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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-03-08 01:07:31 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-03-08 01:07:31 +0100
commit19bc45a59caf0ed2c2576da4d89c0ef8a8be1f63 (patch)
tree3a614731b62fb1fc8bf00bd276b189d6dfa8b3ac
parentbeb0082efdb9ed54c3a3ca45a778224d59976cc5 (diff)
parent4e97b631f24c927b2302368f4f83efbba82076ee (diff)
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
-rw-r--r--drivers/cpufreq/cpufreq.c51
1 files changed, 23 insertions, 28 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index cb003a6b72c8..cf485d928903 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -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;
-
- BUG_ON(!policy);
-
- if (!down_read_trylock(&cpufreq_rwsem))
- return 0;
-
- down_read(&policy->rwsem);
-
- ret_freq = __cpufreq_get(cpu);
+ if (policy) {
+ down_read(&policy->rwsem);
+ ret_freq = __cpufreq_get(cpu);
+ up_read(&policy->rwsem);
- up_read(&policy->rwsem);
- up_read(&cpufreq_rwsem);
+ cpufreq_cpu_put(policy);
+ }
return ret_freq;
}