xref: /linux-6.15/include/linux/atomic.h (revision ade5ef92)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* Atomic operations usable in machine independent code */
3 #ifndef _LINUX_ATOMIC_H
4 #define _LINUX_ATOMIC_H
5 #include <linux/types.h>
6 
7 #include <asm/atomic.h>
8 #include <asm/barrier.h>
9 
10 /*
11  * Relaxed variants of xchg, cmpxchg and some atomic operations.
12  *
13  * We support four variants:
14  *
15  * - Fully ordered: The default implementation, no suffix required.
16  * - Acquire: Provides ACQUIRE semantics, _acquire suffix.
17  * - Release: Provides RELEASE semantics, _release suffix.
18  * - Relaxed: No ordering guarantees, _relaxed suffix.
19  *
20  * For compound atomics performing both a load and a store, ACQUIRE
21  * semantics apply only to the load and RELEASE semantics only to the
22  * store portion of the operation. Note that a failed cmpxchg_acquire
23  * does -not- imply any memory ordering constraints.
24  *
25  * See Documentation/memory-barriers.txt for ACQUIRE/RELEASE definitions.
26  */
27 
28 #ifndef atomic_read_acquire
29 #define  atomic_read_acquire(v)		smp_load_acquire(&(v)->counter)
30 #endif
31 
32 #ifndef atomic_set_release
33 #define  atomic_set_release(v, i)	smp_store_release(&(v)->counter, (i))
34 #endif
35 
36 /*
37  * The idea here is to build acquire/release variants by adding explicit
38  * barriers on top of the relaxed variant. In the case where the relaxed
39  * variant is already fully ordered, no additional barriers are needed.
40  *
41  * Besides, if an arch has a special barrier for acquire/release, it could
42  * implement its own __atomic_op_* and use the same framework for building
43  * variants
44  *
45  * If an architecture overrides __atomic_op_acquire() it will probably want
46  * to define smp_mb__after_spinlock().
47  */
48 #ifndef __atomic_op_acquire
49 #define __atomic_op_acquire(op, args...)				\
50 ({									\
51 	typeof(op##_relaxed(args)) __ret  = op##_relaxed(args);		\
52 	smp_mb__after_atomic();						\
53 	__ret;								\
54 })
55 #endif
56 
57 #ifndef __atomic_op_release
58 #define __atomic_op_release(op, args...)				\
59 ({									\
60 	smp_mb__before_atomic();					\
61 	op##_relaxed(args);						\
62 })
63 #endif
64 
65 #ifndef __atomic_op_fence
66 #define __atomic_op_fence(op, args...)					\
67 ({									\
68 	typeof(op##_relaxed(args)) __ret;				\
69 	smp_mb__before_atomic();					\
70 	__ret = op##_relaxed(args);					\
71 	smp_mb__after_atomic();						\
72 	__ret;								\
73 })
74 #endif
75 
76 /* atomic_add_return_relaxed */
77 #ifndef atomic_add_return_relaxed
78 #define  atomic_add_return_relaxed	atomic_add_return
79 #define  atomic_add_return_acquire	atomic_add_return
80 #define  atomic_add_return_release	atomic_add_return
81 
82 #else /* atomic_add_return_relaxed */
83 
84 #ifndef atomic_add_return_acquire
85 #define  atomic_add_return_acquire(...)					\
86 	__atomic_op_acquire(atomic_add_return, __VA_ARGS__)
87 #endif
88 
89 #ifndef atomic_add_return_release
90 #define  atomic_add_return_release(...)					\
91 	__atomic_op_release(atomic_add_return, __VA_ARGS__)
92 #endif
93 
94 #ifndef atomic_add_return
95 #define  atomic_add_return(...)						\
96 	__atomic_op_fence(atomic_add_return, __VA_ARGS__)
97 #endif
98 #endif /* atomic_add_return_relaxed */
99 
100 /* atomic_inc_return_relaxed */
101 #ifndef atomic_inc_return_relaxed
102 #define  atomic_inc_return_relaxed	atomic_inc_return
103 #define  atomic_inc_return_acquire	atomic_inc_return
104 #define  atomic_inc_return_release	atomic_inc_return
105 
106 #else /* atomic_inc_return_relaxed */
107 
108 #ifndef atomic_inc_return_acquire
109 #define  atomic_inc_return_acquire(...)					\
110 	__atomic_op_acquire(atomic_inc_return, __VA_ARGS__)
111 #endif
112 
113 #ifndef atomic_inc_return_release
114 #define  atomic_inc_return_release(...)					\
115 	__atomic_op_release(atomic_inc_return, __VA_ARGS__)
116 #endif
117 
118 #ifndef atomic_inc_return
119 #define  atomic_inc_return(...)						\
120 	__atomic_op_fence(atomic_inc_return, __VA_ARGS__)
121 #endif
122 #endif /* atomic_inc_return_relaxed */
123 
124 /* atomic_sub_return_relaxed */
125 #ifndef atomic_sub_return_relaxed
126 #define  atomic_sub_return_relaxed	atomic_sub_return
127 #define  atomic_sub_return_acquire	atomic_sub_return
128 #define  atomic_sub_return_release	atomic_sub_return
