xref: /netbsd-src/lib/libc/arch/alpha/gen/swapcontext.S (revision 276edc129d198a79e89cfd07539d58eb35a5f1b4)
1/*	$NetBSD: swapcontext.S,v 1.5 2021/07/06 12:38:40 thorpej 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 "assym.h"
34
35#define	FRAME_SIZE	32
36#define	FRAME_RA	(32-16)
37#define	FRAME_OUCP	(32-24)
38#define	FRAME_UCP	(32-32)
39
40NESTED(swapcontext, 2, FRAME_SIZE, ra, IM_RA|IM_A0|IM_A1, 0)
41	LDGP(pv)
42	lda	sp, -FRAME_SIZE(sp)
43	stq	ra, FRAME_RA(sp)	/* must save ra, oucp, ucp */
44	stq	a0, FRAME_OUCP(sp)
45	stq	a1, FRAME_UCP(sp)
46	CALL(_getcontext)		/* getcontext(oucp) */
47	ldq	t0, FRAME_OUCP(sp)
48	bne	v0, Lerr
49	ldq	t1, FRAME_RA(sp)
50	stq	t1, (UC_GREGS + _REG_RA*8)(t0)	/* Adjust saved RA */
51	stq	t1, (UC_GREGS + _REG_PC*8)(t0)	/* Adjust saved PC */
52	lda	t1, FRAME_SIZE(sp)
53	stq	t1, (UC_GREGS + _REG_SP*8)(t0)	/* Adjust saved SP */
54
55	ldq	a0, FRAME_UCP(sp)
56	CALL(setcontext)		/* setcontext(ucp) */
57Lerr:
58	ldq	ra, FRAME_RA(sp)
59	lda	sp, FRAME_SIZE(sp)
60	RET
61END(swapcontext)
62