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Merge branch 'pm-cpufreq' 

* pm-cpufreq:
  cpufreq: Initialize governor for a new policy under policy->rwsem
  cpufreq: Initialize policy before making it available for others to use
  cpufreq: use cpufreq_cpu_get() to avoid cpufreq_get() race conditions
This commit is contained in:
Rafael J. Wysocki 2014-03-08 01:07:31 +01:00
parent beb0082efd 4e97b631f2
commit 19bc45a59c
1 changed files with 23 additions and 28 deletions
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51
drivers/cpufreq/cpufreq.c
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@ -1109,6 +1109,21 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
goto err_set_policy_cpu;
}
/* related cpus should atleast have policy->cpus */
cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus);
/*
* affected cpus must always be the one, which are online. We aren't
* managing offline cpus here.
*/
cpumask_and(policy->cpus, policy->cpus, cpu_online_mask);
if (!frozen) {
policy->user_policy.min = policy->min;
policy->user_policy.max = policy->max;
}
down_write(&policy->rwsem);
write_lock_irqsave(&cpufreq_driver_lock, flags);
for_each_cpu(j, policy->cpus)
per_cpu(cpufreq_cpu_data, j) = policy;
@ -1162,20 +1177,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
}
}
/* related cpus should atleast have policy->cpus */
cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus);
/*
* affected cpus must always be the one, which are online. We aren't
* managing offline cpus here.
*/
cpumask_and(policy->cpus, policy->cpus, cpu_online_mask);
if (!frozen) {
policy->user_policy.min = policy->min;
policy->user_policy.max = policy->max;
}
blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
CPUFREQ_START, policy);
@ -1206,6 +1207,7 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
policy->user_policy.policy = policy->policy;
policy->user_policy.governor = policy->governor;
}
up_write(&policy->rwsem);
kobject_uevent(&policy->kobj, KOBJ_ADD);
up_read(&cpufreq_rwsem);
@ -1546,23 +1548,16 @@ static unsigned int __cpufreq_get(unsigned int cpu)
*/
unsigned int cpufreq_get(unsigned int cpu)
{
struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
unsigned int ret_freq = 0;
if (cpufreq_disabled() || !cpufreq_driver)
return -ENOENT;
if (policy) {
down_read(&policy->rwsem);
ret_freq = __cpufreq_get(cpu);
up_read(&policy->rwsem);
BUG_ON(!policy);
if (!down_read_trylock(&cpufreq_rwsem))
return 0;
down_read(&policy->rwsem);
ret_freq = __cpufreq_get(cpu);
up_read(&policy->rwsem);
up_read(&cpufreq_rwsem);
cpufreq_cpu_put(policy);
}
return ret_freq;
}