linux/arch/x86/kernel/cpu/common.c
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   1#include <linux/bootmem.h>
   2#include <linux/linkage.h>
   3#include <linux/bitops.h>
   4#include <linux/kernel.h>
   5#include <linux/module.h>
   6#include <linux/percpu.h>
   7#include <linux/string.h>
   8#include <linux/delay.h>
   9#include <linux/sched.h>
  10#include <linux/init.h>
  11#include <linux/kgdb.h>
  12#include <linux/smp.h>
  13#include <linux/io.h>
  14
  15#include <asm/stackprotector.h>
  16#include <asm/perf_event.h>
  17#include <asm/mmu_context.h>
  18#include <asm/hypervisor.h>
  19#include <asm/processor.h>
  20#include <asm/sections.h>
  21#include <linux/topology.h>
  22#include <linux/cpumask.h>
  23#include <asm/pgtable.h>
  24#include <linux/atomic.h>
  25#include <asm/proto.h>
  26#include <asm/setup.h>
  27#include <asm/apic.h>
  28#include <asm/desc.h>
  29#include <asm/i387.h>
  30#include <asm/mtrr.h>
  31#include <linux/numa.h>
  32#include <asm/asm.h>
  33#include <asm/cpu.h>
  34#include <asm/mce.h>
  35#include <asm/msr.h>
  36#include <asm/pat.h>
  37
  38#ifdef CONFIG_X86_LOCAL_APIC
  39#include <asm/uv/uv.h>
  40#endif
  41
  42#include "cpu.h"
  43
  44/* all of these masks are initialized in setup_cpu_local_masks() */
  45cpumask_var_t cpu_initialized_mask;
  46cpumask_var_t cpu_callout_mask;
  47cpumask_var_t cpu_callin_mask;
  48
  49/* representing cpus for which sibling maps can be computed */
  50cpumask_var_t cpu_sibling_setup_mask;
  51
  52/* correctly size the local cpu masks */
  53void __init setup_cpu_local_masks(void)
  54{
  55        alloc_bootmem_cpumask_var(&cpu_initialized_mask);
  56        alloc_bootmem_cpumask_var(&cpu_callin_mask);
  57        alloc_bootmem_cpumask_var(&cpu_callout_mask);
  58        alloc_bootmem_cpumask_var(&cpu_sibling_setup_mask);
  59}
  60
  61static void __cpuinit default_init(struct cpuinfo_x86 *c)
  62{
  63#ifdef CONFIG_X86_64
  64        cpu_detect_cache_sizes(c);
  65#else
  66        /* Not much we can do here... */
  67        /* Check if at least it has cpuid */
  68        if (c->cpuid_level == -1) {
  69                /* No cpuid. It must be an ancient CPU */
  70                if (c->x86 == 4)
  71                        strcpy(c->x86_model_id, "486");
  72                else if (c->x86 == 3)
  73                        strcpy(c->x86_model_id, "386");
  74        }
  75#endif
  76}
  77
  78static const struct cpu_dev __cpuinitconst default_cpu = {
  79        .c_init         = default_init,
  80        .c_vendor       = "Unknown",
  81        .c_x86_vendor   = X86_VENDOR_UNKNOWN,
  82};
  83
  84static const struct cpu_dev *this_cpu __cpuinitdata = &default_cpu;
  85
  86DEFINE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page) = { .gdt = {
  87#ifdef CONFIG_X86_64
  88        /*
  89         * We need valid kernel segments for data and code in long mode too
  90         * IRET will check the segment types  kkeil 2000/10/28
  91         * Also sysret mandates a special GDT layout
  92         *
  93         * TLS descriptors are currently at a different place compared to i386.
  94         * Hopefully nobody expects them at a fixed place (Wine?)
  95         */
  96        [GDT_ENTRY_KERNEL32_CS]         = GDT_ENTRY_INIT(0xc09b, 0, 0xfffff),
  97        [GDT_ENTRY_KERNEL_CS]           = GDT_ENTRY_INIT(0xa09b, 0, 0xfffff),
  98        [GDT_ENTRY_KERNEL_DS]           = GDT_ENTRY_INIT(0xc093, 0, 0xfffff),
  99        [GDT_ENTRY_DEFAULT_USER32_CS]   = GDT_ENTRY_INIT(0xc0fb, 0, 0xfffff),
 100        [GDT_ENTRY_DEFAULT_USER_DS]     = GDT_ENTRY_INIT(0xc0f3, 0, 0xfffff),
 101        [GDT_ENTRY_DEFAULT_USER_CS]     = GDT_ENTRY_INIT(0xa0fb, 0, 0xfffff),
 102#else
 103        [GDT_ENTRY_KERNEL_CS]           = GDT_ENTRY_INIT(0xc09a, 0, 0xfffff),
 104        [GDT_ENTRY_KERNEL_DS]           = GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
 105        [GDT_ENTRY_DEFAULT_USER_CS]     = GDT_ENTRY_INIT(0xc0fa, 0, 0xfffff),
 106        [GDT_ENTRY_DEFAULT_USER_DS]     = GDT_ENTRY_INIT(0xc0f2, 0, 0xfffff),
 107        /*
 108         * Segments used for calling PnP BIOS have byte granularity.
 109         * They code segments and data segments have fixed 64k limits,
 110         * the transfer segment sizes are set at run time.
 111         */
 112        /* 32-bit code */
 113        [GDT_ENTRY_PNPBIOS_CS32]        = GDT_ENTRY_INIT(0x409a, 0, 0xffff),
 114        /* 16-bit code */
 115        [GDT_ENTRY_PNPBIOS_CS16]        = GDT_ENTRY_INIT(0x009a, 0, 0xffff),
 116        /* 16-bit data */
 117        [GDT_ENTRY_PNPBIOS_DS]          = GDT_ENTRY_INIT(0x0092, 0, 0xffff),
 118        /* 16-bit data */
 119        [GDT_ENTRY_PNPBIOS_TS1]         = GDT_ENTRY_INIT(0x0092, 0, 0),
 120        /* 16-bit data */
 121        [GDT_ENTRY_PNPBIOS_TS2]         = GDT_ENTRY_INIT(0x0092, 0, 0),
 122        /*
 123         * The APM segments have byte granularity and their bases
 124         * are set at run time.  All have 64k limits.
