From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@ppc970.osdl.org>
Date: Sat, 16 Apr 2005 15:20:36 -0700
Subject: Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
---
 include/asm-m68knommu/semaphore.h | 157 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 157 insertions(+)
 create mode 100644 include/asm-m68knommu/semaphore.h

(limited to 'include/asm-m68knommu/semaphore.h')

diff --git a/include/asm-m68knommu/semaphore.h b/include/asm-m68knommu/semaphore.h
new file mode 100644
index 00000000000..febe85add50
--- /dev/null
+++ b/include/asm-m68knommu/semaphore.h
@@ -0,0 +1,157 @@
+#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 <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)
+
+extern 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);
+
+extern spinlock_t semaphore_wake_lock;
+
+/*
+ * 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
+ */
+extern inline void down(struct semaphore * sem)
+{
+	might_sleep();
+	__asm__ __volatile__(
+		"| atomic down operation\n\t"
+		"movel	%0, %%a1\n\t"
+		"lea	%%pc@(1f), %%a0\n\t"
+		"subql	#1, %%a1@\n\t"
+		"jmi __down_failed\n"
+		"1:"
+		: /* no outputs */
+		: "g" (sem)
+		: "cc", "%a0", "%a1", "memory");
+}
+
+extern inline int down_interruptible(struct semaphore * sem)
+{
+	int ret;
+
+	might_sleep();
+	__asm__ __volatile__(
+		"| atomic down operation\n\t"
+		"movel	%1, %%a1\n\t"
+		"lea	%%pc@(1f), %%a0\n\t"
+		"subql	#1, %%a1@\n\t"
+		"jmi __down_failed_interruptible\n\t"
+		"clrl	%%d0\n"
+		"1: movel	%%d0, %0\n"
+		: "=d" (ret)
+		: "g" (sem)
+		: "cc", "%d0", "%a0", "%a1", "memory");
+	return(ret);
+}
+
+extern 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"
+		".section .text.lock,\"ax\"\n"
+		".even\n"
+		"2:\tpea 1b\n\t"
+		"jbra __down_failed_trylock\n"
+		".previous"
+		: "=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().
+ */
+extern inline void up(struct semaphore * sem)
+{
+	__asm__ __volatile__(
+		"| atomic up operation\n\t"
+		"movel	%0, %%a1\n\t"
+		"lea	%%pc@(1f), %%a0\n\t"
+		"addql	#1, %%a1@\n\t"
+		"jle __up_wakeup\n"
+		"1:"
+		: /* no outputs */
+		: "g" (sem)
+		: "cc", "%a0", "%a1", "memory");
+}
+
+#endif /* __ASSEMBLY__ */
+
+#endif
-- 
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