1 // SPDX-License-Identifier: BSD-2-Clause
2 /*
3 * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include <sys/param.h>
29 #include <sys/lock.h>
30 #include <sys/mutex.h>
31 #include <sys/atomic.h>
32
33 #if !defined(__LP64__) && !defined(__mips_n32) && \
34 !defined(ARM_HAVE_ATOMIC64) && !defined(I386_HAVE_ATOMIC64) && \
35 !defined(HAS_EMULATED_ATOMIC64)
36
37 #ifdef _KERNEL
38 #include <sys/kernel.h>
39
40 struct mtx atomic_mtx;
41 MTX_SYSINIT(atomic, &atomic_mtx, "atomic", MTX_DEF);
42 #else
43 #include <pthread.h>
44
45 #define mtx_lock(lock) pthread_mutex_lock(lock)
46 #define mtx_unlock(lock) pthread_mutex_unlock(lock)
47
48 static pthread_mutex_t atomic_mtx;
49
50 static __attribute__((constructor)) void
atomic_init(void)51 atomic_init(void)
52 {
53 pthread_mutex_init(&atomic_mtx, NULL);
54 }
55 #endif
56
57 void
atomic_add_64(volatile uint64_t * target,int64_t delta)58 atomic_add_64(volatile uint64_t *target, int64_t delta)
59 {
60
61 mtx_lock(&atomic_mtx);
62 *target += delta;
63 mtx_unlock(&atomic_mtx);
64 }
65
66 void
atomic_dec_64(volatile uint64_t * target)67 atomic_dec_64(volatile uint64_t *target)
68 {
69
70 mtx_lock(&atomic_mtx);
71 *target -= 1;
72 mtx_unlock(&atomic_mtx);
73 }
74
75 uint64_t
atomic_swap_64(volatile uint64_t * a,uint64_t value)76 atomic_swap_64(volatile uint64_t *a, uint64_t value)
77 {
78 uint64_t ret;
79
80 mtx_lock(&atomic_mtx);
81 ret = *a;
82 *a = value;
83 mtx_unlock(&atomic_mtx);
84 return (ret);
85 }
86
87 uint64_t
atomic_load_64(volatile uint64_t * a)88 atomic_load_64(volatile uint64_t *a)
89 {
90 uint64_t ret;
91
92 mtx_lock(&atomic_mtx);
93 ret = *a;
94 mtx_unlock(&atomic_mtx);
95 return (ret);
96 }
97
98 uint64_t
atomic_add_64_nv(volatile uint64_t * target,int64_t delta)99 atomic_add_64_nv(volatile uint64_t *target, int64_t delta)
100 {
101 uint64_t newval;
102
103 mtx_lock(&atomic_mtx);
104 newval = (*target += delta);
105 mtx_unlock(&atomic_mtx);
106 return (newval);
107 }
108
109 uint64_t
atomic_cas_64(volatile uint64_t * target,uint64_t cmp,uint64_t newval)110 atomic_cas_64(volatile uint64_t *target, uint64_t cmp, uint64_t newval)
111 {
112 uint64_t oldval;
113
114 mtx_lock(&atomic_mtx);
115 oldval = *target;
116 if (oldval == cmp)
117 *target = newval;
118 mtx_unlock(&atomic_mtx);
119 return (oldval);
120 }
121 #endif
122