linux/arch/x86/kernel/cpu/common.c History
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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_counter.h>
  17#include <asm/mmu_context.h>
  18#include <asm/hypervisor.h>
  19#include <asm/processor.h>
  20#include <asm/sections.h>
  21#include <asm/topology.h>
  22#include <asm/cpumask.h>
  23#include <asm/pgtable.h>
  24#include <asm/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 <asm/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#include <asm/smp.h>
  38
  39#ifdef CONFIG_X86_LOCAL_APIC
  40#include <asm/uv/uv.h>
  41#endif
  42
  43#include "cpu.h"
  44
  45/* all of these masks are initialized in setup_cpu_local_masks() */
  46cpumask_var_t cpu_initialized_mask;
  47cpumask_var_t cpu_callout_mask;
  48cpumask_var_t cpu_callin_mask;
  49
  50/* representing cpus for which sibling maps can be computed */
  51cpumask_var_t cpu_sibling_setup_mask;
  52
  53/* correctly size the local cpu masks */
  54void __init setup_cpu_local_masks(void)
  55{
  56        alloc_bootmem_cpumask_var(&cpu_initialized_mask);
  57        alloc_bootmem_cpumask_var(&cpu_callin_mask);
  58        alloc_bootmem_cpumask_var(&cpu_callout_mask);
  59        alloc_bootmem_cpumask_var(&cpu_sibling_setup_mask);
  60}
  61
  62static void __cpuinit default_init(struct cpuinfo_x86 *c)
  63{
  64#ifdef CONFIG_X86_64
  65        display_cacheinfo(c);
  66#else
  67        /* Not much we can do here... */
  68        /* Check if at least it has cpuid */
  69        if (c->cpuid_level == -1) {
  70                /* No cpuid. It must be an ancient CPU */
  71                if (c->x86 == 4)
  72                        strcpy(c->x86_model_id, "486");
  73                else if (c->x86 == 3)
  74                        strcpy(c->x86_model_id, "386");
  75        }
  76#endif
  77}
  78
  79static const struct cpu_dev __cpuinitconst default_cpu = {
  80        .c_init         = default_init,
  81        .c_vendor       = "Unknown",
  82        .c_x86_vendor   = X86_VENDOR_UNKNOWN,
  83};
  84
  85static const struct cpu_dev *this_cpu __cpuinitdata = &default_cpu;
  86
  87DEFINE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page) = { .gdt = {
  88#ifdef CONFIG_X86_64
  89        /*
  90         * We need valid kernel segments for data and code in long mode too
  91         * IRET will check the segment types  kkeil 2000/10/28
  92         * Also sysret mandates a special GDT layout
  93         *
  94         * TLS descriptors are currently at a different place compared to i386.
  95         * Hopefully nobody expects them at a fixed place (Wine?)
  96         */
  97        [GDT_ENTRY_KERNEL32_CS]         = { { { 0x0000ffff, 0x00cf9b00 } } },
  98        [GDT_ENTRY_KERNEL_CS]           = { { { 0x0000ffff, 0x00af9b00 } } },
  99        [GDT_ENTRY_KERNEL_DS]           = { { { 0x0000ffff, 0x00cf9300 } } },
 100        [GDT_ENTRY_DEFAULT_USER32_CS]   = { { { 0x0000ffff, 0x00cffb00 } } },
 101        [GDT_ENTRY_DEFAULT_USER_DS]     = { { { 0x0000ffff, 0x00cff300 } } },
 102        [GDT_ENTRY_DEFAULT_USER_CS]     = { { { 0x0000ffff, 0x00affb00 } } },
 103#else
 104        [GDT_ENTRY_KERNEL_CS]           = { { { 0x0000ffff, 0x00cf9a00 } } },
 105        [GDT_ENTRY_KERNEL_DS]           = { { { 0x0000ffff, 0x00cf9200 } } },
 106        [GDT_ENTRY_DEFAULT_USER_CS]     = { { { 0x0000ffff, 0x00cffa00 } } },
 107        [GDT_ENTRY_DEFAULT_USER_DS]     = { { { 0x0000ffff, 0x00cff200 } } },
 108        /*
 109         * Segments used for calling PnP BIOS have byte granularity.
 110         * They code segments and data segments have fixed 64k limits,
 111         * the transfer segment sizes are set at run time.
 112         */
 113        /* 32-bit code */
 114        [GDT_ENTRY_PNPBIOS_CS32]        = { { { 0x0000ffff, 0x00409a00 } } },
 115        /* 16-bit code */
 116        [GDT_ENTRY_PNPBIOS_CS16]        = { { { 0x0000ffff, 0x00009a00 } } },
 117        /* 16-bit data */
 118        [GDT_ENTRY_PNPBIOS_DS]          = { { { 0x0000ffff, 0x00009200 } } },
 119        /* 16-bit data */
 120        [GDT_ENTRY_PNPBIOS_TS1]         = { { { 0x00000000, 0x00009200 } } },
 121        /* 16-bit data */
 122        [GDT_ENTRY_PNPBIOS_TS2]         = { { { 0x00000000, 0x00009200 } } },
 123        /*
 124         * The APM segments have byte granularity and their bases
 125         * are set at run time.  All have 64k limits.
