pt-machine.h 2.7 KB

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  1. /* Machine-dependent pthreads configuration and inline functions.
  2. ARM version.
  3. Copyright (C) 1997, 1998, 2000, 2002 Free Software Foundation, Inc.
  4. This file is part of the GNU C Library.
  5. Contributed by Philip Blundell <philb@gnu.org>.
  6. The GNU C Library is free software; you can redistribute it and/or
  7. modify it under the terms of the GNU Lesser General Public License as
  8. published by the Free Software Foundation; either version 2.1 of the
  9. License, or (at your option) any later version.
  10. The GNU C Library is distributed in the hope that it will be useful,
  11. but WITHOUT ANY WARRANTY; without even the implied warranty of
  12. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13. Lesser General Public License for more details.
  14. You should have received a copy of the GNU Lesser General Public
  15. License along with the GNU C Library; see the file COPYING.LIB. If
  16. not, see <http://www.gnu.org/licenses/>. */
  17. #ifndef _PT_MACHINE_H
  18. #define _PT_MACHINE_H 1
  19. #include <sys/syscall.h>
  20. #include <unistd.h>
  21. #ifndef PT_EI
  22. # define PT_EI __extern_always_inline
  23. #endif
  24. #if defined(__thumb2__)
  25. PT_EI long int ldrex(int *spinlock)
  26. {
  27. long int ret;
  28. __asm__ __volatile__(
  29. "ldrex %0, [%1]\n"
  30. : "=r"(ret)
  31. : "r"(spinlock) : "memory");
  32. return ret;
  33. }
  34. PT_EI long int strex(int val, int *spinlock)
  35. {
  36. long int ret;
  37. __asm__ __volatile__(
  38. "strex %0, %1, [%2]\n"
  39. : "=r"(ret)
  40. : "r" (val), "r"(spinlock) : "memory");
  41. return ret;
  42. }
  43. /* Spinlock implementation; required. */
  44. PT_EI long int
  45. testandset (int *spinlock)
  46. {
  47. register unsigned int ret;
  48. do {
  49. ret = ldrex(spinlock);
  50. } while (strex(1, spinlock));
  51. return ret;
  52. }
  53. #elif defined(__thumb__)
  54. /* This will not work on ARM1 or ARM2 because SWP is lacking on those
  55. machines. Unfortunately we have no way to detect this at compile
  56. time; let's hope nobody tries to use one. */
  57. /* Spinlock implementation; required. */
  58. PT_EI long int testandset (int *spinlock);
  59. PT_EI long int testandset (int *spinlock)
  60. {
  61. register unsigned int ret;
  62. void *pc;
  63. __asm__ __volatile__(
  64. ".align 0\n"
  65. "\tbx pc\n"
  66. "\tnop\n"
  67. "\t.arm\n"
  68. "\tswp %0, %2, [%3]\n"
  69. "\torr %1, pc, #1\n"
  70. "\tbx %1\n"
  71. "\t.force_thumb"
  72. : "=r"(ret), "=r"(pc)
  73. : "0"(1), "r"(spinlock));
  74. return ret;
  75. }
  76. #else /* __thumb__ */
  77. PT_EI long int testandset (int *spinlock);
  78. PT_EI long int testandset (int *spinlock)
  79. {
  80. register unsigned int ret;
  81. __asm__ __volatile__("swp %0, %1, [%2]"
  82. : "=r"(ret)
  83. : "0"(1), "r"(spinlock));
  84. return ret;
  85. }
  86. #endif
  87. /* Get some notion of the current stack. Need not be exactly the top
  88. of the stack, just something somewhere in the current frame. */
  89. #define CURRENT_STACK_FRAME stack_pointer
  90. register char * stack_pointer __asm__ ("sp");
  91. #endif /* pt-machine.h */