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/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/lock.h>
32 #include <sys/mutex.h>
33 #include <sys/atomic.h>
34 
35 #ifdef _KERNEL
36 #include <sys/kernel.h>
37 
38 struct mtx atomic_mtx;
39 MTX_SYSINIT(atomic, &atomic_mtx, "atomic", MTX_DEF);
40 #else
41 #include <pthread.h>
42 
43 #define	mtx_lock(lock)		pthread_mutex_lock(lock)
44 #define	mtx_unlock(lock)	pthread_mutex_unlock(lock)
45 
46 static pthread_mutex_t atomic_mtx;
47 
48 static __attribute__((constructor)) void
49 atomic_init(void)
50 {
51 	pthread_mutex_init(&atomic_mtx, NULL);
52 }
53 #endif
54 
55 #if !defined(__LP64__) && !defined(__mips_n32) && \
56     !defined(ARM_HAVE_ATOMIC64) && !defined(I386_HAVE_ATOMIC64)
57 void
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
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 #endif
75 
76 uint64_t
77 atomic_add_64_nv(volatile uint64_t *target, int64_t delta)
78 {
79 	uint64_t newval;
80 
81 	mtx_lock(&atomic_mtx);
82 	newval = (*target += delta);
83 	mtx_unlock(&atomic_mtx);
84 	return (newval);
85 }
86 
87 #if defined(__powerpc__) || defined(__arm__) || defined(__mips__)
88 void
89 atomic_or_8(volatile uint8_t *target, uint8_t value)
90 {
91 	mtx_lock(&atomic_mtx);
92 	*target |= value;
93 	mtx_unlock(&atomic_mtx);
94 }
95 #endif
96 
97 uint8_t
98 atomic_or_8_nv(volatile uint8_t *target, uint8_t value)
99 {
100 	uint8_t newval;
101 
102 	mtx_lock(&atomic_mtx);
103 	newval = (*target |= value);
104 	mtx_unlock(&atomic_mtx);
105 	return (newval);
106 }
107 
108 uint64_t
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 
121 uint32_t
122 atomic_cas_32(volatile uint32_t *target, uint32_t cmp, uint32_t newval)
123 {
124 	uint32_t oldval;
125 
126 	mtx_lock(&atomic_mtx);
127 	oldval = *target;
128 	if (oldval == cmp)
129 		*target = newval;
130 	mtx_unlock(&atomic_mtx);
131 	return (oldval);
132 }
133 
134 void
135 membar_producer(void)
136 {
137 	/* nothing */
138 }
139