diff options
Diffstat (limited to 'kernel/arch/x86/kernel/cpu/perf_event_amd_uncore.c')
-rw-r--r-- | kernel/arch/x86/kernel/cpu/perf_event_amd_uncore.c | 600 |
1 files changed, 600 insertions, 0 deletions
diff --git a/kernel/arch/x86/kernel/cpu/perf_event_amd_uncore.c b/kernel/arch/x86/kernel/cpu/perf_event_amd_uncore.c new file mode 100644 index 000000000..cc6cedb8f --- /dev/null +++ b/kernel/arch/x86/kernel/cpu/perf_event_amd_uncore.c @@ -0,0 +1,600 @@ +/* + * Copyright (C) 2013 Advanced Micro Devices, Inc. + * + * Author: Jacob Shin <jacob.shin@amd.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/perf_event.h> +#include <linux/percpu.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/cpu.h> +#include <linux/cpumask.h> + +#include <asm/cpufeature.h> +#include <asm/perf_event.h> +#include <asm/msr.h> + +#define NUM_COUNTERS_NB 4 +#define NUM_COUNTERS_L2 4 +#define MAX_COUNTERS NUM_COUNTERS_NB + +#define RDPMC_BASE_NB 6 +#define RDPMC_BASE_L2 10 + +#define COUNTER_SHIFT 16 + +struct amd_uncore { + int id; + int refcnt; + int cpu; + int num_counters; + int rdpmc_base; + u32 msr_base; + cpumask_t *active_mask; + struct pmu *pmu; + struct perf_event *events[MAX_COUNTERS]; + struct amd_uncore *free_when_cpu_online; +}; + +static struct amd_uncore * __percpu *amd_uncore_nb; +static struct amd_uncore * __percpu *amd_uncore_l2; + +static struct pmu amd_nb_pmu; +static struct pmu amd_l2_pmu; + +static cpumask_t amd_nb_active_mask; +static cpumask_t amd_l2_active_mask; + +static bool is_nb_event(struct perf_event *event) +{ + return event->pmu->type == amd_nb_pmu.type; +} + +static bool is_l2_event(struct perf_event *event) +{ + return event->pmu->type == amd_l2_pmu.type; +} + +static struct amd_uncore *event_to_amd_uncore(struct perf_event *event) +{ + if (is_nb_event(event) && amd_uncore_nb) + return *per_cpu_ptr(amd_uncore_nb, event->cpu); + else if (is_l2_event(event) && amd_uncore_l2) + return *per_cpu_ptr(amd_uncore_l2, event->cpu); + + return NULL; +} + +static void amd_uncore_read(struct perf_event *event) +{ + struct hw_perf_event *hwc = &event->hw; + u64 prev, new; + s64 delta; + + /* + * since we do not enable counter overflow interrupts, + * we do not have to worry about prev_count changing on us + */ + + prev = local64_read(&hwc->prev_count); + rdpmcl(hwc->event_base_rdpmc, new); + local64_set(&hwc->prev_count, new); + delta = (new << COUNTER_SHIFT) - (prev << COUNTER_SHIFT); + delta >>= COUNTER_SHIFT; + local64_add(delta, &event->count); +} + +static void amd_uncore_start(struct perf_event *event, int flags) +{ + struct hw_perf_event *hwc = &event->hw; + + if (flags & PERF_EF_RELOAD) + wrmsrl(hwc->event_base, (u64)local64_read(&hwc->prev_count)); + + hwc->state = 0; + wrmsrl(hwc->config_base, (hwc->config | ARCH_PERFMON_EVENTSEL_ENABLE)); + perf_event_update_userpage(event); +} + +static void amd_uncore_stop(struct perf_event *event, int flags) +{ + struct hw_perf_event *hwc = &event->hw; + + wrmsrl(hwc->config_base, hwc->config); + hwc->state |= PERF_HES_STOPPED; + + if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) { + amd_uncore_read(event); + hwc->state |= PERF_HES_UPTODATE; + } +} + +static int amd_uncore_add(struct perf_event *event, int flags) +{ + int i; + struct amd_uncore *uncore = event_to_amd_uncore(event); + struct hw_perf_event *hwc = &event->hw; + + /* are we already assigned? */ + if (hwc->idx != -1 && uncore->events[hwc->idx] == event) + goto out; + + for (i = 0; i < uncore->num_counters; i++) { + if (uncore->events[i] == event) { + hwc->idx = i; + goto out; + } + } + + /* if not, take