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
  13 struct poll_table_struct;
  14
  15 /*
  16  * structures and helpers for f_op->poll implementations
  17  */
  18 typedef void (*poll_queue_proc)(struct file *, wait_queue_head_t *, struct poll_table_struct *);
  19
  20 typedef struct poll_table_struct {
  21         poll_queue_proc qproc;
  22 } poll_table;
  23
  24 static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p)
  25 {
  26         if (p && wait_address)
  27                 p->qproc(filp, wait_address, p);
  28 }
  29
  30 static inline void init_poll_funcptr(poll_table *pt, poll_queue_proc qproc)
  31 {
  32         pt->qproc = qproc;
  33 }
  34
  35 /*
  36  * Structures and helpers for sys_poll/sys_poll
  37  */
  38 struct poll_wqueues {
  39         poll_table pt;
  40         struct poll_table_page * table;
  41         int error;
  42 };
  43
  44 extern void poll_initwait(struct poll_wqueues *pwq);
  45 extern void poll_freewait(struct poll_wqueues *pwq);
  46
  47 /*
  48  * Scaleable version of the fd_set.
  49  */
  50
  51 typedef struct {
  52         unsigned long *in, *out, *ex;
  53         unsigned long *res_in, *res_out, *res_ex;
  54 } fd_set_bits;
  55
  56 /*
  57  * How many longwords for "nr" bits?
  58  */
  59 #define FDS_BITPERLONG  (8*sizeof(long))
  60 #define FDS_LONGS(nr)   (((nr)+FDS_BITPERLONG-1)/FDS_BITPERLONG)
  61 #define FDS_BYTES(nr)   (FDS_LONGS(nr)*sizeof(long))
  62
  63 /*
  64  * We do a VERIFY_WRITE here even though we are only reading this time:
  65  * we'll write to it eventually..
  66  *
  67  * Use "unsigned long" accesses to let user-mode fd_set's be long-aligned.
  68  */
  69 static inline
  70 int get_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)
  71 {
  72         nr = FDS_BYTES(nr);
  73         if (ufdset) {
  74                 int error;
  75                 error = verify_area(VERIFY_WRITE, ufdset, nr);
  76                 if (!error && __copy_from_user(fdset, ufdset, nr))
  77                         error = -EFAULT;
  78                 return error;
  79         }
  80         memset(fdset, 0, nr);
  81         return 0;
  82 }
  83
  84 static inline
  85 void set_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)
  86 {
  87         if (ufdset)
  88                 __copy_to_user(ufdset, fdset, FDS_BYTES(nr));
  89 }
  90
  91 static inline
  92 void zero_fd_set(unsigned long nr, unsigned long *fdset)
  93 {
  94         memset(fdset, 0, FDS_BYTES(nr));
  95 }
  96
  97 extern int do_select(int n, fd_set_bits *fds, long *timeout);
  98
  99 #endif /* KERNEL */
 100
 101 #endif /* _LINUX_POLL_H */