drm/radeon/kms: add some new pci ids
[linux-2.6.git] / include / linux / freezer.h
1 /* Freezer declarations */
2
3 #ifndef FREEZER_H_INCLUDED
4 #define FREEZER_H_INCLUDED
5
6 #include <linux/sched.h>
7 #include <linux/wait.h>
8
9 #ifdef CONFIG_FREEZER
10 /*
11  * Check if a process has been frozen
12  */
13 static inline int frozen(struct task_struct *p)
14 {
15         return p->flags & PF_FROZEN;
16 }
17
18 /*
19  * Check if there is a request to freeze a process
20  */
21 static inline int freezing(struct task_struct *p)
22 {
23         return test_tsk_thread_flag(p, TIF_FREEZE);
24 }
25
26 /*
27  * Request that a process be frozen
28  */
29 static inline void set_freeze_flag(struct task_struct *p)
30 {
31         set_tsk_thread_flag(p, TIF_FREEZE);
32 }
33
34 /*
35  * Sometimes we may need to cancel the previous 'freeze' request
36  */
37 static inline void clear_freeze_flag(struct task_struct *p)
38 {
39         clear_tsk_thread_flag(p, TIF_FREEZE);
40 }
41
42 static inline bool should_send_signal(struct task_struct *p)
43 {
44         return !(p->flags & PF_FREEZER_NOSIG);
45 }
46
47 /* Takes and releases task alloc lock using task_lock() */
48 extern int thaw_process(struct task_struct *p);
49
50 extern void refrigerator(void);
51 extern int freeze_processes(void);
52 extern int freeze_kernel_threads(void);
53 extern void thaw_processes(void);
54
55 static inline int try_to_freeze(void)
56 {
57         if (freezing(current)) {
58                 refrigerator();
59                 return 1;
60         } else
61                 return 0;
62 }
63
64 extern bool freeze_task(struct task_struct *p, bool sig_only);
65 extern void cancel_freezing(struct task_struct *p);
66
67 #ifdef CONFIG_CGROUP_FREEZER
68 extern int cgroup_freezing_or_frozen(struct task_struct *task);
69 #else /* !CONFIG_CGROUP_FREEZER */
70 static inline int cgroup_freezing_or_frozen(struct task_struct *task)
71 {
72         return 0;
73 }
74 #endif /* !CONFIG_CGROUP_FREEZER */
75
76 /*
77  * The PF_FREEZER_SKIP flag should be set by a vfork parent right before it
78  * calls wait_for_completion(&vfork) and reset right after it returns from this
79  * function.  Next, the parent should call try_to_freeze() to freeze itself
80  * appropriately in case the child has exited before the freezing of tasks is
81  * complete.  However, we don't want kernel threads to be frozen in unexpected
82  * places, so we allow them to block freeze_processes() instead or to set
83  * PF_NOFREEZE if needed and PF_FREEZER_SKIP is only set for userland vfork
84  * parents.  Fortunately, in the ____call_usermodehelper() case the parent won't
85  * really block freeze_processes(), since ____call_usermodehelper() (the child)
86  * does a little before exec/exit and it can't be frozen before waking up the
87  * parent.
88  */
89
90 /*
91  * If the current task is a user space one, tell the freezer not to count it as
92  * freezable.
93  */
94 static inline void freezer_do_not_count(void)
95 {
96         if (current->mm)
97                 current->flags |= PF_FREEZER_SKIP;
98 }
99
100 /*
101  * If the current task is a user space one, tell the freezer to count it as
102  * freezable again and try to freeze it.
103  */
104 static inline void freezer_count(void)
105 {
106         if (current->mm) {
107                 current->flags &= ~PF_FREEZER_SKIP;
108                 try_to_freeze();
109         }
110 }
111
112 /*
113  * Check if the task should be counted as freezable by the freezer
114  */
115 static inline int freezer_should_skip(struct task_struct *p)
116 {
117         return !!(p->flags & PF_FREEZER_SKIP);
118 }
119
120 /*
121  * Tell the freezer that the current task should be frozen by it
122  */
123 static inline void set_freezable(void)
124 {
125         current->flags &= ~PF_NOFREEZE;
126 }
127
128 /*
129  * Tell the freezer that the current task should be frozen by it and that it
130  * should send a fake signal to the task to freeze it.
131  */
132 static inline void set_freezable_with_signal(void)
133 {
134         current->flags &= ~(PF_NOFREEZE | PF_FREEZER_NOSIG);
135 }
136
137 /*
138  * Freezer-friendly wrappers around wait_event_interruptible(),
139  * wait_event_killable() and wait_event_interruptible_timeout(), originally
140  * defined in <linux/wait.h>
141  */
142
143 #define wait_event_freezekillable(wq, condition)                        \
144 ({                                                                      \
145         int __retval;                                                   \
146         freezer_do_not_count();                                         \
147         __retval = wait_event_killable(wq, (condition));                \
148         freezer_count();                                                \
149         __retval;                                                       \
150 })
151
152 #define wait_event_freezable(wq, condition)                             \
153 ({                                                                      \
154         int __retval;                                                   \
155         do {                                                            \
156                 __retval = wait_event_interruptible(wq,                 \
157                                 (condition) || freezing(current));      \
158                 if (__retval && !freezing(current))                     \
159                         break;                                          \
160                 else if (!(condition))                                  \
161                         __retval = -ERESTARTSYS;                        \
162         } while (try_to_freeze());                                      \
163         __retval;                                                       \
164 })
165
166
167 #define wait_event_freezable_timeout(wq, condition, timeout)            \
168 ({                                                                      \
169         long __retval = timeout;                                        \
170         do {                                                            \
171                 __retval = wait_event_interruptible_timeout(wq,         \
172                                 (condition) || freezing(current),       \
173                                 __retval);                              \
174         } while (try_to_freeze());                                      \
175         __retval;                                                       \
176 })
177 #else /* !CONFIG_FREEZER */
178 static inline int frozen(struct task_struct *p) { return 0; }
179 static inline int freezing(struct task_struct *p) { return 0; }
180 static inline void set_freeze_flag(struct task_struct *p) {}
181 static inline void clear_freeze_flag(struct task_struct *p) {}
182 static inline int thaw_process(struct task_struct *p) { return 1; }
183
184 static inline void refrigerator(void) {}
185 static inline int freeze_processes(void) { return -ENOSYS; }
186 static inline int freeze_kernel_threads(void) { return -ENOSYS; }
187 static inline void thaw_processes(void) {}
188
189 static inline int try_to_freeze(void) { return 0; }
190
191 static inline void freezer_do_not_count(void) {}
192 static inline void freezer_count(void) {}
193 static inline int freezer_should_skip(struct task_struct *p) { return 0; }
194 static inline void set_freezable(void) {}
195 static inline void set_freezable_with_signal(void) {}
196
197 #define wait_event_freezable(wq, condition)                             \
198                 wait_event_interruptible(wq, condition)
199
200 #define wait_event_freezable_timeout(wq, condition, timeout)            \
201                 wait_event_interruptible_timeout(wq, condition, timeout)
202
203 #define wait_event_freezekillable(wq, condition)                \
204                 wait_event_killable(wq, condition)
205
206 #endif /* !CONFIG_FREEZER */
207
208 #endif  /* FREEZER_H_INCLUDED */