linux/arch/x86/kernel/cpu/intel.c
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   1#include <linux/init.h>
   2#include <linux/kernel.h>
   3
   4#include <linux/string.h>
   5#include <linux/bitops.h>
   6#include <linux/smp.h>
   7#include <linux/sched.h>
   8#include <linux/thread_info.h>
   9#include <linux/module.h>
  10
  11#include <asm/processor.h>
  12#include <asm/pgtable.h>
  13#include <asm/msr.h>
  14#include <asm/uaccess.h>
  15#include <asm/ds.h>
  16#include <asm/bugs.h>
  17#include <asm/cpu.h>
  18
  19#ifdef CONFIG_X86_64
  20#include <asm/topology.h>
  21#include <asm/numa_64.h>
  22#endif
  23
  24#include "cpu.h"
  25
  26#ifdef CONFIG_X86_LOCAL_APIC
  27#include <asm/mpspec.h>
  28#include <asm/apic.h>
  29#endif
  30
  31static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
  32{
  33        /* Unmask CPUID levels if masked: */
  34        if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
  35                u64 misc_enable;
  36
  37                rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
  38
  39                if (misc_enable & MSR_IA32_MISC_ENABLE_LIMIT_CPUID) {
  40                        misc_enable &= ~MSR_IA32_MISC_ENABLE_LIMIT_CPUID;
  41                        wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
  42                        c->cpuid_level = cpuid_eax(0);
  43                }
  44        }
  45
  46        if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
  47                (c->x86 == 0x6 && c->x86_model >= 0x0e))
  48                set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
  49
  50#ifdef CONFIG_X86_64
  51        set_cpu_cap(c, X86_FEATURE_SYSENTER32);
  52#else
  53        /* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */
  54        if (c->x86 == 15 && c->x86_cache_alignment == 64)
  55                c->x86_cache_alignment = 128;
  56#endif
  57
  58        /* CPUID workaround for 0F33/0F34 CPU */
  59        if (c->x86 == 0xF && c->x86_model == 0x3
  60            && (c->x86_mask == 0x3 || c->x86_mask == 0x4))
  61                c->x86_phys_bits = 36;
  62
  63        /*
  64         * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
  65         * with P/T states and does not stop in deep C-states.
  66         *
  67         * It is also reliable across cores and sockets. (but not across
  68         * cabinets - we turn it off in that case explicitly.)
  69         */
  70        if (c->x86_power & (1 << 8)) {
  71                set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
  72                set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
  73                set_cpu_cap(c, X86_FEATURE_TSC_RELIABLE);
  74                sched_clock_stable = 1;
  75        }
  76
  77        /*
  78         * There is a known erratum on Pentium III and Core Solo
  79         * and Core Duo CPUs.
  80         * " Page with PAT set to WC while associated MTRR is UC
  81         *   may consolidate to UC "
  82         * Because of this erratum, it is better to stick with
  83         * setting WC in MTRR rather than using PAT on these CPUs.
  84         *
  85         * Enable PAT WC only on P4, Core 2 or later CPUs.
  86         */
  87        if (c->x86 == 6 && c->x86_model < 15)
  88                clear_cpu_cap(c, X86_FEATURE_PAT);
  89
  90#ifdef CONFIG_KMEMCHECK
  91        /*
  92         * P4s have a "fast strings" feature which causes single-
  93         * stepping REP instructions to only generate a #DB on
  94         * cache-line boundaries.
  95         *
  96         * Ingo Molnar reported a Pentium D (model 6) and a Xeon
  97         * (model 2) with the same problem.
  98         */
  99        if (c->x86 == 15) {
 100                u64 misc_enable;
 101
 102                rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
 103
 104                if (misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING) {
 105                        printk(KERN_INFO "kmemcheck: Disabling fast string operations\n");
 106
 107                        misc_enable &= ~MSR_IA32_MISC_ENABLE_FAST_STRING;
 108                        wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
 109                }
 110        }
 111#endif
 112}
 113
 114#ifdef CONFIG_X86_32
 115/*
 116 *      Early probe support logic for ppro memory erratum #50
 117 *
 118 *      This is called before we do cpu ident work
 119 */
 120
 121int __cpuinit ppro_with_ram_bug(void)
 122{
 123        /* Uses data from early_cpu_detect now */
 124        if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
 125            boot_cpu_data.x86 == 6 &&
 126            boot_cpu_data.x86_model == 1 &&
 127            boot_cpu_data.x86_mask < 8) {
 128                printk(KERN_INFO "Pentium Pro with Errata#50 detected. Taking evasive action.\n");
 129                return 1;
 130        }
 131        return 0;
 132}
 133
 134#ifdef CONFIG_X86_F00F_BUG
 135static void __cpuinit trap_init_f00f_bug(void)
 136{
 137        __set_fixmap(FIX_F00F_IDT, __pa(&idt_table), PAGE_KERNEL_RO);
 138
 139        /*
 140         * Update the IDT descriptor and reload the IDT so that
 141         * it uses the read-only mapped virtual address.
