diff options
Diffstat (limited to 'drivers/gator/gator_events_perf_pmu.c')
| -rw-r--r-- | drivers/gator/gator_events_perf_pmu.c | 516 |
1 files changed, 516 insertions, 0 deletions
diff --git a/drivers/gator/gator_events_perf_pmu.c b/drivers/gator/gator_events_perf_pmu.c new file mode 100644 index 00000000000..53b2d0a5afb --- /dev/null +++ b/drivers/gator/gator_events_perf_pmu.c @@ -0,0 +1,516 @@ +/** + * Copyright (C) ARM Limited 2010-2013. All rights reserved. + * + * 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/slab.h> +#include <linux/perf_event.h> +#include "gator.h" + +// gator_events_armvX.c is used for Linux 2.6.x +#if GATOR_PERF_PMU_SUPPORT + +extern bool event_based_sampling; + +// Maximum number of per-core counters - currently reserves enough space for two full hardware PMUs for big.LITTLE +#define CNTMAX 16 +#define CCI_400 4 +// Maximum number of uncore counters +// + 1 for the cci-400 cycles counter +#define UCCNT (CCI_400 + 1) + +// A gator_attr is needed for every counter +struct gator_attr { + // Set once in gator_events_perf_pmu_*_init - the name of the event in the gatorfs + char name[40]; + // Exposed in gatorfs - set by gatord to enable this counter + unsigned long enabled; + // Set once in gator_events_perf_pmu_*_init - the perf type to use, see perf_type_id in the perf_event.h header file. + unsigned long type; + // Exposed in gatorfs - set by gatord to select the event to collect + unsigned long event; + // Exposed in gatorfs - set by gatord with the sample period to use and enable EBS for this counter + unsigned long count; + // Exposed as read only in gatorfs - set once in __attr_init as the key to use in the APC data + unsigned long key; +}; + +// Per-core counter attributes +static struct gator_attr attrs[CNTMAX]; +// Number of initialized per-core counters +static int attr_count; +// Uncore counter attributes +static struct gator_attr uc_attrs[UCCNT]; +// Number of initialized uncore counters +static int uc_attr_count; + +struct gator_event { + int curr; + int prev; + int prev_delta; + bool zero; + struct perf_event *pevent; + struct perf_event_attr *pevent_attr; +}; + +static DEFINE_PER_CPU(struct gator_event[CNTMAX], events); +static struct gator_event uc_events[UCCNT]; +static DEFINE_PER_CPU(int[(CNTMAX + UCCNT)*2], perf_cnt); + +static void gator_events_perf_pmu_stop(void); + +static int __create_files(struct super_block *sb, struct dentry *root, struct gator_attr *const attr) +{ + struct dentry *dir; + + if (attr->name[0] == '\0') { + return 0; + } + dir = gatorfs_mkdir(sb, root, attr->name); + if (!dir) { + return -1; + } + gatorfs_create_ulong(sb, dir, "enabled", &attr->enabled); + gatorfs_create_ulong(sb, dir, "count", &attr->count); + gatorfs_create_ro_ulong(sb, dir, "key", &attr->key); + gatorfs_create_ulong(sb, dir, "event", &attr->event); + + return 0; +} + +static int gator_events_perf_pmu_create_files(struct super_block *sb, struct dentry *root) +{ + int cnt; + + for (cnt = 0; cnt < attr_count; cnt++) { + if (__create_files(sb, root, &attrs[cnt]) != 0) { + return -1; + } + } + + for (cnt = 0; cnt < uc_attr_count; cnt++) { + if (__create_files(sb, root, &uc_attrs[cnt]) != 0) { + return -1; + } + } + + return 0; +} + +#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 1, 0) +static void ebs_overflow_handler(struct perf_event *event, int unused, struct perf_sample_data *data, struct