summaryrefslogtreecommitdiff
path: root/arch/mips/include/asm/atomic.h
blob: 43fcd35e295759d7368268d48bfa6534b074f117 (plain)
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
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
/*
 * 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 <asm/barrier.h>
#include <asm/compiler.h>
#include <asm/cpu-features.h>
#include <asm/cmpxchg.h>
#include <asm/war.h>

/*
 * Using a branch-likely instruction to check the result of an sc instruction
 * works around a bug present in R10000 CPUs prior to revision 3.0 that could
 * cause ll-sc sequences to execute non-atomically.
 */
#if R10000_LLSC_WAR
# define __scbeqz "beqzl"
#else
# define __scbeqz "beqz"
#endif

#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)		READ_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)	WRITE_ONCE((v)->counter, (i))

#define ATOMIC_OP(op, c_op, asm_op)					      \
static __inline__ void atomic_##op(int i, atomic_t * v)			      \
{									      \
	if (kernel_uses_llsc) {						      \
		int temp;						      \
									      \
		__asm__ __volatile__(					      \
		"	.set	push					\n"   \
		"	.set	"MIPS_ISA_LEVEL"			\n"   \
		"1:	ll	%0, %1		# atomic_" #op "	\n"   \
		"	" #asm_op " %0, %2				\n"   \
		"	sc	%0, %1					\n"   \
		"\t" __scbeqz "	%0, 1b					\n"   \
		"	.set	pop					\n"   \
		: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter)	      \
		: "Ir" (i));						      \
	} else {							      \
		unsigned long flags;					      \
									      \
		raw_local_irq_save(flags);				      \
		v->counter c_op i;					      \
		raw_local_irq_restore(flags);				      \
	}								      \
}

#define ATOMIC_OP_RETURN(op, c_op, asm_op)				      \
static __inline__ int atomic_##op##_return_relaxed(int i, atomic_t * v)	      \
{									      \
	int result;							      \
									      \
	if (kernel_uses_llsc) {						      \
		int temp;						      \
									      \
		__asm__ __volatile__(					      \
		"	.set	push					\n"   \
		"	.set	"MIPS_ISA_LEVEL"			\n"   \
		"1:	ll	%1, %2		# atomic_" #op "_return	\n"   \
		"	" #asm_op " %0, %1, %3				\n"   \
		"	sc	%0, %2					\n"   \
		"\t" __scbeqz "	%0, 1b					\n"   \
		"	" #asm_op " %0, %1, %3				\n"   \
		"	.set	pop					\n"   \
		: "=&r" (result), "=&r" (temp),				      \
		  "+" GCC_OFF_SMALL_ASM() (v->counter)			      \
		: "Ir" (i));						      \
	} else {							      \
		unsigned long flags;					      \
									      \
		raw_local_irq_save(flags);				      \
		result = v->counter;					      \
		result c_op i;						      \
		v->counter = result;					      \
		raw_local_irq_restore(flags);				      \
	}								      \
									      \
	return result;							      \
}

#define ATOMIC_FETCH_OP(op, c_op, asm_op)				      \
static __inline__ int atomic_fetch_##op##_relaxed(int i, atomic_t * v)	      \
{									      \
	int result;							      \
									      \
	if (kernel_uses_llsc) {						      \
		int temp;						      \
									      \
		__asm__ __volatile__(					      \
		"	.set	push					\n"   \
		"	.set	"MIPS_ISA_LEVEL"			\n"   \
		"1:	ll	%1, %2		# atomic_fetch_" #op "	\n"   \
		"	" #asm_op " %0, %1, %3				\n"   \
		"	sc	%0, %2					\n"   \
		"\t" __scbeqz "	%0, 1b					\n"   \
		"	.set	pop					\n"   \
		"	move	%0, %1					\n"   \
		: "=&r" (result), "=&r" (temp),				      \
		  "+" GCC_OFF_SMALL_ASM() (v->counter)			      \
		: "Ir" (i));						      \
	} else {							      \
		unsigned long flags;					      \
									      \
		raw_local_irq_save(flags);				      \
		result = v->counter;					      \
		v->counter c_op i;					      \
		raw_local_irq_restore(flags);				      \
	}								      \
									      \
	return result;							      \
}

#define ATOMIC_OPS(op, c_op, asm_op)					      \
	ATOMIC_OP(op, c_op, asm_op)					      \
	ATOMIC_OP_RETURN(op, c_op, asm_op)				      \
	ATOMIC_FETCH_OP(op, c_op, asm_op)

