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/mmu_context.h>
  17#include <asm/hypervisor.h>
  18#include <asm/processor.h>
  19#include <asm/sections.h>
  20#include <asm/topology.h>
  21#include <asm/cpumask.h>
  22#include <asm/pgtable.h>
  23#include <asm/atomic.h>
  24#include <asm/proto.h>
  25#include <asm/setup.h>
  26#include <asm/apic.h>
  27#include <asm/desc.h>
  28#include <asm/i387.h>
  29#include <asm/mtrr.h>
  30#include <asm/numa.h>
  31#include <asm/asm.h>
  32#include <asm/cpu.h>
  33#include <asm/mce.h>
  34#include <asm/msr.h>
  35#include <asm/pat.h>
  36#include <asm/smp.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 const struct cpu_dev *this_cpu __cpuinitdata;
  62
  63DEFINE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page) = { .gdt = {
  64#ifdef CONFIG_X86_64
  65        /*
  66         * We need valid kernel segments for data and code in long mode too
  67         * IRET will check the segment types  kkeil 2000/10/28
  68         * Also sysret mandates a special GDT layout
  69         *
  70         * TLS descriptors are currently at a different place compared to i386.
  71         * Hopefully nobody expects them at a fixed place (Wine?)
  72         */
  73        [GDT_ENTRY_KERNEL32_CS]         = { { { 0x0000ffff, 0x00cf9b00 } } },
  74        [GDT_ENTRY_KERNEL_CS]           = { { { 0x0000ffff, 0x00af9b00 } } },
  75        [GDT_ENTRY_KERNEL_DS]           = { { { 0x0000ffff, 0x00cf9300 } } },
  76        [GDT_ENTRY_DEFAULT_USER32_CS]   = { { { 0x0000ffff, 0x00cffb00 } } },
  77        [GDT_ENTRY_DEFAULT_USER_DS]     = { { { 0x0000ffff, 0x00cff300 } } },
  78        [GDT_ENTRY_DEFAULT_USER_CS]     = { { { 0x0000ffff, 0x00affb00 } } },
  79#else
  80        [GDT_ENTRY_KERNEL_CS]           = { { { 0x0000ffff, 0x00cf9a00 } } },
  81        [GDT_ENTRY_KERNEL_DS]           = { { { 0x0000ffff, 0x00cf9200 } } },
  82        [GDT_ENTRY_DEFAULT_USER_CS]     = { { { 0x0000ffff, 0x00cffa00 } } },
  83        [GDT_ENTRY_DEFAULT_USER_DS]     = { { { 0x0000ffff, 0x00cff200 } } },
  84        /*
  85         * Segments used for calling PnP BIOS have byte granularity.
  86         * They code segments and data segments have fixed 64k limits,
  87         * the transfer segment sizes are set at run time.
  88         */
  89        /* 32-bit code */
  90        [GDT_ENTRY_PNPBIOS_CS32]        = { { { 0x0000ffff, 0x00409a00 } } },
  91        /* 16-bit code */
  92        [GDT_ENTRY_PNPBIOS_CS16]        = { { { 0x0000ffff, 0x00009a00 } } },
  93        /* 16-bit data */
  94        [GDT_ENTRY_PNPBIOS_DS]          = { { { 0x0000ffff, 0x00009200 } } },
  95        /* 16-bit data */
  96        [GDT_ENTRY_PNPBIOS_TS1]         = { { { 0x00000000, 0x00009200 } } },
  97        /* 16-bit data */
  98        [GDT_ENTRY_PNPBIOS_TS2]         = { { { 0x00000000, 0x00009200 } } },
  99        /*
 100         * The APM segments have byte granularity and their bases
 101         * are set at run time.  All have 64k limits.
 102         */
 103        /* 32-bit code */
 104        [GDT_ENTRY_APMBIOS_BASE]        = { { { 0x0000ffff, 0x00409a00 } } },
 105        /* 16-bit code */
 106        [GDT_ENTRY_APMBIOS_BASE+1]      = { { { 0x0000ffff, 0x00009a00 } } },
 107        /* data */
 108        [GDT_ENTRY_APMBIOS_BASE+2]      = { { { 0x0000ffff, 0x00409200 } } },
 109
 110        [GDT_ENTRY_ESPFIX_SS]           = { { { 0x00000000, 0x00c09200 } } },
 111        [GDT_ENTRY_PERCPU]              = { { { 0x0000ffff, 0x00cf9200 } } },
 112        GDT_STACK_CANARY_INIT
 113#endif
 114} };
 115EXPORT_PER_CPU_SYMBOL_GPL(gdt_page);
 116
 117static int __init x86_xsave_setup(char *s)
 118{
 119        setup_clear_cpu_cap(X86_FEATURE_XSAVE);
 120        return 1;
 121}
 122__setup("noxsave", x86_xsave_setup);
 123
 124#ifdef CONFIG_X86_32
 125static int cachesize_override __cpuinitdata = -1;
 126static int disable_x86_serial_nr __cpuinitdata = 1;
 127
 128static int __init cachesize_setup(char *str)
 129{
 130        get_option(&str, &cachesize_override);
 131        return 1;
 132}
 133__setup("cachesize=", cachesize_setup);
 134
 135static int __init x86_fxsr_setup(char *s)
 136{
 137        setup_clear_cpu_cap(X86_FEATURE_FXSR);
 138        setup_clear_cpu_cap(X86_FEATURE_XMM);
 139        return 1;
 140}
 141__setup("nofxsr", x86_fxsr_setup);
 142
 143static int __init x86_sep_setup(char *s)
 144{
 145        setup_clear_cpu_cap(X86_FEATURE_SEP);
 146        return 1;
 147}
 148__setup("nosep", x86_sep_setup);
 149
 150/* Standard macro to see if a specific flag is changeable */
 151static inline int flag_is_changeable_p(u32 flag)
 152{
 153        u32 f1, f2;
 154
 155        /*
 156         * Cyrix and IDT cpus allow disabling of CPUID
 157         * so the code below may return different results
 158         * when it is executed before and after enabling
 159         * the CPUID. Add "volatile" to not allow gcc to
 160         * optimize the subsequent calls to this function.
