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1/*
2 * Atomic operations that C can't guarantee us. Useful for
3 * resource counting etc..
4 *
5 * But use these as seldom as possible since they are much more slower
6 * than regular operations.
7 *
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License. See the file "COPYING" in the main directory of this archive
10 * for more details.
11 *
12 * Copyright (C) 1996, 97, 99, 2000, 03, 04, 06 by Ralf Baechle
13 */
14#ifndef _ASM_ATOMIC_H
15#define _ASM_ATOMIC_H
16
17#include <linux/irqflags.h>
18#include <linux/types.h>
19#include <asm/barrier.h>
20#include <asm/cpu-features.h>
21#include <asm/war.h>
22#include <asm/system.h>
23
24#define ATOMIC_INIT(i) { (i) }
25
26/*
27 * atomic_read - read atomic variable
28 * @v: pointer of type atomic_t
29 *
30 * Atomically reads the value of @v.
31 */
32#define atomic_read(v) (*(volatile int *)&(v)->counter)
33
34/*
35 * atomic_set - set atomic variable
36 * @v: pointer of type atomic_t
37 * @i: required value
38 *
39 * Atomically sets the value of @v to @i.
40 */
41#define atomic_set(v, i) ((v)->counter = (i))
42
43/*
44 * atomic_add - add integer to atomic variable
45 * @i: integer value to add
46 * @v: pointer of type atomic_t
47 *
48 * Atomically adds @i to @v.
49 */
50static __inline__ void atomic_add(int i, atomic_t * v)
51{
52 if (kernel_uses_llsc && R10000_LLSC_WAR) {
53 int temp;
54
55 __asm__ __volatile__(
56 " .set mips3 \n"
57 "1: ll %0, %1 # atomic_add \n"
58 " addu %0, %2 \n"
59 " sc %0, %1 \n"
60 " beqzl %0, 1b \n"
61 " .set mips0 \n"
62 : "=&r" (temp), "=m" (v->counter)
63 : "Ir" (i), "m" (v->counter));
64 } else if (kernel_uses_llsc) {
65 int temp;
66
67 do {
68 __asm__ __volatile__(
69 " .set mips3 \n"
70 " ll %0, %1 # atomic_add \n"
71 " addu %0, %2 \n"
72 " sc %0, %1 \n"
73 " .set mips0 \n"
74 : "=&r" (temp), "=m" (v->counter)
75 : "Ir" (i), "m" (v->counter));
76 } while (unlikely(!temp));
77 } else {
78 unsigned long flags;
79
80 raw_local_irq_save(flags);
81 v->counter += i;
82 raw_local_irq_restore(flags);
83 }
84}
85
86/*
87 * atomic_sub - subtract the atomic variable
88 * @i: integer value to subtract
89 * @v: pointer of type atomic_t
90 *
91 * Atomically subtracts @i from @v.
92 */
93static __inline__ void atomic_sub(int i, atomic_t * v)
94{
95 if (kernel_uses_llsc && R10000_LLSC_WAR) {
96 int temp;
97
98 __asm__ __volatile__(
99 " .set mips3 \n"
100 "1: ll %0, %1 # atomic_sub \n"
101 " subu %0, %2 \n"
102 " sc %0, %1 \n"
103 " beqzl %0, 1b \n"
104 " .set mips0 \n"
105 : "=&r" (temp), "=m" (v->counter)
106 : "Ir" (i), "m" (v->counter));
107 } else if (kernel_uses_llsc) {
108 int temp;
109
110 do {
111 __asm__ __volatile__(
112 " .set mips3 \n"
113 " ll %0, %1 # atomic_sub \n"
114 " subu %0, %2 \n"
115 " sc %0, %1 \n"
116 " .set mips0 \n"
117 : "=&r" (temp), "=m" (v->counter)
118 : "Ir" (i), "m" (v->counter));
119 } while (unlikely(!temp));
120 } else {
121 unsigned long flags;
122
123 raw_local_irq_save(flags);
124 v->counter -= i;
125 raw_local_irq_restore(flags);
126 }
127}
128
129/*
130 * Same as above, but return the result value
131 */
132static __inline__ int atomic_add_return(int i, atomic_t * v)
133{
134 int result;
135
136 smp_mb__before_llsc();
137
138 if (kernel_uses_llsc && R10000_LLSC_WAR) {
139 int temp;
140
141 __asm__ __volatile__(
142 " .set mips3 \n"
143 "1: ll %1, %2 # atomic_add_return \n"
144 " addu %0, %1, %3 \n"
145 " sc %0, %2 \n"
146 " beqzl %0, 1b \n"
147 " addu %0, %1, %3 \n"
148 " .set mips0 \n"
149 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
150 : "Ir" (i), "m" (v->counter)
151 : "memory");
152 } else if (kernel_uses_llsc) {
153 int temp;
154
155 do {
156 __asm__ __volatile__(
157 " .set mips3 \n"
158 " ll %1, %2 # atomic_add_return \n"
159 " addu %0, %1, %3 \n"
160 " sc %0, %2 \n"
161 " .set mips0 \n"
162 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
163 : "Ir" (i), "m" (v->counter)
164 : "memory");
165 } while (unlikely(!result));
166
167 result = temp + i;
168 } else {
169 unsigned long flags;
170
171 raw_local_irq_save(flags);
172 result = v->counter;
173 result += i;
174 v->counter = result;
175 raw_local_irq_restore(flags);
176 }
177
178 smp_llsc_mb();
179
180 return result;
181}
182
183static __inline__ int atomic_sub_return(int i, atomic_t * v)
184{
185 int result;
186
187 smp_mb__before_llsc();
188
189 if (kernel_uses_llsc && R10000_LLSC_WAR) {
190 int temp;
191
192 __asm__ __volatile__(
193 " .set mips3 \n"
194 "1: ll %1, %2 # atomic_sub_return \n"
195 " subu %0, %1, %3 \n"
196 " sc %0, %2 \n"
197 " beqzl %0, 1b \n"
198 " subu %0, %1, %3 \n"
199 " .set mips0 \n"
200 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
201 : "Ir" (i), "m" (v->counter)
202 : "memory");
203
204 result = temp - i;
205 } else if (kernel_uses_llsc) {
206 int temp;
207
208 do {
209 __asm__ __volatile__(
210 " .set mips3 \n"
211 " ll %1, %2 # atomic_sub_return \n"
212 " subu %0, %1, %3 \n"
213 " sc %0, %2 \n"
214 " .set mips0 \n"
215 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
216 : "Ir" (i), "m" (v->counter)
217 : "memory");
218 } while (unlikely(!result));
219
220 result = temp - i;
221 } else {
222 unsigned long flags;
223
224 raw_local_irq_save(flags);
225 result = v->counter;
226 result -= i;
227 v->counter = result;
228 raw_local_irq_restore(flags);
229 }
230
231 smp_llsc_mb();
232
233 return result;
234}
235
236/*
237 * atomic_sub_if_positive - conditionally subtract integer from atomic variable
238 * @i: integer value to subtract
239 * @v: pointer of type atomic_t
240 *
241 * Atomically test @v and subtract @i if @v is greater or equal than @i.
