arch/x86/kernel/cpu/intel.c

   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 #include <linux/uaccess.h>
  11
  12 #include <asm/processor.h>
  13 #include <asm/pgtable.h>
  14 #include <asm/msr.h>
  15 #include <asm/bugs.h>
  16 #include <asm/cpu.h>
  17
  18 #ifdef CONFIG_X86_64
  19 #include <linux/topology.h>
  20 #include <asm/numa_64.h>
  21 #endif
  22
  23 #include "cpu.h"
  24
  25 #ifdef CONFIG_X86_LOCAL_APIC
  26 #include <asm/mpspec.h>
  27 #include <asm/apic.h>
  28 #endif
  29
  30 static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
  31 {
  32         u64 misc_enable;
  33
  34         /* Unmask CPUID levels if masked: */
  35         if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
  36                 rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
  37
  38                 if (misc_enable & MSR_IA32_MISC_ENABLE_LIMIT_CPUID) {
  39                         misc_enable &= ~MSR_IA32_MISC_ENABLE_LIMIT_CPUID;
  40                         wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
  41                         c->cpuid_level = cpuid_eax(0);
  42                         get_cpu_cap(c);
  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         if (c->x86 >= 6 && !cpu_has(c, X86_FEATURE_IA64)) {
  51                 unsigned lower_word;
  52
  53                 wrmsr(MSR_IA32_UCODE_REV, 0, 0);
  54                 /* Required by the SDM */
  55                 sync_core();
  56                 rdmsr(MSR_IA32_UCODE_REV, lower_word, c->microcode);
  57         }
  58
  59         /*
  60          * Atom erratum AAE44/AAF40/AAG38/AAH41:
  61          *
  62          * A race condition between speculative fetches and invalidating
  63          * a large page.  This is worked around in microcode, but we
  64          * need the microcode to have already been loaded... so if it is
  65          * not, recommend a BIOS update and disable large pages.
  66          */
  67         if (c->x86 == 6 && c->x86_model == 0x1c && c->x86_mask <= 2 &&
  68             c->microcode < 0x20e) {
  69                 printk(KERN_WARNING "Atom PSE erratum detected, BIOS microcode update recommended\n");
  70                 clear_cpu_cap(c, X86_FEATURE_PSE);
  71         }
  72
  73 #ifdef CONFIG_X86_64
  74         set_cpu_cap(c, X86_FEATURE_SYSENTER32);
  75 #else
  76         /* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */
  77         if (c->x86 == 15 && c->x86_cache_alignment == 64)
  78                 c->x86_cache_alignment = 128;
  79 #endif
  80
  81         /* CPUID workaround for 0F33/0F34 CPU */
  82         if (c->x86 == 0xF && c->x86_model == 0x3
  83             && (c->x86_mask == 0x3 || c->x86_mask == 0x4))
  84                 c->x86_phys_bits = 36;
  85
  86         /*
  87          * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
  88          * with P/T states and does not stop in deep C-states.
  89          *
  90          * It is also reliable across cores and sockets. (but not across
  91          * cabinets - we turn it off in that case explicitly.)
  92          */
  93         if (c->x86_power & (1 << 8)) {
  94                 set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
  95                 set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
  96                 if (!check_tsc_unstable())
  97                         sched_clock_stable = 1;
  98         }
  99
 100         /*
 101          * There is a known erratum on Pentium III and Core Solo
 102          * and Core Duo CPUs.
 103          * " Page with PAT set to WC while associated MTRR is UC
 104          *   may consolidate to UC "
 105          * Because of this erratum, it is better to stick with
 106          * setting WC in MTRR rather than using PAT on these CPUs.
 107          *
 108          * Enable PAT WC only on P4, Core 2 or later CPUs.
 109          */
 110         if (c->x86 == 6 && c->x86_model < 15)
 111                 clear_cpu_cap(c, X86_FEATURE_PAT);
 112
 113 #ifdef CONFIG_KMEMCHECK
 114         /*
 115          * P4s have a "fast strings" feature which causes single-
 116          * stepping REP instructions to only generate a #DB on
 117          * cache-line boundaries.
 118          *
 119          * Ingo Molnar reported a Pentium D (model 6) and a Xeon
 120          * (model 2) with the same problem.
