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-rw-r--r--arch/alpha/include/asm/atomic.h267
1 files changed, 267 insertions, 0 deletions
diff --git a/arch/alpha/include/asm/atomic.h b/arch/alpha/include/asm/atomic.h
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1#ifndef _ALPHA_ATOMIC_H
2#define _ALPHA_ATOMIC_H
3
4#include <asm/barrier.h>
5#include <asm/system.h>
6
7/*
8 * Atomic operations that C can't guarantee us. Useful for
9 * resource counting etc...
10 *
11 * But use these as seldom as possible since they are much slower
12 * than regular operations.
13 */
14
15
16/*
17 * Counter is volatile to make sure gcc doesn't try to be clever
18 * and move things around on us. We need to use _exactly_ the address
19 * the user gave us, not some alias that contains the same information.
20 */
21typedef struct { volatile int counter; } atomic_t;
22typedef struct { volatile long counter; } atomic64_t;
23
24#define ATOMIC_INIT(i) ( (atomic_t) { (i) } )
25#define ATOMIC64_INIT(i) ( (atomic64_t) { (i) } )
26
27#define atomic_read(v) ((v)->counter + 0)
28#define atomic64_read(v) ((v)->counter + 0)
29
30#define atomic_set(v,i) ((v)->counter = (i))
31#define atomic64_set(v,i) ((v)->counter = (i))
32
33/*
34 * To get proper branch prediction for the main line, we must branch
35 * forward to code at the end of this object's .text section, then
36 * branch back to restart the operation.
37 */
38
39static __inline__ void atomic_add(int i, atomic_t * v)
40{
41 unsigned long temp;
42 __asm__ __volatile__(
43 "1: ldl_l %0,%1\n"
44 " addl %0,%2,%0\n"
45 " stl_c %0,%1\n"
46 " beq %0,2f\n"
47 ".subsection 2\n"
48 "2: br 1b\n"
49 ".previous"
50 :"=&r" (temp), "=m" (v->counter)
51 :"Ir" (i), "m" (v->counter));
52}
53
54static __inline__ void atomic64_add(long i, atomic64_t * v)
55{
56 unsigned long temp;
57 __asm__ __volatile__(
58 "1: ldq_l %0,%1\n"
59 " addq %0,%2,%0\n"
60 " stq_c %0,%1\n"
61 " beq %0,2f\n"
62 ".subsection 2\n"
63 "2: br 1b\n"
64 ".previous"
65 :"=&r" (temp), "=m" (v->counter)
66 :"Ir" (i), "m" (v->counter));
67}
68
69static __inline__ void atomic_sub(int i, atomic_t * v)
70{
71 unsigned long temp;
72 __asm__ __volatile__(
73 "1: ldl_l %0,%1\n"
74 " subl %0,%2,%0\n"
75 " stl_c %0,%1\n"
76 " beq %0,2f\n"
77 ".subsection 2\n"
78 "2: br 1b\n"
79 ".previous"
80 :"=&r" (temp), "=m" (v->counter)
81 :"Ir" (i), "m" (v->counter));
82}
83
84static __inline__ void atomic64_sub(long i, atomic64_t * v)
85{
86 unsigned long temp;
87 __asm__ __volatile__(
88 "1: ldq_l %0,%1\n"
89 " subq %0,%2,%0\n"
90 " stq_c %0,%1\n"
91 " beq %0,2f\n"
92 ".subsection 2\n"
93 "2: br 1b\n"
94 ".previous"
95 :"=&r" (temp), "=m" (v->counter)
96 :"Ir" (i), "m" (v->counter));
97}
98
99
100/*
101 * Same as above, but return the result value
102 */
103static inline int atomic_add_return(int i, atomic_t *v)
104{
105 long temp, result;
106 smp_mb();
107 __asm__ __volatile__(
108 "1: ldl_l %0,%1\n"
109 " addl %0,%3,%2\n"
110 " addl %0,%3,%0\n"
111 " stl_c %0,%1\n"
112 " beq %0,2f\n"
113 ".subsection 2\n"
114 "2: br 1b\n"
115 ".previous"
116 :"=&r" (temp), "=m" (v->counter), "=&r" (result)
117 :"Ir" (i), "m" (v->counter) : "memory");
118 smp_mb();
119 return result;
120}
121
122static __inline__ long atomic64_add_return(long i, atomic64_t * v)
123{
124 long temp, result;
125 smp_mb();
126 __asm__ __volatile__(
127 "1: ldq_l %0,%1\n"
128 " addq %0,%3,%2\n"
129 " addq %0,%3,%0\n"
130 " stq_c %0,%1\n"
131 " beq %0,2f\n"
132 ".subsection 2\n"
133 "2: br 1b\n"
134 ".previous"
135 :"=&r" (temp), "=m" (v->counter), "=&r" (result)
136 :"Ir" (i), "m" (v->counter) : "memory");
137 smp_mb();
138 return result;
139}
140
141static __inline__ long atomic_sub_return(int i, atomic_t * v)
