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1da177e4 LT |
1 | #ifndef _LINUX_POLL_H |
2 | #define _LINUX_POLL_H | |
3 | ||
1da177e4 LT |
4 | |
5 | #include <linux/compiler.h> | |
a99bbaf5 | 6 | #include <linux/ktime.h> |
1da177e4 LT |
7 | #include <linux/wait.h> |
8 | #include <linux/string.h> | |
f23f6e08 | 9 | #include <linux/fs.h> |
9ff99339 | 10 | #include <linux/sysctl.h> |
7c0f6ba6 | 11 | #include <linux/uaccess.h> |
607ca46e | 12 | #include <uapi/linux/poll.h> |
1da177e4 | 13 | |
9ff99339 | 14 | extern struct ctl_table epoll_table[]; /* for sysctl */ |
70674f95 AK |
15 | /* ~832 bytes of stack space used max in sys_select/sys_poll before allocating |
16 | additional memory. */ | |
17 | #define MAX_STACK_ALLOC 832 | |
18 | #define FRONTEND_STACK_ALLOC 256 | |
19 | #define SELECT_STACK_ALLOC FRONTEND_STACK_ALLOC | |
20 | #define POLL_STACK_ALLOC FRONTEND_STACK_ALLOC | |
21 | #define WQUEUES_STACK_ALLOC (MAX_STACK_ALLOC - FRONTEND_STACK_ALLOC) | |
22 | #define N_INLINE_POLL_ENTRIES (WQUEUES_STACK_ALLOC / sizeof(struct poll_table_entry)) | |
23 | ||
dd23aae4 AD |
24 | #define DEFAULT_POLLMASK (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM) |
25 | ||
1da177e4 LT |
26 | struct poll_table_struct; |
27 | ||
28 | /* | |
29 | * structures and helpers for f_op->poll implementations | |
30 | */ | |
31 | typedef void (*poll_queue_proc)(struct file *, wait_queue_head_t *, struct poll_table_struct *); | |
32 | ||
626cf236 HV |
33 | /* |
34 | * Do not touch the structure directly, use the access functions | |
35 | * poll_does_not_wait() and poll_requested_events() instead. | |
36 | */ | |
1da177e4 | 37 | typedef struct poll_table_struct { |
626cf236 HV |
38 | poll_queue_proc _qproc; |
39 | unsigned long _key; | |
1da177e4 LT |
40 | } poll_table; |
41 | ||
42 | static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p) | |
43 | { | |
626cf236 HV |
44 | if (p && p->_qproc && wait_address) |
45 | p->_qproc(filp, wait_address, p); | |
46 | } | |
47 | ||
48 | /* | |
49 | * Return true if it is guaranteed that poll will not wait. This is the case | |
50 | * if the poll() of another file descriptor in the set got an event, so there | |
51 | * is no need for waiting. | |
52 | */ | |
53 | static inline bool poll_does_not_wait(const poll_table *p) | |
54 | { | |
55 | return p == NULL || p->_qproc == NULL; | |
56 | } | |
57 | ||
58 | /* | |
59 | * Return the set of events that the application wants to poll for. | |
60 | * This is useful for drivers that need to know whether a DMA transfer has | |
61 | * to be started implicitly on poll(). You typically only want to do that | |
62 | * if the application is actually polling for POLLIN and/or POLLOUT. | |
63 | */ | |
64 | static inline unsigned long poll_requested_events(const poll_table *p) | |
65 | { | |
66 | return p ? p->_key : ~0UL; | |
1da177e4 LT |
67 | } |
68 | ||
69 | static inline void init_poll_funcptr(poll_table *pt, poll_queue_proc qproc) | |
70 | { | |
626cf236 HV |
71 | pt->_qproc = qproc; |
72 | pt->_key = ~0UL; /* all events enabled */ | |
1da177e4 LT |
73 | } |
74 | ||
70674f95 | 75 | struct poll_table_entry { |
5f820f64 | 76 | struct file *filp; |
4938d7e0 | 77 | unsigned long key; |
70674f95 | 78 | wait_queue_t wait; |
5f820f64 | 79 | wait_queue_head_t *wait_address; |
70674f95 AK |
80 | }; |
81 | ||
1da177e4 | 82 | /* |
dac36dd8 | 83 | * Structures and helpers for select/poll syscall |
1da177e4 LT |
84 | */ |
85 | struct poll_wqueues { | |
86 | poll_table pt; | |
5f820f64 TH |
87 | struct poll_table_page *table; |
88 | struct task_struct *polling_task; | |
89 | int triggered; | |
1da177e4 | 90 | int error; |
70674f95 AK |
91 | int inline_index; |
92 | struct poll_table_entry inline_entries[N_INLINE_POLL_ENTRIES]; | |
1da177e4 LT |
93 | }; |
94 | ||
95 | extern void poll_initwait(struct poll_wqueues *pwq); | |
96 | extern void poll_freewait(struct poll_wqueues *pwq); | |
5f820f64 TH |
97 | extern int poll_schedule_timeout(struct poll_wqueues *pwq, int state, |
98 | ktime_t *expires, unsigned long slack); | |
766b9f92 | 99 | extern u64 select_estimate_accuracy(struct timespec64 *tv); |
95aac7b1 | 100 | |
9f72949f DW |
101 | #define MAX_INT64_SECONDS (((s64)(~((u64)0)>>1)/HZ)-1) |
102 | ||
a2dcb44c | 103 | extern int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp, |
766b9f92 | 104 | fd_set __user *exp, struct timespec64 *end_time); |
1da177e4 | 105 | |
766b9f92 DD |
106 | extern int poll_select_set_timeout(struct timespec64 *to, time64_t sec, |
107 | long nsec); | |
b773ad40 | 108 | |
1da177e4 | 109 | #endif /* _LINUX_POLL_H */ |