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/* 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 <assert.h>
#include <stdbool.h>
#include <stdlib.h>
#include <unistd.h>
static long int linux_sysconf (int name);
static 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;
}
/* 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_ASSOC)
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);
// 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"
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