linux/arch/i386/kernel/cpu/common.c
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   1#include <linux/init.h>
   2#include <linux/string.h>
   3#include <linux/delay.h>
   4#include <linux/smp.h>
   5#include <linux/module.h>
   6#include <linux/percpu.h>
   7#include <linux/bootmem.h>
   8#include <asm/semaphore.h>
   9#include <asm/processor.h>
  10#include <asm/i387.h>
  11#include <asm/msr.h>
  12#include <asm/io.h>
  13#include <asm/mmu_context.h>
  14#include <asm/mtrr.h>
  15#include <asm/mce.h>
  16#ifdef CONFIG_X86_LOCAL_APIC
  17#include <asm/mpspec.h>
  18#include <asm/apic.h>
  19#include <mach_apic.h>
  20#endif
  21
  22#include "cpu.h"
  23
  24DEFINE_PER_CPU(struct gdt_page, gdt_page) = { .gdt = {
  25        [GDT_ENTRY_KERNEL_CS] = { 0x0000ffff, 0x00cf9a00 },
  26        [GDT_ENTRY_KERNEL_DS] = { 0x0000ffff, 0x00cf9200 },
  27        [GDT_ENTRY_DEFAULT_USER_CS] = { 0x0000ffff, 0x00cffa00 },
  28        [GDT_ENTRY_DEFAULT_USER_DS] = { 0x0000ffff, 0x00cff200 },
  29        /*
  30         * Segments used for calling PnP BIOS have byte granularity.
  31         * They code segments and data segments have fixed 64k limits,
  32         * the transfer segment sizes are set at run time.
  33         */
  34        [GDT_ENTRY_PNPBIOS_CS32] = { 0x0000ffff, 0x00409a00 },/* 32-bit code */
  35        [GDT_ENTRY_PNPBIOS_CS16] = { 0x0000ffff, 0x00009a00 },/* 16-bit code */
  36        [GDT_ENTRY_PNPBIOS_DS] = { 0x0000ffff, 0x00009200 }, /* 16-bit data */
  37        [GDT_ENTRY_PNPBIOS_TS1] = { 0x00000000, 0x00009200 },/* 16-bit data */
  38        [GDT_ENTRY_PNPBIOS_TS2] = { 0x00000000, 0x00009200 },/* 16-bit data */
  39        /*
  40         * The APM segments have byte granularity and their bases
  41         * are set at run time.  All have 64k limits.
  42         */
  43        [GDT_ENTRY_APMBIOS_BASE] = { 0x0000ffff, 0x00409a00 },/* 32-bit code */
  44        /* 16-bit code */
  45        [GDT_ENTRY_APMBIOS_BASE+1] = { 0x0000ffff, 0x00009a00 },
  46        [GDT_ENTRY_APMBIOS_BASE+2] = { 0x0000ffff, 0x00409200 }, /* data */
  47
  48        [GDT_ENTRY_ESPFIX_SS] = { 0x00000000, 0x00c09200 },
  49        [GDT_ENTRY_PERCPU] = { 0x00000000, 0x00000000 },
  50} };
  51EXPORT_PER_CPU_SYMBOL_GPL(gdt_page);
  52
  53static int cachesize_override __cpuinitdata = -1;
  54static int disable_x86_fxsr __cpuinitdata;
  55static int disable_x86_serial_nr __cpuinitdata = 1;
  56static int disable_x86_sep __cpuinitdata;
  57
  58struct cpu_dev * cpu_devs[X86_VENDOR_NUM] = {};
  59
  60extern int disable_pse;
  61
  62static void __cpuinit default_init(struct cpuinfo_x86 * c)
  63{
  64        /* Not much we can do here... */
  65        /* Check if at least it has cpuid */
  66        if (c->cpuid_level == -1) {
  67                /* No cpuid. It must be an ancient CPU */
  68                if (c->x86 == 4)
  69                        strcpy(c->x86_model_id, "486");
  70                else if (c->x86 == 3)
  71                        strcpy(c->x86_model_id, "386");
  72        }
  73}
  74
  75static struct cpu_dev __cpuinitdata default_cpu = {
  76        .c_init = default_init,
  77        .c_vendor = "Unknown",
  78};
  79static struct cpu_dev * this_cpu __cpuinitdata = &default_cpu;
  80
  81static int __init cachesize_setup(char *str)
  82{
  83        get_option (&str, &cachesize_override);
  84        return 1;
  85}
  86__setup("cachesize=", cachesize_setup);
  87
  88int __cpuinit get_model_name(struct cpuinfo_x86 *c)
  89{
  90        unsigned int *v;
  91        char *p, *q;
  92
  93        if (cpuid_eax(0x80000000) < 0x80000004)
  94                return 0;
  95
  96        v = (unsigned int *) c->x86_model_id;
  97        cpuid(0x80000002, &v[0], &v[1], &v[2], &v[3]);
  98        cpuid(0x80000003, &v[4], &v[5], &v[6], &v[7]);
  99        cpuid(0x80000004, &v[8], &v[9], &v[10], &v[11]);
 100        c->x86_model_id[48] = 0;
 101
 102        /* Intel chips right-justify this string for some dumb reason;
