1 files changed, 205 insertions, 124 deletions

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 5db704f02e71..6471b559230e 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -131,7 +131,7 @@ static const struct genpd_lock_ops genpd_spin_ops = {
 #define genpd_is_cpu_domain(genpd)	(genpd->flags & GENPD_FLAG_CPU_DOMAIN)
 #define genpd_is_rpm_always_on(genpd)	(genpd->flags & GENPD_FLAG_RPM_ALWAYS_ON)
 
-static inline bool irq_safe_dev_in_no_sleep_domain(struct device *dev,
+static inline bool irq_safe_dev_in_sleep_domain(struct device *dev,
 		const struct generic_pm_domain *genpd)
 {
 	bool ret;
@@ -139,11 +139,14 @@ static inline bool irq_safe_dev_in_no_sleep_domain(struct device *dev,
 	ret = pm_runtime_is_irq_safe(dev) && !genpd_is_irq_safe(genpd);
 
 	/*
-	 * Warn once if an IRQ safe device is attached to a no sleep domain, as
-	 * to indicate a suboptimal configuration for PM. For an always on
-	 * domain this isn't case, thus don't warn.
+	 * Warn once if an IRQ safe device is attached to a domain, which
+	 * callbacks are allowed to sleep. This indicates a suboptimal
+	 * configuration for PM, but it doesn't matter for an always on domain.
 	 */
-	if (ret && !genpd_is_always_on(genpd))
+	if (genpd_is_always_on(genpd) || genpd_is_rpm_always_on(genpd))
+		return ret;
+
+	if (ret)
 		dev_warn_once(dev, "PM domain %s will not be powered off\n",
 				genpd->name);
 
@@ -219,30 +222,32 @@ static void genpd_debug_remove(struct generic_pm_domain *genpd)
 {
 	struct dentry *d;
 
+	if (!genpd_debugfs_dir)
+		return;
+
 	d = debugfs_lookup(genpd->name, genpd_debugfs_dir);
 	debugfs_remove(d);
 }
 
 static void genpd_update_accounting(struct generic_pm_domain *genpd)
 {
-	ktime_t delta, now;
+	u64 delta, now;
+
+	now = ktime_get_mono_fast_ns();
+	if (now <= genpd->accounting_time)
+		return;
 
-	now = ktime_get();
-	delta = ktime_sub(now, genpd->accounting_time);
+	delta = now - genpd->accounting_time;
 
 	/*
 	 * If genpd->status is active, it means we are just
 	 * out of off and so update the idle time and vice
 	 * versa.
 	 */
-	if (genpd->status == GENPD_STATE_ON) {
-		int state_idx = genpd->state_idx;
-
-		genpd->states[state_idx].idle_time =
-			ktime_add(genpd->states[state_idx].idle_time, delta);
-	} else {
-		genpd->on_time = ktime_add(genpd->on_time, delta);
-	}
+	if (genpd->status == GENPD_STATE_ON)
+		genpd->states[genpd->state_idx].idle_time += delta;
+	else
+		genpd->on_time += delta;
 
 	genpd->accounting_time = now;
 }
@@ -476,15 +481,16 @@ 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);
 
@@ -506,6 +512,7 @@ static int _genpd_power_on(struct generic_pm_domain *genpd, bool timed)
 	if (!genpd->power_on)
 		goto out;
 
+	timed = timed && genpd->gd && !genpd->states[state_idx].fwnode;
 	if (!timed) {
 		ret = genpd->power_on(genpd);
 		if (ret)
@@ -524,7 +531,7 @@ static int _genpd_power_on(struct generic_pm_domain *genpd, bool timed)
 		goto out;
 
 	genpd->states[state_idx].power_on_latency_ns = elapsed_ns;
-	genpd->max_off_time_changed = true;
+	genpd->gd->max_off_time_changed = true;
 	pr_debug("%s: Power-%s latency exceeded, new value %lld ns\n",
 		 genpd->name, "on", elapsed_ns);
 