 142         */
 143        idt_descr.address = fix_to_virt(FIX_F00F_IDT);
 144        load_idt(&idt_descr);
 145}
 146#endif
 147
 148static void __cpuinit intel_smp_check(struct cpuinfo_x86 *c)
 149{
 150#ifdef CONFIG_SMP
 151        /* calling is from identify_secondary_cpu() ? */
 152        if (c->cpu_index == boot_cpu_id)
 153                return;
 154
 155        /*
 156         * Mask B, Pentium, but not Pentium MMX
 157         */
 158        if (c->x86 == 5 &&
 159            c->x86_mask >= 1 && c->x86_mask <= 4 &&
 160            c->x86_model <= 3) {
 161                /*
 162                 * Remember we have B step Pentia with bugs
 163                 */
 164                WARN_ONCE(1, "WARNING: SMP operation may be unreliable"
 165                                    "with B stepping processors.\n");
 166        }
 167#endif
 168}
 169
 170static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)
 171{
 172        unsigned long lo, hi;
 173
 174#ifdef CONFIG_X86_F00F_BUG
 175        /*
 176         * All current models of Pentium and Pentium with MMX technology CPUs
 177         * have the F0 0F bug, which lets nonprivileged users lock up the system.
 178         * Note that the workaround only should be initialized once...
 179         */
 180        c->f00f_bug = 0;
 181        if (!paravirt_enabled() && c->x86 == 5) {
 182                static int f00f_workaround_enabled;
 183
 184                c->f00f_bug = 1;
 185                if (!f00f_workaround_enabled) {
 186                        trap_init_f00f_bug();
 187                        printk(KERN_NOTICE "Intel Pentium with F0 0F bug - workaround enabled.\n");
 188                        f00f_workaround_enabled = 1;
 189                }
 190        }
 191#endif
 192
 193        /*
 194         * SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until
 195         * model 3 mask 3
 196         */
 197        if ((c->x86<<8 | c->x86_model<<4 | c->x86_mask) < 0x633)
 198                clear_cpu_cap(c, X86_FEATURE_SEP);
 199
 200        /*
 201         * P4 Xeon errata 037 workaround.
 202         * Hardware prefetcher may cause stale data to be loaded into the cache.
 203         */
 204        if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
 205                rdmsr(MSR_IA32_MISC_ENABLE, lo, hi);
 206                if ((lo & MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE) == 0) {
 207                        printk (KERN_INFO "CPU: C0 stepping P4 Xeon detected.\n");
 208                        printk (KERN_INFO "CPU: Disabling hardware prefetching (Errata 037)\n");
 209                        lo |= MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE;
 210                        wrmsr (MSR_IA32_MISC_ENABLE, lo, hi);
 211                }
 212        }
 213
 214        /*
 215         * See if we have a good local APIC by checking for buggy Pentia,
 216         * i.e. all B steppings and the C2 stepping of P54C when using their
 217         * integrated APIC (see 11AP erratum in "Pentium Processor
 218         * Specification Update").
 219         */
 220        if (cpu_has_apic && (c->x86<<8 | c->x86_model<<4) == 0x520 &&
 221            (c->x86_mask < 0x6 || c->x86_mask == 0xb))
 222                set_cpu_cap(c, X86_FEATURE_11AP);
 223
 224
 225#ifdef CONFIG_X86_INTEL_USERCOPY
 226        /*
 227         * Set up the preferred alignment for movsl bulk memory moves
 228         */
 229        switch (c->x86) {
 230        case 4:         /* 486: untested */
 231                break;
 232        case 5:         /* Old Pentia: untested */
 233                break;
 234        case 6:         /* PII/PIII only like movsl with 8-byte alignment */
 235                movsl_mask.mask = 7;
 236                break;
 237        case 15:        /* P4 is OK down to 8-byte alignment */
 238                movsl_mask.mask = 7;
 239                break;
 240        }
 241#endif
 242
 243#ifdef CONFIG_X86_NUMAQ
 244        numaq_tsc_disable();
 245#endif
 246
 247        intel_smp_check(c);
 248}
 249#else
 250static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)
 251{
 252}
 253#endif
 254
 255static void __cpuinit srat_detect_node(struct cpuinfo_x86 *c)
 256{
 257#if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
 258        unsigned node;
 259        int cpu = smp_processor_id();
 260        int apicid = cpu_has_apic ? hard_smp_processor_id() : c->apicid;
 261
 262        /* Don't do the funky fallback heuristics the AMD version employs
 263           for now. */
 264        node = apicid_to_node[apicid];
 265        if (node == NUMA_NO_NODE || !node_online(node))
 266                node = first_node(node_online_map);
