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Release 4.11 drivers/perf/arm_pmu.c

Directory: drivers/perf

#undef DEBUG

/*
 * ARM performance counter support.
 *
 * Copyright (C) 2009 picoChip Designs, Ltd., Jamie Iles
 * Copyright (C) 2010 ARM Ltd., Will Deacon <will.deacon@arm.com>
 *
 * This code is based on the sparc64 perf event code, which is in turn based
 * on the x86 code.
 */

#define pr_fmt(fmt) "hw perfevents: " fmt

#include <linux/bitmap.h>
#include <linux/cpumask.h>
#include <linux/cpu_pm.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/of_device.h>
#include <linux/perf/arm_pmu.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/sched/clock.h>
#include <linux/spinlock.h>
#include <linux/irq.h>
#include <linux/irqdesc.h>

#include <asm/cputype.h>
#include <asm/irq_regs.h>

static int

armpmu_map_cache_event(const unsigned (*cache_map)
				      [PERF_COUNT_HW_CACHE_MAX]
				      [PERF_COUNT_HW_CACHE_OP_MAX]
				      [PERF_COUNT_HW_CACHE_RESULT_MAX],
		       u64 config)
{
	unsigned int cache_type, cache_op, cache_result, ret;

	cache_type = (config >>  0) & 0xff;
	if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
		return -EINVAL;

	cache_op = (config >>  8) & 0xff;
	if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX)
		return -EINVAL;

	cache_result = (config >> 16) & 0xff;
	if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
		return -EINVAL;

	ret = (int)(*cache_map)[cache_type][cache_op][cache_result];

	if (ret == CACHE_OP_UNSUPPORTED)
		return -ENOENT;

	return ret;
}

static int

armpmu_map_hw_event(const unsigned (*event_map)[PERF_COUNT_HW_MAX], u64 config)
{
	int mapping;

	if (config >= PERF_COUNT_HW_MAX)
		return -EINVAL;

	mapping = (*event_map)[config];
	return mapping == HW_OP_UNSUPPORTED ? -ENOENT : mapping;
}


static int armpmu_map_raw_event(u32 raw_event_mask, u64 config) { return (int)(config & raw_event_mask); }

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Will Deacon1986.36%150.00%
Mark Rutland313.64%150.00%
Total22100.00%2100.00%

int armpmu_map_event(struct perf_event *event, const unsigned (*event_map)[PERF_COUNT_HW_MAX], const unsigned (*cache_map) [PERF_COUNT_HW_CACHE_MAX] [PERF_COUNT_HW_CACHE_OP_MAX] [PERF_COUNT_HW_CACHE_RESULT_MAX], u32 raw_event_mask) { u64 config = event->attr.config; int type = event->attr.type; if (type == event->pmu->type) return armpmu_map_raw_event(raw_event_mask, config); switch (type) { case PERF_TYPE_HARDWARE: return armpmu_map_hw_event(event_map, config); case PERF_TYPE_HW_CACHE: return armpmu_map_cache_event(cache_map, config); case PERF_TYPE_RAW: return armpmu_map_raw_event(raw_event_mask, config); } return -ENOENT; }
int armpmu_event_set_period(struct perf_event *event) { struct arm_pmu *armpmu = to_arm_pmu(event->pmu); struct hw_perf_event *hwc = &event->hw; s64 left = local64_read(&hwc->period_left); s64 period = hwc->sample_period; int ret = 0; if (unlikely(left <= -period)) { left = period; local64_set(&hwc->period_left, left); hwc->last_period = period; ret = 1; } if (unlikely(left <= 0)) { left += period; local64_set(&hwc->period_left, left); hwc->last_period = period; ret = 1; } /* * Limit the maximum period to prevent the counter value * from overtaking the one we are about to program. In * effect we are reducing max_period to account for * interrupt latency (and we are being very conservative). */ if (left > (armpmu->max_period >> 1)) left = armpmu->max_period >> 1; local64_set(&hwc->prev_count, (u64)-left); armpmu->write_counter(event, (u64)(-left) & 0xffffffff); perf_event_update_userpage(event); return ret; }

