2
* Atomic operations that C can't guarantee us. Useful for
3
* resource counting etc..
5
* But use these as seldom as possible since they are much more slower
6
* than regular operations.
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
12
* Copyright (C) 1996, 97, 99, 2000, 03, 04, 06 by Ralf Baechle
17
#include <linux/irqflags.h>
18
#include <linux/types.h>
19
#include <asm/barrier.h>
20
#include <asm/cpu-features.h>
22
#include <asm/system.h>
24
#define ATOMIC_INIT(i) { (i) }
27
* atomic_read - read atomic variable
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* @v: pointer of type atomic_t
30
* Atomically reads the value of @v.
32
#define atomic_read(v) (*(volatile int *)&(v)->counter)
35
* atomic_set - set atomic variable
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* @v: pointer of type atomic_t
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* Atomically sets the value of @v to @i.
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#define atomic_set(v, i) ((v)->counter = (i))
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* atomic_add - add integer to atomic variable
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* @i: integer value to add
46
* @v: pointer of type atomic_t
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* Atomically adds @i to @v.
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static __inline__ void atomic_add(int i, atomic_t * v)
52
if (kernel_uses_llsc && R10000_LLSC_WAR) {
57
"1: ll %0, %1 # atomic_add \n"
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: "=&r" (temp), "=m" (v->counter)
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: "Ir" (i), "m" (v->counter));
64
} else if (kernel_uses_llsc) {
70
" ll %0, %1 # atomic_add \n"
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: "=&r" (temp), "=m" (v->counter)
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: "Ir" (i), "m" (v->counter));
76
} while (unlikely(!temp));
80
raw_local_irq_save(flags);
82
raw_local_irq_restore(flags);
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* atomic_sub - subtract the atomic variable
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* @i: integer value to subtract
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* @v: pointer of type atomic_t
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* Atomically subtracts @i from @v.
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static __inline__ void atomic_sub(int i, atomic_t * v)
95
if (kernel_uses_llsc && R10000_LLSC_WAR) {
100
"1: ll %0, %1 # atomic_sub \n"
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: "=&r" (temp), "=m" (v->counter)
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: "Ir" (i), "m" (v->counter));
107
} else if (kernel_uses_llsc) {
111
__asm__ __volatile__(
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" ll %0, %1 # atomic_sub \n"
117
: "=&r" (temp), "=m" (v->counter)
118
: "Ir" (i), "m" (v->counter));
119
} while (unlikely(!temp));
123
raw_local_irq_save(flags);
125
raw_local_irq_restore(flags);
130
* Same as above, but return the result value
132
static __inline__ int atomic_add_return(int i, atomic_t * v)
136
smp_mb__before_llsc();
138
if (kernel_uses_llsc && R10000_LLSC_WAR) {
141
__asm__ __volatile__(
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"1: ll %1, %2 # atomic_add_return \n"
144
" addu %0, %1, %3 \n"
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" addu %0, %1, %3 \n"
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: "=&r" (result), "=&r" (temp), "=m" (v->counter)
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: "Ir" (i), "m" (v->counter)
152
} else if (kernel_uses_llsc) {
156
__asm__ __volatile__(
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" ll %1, %2 # atomic_add_return \n"
159
" addu %0, %1, %3 \n"
162
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
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: "Ir" (i), "m" (v->counter)
165
} while (unlikely(!result));
171
raw_local_irq_save(flags);
175
raw_local_irq_restore(flags);
183
static __inline__ int atomic_sub_return(int i, atomic_t * v)
187
smp_mb__before_llsc();
189
if (kernel_uses_llsc && R10000_LLSC_WAR) {
192
__asm__ __volatile__(
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"1: ll %1, %2 # atomic_sub_return \n"
195
" subu %0, %1, %3 \n"
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" subu %0, %1, %3 \n"
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: "=&r" (result), "=&r" (temp), "=m" (v->counter)
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: "Ir" (i), "m" (v->counter)
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} else if (kernel_uses_llsc) {
209
__asm__ __volatile__(
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" ll %1, %2 # atomic_sub_return \n"
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" subu %0, %1, %3 \n"
215
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
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: "Ir" (i), "m" (v->counter)
218
} while (unlikely(!result));
224
raw_local_irq_save(flags);
228
raw_local_irq_restore(flags);
237
* atomic_sub_if_positive - conditionally subtract integer from atomic variable
238
* @i: integer value to subtract
239
* @v: pointer of type atomic_t
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.