 103           undo that brain damage */
 104        p = q = &c->x86_model_id[0];
 105        while ( *p == ' ' )
 106             p++;
 107        if ( p != q ) {
 108             while ( *p )
 109                  *q++ = *p++;
 110             while ( q <= &c->x86_model_id[48] )
 111                  *q++ = '\0';  /* Zero-pad the rest */
 112        }
 113
 114        return 1;
 115}
 116
 117
 118void __cpuinit display_cacheinfo(struct cpuinfo_x86 *c)
 119{
 120        unsigned int n, dummy, ecx, edx, l2size;
 121
 122        n = cpuid_eax(0x80000000);
 123
 124        if (n >= 0x80000005) {
 125                cpuid(0x80000005, &dummy, &dummy, &ecx, &edx);
 126                printk(KERN_INFO "CPU: L1 I Cache: %dK (%d bytes/line), D cache %dK (%d bytes/line)\n",
 127                        edx>>24, edx&0xFF, ecx>>24, ecx&0xFF);
 128                c->x86_cache_size=(ecx>>24)+(edx>>24);  
 129        }
 130
 131        if (n < 0x80000006)     /* Some chips just has a large L1. */
 132                return;
 133
 134        ecx = cpuid_ecx(0x80000006);
 135        l2size = ecx >> 16;
 136        
 137        /* do processor-specific cache resizing */
 138        if (this_cpu->c_size_cache)
 139                l2size = this_cpu->c_size_cache(c,l2size);
 140
 141        /* Allow user to override all this if necessary. */
 142        if (cachesize_override != -1)
 143                l2size = cachesize_override;
 144
 145        if ( l2size == 0 )
 146                return;         /* Again, no L2 cache is possible */
 147
 148        c->x86_cache_size = l2size;
 149
 150        printk(KERN_INFO "CPU: L2 Cache: %dK (%d bytes/line)\n",
 151               l2size, ecx & 0xFF);
 152}
 153
 154/* Naming convention should be: <Name> [(<Codename>)] */
 155/* This table only is used unless init_<vendor>() below doesn't set it; */
 156/* in particular, if CPUID levels 0x80000002..4 are supported, this isn't used */
 157
 158/* Look up CPU names by table lookup. */
 159static char __cpuinit *table_lookup_model(struct cpuinfo_x86 *c)
 160{
 161        struct cpu_model_info *info;
 162
 163        if ( c->x86_model >= 16 )
 164                return NULL;    /* Range check */
 165
 166        if (!this_cpu)
 167                return NULL;
 168
 169        info = this_cpu->c_models;
 170
 171        while (info && info->family) {
 172                if (info->family == c->x86)
 173                        return info->model_names[c->x86_model];
 174                info++;
 175        }
 176        return NULL;            /* Not found */
 177}
 178
 179
 180static void __cpuinit get_cpu_vendor(struct cpuinfo_x86 *c, int early)
 181{
 182        char *v = c->x86_vendor_id;
 183        int i;
 184        static int printed;
 185
 186        for (i = 0; i < X86_VENDOR_NUM; i++) {
 187                if (cpu_devs[i]) {
 188                        if (!strcmp(v,cpu_devs[i]->c_ident[0]) ||
 189                            (cpu_devs[i]->c_ident[1] && 
 190                             !strcmp(v,cpu_devs[i]->c_ident[1]))) {
 191                                c->x86_vendor = i;
 192                                if (!early)
 193                                        this_cpu = cpu_devs[i];
 194                                return;
 195                        }
 196                }
 197        }
 198        if (!printed) {
 199                printed++;
 200                printk(KERN_ERR "CPU: Vendor unknown, using generic init.\n");
 201                printk(KERN_ERR "CPU: Your system may be unstable.\n");
 202        }
 203        c->x86_vendor = X86_VENDOR_UNKNOWN;
 204        this_cpu = &default_cpu;
 205}
 206
 207
 208static int __init x86_fxsr_setup(char * s)
 209{
 210        /* Tell all the other CPU's to not use it... */
 211        disable_x86_fxsr = 1;
 212
 213        /*
 214         * ... and clear the bits early in the boot_cpu_data
 215         * so that the bootup process doesn't try to do this
 216         * either.