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Jamie Iles15281.72%120.00%
Mark Rutland126.45%120.00%
Sudeep KarkadaNagesha126.45%120.00%
Daniel R Thompson63.23%120.00%
Peter Zijlstra42.15%120.00%
Total186100.00%5100.00%


u64 armpmu_event_update(struct perf_event *event) { struct arm_pmu *armpmu = to_arm_pmu(event->pmu); struct hw_perf_event *hwc = &event->hw; u64 delta, prev_raw_count, new_raw_count; again: prev_raw_count = local64_read(&hwc->prev_count); new_raw_count = armpmu->read_counter(event); if (local64_cmpxchg(&hwc->prev_count, prev_raw_count, new_raw_count) != prev_raw_count) goto again; delta = (new_raw_count - prev_raw_count) & armpmu->max_period; local64_add(delta, &event->count); local64_sub(delta, &hwc->period_left); return new_raw_count; }

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PersonTokensPropCommitsCommitProp
Jamie Iles7364.04%116.67%
Will Deacon1311.40%233.33%
Sudeep KarkadaNagesha1210.53%116.67%
Mark Rutland1210.53%116.67%
Peter Zijlstra43.51%116.67%
Total114100.00%6100.00%


static void armpmu_read(struct perf_event *event) { armpmu_event_update(event); }

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Jamie Iles1275.00%150.00%
Peter Zijlstra425.00%150.00%
Total16100.00%2100.00%


static void armpmu_stop(struct perf_event *event, int flags) { struct arm_pmu *armpmu = to_arm_pmu(event->pmu); struct hw_perf_event *hwc = &event->hw; /* * ARM pmu always has to update the counter, so ignore * PERF_EF_UPDATE, see comments in armpmu_start(). */ if (!(hwc->state & PERF_HES_STOPPED)) { armpmu->disable(event); armpmu_event_update(event); hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE; } }

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Peter Zijlstra4462.86%125.00%
Jamie Iles1318.57%125.00%
Mark Rutland1217.14%125.00%
Sudeep KarkadaNagesha11.43%125.00%
Total70100.00%4100.00%


static void armpmu_start(struct perf_event *event, int flags) { struct arm_pmu *armpmu = to_arm_pmu(event->pmu); struct hw_perf_event *hwc = &event->hw; /* * ARM pmu always has to reprogram the period, so ignore * PERF_EF_RELOAD, see the comment below. */ if (flags & PERF_EF_RELOAD) WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE)); hwc->state = 0; /* * Set the period again. Some counters can't be stopped, so when we * were stopped we simply disabled the IRQ source and the counter * may have been left counting. If we don't do this step then we may * get an interrupt too soon or *way* too late if the overflow has * happened since disabling. */ armpmu_event_set_period(event); armpmu->enable(event); }

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Peter Zijlstra3445.95%125.00%
Jamie Iles2736.49%125.00%
Mark Rutland1216.22%125.00%
Sudeep KarkadaNagesha11.35%125.00%
Total74100.00%4100.00%


static void armpmu_del(struct perf_event *event, int flags) { struct arm_pmu *armpmu = to_arm_pmu(event->pmu); struct pmu_hw_events *hw_events = this_cpu_ptr(armpmu->hw_events); struct hw_perf_event *hwc = &event->hw; int idx = hwc->idx; armpmu_stop(event, PERF_EF_UPDATE); hw_events->events[idx] = NULL; clear_bit(idx, hw_events->used_mask); if (armpmu->clear_event_idx) armpmu->clear_event_idx(hw_events, event); perf_event_update_userpage(event); }

