1 /*-
2 * Copyright (c) 2010 Isilon Systems, Inc.
3 * Copyright (c) 2010 iX Systems, Inc.
4 * Copyright (c) 2010 Panasas, Inc.
5 * Copyright (c) 2013, 2014 Mellanox Technologies, Ltd.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice unmodified, this list of conditions, and the following
13 * disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #ifndef _ASM_ATOMIC_H_
31 #define _ASM_ATOMIC_H_
32
33 #include <sys/cdefs.h>
34 #include <sys/types.h>
35 #include <machine/atomic.h>
36
37 typedef struct {
38 volatile u_int counter;
39 } atomic_t;
40
41 #define atomic_add(i, v) atomic_add_return((i), (v))
42 #define atomic_sub(i, v) atomic_sub_return((i), (v))
43 #define atomic_inc_return(v) atomic_add_return(1, (v))
44 #define atomic_add_negative(i, v) (atomic_add_return((i), (v)) < 0)
45 #define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
46 #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
47 #define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
48 #define atomic_dec_return(v) atomic_sub_return(1, (v))
49
50 static inline int
atomic_add_return(int i,atomic_t * v)51 atomic_add_return(int i, atomic_t *v)
52 {
53 return i + atomic_fetchadd_int(&v->counter, i);
54 }
55
56 static inline int
atomic_sub_return(int i,atomic_t * v)57 atomic_sub_return(int i, atomic_t *v)
58 {
59 return atomic_fetchadd_int(&v->counter, -i) - i;
60 }
61
62 static inline void
atomic_set(atomic_t * v,int i)63 atomic_set(atomic_t *v, int i)
64 {
65 atomic_store_rel_int(&v->counter, i);
66 }
67
68 static inline int
atomic_read(atomic_t * v)69 atomic_read(atomic_t *v)
70 {
71 return atomic_load_acq_int(&v->counter);
72 }
73
74 static inline int
atomic_inc(atomic_t * v)75 atomic_inc(atomic_t *v)
76 {
77 return atomic_fetchadd_int(&v->counter, 1) + 1;
78 }
79
80 static inline int
atomic_dec(atomic_t * v)81 atomic_dec(atomic_t *v)
82 {
83 return atomic_fetchadd_int(&v->counter, -1) - 1;
84 }
85
atomic_add_unless(atomic_t * v,int a,int u)86 static inline int atomic_add_unless(atomic_t *v, int a, int u)
87 {
88 int c, old;
89 c = atomic_read(v);
90 for (;;) {
91 if (unlikely(c == (u)))
92 break;
93 old = atomic_cmpset_int(&v->counter, c, c + (a));
94 if (likely(old == c))
95 break;
96 c = old;
97 }
98 return c != (u);
99 }
100
101 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
102
103
104
105
106 #endif /* _ASM_ATOMIC_H_ */
107