xref: /openbmc/linux/include/linux/kdev_t.h (revision e23feb16)
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 */
23 static inline int old_valid_dev(dev_t dev)
24 {
25 	return MAJOR(dev) < 256 && MINOR(dev) < 256;
26 }
27 
28 static inline u16 old_encode_dev(dev_t dev)
29 {
30 	return (MAJOR(dev) << 8) | MINOR(dev);
31 }
32 
33 static inline dev_t old_decode_dev(u16 val)
34 {
35 	return MKDEV((val >> 8) & 255, val & 255);
36 }
37 
38 static inline int new_valid_dev(dev_t dev)
39 {
40 	return 1;
41 }
42 
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 
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 
57 static inline int huge_valid_dev(dev_t dev)
58 {
59 	return 1;
60 }
61 
62 static inline u64 huge_encode_dev(dev_t dev)
63 {
64 	return new_encode_dev(dev);
65 }
66 
67 static inline dev_t huge_decode_dev(u64 dev)
68 {
69 	return new_decode_dev(dev);
70 }
71 
72 static inline int sysv_valid_dev(dev_t dev)
73 {
74 	return MAJOR(dev) < (1<<14) && MINOR(dev) < (1<<18);
75 }
76 
77 static inline u32 sysv_encode_dev(dev_t dev)
78 {
79 	return MINOR(dev) | (MAJOR(dev) << 18);
80 }
81 
82 static inline unsigned sysv_major(u32 dev)
83 {
84 	return (dev >> 18) & 0x3fff;
85 }
86 
87 static inline unsigned sysv_minor(u32 dev)
88 {
89 	return dev & 0x3ffff;
90 }
91 
92 #endif
93