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smplock.h
Package: linux-2.4.20.tar.gz　[view]
Upload User: jlfgdled
Upload Date: 2013-04-10
Package Size: 33168k
Code Size: 1k
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Linux-Unix program

Development Platform:

Unix_Linux

smplock.h：Code Content
  1. /*
  2.  * <asm/smplock.h>
  3.  */
  4. #include <linux/interrupt.h>
  5. #include <linux/spinlock.h>
  6. #include <linux/sched.h>
  7. #include <asm/current.h>
  9. extern spinlock_cacheline_t kernel_flag_cacheline;  
  10. #define kernel_flag kernel_flag_cacheline.lock      
  12. #define kernel_locked() spin_is_locked(&kernel_flag)
  14. /*
  15.  * Release global kernel lock and global interrupt lock
  16.  */
  17. #define release_kernel_lock(task, cpu) 
  18. do { 
  19. if (task->lock_depth >= 0) 
  20. spin_unlock(&kernel_flag); 
  21. release_irqlock(cpu); 
  22. __sti(); 
  23. } while (0)
  25. /*
  26.  * Re-acquire the kernel lock
  27.  */
  28. #define reacquire_kernel_lock(task) 
  29. do { 
  30. if (task->lock_depth >= 0) 
  31. spin_lock(&kernel_flag); 
  32. } while (0)
  35. /*
  36.  * Getting the big kernel lock.
  37.  *
  38.  * This cannot happen asynchronously,
  39.  * so we only need to worry about other
  40.  * CPU's.
  41.  */
  42. extern __inline__ void lock_kernel(void)
  43. {
  44. #if 1
  45. if (!++current->lock_depth)
  46. spin_lock(&kernel_flag);
  47. #else
  48. __asm__ __volatile__(
  49. "incl %1nt"
  50. "jne 9f"
  51. spin_lock_string
  52. "n9:"
  53. :"=m" (__dummy_lock(&kernel_flag)),
  54.  "=m" (current->lock_depth));
  55. #endif
  56. }
  58. extern __inline__ void unlock_kernel(void)
  59. {
  60. if (current->lock_depth < 0)
  61. out_of_line_bug();
  62. #if 1
  63. if (--current->lock_depth < 0)
  64. spin_unlock(&kernel_flag);
  65. #else
  66. __asm__ __volatile__(
  67. "decl %1nt"
  68. "jns 9fnt"
  69. spin_unlock_string
  70. "n9:"
  71. :"=m" (__dummy_lock(&kernel_flag)),
  72.  "=m" (current->lock_depth));
  73. #endif
  74. }