 161         */
 162        asm volatile ("pushfl           \n\t"
 163                      "pushfl           \n\t"
 164                      "popl %0          \n\t"
 165                      "movl %0, %1      \n\t"
 166                      "xorl %2, %0      \n\t"
 167                      "pushl %0         \n\t"
 168                      "popfl            \n\t"
 169                      "pushfl           \n\t"
 170                      "popl %0          \n\t"
 171                      "popfl            \n\t"
 172
 173                      : "=&r" (f1), "=&r" (f2)
 174                      : "ir" (flag));
 175
 176        return ((f1^f2) & flag) != 0;
 177}
 178
 179/* Probe for the CPUID instruction */
 180static int __cpuinit have_cpuid_p(void)
 181{
 182        return flag_is_changeable_p(X86_EFLAGS_ID);
 183}
 184
 185static void __cpuinit squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
 186{
 187        unsigned long lo, hi;
 188
 189        if (!cpu_has(c, X86_FEATURE_PN) || !disable_x86_serial_nr)
 190                return;
 191
 192        /* Disable processor serial number: */
 193
 194        rdmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
 195        lo |= 0x200000;
 196        wrmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
 197
 198        printk(KERN_NOTICE "CPU serial number disabled.\n");
 199        clear_cpu_cap(c, X86_FEATURE_PN);
 200
 201        /* Disabling the serial number may affect the cpuid level */
 202        c->cpuid_level = cpuid_eax(0);
 203}
 204
 205static int __init x86_serial_nr_setup(char *s)
 206{
 207        disable_x86_serial_nr = 0;
 208        return 1;
 209}
 210__setup("serialnumber", x86_serial_nr_setup);
 211#else
 212static inline int flag_is_changeable_p(u32 flag)
 213{
 214        return 1;
 215}
 216/* Probe for the CPUID instruction */
 217static inline int have_cpuid_p(void)
 218{
 219        return 1;
 220}
 221static inline void squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
 222{
 223}
 224#endif
 225
 226/*
 227 * Some CPU features depend on higher CPUID levels, which may not always
 228 * be available due to CPUID level capping or broken virtualization
 229 * software.  Add those features to this table to auto-disable them.
 230 */
 231struct cpuid_dependent_feature {
 232        u32 feature;
 233        u32 level;
 234};
 235
 236static const struct cpuid_dependent_feature __cpuinitconst
 237cpuid_dependent_features[] = {
 238        { X86_FEATURE_MWAIT,            0x00000005 },
 239        { X86_FEATURE_DCA,              0x00000009 },
 240        { X86_FEATURE_XSAVE,            0x0000000d },
 241        { 0, 0 }
 242};
 243
 244static void __cpuinit filter_cpuid_features(struct cpuinfo_x86 *c, bool warn)
 245{
 246        const struct cpuid_dependent_feature *df;
 247
 248        for (df = cpuid_dependent_features; df->feature; df++) {
 249
 250                if (!cpu_has(c, df->feature))
 251                        continue;
 252                /*
 253                 * Note: cpuid_level is set to -1 if unavailable, but
 254                 * extended_extended_level is set to 0 if unavailable
 255                 * and the legitimate extended levels are all negative
 256                 * when signed; hence the weird messing around with
 257                 * signs here...
 258                 */
 259                if (!((s32)df->level < 0 ?
 260                     (u32)df->level > (u32)c->extended_cpuid_level :
 261                     (s32)df->level > (s32)c->cpuid_level))
 262                        continue;
 263
 264                clear_cpu_cap(c, df->feature);
 265                if (!warn)
 266                        continue;
 267
 268                printk(KERN_WARNING
 269                       "CPU: CPU feature %s disabled, no CPUID level 0x%x\n",
 270                                x86_cap_flags[df->feature], df->level);
 271        }
 272}
 273
 274/*
 275 * Naming convention should be: <Name> [(<Codename>)]
 276 * This table only is used unless init_<vendor>() below doesn't set it;
 277 * in particular, if CPUID levels 0x80000002..4 are supported, this
 278 * isn't used
 279 */
 280
 281/* Look up CPU names by table lookup. */
 282static const char *__cpuinit table_lookup_model(struct cpuinfo_x86 *c)
 283{
 284        const struct cpu_model_info *info;
 285
 286        if (c->x86_model >= 16)
 287                return NULL;    /* Range check */
 288
 289        if (!this_cpu)
 290                return NULL;
 291
 292        info = this_cpu->c_models;
 293
 294        while (info && info->family) {
 295                if (info->family == c->x86)
 296                        return info->model_names[c->x86_model];
 297                info++;
 298        }
 299        return NULL;            /* Not found */
 300}
 301
 302__u32 cleared_cpu_caps[NCAPINTS] __cpuinitdata;
 303
 304void load_percpu_segment(int cpu)
 305{
 306#ifdef CONFIG_X86_32
 307        loadsegment(fs, __KERNEL_PERCPU);
 308#else
 309        loadsegment(gs, 0);
 310        wrmsrl(MSR_GS_BASE, (unsigned long)per_cpu(irq_stack_union.gs_base, cpu));
 311#endif
 312        load_stack_canary_segment();
 313}
 314
 315/*
 316 * Current gdt points %fs at the "master" per-cpu area: after this,
 317 * it's on the real one.
