/*
 * Portions of this file taken from the Linux kernel,
 * Copyright 1991-2009 Linus Torvalds and contributors
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*/

#include <stdio.h>
#include <string.h>
#include "cpuid.h"

struct cpu_dev *cpu_devs[X86_VENDOR_NUM] = { };

/*
* CPUID functions returning a single datum
*/

/* Probe for the CPUID instruction */
static int have_cpuid_p(void)
{
    return cpu_has_eflag(X86_EFLAGS_ID);
}

static struct cpu_dev amd_cpu_dev = {
    .c_vendor = "AMD",
    .c_ident = {"AuthenticAMD"}
};

static struct cpu_dev intel_cpu_dev = {
    .c_vendor = "Intel",
    .c_ident = {"GenuineIntel"}
};

static struct cpu_dev cyrix_cpu_dev = {
    .c_vendor = "Cyrix",
    .c_ident = {"CyrixInstead"}
};

static struct cpu_dev umc_cpu_dev = {
    .c_vendor = "UMC",
    .c_ident = {"UMC UMC UMC"}

};

static struct cpu_dev nexgen_cpu_dev = {
    .c_vendor = "Nexgen",
    .c_ident = {"NexGenDriven"}
};

static struct cpu_dev centaur_cpu_dev = {
    .c_vendor = "Centaur",
    .c_ident = {"CentaurHauls"}
};

static struct cpu_dev rise_cpu_dev = {
    .c_vendor = "Rise",
    .c_ident = {"RiseRiseRise"}
};

static struct cpu_dev transmeta_cpu_dev = {
    .c_vendor = "Transmeta",
    .c_ident = {"GenuineTMx86", "TransmetaCPU"}
};

void init_cpu_devs(void)
{
    cpu_devs[X86_VENDOR_INTEL] = &intel_cpu_dev;
    cpu_devs[X86_VENDOR_CYRIX] = &cyrix_cpu_dev;
    cpu_devs[X86_VENDOR_AMD] = &amd_cpu_dev;
    cpu_devs[X86_VENDOR_UMC] = &umc_cpu_dev;
    cpu_devs[X86_VENDOR_NEXGEN] = &nexgen_cpu_dev;
    cpu_devs[X86_VENDOR_CENTAUR] = &centaur_cpu_dev;
    cpu_devs[X86_VENDOR_RISE] = &rise_cpu_dev;
    cpu_devs[X86_VENDOR_TRANSMETA] = &transmeta_cpu_dev;
}

void get_cpu_vendor(struct cpuinfo_x86 *c)
{
    char *v = c->x86_vendor_id;
    int i;
    init_cpu_devs();
    for (i = 0; i < X86_VENDOR_NUM; i++) {
	if (cpu_devs[i]) {
	    if (!strcmp(v, cpu_devs[i]->c_ident[0]) ||
		(cpu_devs[i]->c_ident[1] &&
		 !strcmp(v, cpu_devs[i]->c_ident[1]))) {
		c->x86_vendor = i;
		return;
	    }
	}
    }

    c->x86_vendor = X86_VENDOR_UNKNOWN;
}

int get_model_name(struct cpuinfo_x86 *c)
{
    unsigned int *v;
    char *p, *q;

    if (cpuid_eax(0x80000000) < 0x80000004)
	return 0;

    v = (unsigned int *)c->x86_model_id;
    cpuid(0x80000002, &v[0], &v[1], &v[2], &v[3]);
    cpuid(0x80000003, &v[4], &v[5], &v[6], &v[7]);
    cpuid(0x80000004, &v[8], &v[9], &v[10], &v[11]);
    c->x86_model_id[48] = 0;

    /* Intel chips right-justify this string for some dumb reason;
       undo that brain damage */
    p = q = &c->x86_model_id[0];
    while (*p == ' ')
	p++;
    if (p != q) {
	while (*p)
	    *q++ = *p++;
	while (q <= &c->x86_model_id[48])
	    *q++ = '\0';	/* Zero-pad the rest */
    }

    return 1;
}

void generic_identify(struct cpuinfo_x86 *c)
{
    uint32_t tfms, xlvl;
    unsigned int ebx;