@@ -555,6 +562,7 @@ static int _genpd_power_off(struct generic_pm_domain *genpd, bool timed)
 	if (!genpd->power_off)
 		goto out;
 
+	timed = timed && genpd->gd && !genpd->states[state_idx].fwnode;
 	if (!timed) {
 		ret = genpd->power_off(genpd);
 		if (ret)
@@ -573,7 +581,7 @@ static int _genpd_power_off(struct generic_pm_domain *genpd, bool timed)
 		goto out;
 
 	genpd->states[state_idx].power_off_latency_ns = elapsed_ns;
-	genpd->max_off_time_changed = true;
+	genpd->gd->max_off_time_changed = true;
 	pr_debug("%s: Power-%s latency exceeded, new value %lld ns\n",
 		 genpd->name, "off", elapsed_ns);
 
@@ -636,19 +644,25 @@ static int genpd_power_off(struct generic_pm_domain *genpd, bool one_dev_on,
 			atomic_read(&genpd->sd_count) > 0)
 		return -EBUSY;
 
-	list_for_each_entry(pdd, &genpd->dev_list, list_node) {
-		enum pm_qos_flags_status stat;
-
-		stat = dev_pm_qos_flags(pdd->dev, PM_QOS_FLAG_NO_POWER_OFF);
-		if (stat > PM_QOS_FLAGS_NONE)
+	/*
+	 * The children must be in their deepest (powered-off) states to allow
+	 * the parent to be powered off. Note that, there's no need for
+	 * additional locking, as powering on a child, requires the parent's
+	 * lock to be acquired first.
+	 */
+	list_for_each_entry(link, &genpd->parent_links, parent_node) {
+		struct generic_pm_domain *child = link->child;
+		if (child->state_idx < child->state_count - 1)
 			return -EBUSY;
+	}
 
+	list_for_each_entry(pdd, &genpd->dev_list, list_node) {
 		/*
 		 * Do not allow PM domain to be powered off, when an IRQ safe
 		 * device is part of a non-IRQ safe domain.
 		 */
 		if (!pm_runtime_suspended(pdd->dev) ||
-			irq_safe_dev_in_no_sleep_domain(pdd->dev, genpd))
+			irq_safe_dev_in_sleep_domain(pdd->dev, genpd))
 			not_suspended++;
 	}
 
@@ -763,25 +777,27 @@ static int genpd_dev_pm_qos_notifier(struct notifier_block *nb,
 	dev = gpd_data->base.dev;
 
 	for (;;) {
-		struct generic_pm_domain *genpd;
+		struct generic_pm_domain *genpd = ERR_PTR(-ENODATA);
 		struct pm_domain_data *pdd;
+		struct gpd_timing_data *td;
 
 		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);
+			td = to_gpd_data(pdd)->td;
+			if (td) {
+				td->constraint_changed = true;
+				genpd = dev_to_genpd(dev);
+			}
 		}
 
 		spin_unlock_irq(&dev->power.lock);
 
 		if (!IS_ERR(genpd)) {
 			genpd_lock(genpd);
-			genpd->max_off_time_changed = true;
+			genpd->gd->max_off_time_changed = true;
 			genpd_unlock(genpd);
 		}
 
@@ -867,9 +883,9 @@ static int genpd_runtime_suspend(struct device *dev)
 	struct generic_pm_domain *genpd;
 	bool (*suspend_ok)(struct device *__dev);
 	struct generic_pm_domain_data *gpd_data = dev_gpd_data(dev);
-	struct gpd_timing_data *td = &gpd_data->td;
+	struct gpd_timing_data *td = gpd_data->td;
 	bool runtime_pm = pm_runtime_enabled(dev);
-	ktime_t time_start;
+	ktime_t time_start = 0;
 	s64 elapsed_ns;
 	int ret;
 
