+
+/*
+ * Mutex which allows recursive locking from the same process.
+ */
+struct radeon_mutex {
+ struct mutex mutex;
+ struct task_struct *owner;
+ int level;
+};
+
+static inline void radeon_mutex_init(struct radeon_mutex *mutex)
+{
+ mutex_init(&mutex->mutex);
+ mutex->owner = NULL;
+ mutex->level = 0;
+}
+
+static inline void radeon_mutex_lock(struct radeon_mutex *mutex)
+{
+ if (mutex_trylock(&mutex->mutex)) {
+ /* The mutex was unlocked before, so it's ours now */
+ mutex->owner = current;
+ } else if (mutex->owner != current) {
+ /* Another process locked the mutex, take it */
+ mutex_lock(&mutex->mutex);
+ mutex->owner = current;
+ }
+ /* Otherwise the mutex was already locked by this process */
+
+ mutex->level++;
+}
+
+static inline void radeon_mutex_unlock(struct radeon_mutex *mutex)
+{
+ if (--mutex->level > 0)
+ return;
+
+ mutex->owner = NULL;
+ mutex_unlock(&mutex->mutex);
+}
+
+