 318 */
 319void switch_to_new_gdt(int cpu)
 320{
 321        struct desc_ptr gdt_descr;
 322
 323        gdt_descr.address = (long)get_cpu_gdt_table(cpu);
 324        gdt_descr.size = GDT_SIZE - 1;
 325        load_gdt(&gdt_descr);
 326        /* Reload the per-cpu base */
 327
 328        load_percpu_segment(cpu);
 329}
 330
 331static const struct cpu_dev *__cpuinitdata cpu_devs[X86_VENDOR_NUM] = {};
 332
 333static void __cpuinit default_init(struct cpuinfo_x86 *c)
 334{
 335#ifdef CONFIG_X86_64
 336        display_cacheinfo(c);
 337#else
 338        /* Not much we can do here... */
 339        /* Check if at least it has cpuid */
 340        if (c->cpuid_level == -1) {
 341                /* No cpuid. It must be an ancient CPU */
 342                if (c->x86 == 4)
 343                        strcpy(c->x86_model_id, "486");
 344                else if (c->x86 == 3)
 345                        strcpy(c->x86_model_id, "386");
 346        }
 347#endif
 348}
 349
 350static const struct cpu_dev __cpuinitconst default_cpu = {
 351        .c_init = default_init,
 352        .c_vendor = "Unknown",
 353        .c_x86_vendor = X86_VENDOR_UNKNOWN,
 354};
 355
 356static void __cpuinit get_model_name(struct cpuinfo_x86 *c)
 357{
 358        unsigned int *v;
 359        char *p, *q;
 360
 361        if (c->extended_cpuid_level < 0x80000004)
 362                return;
 363
 364        v = (unsigned int *)c->x86_model_id;
 365        cpuid(0x80000002, &v[0], &v[1], &v[2], &v[3]);
 366        cpuid(0x80000003, &v[4], &v[5], &v[6], &v[7]);
 367        cpuid(0x80000004, &v[8], &v[9], &v[10], &v[11]);
 368        c->x86_model_id[48] = 0;
 369
 370        /*
 371         * Intel chips right-justify this string for some dumb reason;
 372         * undo that brain damage:
 373         */
 374        p = q = &c->x86_model_id[0];
 375        while (*p == ' ')
 376                p++;
 377        if (p != q) {
 378                while (*p)
 379                        *q++ = *p++;
 380                while (q <= &c->x86_model_id[48])
 381                        *q++ = '\0';    /* Zero-pad the rest */
 382        }
 383}
 384
 385void __cpuinit display_cacheinfo(struct cpuinfo_x86 *c)
 386{
 387        unsigned int n, dummy, ebx, ecx, edx, l2size;
 388
 389        n = c->extended_cpuid_level;
 390
 391        if (n >= 0x80000005) {
 392                cpuid(0x80000005, &dummy, &ebx, &ecx, &edx);
 393                printk(KERN_INFO "CPU: L1 I Cache: %dK (%d bytes/line), D cache %dK (%d bytes/line)\n",
 394                                edx>>24, edx&0xFF, ecx>>24, ecx&0xFF);
 395                c->x86_cache_size = (ecx>>24) + (edx>>24);
 396#ifdef CONFIG_X86_64
 397                /* On K8 L1 TLB is inclusive, so don't count it */
 398                c->x86_tlbsize = 0;
 399#endif
 400        }
 401
 402        if (n < 0x80000006)     /* Some chips just has a large L1. */
 403                return;
 404
 405        cpuid(0x80000006, &dummy, &ebx, &ecx, &edx);
 406        l2size = ecx >> 16;
 407
 408#ifdef CONFIG_X86_64
 409        c->x86_tlbsize += ((ebx >> 16) & 0xfff) + (ebx & 0xfff);
 410#else
 411        /* do processor-specific cache resizing */
 412        if (this_cpu->c_size_cache)
 413                l2size = this_cpu->c_size_cache(c, l2size);
 414
 415        /* Allow user to override all this if necessary. */
 416        if (cachesize_override != -1)
 417                l2size = cachesize_override;
 418
 419        if (l2size == 0)
 420                return;         /* Again, no L2 cache is possible */
 421#endif
 422
 423        c->x86_cache_size = l2size;
 424
 425        printk(KERN_INFO "CPU: L2 Cache: %dK (%d bytes/line)\n",
 426                        l2size, ecx & 0xFF);
 427}
 428
 429void __cpuinit detect_ht(struct cpuinfo_x86 *c)
 430{
 431#ifdef CONFIG_X86_HT
 432        u32 eax, ebx, ecx, edx;
 433        int index_msb, core_bits;
 434
 435        if (!cpu_has(c, X86_FEATURE_HT))
 436                return;
 437
 438        if (cpu_has(c, X86_FEATURE_CMP_LEGACY))
 439                goto out;
 440
 441        if (cpu_has(c, X86_FEATURE_XTOPOLOGY))
 442                return;
 443
 444        cpuid(1, &eax, &ebx, &ecx, &edx);
 445
 446        smp_num_siblings = (ebx & 0xff0000) >> 16;
 447
 448        if (smp_num_siblings == 1) {
 449                printk(KERN_INFO  "CPU: Hyper-Threading is disabled\n");
 450                goto out;
 451        }
 452
 453        if (smp_num_siblings <= 1)
 454                goto out;
 455
 456        if (smp_num_siblings > nr_cpu_ids) {
 457                pr_warning("CPU: Unsupported number of siblings %d",
 458                           smp_num_siblings);
 459                smp_num_siblings = 1;
 460                return;
 461        }
 462
 463        index_msb = get_count_order(smp_num_siblings);
 464        c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, index_msb);
 465
 466        smp_num_siblings = smp_num_siblings / c->x86_max_cores;
 467
 468        index_msb = get_count_order(smp_num_siblings);
 469
 470        core_bits = get_count_order(c->x86_max_cores);
 471
 472        c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid, index_msb) &
 473                                       ((1 << core_bits) - 1);
 474
 475out:
 476        if ((c->x86_max_cores * smp_num_siblings) > 1) {
 477                printk(KERN_INFO  "CPU: Physical Processor ID: %d\n",
 478                       c->phys_proc_id);
 479                printk(KERN_INFO  "CPU: Processor Core ID: %d\n",
 480                       c->cpu_core_id);
 481        }
 482#endif
 483}
 484
 485static void __cpuinit get_cpu_vendor(struct cpuinfo_x86 *c)
 486{
 487        char *v = c->x86_vendor_id;
 488        static int printed;
 489        int i;
 490
 491        for (i = 0; i < X86_VENDOR_NUM; i++) {
 492                if (!cpu_devs[i])
 493                        break;
 494
 495                if (!strcmp(v, cpu_devs[i]->c_ident[0]) ||
 496                    (cpu_devs[i]->c_ident[1] &&
 497                     !strcmp(v, cpu_devs[i]->c_ident[1]))) {
 498
 499                        this_cpu = cpu_devs[i];
 500                        c->x86_vendor = this_cpu->c_x86_vendor;
 501                        return;
 502                }
 503        }
 504
 505        if (!printed) {
 506                printed++;
 507                printk(KERN_ERR
 508                    "CPU: vendor_id '%s' unknown, using generic init.\n", v);
 509
 510                printk(KERN_ERR "CPU: Your system may be unstable.\n");
 511        }
 512
 513        c->x86_vendor = X86_VENDOR_UNKNOWN;
 514        this_cpu = &default_cpu;
 515}
 516
 517void __cpuinit cpu_detect(struct cpuinfo_x86 *c)
 518{
 519        /* Get vendor name */
 520        cpuid(0x00000000, (unsigned int *)&c->cpuid_level,
 521              (unsigned int *)&c->x86_vendor_id[0],
 522              (unsigned int *)&c->x86_vendor_id[8],
 523              (unsigned int *)&c->x86_vendor_id[4]);
 524
 525        c->x86 = 4;
 526        /* Intel-defined flags: level 0x00000001 */
 527        if (c->cpuid_level >= 0x00000001) {
 528                u32 junk, tfms, cap0, misc;
 529
 530                cpuid(0x00000001, &tfms, &misc, &junk, &cap0);
 531                c->x86 = (tfms >> 8) & 0xf;
 532                c->x86_model = (tfms >> 4) & 0xf;
 533                c->x86_mask = tfms & 0xf;
 534
 535                if (c->x86 == 0xf)
 536                        c->x86 += (tfms >> 20) & 0xff;
 537                if (c->x86 >= 0x6)
 538                        c->x86_model += ((tfms >> 16) & 0xf) << 4;
 539
 540                if (cap0 & (1<<19)) {
 541                        c->x86_clflush_size = ((misc >> 8) & 0xff) * 8;
 542                        c->x86_cache_alignment = c->x86_clflush_size;
 543                }
 544        }
 545}
 546
 547static void __cpuinit get_cpu_cap(struct cpuinfo_x86 *c)
 548{
 549        u32 tfms, xlvl;
 550        u32 ebx;
 551
 552        /* Intel-defined flags: level 0x00000001 */
 553        if (c->cpuid_level >= 0x00000001) {
 554                u32 capability, excap;
 555
 556                cpuid(0x00000001, &tfms, &ebx, &excap, &capability);
 557                c->x86_capability[0] = capability;
 558                c->x86_capability[4] = excap;
 559        }
 560
 561        /* AMD-defined flags: level 0x80000001 */
 562        xlvl = cpuid_eax(0x80000000);
 563        c->extended_cpuid_level = xlvl;
 564
 565        if ((xlvl & 0xffff0000) == 0x80000000) {
 566                if (xlvl >= 0x80000001) {
 567                        c->x86_capability[1] = cpuid_edx(0x80000001);
 568                        c->x86_capability[6] = cpuid_ecx(0x80000001);
 569                }
 570        }
 571
 572        if (c->extended_cpuid_level >= 0x80000008) {
 573                u32 eax = cpuid_eax(0x80000008);
 574
 575                c->x86_virt_bits = (eax >> 8) & 0xff;
 576                c->x86_phys_bits = eax & 0xff;
 577        }
 578#ifdef CONFIG_X86_32
 579        else if (cpu_has(c, X86_FEATURE_PAE) || cpu_has(c, X86_FEATURE_PSE36))
 580                c->x86_phys_bits = 36;
 581#endif
 582
 583        if (c->extended_cpuid_level >= 0x80000007)
 584                c->x86_power = cpuid_edx(0x80000007);
 585
 586}
 587
 588static void __cpuinit identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
 589{
 590#ifdef CONFIG_X86_32
 591        int i;
 592
 593        /*
 594         * First of all, decide if this is a 486 or higher
 595         * It's a 486 if we can modify the AC flag
 596         */
 597        if (flag_is_changeable_p(X86_EFLAGS_AC))
 598                c->x86 = 4;
 599        else
 600                c->x86 = 3;
 601
 602        for (i = 0; i < X86_VENDOR_NUM; i++)
 603                if (cpu_devs[i] && cpu_devs[i]->c_identify) {
 604                        c->x86_vendor_id[0] = 0;
 605                        cpu_devs[i]->c_identify(c);
 606                        if (c->x86_vendor_id[0]) {
 607                                get_cpu_vendor(c);
 608                                break;
 609                        }
 610                }
 611#endif
 612}
 613
 614/*
 615 * Do minimum CPU detection early.
