[PATCH v6 6/7] arm64/perf: Filter common events based on PMCEIDn_EL0
Mark Rutland
mark.rutland at arm.com
Thu Apr 21 06:49:33 PDT 2016
On Thu, Apr 21, 2016 at 05:58:44AM -0700, Ashok Kumar wrote:
> The complete common architectural and micro-architectural
> event number structure is filtered based on PMCEIDn_EL0 and
> exposed to /sys using is_visibile function pointer in events
> attribute_group.
> To filter the events in is_visible function, pmceid based bitmap
> is stored in arm_pmu structure and the id field from
> perf_pmu_events_attr is used to check against the bitmap.
>
> The function which derives event bitmap from PMCEIDn_EL0 is
> executed in the cpus, which has the pmu being initialized,
> for heterogeneous pmu support.
>
> Signed-off-by: Ashok Kumar <ashoks at broadcom.com>
Acked-by: Mark Rutland <mark.rutland at arm.com>
Mark.
> ---
> arch/arm64/kernel/perf_event.c | 70 +++++++++++++++++++++++++++++++++---------
> include/linux/perf/arm_pmu.h | 2 ++
> 2 files changed, 57 insertions(+), 15 deletions(-)
>
> diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
> index 946ce4b..e6a0fdb 100644
> --- a/arch/arm64/kernel/perf_event.c
> +++ b/arch/arm64/kernel/perf_event.c
> @@ -326,10 +326,22 @@ static const unsigned armv8_thunder_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
> [C(BPU)][C(OP_WRITE)][C(RESULT_MISS)] = ARMV8_PMUV3_PERFCTR_BR_MIS_PRED,
> };
>
> +
> +static ssize_t
> +armv8pmu_events_sysfs_show(struct device *dev,
> + struct device_attribute *attr, char *page)
> +{
> + struct perf_pmu_events_attr *pmu_attr;
> +
> + pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
> +
> + return sprintf(page, "event=0x%03llx\n", pmu_attr->id);
> +}
> +
> #define ARMV8_EVENT_ATTR_RESOLVE(m) #m
> #define ARMV8_EVENT_ATTR(name, config) \
> - PMU_EVENT_ATTR_STRING(name, armv8_event_attr_##name, \
> - "event=" ARMV8_EVENT_ATTR_RESOLVE(config))
> + PMU_EVENT_ATTR(name, armv8_event_attr_##name, \
> + config, armv8pmu_events_sysfs_show)
>
> ARMV8_EVENT_ATTR(sw_incr, ARMV8_PMUV3_PERFCTR_SW_INCR);
> ARMV8_EVENT_ATTR(l1i_cache_refill, ARMV8_PMUV3_PERFCTR_L1I_CACHE_REFILL);
> @@ -434,9 +446,27 @@ static struct attribute *armv8_pmuv3_event_attrs[] = {
> NULL,
> };
>
> +static umode_t
> +armv8pmu_event_attr_is_visible(struct kobject *kobj,
> + struct attribute *attr, int unused)
> +{
> + struct device *dev = kobj_to_dev(kobj);
> + struct pmu *pmu = dev_get_drvdata(dev);
> + struct arm_pmu *cpu_pmu = container_of(pmu, struct arm_pmu, pmu);
> + struct perf_pmu_events_attr *pmu_attr;
> +
> + pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr.attr);
> +
> + if (test_bit(pmu_attr->id, cpu_pmu->pmceid_bitmap))
> + return attr->mode;
> +
> + return 0;
> +}
> +
> static struct attribute_group armv8_pmuv3_events_attr_group = {
> .name = "events",
> .attrs = armv8_pmuv3_event_attrs,
> + .is_visible = armv8pmu_event_attr_is_visible,
> };
>
> PMU_FORMAT_ATTR(event, "config:0-9");
> @@ -859,22 +889,31 @@ static int armv8_thunder_map_event(struct perf_event *event)
> ARMV8_PMU_EVTYPE_EVENT);
> }
>
> -static void armv8pmu_read_num_pmnc_events(void *info)
> +static void __armv8pmu_probe_pmu(void *info)
> {
> - int *nb_cnt = info;
> + struct arm_pmu *cpu_pmu = info;
> + u32 pmceid[2];
>
> /* Read the nb of CNTx counters supported from PMNC */
