1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/******************************************************************************
3 *
4 *   Copyright �� International Business Machines  Corp., 2009
5 *
6 * DESCRIPTION
7 *      GCC atomic builtin wrappers
8 *      http://gcc.gnu.org/onlinedocs/gcc-4.1.0/gcc/Atomic-Builtins.html
9 *
10 * AUTHOR
11 *      Darren Hart <dvhart@linux.intel.com>
12 *
13 * HISTORY
14 *      2009-Nov-17: Initial version by Darren Hart <dvhart@linux.intel.com>
15 *
16 *****************************************************************************/
17
18#ifndef _ATOMIC_H
19#define _ATOMIC_H
20
21typedef struct {
22	volatile int val;
23} atomic_t;
24
25#define ATOMIC_INITIALIZER { 0 }
26
27/**
28 * atomic_cmpxchg() - Atomic compare and exchange
29 * @uaddr:	The address of the futex to be modified
30 * @oldval:	The expected value of the futex
31 * @newval:	The new value to try and assign the futex
32 *
33 * Return the old value of addr->val.
34 */
35static inline int
36atomic_cmpxchg(atomic_t *addr, int oldval, int newval)
37{
38	return __sync_val_compare_and_swap(&addr->val, oldval, newval);
39}
40
41/**
42 * atomic_inc() - Atomic incrememnt
43 * @addr:	Address of the variable to increment
44 *
45 * Return the new value of addr->val.
46 */
47static inline int
48atomic_inc(atomic_t *addr)
49{
50	return __sync_add_and_fetch(&addr->val, 1);
51}
52
53/**
54 * atomic_dec() - Atomic decrement
55 * @addr:	Address of the variable to decrement
56 *
57 * Return the new value of addr-val.
58 */
59static inline int
60atomic_dec(atomic_t *addr)
61{
62	return __sync_sub_and_fetch(&addr->val, 1);
63}
64
65/**
66 * atomic_set() - Atomic set
67 * @addr:	Address of the variable to set
68 * @newval:	New value for the atomic_t
69 *
70 * Return the new value of addr->val.
71 */
72static inline int
73atomic_set(atomic_t *addr, int newval)
74{
75	addr->val = newval;
76	return newval;
77}
78
79#endif
80