1
2
3
4
5
6
7
8
9
10
11
12
13
14
15#ifndef __ASM_GENERIC_ATOMIC_H
16#define __ASM_GENERIC_ATOMIC_H
17
18#include <asm/cmpxchg.h>
19#include <asm/barrier.h>
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38#ifdef CONFIG_SMP
39
40
41
42#define ATOMIC_OP(op, c_op) \
43static inline void atomic_##op(int i, atomic_t *v) \
44{ \
45 int c, old; \
46 \
47 c = v->counter; \
48 while ((old = cmpxchg(&v->counter, c, c c_op i)) != c) \
49 c = old; \
50}
51
52#define ATOMIC_OP_RETURN(op, c_op) \
53static inline int atomic_##op##_return(int i, atomic_t *v) \
54{ \
55 int c, old; \
56 \
57 c = v->counter; \
58 while ((old = cmpxchg(&v->counter, c, c c_op i)) != c) \
59 c = old; \
60 \
61 return c c_op i; \
62}
63
64#define ATOMIC_FETCH_OP(op, c_op) \
65static inline int atomic_fetch_##op(int i, atomic_t *v) \
66{ \
67 int c, old; \
68 \
69 c = v->counter; \
70 while ((old = cmpxchg(&v->counter, c, c c_op i)) != c) \
71 c = old; \
72 \
73 return c; \
74}
75
76#else
77
78#include <linux/irqflags.h>
79
80#define ATOMIC_OP(op, c_op) \
81static inline void atomic_##op(int i, atomic_t *v) \
82{ \
83 unsigned long flags; \
84 \
85 raw_local_irq_save(flags); \
86 v->counter = v->counter c_op i; \
87 raw_local_irq_restore(flags); \
88}
89
90#define ATOMIC_OP_RETURN(op, c_op) \
91static inline int atomic_##op##_return(int i, atomic_t *v) \
92{ \
93 unsigned long flags; \
94 int ret; \
95 \
96 raw_local_irq_save(flags); \
97 ret = (v->counter = v->counter c_op i); \
98 raw_local_irq_restore(flags); \
99 \
100 return ret; \
101}
102
103#define ATOMIC_FETCH_OP(op, c_op) \
104static inline int atomic_fetch_##op(int i, atomic_t *v) \
105{ \
106 unsigned long flags; \
107 int ret; \
108 \
109 raw_local_irq_save(flags); \
110 ret = v->counter; \
111 v->counter = v->counter c_op i; \
112 raw_local_irq_restore(flags); \
113 \
114 return ret; \
115}
116
117#endif
118
119#ifndef atomic_add_return
120ATOMIC_OP_RETURN(add, +)
121#endif
122
123#ifndef atomic_sub_return
124ATOMIC_OP_RETURN(sub, -)
125#endif
126
127#ifndef atomic_fetch_add
128ATOMIC_FETCH_OP(add, +)
129#endif
130
131#ifndef atomic_fetch_sub
132ATOMIC_FETCH_OP(sub, -)
133#endif
134
135#ifndef atomic_fetch_and
136ATOMIC_FETCH_OP(and, &)
137#endif
138
139#ifndef atomic_fetch_or
140ATOMIC_FETCH_OP(or, |)
141#endif
142
143#ifndef atomic_fetch_xor
144ATOMIC_FETCH_OP(xor, ^)
145#endif
146
147#ifndef atomic_and
148ATOMIC_OP(and, &)
149#endif
150
151#ifndef atomic_or
152ATOMIC_OP(or, |)
153#endif
154
155#ifndef atomic_xor
156ATOMIC_OP(xor, ^)
157#endif
158
159#undef ATOMIC_FETCH_OP
160#undef ATOMIC_OP_RETURN
161#undef ATOMIC_OP
162
163
164
165
166
167
168#define ATOMIC_INIT(i) { (i) }
169
170
171
172
173
174
175
176#ifndef atomic_read
177#define atomic_read(v) READ_ONCE((v)->counter)
178#endif
179
180
181
182
183
184
185
186
187#define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i))
188
189#include <linux/irqflags.h>
190
191static inline int atomic_add_negative(int i, atomic_t *v)
192{
193 return atomic_add_return(i, v) < 0;
194}
195
196static inline void atomic_add(int i, atomic_t *v)
197{
198 atomic_add_return(i, v);
199}
200
201static inline void atomic_sub(int i, atomic_t *v)
202{
203 atomic_sub_return(i, v);
204}
205
206static inline void atomic_inc(atomic_t *v)
207{
208 atomic_add_return(1, v);
209}
210
211static inline void atomic_dec(atomic_t *v)
212{
213 atomic_sub_return(1, v);
214}
215
216#define atomic_dec_return(v) atomic_sub_return(1, (v))
217#define atomic_inc_return(v) atomic_add_return(1, (v))
218
219#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
220#define atomic_dec_and_test(v) (atomic_dec_return(v) == 0)
221#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
222
223#define atomic_xchg(ptr, v) (xchg(&(ptr)->counter, (v)))
224#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new)))
225
226static inline int __atomic_add_unless(atomic_t *v, int a, int u)
227{
228 int c, old;
229 c = atomic_read(v);
230 while (c != u && (old = atomic_cmpxchg(v, c, c + a)) != c)
231 c = old;
232 return c;
233}
234
235#endif
236