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Merge branch 'pm-opp'

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* pm-opp:
  PM / OPP: take RCU lock in dev_pm_opp_get_opp_count
  PM / OPP: fix warning in of_free_opp_table()
  PM / OPP: add some lockdep annotations
This commit is contained in:
Rafael J. Wysocki 2014-12-29 21:23:13 +01:00
commit e0288b0e9e
1 changed files with 31 additions and 8 deletions
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39
drivers/base/power/opp.c
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@ -108,6 +108,14 @@ static LIST_HEAD(dev_opp_list);
/* Lock to allow exclusive modification to the device and opp lists */
static DEFINE_MUTEX(dev_opp_list_lock);
#define opp_rcu_lockdep_assert() \
do { \
rcu_lockdep_assert(rcu_read_lock_held() || \
lockdep_is_held(&dev_opp_list_lock), \
"Missing rcu_read_lock() or " \
"dev_opp_list_lock protection"); \
} while (0)
/**
* find_device_opp() - find device_opp struct using device pointer
* @dev: device pointer used to lookup device OPPs
@ -208,9 +216,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_get_freq);
* This function returns the number of available opps if there are any,
* else returns 0 if none or the corresponding error value.
*
* Locking: This function must be called under rcu_read_lock(). This function
* internally references two RCU protected structures: device_opp and opp which
* are safe as long as we are under a common RCU locked section.
* Locking: This function takes rcu_read_lock().
*/
int dev_pm_opp_get_opp_count(struct device *dev)
{
@ -218,11 +224,14 @@ int dev_pm_opp_get_opp_count(struct device *dev)
struct dev_pm_opp *temp_opp;
int count = 0;
rcu_read_lock();
dev_opp = find_device_opp(dev);
if (IS_ERR(dev_opp)) {
int r = PTR_ERR(dev_opp);
dev_err(dev, "%s: device OPP not found (%d)\n", __func__, r);
return r;
count = PTR_ERR(dev_opp);
dev_err(dev, "%s: device OPP not found (%d)\n",
__func__, count);
goto out_unlock;
}
list_for_each_entry_rcu(temp_opp, &dev_opp->opp_list, node) {
@ -230,6 +239,8 @@ int dev_pm_opp_get_opp_count(struct device *dev)
count++;
}
out_unlock:
rcu_read_unlock();
return count;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_count);
@ -267,6 +278,8 @@ struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
struct device_opp *dev_opp;
struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
opp_rcu_lockdep_assert();
dev_opp = find_device_opp(dev);
if (IS_ERR(dev_opp)) {
int r = PTR_ERR(dev_opp);
@ -313,6 +326,8 @@ struct dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev,
struct device_opp *dev_opp;
struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
opp_rcu_lockdep_assert();
if (!dev || !freq) {
dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);
return ERR_PTR(-EINVAL);
@ -361,6 +376,8 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
struct device_opp *dev_opp;
struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
opp_rcu_lockdep_assert();
if (!dev || !freq) {
dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);
return ERR_PTR(-EINVAL);
@ -783,9 +800,15 @@ void of_free_opp_table(struct device *dev)
/* Check for existing list for 'dev' */
dev_opp = find_device_opp(dev);
if (WARN(IS_ERR(dev_opp), "%s: dev_opp: %ld\n", dev_name(dev),
PTR_ERR(dev_opp)))
if (IS_ERR(dev_opp)) {
int error = PTR_ERR(dev_opp);
if (error != -ENODEV)
WARN(1, "%s: dev_opp: %d\n",
IS_ERR_OR_NULL(dev) ?
"Invalid device" : dev_name(dev),
error);
return;
}
/* Hold our list modification lock here */
mutex_lock(&dev_opp_list_lock);