 125         */
 126        /* 32-bit code */
 127        [GDT_ENTRY_APMBIOS_BASE]        = GDT_ENTRY_INIT(0x409a, 0, 0xffff),
 128        /* 16-bit code */
 129        [GDT_ENTRY_APMBIOS_BASE+1]      = GDT_ENTRY_INIT(0x009a, 0, 0xffff),
 130        /* data */
 131        [GDT_ENTRY_APMBIOS_BASE+2]      = GDT_ENTRY_INIT(0x4092, 0, 0xffff),
 132
 133        [GDT_ENTRY_ESPFIX_SS]           = GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
 134        [GDT_ENTRY_PERCPU]              = GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
 135        GDT_STACK_CANARY_INIT
 136#endif
 137} };
 138EXPORT_PER_CPU_SYMBOL_GPL(gdt_page);
 139
 140static int __init x86_xsave_setup(char *s)
 141{
 142        setup_clear_cpu_cap(X86_FEATURE_XSAVE);
 143        setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT);
 144        return 1;
 145}
 146__setup("noxsave", x86_xsave_setup);
 147
 148static int __init x86_xsaveopt_setup(char *s)
 149{
 150        setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT);
 151        return 1;
 152}
 153__setup("noxsaveopt", x86_xsaveopt_setup);
 154
 155#ifdef CONFIG_X86_32
 156static int cachesize_override __cpuinitdata = -1;
 157static int disable_x86_serial_nr __cpuinitdata = 1;
 158
 159static int __init cachesize_setup(char *str)
 160{
 161        get_option(&str, &cachesize_override);
 162        return 1;
 163}
 164__setup("cachesize=", cachesize_setup);
 165
 166static int __init x86_fxsr_setup(char *s)
 167{
 168        setup_clear_cpu_cap(X86_FEATURE_FXSR);
 169        setup_clear_cpu_cap(X86_FEATURE_XMM);
 170        return 1;
 171}
 172__setup("nofxsr", x86_fxsr_setup);
 173
 174static int __init x86_sep_setup(char *s)
 175{
 176        setup_clear_cpu_cap(X86_FEATURE_SEP);
 177        return 1;
 178}
 179__setup("nosep", x86_sep_setup);
 180
 181/* Standard macro to see if a specific flag is changeable */
 182static inline int flag_is_changeable_p(u32 flag)
 183{
 184        u32 f1, f2;
 185
 186        /*
 187         * Cyrix and IDT cpus allow disabling of CPUID
 188         * so the code below may return different results
 189         * when it is executed before and after enabling
 190         * the CPUID. Add "volatile" to not allow gcc to
 191         * optimize the subsequent calls to this function.
 192         */
 193        asm volatile ("pushfl           \n\t"
 194                      "pushfl           \n\t"
 195                      "popl %0          \n\t"
 196                      "movl %0, %1      \n\t"
 197                      "xorl %2, %0      \n\t"
 198                      "pushl %0         \n\t"
 199                      "popfl            \n\t"
 200                      "pushfl           \n\t"
 201                      "popl %0          \n\t"
 202                      "popfl            \n\t"
 203
 204                      : "=&r" (f1), "=&r" (f2)
 205                      : "ir" (flag));
 206
 207        return ((f1^f2) & flag) != 0;
 208}
 209
 210/* Probe for the CPUID instruction */
 211static int __cpuinit have_cpuid_p(void)
 212{
 213        return flag_is_changeable_p(X86_EFLAGS_ID);
 214}
 215
 216static void __cpuinit squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
 217{
 218        unsigned long lo, hi;
 219
 220        if (!cpu_has(c, X86_FEATURE_PN) || !disable_x86_serial_nr)
 221                return;
 222
 223        /* Disable processor serial number: */
 224
 225        rdmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
 226        lo |= 0x200000;
 227        wrmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
 228
 229        printk(KERN_NOTICE "CPU serial number disabled.\n");
 230        clear_cpu_cap(c, X86_FEATURE_PN);
 231
 232        /* Disabling the serial number may affect the cpuid level */
 233        c->cpuid_level = cpuid_eax(0);
 234}
 235
 236static int __init x86_serial_nr_setup(char *s)
 237{
 238        disable_x86_serial_nr = 0;
 239        return 1;
 240}
 241__setup("serialnumber", x86_serial_nr_setup);
 242#else
 243static inline int flag_is_changeable_p(u32 flag)
 244{
 245        return 1;
 246}
 247/* Probe for the CPUID instruction */
 248static inline int have_cpuid_p(void)
 249{
 250        return 1;
 251}
 252static inline void squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
 253{
 254}
 255#endif
 256
 257static int disable_smep __cpuinitdata;
 258static __init int setup_disable_smep(char *arg)
 259{
 260        disable_smep = 1;
 261        return 1;
 262}
 263__setup("nosmep", setup_disable_smep);
 264
 265static __cpuinit void setup_smep(struct cpuinfo_x86 *c)
 266{
 267        if (cpu_has(c, X86_FEATURE_SMEP)) {
 268                if (unlikely(disable_smep)) {
 269                        setup_clear_cpu_cap(X86_FEATURE_SMEP);
 270                        clear_in_cr4(X86_CR4_SMEP);
 271                } else
 272                        set_in_cr4(X86_CR4_SMEP);
 273        }
 274}
 275
 276/*
 277 * Some CPU features depend on higher CPUID levels, which may not always
 278 * be available due to CPUID level capping or broken virtualization
 279 * software.  Add those features to this table to auto-disable them.
