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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _ALPHA_ATOMIC_H
2#define _ALPHA_ATOMIC_H
3
Matthew Wilcoxea4354672009-01-06 14:40:39 -08004#include <linux/types.h>
Andrew Morton0db9ae42005-10-24 23:05:58 -07005#include <asm/barrier.h>
Mathieu Desnoyers2856f5e2007-05-08 00:34:38 -07006#include <asm/system.h>
Andrew Morton0db9ae42005-10-24 23:05:58 -07007
Linus Torvalds1da177e2005-04-16 15:20:36 -07008/*
9 * Atomic operations that C can't guarantee us. Useful for
10 * resource counting etc...
11 *
12 * But use these as seldom as possible since they are much slower
13 * than regular operations.
14 */
15
16
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#define ATOMIC_INIT(i) ( (atomic_t) { (i) } )
18#define ATOMIC64_INIT(i) ( (atomic64_t) { (i) } )
19
Anton Blanchardf3d46f92010-05-17 14:33:53 +100020#define atomic_read(v) (*(volatile int *)&(v)->counter)
21#define atomic64_read(v) (*(volatile long *)&(v)->counter)
Linus Torvalds1da177e2005-04-16 15:20:36 -070022
23#define atomic_set(v,i) ((v)->counter = (i))
24#define atomic64_set(v,i) ((v)->counter = (i))
25
26/*
27 * To get proper branch prediction for the main line, we must branch
28 * forward to code at the end of this object's .text section, then
29 * branch back to restart the operation.
30 */
31
32static __inline__ void atomic_add(int i, atomic_t * v)
33{
34 unsigned long temp;
35 __asm__ __volatile__(
36 "1: ldl_l %0,%1\n"
37 " addl %0,%2,%0\n"
38 " stl_c %0,%1\n"
39 " beq %0,2f\n"
40 ".subsection 2\n"
41 "2: br 1b\n"
42 ".previous"
43 :"=&r" (temp), "=m" (v->counter)
44 :"Ir" (i), "m" (v->counter));
45}
46
47static __inline__ void atomic64_add(long i, atomic64_t * v)
48{
49 unsigned long temp;
50 __asm__ __volatile__(
51 "1: ldq_l %0,%1\n"
52 " addq %0,%2,%0\n"
53 " stq_c %0,%1\n"
54 " beq %0,2f\n"
55 ".subsection 2\n"
56 "2: br 1b\n"
57 ".previous"
58 :"=&r" (temp), "=m" (v->counter)
59 :"Ir" (i), "m" (v->counter));
60}
61
62static __inline__ void atomic_sub(int i, atomic_t * v)
63{
64 unsigned long temp;
65 __asm__ __volatile__(
66 "1: ldl_l %0,%1\n"
67 " subl %0,%2,%0\n"
68 " stl_c %0,%1\n"
69 " beq %0,2f\n"
70 ".subsection 2\n"
71 "2: br 1b\n"
72 ".previous"
73 :"=&r" (temp), "=m" (v->counter)
74 :"Ir" (i), "m" (v->counter));
75}
76
77static __inline__ void atomic64_sub(long i, atomic64_t * v)
78{
79 unsigned long temp;
80 __asm__ __volatile__(
81 "1: ldq_l %0,%1\n"
82 " subq %0,%2,%0\n"
83 " stq_c %0,%1\n"
84 " beq %0,2f\n"
85 ".subsection 2\n"
86 "2: br 1b\n"
87 ".previous"
88 :"=&r" (temp), "=m" (v->counter)
89 :"Ir" (i), "m" (v->counter));
90}
91
92
93/*
94 * Same as above, but return the result value
95 */
Andrew Morton26a6e662008-02-04 22:30:02 -080096static inline int atomic_add_return(int i, atomic_t *v)
Linus Torvalds1da177e2005-04-16 15:20:36 -070097{
98 long temp, result;
Ivan Kokshayskyd475f3f2005-10-21 22:06:15 +040099 smp_mb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 __asm__ __volatile__(
101 "1: ldl_l %0,%1\n"
102 " addl %0,%3,%2\n"
103 " addl %0,%3,%0\n"
104 " stl_c %0,%1\n"
105 " beq %0,2f\n"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 ".subsection 2\n"
107 "2: br 1b\n"
108 ".previous"
109 :"=&r" (temp), "=m" (v->counter), "=&r" (result)
110 :"Ir" (i), "m" (v->counter) : "memory");
Ivan Kokshayskyd475f3f2005-10-21 22:06:15 +0400111 smp_mb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 return result;
113}
114
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115static __inline__ long atomic64_add_return(long i, atomic64_t * v)
116{
117 long temp, result;
Ivan Kokshayskyd475f3f2005-10-21 22:06:15 +0400118 smp_mb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 __asm__ __volatile__(
120 "1: ldq_l %0,%1\n"
121 " addq %0,%3,%2\n"
122 " addq %0,%3,%0\n"
123 " stq_c %0,%1\n"
124 " beq %0,2f\n"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 ".subsection 2\n"
126 "2: br 1b\n"
127 ".previous"
128 :"=&r" (temp), "=m" (v->counter), "=&r" (result)
129 :"Ir" (i), "m" (v->counter) : "memory");
Ivan Kokshayskyd475f3f2005-10-21 22:06:15 +0400130 smp_mb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 return result;
132}
133
134static __inline__ long atomic_sub_return(int i, atomic_t * v)
135{
136 long temp, result;
Ivan Kokshayskyd475f3f2005-10-21 22:06:15 +0400137 smp_mb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 __asm__ __volatile__(
139 "1: ldl_l %0,%1\n"
140 " subl %0,%3,%2\n"
141 " subl %0,%3,%0\n"
142 " stl_c %0,%1\n"