 217         */
 218        clear_bit(X86_FEATURE_FXSR, boot_cpu_data.x86_capability);
 219        clear_bit(X86_FEATURE_XMM, boot_cpu_data.x86_capability);
 220        return 1;
 221}
 222__setup("nofxsr", x86_fxsr_setup);
 223
 224
 225static int __init x86_sep_setup(char * s)
 226{
 227        disable_x86_sep = 1;
 228        return 1;
 229}
 230__setup("nosep", x86_sep_setup);
 231
 232
 233/* Standard macro to see if a specific flag is changeable */
 234static inline int flag_is_changeable_p(u32 flag)
 235{
 236        u32 f1, f2;
 237
 238        asm("pushfl\n\t"
 239            "pushfl\n\t"
 240            "popl %0\n\t"
 241            "movl %0,%1\n\t"
 242            "xorl %2,%0\n\t"
 243            "pushl %0\n\t"
 244            "popfl\n\t"
 245            "pushfl\n\t"
 246            "popl %0\n\t"
 247            "popfl\n\t"
 248            : "=&r" (f1), "=&r" (f2)
 249            : "ir" (flag));
 250
 251        return ((f1^f2) & flag) != 0;
 252}
 253
 254
 255/* Probe for the CPUID instruction */
 256static int __cpuinit have_cpuid_p(void)
 257{
 258        return flag_is_changeable_p(X86_EFLAGS_ID);
 259}
 260
 261void __init cpu_detect(struct cpuinfo_x86 *c)
 262{
 263        /* Get vendor name */
 264        cpuid(0x00000000, &c->cpuid_level,
 265              (int *)&c->x86_vendor_id[0],
 266              (int *)&c->x86_vendor_id[8],
 267              (int *)&c->x86_vendor_id[4]);
 268
 269        c->x86 = 4;
 270        if (c->cpuid_level >= 0x00000001) {
 271                u32 junk, tfms, cap0, misc;
 272                cpuid(0x00000001, &tfms, &misc, &junk, &cap0);
 273                c->x86 = (tfms >> 8) & 15;
 274                c->x86_model = (tfms >> 4) & 15;
 275                if (c->x86 == 0xf)
 276                        c->x86 += (tfms >> 20) & 0xff;
 277                if (c->x86 >= 0x6)
 278                        c->x86_model += ((tfms >> 16) & 0xF) << 4;
 279                c->x86_mask = tfms & 15;
 280                if (cap0 & (1<<19))
 281                        c->x86_cache_alignment = ((misc >> 8) & 0xff) * 8;
 282        }
 283}
 284
 285/* Do minimum CPU detection early.