 126         */
 127        /* 32-bit code */
 128        [GDT_ENTRY_APMBIOS_BASE]        = { { { 0x0000ffff, 0x00409a00 } } },
 129        /* 16-bit code */
 130        [GDT_ENTRY_APMBIOS_BASE+1]      = { { { 0x0000ffff, 0x00009a00 } } },
 131        /* data */
 132        [GDT_ENTRY_APMBIOS_BASE+2]      = { { { 0x0000ffff, 0x00409200 } } },
 133
 134        [GDT_ENTRY_ESPFIX_SS]           = { { { 0x0000ffff, 0x00cf9200 } } },
 135        [GDT_ENTRY_PERCPU]              = { { { 0x0000ffff, 0x00cf9200 } } },
 136        GDT_STACK_CANARY_INIT
 137#endif
 138} };
 139EXPORT_PER_CPU_SYMBOL_GPL(gdt_page);
 140
 141static int __init x86_xsave_setup(char *s)
 142{
 143        setup_clear_cpu_cap(X86_FEATURE_XSAVE);
 144        return 1;
 145}
 146__setup("noxsave", x86_xsave_setup);
 147
 148#ifdef CONFIG_X86_32
 149static int cachesize_override __cpuinitdata = -1;
 150static int disable_x86_serial_nr __cpuinitdata = 1;
 151
 152static int __init cachesize_setup(char *str)
 153{
 154        get_option(&str, &cachesize_override);
 155        return 1;
 156}
 157__setup("cachesize=", cachesize_setup);
 158
 159static int __init x86_fxsr_setup(char *s)
 160{
 161        setup_clear_cpu_cap(X86_FEATURE_FXSR);
 162        setup_clear_cpu_cap(X86_FEATURE_XMM);
 163        return 1;
 164}
 165__setup("nofxsr", x86_fxsr_setup);
 166
 167static int __init x86_sep_setup(char *s)
 168{
 169        setup_clear_cpu_cap(X86_FEATURE_SEP);
 170        return 1;
 171}
 172__setup("nosep", x86_sep_setup);
 173
 174/* Standard macro to see if a specific flag is changeable */
 175static inline int flag_is_changeable_p(u32 flag)
 176{
 177        u32 f1, f2;
 178
 179        /*
 180         * Cyrix and IDT cpus allow disabling of CPUID
 181         * so the code below may return different results
 182         * when it is executed before and after enabling
 183         * the CPUID. Add "volatile" to not allow gcc to
 184         * optimize the subsequent calls to this function.
 185         */
 186        asm volatile ("pushfl           \n\t"
 187                      "pushfl           \n\t"
 188                      "popl %0          \n\t"
 189                      "movl %0, %1      \n\t"
 190                      "xorl %2, %0      \n\t"
 191                      "pushl %0         \n\t"
 192                      "popfl            \n\t"
 193                      "pushfl           \n\t"
 194                      "popl %0          \n\t"
 195                      "popfl            \n\t"
 196
 197                      : "=&r" (f1), "=&r" (f2)
 198                      : "ir" (flag));
 199
 200        return ((f1^f2) & flag) != 0;
 201}
 202
 203/* Probe for the CPUID instruction */
 204static int __cpuinit have_cpuid_p(void)
 205{
 206        return flag_is_changeable_p(X86_EFLAGS_ID);
 207}
 208
 209static void __cpuinit squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
 210{
 211        unsigned long lo, hi;
 212
 213        if (!cpu_has(c, X86_FEATURE_PN) || !disable_x86_serial_nr)
 214                return;
 215
 216        /* Disable processor serial number: */
 217
 218        rdmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
 219        lo |= 0x200000;
 220        wrmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
 221
 222        printk(KERN_NOTICE "CPU serial number disabled.\n");
 223        clear_cpu_cap(c, X86_FEATURE_PN);
 224
 225        /* Disabling the serial number may affect the cpuid level */
 226        c->cpuid_level = cpuid_eax(0);
 227}
 228
 229static int __init x86_serial_nr_setup(char *s)
 230{
 231        disable_x86_serial_nr = 0;
 232        return 1;
 233}
 234__setup("serialnumber", x86_serial_nr_setup);
 235#else
 236static inline int flag_is_changeable_p(u32 flag)
 237{
 238        return 1;
 239}
 240/* Probe for the CPUID instruction */
 241static inline int have_cpuid_p(void)
 242{
 243        return 1;
 244}
 245static inline void squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
 246{
 247}
 248#endif
 249
 250/*
 251 * Some CPU features depend on higher CPUID levels, which may not always
 252 * be available due to CPUID level capping or broken virtualization
 253 * software.  Add those features to this table to auto-disable them.
 254 */
 255struct cpuid_dependent_feature {
 256        u32 feature;
 257        u32 level;
 258};
 259
 260static const struct cpuid_dependent_feature __cpuinitconst
 261cpuid_dependent_features[] = {
 262        { X86_FEATURE_MWAIT,            0x00000005 },
 263        { X86_FEATURE_DCA,              0x00000009 },
 264        { X86_FEATURE_XSAVE,            0x0000000d },
 265        { 0, 0 }
 266};
 267
 268static void __cpuinit filter_cpuid_features(struct cpuinfo_x86 *c, bool warn)
 269{
 270        const struct cpuid_dependent_feature *df;
 271
 272        for (df = cpuid_dependent_features; df->feature; df++) {
 273
 274                if (!cpu_has(c, df->feature))
 275                        continue;
 276                /*
 277                 * Note: cpuid_level is set to -1 if unavailable, but
 278                 * extended_extended_level is set to 0 if unavailable
 279                 * and the legitimate extended levels are all negative
 280                 * when signed; hence the weird messing around with
 281                 * signs here...
 282                 */
 283                if (!((s32)df->level < 0 ?
