diff options
Diffstat (limited to 'drivers/perf')
| -rw-r--r-- | drivers/perf/arm_smmuv3_pmu.c | 48 |
1 files changed, 41 insertions, 7 deletions
diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c index a4f4b488a2de..da71c741cb46 100644 --- a/drivers/perf/arm_smmuv3_pmu.c +++ b/drivers/perf/arm_smmuv3_pmu.c @@ -35,6 +35,7 @@ */ #include <linux/acpi.h> +#include <linux/acpi_iort.h> #include <linux/bitfield.h> #include <linux/bitops.h> #include <linux/cpuhotplug.h> @@ -93,6 +94,8 @@ #define SMMU_PMCG_PA_SHIFT 12 +#define SMMU_PMCG_EVCNTR_RDONLY BIT(0) + static int cpuhp_state_num; struct smmu_pmu { @@ -108,6 +111,7 @@ struct smmu_pmu { void __iomem *reg_base; void __iomem *reloc_base; u64 counter_mask; + u32 options; bool global_filter; u32 global_filter_span; u32 global_filter_sid; @@ -222,15 +226,27 @@ static void smmu_pmu_set_period(struct smmu_pmu *smmu_pmu, u32 idx = hwc->idx; u64 new; - /* - * We limit the max period to half the max counter value of the counter - * size, so that even in the case of extreme interrupt latency the - * counter will (hopefully) not wrap past its initial value. - */ - new = smmu_pmu->counter_mask >> 1; + if (smmu_pmu->options & SMMU_PMCG_EVCNTR_RDONLY) { + /* + * On platforms that require this quirk, if the counter starts + * at < half_counter value and wraps, the current logic of + * handling the overflow may not work. It is expected that, + * those platforms will have full 64 counter bits implemented + * so that such a possibility is remote(eg: HiSilicon HIP08). + */ + new = smmu_pmu_counter_get_value(smmu_pmu, idx); + } else { + /* + * We limit the max period to half the max counter value + * of the counter size, so that even in the case of extreme + * interrupt latency the counter will (hopefully) not wrap + * past its initial value. + */ + new = smmu_pmu->counter_mask >> 1; + smmu_pmu_counter_set_value(smmu_pmu, idx, new); + } local64_set(&hwc->prev_count, new); - smmu_pmu_counter_set_value(smmu_pmu, idx, new); } static void smmu_pmu_set_event_filter(struct perf_event *event, @@ -665,6 +681,22 @@ static void smmu_pmu_reset(struct smmu_pmu *smmu_pmu) smmu_pmu->reloc_base + SMMU_PMCG_OVSCLR0); } +static void smmu_pmu_get_acpi_options(struct smmu_pmu *smmu_pmu) +{ + u32 model; + + model = *(u32 *)dev_get_platdata(smmu_pmu->dev); + + switch (model) { + case IORT_SMMU_V3_PMCG_HISI_HIP08: + /* HiSilicon Erratum 162001800 */ + smmu_pmu->options |= SMMU_PMCG_EVCNTR_RDONLY; + break; + } + + dev_notice(smmu_pmu->dev, "option mask 0x%x\n", smmu_pmu->options); +} + static int smmu_pmu_probe(struct platform_device *pdev) { struct smmu_pmu *smmu_pmu; @@ -744,6 +776,8 @@ static int smmu_pmu_probe(struct platform_device *pdev) return -EINVAL; } + smmu_pmu_get_acpi_options(smmu_pmu); + /* Pick one CPU to be the preferred one to use */ smmu_pmu->on_cpu = raw_smp_processor_id(); WARN_ON(irq_set_affinity_hint(smmu_pmu->irq, |