+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright 2010 ARM Ltd.
- * Copyright 2012 Advanced Micro Devices, Inc., Robert Richter
- *
- * Perf-events backend for OProfile.
- */
-#include <linux/perf_event.h>
-#include <linux/platform_device.h>
-#include <linux/oprofile.h>
-#include <linux/slab.h>
-
-/*
- * Per performance monitor configuration as set via oprofilefs.
- */
-struct op_counter_config {
- unsigned long count;
- unsigned long enabled;
- unsigned long event;
- unsigned long unit_mask;
- unsigned long kernel;
- unsigned long user;
- struct perf_event_attr attr;
-};
-
-static int oprofile_perf_enabled;
-static DEFINE_MUTEX(oprofile_perf_mutex);
-
-static struct op_counter_config *counter_config;
-static DEFINE_PER_CPU(struct perf_event **, perf_events);
-static int num_counters;
-
-/*
- * Overflow callback for oprofile.
- */
-static void op_overflow_handler(struct perf_event *event,
- struct perf_sample_data *data, struct pt_regs *regs)
-{
- int id;
- u32 cpu = smp_processor_id();
-
- for (id = 0; id < num_counters; ++id)
- if (per_cpu(perf_events, cpu)[id] == event)
- break;
-
- if (id != num_counters)
- oprofile_add_sample(regs, id);
- else
- pr_warn("oprofile: ignoring spurious overflow on cpu %u\n",
- cpu);
-}
-
-/*
- * Called by oprofile_perf_setup to create perf attributes to mirror the oprofile
- * settings in counter_config. Attributes are created as `pinned' events and
- * so are permanently scheduled on the PMU.
- */
-static void op_perf_setup(void)
-{
- int i;
- u32 size = sizeof(struct perf_event_attr);
- struct perf_event_attr *attr;
-
- for (i = 0; i < num_counters; ++i) {
- attr = &counter_config[i].attr;
- memset(attr, 0, size);
- attr->type = PERF_TYPE_RAW;
- attr->size = size;
- attr->config = counter_config[i].event;
- attr->sample_period = counter_config[i].count;
- attr->pinned = 1;
- }
-}
-
-static int op_create_counter(int cpu, int event)
-{
- struct perf_event *pevent;
-
- if (!counter_config[event].enabled || per_cpu(perf_events, cpu)[event])
- return 0;
-
- pevent = perf_event_create_kernel_counter(&counter_config[event].attr,
- cpu, NULL,
- op_overflow_handler, NULL);
-
- if (IS_ERR(pevent))
- return PTR_ERR(pevent);
-
- if (pevent->state != PERF_EVENT_STATE_ACTIVE) {
- perf_event_release_kernel(pevent);
- pr_warn("oprofile: failed to enable event %d on CPU %d\n",
- event, cpu);
- return -EBUSY;
- }
-
- per_cpu(perf_events, cpu)[event] = pevent;
-
- return 0;
-}
-
-static void op_destroy_counter(int cpu, int event)
-{
- struct perf_event *pevent = per_cpu(perf_events, cpu)[event];
-
- if (pevent) {
- perf_event_release_kernel(pevent);
- per_cpu(perf_events, cpu)[event] = NULL;
- }
-}
-
-/*
- * Called by oprofile_perf_start to create active perf events based on the
- * perviously configured attributes.
- */
-static int op_perf_start(void)
-{
- int cpu, event, ret = 0;
-
- for_each_online_cpu(cpu) {
- for (event = 0; event < num_counters; ++event) {
- ret = op_create_counter(cpu, event);
- if (ret)
- return ret;
- }
- }
-
- return ret;
-}
-
-/*
- * Called by oprofile_perf_stop at the end of a profiling run.
