xref: /OK3568_Linux_fs/kernel/arch/alpha/include/uapi/asm/ioctl.h (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2*4882a593Smuzhiyun #ifndef _ALPHA_IOCTL_H
3*4882a593Smuzhiyun #define _ALPHA_IOCTL_H
4*4882a593Smuzhiyun 
5*4882a593Smuzhiyun /*
6*4882a593Smuzhiyun  * The original linux ioctl numbering scheme was just a general
7*4882a593Smuzhiyun  * "anything goes" setup, where more or less random numbers were
8*4882a593Smuzhiyun  * assigned.  Sorry, I was clueless when I started out on this.
9*4882a593Smuzhiyun  *
10*4882a593Smuzhiyun  * On the alpha, we'll try to clean it up a bit, using a more sane
11*4882a593Smuzhiyun  * ioctl numbering, and also trying to be compatible with OSF/1 in
12*4882a593Smuzhiyun  * the process. I'd like to clean it up for the i386 as well, but
13*4882a593Smuzhiyun  * it's so painful recognizing both the new and the old numbers..
14*4882a593Smuzhiyun  */
15*4882a593Smuzhiyun 
16*4882a593Smuzhiyun #define _IOC_NRBITS	8
17*4882a593Smuzhiyun #define _IOC_TYPEBITS	8
18*4882a593Smuzhiyun #define _IOC_SIZEBITS	13
19*4882a593Smuzhiyun #define _IOC_DIRBITS	3
20*4882a593Smuzhiyun 
21*4882a593Smuzhiyun #define _IOC_NRMASK	((1 << _IOC_NRBITS)-1)
22*4882a593Smuzhiyun #define _IOC_TYPEMASK	((1 << _IOC_TYPEBITS)-1)
23*4882a593Smuzhiyun #define _IOC_SIZEMASK	((1 << _IOC_SIZEBITS)-1)
24*4882a593Smuzhiyun #define _IOC_DIRMASK	((1 << _IOC_DIRBITS)-1)
25*4882a593Smuzhiyun 
26*4882a593Smuzhiyun #define _IOC_NRSHIFT	0
27*4882a593Smuzhiyun #define _IOC_TYPESHIFT	(_IOC_NRSHIFT+_IOC_NRBITS)
28*4882a593Smuzhiyun #define _IOC_SIZESHIFT	(_IOC_TYPESHIFT+_IOC_TYPEBITS)
29*4882a593Smuzhiyun #define _IOC_DIRSHIFT	(_IOC_SIZESHIFT+_IOC_SIZEBITS)
30*4882a593Smuzhiyun 
31*4882a593Smuzhiyun /*
32*4882a593Smuzhiyun  * Direction bits _IOC_NONE could be 0, but OSF/1 gives it a bit.
33*4882a593Smuzhiyun  * And this turns out useful to catch old ioctl numbers in header
34*4882a593Smuzhiyun  * files for us.
35*4882a593Smuzhiyun  */
36*4882a593Smuzhiyun #define _IOC_NONE	1U
37*4882a593Smuzhiyun #define _IOC_READ	2U
38*4882a593Smuzhiyun #define _IOC_WRITE	4U
39*4882a593Smuzhiyun 
40*4882a593Smuzhiyun #define _IOC(dir,type,nr,size)			\
41*4882a593Smuzhiyun 	((unsigned int)				\
42*4882a593Smuzhiyun 	 (((dir)  << _IOC_DIRSHIFT) |		\
43*4882a593Smuzhiyun 	  ((type) << _IOC_TYPESHIFT) |		\
44*4882a593Smuzhiyun 	  ((nr)   << _IOC_NRSHIFT) |		\
45*4882a593Smuzhiyun 	  ((size) << _IOC_SIZESHIFT)))
46*4882a593Smuzhiyun 
47*4882a593Smuzhiyun /* used to create numbers */
48*4882a593Smuzhiyun #define _IO(type,nr)		_IOC(_IOC_NONE,(type),(nr),0)
49*4882a593Smuzhiyun #define _IOR(type,nr,size)	_IOC(_IOC_READ,(type),(nr),sizeof(size))
50*4882a593Smuzhiyun #define _IOW(type,nr,size)	_IOC(_IOC_WRITE,(type),(nr),sizeof(size))
51*4882a593Smuzhiyun #define _IOWR(type,nr,size)	_IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size))
52*4882a593Smuzhiyun 
53*4882a593Smuzhiyun /* used to decode them.. */
54*4882a593Smuzhiyun #define _IOC_DIR(nr)		(((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK)
55*4882a593Smuzhiyun #define _IOC_TYPE(nr)		(((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK)
56*4882a593Smuzhiyun #define _IOC_NR(nr)		(((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK)
57*4882a593Smuzhiyun #define _IOC_SIZE(nr)		(((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK)
58*4882a593Smuzhiyun 
59*4882a593Smuzhiyun /* ...and for the drivers/sound files... */
60*4882a593Smuzhiyun 
61*4882a593Smuzhiyun #define IOC_IN		(_IOC_WRITE << _IOC_DIRSHIFT)
62*4882a593Smuzhiyun #define IOC_OUT		(_IOC_READ << _IOC_DIRSHIFT)
63*4882a593Smuzhiyun #define IOC_INOUT	((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT)
64*4882a593Smuzhiyun #define IOCSIZE_MASK	(_IOC_SIZEMASK << _IOC_SIZESHIFT)
65*4882a593Smuzhiyun #define IOCSIZE_SHIFT	(_IOC_SIZESHIFT)
66*4882a593Smuzhiyun 
67*4882a593Smuzhiyun #endif /* _ALPHA_IOCTL_H */
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