common.c

linux 内核源代码

#include <linux/init.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/smp.h>
#include <linux/module.h>
#include <linux/percpu.h>
#include <linux/bootmem.h>
#include <asm/semaphore.h>
#include <asm/processor.h>
#include <asm/i387.h>
#include <asm/msr.h>
#include <asm/io.h>
#include <asm/mmu_context.h>
#include <asm/mtrr.h>
#include <asm/mce.h>
#ifdef CONFIG_X86_LOCAL_APIC
#include <asm/mpspec.h>
#include <asm/apic.h>
#include <mach_apic.h>
#endif

#include "cpu.h"

DEFINE_PER_CPU(struct gdt_page, gdt_page) = { .gdt = {
	[GDT_ENTRY_KERNEL_CS] = { 0x0000ffff, 0x00cf9a00 },
	[GDT_ENTRY_KERNEL_DS] = { 0x0000ffff, 0x00cf9200 },
	[GDT_ENTRY_DEFAULT_USER_CS] = { 0x0000ffff, 0x00cffa00 },
	[GDT_ENTRY_DEFAULT_USER_DS] = { 0x0000ffff, 0x00cff200 },
	/*
	 * Segments used for calling PnP BIOS have byte granularity.
	 * They code segments and data segments have fixed 64k limits,
	 * the transfer segment sizes are set at run time.
	 */
	[GDT_ENTRY_PNPBIOS_CS32] = { 0x0000ffff, 0x00409a00 },/* 32-bit code */
	[GDT_ENTRY_PNPBIOS_CS16] = { 0x0000ffff, 0x00009a00 },/* 16-bit code */
	[GDT_ENTRY_PNPBIOS_DS] = { 0x0000ffff, 0x00009200 }, /* 16-bit data */
	[GDT_ENTRY_PNPBIOS_TS1] = { 0x00000000, 0x00009200 },/* 16-bit data */
	[GDT_ENTRY_PNPBIOS_TS2] = { 0x00000000, 0x00009200 },/* 16-bit data */
	/*
	 * The APM segments have byte granularity and their bases
	 * are set at run time.  All have 64k limits.
	 */
	[GDT_ENTRY_APMBIOS_BASE] = { 0x0000ffff, 0x00409a00 },/* 32-bit code */
	/* 16-bit code */
	[GDT_ENTRY_APMBIOS_BASE+1] = { 0x0000ffff, 0x00009a00 },
	[GDT_ENTRY_APMBIOS_BASE+2] = { 0x0000ffff, 0x00409200 }, /* data */

	[GDT_ENTRY_ESPFIX_SS] = { 0x00000000, 0x00c09200 },
	[GDT_ENTRY_PERCPU] = { 0x00000000, 0x00000000 },
} };
EXPORT_PER_CPU_SYMBOL_GPL(gdt_page);

static int cachesize_override __cpuinitdata = -1;
static int disable_x86_fxsr __cpuinitdata;
static int disable_x86_serial_nr __cpuinitdata = 1;
static int disable_x86_sep __cpuinitdata;

struct cpu_dev * cpu_devs[X86_VENDOR_NUM] = {};

extern int disable_pse;

static void __cpuinit default_init(struct cpuinfo_x86 * c)
{
	/* Not much we can do here... */
	/* Check if at least it has cpuid */
	if (c->cpuid_level == -1) {
		/* No cpuid. It must be an ancient CPU */
		if (c->x86 == 4)
			strcpy(c->x86_model_id, "486");
		else if (c->x86 == 3)
			strcpy(c->x86_model_id, "386");
	}
}

static struct cpu_dev __cpuinitdata default_cpu = {
	.c_init	= default_init,
	.c_vendor = "Unknown",
};
static struct cpu_dev * this_cpu __cpuinitdata = &default_cpu;

static int __init cachesize_setup(char *str)
{
	get_option (&str, &cachesize_override);
	return 1;
}
__setup("cachesize=", cachesize_setup);

int __cpuinit 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 __cpuinit display_cacheinfo(struct cpuinfo_x86 *c)
{
	unsigned int n, dummy, ecx, edx, l2size;

	n = cpuid_eax(0x80000000);

	if (n >= 0x80000005) {
		cpuid(0x80000005, &dummy, &dummy, &ecx, &edx);
		printk(KERN_INFO "CPU: L1 I Cache: %dK (%d bytes/line), D cache %dK (%d bytes/line)\n",
			edx>>24, edx&0xFF, ecx>>24, ecx&0xFF);
		c->x86_cache_size=(ecx>>24)+(edx>>24);	
	}

	if (n < 0x80000006)	/* Some chips just has a large L1. */
		return;

	ecx = cpuid_ecx(0x80000006);
	l2size = ecx >> 16;
	
	/* do processor-specific cache resizing */
	if (this_cpu->c_size_cache)
		l2size = this_cpu->c_size_cache(c,l2size);

	/* Allow user to override all this if necessary. */
	if (cachesize_override != -1)
		l2size = cachesize_override;

	if ( l2size == 0 )
		return;		/* Again, no L2 cache is possible */

	c->x86_cache_size = l2size;

	printk(KERN_INFO "CPU: L2 Cache: %dK (%d bytes/line)\n",
	       l2size, ecx & 0xFF);
}

