cpuidle: refactor out cpuidle_enter_state

Split the code to enter a state and update the stats into a helper
function, cpuidle_enter_state, and export it.  This function will
be called by the coupled state code to handle entering the safe
state and the final coupled state.

Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Colin Cross <ccross@android.com>
Reviewed-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/cpuidle/cpuidle.c

@@ -102,6 +102,34 @@ int cpuidle_play_dead(void)
 	return -ENODEV;
 }
 
+/**
+ * cpuidle_enter_state - enter the state and update stats
+ * @dev: cpuidle device for this cpu
+ * @drv: cpuidle driver for this cpu
+ * @next_state: index into drv->states of the state to enter
+ */
+int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
+		int next_state)
+{
+	int entered_state;
+
+	entered_state = cpuidle_enter_ops(dev, drv, next_state);
+
+	if (entered_state >= 0) {
+		/* Update cpuidle counters */
+		/* This can be moved to within driver enter routine
+		 * but that results in multiple copies of same code.
+		 */
+		dev->states_usage[entered_state].time +=
+				(unsigned long long)dev->last_residency;
+		dev->states_usage[entered_state].usage++;
+	} else {
+		dev->last_residency = 0;
+	}
+
+	return entered_state;
+}
+
 /**
  * cpuidle_idle_call - the main idle loop
  *
@@ -143,23 +171,11 @@ int cpuidle_idle_call(void)
 	trace_power_start_rcuidle(POWER_CSTATE, next_state, dev->cpu);
 	trace_cpu_idle_rcuidle(next_state, dev->cpu);
 
-	entered_state = cpuidle_enter_ops(dev, drv, next_state);
+	entered_state = cpuidle_enter_state(dev, drv, next_state);
 
 	trace_power_end_rcuidle(dev->cpu);
 	trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu);
 
-	if (entered_state >= 0) {
-		/* Update cpuidle counters */
-		/* This can be moved to within driver enter routine
-		 * but that results in multiple copies of same code.
-		 */
-		dev->states_usage[entered_state].time +=
-				(unsigned long long)dev->last_residency;
-		dev->states_usage[entered_state].usage++;
-	} else {
-		dev->last_residency = 0;
-	}
-
 	/* give the governor an opportunity to reflect on the outcome */
 	if (cpuidle_curr_governor->reflect)
 		cpuidle_curr_governor->reflect(dev, entered_state);

drivers/cpuidle/cpuidle.h

@@ -14,6 +14,8 @@ extern struct list_head cpuidle_detected_devices;
 extern struct mutex cpuidle_lock;
 extern spinlock_t cpuidle_driver_lock;
 extern int cpuidle_disabled(void);
+extern int cpuidle_enter_state(struct cpuidle_device *dev,
+		struct cpuidle_driver *drv, int next_state);
 
 /* idle loop */
 extern void cpuidle_install_idle_handler(void);