xref: /freebsd/sys/compat/linuxkpi/common/include/asm/atomic64.h (revision 1f4bcc459a76b7aa664f3fd557684cd0ba6da352)
1 /*-
2  * Copyright (c) 2016 Mellanox Technologies, Ltd.
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 unmodified, this list of conditions, and the following
10  *    disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 #ifndef	_ASM_ATOMIC64_H_
29 #define	_ASM_ATOMIC64_H_
30 
31 #include <sys/cdefs.h>
32 #include <sys/types.h>
33 #include <machine/atomic.h>
34 
35 typedef struct {
36 	volatile int64_t counter;
37 } atomic64_t;
38 
39 /*------------------------------------------------------------------------*
40  *	64-bit atomic operations
41  *------------------------------------------------------------------------*/
42 
43 #define	atomic64_add(i, v)		atomic64_add_return((i), (v))
44 #define	atomic64_sub(i, v)		atomic64_sub_return((i), (v))
45 #define	atomic64_inc_return(v)		atomic64_add_return(1, (v))
46 #define	atomic64_add_negative(i, v)	(atomic64_add_return((i), (v)) < 0)
47 #define	atomic64_sub_and_test(i, v)	(atomic64_sub_return((i), (v)) == 0)
48 #define	atomic64_dec_and_test(v)	(atomic64_sub_return(1, (v)) == 0)
49 #define	atomic64_inc_and_test(v)	(atomic64_add_return(1, (v)) == 0)
50 #define	atomic64_dec_return(v)		atomic64_sub_return(1, (v))
51 #define	atomic64_inc_not_zero(v)	atomic64_add_unless((v), 1, 0)
52 
53 static inline int64_t
54 atomic64_add_return(int64_t i, atomic64_t *v)
55 {
56 	return i + atomic_fetchadd_64(&v->counter, i);
57 }
58 
59 static inline int64_t
60 atomic64_sub_return(int64_t i, atomic64_t *v)
61 {
62 	return atomic_fetchadd_64(&v->counter, -i) - i;
63 }
64 
65 static inline void
66 atomic64_set(atomic64_t *v, int64_t i)
67 {
68 	atomic_store_rel_64(&v->counter, i);
69 }
70 
71 static inline int64_t
72 atomic64_read(atomic64_t *v)
73 {
74 	return atomic_load_acq_64(&v->counter);
75 }
76 
77 static inline int64_t
78 atomic64_inc(atomic64_t *v)
79 {
80 	return atomic_fetchadd_64(&v->counter, 1) + 1;
81 }
82 
83 static inline int64_t
84 atomic64_dec(atomic64_t *v)
85 {
86 	return atomic_fetchadd_64(&v->counter, -1) - 1;
87 }
88 
89 static inline int64_t
90 atomic64_add_unless(atomic64_t *v, int64_t a, int64_t u)
91 {
92 	int64_t c;
93 
94 	for (;;) {
95 		c = atomic64_read(v);
96 		if (unlikely(c == u))
97 			break;
98 		if (likely(atomic_cmpset_64(&v->counter, c, c + a)))
99 			break;
100 	}
101 	return (c != u);
102 }
103 
104 #endif					/* _ASM_ATOMIC64_H_ */
105