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/* Freezer declarations */
#include <linux/sched.h>
#ifdef CONFIG_PM
/*
* Check if a process has been frozen
*/
static inline int frozen(struct task_struct *p)
{
return p->flags & PF_FROZEN;
}
/*
* Check if there is a request to freeze a process
*/
static inline int freezing(struct task_struct *p)
{
return test_tsk_thread_flag(p, TIF_FREEZE);
}
/*
* Request that a process be frozen
*/
static inline void freeze(struct task_struct *p)
{
set_tsk_thread_flag(p, TIF_FREEZE);
}
/*
* Sometimes we may need to cancel the previous 'freeze' request
*/
static inline void do_not_freeze(struct task_struct *p)
{
clear_tsk_thread_flag(p, TIF_FREEZE);
}
/*
* Wake up a frozen process
*
* task_lock() is taken to prevent the race with refrigerator() which may
* occur if the freezing of tasks fails. Namely, without the lock, if the
* freezing of tasks failed, thaw_tasks() might have run before a task in
* refrigerator() could call frozen_process(), in which case the task would be
* frozen and no one would thaw it.
*/
static inline int thaw_process(struct task_struct *p)
{
task_lock(p);
if (frozen(p)) {
p->flags &= ~PF_FROZEN;
task_unlock(p);
wake_up_process(p);
return 1;
}
clear_tsk_thread_flag(p, TIF_FREEZE);
task_unlock(p);
return 0;
}
/*
* freezing is complete, mark process as frozen
*/
static inline void frozen_process(struct task_struct *p)
{
p->flags |= PF_FROZEN;
wmb();
clear_tsk_thread_flag(p, TIF_FREEZE);
}
extern void refrigerator(void);
extern int freeze_processes(void);
extern void thaw_processes(void);
static inline int try_to_freeze(void)
{
if (freezing(current)) {
refrigerator();
return 1;
} else
return 0;
}
extern void thaw_some_processes(int all);
#else
static inline int frozen(struct task_struct *p) { return 0; }
static inline int freezing(struct task_struct *p) { return 0; }
static inline void freeze(struct task_struct *p) { BUG(); }
static inline int thaw_process(struct task_struct *p) { return 1; }
static inline void frozen_process(struct task_struct *p) { BUG(); }
static inline void refrigerator(void) {}
static inline int freeze_processes(void) { BUG(); return 0; }
static inline void thaw_processes(void) {}
static inline int try_to_freeze(void) { return 0; }
#endif
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