    /* Get vendor name */
    cpuid(0x00000000,
	  (uint32_t *) & c->cpuid_level,
	  (uint32_t *) & c->x86_vendor_id[0],
	  (uint32_t *) & c->x86_vendor_id[8],
	  (uint32_t *) & c->x86_vendor_id[4]);

    get_cpu_vendor(c);
    /* Intel-defined flags: level 0x00000001 */
    if (c->cpuid_level >= 0x00000001) {
	uint32_t capability, excap;
	cpuid(0x00000001, &tfms, &ebx, &excap, &capability);
	c->x86_capability[0] = capability;
	c->x86_capability[4] = excap;
	c->x86 = (tfms >> 8) & 15;
	c->x86_model = (tfms >> 4) & 15;
	if (c->x86 == 0xf)
	    c->x86 += (tfms >> 20) & 0xff;
	if (c->x86 >= 0x6)
	    c->x86_model += ((tfms >> 16) & 0xF) << 4;
	c->x86_mask = tfms & 15;
	if (cpu_has(c, X86_FEATURE_CLFLSH))
	    c->x86_clflush_size = ((ebx >> 8) & 0xff) * 8;
    } else {
	/* Have CPUID level 0 only - unheard of */
	c->x86 = 4;
    }

    /* AMD-defined flags: level 0x80000001 */
    xlvl = cpuid_eax(0x80000000);
    if ((xlvl & 0xffff0000) == 0x80000000) {
	if (xlvl >= 0x80000001) {
	    c->x86_capability[1] = cpuid_edx(0x80000001);
	    c->x86_capability[6] = cpuid_ecx(0x80000001);
	}
	if (xlvl >= 0x80000004)
	    get_model_name(c);	/* Default name */
    }
}

/*
 * Checksum an MP configuration block.
 */

static int mpf_checksum(unsigned char *mp, int len)
{
    int sum = 0;

    while (len--)
	sum += *mp++;

    return sum & 0xFF;
}

static int smp_scan_config(unsigned long base, unsigned long length)
{
    unsigned long *bp = (unsigned long *)base;
    struct intel_mp_floating *mpf;

//        printf("Scan SMP from %p for %ld bytes.\n", bp,length);
    if (sizeof(*mpf) != 16) {
	printf("Error: MPF size\n");
	return 0;
    }

    while (length > 0) {
	mpf = (struct intel_mp_floating *)bp;
	if ((*bp == SMP_MAGIC_IDENT) &&
	    (mpf->mpf_length == 1) &&
	    !mpf_checksum((unsigned char *)bp, 16) &&
	    ((mpf->mpf_specification == 1)
	     || (mpf->mpf_specification == 4))) {
	    return 1;
	}
	bp += 4;
	length -= 16;
    }
    return 0;
}

int find_smp_config(void)
{
//        unsigned int address;

    /*
     * FIXME: Linux assumes you have 640K of base ram..
     * this continues the error...
     *
     * 1) Scan the bottom 1K for a signature
     * 2) Scan the top 1K of base RAM
     * 3) Scan the 64K of bios
     */
    if (smp_scan_config(0x0, 0x400) ||
	smp_scan_config(639 * 0x400, 0x400) ||
	smp_scan_config(0xF0000, 0x10000))
	return 1;
    /*
     * If it is an SMP machine we should know now, unless the
     * configuration is in an EISA/MCA bus machine with an
     * extended bios data area.
     *
     * there is a real-mode segmented pointer pointing to the
     * 4K EBDA area at 0x40E, calculate and scan it here.
     *
     * NOTE! There are Linux loaders that will corrupt the EBDA
     * area, and as such this kind of SMP config may be less
     * trustworthy, simply because the SMP table may have been
     * stomped on during early boot. These loaders are buggy and
     * should be fixed.
     *
     * MP1.4 SPEC states to only scan first 1K of 4K EBDA.
     */

