1/* SPDX-License-Identifier: GPL-2.0 */ 2/* Freezer declarations */ 3 4#ifndef FREEZER_H_INCLUDED 5#define FREEZER_H_INCLUDED 6 7#include <linux/debug_locks.h> 8#include <linux/sched.h> 9#include <linux/wait.h> 10#include <linux/atomic.h> 11#include <linux/jump_label.h> 12 13#ifdef CONFIG_FREEZER 14DECLARE_STATIC_KEY_FALSE(freezer_active); 15 16extern bool pm_freezing; /* PM freezing in effect */ 17extern bool pm_nosig_freezing; /* PM nosig freezing in effect */ 18 19/* 20 * Timeout for stopping processes 21 */ 22extern unsigned int freeze_timeout_msecs; 23 24/* 25 * Check if a process has been frozen 26 */ 27extern bool frozen(struct task_struct *p); 28 29extern bool freezing_slow_path(struct task_struct *p); 30 31/* 32 * Check if there is a request to freeze a process 33 */ 34static inline bool freezing(struct task_struct *p) 35{ 36 if (static_branch_unlikely(&freezer_active)) 37 return freezing_slow_path(p); 38 39 return false; 40} 41 42/* Takes and releases task alloc lock using task_lock() */ 43extern void __thaw_task(struct task_struct *t); 44 45extern bool __refrigerator(bool check_kthr_stop); 46extern int freeze_processes(void); 47extern int freeze_kernel_threads(void); 48extern void thaw_processes(void); 49extern void thaw_kernel_threads(void); 50 51static inline bool try_to_freeze(void) 52{ 53 might_sleep(); 54 if (likely(!freezing(current))) 55 return false; 56 if (!(current->flags & PF_NOFREEZE)) 57 debug_check_no_locks_held(); 58 return __refrigerator(false); 59} 60 61extern bool freeze_task(struct task_struct *p); 62extern bool set_freezable(void); 63 64#ifdef CONFIG_CGROUP_FREEZER 65extern bool cgroup_freezing(struct task_struct *task); 66#else /* !CONFIG_CGROUP_FREEZER */ 67static inline bool cgroup_freezing(struct task_struct *task) 68{ 69 return false; 70} 71#endif /* !CONFIG_CGROUP_FREEZER */ 72 73#else /* !CONFIG_FREEZER */ 74static inline bool frozen(struct task_struct *p) { return false; } 75static inline bool freezing(struct task_struct *p) { return false; } 76static inline void __thaw_task(struct task_struct *t) {} 77 78static inline bool __refrigerator(bool check_kthr_stop) { return false; } 79static inline int freeze_processes(void) { return -ENOSYS; } 80static inline int freeze_kernel_threads(void) { return -ENOSYS; } 81static inline void thaw_processes(void) {} 82static inline void thaw_kernel_threads(void) {} 83 84static inline bool try_to_freeze(void) { return false; } 85 86static inline void set_freezable(void) {} 87 88#endif /* !CONFIG_FREEZER */ 89 90#endif /* FREEZER_H_INCLUDED */ 91