 121          */
 122         if (c->x86 == 15) {
 123                 rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
 124
 125                 if (misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING) {
 126                         printk(KERN_INFO "kmemcheck: Disabling fast string operations\n");
 127
 128                         misc_enable &= ~MSR_IA32_MISC_ENABLE_FAST_STRING;
 129                         wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
 130                 }
 131         }
 132 #endif
 133
 134         /*
 135          * If fast string is not enabled in IA32_MISC_ENABLE for any reason,
 136          * clear the fast string and enhanced fast string CPU capabilities.
 137          */
 138         if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
 139                 rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
 140                 if (!(misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING)) {
 141                         printk(KERN_INFO "Disabled fast string operations\n");
 142                         setup_clear_cpu_cap(X86_FEATURE_REP_GOOD);
 143                         setup_clear_cpu_cap(X86_FEATURE_ERMS);
 144                 }
 145         }
 146 }
 147
 148 #ifdef CONFIG_X86_32
 149 /*
 150  *      Early probe support logic for ppro memory erratum #50
 151  *
 152  *      This is called before we do cpu ident work
 153  */
 154
 155 int __cpuinit ppro_with_ram_bug(void)
 156 {
 157         /* Uses data from early_cpu_detect now */
 158         if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
 159             boot_cpu_data.x86 == 6 &&
 160             boot_cpu_data.x86_model == 1 &&
 161             boot_cpu_data.x86_mask < 8) {
 162                 printk(KERN_INFO "Pentium Pro with Errata#50 detected. Taking evasive action.\n");
 163                 return 1;
 164         }
 165         return 0;
 166 }
 167
 168 #ifdef CONFIG_X86_F00F_BUG
 169 static void __cpuinit trap_init_f00f_bug(void)
 170 {
 171         __set_fixmap(FIX_F00F_IDT, __pa(&idt_table), PAGE_KERNEL_RO);
 172
 173         /*
 174          * Update the IDT descriptor and reload the IDT so that
 175          * it uses the read-only mapped virtual address.
 176          */
 177         idt_descr.address = fix_to_virt(FIX_F00F_IDT);
 178         load_idt(&idt_descr);
 179 }
 180 #endif
 181
 182 static void __cpuinit intel_smp_check(struct cpuinfo_x86 *c)
 183 {
 184 #ifdef CONFIG_SMP
 185         /* calling is from identify_secondary_cpu() ? */
 186         if (!c->cpu_index)
 187                 return;
 188
 189         /*
 190          * Mask B, Pentium, but not Pentium MMX
 191          */
 192         if (c->x86 == 5 &&
 193             c->x86_mask >= 1 && c->x86_mask <= 4 &&
 194             c->x86_model <= 3) {
 195                 /*
 196                  * Remember we have B step Pentia with bugs
 197                  */
 198                 WARN_ONCE(1, "WARNING: SMP operation may be unreliable"
 199                                     "with B stepping processors.\n");
 200         }
 201 #endif
 202 }
 203
 204 static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)
 205 {
 206         unsigned long lo, hi;
 207
 208 #ifdef CONFIG_X86_F00F_BUG
 209         /*
 210          * All current models of Pentium and Pentium with MMX technology CPUs
 211          * have the F0 0F bug, which lets nonprivileged users lock up the
 212          * system.
 213          * Note that the workaround only should be initialized once...
 214          */
 215         c->f00f_bug = 0;
 216         if (!paravirt_enabled() && c->x86 == 5) {
 217                 static int f00f_workaround_enabled;
 218
 219                 c->f00f_bug = 1;
 220                 if (!f00f_workaround_enabled) {
 221                         trap_init_f00f_bug();
 222                         printk(KERN_NOTICE "Intel Pentium with F0 0F bug - workaround enabled.\n");
 223                         f00f_workaround_enabled = 1;
 224                 }
 225         }
 226 #endif
 227
 228         /*
 229          * SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until
 230          * model 3 mask 3
 231          */
 232         if ((c->x86<<8 | c->x86_model<<4 | c->x86_mask) < 0x633)
 233                 clear_cpu_cap(c, X86_FEATURE_SEP);
 234
 235         /*
 236          * P4 Xeon errata 037 workaround.
 237          * Hardware prefetcher may cause stale data to be loaded into the cache.
