Merge branch 'pm-domains'

* pm-domains:
  PM / Domains: Fix computation of maximum domain off time
  PM / Domains: Fix link checking when add subdomain
  PM / Domains: Cache device stop and domain power off governor results, v3
  PM / Domains: Make device removal more straightforward
  PM / QoS: Create device constraints objects on notifier registration
  PM / Runtime: Remove device fields related to suspend time, v2
  PM / Domains: Rework default domain power off governor function, v2
  PM / Domains: Rework default device stop governor function, v2

drivers/base/power/domain.c

@@ -11,6 +11,7 @@
 #include <linux/io.h>
 #include <linux/pm_runtime.h>
 #include <linux/pm_domain.h>
+#include <linux/pm_qos.h>
 #include <linux/slab.h>
 #include <linux/err.h>
 #include <linux/sched.h>
@@ -38,11 +39,13 @@
 	ktime_t __start = ktime_get();						\
 	type __retval = GENPD_DEV_CALLBACK(genpd, type, callback, dev);		\
 	s64 __elapsed = ktime_to_ns(ktime_sub(ktime_get(), __start));		\
-	struct generic_pm_domain_data *__gpd_data = dev_gpd_data(dev);		\
-	if (__elapsed > __gpd_data->td.field) {					\
-		__gpd_data->td.field = __elapsed;				\
+	struct gpd_timing_data *__td = &dev_gpd_data(dev)->td;			\
+	if (!__retval && __elapsed > __td->field) {				\
+		__td->field = __elapsed;					\
 		dev_warn(dev, name " latency exceeded, new value %lld ns\n",	\
 			__elapsed);						\
+		genpd->max_off_time_changed = true;				\
+		__td->constraint_changed = true;				\
 	}									\
 	__retval;								\
 })
@@ -211,6 +214,7 @@ int __pm_genpd_poweron(struct generic_pm_domain *genpd)
 		elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
 		if (elapsed_ns > genpd->power_on_latency_ns) {
 			genpd->power_on_latency_ns = elapsed_ns;
+			genpd->max_off_time_changed = true;
 			if (genpd->name)
 				pr_warning("%s: Power-on latency exceeded, "
 					"new value %lld ns\n", genpd->name,
@@ -247,6 +251,53 @@ int pm_genpd_poweron(struct generic_pm_domain *genpd)
 
 #ifdef CONFIG_PM_RUNTIME
 
+static int genpd_dev_pm_qos_notifier(struct notifier_block *nb,
+				     unsigned long val, void *ptr)
+{
+	struct generic_pm_domain_data *gpd_data;
+	struct device *dev;
+
+	gpd_data = container_of(nb, struct generic_pm_domain_data, nb);
+
+	mutex_lock(&gpd_data->lock);
+	dev = gpd_data->base.dev;
+	if (!dev) {
+		mutex_unlock(&gpd_data->lock);
+		return NOTIFY_DONE;
+	}
+	mutex_unlock(&gpd_data->lock);
+
+	for (;;) {
+		struct generic_pm_domain *genpd;
+		struct pm_domain_data *pdd;
+
+		spin_lock_irq(&dev->power.lock);
+
+		pdd = dev->power.subsys_data ?
+				dev->power.subsys_data->domain_data : NULL;
+		if (pdd) {
+			to_gpd_data(pdd)->td.constraint_changed = true;
+			genpd = dev_to_genpd(dev);
+		} else {
+			genpd = ERR_PTR(-ENODATA);
+		}
+
+		spin_unlock_irq(&dev->power.lock);
+
+		if (!IS_ERR(genpd)) {
+			mutex_lock(&genpd->lock);
+			genpd->max_off_time_changed = true;
+			mutex_unlock(&genpd->lock);
+		}
+
+		dev = dev->parent;
+		if (!dev || dev->power.ignore_children)
+			break;
+	}
+
+	return NOTIFY_DONE;
+}
+
 /**
  * __pm_genpd_save_device - Save the pre-suspend state of a device.
  * @pdd: Domain data of the device to save the state of.
@@ -435,6 +486,7 @@ static int pm_genpd_poweroff(struct generic_pm_domain *genpd)
 		elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
 		if (elapsed_ns > genpd->power_off_latency_ns) {
 			genpd->power_off_latency_ns = elapsed_ns;
+			genpd->max_off_time_changed = true;
 			if (genpd->name)
 				pr_warning("%s: Power-off latency exceeded, "
 					"new value %lld ns\n", genpd->name,
@@ -443,17 +495,6 @@ static int pm_genpd_poweroff(struct generic_pm_domain *genpd)
 	}
 