 616 * Fields really needed: vendor, cpuid_level, family, model, mask,
 617 * cache alignment.
 618 * The others are not touched to avoid unwanted side effects.
 619 *
 620 * WARNING: this function is only called on the BP.  Don't add code here
 621 * that is supposed to run on all CPUs.
 622 */
 623static void __init early_identify_cpu(struct cpuinfo_x86 *c)
 624{
 625#ifdef CONFIG_X86_64
 626        c->x86_clflush_size = 64;
 627        c->x86_phys_bits = 36;
 628        c->x86_virt_bits = 48;
 629#else
 630        c->x86_clflush_size = 32;
 631        c->x86_phys_bits = 32;
 632        c->x86_virt_bits = 32;
 633#endif
 634        c->x86_cache_alignment = c->x86_clflush_size;
 635
 636        memset(&c->x86_capability, 0, sizeof c->x86_capability);
 637        c->extended_cpuid_level = 0;
 638
 639        if (!have_cpuid_p())
 640                identify_cpu_without_cpuid(c);
 641
 642        /* cyrix could have cpuid enabled via c_identify()*/
 643        if (!have_cpuid_p())
 644                return;
 645
 646        cpu_detect(c);
 647
 648        get_cpu_vendor(c);
 649
 650        get_cpu_cap(c);
 651
 652        if (this_cpu->c_early_init)
 653                this_cpu->c_early_init(c);
 654
 655#ifdef CONFIG_SMP
 656        c->cpu_index = boot_cpu_id;
 657#endif
 658        filter_cpuid_features(c, false);
 659}
 660
 661void __init early_cpu_init(void)
 662{
 663        const struct cpu_dev *const *cdev;
 664        int count = 0;
 665
 666        printk(KERN_INFO "KERNEL supported cpus:\n");
 667        for (cdev = __x86_cpu_dev_start; cdev < __x86_cpu_dev_end; cdev++) {
 668                const struct cpu_dev *cpudev = *cdev;
 669                unsigned int j;
 670
 671                if (count >= X86_VENDOR_NUM)
 672                        break;
 673                cpu_devs[count] = cpudev;
 674                count++;
 675
 676                for (j = 0; j < 2; j++) {
 677                        if (!cpudev->c_ident[j])
 678                                continue;
 679                        printk(KERN_INFO "  %s %s\n", cpudev->c_vendor,
 680                                cpudev->c_ident[j]);
 681                }
 682        }
 683
 684        early_identify_cpu(&boot_cpu_data);
 685}
 686
 687/*
 688 * The NOPL instruction is supposed to exist on all CPUs with
 689 * family >= 6; unfortunately, that's not true in practice because
 690 * of early VIA chips and (more importantly) broken virtualizers that
 691 * are not easy to detect.  In the latter case it doesn't even *fail*
 692 * reliably, so probing for it doesn't even work.  Disable it completely
 693 * unless we can find a reliable way to detect all the broken cases.
 694 */
 695static void __cpuinit detect_nopl(struct cpuinfo_x86 *c)
 696{
 697        clear_cpu_cap(c, X86_FEATURE_NOPL);
 698}
 699
 700static void __cpuinit generic_identify(struct cpuinfo_x86 *c)
 701{
 702        c->extended_cpuid_level = 0;
 703
 704        if (!have_cpuid_p())
 705                identify_cpu_without_cpuid(c);
 706
 707        /* cyrix could have cpuid enabled via c_identify()*/
 708        if (!have_cpuid_p())
 709                return;
 710
 711        cpu_detect(c);
 712
 713        get_cpu_vendor(c);
 714
 715        get_cpu_cap(c);
 716
 717        if (c->cpuid_level >= 0x00000001) {
 718                c->initial_apicid = (cpuid_ebx(1) >> 24) & 0xFF;
 719#ifdef CONFIG_X86_32
 720# ifdef CONFIG_X86_HT
 721                c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
 722# else
 723                c->apicid = c->initial_apicid;
 724# endif
 725#endif
 726
 727#ifdef CONFIG_X86_HT
 728                c->phys_proc_id = c->initial_apicid;
 729#endif
 730        }
 731
 732        get_model_name(c); /* Default name */
 733
 734        init_scattered_cpuid_features(c);
 735        detect_nopl(c);
 736}
 737
 738/*
 739 * This does the hard work of actually picking apart the CPU stuff...
 740 */
 741static void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
 742{
 743        int i;
 744
 745        c->loops_per_jiffy = loops_per_jiffy;
 746        c->x86_cache_size = -1;
 747        c->x86_vendor = X86_VENDOR_UNKNOWN;
 748        c->x86_model = c->x86_mask = 0; /* So far unknown... */
 749        c->x86_vendor_id[0] = '\0'; /* Unset */
 750        c->x86_model_id[0] = '\0';  /* Unset */
 751        c->x86_max_cores = 1;
 752        c->x86_coreid_bits = 0;
 753#ifdef CONFIG_X86_64
 754        c->x86_clflush_size = 64;
 755        c->x86_phys_bits = 36;
 756        c->x86_virt_bits = 48;
 757#else
 758        c->cpuid_level = -1;    /* CPUID not detected */
 759        c->x86_clflush_size = 32;
 760        c->x86_phys_bits = 32;
 761        c->x86_virt_bits = 32;
 762#endif
 763        c->x86_cache_alignment = c->x86_clflush_size;
 764        memset(&c->x86_capability, 0, sizeof c->x86_capability);
 765
 766        generic_identify(c);
 767
 768        if (this_cpu->c_identify)
 769                this_cpu->c_identify(c);
 770
 771#ifdef CONFIG_X86_64
 772        c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
 773#endif
 774
 775        /*
 776         * Vendor-specific initialization.  In this section we
 777         * canonicalize the feature flags, meaning if there are
 778         * features a certain CPU supports which CPUID doesn't
 779         * tell us, CPUID claiming incorrect flags, or other bugs,
 780         * we handle them here.