 284                     (u32)df->level > (u32)c->extended_cpuid_level :
 285                     (s32)df->level > (s32)c->cpuid_level))
 286                        continue;
 287
 288                clear_cpu_cap(c, df->feature);
 289                if (!warn)
 290                        continue;
 291
 292                printk(KERN_WARNING
 293                       "CPU: CPU feature %s disabled, no CPUID level 0x%x\n",
 294                                x86_cap_flags[df->feature], df->level);
 295        }
 296}
 297
 298/*
 299 * Naming convention should be: <Name> [(<Codename>)]
 300 * This table only is used unless init_<vendor>() below doesn't set it;
 301 * in particular, if CPUID levels 0x80000002..4 are supported, this
 302 * isn't used
 303 */
 304
 305/* Look up CPU names by table lookup. */
 306static const char *__cpuinit table_lookup_model(struct cpuinfo_x86 *c)
 307{
 308        const struct cpu_model_info *info;
 309
 310        if (c->x86_model >= 16)
 311                return NULL;    /* Range check */
 312
 313        if (!this_cpu)
 314                return NULL;
 315
 316        info = this_cpu->c_models;
 317
 318        while (info && info->family) {
 319                if (info->family == c->x86)
 320                        return info->model_names[c->x86_model];
 321                info++;
 322        }
 323        return NULL;            /* Not found */
 324}
 325
 326__u32 cpu_caps_cleared[NCAPINTS] __cpuinitdata;
 327__u32 cpu_caps_set[NCAPINTS] __cpuinitdata;
 328
 329void load_percpu_segment(int cpu)
 330{
 331#ifdef CONFIG_X86_32
 332        loadsegment(fs, __KERNEL_PERCPU);
 333#else
 334        loadsegment(gs, 0);
 335        wrmsrl(MSR_GS_BASE, (unsigned long)per_cpu(irq_stack_union.gs_base, cpu));
 336#endif
 337        load_stack_canary_segment();
 338}
 339
 340/*
 341 * Current gdt points %fs at the "master" per-cpu area: after this,
 342 * it's on the real one.
 343 */
 344void switch_to_new_gdt(int cpu)
 345{
 346        struct desc_ptr gdt_descr;
 347
 348        gdt_descr.address = (long)get_cpu_gdt_table(cpu);
 349        gdt_descr.size = GDT_SIZE - 1;
 350        load_gdt(&gdt_descr);
 351        /* Reload the per-cpu base */
 352
 353        load_percpu_segment(cpu);
 354}
 355
 356static const struct cpu_dev *__cpuinitdata cpu_devs[X86_VENDOR_NUM] = {};
 357
 358static void __cpuinit get_model_name(struct cpuinfo_x86 *c)
 359{
 360        unsigned int *v;
 361        char *p, *q;
 362
 363        if (c->extended_cpuid_level < 0x80000004)
 364                return;
 365
 366        v = (unsigned int *)c->x86_model_id;
 367        cpuid(0x80000002, &v[0], &v[1], &v[2], &v[3]);
 368        cpuid(0x80000003, &v[4], &v[5], &v[6], &v[7]);
 369        cpuid(0x80000004, &v[8], &v[9], &v[10], &v[11]);
 370        c->x86_model_id[48] = 0;
 371
 372        /*
 373         * Intel chips right-justify this string for some dumb reason;
 374         * undo that brain damage:
 375         */
 376        p = q = &c->x86_model_id[0];
 377        while (*p == ' ')
 378                p++;
 379        if (p != q) {
 380                while (*p)
 381                        *q++ = *p++;
 382                while (q <= &c->x86_model_id[48])
 383                        *q++ = '\0';    /* Zero-pad the rest */
 384        }
 385}
 386
 387void __cpuinit display_cacheinfo(struct cpuinfo_x86 *c)
 388{
 389        unsigned int n, dummy, ebx, ecx, edx, l2size;
 390
 391        n = c->extended_cpuid_level;
 392
 393        if (n >= 0x80000005) {
 394                cpuid(0x80000005, &dummy, &ebx, &ecx, &edx);
 395                printk(KERN_INFO "CPU: L1 I Cache: %dK (%d bytes/line), D cache %dK (%d bytes/line)\n",
 396                                edx>>24, edx&0xFF, ecx>>24, ecx&0xFF);
 397                c->x86_cache_size = (ecx>>24) + (edx>>24);
 398#ifdef CONFIG_X86_64
 399                /* On K8 L1 TLB is inclusive, so don't count it */
 400                c->x86_tlbsize = 0;
 401#endif
 402        }
 403
 404        if (n < 0x80000006)     /* Some chips just has a large L1. */
 405                return;
 406
 407        cpuid(0x80000006, &dummy, &ebx, &ecx, &edx);
 408        l2size = ecx >> 16;
 409
 410#ifdef CONFIG_X86_64
 411        c->x86_tlbsize += ((ebx >> 16) & 0xfff) + (ebx & 0xfff);
 412#else
 413        /* do processor-specific cache resizing */
 414        if (this_cpu->c_size_cache)
 415                l2size = this_cpu->c_size_cache(c, l2size);
 416
 417        /* Allow user to override all this if necessary. */
 418        if (cachesize_override != -1)
 419                l2size = cachesize_override;
 420
 421        if (l2size == 0)
 422                return;         /* Again, no L2 cache is possible */
 423#endif
 424
 425        c->x86_cache_size = l2size;
 426
 427        printk(KERN_INFO "CPU: L2 Cache: %dK (%d bytes/line)\n",
 428                        l2size, ecx & 0xFF);
 429}
 430
 431void __cpuinit detect_ht(struct cpuinfo_x86 *c)
 432{
 433#ifdef CONFIG_X86_HT
 434        u32 eax, ebx, ecx, edx;
 435        int index_msb, core_bits;
 436
 437        if (!cpu_has(c, X86_FEATURE_HT))
 438                return;
 439
 440        if (cpu_has(c, X86_FEATURE_CMP_LEGACY))
 441                goto out;
 442
 443        if (cpu_has(c, X86_FEATURE_XTOPOLOGY))
 444                return;
 445
 446        cpuid(1, &eax, &ebx, &ecx, &edx);
 447
 448        smp_num_siblings = (ebx & 0xff0000) >> 16;
 449
 450        if (smp_num_siblings == 1) {
 451                printk(KERN_INFO  "CPU: Hyper-Threading is disabled\n");
 452                goto out;
 453        }
 454
