1 files changed, 167 insertions, 0 deletions
diff --git a/include/asm-m68k/semaphore.h b/include/asm-m68k/semaphore.h
new file mode 100644
index 00000000000..ab94cf3ed44
--- /dev/null
+++ b/include/asm-m68k/semaphore.h
@@ -0,0 +1,167 @@
+#ifndef _M68K_SEMAPHORE_H
+#define _M68K_SEMAPHORE_H
+
+#define RW_LOCK_BIAS		 0x01000000
+
+#ifndef __ASSEMBLY__
+
+#include <linux/linkage.h>
+#include <linux/wait.h>
+#include <linux/spinlock.h>
+#include <linux/rwsem.h>
+#include <linux/stringify.h>
+
+#include <asm/system.h>
+#include <asm/atomic.h>
+
+/*
+ * Interrupt-safe semaphores..
+ *
+ * (C) Copyright 1996 Linus Torvalds
+ *
+ * m68k version by Andreas Schwab
+ */
+
+
+struct semaphore {
+	atomic_t count;
+	atomic_t waking;
+	wait_queue_head_t wait;
+};
+
+#define __SEMAPHORE_INITIALIZER(name, n)				\
+{									\
+	.count		= ATOMIC_INIT(n),				\
+	.waking		= ATOMIC_INIT(0),				\
+	.wait		= __WAIT_QUEUE_HEAD_INITIALIZER((name).wait)	\
+}
+
+#define __MUTEX_INITIALIZER(name) \
+	__SEMAPHORE_INITIALIZER(name,1)
+
+#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
+	struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
+
+#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
+#define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0)
+
+static inline void sema_init(struct semaphore *sem, int val)
+{
+	*sem = (struct semaphore)__SEMAPHORE_INITIALIZER(*sem, val);
+}
+
+static inline void init_MUTEX (struct semaphore *sem)
+{
+	sema_init(sem, 1);
+}
+
+static inline void init_MUTEX_LOCKED (struct semaphore *sem)
+{
+	sema_init(sem, 0);
+}
+
+asmlinkage void __down_failed(void /* special register calling convention */);
+asmlinkage int  __down_failed_interruptible(void  /* params in registers */);
+asmlinkage int  __down_failed_trylock(void  /* params in registers */);
+asmlinkage void __up_wakeup(void /* special register calling convention */);
+
+asmlinkage void __down(struct semaphore * sem);
+asmlinkage int  __down_interruptible(struct semaphore * sem);
+asmlinkage int  __down_trylock(struct semaphore * sem);
+asmlinkage void __up(struct semaphore * sem);
+
+/*
+ * This is ugly, but we want the default case to fall through.
+ * "down_failed" is a special asm handler that calls the C
+ * routine that actually waits. See arch/m68k/lib/semaphore.S
+ */
+static inline void down(struct semaphore *sem)
+{
+	register struct semaphore *sem1 __asm__ ("%a1") = sem;
+
+	might_sleep();
+	__asm__ __volatile__(
+		"| atomic down operation\n\t"
+		"subql #1,%0@\n\t"
+		"jmi 2f\n\t"
+		"1:\n"
+		LOCK_SECTION_START(".even\n\t")
+		"2:\tpea 1b\n\t"
+		"jbra __down_failed\n"
+		LOCK_SECTION_END
+		: /* no outputs */
+		: "a" (sem1)
+		: "memory");
+}
+
+static inline int down_interruptible(struct semaphore *sem)
+{
+	register struct semaphore *sem1 __asm__ ("%a1") = sem;
+	register int result __asm__ ("%d0");
+
+	might_sleep();
+	__asm__ __volatile__(
+		"| atomic interruptible down operation\n\t"
+		"subql #1,%1@\n\t"
+		"jmi 2f\n\t"
+		"clrl %0\n"
+		"1:\n"
+		LOCK_SECTION_START(".even\n\t")
+		"2:\tpea 1b\n\t"
+		"jbra __down_failed_interruptible\n"
+		LOCK_SECTION_END
+		: "=d" (result)
+		: "a" (sem1)
+		: "memory");
+	return result;
+}
+
+static inline int down_trylock(struct semaphore *sem)
+{
+	register struct semaphore *sem1 __asm__ ("%a1") = sem;
+	register int result __asm__ ("%d0");
+
+	__asm__ __volatile__(
+		"| atomic down trylock operation\n\t"
+		"subql #1,%1@\n\t"
+		"jmi 2f\n\t"
+		"clrl %0\n"
+		"1:\n"
+		LOCK_SECTION_START(".even\n\t")
+		"2:\tpea 1b\n\t"
+		"jbra __down_failed_trylock\n"
+		LOCK_SECTION_END
+		: "=d" (result)
+		: "a" (sem1)
+		: "memory");
+	return result;
+}
+
+/*
+ * Note! This is subtle. We jump to wake people up only if
+ * the semaphore was negative (== somebody was waiting on it).
+ * The default case (no contention) will result in NO
+ * jumps for both down() and up().
+ */
+static inline void up(struct semaphore *sem)
+{
+	register struct semaphore *sem1 __asm__ ("%a1") = sem;
+
+	__asm__ __volatile__(
+		"| atomic up operation\n\t"
+		"addql #1,%0@\n\t"
+		"jle 2f\n"
+		"1:\n"
+		LOCK_SECTION_START(".even\n\t")
+		"2:\t"
+		"pea 1b\n\t"
+		"jbra __up_wakeup\n"
+		LOCK_SECTION_END
+		: /* no outputs */
+		: "a" (sem1)
+		: "memory");
+}
+
+#endif /* __ASSEMBLY__ */
+
+#endif