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1da177e4 LT |
1 | #ifndef _LINUX_POLL_H |
2 | #define _LINUX_POLL_H | |
3 | ||
4 | #include <asm/poll.h> | |
5 | ||
6 | #ifdef __KERNEL__ | |
7 | ||
8 | #include <linux/compiler.h> | |
a99bbaf5 | 9 | #include <linux/ktime.h> |
1da177e4 LT |
10 | #include <linux/wait.h> |
11 | #include <linux/string.h> | |
f23f6e08 | 12 | #include <linux/fs.h> |
9ff99339 | 13 | #include <linux/sysctl.h> |
1da177e4 LT |
14 | #include <asm/uaccess.h> |
15 | ||
9ff99339 | 16 | extern struct ctl_table epoll_table[]; /* for sysctl */ |
70674f95 AK |
17 | /* ~832 bytes of stack space used max in sys_select/sys_poll before allocating |
18 | additional memory. */ | |
19 | #define MAX_STACK_ALLOC 832 | |
20 | #define FRONTEND_STACK_ALLOC 256 | |
21 | #define SELECT_STACK_ALLOC FRONTEND_STACK_ALLOC | |
22 | #define POLL_STACK_ALLOC FRONTEND_STACK_ALLOC | |
23 | #define WQUEUES_STACK_ALLOC (MAX_STACK_ALLOC - FRONTEND_STACK_ALLOC) | |
24 | #define N_INLINE_POLL_ENTRIES (WQUEUES_STACK_ALLOC / sizeof(struct poll_table_entry)) | |
25 | ||
dd23aae4 AD |
26 | #define DEFAULT_POLLMASK (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM) |
27 | ||
1da177e4 LT |
28 | struct poll_table_struct; |
29 | ||
30 | /* | |
31 | * structures and helpers for f_op->poll implementations | |
32 | */ | |
33 | typedef void (*poll_queue_proc)(struct file *, wait_queue_head_t *, struct poll_table_struct *); | |
34 | ||
626cf236 HV |
35 | /* |
36 | * Do not touch the structure directly, use the access functions | |
37 | * poll_does_not_wait() and poll_requested_events() instead. | |
38 | */ | |
1da177e4 | 39 | typedef struct poll_table_struct { |
626cf236 HV |
40 | poll_queue_proc _qproc; |
41 | unsigned long _key; | |
1da177e4 LT |
42 | } poll_table; |
43 | ||
44 | static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p) | |
45 | { | |
626cf236 HV |
46 | if (p && p->_qproc && wait_address) |
47 | p->_qproc(filp, wait_address, p); | |
48 | } | |
49 | ||
50 | /* | |
51 | * Return true if it is guaranteed that poll will not wait. This is the case | |
52 | * if the poll() of another file descriptor in the set got an event, so there | |
53 | * is no need for waiting. | |
54 | */ | |
55 | static inline bool poll_does_not_wait(const poll_table *p) | |
56 | { | |
57 | return p == NULL || p->_qproc == NULL; | |
58 | } | |
59 | ||
60 | /* | |
61 | * Return the set of events that the application wants to poll for. | |
62 | * This is useful for drivers that need to know whether a DMA transfer has | |
63 | * to be started implicitly on poll(). You typically only want to do that | |
64 | * if the application is actually polling for POLLIN and/or POLLOUT. | |
65 | */ | |
66 | static inline unsigned long poll_requested_events(const poll_table *p) | |
67 | { | |
68 | return p ? p->_key : ~0UL; | |
1da177e4 LT |
69 | } |
70 | ||
71 | static inline void init_poll_funcptr(poll_table *pt, poll_queue_proc qproc) | |
72 | { | |
626cf236 HV |
73 | pt->_qproc = qproc; |
74 | pt->_key = ~0UL; /* all events enabled */ | |
1da177e4 LT |
75 | } |
76 | ||
70674f95 | 77 | struct poll_table_entry { |
5f820f64 | 78 | struct file *filp; |
4938d7e0 | 79 | unsigned long key; |
70674f95 | 80 | wait_queue_t wait; |