 	genpd->status = GPD_STATE_POWER_OFF;
-	genpd->power_off_time = ktime_get();
-
-	/* Update PM QoS information for devices in the domain. */
-	list_for_each_entry_reverse(pdd, &genpd->dev_list, list_node) {
-		struct gpd_timing_data *td = &to_gpd_data(pdd)->td;
-
-		pm_runtime_update_max_time_suspended(pdd->dev,
-					td->start_latency_ns +
-					td->restore_state_latency_ns +
-					genpd->power_on_latency_ns);
-	}
 
 	list_for_each_entry(link, &genpd->slave_links, slave_node) {
 		genpd_sd_counter_dec(link->master);
@@ -514,9 +555,6 @@ static int pm_genpd_runtime_suspend(struct device *dev)
 	if (ret)
 		return ret;
 
-	pm_runtime_update_max_time_suspended(dev,
-				dev_gpd_data(dev)->td.start_latency_ns);
-
 	/*
 	 * If power.irq_safe is set, this routine will be run with interrupts
 	 * off, so it can't use mutexes.
@@ -613,6 +651,12 @@ void pm_genpd_poweroff_unused(void)
 
 #else
 
+static inline int genpd_dev_pm_qos_notifier(struct notifier_block *nb,
+					    unsigned long val, void *ptr)
+{
+	return NOTIFY_DONE;
+}
+
 static inline void genpd_power_off_work_fn(struct work_struct *work) {}
 
 #define pm_genpd_runtime_suspend	NULL
@@ -1209,6 +1253,14 @@ int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
 	if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev))
 		return -EINVAL;
 
+	gpd_data = kzalloc(sizeof(*gpd_data), GFP_KERNEL);
+	if (!gpd_data)
+		return -ENOMEM;
+
+	mutex_init(&gpd_data->lock);
+	gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier;
+	dev_pm_qos_add_notifier(dev, &gpd_data->nb);
+
 	genpd_acquire_lock(genpd);
 
 	if (genpd->status == GPD_STATE_POWER_OFF) {
@@ -1227,26 +1279,35 @@ int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
 			goto out;
 		}
 
-	gpd_data = kzalloc(sizeof(*gpd_data), GFP_KERNEL);
-	if (!gpd_data) {
-		ret = -ENOMEM;
-		goto out;
-	}
-
 	genpd->device_count++;
+	genpd->max_off_time_changed = true;
 
-	dev->pm_domain = &genpd->domain;
 	dev_pm_get_subsys_data(dev);
+
+	mutex_lock(&gpd_data->lock);
+	spin_lock_irq(&dev->power.lock);
+	dev->pm_domain = &genpd->domain;
 	dev->power.subsys_data->domain_data = &gpd_data->base;
 	gpd_data->base.dev = dev;
-	gpd_data->need_restore = false;
 	list_add_tail(&gpd_data->base.list_node, &genpd->dev_list);
+	gpd_data->need_restore = false;
 	if (td)
 		gpd_data->td = *td;
 
+	gpd_data->td.constraint_changed = true;
+	gpd_data->td.effective_constraint_ns = -1;
+	spin_unlock_irq(&dev->power.lock);
+	mutex_unlock(&gpd_data->lock);
+
+	genpd_release_lock(genpd);
+
+	return 0;
+
  out:
 	genpd_release_lock(genpd);
 
+	dev_pm_qos_remove_notifier(dev, &gpd_data->nb);
+	kfree(gpd_data);
 	return ret;
 }
 
@@ -1290,12 +1351,15 @@ int __pm_genpd_of_add_device(struct device_node *genpd_node, struct device *dev,
 int pm_genpd_remove_device(struct generic_pm_domain *genpd,
 			   struct device *dev)
 {
+	struct generic_pm_domain_data *gpd_data;
 	struct pm_domain_data *pdd;
-	int ret = -EINVAL;
+	int ret = 0;
 
 	dev_dbg(dev, "%s()\n", __func__);
 
