1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
|
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ALPHA_ATOMIC_H
#define _ALPHA_ATOMIC_H
#include <linux/types.h>
#include <asm/barrier.h>
#include <asm/cmpxchg.h>
/*
* Atomic operations that C can't guarantee us. Useful for
* resource counting etc...
*
* But use these as seldom as possible since they are much slower
* than regular operations.
*/
/*
* To ensure dependency ordering is preserved for the _relaxed and
* _release atomics, an smp_read_barrier_depends() is unconditionally
* inserted into the _relaxed variants, which are used to build the
* barriered versions. Avoid redundant back-to-back fences in the
* _acquire and _fence versions.
*/
#define __atomic_acquire_fence()
#define __atomic_post_full_fence()
#define ATOMIC_INIT(i) { (i) }
#define ATOMIC64_INIT(i) { (i) }
#define atomic_read(v) READ_ONCE((v)->counter)
#define atomic64_read(v) READ_ONCE((v)->counter)
#define atomic_set(v,i) WRITE_ONCE((v)->counter, (i))
#define atomic64_set(v,i) WRITE_ONCE((v)->counter, (i))
/*
* To get proper branch prediction for the main line, we must branch
* forward to code at the end of this object's .text section, then
* branch back to restart the operation.
*/
#define ATOMIC_OP(op, asm_op) \
static __inline__ void atomic_##op(int i, atomic_t * v) \
{ \
unsigned long temp; \
__asm__ __volatile__( \
"1: ldl_l %0,%1\n" \
" " #asm_op " %0,%2,%0\n" \
" stl_c %0,%1\n" \
" beq %0,2f\n" \
".subsection 2\n" \
"2: br 1b\n" \
".previous" \
:"=&r" (temp), "=m" (v->counter) \
:"Ir" (i), "m" (v->counter)); \
} \
#define ATOMIC_OP_RETURN(op, asm_op) \
static inline int atomic_##op##_return_relaxed(int i, atomic_t *v) \
{ \
long temp, result; \
__asm__ __volatile__( \
"1: ldl_l %0,%1\n" \
" " #asm_op " %0,%3,%2\n" \
" " #asm_op " %0,%3,%0\n" \
" stl_c %0,%1\n" \
" beq %0,2f\n" \
".subsection 2\n" \
"2: br 1b\n" \
".previous" \
:"=&r" (temp), "=m" (v->counter), "=&r" (result) \
:"Ir" (i), "m" (v->counter) : "memory"); \
smp_read_barrier_depends(); \
return result; \
}
#define ATOMIC_FETCH_OP(op, asm_op) \
static inline int atomic_fetch_##op##_relaxed(int i, atomic_t *v) \
{ \
long temp, result; \
__asm__ __volatile__( \
"1: ldl_l %2,%1\n" \
" " #asm_op " %2,%3,%0\n" \
" stl_c %0,%1\n" \
" beq %0,2f\n" \
".subsection 2\n" \
"2: br 1b\n" \
".previous" \
:"=&r" (temp), "=m" (v->counter), "=&r" (result) \
:"Ir" (i), "m" (v->counter) : "memory"); \
smp_read_barrier_depends(); \
return result; \
}
#define ATOMIC64_OP(op, asm_op) \
static __inline__ void atomic64_##op(s64 i, atomic64_t * v) \
{ \
s64 temp; \
__asm__ __volatile__( \
"1: ldq_l %0,%1\n" \
" " #asm_op " %0,%2,%0\n" \
" stq_c %0,%1\n" \
" beq %0,2f\n" \
".subsection 2\n" \
"2: br 1b\n" \
".previous" \
:"=&r" (temp), "=m" (v->counter) \
:"Ir" (i), "m" (v->counter)); \
} \
#define ATOMIC64_OP_RETURN(op, asm_op) \
static __inline__ s64 atomic64_##op##_return_relaxed(s64 i, atomic64_t * v) \
{ \
s64 temp, result; \
__asm__ __volatile__( \
"1: ldq_l %0,%1\n" \
" " #asm_op " %0,%3,%2\n" \
" " #asm_op " %0,%3,%0\n" \
" stq_c %0,%1\n" \
" beq %0,2f\n" \
".subsection 2\n" \
"2: br 1b\n" \
".previous" \
:"=&r" (temp), "=m" (v->counter), "=&r" (result) \
:"Ir" (i), "m" (v->counter) : "memory"); \
smp_read_barrier_depends(); \
return result; \
}
#define ATOMIC64_FETCH_OP(op, asm_op) \
static __inline__ s64 atomic64_fetch_##op##_relaxed(s64 i, atomic64_t * v) \
{ \
s64 temp, result; \
__asm__ __volatile__( \
"1: ldq_l %2,%1\n" \
" " #asm_op " %2,%3,%0\n" \
" stq_c %0,%1\n" \
" beq %0,2f\n" \
".subsection 2\n" \
"2: br 1b\n" \
".previous" \
:"=&r" (temp), "=m" (v->counter), "=&r" (result) \
:"Ir" (i), "m" (v->counter) : "memory"); \
smp_read_barrier_depends(); \
return result; \
}
#define ATOMIC_OPS(op) \
ATOMIC_OP(op, op##l) \
ATOMIC_OP_RETURN(op, op##l) \
ATOMIC_FETCH_OP(op, op##l) \
