1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/kernel.h> 3 #include <linux/pgtable.h> 4 5 #include <linux/string.h> 6 #include <linux/bitops.h> 7 #include <linux/smp.h> 8 #include <linux/sched.h> 9 #include <linux/sched/clock.h> 10 #include <linux/semaphore.h> 11 #include <linux/thread_info.h> 12 #include <linux/init.h> 13 #include <linux/uaccess.h> 14 #include <linux/workqueue.h> 15 #include <linux/delay.h> 16 #include <linux/cpuhotplug.h> 17 18 #include <asm/cpufeature.h> 19 #include <asm/msr.h> 20 #include <asm/bugs.h> 21 #include <asm/cpu.h> 22 #include <asm/intel-family.h> 23 #include <asm/microcode_intel.h> 24 #include <asm/hwcap2.h> 25 #include <asm/elf.h> 26 #include <asm/cpu_device_id.h> 27 #include <asm/cmdline.h> 28 #include <asm/traps.h> 29 #include <asm/resctrl.h> 30 #include <asm/numa.h> 31 #include <asm/thermal.h> 32 33 #ifdef CONFIG_X86_64 34 #include <linux/topology.h> 35 #endif 36 37 #include "cpu.h" 38 39 #ifdef CONFIG_X86_LOCAL_APIC 40 #include <asm/mpspec.h> 41 #include <asm/apic.h> 42 #endif 43 44 enum split_lock_detect_state { 45 sld_off = 0, 46 sld_warn, 47 sld_fatal, 48 sld_ratelimit, 49 }; 50 51 /* 52 * Default to sld_off because most systems do not support split lock detection. 53 * sld_state_setup() will switch this to sld_warn on systems that support 54 * split lock/bus lock detect, unless there is a command line override. 55 */ 56 static enum split_lock_detect_state sld_state __ro_after_init = sld_off; 57 static u64 msr_test_ctrl_cache __ro_after_init; 58 59 /* 60 * With a name like MSR_TEST_CTL it should go without saying, but don't touch 61 * MSR_TEST_CTL unless the CPU is one of the whitelisted models. Writing it 62 * on CPUs that do not support SLD can cause fireworks, even when writing '0'. 63 */ 64 static bool cpu_model_supports_sld __ro_after_init; 65 66 /* 67 * Processors which have self-snooping capability can handle conflicting 68 * memory type across CPUs by snooping its own cache. However, there exists 69 * CPU models in which having conflicting memory types still leads to 70 * unpredictable behavior, machine check errors, or hangs. Clear this 71 * feature to prevent its use on machines with known erratas. 72 */ 73 static void check_memory_type_self_snoop_errata(struct cpuinfo_x86 *c) 74 { 75 switch (c->x86_model) { 76 case INTEL_FAM6_CORE_YONAH: 77 case INTEL_FAM6_CORE2_MEROM: 78 case INTEL_FAM6_CORE2_MEROM_L: 79 case INTEL_FAM6_CORE2_PENRYN: 80 case INTEL_FAM6_CORE2_DUNNINGTON: 81 case INTEL_FAM6_NEHALEM: 82 case INTEL_FAM6_NEHALEM_G: 83 case INTEL_FAM6_NEHALEM_EP: 84 case INTEL_FAM6_NEHALEM_EX: 85 case INTEL_FAM6_WESTMERE: 86 case INTEL_FAM6_WESTMERE_EP: 87 case INTEL_FAM6_SANDYBRIDGE: 88 setup_clear_cpu_cap(X86_FEATURE_SELFSNOOP); 89 } 90 } 91 92 static bool ring3mwait_disabled __read_mostly; 93 94 static int __init ring3mwait_disable(char *__unused) 95 { 96 ring3mwait_disabled = true; 97 return 1; 98 } 99 __setup("ring3mwait=disable", ring3mwait_disable); 100 101 static void probe_xeon_phi_r3mwait(struct cpuinfo_x86 *c) 102 { 103 /* 104 * Ring 3 MONITOR/MWAIT feature cannot be detected without 105 * cpu model and family comparison. 106 */ 107 if (c->x86 != 6) 108 return; 109 switch (c->x86_model) { 110 case INTEL_FAM6_XEON_PHI_KNL: 111 case INTEL_FAM6_XEON_PHI_KNM: 112 break; 113 default: 114 return; 115 } 116 117 if (ring3mwait_disabled) 118 return; 119 120 set_cpu_cap(c, X86_FEATURE_RING3MWAIT); 121 this_cpu_or(msr_misc_features_shadow, 122 1UL << MSR_MISC_FEATURES_ENABLES_RING3MWAIT_BIT); 123 124 if (c == &boot_cpu_data) 125 ELF_HWCAP2 |= HWCAP2_RING3MWAIT; 126 } 127 128 /* 129 * Early microcode releases for the Spectre v2 mitigation were broken. 