xref: /netbsd-src/lib/libc/arch/mips/gen/swapcontext.S (revision de4fa6c51a9708fc05f88b618fa6fad87c9508ec)
1/*	$NetBSD: swapcontext.S,v 1.3 2008/04/28 20:22:56 martin Exp $	*/
2
3/*-
4 * Copyright (c) 2001 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Klaus Klein.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include "SYS.h"
33#include <machine/mcontext.h>
34
35#if defined(SYSLIBC_SCCS) && !defined(lint)
36	ASMSTR("$NetBSD: swapcontext.S,v 1.3 2008/04/28 20:22:56 martin Exp $")
37#endif /* SYSLIBC_SCCS && !lint */
38
39#ifdef __ABICALLS__
40	.abicalls
41#endif
42	.set	reorder
43
44NESTED(swapcontext, CALLFRAME_SIZ, ra)
45	.mask	0x80000030, (CALLFRAME_RA - CALLFRAME_SIZ)
46	subu	sp, sp, CALLFRAME_SIZ
47	sw	ra, CALLFRAME_RA(sp)	# save ra
48	sw	a0, 0(sp)		# stash away oucp
49	sw	a1, 4(sp)		# stash away ucp
50	SYSTRAP(getcontext)
51	lw	ra, CALLFRAME_RA(sp)
52	bne	a3, zero, 1f
53
54	lw	v1, 0(sp)		# load oucp again for adjustment
55	lw	a0, 4(sp)		# load ucp
56	addiu	v0, sp, CALLFRAME_SIZ
57	REG_PROLOGUE
58	REG_S	zero, (_OFFSETOF_UC_GREGS + _REG_V0 * SZREG)(v1)
59	REG_S	ra, (_OFFSETOF_UC_GREGS + _REG_EPC * SZREG)(v1)
60	REG_S	v0, (_OFFSETOF_UC_GREGS + _REG_SP * SZREG)(v1)
61	REG_EPILOGUE
62
63	SYSTRAP(setcontext)
64	/* NOTREACHED */
651:
66	addiu	sp, sp, CALLFRAME_SIZ
67	la	t9, _C_LABEL(__cerror)
68	jr	t9
69END(swapcontext)
70