244
static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
248
smp_mb__before_llsc();
250
if (kernel_uses_llsc && R10000_LLSC_WAR) {
253
__asm__ __volatile__(
255
"1: ll %1, %2 # atomic_sub_if_positive\n"
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" subu %0, %1, %3 \n"
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" subu %0, %1, %3 \n"
265
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
266
: "Ir" (i), "m" (v->counter)
268
} else if (kernel_uses_llsc) {
271
__asm__ __volatile__(
273
"1: ll %1, %2 # atomic_sub_if_positive\n"
274
" subu %0, %1, %3 \n"
279
" subu %0, %1, %3 \n"
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: "=&r" (result), "=&r" (temp), "=m" (v->counter)
284
: "Ir" (i), "m" (v->counter)
289
raw_local_irq_save(flags);
294
raw_local_irq_restore(flags);
302
#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
303
#define atomic_xchg(v, new) (xchg(&((v)->counter), (new)))
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.
311
* Atomically adds @a to @v, so long as it was not @u.
312
* Returns the old value of @v.
314
static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
319
if (unlikely(c == (u)))
321
old = atomic_cmpxchg((v), c, c + (a));
322
if (likely(old == c))
329
#define atomic_dec_return(v) atomic_sub_return(1, (v))
330
#define atomic_inc_return(v) atomic_add_return(1, (v))
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
337
* Atomically subtracts @i from @v and returns
338
* true if the result is zero, or false for all
341
#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
344
* atomic_inc_and_test - increment and test
345
* @v: pointer of type atomic_t
347
* Atomically increments @v by 1
348
* and returns true if the result is zero, or false for all
351
#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
354
* atomic_dec_and_test - decrement by 1 and test
355
* @v: pointer of type atomic_t
357
* Atomically decrements @v by 1 and
358
* returns true if the result is 0, or false for all other
361
#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
364
* atomic_dec_if_positive - decrement by 1 if old value positive
365
* @v: pointer of type atomic_t
367
#define atomic_dec_if_positive(v) atomic_sub_if_positive(1, v)
370
* atomic_inc - increment atomic variable
371
* @v: pointer of type atomic_t
373
* Atomically increments @v by 1.
375
#define atomic_inc(v) atomic_add(1, (v))
378
* atomic_dec - decrement and test
379
* @v: pointer of type atomic_t
381
* Atomically decrements @v by 1.
383
#define atomic_dec(v) atomic_sub(1, (v))
386
* atomic_add_negative - add and test if negative
387
* @v: pointer of type atomic_t
388
* @i: integer value to add
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.
394
#define atomic_add_negative(i, v) (atomic_add_return(i, (v)) < 0)
398
#define ATOMIC64_INIT(i) { (i) }
401
* atomic64_read - read atomic variable
402
* @v: pointer of type atomic64_t
405
#define atomic64_read(v) (*(volatile long *)&(v)->counter)
408
* atomic64_set - set atomic variable
409
* @v: pointer of type atomic64_t
412
#define atomic64_set(v, i) ((v)->counter = (i))
415
* atomic64_add - add integer to atomic variable
416
* @i: integer value to add
417
* @v: pointer of type atomic64_t
419
* Atomically adds @i to @v.
421
static __inline__ void atomic64_add(long i, atomic64_t * v)
423
if (kernel_uses_llsc && R10000_LLSC_WAR) {
426
__asm__ __volatile__(
428
"1: lld %0, %1 # atomic64_add \n"
433
: "=&r" (temp), "=m" (v->counter)
434
: "Ir" (i), "m" (v->counter));
435
} else if (kernel_uses_llsc) {
439
__asm__ __volatile__(
441
" lld %0, %1 # atomic64_add \n"
445
: "=&r" (temp), "=m" (v->counter)
446
: "Ir" (i), "m" (v->counter));
447
} while (unlikely(!temp));
451
raw_local_irq_save(flags);
453
raw_local_irq_restore(flags);
458
* atomic64_sub - subtract the atomic variable
459
* @i: integer value to subtract
460
* @v: pointer of type atomic64_t
462
* Atomically subtracts @i from @v.