242 * The function returns the old value of @v minus @i.
243 */
244static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
245{
246 int result;
247
248 smp_mb__before_llsc();
249
250 if (kernel_uses_llsc && R10000_LLSC_WAR) {
251 int temp;
252
253 __asm__ __volatile__(
254 " .set mips3 \n"
255 "1: ll %1, %2 # atomic_sub_if_positive\n"
256 " subu %0, %1, %3 \n"
257 " bltz %0, 1f \n"
258 " sc %0, %2 \n"
259 " .set noreorder \n"
260 " beqzl %0, 1b \n"
261 " subu %0, %1, %3 \n"
262 " .set reorder \n"
263 "1: \n"
264 " .set mips0 \n"
265 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
266 : "Ir" (i), "m" (v->counter)
267 : "memory");
268 } else if (kernel_uses_llsc) {
269 int temp;
270
271 __asm__ __volatile__(
272 " .set mips3 \n"
273 "1: ll %1, %2 # atomic_sub_if_positive\n"
274 " subu %0, %1, %3 \n"
275 " bltz %0, 1f \n"
276 " sc %0, %2 \n"
277 " .set noreorder \n"
278 " beqz %0, 1b \n"
279 " subu %0, %1, %3 \n"
280 " .set reorder \n"
281 "1: \n"
282 " .set mips0 \n"
283 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
284 : "Ir" (i), "m" (v->counter)
285 : "memory");
286 } else {
287 unsigned long flags;
288
289 raw_local_irq_save(flags);
290 result = v->counter;
291 result -= i;
292 if (result >= 0)
293 v->counter = result;
294 raw_local_irq_restore(flags);
295 }
296
297 smp_llsc_mb();
298
299 return result;
300}
301
302#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
303#define atomic_xchg(v, new) (xchg(&((v)->counter), (new)))
304
305/**
306 * __atomic_add_unless - add unless the number is a given value
307 * @v: pointer of type atomic_t
308 * @a: the amount to add to v...
309 * @u: ...unless v is equal to u.
310 *
311 * Atomically adds @a to @v, so long as it was not @u.
312 * Returns the old value of @v.
313 */
314static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
315{
316 int c, old;
317 c = atomic_read(v);
318 for (;;) {
319 if (unlikely(c == (u)))
320 break;
321 old = atomic_cmpxchg((v), c, c + (a));
322 if (likely(old == c))
323 break;
324 c = old;
325 }
326 return c;
327}
328
329#define atomic_dec_return(v) atomic_sub_return(1, (v))
330#define atomic_inc_return(v) atomic_add_return(1, (v))
331
332/*
333 * atomic_sub_and_test - subtract value from variable and test result
334 * @i: integer value to subtract
335 * @v: pointer of type atomic_t
336 *
337 * Atomically subtracts @i from @v and returns
338 * true if the result is zero, or false for all
339 * other cases.
340 */
341#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
342
343/*
344 * atomic_inc_and_test - increment and test
345 * @v: pointer of type atomic_t
346 *
347 * Atomically increments @v by 1
348 * and returns true if the result is zero, or false for all
349 * other cases.
350 */
351#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
352
353/*
354 * atomic_dec_and_test - decrement by 1 and test
355 * @v: pointer of type atomic_t
356 *
357 * Atomically decrements @v by 1 and
358 * returns true if the result is 0, or false for all other
359 * cases.
360 */
361#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
362
363/*
364 * atomic_dec_if_positive - decrement by 1 if old value positive
365 * @v: pointer of type atomic_t
366 */
367#define atomic_dec_if_positive(v) atomic_sub_if_positive(1, v)
368
369/*
370 * atomic_inc - increment atomic variable
371 * @v: pointer of type atomic_t
372 *
373 * Atomically increments @v by 1.
374 */
375#define atomic_inc(v) atomic_add(1, (v))
376
377/*
378 * atomic_dec - decrement and test
379 * @v: pointer of type atomic_t
380 *
381 * Atomically decrements @v by 1.
382 */
383#define atomic_dec(v) atomic_sub(1, (v))
384
385/*
386 * atomic_add_negative - add and test if negative
387 * @v: pointer of type atomic_t
388 * @i: integer value to add
389 *
390 * Atomically adds @i to @v and returns true
391 * if the result is negative, or false when
392 * result is greater than or equal to zero.