130 * Information taken from; 131 * - https://newsroom.intel.com/wp-content/uploads/sites/11/2018/03/microcode-update-guidance.pdf 132 * - https://kb.vmware.com/s/article/52345 133 * - Microcode revisions observed in the wild 134 * - Release note from 20180108 microcode release 135 */ 136 struct sku_microcode { 137 u8 model; 138 u8 stepping; 139 u32 microcode; 140 }; 141 static const struct sku_microcode spectre_bad_microcodes[] = { 142 { INTEL_FAM6_KABYLAKE, 0x0B, 0x80 }, 143 { INTEL_FAM6_KABYLAKE, 0x0A, 0x80 }, 144 { INTEL_FAM6_KABYLAKE, 0x09, 0x80 }, 145 { INTEL_FAM6_KABYLAKE_L, 0x0A, 0x80 }, 146 { INTEL_FAM6_KABYLAKE_L, 0x09, 0x80 }, 147 { INTEL_FAM6_SKYLAKE_X, 0x03, 0x0100013e }, 148 { INTEL_FAM6_SKYLAKE_X, 0x04, 0x0200003c }, 149 { INTEL_FAM6_BROADWELL, 0x04, 0x28 }, 150 { INTEL_FAM6_BROADWELL_G, 0x01, 0x1b }, 151 { INTEL_FAM6_BROADWELL_D, 0x02, 0x14 }, 152 { INTEL_FAM6_BROADWELL_D, 0x03, 0x07000011 }, 153 { INTEL_FAM6_BROADWELL_X, 0x01, 0x0b000025 }, 154 { INTEL_FAM6_HASWELL_L, 0x01, 0x21 }, 155 { INTEL_FAM6_HASWELL_G, 0x01, 0x18 }, 156 { INTEL_FAM6_HASWELL, 0x03, 0x23 }, 157 { INTEL_FAM6_HASWELL_X, 0x02, 0x3b }, 158 { INTEL_FAM6_HASWELL_X, 0x04, 0x10 }, 159 { INTEL_FAM6_IVYBRIDGE_X, 0x04, 0x42a }, 160 /* Observed in the wild */ 161 { INTEL_FAM6_SANDYBRIDGE_X, 0x06, 0x61b }, 162 { INTEL_FAM6_SANDYBRIDGE_X, 0x07, 0x712 }, 163 }; 164 165 static bool bad_spectre_microcode(struct cpuinfo_x86 *c) 166 { 167 int i; 168 169 /* 170 * We know that the hypervisor lie to us on the microcode version so 171 * we may as well hope that it is running the correct version. 172 */ 173 if (cpu_has(c, X86_FEATURE_HYPERVISOR)) 174 return false; 175 176 if (c->x86 != 6) 177 return false; 178 179 for (i = 0; i < ARRAY_SIZE(spectre_bad_microcodes); i++) { 180 if (c->x86_model == spectre_bad_microcodes[i].model && 181 c->x86_stepping == spectre_bad_microcodes[i].stepping) 182 return (c->microcode <= spectre_bad_microcodes[i].microcode); 183 } 184 return false; 185 } 186 187 int intel_cpu_collect_info(struct ucode_cpu_info *uci) 188 { 189 unsigned int val[2]; 190 unsigned int family, model; 191 struct cpu_signature csig = { 0 }; 192 unsigned int eax, ebx, ecx, edx; 193 194 memset(uci, 0, sizeof(*uci)); 195 196 eax = 0x00000001; 197 ecx = 0; 198 native_cpuid(&eax, &ebx, &ecx, &edx); 199 csig.sig = eax; 200 201 family = x86_family(eax); 202 model = x86_model(eax); 203 204 if (model >= 5 || family > 6) { 205 /* get processor flags from MSR 0x17 */ 206 native_rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]); 207 csig.pf = 1 << ((val[1] >> 18) & 7); 208 } 209 210 csig.rev = intel_get_microcode_revision(); 211 212 uci->cpu_sig = csig; 213 uci->valid = 1; 214 215 return 0; 216 } 217 EXPORT_SYMBOL_GPL(intel_cpu_collect_info); 218 219 static void early_init_intel(struct cpuinfo_x86 *c) 220 { 221 u64 misc_enable; 222 223 /* Unmask CPUID levels if masked: */ 224 if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) { 225 if (msr_clear_bit(MSR_IA32_MISC_ENABLE, 226 MSR_IA32_MISC_ENABLE_LIMIT_CPUID_BIT) > 0) { 227 c->cpuid_level = cpuid_eax(0); 228 get_cpu_cap(c); 229 } 230 } 231 232 if ((c->x86 == 0xf && c->x86_model >= 0x03) || 233 (c->x86 == 0x6 && c->x86_model >= 0x0e)) 234 set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); 235 236 if (c->x86 >= 6 && !cpu_has(c, X86_FEATURE_IA64)) 237 c->microcode = intel_get_microcode_revision(); 238 239 /* Now if any of them are set, check the blacklist and clear the lot */ 240 if ((cpu_has(c, X86_FEATURE_SPEC_CTRL) || 241 cpu_has(c, X86_FEATURE_INTEL_STIBP) || 242 cpu_has(c, X86_FEATURE_IBRS) || cpu_has(c, X86_FEATURE_IBPB) || 243 cpu_has(c, X86_FEATURE_STIBP)) && bad_spectre_microcode(c)) { 244 pr_warn("Intel Spectre v2 broken microcode detected; disabling Speculation Control\n"); 245 setup_clear_cpu_cap(X86_FEATURE_IBRS); 246 setup_clear_cpu_cap(X86_FEATURE_IBPB); 247 setup_clear_cpu_cap(X86_FEATURE_STIBP); 248 setup_clear_cpu_cap(X86_FEATURE_SPEC_CTRL); 249 setup_clear_cpu_cap(X86_FEATURE_MSR_SPEC_CTRL); 250 setup_clear_cpu_cap(X86_FEATURE_INTEL_STIBP); 251 setup_clear_cpu_cap(X86_FEATURE_SSBD); 252 setup_clear_cpu_cap(X86_FEATURE_SPEC_CTRL_SSBD); 253 } 254 255 /* 256 * Atom erratum AAE44/AAF40/AAG38/AAH41: 257 * 258 * A race condition between speculative fetches and invalidating 259 * a large page. This is worked around in microcode, but we 260 * need the microcode to have already been loaded... so if it is 261 * not, recommend a BIOS update and disable large pages. 262 */ 263 if (c->x86 == 6 && c->x86_model == 0x1c && c->x86_stepping <= 2 && 264 c->microcode < 0x20e) { 265 pr_warn("Atom PSE erratum detected, BIOS microcode update recommended\n"); 266 clear_cpu_cap(c, X86_FEATURE_PSE); 267 } 268 269 #ifdef CONFIG_X86_64 270 set_cpu_cap(c, X86_FEATURE_SYSENTER32); 271 #else 272 /* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */ 273 if (c->x86 == 15 && c->x86_cache_alignment == 64) 274 c->x86_cache_alignment = 128; 275 #endif 276 277 /* CPUID workaround for 0F33/0F34 CPU */ 278 if (c->x86 == 0xF && c->x86_model == 0x3 279 && (c->x86_stepping == 0x3 || c->x86_stepping == 0x4)) 280 c->x86_phys_bits = 36; 281 282 /* 283 * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate 284 * with P/T states and does not stop in deep C-states. 285 * 286 * It is also reliable across cores and sockets. (but not across 287 * cabinets - we turn it off in that case explicitly.) 288 */ 289 if (c->x86_power & (1 << 8)) { 290 set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); 291 set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC); 292 } 293 294 /* Penwell and Cloverview have the TSC which doesn't sleep on S3 */ 295 if (c->x86 == 6) { 296 switch (c->x86_model) { 297 case INTEL_FAM6_ATOM_SALTWELL_MID: 298 case INTEL_FAM6_ATOM_SALTWELL_TABLET: 299 case INTEL_FAM6_ATOM_SILVERMONT_MID: 300 case INTEL_FAM6_ATOM_AIRMONT_NP: 301 set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC_S3); 302 break; 303 default: 304 break; 305 } 306 } 307 308 /* 309 * There is a known erratum on Pentium III and Core Solo 310 * and Core Duo CPUs. 311 * " Page with PAT set to WC while associated MTRR is UC 312 * may consolidate to UC " 313 * Because of this erratum, it is better to stick with 314 * setting WC in MTRR rather than using PAT on these CPUs. 315 * 316 * Enable PAT WC only on P4, Core 2 or later CPUs. 317 */ 318 if (c->x86 == 6 && c->x86_model < 15) 319 clear_cpu_cap(c, X86_FEATURE_PAT); 320 321 /* 322 * If fast string is not enabled in IA32_MISC_ENABLE for any reason, 323 * clear the fast string and enhanced fast string CPU capabilities. 324 */ 325 if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) { 326 rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable); 327 if (!(misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING)) { 328 pr_info("Disabled fast string operations\n"); 329 setup_clear_cpu_cap(X86_FEATURE_REP_GOOD); 330 setup_clear_cpu_cap(X86_FEATURE_ERMS); 331 } 332 } 333 334 /* 335 * Intel Quark Core DevMan_001.pdf section 6.4.11 336 * "The operating system also is required to invalidate (i.e., flush) 337 * the TLB when any changes are made to any of the page table entries. 