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Peter Zijlstra3434.00%114.29%
Jamie Iles2929.00%114.29%
Mark Rutland2222.00%457.14%
Stephen Boyd1515.00%114.29%
Total100100.00%7100.00%


static int armpmu_add(struct perf_event *event, int flags) { struct arm_pmu *armpmu = to_arm_pmu(event->pmu); struct pmu_hw_events *hw_events = this_cpu_ptr(armpmu->hw_events); struct hw_perf_event *hwc = &event->hw; int idx; int err = 0; /* An event following a process won't be stopped earlier */ if (!cpumask_test_cpu(smp_processor_id(), &armpmu->supported_cpus)) return -ENOENT; perf_pmu_disable(event->pmu); /* If we don't have a space for the counter then finish early. */ idx = armpmu->get_event_idx(hw_events, event); if (idx < 0) { err = idx; goto out; } /* * If there is an event in the counter we are going to use then make * sure it is disabled. */ event->hw.idx = idx; armpmu->disable(event); hw_events->events[idx] = event; hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE; if (flags & PERF_EF_START) armpmu_start(event, PERF_EF_RELOAD); /* Propagate our changes to the userspace mapping. */ perf_event_update_userpage(event); out: perf_pmu_enable(event->pmu); return err; }

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Jamie Iles9756.07%110.00%
Mark Rutland4123.70%550.00%
Peter Zijlstra3319.08%330.00%
Sudeep KarkadaNagesha21.16%110.00%
Total173100.00%10100.00%


static int validate_event(struct pmu *pmu, struct pmu_hw_events *hw_events, struct perf_event *event) { struct arm_pmu *armpmu; if (is_software_event(event)) return 1; /* * Reject groups spanning multiple HW PMUs (e.g. CPU + CCI). The * core perf code won't check that the pmu->ctx == leader->ctx * until after pmu->event_init(event). */ if (event->pmu != pmu) return 0; if (event->state < PERF_EVENT_STATE_OFF) return 1; if (event->state == PERF_EVENT_STATE_OFF && !event->attr.enable_on_exec) return 1; armpmu = to_arm_pmu(event->pmu); return armpmu->get_event_idx(hw_events, event) >= 0; }

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Will Deacon3232.65%337.50%
Jamie Iles3232.65%112.50%
Suzuki K. Poulose2626.53%112.50%
Mark Rutland77.14%225.00%
Sudeep KarkadaNagesha11.02%112.50%
Total98100.00%8100.00%


static int validate_group(struct perf_event *event) { struct perf_event *sibling, *leader = event->group_leader; struct pmu_hw_events fake_pmu; /* * Initialise the fake PMU. We only need to populate the * used_mask for the purposes of validation. */ memset(&fake_pmu.used_mask, 0, sizeof(fake_pmu.used_mask)); if (!validate_event(event->pmu, &fake_pmu, leader)) return -EINVAL; list_for_each_entry(sibling, &leader->sibling_list, group_entry) { if (!validate_event(event->pmu, &fake_pmu, sibling)) return -EINVAL; } if (!validate_event(event->pmu, &fake_pmu, event)) return -EINVAL; return 0; }

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Jamie Iles8876.52%116.67%
Suzuki K. Poulose1210.43%116.67%
Mark Rutland76.09%233.33%
Will Deacon54.35%116.67%
Peter Zijlstra32.61%116.67%
Total115100.00%6100.00%


static irqreturn_t armpmu_dispatch_irq(int irq, void *dev) { struct arm_pmu *armpmu; struct platform_device *plat_device; struct arm_pmu_platdata *plat; int ret; u64 start_clock, finish_clock; /* * we request the IRQ with a (possibly percpu) struct arm_pmu**, but * the handlers expect a struct arm_pmu*. The percpu_irq framework will * do any necessary shifting, we just need to perform the first * dereference. */ armpmu = *(void **)dev; plat_device = armpmu->plat_device; plat = dev_get_platdata(&plat_device->dev); start_clock = sched_clock(); if (plat && plat->handle_irq) ret = plat->handle_irq(irq, armpmu, armpmu->handle_irq); else ret = armpmu->handle_irq(irq, armpmu); finish_clock = sched_clock(); perf_sample_event_took(finish_clock - start_clock); return ret; }

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Will Deacon3327.97%114.29%
Rabin Vincent3327.97%114.29%
Stephen Boyd1916.10%114.29%
Sudeep KarkadaNagesha1815.25%114.29%
Mark Rutland1512.71%342.86%
Total118100.00%7100.00%


static void armpmu_release_hardware(struct arm_pmu *armpmu) { armpmu->free_irq(armpmu); }