 286   Fields really needed: vendor, cpuid_level, family, model, mask, cache alignment.
 287   The others are not touched to avoid unwanted side effects.
 288
 289   WARNING: this function is only called on the BP.  Don't add code here
 290   that is supposed to run on all CPUs. */
 291static void __init early_cpu_detect(void)
 292{
 293        struct cpuinfo_x86 *c = &boot_cpu_data;
 294
 295        c->x86_cache_alignment = 32;
 296
 297        if (!have_cpuid_p())
 298                return;
 299
 300        cpu_detect(c);
 301
 302        get_cpu_vendor(c, 1);
 303}
 304
 305static void __cpuinit generic_identify(struct cpuinfo_x86 * c)
 306{
 307        u32 tfms, xlvl;
 308        int ebx;
 309
 310        if (have_cpuid_p()) {
 311                /* Get vendor name */
 312                cpuid(0x00000000, &c->cpuid_level,
 313                      (int *)&c->x86_vendor_id[0],
 314                      (int *)&c->x86_vendor_id[8],
 315                      (int *)&c->x86_vendor_id[4]);
 316                
 317                get_cpu_vendor(c, 0);
 318                /* Initialize the standard set of capabilities */
 319                /* Note that the vendor-specific code below might override */
 320        
 321                /* Intel-defined flags: level 0x00000001 */
 322                if ( c->cpuid_level >= 0x00000001 ) {
 323                        u32 capability, excap;
 324                        cpuid(0x00000001, &tfms, &ebx, &excap, &capability);
 325                        c->x86_capability[0] = capability;
 326                        c->x86_capability[4] = excap;
 327                        c->x86 = (tfms >> 8) & 15;
 328                        c->x86_model = (tfms >> 4) & 15;
 329                        if (c->x86 == 0xf)
 330                                c->x86 += (tfms >> 20) & 0xff;
 331                        if (c->x86 >= 0x6)
 332                                c->x86_model += ((tfms >> 16) & 0xF) << 4;
 333                        c->x86_mask = tfms & 15;
 334#ifdef CONFIG_X86_HT
 335                        c->apicid = phys_pkg_id((ebx >> 24) & 0xFF, 0);
 336#else
 337                        c->apicid = (ebx >> 24) & 0xFF;
 338#endif
 339                        if (c->x86_capability[0] & (1<<19))
 340                                c->x86_clflush_size = ((ebx >> 8) & 0xff) * 8;
 341                } else {
 342                        /* Have CPUID level 0 only - unheard of */
 343                        c->x86 = 4;
 344                }
 345
 346                /* AMD-defined flags: level 0x80000001 */
 347                xlvl = cpuid_eax(0x80000000);
 348                if ( (xlvl & 0xffff0000) == 0x80000000 ) {
 349                        if ( xlvl >= 0x80000001 ) {
 350                                c->x86_capability[1] = cpuid_edx(0x80000001);
 351                                c->x86_capability[6] = cpuid_ecx(0x80000001);
 352                        }
 353                        if ( xlvl >= 0x80000004 )
 354                                get_model_name(c); /* Default name */
 355                }
 356
 357                init_scattered_cpuid_features(c);
 358        }
 359
 360        early_intel_workaround(c);
 361
 362#ifdef CONFIG_X86_HT
 363        c->phys_proc_id = (cpuid_ebx(1) >> 24) & 0xff;
 364#endif
 365}
 366
 367static void __cpuinit squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
 368{
 369        if (cpu_has(c, X86_FEATURE_PN) && disable_x86_serial_nr ) {
 370                /* Disable processor serial number */
 371                unsigned long lo,hi;
 372                rdmsr(MSR_IA32_BBL_CR_CTL,lo,hi);
 373                lo |= 0x200000;
 374                wrmsr(MSR_IA32_BBL_CR_CTL,lo,hi);
 375                printk(KERN_NOTICE "CPU serial number disabled.\n");
 376                clear_bit(X86_FEATURE_PN, c->x86_capability);
 377
 378                /* Disabling the serial number may affect the cpuid level */
 379                c->cpuid_level = cpuid_eax(0);
 380        }
 381}
 382
 383static int __init x86_serial_nr_setup(char *s)
 384{
 385        disable_x86_serial_nr = 0;
 386        return 1;
 387}
 388__setup("serialnumber", x86_serial_nr_setup);
 389
 390
 391
 392/*
 393 * This does the hard work of actually picking apart the CPU stuff...