 280 */
 281struct cpuid_dependent_feature {
 282        u32 feature;
 283        u32 level;
 284};
 285
 286static const struct cpuid_dependent_feature __cpuinitconst
 287cpuid_dependent_features[] = {
 288        { X86_FEATURE_MWAIT,            0x00000005 },
 289        { X86_FEATURE_DCA,              0x00000009 },
 290        { X86_FEATURE_XSAVE,            0x0000000d },
 291        { 0, 0 }
 292};
 293
 294static void __cpuinit filter_cpuid_features(struct cpuinfo_x86 *c, bool warn)
 295{
 296        const struct cpuid_dependent_feature *df;
 297
 298        for (df = cpuid_dependent_features; df->feature; df++) {
 299
 300                if (!cpu_has(c, df->feature))
 301                        continue;
 302                /*
 303                 * Note: cpuid_level is set to -1 if unavailable, but
 304                 * extended_extended_level is set to 0 if unavailable
 305                 * and the legitimate extended levels are all negative
 306                 * when signed; hence the weird messing around with
 307                 * signs here...
 308                 */
 309                if (!((s32)df->level < 0 ?
 310                     (u32)df->level > (u32)c->extended_cpuid_level :
 311                     (s32)df->level > (s32)c->cpuid_level))
 312                        continue;
 313
 314                clear_cpu_cap(c, df->feature);
 315                if (!warn)
 316                        continue;
 317
 318                printk(KERN_WARNING
 319                       "CPU: CPU feature %s disabled, no CPUID level 0x%x\n",
 320                                x86_cap_flags[df->feature], df->level);
 321        }
 322}
 323
 324/*
 325 * Naming convention should be: <Name> [(<Codename>)]
 326 * This table only is used unless init_<vendor>() below doesn't set it;
 327 * in particular, if CPUID levels 0x80000002..4 are supported, this
 328 * isn't used
 329 */
 330
 331/* Look up CPU names by table lookup. */
 332static const char *__cpuinit table_lookup_model(struct cpuinfo_x86 *c)
 333{
 334        const struct cpu_model_info *info;
 335
 336        if (c->x86_model >= 16)
 337                return NULL;    /* Range check */
 338
 339        if (!this_cpu)
 340                return NULL;
 341
 342        info = this_cpu->c_models;
 343
 344        while (info && info->family) {
 345                if (info->family == c->x86)
 346                        return info->model_names[c->x86_model];
 347                info++;
 348        }
 349        return NULL;            /* Not found */
 350}
 351
 352__u32 cpu_caps_cleared[NCAPINTS] __cpuinitdata;
 353__u32 cpu_caps_set[NCAPINTS] __cpuinitdata;
 354
 355void load_percpu_segment(int cpu)
 356{
 357#ifdef CONFIG_X86_32
 358        loadsegment(fs, __KERNEL_PERCPU);
 359#else
 360        loadsegment(gs, 0);
 361        wrmsrl(MSR_GS_BASE, (unsigned long)per_cpu(irq_stack_union.gs_base, cpu));
 362#endif
 363        load_stack_canary_segment();
 364}
 365
 366/*
 367 * Current gdt points %fs at the "master" per-cpu area: after this,
 368 * it's on the real one.
 369 */
 370void switch_to_new_gdt(int cpu)
 371{
 372        struct desc_ptr gdt_descr;
 373
 374        gdt_descr.address = (long)get_cpu_gdt_table(cpu);
 375        gdt_descr.size = GDT_SIZE - 1;
 376        load_gdt(&gdt_descr);
 377        /* Reload the per-cpu base */
 378
 379        load_percpu_segment(cpu);
 380}
 381
 382static const struct cpu_dev *__cpuinitdata cpu_devs[X86_VENDOR_NUM] = {};
 383
 384static void __cpuinit get_model_name(struct cpuinfo_x86 *c)
 385{
 386        unsigned int *v;
 387        char *p, *q;
 388
 389        if (c->extended_cpuid_level < 0x80000004)
 390                return;
 391
 392        v = (unsigned int *)c->x86_model_id;
 393        cpuid(0x80000002, &v[0], &v[1], &v[2], &v[3]);
 394        cpuid(0x80000003, &v[4], &v[5], &v[6], &v[7]);
 395        cpuid(0x80000004, &v[8], &v[9], &v[10], &v[11]);
 396        c->x86_model_id[48] = 0;
 397
 398        /*
 399         * Intel chips right-justify this string for some dumb reason;
 400         * undo that brain damage:
 401         */
 402        p = q = &c->x86_model_id[0];
 403        while (*p == ' ')
 404                p++;
 405        if (p != q) {
 406                while (*p)
 407                        *q++ = *p++;
 408                while (q <= &c->x86_model_id[48])
 409                        *q++ = '\0';    /* Zero-pad the rest */
 410        }
 411}
 412
 413void __cpuinit cpu_detect_cache_sizes(struct cpuinfo_x86 *c)
 414{
 415        unsigned int n, dummy, ebx, ecx, edx, l2size;
 416
 417        n = c->extended_cpuid_level;
 418
 419        if (n >= 0x80000005) {
 420                cpuid(0x80000005, &dummy, &ebx, &ecx, &edx);
 421                c->x86_cache_size = (ecx>>24) + (edx>>24);
 422#ifdef CONFIG_X86_64
 423                /* On K8 L1 TLB is inclusive, so don't count it */
 424                c->x86_tlbsize = 0;
 425#endif
 426        }
 427
 428        if (n < 0x80000006)     /* Some chips just has a large L1. */
 429                return;
 430
 431        cpuid(0x80000006, &dummy, &ebx, &ecx, &edx);
 432        l2size = ecx >> 16;
 433
 434#ifdef CONFIG_X86_64
 435        c->x86_tlbsize += ((ebx >> 16) & 0xfff) + (ebx & 0xfff);
 436#else
 437        /* do processor-specific cache resizing */
 438        if (this_cpu->c_size_cache)
 439                l2size = this_cpu->c_size_cache(c, l2size);
 440
 441        /* Allow user to override all this if necessary. */
 442        if (cachesize_override != -1)
 443                l2size = cachesize_override;
 444
 445        if (l2size == 0)
 446                return;         /* Again, no L2 cache is possible */
 447#endif
 448
 449        c->x86_cache_size = l2size;
 450}
 451
 452void __cpuinit detect_ht(struct cpuinfo_x86 *c)
 453{
 454#ifdef CONFIG_X86_HT
 455        u32 eax, ebx, ecx, edx;
 456        int index_msb, core_bits;
 457        static bool printed;
 458
 459        if (!cpu_has(c, X86_FEATURE_HT))
 460                return;
 461
 462        if (cpu_has(c, X86_FEATURE_CMP_LEGACY))
 463                goto out;
 464
