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gerrit-public.fairphone.software / kernel / msm-4.9 / 1871c6020d7308afb99127bba51f04548e7ca84e / . / arch / x86 / include / asm / atomic64_32.h
blob: 03027bf28de5790afd8c6eb7c01b8362b19a78f6 [file] [log] [blame]
Brian Gerst1a3b1d82010-01-07 11:53:33 -0500[diff] [blame]1#ifndef _ASM_X86_ATOMIC64_32_H
2#define _ASM_X86_ATOMIC64_32_H
3
4#include <linux/compiler.h>
5#include <linux/types.h>
6#include <asm/processor.h>
7//#include <asm/cmpxchg.h>
8
9/* An 64bit atomic type */
10
11typedef struct {
12 u64 __aligned(8) counter;
13} atomic64_t;
14
15#define ATOMIC64_INIT(val) { (val) }
16
17extern u64 atomic64_cmpxchg(atomic64_t *ptr, u64 old_val, u64 new_val);
18
19/**
20 * atomic64_xchg - xchg atomic64 variable
21 * @ptr: pointer to type atomic64_t
22 * @new_val: value to assign
23 *
24 * Atomically xchgs the value of @ptr to @new_val and returns
25 * the old value.
26 */
27extern u64 atomic64_xchg(atomic64_t *ptr, u64 new_val);
28
29/**
30 * atomic64_set - set atomic64 variable
31 * @ptr: pointer to type atomic64_t
32 * @new_val: value to assign
33 *
34 * Atomically sets the value of @ptr to @new_val.
35 */
36extern void atomic64_set(atomic64_t *ptr, u64 new_val);
37
38/**
39 * atomic64_read - read atomic64 variable
40 * @ptr: pointer to type atomic64_t
41 *
42 * Atomically reads the value of @ptr and returns it.
43 */
44static inline u64 atomic64_read(atomic64_t *ptr)
45{
46 u64 res;
47
48 /*
49 * Note, we inline this atomic64_t primitive because
50 * it only clobbers EAX/EDX and leaves the others
51 * untouched. We also (somewhat subtly) rely on the
52 * fact that cmpxchg8b returns the current 64-bit value
53 * of the memory location we are touching:
54 */
55 asm volatile(
56 "mov %%ebx, %%eax\n\t"
57 "mov %%ecx, %%edx\n\t"
58 LOCK_PREFIX "cmpxchg8b %1\n"
59 : "=&A" (res)
60 : "m" (*ptr)
61 );
62
63 return res;
64}
65
66extern u64 atomic64_read(atomic64_t *ptr);
67
68/**
69 * atomic64_add_return - add and return
70 * @delta: integer value to add
71 * @ptr: pointer to type atomic64_t
72 *
73 * Atomically adds @delta to @ptr and returns @delta + *@ptr
74 */
75extern u64 atomic64_add_return(u64 delta, atomic64_t *ptr);
76
77/*
78 * Other variants with different arithmetic operators:
79 */
80extern u64 atomic64_sub_return(u64 delta, atomic64_t *ptr);
81extern u64 atomic64_inc_return(atomic64_t *ptr);
82extern u64 atomic64_dec_return(atomic64_t *ptr);
83
84/**
85 * atomic64_add - add integer to atomic64 variable
86 * @delta: integer value to add
87 * @ptr: pointer to type atomic64_t
88 *
89 * Atomically adds @delta to @ptr.
90 */
91extern void atomic64_add(u64 delta, atomic64_t *ptr);
92
93/**
94 * atomic64_sub - subtract the atomic64 variable
95 * @delta: integer value to subtract
96 * @ptr: pointer to type atomic64_t
97 *
98 * Atomically subtracts @delta from @ptr.
99 */
100extern void atomic64_sub(u64 delta, atomic64_t *ptr);
101
102/**
103 * atomic64_sub_and_test - subtract value from variable and test result
104 * @delta: integer value to subtract
105 * @ptr: pointer to type atomic64_t
106 *
107 * Atomically subtracts @delta from @ptr and returns
108 * true if the result is zero, or false for all
109 * other cases.
110 */
111extern int atomic64_sub_and_test(u64 delta, atomic64_t *ptr);
112
113/**
114 * atomic64_inc - increment atomic64 variable
115 * @ptr: pointer to type atomic64_t
116 *
117 * Atomically increments @ptr by 1.
118 */
119extern void atomic64_inc(atomic64_t *ptr);
120
121/**
122 * atomic64_dec - decrement atomic64 variable
123 * @ptr: pointer to type atomic64_t
124 *
125 * Atomically decrements @ptr by 1.
126 */
127extern void atomic64_dec(atomic64_t *ptr);
128
129/**
130 * atomic64_dec_and_test - decrement and test
131 * @ptr: pointer to type atomic64_t
132 *
133 * Atomically decrements @ptr by 1 and
134 * returns true if the result is 0, or false for all other
135 * cases.
136 */
137extern int atomic64_dec_and_test(atomic64_t *ptr);
138
139/**
140 * atomic64_inc_and_test - increment and test
141 * @ptr: pointer to type atomic64_t
142 *
143 * Atomically increments @ptr by 1
144 * and returns true if the result is zero, or false for all
145 * other cases.
146 */
147extern int atomic64_inc_and_test(atomic64_t *ptr);
148
149/**
150 * atomic64_add_negative - add and test if negative
151 * @delta: integer value to add
152 * @ptr: pointer to type atomic64_t
153 *
154 * Atomically adds @delta to @ptr and returns true
155 * if the result is negative, or false when
156 * result is greater than or equal to zero.
157 */
158extern int atomic64_add_negative(u64 delta, atomic64_t *ptr);
159
160#endif /* _ASM_X86_ATOMIC64_32_H */