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Will Deacon738.89%116.67%
Mark Rutland633.33%233.33%
Sudeep KarkadaNagesha422.22%233.33%
Jamie Iles15.56%116.67%
Total18100.00%6100.00%


static int armpmu_reserve_hardware(struct arm_pmu *armpmu) { int err = armpmu->request_irq(armpmu, armpmu_dispatch_irq); if (err) { armpmu_release_hardware(armpmu); return err; } return 0; }

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Jamie Iles2050.00%114.29%
Mark Rutland1127.50%342.86%
Will Deacon615.00%114.29%
Sudeep KarkadaNagesha37.50%228.57%
Total40100.00%7100.00%


static void hw_perf_event_destroy(struct perf_event *event) { struct arm_pmu *armpmu = to_arm_pmu(event->pmu); atomic_t *active_events = &armpmu->active_events; struct mutex *pmu_reserve_mutex = &armpmu->reserve_mutex; if (atomic_dec_and_mutex_lock(active_events, pmu_reserve_mutex)) { armpmu_release_hardware(armpmu); mutex_unlock(pmu_reserve_mutex); } }

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Mark Rutland3453.97%266.67%
Jamie Iles2946.03%133.33%
Total63100.00%3100.00%


static int event_requires_mode_exclusion(struct perf_event_attr *attr) { return attr->exclude_idle || attr->exclude_user || attr->exclude_kernel || attr->exclude_hv; }

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Will Deacon2692.86%150.00%
Jamie Iles27.14%150.00%
Total28100.00%2100.00%


static int __hw_perf_event_init(struct perf_event *event) { struct arm_pmu *armpmu = to_arm_pmu(event->pmu); struct hw_perf_event *hwc = &event->hw; int mapping; mapping = armpmu->map_event(event); if (mapping < 0) { pr_debug("event %x:%llx not supported\n", event->attr.type, event->attr.config); return mapping; } /* * We don't assign an index until we actually place the event onto * hardware. Use -1 to signify that we haven't decided where to put it * yet. For SMP systems, each core has it's own PMU so we can't do any * clever allocation or constraints checking at this point. */ hwc->idx = -1; hwc->config_base = 0; hwc->config = 0; hwc->event_base = 0; /* * Check whether we need to exclude the counter from certain modes. */ if ((!armpmu->set_event_filter || armpmu->set_event_filter(hwc, &event->attr)) && event_requires_mode_exclusion(&event->attr)) { pr_debug("ARM performance counters do not support " "mode exclusion\n"); return -EOPNOTSUPP; } /* * Store the event encoding into the config_base field. */ hwc->config_base |= (unsigned long)mapping; if (!is_sampling_event(event)) { /* * For non-sampling runs, limit the sample_period to half * of the counter width. That way, the new counter value * is far less likely to overtake the previous one unless * you have some serious IRQ latency issues. */ hwc->sample_period = armpmu->max_period >> 1; hwc->last_period = hwc->sample_period; local64_set(&hwc->period_left, hwc->sample_period); } if (event->group_leader != event) { if (validate_group(event) != 0) return -EINVAL; } return 0; }

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Jamie Iles14365.30%111.11%
Will Deacon5223.74%333.33%
Mark Rutland198.68%333.33%
Vince Weaver41.83%111.11%
Peter Zijlstra10.46%111.11%
Total219100.00%9100.00%


static int armpmu_event_init(struct perf_event *event) { struct arm_pmu *armpmu = to_arm_pmu(event->pmu); int err = 0; atomic_t *active_events = &armpmu->active_events; /* * Reject CPU-affine events for CPUs that are of a different class to * that which this PMU handles. Process-following events (where * event->cpu == -1) can be migrated between CPUs, and thus we have to * reject them later (in armpmu_add) if they're scheduled on a * different class of CPU. */ if (event->cpu != -1 && !cpumask_test_cpu(event->cpu, &armpmu->supported_cpus)) return -ENOENT; /* does not support taken branch sampling */ if (has_branch_stack(event)) return -EOPNOTSUPP; if (armpmu->map_event(event) == -ENOENT) return -ENOENT; event->destroy = hw_perf_event_destroy; if (!atomic_inc_not_zero(active_events)) { mutex_lock(&armpmu->reserve_mutex); if (atomic_read(active_events) == 0) err = armpmu_reserve_hardware(armpmu); if (!err) atomic_inc(active_events); mutex_unlock(&armpmu->reserve_mutex); } if (err) return err; err = __hw_perf_event_init(event); if (err) hw_perf_event_destroy(event); return err; }

