[thirdparty/kernel/stable.git] / include / uapi / asm-generic / ioctl.h

#ifndef _UAPI_ASM_GENERIC_IOCTL_H
#define _UAPI_ASM_GENERIC_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 generic 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

/*
 * Let any architecture override either of the following before
 * including this file.
 */

#ifndef _IOC_SIZEBITS
# define _IOC_SIZEBITS	14
#endif

#ifndef _IOC_DIRBITS
# define _IOC_DIRBITS	2
#endif

#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, which any architecture can choose to override
 * before including this file.
 *
 * NOTE: _IOC_WRITE means userland is writing and kernel is
 * reading. _IOC_READ means userland is reading and kernel is writing.
 */

#ifndef _IOC_NONE
# define _IOC_NONE	0U
#endif

#ifndef _IOC_WRITE
# define _IOC_WRITE	1U
#endif

#ifndef _IOC_READ
# define _IOC_READ	2U
#endif

#define _IOC(dir,type,nr,size) \
	(((dir)  << _IOC_DIRSHIFT) | \
	 ((type) << _IOC_TYPESHIFT) | \
	 ((nr)   << _IOC_NRSHIFT) | \
	 ((size) << _IOC_SIZESHIFT))

#ifndef __KERNEL__
#define _IOC_TYPECHECK(t) (sizeof(t))
#endif

/*
 * Used to create numbers.
 *
 * NOTE: _IOW means userland is writing and kernel is reading. _IOR
 * means userland is reading and kernel is writing.
 */
#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 /* _UAPI_ASM_GENERIC_IOCTL_H */
Commit	Line	Data
8a1ab315 DH	1	#ifndef _UAPI_ASM_GENERIC_IOCTL_H
	2	#define _UAPI_ASM_GENERIC_IOCTL_H
	3
	4	/* ioctl command encoding: 32 bits total, command in lower 16 bits,
	5	* size of the parameter structure in the lower 14 bits of the
	6	* upper 16 bits.
	7	* Encoding the size of the parameter structure in the ioctl request
	8	* is useful for catching programs compiled with old versions
	9	* and to avoid overwriting user space outside the user buffer area.
	10	* The highest 2 bits are reserved for indicating the ``access mode''.
	11	* NOTE: This limits the max parameter size to 16kB -1 !
	12	*/
	13
	14	/*
	15	* The following is for compatibility across the various Linux
	16	* platforms. The generic ioctl numbering scheme doesn't really enforce
	17	* a type field. De facto, however, the top 8 bits of the lower 16
	18	* bits are indeed used as a type field, so we might just as well make
	19	* this explicit here. Please be sure to use the decoding macros
	20	* below from now on.
	21	*/
	22	#define _IOC_NRBITS 8
	23	#define _IOC_TYPEBITS 8
	24
	25	/*
	26	* Let any architecture override either of the following before
	27	* including this file.
	28	*/
	29
	30	#ifndef _IOC_SIZEBITS
	31	# define _IOC_SIZEBITS 14
	32	#endif
	33
	34	#ifndef _IOC_DIRBITS
	35	# define _IOC_DIRBITS 2
	36	#endif
	37
	38	#define _IOC_NRMASK ((1 << _IOC_NRBITS)-1)
	39	#define _IOC_TYPEMASK ((1 << _IOC_TYPEBITS)-1)
	40	#define _IOC_SIZEMASK ((1 << _IOC_SIZEBITS)-1)
	41	#define _IOC_DIRMASK ((1 << _IOC_DIRBITS)-1)
	42
	43	#define _IOC_NRSHIFT 0
	44	#define _IOC_TYPESHIFT (_IOC_NRSHIFT+_IOC_NRBITS)
	45	#define _IOC_SIZESHIFT (_IOC_TYPESHIFT+_IOC_TYPEBITS)
	46	#define _IOC_DIRSHIFT (_IOC_SIZESHIFT+_IOC_SIZEBITS)
	47
	48	/*
	49	* Direction bits, which any architecture can choose to override
	50	* before including this file.
e067eba5 AA	51	*
	52	* NOTE: _IOC_WRITE means userland is writing and kernel is
	53	* reading. _IOC_READ means userland is reading and kernel is writing.
8a1ab315 DH	54	*/
	55
	56	#ifndef _IOC_NONE
	57	# define _IOC_NONE 0U
	58	#endif
	59
	60	#ifndef _IOC_WRITE
	61	# define _IOC_WRITE 1U
	62	#endif
	63
	64	#ifndef _IOC_READ
	65	# define _IOC_READ 2U
	66	#endif
	67
	68	#define _IOC(dir,type,nr,size) \
	69	(((dir) << _IOC_DIRSHIFT) \| \
	70	((type) << _IOC_TYPESHIFT) \| \
	71	((nr) << _IOC_NRSHIFT) \| \
	72	((size) << _IOC_SIZESHIFT))
	73
	74	#ifndef __KERNEL__
	75	#define _IOC_TYPECHECK(t) (sizeof(t))
	76	#endif
	77
e067eba5 AA	78	/*
	79	* Used to create numbers.
	80	*
	81	* NOTE: _IOW means userland is writing and kernel is reading. _IOR
	82	* means userland is reading and kernel is writing.
	83	*/
8a1ab315 DH	84	#define _IO(type,nr) _IOC(_IOC_NONE,(type),(nr),0)
	85	#define _IOR(type,nr,size) _IOC(_IOC_READ,(type),(nr),(_IOC_TYPECHECK(size)))
	86	#define _IOW(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size)))
	87	#define _IOWR(type,nr,size) _IOC(_IOC_READ\|_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size)))
	88	#define _IOR_BAD(type,nr,size) _IOC(_IOC_READ,(type),(nr),sizeof(size))
	89	#define _IOW_BAD(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),sizeof(size))
	90	#define _IOWR_BAD(type,nr,size) _IOC(_IOC_READ\|_IOC_WRITE,(type),(nr),sizeof(size))
	91
	92	/* used to decode ioctl numbers.. */
	93	#define _IOC_DIR(nr) (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK)
	94	#define _IOC_TYPE(nr) (((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK)
	95	#define _IOC_NR(nr) (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK)
	96	#define _IOC_SIZE(nr) (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK)
	97
	98	/* ...and for the drivers/sound files... */
	99
	100	#define IOC_IN (_IOC_WRITE << _IOC_DIRSHIFT)
	101	#define IOC_OUT (_IOC_READ << _IOC_DIRSHIFT)
	102	#define IOC_INOUT ((_IOC_WRITE\|_IOC_READ) << _IOC_DIRSHIFT)
	103	#define IOCSIZE_MASK (_IOC_SIZEMASK << _IOC_SIZESHIFT)
	104	#define IOCSIZE_SHIFT (_IOC_SIZESHIFT)
	105
	106	#endif /* _UAPI_ASM_GENERIC_IOCTL_H */