* @file common.c
*
* @remark Copyright 2004 Oprofile Authors
+ * @remark Copyright 2010 ARM Ltd.
* @remark Read the file COPYING
*
* @author Zwane Mwaikambo
+ * @author Will Deacon [move to perf]
*/
+#include <linux/cpumask.h>
+#include <linux/errno.h>
#include <linux/init.h>
+#include <linux/mutex.h>
#include <linux/oprofile.h>
-#include <linux/errno.h>
+#include <linux/perf_event.h>
#include <linux/slab.h>
#include <linux/sysdev.h>
-#include <linux/mutex.h>
+#include <asm/stacktrace.h>
+#include <linux/uaccess.h>
+
+#include <asm/perf_event.h>
+#include <asm/ptrace.h>
-#include "op_counter.h"
-#include "op_arm_model.h"
+#ifdef CONFIG_HW_PERF_EVENTS
+/*
+ * 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 struct op_arm_model_spec *op_arm_model;
static int op_arm_enabled;
static DEFINE_MUTEX(op_arm_mutex);
-struct op_counter_config *counter_config;
+static struct op_counter_config *counter_config;
+static struct perf_event **perf_events[nr_cpumask_bits];
+static int perf_num_counters;
+
+/*
+ * Overflow callback for oprofile.
+ */
+static void op_overflow_handler(struct perf_event *event, int unused,
+ struct perf_sample_data *data, struct pt_regs *regs)
+{
+ int id;
+ u32 cpu = smp_processor_id();
+
+ for (id = 0; id < perf_num_counters; ++id)
+ if (perf_events[cpu][id] == event)
+ break;
+
+ if (id != perf_num_counters)
+ oprofile_add_sample(regs, id);
+ else
+ pr_warning("oprofile: ignoring spurious overflow "
+ "on cpu %u\n", cpu);
+}
+
+/*
+ * Called by op_arm_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 < perf_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)
+{
+ int ret = 0;
+ struct perf_event *pevent;
+
+ if (!counter_config[event].enabled || (perf_events[cpu][event] != NULL))
+ return ret;
+
+ pevent = perf_event_create_kernel_counter(&counter_config[event].attr,
+ cpu, -1,
+ op_overflow_handler);
+
+ if (IS_ERR(pevent)) {
+ ret = PTR_ERR(pevent);
+ } else if (pevent->state != PERF_EVENT_STATE_ACTIVE) {
+ pr_warning("oprofile: failed to enable event %d "
+ "on CPU %d\n", event, cpu);
+ ret = -EBUSY;
+ } else {
+ perf_events[cpu][event] = pevent;
+ }
+
+ return ret;
+}
+
+static void op_destroy_counter(int cpu, int event)
+{
+ struct perf_event *pevent = perf_events[cpu][event];
+
+ if (pevent) {
+ perf_event_release_kernel(pevent);
+ perf_events[cpu][event] = NULL;
+ }
+}
+
+/*
+ * Called by op_arm_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 < perf_num_counters; ++event) {
+ ret = op_create_counter(cpu, event);
+ if (ret)
+ goto out;
+ }
+ }
+
+out:
+ return ret;
+}
+
+/*
+ * Called by op_arm_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 < perf_num_counters; ++event)
+ op_destroy_counter(cpu, event);
+}
+
+
+static char *op_name_from_perf_id(enum arm_perf_pmu_ids id)
+{
+ switch (id) {
+ case ARM_PERF_PMU_ID_XSCALE1:
+ return "arm/xscale1";
+ case ARM_PERF_PMU_ID_XSCALE2:
+ return "arm/xscale2";
+ case ARM_PERF_PMU_ID_V6:
+ return "arm/armv6";
+ case ARM_PERF_PMU_ID_V6MP:
+ return "arm/mpcore";
+ case ARM_PERF_PMU_ID_CA8:
+ return "arm/armv7";
+ case ARM_PERF_PMU_ID_CA9:
+ return "arm/armv7-ca9";
+ default:
+ return NULL;
+ }
+}
static int op_arm_create_files(struct super_block *sb, struct dentry *root)
{
unsigned int i;
- for (i = 0; i < op_arm_model->num_counters; i++) {
+ for (i = 0; i < perf_num_counters; i++) {
struct dentry *dir;
char buf[4];
static int op_arm_setup(void)
{
- int ret;
-
spin_lock(&oprofilefs_lock);
- ret = op_arm_model->setup_ctrs();
+ op_perf_setup();
spin_unlock(&oprofilefs_lock);
- return ret;
+ return 0;
}
static int op_arm_start(void)
mutex_lock(&op_arm_mutex);
if (!op_arm_enabled) {
- ret = op_arm_model->start();
- op_arm_enabled = !ret;
+ ret = 0;
+ op_perf_start();
+ op_arm_enabled = 1;
}
mutex_unlock(&op_arm_mutex);
return ret;
{
mutex_lock(&op_arm_mutex);
if (op_arm_enabled)
- op_arm_model->stop();
+ op_perf_stop();
op_arm_enabled = 0;
mutex_unlock(&op_arm_mutex);
}
{
mutex_lock(&op_arm_mutex);
if (op_arm_enabled)
- op_arm_model->stop();
+ op_perf_stop();
mutex_unlock(&op_arm_mutex);
return 0;
}
static int op_arm_resume(struct sys_device *dev)
{
mutex_lock(&op_arm_mutex);
- if (op_arm_enabled && op_arm_model->start())
+ if (op_arm_enabled && op_perf_start())
op_arm_enabled = 0;
mutex_unlock(&op_arm_mutex);
return 0;