393 */
394#define atomic_add_negative(i, v) (atomic_add_return(i, (v)) < 0)
395
396#ifdef CONFIG_64BIT
397
398#define ATOMIC64_INIT(i) { (i) }
399
400/*
401 * atomic64_read - read atomic variable
402 * @v: pointer of type atomic64_t
403 *
404 */
405#define atomic64_read(v) (*(volatile long *)&(v)->counter)
406
407/*
408 * atomic64_set - set atomic variable
409 * @v: pointer of type atomic64_t
410 * @i: required value
411 */
412#define atomic64_set(v, i) ((v)->counter = (i))
413
414/*
415 * atomic64_add - add integer to atomic variable
416 * @i: integer value to add
417 * @v: pointer of type atomic64_t
418 *
419 * Atomically adds @i to @v.
420 */
421static __inline__ void atomic64_add(long i, atomic64_t * v)
422{
423 if (kernel_uses_llsc && R10000_LLSC_WAR) {
424 long temp;
425
426 __asm__ __volatile__(
427 " .set mips3 \n"
428 "1: lld %0, %1 # atomic64_add \n"
429 " daddu %0, %2 \n"
430 " scd %0, %1 \n"
431 " beqzl %0, 1b \n"
432 " .set mips0 \n"
433 : "=&r" (temp), "=m" (v->counter)
434 : "Ir" (i), "m" (v->counter));
435 } else if (kernel_uses_llsc) {
436 long temp;
437
438 do {
439 __asm__ __volatile__(
440 " .set mips3 \n"
441 " lld %0, %1 # atomic64_add \n"
442 " daddu %0, %2 \n"
443 " scd %0, %1 \n"
444 " .set mips0 \n"
445 : "=&r" (temp), "=m" (v->counter)
446 : "Ir" (i), "m" (v->counter));
447 } while (unlikely(!temp));
448 } else {
449 unsigned long flags;
450
451 raw_local_irq_save(flags);
452 v->counter += i;
453 raw_local_irq_restore(flags);
454 }
455}
456
457/*
458 * atomic64_sub - subtract the atomic variable
459 * @i: integer value to subtract
460 * @v: pointer of type atomic64_t
461 *
462 * Atomically subtracts @i from @v.
463 */
464static __inline__ void atomic64_sub(long i, atomic64_t * v)
465{
466 if (kernel_uses_llsc && R10000_LLSC_WAR) {
467 long temp;
468
469 __asm__ __volatile__(
470 " .set mips3 \n"
471 "1: lld %0, %1 # atomic64_sub \n"
472 " dsubu %0, %2 \n"
473 " scd %0, %1 \n"
474 " beqzl %0, 1b \n"
475 " .set mips0 \n"
476 : "=&r" (temp), "=m" (v->counter)
477 : "Ir" (i), "m" (v->counter));
478 } else if (kernel_uses_llsc) {
479 long temp;
480
481 do {
482 __asm__ __volatile__(
483 " .set mips3 \n"
484 " lld %0, %1 # atomic64_sub \n"
485 " dsubu %0, %2 \n"
486 " scd %0, %1 \n"
487 " .set mips0 \n"
488 : "=&r" (temp), "=m" (v->counter)
489 : "Ir" (i), "m" (v->counter));
490 } while (unlikely(!temp));
491 } else {
492 unsigned long flags;
493
494 raw_local_irq_save(flags);
495 v->counter -= i;
496 raw_local_irq_restore(flags);
497 }
498}
499
500/*
501 * Same as above, but return the result value
502 */
503static __inline__ long atomic64_add_return(long i, atomic64_t * v)
504{
505 long result;
506
507 smp_mb__before_llsc();
508
509 if (kernel_uses_llsc && R10000_LLSC_WAR) {
510 long temp;
511
512 __asm__ __volatile__(
513 " .set mips3 \n"
514 "1: lld %1, %2 # atomic64_add_return \n"
515 " daddu %0, %1, %3 \n"
516 " scd %0, %2 \n"
517 " beqzl %0, 1b \n"
518 " daddu %0, %1, %3 \n"
519 " .set mips0 \n"
520 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
521 : "Ir" (i), "m" (v->counter)
522 : "memory");
523 } else if (kernel_uses_llsc) {
524 long temp;
525
526 do {
527 __asm__ __volatile__(
528 " .set mips3 \n"
529 " lld %1, %2 # atomic64_add_return \n"
530 " daddu %0, %1, %3 \n"
531 " scd %0, %2 \n"
532 " .set mips0 \n"
533 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
534 : "Ir" (i), "m" (v->counter)
535 : "memory");
536 } while (unlikely(!result));
537
538 result = temp + i;
539 } else {
540 unsigned long flags;
541
542 raw_local_irq_save(flags);
543 result = v->counter;
544 result += i;
545 v->counter = result;
546 raw_local_irq_restore(flags);
547 }
548
549 smp_llsc_mb();
550
551 return result;
552}
553
554static __inline__ long atomic64_sub_return(long i, atomic64_t * v)
555{
556 long result;
557
558 smp_mb__before_llsc();
559
560 if (kernel_uses_llsc && R10000_LLSC_WAR) {
561 long temp;
562
563 __asm__ __volatile__(
564 " .set mips3 \n"
565 "1: lld %1, %2 # atomic64_sub_return \n"
566 " dsubu %0, %1, %3 \n"
567 " scd %0, %2 \n"
568 " beqzl %0, 1b \n"
569 " dsubu %0, %1, %3 \n"
570 " .set mips0 \n"
571 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
572 : "Ir" (i), "m" (v->counter)
573 : "memory");
574 } else if (kernel_uses_llsc) {
575 long temp;
576
577 do {
578 __asm__ __volatile__(
579 " .set mips3 \n"
580 " lld %1, %2 # atomic64_sub_return \n"
581 " dsubu %0, %1, %3 \n"
582 " scd %0, %2 \n"
583 " .set mips0 \n"
584 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
585 : "Ir" (i), "m" (v->counter)
586 : "memory");
587 } while (unlikely(!result));
588
589 result = temp - i;
590 } else {
591 unsigned long flags;
592
593 raw_local_irq_save(flags);
594 result = v->counter;
595 result -= i;
596 v->counter = result;
597 raw_local_irq_restore(flags);
598 }
599
600 smp_llsc_mb();
601
602 return result;
603}
604
605/*
606 * atomic64_sub_if_positive - conditionally subtract integer from atomic variable
607 * @i: integer value to subtract
608 * @v: pointer of type atomic64_t
609 *
610 * Atomically test @v and subtract @i if @v is greater or equal than @i.
