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} poll_table;
36
37static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p)
38{
39 if (p && wait_address)
40 p->qproc(filp, wait_address, p);
41}
42
43static inline void init_poll_funcptr(poll_table *pt, poll_queue_proc qproc)
44{
45 pt->qproc = qproc;
46}
47
48struct poll_table_entry {
49 struct file * filp;
50 wait_queue_t wait;
51 wait_queue_head_t * wait_address;
52};
53
54/*
55 * Structures and helpers for sys_poll/sys_poll
56 */
57struct poll_wqueues {
58 poll_table pt;
59 struct poll_table_page * table;
60 int error;
61 int inline_index;
62 struct poll_table_entry inline_entries[N_INLINE_POLL_ENTRIES];
63};
64
65extern void poll_initwait(struct poll_wqueues *pwq);
66extern void poll_freewait(struct poll_wqueues *pwq);
67
68/*
69 * Scaleable version of the fd_set.
70 */
71
72typedef struct {
73 unsigned long *in, *out, *ex;
74 unsigned long *res_in, *res_out, *res_ex;
75} fd_set_bits;
76
77/*
78 * How many longwords for "nr" bits?
79 */
80#define FDS_BITPERLONG (8*sizeof(long))
81#define FDS_LONGS(nr) (((nr)+FDS_BITPERLONG-1)/FDS_BITPERLONG)
82#define FDS_BYTES(nr) (FDS_LONGS(nr)*sizeof(long))
83
84/*
85 * We do a VERIFY_WRITE here even though we are only reading this time:
86 * we'll write to it eventually..
87 *
88 * Use "unsigned long" accesses to let user-mode fd_set's be long-aligned.
89 */
90static inline
91int get_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)
92{
93 nr = FDS_BYTES(nr);
94 if (ufdset)
95 return copy_from_user(fdset, ufdset, nr) ? -EFAULT : 0;
96
97 memset(fdset, 0, nr);
98 return 0;
99}
100
101static inline unsigned long __must_check
102set_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)
103{
104 if (ufdset)
105 return __copy_to_user(ufdset, fdset, FDS_BYTES(nr));
106 return 0;
107}
108
109static inline
110void zero_fd_set(unsigned long nr, unsigned long *fdset)
111{
112 memset(fdset, 0, FDS_BYTES(nr));
113}
114
115#define MAX_INT64_SECONDS (((s64)(~((u64)0)>>1)/HZ)-1)
116
117extern int do_select(int n, fd_set_bits *fds, struct timespec *end_time);
118extern int do_sys_poll(struct pollfd __user * ufds, unsigned int nfds,
119 struct timespec *end_time);
120extern int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
121 fd_set __user *exp, struct timespec *end_time);
122
123extern int poll_select_set_timeout(struct timespec *to, long sec, long nsec);
124
125#endif /* KERNEL */
126
127#endif /* _LINUX_POLL_H */