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-rw-r--r--drivers/oprofile/nmi_timer_int.c173
-rw-r--r--drivers/oprofile/oprof.c30
-rw-r--r--drivers/oprofile/oprof.h10
-rw-r--r--drivers/oprofile/oprofile_files.c7
-rw-r--r--drivers/oprofile/oprofilefs.c11
-rw-r--r--drivers/oprofile/timer_int.c30
6 files changed, 222 insertions, 39 deletions
diff --git a/drivers/oprofile/nmi_timer_int.c b/drivers/oprofile/nmi_timer_int.c
new file mode 100644
index 00000000000..76f1c9357f3
--- /dev/null
+++ b/drivers/oprofile/nmi_timer_int.c
@@ -0,0 +1,173 @@
+/**
+ * @file nmi_timer_int.c
+ *
+ * @remark Copyright 2011 Advanced Micro Devices, Inc.
+ *
+ * @author Robert Richter <robert.richter@amd.com>
+ */
+
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/errno.h>
+#include <linux/oprofile.h>
+#include <linux/perf_event.h>
+
+#ifdef CONFIG_OPROFILE_NMI_TIMER
+
+static DEFINE_PER_CPU(struct perf_event *, nmi_timer_events);
+static int ctr_running;
+
+static struct perf_event_attr nmi_timer_attr = {
+ .type = PERF_TYPE_HARDWARE,
+ .config = PERF_COUNT_HW_CPU_CYCLES,
+ .size = sizeof(struct perf_event_attr),
+ .pinned = 1,
+ .disabled = 1,
+};
+
+static void nmi_timer_callback(struct perf_event *event,
+ struct perf_sample_data *data,
+ struct pt_regs *regs)
+{
+ event->hw.interrupts = 0; /* don't throttle interrupts */
+ oprofile_add_sample(regs, 0);
+}
+
+static int nmi_timer_start_cpu(int cpu)
+{
+ struct perf_event *event = per_cpu(nmi_timer_events, cpu);
+
+ if (!event) {
+ event = perf_event_create_kernel_counter(&nmi_timer_attr, cpu, NULL,
+ nmi_timer_callback, NULL);
+ if (IS_ERR(event))
+ return PTR_ERR(event);
+ per_cpu(nmi_timer_events, cpu) = event;
+ }
+
+ if (event && ctr_running)
+ perf_event_enable(event);
+
+ return 0;
+}
+
+static void nmi_timer_stop_cpu(int cpu)
+{
+ struct perf_event *event = per_cpu(nmi_timer_events, cpu);
+
+ if (event && ctr_running)
+ perf_event_disable(event);
+}
+
+static int nmi_timer_cpu_notifier(struct notifier_block *b, unsigned long action,
+ void *data)
+{
+ int cpu = (unsigned long)data;
+ switch (action) {
+ case CPU_DOWN_FAILED:
+ case CPU_ONLINE:
+ nmi_timer_start_cpu(cpu);
+ break;
+ case CPU_DOWN_PREPARE:
+ nmi_timer_stop_cpu(cpu);
+ break;
+ }
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block nmi_timer_cpu_nb = {
+ .notifier_call = nmi_timer_cpu_notifier
+};
+
+static int nmi_timer_start(void)
+{
+ int cpu;
+
+ get_online_cpus();
+ ctr_running = 1;
+ for_each_online_cpu(cpu)
+ nmi_timer_start_cpu(cpu);
+ put_online_cpus();
+
+ return 0;
+}
+
+static void nmi_timer_stop(void)
+{
+ int cpu;
+
+ get_online_cpus();
+ for_each_online_cpu(cpu)
+ nmi_timer_stop_cpu(cpu);
+ ctr_running = 0;
+ put_online_cpus();
+}
+
+static void nmi_timer_shutdown(void)
+{
+ struct perf_event *event;
+ int cpu;
+
+ get_online_cpus();
+ unregister_cpu_notifier(&nmi_timer_cpu_nb);
+ for_each_possible_cpu(cpu) {
+ event = per_cpu(nmi_timer_events, cpu);
+ if (!event)
+ continue;
+ perf_event_disable(event);
+ per_cpu(nmi_timer_events, cpu) = NULL;
+ perf_event_release_kernel(event);
+ }
+
+ put_online_cpus();
+}
+
+static int nmi_timer_setup(void)
+{
+ int cpu, err;
