include/minix/ioctl.h

   1 /*      minix/ioctl.h - Ioctl helper definitions.       Author: Kees J. Bot
   2  *                                                              23 Nov 2002
   3  *
   4  * This file is included by every header file that defines ioctl codes.
   5  */
   6
   7 #ifndef _M_IOCTL_H
   8 #define _M_IOCTL_H
   9
  10 #ifndef _TYPES_H
  11 #include <sys/types.h>
  12 #endif
  13
  14 #if _EM_WSIZE >= 4
  15 /* Ioctls have the command encoded in the low-order word, and the size
  16  * of the parameter in the high-order word. The 3 high bits of the high-
  17  * order word are used to encode the in/out/void status of the parameter.
  18  */
  19 #define _IOCPARM_MASK           0x0FFF
  20 #define _IOCPARM_MASK_BIG       0x0FFFFF
  21 #define _IOC_VOID               0x20000000
  22 #define _IOCTYPE_MASK           0xFFFF
  23 #define _IOC_IN                 0x40000000
  24 #define _IOC_OUT                0x80000000
  25 #define _IOC_INOUT              (_IOC_IN | _IOC_OUT)
  26
  27 /* Flag indicating ioctl format with only one type field, and more bits
  28  * for the size field (using mask _IOCPARM_MASK_BIG).
  29  */
  30 #define _IOC_BIG                0x10000000
  31
  32 #define _IO(x,y)        ((x << 8) | y | _IOC_VOID)
  33 #define _IOR(x,y,t)     ((x << 8) | y | ((sizeof(t) & _IOCPARM_MASK) << 16) |\
  34                                 _IOC_OUT)
  35 #define _IOW(x,y,t)     ((x << 8) | y | ((sizeof(t) & _IOCPARM_MASK) << 16) |\
  36                                 _IOC_IN)
  37 #define _IORW(x,y,t)    ((x << 8) | y | ((sizeof(t) & _IOCPARM_MASK) << 16) |\
  38                                 _IOC_INOUT)
  39
  40 #define _IOW_BIG(y,t)  (y | ((sizeof(t) & _IOCPARM_MASK_BIG) << 8) \
  41         | _IOC_IN | _IOC_BIG)
  42 #define _IOR_BIG(y,t)  (y | ((sizeof(t) & _IOCPARM_MASK_BIG) << 8) \
  43         | _IOC_OUT | _IOC_BIG)
  44 #define _IORW_BIG(y,t) (y | ((sizeof(t) & _IOCPARM_MASK_BIG) << 8) \
  45         | _IOC_INOUT | _IOC_BIG)
  46
  47 /* Decode an ioctl call. */
  48 #define _MINIX_IOCTL_SIZE(i)            (((i) >> 16) & _IOCPARM_MASK)
  49 #define _MINIX_IOCTL_IOR(i)             ((i) & _IOC_OUT)
  50 #define _MINIX_IOCTL_IORW(i)            ((i) & _IOC_INOUT)
  51 #define _MINIX_IOCTL_IOW(i)             ((i) & _IOC_IN)
  52
  53 /* Recognize and decode size of a 'big' ioctl call. */
  54 #define _MINIX_IOCTL_BIG(i)             ((i) & _IOC_BIG)
  55 #define _MINIX_IOCTL_SIZE_BIG(i)        (((i) >> 8) & _IOCPARM_MASK_BIG)
  56
  57 #else
  58 /* No fancy encoding on a 16-bit machine. */
  59
  60 #define _IO(x,y)        ((x << 8) | y)
  61 #define _IOR(x,y,t)     _IO(x,y)
  62 #define _IOW(x,y,t)     _IO(x,y)
  63 #define _IORW(x,y,t)    _IO(x,y)
  64 #endif
  65
  66 int ioctl(int _fd, int _request, void *_data);
  67
  68 #endif /* _M_IOCTL_H */