Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
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/ktime.h>
10#include <linux/wait.h>
11#include <linux/string.h>
12#include <linux/fs.h>
13#include <linux/sysctl.h>
14#include <asm/uaccess.h>
15
16extern struct ctl_table epoll_table[]; /* for sysctl */
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
26#define DEFAULT_POLLMASK (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)
27
28struct 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;
37 unsigned long key;
38} 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;
49 pt->key = ~0UL; /* all events enabled */
50}
51
52struct poll_table_entry {
53 struct file *filp;
54 unsigned long key;
55 wait_queue_t wait;
56 wait_queue_head_t *wait_address;
57};
58
59/*
60 * Structures and helpers for select/poll syscall
61 */
62struct poll_wqueues {
63 poll_table pt;
64 struct poll_table_page *table;
65 struct task_struct *polling_task;
66 int triggered;
67 int error;
68 int inline_index;
69 struct poll_table_entry inline_entries[N_INLINE_POLL_ENTRIES];
70};
71
72extern void poll_initwait(struct poll_wqueues *pwq);
73extern void poll_freewait(struct poll_wqueues *pwq);
74extern int poll_schedule_timeout(struct poll_wqueues *pwq, int state,
75 ktime_t *expires, unsigned long slack);
76extern long select_estimate_accuracy(struct timespec *tv);
77
78
79static inline int poll_schedule(struct poll_wqueues *pwq, int state)
80{
81 return poll_schedule_timeout(pwq, state, NULL, 0);
82}
83
84/*
85 * Scalable version of the fd_set.
86 */
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
131#define MAX_INT64_SECONDS (((s64)(~((u64)0)>>1)/HZ)-1)
132
133extern int do_select(int n, fd_set_bits *fds, struct timespec *end_time);
134extern int do_sys_poll(struct pollfd __user * ufds, unsigned int nfds,
135 struct timespec *end_time);
136extern int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
137 fd_set __user *exp, struct timespec *end_time);
138
139extern int poll_select_set_timeout(struct timespec *to, long sec, long nsec);
140
141#endif /* KERNEL */
142
143#endif /* _LINUX_POLL_H */