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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/compiler.h>
21#include <asm/cpu-features.h>
22#include <asm/cmpxchg.h>
23#include <asm/war.h>
24
25#define ATOMIC_INIT(i) { (i) }
26
27/*
28 * atomic_read - read atomic variable
29 * @v: pointer of type atomic_t
30 *
31 * Atomically reads the value of @v.
32 */
33#define atomic_read(v) READ_ONCE((v)->counter)
34
35/*
36 * atomic_set - set atomic variable
37 * @v: pointer of type atomic_t
38 * @i: required value
39 *
40 * Atomically sets the value of @v to @i.
41 */
42#define atomic_set(v, i) WRITE_ONCE((v)->counter, (i))
43
44#define ATOMIC_OP(op, c_op, asm_op) \
45static __inline__ void atomic_##op(int i, atomic_t * v) \
46{ \
47 if (kernel_uses_llsc && R10000_LLSC_WAR) { \
48 int temp; \
49 \
50 __asm__ __volatile__( \
51 " .set arch=r4000 \n" \
52 "1: ll %0, %1 # atomic_" #op " \n" \
53 " " #asm_op " %0, %2 \n" \
54 " sc %0, %1 \n" \
55 " beqzl %0, 1b \n" \
56 " .set mips0 \n" \
57 : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
58 : "Ir" (i)); \
59 } else if (kernel_uses_llsc) { \
60 int temp; \
61 \
62 do { \
63 __asm__ __volatile__( \
64 " .set "MIPS_ISA_LEVEL" \n" \
65 " ll %0, %1 # atomic_" #op "\n" \
66 " " #asm_op " %0, %2 \n" \
67 " sc %0, %1 \n" \
68 " .set mips0 \n" \
69 : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
70 : "Ir" (i)); \
71 } while (unlikely(!temp)); \
72 } else { \
73 unsigned long flags; \
74 \
75 raw_local_irq_save(flags); \
76 v->counter c_op i; \
77 raw_local_irq_restore(flags); \
78 } \
79}
80
81#define ATOMIC_OP_RETURN(op, c_op, asm_op) \
82static __inline__ int atomic_##op##_return_relaxed(int i, atomic_t * v) \
83{ \
84 int result; \
85 \
86 if (kernel_uses_llsc && R10000_LLSC_WAR) { \
87 int temp; \
88 \
89 __asm__ __volatile__( \
90 " .set arch=r4000 \n" \
91 "1: ll %1, %2 # atomic_" #op "_return \n" \
92 " " #asm_op " %0, %1, %3 \n" \
93 " sc %0, %2 \n" \
94 " beqzl %0, 1b \n" \
95 " " #asm_op " %0, %1, %3 \n" \
96 " .set mips0 \n" \
97 : "=&r" (result), "=&r" (temp), \
98 "+" GCC_OFF_SMALL_ASM() (v->counter) \
99 : "Ir" (i)); \
100 } else if (kernel_uses_llsc) { \
101 int temp; \
102 \
103 do { \
104 __asm__ __volatile__( \
105 " .set "MIPS_ISA_LEVEL" \n" \
106 " ll %1, %2 # atomic_" #op "_return \n" \
107 " " #asm_op " %0, %1, %3 \n" \
108 " sc %0, %2 \n" \
109 " .set mips0 \n" \
110 : "=&r" (result), "=&r" (temp), \
111 "+" GCC_OFF_SMALL_ASM() (v->counter) \
112 : "Ir" (i)); \
113 } while (unlikely(!result)); \
114 \
115 result = temp; result c_op i; \
116 } else { \
117 unsigned long flags; \
118 \
119 raw_local_irq_save(flags); \
120 result = v->counter; \
121 result c_op i; \
122 v->counter = result; \
123 raw_local_irq_restore(flags); \
124 } \
125 \
126 return result; \
127}
128
129#define ATOMIC_FETCH_OP(op, c_op, asm_op) \
130static __inline__ int atomic_fetch_##op##_relaxed(int i, atomic_t * v) \
131{ \
132 int result; \
133 \
134 if (kernel_uses_llsc && R10000_LLSC_WAR) { \
135 int temp; \
136 \
137 __asm__ __volatile__( \
138 " .set arch=r4000 \n" \
139 "1: ll %1, %2 # atomic_fetch_" #op " \n" \
140 " " #asm_op " %0, %1, %3 \n" \
141 " sc %0, %2 \n" \
142 " beqzl %0, 1b \n" \
143 " move %0, %1 \n" \
144 " .set mips0 \n" \
145 : "=&r" (result), "=&r" (temp), \
146 "+" GCC_OFF_SMALL_ASM() (v->counter) \
147 : "Ir" (i)); \
148 } else if (kernel_uses_llsc) { \
149 int temp; \
150 \
151 do { \
152 __asm__ __volatile__( \
153 " .set "MIPS_ISA_LEVEL" \n" \
154 " ll %1, %2 # atomic_fetch_" #op " \n" \
155 " " #asm_op " %0, %1, %3 \n" \
156 " sc %0, %2 \n" \
157 " .set mips0 \n" \
158 : "=&r" (result), "=&r" (temp), \
159 "+" GCC_OFF_SMALL_ASM() (v->counter) \
160 : "Ir" (i)); \
161 } while (unlikely(!result)); \
162 \
163 result = temp; \
164 } else { \
165 unsigned long flags; \
166 \
167 raw_local_irq_save(flags); \
168 result = v->counter; \
169 v->counter c_op i; \
170 raw_local_irq_restore(flags); \
171 } \
172 \
173 return result; \
174}
175
176#define ATOMIC_OPS(op, c_op, asm_op) \
177 ATOMIC_OP(op, c_op, asm_op) \
178 ATOMIC_OP_RETURN(op, c_op, asm_op) \
179 ATOMIC_FETCH_OP(op, c_op, asm_op)
