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63eb8df8 | 1 | /* Definitions of macros to access `dev_t' values. |
dff8da6b | 2 | Copyright (C) 1996-2024 Free Software Foundation, Inc. |
63eb8df8 ZW |
3 | This file is part of the GNU C Library. |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
6 | modify it under the terms of the GNU Lesser General Public | |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
9 | ||
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | Lesser General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public | |
16 | License along with the GNU C Library; if not, see | |
5a82c748 | 17 | <https://www.gnu.org/licenses/>. */ |
63eb8df8 ZW |
18 | |
19 | #ifndef _BITS_SYSMACROS_H | |
20 | #define _BITS_SYSMACROS_H 1 | |
21 | ||
22 | #ifndef _SYS_SYSMACROS_H | |
23 | # error "Never include <bits/sysmacros.h> directly; use <sys/sysmacros.h> instead." | |
24 | #endif | |
25 | ||
26 | /* dev_t in glibc is a 64-bit quantity, with 32-bit major and minor numbers. | |
27 | Our default encoding is MMMM Mmmm mmmM MMmm, where M is a hex digit of | |
28 | the major number and m is a hex digit of the minor number. This is | |
29 | downward compatible with legacy systems where dev_t is 16 bits wide, | |
30 | encoded as MMmm. It is also downward compatible with the Linux kernel, | |
31 | which (as of 2016) uses 32-bit dev_t, encoded as mmmM MMmm. | |
32 | ||
33 | Systems that use an incompatible encoding for dev_t should override this | |
34 | file in the appropriate sysdeps subdirectory. */ | |
35 | ||
36 | #define __SYSMACROS_DECLARE_MAJOR(DECL_TEMPL) \ | |
37 | DECL_TEMPL(unsigned int, major, (__dev_t __dev)) | |
38 | ||
39 | #define __SYSMACROS_DEFINE_MAJOR(DECL_TEMPL) \ | |
40 | __SYSMACROS_DECLARE_MAJOR (DECL_TEMPL) \ | |
41 | { \ | |
42 | unsigned int __major; \ | |
43 | __major = ((__dev & (__dev_t) 0x00000000000fff00u) >> 8); \ | |
44 | __major |= ((__dev & (__dev_t) 0xfffff00000000000u) >> 32); \ | |
45 | return __major; \ | |
46 | } | |
47 | ||
48 | #define __SYSMACROS_DECLARE_MINOR(DECL_TEMPL) \ | |
49 | DECL_TEMPL(unsigned int, minor, (__dev_t __dev)) | |
50 | ||
51 | #define __SYSMACROS_DEFINE_MINOR(DECL_TEMPL) \ | |
52 | __SYSMACROS_DECLARE_MINOR (DECL_TEMPL) \ | |
53 | { \ | |
54 | unsigned int __minor; \ | |
55 | __minor = ((__dev & (__dev_t) 0x00000000000000ffu) >> 0); \ | |
56 | __minor |= ((__dev & (__dev_t) 0x00000ffffff00000u) >> 12); \ | |
57 | return __minor; \ | |
58 | } | |
59 | ||
60 | #define __SYSMACROS_DECLARE_MAKEDEV(DECL_TEMPL) \ | |
61 | DECL_TEMPL(__dev_t, makedev, (unsigned int __major, unsigned int __minor)) | |
62 | ||
63 | #define __SYSMACROS_DEFINE_MAKEDEV(DECL_TEMPL) \ | |
64 | __SYSMACROS_DECLARE_MAKEDEV (DECL_TEMPL) \ | |
65 | { \ | |
66 | __dev_t __dev; \ | |
67 | __dev = (((__dev_t) (__major & 0x00000fffu)) << 8); \ | |
68 | __dev |= (((__dev_t) (__major & 0xfffff000u)) << 32); \ | |
69 | __dev |= (((__dev_t) (__minor & 0x000000ffu)) << 0); \ | |
70 | __dev |= (((__dev_t) (__minor & 0xffffff00u)) << 12); \ | |
71 | return __dev; \ | |
72 | } | |
73 | ||
74 | #endif /* bits/sysmacros.h */ |