/* Naming convention should be: <Name> [(<Codename>)] */
/* This table only is used unless init_<vendor>() below doesn't set it; */
/* in particular, if CPUID levels 0x80000002..4 are supported, this isn't used */

/* Look up CPU names by table lookup. */
static char __cpuinit *table_lookup_model(struct cpuinfo_x86 *c)
{
	struct cpu_model_info *info;

	if ( c->x86_model >= 16 )
		return NULL;	/* Range check */

	if (!this_cpu)
		return NULL;

	info = this_cpu->c_models;

	while (info && info->family) {
		if (info->family == c->x86)
			return info->model_names[c->x86_model];
		info++;
	}
	return NULL;		/* Not found */
}


static void __cpuinit get_cpu_vendor(struct cpuinfo_x86 *c, int early)
{
	char *v = c->x86_vendor_id;
	int i;
	static int printed;

	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;
				if (!early)
					this_cpu = cpu_devs[i];
				return;
			}
		}
	}
	if (!printed) {
		printed++;
		printk(KERN_ERR "CPU: Vendor unknown, using generic init.\n");
		printk(KERN_ERR "CPU: Your system may be unstable.\n");
	}
	c->x86_vendor = X86_VENDOR_UNKNOWN;
	this_cpu = &default_cpu;
}


static int __init x86_fxsr_setup(char * s)
{
	/* Tell all the other CPUs to not use it... */
	disable_x86_fxsr = 1;

	/*
	 * ... and clear the bits early in the boot_cpu_data
	 * so that the bootup process doesn't try to do this
	 * either.
	 */
	clear_bit(X86_FEATURE_FXSR, boot_cpu_data.x86_capability);
	clear_bit(X86_FEATURE_XMM, boot_cpu_data.x86_capability);
	return 1;
}
__setup("nofxsr", x86_fxsr_setup);


static int __init x86_sep_setup(char * s)
{
	disable_x86_sep = 1;
	return 1;
}
__setup("nosep", x86_sep_setup);


/* Standard macro to see if a specific flag is changeable */
static inline int flag_is_changeable_p(u32 flag)
{
	u32 f1, f2;

	asm("pushfl\n\t"
	    "pushfl\n\t"
	    "popl %0\n\t"
	    "movl %0,%1\n\t"
	    "xorl %2,%0\n\t"
	    "pushl %0\n\t"
	    "popfl\n\t"
	    "pushfl\n\t"
	    "popl %0\n\t"
	    "popfl\n\t"
	    : "=&r" (f1), "=&r" (f2)
	    : "ir" (flag));

	return ((f1^f2) & flag) != 0;
}


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

void __init cpu_detect(struct cpuinfo_x86 *c)
{
	/* Get vendor name */
	cpuid(0x00000000, &c->cpuid_level,
	      (int *)&c->x86_vendor_id[0],
	      (int *)&c->x86_vendor_id[8],
	      (int *)&c->x86_vendor_id[4]);

	c->x86 = 4;
	if (c->cpuid_level >= 0x00000001) {
		u32 junk, tfms, cap0, misc;
		cpuid(0x00000001, &tfms, &misc, &junk, &cap0);
		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 (cap0 & (1<<19))
			c->x86_cache_alignment = ((misc >> 8) & 0xff) * 8;
	}
}

/* Do minimum CPU detection early.
   Fields really needed: vendor, cpuid_level, family, model, mask, cache alignment.
   The others are not touched to avoid unwanted side effects.

   WARNING: this function is only called on the BP.  Don't add code here
   that is supposed to run on all CPUs. */
static void __init early_cpu_detect(void)
{
	struct cpuinfo_x86 *c = &boot_cpu_data;

	c->x86_cache_alignment = 32;

	if (!have_cpuid_p())
		return;

	cpu_detect(c);

	get_cpu_vendor(c, 1);
}

static void __cpuinit generic_identify(struct cpuinfo_x86 * c)
{
	u32 tfms, xlvl;
	int ebx;

	if (have_cpuid_p()) {
		/* Get vendor name */
		cpuid(0x00000000, &c->cpuid_level,
		      (int *)&c->x86_vendor_id[0],
		      (int *)&c->x86_vendor_id[8],
		      (int *)&c->x86_vendor_id[4]);
		
		get_cpu_vendor(c, 0);
		/* Initialize the standard set of capabilities */
		/* Note that the vendor-specific code below might override */
	
		/* Intel-defined flags: level 0x00000001 */
		if ( c->cpuid_level >= 0x00000001 ) {
			u32 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;
#ifdef CONFIG_X86_HT
			c->apicid = phys_pkg_id((ebx >> 24) & 0xFF, 0);
#else
			c->apicid = (ebx >> 24) & 0xFF;
#endif
			if (c->x86_capability[0] & (1<<19))
				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 */
		}

		init_scattered_cpuid_features(c);
	}

	early_intel_workaround(c);

#ifdef CONFIG_X86_HT
	c->phys_proc_id = (cpuid_ebx(1) >> 24) & 0xff;
#endif
}

static void __cpuinit squash_the_stupid_serial_number(struct cpuinfo_x86 *c)