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