 455        if (smp_num_siblings <= 1)
 456                goto out;
 457
 458        if (smp_num_siblings > nr_cpu_ids) {
 459                pr_warning("CPU: Unsupported number of siblings %d",
 460                           smp_num_siblings);
 461                smp_num_siblings = 1;
 462                return;
 463        }
 464
 465        index_msb = get_count_order(smp_num_siblings);
 466        c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, index_msb);
 467
 468        smp_num_siblings = smp_num_siblings / c->x86_max_cores;
 469
 470        index_msb = get_count_order(smp_num_siblings);
 471
 472        core_bits = get_count_order(c->x86_max_cores);
 473
 474        c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid, index_msb) &
 475                                       ((1 << core_bits) - 1);
 476
 477out:
 478        if ((c->x86_max_cores * smp_num_siblings) > 1) {
 479                printk(KERN_INFO  "CPU: Physical Processor ID: %d\n",
 480                       c->phys_proc_id);
 481                printk(KERN_INFO  "CPU: Processor Core ID: %d\n",
 482                       c->cpu_core_id);
 483        }
 484#endif
 485}
 486
 487static void __cpuinit get_cpu_vendor(struct cpuinfo_x86 *c)
 488{
 489        char *v = c->x86_vendor_id;
 490        int i;
 491
 492        for (i = 0; i < X86_VENDOR_NUM; i++) {
 493                if (!cpu_devs[i])
 494                        break;
 495
 496                if (!strcmp(v, cpu_devs[i]->c_ident[0]) ||
 497                    (cpu_devs[i]->c_ident[1] &&
 498                     !strcmp(v, cpu_devs[i]->c_ident[1]))) {
 499
 500                        this_cpu = cpu_devs[i];
 501                        c->x86_vendor = this_cpu->c_x86_vendor;
 502                        return;
 503                }
 504        }
 505
 506        printk_once(KERN_ERR
 507                        "CPU: vendor_id '%s' unknown, using generic init.\n" \
 508                        "CPU: Your system may be unstable.\n", v);
 509
 510        c->x86_vendor = X86_VENDOR_UNKNOWN;
 511        this_cpu = &default_cpu;
 512}
 513
 514void __cpuinit cpu_detect(struct cpuinfo_x86 *c)
 515{
 516        /* Get vendor name */
 517        cpuid(0x00000000, (unsigned int *)&c->cpuid_level,
 518              (unsigned int *)&c->x86_vendor_id[0],
 519              (unsigned int *)&c->x86_vendor_id[8],
 520              (unsigned int *)&c->x86_vendor_id[4]);
 521
 522        c->x86 = 4;
 523        /* Intel-defined flags: level 0x00000001 */
 524        if (c->cpuid_level >= 0x00000001) {
 525                u32 junk, tfms, cap0, misc;
 526
 527                cpuid(0x00000001, &tfms, &misc, &junk, &cap0);
 528                c->x86 = (tfms >> 8) & 0xf;
 529                c->x86_model = (tfms >> 4) & 0xf;
 530                c->x86_mask = tfms & 0xf;
 531
 532                if (c->x86 == 0xf)
 533                        c->x86 += (tfms >> 20) & 0xff;
 534                if (c->x86 >= 0x6)
 535                        c->x86_model += ((tfms >> 16) & 0xf) << 4;
 536
 537                if (cap0 & (1<<19)) {
 538                        c->x86_clflush_size = ((misc >> 8) & 0xff) * 8;
 539                        c->x86_cache_alignment = c->x86_clflush_size;
 540                }
 541        }
 542}
 543
 544static void __cpuinit get_cpu_cap(struct cpuinfo_x86 *c)
 545{
 546        u32 tfms, xlvl;
 547        u32 ebx;
 548
 549        /* Intel-defined flags: level 0x00000001 */
 550        if (c->cpuid_level >= 0x00000001) {
 551                u32 capability, excap;
 552
 553                cpuid(0x00000001, &tfms, &ebx, &excap, &capability);
 554                c->x86_capability[0] = capability;
 555                c->x86_capability[4] = excap;
 556        }
 557
 558        /* AMD-defined flags: level 0x80000001 */
 559        xlvl = cpuid_eax(0x80000000);
 560        c->extended_cpuid_level = xlvl;
 561
 562        if ((xlvl & 0xffff0000) == 0x80000000) {
 563                if (xlvl >= 0x80000001) {
 564                        c->x86_capability[1] = cpuid_edx(0x80000001);
 565                        c->x86_capability[6] = cpuid_ecx(0x80000001);
 566                }
 567        }
 568
 569        if (c->extended_cpuid_level >= 0x80000008) {
 570                u32 eax = cpuid_eax(0x80000008);
 571
 572                c->x86_virt_bits = (eax >> 8) & 0xff;
 573                c->x86_phys_bits = eax & 0xff;
 574        }
 575#ifdef CONFIG_X86_32
 576        else if (cpu_has(c, X86_FEATURE_PAE) || cpu_has(c, X86_FEATURE_PSE36))
 577                c->x86_phys_bits = 36;
 578#endif
 579
 580        if (c->extended_cpuid_level >= 0x80000007)
 581                c->x86_power = cpuid_edx(0x80000007);
 582
 583}
 584
 585static void __cpuinit identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
 586{
 587#ifdef CONFIG_X86_32
 588        int i;
 589
 590        /*
 591         * First of all, decide if this is a 486 or higher
 592         * It's a 486 if we can modify the AC flag
 593         */
 594        if (flag_is_changeable_p(X86_EFLAGS_AC))
 595                c->x86 = 4;
 596        else
 597                c->x86 = 3;
 598
 599        for (i = 0; i < X86_VENDOR_NUM; i++)
 600                if (cpu_devs[i] && cpu_devs[i]->c_identify) {
 601                        c->x86_vendor_id[0] = 0;
 602                        cpu_devs[i]->c_identify(c);
 603                        if (c->x86_vendor_id[0]) {
 604                                get_cpu_vendor(c);
 605                                break;
 606                        }
 607                }
 608#endif
 609}
 610
 611/*
 612 * Do minimum CPU detection early.
 613 * Fields really needed: vendor, cpuid_level, family, model, mask,
 614 * cache alignment.
 615 * The others are not touched to avoid unwanted side effects.
 616 *
 617 * WARNING: this function is only called on the BP.  Don't add code here
 618 * that is supposed to run on all CPUs.
 619 */
 620static void __init early_identify_cpu(struct cpuinfo_x86 *c)
 621{
 622#ifdef CONFIG_X86_64
 623        c->x86_clflush_size = 64;
 624        c->x86_phys_bits = 36;
 625        c->x86_virt_bits = 48;
 626#else
 627        c->x86_clflush_size = 32;
 628        c->x86_phys_bits = 32;
 629        c->x86_virt_bits = 32;
 630#endif
 631        c->x86_cache_alignment = c->x86_clflush_size;
 632
 633        memset(&c->x86_capability, 0, sizeof c->x86_capability);
 634        c->extended_cpuid_level = 0;
 635
 636        if (!have_cpuid_p())
 637                identify_cpu_without_cpuid(c);
 638
 639        /* cyrix could have cpuid enabled via c_identify()*/
 640        if (!have_cpuid_p())
 641                return;
 642
 643        cpu_detect(c);
 644
 645        get_cpu_vendor(c);
 646
 647        get_cpu_cap(c);
 648
 649        if (this_cpu->c_early_init)
 650                this_cpu->c_early_init(c);
 651
 652#ifdef CONFIG_SMP
 653        c->cpu_index = boot_cpu_id;
 654#endif
 655        filter_cpuid_features(c, false);
 656}
 657
 658void __init early_cpu_init(void)
 659{
 660        const struct cpu_dev *const *cdev;
 661        int count = 0;
 662
 663        printk(KERN_INFO "KERNEL supported cpus:\n");
 664        for (cdev = __x86_cpu_dev_start; cdev < __x86_cpu_dev_end; cdev++) {
 665                const struct cpu_dev *cpudev = *cdev;
 666                unsigned int j;
 667
 668                if (count >= X86_VENDOR_NUM)
 669                        break;
 670                cpu_devs[count] = cpudev;
 671                count++;
 672
 673                for (j = 0; j < 2; j++) {
 674                        if (!cpudev->c_ident[j])
 675                                continue;
 676                        printk(KERN_INFO "  %s %s\n", cpudev->c_vendor,
 677                                cpudev->c_ident[j]);
 678                }
 679        }
 680
 681        early_identify_cpu(&boot_cpu_data);
 682}
 683
 684/*
 685 * The NOPL instruction is supposed to exist on all CPUs with
 686 * family >= 6; unfortunately, that's not true in practice because
 687 * of early VIA chips and (more importantly) broken virtualizers that
 688 * are not easy to detect.  In the latter case it doesn't even *fail*
 689 * reliably, so probing for it doesn't even work.  Disable it completely
 690 * unless we can find a reliable way to detect all the broken cases.
 691 */
 692static void __cpuinit detect_nopl(struct cpuinfo_x86 *c)
 693{
 694        clear_cpu_cap(c, X86_FEATURE_NOPL);
 695}
 696
 697static void __cpuinit generic_identify(struct cpuinfo_x86 *c)
 698{
 699        c->extended_cpuid_level = 0;
 700
 701        if (!have_cpuid_p())
 702                identify_cpu_without_cpuid(c);
 703
 704        /* cyrix could have cpuid enabled via c_identify()*/
 705        if (!have_cpuid_p())
 706                return;
 707
 708        cpu_detect(c);
 709
 710        get_cpu_vendor(c);
 711
 712        get_cpu_cap(c);
 713
 714        if (c->cpuid_level >= 0x00000001) {
 715                c->initial_apicid = (cpuid_ebx(1) >> 24) & 0xFF;
 716#ifdef CONFIG_X86_32
 717# ifdef CONFIG_X86_HT
 718                c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
 719# else
 720                c->apicid = c->initial_apicid;
 721# endif
 722#endif
 723
 724#ifdef CONFIG_X86_HT
 725                c->phys_proc_id = c->initial_apicid;
 726#endif
 727        }
 728
 729        get_model_name(c); /* Default name */
 730
 731        init_scattered_cpuid_features(c);
 732        detect_nopl(c);
 733}
 734
 735/*
 736 * This does the hard work of actually picking apart the CPU stuff...
 737 */
 738static void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
 739{
 740        int i;
 741
 742        c->loops_per_jiffy = loops_per_jiffy;
 743        c->x86_cache_size = -1;
 744        c->x86_vendor = X86_VENDOR_UNKNOWN;
 745        c->x86_model = c->x86_mask = 0; /* So far unknown... */
 746        c->x86_vendor_id[0] = '\0'; /* Unset */
 747        c->x86_model_id[0] = '\0';  /* Unset */
 748        c->x86_max_cores = 1;
 749        c->x86_coreid_bits = 0;
 750#ifdef CONFIG_X86_64
 751        c->x86_clflush_size = 64;
 752        c->x86_phys_bits = 36;
 753        c->x86_virt_bits = 48;
 754#else
 755        c->cpuid_level = -1;    /* CPUID not detected */
 756        c->x86_clflush_size = 32;
 757        c->x86_phys_bits = 32;
 758        c->x86_virt_bits = 32;
 759#endif
 760        c->x86_cache_alignment = c->x86_clflush_size;
 761        memset(&c->x86_capability, 0, sizeof c->x86_capability);
 762
 763        generic_identify(c);
 764
 765        if (this_cpu->c_identify)
 766                this_cpu->c_identify(c);
 767
 768        /* Clear/Set all flags overriden by options, after probe */
 769        for (i = 0; i < NCAPINTS; i++) {
 770                c->x86_capability[i] &= ~cpu_caps_cleared[i];
 771                c->x86_capability[i] |= cpu_caps_set[i];
 772        }
 773
 774#ifdef CONFIG_X86_64
 775        c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
 776#endif
 777
 778        /*
 779         * Vendor-specific initialization.  In this section we
 780         * canonicalize the feature flags, meaning if there are
 781         * features a certain CPU supports which CPUID doesn't
 782         * tell us, CPUID claiming incorrect flags, or other bugs,
 783         * we handle them here.
