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129 lines
2.9 KiB
129 lines
2.9 KiB
/*
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* jit-cpuid-x86.c - Wrapper for the CPUID instruction.
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*
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* Copyright (C) 2004 Southern Storm Software, Pty Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include "jit-cpuid-x86.h"
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#if defined(__i386) || defined(__i386__) || defined(_M_IX86)
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/*
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* Determine if the "cpuid" instruction is present by twiddling
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* bit 21 of the EFLAGS register.
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*/
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static int cpuid_present(void)
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{
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#if defined(__GNUC__)
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int result;
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__asm__ __volatile__ (
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"\tpushfl\n"
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"\tpopl %%eax\n"
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"\tmovl %%eax, %%ecx\n"
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"\tandl $0x200000, %%ecx\n"
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"\txorl $0x200000, %%eax\n"
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"\tpushl %%eax\n"
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"\tpopfl\n"
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"\tpushfl\n"
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"\tandl $0x200000, %%eax\n"
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"\txorl %%ecx, %%eax\n"
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"\tmovl %%eax, %0\n"
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: "=m" (result) : : "eax", "ecx"
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);
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return (result != 0);
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#else
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return 0;
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#endif
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}
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/*
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* Issue a "cpuid" query and get the result.
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*/
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static void cpuid_query(unsigned int index, jit_cpuid_x86_t *info)
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{
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#if defined(__GNUC__)
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__asm__ __volatile__ (
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"\tmovl %0, %%eax\n"
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"\tpushl %%ebx\n"
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"\txorl %%ebx, %%ebx\n"
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"\txorl %%ecx, %%ecx\n"
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"\txorl %%edx, %%edx\n"
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"\t.byte 0x0F\n" /* cpuid, safe against old assemblers */
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"\t.byte 0xA2\n"
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"\tmovl %1, %%esi\n"
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"\tmovl %%eax, (%%esi)\n"
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"\tmovl %%ebx, 4(%%esi)\n"
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"\tmovl %%ecx, 8(%%esi)\n"
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"\tmovl %%edx, 12(%%esi)\n"
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"\tpopl %%ebx\n"
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: : "m"(index), "m"(info) : "eax", "ecx", "edx", "esi"
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);
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#endif
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}
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int _jit_cpuid_x86_get(unsigned int index, jit_cpuid_x86_t *info)
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{
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/* Determine if this cpu has the "cpuid" instruction */
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if(!cpuid_present())
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{
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return 0;
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}
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/* Validate the index */
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if((index & 0x80000000) == 0)
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{
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cpuid_query(0, info);
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}
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else
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{
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cpuid_query(0x80000000, info);
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}
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if(index > info->eax)
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{
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return 0;
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}
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/* Execute the actual requested query */
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cpuid_query(index, info);
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return 1;
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}
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int _jit_cpuid_x86_has_feature(unsigned int feature)
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{
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jit_cpuid_x86_t info;
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if(!_jit_cpuid_x86_get(JIT_X86CPUID_FEATURES, &info))
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{
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return 0;
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}
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return ((info.edx & feature) != 0);
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}
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unsigned int _jit_cpuid_x86_line_size(void)
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{
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jit_cpuid_x86_t info;
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if(!_jit_cpuid_x86_get(JIT_X86CPUID_FEATURES, &info))
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{
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return 0;
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}
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if((info.edx & JIT_X86FEATURE_CLFSH) == 0)
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{
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return 0;
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}
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return ((info.ebx & 0x0000FF00) >> 5);
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}
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#endif /* i386 */
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