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Jamie Iles8850.00%114.29%
Mark Rutland6637.50%457.14%
Stéphane Eranian126.82%114.29%
Peter Zijlstra105.68%114.29%
Total176100.00%7100.00%


static void armpmu_enable(struct pmu *pmu) { struct arm_pmu *armpmu = to_arm_pmu(pmu); struct pmu_hw_events *hw_events = this_cpu_ptr(armpmu->hw_events); int enabled = bitmap_weight(hw_events->used_mask, armpmu->num_events); /* For task-bound events we may be called on other CPUs */ if (!cpumask_test_cpu(smp_processor_id(), &armpmu->supported_cpus)) return; if (enabled) armpmu->start(armpmu); }

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Mark Rutland4358.11%650.00%
Jamie Iles1824.32%18.33%
Peter Zijlstra68.11%325.00%
Will Deacon45.41%18.33%
Sudeep KarkadaNagesha34.05%18.33%
Total74100.00%12100.00%


static void armpmu_disable(struct pmu *pmu) { struct arm_pmu *armpmu = to_arm_pmu(pmu); /* For task-bound events we may be called on other CPUs */ if (!cpumask_test_cpu(smp_processor_id(), &armpmu->supported_cpus)) return; armpmu->stop(armpmu); }

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Mark Rutland2659.09%233.33%
Jamie Iles920.45%116.67%
Peter Zijlstra613.64%233.33%
Sudeep KarkadaNagesha36.82%116.67%
Total44100.00%6100.00%

/* * In heterogeneous systems, events are specific to a particular * microarchitecture, and aren't suitable for another. Thus, only match CPUs of * the same microarchitecture. */
static int armpmu_filter_match(struct perf_event *event) { struct arm_pmu *armpmu = to_arm_pmu(event->pmu); unsigned int cpu = smp_processor_id(); return cpumask_test_cpu(cpu, &armpmu->supported_cpus); }

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Mark Rutland41100.00%1100.00%
Total41100.00%1100.00%


static ssize_t armpmu_cpumask_show(struct device *dev, struct device_attribute *attr, char *buf) { struct arm_pmu *armpmu = to_arm_pmu(dev_get_drvdata(dev)); return cpumap_print_to_pagebuf(true, buf, &armpmu->supported_cpus); }

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static DEVICE_ATTR(cpus, S_IRUGO, armpmu_cpumask_show, NULL); static struct attribute *armpmu_common_attrs[] = { &dev_attr_cpus.attr, NULL, }; static struct attribute_group armpmu_common_attr_group = { .attrs = armpmu_common_attrs, };
static void armpmu_init(struct arm_pmu *armpmu) { atomic_set(&armpmu->active_events, 0); mutex_init(&armpmu->reserve_mutex); armpmu->pmu = (struct pmu) { .pmu_enable = armpmu_enable, .pmu_disable = armpmu_disable, .event_init = armpmu_event_init, .add = armpmu_add, .del = armpmu_del, .start = armpmu_start, .stop = armpmu_stop, .read = armpmu_read, .filter_match = armpmu_filter_match, .attr_groups = armpmu->attr_groups, }; armpmu->attr_groups[ARMPMU_ATTR_GROUP_COMMON] = &armpmu_common_attr_group; }

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Mark Rutland5756.44%457.14%
Peter Zijlstra4342.57%228.57%
Jamie Iles10.99%114.29%
Total101100.00%7100.00%

/* Set at runtime when we know what CPU type we are. */ static struct arm_pmu *__oprofile_cpu_pmu; /* * Despite the names, these two functions are CPU-specific and are used * by the OProfile/perf code. */
const char *perf_pmu_name(void) { if (!__oprofile_cpu_pmu) return NULL; return __oprofile_cpu_pmu->name; }

