cpufreq: Register notifiers with the PM QoS framework
Register notifiers for min/max frequency constraints with the PM QoS
framework. The constraints are also taken into consideration in
cpufreq_set_policy().
This also relocates cpufreq_policy_put_kobj() as it is required to be
called from cpufreq_policy_alloc() now.
refresh_frequency_limits() is updated to avoid calling
cpufreq_set_policy() for inactive policies and handle_update() is
updated to have proper locking in place.
No constraints are added until now though.
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index ceb57af..b96ef6d 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -26,6 +26,7 @@
#include <linux/kernel_stat.h>
#include <linux/module.h>
#include <linux/mutex.h>
+#include <linux/pm_qos.h>
#include <linux/slab.h>
#include <linux/suspend.h>
#include <linux/syscore_ops.h>
@@ -999,7 +1000,7 @@ static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu)
{
struct device *dev = get_cpu_device(cpu);
- if (!dev)
+ if (unlikely(!dev))
return;
if (cpumask_test_and_set_cpu(cpu, policy->real_cpus))
@@ -1117,14 +1118,16 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cp
static void refresh_frequency_limits(struct cpufreq_policy *policy)
{
- struct cpufreq_policy new_policy = *policy;
+ struct cpufreq_policy new_policy;
- pr_debug("updating policy for CPU %u\n", policy->cpu);
+ if (!policy_is_inactive(policy)) {
+ new_policy = *policy;
+ pr_debug("updating policy for CPU %u\n", policy->cpu);
- new_policy.min = policy->user_policy.min;
- new_policy.max = policy->user_policy.max;
-
- cpufreq_set_policy(policy, &new_policy);
+ new_policy.min = policy->user_policy.min;
+ new_policy.max = policy->user_policy.max;
+ cpufreq_set_policy(policy, &new_policy);
+ }
}
static void handle_update(struct work_struct *work)
@@ -1133,60 +1136,27 @@ static void handle_update(struct work_struct *work)
container_of(work, struct cpufreq_policy, update);
pr_debug("handle_update for cpu %u called\n", policy->cpu);
+ down_write(&policy->rwsem);
refresh_frequency_limits(policy);
+ up_write(&policy->rwsem);
}
-static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
+static int cpufreq_notifier_min(struct notifier_block *nb, unsigned long freq,
+ void *data)
{
- struct cpufreq_policy *policy;
- int ret;
+ struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_min);
- policy = kzalloc(sizeof(*policy), GFP_KERNEL);
- if (!policy)
- return NULL;
+ schedule_work(&policy->update);
+ return 0;
+}
- if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL))
- goto err_free_policy;
+static int cpufreq_notifier_max(struct notifier_block *nb, unsigned long freq,
+ void *data)
+{
+ struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_max);
- if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL))
- goto err_free_cpumask;
-
- if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL))
- goto err_free_rcpumask;
-
- ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
- cpufreq_global_kobject, "policy%u", cpu);
- if (ret) {
- pr_err("%s: failed to init policy->kobj: %d\n", __func__, ret);
- /*
- * The entire policy object will be freed below, but the extra
- * memory allocated for the kobject name needs to be freed by
- * releasing the kobject.
- */
- kobject_put(&policy->kobj);
- goto err_free_real_cpus;
- }
-
- INIT_LIST_HEAD(&policy->policy_list);
- init_rwsem(&policy->rwsem);
- spin_lock_init(&policy->transition_lock);
- init_waitqueue_head(&policy->transition_wait);
- init_completion(&policy->kobj_unregister);
- INIT_WORK(&policy->update, handle_update);
-
- policy->cpu = cpu;
- return policy;
-
-err_free_real_cpus:
- free_cpumask_var(policy->real_cpus);
-err_free_rcpumask:
- free_cpumask_var(policy->related_cpus);
-err_free_cpumask:
- free_cpumask_var(policy->cpus);
-err_free_policy:
- kfree(policy);
-
- return NULL;
+ schedule_work(&policy->update);
+ return 0;
}
static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy)
@@ -1211,8 +1181,90 @@ static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy)
pr_debug("wait complete\n");
}
+static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
+{
+ struct cpufreq_policy *policy;
+ struct device *dev = get_cpu_device(cpu);
+ int ret;
+
+ if (!dev)
+ return NULL;
+
+ policy = kzalloc(sizeof(*policy), GFP_KERNEL);
+ if (!policy)
+ return NULL;
+
+ if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL))
+ goto err_free_policy;
+
+ if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL))
+ goto err_free_cpumask;
+
+ if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL))
+ goto err_free_rcpumask;
+
+ ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
+ cpufreq_global_kobject, "policy%u", cpu);
+ if (ret) {
+ dev_err(dev, "%s: failed to init policy->kobj: %d\n", __func__, ret);
+ /*
+ * The entire policy object will be freed below, but the extra
+ * memory allocated for the kobject name needs to be freed by
+ * releasing the kobject.
