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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _LINUX_KDEV_T_H
2#define _LINUX_KDEV_T_H
David Howells607ca462012-10-13 10:46:48 +01003
4#include <uapi/linux/kdev_t.h>
5
Linus Torvalds1da177e2005-04-16 15:20:36 -07006#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 */
23static inline int old_valid_dev(dev_t dev)
24{
25 return MAJOR(dev) < 256 && MINOR(dev) < 256;
26}
27
28static inline u16 old_encode_dev(dev_t dev)
29{
30 return (MAJOR(dev) << 8) | MINOR(dev);
31}
32
33static inline dev_t old_decode_dev(u16 val)
34{
35 return MKDEV((val >> 8) & 255, val & 255);
36}
37
38static inline int new_valid_dev(dev_t dev)
39{
40 return 1;
41}
42
43static inline u32 new_encode_dev(dev_t dev)
44{
45 unsigned major = MAJOR(dev);
46 unsigned minor = MINOR(dev);
47 return (minor & 0xff) | (major << 8) | ((minor & ~0xff) << 12);
48}
49
50static inline dev_t new_decode_dev(u32 dev)
51{
52 unsigned major = (dev & 0xfff00) >> 8;
53 unsigned minor = (dev & 0xff) | ((dev >> 12) & 0xfff00);
54 return MKDEV(major, minor);
55}
56
57static inline int huge_valid_dev(dev_t dev)
58{
59 return 1;
60}
61
62static inline u64 huge_encode_dev(dev_t dev)
63{
64 return new_encode_dev(dev);
65}
66
67static inline dev_t huge_decode_dev(u64 dev)
68{
69 return new_decode_dev(dev);
70}
71
72static inline int sysv_valid_dev(dev_t dev)
73{
74 return MAJOR(dev) < (1<<14) && MINOR(dev) < (1<<18);
75}
76
77static inline u32 sysv_encode_dev(dev_t dev)
78{
79 return MINOR(dev) | (MAJOR(dev) << 18);
80}
81
82static inline unsigned sysv_major(u32 dev)
83{
84 return (dev >> 18) & 0x3fff;
85}
86
87static inline unsigned sysv_minor(u32 dev)
88{
89 return dev & 0x3ffff;
90}
91
Linus Torvalds1da177e2005-04-16 15:20:36 -070092#endif