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path: root/drivers/cpufreq/cpufreq.c
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Diffstat (limited to 'drivers/cpufreq/cpufreq.c')
-rw-r--r--drivers/cpufreq/cpufreq.c100
1 files changed, 73 insertions, 27 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index e10922709d13..7ea217c88c2e 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -34,11 +34,6 @@
static LIST_HEAD(cpufreq_policy_list);
-static inline bool policy_is_inactive(struct cpufreq_policy *policy)
-{
- return cpumask_empty(policy->cpus);
-}
-
/* Macros to iterate over CPU policies */
#define for_each_suitable_policy(__policy, __active) \
list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) \
@@ -250,6 +245,51 @@ void cpufreq_cpu_put(struct cpufreq_policy *policy)
}
EXPORT_SYMBOL_GPL(cpufreq_cpu_put);
+/**
+ * cpufreq_cpu_release - Unlock a policy and decrement its usage counter.
+ * @policy: cpufreq policy returned by cpufreq_cpu_acquire().
+ */
+void cpufreq_cpu_release(struct cpufreq_policy *policy)
+{
+ if (WARN_ON(!policy))
+ return;
+
+ lockdep_assert_held(&policy->rwsem);
+
+ up_write(&policy->rwsem);
+
+ cpufreq_cpu_put(policy);
+}
+
+/**
+ * cpufreq_cpu_acquire - Find policy for a CPU, mark it as busy and lock it.
+ * @cpu: CPU to find the policy for.
+ *
+ * Call cpufreq_cpu_get() to get a reference on the cpufreq policy for @cpu and
+ * if the policy returned by it is not NULL, acquire its rwsem for writing.
+ * Return the policy if it is active or release it and return NULL otherwise.
+ *
+ * The policy returned by this function has to be released with the help of
+ * cpufreq_cpu_release() in order to release its rwsem and balance its usage
+ * counter properly.
+ */
+struct cpufreq_policy *cpufreq_cpu_acquire(unsigned int cpu)
+{
+ struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
+
+ if (!policy)
+ return NULL;
+
+ down_write(&policy->rwsem);
+
+ if (policy_is_inactive(policy)) {
+ cpufreq_cpu_release(policy);
+ return NULL;
+ }
+
+ return policy;
+}
+
/*********************************************************************
* EXTERNALLY AFFECTING FREQUENCY CHANGES *
*********************************************************************/
@@ -669,9 +709,6 @@ static ssize_t show_scaling_cur_freq(struct cpufreq_policy *policy, char *buf)
return ret;
}
-static int cpufreq_set_policy(struct cpufreq_policy *policy,
- struct cpufreq_policy *new_policy);
-
/**
* cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
*/
@@ -857,11 +894,9 @@ static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf)
{
unsigned int limit;
int ret;
- if (cpufreq_driver->bios_limit) {
- ret = cpufreq_driver->bios_limit(policy->cpu, &limit);
- if (!ret)
- return sprintf(buf, "%u\n", limit);
- }
+ ret = cpufreq_driver->bios_limit(policy->cpu, &limit);
+ if (!ret)
+ return sprintf(buf, "%u\n", limit);
return sprintf(buf, "%u\n", policy->cpuinfo.max_freq);
}
@@ -1098,6 +1133,7 @@ static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu)
cpufreq_global_kobject, "policy%u", cpu);
if (ret) {
pr_err("%s: failed to init policy->kobj: %d\n", __func__, ret);
+ kobject_put(&policy->kobj);
goto err_free_real_cpus;
}
@@ -1550,7 +1586,7 @@ static unsigned int __cpufreq_get(struct cpufreq_policy *policy)
{
unsigned int ret_freq = 0;
- if (unlikely(policy_is_inactive(policy)) || !cpufreq_driver->get)
+ if (unlikely(policy_is_inactive(policy)))
return ret_freq;
ret_freq = cpufreq_driver->get(policy->cpu);
@@ -1588,7 +1624,8 @@ unsigned int cpufreq_get(unsigned int cpu)
if (policy) {
down_read(&policy->rwsem);
- ret_freq = __cpufreq_get(policy);
+ if (cpufreq_driver->get)
+ ret_freq = __cpufreq_get(policy);
up_read(&policy->rwsem);
cpufreq_cpu_put(policy);
@@ -2229,8 +2266,8 @@ EXPORT_SYMBOL(cpufreq_get_policy);
*
* The cpuinfo part of @policy is not updated by this function.
*/
-static int cpufreq_set_policy(struct cpufreq_policy *policy,
- struct cpufreq_policy *new_policy)
+int cpufreq_set_policy(struct cpufreq_policy *policy,
+ struct cpufreq_policy *new_policy)
{
struct cpufreq_governor *old_gov;
int ret;
@@ -2337,17 +2374,12 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy,
*/
void cpufreq_update_policy(unsigned int cpu)
{
- struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
+ struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpu);
struct cpufreq_policy new_policy;
if (!policy)
return;
- down_write(&policy->rwsem);
-
- if (policy_is_inactive(policy))
- goto unlock;
-
/*
* BIOS might change freq behind our back
* -> ask driver for current freq and notify governors about a change
@@ -2364,12 +2396,26 @@ void cpufreq_update_policy(unsigned int cpu)
cpufreq_set_policy(policy, &new_policy);
unlock:
- up_write(&policy->rwsem);
-
- cpufreq_cpu_put(policy);
+ cpufreq_cpu_release(policy);
}
EXPORT_SYMBOL(cpufreq_update_policy);
+/**
+ * cpufreq_update_limits - Update policy limits for a given CPU.
+ * @cpu: CPU to update the policy limits for.
+ *
+ * Invoke the driver's ->update_limits callback if present or call
+ * cpufreq_update_policy() for @cpu.
+ */
+void cpufreq_update_limits(unsigned int cpu)
+{
+ if (cpufreq_driver->update_limits)
+ cpufreq_driver->update_limits(cpu);
+ else
+ cpufreq_update_policy(cpu);
+}
+EXPORT_SYMBOL_GPL(cpufreq_update_limits);
+
/*********************************************************************
* BOOST *
*********************************************************************/
@@ -2426,7 +2472,7 @@ int cpufreq_boost_trigger_state(int state)
static bool cpufreq_boost_supported(void)
{
- return likely(cpufreq_driver) && cpufreq_driver->set_boost;
+ return cpufreq_driver->set_boost;
}
static int create_boost_sysfs_file(void)