143 " beq %0,2f\n"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 ".subsection 2\n"
145 "2: br 1b\n"
146 ".previous"
147 :"=&r" (temp), "=m" (v->counter), "=&r" (result)
148 :"Ir" (i), "m" (v->counter) : "memory");
Ivan Kokshayskyd475f3f2005-10-21 22:06:15 +0400149 smp_mb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 return result;
151}
152
153static __inline__ long atomic64_sub_return(long i, atomic64_t * v)
154{
155 long temp, result;
Ivan Kokshayskyd475f3f2005-10-21 22:06:15 +0400156 smp_mb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 __asm__ __volatile__(
158 "1: ldq_l %0,%1\n"
159 " subq %0,%3,%2\n"
160 " subq %0,%3,%0\n"
161 " stq_c %0,%1\n"
162 " beq %0,2f\n"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 ".subsection 2\n"
164 "2: br 1b\n"
165 ".previous"
166 :"=&r" (temp), "=m" (v->counter), "=&r" (result)
167 :"Ir" (i), "m" (v->counter) : "memory");
Ivan Kokshayskyd475f3f2005-10-21 22:06:15 +0400168 smp_mb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 return result;
170}
171
Mathieu Desnoyerse96e6992007-05-08 00:34:18 -0700172#define atomic64_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
173#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
174
175#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
Ingo Molnarffbf6702006-01-09 15:59:17 -0800176#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
Nick Piggin4a6dae62005-11-13 16:07:24 -0800177
Mathieu Desnoyerse96e6992007-05-08 00:34:18 -0700178/**
179 * atomic_add_unless - add unless the number is a given value
180 * @v: pointer of type atomic_t
181 * @a: the amount to add to v...
182 * @u: ...unless v is equal to u.
183 *
184 * Atomically adds @a to @v, so long as it was not @u.
185 * Returns non-zero if @v was not @u, and zero otherwise.
186 */
Mathieu Desnoyers2856f5e2007-05-08 00:34:38 -0700187static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
188{
189 int c, old;
190 c = atomic_read(v);
191 for (;;) {
192 if (unlikely(c == (u)))
193 break;
194 old = atomic_cmpxchg((v), c, c + (a));
195 if (likely(old == c))
196 break;
197 c = old;
198 }
199 return c != (u);
200}
201
Nick Piggin8426e1f2005-11-13 16:07:25 -0800202#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
203
Mathieu Desnoyerse96e6992007-05-08 00:34:18 -0700204/**
205 * atomic64_add_unless - add unless the number is a given value
206 * @v: pointer of type atomic64_t
207 * @a: the amount to add to v...
208 * @u: ...unless v is equal to u.
209 *
210 * Atomically adds @a to @v, so long as it was not @u.
211 * Returns non-zero if @v was not @u, and zero otherwise.
212 */
Mathieu Desnoyers2856f5e2007-05-08 00:34:38 -0700213static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
214{
215 long c, old;
216 c = atomic64_read(v);
217 for (;;) {
218 if (unlikely(c == (u)))
219 break;
220 old = atomic64_cmpxchg((v), c, c + (a));
221 if (likely(old == c))
222 break;
223 c = old;
224 }
225 return c != (u);
226}
227
Mathieu Desnoyerse96e6992007-05-08 00:34:18 -0700228#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
229
Hugh Dickins7c72aaf2005-11-23 13:37:40 -0800230#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
231#define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0)
232
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233#define atomic_dec_return(v) atomic_sub_return(1,(v))
234#define atomic64_dec_return(v) atomic64_sub_return(1,(v))
235
236#define atomic_inc_return(v) atomic_add_return(1,(v))
237#define atomic64_inc_return(v) atomic64_add_return(1,(v))
238
239#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
240#define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0)
241
242#define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
Hugh Dickins7c72aaf2005-11-23 13:37:40 -0800243#define atomic64_inc_and_test(v) (atomic64_add_return(1, (v)) == 0)
244
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
246#define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)
247
248#define atomic_inc(v) atomic_add(1,(v))
249#define atomic64_inc(v) atomic64_add(1,(v))
250
251#define atomic_dec(v) atomic_sub(1,(v))
252#define atomic64_dec(v) atomic64_sub(1,(v))
253
254#define smp_mb__before_atomic_dec() smp_mb()
255#define smp_mb__after_atomic_dec() smp_mb()
256#define smp_mb__before_atomic_inc() smp_mb()
257#define smp_mb__after_atomic_inc() smp_mb()
258
Arnd Bergmann72099ed2009-05-13 22:56:29 +0000259#include <asm-generic/atomic-long.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260#endif /* _ALPHA_ATOMIC_H */