129 
130 #else /* atomic_sub_return_relaxed */
131 
132 #ifndef atomic_sub_return_acquire
133 #define  atomic_sub_return_acquire(...)					\
134 	__atomic_op_acquire(atomic_sub_return, __VA_ARGS__)
135 #endif
136 
137 #ifndef atomic_sub_return_release
138 #define  atomic_sub_return_release(...)					\
139 	__atomic_op_release(atomic_sub_return, __VA_ARGS__)
140 #endif
141 
142 #ifndef atomic_sub_return
143 #define  atomic_sub_return(...)						\
144 	__atomic_op_fence(atomic_sub_return, __VA_ARGS__)
145 #endif
146 #endif /* atomic_sub_return_relaxed */
147 
148 /* atomic_dec_return_relaxed */
149 #ifndef atomic_dec_return_relaxed
150 #define  atomic_dec_return_relaxed	atomic_dec_return
151 #define  atomic_dec_return_acquire	atomic_dec_return
152 #define  atomic_dec_return_release	atomic_dec_return
153 
154 #else /* atomic_dec_return_relaxed */
155 
156 #ifndef atomic_dec_return_acquire
157 #define  atomic_dec_return_acquire(...)					\
158 	__atomic_op_acquire(atomic_dec_return, __VA_ARGS__)
159 #endif
160 
161 #ifndef atomic_dec_return_release
162 #define  atomic_dec_return_release(...)					\
163 	__atomic_op_release(atomic_dec_return, __VA_ARGS__)
164 #endif
165 
166 #ifndef atomic_dec_return
167 #define  atomic_dec_return(...)						\
168 	__atomic_op_fence(atomic_dec_return, __VA_ARGS__)
169 #endif
170 #endif /* atomic_dec_return_relaxed */
171 
172 
173 /* atomic_fetch_add_relaxed */
174 #ifndef atomic_fetch_add_relaxed
175 #define atomic_fetch_add_relaxed	atomic_fetch_add
176 #define atomic_fetch_add_acquire	atomic_fetch_add
177 #define atomic_fetch_add_release	atomic_fetch_add
178 
179 #else /* atomic_fetch_add_relaxed */
180 
181 #ifndef atomic_fetch_add_acquire
182 #define atomic_fetch_add_acquire(...)					\
183 	__atomic_op_acquire(atomic_fetch_add, __VA_ARGS__)
184 #endif
185 
186 #ifndef atomic_fetch_add_release
187 #define atomic_fetch_add_release(...)					\
188 	__atomic_op_release(atomic_fetch_add, __VA_ARGS__)
189 #endif
190 
191 #ifndef atomic_fetch_add
192 #define atomic_fetch_add(...)						\
193 	__atomic_op_fence(atomic_fetch_add, __VA_ARGS__)
194 #endif
195 #endif /* atomic_fetch_add_relaxed */
196 
197 /* atomic_fetch_inc_relaxed */
198 #ifndef atomic_fetch_inc_relaxed
199 
200 #ifndef atomic_fetch_inc
201 #define atomic_fetch_inc(v)	        atomic_fetch_add(1, (v))
202 #define atomic_fetch_inc_relaxed(v)	atomic_fetch_add_relaxed(1, (v))
203 #define atomic_fetch_inc_acquire(v)	atomic_fetch_add_acquire(1, (v))
204 #define atomic_fetch_inc_release(v)	atomic_fetch_add_release(1, (v))
205 #else /* atomic_fetch_inc */
206 #define atomic_fetch_inc_relaxed	atomic_fetch_inc
207 #define atomic_fetch_inc_acquire	atomic_fetch_inc
208 #define atomic_fetch_inc_release	atomic_fetch_inc
209 #endif /* atomic_fetch_inc */
210 
211 #else /* atomic_fetch_inc_relaxed */
212 
213 #ifndef atomic_fetch_inc_acquire
214 #define atomic_fetch_inc_acquire(...)					\
215 	__atomic_op_acquire(atomic_fetch_inc, __VA_ARGS__)
216 #endif
217 
218 #ifndef atomic_fetch_inc_release
219 #define atomic_fetch_inc_release(...)					\
220 	__atomic_op_release(atomic_fetch_inc, __VA_ARGS__)
221 #endif
222 
223 #ifndef atomic_fetch_inc
224 #define atomic_fetch_inc(...)						\
225 	__atomic_op_fence(atomic_fetch_inc, __VA_ARGS__)
226 #endif
227 #endif /* atomic_fetch_inc_relaxed */
228 
229 /* atomic_fetch_sub_relaxed */
230 #ifndef atomic_fetch_sub_relaxed
231 #define atomic_fetch_sub_relaxed	atomic_fetch_sub
232 #define atomic_fetch_sub_acquire	atomic_fetch_sub
233 #define atomic_fetch_sub_release	atomic_fetch_sub
234 
235 #else /* atomic_fetch_sub_relaxed */
236 
237 #ifndef atomic_fetch_sub_acquire
238 #define atomic_fetch_sub_acquire(...)					\
239 	__atomic_op_acquire(atomic_fetch_sub, __VA_ARGS__)
240 #endif
241 
242 #ifndef atomic_fetch_sub_release
243 #define atomic_fetch_sub_release(...)					\
244 	__atomic_op_release(atomic_fetch_sub, __VA_ARGS__)
245 #endif
246 
247 #ifndef atomic_fetch_sub
248 #define atomic_fetch_sub(...)						\
249 	__atomic_op_fence(atomic_fetch_sub, __VA_ARGS__)
250 #endif
251 #endif /* atomic_fetch_sub_relaxed */
252 
253 /* atomic_fetch_dec_relaxed */
254 #ifndef atomic_fetch_dec_relaxed
255 
256 #ifndef atomic_fetch_dec
257 #define atomic_fetch_dec(v)	        atomic_fetch_sub(1, (v))
258 #define atomic_fetch_dec_relaxed(v)	atomic_fetch_sub_relaxed(1, (v))