ATOMIC_OPS(add, +=, addu)
ATOMIC_OPS(sub, -=, subu)

#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

#undef ATOMIC_OPS
#define ATOMIC_OPS(op, c_op, asm_op)					      \
	ATOMIC_OP(op, c_op, asm_op)					      \
	ATOMIC_FETCH_OP(op, c_op, asm_op)

ATOMIC_OPS(and, &=, and)
ATOMIC_OPS(or, |=, or)
ATOMIC_OPS(xor, ^=, xor)

#define atomic_fetch_and_relaxed	atomic_fetch_and_relaxed
#define atomic_fetch_or_relaxed		atomic_fetch_or_relaxed
#define atomic_fetch_xor_relaxed	atomic_fetch_xor_relaxed

#undef ATOMIC_OPS
#undef ATOMIC_FETCH_OP
#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP

/*
 * 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)
{
	int result;

	smp_mb__before_llsc();

	if (kernel_uses_llsc) {
		int temp;

		__asm__ __volatile__(
		"	.set	push					\n"
		"	.set	"MIPS_ISA_LEVEL"			\n"
		"1:	ll	%1, %2		# atomic_sub_if_positive\n"
		"	.set	pop					\n"
		"	subu	%0, %1, %3				\n"
		"	move	%1, %0					\n"
		"	bltz	%0, 1f					\n"
		"	.set	push					\n"
		"	.set	"MIPS_ISA_LEVEL"			\n"
		"	sc	%1, %2					\n"
		"\t" __scbeqz "	%1, 1b					\n"
		"1:							\n"
		"	.set	pop					\n"
		: "=&r" (result), "=&r" (temp),
		  "+" GCC_OFF_SMALL_ASM() (v->counter)
		: "Ir" (i));
	} else {
		unsigned long flags;

		raw_local_irq_save(flags);
		result = v->counter;
		result -= i;
		if (result >= 0)
			v->counter = result;
		raw_local_irq_restore(flags);
	}

	smp_llsc_mb();

	return result;
}

#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
#define atomic_xchg(v, new) (xchg(&((v)->counter), (new)))

/*
 * 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)

#ifdef CONFIG_64BIT

#define ATOMIC64_INIT(i)    { (i) }

/*
 * atomic64_read - read atomic variable
 * @v: pointer of type atomic64_t
 *
 */
#define atomic64_read(v)	READ_ONCE((v)->counter)

/*
 * atomic64_set - set atomic variable
 * @v: pointer of type atomic64_t
 * @i: required value
 */
#define atomic64_set(v, i)	WRITE_ONCE((v)->counter, (i))

#define ATOMIC64_OP(op, c_op, asm_op)					      \
static __inline__ void atomic64_##op(long i, atomic64_t * v)		      \
{									      \
	if (kernel_uses_llsc) {						      \
		long temp;						      \
									      \
		__asm__ __volatile__(					      \
		"	.set	push					\n"   \
		"	.set	"MIPS_ISA_LEVEL"			\n"   \
		"1:	lld	%0, %1		# atomic64_" #op "	\n"   \
		"	" #asm_op " %0, %2				\n"   \
		"	scd	%0, %1					\n"   \
		"\t" __scbeqz "	%0, 1b					\n"   \
		"	.set	pop					\n"   \
		: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter)	      \
		: "Ir" (i));						      \
	} else {							      \
		unsigned long flags;					      \
									      \
		raw_local_irq_save(flags);				      \
		v->counter c_op i;					      \
		raw_local_irq_restore(flags);				      \
	}								      \
}

#define ATOMIC64_OP_RETURN(op, c_op, asm_op)				      \
static __inline__ long atomic64_##op##_return_relaxed(long i, atomic64_t * v) \
{									      \
	long result;							      \
									      \
	if (kernel_uses_llsc) {						      \
		long temp;						      \
									      \
		__asm__ __volatile__(					      \
		"	.set	push					\n"   \
		"	.set	"MIPS_ISA_LEVEL"			\n"   \
		"1:	lld	%1, %2		# atomic64_" #op "_return\n"  \
		"	" #asm_op " %0, %1, %3				\n"   \
		"	scd	%0, %2					\n"   \
		"\t" __scbeqz "	%0, 1b					\n"   \
		"	" #asm_op " %0, %1, %3				\n"   \
		"	.set	pop					\n"   \
		: "=&r" (result), "=&r" (temp),				      \
		  "+" GCC_OFF_SMALL_ASM() (v->counter)			      \
		: "Ir" (i));						      \
	} else {							      \
		unsigned long flags;					      \
									      \
		raw_local_irq_save(flags);				      \
		result = v->counter;					      \
		result c_op i;						      \
		v->counter = result;					      \
		raw_local_irq_restore(flags);				      \
	}								      \
									      \
	return result;							      \
}

