atomic64.h 1.8 KB

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  1. /*
  2. * Generic implementation of 64-bit atomics using spinlocks,
  3. * useful on processors that don't have 64-bit atomic instructions.
  4. *
  5. * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
  6. *
  7. * This program is free software; you can redistribute it and/or
  8. * modify it under the terms of the GNU General Public License
  9. * as published by the Free Software Foundation; either version
  10. * 2 of the License, or (at your option) any later version.
  11. */
  12. #ifndef _ASM_GENERIC_ATOMIC64_H
  13. #define _ASM_GENERIC_ATOMIC64_H
  14. typedef struct {
  15. long long counter;
  16. } atomic64_t;
  17. #define ATOMIC64_INIT(i) { (i) }
  18. extern long long atomic64_read(const atomic64_t *v);
  19. extern void atomic64_set(atomic64_t *v, long long i);
  20. extern void atomic64_add(long long a, atomic64_t *v);
  21. extern long long atomic64_add_return(long long a, atomic64_t *v);
  22. extern void atomic64_sub(long long a, atomic64_t *v);
  23. extern long long atomic64_sub_return(long long a, atomic64_t *v);
  24. extern long long atomic64_dec_if_positive(atomic64_t *v);
  25. extern long long atomic64_cmpxchg(atomic64_t *v, long long o, long long n);
  26. extern long long atomic64_xchg(atomic64_t *v, long long new);
  27. extern int atomic64_add_unless(atomic64_t *v, long long a, long long u);
  28. #define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0)
  29. #define atomic64_inc(v) atomic64_add(1LL, (v))
  30. #define atomic64_inc_return(v) atomic64_add_return(1LL, (v))
  31. #define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
  32. #define atomic64_sub_and_test(a, v) (atomic64_sub_return((a), (v)) == 0)
  33. #define atomic64_dec(v) atomic64_sub(1LL, (v))
  34. #define atomic64_dec_return(v) atomic64_sub_return(1LL, (v))
  35. #define atomic64_dec_and_test(v) (atomic64_dec_return((v)) == 0)
  36. #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1LL, 0LL)
  37. #endif /* _ASM_GENERIC_ATOMIC64_H */