259 #define atomic_fetch_dec_acquire(v)	atomic_fetch_sub_acquire(1, (v))
260 #define atomic_fetch_dec_release(v)	atomic_fetch_sub_release(1, (v))
261 #else /* atomic_fetch_dec */
262 #define atomic_fetch_dec_relaxed	atomic_fetch_dec
263 #define atomic_fetch_dec_acquire	atomic_fetch_dec
264 #define atomic_fetch_dec_release	atomic_fetch_dec
265 #endif /* atomic_fetch_dec */
266 
267 #else /* atomic_fetch_dec_relaxed */
268 
269 #ifndef atomic_fetch_dec_acquire
270 #define atomic_fetch_dec_acquire(...)					\
271 	__atomic_op_acquire(atomic_fetch_dec, __VA_ARGS__)
272 #endif
273 
274 #ifndef atomic_fetch_dec_release
275 #define atomic_fetch_dec_release(...)					\
276 	__atomic_op_release(atomic_fetch_dec, __VA_ARGS__)
277 #endif
278 
279 #ifndef atomic_fetch_dec
280 #define atomic_fetch_dec(...)						\
281 	__atomic_op_fence(atomic_fetch_dec, __VA_ARGS__)
282 #endif
283 #endif /* atomic_fetch_dec_relaxed */
284 
285 /* atomic_fetch_or_relaxed */
286 #ifndef atomic_fetch_or_relaxed
287 #define atomic_fetch_or_relaxed	atomic_fetch_or
288 #define atomic_fetch_or_acquire	atomic_fetch_or
289 #define atomic_fetch_or_release	atomic_fetch_or
290 
291 #else /* atomic_fetch_or_relaxed */
292 
293 #ifndef atomic_fetch_or_acquire
294 #define atomic_fetch_or_acquire(...)					\
295 	__atomic_op_acquire(atomic_fetch_or, __VA_ARGS__)
296 #endif
297 
298 #ifndef atomic_fetch_or_release
299 #define atomic_fetch_or_release(...)					\
300 	__atomic_op_release(atomic_fetch_or, __VA_ARGS__)
301 #endif
302 
303 #ifndef atomic_fetch_or
304 #define atomic_fetch_or(...)						\
305 	__atomic_op_fence(atomic_fetch_or, __VA_ARGS__)
306 #endif
307 #endif /* atomic_fetch_or_relaxed */
308 
309 /* atomic_fetch_and_relaxed */
310 #ifndef atomic_fetch_and_relaxed
311 #define atomic_fetch_and_relaxed	atomic_fetch_and
312 #define atomic_fetch_and_acquire	atomic_fetch_and
313 #define atomic_fetch_and_release	atomic_fetch_and
314 
315 #else /* atomic_fetch_and_relaxed */
316 
317 #ifndef atomic_fetch_and_acquire
318 #define atomic_fetch_and_acquire(...)					\
319 	__atomic_op_acquire(atomic_fetch_and, __VA_ARGS__)
320 #endif
321 
322 #ifndef atomic_fetch_and_release
323 #define atomic_fetch_and_release(...)					\
324 	__atomic_op_release(atomic_fetch_and, __VA_ARGS__)
325 #endif
326 
327 #ifndef atomic_fetch_and
328 #define atomic_fetch_and(...)						\
329 	__atomic_op_fence(atomic_fetch_and, __VA_ARGS__)
330 #endif
331 #endif /* atomic_fetch_and_relaxed */
332 
333 #ifdef atomic_andnot
334 /* atomic_fetch_andnot_relaxed */
335 #ifndef atomic_fetch_andnot_relaxed
336 #define atomic_fetch_andnot_relaxed	atomic_fetch_andnot
337 #define atomic_fetch_andnot_acquire	atomic_fetch_andnot
338 #define atomic_fetch_andnot_release	atomic_fetch_andnot
339 
340 #else /* atomic_fetch_andnot_relaxed */
341 
342 #ifndef atomic_fetch_andnot_acquire
343 #define atomic_fetch_andnot_acquire(...)					\
344 	__atomic_op_acquire(atomic_fetch_andnot, __VA_ARGS__)
345 #endif
346 
347 #ifndef atomic_fetch_andnot_release
348 #define atomic_fetch_andnot_release(...)					\
349 	__atomic_op_release(atomic_fetch_andnot, __VA_ARGS__)
350 #endif
351 
352 #ifndef atomic_fetch_andnot
353 #define atomic_fetch_andnot(...)						\
354 	__atomic_op_fence(atomic_fetch_andnot, __VA_ARGS__)
355 #endif
356 #endif /* atomic_fetch_andnot_relaxed */
357 #endif /* atomic_andnot */
358 
359 /* atomic_fetch_xor_relaxed */
360 #ifndef atomic_fetch_xor_relaxed
361 #define atomic_fetch_xor_relaxed	atomic_fetch_xor
362 #define atomic_fetch_xor_acquire	atomic_fetch_xor
363 #define atomic_fetch_xor_release	atomic_fetch_xor
364 
365 #else /* atomic_fetch_xor_relaxed */
366 
367 #ifndef atomic_fetch_xor_acquire
368 #define atomic_fetch_xor_acquire(...)					\
369 	__atomic_op_acquire(atomic_fetch_xor, __VA_ARGS__)
370 #endif
371 
372 #ifndef atomic_fetch_xor_release
373 #define atomic_fetch_xor_release(...)					\
374 	__atomic_op_release(atomic_fetch_xor, __VA_ARGS__)
375 #endif
376 
377 #ifndef atomic_fetch_xor
378 #define atomic_fetch_xor(...)						\
379 	__atomic_op_fence(atomic_fetch_xor, __VA_ARGS__)
380 #endif
381 #endif /* atomic_fetch_xor_relaxed */
382 
383 
384 /* atomic_xchg_relaxed */
385 #ifndef atomic_xchg_relaxed
386 #define  atomic_xchg_relaxed		atomic_xchg
387 #define  atomic_xchg_acquire		atomic_xchg
388 #define  atomic_xchg_release		atomic_xchg
