futex.h 2.9 KB

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  1. /* Copyright (C) 2005-2015 Free Software Foundation, Inc.
  2. Contributed by Jakub Jelinek <jakub@redhat.com>.
  3. This file is part of the GNU Offloading and Multi Processing Library
  4. (libgomp).
  5. Libgomp is free software; you can redistribute it and/or modify it
  6. under the terms of the GNU General Public License as published by
  7. the Free Software Foundation; either version 3, or (at your option)
  8. any later version.
  9. Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
  10. WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  11. FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  12. more details.
  13. Under Section 7 of GPL version 3, you are granted additional
  14. permissions described in the GCC Runtime Library Exception, version
  15. 3.1, as published by the Free Software Foundation.
  16. You should have received a copy of the GNU General Public License and
  17. a copy of the GCC Runtime Library Exception along with this program;
  18. see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
  19. <http://www.gnu.org/licenses/>. */
  20. /* Provide target-specific access to the futex system call. */
  21. #include <sys/syscall.h>
  22. static inline long
  23. sys_futex0 (int *addr, int op, int val)
  24. {
  25. register long int g1 __asm__ ("g1");
  26. register long int o0 __asm__ ("o0");
  27. register long int o1 __asm__ ("o1");
  28. register long int o2 __asm__ ("o2");
  29. register long int o3 __asm__ ("o3");
  30. g1 = SYS_futex;
  31. o0 = (long) addr;
  32. o1 = op;
  33. o2 = val;
  34. o3 = 0;
  35. #ifdef __arch64__
  36. # define SYSCALL_STRING "ta\t0x6d; bcs,a,pt %%xcc, 1f; sub %%g0, %%o0, %%o0; 1:"
  37. #else
  38. # define SYSCALL_STRING "ta\t0x10; bcs,a 1f; sub %%g0, %%o0, %%o0; 1:"
  39. #endif
  40. __asm volatile (SYSCALL_STRING
  41. : "=r" (g1), "=r" (o0)
  42. : "0" (g1), "1" (o0), "r" (o1), "r" (o2), "r" (o3)
  43. : "g2", "g3", "g4", "g5", "g6",
  44. "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",
  45. "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15",
  46. "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23",
  47. "f24", "f25", "f26", "f27", "f28", "f29", "f30", "f31",
  48. #ifdef __arch64__
  49. "f32", "f34", "f36", "f38", "f40", "f42", "f44", "f46",
  50. "f48", "f50", "f52", "f54", "f56", "f58", "f60", "f62",
  51. #endif
  52. "cc", "memory");
  53. return o0;
  54. }
  55. static inline void
  56. futex_wait (int *addr, int val)
  57. {
  58. long err = sys_futex0 (addr, gomp_futex_wait, val);
  59. if (__builtin_expect (err == ENOSYS, 0))
  60. {
  61. gomp_futex_wait &= ~FUTEX_PRIVATE_FLAG;
  62. gomp_futex_wake &= ~FUTEX_PRIVATE_FLAG;
  63. sys_futex0 (addr, gomp_futex_wait, val);
  64. }
  65. }
  66. static inline void
  67. futex_wake (int *addr, int count)
  68. {
  69. long err = sys_futex0 (addr, gomp_futex_wake, count);
  70. if (__builtin_expect (err == ENOSYS, 0))
  71. {
  72. gomp_futex_wait &= ~FUTEX_PRIVATE_FLAG;
  73. gomp_futex_wake &= ~FUTEX_PRIVATE_FLAG;
  74. sys_futex0 (addr, gomp_futex_wake, count);
  75. }
  76. }
  77. static inline void
  78. cpu_relax (void)
  79. {
  80. __asm volatile ("rd %%ccr, %%g0" : : : "memory");
  81. }