the first available counter */ + hwc->idx = -1; + for (i = 0; i < uncore->num_counters; i++) { + if (cmpxchg(&uncore->events[i], NULL, event) == NULL) { + hwc->idx = i; + break; + } + } + +out: + if (hwc->idx == -1) + return -EBUSY; + + hwc->config_base = uncore->msr_base + (2 * hwc->idx); + hwc->event_base = uncore->msr_base + 1 + (2 * hwc->idx); + hwc->event_base_rdpmc = uncore->rdpmc_base + hwc->idx; + hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED; + + if (flags & PERF_EF_START) + amd_uncore_start(event, PERF_EF_RELOAD); + + return 0; +} + +static void amd_uncore_del(struct perf_event *event, int flags) +{ + int i; + struct amd_uncore *uncore = event_to_amd_uncore(event); + struct hw_perf_event *hwc = &event->hw; + + amd_uncore_stop(event, PERF_EF_UPDATE); + + for (i = 0; i < uncore->num_counters; i++) { + if (cmpxchg(&uncore->events[i], event, NULL) == event) + break; + } + + hwc->idx = -1; +} + +static int amd_uncore_event_init(struct perf_event *event) +{ + struct amd_uncore *uncore; + struct hw_perf_event *hwc = &event->hw; + + if (event->attr.type != event->pmu->type) + return -ENOENT; + + /* + * NB and L2 counters (MSRs) are shared across all cores that share the + * same NB / L2 cache. Interrupts can be directed to a single target + * core, however, event counts generated by processes running on other + * cores cannot be masked out. So we do not support sampling and + * per-thread events. + */ + if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK) + return -EINVAL; + + /* NB and L2 counters do not have usr/os/guest/host bits */ + if (event->attr.exclude_user || event->attr.exclude_kernel || + event->attr.exclude_host || event->attr.exclude_guest) + return -EINVAL; + + /* and we do not enable counter overflow interrupts */ + hwc->config = event->attr.config & AMD64_RAW_EVENT_MASK_NB; + hwc->idx = -1; + + if (event->cpu < 0) + return -EINVAL; + + uncore = event_to_amd_uncore(event); + if (!uncore) + return -ENODEV; + + /* + * since request can come in to any of the shared cores, we will remap + * to a single common cpu. + */ + event->cpu = uncore->cpu; + + return 0; +} + +static ssize_t amd_uncore_attr_show_cpumask(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + cpumask_t *active_mask; + struct pmu *pmu = dev_get_drvdata(dev); + + if (pmu->type == amd_nb_pmu.type) + active_mask = &amd_nb_active_mask; + else if (pmu->type == amd_l2_pmu.type) + active_mask = &amd_l2_active_mask; + else + return 0; + + return cpumap_print_to_pagebuf(true, buf, active_mask); +} +static DEVICE_ATTR(cpumask, S_IRUGO, amd_uncore_attr_show_cpumask, NULL); + +static struct attribute *amd_uncore_attrs[] = { + &dev_attr_cpumask.attr, + NULL, +}; + +static struct attribute_group amd_uncore_attr_group = { + .attrs = amd_uncore_attrs, +}; + +PMU_FORMAT_ATTR(event, "config:0-7,32-35"); +PMU_FORMAT_ATTR(umask, "config:8-15"); + +static struct attribute *amd_uncore_format_attr[] = { + &format_attr_event.attr, + &format_attr_umask.attr, + NULL, +}; + +static struct attribute_group amd_uncore_format_group = { + .name = "format", + .attrs = amd_uncore_format_attr, +}; + +static const struct attribute_group *amd_uncore_attr_groups[] = { + &amd_uncore_attr_group, + &amd_uncore_format_group, + NULL, +}; + +static struct pmu amd_nb_pmu = { + .attr_groups = amd_uncore_attr_groups, + .name = "amd_nb", + .event_init = amd_uncore_event_init, + .add = amd_uncore_add, + .del = amd_uncore_del, + .start = amd_uncore_start, + .stop = amd_uncore_stop, + .read = amd_uncore_read, +}; + +static struct pmu amd_l2_pmu = { + .attr_groups = amd_uncore_attr_groups, + .name = "amd_l2", + .event_init = amd_uncore_event_init, + .add = amd_uncore_add, + .del = amd_uncore_del, + .start = amd_uncore_start, + .stop = amd_uncore_stop, + .read = amd_uncore_read, +}; + +static struct amd_uncore *amd_uncore_alloc(unsigned int cpu) +{ + return kzalloc_node(sizeof(struct amd_uncore), GFP_KERNEL, + cpu_to_node(cpu)); +} + +static int amd_uncore_cpu_up_prepare(unsigned int cpu) +{ + struct amd_uncore *uncore_nb = NULL, *uncore_l2; + + if (amd_uncore_nb) { + uncore_nb = amd_uncore_alloc(cpu); + if (!uncore_nb) + goto fail; + uncore_nb->cpu = cpu; + uncore_nb->num_counters = NUM_COUNTERS_NB; + uncore_nb->rdpmc_base = RDPMC_BASE_NB; + uncore_nb->msr_base = MSR_F15H_NB_PERF_CTL; + uncore_nb->active_mask = &amd_nb_active_mask; + uncore_nb->pmu = &amd_nb_pmu; + *per_cpu_ptr(amd_uncore_nb, cpu) = uncore_nb; + } + + if (amd_uncore_l2) { + uncore_l2 = amd_uncore_alloc(cpu); + if (!uncore_l2) + goto fail; + uncore_l2->cpu = cpu; + uncore_l2->num_counters = NUM_COUNTERS_L2; + uncore_l2->rdpmc_base = RDPMC_BASE_L2; + uncore_l2->msr_base = MSR_F16H_L2I_PERF_CTL; + uncore_l2->active_mask = &amd_l2_active_mask; + uncore_l2->pmu = &amd_l2_pmu; + *per_cpu_ptr(amd_uncore_l2, cpu) = uncore_l2; + } + + return 0; + +fail: + kfree(uncore_nb); + return -ENOMEM; +} + +static struct amd_uncore * +amd_uncore_find_online_sibling(struct amd_uncore *this, + struct amd_uncore * __percpu *uncores) +{ + unsigned int cpu; + struct amd_uncore *that; + + for_each_online_cpu(cpu) { + that = *per_cpu_ptr(uncores, cpu); + + if (!that) + continue; + + if (this == that) + continue; + + if (this->id == that->id) { + that->free_when_cpu_online = this; + this = that; + break; + } + } + + this->refcnt++; + return this; +} + +static void amd_uncore_cpu_starting(unsigned int cpu) +{ + unsigned int eax, ebx, ecx, edx; + struct amd_uncore *uncore; + + if (amd_uncore_nb) { + uncore = *per_cpu_ptr(amd_uncore_nb, cpu); + cpuid(0x8000001e, &eax, &ebx, &ecx, &edx); + uncore->id = ecx & 0xff; + + uncore = amd_uncore_find_online_sibling(uncore, amd_uncore_nb); + *per_cpu_ptr(amd_uncore_nb, cpu) = uncore; + } + + if (amd_uncore_l2) { + unsigned int apicid = cpu_data(cpu).apicid; + unsigned int nshared; + + uncore = *per_cpu_ptr(amd_uncore_l2, cpu); + cpuid_count(0x8000001d, 2, &eax, &ebx, &ecx, &edx); + nshared = ((eax >> 14) & 0xfff) + 1; + uncore->id = apicid - (apicid % nshared); + + uncore = amd_uncore_find_online_sibling(uncore, amd_uncore_l2); + *per_cpu_ptr(amd_uncore_l2, cpu) = uncore; + } +} + +static void uncore_online(unsigned int cpu, + struct amd_uncore * __percpu *uncores) +{ + struct amd_uncore *uncore = *per_cpu_ptr(uncores, cpu); + + kfree(uncore->free_when_cpu_online); + uncore->free_when_cpu_online = NULL; + + if (cpu == uncore->cpu) + cpumask_set_cpu(cpu, uncore->active_mask); +} + +static void amd_uncore_cpu_online(unsigned int cpu) +{ + if (amd_uncore_nb) + uncore_online(cpu, amd_uncore_nb); + + if (amd_uncore_l2) + uncore_online(cpu, amd_uncore_l2); +} + +static void uncore_down_prepare(unsigned int cpu, + struct amd_uncore * __percpu *uncores) +{ + unsigned int i; + struct amd_uncore *this = *per_cpu_ptr(uncores, cpu); + + if (this->cpu != cpu) + return; + + /* this cpu is going down, migrate to a shared sibling if possible */ + for_each_online_cpu(i) { + struct amd_uncore *that = *per_cpu_ptr(uncores, i); + + if (cpu == i) + continue; + + if (this == that) { + perf_pmu_migrate_context(this->pmu, cpu, i); + cpumask_clear_cpu(cpu, that->active_mask); + cpumask_set_cpu(i, that->active_mask); + that->cpu = i; + break; + } + } +} + +static void amd_uncore_cpu_down_prepare(unsigned int cpu) +{ + if (amd_uncore_nb) + uncore_down_prepare(cpu, amd_uncore_nb); + + if (amd_uncore_l2) + uncore_down_prepare(cpu, amd_uncore_l2); +} + +static void uncore_dead(unsigned int cpu, struct amd_uncore * __percpu *uncores) +{ + struct amd_uncore *uncore = *per_cpu_ptr(uncores, cpu); + + if (cpu == uncore->cpu) + cpumask_clear_cpu(cpu, uncore->active_mask); + + if (!