source: mainline/kernel/arch/amd64/src/cpu/cpu.c@ 8e8c1a5

/*
 * Copyright (c) 2001-2004 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup amd64
 * @{
 */
/** @file
 */

#include <cpu.h>
#include <arch/cpu.h>
#include <arch/cpuid.h>
#include <arch/pm.h>

#include <arch.h>
#include <arch/types.h>
#include <print.h>
#include <fpu_context.h>

/*
 * Identification of CPUs.
 * Contains only non-MP-Specification specific SMP code.
 */
#define AMD_CPUID_EBX   0x68747541
#define AMD_CPUID_ECX   0x444d4163
#define AMD_CPUID_EDX   0x69746e65

#define INTEL_CPUID_EBX 0x756e6547
#define INTEL_CPUID_ECX 0x6c65746e
#define INTEL_CPUID_EDX 0x49656e69


enum vendor {
        VendorUnknown = 0,
        VendorAMD,
        VendorIntel
};

static char *vendor_str[] = {
        "Unknown Vendor",
        "AuthenticAMD",
        "GenuineIntel"
};


/** Setup flags on processor so that we can use the FPU
 *
 * cr0.osfxsr = 1 -> we do support fxstor/fxrestor
 * cr0.em = 0 -> we do not emulate coprocessor
 * cr0.mp = 1 -> we do want lazy context switch
 */
void cpu_setup_fpu(void)
{
        asm volatile (
                "movq %%cr0, %%rax;"
                "btsq $1, %%rax;" /* cr0.mp */
                "btrq $2, %%rax;"  /* cr0.em */
                "movq %%rax, %%cr0;"

                "movq %%cr4, %%rax;"
                "bts $9, %%rax;" /* cr4.osfxsr */
                "movq %%rax, %%cr4;"
                :
                :
                :"%rax"
                );
}

/** Set the TS flag to 1. 
 *
 * If a thread accesses coprocessor, exception is run, which 
 * does a lazy fpu context switch.
 *
 */
void fpu_disable(void)
{
        asm     volatile (
                "mov %%cr0,%%rax;"
                "bts $3,%%rax;"
                "mov %%rax,%%cr0;"
                :
                :
                :"%rax"
                );
}

void fpu_enable(void)
{
        asm     volatile (
                "mov %%cr0,%%rax;"
                "btr $3,%%rax;"
                "mov %%rax,%%cr0;"
                :
                :
                :"%rax"
                );      
}

void cpu_arch_init(void)
{
        CPU->arch.tss = tss_p;
        CPU->arch.tss->iomap_base = &CPU->arch.tss->iomap[0] - ((uint8_t *) CPU->arch.tss);
        CPU->fpu_owner = NULL;
}

void cpu_identify(void)
{
        cpu_info_t info;

        CPU->arch.vendor = VendorUnknown;
        if (has_cpuid()) {
                cpuid(0, &info);

                /*
                 * Check for AMD processor.
                 */
                if (info.cpuid_ebx==AMD_CPUID_EBX && info.cpuid_ecx==AMD_CPUID_ECX && info.cpuid_edx==AMD_CPUID_EDX) {
                        CPU->arch.vendor = VendorAMD;
                }

                /*
                 * Check for Intel processor.
                 */             
                if (info.cpuid_ebx==INTEL_CPUID_EBX && info.cpuid_ecx==INTEL_CPUID_ECX && info.cpuid_edx==INTEL_CPUID_EDX) {
                        CPU->arch.vendor = VendorIntel;
                }
                                
                cpuid(1, &info);
                CPU->arch.family = (info.cpuid_eax>>8)&0xf;
                CPU->arch.model = (info.cpuid_eax>>4)&0xf;
                CPU->arch.stepping = (info.cpuid_eax>>0)&0xf;                                           
        }
}

void cpu_print_report(cpu_t* m)
{
        printf("cpu%d: (%s family=%d model=%d stepping=%d) %dMHz\n",
                m->id, vendor_str[m->arch.vendor], m->arch.family, m->arch.model, m->arch.stepping,
                m->frequency_mhz);
}

/** @}
 */