@@ -890,8 +906,7 @@ static int genpd_runtime_suspend(struct device *dev)
 		return -EBUSY;
 
 	/* Measure suspend latency. */
-	time_start = 0;
-	if (runtime_pm)
+	if (td && runtime_pm)
 		time_start = ktime_get();
 
 	ret = __genpd_runtime_suspend(dev);
@@ -905,13 +920,13 @@ static int genpd_runtime_suspend(struct device *dev)
 	}
 
 	/* Update suspend latency value if the measured time exceeds it. */
-	if (runtime_pm) {
+	if (td && runtime_pm) {
 		elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
 		if (elapsed_ns > td->suspend_latency_ns) {
 			td->suspend_latency_ns = elapsed_ns;
 			dev_dbg(dev, "suspend latency exceeded, %lld ns\n",
 				elapsed_ns);
-			genpd->max_off_time_changed = true;
+			genpd->gd->max_off_time_changed = true;
 			td->constraint_changed = true;
 		}
 	}
@@ -920,7 +935,7 @@ static int genpd_runtime_suspend(struct device *dev)
 	 * If power.irq_safe is set, this routine may be run with
 	 * IRQs disabled, so suspend only if the PM domain also is irq_safe.
 	 */
-	if (irq_safe_dev_in_no_sleep_domain(dev, genpd))
+	if (irq_safe_dev_in_sleep_domain(dev, genpd))
 		return 0;
 
 	genpd_lock(genpd);
@@ -943,12 +958,11 @@ static int genpd_runtime_resume(struct device *dev)
 {
 	struct generic_pm_domain *genpd;
 	struct generic_pm_domain_data *gpd_data = dev_gpd_data(dev);
-	struct gpd_timing_data *td = &gpd_data->td;
-	bool runtime_pm = pm_runtime_enabled(dev);
-	ktime_t time_start;
+	struct gpd_timing_data *td = gpd_data->td;
+	bool timed = td && pm_runtime_enabled(dev);
+	ktime_t time_start = 0;
 	s64 elapsed_ns;
 	int ret;
-	bool timed = true;
 
 	dev_dbg(dev, "%s()\n", __func__);
 
@@ -960,10 +974,8 @@ static int genpd_runtime_resume(struct device *dev)
 	 * As we don't power off a non IRQ safe domain, which holds
 	 * an IRQ safe device, we don't need to restore power to it.
 	 */
-	if (irq_safe_dev_in_no_sleep_domain(dev, genpd)) {
-		timed = false;
+	if (irq_safe_dev_in_sleep_domain(dev, genpd))
 		goto out;
-	}
 
 	genpd_lock(genpd);
 	ret = genpd_power_on(genpd, 0);
@@ -976,8 +988,7 @@ static int genpd_runtime_resume(struct device *dev)
 
  out:
 	/* Measure resume latency. */
-	time_start = 0;
-	if (timed && runtime_pm)
+	if (timed)
 		time_start = ktime_get();
 
 	ret = genpd_start_dev(genpd, dev);
@@ -989,13 +1000,13 @@ static int genpd_runtime_resume(struct device *dev)
 		goto err_stop;
 
 	/* Update resume latency value if the measured time exceeds it. */
-	if (timed && runtime_pm) {
+	if (timed) {
 		elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
 		if (elapsed_ns > td->resume_latency_ns) {
 			td->resume_latency_ns = elapsed_ns;
 			dev_dbg(dev, "resume latency exceeded, %lld ns\n",
 				elapsed_ns);
-			genpd->max_off_time_changed = true;
+			genpd->gd->max_off_time_changed = true;
 			td->constraint_changed = true;
 		}
 	}
@@ -1073,6 +1084,13 @@ static void genpd_sync_power_off(struct generic_pm_domain *genpd, bool use_lock,
 	    || atomic_read(&genpd->sd_count) > 0)
 		return;
 
