LXR linux-old/include/asm-parisc/ioctl.h

   1/* $Id: ioctl.h,v 1.2 1999/12/29 22:18:15 willy Exp $
   2 *
   3 * linux/ioctl.h for Linux by H.H. Bergman.
   4 */
   5
   6#ifndef _ASM_PARISC_IOCTL_H
   7#define _ASM_PARISC_IOCTL_H
   8
   9/* ioctl command encoding: 32 bits total, command in lower 16 bits,
  10 * size of the parameter structure in the lower 14 bits of the
  11 * upper 16 bits.
  12 * Encoding the size of the parameter structure in the ioctl request
  13 * is useful for catching programs compiled with old versions
  14 * and to avoid overwriting user space outside the user buffer area.
  15 * The highest 2 bits are reserved for indicating the ``access mode''.
  16 * NOTE: This limits the max parameter size to 16kB -1 !
  17 */
  18
  19#define _IOC_NRBITS     8
  20#define _IOC_TYPEBITS   8
  21#define _IOC_SIZEBITS   14
  22#define _IOC_DIRBITS    2
  23
  24#define _IOC_NRMASK     ((1 << _IOC_NRBITS)-1)
  25#define _IOC_TYPEMASK   ((1 << _IOC_TYPEBITS)-1)
  26#define _IOC_SIZEMASK   ((1 << _IOC_SIZEBITS)-1)
  27#define _IOC_DIRMASK    ((1 << _IOC_DIRBITS)-1)
  28
  29#define _IOC_NRSHIFT    0
  30#define _IOC_TYPESHIFT  (_IOC_NRSHIFT+_IOC_NRBITS)
  31#define _IOC_SIZESHIFT  (_IOC_TYPESHIFT+_IOC_TYPEBITS)
  32#define _IOC_DIRSHIFT   (_IOC_SIZESHIFT+_IOC_SIZEBITS)
  33
  34/*
  35 * Direction bits.
  36 */
  37#define _IOC_NONE       0U
  38#define _IOC_WRITE      2U
  39#define _IOC_READ       1U
  40
  41#define _IOC(dir,type,nr,size) \
  42        (((dir)  << _IOC_DIRSHIFT) | \
  43         ((type) << _IOC_TYPESHIFT) | \
  44         ((nr)   << _IOC_NRSHIFT) | \
  45         ((size) << _IOC_SIZESHIFT))
  46
  47/* used to create numbers */
  48#define _IO(type,nr)            _IOC(_IOC_NONE,(type),(nr),0)
  49#define _IOR(type,nr,size)      _IOC(_IOC_READ,(type),(nr),sizeof(size))
  50#define _IOW(type,nr,size)      _IOC(_IOC_WRITE,(type),(nr),sizeof(size))
  51#define _IOWR(type,nr,size)     _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size))
  52
  53/* used to decode ioctl numbers.. */
  54#define _IOC_DIR(nr)            (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK)
  55#define _IOC_TYPE(nr)           (((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK)
  56#define _IOC_NR(nr)             (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK)
  57#define _IOC_SIZE(nr)           (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK)
  58
  59/* ...and for the drivers/sound files... */
  60
  61#define IOC_IN          (_IOC_WRITE << _IOC_DIRSHIFT)
  62#define IOC_OUT         (_IOC_READ << _IOC_DIRSHIFT)
  63#define IOC_INOUT       ((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT)
  64#define IOCSIZE_MASK    (_IOC_SIZEMASK << _IOC_SIZESHIFT)
  65#define IOCSIZE_SHIFT   (_IOC_SIZESHIFT)
  66
  67#endif /* _ASM_PARISC_IOCTL_H */
  68