Brute force _lock_cas() by disabling interrupts.

Need to redo it with RAS later.

sys/arch/sh3/sh3/lock_stubs.S

@@ -1,6 +1,34 @@
-/*	$NetBSD: lock_stubs.S,v 1.1 2007/02/22 22:53:26 uwe Exp $	*/
+/*	$NetBSD: lock_stubs.S,v 1.2 2007/02/23 03:24:47 uwe Exp $	*/
+
+/*
+ * Copyright (c) 2007 Valeriy E. Ushakov
+ * All rights reserved.
+ *
+ * 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. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
+ */
 
 #include <sh3/asm.h>
+#include <sh3/psl.h>
 
 /*
  * LINTSTUB: include <sys/types.h>
@@ -9,7 +37,23 @@
 
 /*
  * LINTSTUB: Func: int _lock_cas(volatile uintptr_t *ptr, uintptr_t old, uintptr_t new);
+ *
+ *	Brute force with splhigh() for now.  Need to be redone as RAS.
  */
 NENTRY(_lock_cas)
+	mov	#PSL_IMASK, r2	! 0xf0 - gets sign extended
+	stc	sr, r3
+	extu.b	r2, r2		! undo sign extention
+	mov	r3, r7		! preserve SR
+	or	r2, r3		! mask all interrupts
+	ldc	r3, sr
+
+	mov.l	@r4, r1
+	cmp/eq	r1, r5		! T = (*ptr == old)
+	bf.s	1f
+	 movt	r0		! retval = T
+	mov.l	r6, @r4		! *ptr = new
+1:
+	ldc	r7, sr		! restore SR (cannot be in delay slot)
 	rts
-	 mov	#0, r0
+	 nop