diff options
| author | Rafael J. Wysocki <rjw@sisk.pl> | 2012-06-16 15:20:11 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rjw@sisk.pl> | 2012-07-03 19:06:25 +0200 |
| commit | 6e797a078824b30afbfae6cc4b1c2b21c51761ef (patch) | |
| tree | 7f58824b2c1e62b954683900024a5b97a4d30b4d | |
| parent | dc7fd275ae60ef8edf952aff2a62462f5d892fd4 (diff) | |
PM / cpuidle: Add driver reference counter
Add a reference counter for the cpuidle driver, so that it can't
be unregistered when it is in use.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
| -rw-r--r-- | drivers/cpuidle/driver.c | 29 | ||||
| -rw-r--r-- | include/linux/cpuidle.h | 6 |
2 files changed, 33 insertions, 2 deletions
diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c index 40cd3f3024df..58bf3b1ac9c4 100644 --- a/drivers/cpuidle/driver.c +++ b/drivers/cpuidle/driver.c @@ -16,6 +16,7 @@ static struct cpuidle_driver *cpuidle_curr_driver; DEFINE_SPINLOCK(cpuidle_driver_lock); +int cpuidle_driver_refcount; static void __cpuidle_register_driver(struct cpuidle_driver *drv) { @@ -89,8 +90,34 @@ void cpuidle_unregister_driver(struct cpuidle_driver *drv) } spin_lock(&cpuidle_driver_lock); - cpuidle_curr_driver = NULL; + + if (!WARN_ON(cpuidle_driver_refcount > 0)) + cpuidle_curr_driver = NULL; + spin_unlock(&cpuidle_driver_lock); } EXPORT_SYMBOL_GPL(cpuidle_unregister_driver); + +struct cpuidle_driver *cpuidle_driver_ref(void) +{ + struct cpuidle_driver *drv; + + spin_lock(&cpuidle_driver_lock); + + drv = cpuidle_curr_driver; + cpuidle_driver_refcount++; + + spin_unlock(&cpuidle_driver_lock); + return drv; +} + +void cpuidle_driver_unref(void) +{ + spin_lock(&cpuidle_driver_lock); + + if (!WARN_ON(cpuidle_driver_refcount <= 0)) + cpuidle_driver_refcount--; + + spin_unlock(&cpuidle_driver_lock); +} diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 8570012a535a..27cfced7b57b 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -136,7 +136,9 @@ struct cpuidle_driver { extern void disable_cpuidle(void); extern int cpuidle_idle_call(void); extern int cpuidle_register_driver(struct cpuidle_driver *drv); -struct cpuidle_driver *cpuidle_get_driver(void); +extern struct cpuidle_driver *cpuidle_get_driver(void); +extern struct cpuidle_driver *cpuidle_driver_ref(void); +extern void cpuidle_driver_unref(void); extern void cpuidle_unregister_driver(struct cpuidle_driver *drv); extern int cpuidle_register_device(struct cpuidle_device *dev); extern void cpuidle_unregister_device(struct cpuidle_device *dev); @@ -157,6 +159,8 @@ static inline int cpuidle_idle_call(void) { return -ENODEV; } static inline int cpuidle_register_driver(struct cpuidle_driver *drv) {return -ENODEV; } static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; } +static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; } +static inline void cpuidle_driver_unref(void) {} static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { } static inline int cpuidle_register_device(struct cpuidle_device *dev) {return -ENODEV; } |