include/asm-parisc/ioctl.h

   1 /*
   2  *    Linux/PA-RISC Project (http://www.parisc-linux.org/)
   3  *    Copyright (C) 1999,2003 Matthew Wilcox < willy at debian . org >
   4  *    portions from "linux/ioctl.h for Linux" by H.H. Bergman.
   5  *
   6  *    This program is free software; you can redistribute it and/or modify
   7  *    it under the terms of the GNU General Public License as published by
   8  *    the Free Software Foundation; either version 2 of the License, or
   9  *    (at your option) any later version.
  10  *
  11  *    This program is distributed in the hope that it will be useful,
  12  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *    GNU General Public License for more details.
  15  *
  16  *    You should have received a copy of the GNU General Public License
  17  *    along with this program; if not, write to the Free Software
  18  *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21
  22 #ifndef _ASM_PARISC_IOCTL_H
  23 #define _ASM_PARISC_IOCTL_H
  24
  25 /* ioctl command encoding: 32 bits total, command in lower 16 bits,
  26  * size of the parameter structure in the lower 14 bits of the
  27  * upper 16 bits.
  28  * Encoding the size of the parameter structure in the ioctl request
  29  * is useful for catching programs compiled with old versions
  30  * and to avoid overwriting user space outside the user buffer area.
  31  * The highest 2 bits are reserved for indicating the ``access mode''.
  32  * NOTE: This limits the max parameter size to 16kB -1 !
  33  */
  34
  35 #define _IOC_NRBITS     8
  36 #define _IOC_TYPEBITS   8
  37 #define _IOC_SIZEBITS   14
  38 #define _IOC_DIRBITS    2
  39
  40 #define _IOC_NRMASK     ((1 << _IOC_NRBITS)-1)
  41 #define _IOC_TYPEMASK   ((1 << _IOC_TYPEBITS)-1)
  42 #define _IOC_SIZEMASK   ((1 << _IOC_SIZEBITS)-1)
  43 #define _IOC_DIRMASK    ((1 << _IOC_DIRBITS)-1)
  44
  45 #define _IOC_NRSHIFT    0
  46 #define _IOC_TYPESHIFT  (_IOC_NRSHIFT+_IOC_NRBITS)
  47 #define _IOC_SIZESHIFT  (_IOC_TYPESHIFT+_IOC_TYPEBITS)
  48 #define _IOC_DIRSHIFT   (_IOC_SIZESHIFT+_IOC_SIZEBITS)
  49
  50 /*
  51  * Direction bits.
  52  */
  53 #define _IOC_NONE       0U
  54 #define _IOC_WRITE      2U
  55 #define _IOC_READ       1U
  56
  57 #define _IOC(dir,type,nr,size) \
  58         (((dir)  << _IOC_DIRSHIFT) | \
  59          ((type) << _IOC_TYPESHIFT) | \
  60          ((nr)   << _IOC_NRSHIFT) | \
  61          ((size) << _IOC_SIZESHIFT))
  62
  63 /* provoke compile error for invalid uses of size argument */
  64 extern unsigned int __invalid_size_argument_for_IOC;
  65 #define _IOC_TYPECHECK(t) \
  66         ((sizeof(t) == sizeof(t[1]) && \
  67           sizeof(t) < (1 << _IOC_SIZEBITS)) ? \
  68           sizeof(t) : __invalid_size_argument_for_IOC)
  69
  70 /* used to create numbers */
  71 #define _IO(type,nr)            _IOC(_IOC_NONE,(type),(nr),0)
  72 #define _IOR(type,nr,size)      _IOC(_IOC_READ,(type),(nr),(_IOC_TYPECHECK(size)))
  73 #define _IOW(type,nr,size)      _IOC(_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size)))
  74 #define _IOWR(type,nr,size)     _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size)))
  75 #define _IOR_BAD(type,nr,size)  _IOC(_IOC_READ,(type),(nr),sizeof(size))
  76 #define _IOW_BAD(type,nr,size)  _IOC(_IOC_WRITE,(type),(nr),sizeof(size))
  77 #define _IOWR_BAD(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size))
  78
  79 /* used to decode ioctl numbers.. */
  80 #define _IOC_DIR(nr)            (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK)
  81 #define _IOC_TYPE(nr)           (((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK)
  82 #define _IOC_NR(nr)             (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK)
  83 #define _IOC_SIZE(nr)           (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK)
  84
  85 /* ...and for the drivers/sound files... */
  86
  87 #define IOC_IN          (_IOC_WRITE << _IOC_DIRSHIFT)
  88 #define IOC_OUT         (_IOC_READ << _IOC_DIRSHIFT)
  89 #define IOC_INOUT       ((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT)
  90 #define IOCSIZE_MASK    (_IOC_SIZEMASK << _IOC_SIZESHIFT)
  91 #define IOCSIZE_SHIFT   (_IOC_SIZESHIFT)
  92
  93 #endif /* _ASM_PARISC_IOCTL_H */