sysdeps/x86/cacheinfo.c

   1 /* x86 cache info.
   2    Copyright (C) 2003-2023 Free Software Foundation, Inc.
   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
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #if IS_IN (libc)
  20
  21 #include <unistd.h>
  22 #include <ldsodefs.h>
  23
  24 /* Get the value of the system variable NAME.  */
  25 long int
  26 attribute_hidden
  27 __cache_sysconf (int name)
  28 {
  29   const struct cpu_features *cpu_features = __get_cpu_features ();
  30   switch (name)
  31     {
  32     case _SC_LEVEL1_ICACHE_SIZE:
  33       return cpu_features->level1_icache_size;
  34
  35     case _SC_LEVEL1_ICACHE_LINESIZE:
  36       return cpu_features->level1_icache_linesize;
  37
  38     case _SC_LEVEL1_DCACHE_SIZE:
  39       return cpu_features->level1_dcache_size;
  40
  41     case _SC_LEVEL1_DCACHE_ASSOC:
  42       return cpu_features->level1_dcache_assoc;
  43
  44     case _SC_LEVEL1_DCACHE_LINESIZE:
  45       return cpu_features->level1_dcache_linesize;
  46
  47     case _SC_LEVEL2_CACHE_SIZE:
  48       return cpu_features->level2_cache_size;
  49
  50     case _SC_LEVEL2_CACHE_ASSOC:
  51       return cpu_features->level2_cache_assoc;
  52
  53     case _SC_LEVEL2_CACHE_LINESIZE:
  54       return cpu_features->level2_cache_linesize;
  55
  56     case _SC_LEVEL3_CACHE_SIZE:
  57       return cpu_features->level3_cache_size;
  58
  59     case _SC_LEVEL3_CACHE_ASSOC:
  60       return cpu_features->level3_cache_assoc;
  61
  62     case _SC_LEVEL3_CACHE_LINESIZE:
  63       return cpu_features->level3_cache_linesize;
  64
  65     case _SC_LEVEL4_CACHE_SIZE:
  66       return cpu_features->level4_cache_size;
  67
  68     default:
  69       break;
  70     }
  71   return -1;
  72 }
  73
  74 # ifdef SHARED
  75 /* NB: In libc.a, cacheinfo.h is included in libc-start.c.  In libc.so,
  76    cacheinfo.h is included here and call init_cacheinfo by initializing
  77    a dummy function pointer via IFUNC relocation after CPU features in
  78    ld.so have been initialized by DL_PLATFORM_INIT or IFUNC relocation.  */
  79 # include <cacheinfo.h>
  80 # include <ifunc-init.h>
  81
  82 extern void __x86_cacheinfo (void) attribute_hidden;
  83 void (*const __x86_cacheinfo_p) (void) attribute_hidden
  84   = __x86_cacheinfo;
  85
  86 __ifunc (__x86_cacheinfo, __x86_cacheinfo, NULL, void, init_cacheinfo);
  87 # endif
  88 #endif