1 #ifndef _LINUX_KDEV_T_H
2 #define _LINUX_KDEV_T_H
3
4 #include <uapi/linux/kdev_t.h>
5
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 */
old_valid_dev(dev_t dev)23 static inline int old_valid_dev(dev_t dev)
24 {
25 return MAJOR(dev) < 256 && MINOR(dev) < 256;
26 }
27
old_encode_dev(dev_t dev)28 static inline u16 old_encode_dev(dev_t dev)
29 {
30 return (MAJOR(dev) << 8) | MINOR(dev);
31 }
32
old_decode_dev(u16 val)33 static inline dev_t old_decode_dev(u16 val)
34 {
35 return MKDEV((val >> 8) & 255, val & 255);
36 }
37
new_valid_dev(dev_t dev)38 static inline int new_valid_dev(dev_t dev)
39 {
40 return 1;
41 }
42
new_encode_dev(dev_t dev)43 static 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
new_decode_dev(u32 dev)50 static 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
huge_valid_dev(dev_t dev)57 static inline int huge_valid_dev(dev_t dev)
58 {
59 return 1;
60 }
61
huge_encode_dev(dev_t dev)62 static inline u64 huge_encode_dev(dev_t dev)
63 {
64 return new_encode_dev(dev);
65 }
66
huge_decode_dev(u64 dev)67 static inline dev_t huge_decode_dev(u64 dev)
68 {
69 return new_decode_dev(dev);
70 }
71
sysv_valid_dev(dev_t dev)72 static inline int sysv_valid_dev(dev_t dev)
73 {
74 return MAJOR(dev) < (1<<14) && MINOR(dev) < (1<<18);
75 }
76
sysv_encode_dev(dev_t dev)77 static inline u32 sysv_encode_dev(dev_t dev)
78 {
79 return MINOR(dev) | (MAJOR(dev) << 18);
80 }
81
sysv_major(u32 dev)82 static inline unsigned sysv_major(u32 dev)
83 {
84 return (dev >> 18) & 0x3fff;
85 }
86
sysv_minor(u32 dev)87 static inline unsigned sysv_minor(u32 dev)
88 {
89 return dev & 0x3ffff;
90 }
91
92 #endif
93