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 | */ |
34 | static 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 | |
51 | static 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(check_kthr_stop: 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 */ |
67 | static inline bool cgroup_freezing(struct task_struct *task) |
68 | { |
69 | return false; |
70 | } |
71 | #endif /* !CONFIG_CGROUP_FREEZER */ |
72 | |
73 | #else /* !CONFIG_FREEZER */ |
74 | static inline bool frozen(struct task_struct *p) { return false; } |
75 | static inline bool freezing(struct task_struct *p) { return false; } |
76 | static inline void __thaw_task(struct task_struct *t) {} |
77 | |
78 | static inline bool __refrigerator(bool check_kthr_stop) { return false; } |
79 | static inline int freeze_processes(void) { return -ENOSYS; } |
80 | static inline int freeze_kernel_threads(void) { return -ENOSYS; } |
81 | static inline void thaw_processes(void) {} |
82 | static inline void thaw_kernel_threads(void) {} |
83 | |
84 | static inline bool try_to_freeze(void) { return false; } |
85 | |
86 | static inline void set_freezable(void) {} |
87 | |
88 | #endif /* !CONFIG_FREEZER */ |
89 | |
90 | #endif /* FREEZER_H_INCLUDED */ |
91 | |