--uncore->refcnt) + kfree(uncore); + *per_cpu_ptr(uncores, cpu) = NULL; +} + +static void amd_uncore_cpu_dead(unsigned int cpu) +{ + if (amd_uncore_nb) + uncore_dead(cpu, amd_uncore_nb); + + if (amd_uncore_l2) + uncore_dead(cpu, amd_uncore_l2); +} + +static int +amd_uncore_cpu_notifier(struct notifier_block *self, unsigned long action, + void *hcpu) +{ + unsigned int cpu = (long)hcpu; + + switch (action & ~CPU_TASKS_FROZEN) { + case CPU_UP_PREPARE: + if (amd_uncore_cpu_up_prepare(cpu)) + return notifier_from_errno(-ENOMEM); + break; + + case CPU_STARTING: + amd_uncore_cpu_starting(cpu); + break; + + case CPU_ONLINE: + amd_uncore_cpu_online(cpu); + break; + + case CPU_DOWN_PREPARE: + amd_uncore_cpu_down_prepare(cpu); + break; + + case CPU_UP_CANCELED: + case CPU_DEAD: + amd_uncore_cpu_dead(cpu); + break; + + default: + break; + } + + return NOTIFY_OK; +} + +static struct notifier_block amd_uncore_cpu_notifier_block = { + .notifier_call = amd_uncore_cpu_notifier, + .priority = CPU_PRI_PERF + 1, +}; + +static void __init init_cpu_already_online(void *dummy) +{ + unsigned int cpu = smp_processor_id(); + + amd_uncore_cpu_starting(cpu); + amd_uncore_cpu_online(cpu); +} + +static void cleanup_cpu_online(void *dummy) +{ + unsigned int cpu = smp_processor_id(); + + amd_uncore_cpu_dead(cpu); +} + +static int __init amd_uncore_init(void) +{ + unsigned int cpu, cpu2; + int ret = -ENODEV; + + if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) + goto fail_nodev; + + if (!cpu_has_topoext) + goto fail_nodev; + + if (cpu_has_perfctr_nb) { + amd_uncore_nb = alloc_percpu(struct amd_uncore *); + if (!amd_uncore_nb) { + ret = -ENOMEM; + goto fail_nb; + } + ret = perf_pmu_register(&amd_nb_pmu, amd_nb_pmu.name, -1); + if (ret) + goto fail_nb; + + printk(KERN_INFO "perf: AMD NB counters detected\n"); + ret = 0; + } + + if (cpu_has_perfctr_l2) { + amd_uncore_l2 = alloc_percpu(struct amd_uncore *); + if (!amd_uncore_l2) { + ret = -ENOMEM; + goto fail_l2; + } + ret = perf_pmu_register(&amd_l2_pmu, amd_l2_pmu.name, -1); + if (ret) + goto fail_l2; + + printk(KERN_INFO "perf: AMD L2I counters detected\n"); + ret = 0; + } + + if (ret) + goto fail_nodev; + + cpu_notifier_register_begin(); + + /* init cpus already online before registering for hotplug notifier */ + for_each_online_cpu(cpu) { + ret = amd_uncore_cpu_up_prepare(cpu); + if (ret) + goto fail_online; + smp_call_function_single(cpu, init_cpu_already_online, NULL, 1); + } + + __register_cpu_notifier(&amd_uncore_cpu_notifier_block); + cpu_notifier_register_done(); + + return 0; + + +fail_online: + for_each_online_cpu(cpu2) { + if (cpu2 == cpu) + break; + smp_call_function_single(cpu, cleanup_cpu_online, NULL, 1); + } + cpu_notifier_register_done(); + + /* amd_uncore_nb/l2 should have been freed by cleanup_cpu_online */ + amd_uncore_nb = amd_uncore_l2 = NULL; + if (cpu_has_perfctr_l2) + perf_pmu_unregister(&amd_l2_pmu); +fail_l2: + if (cpu_has_perfctr_nb) + perf_pmu_unregister(&amd_nb_pmu); + if (amd_uncore_l2) + free_percpu(amd_uncore_l2); +fail_nb: + if (amd_uncore_nb) + free_percpu(amd_uncore_nb); + +fail_nodev: + return ret; +} +device_initcall(amd_uncore_init); |