/* Get file-specific information about a file. Linux version. Copyright (C) 2003, 2004 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, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ #include #include #include #include static long int linux_sysconf (int name); static const struct intel_02_cache_info { unsigned int idx; int name; long int size; long int assoc; long int linesize; } intel_02_known[] = { { 0x06, _SC_LEVEL1_ICACHE_SIZE, 8192, 4, 32 }, { 0x08, _SC_LEVEL1_ICACHE_SIZE, 16384, 4, 32 }, { 0x0a, _SC_LEVEL1_DCACHE_SIZE, 8192, 2, 32 }, { 0x0c, _SC_LEVEL1_DCACHE_SIZE, 16384, 4, 32 }, { 0x22, _SC_LEVEL3_CACHE_SIZE, 524288, 4, 64 }, { 0x23, _SC_LEVEL3_CACHE_SIZE, 1048576, 8, 64 }, { 0x25, _SC_LEVEL3_CACHE_SIZE, 2097152, 8, 64 }, { 0x29, _SC_LEVEL3_CACHE_SIZE, 4194304, 8, 64 }, { 0x2c, _SC_LEVEL1_DCACHE_SIZE, 32768, 8, 64 }, { 0x30, _SC_LEVEL1_ICACHE_SIZE, 32768, 8, 64 }, { 0x41, _SC_LEVEL2_CACHE_SIZE, 131072, 4, 32 }, { 0x42, _SC_LEVEL2_CACHE_SIZE, 262144, 4, 32 }, { 0x43, _SC_LEVEL2_CACHE_SIZE, 524288, 4, 32 }, { 0x44, _SC_LEVEL2_CACHE_SIZE, 1048576, 4, 32 }, { 0x45, _SC_LEVEL2_CACHE_SIZE, 2097152, 4, 32 }, { 0x60, _SC_LEVEL1_DCACHE_SIZE, 16384, 8, 64 }, { 0x66, _SC_LEVEL1_DCACHE_SIZE, 8192, 4, 64 }, { 0x67, _SC_LEVEL1_DCACHE_SIZE, 16384, 4, 64 }, { 0x68, _SC_LEVEL1_DCACHE_SIZE, 32768, 4, 64 }, { 0x78, _SC_LEVEL2_CACHE_SIZE, 1048576, 8, 64 }, { 0x79, _SC_LEVEL2_CACHE_SIZE, 131072, 8, 64 }, { 0x7a, _SC_LEVEL2_CACHE_SIZE, 262144, 8, 64 }, { 0x7b, _SC_LEVEL2_CACHE_SIZE, 524288, 8, 64 }, { 0x7c, _SC_LEVEL2_CACHE_SIZE, 1048576, 8, 64 }, { 0x7d, _SC_LEVEL2_CACHE_SIZE, 2097152, 8, 64 }, { 0x82, _SC_LEVEL2_CACHE_SIZE, 262144, 8, 32 }, { 0x83, _SC_LEVEL2_CACHE_SIZE, 524288, 8, 32 }, { 0x84, _SC_LEVEL2_CACHE_SIZE, 1048576, 8, 32 }, { 0x85, _SC_LEVEL2_CACHE_SIZE, 2097152, 8, 32 }, { 0x86, _SC_LEVEL2_CACHE_SIZE, 524288, 4, 64 }, { 0x87, _SC_LEVEL2_CACHE_SIZE, 1048576, 8, 64 }, }; #define nintel_02_known (sizeof (intel_02_known) / sizeof (intel_02_known[0])) static int intel_02_known_compare (const void *p1, const void *p2) { const struct intel_02_cache_info *i1; const struct intel_02_cache_info *i2; i1 = (const struct intel_02_cache_info *) p1; i2 = (const struct intel_02_cache_info *) p2; if (i1->idx == i2->idx) return 0; return i1->idx < i2->idx ? -1 : 1; } static long int intel_check_word (int name, unsigned int value, bool *has_level_2, bool *no_level_2_or_3) { if ((value & 0x80000000) != 0) /* The register value is reserved. */ return 0; /* Fold the name. The _SC_ constants are always in the order SIZE, ASSOC, LINESIZE. */ int folded_name = (_SC_LEVEL1_ICACHE_SIZE + ((name - _SC_LEVEL1_ICACHE_SIZE) / 3) * 3); while (value != 0) { unsigned int byte = value & 0xff; if (byte == 0x40) { *no_level_2_or_3 = true; if (folded_name == _SC_LEVEL3_CACHE_SIZE) /* No need to look further. */ break; } else { struct intel_02_cache_info *found; struct intel_02_cache_info search; search.idx = byte; found = bsearch (&search, intel_02_known, nintel_02_known, sizeof (intel_02_known[0]), intel_02_known_compare); if (found != NULL) { if (found->name == folded_name) { unsigned int offset = name - folded_name; if (offset == 0) /* Cache size. */ return found->size; if (offset == 1) return found->assoc; assert (offset == 2); return found->linesize; } if (found->name == _SC_LEVEL2_CACHE_SIZE) *has_level_2 = true; } } /* Next byte for the next round. */ value >>= 8; } /* Nothing found. */ return 0; } static long int