611 * The function returns the old value of @v minus @i.
612 */
613static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
614{
615 long result;
616
617 smp_mb__before_llsc();
618
619 if (kernel_uses_llsc && R10000_LLSC_WAR) {
620 long temp;
621
622 __asm__ __volatile__(
623 " .set mips3 \n"
624 "1: lld %1, %2 # atomic64_sub_if_positive\n"
625 " dsubu %0, %1, %3 \n"
626 " bltz %0, 1f \n"
627 " scd %0, %2 \n"
628 " .set noreorder \n"
629 " beqzl %0, 1b \n"
630 " dsubu %0, %1, %3 \n"
631 " .set reorder \n"
632 "1: \n"
633 " .set mips0 \n"
634 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
635 : "Ir" (i), "m" (v->counter)
636 : "memory");
637 } else if (kernel_uses_llsc) {
638 long temp;
639
640 __asm__ __volatile__(
641 " .set mips3 \n"
642 "1: lld %1, %2 # atomic64_sub_if_positive\n"
643 " dsubu %0, %1, %3 \n"
644 " bltz %0, 1f \n"
645 " scd %0, %2 \n"
646 " .set noreorder \n"
647 " beqz %0, 1b \n"
648 " dsubu %0, %1, %3 \n"
649 " .set reorder \n"
650 "1: \n"
651 " .set mips0 \n"
652 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
653 : "Ir" (i), "m" (v->counter)
654 : "memory");
655 } else {
656 unsigned long flags;
657
658 raw_local_irq_save(flags);
659 result = v->counter;
660 result -= i;
661 if (result >= 0)
662 v->counter = result;
663 raw_local_irq_restore(flags);
664 }
665
666 smp_llsc_mb();
667
668 return result;
669}
670
671#define atomic64_cmpxchg(v, o, n) \
672 ((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n)))
673#define atomic64_xchg(v, new) (xchg(&((v)->counter), (new)))
674
675/**
676 * atomic64_add_unless - add unless the number is a given value
677 * @v: pointer of type atomic64_t
678 * @a: the amount to add to v...
679 * @u: ...unless v is equal to u.
680 *
681 * Atomically adds @a to @v, so long as it was not @u.
682 * Returns the old value of @v.
683 */
684static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
685{
686 long c, old;
687 c = atomic64_read(v);
688 for (;;) {
689 if (unlikely(c == (u)))
690 break;
691 old = atomic64_cmpxchg((v), c, c + (a));
692 if (likely(old == c))
693 break;
694 c = old;
695 }
696 return c != (u);
697}
698
699#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
700
701#define atomic64_dec_return(v) atomic64_sub_return(1, (v))
702#define atomic64_inc_return(v) atomic64_add_return(1, (v))
703
704/*
705 * atomic64_sub_and_test - subtract value from variable and test result
706 * @i: integer value to subtract
707 * @v: pointer of type atomic64_t
708 *
709 * Atomically subtracts @i from @v and returns
710 * true if the result is zero, or false for all
711 * other cases.
712 */
713#define atomic64_sub_and_test(i, v) (atomic64_sub_return((i), (v)) == 0)
714
715/*
716 * atomic64_inc_and_test - increment and test
717 * @v: pointer of type atomic64_t
718 *
719 * Atomically increments @v by 1
720 * and returns true if the result is zero, or false for all
721 * other cases.
722 */
723#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
724
725/*
726 * atomic64_dec_and_test - decrement by 1 and test
727 * @v: pointer of type atomic64_t
728 *
729 * Atomically decrements @v by 1 and
730 * returns true if the result is 0, or false for all other
731 * cases.
732 */
733#define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)
734
735/*
736 * atomic64_dec_if_positive - decrement by 1 if old value positive
737 * @v: pointer of type atomic64_t
738 */
739#define atomic64_dec_if_positive(v) atomic64_sub_if_positive(1, v)
740
741/*
742 * atomic64_inc - increment atomic variable
743 * @v: pointer of type atomic64_t
744 *
745 * Atomically increments @v by 1.
746 */
747#define atomic64_inc(v) atomic64_add(1, (v))
748
749/*
750 * atomic64_dec - decrement and test
751 * @v: pointer of type atomic64_t
752 *
753 * Atomically decrements @v by 1.
754 */
755#define atomic64_dec(v) atomic64_sub(1, (v))
756
757/*
758 * atomic64_add_negative - add and test if negative
759 * @v: pointer of type atomic64_t
760 * @i: integer value to add
761 *
762 * Atomically adds @i to @v and returns true
763 * if the result is negative, or false when
764 * result is greater than or equal to zero.
765 */
766#define atomic64_add_negative(i, v) (atomic64_add_return(i, (v)) < 0)
767
768#endif /* CONFIG_64BIT */
769
770/*
771 * atomic*_return operations are serializing but not the non-*_return
772 * versions.
773 */
774#define smp_mb__before_atomic_dec() smp_mb__before_llsc()
775#define smp_mb__after_atomic_dec() smp_llsc_mb()
776#define smp_mb__before_atomic_inc() smp_mb__before_llsc()
777#define smp_mb__after_atomic_inc() smp_llsc_mb()
778
779#endif /* _ASM_ATOMIC_H */
1/*
2 * Atomic operations that C can't guarantee us. Useful for
3 * resource counting etc..
