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 p->flags & PF_FREEZE;
  20 }
  21
  22 /*
  23  * Request that a process be frozen
  24  * FIXME: SMP problem. We may not modify other process' flags!
  25  */
  26 static inline void freeze(struct task_struct *p)
  27 {
  28         p->flags |= PF_FREEZE;
  29 }
  30
  31 /*
  32  * Sometimes we may need to cancel the previous 'freeze' request
  33  */
  34 static inline void do_not_freeze(struct task_struct *p)
  35 {
  36         p->flags &= ~PF_FREEZE;
  37 }
  38
  39 /*
  40  * Wake up a frozen process
  41  */
  42 static inline int thaw_process(struct task_struct *p)
  43 {
  44         if (frozen(p)) {
  45                 p->flags &= ~PF_FROZEN;
  46                 wake_up_process(p);
  47                 return 1;
  48         }
  49         return 0;
  50 }
  51
  52 /*
  53  * freezing is complete, mark process as frozen
  54  */
  55 static inline void frozen_process(struct task_struct *p)
  56 {
  57         p->flags = (p->flags & ~PF_FREEZE) | PF_FROZEN;
  58 }
  59
  60 extern void refrigerator(void);
  61 extern int freeze_processes(void);
  62 extern void thaw_processes(void);
  63
  64 static inline int try_to_freeze(void)
  65 {
  66         if (freezing(current)) {
  67                 refrigerator();
  68                 return 1;
  69         } else
  70                 return 0;
  71 }
  72
  73 extern void thaw_some_processes(int all);
  74
  75 #else
  76 static inline int frozen(struct task_struct *p) { return 0; }
  77 static inline int freezing(struct task_struct *p) { return 0; }
  78 static inline void freeze(struct task_struct *p) { BUG(); }
  79 static inline int thaw_process(struct task_struct *p) { return 1; }
  80 static inline void frozen_process(struct task_struct *p) { BUG(); }
  81
  82 static inline void refrigerator(void) {}
  83 static inline int freeze_processes(void) { BUG(); return 0; }
  84 static inline void thaw_processes(void) {}
  85
  86 static inline int try_to_freeze(void) { return 0; }
  87
  88
  89 #endif