ATOMIC64_OP(op, op##q) \
ATOMIC64_OP_RETURN(op, op##q) \
ATOMIC64_FETCH_OP(op, op##q)
ATOMIC_OPS(add)
ATOMIC_OPS(sub)
#define atomic_add_return_relaxed atomic_add_return_relaxed
#define atomic_sub_return_relaxed atomic_sub_return_relaxed
#define atomic_fetch_add_relaxed atomic_fetch_add_relaxed
#define atomic_fetch_sub_relaxed atomic_fetch_sub_relaxed
#define atomic64_add_return_relaxed atomic64_add_return_relaxed
#define atomic64_sub_return_relaxed atomic64_sub_return_relaxed
#define atomic64_fetch_add_relaxed atomic64_fetch_add_relaxed
#define atomic64_fetch_sub_relaxed atomic64_fetch_sub_relaxed
#define atomic_andnot atomic_andnot
#define atomic64_andnot atomic64_andnot
#undef ATOMIC_OPS
#define ATOMIC_OPS(op, asm) \
ATOMIC_OP(op, asm) \
ATOMIC_FETCH_OP(op, asm) \
ATOMIC64_OP(op, asm) \
ATOMIC64_FETCH_OP(op, asm)
ATOMIC_OPS(and, and)
ATOMIC_OPS(andnot, bic)
ATOMIC_OPS(or, bis)
ATOMIC_OPS(xor, xor)
#define atomic_fetch_and_relaxed atomic_fetch_and_relaxed
#define atomic_fetch_andnot_relaxed atomic_fetch_andnot_relaxed
#define atomic_fetch_or_relaxed atomic_fetch_or_relaxed
#define atomic_fetch_xor_relaxed atomic_fetch_xor_relaxed
#define atomic64_fetch_and_relaxed atomic64_fetch_and_relaxed
#define atomic64_fetch_andnot_relaxed atomic64_fetch_andnot_relaxed
#define atomic64_fetch_or_relaxed atomic64_fetch_or_relaxed
#define atomic64_fetch_xor_relaxed atomic64_fetch_xor_relaxed
#undef ATOMIC_OPS
#undef ATOMIC64_FETCH_OP
#undef ATOMIC64_OP_RETURN
#undef ATOMIC64_OP
#undef ATOMIC_FETCH_OP
#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP
#define atomic64_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
/**
* atomic_fetch_add_unless - add unless the number is a given value
* @v: pointer of type atomic_t
* @a: the amount to add to v...
* @u: ...unless v is equal to u.
*
* Atomically adds @a to @v, so long as it was not @u.
* Returns the old value of @v.
*/
static __inline__ int atomic_fetch_add_unless(atomic_t *v, int a, int u)
{
int c, new, old;
smp_mb();
__asm__ __volatile__(
"1: ldl_l %[old],%[mem]\n"
" cmpeq %[old],%[u],%[c]\n"
" addl %[old],%[a],%[new]\n"
" bne %[c],2f\n"
" stl_c %[new],%[mem]\n"
" beq %[new],3f\n"
"2:\n"
".subsection 2\n"
"3: br 1b\n"
".previous"
: [old] "=&r"(old), [new] "=&r"(new), [c] "=&r"(c)
: [mem] "m"(*v), [a] "rI"(a), [u] "rI"((long)u)
: "memory");
smp_mb();
return old;
}
#define atomic_fetch_add_unless atomic_fetch_add_unless
/**
* atomic64_fetch_add_unless - add unless the number is a given value
* @v: pointer of type atomic64_t
* @a: the amount to add to v...
* @u: ...unless v is equal to u.
*
* Atomically adds @a to @v, so long as it was not @u.
* Returns the old value of @v.
*/
static __inline__ s64 atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u)
{
s64 c, new, old;
smp_mb();
__asm__ __volatile__(
"1: ldq_l %[old],%[mem]\n"
" cmpeq %[old],%[u],%[c]\n"
" addq %[old],%[a],%[new]\n"
" bne %[c],2f\n"
" stq_c %[new],%[mem]\n"
" beq %[new],3f\n"
"2:\n"
".subsection 2\n"
"3: br 1b\n"
".previous"
: [old] "=&r"(old), [new] "=&r"(new), [c] "=&r"(c)
: [mem] "m"(*v), [a] "rI"(a), [u] "rI"(u)
: "memory");
smp_mb();
return old;
}
#define atomic64_fetch_add_unless atomic64_fetch_add_unless
/*
* atomic64_dec_if_positive - decrement by 1 if old value positive
* @v: pointer of type atomic_t
*
* The function returns the old value of *v minus 1, even if
* the atomic variable, v, was not decremented.
*/
static inline s64 atomic64_dec_if_positive(atomic64_t *v)
{
s64 old, tmp;
smp_mb();
__asm__ __volatile__(
"1: ldq_l %[old],%[mem]\n"
" subq %[old],1,%[tmp]\n"
" ble %[old],2f\n"
" stq_c %[tmp],%[mem]\n"
" beq %[tmp],3f\n"
"2:\n"
".subsection 2\n"
"3: br 1b\n"
".previous"
: [old] "=&r"(old), [tmp] "=&r"(tmp)
: [mem] "m"(*v)
: "memory");
smp_mb();
return old - 1;
}
#define atomic64_dec_if_positive atomic64_dec_if_positive
#endif /* _ALPHA_ATOMIC_H */
|
