governors: unify last_state_idx

Since this field is shared by all governors, move it to
cpuidle device structure.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpuidle/governors/ladder.c

@@ -38,7 +38,6 @@ struct ladder_device_state {
 
 struct ladder_device {
 	struct ladder_device_state states[CPUIDLE_STATE_MAX];
-	int last_state_idx;
 };
 
 static DEFINE_PER_CPU(struct ladder_device, ladder_devices);
@@ -49,12 +48,13 @@ static DEFINE_PER_CPU(struct ladder_device, ladder_devices);
  * @old_idx: the current state index
  * @new_idx: the new target state index
  */
-static inline void ladder_do_selection(struct ladder_device *ldev,
+static inline void ladder_do_selection(struct cpuidle_device *dev,
+				       struct ladder_device *ldev,
 				       int old_idx, int new_idx)
 {
 	ldev->states[old_idx].stats.promotion_count = 0;
 	ldev->states[old_idx].stats.demotion_count = 0;
-	ldev->last_state_idx = new_idx;
+	dev->last_state_idx = new_idx;
 }
 
 /**
@@ -68,13 +68,13 @@ static int ladder_select_state(struct cpuidle_driver *drv,
 {
 	struct ladder_device *ldev = this_cpu_ptr(&ladder_devices);
 	struct ladder_device_state *last_state;
-	int last_residency, last_idx = ldev->last_state_idx;
+	int last_residency, last_idx = dev->last_state_idx;
 	int first_idx = drv->states[0].flags & CPUIDLE_FLAG_POLLING ? 1 : 0;
 	int latency_req = cpuidle_governor_latency_req(dev->cpu);
 
 	/* Special case when user has set very strict latency requirement */
 	if (unlikely(latency_req == 0)) {
-		ladder_do_selection(ldev, last_idx, 0);
+		ladder_do_selection(dev, ldev, last_idx, 0);
 		return 0;
 	}
 
@@ -91,7 +91,7 @@ static int ladder_select_state(struct cpuidle_driver *drv,
 		last_state->stats.promotion_count++;
 		last_state->stats.demotion_count = 0;
 		if (last_state->stats.promotion_count >= last_state->threshold.promotion_count) {
-			ladder_do_selection(ldev, last_idx, last_idx + 1);
+			ladder_do_selection(dev, ldev, last_idx, last_idx + 1);
 			return last_idx + 1;
 		}
 	}
@@ -107,7 +107,7 @@ static int ladder_select_state(struct cpuidle_driver *drv,
 			if (drv->states[i].exit_latency <= latency_req)
 				break;
 		}
-		ladder_do_selection(ldev, last_idx, i);
+		ladder_do_selection(dev, ldev, last_idx, i);
 		return i;
 	}
 
@@ -116,7 +116,7 @@ static int ladder_select_state(struct cpuidle_driver *drv,
 		last_state->stats.demotion_count++;
 		last_state->stats.promotion_count = 0;
 		if (last_state->stats.demotion_count >= last_state->threshold.demotion_count) {
-			ladder_do_selection(ldev, last_idx, last_idx - 1);
+			ladder_do_selection(dev, ldev, last_idx, last_idx - 1);
 			return last_idx - 1;
 		}
 	}
@@ -139,7 +139,7 @@ static int ladder_enable_device(struct cpuidle_driver *drv,
 	struct ladder_device_state *lstate;
 	struct cpuidle_state *state;
 
-	ldev->last_state_idx = first_idx;
+	dev->last_state_idx = first_idx;
 
 	for (i = first_idx; i < drv->state_count; i++) {
 		state = &drv->states[i];
@@ -167,9 +167,8 @@ static int ladder_enable_device(struct cpuidle_driver *drv,
  */
 static void ladder_reflect(struct cpuidle_device *dev, int index)
 {
-	struct ladder_device *ldev = this_cpu_ptr(&ladder_devices);
 	if (index > 0)
-		ldev->last_state_idx = index;
+		dev->last_state_idx = index;
 }
 
 static struct cpuidle_governor ladder_governor = {

drivers/cpuidle/governors/menu.c

@@ -117,7 +117,6 @@
  */
 
 struct menu_device {
-	int		last_state_idx;
 	int             needs_update;
 	int             tick_wakeup;
 
@@ -455,7 +454,7 @@ static void menu_reflect(struct cpuidle_device *dev, int index)
 {
 	struct menu_device *data = this_cpu_ptr(&menu_devices);
 
-	data->last_state_idx = index;
+	dev->last_state_idx = index;
 	data->needs_update = 1;
 	data->tick_wakeup = tick_nohz_idle_got_tick();
 }
@@ -468,7 +467,7 @@ static void menu_reflect(struct cpuidle_device *dev, int index)
 static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 {
 	struct menu_device *data = this_cpu_ptr(&menu_devices);
-	int last_idx = data->last_state_idx;
+	int last_idx = dev->last_state_idx;
 	struct cpuidle_state *target = &drv->states[last_idx];
 	unsigned int measured_us;
 	unsigned int new_factor;

drivers/cpuidle/governors/teo.c

@@ -96,7 +96,6 @@ struct teo_idle_state {
  * @time_span_ns: Time between idle state selection and post-wakeup update.
  * @sleep_length_ns: Time till the closest timer event (at the selection time).
  * @states: Idle states data corresponding to this CPU.
- * @last_state: Idle state entered by the CPU last time.
  * @interval_idx: Index of the most recent saved idle interval.
  * @intervals: Saved idle duration values.
  */
@@ -104,7 +103,6 @@ struct teo_cpu {
 	u64 time_span_ns;
 	u64 sleep_length_ns;
 	struct teo_idle_state states[CPUIDLE_STATE_MAX];
-	int last_state;
 	int interval_idx;
 	unsigned int intervals[INTERVALS];
 };
@@ -130,7 +128,9 @@ static void teo_update(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 		 */
 		measured_us = sleep_length_us;
 	} else {
-		unsigned int lat = drv->states[cpu_data->last_state].exit_latency;
+		unsigned int lat;
+
+		lat = drv->states[dev->last_state_idx].exit_latency;
 
 		measured_us = ktime_to_us(cpu_data->time_span_ns);
 		/*
@@ -245,9 +245,9 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
 	int max_early_idx, idx, i;
 	ktime_t delta_tick;
 
-	if (cpu_data->last_state >= 0) {
+	if (dev->last_state_idx >= 0) {
 		teo_update(drv, dev);
-		cpu_data->last_state = -1;
+		dev->last_state_idx = -1;
 	}
 
 	cpu_data->time_span_ns = local_clock();
@@ -394,7 +394,7 @@ static void teo_reflect(struct cpuidle_device *dev, int state)
 {
 	struct teo_cpu *cpu_data = per_cpu_ptr(&teo_cpus, dev->cpu);
 
-	cpu_data->last_state = state;
+	dev->last_state_idx = state;
 	/*
 	 * If the wakeup was not "natural", but triggered by one of the safety
 	 * nets, assume that the CPU might have been idle for the entire sleep

include/linux/cpuidle.h

@@ -85,6 +85,7 @@ struct cpuidle_device {
 	unsigned int		cpu;
 	ktime_t			next_hrtimer;
 
+	int			last_state_idx;
 	int			last_residency;
 	u64			poll_limit_ns;
 	struct cpuidle_state_usage	states_usage[CPUIDLE_STATE_MAX];