+	/* Check that the children are in their deepest (powered-off) state. */
+	list_for_each_entry(link, &genpd->parent_links, parent_node) {
+		struct generic_pm_domain *child = link->child;
+		if (child->state_idx < child->state_count - 1)
+			return;
+	}
+
 	/* Choose the deepest state when suspending */
 	genpd->state_idx = genpd->state_count - 1;
 	if (_genpd_power_off(genpd, false))
@@ -1481,9 +1499,11 @@ EXPORT_SYMBOL_GPL(dev_pm_genpd_resume);
 
 #endif /* CONFIG_PM_SLEEP */
 
-static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev)
+static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev,
+							   bool has_governor)
 {
 	struct generic_pm_domain_data *gpd_data;
+	struct gpd_timing_data *td;
 	int ret;
 
 	ret = dev_pm_get_subsys_data(dev);
@@ -1497,26 +1517,38 @@ static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev)
 	}
 
 	gpd_data->base.dev = dev;
-	gpd_data->td.constraint_changed = true;
-	gpd_data->td.effective_constraint_ns = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS;
 	gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier;
-	gpd_data->next_wakeup = KTIME_MAX;
 
-	spin_lock_irq(&dev->power.lock);
+	/* Allocate data used by a governor. */
+	if (has_governor) {
+		td = kzalloc(sizeof(*td), GFP_KERNEL);
+		if (!td) {
+			ret = -ENOMEM;
+			goto err_free;
+		}
 
-	if (dev->power.subsys_data->domain_data) {
-		ret = -EINVAL;
-		goto err_free;
+		td->constraint_changed = true;
+		td->effective_constraint_ns = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS;
+		td->next_wakeup = KTIME_MAX;
+		gpd_data->td = td;
 	}
 
-	dev->power.subsys_data->domain_data = &gpd_data->base;
+	spin_lock_irq(&dev->power.lock);
+
+	if (dev->power.subsys_data->domain_data)
+		ret = -EINVAL;
+	else
+		dev->power.subsys_data->domain_data = &gpd_data->base;
 
 	spin_unlock_irq(&dev->power.lock);
 
+	if (ret)
+		goto err_free;
+
 	return gpd_data;
 
  err_free:
-	spin_unlock_irq(&dev->power.lock);
+	kfree(gpd_data->td);
 	kfree(gpd_data);
  err_put:
 	dev_pm_put_subsys_data(dev);
@@ -1532,6 +1564,7 @@ static void genpd_free_dev_data(struct device *dev,
 
 	spin_unlock_irq(&dev->power.lock);
 
+	kfree(gpd_data->td);
 	kfree(gpd_data);
 	dev_pm_put_subsys_data(dev);
 }
@@ -1588,6 +1621,7 @@ static int genpd_get_cpu(struct generic_pm_domain *genpd, struct device *dev)
 static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
 			    struct device *base_dev)
 {
+	struct genpd_governor_data *gd = genpd->gd;
 	struct generic_pm_domain_data *gpd_data;
 	int ret;
 
@@ -1596,7 +1630,7 @@ static int 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 = genpd_alloc_dev_data(dev);
+	gpd_data = genpd_alloc_dev_data(dev, gd);
 	if (IS_ERR(gpd_data))
 		return PTR_ERR(gpd_data);
 
@@ -1612,7 +1646,8 @@ static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
 	dev_pm_domain_set(dev, &genpd->domain);
 
 	genpd->device_count++;
-	genpd->max_off_time_changed = true;
+	if (gd)
+		gd->max_off_time_changed = true;
 
 	list_add_tail(&gpd_data->base.list_node, &genpd->dev_list);
 