 784         *
 785         * At the end of this section, c->x86_capability better
 786         * indicate the features this CPU genuinely supports!
 787         */
 788        if (this_cpu->c_init)
 789                this_cpu->c_init(c);
 790
 791        /* Disable the PN if appropriate */
 792        squash_the_stupid_serial_number(c);
 793
 794        /*
 795         * The vendor-specific functions might have changed features.
 796         * Now we do "generic changes."
 797         */
 798
 799        /* Filter out anything that depends on CPUID levels we don't have */
 800        filter_cpuid_features(c, true);
 801
 802        /* If the model name is still unset, do table lookup. */
 803        if (!c->x86_model_id[0]) {
 804                const char *p;
 805                p = table_lookup_model(c);
 806                if (p)
 807                        strcpy(c->x86_model_id, p);
 808                else
 809                        /* Last resort... */
 810                        sprintf(c->x86_model_id, "%02x/%02x",
 811                                c->x86, c->x86_model);
 812        }
 813
 814#ifdef CONFIG_X86_64
 815        detect_ht(c);
 816#endif
 817
 818        init_hypervisor(c);
 819
 820        /*
 821         * Clear/Set all flags overriden by options, need do it
 822         * before following smp all cpus cap AND.
 823         */
 824        for (i = 0; i < NCAPINTS; i++) {
 825                c->x86_capability[i] &= ~cpu_caps_cleared[i];
 826                c->x86_capability[i] |= cpu_caps_set[i];
 827        }
 828
 829        /*
 830         * On SMP, boot_cpu_data holds the common feature set between
 831         * all CPUs; so make sure that we indicate which features are
 832         * common between the CPUs.  The first time this routine gets
 833         * executed, c == &boot_cpu_data.
 834         */
 835        if (c != &boot_cpu_data) {
 836                /* AND the already accumulated flags with these */
 837                for (i = 0; i < NCAPINTS; i++)
 838                        boot_cpu_data.x86_capability[i] &= c->x86_capability[i];
 839        }
 840
 841#ifdef CONFIG_X86_MCE
 842        /* Init Machine Check Exception if available. */
 843        mcheck_init(c);
 844#endif
 845
 846        select_idle_routine(c);
 847
 848#if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
 849        numa_add_cpu(smp_processor_id());
 850#endif
 851}
 852
 853#ifdef CONFIG_X86_64
 854static void vgetcpu_set_mode(void)
 855{
 856        if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP))
 857                vgetcpu_mode = VGETCPU_RDTSCP;
 858        else
 859                vgetcpu_mode = VGETCPU_LSL;
 860}
 861#endif
 862
 863void __init identify_boot_cpu(void)
 864{
 865        identify_cpu(&boot_cpu_data);
 866        init_c1e_mask();
 867#ifdef CONFIG_X86_32
 868        sysenter_setup();
 869        enable_sep_cpu();
 870#else
 871        vgetcpu_set_mode();
 872#endif
 873        init_hw_perf_counters();
 874}
 875
 876void __cpuinit identify_secondary_cpu(struct cpuinfo_x86 *c)
 877{
 878        BUG_ON(c == &boot_cpu_data);
 879        identify_cpu(c);
 880#ifdef CONFIG_X86_32
 881        enable_sep_cpu();
 882#endif
 883        mtrr_ap_init();
 884}
 885
 886struct msr_range {
 887        unsigned        min;
 888        unsigned        max;
 889};
 890
 891static const struct msr_range msr_range_array[] __cpuinitconst = {
 892        { 0x00000000, 0x00000418},
 893        { 0xc0000000, 0xc000040b},
 894        { 0xc0010000, 0xc0010142},
 895        { 0xc0011000, 0xc001103b},
 896};
 897
 898static void __cpuinit print_cpu_msr(void)
 899{
 900        unsigned index_min, index_max;
 901        unsigned index;
 902        u64 val;
 903        int i;
 904
 905        for (i = 0; i < ARRAY_SIZE(msr_range_array); i++) {
 906                index_min = msr_range_array[i].min;
 907                index_max = msr_range_array[i].max;
 908
 909                for (index = index_min; index < index_max; index++) {
 910                        if (rdmsrl_amd_safe(index, &val))
 911                                continue;
 912                        printk(KERN_INFO " MSR%08x: %016llx\n", index, val);
 913                }
 914        }
 915}
 916
 917static int show_msr __cpuinitdata;
 918
 919static __init int setup_show_msr(char *arg)
 920{
 921        int num;
 922
 923        get_option(&arg, &num);
 924
 925        if (num > 0)
 926                show_msr = num;
 927        return 1;
 928}
 929__setup("show_msr=", setup_show_msr);
 930
 931static __init int setup_noclflush(char *arg)
 932{
 933        setup_clear_cpu_cap(X86_FEATURE_CLFLSH);
 934        return 1;
 935}
