diff options
Diffstat (limited to 'drivers/perf/arm_pmu.c')
| -rw-r--r-- | drivers/perf/arm_pmu.c | 1007 |
1 files changed, 1007 insertions, 0 deletions
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c new file mode 100644 index 000000000..7fd11ef5c --- /dev/null +++ b/drivers/perf/arm_pmu.c @@ -0,0 +1,1007 @@ +// SPDX-License-Identifier: GPL-2.0-only +#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/perf/arm_pmu.h> +#include <linux/slab.h> +#include <linux/sched/clock.h> +#include <linux/spinlock.h> +#include <linux/irq.h> +#include <linux/irqdesc.h> + +#include <asm/irq_regs.h> + +static int armpmu_count_irq_users(const int irq); + +struct pmu_irq_ops { + void (*enable_pmuirq)(unsigned int irq); + void (*disable_pmuirq)(unsigned int irq); + void (*free_pmuirq)(unsigned int irq, int cpu, void __percpu *devid); +}; + +static void armpmu_free_pmuirq(unsigned int irq, int cpu, void __percpu *devid) +{ + free_irq(irq, per_cpu_ptr(devid, cpu)); +} + +static const struct pmu_irq_ops pmuirq_ops = { + .enable_pmuirq = enable_irq, + .disable_pmuirq = disable_irq_nosync, + .free_pmuirq = armpmu_free_pmuirq +}; + +static void armpmu_free_pmunmi(unsigned int irq, int cpu, void __percpu *devid) +{ + free_nmi(irq, per_cpu_ptr(devid, cpu)); +} + +static const struct pmu_irq_ops pmunmi_ops = { + .enable_pmuirq = enable_nmi, + .disable_pmuirq = disable_nmi_nosync, + .free_pmuirq = armpmu_free_pmunmi +}; + +static void armpmu_enable_percpu_pmuirq(unsigned int irq) +{ + enable_percpu_irq(irq, IRQ_TYPE_NONE); +} + +static void armpmu_free_percpu_pmuirq(unsigned int irq, int cpu, + void __percpu *devid) +{ + if (armpmu_count_irq_users(irq) == 1) + free_percpu_irq(irq, devid); +} + +static const struct pmu_irq_ops percpu_pmuirq_ops = { + .enable_pmuirq = armpmu_enable_percpu_pmuirq, + .disable_pmuirq = disable_percpu_irq, + .free_pmuirq = armpmu_free_percpu_pmuirq +}; + +static void armpmu_enable_percpu_pmunmi(unsigned int irq) +{ + if (!prepare_percpu_nmi(irq)) + enable_percpu_nmi(irq, IRQ_TYPE_NONE); +} + +static void armpmu_disable_percpu_pmunmi(unsigned int irq) +{ + disable_percpu_nmi(irq); + teardown_percpu_nmi(irq); +} + +static void armpmu_free_percpu_pmunmi(unsigned int irq, int cpu, + void __percpu *devid) +{ + if (armpmu_count_irq_users(irq) == 1) + free_percpu_nmi(irq, devid); +} + +static const struct pmu_irq_ops percpu_pmunmi_ops = { + .enable_pmuirq = armpmu_enable_percpu_pmunmi, + .disable_pmuirq = armpmu_disable_percpu_pmunmi, + .free_pmuirq = armpmu_free_percpu_pmunmi +}; + +static DEFINE_PER_CPU(struct arm_pmu *, cpu_armpmu); +static DEFINE_PER_CPU(int, cpu_irq); +static DEFINE_PER_CPU(const struct pmu_irq_ops *, cpu_irq_ops); + +static bool has_nmi; + +static inline u64 arm_pmu_event_max_period(struct perf_event *event) +{ + if (event->hw.flags & ARMPMU_EVT_64BIT) + return GENMASK_ULL(63, 0); + else + return GENMASK_ULL(31, 0); +} + +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; + + if (!cache_map) + return -ENOENT; + + 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; + + if (!event_map) + return -ENOENT; + + 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); +} + +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; + u64 max_period; + int ret = 0; + + max_period = arm_pmu_event_max_period(event); + 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 > (max_period >> 1)) + left = (max_period >> 1); + + local64_set(&hwc->prev_count, (u64)-left); + + armpmu->write_counter(event, (u64)(-left) & max_period); + + perf_event_update_userpage(event); + + return ret; +} + +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; + u64 max_period = arm_pmu_event_max_period(event); + +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) & max_period; + + local64_add(delta, &event->count); + local64_sub(delta, &hwc->period_left); + + return