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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#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>
Alexey Dobriyana99bbaf2009-10-04 16:11:37 +04009#include <linux/ktime.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#include <linux/wait.h>
11#include <linux/string.h>
Al Virof23f6e02006-10-20 15:17:02 -040012#include <linux/fs.h>
Dave Young9ff99332010-03-10 15:24:10 -080013#include <linux/sysctl.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <asm/uaccess.h>
15
Dave Young9ff99332010-03-10 15:24:10 -080016extern struct ctl_table epoll_table[]; /* for sysctl */
Andi Kleen70674f92006-03-28 01:56:33 -080017/* ~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
Alexey Dobriyandd23aae2007-09-11 15:23:55 -070026#define DEFAULT_POLLMASK (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)
27
Linus Torvalds1da177e2005-04-16 15:20:36 -070028struct poll_table_struct;
29
30/*
31 * structures and helpers for f_op->poll implementations
32 */
33typedef void (*poll_queue_proc)(struct file *, wait_queue_head_t *, struct poll_table_struct *);
34
35typedef struct poll_table_struct {
36 poll_queue_proc qproc;
Eric Dumazet4938d7e2009-06-16 15:33:36 -070037 unsigned long key;
Linus Torvalds1da177e2005-04-16 15:20:36 -070038} poll_table;
39
40static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p)
41{
42 if (p && wait_address)
43 p->qproc(filp, wait_address, p);
44}
45
46static inline void init_poll_funcptr(poll_table *pt, poll_queue_proc qproc)
47{
48 pt->qproc = qproc;
Eric Dumazet4938d7e2009-06-16 15:33:36 -070049 pt->key = ~0UL; /* all events enabled */
Linus Torvalds1da177e2005-04-16 15:20:36 -070050}
51
Andi Kleen70674f92006-03-28 01:56:33 -080052struct poll_table_entry {
Tejun Heo5f820f62009-01-06 14:40:59 -080053 struct file *filp;
Eric Dumazet4938d7e2009-06-16 15:33:36 -070054 unsigned long key;
Andi Kleen70674f92006-03-28 01:56:33 -080055 wait_queue_t wait;
Tejun Heo5f820f62009-01-06 14:40:59 -080056 wait_queue_head_t *wait_address;
Andi Kleen70674f92006-03-28 01:56:33 -080057};
58
Linus Torvalds1da177e2005-04-16 15:20:36 -070059/*
Namhyung Kimdac36dd2010-12-10 01:57:07 +090060 * Structures and helpers for select/poll syscall
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 */
62struct poll_wqueues {
63 poll_table pt;
Tejun Heo5f820f62009-01-06 14:40:59 -080064 struct poll_table_page *table;
65 struct task_struct *polling_task;
66 int triggered;
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 int error;
Andi Kleen70674f92006-03-28 01:56:33 -080068 int inline_index;
69 struct poll_table_entry inline_entries[N_INLINE_POLL_ENTRIES];
Linus Torvalds1da177e2005-04-16 15:20:36 -070070};
71
72extern void poll_initwait(struct poll_wqueues *pwq);
73extern void poll_freewait(struct poll_wqueues *pwq);
Tejun Heo5f820f62009-01-06 14:40:59 -080074extern int poll_schedule_timeout(struct poll_wqueues *pwq, int state,
75 ktime_t *expires, unsigned long slack);
Shawn Bohrer95aac7b2010-10-27 15:34:54 -070076extern long select_estimate_accuracy(struct timespec *tv);
77
Tejun Heo5f820f62009-01-06 14:40:59 -080078
79static inline int poll_schedule(struct poll_wqueues *pwq, int state)
80{
81 return poll_schedule_timeout(pwq, state, NULL, 0);
82}
Linus Torvalds1da177e2005-04-16 15:20:36 -070083
84/*
Lucas De Marchi25985ed2011-03-30 22:57:33 -030085 * Scalable version of the fd_set.
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 */
87
88typedef struct {
89 unsigned long *in, *out, *ex;
90 unsigned long *res_in, *res_out, *res_ex;
91} fd_set_bits;
92
93/*
94 * How many longwords for "nr" bits?
95 */
96#define FDS_BITPERLONG (8*sizeof(long))
97#define FDS_LONGS(nr) (((nr)+FDS_BITPERLONG-1)/FDS_BITPERLONG)
98#define FDS_BYTES(nr) (FDS_LONGS(nr)*sizeof(long))
99
100/*
101 * We do a VERIFY_WRITE here even though we are only reading this time:
102 * we'll write to it eventually..
103 *
104 * Use "unsigned long" accesses to let user-mode fd_set's be long-aligned.
105 */
106static inline
107int get_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)
108{
109 nr = FDS_BYTES(nr);
110 if (ufdset)
111 return copy_from_user(fdset, ufdset, nr) ? -EFAULT : 0;
112
113 memset(fdset, 0, nr);
114 return 0;
115}
116
117static inline unsigned long __must_check
118set_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)
119{
120 if (ufdset)
121 return __copy_to_user(ufdset, fdset, FDS_BYTES(nr));
122 return 0;
123}
124
125static inline
126void zero_fd_set(unsigned long nr, unsigned long *fdset)
127{
128 memset(fdset, 0, FDS_BYTES(nr));
129}
130
David Woodhouse9f729492006-01-18 17:44:05 -0800131#define MAX_INT64_SECONDS (((s64)(~((u64)0)>>1)/HZ)-1)
132
Arjan van de Ven8ff3e8e2008-08-31 08:26:40 -0700133extern int do_select(int n, fd_set_bits *fds, struct timespec *end_time);
David Woodhouse9f729492006-01-18 17:44:05 -0800134extern int do_sys_poll(struct pollfd __user * ufds, unsigned int nfds,
Arjan van de Ven8ff3e8e2008-08-31 08:26:40 -0700135 struct timespec *end_time);
Al Viroa2dcb442008-04-23 14:05:15 -0400136extern int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
Arjan van de Ven8ff3e8e2008-08-31 08:26:40 -0700137 fd_set __user *exp, struct timespec *end_time);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138
Thomas Gleixnerb773ad42008-08-31 08:16:57 -0700139extern int poll_select_set_timeout(struct timespec *to, long sec, long nsec);
140
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141#endif /* KERNEL */
142
143#endif /* _LINUX_POLL_H */