1/*	$NetBSD: atomic_add_16.S,v 1.5 2021/07/28 07:32:20 skrll Exp $	*/
2
3/*-
4 * Copyright (c) 2013 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Matt Thomas <matt@3am-software.com>
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 "atomic_op_asm.h"
33
34#if defined(_ARM_ARCH_6)
35
36ENTRY_NP(_atomic_sub_16)
37	negs	r1, r1
38	/* FALLTHROUGH */
39ENTRY_NP(_atomic_add_16)
40	mov	ip, r0
411:	ldrexh	r0, [ip]		/* load old value */
42	adds	r3, r0, r1		/* calculate new value */
43	strexh	r2, r3, [ip]		/* try to store */
44	cmp	r2, #0			/*   succeed? */
45	bne	1b			/*     no, try again */
46	RET				/* return old value */
47END(_atomic_add_16)
48END(_atomic_sub_16)
49
50ATOMIC_OP_ALIAS(atomic_add_16,_atomic_add_16)
51ATOMIC_OP_ALIAS(atomic_add_short,_atomic_add_16)
52ATOMIC_OP_ALIAS(atomic_add_ushort,_atomic_add_16)
53CRT_ALIAS(__atomic_fetch_add_2,_atomic_add_16)
54STRONG_ALIAS(_atomic_add_short,_atomic_add_16)
55STRONG_ALIAS(_atomic_add_ushort,_atomic_add_16)
56
57ATOMIC_OP_ALIAS(atomic_sub_16,_atomic_sub_16)
58ATOMIC_OP_ALIAS(atomic_sub_short,_atomic_sub_16)
59ATOMIC_OP_ALIAS(atomic_sub_ushort,_atomic_sub_16)
60CRT_ALIAS(__atomic_fetch_sub_2,_atomic_sub_16)
61STRONG_ALIAS(_atomic_sub_short,_atomic_sub_16)
62STRONG_ALIAS(_atomic_sub_ushort,_atomic_sub_16)
63
64ENTRY_NP(__sync_fetch_and_add_2)
65	push    {r4, lr}
66	DMB
67	bl	_atomic_add_16
68	DMB
69	pop	{r4, pc}
70END(__sync_fetch_and_add_2)
71
72ENTRY_NP(__sync_fetch_and_sub_2)
73	push    {r4, lr}
74	DMB
75	bl	_atomic_sub_16
76	DMB
77	pop	{r4, pc}
78END(__sync_fetch_and_sub_2)
79
80
81ENTRY_NP(_atomic_sub_16_nv)
82	negs	r1, r1
83	/* FALLTHROUGH */
84ENTRY_NP(_atomic_add_16_nv)
85	mov	ip, r0			/* need r0 for return value */
861:	ldrexh	r0, [ip]		/* load old value */
87	adds	r0, r0, r1		/* calculate new value (return value) */
88	strexh	r2, r0, [ip]		/* try to store */
89	cmp	r2, #0			/*   succeed? */
90	bne	1b			/*     no, try again? */
91	RET				/* return new value */
92END(_atomic_add_16_nv)
93END(_atomic_sub_16_nv)
94
95ATOMIC_OP_ALIAS(atomic_add_16_nv,_atomic_add_16_nv)
96ATOMIC_OP_ALIAS(atomic_add_short_nv,_atomic_add_16_nv)
97ATOMIC_OP_ALIAS(atomic_add_ushort_nv,_atomic_add_16_nv)
98STRONG_ALIAS(_atomic_add_short_nv,_atomic_add_16_nv)
99STRONG_ALIAS(_atomic_add_ushort_nv,_atomic_add_16_nv)
100ATOMIC_OP_ALIAS(atomic_sub_16_nv,_atomic_sub_16_nv)
101ATOMIC_OP_ALIAS(atomic_sub_short_nv,_atomic_sub_16_nv)
102ATOMIC_OP_ALIAS(atomic_sub_ushort_nv,_atomic_sub_16_nv)
103STRONG_ALIAS(_atomic_sub_short_nv,_atomic_sub_16_nv)
104STRONG_ALIAS(_atomic_sub_ushort_nv,_atomic_sub_16_nv)
105
106ENTRY_NP(__sync_add_and_fetch_2)
107	push    {r4, lr}
108	DMB
109	bl	_atomic_add_16_nv
110	DMB
111	pop	{r4, pc}
112END(__sync_add_and_fetch_2)
113
114ENTRY_NP(__sync_sub_and_fetch_2)
115	push    {r4, lr}
116	DMB
117	bl	_atomic_sub_16_nv
118	DMB
119	pop	{r4, pc}
120END(__sync_sub_and_fetch_2)
121
122#endif /* _ARM_ARCH_6 */
123