> - *nb_cnt = (armv8pmu_pmcr_read() >> ARMV8_PMU_PMCR_N_SHIFT) & ARMV8_PMU_PMCR_N_MASK;
> + cpu_pmu->num_events = (armv8pmu_pmcr_read() >> ARMV8_PMU_PMCR_N_SHIFT)
> + & ARMV8_PMU_PMCR_N_MASK;
>
> /* Add the CPU cycles counter */
> - *nb_cnt += 1;
> + cpu_pmu->num_events += 1;
> +
> + pmceid[0] = read_sysreg(pmceid0_el0);
> + pmceid[1] = read_sysreg(pmceid1_el0);
> +
> + bitmap_from_u32array(cpu_pmu->pmceid_bitmap,
> + ARMV8_PMUV3_MAX_COMMON_EVENTS, pmceid,
> + ARRAY_SIZE(pmceid));
> }
>
> -static int armv8pmu_probe_num_events(struct arm_pmu *arm_pmu)
> +static int armv8pmu_probe_pmu(struct arm_pmu *cpu_pmu)
> {
> - return smp_call_function_any(&arm_pmu->supported_cpus,
> - armv8pmu_read_num_pmnc_events,
> - &arm_pmu->num_events, 1);
> + return smp_call_function_any(&cpu_pmu->supported_cpus,
> + __armv8pmu_probe_pmu,
> + cpu_pmu, 1);
> }
>
> static void armv8_pmu_init(struct arm_pmu *cpu_pmu)
> @@ -897,7 +936,8 @@ static int armv8_pmuv3_init(struct arm_pmu *cpu_pmu)
> armv8_pmu_init(cpu_pmu);
> cpu_pmu->name = "armv8_pmuv3";
> cpu_pmu->map_event = armv8_pmuv3_map_event;
> - return armv8pmu_probe_num_events(cpu_pmu);
> + cpu_pmu->pmu.attr_groups = armv8_pmuv3_attr_groups;
> + return armv8pmu_probe_pmu(cpu_pmu);
> }
>
> static int armv8_a53_pmu_init(struct arm_pmu *cpu_pmu)
> @@ -906,7 +946,7 @@ static int armv8_a53_pmu_init(struct arm_pmu *cpu_pmu)
> cpu_pmu->name = "armv8_cortex_a53";
> cpu_pmu->map_event = armv8_a53_map_event;
> cpu_pmu->pmu.attr_groups = armv8_pmuv3_attr_groups;
> - return armv8pmu_probe_num_events(cpu_pmu);
> + return armv8pmu_probe_pmu(cpu_pmu);
> }
>
> static int armv8_a57_pmu_init(struct arm_pmu *cpu_pmu)
> @@ -915,7 +955,7 @@ static int armv8_a57_pmu_init(struct arm_pmu *cpu_pmu)
> cpu_pmu->name = "armv8_cortex_a57";
> cpu_pmu->map_event = armv8_a57_map_event;
> cpu_pmu->pmu.attr_groups = armv8_pmuv3_attr_groups;
> - return armv8pmu_probe_num_events(cpu_pmu);
> + return armv8pmu_probe_pmu(cpu_pmu);
> }
>
> static int armv8_a72_pmu_init(struct arm_pmu *cpu_pmu)
> @@ -924,7 +964,7 @@ static int armv8_a72_pmu_init(struct arm_pmu *cpu_pmu)
> cpu_pmu->name = "armv8_cortex_a72";
> cpu_pmu->map_event = armv8_a57_map_event;
> cpu_pmu->pmu.attr_groups = armv8_pmuv3_attr_groups;
> - return armv8pmu_probe_num_events(cpu_pmu);
> + return armv8pmu_probe_pmu(cpu_pmu);
> }
>
> static int armv8_thunder_pmu_init(struct arm_pmu *cpu_pmu)
> @@ -933,7 +973,7 @@ static int armv8_thunder_pmu_init(struct arm_pmu *cpu_pmu)
> cpu_pmu->name = "armv8_cavium_thunder";
> cpu_pmu->map_event = armv8_thunder_map_event;
> cpu_pmu->pmu.attr_groups = armv8_pmuv3_attr_groups;
> - return armv8pmu_probe_num_events(cpu_pmu);
> + return armv8pmu_probe_pmu(cpu_pmu);
> }
>
> static const struct of_device_id armv8_pmu_of_device_ids[] = {
> diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
> index 4196c90..d28ac05 100644
> --- a/include/linux/perf/arm_pmu.h
> +++ b/include/linux/perf/arm_pmu.h
> @@ -105,6 +105,8 @@ struct arm_pmu {
> struct mutex reserve_mutex;
> u64 max_period;
> bool secure_access; /* 32-bit ARM only */
> +#define ARMV8_PMUV3_MAX_COMMON_EVENTS 0x40
> + DECLARE_BITMAP(pmceid_bitmap, ARMV8_PMUV3_MAX_COMMON_EVENTS);
> struct platform_device *plat_device;
> struct pmu_hw_events __percpu *hw_events;
> struct notifier_block hotplug_nb;
> --
> 2.1.0
>
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