-	if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev))
+	if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev)
+	    ||  IS_ERR_OR_NULL(dev->pm_domain)
+	    ||  pd_to_genpd(dev->pm_domain) != genpd)
 		return -EINVAL;
 
 	genpd_acquire_lock(genpd);
@@ -1305,21 +1369,27 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd,
 		goto out;
 	}
 
-	list_for_each_entry(pdd, &genpd->dev_list, list_node) {
-		if (pdd->dev != dev)
-			continue;
+	genpd->device_count--;
+	genpd->max_off_time_changed = true;
 
+	spin_lock_irq(&dev->power.lock);
+	dev->pm_domain = NULL;
+	pdd = dev->power.subsys_data->domain_data;
 	list_del_init(&pdd->list_node);
+	dev->power.subsys_data->domain_data = NULL;
+	spin_unlock_irq(&dev->power.lock);
+
+	gpd_data = to_gpd_data(pdd);
+	mutex_lock(&gpd_data->lock);
 	pdd->dev = NULL;
-		dev_pm_put_subsys_data(dev);
-		dev->pm_domain = NULL;
-		kfree(to_gpd_data(pdd));
+	mutex_unlock(&gpd_data->lock);
 
-		genpd->device_count--;
+	genpd_release_lock(genpd);
 
-		ret = 0;
-		break;
-	}
+	dev_pm_qos_remove_notifier(dev, &gpd_data->nb);
+	kfree(gpd_data);
+	dev_pm_put_subsys_data(dev);
+	return 0;
 
  out:
 	genpd_release_lock(genpd);
@@ -1378,7 +1448,7 @@ int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
 		goto out;
 	}
 
-	list_for_each_entry(link, &genpd->slave_links, slave_node) {
+	list_for_each_entry(link, &genpd->master_links, master_node) {
 		if (link->slave == subdomain && link->master == genpd) {
 			ret = -EINVAL;
 			goto out;
@@ -1690,6 +1760,7 @@ void pm_genpd_init(struct generic_pm_domain *genpd,
 	genpd->resume_count = 0;
 	genpd->device_count = 0;
 	genpd->max_off_time_ns = -1;
+	genpd->max_off_time_changed = true;
 	genpd->domain.ops.runtime_suspend = pm_genpd_runtime_suspend;
 	genpd->domain.ops.runtime_resume = pm_genpd_runtime_resume;
 	genpd->domain.ops.runtime_idle = pm_generic_runtime_idle;

drivers/base/power/domain_governor.c

@@ -14,6 +14,31 @@
 
 #ifdef CONFIG_PM_RUNTIME
 
+static int dev_update_qos_constraint(struct device *dev, void *data)
+{
+	s64 *constraint_ns_p = data;
+	s32 constraint_ns = -1;
+
+	if (dev->power.subsys_data && dev->power.subsys_data->domain_data)
+		constraint_ns = dev_gpd_data(dev)->td.effective_constraint_ns;
+
+	if (constraint_ns < 0) {
+		constraint_ns = dev_pm_qos_read_value(dev);
+		constraint_ns *= NSEC_PER_USEC;
+	}
+	if (constraint_ns == 0)
+		return 0;
+
+	/*
+	 * constraint_ns cannot be negative here, because the device has been
+	 * suspended.
+	 */
+	if (constraint_ns < *constraint_ns_p || *constraint_ns_p == 0)
+		*constraint_ns_p = constraint_ns;
+
+	return 0;
+}
+
 /**
  * default_stop_ok - Default PM domain governor routine for stopping devices.
  * @dev: Device to check.
@@ -21,14 +46,52 @@
 bool default_stop_ok(struct device *dev)
 {
 	struct gpd_timing_data *td = &dev_gpd_data(dev)->td;
+	unsigned long flags;
+	s64 constraint_ns;
 
 	dev_dbg(dev, "%s()\n", __func__);
 