4 *
5 * But use these as seldom as possible since they are much more slower
6 * than regular operations.
7 *
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License. See the file "COPYING" in the main directory of this archive
10 * for more details.
11 *
12 * Copyright (C) 1996, 97, 99, 2000, 03, 04, 06 by Ralf Baechle
13 */
14#ifndef _ASM_ATOMIC_H
15#define _ASM_ATOMIC_H
16
17#include <linux/irqflags.h>
18#include <linux/types.h>
19#include <asm/barrier.h>
20#include <asm/cpu-features.h>
21#include <asm/cmpxchg.h>
22#include <asm/war.h>
23
24#define ATOMIC_INIT(i) { (i) }
25
26/*
27 * atomic_read - read atomic variable
28 * @v: pointer of type atomic_t
29 *
30 * Atomically reads the value of @v.
31 */
32#define atomic_read(v) (*(volatile int *)&(v)->counter)
33
34/*
35 * atomic_set - set atomic variable
36 * @v: pointer of type atomic_t
37 * @i: required value
38 *
39 * Atomically sets the value of @v to @i.
40 */
41#define atomic_set(v, i) ((v)->counter = (i))
42
43/*
44 * atomic_add - add integer to atomic variable
45 * @i: integer value to add
46 * @v: pointer of type atomic_t
47 *
48 * Atomically adds @i to @v.
49 */
50static __inline__ void atomic_add(int i, atomic_t * v)
51{
52 if (kernel_uses_llsc && R10000_LLSC_WAR) {
53 int temp;
54
55 __asm__ __volatile__(
56 " .set arch=r4000 \n"
57 "1: ll %0, %1 # atomic_add \n"
58 " addu %0, %2 \n"
59 " sc %0, %1 \n"
60 " beqzl %0, 1b \n"
61 " .set mips0 \n"
62 : "=&r" (temp), "+m" (v->counter)
63 : "Ir" (i));
64 } else if (kernel_uses_llsc) {
65 int temp;
66
67 do {
68 __asm__ __volatile__(
69 " .set arch=r4000 \n"
70 " ll %0, %1 # atomic_add \n"
71 " addu %0, %2 \n"
72 " sc %0, %1 \n"
73 " .set mips0 \n"
74 : "=&r" (temp), "+m" (v->counter)
75 : "Ir" (i));
76 } while (unlikely(!temp));
77 } else {
78 unsigned long flags;
79
80 raw_local_irq_save(flags);
81 v->counter += i;
82 raw_local_irq_restore(flags);
83 }
84}
85
86/*
87 * atomic_sub - subtract the atomic variable
88 * @i: integer value to subtract
89 * @v: pointer of type atomic_t
90 *
91 * Atomically subtracts @i from @v.
92 */
93static __inline__ void atomic_sub(int i, atomic_t * v)
94{
95 if (kernel_uses_llsc && R10000_LLSC_WAR) {
96 int temp;
97
98 __asm__ __volatile__(
99 " .set arch=r4000 \n"
100 "1: ll %0, %1 # atomic_sub \n"
101 " subu %0, %2 \n"
102 " sc %0, %1 \n"
103 " beqzl %0, 1b \n"
104 " .set mips0 \n"
105 : "=&r" (temp), "+m" (v->counter)
106 : "Ir" (i));
107 } else if (kernel_uses_llsc) {
108 int temp;
109
110 do {
111 __asm__ __volatile__(
112 " .set arch=r4000 \n"
113 " ll %0, %1 # atomic_sub \n"
114 " subu %0, %2 \n"
115 " sc %0, %1 \n"
116 " .set mips0 \n"
117 : "=&r" (temp), "+m" (v->counter)
118 : "Ir" (i));
119 } while (unlikely(!temp));
120 } else {
121 unsigned long flags;
122
123 raw_local_irq_save(flags);
124 v->counter -= i;
125 raw_local_irq_restore(flags);
126 }
127}
128
129/*
130 * Same as above, but return the result value
131 */
132static __inline__ int atomic_add_return(int i, atomic_t * v)
133{
134 int result;
135
136 smp_mb__before_llsc();
137
138 if (kernel_uses_llsc && R10000_LLSC_WAR) {
139 int temp;
140
141 __asm__ __volatile__(
142 " .set arch=r4000 \n"
143 "1: ll %1, %2 # atomic_add_return \n"
144 " addu %0, %1, %3 \n"
145 " sc %0, %2 \n"
146 " beqzl %0, 1b \n"
147 " addu %0, %1, %3 \n"
148 " .set mips0 \n"
149 : "=&r" (result), "=&r" (temp), "+m" (v->counter)
150 : "Ir" (i));
151 } else if (kernel_uses_llsc) {
152 int temp;
153
154 do {
155 __asm__ __volatile__(
156 " .set arch=r4000 \n"
157 " ll %1, %2 # atomic_add_return \n"
158 " addu %0, %1, %3 \n"
159 " sc %0, %2 \n"
160 " .set mips0 \n"
161 : "=&r" (result), "=&r" (temp), "+m" (v->counter)
162 : "Ir" (i));
163 } while (unlikely(!result));
164
165 result = temp + i;
166 } else {
167 unsigned long flags;
168
169 raw_local_irq_save(flags);
170 result = v->counter;
171 result += i;
172 v->counter = result;
173 raw_local_irq_restore(flags);
174 }
175
176 smp_llsc_mb();
177
178 return result;
179}
180
181static __inline__ int atomic_sub_return(int i, atomic_t * v)
182{
183 int result;
184
185 smp_mb__before_llsc();
186
187 if (kernel_uses_llsc && R10000_LLSC_WAR) {
188 int temp;
189
190 __asm__ __volatile__(
191 " .set arch=r4000 \n"
192 "1: ll %1, %2 # atomic_sub_return \n"
193 " subu %0, %1, %3 \n"
194 " sc %0, %2 \n"
195 " beqzl %0, 1b \n"
196 " subu %0, %1, %3 \n"
197 " .set mips0 \n"
198 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
199 : "Ir" (i), "m" (v->counter)
200 : "memory");
201
202 result = temp - i;
203 } else if (kernel_uses_llsc) {
204 int temp;
205
206 do {
207 __asm__ __volatile__(
208 " .set arch=r4000 \n"
209 " ll %1, %2 # atomic_sub_return \n"
210 " subu %0, %1, %3 \n"
211 " sc %0, %2 \n"
212 " .set mips0 \n"
213 : "=&r" (result), "=&r" (temp), "+m" (v->counter)
214 : "Ir" (i));
215 } while (unlikely(!result));
216
217 result = temp - i;
218 } else {
219 unsigned long flags;
220
221 raw_local_irq_save(flags);
222 result = v->counter;
223 result -= i;
224 v->counter = result;
225 raw_local_irq_restore(flags);
226 }
227
228 smp_llsc_mb();
229
230 return result;
231}
232
233/*
234 * atomic_sub_if_positive - conditionally subtract integer from atomic variable
235 * @i: integer value to subtract
236 * @v: pointer of type atomic_t
237 *
238 * Atomically test @v and subtract @i if @v is greater or equal than @i.