389 
390 #else /* atomic_xchg_relaxed */
391 
392 #ifndef atomic_xchg_acquire
393 #define  atomic_xchg_acquire(...)					\
394 	__atomic_op_acquire(atomic_xchg, __VA_ARGS__)
395 #endif
396 
397 #ifndef atomic_xchg_release
398 #define  atomic_xchg_release(...)					\
399 	__atomic_op_release(atomic_xchg, __VA_ARGS__)
400 #endif
401 
402 #ifndef atomic_xchg
403 #define  atomic_xchg(...)						\
404 	__atomic_op_fence(atomic_xchg, __VA_ARGS__)
405 #endif
406 #endif /* atomic_xchg_relaxed */
407 
408 /* atomic_cmpxchg_relaxed */
409 #ifndef atomic_cmpxchg_relaxed
410 #define  atomic_cmpxchg_relaxed		atomic_cmpxchg
411 #define  atomic_cmpxchg_acquire		atomic_cmpxchg
412 #define  atomic_cmpxchg_release		atomic_cmpxchg
413 
414 #else /* atomic_cmpxchg_relaxed */
415 
416 #ifndef atomic_cmpxchg_acquire
417 #define  atomic_cmpxchg_acquire(...)					\
418 	__atomic_op_acquire(atomic_cmpxchg, __VA_ARGS__)
419 #endif
420 
421 #ifndef atomic_cmpxchg_release
422 #define  atomic_cmpxchg_release(...)					\
423 	__atomic_op_release(atomic_cmpxchg, __VA_ARGS__)
424 #endif
425 
426 #ifndef atomic_cmpxchg
427 #define  atomic_cmpxchg(...)						\
428 	__atomic_op_fence(atomic_cmpxchg, __VA_ARGS__)
429 #endif
430 #endif /* atomic_cmpxchg_relaxed */
431 
432 #ifndef atomic_try_cmpxchg
433 
434 #define __atomic_try_cmpxchg(type, _p, _po, _n)				\
435 ({									\
436 	typeof(_po) __po = (_po);					\
437 	typeof(*(_po)) __r, __o = *__po;				\
438 	__r = atomic_cmpxchg##type((_p), __o, (_n));			\
439 	if (unlikely(__r != __o))					\
440 		*__po = __r;						\
441 	likely(__r == __o);						\
442 })
443 
444 #define atomic_try_cmpxchg(_p, _po, _n)		__atomic_try_cmpxchg(, _p, _po, _n)
445 #define atomic_try_cmpxchg_relaxed(_p, _po, _n)	__atomic_try_cmpxchg(_relaxed, _p, _po, _n)
446 #define atomic_try_cmpxchg_acquire(_p, _po, _n)	__atomic_try_cmpxchg(_acquire, _p, _po, _n)
447 #define atomic_try_cmpxchg_release(_p, _po, _n)	__atomic_try_cmpxchg(_release, _p, _po, _n)
448 
449 #else /* atomic_try_cmpxchg */
450 #define atomic_try_cmpxchg_relaxed	atomic_try_cmpxchg
451 #define atomic_try_cmpxchg_acquire	atomic_try_cmpxchg
452 #define atomic_try_cmpxchg_release	atomic_try_cmpxchg
453 #endif /* atomic_try_cmpxchg */
454 
455 /* cmpxchg_relaxed */
456 #ifndef cmpxchg_relaxed
457 #define  cmpxchg_relaxed		cmpxchg
458 #define  cmpxchg_acquire		cmpxchg
459 #define  cmpxchg_release		cmpxchg
460 
461 #else /* cmpxchg_relaxed */
462 
463 #ifndef cmpxchg_acquire
464 #define  cmpxchg_acquire(...)						\
465 	__atomic_op_acquire(cmpxchg, __VA_ARGS__)
466 #endif
467 
468 #ifndef cmpxchg_release
469 #define  cmpxchg_release(...)						\
470 	__atomic_op_release(cmpxchg, __VA_ARGS__)
471 #endif
472 
473 #ifndef cmpxchg
474 #define  cmpxchg(...)							\
475 	__atomic_op_fence(cmpxchg, __VA_ARGS__)
476 #endif
477 #endif /* cmpxchg_relaxed */
478 
479 /* cmpxchg64_relaxed */
480 #ifndef cmpxchg64_relaxed
481 #define  cmpxchg64_relaxed		cmpxchg64
482 #define  cmpxchg64_acquire		cmpxchg64
483 #define  cmpxchg64_release		cmpxchg64
484 
485 #else /* cmpxchg64_relaxed */
486 
487 #ifndef cmpxchg64_acquire
488 #define  cmpxchg64_acquire(...)						\
489 	__atomic_op_acquire(cmpxchg64, __VA_ARGS__)
490 #endif
491 
492 #ifndef cmpxchg64_release
493 #define  cmpxchg64_release(...)						\
494 	__atomic_op_release(cmpxchg64, __VA_ARGS__)
495 #endif
496 
497 #ifndef cmpxchg64
498 #define  cmpxchg64(...)							\
499 	__atomic_op_fence(cmpxchg64, __VA_ARGS__)
500 #endif
501 #endif /* cmpxchg64_relaxed */
502 
503 /* xchg_relaxed */
504 #ifndef xchg_relaxed
505 #define  xchg_relaxed			xchg
506 #define  xchg_acquire			xchg
507 #define  xchg_release			xchg
508 
509 #else /* xchg_relaxed */
510 
511 #ifndef xchg_acquire
512 #define  xchg_acquire(...)		__atomic_op_acquire(xchg, __VA_ARGS__)
513 #endif
514 
515 #ifndef xchg_release
516 #define  xchg_release(...)		__atomic_op_release(xchg, __VA_ARGS__)
517 #endif
518 
519 #ifndef xchg
520 #define  xchg(...)			__atomic_op_fence(xchg, __VA_ARGS__)
521 #endif
522 #endif /* xchg_relaxed */
523 
524 /**
525  * atomic_add_unless - add unless the number is already a given value
526  * @v: pointer of type atomic_t
527  * @a: the amount to add to v...
528  * @u: ...unless v is equal to u.
529  *
530  * Atomically adds @a to @v, if @v was not already @u.
531  * Returns true if the addition was done.
