cpufreq: Don't clear cpufreq_cpu_data and policy list for inactive policies
Now that we can check policy->cpus to find if policy is active or not,
we don't need to clean cpufreq_cpu_data and delete policy from the list
on light weight tear down of policies (like in suspend).
To make it consistent and clean, set cpufreq_cpu_data for all related
CPUs when the policy is first created and clean it only while it is
freed.
Also update cpufreq_cpu_get_raw() to check if cpu is part of
policy->cpus mask, so that we don't end up getting policies for offline
CPUs.
In order to make sure that no users of 'policy' are using an inactive
policy, use cpufreq_cpu_get_raw() instead of directly accessing
cpufreq_cpu_data.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 74d9fcb..e899a54 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -239,10 +239,18 @@
}
EXPORT_SYMBOL_GPL(cpufreq_generic_init);
-unsigned int cpufreq_generic_get(unsigned int cpu)
+/* Only for cpufreq core internal use */
+struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
{
struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
+ return policy && cpumask_test_cpu(cpu, policy->cpus) ? policy : NULL;
+}
+
+unsigned int cpufreq_generic_get(unsigned int cpu)
+{
+ struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
+
if (!policy || IS_ERR(policy->clk)) {
pr_err("%s: No %s associated to cpu: %d\n",
__func__, policy ? "clk" : "policy", cpu);
@@ -253,12 +261,6 @@
}
EXPORT_SYMBOL_GPL(cpufreq_generic_get);
-/* Only for cpufreq core internal use */
-struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
-{
- return per_cpu(cpufreq_cpu_data, cpu);
-}
-
/**
* cpufreq_cpu_get: returns policy for a cpu and marks it busy.
*
@@ -292,7 +294,7 @@
if (cpufreq_driver) {
/* get the CPU */
- policy = per_cpu(cpufreq_cpu_data, cpu);
+ policy = cpufreq_cpu_get_raw(cpu);
if (policy)
kobject_get(&policy->kobj);
}
@@ -1042,7 +1044,6 @@
unsigned int cpu, struct device *dev)
{
int ret = 0;
- unsigned long flags;
/* Has this CPU been taken care of already? */
if (cpumask_test_cpu(cpu, policy->cpus))
@@ -1057,13 +1058,7 @@
}
down_write(&policy->rwsem);
-
- write_lock_irqsave(&cpufreq_driver_lock, flags);
-
cpumask_set_cpu(cpu, policy->cpus);
- per_cpu(cpufreq_cpu_data, cpu) = policy;
- write_unlock_irqrestore(&cpufreq_driver_lock, flags);
-
up_write(&policy->rwsem);
if (has_target()) {
@@ -1154,6 +1149,17 @@
static void cpufreq_policy_free(struct cpufreq_policy *policy)
{
+ unsigned long flags;
+ int cpu;
+
+ /* Remove policy from list */
+ write_lock_irqsave(&cpufreq_driver_lock, flags);
+ list_del(&policy->policy_list);
+
+ for_each_cpu(cpu, policy->related_cpus)
+ per_cpu(cpufreq_cpu_data, cpu) = NULL;
+ write_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
free_cpumask_var(policy->related_cpus);
free_cpumask_var(policy->cpus);
kfree(policy);
@@ -1275,12 +1281,12 @@
__func__, ret);
goto err_init_policy_kobj;
}
- }
- write_lock_irqsave(&cpufreq_driver_lock, flags);
- for_each_cpu(j, policy->cpus)
- per_cpu(cpufreq_cpu_data, j) = policy;
- write_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ write_lock_irqsave(&cpufreq_driver_lock, flags);
+ for_each_cpu(j, policy->related_cpus)
+ per_cpu(cpufreq_cpu_data, j) = policy;
+ write_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ }
if (cpufreq_driver->get && !cpufreq_driver->setpolicy) {
policy->cur = cpufreq_driver->get(policy->cpu);
@@ -1339,11 +1345,11 @@
goto err_out_unregister;
blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
CPUFREQ_CREATE_POLICY, policy);
- }
- write_lock_irqsave(&cpufreq_driver_lock, flags);
- list_add(&policy->policy_list, &cpufreq_policy_list);
- write_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ write_lock_irqsave(&cpufreq_driver_lock, flags);
+ list_add(&policy->policy_list, &cpufreq_policy_list);
+ write_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ }
cpufreq_init_policy(policy);
@@ -1367,11 +1373,6 @@
err_out_unregister:
err_get_freq:
- write_lock_irqsave(&cpufreq_driver_lock, flags);
- for_each_cpu(j, policy->cpus)
- per_cpu(cpufreq_cpu_data, j) = NULL;
- write_unlock_irqrestore(&cpufreq_driver_lock, flags);
-
if (!recover_policy) {
kobject_put(&policy->kobj);
wait_for_completion(&policy->kobj_unregister);
@@ -1407,7 +1408,7 @@
write_lock_irqsave(&cpufreq_driver_lock, flags);
- policy = per_cpu(cpufreq_cpu_data, cpu);
+ policy = cpufreq_cpu_get_raw(cpu);
/* Save the policy somewhere when doing a light-weight tear-down */
if (cpufreq_suspended)
@@ -1465,15 +1466,9 @@
static int __cpufreq_remove_dev_finish(struct device *dev,
struct subsys_interface *sif)
{
- unsigned int cpu = dev->id, cpus;
+ unsigned int cpu = dev->id;
int ret;
- unsigned long flags;
- struct cpufreq_policy *policy;
-
- write_lock_irqsave(&cpufreq_driver_lock, flags);
- policy = per_cpu(cpufreq_cpu_data, cpu);
- per_cpu(cpufreq_cpu_data, cpu) = NULL;
- write_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
if (!policy) {
pr_debug("%s: No cpu_data found\n", __func__);
@@ -1481,12 +1476,11 @@
}
down_write(&policy->rwsem);
- cpus = cpumask_weight(policy->cpus);
cpumask_clear_cpu(cpu, policy->cpus);
up_write(&policy->rwsem);
/* If cpu is last user of policy, free policy */
- if (cpus == 1) {
+ if (policy_is_inactive(policy)) {
if (has_target()) {
ret = __cpufreq_governor(policy,
CPUFREQ_GOV_POLICY_EXIT);
@@ -1508,11 +1502,6 @@
if (cpufreq_driver->exit)
cpufreq_driver->exit(policy);
- /* Remove policy from list of active policies */
- write_lock_irqsave(&cpufreq_driver_lock, flags);
- list_del(&policy->policy_list);
- write_unlock_irqrestore(&cpufreq_driver_lock, flags);
-
if (!cpufreq_suspended)
cpufreq_policy_free(policy);
} else if (has_target()) {