@@ -1666,7 +1701,8 @@ static int genpd_remove_device(struct generic_pm_domain *genpd,
 	}
 
 	genpd->device_count--;
-	genpd->max_off_time_changed = true;
+	if (genpd->gd)
+		genpd->gd->max_off_time_changed = true;
 
 	genpd_clear_cpumask(genpd, gpd_data->cpu);
 	dev_pm_domain_set(dev, NULL);
@@ -1939,6 +1975,53 @@ static int genpd_set_default_power_state(struct generic_pm_domain *genpd)
 	return 0;
 }
 
+static int genpd_alloc_data(struct generic_pm_domain *genpd)
+{
+	struct genpd_governor_data *gd = NULL;
+	int ret;
+
+	if (genpd_is_cpu_domain(genpd) &&
+	    !zalloc_cpumask_var(&genpd->cpus, GFP_KERNEL))
+		return -ENOMEM;
+
+	if (genpd->gov) {
+		gd = kzalloc(sizeof(*gd), GFP_KERNEL);
+		if (!gd) {
+			ret = -ENOMEM;
+			goto free;
+		}
+
+		gd->max_off_time_ns = -1;
+		gd->max_off_time_changed = true;
+		gd->next_wakeup = KTIME_MAX;
+	}
+
+	/* Use only one "off" state if there were no states declared */
+	if (genpd->state_count == 0) {
+		ret = genpd_set_default_power_state(genpd);
+		if (ret)
+			goto free;
+	}
+
+	genpd->gd = gd;
+	return 0;
+
+free:
+	if (genpd_is_cpu_domain(genpd))
+		free_cpumask_var(genpd->cpus);
+	kfree(gd);
+	return ret;
+}
+
+static void genpd_free_data(struct generic_pm_domain *genpd)
+{
+	if (genpd_is_cpu_domain(genpd))
+		free_cpumask_var(genpd->cpus);
+	if (genpd->free_states)
+		genpd->free_states(genpd->states, genpd->state_count);
+	kfree(genpd->gd);
+}
+
 static void genpd_lock_init(struct generic_pm_domain *genpd)
 {
 	if (genpd->flags & GENPD_FLAG_IRQ_SAFE) {
@@ -1976,11 +2059,9 @@ int pm_genpd_init(struct generic_pm_domain *genpd,
 	atomic_set(&genpd->sd_count, 0);
 	genpd->status = is_off ? GENPD_STATE_OFF : GENPD_STATE_ON;
 	genpd->device_count = 0;
-	genpd->max_off_time_ns = -1;
-	genpd->max_off_time_changed = true;
 	genpd->provider = NULL;
 	genpd->has_provider = false;
-	genpd->accounting_time = ktime_get();
+	genpd->accounting_time = ktime_get_mono_fast_ns();
 	genpd->domain.ops.runtime_suspend = genpd_runtime_suspend;
 	genpd->domain.ops.runtime_resume = genpd_runtime_resume;
 	genpd->domain.ops.prepare = genpd_prepare;
@@ -1998,26 +2079,24 @@ int pm_genpd_init(struct generic_pm_domain *genpd,
 		genpd->dev_ops.start = pm_clk_resume;
 	}
 
+	/* The always-on governor works better with the corresponding flag. */
+	if (gov == &pm_domain_always_on_gov)
+		genpd->flags |= GENPD_FLAG_RPM_ALWAYS_ON;
+
 	/* Always-on domains must be powered on at initialization. */
 	if ((genpd_is_always_on(genpd) || genpd_is_rpm_always_on(genpd)) &&
-			!genpd_status_on(genpd))
+			!genpd_status_on(genpd)) {
+		pr_err("always-on PM domain %s is not on\n", genpd->name);
 		return -EINVAL;
+	}
 