 238          */
 239         if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
 240                 rdmsr(MSR_IA32_MISC_ENABLE, lo, hi);
 241                 if ((lo & MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE) == 0) {
 242                         printk (KERN_INFO "CPU: C0 stepping P4 Xeon detected.\n");
 243                         printk (KERN_INFO "CPU: Disabling hardware prefetching (Errata 037)\n");
 244                         lo |= MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE;
 245                         wrmsr(MSR_IA32_MISC_ENABLE, lo, hi);
 246                 }
 247         }
 248
 249         /*
 250          * See if we have a good local APIC by checking for buggy Pentia,
 251          * i.e. all B steppings and the C2 stepping of P54C when using their
 252          * integrated APIC (see 11AP erratum in "Pentium Processor
 253          * Specification Update").
 254          */
 255         if (cpu_has_apic && (c->x86<<8 | c->x86_model<<4) == 0x520 &&
 256             (c->x86_mask < 0x6 || c->x86_mask == 0xb))
 257                 set_cpu_cap(c, X86_FEATURE_11AP);
 258
 259
 260 #ifdef CONFIG_X86_INTEL_USERCOPY
 261         /*
 262          * Set up the preferred alignment for movsl bulk memory moves
 263          */
 264         switch (c->x86) {
 265         case 4:         /* 486: untested */
 266                 break;
 267         case 5:         /* Old Pentia: untested */
 268                 break;
 269         case 6:         /* PII/PIII only like movsl with 8-byte alignment */
 270                 movsl_mask.mask = 7;
 271                 break;
 272         case 15:        /* P4 is OK down to 8-byte alignment */
 273                 movsl_mask.mask = 7;
 274                 break;
 275         }
 276 #endif
 277
 278 #ifdef CONFIG_X86_NUMAQ
 279         numaq_tsc_disable();
 280 #endif
 281
 282         intel_smp_check(c);
 283 }
 284 #else
 285 static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)
 286 {
 287 }
 288 #endif
 289
 290 static void __cpuinit srat_detect_node(struct cpuinfo_x86 *c)
 291 {
 292 #ifdef CONFIG_NUMA
 293         unsigned node;
 294         int cpu = smp_processor_id();
 295
 296         /* Don't do the funky fallback heuristics the AMD version employs
 297            for now. */
 298         node = numa_cpu_node(cpu);
 299         if (node == NUMA_NO_NODE || !node_online(node)) {
 300                 /* reuse the value from init_cpu_to_node() */
 301                 node = cpu_to_node(cpu);
 302         }
 303         numa_set_node(cpu, node);
 304 #endif
 305 }
 306
 307 /*
 308  * find out the number of processor cores on the die
 309  */
 310 static int __cpuinit intel_num_cpu_cores(struct cpuinfo_x86 *c)
 311 {
 312         unsigned int eax, ebx, ecx, edx;
 313
 314         if (c->cpuid_level < 4)
 315                 return 1;
 316
 317         /* Intel has a non-standard dependency on %ecx for this CPUID level. */
 318         cpuid_count(4, 0, &eax, &ebx, &ecx, &edx);
 319         if (eax & 0x1f)
 320                 return (eax >> 26) + 1;
 321         else
 322                 return 1;
 323 }
 324
 325 static void __cpuinit detect_vmx_virtcap(struct cpuinfo_x86 *c)
 326 {
 327         /* Intel VMX MSR indicated features */
 328 #define X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW    0x00200000
 329 #define X86_VMX_FEATURE_PROC_CTLS_VNMI          0x00400000
 330 #define X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS      0x80000000
 331 #define X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC    0x00000001
 332 #define X86_VMX_FEATURE_PROC_CTLS2_EPT          0x00000002
 333 #define X86_VMX_FEATURE_PROC_CTLS2_VPID         0x00000020
 334
 335         u32 vmx_msr_low, vmx_msr_high, msr_ctl, msr_ctl2;
 336
 337         clear_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
 338         clear_cpu_cap(c, X86_FEATURE_VNMI);
 339         clear_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
 340         clear_cpu_cap(c, X86_FEATURE_EPT);
 341         clear_cpu_cap(c, X86_FEATURE_VPID);
 342
 343         rdmsr(MSR_IA32_VMX_PROCBASED_CTLS, vmx_msr_low, vmx_msr_high);
 344         msr_ctl = vmx_msr_high | vmx_msr_low;
 345         if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW)
 346                 set_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
 347         if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_VNMI)
 348                 set_cpu_cap(c, X86_FEATURE_VNMI);