 465        if (cpu_has(c, X86_FEATURE_XTOPOLOGY))
 466                return;
 467
 468        cpuid(1, &eax, &ebx, &ecx, &edx);
 469
 470        smp_num_siblings = (ebx & 0xff0000) >> 16;
 471
 472        if (smp_num_siblings == 1) {
 473                printk_once(KERN_INFO "CPU0: Hyper-Threading is disabled\n");
 474                goto out;
 475        }
 476
 477        if (smp_num_siblings <= 1)
 478                goto out;
 479
 480        index_msb = get_count_order(smp_num_siblings);
 481        c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, index_msb);
 482
 483        smp_num_siblings = smp_num_siblings / c->x86_max_cores;
 484
 485        index_msb = get_count_order(smp_num_siblings);
 486
 487        core_bits = get_count_order(c->x86_max_cores);
 488
 489        c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid, index_msb) &
 490                                       ((1 << core_bits) - 1);
 491
 492out:
 493        if (!printed && (c->x86_max_cores * smp_num_siblings) > 1) {
 494                printk(KERN_INFO  "CPU: Physical Processor ID: %d\n",
 495                       c->phys_proc_id);
 496                printk(KERN_INFO  "CPU: Processor Core ID: %d\n",
 497                       c->cpu_core_id);
 498                printed = 1;
 499        }
 500#endif
 501}
 502
 503static void __cpuinit get_cpu_vendor(struct cpuinfo_x86 *c)
 504{
 505        char *v = c->x86_vendor_id;
 506        int i;
 507
 508        for (i = 0; i < X86_VENDOR_NUM; i++) {
 509                if (!cpu_devs[i])
 510                        break;
 511
 512                if (!strcmp(v, cpu_devs[i]->c_ident[0]) ||
 513                    (cpu_devs[i]->c_ident[1] &&
 514                     !strcmp(v, cpu_devs[i]->c_ident[1]))) {
 515
 516                        this_cpu = cpu_devs[i];
 517                        c->x86_vendor = this_cpu->c_x86_vendor;
 518                        return;
 519                }
 520        }
 521
 522        printk_once(KERN_ERR
 523                        "CPU: vendor_id '%s' unknown, using generic init.\n" \
 524                        "CPU: Your system may be unstable.\n", v);
 525
 526        c->x86_vendor = X86_VENDOR_UNKNOWN;
 527        this_cpu = &default_cpu;
 528}
 529
 530void __cpuinit cpu_detect(struct cpuinfo_x86 *c)
 531{
 532        /* Get vendor name */
 533        cpuid(0x00000000, (unsigned int *)&c->cpuid_level,
 534              (unsigned int *)&c->x86_vendor_id[0],
 535              (unsigned int *)&c->x86_vendor_id[8],
 536              (unsigned int *)&c->x86_vendor_id[4]);
 537
 538        c->x86 = 4;
 539        /* Intel-defined flags: level 0x00000001 */
 540        if (c->cpuid_level >= 0x00000001) {
 541                u32 junk, tfms, cap0, misc;
 542
 543                cpuid(0x00000001, &tfms, &misc, &junk, &cap0);
 544                c->x86 = (tfms >> 8) & 0xf;
 545                c->x86_model = (tfms >> 4) & 0xf;
 546                c->x86_mask = tfms & 0xf;
 547
 548                if (c->x86 == 0xf)
 549                        c->x86 += (tfms >> 20) & 0xff;
 550                if (c->x86 >= 0x6)
 551                        c->x86_model += ((tfms >> 16) & 0xf) << 4;
 552
 553                if (cap0 & (1<<19)) {
 554                        c->x86_clflush_size = ((misc >> 8) & 0xff) * 8;
 555                        c->x86_cache_alignment = c->x86_clflush_size;
 556                }
 557        }
 558}
 559
 560void __cpuinit get_cpu_cap(struct cpuinfo_x86 *c)
 561{
 562        u32 tfms, xlvl;
 563        u32 ebx;
 564
 565        /* Intel-defined flags: level 0x00000001 */
 566        if (c->cpuid_level >= 0x00000001) {
 567                u32 capability, excap;
 568
 569                cpuid(0x00000001, &tfms, &ebx, &excap, &capability);
 570                c->x86_capability[0] = capability;
 571                c->x86_capability[4] = excap;
 572        }
 573
 574        /* Additional Intel-defined flags: level 0x00000007 */
 575        if (c->cpuid_level >= 0x00000007) {
 576                u32 eax, ebx, ecx, edx;
 577
 578                cpuid_count(0x00000007, 0, &eax, &ebx, &ecx, &edx);
 579
 580                c->x86_capability[9] = ebx;
 581        }
 582
 583        /* AMD-defined flags: level 0x80000001 */
 584        xlvl = cpuid_eax(0x80000000);
 585        c->extended_cpuid_level = xlvl;
 586
 587        if ((xlvl & 0xffff0000) == 0x80000000) {
 588                if (xlvl >= 0x80000001) {
 589                        c->x86_capability[1] = cpuid_edx(0x80000001);
 590                        c->x86_capability[6] = cpuid_ecx(0x80000001);
 591                }
 592        }
 593
 594        if (c->extended_cpuid_level >= 0x80000008) {
 595                u32 eax = cpuid_eax(0x80000008);
 596
 597                c->x86_virt_bits = (eax >> 8) & 0xff;
 598                c->x86_phys_bits = eax & 0xff;
 599        }
 600#ifdef CONFIG_X86_32
 601        else if (cpu_has(c, X86_FEATURE_PAE) || cpu_has(c, X86_FEATURE_PSE36))
 602                c->x86_phys_bits = 36;
 603#endif
 604
 605        if (c->extended_cpuid_level >= 0x80000007)
 606                c->x86_power = cpuid_edx(0x80000007);
 607
 608        init_scattered_cpuid_features(c);
 609}
 610
 611static void __cpuinit identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
 612{
 613#ifdef CONFIG_X86_32
 614        int i;
 615
 616        /*
 617         * First of all, decide if this is a 486 or higher
 618         * It's a 486 if we can modify the AC flag
 619         */
 620        if (flag_is_changeable_p(X86_EFLAGS_AC))
 621                c->x86 = 4;
 622        else
 623                c->x86 = 3;
 624
 625        for (i = 0; i < X86_VENDOR_NUM; i++)
 626                if (cpu_devs[i] && cpu_devs[i]->c_identify) {
 627                        c->x86_vendor_id[0] = 0;
 628                        cpu_devs[i]->c_identify(c);
 629                        if (c->x86_vendor_id[0]) {
 630                                get_cpu_vendor(c);
 631                                break;
 632                        }
 633                }
 634#endif
 635}
 636
 637/*
 638 * Do minimum CPU detection early.
 639 * Fields really needed: vendor, cpuid_level, family, model, mask,
 640 * cache alignment.
 641 * The others are not touched to avoid unwanted side effects.
 642 *
 643 * WARNING: this function is only called on the BP.  Don't add code here
 644 * that is supposed to run on all CPUs.
 645 */
 646static void __init early_identify_cpu(struct cpuinfo_x86 *c)
 647{
 648#ifdef CONFIG_X86_64
 649        c->x86_clflush_size = 64;
 650        c->x86_phys_bits = 36;
 651        c->x86_virt_bits = 48;
 652#else
 653        c->x86_clflush_size = 32;
 654        c->x86_phys_bits = 32;
 655        c->x86_virt_bits = 32;
 656#endif
 657        c->x86_cache_alignment = c->x86_clflush_size;
 658
 659        memset(&c->x86_capability, 0, sizeof c->x86_capability);
 660        c->extended_cpuid_level = 0;
 661
 662        if (!have_cpuid_p())
 663                identify_cpu_without_cpuid(c);
 664
 665        /* cyrix could have cpuid enabled via c_identify()*/
 666        if (!have_cpuid_p())
 667                return;
 668
 669        cpu_detect(c);
 670
 671        get_cpu_vendor(c);
 672
 673        get_cpu_cap(c);
 674
 675        if (this_cpu->c_early_init)
 676                this_cpu->c_early_init(c);
 677
 678#ifdef CONFIG_SMP
 679        c->cpu_index = 0;
 680#endif
 681        filter_cpuid_features(c, false);
 682
 683        setup_smep(c);
 684}
 685
 686void __init early_cpu_init(void)
 687{
 688        const struct cpu_dev *const *cdev;
 689        int count = 0;
 690
 691#ifdef CONFIG_PROCESSOR_SELECT
 692        printk(KERN_INFO "KERNEL supported cpus:\n");
 693#endif
 694
 695        for (cdev = __x86_cpu_dev_start; cdev < __x86_cpu_dev_end; cdev++) {
 696                const struct cpu_dev *cpudev = *cdev;
 697
 698                if (count >= X86_VENDOR_NUM)
 699                        break;
 700                cpu_devs[count] = cpudev;
 701                count++;
 702
 703#ifdef CONFIG_PROCESSOR_SELECT
 704                {
 705                        unsigned int j;
 706
 707                        for (j = 0; j < 2; j++) {
 708                                if (!cpudev->c_ident[j])
 709                                        continue;
 710                                printk(KERN_INFO "  %s %s\n", cpudev->c_vendor,
 711                                        cpudev->c_ident[j]);
 712                        }
 713                }
 714#endif
 715        }
 716        early_identify_cpu(&boot_cpu_data);
 717}
 718
 719/*
 720 * The NOPL instruction is supposed to exist on all CPUs of family >= 6;
 721 * unfortunately, that's not true in practice because of early VIA
 722 * chips and (more importantly) broken virtualizers that are not easy
 723 * to detect. In the latter case it doesn't even *fail* reliably, so
 724 * probing for it doesn't even work. Disable it completely on 32-bit
 725 * unless we can find a reliable way to detect all the broken cases.
 726 * Enable it explicitly on 64-bit for non-constant inputs of cpu_has().
 727 */
 728static void __cpuinit detect_nopl(struct cpuinfo_x86 *c)
 729{
 730#ifdef CONFIG_X86_32
 731        clear_cpu_cap(c, X86_FEATURE_NOPL);
 732#else
 733        set_cpu_cap(c, X86_FEATURE_NOPL);
 734#endif
 735}
 736
 737static void __cpuinit generic_identify(struct cpuinfo_x86 *c)
 738{
 739        c->extended_cpuid_level = 0;
 740
 741        if (!have_cpuid_p())
 742                identify_cpu_without_cpuid(c);
 743
 744        /* cyrix could have cpuid enabled via c_identify()*/
 745        if (!have_cpuid_p())
 746                return;
 747
 748        cpu_detect(c);
 749
 750        get_cpu_vendor(c);
 751
 752        get_cpu_cap(c);
 753
 754        if (c->cpuid_level >= 0x00000001) {
 755                c->initial_apicid = (cpuid_ebx(1) >> 24) & 0xFF;
 756#ifdef CONFIG_X86_32
 757# ifdef CONFIG_X86_HT
 758                c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
 759# else
 760                c->apicid = c->initial_apicid;
 761# endif
 762#endif
 763
 764#ifdef CONFIG_X86_HT
 765                c->phys_proc_id = c->initial_apicid;
 766#endif
 767        }
 768
 769        setup_smep(c);
 770
 771        get_model_name(c); /* Default name */
 772
 773        detect_nopl(c);
 774}
 775
 776/*
 777 * This does the hard work of actually picking apart the CPU stuff...
 778 */
 779static void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
 780{
 781        int i;
 782
 783        c->loops_per_jiffy = loops_per_jiffy;
 784        c->x86_cache_size = -1;
 785        c->x86_vendor = X86_VENDOR_UNKNOWN;
 786        c->x86_model = c->x86_mask = 0; /* So far unknown... */
 787        c->x86_vendor_id[0] = '\0'; /* Unset */
 788        c->x86_model_id[0] = '\0';  /* Unset */
 789        c->x86_max_cores = 1;
 790        c->x86_coreid_bits = 0;
 791#ifdef CONFIG_X86_64
 792        c->x86_clflush_size = 64;
 793        c->x86_phys_bits = 36;
 794        c->x86_virt_bits = 48;
 795#else
 796        c->cpuid_level = -1;    /* CPUID not detected */
 797        c->x86_clflush_size = 32;
 798        c->x86_phys_bits = 32;
 799        c->x86_virt_bits = 32;
 800#endif
 801        c->x86_cache_alignment = c->x86_clflush_size;
 802        memset(&c->x86_capability, 0, sizeof c->x86_capability);
 803
 804        generic_identify(c);
 805
 806        if (this_cpu->c_identify)
 807                this_cpu->c_identify(c);
 808
 809        /* Clear/Set all flags overriden by options, after probe */
 810        for (i = 0; i < NCAPINTS; i++) {
 811                c->x86_capability[i] &= ~cpu_caps_cleared[i];
 812                c->x86_capability[i] |= cpu_caps_set[i];
 813        }
 814
 815#ifdef CONFIG_X86_64
 816        c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
 817#endif
 818
 819        /*
 820         * Vendor-specific initialization.  In this section we
 821         * canonicalize the feature flags, meaning if there are
 822         * features a certain CPU supports which CPUID doesn't
 823         * tell us, CPUID claiming incorrect flags, or other bugs,
 824         * we handle them here.
 825         *
 826         * At the end of this section, c->x86_capability better
 827         * indicate the features this CPU genuinely supports!
 828         */
 829        if (this_cpu->c_init)
 830                this_cpu->c_init(c);
 831
 832        /* Disable the PN if appropriate */
 833        squash_the_stupid_serial_number(c);
 834
 835        /*
 836         * The vendor-specific functions might have changed features.
 837         * Now we do "generic changes."
 838         */
 839
 840        /* Filter out anything that depends on CPUID levels we don't have */
 841        filter_cpuid_features(c, true);
 842
 843        /* If the model name is still unset, do table lookup. */
 844        if (!c->x86_model_id[0]) {
 845                const char *p;
 846                p = table_lookup_model(c);
 847                if (p)
 848                        strcpy(c->x86_model_id, p);
 849                else
 850                        /* Last resort... */
 851                        sprintf(c->x86_model_id, "%02x/%02x",
 852                                c->x86, c->x86_model);
 853        }
 854
 855#ifdef CONFIG_X86_64
 856        detect_ht(c);
 857#endif
 858
 859        init_hypervisor(c);
 860
 861        /*
 862         * Clear/Set all flags overriden by options, need do it
 863         * before following smp all cpus cap AND.
 864         */
 865        for (i = 0; i < NCAPINTS; i++) {
 866                c->x86_capability[i] &= ~cpu_caps_cleared[i];
 867                c->x86_capability[i] |= cpu_caps_set[i];
 868        }
 869
 870        /*
 871         * On SMP, boot_cpu_data holds the common feature set between
 872         * all CPUs; so make sure that we indicate which features are
 873         * common between the CPUs.  The first time this routine gets
 874         * executed, c == &boot_cpu_data.
 875         */
 876        if (c != &boot_cpu_data) {
 877                /* AND the already accumulated flags with these */
 878                for (i = 0; i < NCAPINTS; i++)
 879                        boot_cpu_data.x86_capability[i] &= c->x86_capability[i];
 880        }
 881
 882        /* Init Machine Check Exception if available. */
 883        mcheck_cpu_init(c);
 884
 885        select_idle_routine(c);
 886
 887#ifdef CONFIG_NUMA
 888        numa_add_cpu(smp_processor_id());
 889#endif
 890}
 891
 892#ifdef CONFIG_X86_64
 893static void vgetcpu_set_mode(void)
 894{
 895        if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP))
 896                vgetcpu_mode = VGETCPU_RDTSCP;
 897        else
 898                vgetcpu_mode = VGETCPU_LSL;
 899}
 900#endif
 901
 902void __init identify_boot_cpu(void)
 903{
 904        identify_cpu(&boot_cpu_data);
 905        init_amd_e400_c1e_mask();
 906#ifdef CONFIG_X86_32
 907        sysenter_setup();
 908        enable_sep_cpu();
 909#else
 910        vgetcpu_set_mode();
 911#endif
 912}
 913
 914void __cpuinit identify_secondary_cpu(struct cpuinfo_x86 *c)
 915{
 916        BUG_ON(c == &boot_cpu_data);
 917        identify_cpu(c);
 918#ifdef CONFIG_X86_32
 919        enable_sep_cpu();
 920#endif
 921        mtrr_ap_init();
 922}
 923
 924struct msr_range {
 925        unsigned        min;
 926        unsigned        max;
 927};
 928
 929static const struct msr_range msr_range_array[] __cpuinitconst = {
 930        { 0x00000000, 0x00000418},
 931        { 0xc0000000, 0xc000040b},
 932        { 0xc0010000, 0xc0010142},
 933        { 0xc0011000, 0xc001103b},
 934};
 935
 936static void __cpuinit print_cpu_msr(void)
 937{
 938        unsigned index_min, index_max;
 939        unsigned index;
 940        u64 val;
 941        int i;
 942
 943        for (i = 0; i < ARRAY_SIZE(msr_range_array); i++) {
 944                index_min = msr_range_array[i].min;
 945                index_max = msr_range_array[i].max;
 946
 947                for (index = index_min; index < index_max; index++) {
