/* $Id: ioctl.h,v 1.5 1993/07/19 21:53:50 root Exp root $ * * linux/ioctl.h for Linux by H.H. Bergman. */#ifndef _ASMI386_IOCTL_H#define _ASMI386_IOCTL_H/* ioctl command encoding: 32 bits total, command in lower 16 bits, * size of the parameter structure in the lower 14 bits of the * upper 16 bits. * Encoding the size of the parameter structure in the ioctl request * is useful for catching programs compiled with old versions * and to avoid overwriting user space outside the user buffer area. * The highest 2 bits are reserved for indicating the ``access mode''. * NOTE: This limits the max parameter size to 16kB -1 ! *//* * The following is for compatibility across the various Linux * platforms.  The i386 ioctl numbering scheme doesn't really enforce * a type field.  De facto, however, the top 8 bits of the lower 16 * bits are indeed used as a type field, so we might just as well make * this explicit here.  Please be sure to use the decoding macros * below from now on. */#define _IOC_NRBITS	8#define _IOC_TYPEBITS	8#define _IOC_SIZEBITS	14#define _IOC_DIRBITS	2#define _IOC_NRMASK	((1 << _IOC_NRBITS)-1)#define _IOC_TYPEMASK	((1 << _IOC_TYPEBITS)-1)#define _IOC_SIZEMASK	((1 << _IOC_SIZEBITS)-1)#define _IOC_DIRMASK	((1 << _IOC_DIRBITS)-1)#define _IOC_NRSHIFT	0#define _IOC_TYPESHIFT	(_IOC_NRSHIFT+_IOC_NRBITS)#define _IOC_SIZESHIFT	(_IOC_TYPESHIFT+_IOC_TYPEBITS)#define _IOC_DIRSHIFT	(_IOC_SIZESHIFT+_IOC_SIZEBITS)/* * Direction bits. */#define _IOC_NONE	0U#define _IOC_WRITE	1U#define _IOC_READ	2U#define _IOC(dir,type,nr,size) \	(((dir)  << _IOC_DIRSHIFT) | \	 ((type) << _IOC_TYPESHIFT) | \	 ((nr)   << _IOC_NRSHIFT) | \	 ((size) << _IOC_SIZESHIFT))/* used to create numbers */#define _IO(type,nr)		_IOC(_IOC_NONE,(type),(nr),0)#define _IOR(type,nr,size)	_IOC(_IOC_READ,(type),(nr),sizeof(size))#define _IOW(type,nr,size)	_IOC(_IOC_WRITE,(type),(nr),sizeof(size))#define _IOWR(type,nr,size)	_IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size))/* used to decode ioctl numbers.. */#define _IOC_DIR(nr)		(((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK)#define _IOC_TYPE(nr)		(((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK)#define _IOC_NR(nr)		(((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK)#define _IOC_SIZE(nr)		(((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK)/* ...and for the drivers/sound files... */#define IOC_IN		(_IOC_WRITE << _IOC_DIRSHIFT)#define IOC_OUT		(_IOC_READ << _IOC_DIRSHIFT)#define IOC_INOUT	((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT)#define IOCSIZE_MASK	(_IOC_SIZEMASK << _IOC_SIZESHIFT)#define IOCSIZE_SHIFT	(_IOC_SIZESHIFT)#endif /* _ASMI386_IOCTL_H */