180
181ATOMIC_OPS(add, +=, addu)
182ATOMIC_OPS(sub, -=, subu)
183
184#define atomic_add_return_relaxed atomic_add_return_relaxed
185#define atomic_sub_return_relaxed atomic_sub_return_relaxed
186#define atomic_fetch_add_relaxed atomic_fetch_add_relaxed
187#define atomic_fetch_sub_relaxed atomic_fetch_sub_relaxed
188
189#undef ATOMIC_OPS
190#define ATOMIC_OPS(op, c_op, asm_op) \
191 ATOMIC_OP(op, c_op, asm_op) \
192 ATOMIC_FETCH_OP(op, c_op, asm_op)
193
194ATOMIC_OPS(and, &=, and)
195ATOMIC_OPS(or, |=, or)
196ATOMIC_OPS(xor, ^=, xor)
197
198#define atomic_fetch_and_relaxed atomic_fetch_and_relaxed
199#define atomic_fetch_or_relaxed atomic_fetch_or_relaxed
200#define atomic_fetch_xor_relaxed atomic_fetch_xor_relaxed
201
202#undef ATOMIC_OPS
203#undef ATOMIC_FETCH_OP
204#undef ATOMIC_OP_RETURN
205#undef ATOMIC_OP
206
207/*
208 * atomic_sub_if_positive - conditionally subtract integer from atomic variable
209 * @i: integer value to subtract
210 * @v: pointer of type atomic_t
211 *
212 * Atomically test @v and subtract @i if @v is greater or equal than @i.
213 * The function returns the old value of @v minus @i.
214 */
215static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
216{
217 int result;
218
219 smp_mb__before_llsc();
220
221 if (kernel_uses_llsc && R10000_LLSC_WAR) {
222 int temp;
223
224 __asm__ __volatile__(
225 " .set arch=r4000 \n"
226 "1: ll %1, %2 # atomic_sub_if_positive\n"
227 " subu %0, %1, %3 \n"
228 " bltz %0, 1f \n"
229 " sc %0, %2 \n"
230 " .set noreorder \n"
231 " beqzl %0, 1b \n"
232 " subu %0, %1, %3 \n"
233 " .set reorder \n"
234 "1: \n"
235 " .set mips0 \n"
236 : "=&r" (result), "=&r" (temp),
237 "+" GCC_OFF_SMALL_ASM() (v->counter)
238 : "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter)
239 : "memory");
240 } else if (kernel_uses_llsc) {
241 int temp;
242
243 __asm__ __volatile__(
244 " .set "MIPS_ISA_LEVEL" \n"
245 "1: ll %1, %2 # atomic_sub_if_positive\n"
246 " subu %0, %1, %3 \n"
247 " bltz %0, 1f \n"
248 " sc %0, %2 \n"
249 " .set noreorder \n"
250 " beqz %0, 1b \n"
251 " subu %0, %1, %3 \n"
252 " .set reorder \n"
253 "1: \n"
254 " .set mips0 \n"
255 : "=&r" (result), "=&r" (temp),
256 "+" GCC_OFF_SMALL_ASM() (v->counter)
257 : "Ir" (i));
258 } else {
259 unsigned long flags;
260
261 raw_local_irq_save(flags);
262 result = v->counter;
263 result -= i;
264 if (result >= 0)
265 v->counter = result;
266 raw_local_irq_restore(flags);
267 }
268
269 smp_llsc_mb();
270
271 return result;
272}
273
274#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
275#define atomic_xchg(v, new) (xchg(&((v)->counter), (new)))
276
277/**
278 * __atomic_add_unless - add unless the number is a given value
279 * @v: pointer of type atomic_t
280 * @a: the amount to add to v...
281 * @u: ...unless v is equal to u.
282 *
283 * Atomically adds @a to @v, so long as it was not @u.
284 * Returns the old value of @v.
285 */
286static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
287{
288 int c, old;
289 c = atomic_read(v);
290 for (;;) {
291 if (unlikely(c == (u)))
292 break;
293 old = atomic_cmpxchg((v), c, c + (a));
294 if (likely(old == c))
295 break;
296 c = old;
297 }
298 return c;
299}
300
301#define atomic_dec_return(v) atomic_sub_return(1, (v))
302#define atomic_inc_return(v) atomic_add_return(1, (v))
303
304/*
305 * atomic_sub_and_test - subtract value from variable and test result
306 * @i: integer value to subtract
307 * @v: pointer of type atomic_t
308 *
309 * Atomically subtracts @i from @v and returns
310 * true if the result is zero, or false for all
311 * other cases.
312 */
313#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
314
315/*
316 * atomic_inc_and_test - increment and test
317 * @v: pointer of type atomic_t
318 *
319 * Atomically increments @v by 1
320 * and returns true if the result is zero, or false for all
321 * other cases.
322 */
323#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
324
325/*
326 * atomic_dec_and_test - decrement by 1 and test
327 * @v: pointer of type atomic_t
328 *
329 * Atomically decrements @v by 1 and
330 * returns true if the result is 0, or false for all other
331 * cases.
