Linux 2.6.33-rc2
[pohmelfs.git] / include / linux / poll.h
blob6673743946f776d2bd7a61bacd68afdc6fd94f36
1 #ifndef _LINUX_POLL_H
2 #define _LINUX_POLL_H
4 #include <asm/poll.h>
6 #ifdef __KERNEL__
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>
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))
24 #define DEFAULT_POLLMASK (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)
26 struct poll_table_struct;
28 /*
29 * structures and helpers for f_op->poll implementations
31 typedef void (*poll_queue_proc)(struct file *, wait_queue_head_t *, struct poll_table_struct *);
33 typedef struct poll_table_struct {
34 poll_queue_proc qproc;
35 unsigned long key;
36 } poll_table;
38 static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p)
40 if (p && wait_address)
41 p->qproc(filp, wait_address, p);
44 static inline void init_poll_funcptr(poll_table *pt, poll_queue_proc qproc)
46 pt->qproc = qproc;
47 pt->key = ~0UL; /* all events enabled */
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;
58 * Structures and helpers for sys_poll/sys_poll
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];
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);
75 static inline int poll_schedule(struct poll_wqueues *pwq, int state)
77 return poll_schedule_timeout(pwq, state, NULL, 0);
81 * Scaleable version of the fd_set.
84 typedef struct {
85 unsigned long *in, *out, *ex;
86 unsigned long *res_in, *res_out, *res_ex;
87 } fd_set_bits;
90 * How many longwords for "nr" bits?
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))
97 * We do a VERIFY_WRITE here even though we are only reading this time:
98 * we'll write to it eventually..
100 * Use "unsigned long" accesses to let user-mode fd_set's be long-aligned.
102 static inline
103 int get_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)
105 nr = FDS_BYTES(nr);
106 if (ufdset)
107 return copy_from_user(fdset, ufdset, nr) ? -EFAULT : 0;
109 memset(fdset, 0, nr);
110 return 0;
113 static inline unsigned long __must_check
114 set_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)
116 if (ufdset)
117 return __copy_to_user(ufdset, fdset, FDS_BYTES(nr));
118 return 0;
121 static inline
122 void zero_fd_set(unsigned long nr, unsigned long *fdset)
124 memset(fdset, 0, FDS_BYTES(nr));
127 #define MAX_INT64_SECONDS (((s64)(~((u64)0)>>1)/HZ)-1)
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);
135 extern int poll_select_set_timeout(struct timespec *to, long sec, long nsec);
137 #endif /* KERNEL */
139 #endif /* _LINUX_POLL_H */