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EXPORT_SYMBOL_GPL(perf_pmu_name);
int perf_num_counters(void) { int max_events = 0; if (__oprofile_cpu_pmu != NULL) max_events = __oprofile_cpu_pmu->num_events; return max_events; }

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EXPORT_SYMBOL_GPL(perf_num_counters);
static void cpu_pmu_enable_percpu_irq(void *data) { int irq = *(int *)data; enable_percpu_irq(irq, IRQ_TYPE_NONE); }

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static void cpu_pmu_disable_percpu_irq(void *data) { int irq = *(int *)data; disable_percpu_irq(irq); }

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static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu) { int i, irq, irqs; struct platform_device *pmu_device = cpu_pmu->plat_device; struct pmu_hw_events __percpu *hw_events = cpu_pmu->hw_events; irqs = min(pmu_device->num_resources, num_possible_cpus()); irq = platform_get_irq(pmu_device, 0); if (irq > 0 && irq_is_percpu(irq)) { on_each_cpu_mask(&cpu_pmu->supported_cpus, cpu_pmu_disable_percpu_irq, &irq, 1); free_percpu_irq(irq, &hw_events->percpu_pmu); } else { for (i = 0; i < irqs; ++i) { int cpu = i; if (cpu_pmu->irq_affinity) cpu = cpu_pmu->irq_affinity[i]; if (!cpumask_test_and_clear_cpu(cpu, &cpu_pmu->active_irqs)) continue; irq = platform_get_irq(pmu_device, i); if (irq > 0) free_irq(irq, per_cpu_ptr(&hw_events->percpu_pmu, cpu)); } } }

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Mark Rutland17095.51%133.33%
Marc Zyngier84.49%266.67%
Total178100.00%3100.00%


static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler) { int i, err, irq, irqs; struct platform_device *pmu_device = cpu_pmu->plat_device; struct pmu_hw_events __percpu *hw_events = cpu_pmu->hw_events; if (!pmu_device) return -ENODEV; irqs = min(pmu_device->num_resources, num_possible_cpus()); if (irqs < 1) { pr_warn_once("perf/ARM: No irqs for PMU defined, sampling events not supported\n"); return 0; } irq = platform_get_irq(pmu_device, 0); if (irq > 0 && irq_is_percpu(irq)) { err = request_percpu_irq(irq, handler, "arm-pmu", &hw_events->percpu_pmu); if (err) { pr_err("unable to request IRQ%d for ARM PMU counters\n", irq); return err; } on_each_cpu_mask(&cpu_pmu->supported_cpus, cpu_pmu_enable_percpu_irq, &irq, 1); } else { for (i = 0; i < irqs; ++i) { int cpu = i; err = 0; irq = platform_get_irq(pmu_device, i); if (irq < 0) continue; if (cpu_pmu->irq_affinity) cpu = cpu_pmu->irq_affinity[i]; /* * If we have a single PMU interrupt that we can't shift, * assume that we're running on a uniprocessor machine and * continue. Otherwise, continue without this interrupt. */ if (irq_set_affinity(irq, cpumask_of(cpu)) && irqs > 1) { pr_warn("unable to set irq affinity (irq=%d, cpu=%u)\n", irq, cpu); continue; } err = request_irq(irq, handler, IRQF_NOBALANCING | IRQF_NO_THREAD, "arm-pmu", per_cpu_ptr(&hw_events->percpu_pmu, cpu)); if (err) { pr_err("unable to request IRQ%d for ARM PMU counters\n", irq); return err; } cpumask_set_cpu(cpu, &cpu_pmu->active_irqs); } } return 0; }

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Mark Rutland28297.58%133.33%
Marc Zyngier72.42%266.67%
Total289100.00%3100.00%

/* * PMU hardware loses all context when a CPU goes offline. * When a CPU is hotplugged back in, since some hardware registers are * UNKNOWN at reset, the PMU must be explicitly reset to avoid reading * junk values out of them. */
static int arm_perf_starting_cpu(unsigned int cpu, struct hlist_node *node) { struct arm_pmu *pmu = hlist_entry_safe(node, struct arm_pmu, node); if (!cpumask_test_cpu