1 /*-
2 * Copyright (c) 2010 Isilon Systems, Inc.
3 * Copyright (c) 2010 iX Systems, Inc.
4 * Copyright (c) 2010 Panasas, Inc.
5 * Copyright (c) 2013-2017 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 * $FreeBSD$
30 */
31 #ifndef _ATOMIC_LONG_H_
32 #define _ATOMIC_LONG_H_
33
34 #include <linux/compiler.h>
35 #include <sys/types.h>
36 #include <machine/atomic.h>
37
38 #define ATOMIC_LONG_INIT(x) { .counter = (x) }
39
40 typedef struct {
41 volatile long counter;
42 } atomic_long_t;
43
44 #define atomic_long_add(i, v) atomic_long_add_return((i), (v))
45 #define atomic_long_sub(i, v) atomic_long_add_return(-(i), (v))
46 #define atomic_long_inc_return(v) atomic_long_add_return(1, (v))
47 #define atomic_long_inc_not_zero(v) atomic_long_add_unless((v), 1, 0)
48
49 static inline long
atomic_long_add_return(long i,atomic_long_t * v)50 atomic_long_add_return(long i, atomic_long_t *v)
51 {
52 return i + atomic_fetchadd_long(&v->counter, i);
53 }
54
55 static inline void
atomic_long_set(atomic_long_t * v,long i)56 atomic_long_set(atomic_long_t *v, long i)
57 {
58 WRITE_ONCE(v->counter, i);
59 }
60
61 static inline long
atomic_long_read(atomic_long_t * v)62 atomic_long_read(atomic_long_t *v)
63 {
64 return READ_ONCE(v->counter);
65 }
66
67 static inline long
atomic_long_inc(atomic_long_t * v)68 atomic_long_inc(atomic_long_t *v)
69 {
70 return atomic_fetchadd_long(&v->counter, 1) + 1;
71 }
72
73 static inline long
atomic_long_dec(atomic_long_t * v)74 atomic_long_dec(atomic_long_t *v)
75 {
76 return atomic_fetchadd_long(&v->counter, -1) - 1;
77 }
78
79 static inline long
atomic_long_xchg(atomic_long_t * v,long val)80 atomic_long_xchg(atomic_long_t *v, long val)
81 {
82 #if defined(__i386__) || defined(__amd64__) || defined(__aarch64__)
83 return atomic_swap_long(&v->counter, val);
84 #else
85 long ret = atomic_long_read(v);
86
87 while (!atomic_fcmpset_long(&v->counter, &ret, val))
88 ;
89 return (ret);
90 #endif
91 }
92
93 static inline long
atomic_long_cmpxchg(atomic_long_t * v,long old,long new)94 atomic_long_cmpxchg(atomic_long_t *v, long old, long new)
95 {
96 long ret = old;
97
98 for (;;) {
99 if (atomic_fcmpset_long(&v->counter, &ret, new))
100 break;
101 if (ret != old)
102 break;
103 }
104 return (ret);
105 }
106
107 static inline int
atomic_long_add_unless(atomic_long_t * v,long a,long u)108 atomic_long_add_unless(atomic_long_t *v, long a, long u)
109 {
110 long c = atomic_long_read(v);
111
112 for (;;) {
113 if (unlikely(c == u))
114 break;
115 if (likely(atomic_fcmpset_long(&v->counter, &c, c + a)))
116 break;
117 }
118 return (c != u);
119 }
120
121 static inline long
atomic_long_dec_and_test(atomic_long_t * v)122 atomic_long_dec_and_test(atomic_long_t *v)
123 {
124 long i = atomic_long_add(-1, v);
125 return i == 0 ;
126 }
127
128 #endif /* _ATOMIC_LONG_H_ */
129