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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.c152
1 files changed, 102 insertions, 50 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 5c75e3147a60..43c24aa756f6 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -280,13 +280,6 @@ static void __cpufreq_notify_transition(struct cpufreq_policy *policy,
switch (state) {
case CPUFREQ_PRECHANGE:
- if (WARN(policy->transition_ongoing ==
- cpumask_weight(policy->cpus),
- "In middle of another frequency transition\n"))
- return;
-
- policy->transition_ongoing++;
-
/* detect if the driver reported a value as "old frequency"
* which is not equal to what the cpufreq core thinks is
* "old frequency".
@@ -306,12 +299,6 @@ static void __cpufreq_notify_transition(struct cpufreq_policy *policy,
break;
case CPUFREQ_POSTCHANGE:
- if (WARN(!policy->transition_ongoing,
- "No frequency transition in progress\n"))
- return;
-
- policy->transition_ongoing--;
-
adjust_jiffies(CPUFREQ_POSTCHANGE, freqs);
pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new,
(unsigned long)freqs->cpu);
@@ -437,7 +424,7 @@ static int __cpufreq_set_policy(struct cpufreq_policy *policy,
static ssize_t store_##file_name \
(struct cpufreq_policy *policy, const char *buf, size_t count) \
{ \
- unsigned int ret; \
+ int ret; \
struct cpufreq_policy new_policy; \
\
ret = cpufreq_get_policy(&new_policy, policy->cpu); \
@@ -490,7 +477,7 @@ static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf)
static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
const char *buf, size_t count)
{
- unsigned int ret;
+ int ret;
char str_governor[16];
struct cpufreq_policy new_policy;
@@ -694,8 +681,13 @@ static ssize_t store(struct kobject *kobj, struct attribute *attr,
struct freq_attr *fattr = to_attr(attr);
ssize_t ret = -EINVAL;
+ get_online_cpus();
+
+ if (!cpu_online(policy->cpu))
+ goto unlock;
+
if (!down_read_trylock(&cpufreq_rwsem))
- goto exit;
+ goto unlock;
if (lock_policy_rwsem_write(policy->cpu) < 0)
goto up_read;
@@ -709,7 +701,9 @@ static ssize_t store(struct kobject *kobj, struct attribute *attr,
up_read:
up_read(&cpufreq_rwsem);
-exit:
+unlock:
+ put_online_cpus();
+
return ret;
}
@@ -912,11 +906,11 @@ static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu)
struct cpufreq_policy *policy;
unsigned long flags;
- write_lock_irqsave(&cpufreq_driver_lock, flags);
+ read_lock_irqsave(&cpufreq_driver_lock, flags);
policy = per_cpu(cpufreq_cpu_data_fallback, cpu);
- write_unlock_irqrestore(&cpufreq_driver_lock, flags);
+ read_unlock_irqrestore(&cpufreq_driver_lock, flags);
return policy;
}
@@ -953,6 +947,21 @@ static void cpufreq_policy_free(struct cpufreq_policy *policy)
kfree(policy);
}
+static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
+{
+ if (cpu == policy->cpu)
+ return;
+
+ policy->last_cpu = policy->cpu;
+ policy->cpu = cpu;
+
+#ifdef CONFIG_CPU_FREQ_TABLE
+ cpufreq_frequency_table_update_policy_cpu(policy);
+#endif
+ blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
+ CPUFREQ_UPDATE_POLICY_CPU, policy);
+}
+
static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
bool frozen)
{
@@ -1006,7 +1015,18 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
if (!policy)
goto nomem_out;
- policy->cpu = cpu;
+
+ /*
+ * In the resume path, since we restore a saved policy, the assignment
+ * to policy->cpu is like an update of the existing policy, rather than
+ * the creation of a brand new one. So we need to perform this update
+ * by invoking update_policy_cpu().
+ */
+ if (frozen && cpu != policy->cpu)
+ update_policy_cpu(policy, cpu);
+ else
+ policy->cpu = cpu;
+
policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
cpumask_copy(policy->cpus, cpumask_of(cpu));
@@ -1098,18 +1118,6 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
return __cpufreq_add_dev(dev, sif, false);
}
-static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
-{
- policy->last_cpu = policy->cpu;
- policy->cpu = cpu;
-
-#ifdef CONFIG_CPU_FREQ_TABLE
- cpufreq_frequency_table_update_policy_cpu(policy);
-#endif
- blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
- CPUFREQ_UPDATE_POLICY_CPU, policy);
-}
-
static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy,
unsigned int old_cpu, bool frozen)
{
@@ -1141,22 +1149,14 @@ static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy,
return cpu_dev->id;
}
-/**
- * __cpufreq_remove_dev - remove a CPU device
- *
- * Removes the cpufreq interface for a CPU device.