+ */
+ kobject_put(&policy->kobj);
+ goto err_free_real_cpus;
+ }
+
+ policy->nb_min.notifier_call = cpufreq_notifier_min;
+ policy->nb_max.notifier_call = cpufreq_notifier_max;
+
+ ret = dev_pm_qos_add_notifier(dev, &policy->nb_min,
+ DEV_PM_QOS_MIN_FREQUENCY);
+ if (ret) {
+ dev_err(dev, "Failed to register MIN QoS notifier: %d (%*pbl)\n",
+ ret, cpumask_pr_args(policy->cpus));
+ goto err_kobj_remove;
+ }
+
+ ret = dev_pm_qos_add_notifier(dev, &policy->nb_max,
+ DEV_PM_QOS_MAX_FREQUENCY);
+ if (ret) {
+ dev_err(dev, "Failed to register MAX QoS notifier: %d (%*pbl)\n",
+ ret, cpumask_pr_args(policy->cpus));
+ goto err_min_qos_notifier;
+ }
+
+ INIT_LIST_HEAD(&policy->policy_list);
+ init_rwsem(&policy->rwsem);
+ spin_lock_init(&policy->transition_lock);
+ init_waitqueue_head(&policy->transition_wait);
+ init_completion(&policy->kobj_unregister);
+ INIT_WORK(&policy->update, handle_update);
+
+ policy->cpu = cpu;
+ return policy;
+
+err_min_qos_notifier:
+ dev_pm_qos_remove_notifier(dev, &policy->nb_min,
+ DEV_PM_QOS_MIN_FREQUENCY);
+err_kobj_remove:
+ cpufreq_policy_put_kobj(policy);
+err_free_real_cpus:
+ free_cpumask_var(policy->real_cpus);
+err_free_rcpumask:
+ free_cpumask_var(policy->related_cpus);
+err_free_cpumask:
+ free_cpumask_var(policy->cpus);
+err_free_policy:
+ kfree(policy);
+
+ return NULL;
+}
+
static void cpufreq_policy_free(struct cpufreq_policy *policy)
{
+ struct device *dev = get_cpu_device(policy->cpu);
unsigned long flags;
int cpu;
@@ -1224,6 +1276,11 @@ static void cpufreq_policy_free(struct cpufreq_policy *policy)
per_cpu(cpufreq_cpu_data, cpu) = NULL;
write_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ dev_pm_qos_remove_notifier(dev, &policy->nb_max,
+ DEV_PM_QOS_MAX_FREQUENCY);
+ dev_pm_qos_remove_notifier(dev, &policy->nb_min,
+ DEV_PM_QOS_MIN_FREQUENCY);
+
cpufreq_policy_put_kobj(policy);
free_cpumask_var(policy->real_cpus);
free_cpumask_var(policy->related_cpus);
@@ -2283,6 +2340,8 @@ int cpufreq_set_policy(struct cpufreq_policy *policy,
struct cpufreq_policy *new_policy)
{
struct cpufreq_governor *old_gov;
+ struct device *cpu_dev = get_cpu_device(policy->cpu);
+ unsigned long min, max;
int ret;
pr_debug("setting new policy for CPU %u: %u - %u kHz\n",
@@ -2297,11 +2356,27 @@ int cpufreq_set_policy(struct cpufreq_policy *policy,
if (new_policy->min > new_policy->max)
return -EINVAL;
+ /*
+ * PM QoS framework collects all the requests from users and provide us
+ * the final aggregated value here.
+ */
+ min = dev_pm_qos_read_value(cpu_dev, DEV_PM_QOS_MIN_FREQUENCY);
+ max = dev_pm_qos_read_value(cpu_dev, DEV_PM_QOS_MAX_FREQUENCY);
+
+ if (min > new_policy->min)
+ new_policy->min = min;
+ if (max < new_policy->max)
+ new_policy->max = max;
+
/* verify the cpu speed can be set within this limit */
ret = cpufreq_driver->verify(new_policy);
if (ret)
return ret;
+ /*
+ * The notifier-chain shall be removed once all the users of
+ * CPUFREQ_ADJUST are moved to use the QoS framework.
+ */
/* adjust if necessary - all reasons */
blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
CPUFREQ_ADJUST, new_policy);