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author | Mark Rutland | 2015-05-26 18:23:39 +0200 |
---|---|---|
committer | Will Deacon | 2015-05-28 18:13:26 +0200 |
commit | 74cf0bc75f1671b8da3b2e6ef7b2dc75cab0016a (patch) | |
tree | 1a4d0de76bd5e807834fc2d6b3030b29e7264883 /arch/arm/kernel/perf_event.c | |
parent | arm: perf: factor out armv7 pmu driver (diff) | |
download | kernel-qcow2-linux-74cf0bc75f1671b8da3b2e6ef7b2dc75cab0016a.tar.gz kernel-qcow2-linux-74cf0bc75f1671b8da3b2e6ef7b2dc75cab0016a.tar.xz kernel-qcow2-linux-74cf0bc75f1671b8da3b2e6ef7b2dc75cab0016a.zip |
arm: perf: unify perf_event{,_cpu}.c
Now that the arm_pmu framework is only used for CPU PMUs, there's no
reason to keep the pseudo-generic and CPU-specific framework portions
separate.
This patch folds the two into perf_event.c.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
[will: fixed up irq cfg to match upstream]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm/kernel/perf_event.c')
-rw-r--r-- | arch/arm/kernel/perf_event.c | 340 |
1 files changed, 340 insertions, 0 deletions
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c index 0072e8bb78f4..357f57ea83f4 100644 --- a/arch/arm/kernel/perf_event.c +++ b/arch/arm/kernel/perf_event.c @@ -11,12 +11,18 @@ */ #define pr_fmt(fmt) "hw perfevents: " fmt +#include <linux/bitmap.h> #include <linux/cpumask.h> +#include <linux/export.h> #include <linux/kernel.h> +#include <linux/of.h> #include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/spinlock.h> #include <linux/irq.h> #include <linux/irqdesc.h> +#include <asm/cputype.h> #include <asm/irq_regs.h> #include <asm/pmu.h> @@ -553,3 +559,337 @@ int armpmu_register(struct arm_pmu *armpmu, int type) return perf_pmu_register(&armpmu->pmu, armpmu->name, type); } +/* 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 void cpu_pmu_enable_percpu_irq(void *data) +{ + int irq = *(int *)data; + + enable_percpu_irq(irq, IRQ_TYPE_NONE); +} + +static void cpu_pmu_disable_percpu_irq(void *data) +{ + int irq = *(int *)data; + + disable_percpu_irq(irq); +} + +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(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)); + } + } +} + +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(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; +} + +/* + * 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 cpu_pmu_notify(struct notifier_block *b, unsigned long action, + void *hcpu) +{ + int cpu = (unsigned long)hcpu; + struct arm_pmu *pmu = container_of(b, struct arm_pmu, hotplug_nb); + + if ((action & ~CPU_TASKS_FROZEN) != CPU_STARTING) + return NOTIFY_DONE; + + if (!cpumask_test_cpu(cpu, &pmu->supported_cpus)) + return NOTIFY_DONE; + + if (pmu->reset) + pmu->reset(pmu); + else + return NOTIFY_DONE; + + return NOTIFY_OK; +} + +static int cpu_pmu_init(struct arm_pmu *cpu_pmu) +{ + int err; + int cpu; + struct pmu_hw_events __percpu *cpu_hw_events; + + cpu_hw_events = alloc_percpu(struct pmu_hw_events); + if (!cpu_hw_events) + return -ENOMEM; + + cpu_pmu->hotplug_nb.notifier_call = cpu_pmu_notify; + err = register_cpu_notifier(&cpu_pmu->hotplug_nb); + if (err) + goto out_hw_events; + + for_each_possible_cpu(cpu) { + struct pmu_hw_events *events = per_cpu_ptr(cpu_hw_events, cpu); + raw_spin_lock_init(&events->pmu_lock); + events->percpu_pmu = cpu_pmu; + } + + cpu_pmu->hw_events = cpu_hw_events; + cpu_pmu->request_irq = cpu_pmu_request_irq; + cpu_pmu->free_irq = cpu_pmu_free_irq; + + /* Ensure the PMU has sane values out of reset. */ + if (cpu_pmu->reset) + on_each_cpu_mask(&cpu_pmu->supported_cpus, cpu_pmu->reset, + cpu_pmu, 1); + + /* If no interrupts available, set the corresponding capability flag */ + if (!platform_get_irq(cpu_pmu->plat_device, 0)) + cpu_pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT; + + return 0; + +out_hw_events: + free_percpu(cpu_hw_events); + return err; +} + +static void cpu_pmu_destroy(struct arm_pmu *cpu_pmu) +{ + unregister_cpu_notifier(&cpu_pmu->hotplug_nb); + free_percpu(cpu_pmu->hw_events); +} + +/* + * CPU PMU identification and probing. + */ +static int probe_current_pmu(struct arm_pmu *pmu, + const struct pmu_probe_info *info) +{ + int cpu = get_cpu(); + unsigned int cpuid = read_cpuid_id(); + int ret = -ENODEV; + + pr_info("probing PMU on CPU %d\n", cpu); + + for (; info->init != NULL; info++) { + if ((cpuid & info->mask) != info->cpuid) + continue; + ret = info->init(pmu); + break; + } + + put_cpu(); + return ret; +} + +static int of_pmu_irq_cfg(struct arm_pmu *pmu) +{ + int i, irq, *irqs; + struct platform_device *pdev = pmu->plat_device; + + /* Don't bother with PPIs; they're already affine */ + irq = platform_get_irq(pdev, 0); + if (irq >= 0 && irq_is_percpu(irq)) + return 0; + + irqs = kcalloc(pdev->num_resources, sizeof(*irqs), GFP_KERNEL); + if (!irqs) + return -ENOMEM; + + for (i = 0; i < pdev->num_resources; ++i) { + struct device_node *dn; + int cpu; + + dn = of_parse_phandle(pdev->dev.of_node, "interrupt-affinity", + i); + if (!dn) { + pr_warn("Failed to parse %s/interrupt-affinity[%d]\n", + of_node_full_name(pdev->dev.of_node), i); + break; + } + + for_each_possible_cpu(cpu) + if (arch_find_n_match_cpu_physical_id(dn, cpu, NULL)) + break; + + of_node_put(dn); + if (cpu >= nr_cpu_ids) { + pr_warn("Failed to find logical CPU for %s\n", + dn->name); + break; + } + + irqs[i] = cpu; + cpumask_set_cpu(cpu, &pmu->supported_cpus); + } + + if (i == pdev->num_resources) { + pmu->irq_affinity = irqs; + } else { + kfree(irqs); + cpumask_setall(&pmu->supported_cpus); + } + + return 0; +} + +int arm_pmu_device_probe(struct platform_device *pdev, + const struct of_device_id *of_table, + const struct pmu_probe_info *probe_table) +{ + const struct of_device_id *of_id; + const int (*init_fn)(struct arm_pmu *); + struct device_node *node = pdev->dev.of_node; + struct arm_pmu *pmu; + int ret = -ENODEV; + + pmu = kzalloc(sizeof(struct arm_pmu), GFP_KERNEL); + if (!pmu) { + pr_info("failed to allocate PMU device!\n"); + return -ENOMEM; + } + + if (!__oprofile_cpu_pmu) + __oprofile_cpu_pmu = pmu; + + pmu->plat_device = pdev; + + if (node && (of_id = of_match_node(of_table, pdev->dev.of_node))) { + init_fn = of_id->data; + + ret = of_pmu_irq_cfg(pmu); + if (!ret) + ret = init_fn(pmu); + } else { + ret = probe_current_pmu(pmu, probe_table); + cpumask_setall(&pmu->supported_cpus); + } + + if (ret) { + pr_info("failed to probe PMU!\n"); + goto out_free; + } + + ret = cpu_pmu_init(pmu); + if (ret) + goto out_free; + + ret = armpmu_register(pmu, -1); + if (ret) + goto out_destroy; + + return 0; + +out_destroy: + cpu_pmu_destroy(pmu); +out_free: + pr_info("failed to register PMU devices!\n"); + kfree(pmu); + return ret; +} |