linux/arch/x86/kernel/cpu/intel.c
<<
>>
Prefs
   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
  91#ifdef CONFIG_X86_32
  92/*
  93 *      Early probe support logic for ppro memory erratum #50
  94 *
  95 *      This is called before we do cpu ident work
  96 */
  97
  98int __cpuinit ppro_with_ram_bug(void)
  99{
 100        /* Uses data from early_cpu_detect now */
 101        if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
 102            boot_cpu_data.x86 == 6 &&
 103            boot_cpu_data.x86_model == 1 &&
 104            boot_cpu_data.x86_mask < 8) {
 105                printk(KERN_INFO "Pentium Pro with Errata#50 detected. Taking evasive action.\n");
 106                return 1;
 107        }
 108        return 0;
 109}
 110
 111#ifdef CONFIG_X86_F00F_BUG
 112static void __cpuinit trap_init_f00f_bug(void)
 113{
 114        __set_fixmap(FIX_F00F_IDT, __pa(&idt_table), PAGE_KERNEL_RO);
 115
 116        /*
 117         * Update the IDT descriptor and reload the IDT so that
 118         * it uses the read-only mapped virtual address.
 119         */
 120        idt_descr.address = fix_to_virt(FIX_F00F_IDT);
 121        load_idt(&idt_descr);
 122}
 123#endif
 124
 125static void __cpuinit intel_smp_check(struct cpuinfo_x86 *c)
 126{
 127#ifdef CONFIG_SMP
 128        /* calling is from identify_secondary_cpu() ? */
 129        if (c->cpu_index == boot_cpu_id)
 130                return;
 131
 132        /*
 133         * Mask B, Pentium, but not Pentium MMX
 134         */
 135        if (c->x86 == 5 &&
 136            c->x86_mask >= 1 && c->x86_mask <= 4 &&
 137            c->x86_model <= 3) {
 138                /*
 139                 * Remember we have B step Pentia with bugs
 140                 */
 141                WARN_ONCE(1, "WARNING: SMP operation may be unreliable"
 142                                    "with B stepping processors.\n");
 143        }
 144#endif
 145}
 146
 147static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)
 148{
 149        unsigned long lo, hi;
 150
 151#ifdef CONFIG_X86_F00F_BUG
 152        /*
 153         * All current models of Pentium and Pentium with MMX technology CPUs
 154         * have the F0 0F bug, which lets nonprivileged users lock up the system.
 155         * Note that the workaround only should be initialized once...
 156         */
 157        c->f00f_bug = 0;
 158        if (!paravirt_enabled() && c->x86 == 5) {
 159                static int f00f_workaround_enabled;
 160
 161                c->f00f_bug = 1;
 162                if (!f00f_workaround_enabled) {
 163                        trap_init_f00f_bug();
 164                        printk(KERN_NOTICE "Intel Pentium with F0 0F bug - workaround enabled.\n");
 165                        f00f_workaround_enabled = 1;
 166                }
 167        }
 168#endif
 169
 170        /*
 171         * SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until
 172         * model 3 mask 3
 173         */
 174        if ((c->x86<<8 | c->x86_model<<4 | c->x86_mask) < 0x633)
 175                clear_cpu_cap(c, X86_FEATURE_SEP);
 176
 177        /*
 178         * P4 Xeon errata 037 workaround.
 179         * Hardware prefetcher may cause stale data to be loaded into the cache.
 180         */
 181        if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
 182                rdmsr(MSR_IA32_MISC_ENABLE, lo, hi);
 183                if ((lo & MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE) == 0) {
 184                        printk (KERN_INFO "CPU: C0 stepping P4 Xeon detected.\n");
 185                        printk (KERN_INFO "CPU: Disabling hardware prefetching (Errata 037)\n");
 186                        lo |= MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE;
 187                        wrmsr (MSR_IA32_MISC_ENABLE, lo, hi);
 188                }
 189        }
 190
 191        /*
 192         * See if we have a good local APIC by checking for buggy Pentia,
 193         * i.e. all B steppings and the C2 stepping of P54C when using their
 194         * integrated APIC (see 11AP erratum in "Pentium Processor
 195         * Specification Update").