- */
-static void op_perf_stop(void)
-{
- int cpu, event;
-
- for_each_online_cpu(cpu)
- for (event = 0; event < num_counters; ++event)
- op_destroy_counter(cpu, event);
-}
-
-static int oprofile_perf_create_files(struct dentry *root)
-{
- unsigned int i;
-
- for (i = 0; i < num_counters; i++) {
- struct dentry *dir;
- char buf[4];
-
- snprintf(buf, sizeof buf, "%d", i);
- dir = oprofilefs_mkdir(root, buf);
- oprofilefs_create_ulong(dir, "enabled", &counter_config[i].enabled);
- oprofilefs_create_ulong(dir, "event", &counter_config[i].event);
- oprofilefs_create_ulong(dir, "count", &counter_config[i].count);
- oprofilefs_create_ulong(dir, "unit_mask", &counter_config[i].unit_mask);
- oprofilefs_create_ulong(dir, "kernel", &counter_config[i].kernel);
- oprofilefs_create_ulong(dir, "user", &counter_config[i].user);
- }
-
- return 0;
-}
-
-static int oprofile_perf_setup(void)
-{
- raw_spin_lock(&oprofilefs_lock);
- op_perf_setup();
- raw_spin_unlock(&oprofilefs_lock);
- return 0;
-}
-
-static int oprofile_perf_start(void)
-{
- int ret = -EBUSY;
-
- mutex_lock(&oprofile_perf_mutex);
- if (!oprofile_perf_enabled) {
- ret = 0;
- op_perf_start();
- oprofile_perf_enabled = 1;
- }
- mutex_unlock(&oprofile_perf_mutex);
- return ret;
-}
-
-static void oprofile_perf_stop(void)
-{
- mutex_lock(&oprofile_perf_mutex);
- if (oprofile_perf_enabled)
- op_perf_stop();
- oprofile_perf_enabled = 0;
- mutex_unlock(&oprofile_perf_mutex);
-}
-
-#ifdef CONFIG_PM
-
-static int oprofile_perf_suspend(struct platform_device *dev, pm_message_t state)
-{
- mutex_lock(&oprofile_perf_mutex);
- if (oprofile_perf_enabled)
- op_perf_stop();
- mutex_unlock(&oprofile_perf_mutex);
- return 0;
-}
-
-static int oprofile_perf_resume(struct platform_device *dev)
-{
- mutex_lock(&oprofile_perf_mutex);
- if (oprofile_perf_enabled && op_perf_start())
- oprofile_perf_enabled = 0;
- mutex_unlock(&oprofile_perf_mutex);
- return 0;
-}
-
-static struct platform_driver oprofile_driver = {
- .driver = {
- .name = "oprofile-perf",
- },
- .resume = oprofile_perf_resume,
- .suspend = oprofile_perf_suspend,
-};
-
-static struct platform_device *oprofile_pdev;
-
-static int __init init_driverfs(void)
-{
- int ret;
-
- ret = platform_driver_register(&oprofile_driver);
- if (ret)
- return ret;
-
- oprofile_pdev = platform_device_register_simple(
- oprofile_driver.driver.name, 0, NULL, 0);
- if (IS_ERR(oprofile_pdev)) {
- ret = PTR_ERR(oprofile_pdev);
- platform_driver_unregister(&oprofile_driver);
- }
-
- return ret;
-}
-
-static void exit_driverfs(void)
-{
- platform_device_unregister(oprofile_pdev);
- platform_driver_unregister(&oprofile_driver);
-}
-
-#else
-
-static inline int init_driverfs(void) { return 0; }
-static inline void exit_driverfs(void) { }
-
-#endif /* CONFIG_PM */
-
-void oprofile_perf_exit(void)
-{
- int cpu, id;
- struct perf_event *event;
-
- for_each_possible_cpu(cpu) {
- for (id = 0; id < num_counters; ++id) {
- event = per_cpu(perf_events, cpu)[id];
- if (event)
- perf_event_release_kernel(event);
- }
-
- kfree(per_cpu(perf_events, cpu));
- }
-
- kfree(counter_config);
- exit_driverfs();
-}
-
-int __init oprofile_perf_init(struct oprofile_operations *ops)
-{
- int cpu, ret = 0;
-
- ret = init_driverfs();
- if (ret)
- return ret;
-
- num_counters = perf_num_counters();
- if (num_counters <= 0) {
- pr_info("oprofile: no performance counters\n");
- ret = -ENODEV;
- goto out;
- }
-
- counter_config = kcalloc(num_counters,
- sizeof(struct op_counter_config), GFP_KERNEL);
-
- if (!counter_config) {
- pr_info("oprofile: failed to allocate %d "
- "counters\n", num_counters);
- ret = -ENOMEM;
- num_counters = 0;
- goto out;
- }
-
- for_each_possible_cpu(cpu) {
- per_cpu(perf_events, cpu) = kcalloc(num_counters,
- sizeof(struct perf_event *), GFP_KERNEL);
- if (!per_cpu(perf_events, cpu)) {
- pr_info("oprofile: failed to allocate %d perf events "
- "for cpu %d\n", num_counters, cpu);
- ret = -ENOMEM;
- goto out;
- }
- }
-
- ops->create_files = oprofile_perf_create_files;
- ops->setup = oprofile_perf_setup;
- ops->start = oprofile_perf_start;
- ops->stop = oprofile_perf_stop;
- ops->shutdown = oprofile_perf_stop;
- ops->cpu_type = op_name_from_perf_id();
-
- if (!ops->cpu_type)
- ret = -ENODEV;
- else
- pr_info("oprofile: using %s\n", ops->cpu_type);
-
-out:
- if (ret)
- oprofile_perf_exit();
-
- return ret;
-}
projects / linux-2.6-block.git / blobdiff