diff --git a/sys/arch/acorn32/include/lock.h b/sys/arch/acorn32/include/lock.h
index 956dc29e495c..ef4624c76e0b 100644
--- a/sys/arch/acorn32/include/lock.h
+++ b/sys/arch/acorn32/include/lock.h
@@ -1,3 +1,101 @@
-/*	$NetBSD: lock.h,v 1.1 2001/10/05 22:27:51 reinoud Exp $	*/
+/*	$NetBSD: lock.h,v 1.2 2002/10/07 23:23:53 bjh21 Exp $	*/
 
+/*-
+ * Copyright (c) 2000, 2001 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Jason R. Thorpe.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the NetBSD
+ *	Foundation, Inc. and its contributors.
+ * 4. Neither the name of The NetBSD Foundation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _ACORN32_LOCK_H_
+#define _ACORN32_LOCK_H_
+
+#ifdef _KERNEL_OPT
+#include "opt_multiprocessor.h"
+#endif
+
+#if defined(_KERNEL) && defined(MULTIPROCESSOR)
+
+#include <arm/cpufunc.h>
+
+typedef	__volatile int __cpu_simple_lock_t;
+
+#define	__SIMPLELOCK_LOCKED	1
+#define	__SIMPLELOCK_UNLOCKED	0
+
+static __inline int
+__swp(int __val, __volatile int *__ptr)
+{
+
+	__asm __volatile("swp %0, %1, [%2]"
+	    : "=r" (__val) : "r" (__val), "r" (__ptr) : "memory");
+	return __val;
+}
+
+static __inline void __attribute__((__unused__))
+__cpu_simple_lock_init(__cpu_simple_lock_t *alp)
+{
+
+	*alp = __SIMPLELOCK_UNLOCKED;
+}
+
+static __inline void __attribute__((__unused__))
+__cpu_simple_lock(__cpu_simple_lock_t *alp)
+{
+
+	while (__swp(__SIMPLELOCK_LOCKED, alp) != __SIMPLELOCK_UNLOCKED)
+		continue;
+	cpu_idcache_wbinv_all();
+}
+
+static __inline int __attribute__((__unused__))
+__cpu_simple_lock_try(__cpu_simple_lock_t *alp)
+{
+	int __result;
+
+	__result = __swp(__SIMPLELOCK_LOCKED, alp) == __SIMPLELOCK_UNLOCKED;
+	if (__result)
+		cpu_idcache_wbinv_all();
+	return __result;
+}
+
+static __inline void __attribute__((__unused__))
+__cpu_simple_unlock(__cpu_simple_lock_t *alp)
+{
+
+	*alp = __SIMPLELOCK_UNLOCKED;
+}
+
+#else /* !(_KERNEL && MULTIPROCESSOR) */
 #include <arm/lock.h>
+#endif /* !(_KERNEL && MULTIPROCESSOR) */
+#endif