5f820f64 | 81 | wait_queue_head_t *wait_address; |
70674f95 AK |
82 | }; |
83 | ||
1da177e4 | 84 | /* |
dac36dd8 | 85 | * Structures and helpers for select/poll syscall |
1da177e4 LT |
86 | */ |
87 | struct poll_wqueues { | |
88 | poll_table pt; | |
5f820f64 TH |
89 | struct poll_table_page *table; |
90 | struct task_struct *polling_task; | |
91 | int triggered; | |
1da177e4 | 92 | int error; |
70674f95 AK |
93 | int inline_index; |
94 | struct poll_table_entry inline_entries[N_INLINE_POLL_ENTRIES]; | |
1da177e4 LT |
95 | }; |
96 | ||
97 | extern void poll_initwait(struct poll_wqueues *pwq); | |
98 | extern void poll_freewait(struct poll_wqueues *pwq); | |
5f820f64 TH |
99 | extern int poll_schedule_timeout(struct poll_wqueues *pwq, int state, |
100 | ktime_t *expires, unsigned long slack); | |
95aac7b1 SB |
101 | extern long select_estimate_accuracy(struct timespec *tv); |
102 | ||
5f820f64 TH |
103 | |
104 | static inline int poll_schedule(struct poll_wqueues *pwq, int state) | |
105 | { | |
106 | return poll_schedule_timeout(pwq, state, NULL, 0); | |
107 | } | |
1da177e4 LT |
108 | |
109 | /* | |
25985edc | 110 | * Scalable version of the fd_set. |
1da177e4 LT |
111 | */ |
112 | ||
113 | typedef struct { | |
114 | unsigned long *in, *out, *ex; | |
115 | unsigned long *res_in, *res_out, *res_ex; | |
116 | } fd_set_bits; | |
117 | ||
118 | /* | |
119 | * How many longwords for "nr" bits? | |
120 | */ | |
121 | #define FDS_BITPERLONG (8*sizeof(long)) | |
122 | #define FDS_LONGS(nr) (((nr)+FDS_BITPERLONG-1)/FDS_BITPERLONG) | |
123 | #define FDS_BYTES(nr) (FDS_LONGS(nr)*sizeof(long)) | |
124 | ||
125 | /* | |
126 | * We do a VERIFY_WRITE here even though we are only reading this time: | |
127 | * we'll write to it eventually.. | |
128 | * | |
129 | * Use "unsigned long" accesses to let user-mode fd_set's be long-aligned. | |
130 | */ | |
131 | static inline | |
132 | int get_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset) | |
133 | { | |
134 | nr = FDS_BYTES(nr); | |
135 | if (ufdset) | |
136 | return copy_from_user(fdset, ufdset, nr) ? -EFAULT : 0; | |
137 | ||
138 | memset(fdset, 0, nr); | |
139 | return 0; | |
140 | } | |
141 | ||
142 | static inline unsigned long __must_check | |
143 | set_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset) | |
144 | { | |
145 | if (ufdset) | |
146 | return __copy_to_user(ufdset, fdset, FDS_BYTES(nr)); | |
147 | return 0; | |
148 | } | |
149 | ||
150 | static inline | |
151 | void zero_fd_set(unsigned long nr, unsigned long *fdset) | |
152 | { | |
153 | memset(fdset, 0, FDS_BYTES(nr)); | |
154 | } | |
155 | ||
9f72949f DW |
156 | #define MAX_INT64_SECONDS (((s64)(~((u64)0)>>1)/HZ)-1) |
157 | ||
8ff3e8e8 | 158 | extern int do_select(int n, fd_set_bits *fds, struct timespec *end_time); |
9f72949f | 159 | extern int do_sys_poll(struct pollfd __user * ufds, unsigned int nfds, |
8ff3e8e8 | 160 | struct timespec *end_time); |
a2dcb44c | 161 | extern int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp, |
8ff3e8e8 | 162 | fd_set __user *exp, struct timespec *end_time); |
1da177e4 | 163 | |
b773ad40 TG |
164 | extern int poll_select_set_timeout(struct timespec *to, long sec, long nsec); |
165 | ||
1da177e4 LT |
166 | #endif /* KERNEL */ |
167 | ||
168 | #endif /* _LINUX_POLL_H */ |