 948                        if (rdmsrl_amd_safe(index, &val))
 949                                continue;
 950                        printk(KERN_INFO " MSR%08x: %016llx\n", index, val);
 951                }
 952        }
 953}
 954
 955static int show_msr __cpuinitdata;
 956
 957static __init int setup_show_msr(char *arg)
 958{
 959        int num;
 960
 961        get_option(&arg, &num);
 962
 963        if (num > 0)
 964                show_msr = num;
 965        return 1;
 966}
 967__setup("show_msr=", setup_show_msr);
 968
 969static __init int setup_noclflush(char *arg)
 970{
 971        setup_clear_cpu_cap(X86_FEATURE_CLFLSH);
 972        return 1;
 973}
 974__setup("noclflush", setup_noclflush);
 975
 976void __cpuinit print_cpu_info(struct cpuinfo_x86 *c)
 977{
 978        const char *vendor = NULL;
 979
 980        if (c->x86_vendor < X86_VENDOR_NUM) {
 981                vendor = this_cpu->c_vendor;
 982        } else {
 983                if (c->cpuid_level >= 0)
 984                        vendor = c->x86_vendor_id;
 985        }
 986
 987        if (vendor && !strstr(c->x86_model_id, vendor))
 988                printk(KERN_CONT "%s ", vendor);
 989
 990        if (c->x86_model_id[0])
 991                printk(KERN_CONT "%s", c->x86_model_id);
 992        else
 993                printk(KERN_CONT "%d86", c->x86);
 994
 995        if (c->x86_mask || c->cpuid_level >= 0)
 996                printk(KERN_CONT " stepping %02x\n", c->x86_mask);
 997        else
 998                printk(KERN_CONT "\n");
 999
1000#ifdef CONFIG_SMP
1001        if (c->cpu_index < show_msr)
1002                print_cpu_msr();
1003#else
1004        if (show_msr)
1005                print_cpu_msr();
1006#endif
1007}
1008
1009static __init int setup_disablecpuid(char *arg)
1010{
1011        int bit;
1012
1013        if (get_option(&arg, &bit) && bit < NCAPINTS*32)
1014                setup_clear_cpu_cap(bit);
1015        else
1016                return 0;
1017
1018        return 1;
1019}
1020__setup("clearcpuid=", setup_disablecpuid);
1021
1022#ifdef CONFIG_X86_64
1023struct desc_ptr idt_descr = { NR_VECTORS * 16 - 1, (unsigned long) idt_table };
1024
1025DEFINE_PER_CPU_FIRST(union irq_stack_union,
1026                     irq_stack_union) __aligned(PAGE_SIZE);
1027
1028/*
1029 * The following four percpu variables are hot.  Align current_task to
1030 * cacheline size such that all four fall in the same cacheline.
1031 */
1032DEFINE_PER_CPU(struct task_struct *, current_task) ____cacheline_aligned =
1033        &init_task;
1034EXPORT_PER_CPU_SYMBOL(current_task);
1035
1036DEFINE_PER_CPU(unsigned long, kernel_stack) =
1037        (unsigned long)&init_thread_union - KERNEL_STACK_OFFSET + THREAD_SIZE;
1038EXPORT_PER_CPU_SYMBOL(kernel_stack);
1039
1040DEFINE_PER_CPU(char *, irq_stack_ptr) =
1041        init_per_cpu_var(irq_stack_union.irq_stack) + IRQ_STACK_SIZE - 64;
1042
1043DEFINE_PER_CPU(unsigned int, irq_count) = -1;
1044
1045/*
1046 * Special IST stacks which the CPU switches to when it calls
1047 * an IST-marked descriptor entry. Up to 7 stacks (hardware
1048 * limit), all of them are 4K, except the debug stack which
1049 * is 8K.
1050 */
1051static const unsigned int exception_stack_sizes[N_EXCEPTION_STACKS] = {
1052          [0 ... N_EXCEPTION_STACKS - 1]        = EXCEPTION_STKSZ,
1053          [DEBUG_STACK - 1]                     = DEBUG_STKSZ
1054};
1055
1056static DEFINE_PER_CPU_PAGE_ALIGNED(char, exception_stacks
1057        [(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ]);
1058
1059/* May not be marked __init: used by software suspend */
1060void syscall_init(void)
1061{
1062        /*
1063         * LSTAR and STAR live in a bit strange symbiosis.
1064         * They both write to the same internal register. STAR allows to
1065         * set CS/DS but only a 32bit target. LSTAR sets the 64bit rip.
1066         */
1067        wrmsrl(MSR_STAR,  ((u64)__USER32_CS)<<48  | ((u64)__KERNEL_CS)<<32);
1068        wrmsrl(MSR_LSTAR, system_call);
1069        wrmsrl(MSR_CSTAR, ignore_sysret);
1070
1071#ifdef CONFIG_IA32_EMULATION
1072        syscall32_cpu_init();
1073#endif
1074
1075        /* Flags to clear on syscall */
1076        wrmsrl(MSR_SYSCALL_MASK,
1077               X86_EFLAGS_TF|X86_EFLAGS_DF|X86_EFLAGS_IF|X86_EFLAGS_IOPL);
1078}
1079
1080unsigned long kernel_eflags;
1081
1082/*
1083 * Copies of the original ist values from the tss are only accessed during
1084 * debugging, no special alignment required.
1085 */
1086DEFINE_PER_CPU(struct orig_ist, orig_ist);
1087
1088#else   /* CONFIG_X86_64 */
1089
1090DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task;
1091EXPORT_PER_CPU_SYMBOL(current_task);
1092
1093#ifdef CONFIG_CC_STACKPROTECTOR
1094DEFINE_PER_CPU_ALIGNED(struct stack_canary, stack_canary);
1095#endif
1096
1097/* Make sure %fs and %gs are initialized properly in idle threads */
1098struct pt_regs * __cpuinit idle_regs(struct pt_regs *regs)
1099{
1100        memset(regs, 0, sizeof(struct pt_regs));
1101        regs->fs = __KERNEL_PERCPU;
1102        regs->gs = __KERNEL_STACK_CANARY;
1103
1104        return regs;
1105}
1106#endif  /* CONFIG_X86_64 */
1107
1108/*
1109 * Clear all 6 debug registers:
1110 */
1111static void clear_all_debug_regs(void)
1112{
1113        int i;
1114
1115        for (i = 0; i < 8; i++) {
1116                /* Ignore db4, db5 */
1117                if ((i == 4) || (i == 5))
1118                        continue;
1119
1120                set_debugreg(0, i);
1121        }
1122}
1123
1124#ifdef CONFIG_KGDB
1125/*
1126 * Restore debug regs if using kgdbwait and you have a kernel debugger
1127 * connection established.
