include/asm-frv/ioctl.h

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