- * Caller should already have policy_rwsem in write mode for this CPU.
- * This routine frees the rwsem before returning.
- */
-static int __cpufreq_remove_dev(struct device *dev,
- struct subsys_interface *sif, bool frozen)
+static int __cpufreq_remove_dev_prepare(struct device *dev,
+ struct subsys_interface *sif,
+ bool frozen)
{
unsigned int cpu = dev->id, cpus;
int new_cpu, ret;
unsigned long flags;
struct cpufreq_policy *policy;
- struct kobject *kobj;
- struct completion *cmp;
pr_debug("%s: unregistering CPU %u\n", __func__, cpu);
@@ -1196,8 +1196,9 @@ static int __cpufreq_remove_dev(struct device *dev,
cpumask_clear_cpu(cpu, policy->cpus);
unlock_policy_rwsem_write(cpu);
- if (cpu != policy->cpu && !frozen) {
- sysfs_remove_link(&dev->kobj, "cpufreq");
+ if (cpu != policy->cpu) {
+ if (!frozen)
+ sysfs_remove_link(&dev->kobj, "cpufreq");
} else if (cpus > 1) {
new_cpu = cpufreq_nominate_new_policy_cpu(policy, cpu, frozen);
@@ -1213,6 +1214,33 @@ static int __cpufreq_remove_dev(struct device *dev,
}
}
+ return 0;
+}
+
+static int __cpufreq_remove_dev_finish(struct device *dev,
+ struct subsys_interface *sif,
+ bool frozen)
+{
+ unsigned int cpu = dev->id, cpus;
+ int ret;
+ unsigned long flags;
+ struct cpufreq_policy *policy;
+ struct kobject *kobj;
+ struct completion *cmp;
+
+ read_lock_irqsave(&cpufreq_driver_lock, flags);
+ policy = per_cpu(cpufreq_cpu_data, cpu);
+ read_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+ if (!policy) {
+ pr_debug("%s: No cpu_data found\n", __func__);
+ return -EINVAL;
+ }
+
+ lock_policy_rwsem_read(cpu);
+ cpus = cpumask_weight(policy->cpus);
+ unlock_policy_rwsem_read(cpu);
+
/* If cpu is last user of policy, free policy */
if (cpus == 1) {
if (cpufreq_driver->target) {
@@ -1272,6 +1300,27 @@ static int __cpufreq_remove_dev(struct device *dev,
return 0;
}
+/**
+ * __cpufreq_remove_dev - remove a CPU device
+ *
+ * Removes the cpufreq interface for a CPU device.
+ * Caller should already have policy_rwsem in write mode for this CPU.
+ * This routine frees the rwsem before returning.
+ */
+static inline int __cpufreq_remove_dev(struct device *dev,
+ struct subsys_interface *sif,
+ bool frozen)
+{
+ int ret;
+
+ ret = __cpufreq_remove_dev_prepare(dev, sif, frozen);
+
+ if (!ret)
+ ret = __cpufreq_remove_dev_finish(dev, sif, frozen);
+
+ return ret;
+}
+
static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif)
{
unsigned int cpu = dev->id;
@@ -1610,8 +1659,6 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
if (cpufreq_disabled())
return -ENODEV;
- if (policy->transition_ongoing)
- return -EBUSY;
/* Make sure that target_freq is within supported range */
if (target_freq > policy->max)
@@ -1692,8 +1739,9 @@ static int __cpufreq_governor(struct cpufreq_policy *policy,
policy->cpu, event);
mutex_lock(&cpufreq_governor_lock);
- if ((!policy->governor_enabled && (event == CPUFREQ_GOV_STOP)) ||
- (policy->governor_enabled && (event == CPUFREQ_GOV_START))) {
+ if ((policy->governor_enabled && event == CPUFREQ_GOV_START)
+ || (!policy->governor_enabled
+ && (event == CPUFREQ_GOV_LIMITS || event == CPUFREQ_GOV_STOP))) {
mutex_unlock(&cpufreq_governor_lock);
return -EBUSY;
}
@@ -1994,7 +2042,11 @@ static int cpufreq_cpu_callback(struct notifier_block *nfb,
break;
case CPU_DOWN_PREPARE:
- __cpufreq_remove_dev(dev, NULL, frozen);
+ __cpufreq_remove_dev_prepare(dev, NULL, frozen);
+ break;
+
+ case CPU_POST_DEAD:
+ __cpufreq_remove_dev_finish(dev, NULL, frozen);
break;
case CPU_DOWN_FAILED: