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1 | #ifndef _ASM_GENERIC_IOCTL_H |
2 | #define _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 | |
10521bd9 RD |
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 | |
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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 | /* | |
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49 | * Direction bits, which any architecture can choose to override |
50 | * before including this file. | |
af4cd3fe | 51 | */ |
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52 | |
53 | #ifndef _IOC_NONE | |
54 | # define _IOC_NONE 0U | |
55 | #endif | |
56 | ||
57 | #ifndef _IOC_WRITE | |
58 | # define _IOC_WRITE 1U | |
59 | #endif | |
60 | ||
61 | #ifndef _IOC_READ | |
62 | # define _IOC_READ 2U | |
63 | #endif | |
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64 | |
65 | #define _IOC(dir,type,nr,size) \ | |
66 | (((dir) << _IOC_DIRSHIFT) | \ | |
67 | ((type) << _IOC_TYPESHIFT) | \ | |
68 | ((nr) << _IOC_NRSHIFT) | \ | |
69 | ((size) << _IOC_SIZESHIFT)) | |
70 | ||
71 | /* provoke compile error for invalid uses of size argument */ | |
72 | extern unsigned int __invalid_size_argument_for_IOC; | |
73 | #define _IOC_TYPECHECK(t) \ | |
74 | ((sizeof(t) == sizeof(t[1]) && \ | |
75 | sizeof(t) < (1 << _IOC_SIZEBITS)) ? \ | |
76 | sizeof(t) : __invalid_size_argument_for_IOC) | |
77 | ||
78 | /* used to create numbers */ | |
79 | #define _IO(type,nr) _IOC(_IOC_NONE,(type),(nr),0) | |
80 | #define _IOR(type,nr,size) _IOC(_IOC_READ,(type),(nr),(_IOC_TYPECHECK(size))) | |
81 | #define _IOW(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size))) | |
82 | #define _IOWR(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size))) | |
83 | #define _IOR_BAD(type,nr,size) _IOC(_IOC_READ,(type),(nr),sizeof(size)) | |
84 | #define _IOW_BAD(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),sizeof(size)) | |
85 | #define _IOWR_BAD(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size)) | |
86 | ||
87 | /* used to decode ioctl numbers.. */ | |
88 | #define _IOC_DIR(nr) (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK) | |
89 | #define _IOC_TYPE(nr) (((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK) | |
90 | #define _IOC_NR(nr) (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK) | |
91 | #define _IOC_SIZE(nr) (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK) | |
92 | ||
93 | /* ...and for the drivers/sound files... */ | |
94 | ||
95 | #define IOC_IN (_IOC_WRITE << _IOC_DIRSHIFT) | |
96 | #define IOC_OUT (_IOC_READ << _IOC_DIRSHIFT) | |
97 | #define IOC_INOUT ((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT) | |
98 | #define IOCSIZE_MASK (_IOC_SIZEMASK << _IOC_SIZESHIFT) | |
99 | #define IOCSIZE_SHIFT (_IOC_SIZESHIFT) | |
100 | ||
101 | #endif /* _ASM_GENERIC_IOCTL_H */ |