1128 */
1129static void dbg_restore_debug_regs(void)
1130{
1131        if (unlikely(kgdb_connected && arch_kgdb_ops.correct_hw_break))
1132                arch_kgdb_ops.correct_hw_break();
1133}
1134#else /* ! CONFIG_KGDB */
1135#define dbg_restore_debug_regs()
1136#endif /* ! CONFIG_KGDB */
1137
1138/*
1139 * cpu_init() initializes state that is per-CPU. Some data is already
1140 * initialized (naturally) in the bootstrap process, such as the GDT
1141 * and IDT. We reload them nevertheless, this function acts as a
1142 * 'CPU state barrier', nothing should get across.
1143 * A lot of state is already set up in PDA init for 64 bit
1144 */
1145#ifdef CONFIG_X86_64
1146
1147void __cpuinit cpu_init(void)
1148{
1149        struct orig_ist *oist;
1150        struct task_struct *me;
1151        struct tss_struct *t;
1152        unsigned long v;
1153        int cpu;
1154        int i;
1155
1156        cpu = stack_smp_processor_id();
1157        t = &per_cpu(init_tss, cpu);
1158        oist = &per_cpu(orig_ist, cpu);
1159
1160#ifdef CONFIG_NUMA
1161        if (cpu != 0 && percpu_read(numa_node) == 0 &&
1162            early_cpu_to_node(cpu) != NUMA_NO_NODE)
1163                set_numa_node(early_cpu_to_node(cpu));
1164#endif
1165
1166        me = current;
1167
1168        if (cpumask_test_and_set_cpu(cpu, cpu_initialized_mask))
1169                panic("CPU#%d already initialized!\n", cpu);
1170
1171        pr_debug("Initializing CPU#%d\n", cpu);
1172
1173        clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1174
1175        /*
1176         * Initialize the per-CPU GDT with the boot GDT,
1177         * and set up the GDT descriptor:
1178         */
1179
1180        switch_to_new_gdt(cpu);
1181        loadsegment(fs, 0);
1182
1183        load_idt((const struct desc_ptr *)&idt_descr);
1184
1185        memset(me->thread.tls_array, 0, GDT_ENTRY_TLS_ENTRIES * 8);
1186        syscall_init();
1187
1188        wrmsrl(MSR_FS_BASE, 0);
1189        wrmsrl(MSR_KERNEL_GS_BASE, 0);
1190        barrier();
1191
1192        x86_configure_nx();
1193        if (cpu != 0)
1194                enable_x2apic();
1195
1196        /*
1197         * set up and load the per-CPU TSS
1198         */
1199        if (!oist->ist[0]) {
1200                char *estacks = per_cpu(exception_stacks, cpu);
1201
1202                for (v = 0; v < N_EXCEPTION_STACKS; v++) {
1203                        estacks += exception_stack_sizes[v];
1204                        oist->ist[v] = t->x86_tss.ist[v] =
1205                                        (unsigned long)estacks;
1206                }
1207        }
1208
1209        t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
1210
1211        /*
1212         * <= is required because the CPU will access up to
1213         * 8 bits beyond the end of the IO permission bitmap.
1214         */
1215        for (i = 0; i <= IO_BITMAP_LONGS; i++)
1216                t->io_bitmap[i] = ~0UL;
1217
1218        atomic_inc(&init_mm.mm_count);
1219        me->active_mm = &init_mm;
1220        BUG_ON(me->mm);
1221        enter_lazy_tlb(&init_mm, me);
1222
1223        load_sp0(t, &current->thread);
1224        set_tss_desc(cpu, t);
1225        load_TR_desc();
1226        load_LDT(&init_mm.context);
1227
1228        clear_all_debug_regs();
1229        dbg_restore_debug_regs();
1230
1231        fpu_init();
1232        xsave_init();
1233
1234        raw_local_save_flags(kernel_eflags);
1235
1236        if (is_uv_system())
1237                uv_cpu_init();
1238}
1239
1240#else
1241
1242void __cpuinit cpu_init(void)
1243{
1244        int cpu = smp_processor_id();
1245        struct task_struct *curr = current;
1246        struct tss_struct *t = &per_cpu(init_tss, cpu);
1247        struct thread_struct *thread = &curr->thread;
1248
1249        if (cpumask_test_and_set_cpu(cpu, cpu_initialized_mask)) {
1250                printk(KERN_WARNING "CPU#%d already initialized!\n", cpu);
1251                for (;;)
1252                        local_irq_enable();
1253        }
1254
1255        printk(KERN_INFO "Initializing CPU#%d\n", cpu);
1256
1257        if (cpu_has_vme || cpu_has_tsc || cpu_has_de)
1258                clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1259
1260        load_idt(&idt_descr);
1261        switch_to_new_gdt(cpu);
1262
1263        /*
1264         * Set up and load the per-CPU TSS and LDT
1265         */
1266        atomic_inc(&init_mm.mm_count);
1267        curr->active_mm = &init_mm;
1268        BUG_ON(curr->mm);
1269        enter_lazy_tlb(&init_mm, curr);
1270
1271        load_sp0(t, thread);
1272        set_tss_desc(cpu, t);
1273        load_TR_desc();
1274        load_LDT(&init_mm.context);
1275
1276        t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
1277
1278#ifdef CONFIG_DOUBLEFAULT
1279        /* Set up doublefault TSS pointer in the GDT */
1280        __set_tss_desc(cpu, GDT_ENTRY_DOUBLEFAULT_TSS, &doublefault_tss);
1281#endif
1282
1283        clear_all_debug_regs();
1284        dbg_restore_debug_regs();
1285
1286        fpu_init();
1287        xsave_init();
1288}
1289#endif
1290