 267        numa_set_node(cpu, node);
 268
 269        printk(KERN_INFO "CPU %d/0x%x -> Node %d\n", cpu, apicid, node);
 270#endif
 271}
 272
 273/*
 274 * find out the number of processor cores on the die
 275 */
 276static int __cpuinit intel_num_cpu_cores(struct cpuinfo_x86 *c)
 277{
 278        unsigned int eax, ebx, ecx, edx;
 279
 280        if (c->cpuid_level < 4)
 281                return 1;
 282
 283        /* Intel has a non-standard dependency on %ecx for this CPUID level. */
 284        cpuid_count(4, 0, &eax, &ebx, &ecx, &edx);
 285        if (eax & 0x1f)
 286                return ((eax >> 26) + 1);
 287        else
 288                return 1;
 289}
 290
 291static void __cpuinit detect_vmx_virtcap(struct cpuinfo_x86 *c)
 292{
 293        /* Intel VMX MSR indicated features */
 294#define X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW    0x00200000
 295#define X86_VMX_FEATURE_PROC_CTLS_VNMI          0x00400000
 296#define X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS      0x80000000
 297#define X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC    0x00000001
 298#define X86_VMX_FEATURE_PROC_CTLS2_EPT          0x00000002
 299#define X86_VMX_FEATURE_PROC_CTLS2_VPID         0x00000020
 300
 301        u32 vmx_msr_low, vmx_msr_high, msr_ctl, msr_ctl2;
 302
 303        clear_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
 304        clear_cpu_cap(c, X86_FEATURE_VNMI);
 305        clear_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
 306        clear_cpu_cap(c, X86_FEATURE_EPT);
 307        clear_cpu_cap(c, X86_FEATURE_VPID);
 308
 309        rdmsr(MSR_IA32_VMX_PROCBASED_CTLS, vmx_msr_low, vmx_msr_high);
 310        msr_ctl = vmx_msr_high | vmx_msr_low;
 311        if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW)
 312                set_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
 313        if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_VNMI)
 314                set_cpu_cap(c, X86_FEATURE_VNMI);
 315        if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS) {
 316                rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2,
 317                      vmx_msr_low, vmx_msr_high);
 318                msr_ctl2 = vmx_msr_high | vmx_msr_low;
 319                if ((msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC) &&
 320                    (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW))
 321                        set_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
 322                if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_EPT)
 323                        set_cpu_cap(c, X86_FEATURE_EPT);
 324                if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VPID)
 325                        set_cpu_cap(c, X86_FEATURE_VPID);
 326        }
 327}
 328
 329static void __cpuinit init_intel(struct cpuinfo_x86 *c)
 330{
 331        unsigned int l2 = 0;
 332
 333        early_init_intel(c);
 334
 335        intel_workarounds(c);
 336
 337        /*
 338         * Detect the extended topology information if available. This
 339         * will reinitialise the initial_apicid which will be used
 340         * in init_intel_cacheinfo()
 341         */
 342        detect_extended_topology(c);
 343
 344        l2 = init_intel_cacheinfo(c);
 345        if (c->cpuid_level > 9) {
 346                unsigned eax = cpuid_eax(10);
 347                /* Check for version and the number of counters */
 348                if ((eax & 0xff) && (((eax>>8) & 0xff) > 1))
 349                        set_cpu_cap(c, X86_FEATURE_ARCH_PERFMON);
 350        }
 351
 352        if (cpu_has_xmm2)
 353                set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
 354        if (cpu_has_ds) {
 355                unsigned int l1;
 356                rdmsr(MSR_IA32_MISC_ENABLE, l1, l2);
 357                if (!(l1 & (1<<11)))
 358                        set_cpu_cap(c, X86_FEATURE_BTS);
 359                if (!(l1 & (1<<12)))
 360                        set_cpu_cap(c, X86_FEATURE_PEBS);
 361                ds_init_intel(c);
 362        }
 363
 364        if (c->x86 == 6 && c->x86_model == 29 && cpu_has_clflush)
 365                set_cpu_cap(c, X86_FEATURE_CLFLUSH_MONITOR);
 366
 367#ifdef CONFIG_X86_64
 368        if (c->x86 == 15)
 369                c->x86_cache_alignment = c->x86_clflush_size * 2;
 370        if (c->x86 == 6)
 371                set_cpu_cap(c, X86_FEATURE_REP_GOOD);
 372#else
 373        /*
 374         * Names for the Pentium II/Celeron processors
 375         * detectable only by also checking the cache size.
 376         * Dixon is NOT a Celeron.
