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
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
|
/*
* Atomic operations that C can't guarantee us. Useful for
* resource counting etc..
*
* But use these as seldom as possible since they are much more slower
* than regular operations.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1996, 97, 99, 2000, 03, 04, 06 by Ralf Baechle
*/
#ifndef _ASM_ATOMIC_H
#define _ASM_ATOMIC_H
#include <linux/irqflags.h>
#include <linux/types.h>
#include <linux/linkage.h>
#include <asm/barrier.h>
#include <asm/cpu-features.h>
#include <asm/system.h>
#define ATOMIC_INIT(i) { (i) }
/*
* atomic_read - read atomic variable
* @v: pointer of type atomic_t
*
* Atomically reads the value of @v.
*/
#define atomic_read(v) ((v)->counter)
/*
* atomic_set - set atomic variable
* @v: pointer of type atomic_t
* @i: required value
*
* Atomically sets the value of @v to @i.
*/
#define atomic_set(v, i) ((v)->counter = (i))
/*
* atomic_add - add integer to atomic variable
* @i: integer value to add
* @v: pointer of type atomic_t
*
* Atomically adds @i to @v.
*/
static __inline__ void atomic_add(int i, atomic_t * v)
{
#ifdef CONFIG_CPU_HAS_LLSC
int temp;
smp_llsc_mb();
__asm__ __volatile__(
"1: ll %0, %1 # atomic_add \n"
#if defined(CONFIG_CPU_RLX4181) || defined(CONFIG_CPU_RLX5181) || defined(CONFIG_CPU_RLX5281)
" nop \n"
#endif
" addu %0, %2 \n"
" sc %0, %1 \n"
" beqz %0, 2f \n"
" .subsection 2 \n"
"2: b 1b \n"
" .previous \n"
: "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter));
smp_llsc_mb();
#else
unsigned long flags;
raw_local_irq_save(flags);
v->counter += i;
raw_local_irq_restore(flags);
#endif
}
/*
* atomic_sub - subtract the atomic variable
* @i: integer value to subtract
* @v: pointer of type atomic_t
*
* Atomically subtracts @i from @v.
*/
static __inline__ void atomic_sub(int i, atomic_t * v)
{
#ifdef CONFIG_CPU_HAS_LLSC
int temp;
smp_llsc_mb();
__asm__ __volatile__(
"1: ll %0, %1 # atomic_sub \n"
#if defined(CONFIG_CPU_RLX4181) || defined(CONFIG_CPU_RLX5181) || defined(CONFIG_CPU_RLX5281)
" nop \n"
#endif
" subu %0, %2 \n"
" sc %0, %1 \n"
" beqz %0, 2f \n"
" .subsection 2 \n"
"2: b 1b \n"
" .previous \n"
: "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter));
smp_llsc_mb();
#else
unsigned long flags;
raw_local_irq_save(flags);
v->counter -= i;
raw_local_irq_restore(flags);
#endif
}
/*
* Same as above, but return the result value
*/
static __inline__ int atomic_add_return(int i, atomic_t * v)
{
#ifdef CONFIG_CPU_HAS_LLSC
int result;
int temp;
smp_llsc_mb();
__asm__ __volatile__(
"1: ll %1, %2 # atomic_add_return \n"
#if defined(CONFIG_CPU_RLX4181) || defined(CONFIG_CPU_RLX5181) || defined(CONFIG_CPU_RLX5281)
" nop \n"
#endif
" addu %0, %1, %3 \n"
" sc %0, %2 \n"
" beqz %0, 2f \n"
" addu %0, %1, %3 \n"
" .subsection 2 \n"
"2: b 1b \n"
" .previous \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
: "memory");
smp_llsc_mb();
#else
int result;
unsigned long flags;
raw_local_irq_save(flags);
result = v->counter;
result += i;
v->counter = result;
raw_local_irq_restore(flags);
#endif
return result;
}
static __inline__ int atomic_sub_return(int i, atomic_t * v)
{
#ifdef CONFIG_CPU_HAS_LLSC
int result;
int temp;
smp_llsc_mb();
__asm__ __volatile__(
"1: ll %1, %2 # atomic_sub_return \n"
#if defined(CONFIG_CPU_RLX4181) || defined(CONFIG_CPU_RLX5181) || defined(CONFIG_CPU_RLX5281)
" nop \n"
#endif
" subu %0, %1, %3 \n"
" sc %0, %2 \n"
" beqz %0, 2f \n"
" subu %0, %1, %3 \n"
" .subsection 2 \n"
"2: b 1b \n"
" .previous \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
: "memory");
smp_llsc_mb();
#else
unsigned long flags;
int result;
raw_local_irq_save(flags);
result = v->counter;
result -= i;
v->counter = result;
raw_local_irq_restore(flags);
#endif
return result;
}
/*
* atomic_sub_if_positive - conditionally subtract integer from atomic variable
* @i: integer value to subtract
* @v: pointer of type atomic_t
*
* Atomically test @v and subtract @i if @v is greater or equal than @i.