332 */
333#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
334
335/*
336 * atomic_dec_if_positive - decrement by 1 if old value positive
337 * @v: pointer of type atomic_t
338 */
339#define atomic_dec_if_positive(v) atomic_sub_if_positive(1, v)
340
341/*
342 * atomic_inc - increment atomic variable
343 * @v: pointer of type atomic_t
344 *
345 * Atomically increments @v by 1.
346 */
347#define atomic_inc(v) atomic_add(1, (v))
348
349/*
350 * atomic_dec - decrement and test
351 * @v: pointer of type atomic_t
352 *
353 * Atomically decrements @v by 1.
354 */
355#define atomic_dec(v) atomic_sub(1, (v))
356
357/*
358 * atomic_add_negative - add and test if negative
359 * @v: pointer of type atomic_t
360 * @i: integer value to add
361 *
362 * Atomically adds @i to @v and returns true
363 * if the result is negative, or false when
364 * result is greater than or equal to zero.
365 */
366#define atomic_add_negative(i, v) (atomic_add_return(i, (v)) < 0)
367
368#ifdef CONFIG_64BIT
369
370#define ATOMIC64_INIT(i) { (i) }
371
372/*
373 * atomic64_read - read atomic variable
374 * @v: pointer of type atomic64_t
375 *
376 */
377#define atomic64_read(v) READ_ONCE((v)->counter)
378
379/*
380 * atomic64_set - set atomic variable
381 * @v: pointer of type atomic64_t
382 * @i: required value
383 */
384#define atomic64_set(v, i) WRITE_ONCE((v)->counter, (i))
385
386#define ATOMIC64_OP(op, c_op, asm_op) \
387static __inline__ void atomic64_##op(long i, atomic64_t * v) \
388{ \
389 if (kernel_uses_llsc && R10000_LLSC_WAR) { \
390 long temp; \
391 \
392 __asm__ __volatile__( \
393 " .set arch=r4000 \n" \
394 "1: lld %0, %1 # atomic64_" #op " \n" \
395 " " #asm_op " %0, %2 \n" \
396 " scd %0, %1 \n" \
397 " beqzl %0, 1b \n" \
398 " .set mips0 \n" \
399 : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
400 : "Ir" (i)); \
401 } else if (kernel_uses_llsc) { \
402 long temp; \
403 \
404 do { \
405 __asm__ __volatile__( \
406 " .set "MIPS_ISA_LEVEL" \n" \
407 " lld %0, %1 # atomic64_" #op "\n" \
408 " " #asm_op " %0, %2 \n" \
409 " scd %0, %1 \n" \
410 " .set mips0 \n" \
411 : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
412 : "Ir" (i)); \
413 } while (unlikely(!temp)); \
414 } else { \
415 unsigned long flags; \
416 \
417 raw_local_irq_save(flags); \
418 v->counter c_op i; \
419 raw_local_irq_restore(flags); \
420 } \
421}
422
423#define ATOMIC64_OP_RETURN(op, c_op, asm_op) \
424static __inline__ long atomic64_##op##_return_relaxed(long i, atomic64_t * v) \
425{ \
426 long result; \
427 \
428 if (kernel_uses_llsc && R10000_LLSC_WAR) { \
429 long temp; \
430 \
431 __asm__ __volatile__( \
432 " .set arch=r4000 \n" \
433 "1: lld %1, %2 # atomic64_" #op "_return\n" \
434 " " #asm_op " %0, %1, %3 \n" \
435 " scd %0, %2 \n" \
436 " beqzl %0, 1b \n" \
437 " " #asm_op " %0, %1, %3 \n" \
438 " .set mips0 \n" \
439 : "=&r" (result), "=&r" (temp), \
440 "+" GCC_OFF_SMALL_ASM() (v->counter) \
441 : "Ir" (i)); \
442 } else if (kernel_uses_llsc) { \
443 long temp; \
444 \
445 do { \
446 __asm__ __volatile__( \
447 " .set "MIPS_ISA_LEVEL" \n" \
448 " lld %1, %2 # atomic64_" #op "_return\n" \
449 " " #asm_op " %0, %1, %3 \n" \
450 " scd %0, %2 \n" \
451 " .set mips0 \n" \
452 : "=&r" (result), "=&r" (temp), \
453 "=" GCC_OFF_SMALL_ASM() (v->counter) \
454 : "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter) \
455 : "memory"); \
456 } while (unlikely(!result)); \
457 \
458 result = temp; result c_op i; \
459 } else { \
460 unsigned long flags; \
461 \
462 raw_local_irq_save(flags); \
463 result = v->counter; \
464 result c_op i; \
465 v->counter = result; \
466 raw_local_irq_restore(flags); \
467 } \
468 \
469 return result; \
470}
471
472#define ATOMIC64_FETCH_OP(op, c_op, asm_op) \
473static __inline__ long atomic64_fetch_##op##_relaxed(long i, atomic64_t * v) \
474{ \
475 long result; \
476 \
477 if (kernel_uses_llsc && R10000_LLSC_WAR) { \
478 long temp; \
479 \
480 __asm__ __volatile__( \
481 " .set arch=r4000 \n" \
482 "1: lld %1, %2 # atomic64_fetch_" #op "\n" \
