1 files changed, 75 insertions, 50 deletions

diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c
index 6509c61b9648..42c6f71bdcc1 100644
--- a/drivers/thermal/cpu_cooling.c
+++ b/drivers/thermal/cpu_cooling.c
@@ -68,7 +68,7 @@ struct power_table {
  *	registered cooling device.
  * @cpufreq_state: integer value representing the current state of cpufreq
  *	cooling	devices.
- * @cpufreq_val: integer value representing the absolute value of the clipped
+ * @clipped_freq: integer value representing the absolute value of the clipped
  *	frequency.
  * @max_level: maximum cooling level. One less than total number of valid
  *	cpufreq frequencies.
@@ -91,7 +91,7 @@ struct cpufreq_cooling_device {
 	int id;
 	struct thermal_cooling_device *cool_dev;
 	unsigned int cpufreq_state;
-	unsigned int cpufreq_val;
+	unsigned int clipped_freq;
 	unsigned int max_level;
 	unsigned int *freq_table;	/* In descending order */
 	struct cpumask allowed_cpus;
@@ -107,6 +107,9 @@ struct cpufreq_cooling_device {
 static DEFINE_IDR(cpufreq_idr);
 static DEFINE_MUTEX(cooling_cpufreq_lock);
 
+static unsigned int cpufreq_dev_count;
+
+static DEFINE_MUTEX(cooling_list_lock);
 static LIST_HEAD(cpufreq_dev_list);
 
 /**
@@ -185,14 +188,14 @@ unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq)
 {
 	struct cpufreq_cooling_device *cpufreq_dev;
 
-	mutex_lock(&cooling_cpufreq_lock);
+	mutex_lock(&cooling_list_lock);
 	list_for_each_entry(cpufreq_dev, &cpufreq_dev_list, node) {
 		if (cpumask_test_cpu(cpu, &cpufreq_dev->allowed_cpus)) {
-			mutex_unlock(&cooling_cpufreq_lock);
+			mutex_unlock(&cooling_list_lock);
 			return get_level(cpufreq_dev, freq);
 		}
 	}
-	mutex_unlock(&cooling_cpufreq_lock);
+	mutex_unlock(&cooling_list_lock);
 
 	pr_err("%s: cpu:%d not part of any cooling device\n", __func__, cpu);
 	return THERMAL_CSTATE_INVALID;
@@ -215,29 +218,35 @@ static int cpufreq_thermal_notifier(struct notifier_block *nb,
 				    unsigned long event, void *data)
 {
 	struct cpufreq_policy *policy = data;
-	unsigned long max_freq = 0;
+	unsigned long clipped_freq;
 	struct cpufreq_cooling_device *cpufreq_dev;
 
-	switch (event) {
+	if (event != CPUFREQ_ADJUST)
+		return NOTIFY_DONE;
 
-	case CPUFREQ_ADJUST:
-		mutex_lock(&cooling_cpufreq_lock);
-		list_for_each_entry(cpufreq_dev, &cpufreq_dev_list, node) {
-			if (!cpumask_test_cpu(policy->cpu,
-					      &cpufreq_dev->allowed_cpus))
-				continue;
+	mutex_lock(&cooling_list_lock);
+	list_for_each_entry(cpufreq_dev, &cpufreq_dev_list, node) {
+		if (!cpumask_test_cpu(policy->cpu, &cpufreq_dev->allowed_cpus))
+			continue;
 
-			max_freq = cpufreq_dev->cpufreq_val;
+		/*
+		 * policy->max is the maximum allowed frequency defined by user
+		 * and clipped_freq is the maximum that thermal constraints
+		 * allow.
+		 *
+		 * If clipped_freq is lower than policy->max, then we need to
+		 * readjust policy->max.
+		 *
+		 * But, if clipped_freq is greater than policy->max, we don't
+		 * need to do anything.
+		 */
+		clipped_freq = cpufreq_dev->clipped_freq;
 
-			if (policy->max != max_freq)
-				cpufreq_verify_within_limits(policy, 0,
-							     max_freq);
-		}
-		mutex_unlock(&cooling_cpufreq_lock);
+		if (policy->max > clipped_freq)
+			cpufreq_verify_within_limits(policy, 0, clipped_freq);
 		break;
-	default:
-		return NOTIFY_DONE;
 	}
+	mutex_unlock(&cooling_list_lock);
 
 	return NOTIFY_OK;
 }
@@ -253,7 +262,9 @@ static int cpufreq_thermal_notifier(struct notifier_block *nb,
  * efficiently.  Power is stored in mW, frequency in KHz.  The
  * resulting table is in ascending order.
  *
- * Return: 0 on success, -E* on error.
+ * Return: 0 on success, -EINVAL if there are no OPPs for any CPUs,
+ * -ENOMEM if we run out of memory or -EAGAIN if an OPP was
+ * added/enabled while the function was executing.
  */
 static int build_dyn_power_table(struct cpufreq_cooling_device *cpufreq_device,
 				 u32 capacitance)
@@ -264,8 +275,6 @@ static int build_dyn_power_table(struct cpufreq_cooling_device *cpufreq_device,
 	int num_opps = 0, cpu, i, ret = 0;
 	unsigned long freq;
 
-	rcu_read_lock();
-
 	for_each_cpu(cpu, &cpufreq_device->allowed_cpus) {
 		dev = get_cpu_device(cpu);
 		if (!dev) {
@@ -275,24 +284,20 @@ static int build_dyn_power_table(struct cpufreq_cooling_device *cpufreq_device,
 		}
 
 		num_opps = dev_pm_opp_get_opp_count(dev);
-		if (num_opps > 0) {
+		if (num_opps > 0)
 			break;
-		} else if (num_opps < 0) {
-			ret = num_opps;
-			goto unlock;
-		}
+		else if (num_opps < 0)
+			return num_opps;
 	}
 