-	if (genpd_is_cpu_domain(genpd) &&
-	    !zalloc_cpumask_var(&genpd->cpus, GFP_KERNEL))
-		return -ENOMEM;
-
-	/* Use only one "off" state if there were no states declared */
-	if (genpd->state_count == 0) {
-		ret = genpd_set_default_power_state(genpd);
-		if (ret) {
-			if (genpd_is_cpu_domain(genpd))
-				free_cpumask_var(genpd->cpus);
-			return ret;
-		}
-	} else if (!gov && genpd->state_count > 1) {
+	/* Multiple states but no governor doesn't make sense. */
+	if (!gov && genpd->state_count > 1)
 		pr_warn("%s: no governor for states\n", genpd->name);
-	}
+
+	ret = genpd_alloc_data(genpd);
+	if (ret)
+		return ret;
 
 	device_initialize(&genpd->dev);
 	dev_set_name(&genpd->dev, "%s", genpd->name);
@@ -2058,14 +2137,11 @@ static int genpd_remove(struct generic_pm_domain *genpd)
 		kfree(link);
 	}
 
-	genpd_debug_remove(genpd);
 	list_del(&genpd->gpd_list_node);
 	genpd_unlock(genpd);
+	genpd_debug_remove(genpd);
 	cancel_work_sync(&genpd->power_off_work);
-	if (genpd_is_cpu_domain(genpd))
-		free_cpumask_var(genpd->cpus);
-	if (genpd->free_states)
-		genpd->free_states(genpd->states, genpd->state_count);
+	genpd_free_data(genpd);
 
 	pr_debug("%s: removed %s\n", __func__, genpd->name);
 
@@ -2248,12 +2324,8 @@ int of_genpd_add_provider_simple(struct device_node *np,
 	/* Parse genpd OPP table */
 	if (genpd->set_performance_state) {
 		ret = dev_pm_opp_of_add_table(&genpd->dev);
-		if (ret) {
-			if (ret != -EPROBE_DEFER)
-				dev_err(&genpd->dev, "Failed to add OPP table: %d\n",
-					ret);
-			return ret;
-		}
+		if (ret)
+			return dev_err_probe(&genpd->dev, ret, "Failed to add OPP table\n");
 
 		/*
 		 * Save table for faster processing while setting performance
@@ -2312,9 +2384,8 @@ int of_genpd_add_provider_onecell(struct device_node *np,
 		if (genpd->set_performance_state) {
 			ret = dev_pm_opp_of_add_table_indexed(&genpd->dev, i);
 			if (ret) {
-				if (ret != -EPROBE_DEFER)
-					dev_err(&genpd->dev, "Failed to add OPP table for index %d: %d\n",
-						i, ret);
+				dev_err_probe(&genpd->dev, ret,
+					      "Failed to add OPP table for index %d\n", i);
 				goto error;
 			}
 
@@ -2672,12 +2743,8 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,
 	ret = genpd_add_device(pd, dev, base_dev);
 	mutex_unlock(&gpd_list_lock);
 
-	if (ret < 0) {
-		if (ret != -EPROBE_DEFER)
-			dev_err(dev, "failed to add to PM domain %s: %d",
-				pd->name, ret);
-		return ret;
-	}
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "failed to add to PM domain %s\n", pd->name);
 
 	dev->pm_domain->detach = genpd_dev_pm_detach;
 	dev->pm_domain->sync = genpd_dev_pm_sync;
@@ -2885,6 +2952,10 @@ static int genpd_iterate_idle_states(struct device_node *dn,
 		np = it.node;
 		if (!of_match_node(idle_state_match, np))
 			continue;
+
+		if (!of_device_is_available(np))
+			continue;
+
 		if (states) {
 			ret = genpd_parse_state(&states[i], np);
 			if (ret) {
@@ -3153,6 +3224,7 @@ static int sub_domains_show(struct seq_file *s, void *data)
 static int idle_states_show(struct seq_file *s, void *data)
 {
 	struct generic_pm_domain *genpd = s->private;
+	u64 now, delta, idle_time = 0;
 	unsigned int i;
 	int ret = 0;
 
