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 #include <sys/cdefs.h>
  11 #include <sys/types.h>
  12
  13 /* Ioctls have the command encoded in the low-order word, and the size
  14  * of the parameter in the high-order word. The 3 high bits of the high-
  15  * order word are used to encode the in/out/void status of the parameter.
  16  */
  17 #define _IOCPARM_MASK           0x0FFF
  18 #define _IOCPARM_MASK_BIG       0x0FFFFF
  19 #define _IOC_VOID               0x20000000
  20 #define _IOCTYPE_MASK           0xFFFF
  21 #define _IOC_IN                 0x40000000
  22 #define _IOC_OUT                0x80000000
  23 #define _IOC_INOUT              (_IOC_IN | _IOC_OUT)
  24
  25 /* Flag indicating ioctl format with only one type field, and more bits
  26  * for the size field (using mask _IOCPARM_MASK_BIG).
  27  */
  28 #define _IOC_BIG                0x10000000
  29
  30 #define _IO(x,y)        ((x << 8) | y | _IOC_VOID)
  31 #define _IOR(x,y,t)     ((x << 8) | y | ((sizeof(t) & _IOCPARM_MASK) << 16) |\
  32                                 _IOC_OUT)
  33 #define _IOW(x,y,t)     ((x << 8) | y | ((sizeof(t) & _IOCPARM_MASK) << 16) |\
  34                                 _IOC_IN)
  35 #define _IORW(x,y,t)    ((x << 8) | y | ((sizeof(t) & _IOCPARM_MASK) << 16) |\
  36                                 _IOC_INOUT)
  37
  38 #define _IOW_BIG(y,t)  (y | ((sizeof(t) & _IOCPARM_MASK_BIG) << 8) \
  39         | _IOC_IN | _IOC_BIG)
  40 #define _IOR_BIG(y,t)  (y | ((sizeof(t) & _IOCPARM_MASK_BIG) << 8) \
  41         | _IOC_OUT | _IOC_BIG)
  42 #define _IORW_BIG(y,t) (y | ((sizeof(t) & _IOCPARM_MASK_BIG) << 8) \
  43         | _IOC_INOUT | _IOC_BIG)
  44
  45 /* Decode an ioctl call. */
  46 #define _MINIX_IOCTL_SIZE(i)            (((i) >> 16) & _IOCPARM_MASK)
  47 #define _MINIX_IOCTL_IOR(i)             ((i) & _IOC_OUT)
  48 #define _MINIX_IOCTL_IORW(i)            ((i) & _IOC_INOUT)
  49 #define _MINIX_IOCTL_IOW(i)             ((i) & _IOC_IN)
  50
  51 /* Recognize and decode size of a 'big' ioctl call. */
  52 #define _MINIX_IOCTL_BIG(i)             ((i) & _IOC_BIG)
  53 #define _MINIX_IOCTL_SIZE_BIG(i)        (((i) >> 8) & _IOCPARM_MASK_BIG)
  54
  55 __BEGIN_DECLS
  56 int ioctl(int _fd, int _request, void *_data);
  57 __END_DECLS
  58
  59 #endif /* _M_IOCTL_H */