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
|
/*
* include/asm-xtensa/atomic.h
*
* Atomic operations that C can't guarantee us. Useful for resource counting..
*
* 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) 2001 - 2008 Tensilica Inc.
*/
#ifndef _XTENSA_ATOMIC_H
#define _XTENSA_ATOMIC_H
#include <linux/stringify.h>
#include <linux/types.h>
#ifdef __KERNEL__
#include <asm/processor.h>
#include <asm/cmpxchg.h>
#include <asm/barrier.h>
#define ATOMIC_INIT(i) { (i) }
/*
* This Xtensa implementation assumes that the right mechanism
* for exclusion is for locking interrupts to level EXCM_LEVEL.
*
* Locking interrupts looks like this:
*
* rsil a15, TOPLEVEL
* <code>
* wsr a15, PS
* rsync
*
* Note that a15 is used here because the register allocation
* done by the compiler is not guaranteed and a window overflow
* may not occur between the rsil and wsr instructions. By using
* a15 in the rsil, the machine is guaranteed to be in a state
* where no register reference will cause an overflow.
*/
/**
* atomic_read - read atomic variable
* @v: pointer of type atomic_t
*
* Atomically reads the value of @v.
*/
#define atomic_read(v) ACCESS_ONCE((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))
#if XCHAL_HAVE_S32C1I
#define ATOMIC_OP(op) \
static inline void atomic_##op(int i, atomic_t * v) \
{ \
unsigned long tmp; \
int result; \
\
__asm__ __volatile__( \
"1: l32i %1, %3, 0\n" \
" wsr %1, scompare1\n" \
" " #op " %0, %1, %2\n" \
" s32c1i %0, %3, 0\n" \
" bne %0, %1, 1b\n" \
: "=&a" (result), "=&a" (tmp) \
: "a" (i), "a" (v) \
: "memory" \
); \
} \
#define ATOMIC_OP_RETURN(op) \
static inline int atomic_##op##_return(int i, atomic_t * v) \
{ \
unsigned long tmp; \
int result; \
\
__asm__ __volatile__( \
"1: l32i %1, %3, 0\n" \
" wsr %1, scompare1\n" \
" " #op " %0, %1, %2\n" \
" s32c1i %0, %3, 0\n" \
" bne %0, %1, 1b\n" \
" " #op " %0, %0, %2\n" \
: "=&a" (result), "=&a" (tmp) \
: "a" (i), "a" (v) \
: "memory" \
); \
\
return result; \
}
#else /* XCHAL_HAVE_S32C1I */
#define ATOMIC_OP(op) \
static inline void atomic_##op(int i, atomic_t * v) \
{ \
unsigned int vval; \
\
__asm__ __volatile__( \
" rsil a15, "__stringify(TOPLEVEL)"\n"\
" l32i %0, %2, 0\n" \
" " #op " %0, %0, %1\n" \
" s32i %0, %2, 0\n" \
" wsr a15, ps\n" \
" rsync\n" \
: "=&a" (vval) \
: "a" (i), "a" (v) \
: "a15", "memory" \
); \
} \
#define ATOMIC_OP_RETURN(op) \
static inline int atomic_##op##_return(int i, atomic_t * v) \
{ \
unsigned int vval; \
\
__asm__ __volatile__( \
" rsil a15,"__stringify(TOPLEVEL)"\n" \
" l32i %0, %2, 0\n" \
" " #op " %0, %0, %1\n" \
" s32i %0, %2, 0\n" \
" wsr a15, ps\n" \
" rsync\n" \
: "=&a" (vval) \
: "a" (i), "a" (v) \
: "a15", "memory" \
); \
\
return vval; \
}
#endif /* XCHAL_HAVE_S32C1I */
#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op)
ATOMIC_OPS(add)
ATOMIC_OPS(sub)
#undef ATOMIC_OPS
#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP
/**
* 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 - increment atomic variable
* @v: pointer of type atomic_t
*
* Atomically increments @v by 1.
*/
#define atomic_inc(v) atomic_add(1,(v))
/**
* atomic_inc - increment atomic variable
* @v: pointer of type atomic_t
*
* Atomically increments @v by 1.
*/
#define atomic_inc_return(v) atomic_add_return(1,(v))
/**
* atomic_dec - decrement atomic variable
* @v: pointer of type atomic_t
*
* Atomically decrements @v by 1.
*/
#define atomic_dec(v) atomic_sub(1,(v))
/**
* atomic_dec_return - decrement atomic variable
* @v: pointer of type atomic_t
*
* Atomically decrements @v by 1.
*/
#define atomic_dec_return(v) atomic_sub_return(1,(v))
/**
* atomic_dec_and_test - decrement 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_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_add_return(1,(v)) == 0)
/**
* 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)
#define atomic_cmpxchg(v, o, n) ((int)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 the old value of @v.
*/
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;
}
static inline void atomic_clear_mask(unsigned int mask, atomic_t *v)
{
#if XCHAL_HAVE_S32C1I
unsigned long tmp;
int result;
__asm__ __volatile__(
"1: l32i %1, %3, 0\n"
" wsr %1, scompare1\n"
" and %0, %1, %2\n"
" s32c1i %0, %3, 0\n"
" bne %0, %1, 1b\n"
: "=&a" (result), "=&a" (tmp)
: "a" (~mask), "a" (v)
: "memory"
);
#else
unsigned int all_f = -1;
unsigned int vval;
__asm__ __volatile__(
" rsil a15,"__stringify(TOPLEVEL)"\n"
" l32i %0, %2, 0\n"
" xor %1, %4, %3\n"
" and %0, %0, %4\n"
" s32i %0, %2, 0\n"
" wsr a15, ps\n"
" rsync\n"
: "=&a" (vval), "=a" (mask)
: "a" (v), "a" (all_f), "1" (mask)
: "a15", "memory"
);
#endif
}
static inline void atomic_set_mask(unsigned int mask, atomic_t *v)
{
#if XCHAL_HAVE_S32C1I
unsigned long tmp;
int result;
__asm__ __volatile__(
"1: l32i %1, %3, 0\n"
" wsr %1, scompare1\n"
" or %0, %1, %2\n"
" s32c1i %0, %3, 0\n"
" bne %0, %1, 1b\n"
: "=&a" (result), "=&a" (tmp)
: "a" (mask), "a" (v)
: "memory"
);
#else
unsigned int vval;
__asm__ __volatile__(
" rsil a15,"__stringify(TOPLEVEL)"\n"
" l32i %0, %2, 0\n"
" or %0, %0, %1\n"
" s32i %0, %2, 0\n"
" wsr a15, ps\n"
" rsync\n"
: "=&a" (vval)
: "a" (mask), "a" (v)
: "a15", "memory"
);
#endif
}
#endif /* __KERNEL__ */
#endif /* _XTENSA_ATOMIC_H */
|