@@ -3163,17 +3235,19 @@ static int idle_states_show(struct seq_file *s, void *data)
 	seq_puts(s, "State          Time Spent(ms) Usage          Rejected\n");
 
 	for (i = 0; i < genpd->state_count; i++) {
-		ktime_t delta = 0;
-		s64 msecs;
+		idle_time += genpd->states[i].idle_time;
 
-		if ((genpd->status == GENPD_STATE_OFF) &&
-				(genpd->state_idx == i))
-			delta = ktime_sub(ktime_get(), genpd->accounting_time);
+		if (genpd->status == GENPD_STATE_OFF && genpd->state_idx == i) {
+			now = ktime_get_mono_fast_ns();
+			if (now > genpd->accounting_time) {
+				delta = now - genpd->accounting_time;
+				idle_time += delta;
+			}
+		}
 
-		msecs = ktime_to_ms(
-			ktime_add(genpd->states[i].idle_time, delta));
-		seq_printf(s, "S%-13i %-14lld %-14llu %llu\n", i, msecs,
-			      genpd->states[i].usage, genpd->states[i].rejected);
+		do_div(idle_time, NSEC_PER_MSEC);
+		seq_printf(s, "S%-13i %-14llu %-14llu %llu\n", i, idle_time,
+			   genpd->states[i].usage, genpd->states[i].rejected);
 	}
 
 	genpd_unlock(genpd);
@@ -3183,18 +3257,22 @@ static int idle_states_show(struct seq_file *s, void *data)
 static int active_time_show(struct seq_file *s, void *data)
 {
 	struct generic_pm_domain *genpd = s->private;
-	ktime_t delta = 0;
+	u64 now, on_time, delta = 0;
 	int ret = 0;
 
 	ret = genpd_lock_interruptible(genpd);
 	if (ret)
 		return -ERESTARTSYS;
 
-	if (genpd->status == GENPD_STATE_ON)
-		delta = ktime_sub(ktime_get(), genpd->accounting_time);
+	if (genpd->status == GENPD_STATE_ON) {
+		now = ktime_get_mono_fast_ns();
+		if (now > genpd->accounting_time)
+			delta = now - genpd->accounting_time;
+	}
 
-	seq_printf(s, "%lld ms\n", ktime_to_ms(
-				ktime_add(genpd->on_time, delta)));
+	on_time = genpd->on_time + delta;
+	do_div(on_time, NSEC_PER_MSEC);
+	seq_printf(s, "%llu ms\n", on_time);
 
 	genpd_unlock(genpd);
 	return ret;
@@ -3203,7 +3281,7 @@ static int active_time_show(struct seq_file *s, void *data)
 static int total_idle_time_show(struct seq_file *s, void *data)
 {
 	struct generic_pm_domain *genpd = s->private;
-	ktime_t delta = 0, total = 0;
+	u64 now, delta, total = 0;
 	unsigned int i;
 	int ret = 0;
 
@@ -3212,16 +3290,19 @@ static int total_idle_time_show(struct seq_file *s, void *data)
 		return -ERESTARTSYS;
 
 	for (i = 0; i < genpd->state_count; i++) {
+		total += genpd->states[i].idle_time;
 
-		if ((genpd->status == GENPD_STATE_OFF) &&
-				(genpd->state_idx == i))
-			delta = ktime_sub(ktime_get(), genpd->accounting_time);
-
-		total = ktime_add(total, genpd->states[i].idle_time);
+		if (genpd->status == GENPD_STATE_OFF && genpd->state_idx == i) {
+			now = ktime_get_mono_fast_ns();
+			if (now > genpd->accounting_time) {
+				delta = now - genpd->accounting_time;
+				total += delta;
+			}
+		}
 	}
-	total = ktime_add(total, delta);
 
-	seq_printf(s, "%lld ms\n", ktime_to_ms(total));
+	do_div(total, NSEC_PER_MSEC);
+	seq_printf(s, "%llu ms\n", total);
 
 	genpd_unlock(genpd);
 	return ret;