Linux kernel mirror (for testing)
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linux
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>
9#include <linux/wait.h>
10#include <linux/string.h>
11#include <linux/fs.h>
12#include <linux/sched.h>
13#include <asm/uaccess.h>
14
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
24#define DEFAULT_POLLMASK (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)
25
26struct poll_table_struct;
27
28/*
29 * structures and helpers for f_op->poll implementations
30 */
31typedef void (*poll_queue_proc)(struct file *, wait_queue_head_t *, struct poll_table_struct *);
32
33typedef struct poll_table_struct {
34 poll_queue_proc qproc;
35 unsigned long key;
36} poll_table;
37
38static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p)
39{
40 if (p && wait_address)
41 p->qproc(filp, wait_address, p);
42}
43
44static inline void init_poll_funcptr(poll_table *pt, poll_queue_proc qproc)
45{
46 pt->qproc = qproc;
47 pt->key = ~0UL; /* all events enabled */
48}
49
50struct poll_table_entry {
51 struct file *filp;
52 unsigned long key;
53 wait_queue_t wait;
54 wait_queue_head_t *wait_address;
55};
56
57/*
58 * Structures and helpers for sys_poll/sys_poll
59 */
60struct poll_wqueues {
61 poll_table pt;
62 struct poll_table_page *table;
63 struct task_struct *polling_task;
64 int triggered;
65 int error;
66 int inline_index;
67 struct poll_table_entry inline_entries[N_INLINE_POLL_ENTRIES];
68};
69
70extern void poll_initwait(struct poll_wqueues *pwq);
71extern void poll_freewait(struct poll_wqueues *pwq);
72extern int poll_schedule_timeout(struct poll_wqueues *pwq, int state,
73 ktime_t *expires, unsigned long slack);
74
75static inline int poll_schedule(struct poll_wqueues *pwq, int state)
76{
77 return poll_schedule_timeout(pwq, state, NULL, 0);
78}
79
80/*
81 * Scaleable version of the fd_set.
82 */
83
84typedef struct {
85 unsigned long *in, *out, *ex;
86 unsigned long *res_in, *res_out, *res_ex;
87} fd_set_bits;
88
89/*
90 * How many longwords for "nr" bits?
91 */
92#define FDS_BITPERLONG (8*sizeof(long))
93#define FDS_LONGS(nr) (((nr)+FDS_BITPERLONG-1)/FDS_BITPERLONG)
94#define FDS_BYTES(nr) (FDS_LONGS(nr)*sizeof(long))
95
96/*
97 * We do a VERIFY_WRITE here even though we are only reading this time:
98 * we'll write to it eventually..
99 *
100 * Use "unsigned long" accesses to let user-mode fd_set's be long-aligned.
101 */
102static inline
103int get_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)
104{
105 nr = FDS_BYTES(nr);
106 if (ufdset)
107 return copy_from_user(fdset, ufdset, nr) ? -EFAULT : 0;
108
109 memset(fdset, 0, nr);
110 return 0;
111}
112
113static inline unsigned long __must_check
114set_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)
115{
116 if (ufdset)
117 return __copy_to_user(ufdset, fdset, FDS_BYTES(nr));
118 return 0;
119}
120
121static inline
122void zero_fd_set(unsigned long nr, unsigned long *fdset)
123{
124 memset(fdset, 0, FDS_BYTES(nr));
125}
126
127#define MAX_INT64_SECONDS (((s64)(~((u64)0)>>1)/HZ)-1)
128
129extern int do_select(int n, fd_set_bits *fds, struct timespec *end_time);
130extern int do_sys_poll(struct pollfd __user * ufds, unsigned int nfds,
131 struct timespec *end_time);
132extern int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
133 fd_set __user *exp, struct timespec *end_time);
134
135extern int poll_select_set_timeout(struct timespec *to, long sec, long nsec);
136
137#endif /* KERNEL */
138
139#endif /* _LINUX_POLL_H */