xf86atomic.h 2.8 KB

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  1. /*
  2. * SPDX-FileCopyrightText: 2009 Intel Corporation
  3. * SPDX-License-Identifier: MIT
  4. * SPDX-FileContributor: Chris Wilson <chris@chris-wilson.co.uk>
  5. */
  6. /**
  7. * @file xf86atomics.h
  8. *
  9. * Private definitions for atomic operations
  10. */
  11. #ifndef LIBDRM_ATOMICS_H
  12. #define LIBDRM_ATOMICS_H
  13. #if HAVE_LIBDRM_ATOMIC_PRIMITIVES
  14. #define HAS_ATOMIC_OPS 1
  15. typedef struct {
  16. int atomic;
  17. } atomic_t;
  18. # define atomic_read(x) ((x)->atomic)
  19. # define atomic_set(x, val) ((x)->atomic = (val))
  20. # define atomic_inc(x) ((void) __sync_fetch_and_add (&(x)->atomic, 1))
  21. # define atomic_inc_return(x) (__sync_add_and_fetch (&(x)->atomic, 1))
  22. # define atomic_dec_and_test(x) (__sync_add_and_fetch (&(x)->atomic, -1) == 0)
  23. # define atomic_add(x, v) ((void) __sync_add_and_fetch(&(x)->atomic, (v)))
  24. # define atomic_dec(x, v) ((void) __sync_sub_and_fetch(&(x)->atomic, (v)))
  25. # define atomic_cmpxchg(x, oldv, newv) __sync_val_compare_and_swap (&(x)->atomic, oldv, newv)
  26. #endif
  27. #if HAVE_LIB_ATOMIC_OPS
  28. #define AO_REQUIRE_CAS
  29. #include <atomic_ops.h>
  30. #define HAS_ATOMIC_OPS 1
  31. typedef struct {
  32. AO_t atomic;
  33. } atomic_t;
  34. # define atomic_read(x) AO_load_full(&(x)->atomic)
  35. # define atomic_set(x, val) AO_store_full(&(x)->atomic, (val))
  36. # define atomic_inc(x) ((void) AO_fetch_and_add1_full(&(x)->atomic))
  37. # define atomic_inc_return(x) (AO_fetch_and_add1_full(&(x)->atomic) + 1)
  38. # define atomic_add(x, v) ((void) AO_fetch_and_add_full(&(x)->atomic, (v)))
  39. # define atomic_dec(x, v) ((void) AO_fetch_and_add_full(&(x)->atomic, -(v)))
  40. # define atomic_dec_and_test(x) (AO_fetch_and_sub1_full(&(x)->atomic) == 1)
  41. # define atomic_cmpxchg(x, oldv, newv) AO_compare_and_swap_full(&(x)->atomic, oldv, newv)
  42. #endif
  43. #if (defined(__sun) || defined(__NetBSD__)) && !defined(HAS_ATOMIC_OPS) /* Solaris & OpenSolaris & NetBSD */
  44. #include <sys/atomic.h>
  45. #define HAS_ATOMIC_OPS 1
  46. #if defined(__NetBSD__)
  47. #define LIBDRM_ATOMIC_TYPE int
  48. #else
  49. #define LIBDRM_ATOMIC_TYPE uint_t
  50. #endif
  51. typedef struct { LIBDRM_ATOMIC_TYPE atomic; } atomic_t;
  52. # define atomic_read(x) (int) ((x)->atomic)
  53. # define atomic_set(x, val) ((x)->atomic = (LIBDRM_ATOMIC_TYPE)(val))
  54. # define atomic_inc(x) (atomic_inc_uint (&(x)->atomic))
  55. # define atomic_inc_return(x) (atomic_inc_uint_nv(&(x)->atomic))
  56. # define atomic_dec_and_test(x) (atomic_dec_uint_nv(&(x)->atomic) == 0)
  57. # define atomic_add(x, v) (atomic_add_int(&(x)->atomic, (v)))
  58. # define atomic_dec(x, v) (atomic_add_int(&(x)->atomic, -(v)))
  59. # define atomic_cmpxchg(x, oldv, newv) atomic_cas_uint (&(x)->atomic, oldv, newv)
  60. #endif
  61. #if !defined(HAS_ATOMIC_OPS)
  62. #error libdrm requires atomic operations, please define them for your CPU/compiler.
  63. #endif
  64. static inline int atomic_add_unless(atomic_t *v, int add, int unless)
  65. {
  66. int c, old;
  67. c = atomic_read(v);
  68. while (c != unless && (old = atomic_cmpxchg(v, c, c + add)) != c)
  69. c = old;
  70. return c != unless;
  71. }
  72. #endif