 394 */
 395static void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
 396{
 397        int i;
 398
 399        c->loops_per_jiffy = loops_per_jiffy;
 400        c->x86_cache_size = -1;
 401        c->x86_vendor = X86_VENDOR_UNKNOWN;
 402        c->cpuid_level = -1;    /* CPUID not detected */
 403        c->x86_model = c->x86_mask = 0; /* So far unknown... */
 404        c->x86_vendor_id[0] = '\0'; /* Unset */
 405        c->x86_model_id[0] = '\0';  /* Unset */
 406        c->x86_max_cores = 1;
 407        c->x86_clflush_size = 32;
 408        memset(&c->x86_capability, 0, sizeof c->x86_capability);
 409
 410        if (!have_cpuid_p()) {
 411                /* First of all, decide if this is a 486 or higher */
 412                /* It's a 486 if we can modify the AC flag */
 413                if ( flag_is_changeable_p(X86_EFLAGS_AC) )
 414                        c->x86 = 4;
 415                else
 416                        c->x86 = 3;
 417        }
 418
 419        generic_identify(c);
 420
 421        printk(KERN_DEBUG "CPU: After generic identify, caps:");
 422        for (i = 0; i < NCAPINTS; i++)
 423                printk(" %08lx", c->x86_capability[i]);
 424        printk("\n");
 425
 426        if (this_cpu->c_identify) {
 427                this_cpu->c_identify(c);
 428
 429                printk(KERN_DEBUG "CPU: After vendor identify, caps:");
 430                for (i = 0; i < NCAPINTS; i++)
 431                        printk(" %08lx", c->x86_capability[i]);
 432                printk("\n");
 433        }
 434
 435        /*
 436         * Vendor-specific initialization.  In this section we
 437         * canonicalize the feature flags, meaning if there are
 438         * features a certain CPU supports which CPUID doesn't
 439         * tell us, CPUID claiming incorrect flags, or other bugs,
 440         * we handle them here.
 441         *
 442         * At the end of this section, c->x86_capability better
 443         * indicate the features this CPU genuinely supports!
 444         */
 445        if (this_cpu->c_init)
 446                this_cpu->c_init(c);
 447
 448        /* Disable the PN if appropriate */
 449        squash_the_stupid_serial_number(c);
 450
 451        /*
 452         * The vendor-specific functions might have changed features.  Now
 453         * we do "generic changes."
 454         */
 455
 456        /* TSC disabled? */
 457        if ( tsc_disable )
 458                clear_bit(X86_FEATURE_TSC, c->x86_capability);
 459
 460        /* FXSR disabled? */
 461        if (disable_x86_fxsr) {
 462                clear_bit(X86_FEATURE_FXSR, c->x86_capability);
 463                clear_bit(X86_FEATURE_XMM, c->x86_capability);
 464        }
 465
 466        /* SEP disabled? */
 467        if (disable_x86_sep)
 468                clear_bit(X86_FEATURE_SEP, c->x86_capability);
 469
 470        if (disable_pse)
 471                clear_bit(X86_FEATURE_PSE, c->x86_capability);
 472
 473        /* If the model name is still unset, do table lookup. */
 474        if ( !c->x86_model_id[0] ) {
 475                char *p;
 476                p = table_lookup_model(c);
 477                if ( p )
 478                        strcpy(c->x86_model_id, p);
 479                else
 480                        /* Last resort... */
 481                        sprintf(c->x86_model_id, "%02x/%02x",
 482                                c->x86, c->x86_model);
 483        }
 484
 485        /* Now the feature flags better reflect actual CPU features! */
 486
 487        printk(KERN_DEBUG "CPU: After all inits, caps:");
 488        for (i = 0; i < NCAPINTS; i++)
 489                printk(" %08lx", c->x86_capability[i]);
 490        printk("\n");
 491
 492        /*
 493         * On SMP, boot_cpu_data holds the common feature set between
 494         * all CPUs; so make sure that we indicate which features are
 495         * common between the CPUs.  The first time this routine gets
 496         * executed, c == &boot_cpu_data.
