Line data Source code
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 <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 :
26 : struct poll_table_struct;
27 :
28 : /*
29 : * structures and helpers for f_op->poll implementations
30 : */
31 : typedef void (*poll_queue_proc)(struct file *, wait_queue_head_t *, struct poll_table_struct *);
32 1 :
33 : typedef struct poll_table_struct {
34 : poll_queue_proc qproc;
35 : unsigned long key;
36 1 : } poll_table;
37 :
38 : static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p)
39 : {
40 4 : if (p && wait_address)
41 1 : p->qproc(filp, wait_address, p);
42 1 : }
43 :
44 : static 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 :
50 : struct 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 : */
60 : struct 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 :
70 : extern void poll_initwait(struct poll_wqueues *pwq);
71 : extern void poll_freewait(struct poll_wqueues *pwq);
72 : extern int poll_schedule_timeout(struct poll_wqueues *pwq, int state,
73 : ktime_t *expires, unsigned long slack);
74 :
75 : static 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 :
84 : typedef 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 : */
102 : static inline
103 : int 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 :
113 : static inline unsigned long __must_check
114 : set_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 :
121 : static inline
122 : void 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 :
129 : extern int do_select(int n, fd_set_bits *fds, struct timespec *end_time);
130 : extern int do_sys_poll(struct pollfd __user * ufds, unsigned int nfds,
131 : struct timespec *end_time);
132 : extern int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
133 : fd_set __user *exp, struct timespec *end_time);
134 :
135 : extern int poll_select_set_timeout(struct timespec *to, long sec, long nsec);
136 :
137 : #endif /* KERNEL */
138 :
139 : #endif /* _LINUX_POLL_H */
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