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/compiler.h>
   9 #include <linux/wait.h>
  10 #include <linux/string.h>
  11 #include <linux/mm.h>
  12 #include <asm/uaccess.h>
  13
  14 struct poll_table_struct;
  15
  16 /*
  17  * structures and helpers for f_op->poll implementations
  18  */
  19 typedef void (*poll_queue_proc)(struct file *, wait_queue_head_t *, struct poll_table_struct *);
  20
  21 typedef struct poll_table_struct {
  22         poll_queue_proc qproc;
  23 } poll_table;
  24
  25 static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p)
  26 {
  27         if (p && wait_address)
  28                 p->qproc(filp, wait_address, p);
  29 }
  30
  31 static inline void init_poll_funcptr(poll_table *pt, poll_queue_proc qproc)
  32 {
  33         pt->qproc = qproc;
  34 }
  35
  36 /*
  37  * Structures and helpers for sys_poll/sys_poll
  38  */
  39 struct poll_wqueues {
  40         poll_table pt;
  41         struct poll_table_page * table;
  42         int error;
  43 };
  44
  45 extern void poll_initwait(struct poll_wqueues *pwq);
  46 extern void poll_freewait(struct poll_wqueues *pwq);
  47
  48 /*
  49  * Scaleable version of the fd_set.
  50  */
  51
  52 typedef struct {
  53         unsigned long *in, *out, *ex;
  54         unsigned long *res_in, *res_out, *res_ex;
  55 } fd_set_bits;
  56
  57 /*
  58  * How many longwords for "nr" bits?
  59  */
  60 #define FDS_BITPERLONG  (8*sizeof(long))
  61 #define FDS_LONGS(nr)   (((nr)+FDS_BITPERLONG-1)/FDS_BITPERLONG)
  62 #define FDS_BYTES(nr)   (FDS_LONGS(nr)*sizeof(long))
  63
  64 /*
  65  * We do a VERIFY_WRITE here even though we are only reading this time:
  66  * we'll write to it eventually..
  67  *
  68  * Use "unsigned long" accesses to let user-mode fd_set's be long-aligned.
  69  */
  70 static inline
  71 int get_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)
  72 {
  73         nr = FDS_BYTES(nr);
  74         if (ufdset)
  75                 return copy_from_user(fdset, ufdset, nr) ? -EFAULT : 0;
  76
  77         memset(fdset, 0, nr);
  78         return 0;
  79 }
  80
  81 static inline unsigned long __must_check
  82 set_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)
  83 {
  84         if (ufdset)
  85                 return __copy_to_user(ufdset, fdset, FDS_BYTES(nr));
  86         return 0;
  87 }
  88
  89 static inline
  90 void zero_fd_set(unsigned long nr, unsigned long *fdset)
  91 {
  92         memset(fdset, 0, FDS_BYTES(nr));
  93 }
  94
  95 extern int do_select(int n, fd_set_bits *fds, long *timeout);
  96
  97 #endif /* KERNEL */
  98
  99 #endif /* _LINUX_POLL_H */