142{
143 long temp, result;
144 smp_mb();
145 __asm__ __volatile__(
146 "1: ldl_l %0,%1\n"
147 " subl %0,%3,%2\n"
148 " subl %0,%3,%0\n"
149 " stl_c %0,%1\n"
150 " beq %0,2f\n"
151 ".subsection 2\n"
152 "2: br 1b\n"
153 ".previous"
154 :"=&r" (temp), "=m" (v->counter), "=&r" (result)
155 :"Ir" (i), "m" (v->counter) : "memory");
156 smp_mb();
157 return result;
158}
159
160static __inline__ long atomic64_sub_return(long i, atomic64_t * v)
161{
162 long temp, result;
163 smp_mb();
164 __asm__ __volatile__(
165 "1: ldq_l %0,%1\n"
166 " subq %0,%3,%2\n"
167 " subq %0,%3,%0\n"
168 " stq_c %0,%1\n"
169 " beq %0,2f\n"
170 ".subsection 2\n"
171 "2: br 1b\n"
172 ".previous"
173 :"=&r" (temp), "=m" (v->counter), "=&r" (result)
174 :"Ir" (i), "m" (v->counter) : "memory");
175 smp_mb();
176 return result;
177}
178
179#define atomic64_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
180#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
181
182#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
183#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
184
185/**
186 * atomic_add_unless - add unless the number is a given value
187 * @v: pointer of type atomic_t
188 * @a: the amount to add to v...
189 * @u: ...unless v is equal to u.
190 *
191 * Atomically adds @a to @v, so long as it was not @u.
192 * Returns non-zero if @v was not @u, and zero otherwise.
193 */
194static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
195{
196 int c, old;
197 c = atomic_read(v);
198 for (;;) {
199 if (unlikely(c == (u)))
200 break;
201 old = atomic_cmpxchg((v), c, c + (a));
202 if (likely(old == c))
203 break;
204 c = old;
205 }
206 return c != (u);
207}
208
209#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
210
211/**
212 * atomic64_add_unless - add unless the number is a given value
213 * @v: pointer of type atomic64_t
214 * @a: the amount to add to v...
215 * @u: ...unless v is equal to u.
216 *
217 * Atomically adds @a to @v, so long as it was not @u.
218 * Returns non-zero if @v was not @u, and zero otherwise.
219 */
220static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
221{
222 long c, old;
223 c = atomic64_read(v);
224 for (;;) {
225 if (unlikely(c == (u)))
226 break;
227 old = atomic64_cmpxchg((v), c, c + (a));
228 if (likely(old == c))
229 break;
230 c = old;
231 }
232 return c != (u);
233}
234
235#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
236
237#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
238#define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0)
239
240#define atomic_dec_return(v) atomic_sub_return(1,(v))
241#define atomic64_dec_return(v) atomic64_sub_return(1,(v))
242
243#define atomic_inc_return(v) atomic_add_return(1,(v))
244#define atomic64_inc_return(v) atomic64_add_return(1,(v))
245
246#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
247#define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0)
248
249#define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
250#define atomic64_inc_and_test(v) (atomic64_add_return(1, (v)) == 0)
251
252#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
253#define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)
254
255#define atomic_inc(v) atomic_add(1,(v))
256#define atomic64_inc(v) atomic64_add(1,(v))
257
258#define atomic_dec(v) atomic_sub(1,(v))
259#define atomic64_dec(v) atomic64_sub(1,(v))
260
261#define smp_mb__before_atomic_dec() smp_mb()
262#define smp_mb__after_atomic_dec() smp_mb()
263#define smp_mb__before_atomic_inc() smp_mb()
264#define smp_mb__after_atomic_inc() smp_mb()
265
266#include <asm-generic/atomic.h>
267#endif /* _ALPHA_ATOMIC_H */
generated by cgit v1.2.2 (git 2.25.0) at 2024-10-31 20:42:31 -0400