 781         *
 782         * At the end of this section, c->x86_capability better
 783         * indicate the features this CPU genuinely supports!
 784         */
 785        if (this_cpu->c_init)
 786                this_cpu->c_init(c);
 787
 788        /* Disable the PN if appropriate */
 789        squash_the_stupid_serial_number(c);
 790
 791        /*
 792         * The vendor-specific functions might have changed features.
 793         * Now we do "generic changes."
 794         */
 795
 796        /* Filter out anything that depends on CPUID levels we don't have */
 797        filter_cpuid_features(c, true);
 798
 799        /* If the model name is still unset, do table lookup. */
 800        if (!c->x86_model_id[0]) {
 801                const char *p;
 802                p = table_lookup_model(c);
 803                if (p)
 804                        strcpy(c->x86_model_id, p);
 805                else
 806                        /* Last resort... */
 807                        sprintf(c->x86_model_id, "%02x/%02x",
 808                                c->x86, c->x86_model);
 809        }
 810
 811#ifdef CONFIG_X86_64
 812        detect_ht(c);
 813#endif
 814
 815        init_hypervisor(c);
 816        /*
 817         * On SMP, boot_cpu_data holds the common feature set between
 818         * all CPUs; so make sure that we indicate which features are
 819         * common between the CPUs.  The first time this routine gets
 820         * executed, c == &boot_cpu_data.
 821         */
 822        if (c != &boot_cpu_data) {
 823                /* AND the already accumulated flags with these */
 824                for (i = 0; i < NCAPINTS; i++)
 825                        boot_cpu_data.x86_capability[i] &= c->x86_capability[i];
 826        }
 827
 828        /* Clear all flags overriden by options */
 829        for (i = 0; i < NCAPINTS; i++)
 830                c->x86_capability[i] &= ~cleared_cpu_caps[i];
 831
 832#ifdef CONFIG_X86_MCE
 833        /* Init Machine Check Exception if available. */
 834        mcheck_init(c);
 835#endif
 836
 837        select_idle_routine(c);
 838
 839#if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
 840        numa_add_cpu(smp_processor_id());
 841#endif
 842}
 843
 844#ifdef CONFIG_X86_64
 845static void vgetcpu_set_mode(void)
 846{
 847        if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP))
 848                vgetcpu_mode = VGETCPU_RDTSCP;
 849        else
 850                vgetcpu_mode = VGETCPU_LSL;
 851}
 852#endif
 853
 854void __init identify_boot_cpu(void)
 855{
 856        identify_cpu(&boot_cpu_data);
 857        init_c1e_mask();
 858#ifdef CONFIG_X86_32
 859        sysenter_setup();
 860        enable_sep_cpu();
 861#else
 862        vgetcpu_set_mode();
 863#endif
 864}
 865
 866void __cpuinit identify_secondary_cpu(struct cpuinfo_x86 *c)
 867{
 868        BUG_ON(c == &boot_cpu_data);
 869        identify_cpu(c);
 870#ifdef CONFIG_X86_32
 871        enable_sep_cpu();
 872#endif
 873        mtrr_ap_init();
 874}
 875
 876struct msr_range {
 877        unsigned        min;
 878        unsigned        max;
 879};
 880
 881static const struct msr_range msr_range_array[] __cpuinitconst = {
 882        { 0x00000000, 0x00000418},
 883        { 0xc0000000, 0xc000040b},
 884        { 0xc0010000, 0xc0010142},
 885        { 0xc0011000, 0xc001103b},
 886};
 887
 888static void __cpuinit print_cpu_msr(void)
 889{
 890        unsigned index_min, index_max;
 891        unsigned index;
 892        u64 val;
 893        int i;
 894
 895        for (i = 0; i < ARRAY_SIZE(msr_range_array); i++) {
 896                index_min = msr_range_array[i].min;
 897                index_max = msr_range_array[i].max;
 898
 899                for (index = index_min; index < index_max; index++) {
 900                        if (rdmsrl_amd_safe(index, &val))
 901                                continue;
 902                        printk(KERN_INFO " MSR%08x: %016llx\n", index, val);
 903                }
 904        }
 905}
 906
 907static int show_msr __cpuinitdata;
 908
 909static __init int setup_show_msr(char *arg)
 910{
 911        int num;
 912
 913        get_option(&arg, &num);
 914
 915        if (num > 0)
 916                show_msr = num;
 917        return 1;
 918}
 919__setup("show_msr=", setup_show_msr);
 920
 921static __init int setup_noclflush(char *arg)
 922{
 923        setup_clear_cpu_cap(X86_FEATURE_CLFLSH);
 924        return 1;
 925}
 926__setup("noclflush", setup_noclflush);
 927
 928void __cpuinit print_cpu_info(struct cpuinfo_x86 *c)
 929{
 930        const char *vendor = NULL;
 931
 932        if (c->x86_vendor < X86_VENDOR_NUM) {
 933                vendor = this_cpu->c_vendor;
 934        } else {
 935                if (c->cpuid_level >= 0)
 936                        vendor = c->x86_vendor_id;
 937        }
 938
 939        if (vendor && !strstr(c->x86_model_id, vendor))
 940                printk(KERN_CONT "%s ", vendor);
 941
 942        if (c->x86_model_id[0])
 943                printk(KERN_CONT "%s", c->x86_model_id);
 944        else
 945                printk(KERN_CONT "%d86", c->x86);
 946
 947        if (c->x86_mask || c->cpuid_level >= 0)
 948                printk(KERN_CONT " stepping %02x\n", c->x86_mask);
 949        else
 950                printk(KERN_CONT "\n");
 951
 952#ifdef CONFIG_SMP
 953        if (c->cpu_index < show_msr)
 954                print_cpu_msr();
 955#else
 956        if (show_msr)
 957                print_cpu_msr();
 958#endif
 959}
 960
 961static __init int setup_disablecpuid(char *arg)
 962{
 963        int bit;
 964
 965        if (get_option(&arg, &bit) && bit < NCAPINTS*32)
 966                setup_clear_cpu_cap(bit);
 967        else
 968                return 0;
 969
 970        return 1;
 971}
 972__setup("clearcpuid=", setup_disablecpuid);
 973
 974#ifdef CONFIG_X86_64
 975struct desc_ptr idt_descr = { 256 * 16 - 1, (unsigned long) idt_table };
 976
 977DEFINE_PER_CPU_FIRST(union irq_stack_union,
 978                     irq_stack_union) __aligned(PAGE_SIZE);
 979
 980DEFINE_PER_CPU(char *, irq_stack_ptr) =
 981        init_per_cpu_var(irq_stack_union.irq_stack) + IRQ_STACK_SIZE - 64;
 982
 983DEFINE_PER_CPU(unsigned long, kernel_stack) =
 984        (unsigned long)&init_thread_union - KERNEL_STACK_OFFSET + THREAD_SIZE;
 985EXPORT_PER_CPU_SYMBOL(kernel_stack);
 986
 987DEFINE_PER_CPU(unsigned int, irq_count) = -1;
 988
 989/*
 990 * Special IST stacks which the CPU switches to when it calls
 991 * an IST-marked descriptor entry. Up to 7 stacks (hardware
 992 * limit), all of them are 4K, except the debug stack which
 993 * is 8K.
 994 */
 995static const unsigned int exception_stack_sizes[N_EXCEPTION_STACKS] = {
 996          [0 ... N_EXCEPTION_STACKS - 1]        = EXCEPTION_STKSZ,
 997          [DEBUG_STACK - 1]                     = DEBUG_STKSZ
 998};
 999
1000static DEFINE_PER_CPU_PAGE_ALIGNED(char, exception_stacks
1001        [(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ])
1002        __aligned(PAGE_SIZE);
1003
1004/* May not be marked __init: used by software suspend */
1005void syscall_init(void)
1006{
1007        /*
1008         * LSTAR and STAR live in a bit strange symbiosis.
1009         * They both write to the same internal register. STAR allows to
1010         * set CS/DS but only a 32bit target. LSTAR sets the 64bit rip.
1011         */
1012        wrmsrl(MSR_STAR,  ((u64)__USER32_CS)<<48  | ((u64)__KERNEL_CS)<<32);
1013        wrmsrl(MSR_LSTAR, system_call);
1014        wrmsrl(MSR_CSTAR, ignore_sysret);
1015
1016#ifdef CONFIG_IA32_EMULATION
1017        syscall32_cpu_init();
1018#endif
1019
1020        /* Flags to clear on syscall */
1021        wrmsrl(MSR_SYSCALL_MASK,
1022               X86_EFLAGS_TF|X86_EFLAGS_DF|X86_EFLAGS_IF|X86_EFLAGS_IOPL);
1023}
1024
1025unsigned long kernel_eflags;
1026
1027/*
1028 * Copies of the original ist values from the tss are only accessed during
1029 * debugging, no special alignment required.
1030 */
1031DEFINE_PER_CPU(struct orig_ist, orig_ist);
1032
1033#else   /* CONFIG_X86_64 */
1034
1035#ifdef CONFIG_CC_STACKPROTECTOR
1036DEFINE_PER_CPU(struct stack_canary, stack_canary) ____cacheline_aligned;
1037#endif
1038
1039/* Make sure %fs and %gs are initialized properly in idle threads */
1040struct pt_regs * __cpuinit idle_regs(struct pt_regs *regs)
1041{
1042        memset(regs, 0, sizeof(struct pt_regs));
1043        regs->fs = __KERNEL_PERCPU;
1044        regs->gs = __KERNEL_STACK_CANARY;
1045
1046        return regs;
1047}
1048#endif  /* CONFIG_X86_64 */
1049
1050/*
1051 * Clear all 6 debug registers:
1052 */
1053static void clear_all_debug_regs(void)
1054{
1055        int i;
1056
1057        for (i = 0; i < 8; i++) {
1058                /* Ignore db4, db5 */
1059                if ((i == 4) || (i == 5))
1060                        continue;
1061
1062                set_debugreg(0, i);
1063        }
1064}
1065
1066/*
1067 * cpu_init() initializes state that is per-CPU. Some data is already
1068 * initialized (naturally) in the bootstrap process, such as the GDT
1069 * and IDT. We reload them nevertheless, this function acts as a
1070 * 'CPU state barrier', nothing should get across.