 349         if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS) {
 350                 rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2,
 351                       vmx_msr_low, vmx_msr_high);
 352                 msr_ctl2 = vmx_msr_high | vmx_msr_low;
 353                 if ((msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC) &&
 354                     (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW))
 355                         set_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
 356                 if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_EPT)
 357                         set_cpu_cap(c, X86_FEATURE_EPT);
 358                 if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VPID)
 359                         set_cpu_cap(c, X86_FEATURE_VPID);
 360         }
 361 }
 362
 363 static void __cpuinit init_intel(struct cpuinfo_x86 *c)
 364 {
 365         unsigned int l2 = 0;
 366
 367         early_init_intel(c);
 368
 369         intel_workarounds(c);
 370
 371         /*
 372          * Detect the extended topology information if available. This
 373          * will reinitialise the initial_apicid which will be used
 374          * in init_intel_cacheinfo()
 375          */
 376         detect_extended_topology(c);
 377
 378         l2 = init_intel_cacheinfo(c);
 379         if (c->cpuid_level > 9) {
 380                 unsigned eax = cpuid_eax(10);
 381                 /* Check for version and the number of counters */
 382                 if ((eax & 0xff) && (((eax>>8) & 0xff) > 1))
 383                         set_cpu_cap(c, X86_FEATURE_ARCH_PERFMON);
 384         }
 385
 386         if (cpu_has_xmm2)
 387                 set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
 388         if (cpu_has_ds) {
 389                 unsigned int l1;
 390                 rdmsr(MSR_IA32_MISC_ENABLE, l1, l2);
 391                 if (!(l1 & (1<<11)))
 392                         set_cpu_cap(c, X86_FEATURE_BTS);
 393                 if (!(l1 & (1<<12)))
 394                         set_cpu_cap(c, X86_FEATURE_PEBS);
 395         }
 396
 397         if (c->x86 == 6 && c->x86_model == 29 && cpu_has_clflush)
 398                 set_cpu_cap(c, X86_FEATURE_CLFLUSH_MONITOR);
 399
 400 #ifdef CONFIG_X86_64
 401         if (c->x86 == 15)
 402                 c->x86_cache_alignment = c->x86_clflush_size * 2;
 403         if (c->x86 == 6)
 404                 set_cpu_cap(c, X86_FEATURE_REP_GOOD);
 405 #else
 406         /*
 407          * Names for the Pentium II/Celeron processors
 408          * detectable only by also checking the cache size.
 409          * Dixon is NOT a Celeron.
 410          */
 411         if (c->x86 == 6) {
 412                 char *p = NULL;
 413
 414                 switch (c->x86_model) {
 415                 case 5:
 416                         if (l2 == 0)
 417                                 p = "Celeron (Covington)";
 418                         else if (l2 == 256)
 419                                 p = "Mobile Pentium II (Dixon)";
 420                         break;
 421
 422                 case 6:
 423                         if (l2 == 128)
 424                                 p = "Celeron (Mendocino)";
 425                         else if (c->x86_mask == 0 || c->x86_mask == 5)
 426                                 p = "Celeron-A";
 427                         break;
 428
 429                 case 8:
 430                         if (l2 == 128)
 431                                 p = "Celeron (Coppermine)";
 432                         break;
 433                 }
 434
 435                 if (p)
 436                         strcpy(c->x86_model_id, p);
 437         }
 438
 439         if (c->x86 == 15)
 440                 set_cpu_cap(c, X86_FEATURE_P4);
 441         if (c->x86 == 6)
 442                 set_cpu_cap(c, X86_FEATURE_P3);
 443 #endif
 444
 445         if (!cpu_has(c, X86_FEATURE_XTOPOLOGY)) {
 446                 /*
 447                  * let's use the legacy cpuid vector 0x1 and 0x4 for topology
 448                  * detection.
 449                  */
 450                 c->x86_max_cores = intel_num_cpu_cores(c);
 451 #ifdef CONFIG_X86_32
 452                 detect_ht(c);
 453 #endif
 454         }
 455
 456         /* Work around errata */
 457         srat_detect_node(c);
 458
 459         if (cpu_has(c, X86_FEATURE_VMX))
 460                 detect_vmx_virtcap(c);
 461
 462         /*
 463          * Initialize MSR_IA32_ENERGY_PERF_BIAS if BIOS did not.
