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 */ 21static inline int old_valid_dev(dev_t dev) 22{ 23 return MAJOR(dev) < 256 && MINOR(dev) < 256; 24} 25 26static inline u16 old_encode_dev(dev_t dev) 27{ 28 return (MAJOR(dev) << 8) | MINOR(dev); 29} 30 31static inline dev_t old_decode_dev(u16 val) 32{ 33 return MKDEV((val >> 8) & 255, val & 255); 34} 35 36static inline int new_valid_dev(dev_t dev) 37{ 38 return 1; 39} 40 41static 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 48static 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 55static inline int huge_valid_dev(dev_t dev) 56{ 57 return 1; 58} 59 60static inline u64 huge_encode_dev(dev_t dev) 61{ 62 return new_encode_dev(dev); 63} 64 65static inline dev_t huge_decode_dev(u64 dev) 66{ 67 return new_decode_dev(dev); 68} 69 70static inline int sysv_valid_dev(dev_t dev) 71{ 72 return MAJOR(dev) < (1<<14) && MINOR(dev) < (1<<18); 73} 74 75static inline u32 sysv_encode_dev(dev_t dev) 76{ 77 return MINOR(dev) | (MAJOR(dev) << 18); 78} 79 80static inline unsigned sysv_major(u32 dev) 81{ 82 return (dev >> 18) & 0x3fff; 83} 84 85static inline unsigned sysv_minor(u32 dev) 86{ 87 return dev & 0x3ffff; 88} 89 90#else /* __KERNEL__ */ 91 92/* 93Some programs want their definitions of MAJOR and MINOR and MKDEV 94from 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