new_raw_count; +} + +static void +armpmu_read(struct perf_event *event) +{ + armpmu_event_update(event); +} + +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; + } +} + +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); +} + +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; + armpmu->clear_event_idx(hw_events, event); + perf_event_update_userpage(event); + /* Clear the allocated counter */ + hwc->idx = -1; +} + +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; + + /* An event following a process won't be stopped earlier */ + if (!cpumask_test_cpu(smp_processor_id(), &armpmu->supported_cpus)) + return -ENOENT; + + /* If we don't have a space for the counter then finish early. */ + idx = armpmu->get_event_idx(hw_events, event); + if (idx < 0) + return idx; + + /* + * 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); + + return 0; +} + +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; +} + +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; + + if (event == leader) + return 0; + + for_each_sibling_event(sibling, leader) { + if (!validate_event(event->pmu, &fake_pmu, sibling)) + return -EINVAL; + } + + if (!validate_event(event->pmu, &fake_pmu, event)) + return -EINVAL; + + return 0; +} + +static irqreturn_t armpmu_dispatch_irq(int irq, void *dev) +{ + struct arm_pmu *armpmu; + 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; + if (WARN_ON_ONCE(!armpmu)) + return IRQ_NONE; + + start_clock = sched_clock(); + ret = armpmu->handle_irq(armpmu); + finish_clock = sched_clock(); + + perf_sample_event_took(finish_clock - start_clock); + return ret; +} + +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; + + hwc->flags = 0; + 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)) { + 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 = arm_pmu_event_max_period(event) >> 1; + hwc->last_period = hwc->sample_period; + local64_set(&hwc->period_left, hwc->sample_period); + } + + return validate_group(event); +} + +static int armpmu_event_init(struct perf_event *event) +{ + struct arm_pmu *armpmu = to_arm_pmu(event->pmu); + + /* + * 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; + + return __hw_perf_event_init(event); +} + +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); +} + +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); +} + +/* + * 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(); + int ret; + + ret = cpumask_test_cpu(cpu, &armpmu->supported_cpus); + if (ret && armpmu->filter_match) + return armpmu->filter_match(event); + + return ret; +} + +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); +} + +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, +}; + +/* 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; +} +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; +} +EXPORT_SYMBOL_GPL(perf_num_counters); + +static int armpmu_count_irq_users(const int irq) +{ + int cpu, count = 0; + + for_each_possible_cpu(cpu) { + if (per_cpu(cpu_irq, cpu) == irq) + count++; + } + + return count; +} + +static const struct pmu_irq_ops *armpmu_find_irq_ops(int irq) +{ + const struct pmu_irq_ops *ops = NULL; + int cpu; + + for_each_possible_cpu(cpu) { + if (per_cpu(cpu_irq, cpu) != irq) + continue; + + ops = per_cpu(cpu_irq_ops, cpu); + if (ops) + break; + } + + return ops; +} + +void armpmu_free_irq(int irq, int cpu) +{ + if (per_cpu(cpu_irq, cpu) == 0) + return; + if (WARN_ON(irq != per_cpu(cpu_irq, cpu))) + return; + + per_cpu(cpu_irq_ops, cpu)->free_pmuirq(irq, cpu, &cpu_armpmu); + + per_cpu(cpu_irq, cpu) = 0; + per_cpu(cpu_irq_ops, cpu) = NULL; +} + +int armpmu_request_irq(int irq, int cpu) +{ + int err = 0; + const irq_handler_t