483 " " #asm_op " %0, %1, %3 \n" \
484 " scd %0, %2 \n" \
485 " beqzl %0, 1b \n" \
486 " move %0, %1 \n" \
487 " .set mips0 \n" \
488 : "=&r" (result), "=&r" (temp), \
489 "+" GCC_OFF_SMALL_ASM() (v->counter) \
490 : "Ir" (i)); \
491 } else if (kernel_uses_llsc) { \
492 long temp; \
493 \
494 do { \
495 __asm__ __volatile__( \
496 " .set "MIPS_ISA_LEVEL" \n" \
497 " lld %1, %2 # atomic64_fetch_" #op "\n" \
498 " " #asm_op " %0, %1, %3 \n" \
499 " scd %0, %2 \n" \
500 " .set mips0 \n" \
501 : "=&r" (result), "=&r" (temp), \
502 "=" GCC_OFF_SMALL_ASM() (v->counter) \
503 : "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter) \
504 : "memory"); \
505 } while (unlikely(!result)); \
506 \
507 result = temp; \
508 } else { \
509 unsigned long flags; \
510 \
511 raw_local_irq_save(flags); \
512 result = v->counter; \
513 v->counter c_op i; \
514 raw_local_irq_restore(flags); \
515 } \
516 \
517 return result; \
518}
519
520#define ATOMIC64_OPS(op, c_op, asm_op) \
521 ATOMIC64_OP(op, c_op, asm_op) \
522 ATOMIC64_OP_RETURN(op, c_op, asm_op) \
523 ATOMIC64_FETCH_OP(op, c_op, asm_op)
524
525ATOMIC64_OPS(add, +=, daddu)
526ATOMIC64_OPS(sub, -=, dsubu)
527
528#define atomic64_add_return_relaxed atomic64_add_return_relaxed
529#define atomic64_sub_return_relaxed atomic64_sub_return_relaxed
530#define atomic64_fetch_add_relaxed atomic64_fetch_add_relaxed
531#define atomic64_fetch_sub_relaxed atomic64_fetch_sub_relaxed
532
533#undef ATOMIC64_OPS
534#define ATOMIC64_OPS(op, c_op, asm_op) \
535 ATOMIC64_OP(op, c_op, asm_op) \
536 ATOMIC64_FETCH_OP(op, c_op, asm_op)
537
538ATOMIC64_OPS(and, &=, and)
539ATOMIC64_OPS(or, |=, or)
540ATOMIC64_OPS(xor, ^=, xor)
541
542#define atomic64_fetch_and_relaxed atomic64_fetch_and_relaxed
543#define atomic64_fetch_or_relaxed atomic64_fetch_or_relaxed
544#define atomic64_fetch_xor_relaxed atomic64_fetch_xor_relaxed
545
546#undef ATOMIC64_OPS
547#undef ATOMIC64_FETCH_OP
548#undef ATOMIC64_OP_RETURN
549#undef ATOMIC64_OP
550
551/*
552 * atomic64_sub_if_positive - conditionally subtract integer from atomic
553 * variable
554 * @i: integer value to subtract
555 * @v: pointer of type atomic64_t
556 *
557 * Atomically test @v and subtract @i if @v is greater or equal than @i.
558 * The function returns the old value of @v minus @i.
559 */
560static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
561{
562 long result;
563
564 smp_mb__before_llsc();
565
566 if (kernel_uses_llsc && R10000_LLSC_WAR) {
567 long temp;
568
569 __asm__ __volatile__(
570 " .set arch=r4000 \n"
571 "1: lld %1, %2 # atomic64_sub_if_positive\n"
572 " dsubu %0, %1, %3 \n"
573 " bltz %0, 1f \n"
574 " scd %0, %2 \n"
575 " .set noreorder \n"
576 " beqzl %0, 1b \n"
577 " dsubu %0, %1, %3 \n"
578 " .set reorder \n"
579 "1: \n"
580 " .set mips0 \n"
581 : "=&r" (result), "=&r" (temp),
582 "=" GCC_OFF_SMALL_ASM() (v->counter)
583 : "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter)
584 : "memory");
585 } else if (kernel_uses_llsc) {
586 long temp;
587
588 __asm__ __volatile__(
589 " .set "MIPS_ISA_LEVEL" \n"
590 "1: lld %1, %2 # atomic64_sub_if_positive\n"
591 " dsubu %0, %1, %3 \n"
592 " bltz %0, 1f \n"
593 " scd %0, %2 \n"
594 " .set noreorder \n"
595 " beqz %0, 1b \n"
596 " dsubu %0, %1, %3 \n"
597 " .set reorder \n"
598 "1: \n"
599 " .set mips0 \n"
600 : "=&r" (result), "=&r" (temp),
601 "+" GCC_OFF_SMALL_ASM() (v->counter)
602 : "Ir" (i));
603 } else {
604 unsigned long flags;
605
606 raw_local_irq_save(flags);
607 result = v->counter;
608 result -= i;
609 if (result >= 0)
610 v->counter = result;
611 raw_local_irq_restore(flags);
612 }
613
614 smp_llsc_mb();
615
616 return result;
617}
618
619#define atomic64_cmpxchg(v, o, n) \
620 ((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n)))
621#define atomic64_xchg(v, new) (xchg(&((v)->counter), (new)))
622
623/**
624 * atomic64_add_unless - add unless the number is a given value
625 * @v: pointer of type atomic64_t
626 * @a: the amount to add to v...
627 * @u: ...unless v is equal to u.