532  */
533 static inline bool atomic_add_unless(atomic_t *v, int a, int u)
534 {
535 	return atomic_fetch_add_unless(v, a, u) != u;
536 }
537 
538 /**
539  * atomic_inc_not_zero - increment unless the number is zero
540  * @v: pointer of type atomic_t
541  *
542  * Atomically increments @v by 1, if @v is non-zero.
543  * Returns true if the increment was done.
544  */
545 #ifndef atomic_inc_not_zero
546 #define atomic_inc_not_zero(v)		atomic_add_unless((v), 1, 0)
547 #endif
548 
549 #ifndef atomic_andnot
550 static inline void atomic_andnot(int i, atomic_t *v)
551 {
552 	atomic_and(~i, v);
553 }
554 
555 static inline int atomic_fetch_andnot(int i, atomic_t *v)
556 {
557 	return atomic_fetch_and(~i, v);
558 }
559 
560 static inline int atomic_fetch_andnot_relaxed(int i, atomic_t *v)
561 {
562 	return atomic_fetch_and_relaxed(~i, v);
563 }
564 
565 static inline int atomic_fetch_andnot_acquire(int i, atomic_t *v)
566 {
567 	return atomic_fetch_and_acquire(~i, v);
568 }
569 
570 static inline int atomic_fetch_andnot_release(int i, atomic_t *v)
571 {
572 	return atomic_fetch_and_release(~i, v);
573 }
574 #endif
575 
576 #ifndef atomic_inc_unless_negative
577 static inline bool atomic_inc_unless_negative(atomic_t *p)
578 {
579 	int v, v1;
580 	for (v = 0; v >= 0; v = v1) {
581 		v1 = atomic_cmpxchg(p, v, v + 1);
582 		if (likely(v1 == v))
583 			return true;
584 	}
585 	return false;
586 }
587 #endif
588 
589 #ifndef atomic_dec_unless_positive
590 static inline bool atomic_dec_unless_positive(atomic_t *p)
591 {
592 	int v, v1;
593 	for (v = 0; v <= 0; v = v1) {
594 		v1 = atomic_cmpxchg(p, v, v - 1);
595 		if (likely(v1 == v))
596 			return true;
597 	}
598 	return false;
599 }
600 #endif
601 
602 /*
603  * atomic_dec_if_positive - decrement by 1 if old value positive
604  * @v: pointer of type atomic_t
605  *
606  * The function returns the old value of *v minus 1, even if
607  * the atomic variable, v, was not decremented.
608  */
609 #ifndef atomic_dec_if_positive
610 static inline int atomic_dec_if_positive(atomic_t *v)
611 {
612 	int c, old, dec;
613 	c = atomic_read(v);
614 	for (;;) {
615 		dec = c - 1;
616 		if (unlikely(dec < 0))
617 			break;
618 		old = atomic_cmpxchg((v), c, dec);
619 		if (likely(old == c))
620 			break;
621 		c = old;
622 	}
623 	return dec;
624 }
625 #endif
626 
627 #define atomic_cond_read_relaxed(v, c)	smp_cond_load_relaxed(&(v)->counter, (c))
628 #define atomic_cond_read_acquire(v, c)	smp_cond_load_acquire(&(v)->counter, (c))
629 
630 #ifdef CONFIG_GENERIC_ATOMIC64
631 #include <asm-generic/atomic64.h>
632 #endif
633 
634 #ifndef atomic64_read_acquire
635 #define  atomic64_read_acquire(v)	smp_load_acquire(&(v)->counter)
636 #endif
637 
638 #ifndef atomic64_set_release
639 #define  atomic64_set_release(v, i)	smp_store_release(&(v)->counter, (i))
640 #endif
641 
642 /* atomic64_add_return_relaxed */
643 #ifndef atomic64_add_return_relaxed
644 #define  atomic64_add_return_relaxed	atomic64_add_return
645 #define  atomic64_add_return_acquire	atomic64_add_return
646 #define  atomic64_add_return_release	atomic64_add_return
647 
648 #else /* atomic64_add_return_relaxed */
649 
650 #ifndef atomic64_add_return_acquire
651 #define  atomic64_add_return_acquire(...)				\
652 	__atomic_op_acquire(atomic64_add_return, __VA_ARGS__)
653 #endif
654 
655 #ifndef atomic64_add_return_release
656 #define  atomic64_add_return_release(...)				\
657 	__atomic_op_release(atomic64_add_return, __VA_ARGS__)
658 #endif
659 
660 #ifndef atomic64_add_return
661 #define  atomic64_add_return(...)					\
662 	__atomic_op_fence(atomic64_add_return, __VA_ARGS__)
663 #endif
664 #endif /* atomic64_add_return_relaxed */
665 
666 /* atomic64_inc_return_relaxed */
667 #ifndef atomic64_inc_return_relaxed
668 #define  atomic64_inc_return_relaxed	atomic64_inc_return
669 #define  atomic64_inc_return_acquire	atomic64_inc_return
670 #define  atomic64_inc_return_release	atomic64_inc_return
671 
672 #else /* atomic64_inc_return_relaxed */
673 
674 #ifndef atomic64_inc_return_acquire
675 #define  atomic64_inc_return_acquire(...)				\
676 	__atomic_op_acquire(atomic64_inc_return, __VA_ARGS__)
677 #endif
678 
679 #ifndef atomic64_inc_return_release
680 #define  atomic64_inc_return_release(...)				\
681 	__atomic_op_release(atomic64_inc_return, __VA_ARGS__)