handler = armpmu_dispatch_irq; + const struct pmu_irq_ops *irq_ops; + + if (!irq) + return 0; + + if (!irq_is_percpu_devid(irq)) { + unsigned long irq_flags; + + err = irq_force_affinity(irq, cpumask_of(cpu)); + + if (err && num_possible_cpus() > 1) { + pr_warn("unable to set irq affinity (irq=%d, cpu=%u)\n", + irq, cpu); + goto err_out; + } + + irq_flags = IRQF_PERCPU | + IRQF_NOBALANCING | + IRQF_NO_THREAD; + + irq_set_status_flags(irq, IRQ_NOAUTOEN); + + err = request_nmi(irq, handler, irq_flags, "arm-pmu", + per_cpu_ptr(&cpu_armpmu, cpu)); + + /* If cannot get an NMI, get a normal interrupt */ + if (err) { + err = request_irq(irq, handler, irq_flags, "arm-pmu", + per_cpu_ptr(&cpu_armpmu, cpu)); + irq_ops = &pmuirq_ops; + } else { + has_nmi = true; + irq_ops = &pmunmi_ops; + } + } else if (armpmu_count_irq_users(irq) == 0) { + err = request_percpu_nmi(irq, handler, "arm-pmu", &cpu_armpmu); + + /* If cannot get an NMI, get a normal interrupt */ + if (err) { + err = request_percpu_irq(irq, handler, "arm-pmu", + &cpu_armpmu); + irq_ops = &percpu_pmuirq_ops; + } else { + has_nmi= true; + irq_ops = &percpu_pmunmi_ops; + } + } else { + /* Per cpudevid irq was already requested by another CPU */ + irq_ops = armpmu_find_irq_ops(irq); + + if (WARN_ON(!irq_ops)) + err = -EINVAL; + } + + if (err) + goto err_out; + + per_cpu(cpu_irq, cpu) = irq; + per_cpu(cpu_irq_ops, cpu) = irq_ops; + return 0; + +err_out: + pr_err("unable to request IRQ%d for ARM PMU counters\n", irq); + return err; +} + +static int armpmu_get_cpu_irq(struct arm_pmu *pmu, int cpu) +{ + struct pmu_hw_events __percpu *hw_events = pmu->hw_events; + return per_cpu(hw_events->irq, cpu); +} + +/* + * 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); + int irq; + + if (!cpumask_test_cpu(cpu, &pmu->supported_cpus)) + return 0; + if (pmu->reset) + pmu->reset(pmu); + + per_cpu(cpu_armpmu, cpu) = pmu; + + irq = armpmu_get_cpu_irq(pmu, cpu); + if (irq) + per_cpu(cpu_irq_ops, cpu)->enable_pmuirq(irq); + + return 0; +} + +static int arm_perf_teardown_cpu(unsigned int cpu, struct hlist_node *node) +{ + struct arm_pmu *pmu = hlist_entry_safe(node, struct arm_pmu, node); + int irq; + + if (!cpumask_test_cpu(cpu, &pmu->supported_cpus)) + return 0; + + irq = armpmu_get_cpu_irq(pmu, cpu); + if (irq) + per_cpu(cpu_irq_ops, cpu)->disable_pmuirq(irq); + + per_cpu(cpu_armpmu, cpu) = NULL; + + return 0; +} + +#ifdef CONFIG_CPU_PM +static void cpu_pm_pmu_setup(struct arm_pmu *armpmu, unsigned long cmd) +{ + struct pmu_hw_events *hw_events = this_cpu_ptr(armpmu->hw_events); + struct perf_event *event; + int idx; + + for (idx = 0; idx < armpmu->num_events; idx++) { + event = hw_events->events[idx]; + if (!event) + continue; + + switch (cmd) { + case CPU_PM_ENTER: + /* + * Stop and update the counter + */ + armpmu_stop(event, PERF_EF_UPDATE); + break; + case CPU_PM_EXIT: + case CPU_PM_ENTER_FAILED: + /* + * Restore and enable the counter. + * armpmu_start() indirectly calls + * + * perf_event_update_userpage() + * + * that requires RCU read locking to be functional, + * wrap the call within RCU_NONIDLE to make the + * RCU subsystem aware this cpu is not idle from + * an RCU perspective for the armpmu_start() call + * duration. + */ + RCU_NONIDLE(armpmu_start(event, PERF_EF_RELOAD)); + break; + default: + break; + } + } +} + +static int cpu_pm_pmu_notify(struct notifier_block *b, unsigned long cmd, + void *v) +{ + struct arm_pmu *armpmu = container_of(b, struct arm_pmu, cpu_pm_nb); + struct pmu_hw_events *hw_events = this_cpu_ptr(armpmu->hw_events); + int enabled = bitmap_weight(hw_events->used_mask, armpmu->num_events); + + if (!cpumask_test_cpu(smp_processor_id(), &armpmu->supported_cpus)) + return NOTIFY_DONE; + + /* + * Always reset the PMU