 196         */
 197        if (cpu_has_apic && (c->x86<<8 | c->x86_model<<4) == 0x520 &&
 198            (c->x86_mask < 0x6 || c->x86_mask == 0xb))
 199                set_cpu_cap(c, X86_FEATURE_11AP);
 200
 201
 202#ifdef CONFIG_X86_INTEL_USERCOPY
 203        /*
 204         * Set up the preferred alignment for movsl bulk memory moves
 205         */
 206        switch (c->x86) {
 207        case 4:         /* 486: untested */
 208                break;
 209        case 5:         /* Old Pentia: untested */
 210                break;
 211        case 6:         /* PII/PIII only like movsl with 8-byte alignment */
 212                movsl_mask.mask = 7;
 213                break;
 214        case 15:        /* P4 is OK down to 8-byte alignment */
 215                movsl_mask.mask = 7;
 216                break;
 217        }
 218#endif
 219
 220#ifdef CONFIG_X86_NUMAQ
 221        numaq_tsc_disable();
 222#endif
 223
 224        intel_smp_check(c);
 225}
 226#else
 227static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)
 228{
 229}
 230#endif
 231
 232static void __cpuinit srat_detect_node(void)
 233{
 234#if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
 235        unsigned node;
 236        int cpu = smp_processor_id();
 237        int apicid = hard_smp_processor_id();
 238
 239        /* Don't do the funky fallback heuristics the AMD version employs
 240           for now. */
 241        node = apicid_to_node[apicid];
 242        if (node == NUMA_NO_NODE || !node_online(node))
 243                node = first_node(node_online_map);
 244        numa_set_node(cpu, node);
 245
 246        printk(KERN_INFO "CPU %d/0x%x -> Node %d\n", cpu, apicid, node);
 247#endif
 248}
 249
 250/*
 251 * find out the number of processor cores on the die
 252 */
 253static int __cpuinit intel_num_cpu_cores(struct cpuinfo_x86 *c)
 254{
 255        unsigned int eax, ebx, ecx, edx;
 256
 257        if (c->cpuid_level < 4)
 258                return 1;
 259
 260        /* Intel has a non-standard dependency on %ecx for this CPUID level. */
 261        cpuid_count(4, 0, &eax, &ebx, &ecx, &edx);
 262        if (eax & 0x1f)
 263                return ((eax >> 26) + 1);
 264        else
 265                return 1;
 266}
 267
 268static void __cpuinit detect_vmx_virtcap(struct cpuinfo_x86 *c)
 269{
 270        /* Intel VMX MSR indicated features */
 271#define X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW    0x00200000
 272#define X86_VMX_FEATURE_PROC_CTLS_VNMI          0x00400000
 273#define X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS      0x80000000
 274#define X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC    0x00000001
 275#define X86_VMX_FEATURE_PROC_CTLS2_EPT          0x00000002
 276#define X86_VMX_FEATURE_PROC_CTLS2_VPID         0x00000020
 277
 278        u32 vmx_msr_low, vmx_msr_high, msr_ctl, msr_ctl2;
 279
 280        clear_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
 281        clear_cpu_cap(c, X86_FEATURE_VNMI);
 282        clear_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
 283        clear_cpu_cap(c, X86_FEATURE_EPT);
 284        clear_cpu_cap(c, X86_FEATURE_VPID);
 285
 286        rdmsr(MSR_IA32_VMX_PROCBASED_CTLS, vmx_msr_low, vmx_msr_high);
 287        msr_ctl = vmx_msr_high | vmx_msr_low;
 288        if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW)
 289                set_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
 290        if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_VNMI)
 291                set_cpu_cap(c, X86_FEATURE_VNMI);
 292        if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS) {
 293                rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2,
 294                      vmx_msr_low, vmx_msr_high);
 295                msr_ctl2 = vmx_msr_high | vmx_msr_low;
 296                if ((msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC) &&
 297                    (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW))
 298                        set_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
 299                if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_EPT)
 300                        set_cpu_cap(c, X86_FEATURE_EPT);
 301                if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VPID)
 302                        set_cpu_cap(c, X86_FEATURE_VPID);
 303        }
 304}
 305
 306static void __cpuinit init_intel(struct cpuinfo_x86 *c)
 307{
 308        unsigned int l2 = 0;
 309
 310        early_init_intel(c);
 311
 312        intel_workarounds(c);
 313
 314        /*
 315         * Detect the extended topology information if available. This
 316         * will reinitialise the initial_apicid which will be used
 317         * in init_intel_cacheinfo()
 318         */
 319        detect_extended_topology(c);
 320
 321        l2 = init_intel_cacheinfo(c);
 322        if (c->cpuid_level > 9) {
 323                unsigned eax = cpuid_eax(10);
 324                /* Check for version and the number of counters */
 325                if ((eax & 0xff) && (((eax>>8) & 0xff) > 1))
 326                        set_cpu_cap(c, X86_FEATURE_ARCH_PERFMON);
 327        }
 328
 329        if (cpu_has_xmm2)
 330                set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
 331        if (cpu_has_ds) {
 332                unsigned int l1;
 333                rdmsr(MSR_IA32_MISC_ENABLE, l1, l2);
 334                if (!(l1 & (1<<11)))
 335                        set_cpu_cap(c, X86_FEATURE_BTS);
 336                if (!(l1 & (1<<12)))
 337                        set_cpu_cap(c, X86_FEATURE_PEBS);
 338                ds_init_intel(c);
 339        }
 340
 341        if (c->x86 == 6 && c->x86_model == 29 && cpu_has_clflush)
 342                set_cpu_cap(c, X86_FEATURE_CLFLUSH_MONITOR);
 343
 344#ifdef CONFIG_X86_64
 345        if (c->x86 == 15)
 346                c->x86_cache_alignment = c->x86_clflush_size * 2;
 347        if (c->x86 == 6)
 348                set_cpu_cap(c, X86_FEATURE_REP_GOOD);
 349#else
 350        /*
 351         * Names for the Pentium II/Celeron processors
 352         * detectable only by also checking the cache size.