#define ATOMIC64_FETCH_OP(op, c_op, asm_op)				      \
static __inline__ long atomic64_fetch_##op##_relaxed(long i, atomic64_t * v)  \
{									      \
	long result;							      \
									      \
	if (kernel_uses_llsc) {						      \
		long temp;						      \
									      \
		__asm__ __volatile__(					      \
		"	.set	push					\n"   \
		"	.set	"MIPS_ISA_LEVEL"			\n"   \
		"1:	lld	%1, %2		# atomic64_fetch_" #op "\n"   \
		"	" #asm_op " %0, %1, %3				\n"   \
		"	scd	%0, %2					\n"   \
		"\t" __scbeqz "	%0, 1b					\n"   \
		"	move	%0, %1					\n"   \
		"	.set	pop					\n"   \
		: "=&r" (result), "=&r" (temp),				      \
		  "+" GCC_OFF_SMALL_ASM() (v->counter)			      \
		: "Ir" (i));						      \
	} else {							      \
		unsigned long flags;					      \
									      \
		raw_local_irq_save(flags);				      \
		result = v->counter;					      \
		v->counter c_op i;					      \
		raw_local_irq_restore(flags);				      \
	}								      \
									      \
	return result;							      \
}

#define ATOMIC64_OPS(op, c_op, asm_op)					      \
	ATOMIC64_OP(op, c_op, asm_op)					      \
	ATOMIC64_OP_RETURN(op, c_op, asm_op)				      \
	ATOMIC64_FETCH_OP(op, c_op, asm_op)

ATOMIC64_OPS(add, +=, daddu)
ATOMIC64_OPS(sub, -=, dsubu)

#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

#undef ATOMIC64_OPS
#define ATOMIC64_OPS(op, c_op, asm_op)					      \
	ATOMIC64_OP(op, c_op, asm_op)					      \
	ATOMIC64_FETCH_OP(op, c_op, asm_op)

ATOMIC64_OPS(and, &=, and)
ATOMIC64_OPS(or, |=, or)
ATOMIC64_OPS(xor, ^=, xor)

#define atomic64_fetch_and_relaxed	atomic64_fetch_and_relaxed
#define atomic64_fetch_or_relaxed	atomic64_fetch_or_relaxed
#define atomic64_fetch_xor_relaxed	atomic64_fetch_xor_relaxed

#undef ATOMIC64_OPS
#undef ATOMIC64_FETCH_OP
#undef ATOMIC64_OP_RETURN
#undef ATOMIC64_OP

/*
 * atomic64_sub_if_positive - conditionally subtract integer from atomic
 *                            variable
 * @i: integer value to subtract
 * @v: pointer of type atomic64_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__ long atomic64_sub_if_positive(long i, atomic64_t * v)
{
	long result;

	smp_mb__before_llsc();

	if (kernel_uses_llsc) {
		long temp;

		__asm__ __volatile__(
		"	.set	push					\n"
		"	.set	"MIPS_ISA_LEVEL"			\n"
		"1:	lld	%1, %2		# atomic64_sub_if_positive\n"
		"	dsubu	%0, %1, %3				\n"
		"	move	%1, %0					\n"
		"	bltz	%0, 1f					\n"
		"	scd	%1, %2					\n"
		"\t" __scbeqz "	%1, 1b					\n"
		"1:							\n"
		"	.set	pop					\n"
		: "=&r" (result), "=&r" (temp),
		  "+" GCC_OFF_SMALL_ASM() (v->counter)
		: "Ir" (i));
	} else {
		unsigned long flags;

		raw_local_irq_save(flags);
		result = v->counter;
		result -= i;
		if (result >= 0)
			v->counter = result;
		raw_local_irq_restore(flags);
	}

	smp_llsc_mb();

	return result;
}

#define atomic64_cmpxchg(v, o, n) \
	((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n)))
#define atomic64_xchg(v, new) (xchg(&((v)->counter), (new)))

/*
 * atomic64_dec_if_positive - decrement by 1 if old value positive
 * @v: pointer of type atomic64_t
 */
#define atomic64_dec_if_positive(v)	atomic64_sub_if_positive(1, v)

#endif /* CONFIG_64BIT */

#endif /* _ASM_ATOMIC_H */