-	if (dev->power.max_time_suspended_ns < 0 || td->break_even_ns == 0)
-		return true;
+	spin_lock_irqsave(&dev->power.lock, flags);
+
+	if (!td->constraint_changed) {
+		bool ret = td->cached_stop_ok;
 
-	return td->stop_latency_ns + td->start_latency_ns < td->break_even_ns
-		&& td->break_even_ns < dev->power.max_time_suspended_ns;
+		spin_unlock_irqrestore(&dev->power.lock, flags);
+		return ret;
+	}
+	td->constraint_changed = false;
+	td->cached_stop_ok = false;
+	td->effective_constraint_ns = -1;
+	constraint_ns = __dev_pm_qos_read_value(dev);
+
+	spin_unlock_irqrestore(&dev->power.lock, flags);
+
+	if (constraint_ns < 0)
+		return false;
+
+	constraint_ns *= NSEC_PER_USEC;
+	/*
+	 * We can walk the children without any additional locking, because
+	 * they all have been suspended at this point and their
+	 * effective_constraint_ns fields won't be modified in parallel with us.
+	 */
+	if (!dev->power.ignore_children)
+		device_for_each_child(dev, &constraint_ns,
+				      dev_update_qos_constraint);
+
+	if (constraint_ns > 0) {
+		constraint_ns -= td->start_latency_ns;
+		if (constraint_ns == 0)
+			return false;
+	}
+	td->effective_constraint_ns = constraint_ns;
+	td->cached_stop_ok = constraint_ns > td->stop_latency_ns ||
+				constraint_ns == 0;
+	/*
+	 * The children have been suspended already, so we don't need to take
+	 * their stop latencies into account here.
+	 */
+	return td->cached_stop_ok;
 }
 
 /**
@@ -42,9 +105,27 @@ static bool default_power_down_ok(struct dev_pm_domain *pd)
 	struct generic_pm_domain *genpd = pd_to_genpd(pd);
 	struct gpd_link *link;
 	struct pm_domain_data *pdd;
-	s64 min_dev_off_time_ns;
+	s64 min_off_time_ns;
 	s64 off_on_time_ns;
-	ktime_t time_now = ktime_get();
+
+	if (genpd->max_off_time_changed) {
+		struct gpd_link *link;
+
+		/*
+		 * We have to invalidate the cached results for the masters, so
+		 * use the observation that default_power_down_ok() is not
+		 * going to be called for any master until this instance
+		 * returns.
+		 */
+		list_for_each_entry(link, &genpd->slave_links, slave_node)
+			link->master->max_off_time_changed = true;
+
+		genpd->max_off_time_changed = false;
+		genpd->cached_power_down_ok = false;
+		genpd->max_off_time_ns = -1;
+	} else {
+		return genpd->cached_power_down_ok;
+	}
 
 	off_on_time_ns = genpd->power_off_latency_ns +
 				genpd->power_on_latency_ns;
@@ -61,6 +142,7 @@ static bool default_power_down_ok(struct dev_pm_domain *pd)
 				to_gpd_data(pdd)->td.save_state_latency_ns;
 	}
 
+	min_off_time_ns = -1;
 	/*
 	 * Check if subdomains can be off for enough time.
 	 *
@@ -73,8 +155,6 @@ static bool default_power_down_ok(struct dev_pm_domain *pd)
 		if (sd_max_off_ns < 0)
 			continue;
 
-		sd_max_off_ns -= ktime_to_ns(ktime_sub(time_now,
-						       sd->power_off_time));
 		/*
 		 * Check if the subdomain is allowed to be off long enough for
 		 * the current domain to turn off and on (that's how much time
@@ -82,60 +162,64 @@ static bool default_power_down_ok(struct dev_pm_domain *pd)
 		 */
 		if (sd_max_off_ns <= off_on_time_ns)
 			return false;
+
+		if (min_off_time_ns > sd_max_off_ns || min_off_time_ns < 0)
+			min_off_time_ns = sd_max_off_ns;
 	}
 
 	/*
 	 * Check if the devices in the domain can be off enough time.
 	 */
-	min_dev_off_time_ns = -1;
 	list_for_each_entry(pdd, &genpd->dev_list, list_node) {
 		struct gpd_timing_data *td;
-		struct device *dev = pdd->dev;
-		s64 dev_off_time_ns;
+		s64 constraint_ns;
 
