PM: domains: Move the next_wakeup variable into the struct gpd_timing_data

If the corresponding genpd for the device doesn't use a governor, the
variable next_wakeup within the struct generic_pm_domain_data becomes
superfluous.

To avoid wasting memory, let's move it into the struct gpd_timing_data,
which is already being allocated based upon if there is governor assigned.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: Ulf Hansson

drivers/base/power/domain.c

@@ -478,15 +478,16 @@ EXPORT_SYMBOL_GPL(dev_pm_genpd_set_performance_state);
  */
 void dev_pm_genpd_set_next_wakeup(struct device *dev, ktime_t next)
 {
-	struct generic_pm_domain_data *gpd_data;
 	struct generic_pm_domain *genpd;
+	struct gpd_timing_data *td;
 
 	genpd = dev_to_genpd_safe(dev);
 	if (!genpd)
 		return;
 
-	gpd_data = to_gpd_data(dev->power.subsys_data->domain_data);
-	gpd_data->next_wakeup = next;
+	td = to_gpd_data(dev->power.subsys_data->domain_data)->td;
+	if (td)
+		td->next_wakeup = next;
 }
 EXPORT_SYMBOL_GPL(dev_pm_genpd_set_next_wakeup);
 
@@ -1518,7 +1519,6 @@ static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev,
 
 	gpd_data->base.dev = dev;
 	gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier;
-	gpd_data->next_wakeup = KTIME_MAX;
 
 	/* Allocate data used by a governor. */
 	if (has_governor) {
@@ -1530,6 +1530,7 @@ static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev,
 
 		td->constraint_changed = true;
 		td->effective_constraint_ns = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS;
+		td->next_wakeup = KTIME_MAX;
 		gpd_data->td = td;
 	}
 

drivers/base/power/domain_governor.c

@@ -139,7 +139,7 @@ static void update_domain_next_wakeup(struct generic_pm_domain *genpd, ktime_t n
 	 * is able to enter its optimal idle state.
 	 */
 	list_for_each_entry(pdd, &genpd->dev_list, list_node) {
-		next_wakeup = to_gpd_data(pdd)->next_wakeup;
+		next_wakeup = to_gpd_data(pdd)->td->next_wakeup;
 		if (next_wakeup != KTIME_MAX && !ktime_before(next_wakeup, now))
 			if (ktime_before(next_wakeup, domain_wakeup))
 				domain_wakeup = next_wakeup;

include/linux/pm_domain.h

@@ -182,6 +182,7 @@ struct gpd_timing_data {
 	s64 suspend_latency_ns;
 	s64 resume_latency_ns;
 	s64 effective_constraint_ns;
+	ktime_t	next_wakeup;
 	bool constraint_changed;
 	bool cached_suspend_ok;
 };
@@ -200,7 +201,6 @@ struct generic_pm_domain_data {
 	unsigned int performance_state;
 	unsigned int default_pstate;
 	unsigned int rpm_pstate;
-	ktime_t	next_wakeup;
 	void *data;
 };