 936__setup("noclflush", setup_noclflush);
 937
 938void __cpuinit print_cpu_info(struct cpuinfo_x86 *c)
 939{
 940        const char *vendor = NULL;
 941
 942        if (c->x86_vendor < X86_VENDOR_NUM) {
 943                vendor = this_cpu->c_vendor;
 944        } else {
 945                if (c->cpuid_level >= 0)
 946                        vendor = c->x86_vendor_id;
 947        }
 948
 949        if (vendor && !strstr(c->x86_model_id, vendor))
 950                printk(KERN_CONT "%s ", vendor);
 951
 952        if (c->x86_model_id[0])
 953                printk(KERN_CONT "%s", c->x86_model_id);
 954        else
 955                printk(KERN_CONT "%d86", c->x86);
 956
 957        if (c->x86_mask || c->cpuid_level >= 0)
 958                printk(KERN_CONT " stepping %02x\n", c->x86_mask);
 959        else
 960                printk(KERN_CONT "\n");
 961
 962#ifdef CONFIG_SMP
 963        if (c->cpu_index < show_msr)
 964                print_cpu_msr();
 965#else
 966        if (show_msr)
 967                print_cpu_msr();
 968#endif
 969}
 970
 971static __init int setup_disablecpuid(char *arg)
 972{
 973        int bit;
 974
 975        if (get_option(&arg, &bit) && bit < NCAPINTS*32)
 976                setup_clear_cpu_cap(bit);
 977        else
 978                return 0;
 979
 980        return 1;
 981}
 982__setup("clearcpuid=", setup_disablecpuid);
 983
 984#ifdef CONFIG_X86_64
 985struct desc_ptr idt_descr = { 256 * 16 - 1, (unsigned long) idt_table };
 986
 987DEFINE_PER_CPU_FIRST(union irq_stack_union,
 988                     irq_stack_union) __aligned(PAGE_SIZE);
 989
 990DEFINE_PER_CPU(char *, irq_stack_ptr) =
 991        init_per_cpu_var(irq_stack_union.irq_stack) + IRQ_STACK_SIZE - 64;
 992
 993DEFINE_PER_CPU(unsigned long, kernel_stack) =
 994        (unsigned long)&init_thread_union - KERNEL_STACK_OFFSET + THREAD_SIZE;
 995EXPORT_PER_CPU_SYMBOL(kernel_stack);
 996
 997DEFINE_PER_CPU(unsigned int, irq_count) = -1;
 998
 999/*
1000 * Special IST stacks which the CPU switches to when it calls
1001 * an IST-marked descriptor entry. Up to 7 stacks (hardware
1002 * limit), all of them are 4K, except the debug stack which
1003 * is 8K.
1004 */
1005static const unsigned int exception_stack_sizes[N_EXCEPTION_STACKS] = {
1006          [0 ... N_EXCEPTION_STACKS - 1]        = EXCEPTION_STKSZ,
1007          [DEBUG_STACK - 1]                     = DEBUG_STKSZ
1008};
1009
1010static DEFINE_PER_CPU_PAGE_ALIGNED(char, exception_stacks
1011        [(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ])
1012        __aligned(PAGE_SIZE);
1013
1014/* May not be marked __init: used by software suspend */
1015void syscall_init(void)
1016{
1017        /*
1018         * LSTAR and STAR live in a bit strange symbiosis.
1019         * They both write to the same internal register. STAR allows to
1020         * set CS/DS but only a 32bit target. LSTAR sets the 64bit rip.
1021         */
1022        wrmsrl(MSR_STAR,  ((u64)__USER32_CS)<<48  | ((u64)__KERNEL_CS)<<32);
1023        wrmsrl(MSR_LSTAR, system_call);
1024        wrmsrl(MSR_CSTAR, ignore_sysret);
1025
1026#ifdef CONFIG_IA32_EMULATION
1027        syscall32_cpu_init();
1028#endif
1029
1030        /* Flags to clear on syscall */
1031        wrmsrl(MSR_SYSCALL_MASK,
1032               X86_EFLAGS_TF|X86_EFLAGS_DF|X86_EFLAGS_IF|X86_EFLAGS_IOPL);
1033}
1034
1035unsigned long kernel_eflags;
1036
1037/*
1038 * Copies of the original ist values from the tss are only accessed during
1039 * debugging, no special alignment required.
1040 */
1041DEFINE_PER_CPU(struct orig_ist, orig_ist);
1042
1043#else   /* CONFIG_X86_64 */
1044
1045#ifdef CONFIG_CC_STACKPROTECTOR
1046DEFINE_PER_CPU(unsigned long, stack_canary);
1047#endif
1048
1049/* Make sure %fs and %gs are initialized properly in idle threads */
1050struct pt_regs * __cpuinit idle_regs(struct pt_regs *regs)
1051{
1052        memset(regs, 0, sizeof(struct pt_regs));
1053        regs->fs = __KERNEL_PERCPU;
1054        regs->gs = __KERNEL_STACK_CANARY;
1055
1056        return regs;
1057}
1058#endif  /* CONFIG_X86_64 */
1059
1060/*
1061 * Clear all 6 debug registers:
1062 */
1063static void clear_all_debug_regs(void)
1064{
1065        int i;
1066
1067        for (i = 0; i < 8; i++) {
1068                /* Ignore db4, db5 */
1069                if ((i == 4) || (i == 5))
1070                        continue;
1071
1072                set_debugreg(0, i);
1073        }
1074}
1075
1076/*
1077 * cpu_init() initializes state that is per-CPU. Some data is already
1078 * initialized (naturally) in the bootstrap process, such as the GDT
1079 * and IDT. We reload them nevertheless, this function acts as a
1080 * 'CPU state barrier', nothing should get across.
