3 files changed, 46 insertions, 3 deletions

diff --git a/drivers/oprofile/oprof.c b/drivers/oprofile/oprof.c
index f9bda64fcd1b..43b01daa91e1 100644
--- a/drivers/oprofile/oprof.c
+++ b/drivers/oprofile/oprof.c
@@ -239,6 +239,38 @@ int oprofile_set_ulong(unsigned long *addr, unsigned long val)
         return err;
 }
 
+#ifdef CONFIG_HAVE_HWSAMPLER
+int oprofile_set_hwsampler(unsigned long val)
+{
+        int err = 0;
+
+        mutex_lock(&start_mutex);
+
+        if (oprofile_started) {
+                err = -EBUSY;
+                goto out;
+        }
+
+        switch (val) {
+        case 1:
+                /* Switch to hardware sampling. */
+                __oprofile_timer_exit();
+                err = oprofile_arch_set_hwsampler(&oprofile_ops);
+                break;
+        case 0:
+                printk(KERN_INFO "oprofile: using timer interrupt.\n");
+                err = __oprofile_timer_init(&oprofile_ops);
+                break;
+        default:
+                err = -EINVAL;
+        }
+
+out:
+        mutex_unlock(&start_mutex);
+        return err;
+}
+#endif /* CONFIG_HAVE_HWSAMPLER */
+
 static int __init oprofile_init(void)
 {
         int err;
diff --git a/drivers/oprofile/oprof.h b/drivers/oprofile/oprof.h
index 177b73de5e5f..5a6ceb1954a2 100644
--- a/drivers/oprofile/oprof.h
+++ b/drivers/oprofile/oprof.h
@@ -35,7 +35,9 @@ struct dentry;
 
 void oprofile_create_files(struct super_block *sb, struct dentry *root);
 int oprofile_timer_init(struct oprofile_operations *ops);
+int __oprofile_timer_init(struct oprofile_operations *ops);
 void oprofile_timer_exit(void);
+void __oprofile_timer_exit(void);
 
 int oprofile_set_ulong(unsigned long *addr, unsigned long val);
 int oprofile_set_timeout(unsigned long time);
diff --git a/drivers/oprofile/timer_int.c b/drivers/oprofile/timer_int.c
index 010725117dbb..0099a458fd37 100644
--- a/drivers/oprofile/timer_int.c
+++ b/drivers/oprofile/timer_int.c
@@ -97,14 +97,13 @@ static struct notifier_block __refdata oprofile_cpu_notifier = {
         .notifier_call = oprofile_cpu_notify,
 };
 
-int __init oprofile_timer_init(struct oprofile_operations *ops)
+int  __oprofile_timer_init(struct oprofile_operations *ops)
 {
         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;
@@ -113,7 +112,17 @@ int __init oprofile_timer_init(struct oprofile_operations *ops)
         return 0;
 }
 
-void __exit oprofile_timer_exit(void)
+int __init oprofile_timer_init(struct oprofile_operations *ops)
+{
+        return __oprofile_timer_init(ops);
+}
+
+void __oprofile_timer_exit(void)
 {
         unregister_hotcpu_notifier(&oprofile_cpu_notifier);
 }
+
+void __exit oprofile_timer_exit(void)
+{
+        __oprofile_timer_exit();
+}