239 * The function returns the old value of @v minus @i.
240 */
241static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
242{
243 int result;
244
245 smp_mb__before_llsc();
246
247 if (kernel_uses_llsc && R10000_LLSC_WAR) {
248 int temp;
249
250 __asm__ __volatile__(
251 " .set arch=r4000 \n"
252 "1: ll %1, %2 # atomic_sub_if_positive\n"
253 " subu %0, %1, %3 \n"
254 " bltz %0, 1f \n"
255 " sc %0, %2 \n"
256 " .set noreorder \n"
257 " beqzl %0, 1b \n"
258 " subu %0, %1, %3 \n"
259 " .set reorder \n"
260 "1: \n"
261 " .set mips0 \n"
262 : "=&r" (result), "=&r" (temp), "+m" (v->counter)
263 : "Ir" (i), "m" (v->counter)
264 : "memory");
265 } else if (kernel_uses_llsc) {
266 int temp;
267
268 __asm__ __volatile__(
269 " .set arch=r4000 \n"
270 "1: ll %1, %2 # atomic_sub_if_positive\n"
271 " subu %0, %1, %3 \n"
272 " bltz %0, 1f \n"
273 " sc %0, %2 \n"
274 " .set noreorder \n"
275 " beqz %0, 1b \n"
276 " subu %0, %1, %3 \n"
277 " .set reorder \n"
278 "1: \n"
279 " .set mips0 \n"
280 : "=&r" (result), "=&r" (temp), "+m" (v->counter)
281 : "Ir" (i));
282 } else {
283 unsigned long flags;
284
285 raw_local_irq_save(flags);
286 result = v->counter;
287 result -= i;
288 if (result >= 0)
289 v->counter = result;
290 raw_local_irq_restore(flags);
291 }
292
293 smp_llsc_mb();
294
295 return result;
296}
297
298#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
299#define atomic_xchg(v, new) (xchg(&((v)->counter), (new)))
300
301/**
302 * __atomic_add_unless - add unless the number is a given value
303 * @v: pointer of type atomic_t
304 * @a: the amount to add to v...
305 * @u: ...unless v is equal to u.
306 *
307 * Atomically adds @a to @v, so long as it was not @u.
308 * Returns the old value of @v.
309 */
310static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
311{
312 int c, old;
313 c = atomic_read(v);
314 for (;;) {
315 if (unlikely(c == (u)))
316 break;
317 old = atomic_cmpxchg((v), c, c + (a));
318 if (likely(old == c))
319 break;
320 c = old;
321 }
322 return c;
323}
324
325#define atomic_dec_return(v) atomic_sub_return(1, (v))
326#define atomic_inc_return(v) atomic_add_return(1, (v))
327
328/*
329 * atomic_sub_and_test - subtract value from variable and test result
330 * @i: integer value to subtract
331 * @v: pointer of type atomic_t
332 *
333 * Atomically subtracts @i from @v and returns
334 * true if the result is zero, or false for all
335 * other cases.
336 */
337#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
338
339/*
340 * atomic_inc_and_test - increment and test
341 * @v: pointer of type atomic_t
342 *
343 * Atomically increments @v by 1
344 * and returns true if the result is zero, or false for all
345 * other cases.
346 */
347#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
348
349/*
350 * atomic_dec_and_test - decrement by 1 and test
351 * @v: pointer of type atomic_t
352 *
353 * Atomically decrements @v by 1 and
354 * returns true if the result is 0, or false for all other
355 * cases.
356 */
357#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
358
359/*
360 * atomic_dec_if_positive - decrement by 1 if old value positive
361 * @v: pointer of type atomic_t
362 */
363#define atomic_dec_if_positive(v) atomic_sub_if_positive(1, v)
364
365/*
366 * atomic_inc - increment atomic variable
367 * @v: pointer of type atomic_t
368 *
369 * Atomically increments @v by 1.
370 */
371#define atomic_inc(v) atomic_add(1, (v))
372
373/*
374 * atomic_dec - decrement and test
375 * @v: pointer of type atomic_t
376 *
377 * Atomically decrements @v by 1.
378 */
379#define atomic_dec(v) atomic_sub(1, (v))
380
381/*
382 * atomic_add_negative - add and test if negative
383 * @v: pointer of type atomic_t
384 * @i: integer value to add
385 *
386 * Atomically adds @i to @v and returns true
387 * if the result is negative, or false when
388 * result is greater than or equal to zero.