682 #endif
683 
684 #ifndef atomic64_inc_return
685 #define  atomic64_inc_return(...)					\
686 	__atomic_op_fence(atomic64_inc_return, __VA_ARGS__)
687 #endif
688 #endif /* atomic64_inc_return_relaxed */
689 
690 
691 /* atomic64_sub_return_relaxed */
692 #ifndef atomic64_sub_return_relaxed
693 #define  atomic64_sub_return_relaxed	atomic64_sub_return
694 #define  atomic64_sub_return_acquire	atomic64_sub_return
695 #define  atomic64_sub_return_release	atomic64_sub_return
696 
697 #else /* atomic64_sub_return_relaxed */
698 
699 #ifndef atomic64_sub_return_acquire
700 #define  atomic64_sub_return_acquire(...)				\
701 	__atomic_op_acquire(atomic64_sub_return, __VA_ARGS__)
702 #endif
703 
704 #ifndef atomic64_sub_return_release
705 #define  atomic64_sub_return_release(...)				\
706 	__atomic_op_release(atomic64_sub_return, __VA_ARGS__)
707 #endif
708 
709 #ifndef atomic64_sub_return
710 #define  atomic64_sub_return(...)					\
711 	__atomic_op_fence(atomic64_sub_return, __VA_ARGS__)
712 #endif
713 #endif /* atomic64_sub_return_relaxed */
714 
715 /* atomic64_dec_return_relaxed */
716 #ifndef atomic64_dec_return_relaxed
717 #define  atomic64_dec_return_relaxed	atomic64_dec_return
718 #define  atomic64_dec_return_acquire	atomic64_dec_return
719 #define  atomic64_dec_return_release	atomic64_dec_return
720 
721 #else /* atomic64_dec_return_relaxed */
722 
723 #ifndef atomic64_dec_return_acquire
724 #define  atomic64_dec_return_acquire(...)				\
725 	__atomic_op_acquire(atomic64_dec_return, __VA_ARGS__)
726 #endif
727 
728 #ifndef atomic64_dec_return_release
729 #define  atomic64_dec_return_release(...)				\
730 	__atomic_op_release(atomic64_dec_return, __VA_ARGS__)
731 #endif
732 
733 #ifndef atomic64_dec_return
734 #define  atomic64_dec_return(...)					\
735 	__atomic_op_fence(atomic64_dec_return, __VA_ARGS__)
736 #endif
737 #endif /* atomic64_dec_return_relaxed */
738 
739 
740 /* atomic64_fetch_add_relaxed */
741 #ifndef atomic64_fetch_add_relaxed
742 #define atomic64_fetch_add_relaxed	atomic64_fetch_add
743 #define atomic64_fetch_add_acquire	atomic64_fetch_add
744 #define atomic64_fetch_add_release	atomic64_fetch_add
745 
746 #else /* atomic64_fetch_add_relaxed */
747 
748 #ifndef atomic64_fetch_add_acquire
749 #define atomic64_fetch_add_acquire(...)					\
750 	__atomic_op_acquire(atomic64_fetch_add, __VA_ARGS__)
751 #endif
752 
753 #ifndef atomic64_fetch_add_release
754 #define atomic64_fetch_add_release(...)					\
755 	__atomic_op_release(atomic64_fetch_add, __VA_ARGS__)
756 #endif
757 
758 #ifndef atomic64_fetch_add
759 #define atomic64_fetch_add(...)						\
760 	__atomic_op_fence(atomic64_fetch_add, __VA_ARGS__)
761 #endif
762 #endif /* atomic64_fetch_add_relaxed */
763 
764 /* atomic64_fetch_inc_relaxed */
765 #ifndef atomic64_fetch_inc_relaxed
766 
767 #ifndef atomic64_fetch_inc
768 #define atomic64_fetch_inc(v)		atomic64_fetch_add(1, (v))
769 #define atomic64_fetch_inc_relaxed(v)	atomic64_fetch_add_relaxed(1, (v))
770 #define atomic64_fetch_inc_acquire(v)	atomic64_fetch_add_acquire(1, (v))
771 #define atomic64_fetch_inc_release(v)	atomic64_fetch_add_release(1, (v))
772 #else /* atomic64_fetch_inc */
773 #define atomic64_fetch_inc_relaxed	atomic64_fetch_inc
774 #define atomic64_fetch_inc_acquire	atomic64_fetch_inc
775 #define atomic64_fetch_inc_release	atomic64_fetch_inc
776 #endif /* atomic64_fetch_inc */
777 
778 #else /* atomic64_fetch_inc_relaxed */
779 
780 #ifndef atomic64_fetch_inc_acquire
781 #define atomic64_fetch_inc_acquire(...)					\
782 	__atomic_op_acquire(atomic64_fetch_inc, __VA_ARGS__)
783 #endif
784 
785 #ifndef atomic64_fetch_inc_release
786 #define atomic64_fetch_inc_release(...)					\
787 	__atomic_op_release(atomic64_fetch_inc, __VA_ARGS__)
788 #endif
789 
790 #ifndef atomic64_fetch_inc
791 #define atomic64_fetch_inc(...)						\
792 	__atomic_op_fence(atomic64_fetch_inc, __VA_ARGS__)
793 #endif
794 #endif /* atomic64_fetch_inc_relaxed */
795 
796 /* atomic64_fetch_sub_relaxed */
797 #ifndef atomic64_fetch_sub_relaxed
798 #define atomic64_fetch_sub_relaxed	atomic64_fetch_sub
799 #define atomic64_fetch_sub_acquire	atomic64_fetch_sub
800 #define atomic64_fetch_sub_release	atomic64_fetch_sub
801 
802 #else /* atomic64_fetch_sub_relaxed */
803 
804 #ifndef atomic64_fetch_sub_acquire
805 #define atomic64_fetch_sub_acquire(...)					\