+ u64 period;
+
+ /* clock cycles per tick: */
+ period = (u64)cpu_khz * 1000;
+ do_div(period, HZ);
+ nmi_timer_attr.sample_period = period;
+
+ get_online_cpus();
+ err = register_cpu_notifier(&nmi_timer_cpu_nb);
+ if (err)
+ goto out;
+ /* can't attach events to offline cpus: */
+ for_each_online_cpu(cpu) {
+ err = nmi_timer_start_cpu(cpu);
+ if (err)
+ break;
+ }
+ if (err)
+ nmi_timer_shutdown();
+out:
+ put_online_cpus();
+ return err;
+}
+
+int __init op_nmi_timer_init(struct oprofile_operations *ops)
+{
+ int err = 0;
+
+ err = nmi_timer_setup();
+ if (err)
+ return err;
+ nmi_timer_shutdown(); /* only check, don't alloc */
+
+ ops->create_files = NULL;
+ ops->setup = nmi_timer_setup;
+ ops->shutdown = nmi_timer_shutdown;
+ ops->start = nmi_timer_start;
+ ops->stop = nmi_timer_stop;
+ ops->cpu_type = "timer";
+
+ printk(KERN_INFO "oprofile: using NMI timer interrupt.\n");
+
+ return 0;
+}
+
+#endif
diff --git a/drivers/oprofile/oprof.c b/drivers/oprofile/oprof.c
index f8c752e408a..ed2c3ec0702 100644
--- a/drivers/oprofile/oprof.c
+++ b/drivers/oprofile/oprof.c
@@ -246,37 +246,31 @@ static int __init oprofile_init(void)
int err;
/* always init architecture to setup backtrace support */
+ timer_mode = 0;
err = oprofile_arch_init(&oprofile_ops);
+ if (!err) {
+ if (!timer && !oprofilefs_register())
+ return 0;
+ oprofile_arch_exit();
+ }
- timer_mode = err || timer; /* fall back to timer mode on errors */
- if (timer_mode) {
- if (!err)
- oprofile_arch_exit();
+ /* setup timer mode: */
+ timer_mode = 1;
+ /* no nmi timer mode if oprofile.timer is set */
+ if (timer || op_nmi_timer_init(&oprofile_ops)) {
err = oprofile_timer_init(&oprofile_ops);
if (err)
return err;
}
- err = oprofilefs_register();
- if (!err)
- return 0;
-
- /* failed */
- if (timer_mode)
- oprofile_timer_exit();
- else
- oprofile_arch_exit();
-
- return err;
+ return oprofilefs_register();
}
static void __exit oprofile_exit(void)
{
oprofilefs_unregister();
- if (timer_mode)
- oprofile_timer_exit();
- else
+ if (!timer_mode)
oprofile_arch_exit();
}
diff --git a/drivers/oprofile/oprof.h b/drivers/oprofile/oprof.h
index 177b73de5e5..d32ef816337 100644
--- a/drivers/oprofile/oprof.h
+++ b/drivers/oprofile/oprof.h
@@ -35,7 +35,15 @@ struct dentry;
void oprofile_create_files(struct super_block *sb, struct dentry *root);
int oprofile_timer_init(struct oprofile_operations *ops);
-void oprofile_timer_exit(void);
+#ifdef CONFIG_OPROFILE_NMI_TIMER
+int op_nmi_timer_init(struct oprofile_operations *ops);
+#else
+static inline int op_nmi_timer_init(struct oprofile_operations *ops)
+{
+ return -ENODEV;
+}
+#endif
+
int oprofile_set_ulong(unsigned long *addr, unsigned long val);
int oprofile_set_timeout(unsigned long time);
diff --git a/drivers/oprofile/oprofile_files.c b/drivers/oprofile/oprofile_files.c
index 89f63456646..84a208dbed9 100644
--- a/drivers/oprofile/oprofile_files.c
+++ b/drivers/oprofile/oprofile_files.c
@@ -45,7 +45,7 @@ static ssize_t timeout_write(struct file *file, char const __user *buf,
return -EINVAL;
retval = oprofilefs_ulong_from_user(&val, buf, count);
- if (retval)
+ if (retval <= 0)
return retval;