389 */
390#define atomic_add_negative(i, v) (atomic_add_return(i, (v)) < 0)
391
392#ifdef CONFIG_64BIT
393
394#define ATOMIC64_INIT(i) { (i) }
395
396/*
397 * atomic64_read - read atomic variable
398 * @v: pointer of type atomic64_t
399 *
400 */
401#define atomic64_read(v) (*(volatile long *)&(v)->counter)
402
403/*
404 * atomic64_set - set atomic variable
405 * @v: pointer of type atomic64_t
406 * @i: required value
407 */
408#define atomic64_set(v, i) ((v)->counter = (i))
409
410/*
411 * atomic64_add - add integer to atomic variable
412 * @i: integer value to add
413 * @v: pointer of type atomic64_t
414 *
415 * Atomically adds @i to @v.
416 */
417static __inline__ void atomic64_add(long i, atomic64_t * v)
418{
419 if (kernel_uses_llsc && R10000_LLSC_WAR) {
420 long temp;
421
422 __asm__ __volatile__(
423 " .set arch=r4000 \n"
424 "1: lld %0, %1 # atomic64_add \n"
425 " daddu %0, %2 \n"
426 " scd %0, %1 \n"
427 " beqzl %0, 1b \n"
428 " .set mips0 \n"
429 : "=&r" (temp), "+m" (v->counter)
430 : "Ir" (i));
431 } else if (kernel_uses_llsc) {
432 long temp;
433
434 do {
435 __asm__ __volatile__(
436 " .set arch=r4000 \n"
437 " lld %0, %1 # atomic64_add \n"
438 " daddu %0, %2 \n"
439 " scd %0, %1 \n"
440 " .set mips0 \n"
441 : "=&r" (temp), "+m" (v->counter)
442 : "Ir" (i));
443 } while (unlikely(!temp));
444 } else {
445 unsigned long flags;
446
447 raw_local_irq_save(flags);
448 v->counter += i;
449 raw_local_irq_restore(flags);
450 }
451}
452
453/*
454 * atomic64_sub - subtract the atomic variable
455 * @i: integer value to subtract
456 * @v: pointer of type atomic64_t
457 *
458 * Atomically subtracts @i from @v.
459 */
460static __inline__ void atomic64_sub(long i, atomic64_t * v)
461{
462 if (kernel_uses_llsc && R10000_LLSC_WAR) {
463 long temp;
464
465 __asm__ __volatile__(
466 " .set arch=r4000 \n"
467 "1: lld %0, %1 # atomic64_sub \n"
468 " dsubu %0, %2 \n"
469 " scd %0, %1 \n"
470 " beqzl %0, 1b \n"
471 " .set mips0 \n"
472 : "=&r" (temp), "+m" (v->counter)
473 : "Ir" (i));
474 } else if (kernel_uses_llsc) {
475 long temp;
476
477 do {
478 __asm__ __volatile__(
479 " .set arch=r4000 \n"
480 " lld %0, %1 # atomic64_sub \n"
481 " dsubu %0, %2 \n"
482 " scd %0, %1 \n"
483 " .set mips0 \n"
484 : "=&r" (temp), "+m" (v->counter)
485 : "Ir" (i));
486 } while (unlikely(!temp));
487 } else {
488 unsigned long flags;
489
490 raw_local_irq_save(flags);
491 v->counter -= i;
492 raw_local_irq_restore(flags);
493 }
494}
495
496/*
497 * Same as above, but return the result value
498 */
499static __inline__ long atomic64_add_return(long i, atomic64_t * v)
500{
501 long result;
502
503 smp_mb__before_llsc();
504
505 if (kernel_uses_llsc && R10000_LLSC_WAR) {
506 long temp;
507
508 __asm__ __volatile__(
509 " .set arch=r4000 \n"
510 "1: lld %1, %2 # atomic64_add_return \n"
511 " daddu %0, %1, %3 \n"
512 " scd %0, %2 \n"
513 " beqzl %0, 1b \n"
514 " daddu %0, %1, %3 \n"
515 " .set mips0 \n"
516 : "=&r" (result), "=&r" (temp), "+m" (v->counter)
517 : "Ir" (i));
518 } else if (kernel_uses_llsc) {
519 long temp;
520
521 do {
522 __asm__ __volatile__(
523 " .set arch=r4000 \n"
524 " lld %1, %2 # atomic64_add_return \n"
525 " daddu %0, %1, %3 \n"
526 " scd %0, %2 \n"
527 " .set mips0 \n"
528 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
529 : "Ir" (i), "m" (v->counter)
530 : "memory");
531 } while (unlikely(!result));
532
533 result = temp + i;
534 } else {
535 unsigned long flags;
536
537 raw_local_irq_save(flags);
538 result = v->counter;
539 result += i;
540 v->counter = result;
541 raw_local_irq_restore(flags);
542 }
543
544 smp_llsc_mb();
545
546 return result;
547}
548
549static __inline__ long atomic64_sub_return(long i, atomic64_t * v)
550{
551 long result;
552
553 smp_mb__before_llsc();
554
555 if (kernel_uses_llsc && R10000_LLSC_WAR) {
556 long temp;
557
558 __asm__ __volatile__(
559 " .set arch=r4000 \n"
560 "1: lld %1, %2 # atomic64_sub_return \n"
561 " dsubu %0, %1, %3 \n"
562 " scd %0, %2 \n"
563 " beqzl %0, 1b \n"
564 " dsubu %0, %1, %3 \n"
565 " .set mips0 \n"
566 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
567 : "Ir" (i), "m" (v->counter)
568 : "memory");
569 } else if (kernel_uses_llsc) {
570 long temp;
571
572 do {
573 __asm__ __volatile__(
574 " .set arch=r4000 \n"
575 " lld %1, %2 # atomic64_sub_return \n"
576 " dsubu %0, %1, %3 \n"
577 " scd %0, %2 \n"
578 " .set mips0 \n"
579 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
580 : "Ir" (i), "m" (v->counter)
581 : "memory");
582 } while (unlikely(!result));
583
584 result = temp - i;
585 } else {
586 unsigned long flags;
587
588 raw_local_irq_save(flags);
589 result = v->counter;
590 result -= i;
591 v->counter = result;
592 raw_local_irq_restore(flags);
593 }
594
595 smp_llsc_mb();
596
597 return result;
598}
599
600/*
601 * atomic64_sub_if_positive - conditionally subtract integer from atomic variable
602 * @i: integer value to subtract
603 * @v: pointer of type atomic64_t
604 *
605 * Atomically test @v and subtract @i if @v is greater or equal than @i.
