patch-2.1.80 linux/include/asm-arm/semaphore.h

• Lines: 68
• Date: Tue Jan 20 16:39:43 1998
• Orig file: v2.1.79/linux/include/asm-arm/semaphore.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.79/linux/include/asm-arm/semaphore.h linux/include/asm-arm/semaphore.h
@@ -0,0 +1,67 @@
+/*
+ * linux/include/asm-arm/semaphore.h
+ */
+#ifndef __ASM_ARM_SEMAPHORE_H
+#define __ASM_ARM_SEMAPHORE_H
+
+#include <linux/linkage.h>
+#include <asm/system.h>
+#include <asm/atomic.h>
+
+struct semaphore {
+	atomic_t count;
+	int waking;
+	struct wait_queue * wait;
+};
+
+#define MUTEX ((struct semaphore) { ATOMIC_INIT(1), 0, NULL })
+#define MUTEX_LOCKED ((struct semaphore) { ATOMIC_INIT(0), 0, NULL })
+
+asmlinkage void __down_failed (void /* special register calling convention */);
+asmlinkage int  __down_failed_interruptible (void /* special register calling convention */);
+asmlinkage void __up_wakeup (void /* special register calling convention */);
+
+extern void __down(struct semaphore * sem);
+extern void __up(struct semaphore * sem);
+
+#define sema_init(sem, val)	atomic_set(&((sem)->count), (val))
+
+/*
+ * These two _must_ execute atomically wrt each other.
+ *
+ * This is trivially done with load_locked/store_cond,
+ * but on the x86 we need an external synchronizer.
+ * Currently this is just the global interrupt lock,
+ * bah. Go for a smaller spinlock some day.
+ *
+ * (On the other hand this shouldn't be in any critical
+ * path, so..)
+ */
+static inline void wake_one_more(struct semaphore * sem)
+{
+	unsigned long flags;
+
+	save_flags(flags);
+	cli();
+	sem->waking++;
+	restore_flags(flags);
+}
+
+static inline int waking_non_zero(struct semaphore *sem)
+{
+	unsigned long flags;
+	int ret = 0;
+
+	save_flags(flags);
+	cli();
+	if (sem->waking > 0) {
+		sem->waking--;
+		ret = 1;
+	}
+	restore_flags(flags);
+	return ret;
+}
+
+#include <asm/proc/semaphore.h>
+
+#endif