628 *
629 * Atomically adds @a to @v, so long as it was not @u.
630 * Returns true iff @v was not @u.
631 */
632static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
633{
634 long c, old;
635 c = atomic64_read(v);
636 for (;;) {
637 if (unlikely(c == (u)))
638 break;
639 old = atomic64_cmpxchg((v), c, c + (a));
640 if (likely(old == c))
641 break;
642 c = old;
643 }
644 return c != (u);
645}
646
647#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
648
649#define atomic64_dec_return(v) atomic64_sub_return(1, (v))
650#define atomic64_inc_return(v) atomic64_add_return(1, (v))
651
652/*
653 * atomic64_sub_and_test - subtract value from variable and test result
654 * @i: integer value to subtract
655 * @v: pointer of type atomic64_t
656 *
657 * Atomically subtracts @i from @v and returns
658 * true if the result is zero, or false for all
659 * other cases.
660 */
661#define atomic64_sub_and_test(i, v) (atomic64_sub_return((i), (v)) == 0)
662
663/*
664 * atomic64_inc_and_test - increment and test
665 * @v: pointer of type atomic64_t
666 *
667 * Atomically increments @v by 1
668 * and returns true if the result is zero, or false for all
669 * other cases.
670 */
671#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
672
673/*
674 * atomic64_dec_and_test - decrement by 1 and test
675 * @v: pointer of type atomic64_t
676 *
677 * Atomically decrements @v by 1 and
678 * returns true if the result is 0, or false for all other
679 * cases.
680 */
681#define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)
682
683/*
684 * atomic64_dec_if_positive - decrement by 1 if old value positive
685 * @v: pointer of type atomic64_t
686 */
687#define atomic64_dec_if_positive(v) atomic64_sub_if_positive(1, v)
688
689/*
690 * atomic64_inc - increment atomic variable
691 * @v: pointer of type atomic64_t
692 *
693 * Atomically increments @v by 1.
694 */
695#define atomic64_inc(v) atomic64_add(1, (v))
696
697/*
698 * atomic64_dec - decrement and test
699 * @v: pointer of type atomic64_t
700 *
701 * Atomically decrements @v by 1.
702 */
703#define atomic64_dec(v) atomic64_sub(1, (v))
704
705/*
706 * atomic64_add_negative - add and test if negative
707 * @v: pointer of type atomic64_t
708 * @i: integer value to add
709 *
710 * Atomically adds @i to @v and returns true
711 * if the result is negative, or false when
712 * result is greater than or equal to zero.
713 */
714#define atomic64_add_negative(i, v) (atomic64_add_return(i, (v)) < 0)
715
716#endif /* CONFIG_64BIT */
717
718#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/compiler.h>
21#include <asm/cpu-features.h>
22#include <asm/cmpxchg.h>
23#include <asm/war.h>
24
25#define ATOMIC_INIT(i) { (i) }
26
27/*
28 * atomic_read - read atomic variable
29 * @v: pointer of type atomic_t
30 *
31 * Atomically reads the value of @v.
32 */
33#define atomic_read(v) READ_ONCE((v)->counter)
34
35/*
36 * atomic_set - set atomic variable
37 * @v: pointer of type atomic_t
38 * @i: required value
39 *
40 * Atomically sets the value of @v to @i.
41 */
42#define atomic_set(v, i) WRITE_ONCE((v)->counter, (i))
43
44#define ATOMIC_OP(op, c_op, asm_op) \
45static __inline__ void atomic_##op(int i, atomic_t * v) \
46{ \
47 if (kernel_uses_llsc && R10000_LLSC_WAR) { \
48 int temp; \
49 \
50 __asm__ __volatile__( \
51 " .set arch=r4000 \n" \
52 "1: ll %0, %1 # atomic_" #op " \n" \
53 " " #asm_op " %0, %2 \n" \
54 " sc %0, %1 \n" \
55 " beqzl %0, 1b \n" \
56 " .set mips0 \n" \
57 : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
58 : "Ir" (i)); \
59 } else if (kernel_uses_llsc) { \
60 int temp; \
61 \
62 do { \
63 __asm__ __volatile__( \
64 " .set "MIPS_ISA_LEVEL" \n" \
65 " ll %0, %1 # atomic_" #op "\n" \
66 " " #asm_op " %0, %2 \n" \
67 " sc %0, %1 \n" \
68 " .set mips0 \n" \
69 : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
70 : "Ir" (i)); \
71 } while (unlikely(!temp)); \
72 } else { \
73 unsigned long flags; \
74 \
75 raw_local_irq_save(flags); \
76 v->counter c_op i; \
77 raw_local_irq_restore(flags); \
78 } \
79}
80
81#define ATOMIC_OP_RETURN(op, c_op, asm_op) \
82static __inline__ int atomic_##op##_return(int i, atomic_t * v) \
83{ \
84 int result; \
85 \
86 smp_mb__before_llsc(); \
87 \
88 if (kernel_uses_llsc && R10000_LLSC_WAR) { \
89 int temp; \
90 \
91 __asm__ __volatile__( \
92 " .set arch=r4000 \n" \
93 "1: ll %1, %2 # atomic_" #op "_return \n" \
94 " " #asm_op " %0, %1, %3 \n" \
95 " sc %0, %2 \n" \
96 " beqzl %0, 1b \n" \
97 " " #asm_op " %0, %1, %3 \n" \