1081 * A lot of state is already set up in PDA init for 64 bit
1082 */
1083#ifdef CONFIG_X86_64
1084
1085void __cpuinit cpu_init(void)
1086{
1087        struct orig_ist *orig_ist;
1088        struct task_struct *me;
1089        struct tss_struct *t;
1090        unsigned long v;
1091        int cpu;
1092        int i;
1093
1094        cpu = stack_smp_processor_id();
1095        t = &per_cpu(init_tss, cpu);
1096        orig_ist = &per_cpu(orig_ist, cpu);
1097
1098#ifdef CONFIG_NUMA
1099        if (cpu != 0 && percpu_read(node_number) == 0 &&
1100            cpu_to_node(cpu) != NUMA_NO_NODE)
1101                percpu_write(node_number, cpu_to_node(cpu));
1102#endif
1103
1104        me = current;
1105
1106        if (cpumask_test_and_set_cpu(cpu, cpu_initialized_mask))
1107                panic("CPU#%d already initialized!\n", cpu);
1108
1109        printk(KERN_INFO "Initializing CPU#%d\n", cpu);
1110
1111        clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1112
1113        /*
1114         * Initialize the per-CPU GDT with the boot GDT,
1115         * and set up the GDT descriptor:
1116         */
1117
1118        switch_to_new_gdt(cpu);
1119        loadsegment(fs, 0);
1120
1121        load_idt((const struct desc_ptr *)&idt_descr);
1122
1123        memset(me->thread.tls_array, 0, GDT_ENTRY_TLS_ENTRIES * 8);
1124        syscall_init();
1125
1126        wrmsrl(MSR_FS_BASE, 0);
1127        wrmsrl(MSR_KERNEL_GS_BASE, 0);
1128        barrier();
1129
1130        check_efer();
1131        if (cpu != 0)
1132                enable_x2apic();
1133
1134        /*
1135         * set up and load the per-CPU TSS
1136         */
1137        if (!orig_ist->ist[0]) {
1138                char *estacks = per_cpu(exception_stacks, cpu);
1139
1140                for (v = 0; v < N_EXCEPTION_STACKS; v++) {
1141                        estacks += exception_stack_sizes[v];
1142                        orig_ist->ist[v] = t->x86_tss.ist[v] =
1143                                        (unsigned long)estacks;
1144                }
1145        }
1146
1147        t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
1148
1149        /*
1150         * <= is required because the CPU will access up to
1151         * 8 bits beyond the end of the IO permission bitmap.
1152         */
1153        for (i = 0; i <= IO_BITMAP_LONGS; i++)
1154                t->io_bitmap[i] = ~0UL;
1155
1156        atomic_inc(&init_mm.mm_count);
1157        me->active_mm = &init_mm;
1158        BUG_ON(me->mm);
1159        enter_lazy_tlb(&init_mm, me);
1160
1161        load_sp0(t, &current->thread);
1162        set_tss_desc(cpu, t);
1163        load_TR_desc();
1164        load_LDT(&init_mm.context);
1165
1166#ifdef CONFIG_KGDB
1167        /*
1168         * If the kgdb is connected no debug regs should be altered.  This
1169         * is only applicable when KGDB and a KGDB I/O module are built
1170         * into the kernel and you are using early debugging with
1171         * kgdbwait. KGDB will control the kernel HW breakpoint registers.
1172         */
1173        if (kgdb_connected && arch_kgdb_ops.correct_hw_break)
1174                arch_kgdb_ops.correct_hw_break();
1175        else
1176#endif
1177                clear_all_debug_regs();
1178
1179        fpu_init();
1180
1181        raw_local_save_flags(kernel_eflags);
1182
1183        if (is_uv_system())
1184                uv_cpu_init();
1185}
1186
1187#else
1188
1189void __cpuinit cpu_init(void)
1190{
1191        int cpu = smp_processor_id();
1192        struct task_struct *curr = current;
1193        struct tss_struct *t = &per_cpu(init_tss, cpu);
1194        struct thread_struct *thread = &curr->thread;
1195
1196        if (cpumask_test_and_set_cpu(cpu, cpu_initialized_mask)) {
1197                printk(KERN_WARNING "CPU#%d already initialized!\n", cpu);
1198                for (;;)
1199                        local_irq_enable();
1200        }
1201
1202        printk(KERN_INFO "Initializing CPU#%d\n", cpu);
1203
1204        if (cpu_has_vme || cpu_has_tsc || cpu_has_de)
1205                clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1206
1207        load_idt(&idt_descr);
1208        switch_to_new_gdt(cpu);
1209
1210        /*
1211         * Set up and load the per-CPU TSS and LDT
1212         */
1213        atomic_inc(&init_mm.mm_count);
1214        curr->active_mm = &init_mm;
1215        BUG_ON(curr->mm);
1216        enter_lazy_tlb(&init_mm, curr);
1217
1218        load_sp0(t, thread);
1219        set_tss_desc(cpu, t);
1220        load_TR_desc();
1221        load_LDT(&init_mm.context);
1222
1223        t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
1224
1225#ifdef CONFIG_DOUBLEFAULT
1226        /* Set up doublefault TSS pointer in the GDT */
1227        __set_tss_desc(cpu, GDT_ENTRY_DOUBLEFAULT_TSS, &doublefault_tss);
1228#endif
1229
1230        clear_all_debug_regs();
1231
1232        /*
1233         * Force FPU initialization:
1234         */
1235        if (cpu_has_xsave)
1236                current_thread_info()->status = TS_XSAVE;
1237        else
1238                current_thread_info()->status = 0;
1239        clear_used_math();
1240        mxcsr_feature_mask_init();
1241
1242        /*
1243         * Boot processor to setup the FP and extended state context info.
1244         */
1245        if (smp_processor_id() == boot_cpu_id)
1246                init_thread_xstate();
1247
1248        xsave_init();
1249}
1250#endif
1251
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