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/*
 * 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 ia32
 * @{
 */
/** @file
 */

#ifndef KERN_ia32_CPUID_H_
#define KERN_ia32_CPUID_H_

#include <arch/types.h>

typedef struct {
    uint32_t cpuid_eax;
    uint32_t cpuid_ebx;
    uint32_t cpuid_ecx;
    uint32_t cpuid_edx;
} __attribute__ ((packed)) cpu_info_t;

struct __cpuid_extended_feature_info {
    unsigned sse3 :  1;
    unsigned      : 31;
} __attribute__ ((packed));

typedef union cpuid_extended_feature_info {
    struct __cpuid_extended_feature_info bits;
    uint32_t word;
} cpuid_extended_feature_info;

struct __cpuid_feature_info {
    unsigned            : 23;
    unsigned mmx  :  1;
    unsigned fxsr :  1;
    unsigned sse  :  1;
    unsigned sse2 :  1;
    unsigned      :  5;
} __attribute__ ((packed));

typedef union cpuid_feature_info {
    struct __cpuid_feature_info bits;
    uint32_t word;
} cpuid_feature_info;


static inline uint32_t has_cpuid(void)
{
    uint32_t val, ret;
    
    asm volatile (
        "pushf\n"                    /* read flags */
        "popl %[ret]\n"
        "movl %[ret], %[val]\n"
        
        "btcl $21, %[val]\n"         /* swap the ID bit */
        
        "pushl %[val]\n"             /* propagate the change into flags */
        "popf\n"
        "pushf\n"
        "popl %[val]\n"
        
        "andl $(1 << 21), %[ret]\n"  /* interrested only in ID bit */
        "andl $(1 << 21), %[val]\n"
        "xorl %[val], %[ret]\n"
        : [ret] "=r" (ret), [val] "=r" (val)
    );
    
    return ret;
}

static inline void cpuid(uint32_t cmd, cpu_info_t *info)
{
    asm volatile (
        "cpuid\n"
        : "=a" (info->cpuid_eax), "=b" (info->cpuid_ebx),
          "=c" (info->cpuid_ecx), "=d" (info->cpuid_edx)
        : "a" (cmd)
    );
}

#endif

/** @}
 */