LXR linux-old/include/linux/poll.h

   1#ifndef _LINUX_POLL_H
   2#define _LINUX_POLL_H
   3
   4#include <asm/poll.h>
   5
   6#ifdef __KERNEL__
   7
   8#include <linux/wait.h>
   9#include <linux/string.h>
  10#include <linux/mm.h>
  11#include <asm/uaccess.h>
  12
  13struct poll_table_page;
  14
  15typedef struct poll_table_struct {
  16        int error;
  17        struct poll_table_page * table;
  18} poll_table;
  19
  20extern void __pollwait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p);
  21
  22static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p)
  23{
  24        if (p && wait_address)
  25                __pollwait(filp, wait_address, p);
  26}
  27
  28static inline void poll_initwait(poll_table* pt)
  29{
  30        pt->error = 0;
  31        pt->table = NULL;
  32}
  33extern void poll_freewait(poll_table* pt);
  34
  35
  36/*
  37 * Scaleable version of the fd_set.
  38 */
  39
  40typedef struct {
  41        unsigned long *in, *out, *ex;
  42        unsigned long *res_in, *res_out, *res_ex;
  43} fd_set_bits;
  44
  45/*
  46 * How many longwords for "nr" bits?
  47 */
  48#define FDS_BITPERLONG  (8*sizeof(long))
  49#define FDS_LONGS(nr)   (((nr)+FDS_BITPERLONG-1)/FDS_BITPERLONG)
  50#define FDS_BYTES(nr)   (FDS_LONGS(nr)*sizeof(long))
  51
  52/*
  53 * We do a VERIFY_WRITE here even though we are only reading this time:
  54 * we'll write to it eventually..
  55 *
  56 * Use "unsigned long" accesses to let user-mode fd_set's be long-aligned.
  57 */
  58static inline
  59int get_fd_set(unsigned long nr, void *ufdset, unsigned long *fdset)
  60{
  61        nr = FDS_BYTES(nr);
  62        if (ufdset) {
  63                int error;
  64                error = verify_area(VERIFY_WRITE, ufdset, nr);
  65                if (!error && __copy_from_user(fdset, ufdset, nr))
  66                        error = -EFAULT;
  67                return error;
  68        }
  69        memset(fdset, 0, nr);
  70        return 0;
  71}
  72
  73static inline
  74void set_fd_set(unsigned long nr, void *ufdset, unsigned long *fdset)
  75{
  76        if (ufdset)
  77                __copy_to_user(ufdset, fdset, FDS_BYTES(nr));
  78}
  79
  80static inline
  81void zero_fd_set(unsigned long nr, unsigned long *fdset)
  82{
  83        memset(fdset, 0, FDS_BYTES(nr));
  84}
  85
  86extern int do_select(int n, fd_set_bits *fds, long *timeout);
  87
  88#endif /* KERNEL */
  89
  90#endif /* _LINUX_POLL_H */
  91