606 * The function returns the old value of @v minus @i.
607 */
608static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
609{
610 long result;
611
612 smp_mb__before_llsc();
613
614 if (kernel_uses_llsc && R10000_LLSC_WAR) {
615 long temp;
616
617 __asm__ __volatile__(
618 " .set arch=r4000 \n"
619 "1: lld %1, %2 # atomic64_sub_if_positive\n"
620 " dsubu %0, %1, %3 \n"
621 " bltz %0, 1f \n"
622 " scd %0, %2 \n"
623 " .set noreorder \n"
624 " beqzl %0, 1b \n"
625 " dsubu %0, %1, %3 \n"
626 " .set reorder \n"
627 "1: \n"
628 " .set mips0 \n"
629 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
630 : "Ir" (i), "m" (v->counter)
631 : "memory");
632 } else if (kernel_uses_llsc) {
633 long temp;
634
635 __asm__ __volatile__(
636 " .set arch=r4000 \n"
637 "1: lld %1, %2 # atomic64_sub_if_positive\n"
638 " dsubu %0, %1, %3 \n"
639 " bltz %0, 1f \n"
640 " scd %0, %2 \n"
641 " .set noreorder \n"
642 " beqz %0, 1b \n"
643 " dsubu %0, %1, %3 \n"
644 " .set reorder \n"
645 "1: \n"
646 " .set mips0 \n"
647 : "=&r" (result), "=&r" (temp), "+m" (v->counter)
648 : "Ir" (i));
649 } else {
650 unsigned long flags;
651
652 raw_local_irq_save(flags);
653 result = v->counter;
654 result -= i;
655 if (result >= 0)
656 v->counter = result;
657 raw_local_irq_restore(flags);
658 }
659
660 smp_llsc_mb();
661
662 return result;
663}
664
665#define atomic64_cmpxchg(v, o, n) \
666 ((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n)))
667#define atomic64_xchg(v, new) (xchg(&((v)->counter), (new)))
668
669/**
670 * atomic64_add_unless - add unless the number is a given value
671 * @v: pointer of type atomic64_t
672 * @a: the amount to add to v...
673 * @u: ...unless v is equal to u.
674 *
675 * Atomically adds @a to @v, so long as it was not @u.
676 * Returns the old value of @v.
677 */
678static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
679{
680 long c, old;
681 c = atomic64_read(v);
682 for (;;) {
683 if (unlikely(c == (u)))
684 break;
685 old = atomic64_cmpxchg((v), c, c + (a));
686 if (likely(old == c))
687 break;
688 c = old;
689 }
690 return c != (u);
691}
692
693#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
694
695#define atomic64_dec_return(v) atomic64_sub_return(1, (v))
696#define atomic64_inc_return(v) atomic64_add_return(1, (v))
697
698/*
699 * atomic64_sub_and_test - subtract value from variable and test result
700 * @i: integer value to subtract
701 * @v: pointer of type atomic64_t
702 *
703 * Atomically subtracts @i from @v and returns
704 * true if the result is zero, or false for all
705 * other cases.
706 */
707#define atomic64_sub_and_test(i, v) (atomic64_sub_return((i), (v)) == 0)
708
709/*
710 * atomic64_inc_and_test - increment and test
711 * @v: pointer of type atomic64_t
712 *
713 * Atomically increments @v by 1
714 * and returns true if the result is zero, or false for all
715 * other cases.
716 */
717#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
718
719/*
720 * atomic64_dec_and_test - decrement by 1 and test
721 * @v: pointer of type atomic64_t
722 *
723 * Atomically decrements @v by 1 and
724 * returns true if the result is 0, or false for all other
725 * cases.
726 */
727#define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)
728
729/*
730 * atomic64_dec_if_positive - decrement by 1 if old value positive
731 * @v: pointer of type atomic64_t
732 */
733#define atomic64_dec_if_positive(v) atomic64_sub_if_positive(1, v)
734
735/*
736 * atomic64_inc - increment atomic variable
737 * @v: pointer of type atomic64_t
738 *
739 * Atomically increments @v by 1.
740 */
741#define atomic64_inc(v) atomic64_add(1, (v))
742
743/*
744 * atomic64_dec - decrement and test
745 * @v: pointer of type atomic64_t
746 *
747 * Atomically decrements @v by 1.
748 */
749#define atomic64_dec(v) atomic64_sub(1, (v))
750
751/*
752 * atomic64_add_negative - add and test if negative
753 * @v: pointer of type atomic64_t
754 * @i: integer value to add
755 *
756 * Atomically adds @i to @v and returns true
757 * if the result is negative, or false when
758 * result is greater than or equal to zero.
759 */
760#define atomic64_add_negative(i, v) (atomic64_add_return(i, (v)) < 0)
761
762#endif /* CONFIG_64BIT */
763
764/*
765 * atomic*_return operations are serializing but not the non-*_return
766 * versions.
767 */
768#define smp_mb__before_atomic_dec() smp_mb__before_llsc()
769#define smp_mb__after_atomic_dec() smp_llsc_mb()
770#define smp_mb__before_atomic_inc() smp_mb__before_llsc()
771#define smp_mb__after_atomic_inc() smp_llsc_mb()
772
773#endif /* _ASM_ATOMIC_H */