d5c5d9 100644 --- a/drivers/perf/arm_pmu.c +++ b/drivers/perf/arm_pmu.c @@ -726,6 +726,11 @@ static int armpmu_get_cpu_irq(struct arm_pmu *pmu, int cpu) return per_cpu(hw_events->irq, cpu); } +bool arm_pmu_irq_is_nmi(void) +{ + return has_nmi; +} + /* * PMU hardware loses all context when a CPU goes offline. * When a CPU is hotplugged back in, since some hardware registers are diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h index 505480217cf1a9b4f779b454d42bc78c464e189b..bf7966776c5577fd4a92a8c0837943b4f0aa5c54 100644 --- a/include/linux/perf/arm_pmu.h +++ b/include/linux/perf/arm_pmu.h @@ -163,6 +163,8 @@ int arm_pmu_acpi_probe(armpmu_init_fn init_fn); static inline int arm_pmu_acpi_probe(armpmu_init_fn init_fn) { return 0; } #endif +bool arm_pmu_irq_is_nmi(void); + /* Internal functions only for core arm_pmu code */ struct arm_pmu *armpmu_alloc(void); struct arm_pmu *armpmu_alloc_atomic(void);