include/asm-cris/ioctl.h

   1 /*
   2  * linux/ioctl.h for Linux by H.H. Bergman.
   3  *
   4  * This is the same as the i386 version.
   5  */
   6
   7 #ifndef _ASMCRIS_IOCTL_H
   8 #define _ASMCRIS_IOCTL_H
   9
  10 /* ioctl command encoding: 32 bits total, command in lower 16 bits,
  11  * size of the parameter structure in the lower 14 bits of the
  12  * upper 16 bits.
  13  * Encoding the size of the parameter structure in the ioctl request
  14  * is useful for catching programs compiled with old versions
  15  * and to avoid overwriting user space outside the user buffer area.
  16  * The highest 2 bits are reserved for indicating the ``access mode''.
  17  * NOTE: This limits the max parameter size to 16kB -1 !
  18  */
  19
  20 /*
  21  * The following is for compatibility across the various Linux
  22  * platforms.  The i386 ioctl numbering scheme doesn't really enforce
  23  * a type field.  De facto, however, the top 8 bits of the lower 16
  24  * bits are indeed used as a type field, so we might just as well make
  25  * this explicit here.  Please be sure to use the decoding macros
  26  * below from now on.
  27  */
  28 #define _IOC_NRBITS     8
  29 #define _IOC_TYPEBITS   8
  30 #define _IOC_SIZEBITS   14
  31 #define _IOC_DIRBITS    2
  32
  33 #define _IOC_NRMASK     ((1 << _IOC_NRBITS)-1)
  34 #define _IOC_TYPEMASK   ((1 << _IOC_TYPEBITS)-1)
  35 #define _IOC_SIZEMASK   ((1 << _IOC_SIZEBITS)-1)
  36 #define _IOC_DIRMASK    ((1 << _IOC_DIRBITS)-1)
  37
  38 #define _IOC_NRSHIFT    0
  39 #define _IOC_TYPESHIFT  (_IOC_NRSHIFT+_IOC_NRBITS)
  40 #define _IOC_SIZESHIFT  (_IOC_TYPESHIFT+_IOC_TYPEBITS)
  41 #define _IOC_DIRSHIFT   (_IOC_SIZESHIFT+_IOC_SIZEBITS)
  42
  43 /*
  44  * Direction bits.
  45  */
  46 #define _IOC_NONE       0U
  47 #define _IOC_WRITE      1U
  48 #define _IOC_READ       2U
  49
  50 #define _IOC(dir,type,nr,size) \
  51         (((dir)  << _IOC_DIRSHIFT) | \
  52          ((type) << _IOC_TYPESHIFT) | \
  53          ((nr)   << _IOC_NRSHIFT) | \
  54          ((size) << _IOC_SIZESHIFT))
  55
  56 /* provoke compile error for invalid uses of size argument */
  57 extern int __invalid_size_argument_for_IOC;
  58 #define _IOC_TYPECHECK(t) \
  59         ((sizeof(t) == sizeof(t[1]) && \
  60           sizeof(t) < (1 << _IOC_SIZEBITS)) ? \
  61           sizeof(t) : __invalid_size_argument_for_IOC)
  62
  63 /* used to create numbers */
  64 #define _IO(type,nr)            _IOC(_IOC_NONE,(type),(nr),0)
  65 #define _IOR(type,nr,size)      _IOC(_IOC_READ,(type),(nr),(_IOC_TYPECHECK(size)))
  66 #define _IOW(type,nr,size)      _IOC(_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size)))
  67 #define _IOWR(type,nr,size)     _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size)))
  68
  69 /* used to decode ioctl numbers.. */
  70 #define _IOC_DIR(nr)            (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK)
  71 #define _IOC_TYPE(nr)           (((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK)
  72 #define _IOC_NR(nr)             (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK)
  73 #define _IOC_SIZE(nr)           (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK)
  74
  75 /* ...and for the drivers/sound files... */
  76
  77 #define IOC_IN          (_IOC_WRITE << _IOC_DIRSHIFT)
  78 #define IOC_OUT         (_IOC_READ << _IOC_DIRSHIFT)
  79 #define IOC_INOUT       ((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT)
  80 #define IOCSIZE_MASK    (_IOC_SIZEMASK << _IOC_SIZESHIFT)
  81 #define IOCSIZE_SHIFT   (_IOC_SIZESHIFT)
  82
  83 #endif /* _ASMCRIS_IOCTL_H */