* The function returns the old value of @v minus @i.
*/
static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
{
#ifdef CONFIG_CPU_HAS_LLSC
int result;
int temp;
smp_llsc_mb();
__asm__ __volatile__(
"1: ll %1, %2 # atomic_sub_if_positive\n"
#if defined(CONFIG_CPU_RLX4181) || defined(CONFIG_CPU_RLX5181) || defined(CONFIG_CPU_RLX5281)
" nop \n"
#endif
" subu %0, %1, %3 \n"
" bltz %0, 1f \n"
" sc %0, %2 \n"
" .set noreorder \n"
" beqz %0, 2f \n"
" subu %0, %1, %3 \n"
" .set reorder \n"
" .subsection 2 \n"
"2: b 1b \n"
" .previous \n"
"1: \n"
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
: "memory");
smp_llsc_mb();
#else
unsigned long flags;
int result;
raw_local_irq_save(flags);
result = v->counter;
result -= i;
if (result >= 0)
v->counter = result;
raw_local_irq_restore(flags);
#endif
return result;
}
#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
#define atomic_xchg(v, new) (xchg(&((v)->counter), (new)))
/**
* atomic_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 non-zero if @v was not @u, and zero otherwise.
*/
static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
{
int c, old;
c = atomic_read(v);
for (;;) {
if (unlikely(c == (u)))
break;
old = atomic_cmpxchg((v), c, c + (a));
if (likely(old == c))
break;
c = old;
}
return c != (u);
}
#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
#define atomic_dec_return(v) atomic_sub_return(1, (v))
#define atomic_inc_return(v) atomic_add_return(1, (v))
/*
* atomic_sub_and_test - subtract value from variable and test result
* @i: integer value to subtract
* @v: pointer of type atomic_t
*
* Atomically subtracts @i from @v and returns
* true if the result is zero, or false for all
* other cases.
*/
#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
/*
* atomic_inc_and_test - increment and test
* @v: pointer of type atomic_t
*
* Atomically increments @v by 1
* and returns true if the result is zero, or false for all
* other cases.
*/
#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
/*
* atomic_dec_and_test - decrement by 1 and test
* @v: pointer of type atomic_t
*
* Atomically decrements @v by 1 and
* returns true if the result is 0, or false for all other
* cases.
*/
#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
/*
* atomic_dec_if_positive - decrement by 1 if old value positive
* @v: pointer of type atomic_t
*/
#define atomic_dec_if_positive(v) atomic_sub_if_positive(1, v)
/*
* atomic_inc - increment atomic variable
* @v: pointer of type atomic_t
*
* Atomically increments @v by 1.
*/
#define atomic_inc(v) atomic_add(1, (v))
/*
* atomic_dec - decrement and test
* @v: pointer of type atomic_t
*
* Atomically decrements @v by 1.
*/
#define atomic_dec(v) atomic_sub(1, (v))
/*
* atomic_add_negative - add and test if negative
* @v: pointer of type atomic_t
* @i: integer value to add
*
* Atomically adds @i to @v and returns true
* if the result is negative, or false when
* result is greater than or equal to zero.
*/
#define atomic_add_negative(i, v) (atomic_add_return(i, (v)) < 0)
/*
* atomic*_return operations are serializing but not the non-*_return
* versions.
*/
#define smp_mb__before_atomic_dec() smp_llsc_mb()
#define smp_mb__after_atomic_dec() smp_llsc_mb()
#define smp_mb__before_atomic_inc() smp_llsc_mb()
#define smp_mb__after_atomic_inc() smp_llsc_mb()
#include <asm-generic/atomic-long.h>
#endif /* _ASM_ATOMIC_H */
|