registers on power-up even if + * there are no events running. + */ + if (cmd == CPU_PM_EXIT && armpmu->reset) + armpmu->reset(armpmu); + + if (!enabled) + return NOTIFY_OK; + + switch (cmd) { + case CPU_PM_ENTER: + armpmu->stop(armpmu); + cpu_pm_pmu_setup(armpmu, cmd); + break; + case CPU_PM_EXIT: + case CPU_PM_ENTER_FAILED: + cpu_pm_pmu_setup(armpmu, cmd); + armpmu->start(armpmu); + break; + default: + return NOTIFY_DONE; + } + + return NOTIFY_OK; +} + +static int cpu_pm_pmu_register(struct arm_pmu *cpu_pmu) +{ + cpu_pmu->cpu_pm_nb.notifier_call = cpu_pm_pmu_notify; + return cpu_pm_register_notifier(&cpu_pmu->cpu_pm_nb); +} + +static void cpu_pm_pmu_unregister(struct arm_pmu *cpu_pmu) +{ + cpu_pm_unregister_notifier(&cpu_pmu->cpu_pm_nb); +} +#else +static inline int cpu_pm_pmu_register(struct arm_pmu *cpu_pmu) { return 0; } +static inline void cpu_pm_pmu_unregister(struct arm_pmu *cpu_pmu) { } +#endif + +static int cpu_pmu_init(struct arm_pmu *cpu_pmu) +{ + int err; + + err = cpuhp_state_add_instance(CPUHP_AP_PERF_ARM_STARTING, + &cpu_pmu->node); + if (err) + goto out; + + err = cpu_pm_pmu_register(cpu_pmu); + if (err) + goto out_unregister; + + return 0; + +out_unregister: + cpuhp_state_remove_instance_nocalls(CPUHP_AP_PERF_ARM_STARTING, + &cpu_pmu->node); +out: + return err; +} + +static void cpu_pmu_destroy(struct arm_pmu *cpu_pmu) +{ + cpu_pm_pmu_unregister(cpu_pmu); + cpuhp_state_remove_instance_nocalls(CPUHP_AP_PERF_ARM_STARTING, + &cpu_pmu->node); +} + +static struct arm_pmu *__armpmu_alloc(gfp_t flags) +{ + struct arm_pmu *pmu; + int cpu; + + pmu = kzalloc(sizeof(*pmu), flags); + if (!pmu) { + pr_info("failed to allocate PMU device!\n"); + goto out; + } + + pmu->hw_events = alloc_percpu_gfp(struct pmu_hw_events, flags); + if (!pmu->hw_events) { + pr_info("failed to allocate per-cpu PMU data.\n"); + goto out_free_pmu; + } + + pmu->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 = pmu->attr_groups, + /* + * This is a CPU PMU potentially in a heterogeneous + * configuration (e.g. big.LITTLE). This is not an uncore PMU, + * and we have taken ctx sharing into account (e.g. with our + * pmu::filter_match callback and pmu::event_init group + * validation). + */ + .capabilities = PERF_PMU_CAP_HETEROGENEOUS_CPUS, + }; + + pmu->attr_groups[ARMPMU_ATTR_GROUP_COMMON] = + &armpmu_common_attr_group; + + for_each_possible_cpu(cpu) { + struct pmu_hw_events *events; + + events = per_cpu_ptr(pmu->hw_events, cpu); + raw_spin_lock_init(&events->pmu_lock); + events->percpu_pmu = pmu; + } + + return pmu; + +out_free_pmu: + kfree(pmu); +out: + return NULL; +} + +struct arm_pmu *armpmu_alloc(void) +{ + return __armpmu_alloc(GFP_KERNEL); +} + +struct arm_pmu *armpmu_alloc_atomic(void) +{ + return __armpmu_alloc(GFP_ATOMIC); +} + + +void armpmu_free(struct arm_pmu *pmu) +{ + free_percpu(pmu->hw_events); + kfree(pmu); +} + +int armpmu_register(struct arm_pmu *pmu) +{ + int ret; + + ret = cpu_pmu_init(pmu); + if (ret) + return ret; + + if (!pmu->set_event_filter) + pmu->pmu.capabilities |= PERF_PMU_CAP_NO_EXCLUDE; + + ret = perf_pmu_register(&pmu->pmu, pmu->name, -1); + if (ret) + goto out_destroy; + + if (!__oprofile_cpu_pmu) + __oprofile_cpu_pmu = pmu; + + pr_info("enabled with %s PMU driver, %d counters available%s\n", + pmu->name, pmu->num_events, + has_nmi ? ", using NMIs" : ""); + + return 0; + +out_destroy: + cpu_pmu_destroy(pmu); + return ret; +} + +static int arm_pmu_hp_init(void) +{ + int ret; + + ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_ARM_STARTING, + "perf/arm/pmu:starting", + arm_perf_starting_cpu, + arm_perf_teardown_cpu); + if (ret) + pr_err("CPU hotplug notifier for ARM PMU could not be registered: %d\n", + ret); + return ret; +} +subsys_initcall(arm_pmu_hp_init); |