 497         */
 498        if ( c != &boot_cpu_data ) {
 499                /* AND the already accumulated flags with these */
 500                for ( i = 0 ; i < NCAPINTS ; i++ )
 501                        boot_cpu_data.x86_capability[i] &= c->x86_capability[i];
 502        }
 503
 504        /* Init Machine Check Exception if available. */
 505        mcheck_init(c);
 506}
 507
 508void __init identify_boot_cpu(void)
 509{
 510        identify_cpu(&boot_cpu_data);
 511        sysenter_setup();
 512        enable_sep_cpu();
 513        mtrr_bp_init();
 514}
 515
 516void __cpuinit identify_secondary_cpu(struct cpuinfo_x86 *c)
 517{
 518        BUG_ON(c == &boot_cpu_data);
 519        identify_cpu(c);
 520        enable_sep_cpu();
 521        mtrr_ap_init();
 522}
 523
 524#ifdef CONFIG_X86_HT
 525void __cpuinit detect_ht(struct cpuinfo_x86 *c)
 526{
 527        u32     eax, ebx, ecx, edx;
 528        int     index_msb, core_bits;
 529
 530        cpuid(1, &eax, &ebx, &ecx, &edx);
 531
 532        if (!cpu_has(c, X86_FEATURE_HT) || cpu_has(c, X86_FEATURE_CMP_LEGACY))
 533                return;
 534
 535        smp_num_siblings = (ebx & 0xff0000) >> 16;
 536
 537        if (smp_num_siblings == 1) {
 538                printk(KERN_INFO  "CPU: Hyper-Threading is disabled\n");
 539        } else if (smp_num_siblings > 1 ) {
 540
 541                if (smp_num_siblings > NR_CPUS) {
 542                        printk(KERN_WARNING "CPU: Unsupported number of the "
 543                                        "siblings %d", smp_num_siblings);
 544                        smp_num_siblings = 1;
 545                        return;
 546                }
 547
 548                index_msb = get_count_order(smp_num_siblings);
 549                c->phys_proc_id = phys_pkg_id((ebx >> 24) & 0xFF, index_msb);
 550
 551                printk(KERN_INFO  "CPU: Physical Processor ID: %d\n",
 552                       c->phys_proc_id);
 553
 554                smp_num_siblings = smp_num_siblings / c->x86_max_cores;
 555
 556                index_msb = get_count_order(smp_num_siblings) ;
 557
 558                core_bits = get_count_order(c->x86_max_cores);
 559
 560                c->cpu_core_id = phys_pkg_id((ebx >> 24) & 0xFF, index_msb) &
 561                                               ((1 << core_bits) - 1);
 562
 563                if (c->x86_max_cores > 1)
 564                        printk(KERN_INFO  "CPU: Processor Core ID: %d\n",
 565                               c->cpu_core_id);
 566        }
 567}
 568#endif
 569
 570void __cpuinit print_cpu_info(struct cpuinfo_x86 *c)
 571{
 572        char *vendor = NULL;
 573
 574        if (c->x86_vendor < X86_VENDOR_NUM)
 575                vendor = this_cpu->c_vendor;
 576        else if (c->cpuid_level >= 0)
 577                vendor = c->x86_vendor_id;
 578
 579        if (vendor && strncmp(c->x86_model_id, vendor, strlen(vendor)))
 580                printk("%s ", vendor);
 581
 582        if (!c->x86_model_id[0])
 583                printk("%d86", c->x86);
 584        else
 585                printk("%s", c->x86_model_id);
 586
 587        if (c->x86_mask || c->cpuid_level >= 0) 
 588                printk(" stepping %02x\n", c->x86_mask);
 589        else
 590                printk("\n");
 591}
 592
 593cpumask_t cpu_initialized __cpuinitdata = CPU_MASK_NONE;
 594
 595/* This is hacky. :)
 596 * We're emulating future behavior.
 597 * In the future, the cpu-specific init functions will be called implicitly
 598 * via the magic of initcalls.
 599 * They will insert themselves into the cpu_devs structure.
 600 * Then, when cpu_init() is called, we can just iterate over that array.
 601 */
 602
 603extern int intel_cpu_init(void);
 604extern int cyrix_init_cpu(void);
 605extern int nsc_init_cpu(void);
 606extern int amd_init_cpu(void);
 607extern int centaur_init_cpu(void);
 608extern int transmeta_init_cpu(void);
 609extern int nexgen_init_cpu(void);
 610extern int umc_init_cpu(void);
 611
 612void __init early_cpu_init(void)
 613{
 614        intel_cpu_init();
 615        cyrix_init_cpu();
 616        nsc_init_cpu();
 617        amd_init_cpu();
 618        centaur_init_cpu();
 619        transmeta_init_cpu();
 620        nexgen_init_cpu();
 621        umc_init_cpu();
 622        early_cpu_detect();
 623
 624#ifdef CONFIG_DEBUG_PAGEALLOC
 625        /* pse is not compatible with on-the-fly unmapping,
 626         * disable it even if the cpus claim to support it.
