lunaix-os/includes/lunaix/kpreempt.h

   1 #ifndef __LUNAIX_KPREEMPT_H
   2 #define __LUNAIX_KPREEMPT_H
   3
   4 #include <sys/abi.h>
   5 #include <sys/cpu.h>
   6 #include <lunaix/process.h>
   7
   8 #define _preemptible \
   9         __attribute__((section(".kf.preempt"))) no_inline
  10
  11 #define ensure_preempt_caller()                                 \
  12     do {                                                        \
  13         extern int __kf_preempt_start[];                        \
  14         extern int __kf_preempt_end[];                          \
  15         ptr_t _retaddr = abi_get_retaddr();                     \
  16         assert_msg((ptr_t)__kf_preempt_start <= _retaddr        \
  17                     && _retaddr < (ptr_t)__kf_preempt_end,      \
  18                    "caller must be kernel preemptible");        \
  19     } while(0)
  20
  21 static inline void
  22 set_preemption()
  23 {
  24     cpu_enable_interrupt();
  25 }
  26
  27 static inline void
  28 no_preemption()
  29 {
  30     cpu_disable_interrupt();
  31 }
  32
  33 static inline void
  34 __schedule_away()
  35 {
  36     current_thread->stats.last_reentry = clock_systime();
  37
  38     cpu_trap_sched();
  39     set_preemption();
  40 }
  41
  42 /**
  43  * @brief preempt the current thread, and yield the remaining
  44  *        time slice to other threads.
  45  *
  46  *        The current thread is marked as if it is being
  47  *        preempted involuntarily by kernel.
  48  *
  49  */
  50 static inline void
  51 preempt_current()
  52 {
  53     no_preemption();
  54     thread_stats_update_kpreempt();
  55     __schedule_away();
  56 }
  57
  58 /**
  59  * @brief yield the remaining time slice to other threads.
  60  *
  61  *        The current thread is marked as if it is being
  62  *        preempted voluntarily by itself.
  63  *
  64  */
  65 static inline void
  66 yield_current()
  67 {
  68     no_preemption();
  69     __schedule_away();
  70 }
  71
  72 bool
  73 preempt_check_stalled(struct thread* th);
  74
  75 #endif /* __LUNAIX_KPREEMPT_H */