Commit 67d874c3 authored by Viresh Kumar's avatar Viresh Kumar Committed by Rafael J. Wysocki

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: default avatarMatthias Kaehlcke <mka@chromium.org>
Reviewed-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Tested-by: default avatarPavel Machek <pavel@ucw.cz>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 208637b3
......@@ -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;
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);
}
}
static void handle_update(struct work_struct *work)
......@@ -1133,14 +1136,60 @@ 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 int cpufreq_notifier_min(struct notifier_block *nb, unsigned long freq,
void *data)
{
struct cpufreq_policy *policy = container_of(nb, struct cpufreq_policy, nb_min);
schedule_work(&policy->update);
return 0;
}
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);
schedule_work(&policy->update);
return 0;
}
static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy)
{
struct kobject *kobj;
struct completion *cmp;
down_write(&policy->rwsem);
cpufreq_stats_free_table(policy);
kobj = &policy->kobj;
cmp = &policy->kobj_unregister;
up_write(&policy->rwsem);
kobject_put(kobj);
/*
* We need to make sure that the underlying kobj is
* actually not referenced anymore by anybody before we
* proceed with unloading.
*/
pr_debug("waiting for dropping of refcount\n");
wait_for_completion(cmp);
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;
......@@ -1157,7 +1206,7 @@ static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
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);
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
......@@ -1167,6 +1216,25 @@ static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
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);
......@@ -1177,6 +1245,11 @@ static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
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:
......@@ -1189,30 +1262,9 @@ static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
return NULL;
}
static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy)
{
struct kobject *kobj;
struct completion *cmp;
down_write(&policy->rwsem);
cpufreq_stats_free_table(policy);
kobj = &policy->kobj;
cmp = &policy->kobj_unregister;
up_write(&policy->rwsem);
kobject_put(kobj);
/*
* We need to make sure that the underlying kobj is
* actually not referenced anymore by anybody before we
* proceed with unloading.
*/
pr_debug("waiting for dropping of refcount\n");
wait_for_completion(cmp);
pr_debug("wait complete\n");
}
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);
......
......@@ -147,6 +147,9 @@ struct cpufreq_policy {
/* Pointer to the cooling device if used for thermal mitigation */
struct thermal_cooling_device *cdev;
struct notifier_block nb_min;
struct notifier_block nb_max;
};
struct cpufreq_freqs {
......
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