1 /* Copyright (C) 2020-2021 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library. If not, see
16 <https://www.gnu.org/licenses/>. */
17
18 #include <errno.h>
19 #include <unistd.h>
20 #include <sys/auxv.h>
21 #include <stdbool.h>
22
23 static long int linux_sysconf (int name);
24
25 static inline bool
getauxval2_einval(unsigned long int type,unsigned long int * result)26 getauxval2_einval (unsigned long int type, unsigned long int *result)
27 {
28 if (__getauxval2 (type, result))
29 return true;
30
31 __set_errno (EINVAL);
32
33 return false;
34 }
35
36 static inline long int
sysconf_get_cache_associativity(unsigned long type)37 sysconf_get_cache_associativity (unsigned long type)
38 {
39 unsigned long int result;
40
41 if (getauxval2_einval (type, &result))
42 return (result & 0xffff0000) >> 16;
43
44 return -1;
45 }
46
47 static inline long int
sysconf_get_cache_linesize(unsigned long type)48 sysconf_get_cache_linesize (unsigned long type)
49 {
50 unsigned long int result;
51
52 if (getauxval2_einval (type, &result))
53 return result & 0xffff;
54
55 return -1;
56 }
57
58 static inline long int
sysconf_get_cache_size(unsigned long type)59 sysconf_get_cache_size (unsigned long type)
60 {
61 unsigned long int result;
62
63 if (getauxval2_einval (type, &result))
64 return result;
65
66 return -1;
67 }
68
69 /* Get the value of the system variable NAME. */
70 long int
__sysconf(int name)71 __sysconf (int name)
72 {
73 switch (name)
74 {
75 case _SC_LEVEL1_ICACHE_SIZE:
76 return sysconf_get_cache_size (AT_L1I_CACHESIZE);
77 case _SC_LEVEL1_ICACHE_ASSOC:
78 return sysconf_get_cache_associativity (AT_L1I_CACHEGEOMETRY);
79 case _SC_LEVEL1_ICACHE_LINESIZE:
80 return sysconf_get_cache_linesize (AT_L1I_CACHEGEOMETRY);
81 case _SC_LEVEL1_DCACHE_SIZE:
82 return sysconf_get_cache_size (AT_L1D_CACHESIZE);
83 case _SC_LEVEL1_DCACHE_ASSOC:
84 return sysconf_get_cache_associativity (AT_L1D_CACHEGEOMETRY);
85 case _SC_LEVEL1_DCACHE_LINESIZE:
86 return sysconf_get_cache_linesize (AT_L1D_CACHEGEOMETRY);
87 case _SC_LEVEL2_CACHE_SIZE:
88 return sysconf_get_cache_size (AT_L2_CACHESIZE);
89 case _SC_LEVEL2_CACHE_ASSOC:
90 return sysconf_get_cache_associativity (AT_L2_CACHEGEOMETRY);
91 case _SC_LEVEL2_CACHE_LINESIZE:
92 return sysconf_get_cache_linesize (AT_L2_CACHEGEOMETRY);
93 default:
94 return linux_sysconf (name);
95 }
96 }
97
98 /* Now the generic Linux version. */
99 #undef __sysconf
100 #define __sysconf static linux_sysconf
101 #include <sysdeps/unix/sysv/linux/sysconf.c>
102