 464          * x86_energy_perf_policy(8) is available to change it at run-time
 465          */
 466         if (cpu_has(c, X86_FEATURE_EPB)) {
 467                 u64 epb;
 468
 469                 rdmsrl(MSR_IA32_ENERGY_PERF_BIAS, epb);
 470                 if ((epb & 0xF) == ENERGY_PERF_BIAS_PERFORMANCE) {
 471                         printk_once(KERN_WARNING "ENERGY_PERF_BIAS:"
 472                                 " Set to 'normal', was 'performance'\n"
 473                                 "ENERGY_PERF_BIAS: View and update with"
 474                                 " x86_energy_perf_policy(8)\n");
 475                         epb = (epb & ~0xF) | ENERGY_PERF_BIAS_NORMAL;
 476                         wrmsrl(MSR_IA32_ENERGY_PERF_BIAS, epb);
 477                 }
 478         }
 479 }
 480
 481 #ifdef CONFIG_X86_32
 482 static unsigned int __cpuinit intel_size_cache(struct cpuinfo_x86 *c, unsigned int size)
 483 {
 484         /*
 485          * Intel PIII Tualatin. This comes in two flavours.
 486          * One has 256kb of cache, the other 512. We have no way
 487          * to determine which, so we use a boottime override
 488          * for the 512kb model, and assume 256 otherwise.
 489          */
 490         if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
 491                 size = 256;
 492         return size;
 493 }
 494 #endif
 495
 496 static const struct cpu_dev __cpuinitconst intel_cpu_dev = {
 497         .c_vendor       = "Intel",
 498         .c_ident        = { "GenuineIntel" },
 499 #ifdef CONFIG_X86_32
 500         .c_models = {
 501                 { .vendor = X86_VENDOR_INTEL, .family = 4, .model_names =
 502                   {
 503                           [0] = "486 DX-25/33",
 504                           [1] = "486 DX-50",
 505                           [2] = "486 SX",
 506                           [3] = "486 DX/2",
 507                           [4] = "486 SL",
 508                           [5] = "486 SX/2",
 509                           [7] = "486 DX/2-WB",
 510                           [8] = "486 DX/4",
 511                           [9] = "486 DX/4-WB"
 512                   }
 513                 },
 514                 { .vendor = X86_VENDOR_INTEL, .family = 5, .model_names =
 515                   {
 516                           [0] = "Pentium 60/66 A-step",
 517                           [1] = "Pentium 60/66",
 518                           [2] = "Pentium 75 - 200",
 519                           [3] = "OverDrive PODP5V83",
 520                           [4] = "Pentium MMX",
 521                           [7] = "Mobile Pentium 75 - 200",
 522                           [8] = "Mobile Pentium MMX"
 523                   }
 524                 },
 525                 { .vendor = X86_VENDOR_INTEL, .family = 6, .model_names =
 526                   {
 527                           [0] = "Pentium Pro A-step",
 528                           [1] = "Pentium Pro",
 529                           [3] = "Pentium II (Klamath)",
 530                           [4] = "Pentium II (Deschutes)",
 531                           [5] = "Pentium II (Deschutes)",
 532                           [6] = "Mobile Pentium II",
 533                           [7] = "Pentium III (Katmai)",
 534                           [8] = "Pentium III (Coppermine)",
 535                           [10] = "Pentium III (Cascades)",
 536                           [11] = "Pentium III (Tualatin)",
 537                   }
 538                 },
 539                 { .vendor = X86_VENDOR_INTEL, .family = 15, .model_names =
 540                   {
 541                           [0] = "Pentium 4 (Unknown)",
 542                           [1] = "Pentium 4 (Willamette)",
 543                           [2] = "Pentium 4 (Northwood)",
 544                           [4] = "Pentium 4 (Foster)",
 545                           [5] = "Pentium 4 (Foster)",
 546                   }
 547                 },
 548         },
 549         .c_size_cache   = intel_size_cache,
 550 #endif
 551         .c_early_init   = early_init_intel,
 552         .c_init         = init_intel,
 553         .c_x86_vendor   = X86_VENDOR_INTEL,
 554 };
 555
 556 cpu_dev_register(intel_cpu_dev);
 557