1071 * A lot of state is already set up in PDA init for 64 bit
1072 */
1073#ifdef CONFIG_X86_64
1074
1075void __cpuinit cpu_init(void)
1076{
1077        struct orig_ist *orig_ist;
1078        struct task_struct *me;
1079        struct tss_struct *t;
1080        unsigned long v;
1081        int cpu;
1082        int i;
1083
1084        cpu = stack_smp_processor_id();
1085        t = &per_cpu(init_tss, cpu);
1086        orig_ist = &per_cpu(orig_ist, cpu);
1087
1088#ifdef CONFIG_NUMA
1089        if (cpu != 0 && percpu_read(node_number) == 0 &&
1090            cpu_to_node(cpu) != NUMA_NO_NODE)
1091                percpu_write(node_number, cpu_to_node(cpu));
1092#endif
1093
1094        me = current;
1095
1096        if (cpumask_test_and_set_cpu(cpu, cpu_initialized_mask))
1097                panic("CPU#%d already initialized!\n", cpu);
1098
1099        printk(KERN_INFO "Initializing CPU#%d\n", cpu);
1100
1101        clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1102
1103        /*
1104         * Initialize the per-CPU GDT with the boot GDT,
1105         * and set up the GDT descriptor:
1106         */
1107
1108        switch_to_new_gdt(cpu);
1109        loadsegment(fs, 0);
1110
1111        load_idt((const struct desc_ptr *)&idt_descr);
1112
1113        memset(me->thread.tls_array, 0, GDT_ENTRY_TLS_ENTRIES * 8);
1114        syscall_init();
1115
1116        wrmsrl(MSR_FS_BASE, 0);
1117        wrmsrl(MSR_KERNEL_GS_BASE, 0);
1118        barrier();
1119
1120        check_efer();
1121        if (cpu != 0)
1122                enable_x2apic();
1123
1124        /*
1125         * set up and load the per-CPU TSS
1126         */
1127        if (!orig_ist->ist[0]) {
1128                char *estacks = per_cpu(exception_stacks, cpu);
1129
1130                for (v = 0; v < N_EXCEPTION_STACKS; v++) {
1131                        estacks += exception_stack_sizes[v];
1132                        orig_ist->ist[v] = t->x86_tss.ist[v] =
1133                                        (unsigned long)estacks;
1134                }
1135        }
1136
1137        t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
1138
1139        /*
1140         * <= is required because the CPU will access up to
1141         * 8 bits beyond the end of the IO permission bitmap.
1142         */
1143        for (i = 0; i <= IO_BITMAP_LONGS; i++)
1144                t->io_bitmap[i] = ~0UL;
1145
1146        atomic_inc(&init_mm.mm_count);
1147        me->active_mm = &init_mm;
1148        BUG_ON(me->mm);
1149        enter_lazy_tlb(&init_mm, me);
1150
1151        load_sp0(t, &current->thread);
1152        set_tss_desc(cpu, t);
1153        load_TR_desc();
1154        load_LDT(&init_mm.context);
1155
1156#ifdef CONFIG_KGDB
1157        /*
1158         * If the kgdb is connected no debug regs should be altered.  This
1159         * is only applicable when KGDB and a KGDB I/O module are built
1160         * into the kernel and you are using early debugging with
1161         * kgdbwait. KGDB will control the kernel HW breakpoint registers.
1162         */
1163        if (kgdb_connected && arch_kgdb_ops.correct_hw_break)
1164                arch_kgdb_ops.correct_hw_break();
1165        else
1166#endif
1167                clear_all_debug_regs();
1168
1169        fpu_init();
1170
1171        raw_local_save_flags(kernel_eflags);
1172
1173        if (is_uv_system())
1174                uv_cpu_init();
1175}
1176
1177#else
1178
1179void __cpuinit cpu_init(void)
1180{
1181        int cpu = smp_processor_id();
1182        struct task_struct *curr = current;
1183        struct tss_struct *t = &per_cpu(init_tss, cpu);
1184        struct thread_struct *thread = &curr->thread;
1185
1186        if (cpumask_test_and_set_cpu(cpu, cpu_initialized_mask)) {
1187                printk(KERN_WARNING "CPU#%d already initialized!\n", cpu);
1188                for (;;)
1189                        local_irq_enable();
1190        }
1191
1192        printk(KERN_INFO "Initializing CPU#%d\n", cpu);
1193
1194        if (cpu_has_vme || cpu_has_tsc || cpu_has_de)
1195                clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1196
1197        load_idt(&idt_descr);
1198        switch_to_new_gdt(cpu);
1199
1200        /*
1201         * Set up and load the per-CPU TSS and LDT
1202         */
1203        atomic_inc(&init_mm.mm_count);
1204        curr->active_mm = &init_mm;
1205        BUG_ON(curr->mm);
1206        enter_lazy_tlb(&init_mm, curr);
1207
1208        load_sp0(t, thread);
1209        set_tss_desc(cpu, t);
1210        load_TR_desc();
1211        load_LDT(&init_mm.context);
1212
1213        t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
1214
1215#ifdef CONFIG_DOUBLEFAULT
1216        /* Set up doublefault TSS pointer in the GDT */
1217        __set_tss_desc(cpu, GDT_ENTRY_DOUBLEFAULT_TSS, &doublefault_tss);
1218#endif
1219
1220        clear_all_debug_regs();
1221
1222        /*
1223         * Force FPU initialization:
1224         */
1225        if (cpu_has_xsave)
1226                current_thread_info()->status = TS_XSAVE;
1227        else
1228                current_thread_info()->status = 0;
1229        clear_used_math();
1230        mxcsr_feature_mask_init();
1231
1232        /*
1233         * Boot processor to setup the FP and extended state context info.
1234         */
1235        if (smp_processor_id() == boot_cpu_id)
1236                init_thread_xstate();
1237
1238        xsave_init();
1239}
1240#endif
1241
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