464
static __inline__ void atomic64_sub(long i, atomic64_t * v)
466
if (kernel_uses_llsc && R10000_LLSC_WAR) {
469
__asm__ __volatile__(
471
"1: lld %0, %1 # atomic64_sub \n"
476
: "=&r" (temp), "=m" (v->counter)
477
: "Ir" (i), "m" (v->counter));
478
} else if (kernel_uses_llsc) {
482
__asm__ __volatile__(
484
" lld %0, %1 # atomic64_sub \n"
488
: "=&r" (temp), "=m" (v->counter)
489
: "Ir" (i), "m" (v->counter));
490
} while (unlikely(!temp));
494
raw_local_irq_save(flags);
496
raw_local_irq_restore(flags);
501
* Same as above, but return the result value
503
static __inline__ long atomic64_add_return(long i, atomic64_t * v)
507
smp_mb__before_llsc();
509
if (kernel_uses_llsc && R10000_LLSC_WAR) {
512
__asm__ __volatile__(
514
"1: lld %1, %2 # atomic64_add_return \n"
515
" daddu %0, %1, %3 \n"
518
" daddu %0, %1, %3 \n"
520
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
521
: "Ir" (i), "m" (v->counter)
523
} else if (kernel_uses_llsc) {
527
__asm__ __volatile__(
529
" lld %1, %2 # atomic64_add_return \n"
530
" daddu %0, %1, %3 \n"
533
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
534
: "Ir" (i), "m" (v->counter)
536
} while (unlikely(!result));
542
raw_local_irq_save(flags);
546
raw_local_irq_restore(flags);
554
static __inline__ long atomic64_sub_return(long i, atomic64_t * v)
558
smp_mb__before_llsc();
560
if (kernel_uses_llsc && R10000_LLSC_WAR) {
563
__asm__ __volatile__(
565
"1: lld %1, %2 # atomic64_sub_return \n"
566
" dsubu %0, %1, %3 \n"
569
" dsubu %0, %1, %3 \n"
571
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
572
: "Ir" (i), "m" (v->counter)
574
} else if (kernel_uses_llsc) {
578
__asm__ __volatile__(
580
" lld %1, %2 # atomic64_sub_return \n"
581
" dsubu %0, %1, %3 \n"
584
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
585
: "Ir" (i), "m" (v->counter)
587
} while (unlikely(!result));
593
raw_local_irq_save(flags);
597
raw_local_irq_restore(flags);
606
* atomic64_sub_if_positive - conditionally subtract integer from atomic variable
607
* @i: integer value to subtract
608
* @v: pointer of type atomic64_t
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.
613
static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
617
smp_mb__before_llsc();
619
if (kernel_uses_llsc && R10000_LLSC_WAR) {
622
__asm__ __volatile__(
624
"1: lld %1, %2 # atomic64_sub_if_positive\n"
625
" dsubu %0, %1, %3 \n"
630
" dsubu %0, %1, %3 \n"
634
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
635
: "Ir" (i), "m" (v->counter)
637
} else if (kernel_uses_llsc) {
640
__asm__ __volatile__(
642
"1: lld %1, %2 # atomic64_sub_if_positive\n"
643
" dsubu %0, %1, %3 \n"
648
" dsubu %0, %1, %3 \n"
652
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
653
: "Ir" (i), "m" (v->counter)
658
raw_local_irq_save(flags);
663
raw_local_irq_restore(flags);
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)))
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.
681
* Atomically adds @a to @v, so long as it was not @u.
682
* Returns the old value of @v.
684
static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
687
c = atomic64_read(v);
689
if (unlikely(c == (u)))
691
old = atomic64_cmpxchg((v), c, c + (a));
692
if (likely(old == c))
699
#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
701
#define atomic64_dec_return(v) atomic64_sub_return(1, (v))
702
#define atomic64_inc_return(v) atomic64_add_return(1, (v))
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
709
* Atomically subtracts @i from @v and returns
710
* true if the result is zero, or false for all
713
#define atomic64_sub_and_test(i, v) (atomic64_sub_return((i), (v)) == 0)
716
* atomic64_inc_and_test - increment and test
717
* @v: pointer of type atomic64_t
719
* Atomically increments @v by 1
720
* and returns true if the result is zero, or false for all
723
#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
726
* atomic64_dec_and_test - decrement by 1 and test
727
* @v: pointer of type atomic64_t
729
* Atomically decrements @v by 1 and
730
* returns true if the result is 0, or false for all other
733
#define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)
736
* atomic64_dec_if_positive - decrement by 1 if old value positive
737
* @v: pointer of type atomic64_t
739
#define atomic64_dec_if_positive(v) atomic64_sub_if_positive(1, v)
742
* atomic64_inc - increment atomic variable
743
* @v: pointer of type atomic64_t
745
* Atomically increments @v by 1.
747
#define atomic64_inc(v) atomic64_add(1, (v))
750
* atomic64_dec - decrement and test
751
* @v: pointer of type atomic64_t
753
* Atomically decrements @v by 1.
755
#define atomic64_dec(v) atomic64_sub(1, (v))
758
* atomic64_add_negative - add and test if negative
759
* @v: pointer of type atomic64_t
760
* @i: integer value to add
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.
766
#define atomic64_add_negative(i, v) (atomic64_add_return(i, (v)) < 0)
768
#endif /* CONFIG_64BIT */
771
* atomic*_return operations are serializing but not the non-*_return
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()
779
#endif /* _ASM_ATOMIC_H */