patch-2.4.2 linux/include/asm-cris/semaphore-helper.h

• Lines: 78
• Date: Thu Feb 8 16:32:44 2001
• Orig file: v2.4.1/linux/include/asm-cris/semaphore-helper.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.1/linux/include/asm-cris/semaphore-helper.h linux/include/asm-cris/semaphore-helper.h
@@ -0,0 +1,77 @@
+/* $Id: semaphore-helper.h,v 1.1 2000/07/13 16:52:42 bjornw Exp $
+ *
+ * SMP- and interrupt-safe semaphores helper functions. Generic versions, no
+ * optimizations whatsoever... 
+ *
+ */
+
+#ifndef _ASM_SEMAPHORE_HELPER_H
+#define _ASM_SEMAPHORE_HELPER_H
+
+#include <asm/atomic.h>
+
+/*
+ * These two _must_ execute atomically wrt each other.
+ */
+static inline void wake_one_more(struct semaphore * sem)
+{
+	atomic_inc(&sem->waking);
+}
+
+#define read(a) ((a)->counter)
+#define inc(a) (((a)->counter)++)
+#define dec(a) (((a)->counter)--)
+
+#define count_inc(a) ((*(a))++)
+
+static inline int waking_non_zero(struct semaphore *sem)
+{
+	unsigned long flags;
+	int ret = 0;
+
+	save_and_cli(flags);
+	if (read(&sem->waking) > 0) {
+		dec(&sem->waking);
+		ret = 1;
+	}
+	restore_flags(flags);
+	return ret;
+}
+
+static inline int waking_non_zero_interruptible(struct semaphore *sem,
+						struct task_struct *tsk)
+{
+	int ret = 0;
+	unsigned long flags;
+
+	save_and_cli(flags);
+	if (read(&sem->waking) > 0) {
+		dec(&sem->waking);
+		ret = 1;
+	} else if (signal_pending(tsk)) {
+		count_inc(&sem->count);
+		ret = -EINTR;
+	}
+	restore_flags(flags);
+	return ret;
+}
+
+static inline int waking_non_zero_trylock(struct semaphore *sem)
+{
+        int ret = 1;
+	unsigned long flags;
+
+	save_and_cli(flags);
+	if (read(&sem->waking) <= 0)
+		count_inc(&sem->count);
+	else {
+		dec(&sem->waking);
+		ret = 0;
+	}
+	restore_flags(flags);
+	return ret;
+}
+
+#endif /* _ASM_SEMAPHORE_HELPER_H */
+
+