include/linux/preempt.h

   1 #ifndef __LINUX_PREEMPT_H
   2 #define __LINUX_PREEMPT_H
   3
   4 /*
   5  * include/linux/preempt.h - macros for accessing and manipulating
   6  * preempt_count (used for kernel preemption, interrupt count, etc.)
   7  */
   8
   9 #include <linux/config.h>
  10 #include <linux/linkage.h>
  11
  12 #define preempt_count() (current_thread_info()->preempt_count)
  13
  14 #define inc_preempt_count() \
  15 do { \
  16         preempt_count()++; \
  17 } while (0)
  18
  19 #define dec_preempt_count() \
  20 do { \
  21         preempt_count()--; \
  22 } while (0)
  23
  24 #ifdef CONFIG_PREEMPT
  25
  26 asmlinkage void preempt_schedule(void);
  27
  28 #define preempt_disable() \
  29 do { \
  30         inc_preempt_count(); \
  31         barrier(); \
  32 } while (0)
  33
  34 #define preempt_enable_no_resched() \
  35 do { \
  36         barrier(); \
  37         dec_preempt_count(); \
  38 } while (0)
  39
  40 #define preempt_check_resched() \
  41 do { \
  42         if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) \
  43                 preempt_schedule(); \
  44 } while (0)
  45
  46 #define preempt_enable() \
  47 do { \
  48         preempt_enable_no_resched(); \
  49         preempt_check_resched(); \
  50 } while (0)
  51
  52 #else
  53
  54 #define preempt_disable()               do { } while (0)
  55 #define preempt_enable_no_resched()     do { } while (0)
  56 #define preempt_enable()                do { } while (0)
  57 #define preempt_check_resched()         do { } while (0)
  58
  59 #endif
  60
  61 #endif /* __LINUX_PREEMPT_H */