1 #ifndef _LINUX_KDEV_T_H
2 #define _LINUX_KDEV_T_H
3 #ifdef __KERNEL__
4 #define MINORBITS 20
5 #define MINORMASK ((1U << MINORBITS) - 1)
6
7 #define MAJOR(dev) ((unsigned int) ((dev) >> MINORBITS))
8 #define MINOR(dev) ((unsigned int) ((dev) & MINORMASK))
9 #define MKDEV(ma,mi) (((ma) << MINORBITS) | (mi))
10
11 #define print_dev_t(buffer, dev) \
12 sprintf((buffer), "%u:%u\n", MAJOR(dev), MINOR(dev))
13
14 #define format_dev_t(buffer, dev) \
15 ({ \
16 sprintf(buffer, "%u:%u", MAJOR(dev), MINOR(dev)); \
17 buffer; \
18 })
19
20 /* acceptable for old filesystems */
old_valid_dev(dev_t dev)21 static inline int old_valid_dev(dev_t dev)
22 {
23 return MAJOR(dev) < 256 && MINOR(dev) < 256;
24 }
25
old_encode_dev(dev_t dev)26 static inline u16 old_encode_dev(dev_t dev)
27 {
28 return (MAJOR(dev) << 8) | MINOR(dev);
29 }
30
old_decode_dev(u16 val)31 static inline dev_t old_decode_dev(u16 val)
32 {
33 return MKDEV((val >> 8) & 255, val & 255);
34 }
35
new_valid_dev(dev_t dev)36 static inline int new_valid_dev(dev_t dev)
37 {
38 return 1;
39 }
40
new_encode_dev(dev_t dev)41 static inline u32 new_encode_dev(dev_t dev)
42 {
43 unsigned major = MAJOR(dev);
44 unsigned minor = MINOR(dev);
45 return (minor & 0xff) | (major << 8) | ((minor & ~0xff) << 12);
46 }
47
new_decode_dev(u32 dev)48 static inline dev_t new_decode_dev(u32 dev)
49 {
50 unsigned major = (dev & 0xfff00) >> 8;
51 unsigned minor = (dev & 0xff) | ((dev >> 12) & 0xfff00);
52 return MKDEV(major, minor);
53 }
54
huge_valid_dev(dev_t dev)55 static inline int huge_valid_dev(dev_t dev)
56 {
57 return 1;
58 }
59
huge_encode_dev(dev_t dev)60 static inline u64 huge_encode_dev(dev_t dev)
61 {
62 return new_encode_dev(dev);
63 }
64
huge_decode_dev(u64 dev)65 static inline dev_t huge_decode_dev(u64 dev)
66 {
67 return new_decode_dev(dev);
68 }
69
sysv_valid_dev(dev_t dev)70 static inline int sysv_valid_dev(dev_t dev)
71 {
72 return MAJOR(dev) < (1<<14) && MINOR(dev) < (1<<18);
73 }
74
sysv_encode_dev(dev_t dev)75 static inline u32 sysv_encode_dev(dev_t dev)
76 {
77 return MINOR(dev) | (MAJOR(dev) << 18);
78 }
79
sysv_major(u32 dev)80 static inline unsigned sysv_major(u32 dev)
81 {
82 return (dev >> 18) & 0x3fff;
83 }
84
sysv_minor(u32 dev)85 static inline unsigned sysv_minor(u32 dev)
86 {
87 return dev & 0x3ffff;
88 }
89
90 #else /* __KERNEL__ */
91
92 /*
93 Some programs want their definitions of MAJOR and MINOR and MKDEV
94 from the kernel sources. These must be the externally visible ones.
95 */
96 #define MAJOR(dev) ((dev)>>8)
97 #define MINOR(dev) ((dev) & 0xff)
98 #define MKDEV(ma,mi) ((ma)<<8 | (mi))
99 #endif /* __KERNEL__ */
100 #endif
101