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 14 DECLARE_STATIC_KEY_FALSE(freezer_active); 15 16 extern bool pm_freezing; /* PM freezing in effect */ 17 extern bool pm_nosig_freezing; /* PM nosig freezing in effect */ 18 19 /* 20 * Timeout for stopping processes 21 */ 22 extern unsigned int freeze_timeout_msecs; 23 24 /* 25 * Check if a process has been frozen 26 */ 27 extern bool frozen(struct task_struct *p); 28 29 extern bool freezing_slow_path(struct task_struct *p); 30 31 /* 32 * Check if there is a request to freeze a process 33 */ freezing(struct task_struct * p)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() */ 43 extern void __thaw_task(struct task_struct *t); 44 45 extern bool __refrigerator(bool check_kthr_stop); 46 extern int freeze_processes(void); 47 extern int freeze_kernel_threads(void); 48 extern void thaw_processes(void); 49 extern void thaw_kernel_threads(void); 50 try_to_freeze(void)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 61 extern bool freeze_task(struct task_struct *p); 62 extern bool set_freezable(void); 63 64 #ifdef CONFIG_CGROUP_FREEZER 65 extern bool cgroup_freezing(struct task_struct *task); 66 #else /* !CONFIG_CGROUP_FREEZER */ cgroup_freezing(struct task_struct * task)67static inline bool cgroup_freezing(struct task_struct *task) 68 { 69 return false; 70 } 71 #endif /* !CONFIG_CGROUP_FREEZER */ 72 73 #else /* !CONFIG_FREEZER */ frozen(struct task_struct * p)74static inline bool frozen(struct task_struct *p) { return false; } freezing(struct task_struct * p)75static inline bool freezing(struct task_struct *p) { return false; } __thaw_task(struct task_struct * t)76static inline void __thaw_task(struct task_struct *t) {} 77 __refrigerator(bool check_kthr_stop)78static inline bool __refrigerator(bool check_kthr_stop) { return false; } freeze_processes(void)79static inline int freeze_processes(void) { return -ENOSYS; } freeze_kernel_threads(void)80static inline int freeze_kernel_threads(void) { return -ENOSYS; } thaw_processes(void)81static inline void thaw_processes(void) {} thaw_kernel_threads(void)82static inline void thaw_kernel_threads(void) {} 83 try_to_freeze(void)84static inline bool try_to_freeze(void) { return false; } 85 set_freezable(void)86static inline void set_freezable(void) {} 87 88 #endif /* !CONFIG_FREEZER */ 89 90 #endif /* FREEZER_H_INCLUDED */ 91