-		if (!dev->driver || dev->power.max_time_suspended_ns < 0)
+		if (!pdd->dev->driver)
 			continue;
 
+		/*
+		 * Check if the device is allowed to be off long enough for the
+		 * domain to turn off and on (that's how much time it will
+		 * have to wait worst case).
+		 */
 		td = &to_gpd_data(pdd)->td;
-		dev_off_time_ns = dev->power.max_time_suspended_ns -
-			(td->start_latency_ns + td->restore_state_latency_ns +
-				ktime_to_ns(ktime_sub(time_now,
-						dev->power.suspend_time)));
-		if (dev_off_time_ns <= off_on_time_ns)
-			return false;
-
-		if (min_dev_off_time_ns > dev_off_time_ns
-		    || min_dev_off_time_ns < 0)
-			min_dev_off_time_ns = dev_off_time_ns;
+		constraint_ns = td->effective_constraint_ns;
+		/* default_stop_ok() need not be called before us. */
+		if (constraint_ns < 0) {
+			constraint_ns = dev_pm_qos_read_value(pdd->dev);
+			constraint_ns *= NSEC_PER_USEC;
 		}
+		if (constraint_ns == 0)
+			continue;
 
-	if (min_dev_off_time_ns < 0) {
 		/*
-		 * There are no latency constraints, so the domain can spend
-		 * arbitrary time in the "off" state.
+		 * constraint_ns cannot be negative here, because the device has
+		 * been suspended.
 		 */
-		genpd->max_off_time_ns = -1;
-		return true;
+		constraint_ns -= td->restore_state_latency_ns;
+		if (constraint_ns <= off_on_time_ns)
+			return false;
+
+		if (min_off_time_ns > constraint_ns || min_off_time_ns < 0)
+			min_off_time_ns = constraint_ns;
 	}
 
+	genpd->cached_power_down_ok = true;
+
 	/*
-	 * The difference between the computed minimum delta and the time needed
-	 * to turn the domain on is the maximum theoretical time this domain can
-	 * spend in the "off" state.
+	 * If the computed minimum device off time is negative, there are no
+	 * latency constraints, so the domain can spend arbitrary time in the
+	 * "off" state.
 	 */
-	min_dev_off_time_ns -= genpd->power_on_latency_ns;
+	if (min_off_time_ns < 0)
+		return true;
 
 	/*
-	 * If the difference between the computed minimum delta and the time
-	 * needed to turn the domain off and back on on is smaller than the
-	 * domain's power break even time, removing power from the domain is not
-	 * worth it.
+	 * The difference between the computed minimum subdomain or device off
+	 * time and the time needed to turn the domain on is the maximum
+	 * theoretical time this domain can spend in the "off" state.
 	 */
-	if (genpd->break_even_ns >
-	    min_dev_off_time_ns - genpd->power_off_latency_ns)
-		return false;
-
-	genpd->max_off_time_ns = min_dev_off_time_ns;
+	genpd->max_off_time_ns = min_off_time_ns - genpd->power_on_latency_ns;
 	return true;
 }
 

drivers/base/power/qos.c

@@ -352,21 +352,26 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_remove_request);
  *
  * Will register the notifier into a notification chain that gets called
  * upon changes to the target value for the device.
+ *
+ * If the device's constraints object doesn't exist when this routine is called,
+ * it will be created (or error code will be returned if that fails).
  */
 int dev_pm_qos_add_notifier(struct device *dev, struct notifier_block *notifier)
 {
-	int retval = 0;
+	int ret = 0;
 
 	mutex_lock(&dev_pm_qos_mtx);
 
-	/* Silently return if the constraints object is not present. */
-	if (dev->power.constraints)
-		retval = blocking_notifier_chain_register(
-				dev->power.constraints->notifiers,
-				notifier);
+	if (!dev->power.constraints)
+		ret = dev->power.power_state.event != PM_EVENT_INVALID ?
+			dev_pm_qos_constraints_allocate(dev) : -ENODEV;
+
+	if (!ret)
+		ret = blocking_notifier_chain_register(
+				dev->power.constraints->notifiers, notifier);
 
 	mutex_unlock(&dev_pm_qos_mtx);
-	return retval;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(dev_pm_qos_add_notifier);
 

drivers/base/power/runtime.c

@@ -282,47 +282,6 @@ static int rpm_callback(int (*cb)(struct device *), struct device *dev)
 	return retval != -EACCES ? retval : -EIO;
 }
 