806 	__atomic_op_acquire(atomic64_fetch_sub, __VA_ARGS__)
807 #endif
808 
809 #ifndef atomic64_fetch_sub_release
810 #define atomic64_fetch_sub_release(...)					\
811 	__atomic_op_release(atomic64_fetch_sub, __VA_ARGS__)
812 #endif
813 
814 #ifndef atomic64_fetch_sub
815 #define atomic64_fetch_sub(...)						\
816 	__atomic_op_fence(atomic64_fetch_sub, __VA_ARGS__)
817 #endif
818 #endif /* atomic64_fetch_sub_relaxed */
819 
820 /* atomic64_fetch_dec_relaxed */
821 #ifndef atomic64_fetch_dec_relaxed
822 
823 #ifndef atomic64_fetch_dec
824 #define atomic64_fetch_dec(v)		atomic64_fetch_sub(1, (v))
825 #define atomic64_fetch_dec_relaxed(v)	atomic64_fetch_sub_relaxed(1, (v))
826 #define atomic64_fetch_dec_acquire(v)	atomic64_fetch_sub_acquire(1, (v))
827 #define atomic64_fetch_dec_release(v)	atomic64_fetch_sub_release(1, (v))
828 #else /* atomic64_fetch_dec */
829 #define atomic64_fetch_dec_relaxed	atomic64_fetch_dec
830 #define atomic64_fetch_dec_acquire	atomic64_fetch_dec
831 #define atomic64_fetch_dec_release	atomic64_fetch_dec
832 #endif /* atomic64_fetch_dec */
833 
834 #else /* atomic64_fetch_dec_relaxed */
835 
836 #ifndef atomic64_fetch_dec_acquire
837 #define atomic64_fetch_dec_acquire(...)					\
838 	__atomic_op_acquire(atomic64_fetch_dec, __VA_ARGS__)
839 #endif
840 
841 #ifndef atomic64_fetch_dec_release
842 #define atomic64_fetch_dec_release(...)					\
843 	__atomic_op_release(atomic64_fetch_dec, __VA_ARGS__)
844 #endif
845 
846 #ifndef atomic64_fetch_dec
847 #define atomic64_fetch_dec(...)						\
848 	__atomic_op_fence(atomic64_fetch_dec, __VA_ARGS__)
849 #endif
850 #endif /* atomic64_fetch_dec_relaxed */
851 
852 /* atomic64_fetch_or_relaxed */
853 #ifndef atomic64_fetch_or_relaxed
854 #define atomic64_fetch_or_relaxed	atomic64_fetch_or
855 #define atomic64_fetch_or_acquire	atomic64_fetch_or
856 #define atomic64_fetch_or_release	atomic64_fetch_or
857 
858 #else /* atomic64_fetch_or_relaxed */
859 
860 #ifndef atomic64_fetch_or_acquire
861 #define atomic64_fetch_or_acquire(...)					\
862 	__atomic_op_acquire(atomic64_fetch_or, __VA_ARGS__)
863 #endif
864 
865 #ifndef atomic64_fetch_or_release
866 #define atomic64_fetch_or_release(...)					\
867 	__atomic_op_release(atomic64_fetch_or, __VA_ARGS__)
868 #endif
869 
870 #ifndef atomic64_fetch_or
871 #define atomic64_fetch_or(...)						\
872 	__atomic_op_fence(atomic64_fetch_or, __VA_ARGS__)
873 #endif
874 #endif /* atomic64_fetch_or_relaxed */
875 
876 /* atomic64_fetch_and_relaxed */
877 #ifndef atomic64_fetch_and_relaxed
878 #define atomic64_fetch_and_relaxed	atomic64_fetch_and
879 #define atomic64_fetch_and_acquire	atomic64_fetch_and
880 #define atomic64_fetch_and_release	atomic64_fetch_and
881 
882 #else /* atomic64_fetch_and_relaxed */
883 
884 #ifndef atomic64_fetch_and_acquire
885 #define atomic64_fetch_and_acquire(...)					\
886 	__atomic_op_acquire(atomic64_fetch_and, __VA_ARGS__)
887 #endif
888 
889 #ifndef atomic64_fetch_and_release
890 #define atomic64_fetch_and_release(...)					\
891 	__atomic_op_release(atomic64_fetch_and, __VA_ARGS__)
892 #endif
893 
894 #ifndef atomic64_fetch_and
895 #define atomic64_fetch_and(...)						\
896 	__atomic_op_fence(atomic64_fetch_and, __VA_ARGS__)
897 #endif
898 #endif /* atomic64_fetch_and_relaxed */
899 
900 #ifdef atomic64_andnot
901 /* atomic64_fetch_andnot_relaxed */
902 #ifndef atomic64_fetch_andnot_relaxed
903 #define atomic64_fetch_andnot_relaxed	atomic64_fetch_andnot
904 #define atomic64_fetch_andnot_acquire	atomic64_fetch_andnot
905 #define atomic64_fetch_andnot_release	atomic64_fetch_andnot
906 
907 #else /* atomic64_fetch_andnot_relaxed */
908 
909 #ifndef atomic64_fetch_andnot_acquire
910 #define atomic64_fetch_andnot_acquire(...)					\
911 	__atomic_op_acquire(atomic64_fetch_andnot, __VA_ARGS__)
912 #endif
913 
914 #ifndef atomic64_fetch_andnot_release
915 #define atomic64_fetch_andnot_release(...)					\
916 	__atomic_op_release(atomic64_fetch_andnot, __VA_ARGS__)
917 #endif
918 
919 #ifndef atomic64_fetch_andnot
920 #define atomic64_fetch_andnot(...)						\
921 	__atomic_op_fence(atomic64_fetch_andnot, __VA_ARGS__)
922 #endif
923 #endif /* atomic64_fetch_andnot_relaxed */
924 #endif /* atomic64_andnot */
925 
926 /* atomic64_fetch_xor_relaxed */
927 #ifndef atomic64_fetch_xor_relaxed