#define exit_driverfs() do { } while (0)
#endif /* CONFIG_PM */
-int __init oprofile_arch_init(struct oprofile_operations *ops)
+static int report_trace(struct stackframe *frame, void *d)
{
- struct op_arm_model_spec *spec = NULL;
- int ret = -ENODEV;
+ unsigned int *depth = d;
- ops->backtrace = arm_backtrace;
+ if (*depth) {
+ oprofile_add_trace(frame->pc);
+ (*depth)--;
+ }
-#ifdef CONFIG_CPU_XSCALE
- spec = &op_xscale_spec;
-#endif
+ return *depth == 0;
+}
-#ifdef CONFIG_OPROFILE_ARMV6
- spec = &op_armv6_spec;
-#endif
+/*
+ * The registers we're interested in are at the end of the variable
+ * length saved register structure. The fp points at the end of this
+ * structure so the address of this struct is:
+ * (struct frame_tail *)(xxx->fp)-1
+ */
+struct frame_tail {
+ struct frame_tail *fp;
+ unsigned long sp;
+ unsigned long lr;
+} __attribute__((packed));
-#ifdef CONFIG_OPROFILE_MPCORE
- spec = &op_mpcore_spec;
-#endif
+static struct frame_tail* user_backtrace(struct frame_tail *tail)
+{
+ struct frame_tail buftail[2];
-#ifdef CONFIG_OPROFILE_ARMV7
- spec = &op_armv7_spec;
-#endif
+ /* Also check accessibility of one struct frame_tail beyond */
+ if (!access_ok(VERIFY_READ, tail, sizeof(buftail)))
+ return NULL;
+ if (__copy_from_user_inatomic(buftail, tail, sizeof(buftail)))
+ return NULL;
- if (spec) {
- ret = spec->init();
- if (ret < 0)
- return ret;
+ oprofile_add_trace(buftail[0].lr);
- counter_config = kcalloc(spec->num_counters, sizeof(struct op_counter_config),
- GFP_KERNEL);
- if (!counter_config)
- return -ENOMEM;
+ /* frame pointers should strictly progress back up the stack
+ * (towards higher addresses) */
+ if (tail >= buftail[0].fp)
+ return NULL;
+
+ return buftail[0].fp-1;
+}
+
+static void arm_backtrace(struct pt_regs * const regs, unsigned int depth)
+{
+ struct frame_tail *tail = ((struct frame_tail *) regs->ARM_fp) - 1;
+
+ if (!user_mode(regs)) {
+ struct stackframe frame;
+ frame.fp = regs->ARM_fp;
+ frame.sp = regs->ARM_sp;
+ frame.lr = regs->ARM_lr;
+ frame.pc = regs->ARM_pc;
+ walk_stackframe(&frame, report_trace, &depth);
+ return;
+ }
+
+ while (depth-- && tail && !((unsigned long) tail & 3))
+ tail = user_backtrace(tail);
+}
+
+int __init oprofile_arch_init(struct oprofile_operations *ops)
+{
+ int cpu, ret = 0;
+
+ perf_num_counters = armpmu_get_max_events();
+
+ counter_config = kcalloc(perf_num_counters,
+ sizeof(struct op_counter_config), GFP_KERNEL);
- op_arm_model = spec;
- init_driverfs();
- ops->create_files = op_arm_create_files;
- ops->setup = op_arm_setup;
- ops->shutdown = op_arm_stop;
- ops->start = op_arm_start;
- ops->stop = op_arm_stop;
- ops->cpu_type = op_arm_model->name;
- printk(KERN_INFO "oprofile: using %s\n", spec->name);
+ if (!counter_config) {
+ pr_info("oprofile: failed to allocate %d "
+ "counters\n", perf_num_counters);
+ return -ENOMEM;
}
+ for_each_possible_cpu(cpu) {
+ perf_events[cpu] = kcalloc(perf_num_counters,
+ sizeof(struct perf_event *), GFP_KERNEL);
+ if (!perf_events[cpu]) {
+ pr_info("oprofile: failed to allocate %d perf events "
+ "for cpu %d\n", perf_num_counters, cpu);
+ while (--cpu >= 0)
+ kfree(perf_events[cpu]);
+ return -ENOMEM;
+ }
+ }
+
+ init_driverfs();
+ ops->backtrace = arm_backtrace;
+ ops->create_files = op_arm_create_files;
+ ops->setup = op_arm_setup;
+ ops->start = op_arm_start;
+ ops->stop = op_arm_stop;
+ ops->shutdown = op_arm_stop;
+ ops->cpu_type = op_name_from_perf_id(armpmu_get_pmu_id());
+
+ if (!ops->cpu_type)
+ ret = -ENODEV;
+ else
+ pr_info("oprofile: using %s\n", ops->cpu_type);
+
return ret;
}
void oprofile_arch_exit(void)
{
- if (op_arm_model) {
+ int cpu, id;
+ struct perf_event *event;
+
+ if (*perf_events) {
exit_driverfs();
- op_arm_model = NULL;
+ for_each_possible_cpu(cpu) {
+ for (id = 0; id < perf_num_counters; ++id) {
+ event = perf_events[cpu][id];
+ if (event != NULL)
+ perf_event_release_kernel(event);
+ }
+ kfree(perf_events[cpu]);
+ }
}
- kfree(counter_config);
+
+ if (counter_config)
+ kfree(counter_config);
+}
+#else
+int __init oprofile_arch_init(struct oprofile_operations *ops)
+{
+ pr_info("oprofile: hardware counters not available\n");
+ return -ENODEV;
}
+void oprofile_arch_exit(void) {}
+#endif /* CONFIG_HW_PERF_EVENTS */
projects / platform / kernel / linux-stable.git / commitdiff