1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef _LINUX_KDEV_T_H |
3 | #define _LINUX_KDEV_T_H |
4 | |
5 | #include <uapi/linux/kdev_t.h> |
6 | |
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 */ |
24 | static __always_inline bool old_valid_dev(dev_t dev) |
25 | { |
26 | return MAJOR(dev) < 256 && MINOR(dev) < 256; |
27 | } |
28 | |
29 | static __always_inline u16 old_encode_dev(dev_t dev) |
30 | { |
31 | return (MAJOR(dev) << 8) | MINOR(dev); |
32 | } |
33 | |
34 | static __always_inline dev_t old_decode_dev(u16 val) |
35 | { |
36 | return MKDEV((val >> 8) & 255, val & 255); |
37 | } |
38 | |
39 | static __always_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 __always_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 | |
53 | static __always_inline u64 huge_encode_dev(dev_t dev) |
54 | { |
55 | return new_encode_dev(dev); |
56 | } |
57 | |
58 | static __always_inline dev_t huge_decode_dev(u64 dev) |
59 | { |
60 | return new_decode_dev(dev); |
61 | } |
62 | |
63 | static __always_inline int sysv_valid_dev(dev_t dev) |
64 | { |
65 | return MAJOR(dev) < (1<<14) && MINOR(dev) < (1<<18); |
66 | } |
67 | |
68 | static __always_inline u32 sysv_encode_dev(dev_t dev) |
69 | { |
70 | return MINOR(dev) | (MAJOR(dev) << 18); |
71 | } |
72 | |
73 | static __always_inline unsigned sysv_major(u32 dev) |
74 | { |
75 | return (dev >> 18) & 0x3fff; |
76 | } |
77 | |
78 | static __always_inline unsigned sysv_minor(u32 dev) |
79 | { |
80 | return dev & 0x3ffff; |
81 | } |
82 | |
83 | #endif |
84 | |