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) && !defined(ARM_HAVE_ATOMIC64)
56 void
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
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 #endif
74 
75 uint64_t
76 atomic_add_64_nv(volatile uint64_t *target, int64_t delta)
77 {
78 	uint64_t newval;
79 
80 	mtx_lock(&atomic_mtx);
81 	newval = (*target += delta);
82 	mtx_unlock(&atomic_mtx);
83 	return (newval);
84 }
85 
86 #if defined(__powerpc__) || defined(__arm__) || defined(__mips__)
87 void
88 atomic_or_8(volatile uint8_t *target, uint8_t value)
89 {
90 	mtx_lock(&atomic_mtx);
91 	*target |= value;
92 	mtx_unlock(&atomic_mtx);
93 }
94 #endif
95 
96 uint8_t
97 atomic_or_8_nv(volatile uint8_t *target, uint8_t value)
98 {
99 	uint8_t newval;
100 
101 	mtx_lock(&atomic_mtx);
102 	newval = (*target |= value);
103 	mtx_unlock(&atomic_mtx);
104 	return (newval);
105 }
106 
107 uint64_t
108 atomic_cas_64(volatile uint64_t *target, uint64_t cmp, uint64_t newval)
109 {
110 	uint64_t oldval;
111 
112 	mtx_lock(&atomic_mtx);
113 	oldval = *target;
114 	if (oldval == cmp)
115 		*target = newval;
116 	mtx_unlock(&atomic_mtx);
117 	return (oldval);
118 }
119 
120 uint32_t
121 atomic_cas_32(volatile uint32_t *target, uint32_t cmp, uint32_t newval)
122 {
123 	uint32_t oldval;
124 
125 	mtx_lock(&atomic_mtx);
126 	oldval = *target;
127 	if (oldval == cmp)
128 		*target = newval;
129 	mtx_unlock(&atomic_mtx);
130 	return (oldval);
131 }
132 
133 void
134 membar_producer(void)
135 {
136 	/* nothing */
137 }
138