1#ifndef __TOOLS_ASM_GENERIC_ATOMIC_H
 2#define __TOOLS_ASM_GENERIC_ATOMIC_H
 3
 4#include <linux/compiler.h>
 5#include <linux/types.h>
 
 6
 7/*
 8 * Atomic operations that C can't guarantee us.  Useful for
 9 * resource counting etc..
10 *
11 * Excerpts obtained from the Linux kernel sources.
12 */
13
14#define ATOMIC_INIT(i)	{ (i) }
15
16/**
17 * atomic_read - read atomic variable
18 * @v: pointer of type atomic_t
19 *
20 * Atomically reads the value of @v.
21 */
22static inline int atomic_read(const atomic_t *v)
23{
24	return ACCESS_ONCE((v)->counter);
25}
26
27/**
28 * atomic_set - set atomic variable
29 * @v: pointer of type atomic_t
30 * @i: required value
31 *
32 * Atomically sets the value of @v to @i.
33 */
34static inline void atomic_set(atomic_t *v, int i)
35{
36        v->counter = i;
37}
38
39/**
40 * atomic_inc - increment atomic variable
41 * @v: pointer of type atomic_t
42 *
43 * Atomically increments @v by 1.
44 */
45static inline void atomic_inc(atomic_t *v)
46{
47	__sync_add_and_fetch(&v->counter, 1);
48}
49
50/**
51 * atomic_dec_and_test - decrement and test
52 * @v: pointer of type atomic_t
53 *
54 * Atomically decrements @v by 1 and
55 * returns true if the result is 0, or false for all other
56 * cases.
57 */
58static inline int atomic_dec_and_test(atomic_t *v)
59{
60	return __sync_sub_and_fetch(&v->counter, 1) == 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
61}
62
63#endif /* __TOOLS_ASM_GENERIC_ATOMIC_H */

 1/* SPDX-License-Identifier: GPL-2.0 */
 2#ifndef __TOOLS_ASM_GENERIC_ATOMIC_H
 3#define __TOOLS_ASM_GENERIC_ATOMIC_H
 4
 5#include <linux/compiler.h>
 6#include <linux/types.h>
 7#include <linux/bitops.h>
 8
 9/*
10 * Atomic operations that C can't guarantee us.  Useful for
11 * resource counting etc..
12 *
13 * Excerpts obtained from the Linux kernel sources.
14 */
15
16#define ATOMIC_INIT(i)	{ (i) }
17
18/**
19 * atomic_read - read atomic variable
20 * @v: pointer of type atomic_t
21 *
22 * Atomically reads the value of @v.
23 */
24static inline int atomic_read(const atomic_t *v)
25{
26	return READ_ONCE((v)->counter);
27}
28
29/**
30 * atomic_set - set atomic variable
31 * @v: pointer of type atomic_t
32 * @i: required value
33 *
34 * Atomically sets the value of @v to @i.
35 */
36static inline void atomic_set(atomic_t *v, int i)
37{
38        v->counter = i;
39}
40
41/**
42 * atomic_inc - increment atomic variable
43 * @v: pointer of type atomic_t
44 *
45 * Atomically increments @v by 1.
46 */
47static inline void atomic_inc(atomic_t *v)
48{
49	__sync_add_and_fetch(&v->counter, 1);
50}
51
52/**
53 * atomic_dec_and_test - decrement and test
54 * @v: pointer of type atomic_t
55 *
56 * Atomically decrements @v by 1 and
57 * returns true if the result is 0, or false for all other
58 * cases.
59 */
60static inline int atomic_dec_and_test(atomic_t *v)
61{
62	return __sync_sub_and_fetch(&v->counter, 1) == 0;
63}
64
65#define cmpxchg(ptr, oldval, newval) \
66	__sync_val_compare_and_swap(ptr, oldval, newval)
67
68static inline int atomic_cmpxchg(atomic_t *v, int oldval, int newval)
69{
70	return cmpxchg(&(v)->counter, oldval, newval);
71}
72
73static inline int test_and_set_bit(long nr, unsigned long *addr)
74{
75	unsigned long mask = BIT_MASK(nr);
76	long old;
77
78	addr += BIT_WORD(nr);
79
80	old = __sync_fetch_and_or(addr, mask);
81	return !!(old & mask);
82}
83
84static inline int test_and_clear_bit(long nr, unsigned long *addr)
85{
86	unsigned long mask = BIT_MASK(nr);
87	long old;
88
89	addr += BIT_WORD(nr);
90
91	old = __sync_fetch_and_and(addr, ~mask);
92	return !!(old & mask);
93}
94
95#endif /* __TOOLS_ASM_GENERIC_ATOMIC_H */