1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374 |
- /* Definitions of macros to access `dev_t' values.
- Copyright (C) 1996-2021 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, see
- <https://www.gnu.org/licenses/>. */
- #ifndef _BITS_SYSMACROS_H
- #define _BITS_SYSMACROS_H 1
- #ifndef _SYS_SYSMACROS_H
- # error "Never include <bits/sysmacros.h> directly; use <sys/sysmacros.h> instead."
- #endif
- /* dev_t in glibc is a 64-bit quantity, with 32-bit major and minor numbers.
- Our default encoding is MMMM Mmmm mmmM MMmm, where M is a hex digit of
- the major number and m is a hex digit of the minor number. This is
- downward compatible with legacy systems where dev_t is 16 bits wide,
- encoded as MMmm. It is also downward compatible with the Linux kernel,
- which (as of 2016) uses 32-bit dev_t, encoded as mmmM MMmm.
- Systems that use an incompatible encoding for dev_t should override this
- file in the appropriate sysdeps subdirectory. */
- #define __SYSMACROS_DECLARE_MAJOR(DECL_TEMPL) \
- DECL_TEMPL(unsigned int, major, (__dev_t __dev))
- #define __SYSMACROS_DEFINE_MAJOR(DECL_TEMPL) \
- __SYSMACROS_DECLARE_MAJOR (DECL_TEMPL) \
- { \
- unsigned int __major; \
- __major = ((__dev & (__dev_t) 0x00000000000fff00u) >> 8); \
- __major |= ((__dev & (__dev_t) 0xfffff00000000000u) >> 32); \
- return __major; \
- }
- #define __SYSMACROS_DECLARE_MINOR(DECL_TEMPL) \
- DECL_TEMPL(unsigned int, minor, (__dev_t __dev))
- #define __SYSMACROS_DEFINE_MINOR(DECL_TEMPL) \
- __SYSMACROS_DECLARE_MINOR (DECL_TEMPL) \
- { \
- unsigned int __minor; \
- __minor = ((__dev & (__dev_t) 0x00000000000000ffu) >> 0); \
- __minor |= ((__dev & (__dev_t) 0x00000ffffff00000u) >> 12); \
- return __minor; \
- }
- #define __SYSMACROS_DECLARE_MAKEDEV(DECL_TEMPL) \
- DECL_TEMPL(__dev_t, makedev, (unsigned int __major, unsigned int __minor))
- #define __SYSMACROS_DEFINE_MAKEDEV(DECL_TEMPL) \
- __SYSMACROS_DECLARE_MAKEDEV (DECL_TEMPL) \
- { \
- __dev_t __dev; \
- __dev = (((__dev_t) (__major & 0x00000fffu)) << 8); \
- __dev |= (((__dev_t) (__major & 0xfffff000u)) << 32); \
- __dev |= (((__dev_t) (__minor & 0x000000ffu)) << 0); \
- __dev |= (((__dev_t) (__minor & 0xffffff00u)) << 12); \
- return __dev; \
- }
- #endif /* bits/sysmacros.h */
|