handle_intel (int name, unsigned int maxidx) { assert (maxidx >= 2); /* OK, we can use the CPUID instruction to get all info about the caches. */ unsigned int cnt = 0; unsigned int max = 1; long int result = 0; bool no_level_2_or_3 = false; bool has_level_2 = false; while (cnt++ < max) { unsigned int eax; unsigned int ebx; unsigned int ecx; unsigned int edx; asm volatile ("xchgl %%ebx, %1; cpuid; xchgl %%ebx, %1" : "=a" (eax), "=r" (ebx), "=c" (ecx), "=d" (edx) : "0" (2)); /* The low byte of EAX in the first round contain the number of rounds we have to make. At least one, the one we are already doing. */ if (cnt == 1) { max = eax & 0xff; eax &= 0xffffff00; } /* Process the individual registers' value. */ result = intel_check_word (name, eax, &has_level_2, &no_level_2_or_3); if (result != 0) return result; result = intel_check_word (name, ebx, &has_level_2, &no_level_2_or_3); if (result != 0) return result; result = intel_check_word (name, ecx, &has_level_2, &no_level_2_or_3); if (result != 0) return result; result = intel_check_word (name, edx, &has_level_2, &no_level_2_or_3); if (result != 0) return result; } if (name >= _SC_LEVEL2_CACHE_SIZE && name <= _SC_LEVEL3_CACHE_LINESIZE && no_level_2_or_3) return -1; return 0; } static long int handle_amd (int name) { unsigned int eax; unsigned int ebx; unsigned int ecx; unsigned int edx; asm volatile ("xchgl %%ebx, %1; cpuid; xchgl %%ebx, %1" : "=a" (eax), "=r" (ebx), "=c" (ecx), "=d" (edx) : "0" (0x80000000)); if (name >= _SC_LEVEL3_CACHE_SIZE) return 0; unsigned int fn = 0x80000005 + (name >= _SC_LEVEL2_CACHE_SIZE); if (eax < fn) return 0; asm volatile ("xchgl %%ebx, %1; cpuid; xchgl %%ebx, %1" : "=a" (eax), "=r" (ebx), "=c" (ecx), "=d" (edx) : "0" (fn)); if (name < _SC_LEVEL1_DCACHE_SIZE) { name += _SC_LEVEL1_DCACHE_SIZE - _SC_LEVEL1_ICACHE_SIZE; ecx = edx; } switch (name) { case _SC_LEVEL1_DCACHE_SIZE: return (ecx >> 14) & 0x3fc00; case _SC_LEVEL1_DCACHE_ASSOC: ecx >>= 16; if ((ecx & 0xff) == 0xff) /* Fully associative. */ return (ecx << 2) & 0x3fc00; return ecx & 0xff; case _SC_LEVEL1_DCACHE_LINESIZE: return ecx & 0xff; case _SC_LEVEL2_CACHE_SIZE: return (ecx & 0xf000) == 0 ? 0 : (ecx >> 6) & 0x3fffc00; case _SC_LEVEL2_CACHE_ASSOC: ecx >>= 12; switch (ecx & 0xf) { case 0: case 1: case 2: case 4: return ecx & 0xf; case 6: return 8; case 8: return 16; case 0xf: return (ecx << 6) & 0x3fffc00; default: return 0; } case _SC_LEVEL2_CACHE_LINESIZE: return (ecx & 0xf000) == 0 ? 0 : ecx & 0xff; default: assert (! "cannot happen"); } return -1; } /* Get the value of the system variable NAME. */ long int __sysconf (int name) { /* We only handle the cache information here (for now). */ if (name < _SC_LEVEL1_ICACHE_SIZE || name > _SC_LEVEL4_CACHE_LINESIZE) return linux_sysconf (name); /* Find out what brand of processor. */ unsigned int eax; unsigned int ebx; unsigned int ecx; unsigned int edx; asm volatile ("xchgl %%ebx, %1; cpuid; xchgl %%ebx, %1" : "=a" (eax), "=r" (ebx), "=c" (ecx), "=d" (edx) : "0" (0)); /* This spells out "GenuineIntel". */ if (ebx == 0x756e6547 && ecx == 0x6c65746e && edx == 0x49656e69) return handle_intel (name, eax); /* This spells out "AuthenticAMD". */ if (ebx == 0x68747541 && ecx == 0x444d4163 && edx == 0x69746e65) return handle_amd (name); // XXX Fill in more vendors. /* CPU not known, we have no information. */ return 0; } /* Now the generic Linux version. */ #undef __sysconf #define __sysconf static linux_sysconf #include "../sysconf.c"