 353         * Dixon is NOT a Celeron.
 354         */
 355        if (c->x86 == 6) {
 356                char *p = NULL;
 357
 358                switch (c->x86_model) {
 359                case 5:
 360                        if (c->x86_mask == 0) {
 361                                if (l2 == 0)
 362                                        p = "Celeron (Covington)";
 363                                else if (l2 == 256)
 364                                        p = "Mobile Pentium II (Dixon)";
 365                        }
 366                        break;
 367
 368                case 6:
 369                        if (l2 == 128)
 370                                p = "Celeron (Mendocino)";
 371                        else if (c->x86_mask == 0 || c->x86_mask == 5)
 372                                p = "Celeron-A";
 373                        break;
 374
 375                case 8:
 376                        if (l2 == 128)
 377                                p = "Celeron (Coppermine)";
 378                        break;
 379                }
 380
 381                if (p)
 382                        strcpy(c->x86_model_id, p);
 383        }
 384
 385        if (c->x86 == 15)
 386                set_cpu_cap(c, X86_FEATURE_P4);
 387        if (c->x86 == 6)
 388                set_cpu_cap(c, X86_FEATURE_P3);
 389#endif
 390
 391        if (!cpu_has(c, X86_FEATURE_XTOPOLOGY)) {
 392                /*
 393                 * let's use the legacy cpuid vector 0x1 and 0x4 for topology
 394                 * detection.
 395                 */
 396                c->x86_max_cores = intel_num_cpu_cores(c);
 397#ifdef CONFIG_X86_32
 398                detect_ht(c);
 399#endif
 400        }
 401
 402        /* Work around errata */
 403        srat_detect_node();
 404
 405        if (cpu_has(c, X86_FEATURE_VMX))
 406                detect_vmx_virtcap(c);
 407}
 408
 409#ifdef CONFIG_X86_32
 410static unsigned int __cpuinit intel_size_cache(struct cpuinfo_x86 *c, unsigned int size)
 411{
 412        /*
 413         * Intel PIII Tualatin. This comes in two flavours.
 414         * One has 256kb of cache, the other 512. We have no way
 415         * to determine which, so we use a boottime override
 416         * for the 512kb model, and assume 256 otherwise.
 417         */
 418        if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
 419                size = 256;
 420        return size;
 421}
 422#endif
 423
 424static const struct cpu_dev __cpuinitconst intel_cpu_dev = {
 425        .c_vendor       = "Intel",
 426        .c_ident        = { "GenuineIntel" },
 427#ifdef CONFIG_X86_32
 428        .c_models = {
 429                { .vendor = X86_VENDOR_INTEL, .family = 4, .model_names =
 430                  {
 431                          [0] = "486 DX-25/33",
 432                          [1] = "486 DX-50",
 433                          [2] = "486 SX",
 434                          [3] = "486 DX/2",
 435                          [4] = "486 SL",
 436                          [5] = "486 SX/2",
 437                          [7] = "486 DX/2-WB",
 438                          [8] = "486 DX/4",
 439                          [9] = "486 DX/4-WB"
 440                  }
 441                },
 442                { .vendor = X86_VENDOR_INTEL, .family = 5, .model_names =
 443                  {
 444                          [0] = "Pentium 60/66 A-step",
 445                          [1] = "Pentium 60/66",
 446                          [2] = "Pentium 75 - 200",
 447                          [3] = "OverDrive PODP5V83",
 448                          [4] = "Pentium MMX",
 449                          [7] = "Mobile Pentium 75 - 200",
 450                          [8] = "Mobile Pentium MMX"
 451                  }
 452                },
 453                { .vendor = X86_VENDOR_INTEL, .family = 6, .model_names =
 454                  {
 455                          [0] = "Pentium Pro A-step",
 456                          [1] = "Pentium Pro",
 457                          [3] = "Pentium II (Klamath)",
 458                          [4] = "Pentium II (Deschutes)",
 459                          [5] = "Pentium II (Deschutes)",
 460                          [6] = "Mobile Pentium II",
 461                          [7] = "Pentium III (Katmai)",
 462                          [8] = "Pentium III (Coppermine)",
 463                          [10] = "Pentium III (Cascades)",
 464                          [11] = "Pentium III (Tualatin)",
 465                  }
 466                },
 467                { .vendor = X86_VENDOR_INTEL, .family = 15, .model_names =
 468                  {
 469                          [0] = "Pentium 4 (Unknown)",
 470                          [1] = "Pentium 4 (Willamette)",
 471                          [2] = "Pentium 4 (Northwood)",
 472                          [4] = "Pentium 4 (Foster)",
 473                          [5] = "Pentium 4 (Foster)",
 474                  }
 475                },
 476        },
 477        .c_size_cache   = intel_size_cache,
 478#endif
 479        .c_early_init   = early_init_intel,
 480        .c_init         = init_intel,
 481        .c_x86_vendor   = X86_VENDOR_INTEL,
 482};
 483
 484cpu_dev_register(intel_cpu_dev);
 485
 486
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.