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 00000000000..9082b0dc3eb
--- /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 */