retval = oprofile_set_timeout(val);
@@ -84,7 +84,7 @@ static ssize_t depth_write(struct file *file, char const __user *buf, size_t cou
return -EINVAL;
retval = oprofilefs_ulong_from_user(&val, buf, count);
- if (retval)
+ if (retval <= 0)
return retval;
retval = oprofile_set_ulong(&oprofile_backtrace_depth, val);
@@ -141,9 +141,10 @@ static ssize_t enable_write(struct file *file, char const __user *buf, size_t co
return -EINVAL;
retval = oprofilefs_ulong_from_user(&val, buf, count);
- if (retval)
+ if (retval <= 0)
return retval;
+ retval = 0;
if (val)
retval = oprofile_start();
else
diff --git a/drivers/oprofile/oprofilefs.c b/drivers/oprofile/oprofilefs.c
index d0de6cc2d7a..2f0aa0f700e 100644
--- a/drivers/oprofile/oprofilefs.c
+++ b/drivers/oprofile/oprofilefs.c
@@ -60,6 +60,13 @@ ssize_t oprofilefs_ulong_to_user(unsigned long val, char __user *buf, size_t cou
}
+/*
+ * Note: If oprofilefs_ulong_from_user() returns 0, then *val remains
+ * unchanged and might be uninitialized. This follows write syscall
+ * implementation when count is zero: "If count is zero ... [and if]
+ * no errors are detected, 0 will be returned without causing any
+ * other effect." (man 2 write)
+ */
int oprofilefs_ulong_from_user(unsigned long *val, char const __user *buf, size_t count)
{
char tmpbuf[TMPBUFSIZE];
@@ -79,7 +86,7 @@ int oprofilefs_ulong_from_user(unsigned long *val, char const __user *buf, size_
raw_spin_lock_irqsave(&oprofilefs_lock, flags);
*val = simple_strtoul(tmpbuf, NULL, 0);
raw_spin_unlock_irqrestore(&oprofilefs_lock, flags);
- return 0;
+ return count;
}
@@ -99,7 +106,7 @@ static ssize_t ulong_write_file(struct file *file, char const __user *buf, size_
return -EINVAL;
retval = oprofilefs_ulong_from_user(&value, buf, count);
- if (retval)
+ if (retval <= 0)
return retval;
retval = oprofile_set_ulong(file->private_data, value);
diff --git a/drivers/oprofile/timer_int.c b/drivers/oprofile/timer_int.c
index 878fba12658..93404f72dfa 100644
--- a/drivers/oprofile/timer_int.c
+++ b/drivers/oprofile/timer_int.c
@@ -97,24 +97,24 @@ static struct notifier_block __refdata oprofile_cpu_notifier = {
.notifier_call = oprofile_cpu_notify,
};
-int oprofile_timer_init(struct oprofile_operations *ops)
+static int oprofile_hrtimer_setup(void)
{
- int rc;
-
- rc = register_hotcpu_notifier(&oprofile_cpu_notifier);
- if (rc)
- return rc;
- ops->create_files = NULL;
- ops->setup = NULL;
- ops->shutdown = NULL;
- ops->start = oprofile_hrtimer_start;
- ops->stop = oprofile_hrtimer_stop;
- ops->cpu_type = "timer";
- printk(KERN_INFO "oprofile: using timer interrupt.\n");
- return 0;
+ return register_hotcpu_notifier(&oprofile_cpu_notifier);
}
-void oprofile_timer_exit(void)
+static void oprofile_hrtimer_shutdown(void)
{
unregister_hotcpu_notifier(&oprofile_cpu_notifier);
}
+
+int oprofile_timer_init(struct oprofile_operations *ops)
+{
+ ops->create_files = NULL;
+ ops->setup = oprofile_hrtimer_setup;
+ ops->shutdown = oprofile_hrtimer_shutdown;
+ ops->start = oprofile_hrtimer_start;
+ ops->stop = oprofile_hrtimer_stop;
+ ops->cpu_type = "timer";
+ printk(KERN_INFO "oprofile: using timer interrupt.\n");
+ return 0;
+}