1 #ifndef _ASM_IA64_IOCTL_H
2 #define _ASM_IA64_IOCTL_H
3
4 /*
5 * This is mostly derived from the Linux/x86 version.
6 *
7 * Copyright (C) 1998, 1999 Hewlett-Packard Co
8 * Copyright (C) 1998, 1999 David Mosberger-Tang <davidm@hpl.hp.com>
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 */
78
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