 627         */
 628        clear_bit(X86_FEATURE_PSE, boot_cpu_data.x86_capability);
 629        disable_pse = 1;
 630#endif
 631}
 632
 633/* Make sure %fs is initialized properly in idle threads */
 634struct pt_regs * __devinit idle_regs(struct pt_regs *regs)
 635{
 636        memset(regs, 0, sizeof(struct pt_regs));
 637        regs->xfs = __KERNEL_PERCPU;
 638        return regs;
 639}
 640
 641/* Current gdt points %fs at the "master" per-cpu area: after this,
 642 * it's on the real one. */
 643void switch_to_new_gdt(void)
 644{
 645        struct Xgt_desc_struct gdt_descr;
 646
 647        gdt_descr.address = (long)get_cpu_gdt_table(smp_processor_id());
 648        gdt_descr.size = GDT_SIZE - 1;
 649        load_gdt(&gdt_descr);
 650        asm("mov %0, %%fs" : : "r" (__KERNEL_PERCPU) : "memory");
 651}
 652
 653/*
 654 * cpu_init() initializes state that is per-CPU. Some data is already
 655 * initialized (naturally) in the bootstrap process, such as the GDT
 656 * and IDT. We reload them nevertheless, this function acts as a
 657 * 'CPU state barrier', nothing should get across.
 658 */
 659void __cpuinit cpu_init(void)
 660{
 661        int cpu = smp_processor_id();
 662        struct task_struct *curr = current;
 663        struct tss_struct * t = &per_cpu(init_tss, cpu);
 664        struct thread_struct *thread = &curr->thread;
 665
 666        if (cpu_test_and_set(cpu, cpu_initialized)) {
 667                printk(KERN_WARNING "CPU#%d already initialized!\n", cpu);
 668                for (;;) local_irq_enable();
 669        }
 670
 671        printk(KERN_INFO "Initializing CPU#%d\n", cpu);
 672
 673        if (cpu_has_vme || cpu_has_tsc || cpu_has_de)
 674                clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
 675        if (tsc_disable && cpu_has_tsc) {
 676                printk(KERN_NOTICE "Disabling TSC...\n");
 677                /**** FIX-HPA: DOES THIS REALLY BELONG HERE? ****/
 678                clear_bit(X86_FEATURE_TSC, boot_cpu_data.x86_capability);
 679                set_in_cr4(X86_CR4_TSD);
 680        }
 681
 682        load_idt(&idt_descr);
 683        switch_to_new_gdt();
 684
 685        /*
 686         * Set up and load the per-CPU TSS and LDT
 687         */
 688        atomic_inc(&init_mm.mm_count);
 689        curr->active_mm = &init_mm;
 690        if (curr->mm)
 691                BUG();
 692        enter_lazy_tlb(&init_mm, curr);
 693
 694        load_esp0(t, thread);
 695        set_tss_desc(cpu,t);
 696        load_TR_desc();
 697        load_LDT(&init_mm.context);
 698
 699#ifdef CONFIG_DOUBLEFAULT
 700        /* Set up doublefault TSS pointer in the GDT */
 701        __set_tss_desc(cpu, GDT_ENTRY_DOUBLEFAULT_TSS, &doublefault_tss);
 702#endif
 703
 704        /* Clear %gs. */
 705        asm volatile ("mov %0, %%gs" : : "r" (0));
 706
 707        /* Clear all 6 debug registers: */
 708        set_debugreg(0, 0);
 709        set_debugreg(0, 1);
 710        set_debugreg(0, 2);
 711        set_debugreg(0, 3);
 712        set_debugreg(0, 6);
 713        set_debugreg(0, 7);
 714
 715        /*
 716         * Force FPU initialization:
 717         */
 718        current_thread_info()->status = 0;
 719        clear_used_math();
 720        mxcsr_feature_mask_init();
 721}
 722
 723#ifdef CONFIG_HOTPLUG_CPU
 724void __cpuinit cpu_uninit(void)
 725{
 726        int cpu = raw_smp_processor_id();
 727        cpu_clear(cpu, cpu_initialized);
 728
 729        /* lazy TLB state */
 730        per_cpu(cpu_tlbstate, cpu).state = 0;
 731        per_cpu(cpu_tlbstate, cpu).active_mm = &init_mm;
 732}
 733#endif
 734