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1#ifndef _ASM_IA64_IOCTL_H
2#define _ASM_IA64_IOCTL_H
3
4/*
5 * Based on <asm-i386/ioctl.h>.
6 *
7 * Modified 1998, 1999
8 * David Mosberger-Tang <davidm@hpl.hp.com>, Hewlett-Packard Co
9 */
10
11/* ioctl command encoding: 32 bits total, command in lower 16 bits,
12 * size of the parameter structure in the lower 14 bits of the
13 * upper 16 bits.
14 * Encoding the size of the parameter structure in the ioctl request
15 * is useful for catching programs compiled with old versions
16 * and to avoid overwriting user space outside the user buffer area.
17 * The highest 2 bits are reserved for indicating the ``access mode''.
18 * NOTE: This limits the max parameter size to 16kB -1 !
19 */
20
21/*
22 * The following is for compatibility across the various Linux
23 * platforms. The ia64 ioctl numbering scheme doesn't really enforce
24 * a type field. De facto, however, the top 8 bits of the lower 16
25 * bits are indeed used as a type field, so we might just as well make
26 * this explicit here. Please be sure to use the decoding macros
27 * below from now on.
28 */
29#define _IOC_NRBITS 8
30#define _IOC_TYPEBITS 8
31#define _IOC_SIZEBITS 14
32#define _IOC_DIRBITS 2
33
34#define _IOC_NRMASK ((1 << _IOC_NRBITS)-1)
35#define _IOC_TYPEMASK ((1 << _IOC_TYPEBITS)-1)
36#define _IOC_SIZEMASK ((1 << _IOC_SIZEBITS)-1)
37#define _IOC_DIRMASK ((1 << _IOC_DIRBITS)-1)
38
39#define _IOC_NRSHIFT 0
40#define _IOC_TYPESHIFT (_IOC_NRSHIFT+_IOC_NRBITS)
41#define _IOC_SIZESHIFT (_IOC_TYPESHIFT+_IOC_TYPEBITS)
42#define _IOC_DIRSHIFT (_IOC_SIZESHIFT+_IOC_SIZEBITS)
43
44/*
45 * Direction bits.
46 */
47#define _IOC_NONE 0U
48#define _IOC_WRITE 1U
49#define _IOC_READ 2U
50
51#define _IOC(dir,type,nr,size) \
52 (((dir) << _IOC_DIRSHIFT) | \
53 ((type) << _IOC_TYPESHIFT) | \
54 ((nr) << _IOC_NRSHIFT) | \
55 ((size) << _IOC_SIZESHIFT))
56
57/* used to create numbers */
58#define _IO(type,nr) _IOC(_IOC_NONE,(type),(nr),0)
59#define _IOR(type,nr,size) _IOC(_IOC_READ,(type),(nr),sizeof(size))
60#define _IOW(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),sizeof(size))
61#define _IOWR(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size))
62
63/* used to decode ioctl numbers.. */
64#define _IOC_DIR(nr) (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK)
65#define _IOC_TYPE(nr) (((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK)
66#define _IOC_NR(nr) (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK)
67#define _IOC_SIZE(nr) (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK)
68
69/* ...and for the drivers/sound files... */
70
71#define IOC_IN (_IOC_WRITE << _IOC_DIRSHIFT)
72#define IOC_OUT (_IOC_READ << _IOC_DIRSHIFT)
73#define IOC_INOUT ((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT)
74#define IOCSIZE_MASK (_IOC_SIZEMASK << _IOC_SIZESHIFT)
75#define IOCSIZE_SHIFT (_IOC_SIZESHIFT)
76
77#endif /* _ASM_IA64_IOCTL_H */