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6f52b16c | 1 | /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ |
8a1ab315 DH |
2 | #ifndef _UAPI_ASM_GENERIC_IOCTL_H |
3 | #define _UAPI_ASM_GENERIC_IOCTL_H | |
4 | ||
5 | /* ioctl command encoding: 32 bits total, command in lower 16 bits, | |
6 | * size of the parameter structure in the lower 14 bits of the | |
7 | * upper 16 bits. | |
8 | * Encoding the size of the parameter structure in the ioctl request | |
9 | * is useful for catching programs compiled with old versions | |
10 | * and to avoid overwriting user space outside the user buffer area. | |
11 | * The highest 2 bits are reserved for indicating the ``access mode''. | |
12 | * NOTE: This limits the max parameter size to 16kB -1 ! | |
13 | */ | |
14 | ||
15 | /* | |
16 | * The following is for compatibility across the various Linux | |
17 | * platforms. The generic ioctl numbering scheme doesn't really enforce | |
18 | * a type field. De facto, however, the top 8 bits of the lower 16 | |
19 | * bits are indeed used as a type field, so we might just as well make | |
20 | * this explicit here. Please be sure to use the decoding macros | |
21 | * below from now on. | |
22 | */ | |
23 | #define _IOC_NRBITS 8 | |
24 | #define _IOC_TYPEBITS 8 | |
25 | ||
26 | /* | |
27 | * Let any architecture override either of the following before | |
28 | * including this file. | |
29 | */ | |
30 | ||
31 | #ifndef _IOC_SIZEBITS | |
32 | # define _IOC_SIZEBITS 14 | |
33 | #endif | |
34 | ||
35 | #ifndef _IOC_DIRBITS | |
36 | # define _IOC_DIRBITS 2 | |
37 | #endif | |
38 | ||
39 | #define _IOC_NRMASK ((1 << _IOC_NRBITS)-1) | |
40 | #define _IOC_TYPEMASK ((1 << _IOC_TYPEBITS)-1) | |
41 | #define _IOC_SIZEMASK ((1 << _IOC_SIZEBITS)-1) | |
42 | #define _IOC_DIRMASK ((1 << _IOC_DIRBITS)-1) | |
43 | ||
44 | #define _IOC_NRSHIFT 0 | |
45 | #define _IOC_TYPESHIFT (_IOC_NRSHIFT+_IOC_NRBITS) | |
46 | #define _IOC_SIZESHIFT (_IOC_TYPESHIFT+_IOC_TYPEBITS) | |
47 | #define _IOC_DIRSHIFT (_IOC_SIZESHIFT+_IOC_SIZEBITS) | |
48 | ||
49 | /* | |
50 | * Direction bits, which any architecture can choose to override | |
51 | * before including this file. | |
e067eba5 AA |
52 | * |
53 | * NOTE: _IOC_WRITE means userland is writing and kernel is | |
54 | * reading. _IOC_READ means userland is reading and kernel is writing. | |
8a1ab315 DH |
55 | */ |
56 | ||
57 | #ifndef _IOC_NONE | |
58 | # define _IOC_NONE 0U | |
59 | #endif | |
60 | ||
61 | #ifndef _IOC_WRITE | |
62 | # define _IOC_WRITE 1U | |
63 | #endif | |
64 | ||
65 | #ifndef _IOC_READ | |
66 | # define _IOC_READ 2U | |
67 | #endif | |
68 | ||
69 | #define _IOC(dir,type,nr,size) \ | |
70 | (((dir) << _IOC_DIRSHIFT) | \ | |
71 | ((type) << _IOC_TYPESHIFT) | \ | |
72 | ((nr) << _IOC_NRSHIFT) | \ | |
73 | ((size) << _IOC_SIZESHIFT)) | |
74 | ||
75 | #ifndef __KERNEL__ | |
76 | #define _IOC_TYPECHECK(t) (sizeof(t)) | |
77 | #endif | |
78 | ||
e067eba5 AA |
79 | /* |
80 | * Used to create numbers. | |
81 | * | |
82 | * NOTE: _IOW means userland is writing and kernel is reading. _IOR | |
83 | * means userland is reading and kernel is writing. | |
84 | */ | |
8a1ab315 DH |
85 | #define _IO(type,nr) _IOC(_IOC_NONE,(type),(nr),0) |
86 | #define _IOR(type,nr,size) _IOC(_IOC_READ,(type),(nr),(_IOC_TYPECHECK(size))) | |
87 | #define _IOW(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size))) | |
88 | #define _IOWR(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size))) | |
89 | #define _IOR_BAD(type,nr,size) _IOC(_IOC_READ,(type),(nr),sizeof(size)) | |
90 | #define _IOW_BAD(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),sizeof(size)) | |
91 | #define _IOWR_BAD(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size)) | |
92 | ||
93 | /* used to decode ioctl numbers.. */ | |
94 | #define _IOC_DIR(nr) (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK) | |
95 | #define _IOC_TYPE(nr) (((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK) | |
96 | #define _IOC_NR(nr) (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK) | |
97 | #define _IOC_SIZE(nr) (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK) | |
98 | ||
99 | /* ...and for the drivers/sound files... */ | |
100 | ||
101 | #define IOC_IN (_IOC_WRITE << _IOC_DIRSHIFT) | |
102 | #define IOC_OUT (_IOC_READ << _IOC_DIRSHIFT) | |
103 | #define IOC_INOUT ((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT) | |
104 | #define IOCSIZE_MASK (_IOC_SIZEMASK << _IOC_SIZESHIFT) | |
105 | #define IOCSIZE_SHIFT (_IOC_SIZESHIFT) | |
106 | ||
107 | #endif /* _UAPI_ASM_GENERIC_IOCTL_H */ |