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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | #ifndef _LINUX_KDEV_T_H |
3 | #define _LINUX_KDEV_T_H | |
607ca46e DH |
4 | |
5 | #include <uapi/linux/kdev_t.h> | |
6 | ||
1da177e4 LT |
7 | #define MINORBITS 20 |
8 | #define MINORMASK ((1U << MINORBITS) - 1) | |
9 | ||
10 | #define MAJOR(dev) ((unsigned int) ((dev) >> MINORBITS)) | |
11 | #define MINOR(dev) ((unsigned int) ((dev) & MINORMASK)) | |
12 | #define MKDEV(ma,mi) (((ma) << MINORBITS) | (mi)) | |
13 | ||
14 | #define print_dev_t(buffer, dev) \ | |
15 | sprintf((buffer), "%u:%u\n", MAJOR(dev), MINOR(dev)) | |
16 | ||
17 | #define format_dev_t(buffer, dev) \ | |
18 | ({ \ | |
19 | sprintf(buffer, "%u:%u", MAJOR(dev), MINOR(dev)); \ | |
20 | buffer; \ | |
21 | }) | |
22 | ||
23 | /* acceptable for old filesystems */ | |
8b9758b9 | 24 | static inline bool old_valid_dev(dev_t dev) |
1da177e4 LT |
25 | { |
26 | return MAJOR(dev) < 256 && MINOR(dev) < 256; | |
27 | } | |
28 | ||
29 | static inline u16 old_encode_dev(dev_t dev) | |
30 | { | |
31 | return (MAJOR(dev) << 8) | MINOR(dev); | |
32 | } | |
33 | ||
34 | static inline dev_t old_decode_dev(u16 val) | |
35 | { | |
36 | return MKDEV((val >> 8) & 255, val & 255); | |
37 | } | |
38 | ||
1da177e4 LT |
39 | static inline u32 new_encode_dev(dev_t dev) |
40 | { | |
41 | unsigned major = MAJOR(dev); | |
42 | unsigned minor = MINOR(dev); | |
43 | return (minor & 0xff) | (major << 8) | ((minor & ~0xff) << 12); | |
44 | } | |
45 | ||
46 | static inline dev_t new_decode_dev(u32 dev) | |
47 | { | |
48 | unsigned major = (dev & 0xfff00) >> 8; | |
49 | unsigned minor = (dev & 0xff) | ((dev >> 12) & 0xfff00); | |
50 | return MKDEV(major, minor); | |
51 | } | |
52 | ||
1da177e4 LT |
53 | static inline u64 huge_encode_dev(dev_t dev) |
54 | { | |
55 | return new_encode_dev(dev); | |
56 | } | |
57 | ||
58 | static inline dev_t huge_decode_dev(u64 dev) | |
59 | { | |
60 | return new_decode_dev(dev); | |
61 | } | |
62 | ||
63 | static inline int sysv_valid_dev(dev_t dev) | |
64 | { | |
65 | return MAJOR(dev) < (1<<14) && MINOR(dev) < (1<<18); | |
66 | } | |
67 | ||
68 | static inline u32 sysv_encode_dev(dev_t dev) | |
69 | { | |
70 | return MINOR(dev) | (MAJOR(dev) << 18); | |
71 | } | |
72 | ||
73 | static inline unsigned sysv_major(u32 dev) | |
74 | { | |
75 | return (dev >> 18) & 0x3fff; | |
76 | } | |
77 | ||
78 | static inline unsigned sysv_minor(u32 dev) | |
79 | { | |
80 | return dev & 0x3ffff; | |
81 | } | |
82 | ||
1da177e4 | 83 | #endif |