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Diffstat (limited to 'include/asm-blackfin/semaphore-helper.h')
-rw-r--r--include/asm-blackfin/semaphore-helper.h82
1 files changed, 82 insertions, 0 deletions
diff --git a/include/asm-blackfin/semaphore-helper.h b/include/asm-blackfin/semaphore-helper.h
new file mode 100644
index 000000000000..9082b0dc3eb5
--- /dev/null
+++ b/include/asm-blackfin/semaphore-helper.h
@@ -0,0 +1,82 @@
+/* Based on M68K version, Lineo Inc. May 2001 */
+
+#ifndef _BFIN_SEMAPHORE_HELPER_H
+#define _BFIN_SEMAPHORE_HELPER_H
+
+/*
+ * SMP- and interrupt-safe semaphores helper functions.
+ *
+ * (C) Copyright 1996 Linus Torvalds
+ *
+ */
+
+#include <asm/errno.h>
+
+/*
+ * These two _must_ execute atomically wrt each other.
+ */
+static inline void wake_one_more(struct semaphore *sem)
+{
+ atomic_inc(&sem->waking);
+}
+
+static inline int waking_non_zero(struct semaphore *sem)
+{
+ int ret;
+ unsigned long flags = 0;
+
+ spin_lock_irqsave(&semaphore_wake_lock, flags);
+ ret = 0;
+ if (atomic_read(&sem->waking) > 0) {
+ atomic_dec(&sem->waking);
+ ret = 1;
+ }
+ spin_unlock_irqrestore(&semaphore_wake_lock, flags);
+ return ret;
+}
+
+/*
+ * waking_non_zero_interruptible:
+ * 1 got the lock
+ * 0 go to sleep
+ * -EINTR interrupted
+ */
+static inline int waking_non_zero_interruptible(struct semaphore *sem,
+ struct task_struct *tsk)
+{
+ int ret = 0;
+ unsigned long flags = 0;
+
+ spin_lock_irqsave(&semaphore_wake_lock, flags);
+ if (atomic_read(&sem->waking) > 0) {
+ atomic_dec(&sem->waking);
+ ret = 1;
+ } else if (signal_pending(tsk)) {
+ atomic_inc(&sem->count);
+ ret = -EINTR;
+ }
+ spin_unlock_irqrestore(&semaphore_wake_lock, flags);
+ return ret;
+}
+
+/*
+ * waking_non_zero_trylock:
+ * 1 failed to lock
+ * 0 got the lock
+ */
+static inline int waking_non_zero_trylock(struct semaphore *sem)
+{
+ int ret = 1;
+ unsigned long flags = 0;
+
+ spin_lock_irqsave(&semaphore_wake_lock, flags);
+ if (atomic_read(&sem->waking) > 0) {
+ atomic_dec(&sem->waking);
+ ret = 0;
+ } else
+ atomic_inc(&sem->count);
+ spin_unlock_irqrestore(&semaphore_wake_lock, flags);
+ return ret;
+}
+
+#endif /* _BFIN_SEMAPHORE_HELPER_H */