-struct rpm_qos_data {
-	ktime_t time_now;
-	s64 constraint_ns;
-};
-
-/**
- * rpm_update_qos_constraint - Update a given PM QoS constraint data.
- * @dev: Device whose timing data to use.
- * @data: PM QoS constraint data to update.
- *
- * Use the suspend timing data of @dev to update PM QoS constraint data pointed
- * to by @data.
- */
-static int rpm_update_qos_constraint(struct device *dev, void *data)
-{
-	struct rpm_qos_data *qos = data;
-	unsigned long flags;
-	s64 delta_ns;
-	int ret = 0;
-
-	spin_lock_irqsave(&dev->power.lock, flags);
-
-	if (dev->power.max_time_suspended_ns < 0)
-		goto out;
-
-	delta_ns = dev->power.max_time_suspended_ns -
-		ktime_to_ns(ktime_sub(qos->time_now, dev->power.suspend_time));
-	if (delta_ns <= 0) {
-		ret = -EBUSY;
-		goto out;
-	}
-
-	if (qos->constraint_ns > delta_ns || qos->constraint_ns == 0)
-		qos->constraint_ns = delta_ns;
-
- out:
-	spin_unlock_irqrestore(&dev->power.lock, flags);
-
-	return ret;
-}
-
 /**
  * rpm_suspend - Carry out runtime suspend of given device.
  * @dev: Device to suspend.
@@ -349,7 +308,6 @@ static int rpm_suspend(struct device *dev, int rpmflags)
 {
 	int (*callback)(struct device *);
 	struct device *parent = NULL;
-	struct rpm_qos_data qos;
 	int retval;
 
 	trace_rpm_suspend(dev, rpmflags);
@@ -445,38 +403,14 @@ static int rpm_suspend(struct device *dev, int rpmflags)
 		goto out;
 	}
 
-	qos.constraint_ns = __dev_pm_qos_read_value(dev);
-	if (qos.constraint_ns < 0) {
-		/* Negative constraint means "never suspend". */
+	if (__dev_pm_qos_read_value(dev) < 0) {
+		/* Negative PM QoS constraint means "never suspend". */
 		retval = -EPERM;
 		goto out;
 	}
-	qos.constraint_ns *= NSEC_PER_USEC;
-	qos.time_now = ktime_get();
 
 	__update_runtime_status(dev, RPM_SUSPENDING);
 
-	if (!dev->power.ignore_children) {
-		if (dev->power.irq_safe)
-			spin_unlock(&dev->power.lock);
-		else
-			spin_unlock_irq(&dev->power.lock);
-
-		retval = device_for_each_child(dev, &qos,
-					       rpm_update_qos_constraint);
-
-		if (dev->power.irq_safe)
-			spin_lock(&dev->power.lock);
-		else
-			spin_lock_irq(&dev->power.lock);
-
-		if (retval)
-			goto fail;
-	}
-
-	dev->power.suspend_time = qos.time_now;
-	dev->power.max_time_suspended_ns = qos.constraint_ns ? : -1;
-
 	if (dev->pm_domain)
 		callback = dev->pm_domain->ops.runtime_suspend;
 	else if (dev->type && dev->type->pm)
@@ -529,8 +463,6 @@ static int rpm_suspend(struct device *dev, int rpmflags)
 
  fail:
 	__update_runtime_status(dev, RPM_ACTIVE);
-	dev->power.suspend_time = ktime_set(0, 0);
-	dev->power.max_time_suspended_ns = -1;
 	dev->power.deferred_resume = false;
 	wake_up_all(&dev->power.wait_queue);
 
@@ -704,9 +636,6 @@ static int rpm_resume(struct device *dev, int rpmflags)
 	if (dev->power.no_callbacks)
 		goto no_callback;	/* Assume success. */
 