pt_regs *regs) +#else +static void ebs_overflow_handler(struct perf_event *event, struct perf_sample_data *data, struct pt_regs *regs) +#endif +{ + gator_backtrace_handler(regs); +} + +#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 1, 0) +static void dummy_handler(struct perf_event *event, int unused, struct perf_sample_data *data, struct pt_regs *regs) +#else +static void dummy_handler(struct perf_event *event, struct perf_sample_data *data, struct pt_regs *regs) +#endif +{ +// Required as perf_event_create_kernel_counter() requires an overflow handler, even though all we do is poll +} + +static int gator_events_perf_pmu_read(int **buffer); + +static int gator_events_perf_pmu_online(int **buffer, bool migrate) +{ + return gator_events_perf_pmu_read(buffer); +} + +static void __online_dispatch(int cpu, bool migrate, struct gator_attr *const attr, struct gator_event *const event) +{ + perf_overflow_handler_t handler; + + event->zero = true; + + if (event->pevent != NULL || event->pevent_attr == 0 || migrate) { + return; + } + + if (attr->count > 0) { + handler = ebs_overflow_handler; + } else { + handler = dummy_handler; + } + +#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 1, 0) + event->pevent = perf_event_create_kernel_counter(event->pevent_attr, cpu, 0, handler); +#else + event->pevent = perf_event_create_kernel_counter(event->pevent_attr, cpu, 0, handler, 0); +#endif + if (IS_ERR(event->pevent)) { + pr_debug("gator: unable to online a counter on cpu %d\n", cpu); + event->pevent = NULL; + return; + } + + if (event->pevent->state != PERF_EVENT_STATE_ACTIVE) { + pr_debug("gator: inactive counter on cpu %d\n", cpu); + perf_event_release_kernel(event->pevent); + event->pevent = NULL; + return; + } +} + +static void gator_events_perf_pmu_online_dispatch(int cpu, bool migrate) +{ + int cnt; + + cpu = pcpu_to_lcpu(cpu); + + for (cnt = 0; cnt < attr_count; cnt++) { + __online_dispatch(cpu, migrate, &attrs[cnt], &per_cpu(events, cpu)[cnt]); + } + + if (cpu == 0) { + for (cnt = 0; cnt < uc_attr_count; cnt++) { + __online_dispatch(cpu, migrate, &uc_attrs[cnt], &uc_events[cnt]); + } + } +} + +static void __offline_dispatch(int cpu, struct gator_event *const event) +{ + struct perf_event *pe = NULL; + + if (event->pevent) { + pe = event->pevent; + event->pevent = NULL; + } + + if (pe) { + perf_event_release_kernel(pe); + } +} + +static void gator_events_perf_pmu_offline_dispatch(int cpu, bool migrate) +{ + int cnt; + + if (migrate) { + return; + } + cpu = pcpu_to_lcpu(cpu); + + for (cnt = 0; cnt < attr_count; cnt++) { + __offline_dispatch(cpu, &per_cpu(events, cpu)[cnt]); + } + + if (cpu == 0) { + for (cnt = 0; cnt < uc_attr_count; cnt++) { + __offline_dispatch(cpu, &uc_events[cnt]); + } + } +} + +static int __check_ebs(struct gator_attr *const attr) +{ + if (attr->count > 0) { + if (!event_based_sampling) { + event_based_sampling = true; + } else { + printk(KERN_WARNING "gator: Only one ebs counter is allowed\n"); + return -1; + } + } + + return 0; +} + +static int __start(struct gator_attr *const attr, struct gator_event *const event) +{ + u32 size = sizeof(struct perf_event_attr); + + event->pevent = NULL; + if (!attr->enabled) { // Skip disabled counters + return 0; + } + + event->prev = 0; + event->curr = 0; + event->prev_delta = 0; + event->pevent_attr = kmalloc(size, GFP_KERNEL); + if (!event->pevent_attr) { + gator_events_perf_pmu_stop(); + return -1; + } + + memset(event->pevent_attr, 0, size); + event->pevent_attr->type = attr->type; + event->pevent_attr->size = size; + event->pevent_attr->config = attr->event; + event->pevent_attr->sample_period = attr->count; + event->pevent_attr->pinned = 1; + + return 0; +} + +static int gator_events_perf_pmu_start(void) +{ + int cnt, cpu; + + event_based_sampling = false; + for (cnt = 0; cnt < attr_count; cnt++) { + if (__check_ebs(&attrs[cnt]) != 0) { + return -1; + } + } + + for (cnt = 0; cnt < uc_attr_count; cnt++) { + if (__check_ebs(&uc_attrs[cnt]) != 0) { + return -1; + } + } + + for_each_present_cpu(cpu) { + for (cnt = 0; cnt < attr_count; cnt++) { + if (__start(&attrs[cnt], &per_cpu(events, cpu)[cnt]) != 0) { + return -1; + } + } + } + + for (cnt = 0; cnt < uc_attr_count; cnt++) { + if (__start(&uc_attrs[cnt], &uc_events[cnt]) != 0) { + return -1; + } + } + + return 0; +} + +static void __event_stop(struct gator_event *const event) +{ + if (event->pevent_attr) { + kfree(event->pevent_attr); + event->pevent_attr = NULL; + } +} + +static void __attr_stop(struct gator_attr *const attr) +{ + attr->enabled = 0; + attr->event = 0; + attr->count = 0; +} + +static void gator_events_perf_pmu_stop(void) +{ + unsigned int cnt, cpu; + + for_each_present_cpu(cpu) { + for (cnt = 0; cnt < attr_count; cnt++) { + __event_stop(&per_cpu(events, cpu)[cnt]); + } + } + + for (cnt = 0; cnt < uc_attr_count; cnt++) { + __event_stop(&uc_events[cnt]); + } + + for (cnt = 0; cnt < attr_count; cnt++) { + __attr_stop(&attrs[cnt]); + } + + for (cnt = 0; cnt < uc_attr_count; cnt++) { + __attr_stop(&uc_attrs[cnt]); + } +} + +static void __read(int *const len, int cpu, struct gator_attr *const attr, struct gator_event *const event) +{ + int delta; + + struct perf_event *const ev = event->pevent; + if (ev != NULL && ev->state == PERF_EVENT_STATE_ACTIVE) { + /* After creating the perf counter in __online_dispatch, there + * is a race condition between gator_events_perf_pmu_online and + * gator_events_perf_pmu_read. So have + * gator_events_perf_pmu_online call gator_events_perf_pmu_read + * and in __read check to see if it's the first call after + * __online_dispatch and if so, run the online code. + */ + if (event->zero) { + ev->pmu->read(ev); + event->prev = event->curr = local64_read(&ev->count); + event->prev_delta = 0; + per_cpu(perf_cnt, cpu)[(*len)++] = attr->key; + per_cpu(perf_cnt, cpu)[(*len)++] = 0; + event->zero = false; + } else { + ev->pmu->read(ev); + event->curr = local64_read(&ev->count); + delta = event->curr - event->prev; + if (delta != 0 || delta != event->prev_delta) { + event->prev_delta = delta; + event->prev = event->curr; + per_cpu(perf_cnt, cpu)[(*len)++] = attr->key; + if (delta < 0) { + delta *= -1; + } + per_cpu(perf_cnt, cpu)[(*len)++] = delta; + } + } + } +} + +static int gator_events_perf_pmu_read(int **buffer) +{ + int cnt, len = 0; + const int cpu = get_logical_cpu(); + + for (cnt = 0; cnt < attr_count; cnt++) { + __read(&len, cpu, &attrs[cnt], &per_cpu(events, cpu)[cnt]); + } + + if (cpu == 0) { + for (cnt = 0; cnt < uc_attr_count; cnt++) { + __read(&len, cpu, &uc_attrs[cnt], &uc_events[cnt]); + } + } + + if (buffer) { + *buffer = per_cpu(perf_cnt, cpu); + } + + return len; +} + +static struct gator_interface gator_events_perf_pmu_interface = { + .create_files = gator_events_perf_pmu_create_files, + .start = gator_events_perf_pmu_start, + .stop = gator_events_perf_pmu_stop, + .online = gator_events_perf_pmu_online, + .online_dispatch = gator_events_perf_pmu_online_dispatch, + .offline_dispatch = gator_events_perf_pmu_offline_dispatch, + .read = gator_events_perf_pmu_read, +}; + +static void __attr_init(struct gator_attr *const attr) +{ + attr->name[0] = '\0'; + attr->enabled = 0; + attr->type = 0; + attr->event = 0; + attr->count = 0; + attr->key = gator_events_get_key(); +} + +static void gator_events_perf_pmu_cci_init(const int type) +{ + int cnt; + + strncpy(uc_attrs[uc_attr_count].name, "cci-400_ccnt", sizeof(uc_attrs[uc_attr_count].name)); + uc_attrs[uc_attr_count].type = type; + ++uc_attr_count; + + for (cnt = 0; cnt < CCI_400; ++cnt, ++uc_attr_count) { + struct gator_attr *const attr = &uc_attrs[uc_attr_count]; + snprintf(attr->name, sizeof(attr->name), "cci-400_cnt%d", cnt); + attr->type = type; + } +} + +static void gator_events_perf_pmu_cpu_init(const struct gator_cpu *const gator_cpu, const int type) +{ + int cnt; + + snprintf(attrs[attr_count].name, sizeof(attrs[attr_count].name), "%s_ccnt", gator_cpu->pmnc_name); + attrs[attr_count].type = type; + ++attr_count; + + for (cnt = 0; cnt < gator_cpu->pmnc_counters; ++cnt, ++attr_count) { + struct gator_attr *const attr = &attrs[attr_count]; + snprintf(attr->name, sizeof(attr->name), "%s_cnt%d", gator_cpu->pmnc_name, cnt); + attr->type = type; + } +} + +int gator_events_perf_pmu_init(void) +{ + struct perf_event_attr pea; + struct perf_event *pe; + const struct gator_cpu *gator_cpu; + int type; + int cpu; + int cnt; + bool found_cpu = false; + + for (cnt = 0; cnt < CNTMAX; cnt++) { + __attr_init(&attrs[cnt]); + } + for (cnt = 0; cnt < UCCNT; cnt++) { + __attr_init(&uc_attrs[cnt]); + } + + memset(&pea, 0, sizeof(pea)); + pea.size = sizeof(pea); + pea.config = 0xFF; + attr_count = 0; + uc_attr_count = 0; + for (type = PERF_TYPE_MAX; type < 0x20; ++type) { + pea.type = type; + + // A particular PMU may work on some but not all cores, so try on each core + pe = NULL; + for_each_present_cpu(cpu) { +#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 1, 0) + pe = perf_event_create_kernel_counter(&pea, cpu, 0, dummy_handler); +#else + pe = perf_event_create_kernel_counter(&pea, cpu, 0, dummy_handler, 0); +#endif + if (!IS_ERR(pe)) { + break; + } + } + // Assume that valid PMUs are contiguous + if (IS_ERR(pe)) { + break; + } + + if (pe->pmu != NULL && type == pe->pmu->type) { + if (strcmp("CCI", pe->pmu->name) == 0) { + gator_events_perf_pmu_cci_init(type); + } else if ((gator_cpu = gator_find_cpu_by_pmu_name(pe->pmu->name)) != NULL) { + found_cpu = true; + gator_events_perf_pmu_cpu_init(gator_cpu, type); + } + // Initialize gator_attrs for dynamic PMUs here + } + + perf_event_release_kernel(pe); + } + + if (!found_cpu) { + const struct gator_cpu *const gator_cpu = gator_find_cpu_by_cpuid(gator_cpuid()); + if (gator_cpu == NULL) { + return -1; + } + gator_events_perf_pmu_cpu_init(gator_cpu, PERF_TYPE_RAW); + } + + // Initialize gator_attrs for non-dynamic PMUs here + + if (attr_count > CNTMAX) { + printk(KERN_ERR "gator: Too many perf counters\n"); + return -1; + } + + if (uc_attr_count > UCCNT) { + printk(KERN_ERR "gator: Too many perf uncore counters\n"); + return -1; + } + + return gator_events_install(&gator_events_perf_pmu_interface); +} + +gator_events_init(gator_events_perf_pmu_init); +#endif |