oprofile, s390: Rework hwsampler implementation

This patch is a rework of the hwsampler oprofile implementation that
has been applied recently. Now there are less non-architectural
changes. The only changes are:

* introduction of oprofile_add_ext_hw_sample(), and
* removal of section attributes of oprofile_timer_init/_exit().

To setup hwsampler for oprofile we need to modify start()/stop()
callbacks and additional hwsampler control files in oprofilefs. We do
not reinitialize the timer or hwsampler mode by restarting calling
init/exit() anymore, instead hwsampler_running is used to switch the
mode directly in oprofile_hwsampler_start/_stop(). For locking reasons
there is also hwsampler_file that reflects the value in oprofilefs.

The overall diffstat of the oprofile s390 hwsampler implemenation
shows the low impact to non-architectural code:

 arch/Kconfig                         |    3 +
 arch/s390/Kconfig                    |    1 +
 arch/s390/oprofile/Makefile          |    2 +-
 arch/s390/oprofile/hwsampler.c       | 1256 ++++++++++++++++++++++++++++++++++
 arch/s390/oprofile/hwsampler.h       |  113 +++
 arch/s390/oprofile/hwsampler_files.c |  162 +++++
 arch/s390/oprofile/init.c            |    6 +-
 drivers/oprofile/cpu_buffer.c        |   24 +-
 drivers/oprofile/timer_int.c         |    4 +-
 include/linux/oprofile.h             |    7 +
 10 files changed, 1567 insertions(+), 11 deletions(-)

Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>

3 files changed, 3 insertions, 46 deletions

diff --git a/drivers/oprofile/oprof.c b/drivers/oprofile/oprof.c
index 43b01daa91e1..f9bda64fcd1b 100644
--- a/drivers/oprofile/oprof.c
+++ b/drivers/oprofile/oprof.c
@@ -239,38 +239,6 @@ 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 5a6ceb1954a2..177b73de5e5f 100644
--- a/drivers/oprofile/oprof.h
+++ b/drivers/oprofile/oprof.h
@@ -35,9 +35,7 @@ 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 0099a458fd37..3ef44624f510 100644
--- a/drivers/oprofile/timer_int.c
+++ b/drivers/oprofile/timer_int.c
@@ -97,13 +97,14 @@ static struct notifier_block __refdata oprofile_cpu_notifier = {
         .notifier_call = oprofile_cpu_notify,
 };
 
-int  __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;
@@ -112,17 +113,7 @@ int  __oprofile_timer_init(struct oprofile_operations *ops)
         return 0;
 }
 
-int __init oprofile_timer_init(struct oprofile_operations *ops)
-{
-        return __oprofile_timer_init(ops);
-}
-
-void __oprofile_timer_exit(void)
+void oprofile_timer_exit(void)
 {
         unregister_hotcpu_notifier(&oprofile_cpu_notifier);
 }
-
-void __exit oprofile_timer_exit(void)
-{
-        __oprofile_timer_exit();
-}