include/linux/freezer.h

   1 /* Freezer declarations */
   2
   3 #include <linux/sched.h>
   4
   5 #ifdef CONFIG_PM
   6 /*
   7  * Check if a process has been frozen
   8  */
   9 static inline int frozen(struct task_struct *p)
  10 {
  11         return p->flags & PF_FROZEN;
  12 }
  13
  14 /*
  15  * Check if there is a request to freeze a process
  16  */
  17 static inline int freezing(struct task_struct *p)
  18 {
  19         return test_tsk_thread_flag(p, TIF_FREEZE);
  20 }
  21
  22 /*
  23  * Request that a process be frozen
  24  */
  25 static inline void freeze(struct task_struct *p)
  26 {
  27         set_tsk_thread_flag(p, TIF_FREEZE);
  28 }
  29
  30 /*
  31  * Sometimes we may need to cancel the previous 'freeze' request
  32  */
  33 static inline void do_not_freeze(struct task_struct *p)
  34 {
  35         clear_tsk_thread_flag(p, TIF_FREEZE);
  36 }
  37
  38 /*
  39  * Wake up a frozen process
  40  */
  41 static inline int thaw_process(struct task_struct *p)
  42 {
  43         if (frozen(p)) {
  44                 p->flags &= ~PF_FROZEN;
  45                 wake_up_process(p);
  46                 return 1;
  47         }
  48         return 0;
  49 }
  50
  51 /*
  52  * freezing is complete, mark process as frozen
  53  */
  54 static inline void frozen_process(struct task_struct *p)
  55 {
  56         p->flags |= PF_FROZEN;
  57         wmb();
  58         clear_tsk_thread_flag(p, TIF_FREEZE);
  59 }
  60
  61 extern void refrigerator(void);
  62 extern int freeze_processes(void);
  63 extern void thaw_processes(void);
  64
  65 static inline int try_to_freeze(void)
  66 {
  67         if (freezing(current)) {
  68                 refrigerator();
  69                 return 1;
  70         } else
  71                 return 0;
  72 }
  73
  74 extern void thaw_some_processes(int all);
  75
  76 #else
  77 static inline int frozen(struct task_struct *p) { return 0; }
  78 static inline int freezing(struct task_struct *p) { return 0; }
  79 static inline void freeze(struct task_struct *p) { BUG(); }
  80 static inline int thaw_process(struct task_struct *p) { return 1; }
  81 static inline void frozen_process(struct task_struct *p) { BUG(); }
  82
  83 static inline void refrigerator(void) {}
  84 static inline int freeze_processes(void) { BUG(); return 0; }
  85 static inline void thaw_processes(void) {}
  86
  87 static inline int try_to_freeze(void) { return 0; }
  88
  89
  90 #endif