[RFC PATCH 2/4] cpuidle: Add Active Stats calls tracking idle entry/exit

[Lukasz Luba <lukasz.luba@arm.com>]

The Active Stats framework tracks and accounts the activity of the CPU
for each performance level. It accounts the real residency, when the CPU
was not idle, at a given performance level. This patch adds needed calls
which provide the CPU idle entry/exit events to the Active Stats
framework.

Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
---
 drivers/cpuidle/cpuidle.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index ef2ea1b12cd8..24a33c6c4a62 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -8,6 +8,7 @@
  * This code is licenced under the GPL.
  */
 
+#include <linux/active_stats.h>
 #include <linux/clockchips.h>
 #include <linux/kernel.h>
 #include <linux/mutex.h>
@@ -231,6 +232,8 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
 	trace_cpu_idle(index, dev->cpu);
 	time_start = ns_to_ktime(local_clock());
 
+	active_stats_cpu_idle_enter(time_start);
+
 	stop_critical_timings();
 	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE))
 		rcu_idle_enter();
@@ -243,6 +246,8 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
 	time_end = ns_to_ktime(local_clock());
 	trace_cpu_idle(PWR_EVENT_EXIT, dev->cpu);
 
+	active_stats_cpu_idle_exit(time_end);
+
 	/* The cpu is no longer idle or about to enter idle. */
 	sched_idle_set_state(NULL);
 
-- 
2.17.1