98 " .set mips0 \n" \
99 : "=&r" (result), "=&r" (temp), \
100 "+" GCC_OFF_SMALL_ASM() (v->counter) \
101 : "Ir" (i)); \
102 } else if (kernel_uses_llsc) { \
103 int temp; \
104 \
105 do { \
106 __asm__ __volatile__( \
107 " .set "MIPS_ISA_LEVEL" \n" \
108 " ll %1, %2 # atomic_" #op "_return \n" \
109 " " #asm_op " %0, %1, %3 \n" \
110 " sc %0, %2 \n" \
111 " .set mips0 \n" \
112 : "=&r" (result), "=&r" (temp), \
113 "+" GCC_OFF_SMALL_ASM() (v->counter) \
114 : "Ir" (i)); \
115 } while (unlikely(!result)); \
116 \
117 result = temp; result c_op i; \
118 } else { \
119 unsigned long flags; \
120 \
121 raw_local_irq_save(flags); \
122 result = v->counter; \
123 result c_op i; \
124 v->counter = result; \
125 raw_local_irq_restore(flags); \
126 } \
127 \
128 smp_llsc_mb(); \
129 \
130 return result; \
131}
132
133#define ATOMIC_OPS(op, c_op, asm_op) \
134 ATOMIC_OP(op, c_op, asm_op) \
135 ATOMIC_OP_RETURN(op, c_op, asm_op)
136
137ATOMIC_OPS(add, +=, addu)
138ATOMIC_OPS(sub, -=, subu)
139
140ATOMIC_OP(and, &=, and)
141ATOMIC_OP(or, |=, or)
142ATOMIC_OP(xor, ^=, xor)
143
144#undef ATOMIC_OPS
145#undef ATOMIC_OP_RETURN
146#undef ATOMIC_OP
147
148/*
149 * atomic_sub_if_positive - conditionally subtract integer from atomic variable
150 * @i: integer value to subtract
151 * @v: pointer of type atomic_t
152 *
153 * Atomically test @v and subtract @i if @v is greater or equal than @i.
154 * The function returns the old value of @v minus @i.
155 */
156static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
157{
158 int result;
159
160 smp_mb__before_llsc();
161
162 if (kernel_uses_llsc && R10000_LLSC_WAR) {
163 int temp;
164
165 __asm__ __volatile__(
166 " .set arch=r4000 \n"
167 "1: ll %1, %2 # atomic_sub_if_positive\n"
168 " subu %0, %1, %3 \n"
169 " bltz %0, 1f \n"
170 " sc %0, %2 \n"
171 " .set noreorder \n"
172 " beqzl %0, 1b \n"
173 " subu %0, %1, %3 \n"
174 " .set reorder \n"
175 "1: \n"
176 " .set mips0 \n"
177 : "=&r" (result), "=&r" (temp),
178 "+" GCC_OFF_SMALL_ASM() (v->counter)
179 : "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter)
180 : "memory");
181 } else if (kernel_uses_llsc) {
182 int temp;
183
184 __asm__ __volatile__(
185 " .set "MIPS_ISA_LEVEL" \n"
186 "1: ll %1, %2 # atomic_sub_if_positive\n"
187 " subu %0, %1, %3 \n"
188 " bltz %0, 1f \n"
189 " sc %0, %2 \n"
190 " .set noreorder \n"
191 " beqz %0, 1b \n"
192 " subu %0, %1, %3 \n"
193 " .set reorder \n"
194 "1: \n"
195 " .set mips0 \n"
196 : "=&r" (result), "=&r" (temp),
197 "+" GCC_OFF_SMALL_ASM() (v->counter)
198 : "Ir" (i));
199 } else {
200 unsigned long flags;
201
202 raw_local_irq_save(flags);
203 result = v->counter;
204 result -= i;
205 if (result >= 0)
206 v->counter = result;
207 raw_local_irq_restore(flags);
208 }
209
210 smp_llsc_mb();
211
212 return result;
213}
214
215#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
216#define atomic_xchg(v, new) (xchg(&((v)->counter), (new)))
217
218/**
219 * __atomic_add_unless - add unless the number is a given value
220 * @v: pointer of type atomic_t
221 * @a: the amount to add to v...
222 * @u: ...unless v is equal to u.
223 *
224 * Atomically adds @a to @v, so long as it was not @u.
225 * Returns the old value of @v.
226 */
227static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
228{
229 int c, old;
230 c = atomic_read(v);
231 for (;;) {
232 if (unlikely(c == (u)))
233 break;
234 old = atomic_cmpxchg((v), c, c + (a));
235 if (likely(old == c))
236 break;
237 c = old;
238 }
239 return c;
240}
241
242#define atomic_dec_return(v) atomic_sub_return(1, (v))
243#define atomic_inc_return(v) atomic_add_return(1, (v))
244
245/*
246 * atomic_sub_and_test - subtract value from variable and test result
247 * @i: integer value to subtract
248 * @v: pointer of type atomic_t
249 *
250 * Atomically subtracts @i from @v and returns
251 * true if the result is zero, or false for all
252 * other cases.
253 */
254#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
255
256/*
257 * atomic_inc_and_test - increment and test
258 * @v: pointer of type atomic_t
259 *
260 * Atomically increments @v by 1
261 * and returns true if the result is zero, or false for all
262 * other cases.
263 */
264#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
265
266/*
267 * atomic_dec_and_test - decrement by 1 and test
268 * @v: pointer of type atomic_t
269 *
270 * Atomically decrements @v by 1 and
271 * returns true if the result is 0, or false for all other
272 * cases.
