[linux-2.6-block.git] / include / asm-i386 / ioctl.h

/* $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))

/* provoke compile error for invalid uses of size argument */
extern unsigned int __invalid_size_argument_for_IOC;
#define _IOC_TYPECHECK(t) \
	((sizeof(t) == sizeof(t[1]) && \
	  sizeof(t) < (1 << _IOC_SIZEBITS)) ? \
	  sizeof(t) : __invalid_size_argument_for_IOC)

/* used to create numbers */
#define _IO(type,nr)		_IOC(_IOC_NONE,(type),(nr),0)
#define _IOR(type,nr,size)	_IOC(_IOC_READ,(type),(nr),(_IOC_TYPECHECK(size)))
#define _IOW(type,nr,size)	_IOC(_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size)))
#define _IOWR(type,nr,size)	_IOC(_IOC_READ|_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size)))
#define _IOR_BAD(type,nr,size)	_IOC(_IOC_READ,(type),(nr),sizeof(size))
#define _IOW_BAD(type,nr,size)	_IOC(_IOC_WRITE,(type),(nr),sizeof(size))
#define _IOWR_BAD(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 */
Commit	Line	Data
1da177e4 LT	1	/* $Id: ioctl.h,v 1.5 1993/07/19 21:53:50 root Exp root $
	2	*
	3	* linux/ioctl.h for Linux by H.H. Bergman.
	4	*/
	5
	6	#ifndef _ASMI386_IOCTL_H
	7	#define _ASMI386_IOCTL_H
	8
	9	/* ioctl command encoding: 32 bits total, command in lower 16 bits,
	10	* size of the parameter structure in the lower 14 bits of the
	11	* upper 16 bits.
	12	* Encoding the size of the parameter structure in the ioctl request
	13	* is useful for catching programs compiled with old versions
	14	* and to avoid overwriting user space outside the user buffer area.
	15	* The highest 2 bits are reserved for indicating the ``access mode''.
	16	* NOTE: This limits the max parameter size to 16kB -1 !
	17	*/
	18
	19	/*
	20	* The following is for compatibility across the various Linux
	21	* platforms. The i386 ioctl numbering scheme doesn't really enforce
	22	* a type field. De facto, however, the top 8 bits of the lower 16
	23	* bits are indeed used as a type field, so we might just as well make
	24	* this explicit here. Please be sure to use the decoding macros
	25	* below from now on.
	26	*/
	27	#define _IOC_NRBITS 8
	28	#define _IOC_TYPEBITS 8
	29	#define _IOC_SIZEBITS 14
	30	#define _IOC_DIRBITS 2
	31
	32	#define _IOC_NRMASK ((1 << _IOC_NRBITS)-1)
	33	#define _IOC_TYPEMASK ((1 << _IOC_TYPEBITS)-1)
	34	#define _IOC_SIZEMASK ((1 << _IOC_SIZEBITS)-1)
	35	#define _IOC_DIRMASK ((1 << _IOC_DIRBITS)-1)
	36
	37	#define _IOC_NRSHIFT 0
	38	#define _IOC_TYPESHIFT (_IOC_NRSHIFT+_IOC_NRBITS)
	39	#define _IOC_SIZESHIFT (_IOC_TYPESHIFT+_IOC_TYPEBITS)
	40	#define _IOC_DIRSHIFT (_IOC_SIZESHIFT+_IOC_SIZEBITS)
	41
	42	/*
	43	* Direction bits.
	44	*/
	45	#define _IOC_NONE 0U
	46	#define _IOC_WRITE 1U
	47	#define _IOC_READ 2U
	48
	49	#define _IOC(dir,type,nr,size) \
	50	(((dir) << _IOC_DIRSHIFT) \| \
	51	((type) << _IOC_TYPESHIFT) \| \
	52	((nr) << _IOC_NRSHIFT) \| \
	53	((size) << _IOC_SIZESHIFT))
	54
	55	/* provoke compile error for invalid uses of size argument */
	56	extern unsigned int __invalid_size_argument_for_IOC;
	57	#define _IOC_TYPECHECK(t) \
	58	((sizeof(t) == sizeof(t[1]) && \
	59	sizeof(t) < (1 << _IOC_SIZEBITS)) ? \
	60	sizeof(t) : __invalid_size_argument_for_IOC)
	61
	62	/* used to create numbers */
	63	#define _IO(type,nr) _IOC(_IOC_NONE,(type),(nr),0)
	64	#define _IOR(type,nr,size) _IOC(_IOC_READ,(type),(nr),(_IOC_TYPECHECK(size)))
65	#define _IOW(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size)))
66	#define _IOWR(type,nr,size) _IOC(_IOC_READ\|_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size)))
67	#define _IOR_BAD(type,nr,size) _IOC(_IOC_READ,(type),(nr),sizeof(size))
68	#define _IOW_BAD(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),sizeof(size))
69	#define _IOWR_BAD(type,nr,size) _IOC(_IOC_READ\|_IOC_WRITE,(type),(nr),sizeof(size))
70
71	/* used to decode ioctl numbers.. */
72	#define _IOC_DIR(nr) (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK)
73	#define _IOC_TYPE(nr) (((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK)
74	#define _IOC_NR(nr) (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK)
75	#define _IOC_SIZE(nr) (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK)
76
77	/* ...and for the drivers/sound files... */
78
79	#define IOC_IN (_IOC_WRITE << _IOC_DIRSHIFT)
80	#define IOC_OUT (_IOC_READ << _IOC_DIRSHIFT)
81	#define IOC_INOUT ((_IOC_WRITE\|_IOC_READ) << _IOC_DIRSHIFT)
82	#define IOCSIZE_MASK (_IOC_SIZEMASK << _IOC_SIZESHIFT)
83	#define IOCSIZE_SHIFT (_IOC_SIZESHIFT)
84
85	#endif /* _ASMI386_IOCTL_H */