atomic-long.h revision 361181 
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: stable/11/sys/compat/linuxkpi/common/include/asm/atomic-long.h 361181 2020-05-18 09:12:13Z hselasky $
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
40typedef 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_inc_return(v)	atomic_long_add_return(1, (v))
46#define	atomic_long_inc_not_zero(v)	atomic_long_add_unless((v), 1, 0)
47
48static inline long
49atomic_long_add_return(long i, atomic_long_t *v)
50{
51	return i + atomic_fetchadd_long(&v->counter, i);
52}
53
54static inline void
55atomic_long_set(atomic_long_t *v, long i)
56{
57	WRITE_ONCE(v->counter, i);
58}
59
60static inline long
61atomic_long_read(atomic_long_t *v)
62{
63	return READ_ONCE(v->counter);
64}
65
66static inline long
67atomic_long_inc(atomic_long_t *v)
68{
69	return atomic_fetchadd_long(&v->counter, 1) + 1;
70}
71
72static inline long
73atomic_long_dec(atomic_long_t *v)
74{
75	return atomic_fetchadd_long(&v->counter, -1) - 1;
76}
77
78static inline long
79atomic_long_xchg(atomic_long_t *v, long val)
80{
81#if defined(__i386__) || defined(__amd64__) || defined(__aarch64__)
82	return atomic_swap_long(&v->counter, val);
83#else
84	long ret = atomic_long_read(v);
85
86	while (!atomic_fcmpset_long(&v->counter, &ret, val))
87		;
88	return (ret);
89#endif
90}
91
92static inline long
93atomic_long_cmpxchg(atomic_long_t *v, long old, long new)
94{
95	long ret = old;
96
97	for (;;) {
98		if (atomic_fcmpset_long(&v->counter, &ret, new))
99			break;
100		if (ret != old)
101			break;
102	}
103	return (ret);
104}
105
106static inline int
107atomic_long_add_unless(atomic_long_t *v, long a, long u)
108{
109	long c = atomic_long_read(v);
110
111	for (;;) {
112		if (unlikely(c == u))
113			break;
114		if (likely(atomic_fcmpset_long(&v->counter, &c, c + a)))
115			break;
116	}
117	return (c != u);
118}
119
120static inline long
121atomic_long_fetch_add_unless(atomic_long_t *v, long a, long u)
122{
123	long c = atomic_long_read(v);
124
125	for (;;) {
126		if (unlikely(c == u))
127			break;
128		if (likely(atomic_fcmpset_long(&v->counter, &c, c + a)))
129			break;
130	}
131	return (c);
132}
133
134static inline long
135atomic_long_dec_and_test(atomic_long_t *v)
136{
137	long i = atomic_long_add(-1, v);
138	return i == 0 ;
139}
140
141#endif	/* _ATOMIC_LONG_H_ */
142