928 #define atomic64_fetch_xor_relaxed	atomic64_fetch_xor
929 #define atomic64_fetch_xor_acquire	atomic64_fetch_xor
930 #define atomic64_fetch_xor_release	atomic64_fetch_xor
931 
932 #else /* atomic64_fetch_xor_relaxed */
933 
934 #ifndef atomic64_fetch_xor_acquire
935 #define atomic64_fetch_xor_acquire(...)					\
936 	__atomic_op_acquire(atomic64_fetch_xor, __VA_ARGS__)
937 #endif
938 
939 #ifndef atomic64_fetch_xor_release
940 #define atomic64_fetch_xor_release(...)					\
941 	__atomic_op_release(atomic64_fetch_xor, __VA_ARGS__)
942 #endif
943 
944 #ifndef atomic64_fetch_xor
945 #define atomic64_fetch_xor(...)						\
946 	__atomic_op_fence(atomic64_fetch_xor, __VA_ARGS__)
947 #endif
948 #endif /* atomic64_fetch_xor_relaxed */
949 
950 
951 /* atomic64_xchg_relaxed */
952 #ifndef atomic64_xchg_relaxed
953 #define  atomic64_xchg_relaxed		atomic64_xchg
954 #define  atomic64_xchg_acquire		atomic64_xchg
955 #define  atomic64_xchg_release		atomic64_xchg
956 
957 #else /* atomic64_xchg_relaxed */
958 
959 #ifndef atomic64_xchg_acquire
960 #define  atomic64_xchg_acquire(...)					\
961 	__atomic_op_acquire(atomic64_xchg, __VA_ARGS__)
962 #endif
963 
964 #ifndef atomic64_xchg_release
965 #define  atomic64_xchg_release(...)					\
966 	__atomic_op_release(atomic64_xchg, __VA_ARGS__)
967 #endif
968 
969 #ifndef atomic64_xchg
970 #define  atomic64_xchg(...)						\
971 	__atomic_op_fence(atomic64_xchg, __VA_ARGS__)
972 #endif
973 #endif /* atomic64_xchg_relaxed */
974 
975 /* atomic64_cmpxchg_relaxed */
976 #ifndef atomic64_cmpxchg_relaxed
977 #define  atomic64_cmpxchg_relaxed	atomic64_cmpxchg
978 #define  atomic64_cmpxchg_acquire	atomic64_cmpxchg
979 #define  atomic64_cmpxchg_release	atomic64_cmpxchg
980 
981 #else /* atomic64_cmpxchg_relaxed */
982 
983 #ifndef atomic64_cmpxchg_acquire
984 #define  atomic64_cmpxchg_acquire(...)					\
985 	__atomic_op_acquire(atomic64_cmpxchg, __VA_ARGS__)
986 #endif
987 
988 #ifndef atomic64_cmpxchg_release
989 #define  atomic64_cmpxchg_release(...)					\
990 	__atomic_op_release(atomic64_cmpxchg, __VA_ARGS__)
991 #endif
992 
993 #ifndef atomic64_cmpxchg
994 #define  atomic64_cmpxchg(...)						\
995 	__atomic_op_fence(atomic64_cmpxchg, __VA_ARGS__)
996 #endif
997 #endif /* atomic64_cmpxchg_relaxed */
998 
999 #ifndef atomic64_try_cmpxchg
1000 
1001 #define __atomic64_try_cmpxchg(type, _p, _po, _n)			\
1002 ({									\
1003 	typeof(_po) __po = (_po);					\
1004 	typeof(*(_po)) __r, __o = *__po;				\
1005 	__r = atomic64_cmpxchg##type((_p), __o, (_n));			\
1006 	if (unlikely(__r != __o))					\
1007 		*__po = __r;						\
1008 	likely(__r == __o);						\
1009 })
1010 
1011 #define atomic64_try_cmpxchg(_p, _po, _n)		__atomic64_try_cmpxchg(, _p, _po, _n)
1012 #define atomic64_try_cmpxchg_relaxed(_p, _po, _n)	__atomic64_try_cmpxchg(_relaxed, _p, _po, _n)
1013 #define atomic64_try_cmpxchg_acquire(_p, _po, _n)	__atomic64_try_cmpxchg(_acquire, _p, _po, _n)
1014 #define atomic64_try_cmpxchg_release(_p, _po, _n)	__atomic64_try_cmpxchg(_release, _p, _po, _n)
1015 
1016 #else /* atomic64_try_cmpxchg */
1017 #define atomic64_try_cmpxchg_relaxed	atomic64_try_cmpxchg
1018 #define atomic64_try_cmpxchg_acquire	atomic64_try_cmpxchg
1019 #define atomic64_try_cmpxchg_release	atomic64_try_cmpxchg
1020 #endif /* atomic64_try_cmpxchg */
1021 
1022 #ifndef atomic64_andnot
1023 static inline void atomic64_andnot(long long i, atomic64_t *v)
1024 {
1025 	atomic64_and(~i, v);
1026 }
1027 
1028 static inline long long atomic64_fetch_andnot(long long i, atomic64_t *v)
1029 {
1030 	return atomic64_fetch_and(~i, v);
1031 }
1032 
1033 static inline long long atomic64_fetch_andnot_relaxed(long long i, atomic64_t *v)
1034 {
1035 	return atomic64_fetch_and_relaxed(~i, v);
1036 }
1037 
1038 static inline long long atomic64_fetch_andnot_acquire(long long i, atomic64_t *v)
1039 {
1040 	return atomic64_fetch_and_acquire(~i, v);
1041 }
1042 
1043 static inline long long atomic64_fetch_andnot_release(long long i, atomic64_t *v)
1044 {
1045 	return atomic64_fetch_and_release(~i, v);
1046 }
1047 #endif
1048 
1049 #define atomic64_cond_read_relaxed(v, c)	smp_cond_load_relaxed(&(v)->counter, (c))
1050 #define atomic64_cond_read_acquire(v, c)	smp_cond_load_acquire(&(v)->counter, (c))
1051 
1052 #include <asm-generic/atomic-long.h>
1053 
1054 #endif /* _LINUX_ATOMIC_H */
1055