273 */
274#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
275
276/*
277 * atomic_dec_if_positive - decrement by 1 if old value positive
278 * @v: pointer of type atomic_t
279 */
280#define atomic_dec_if_positive(v) atomic_sub_if_positive(1, v)
281
282/*
283 * atomic_inc - increment atomic variable
284 * @v: pointer of type atomic_t
285 *
286 * Atomically increments @v by 1.
287 */
288#define atomic_inc(v) atomic_add(1, (v))
289
290/*
291 * atomic_dec - decrement and test
292 * @v: pointer of type atomic_t
293 *
294 * Atomically decrements @v by 1.
295 */
296#define atomic_dec(v) atomic_sub(1, (v))
297
298/*
299 * atomic_add_negative - add and test if negative
300 * @v: pointer of type atomic_t
301 * @i: integer value to add
302 *
303 * Atomically adds @i to @v and returns true
304 * if the result is negative, or false when
305 * result is greater than or equal to zero.
306 */
307#define atomic_add_negative(i, v) (atomic_add_return(i, (v)) < 0)
308
309#ifdef CONFIG_64BIT
310
311#define ATOMIC64_INIT(i) { (i) }
312
313/*
314 * atomic64_read - read atomic variable
315 * @v: pointer of type atomic64_t
316 *
317 */
318#define atomic64_read(v) READ_ONCE((v)->counter)
319
320/*
321 * atomic64_set - set atomic variable
322 * @v: pointer of type atomic64_t
323 * @i: required value
324 */
325#define atomic64_set(v, i) WRITE_ONCE((v)->counter, (i))
326
327#define ATOMIC64_OP(op, c_op, asm_op) \
328static __inline__ void atomic64_##op(long i, atomic64_t * v) \
329{ \
330 if (kernel_uses_llsc && R10000_LLSC_WAR) { \
331 long temp; \
332 \
333 __asm__ __volatile__( \
334 " .set arch=r4000 \n" \
335 "1: lld %0, %1 # atomic64_" #op " \n" \
336 " " #asm_op " %0, %2 \n" \
337 " scd %0, %1 \n" \
338 " beqzl %0, 1b \n" \
339 " .set mips0 \n" \
340 : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
341 : "Ir" (i)); \
342 } else if (kernel_uses_llsc) { \
343 long temp; \
344 \
345 do { \
346 __asm__ __volatile__( \
347 " .set "MIPS_ISA_LEVEL" \n" \
348 " lld %0, %1 # atomic64_" #op "\n" \
349 " " #asm_op " %0, %2 \n" \
350 " scd %0, %1 \n" \
351 " .set mips0 \n" \
352 : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
353 : "Ir" (i)); \
354 } while (unlikely(!temp)); \
355 } else { \
356 unsigned long flags; \
357 \
358 raw_local_irq_save(flags); \
359 v->counter c_op i; \
360 raw_local_irq_restore(flags); \
361 } \
362}
363
364#define ATOMIC64_OP_RETURN(op, c_op, asm_op) \
365static __inline__ long atomic64_##op##_return(long i, atomic64_t * v) \
366{ \
367 long result; \
368 \
369 smp_mb__before_llsc(); \
370 \
371 if (kernel_uses_llsc && R10000_LLSC_WAR) { \
372 long temp; \
373 \
374 __asm__ __volatile__( \
375 " .set arch=r4000 \n" \
376 "1: lld %1, %2 # atomic64_" #op "_return\n" \
377 " " #asm_op " %0, %1, %3 \n" \
378 " scd %0, %2 \n" \
379 " beqzl %0, 1b \n" \
380 " " #asm_op " %0, %1, %3 \n" \
381 " .set mips0 \n" \
382 : "=&r" (result), "=&r" (temp), \
383 "+" GCC_OFF_SMALL_ASM() (v->counter) \
384 : "Ir" (i)); \
385 } else if (kernel_uses_llsc) { \
386 long temp; \
387 \
388 do { \
389 __asm__ __volatile__( \
390 " .set "MIPS_ISA_LEVEL" \n" \
391 " lld %1, %2 # atomic64_" #op "_return\n" \
392 " " #asm_op " %0, %1, %3 \n" \
393 " scd %0, %2 \n" \
394 " .set mips0 \n" \
395 : "=&r" (result), "=&r" (temp), \
396 "=" GCC_OFF_SMALL_ASM() (v->counter) \
397 : "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter) \
398 : "memory"); \
399 } while (unlikely(!result)); \
400 \
401 result = temp; result c_op i; \
402 } else { \
403 unsigned long flags; \
404 \
405 raw_local_irq_save(flags); \
406 result = v->counter; \
407 result c_op i; \
408 v->counter = result; \
409 raw_local_irq_restore(flags); \
410 } \
411 \
412 smp_llsc_mb(); \
413 \
414 return result; \
415}
416
417#define ATOMIC64_OPS(op, c_op, asm_op) \
418 ATOMIC64_OP(op, c_op, asm_op) \
419 ATOMIC64_OP_RETURN(op, c_op, asm_op)
420
421ATOMIC64_OPS(add, +=, daddu)
422ATOMIC64_OPS(sub, -=, dsubu)
423ATOMIC64_OP(and, &=, and)
424ATOMIC64_OP(or, |=, or)
425ATOMIC64_OP(xor, ^=, xor)
426
427#undef ATOMIC64_OPS
428#undef ATOMIC64_OP_RETURN
429#undef ATOMIC64_OP
430
431/*
432 * atomic64_sub_if_positive - conditionally subtract integer from atomic
433 * variable
434 * @i: integer value to subtract
435 * @v: pointer of type atomic64_t
436 *
437 * Atomically test @v and subtract @i if @v is greater or equal than @i.
