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