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
39 struct mtx atomic_mtx;
40 MTX_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
47 static pthread_mutex_t atomic_mtx;
48
49 static __attribute__((constructor)) void
atomic_init(void)50 atomic_init(void)
51 {
52 pthread_mutex_init(&atomic_mtx, NULL);
53 }
54 #endif
55
56 void
atomic_add_64(volatile uint64_t * target,int64_t delta)57 atomic_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
65 void
atomic_dec_64(volatile uint64_t * target)66 atomic_dec_64(volatile uint64_t *target)
67 {
68
69 mtx_lock(&atomic_mtx);
70 *target -= 1;
71 mtx_unlock(&atomic_mtx);
72 }
73
74 uint64_t
atomic_swap_64(volatile uint64_t * a,uint64_t value)75 atomic_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
86 uint64_t
atomic_load_64(volatile uint64_t * a)87 atomic_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
97 uint64_t
atomic_add_64_nv(volatile uint64_t * target,int64_t delta)98 atomic_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
108 uint64_t
atomic_cas_64(volatile uint64_t * target,uint64_t cmp,uint64_t newval)109 atomic_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