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 bool 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 bool 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 u64 huge_encode_dev(dev_t dev) 58 { 59 return new_encode_dev(dev); 60 } 61 62 static inline dev_t huge_decode_dev(u64 dev) 63 { 64 return new_decode_dev(dev); 65 } 66 67 static inline int sysv_valid_dev(dev_t dev) 68 { 69 return MAJOR(dev) < (1<<14) && MINOR(dev) < (1<<18); 70 } 71 72 static inline u32 sysv_encode_dev(dev_t dev) 73 { 74 return MINOR(dev) | (MAJOR(dev) << 18); 75 } 76 77 static inline unsigned sysv_major(u32 dev) 78 { 79 return (dev >> 18) & 0x3fff; 80 } 81 82 static inline unsigned sysv_minor(u32 dev) 83 { 84 return dev & 0x3ffff; 85 } 86 87 #endif 88