438 * The function returns the old value of @v minus @i.
439 */
440static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
441{
442 long result;
443
444 smp_mb__before_llsc();
445
446 if (kernel_uses_llsc && R10000_LLSC_WAR) {
447 long temp;
448
449 __asm__ __volatile__(
450 " .set arch=r4000 \n"
451 "1: lld %1, %2 # atomic64_sub_if_positive\n"
452 " dsubu %0, %1, %3 \n"
453 " bltz %0, 1f \n"
454 " scd %0, %2 \n"
455 " .set noreorder \n"
456 " beqzl %0, 1b \n"
457 " dsubu %0, %1, %3 \n"
458 " .set reorder \n"
459 "1: \n"
460 " .set mips0 \n"
461 : "=&r" (result), "=&r" (temp),
462 "=" GCC_OFF_SMALL_ASM() (v->counter)
463 : "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter)
464 : "memory");
465 } else if (kernel_uses_llsc) {
466 long temp;
467
468 __asm__ __volatile__(
469 " .set "MIPS_ISA_LEVEL" \n"
470 "1: lld %1, %2 # atomic64_sub_if_positive\n"
471 " dsubu %0, %1, %3 \n"
472 " bltz %0, 1f \n"
473 " scd %0, %2 \n"
474 " .set noreorder \n"
475 " beqz %0, 1b \n"
476 " dsubu %0, %1, %3 \n"
477 " .set reorder \n"
478 "1: \n"
479 " .set mips0 \n"
480 : "=&r" (result), "=&r" (temp),
481 "+" GCC_OFF_SMALL_ASM() (v->counter)
482 : "Ir" (i));
483 } else {
484 unsigned long flags;
485
486 raw_local_irq_save(flags);
487 result = v->counter;
488 result -= i;
489 if (result >= 0)
490 v->counter = result;
491 raw_local_irq_restore(flags);
492 }
493
494 smp_llsc_mb();
495
496 return result;
497}
498
499#define atomic64_cmpxchg(v, o, n) \
500 ((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n)))
501#define atomic64_xchg(v, new) (xchg(&((v)->counter), (new)))
502
503/**
504 * atomic64_add_unless - add unless the number is a given value
505 * @v: pointer of type atomic64_t
506 * @a: the amount to add to v...
507 * @u: ...unless v is equal to u.
508 *
509 * Atomically adds @a to @v, so long as it was not @u.
510 * Returns true iff @v was not @u.
511 */
512static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
513{
514 long c, old;
515 c = atomic64_read(v);
516 for (;;) {
517 if (unlikely(c == (u)))
518 break;
519 old = atomic64_cmpxchg((v), c, c + (a));
520 if (likely(old == c))
521 break;
522 c = old;
523 }
524 return c != (u);
525}
526
527#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
528
529#define atomic64_dec_return(v) atomic64_sub_return(1, (v))
530#define atomic64_inc_return(v) atomic64_add_return(1, (v))
531
532/*
533 * atomic64_sub_and_test - subtract value from variable and test result
534 * @i: integer value to subtract
535 * @v: pointer of type atomic64_t
536 *
537 * Atomically subtracts @i from @v and returns
538 * true if the result is zero, or false for all
539 * other cases.
540 */
541#define atomic64_sub_and_test(i, v) (atomic64_sub_return((i), (v)) == 0)
542
543/*
544 * atomic64_inc_and_test - increment and test
545 * @v: pointer of type atomic64_t
546 *
547 * Atomically increments @v by 1
548 * and returns true if the result is zero, or false for all
549 * other cases.
550 */
551#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
552
553/*
554 * atomic64_dec_and_test - decrement by 1 and test
555 * @v: pointer of type atomic64_t
556 *
557 * Atomically decrements @v by 1 and
558 * returns true if the result is 0, or false for all other
559 * cases.
560 */
561#define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)
562
563/*
564 * atomic64_dec_if_positive - decrement by 1 if old value positive
565 * @v: pointer of type atomic64_t
566 */
567#define atomic64_dec_if_positive(v) atomic64_sub_if_positive(1, v)
568
569/*
570 * atomic64_inc - increment atomic variable
571 * @v: pointer of type atomic64_t
572 *
573 * Atomically increments @v by 1.
574 */
575#define atomic64_inc(v) atomic64_add(1, (v))
576
577/*
578 * atomic64_dec - decrement and test
579 * @v: pointer of type atomic64_t
580 *
581 * Atomically decrements @v by 1.
582 */
583#define atomic64_dec(v) atomic64_sub(1, (v))
584
585/*
586 * atomic64_add_negative - add and test if negative
587 * @v: pointer of type atomic64_t
588 * @i: integer value to add
589 *
590 * Atomically adds @i to @v and returns true
591 * if the result is negative, or false when
592 * result is greater than or equal to zero.
593 */
594#define atomic64_add_negative(i, v) (atomic64_add_return(i, (v)) < 0)
595
596#endif /* CONFIG_64BIT */
597
598#endif /* _ASM_ATOMIC_H */