-	dev->power.suspend_time = ktime_set(0, 0);
-	dev->power.max_time_suspended_ns = -1;
-
 	__update_runtime_status(dev, RPM_RESUMING);
 
 	if (dev->pm_domain)
@@ -1369,9 +1298,6 @@ void pm_runtime_init(struct device *dev)
 	setup_timer(&dev->power.suspend_timer, pm_suspend_timer_fn,
 			(unsigned long)dev);
 
-	dev->power.suspend_time = ktime_set(0, 0);
-	dev->power.max_time_suspended_ns = -1;
-
 	init_waitqueue_head(&dev->power.wait_queue);
 }
 
@@ -1389,28 +1315,3 @@ void pm_runtime_remove(struct device *dev)
 	if (dev->power.irq_safe && dev->parent)
 		pm_runtime_put_sync(dev->parent);
 }
-
-/**
- * pm_runtime_update_max_time_suspended - Update device's suspend time data.
- * @dev: Device to handle.
- * @delta_ns: Value to subtract from the device's max_time_suspended_ns field.
- *
- * Update the device's power.max_time_suspended_ns field by subtracting
- * @delta_ns from it.  The resulting value of power.max_time_suspended_ns is
- * never negative.
- */
-void pm_runtime_update_max_time_suspended(struct device *dev, s64 delta_ns)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&dev->power.lock, flags);
-
-	if (delta_ns > 0 && dev->power.max_time_suspended_ns > 0) {
-		if (dev->power.max_time_suspended_ns > delta_ns)
-			dev->power.max_time_suspended_ns -= delta_ns;
-		else
-			dev->power.max_time_suspended_ns = 0;
-	}
-
-	spin_unlock_irqrestore(&dev->power.lock, flags);
-}

include/linux/pm.h

@@ -544,8 +544,6 @@ struct dev_pm_info {
 	unsigned long		active_jiffies;
 	unsigned long		suspended_jiffies;
 	unsigned long		accounting_timestamp;
-	ktime_t			suspend_time;
-	s64			max_time_suspended_ns;
 	struct dev_pm_qos_request *pq_req;
 #endif
 	struct pm_subsys_data	*subsys_data;  /* Owned by the subsystem. */

include/linux/pm_domain.h

@@ -14,6 +14,7 @@
 #include <linux/pm.h>
 #include <linux/err.h>
 #include <linux/of.h>
+#include <linux/notifier.h>
 
 enum gpd_status {
 	GPD_STATE_ACTIVE = 0,	/* PM domain is active */
@@ -70,9 +71,9 @@ struct generic_pm_domain {
 	int (*power_on)(struct generic_pm_domain *domain);
 	s64 power_on_latency_ns;
 	struct gpd_dev_ops dev_ops;
-	s64 break_even_ns;	/* Power break even for the entire domain. */
 	s64 max_off_time_ns;	/* Maximum allowed "suspended" time. */
-	ktime_t power_off_time;
+	bool max_off_time_changed;
+	bool cached_power_down_ok;
 	struct device_node *of_node; /* Node in device tree */
 };
 
@@ -93,13 +94,17 @@ struct gpd_timing_data {
 	s64 start_latency_ns;
 	s64 save_state_latency_ns;
 	s64 restore_state_latency_ns;
-	s64 break_even_ns;
+	s64 effective_constraint_ns;
+	bool constraint_changed;
+	bool cached_stop_ok;
 };
 
 struct generic_pm_domain_data {
 	struct pm_domain_data base;
 	struct gpd_dev_ops ops;
 	struct gpd_timing_data td;
+	struct notifier_block nb;
+	struct mutex lock;
 	bool need_restore;
 	bool always_on;
 };

include/linux/pm_runtime.h

@@ -150,9 +150,6 @@ static inline void pm_runtime_set_autosuspend_delay(struct device *dev,
 static inline unsigned long pm_runtime_autosuspend_expiration(
 				struct device *dev) { return 0; }
 
-static inline void pm_runtime_update_max_time_suspended(struct device *dev,
-							s64 delta_ns) {}
-
 #endif /* !CONFIG_PM_RUNTIME */
 
 static inline int pm_runtime_idle(struct device *dev)