//        address = get_bios_ebda();
//        if (address)
//                smp_scan_config(address, 0x400);
    return 0;
}

void set_cpu_flags(struct cpuinfo_x86 *c, s_cpu * cpu)
{
    cpu->flags.fpu = cpu_has(c, X86_FEATURE_FPU);
    cpu->flags.vme = cpu_has(c, X86_FEATURE_VME);
    cpu->flags.de = cpu_has(c, X86_FEATURE_DE);
    cpu->flags.pse = cpu_has(c, X86_FEATURE_PSE);
    cpu->flags.tsc = cpu_has(c, X86_FEATURE_TSC);
    cpu->flags.msr = cpu_has(c, X86_FEATURE_MSR);
    cpu->flags.pae = cpu_has(c, X86_FEATURE_PAE);
    cpu->flags.mce = cpu_has(c, X86_FEATURE_MCE);
    cpu->flags.cx8 = cpu_has(c, X86_FEATURE_CX8);
    cpu->flags.apic = cpu_has(c, X86_FEATURE_APIC);
    cpu->flags.sep = cpu_has(c, X86_FEATURE_SEP);
    cpu->flags.mtrr = cpu_has(c, X86_FEATURE_MTRR);
    cpu->flags.pge = cpu_has(c, X86_FEATURE_PGE);
    cpu->flags.mca = cpu_has(c, X86_FEATURE_MCA);
    cpu->flags.cmov = cpu_has(c, X86_FEATURE_CMOV);
    cpu->flags.pat = cpu_has(c, X86_FEATURE_PAT);
    cpu->flags.pse_36 = cpu_has(c, X86_FEATURE_PSE36);
    cpu->flags.psn = cpu_has(c, X86_FEATURE_PN);
    cpu->flags.clflsh = cpu_has(c, X86_FEATURE_CLFLSH);
    cpu->flags.dts = cpu_has(c, X86_FEATURE_DTES);
    cpu->flags.acpi = cpu_has(c, X86_FEATURE_ACPI);
    cpu->flags.mmx = cpu_has(c, X86_FEATURE_MMX);
    cpu->flags.fxsr = cpu_has(c, X86_FEATURE_FXSR);
    cpu->flags.sse = cpu_has(c, X86_FEATURE_XMM);
    cpu->flags.sse2 = cpu_has(c, X86_FEATURE_XMM2);
    cpu->flags.ss = cpu_has(c, X86_FEATURE_SELFSNOOP);
    cpu->flags.htt = cpu_has(c, X86_FEATURE_HT);
    cpu->flags.acc = cpu_has(c, X86_FEATURE_ACC);
    cpu->flags.syscall = cpu_has(c, X86_FEATURE_SYSCALL);
    cpu->flags.mp = cpu_has(c, X86_FEATURE_MP);
    cpu->flags.nx = cpu_has(c, X86_FEATURE_NX);
    cpu->flags.mmxext = cpu_has(c, X86_FEATURE_MMXEXT);
    cpu->flags.lm = cpu_has(c, X86_FEATURE_LM);
    cpu->flags.nowext = cpu_has(c, X86_FEATURE_3DNOWEXT);
    cpu->flags.now = cpu_has(c, X86_FEATURE_3DNOW);
    cpu->flags.smp = find_smp_config();
    cpu->flags.vmx = cpu_has(c, X86_FEATURE_VMX);
    cpu->flags.svm = cpu_has(c, X86_FEATURE_SVM);
}

void set_generic_info(struct cpuinfo_x86 *c, s_cpu * cpu)
{
    cpu->family = c->x86;
    cpu->vendor_id = c->x86_vendor;
    cpu->model_id = c->x86_model;
    cpu->stepping = c->x86_mask;
    strncpy(cpu->vendor, cpu_devs[c->x86_vendor]->c_vendor,
	    sizeof(cpu->vendor));
    strncpy(cpu->model, c->x86_model_id, sizeof(cpu->model));
}

void detect_cpu(s_cpu * cpu)
{
    struct cpuinfo_x86 c;
    c.x86_clflush_size = 32;
    c.x86_cache_size = -1;
    c.x86_vendor = X86_VENDOR_UNKNOWN;
    c.cpuid_level = -1;		/* CPUID not detected */
    c.x86_model = c.x86_mask = 0;	/* So far unknown... */
    c.x86_max_cores = 1;
    memset(&c.x86_capability, 0, sizeof(c.x86_capability));
    memset(&c.x86_vendor_id, 0, sizeof(c.x86_vendor_id));
    memset(&c.x86_model_id, 0, sizeof(c.x86_model_id));

    if (!have_cpuid_p())
	return;

    generic_identify(&c);
    set_generic_info(&c, cpu);
    set_cpu_flags(&c, cpu);
}
