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 */ 21 static inline int old_valid_dev(dev_t dev) 22 { 23 return MAJOR(dev) < 256 && MINOR(dev) < 256; 24 } 25 26 static inline u16 old_encode_dev(dev_t dev) 27 { 28 return (MAJOR(dev) << 8) | MINOR(dev); 29 } 30 31 static inline dev_t old_decode_dev(u16 val) 32 { 33 return MKDEV((val >> 8) & 255, val & 255); 34 } 35 36 static inline int new_valid_dev(dev_t dev) 37 { 38 return 1; 39 } 40 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 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 55 static inline int huge_valid_dev(dev_t dev) 56 { 57 return 1; 58 } 59 60 static inline u64 huge_encode_dev(dev_t dev) 61 { 62 return new_encode_dev(dev); 63 } 64 65 static inline dev_t huge_decode_dev(u64 dev) 66 { 67 return new_decode_dev(dev); 68 } 69 70 static inline int sysv_valid_dev(dev_t dev) 71 { 72 return MAJOR(dev) < (1<<14) && MINOR(dev) < (1<<18); 73 } 74 75 static inline u32 sysv_encode_dev(dev_t dev) 76 { 77 return MINOR(dev) | (MAJOR(dev) << 18); 78 } 79 80 static inline unsigned sysv_major(u32 dev) 81 { 82 return (dev >> 18) & 0x3fff; 83 } 84 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