 377         */
 378        if (c->x86 == 6) {
 379                char *p = NULL;
 380
 381                switch (c->x86_model) {
 382                case 5:
 383                        if (c->x86_mask == 0) {
 384                                if (l2 == 0)
 385                                        p = "Celeron (Covington)";
 386                                else if (l2 == 256)
 387                                        p = "Mobile Pentium II (Dixon)";
 388                        }
 389                        break;
 390
 391                case 6:
 392                        if (l2 == 128)
 393                                p = "Celeron (Mendocino)";
 394                        else if (c->x86_mask == 0 || c->x86_mask == 5)
 395                                p = "Celeron-A";
 396                        break;
 397
 398                case 8:
 399                        if (l2 == 128)
 400                                p = "Celeron (Coppermine)";
 401                        break;
 402                }
 403
 404                if (p)
 405                        strcpy(c->x86_model_id, p);
 406        }
 407
 408        if (c->x86 == 15)
 409                set_cpu_cap(c, X86_FEATURE_P4);
 410        if (c->x86 == 6)
 411                set_cpu_cap(c, X86_FEATURE_P3);
 412#endif
 413
 414        if (!cpu_has(c, X86_FEATURE_XTOPOLOGY)) {
 415                /*
 416                 * let's use the legacy cpuid vector 0x1 and 0x4 for topology
 417                 * detection.
 418                 */
 419                c->x86_max_cores = intel_num_cpu_cores(c);
 420#ifdef CONFIG_X86_32
 421                detect_ht(c);
 422#endif
 423        }
 424
 425        /* Work around errata */
 426        srat_detect_node(c);
 427
 428        if (cpu_has(c, X86_FEATURE_VMX))
 429                detect_vmx_virtcap(c);
 430}
 431
 432#ifdef CONFIG_X86_32
 433static unsigned int __cpuinit intel_size_cache(struct cpuinfo_x86 *c, unsigned int size)
 434{
 435        /*
 436         * Intel PIII Tualatin. This comes in two flavours.
 437         * One has 256kb of cache, the other 512. We have no way
 438         * to determine which, so we use a boottime override
 439         * for the 512kb model, and assume 256 otherwise.
 440         */
 441        if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
 442                size = 256;
 443        return size;
 444}
 445#endif
 446
 447static const struct cpu_dev __cpuinitconst intel_cpu_dev = {
 448        .c_vendor       = "Intel",
 449        .c_ident        = { "GenuineIntel" },
 450#ifdef CONFIG_X86_32
 451        .c_models = {
 452                { .vendor = X86_VENDOR_INTEL, .family = 4, .model_names =
 453                  {
 454                          [0] = "486 DX-25/33",
 455                          [1] = "486 DX-50",
 456                          [2] = "486 SX",
 457                          [3] = "486 DX/2",
 458                          [4] = "486 SL",
 459                          [5] = "486 SX/2",
 460                          [7] = "486 DX/2-WB",
 461                          [8] = "486 DX/4",
 462                          [9] = "486 DX/4-WB"
 463                  }
 464                },
 465                { .vendor = X86_VENDOR_INTEL, .family = 5, .model_names =
 466                  {
 467                          [0] = "Pentium 60/66 A-step",
 468                          [1] = "Pentium 60/66",
 469                          [2] = "Pentium 75 - 200",
 470                          [3] = "OverDrive PODP5V83",
 471                          [4] = "Pentium MMX",
 472                          [7] = "Mobile Pentium 75 - 200",
 473                          [8] = "Mobile Pentium MMX"
 474                  }
 475                },
 476                { .vendor = X86_VENDOR_INTEL, .family = 6, .model_names =
 477                  {
 478                          [0] = "Pentium Pro A-step",
 479                          [1] = "Pentium Pro",
 480                          [3] = "Pentium II (Klamath)",
 481                          [4] = "Pentium II (Deschutes)",
 482                          [5] = "Pentium II (Deschutes)",
 483                          [6] = "Mobile Pentium II",
 484                          [7] = "Pentium III (Katmai)",
 485                          [8] = "Pentium III (Coppermine)",
 486                          [10] = "Pentium III (Cascades)",
 487                          [11] = "Pentium III (Tualatin)",
 488                  }
 489                },
 490                { .vendor = X86_VENDOR_INTEL, .family = 15, .model_names =
 491                  {
 492                          [0] = "Pentium 4 (Unknown)",
 493                          [1] = "Pentium 4 (Willamette)",
 494                          [2] = "Pentium 4 (Northwood)",
 495                          [4] = "Pentium 4 (Foster)",
 496                          [5] = "Pentium 4 (Foster)",
 497                  }
 498                },
 499        },
 500        .c_size_cache   = intel_size_cache,
 501#endif
 502        .c_early_init   = early_init_intel,
 503        .c_init         = init_intel,
 504        .c_x86_vendor   = X86_VENDOR_INTEL,
 505};
 506
 507cpu_dev_register(intel_cpu_dev);
 508
 509
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