1/*
2 * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/param.h>
28#include <sys/lock.h>
29#include <sys/mutex.h>
30#include <sys/atomic.h>
31
32#if !defined(__LP64__) && !defined(__mips_n32) && \
33	!defined(ARM_HAVE_ATOMIC64) && !defined(I386_HAVE_ATOMIC64) && \
34	!defined(HAS_EMULATED_ATOMIC64)
35
36#ifdef _KERNEL
37#include <sys/kernel.h>
38
39struct mtx atomic_mtx;
40MTX_SYSINIT(atomic, &atomic_mtx, "atomic", MTX_DEF);
41#else
42#include <pthread.h>
43
44#define	mtx_lock(lock)		pthread_mutex_lock(lock)
45#define	mtx_unlock(lock)	pthread_mutex_unlock(lock)
46
47static pthread_mutex_t atomic_mtx;
48
49static __attribute__((constructor)) void
50atomic_init(void)
51{
52	pthread_mutex_init(&atomic_mtx, NULL);
53}
54#endif
55
56void
57atomic_add_64(volatile uint64_t *target, int64_t delta)
58{
59
60	mtx_lock(&atomic_mtx);
61	*target += delta;
62	mtx_unlock(&atomic_mtx);
63}
64
65void
66atomic_dec_64(volatile uint64_t *target)
67{
68
69	mtx_lock(&atomic_mtx);
70	*target -= 1;
71	mtx_unlock(&atomic_mtx);
72}
73
74uint64_t
75atomic_swap_64(volatile uint64_t *a, uint64_t value)
76{
77	uint64_t ret;
78
79	mtx_lock(&atomic_mtx);
80	ret = *a;
81	*a = value;
82	mtx_unlock(&atomic_mtx);
83	return (ret);
84}
85
86uint64_t
87atomic_load_64(volatile uint64_t *a)
88{
89	uint64_t ret;
90
91	mtx_lock(&atomic_mtx);
92	ret = *a;
93	mtx_unlock(&atomic_mtx);
94	return (ret);
95}
96
97uint64_t
98atomic_add_64_nv(volatile uint64_t *target, int64_t delta)
99{
100	uint64_t newval;
101
102	mtx_lock(&atomic_mtx);
103	newval = (*target += delta);
104	mtx_unlock(&atomic_mtx);
105	return (newval);
106}
107
108uint64_t
109atomic_cas_64(volatile uint64_t *target, uint64_t cmp, uint64_t newval)
110{
111	uint64_t oldval;
112
113	mtx_lock(&atomic_mtx);
114	oldval = *target;
115	if (oldval == cmp)
116		*target = newval;
117	mtx_unlock(&atomic_mtx);
118	return (oldval);
119}
120#endif
121