-	if (num_opps == 0) {
-		ret = -EINVAL;
-		goto unlock;
-	}
+	if (num_opps == 0)
+		return -EINVAL;
 
 	power_table = kcalloc(num_opps, sizeof(*power_table), GFP_KERNEL);
-	if (!power_table) {
-		ret = -ENOMEM;
-		goto unlock;
-	}
+	if (!power_table)
+		return -ENOMEM;
+
+	rcu_read_lock();
 
 	for (freq = 0, i = 0;
 	     opp = dev_pm_opp_find_freq_ceil(dev, &freq), !IS_ERR(opp);
@@ -300,6 +305,12 @@ static int build_dyn_power_table(struct cpufreq_cooling_device *cpufreq_device,
 		u32 freq_mhz, voltage_mv;
 		u64 power;
 
+		if (i >= num_opps) {
+			rcu_read_unlock();
+			ret = -EAGAIN;
+			goto free_power_table;
+		}
+
 		freq_mhz = freq / 1000000;
 		voltage_mv = dev_pm_opp_get_voltage(opp) / 1000;
 
@@ -317,17 +328,22 @@ static int build_dyn_power_table(struct cpufreq_cooling_device *cpufreq_device,
 		power_table[i].power = power;
 	}
 
-	if (i == 0) {
+	rcu_read_unlock();
+
+	if (i != num_opps) {
 		ret = PTR_ERR(opp);
-		goto unlock;
+		goto free_power_table;
 	}
 
 	cpufreq_device->cpu_dev = dev;
 	cpufreq_device->dyn_power_table = power_table;
 	cpufreq_device->dyn_power_table_entries = i;
 
-unlock:
-	rcu_read_unlock();
+	return 0;
+
+free_power_table:
+	kfree(power_table);
+
 	return ret;
 }
 
@@ -519,7 +535,7 @@ static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev,
 
 	clip_freq = cpufreq_device->freq_table[state];
 	cpufreq_device->cpufreq_state = state;
-	cpufreq_device->cpufreq_val = clip_freq;
+	cpufreq_device->clipped_freq = clip_freq;
 
 	cpufreq_update_policy(cpu);
 
@@ -838,7 +854,7 @@ __cpufreq_cooling_register(struct device_node *np,
 	ret = get_idr(&cpufreq_idr, &cpufreq_dev->id);
 	if (ret) {
 		cool_dev = ERR_PTR(ret);
-		goto free_table;
+		goto free_power_table;
 	}
 
 	snprintf(dev_name, sizeof(dev_name), "thermal-cpufreq-%d",
@@ -861,23 +877,27 @@ __cpufreq_cooling_register(struct device_node *np,
 			pr_debug("%s: freq:%u KHz\n", __func__, freq);
 	}
 
-	cpufreq_dev->cpufreq_val = cpufreq_dev->freq_table[0];
+	cpufreq_dev->clipped_freq = cpufreq_dev->freq_table[0];
 	cpufreq_dev->cool_dev = cool_dev;
 
 	mutex_lock(&cooling_cpufreq_lock);
 
+	mutex_lock(&cooling_list_lock);
+	list_add(&cpufreq_dev->node, &cpufreq_dev_list);
+	mutex_unlock(&cooling_list_lock);
+
 	/* Register the notifier for first cpufreq cooling device */
-	if (list_empty(&cpufreq_dev_list))
+	if (!cpufreq_dev_count++)
 		cpufreq_register_notifier(&thermal_cpufreq_notifier_block,
 					  CPUFREQ_POLICY_NOTIFIER);
-	list_add(&cpufreq_dev->node, &cpufreq_dev_list);
-
 	mutex_unlock(&cooling_cpufreq_lock);
 
 	return cool_dev;
 
 remove_idr:
 	release_idr(&cpufreq_idr, cpufreq_dev->id);
+free_power_table:
+	kfree(cpufreq_dev->dyn_power_table);
 free_table:
 	kfree(cpufreq_dev->freq_table);
 free_time_in_idle_timestamp:
@@ -1013,17 +1033,22 @@ void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)
 		return;
 
 	cpufreq_dev = cdev->devdata;
-	mutex_lock(&cooling_cpufreq_lock);
-	list_del(&cpufreq_dev->node);
 
 	/* Unregister the notifier for the last cpufreq cooling device */
-	if (list_empty(&cpufreq_dev_list))
+	mutex_lock(&cooling_cpufreq_lock);
+	if (!--cpufreq_dev_count)
 		cpufreq_unregister_notifier(&thermal_cpufreq_notifier_block,
 					    CPUFREQ_POLICY_NOTIFIER);
+
+	mutex_lock(&cooling_list_lock);
+	list_del(&cpufreq_dev->node);
+	mutex_unlock(&cooling_list_lock);
+
 	mutex_unlock(&cooling_cpufreq_lock);
 
 	thermal_cooling_device_unregister(cpufreq_dev->cool_dev);
 	release_idr(&cpufreq_idr, cpufreq_dev->id);
+	kfree(cpufreq_dev->dyn_power_table);
 	kfree(cpufreq_dev->time_in_idle_timestamp);
 	kfree(cpufreq_dev->time_in_idle);
 	kfree(cpufreq_dev->freq_table);