/include/linux/smp_lock.h

https://bitbucket.org/thekraven/iscream_thunderc-2.6.35 · C++ Header · 65 lines · 43 code · 13 blank · 9 comment · 7 complexity · af723df5c24229eafb5250e4e7508881 MD5 · raw file 

    

  1. #ifndef __LINUX_SMPLOCK_H
    2. 

  2. #define __LINUX_SMPLOCK_H
    3. 

  3. 

  4. #ifdef CONFIG_LOCK_KERNEL
    5. 

  5. #include <linux/sched.h>
    6. 

  6. 

  7. #define kernel_locked()		(current->lock_depth >= 0)
    8. 

  8. 

  9. extern int __lockfunc __reacquire_kernel_lock(void);
    10. 

  10. extern void __lockfunc __release_kernel_lock(void);
    11. 

  11. 

  12. /*
    13. 

  13.  * Release/re-acquire global kernel lock for the scheduler
    14. 

  14.  */
    15. 

  15. #define release_kernel_lock(tsk) do { 		\
    16. 

  16. 	if (unlikely((tsk)->lock_depth >= 0))	\
    17. 

  17. 		__release_kernel_lock();	\
    18. 

  18. } while (0)
    19. 

  19. 

  20. static inline int reacquire_kernel_lock(struct task_struct *task)
    21. 

  21. {
    22. 

  22. 	if (unlikely(task->lock_depth >= 0))
    23. 

  23. 		return __reacquire_kernel_lock();
    24. 

  24. 	return 0;
    25. 

  25. }
    26. 

  26. 

  27. extern void __lockfunc
    28. 

  28. _lock_kernel(const char *func, const char *file, int line)
    29. 

  29. __acquires(kernel_lock);
    30. 

  30. 

  31. extern void __lockfunc
    32. 

  32. _unlock_kernel(const char *func, const char *file, int line)
    33. 

  33. __releases(kernel_lock);
    34. 

  34. 

  35. #define lock_kernel() do {					\
    36. 

  36. 	_lock_kernel(__func__, __FILE__, __LINE__);		\
    37. 

  37. } while (0)
    38. 

  38. 

  39. #define unlock_kernel()	do {					\
    40. 

  40. 	_unlock_kernel(__func__, __FILE__, __LINE__);		\
    41. 

  41. } while (0)
    42. 

  42. 

  43. /*
    44. 

  44.  * Various legacy drivers don't really need the BKL in a specific
    45. 

  45.  * function, but they *do* need to know that the BKL became available.
    46. 

  46.  * This function just avoids wrapping a bunch of lock/unlock pairs
    47. 

  47.  * around code which doesn't really need it.
    48. 

  48.  */
    49. 

  49. static inline void cycle_kernel_lock(void)
    50. 

  50. {
    51. 

  51. 	lock_kernel();
    52. 

  52. 	unlock_kernel();
    53. 

  53. }
    54. 

  54. 

  55. #else
    56. 

  56. 

  57. #define lock_kernel()
    58. 

  58. #define unlock_kernel()
    59. 

  59. #define release_kernel_lock(task)		do { } while(0)
    60. 

  60. #define cycle_kernel_lock()			do { } while(0)
    61. 

  61. #define reacquire_kernel_lock(task)		0
    62. 

  62. #define kernel_locked()				1
    63. 

  63. 

  64. #endif /* CONFIG_LOCK_KERNEL */
    65. 

  65. #endif /* __LINUX_SMPLOCK_H */
    66.