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1da177e4 LT |
1 | #ifndef _LINUX_KDEV_T_H |
2 | #define _LINUX_KDEV_T_H | |
607ca46e DH |
3 | |
4 | #include <uapi/linux/kdev_t.h> | |
5 | ||
1da177e4 LT |
6 | #define MINORBITS 20 |
7 | #define MINORMASK ((1U << MINORBITS) - 1) | |
8 | ||
9 | #define MAJOR(dev) ((unsigned int) ((dev) >> MINORBITS)) | |
10 | #define MINOR(dev) ((unsigned int) ((dev) & MINORMASK)) | |
11 | #define MKDEV(ma,mi) (((ma) << MINORBITS) | (mi)) | |
12 | ||
13 | #define print_dev_t(buffer, dev) \ | |
14 | sprintf((buffer), "%u:%u\n", MAJOR(dev), MINOR(dev)) | |
15 | ||
16 | #define format_dev_t(buffer, dev) \ | |
17 | ({ \ | |
18 | sprintf(buffer, "%u:%u", MAJOR(dev), MINOR(dev)); \ | |
19 | buffer; \ | |
20 | }) | |
21 | ||
22 | /* acceptable for old filesystems */ | |
8b9758b9 | 23 | static inline bool old_valid_dev(dev_t dev) |
1da177e4 LT |
24 | { |
25 | return MAJOR(dev) < 256 && MINOR(dev) < 256; | |
26 | } | |
27 | ||
28 | static inline u16 old_encode_dev(dev_t dev) | |
29 | { | |
30 | return (MAJOR(dev) << 8) | MINOR(dev); | |
31 | } | |
32 | ||
33 | static inline dev_t old_decode_dev(u16 val) | |
34 | { | |
35 | return MKDEV((val >> 8) & 255, val & 255); | |
36 | } | |
37 | ||
1da177e4 LT |
38 | static inline u32 new_encode_dev(dev_t dev) |
39 | { | |
40 | unsigned major = MAJOR(dev); | |
41 | unsigned minor = MINOR(dev); | |
42 | return (minor & 0xff) | (major << 8) | ((minor & ~0xff) << 12); | |
43 | } | |
44 | ||
45 | static inline dev_t new_decode_dev(u32 dev) | |
46 | { | |
47 | unsigned major = (dev & 0xfff00) >> 8; | |
48 | unsigned minor = (dev & 0xff) | ((dev >> 12) & 0xfff00); | |
49 | return MKDEV(major, minor); | |
50 | } | |
51 | ||
1da177e4 LT |
52 | static inline u64 huge_encode_dev(dev_t dev) |
53 | { | |
54 | return new_encode_dev(dev); | |
55 | } | |
56 | ||
57 | static inline dev_t huge_decode_dev(u64 dev) | |
58 | { | |
59 | return new_decode_dev(dev); | |
60 | } | |
61 | ||
62 | static inline int sysv_valid_dev(dev_t dev) | |
63 | { | |
64 | return MAJOR(dev) < (1<<14) && MINOR(dev) < (1<<18); | |
65 | } | |
66 | ||
67 | static inline u32 sysv_encode_dev(dev_t dev) | |
68 | { | |
69 | return MINOR(dev) | (MAJOR(dev) << 18); | |
70 | } | |
71 | ||
72 | static inline unsigned sysv_major(u32 dev) | |
73 | { | |
74 | return (dev >> 18) & 0x3fff; | |
75 | } | |
76 | ||
77 | static inline unsigned sysv_minor(u32 dev) | |
78 | { | |
79 | return dev & 0x3ffff; | |
80 | } | |
81 | ||
1da177e4 | 82 | #endif |