338 * The operating system must reload CR3 to cause the TLB to be flushed" 339 * 340 * As a result, boot_cpu_has(X86_FEATURE_PGE) in arch/x86/include/asm/tlbflush.h 341 * should be false so that __flush_tlb_all() causes CR3 instead of CR4.PGE 342 * to be modified. 343 */ 344 if (c->x86 == 5 && c->x86_model == 9) { 345 pr_info("Disabling PGE capability bit\n"); 346 setup_clear_cpu_cap(X86_FEATURE_PGE); 347 } 348 349 if (c->cpuid_level >= 0x00000001) { 350 u32 eax, ebx, ecx, edx; 351 352 cpuid(0x00000001, &eax, &ebx, &ecx, &edx); 353 /* 354 * If HTT (EDX[28]) is set EBX[16:23] contain the number of 355 * apicids which are reserved per package. Store the resulting 356 * shift value for the package management code. 357 */ 358 if (edx & (1U << 28)) 359 c->x86_coreid_bits = get_count_order((ebx >> 16) & 0xff); 360 } 361 362 check_memory_type_self_snoop_errata(c); 363 364 /* 365 * Get the number of SMT siblings early from the extended topology 366 * leaf, if available. Otherwise try the legacy SMT detection. 367 */ 368 if (detect_extended_topology_early(c) < 0) 369 detect_ht_early(c); 370 } 371 372 static void bsp_init_intel(struct cpuinfo_x86 *c) 373 { 374 resctrl_cpu_detect(c); 375 } 376 377 #ifdef CONFIG_X86_32 378 /* 379 * Early probe support logic for ppro memory erratum #50 380 * 381 * This is called before we do cpu ident work 382 */ 383 384 int ppro_with_ram_bug(void) 385 { 386 /* Uses data from early_cpu_detect now */ 387 if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && 388 boot_cpu_data.x86 == 6 && 389 boot_cpu_data.x86_model == 1 && 390 boot_cpu_data.x86_stepping < 8) { 391 pr_info("Pentium Pro with Errata#50 detected. Taking evasive action.\n"); 392 return 1; 393 } 394 return 0; 395 } 396 397 static void intel_smp_check(struct cpuinfo_x86 *c) 398 { 399 /* calling is from identify_secondary_cpu() ? */ 400 if (!c->cpu_index) 401 return; 402 403 /* 404 * Mask B, Pentium, but not Pentium MMX 405 */ 406 if (c->x86 == 5 && 407 c->x86_stepping >= 1 && c->x86_stepping <= 4 && 408 c->x86_model <= 3) { 409 /* 410 * Remember we have B step Pentia with bugs 411 */ 412 WARN_ONCE(1, "WARNING: SMP operation may be unreliable" 413 "with B stepping processors.\n"); 414 } 415 } 416 417 static int forcepae; 418 static int __init forcepae_setup(char *__unused) 419 { 420 forcepae = 1; 421 return 1; 422 } 423 __setup("forcepae", forcepae_setup); 424 425 static void intel_workarounds(struct cpuinfo_x86 *c) 426 { 427 #ifdef CONFIG_X86_F00F_BUG 428 /* 429 * All models of Pentium and Pentium with MMX technology CPUs 430 * have the F0 0F bug, which lets nonprivileged users lock up the 431 * system. Announce that the fault handler will be checking for it. 432 * The Quark is also family 5, but does not have the same bug. 433 */ 434 clear_cpu_bug(c, X86_BUG_F00F); 435 if (c->x86 == 5 && c->x86_model < 9) { 436 static int f00f_workaround_enabled; 437 438 set_cpu_bug(c, X86_BUG_F00F); 439 if (!f00f_workaround_enabled) { 440 pr_notice("Intel Pentium with F0 0F bug - workaround enabled.\n"); 441 f00f_workaround_enabled = 1; 442 } 443 } 444 #endif 445 446 /* 447 * SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until 448 * model 3 mask 3 449 */ 450 if ((c->x86<<8 | c->x86_model<<4 | c->x86_stepping) < 0x633) 451 clear_cpu_cap(c, X86_FEATURE_SEP); 452 453 /* 454 * PAE CPUID issue: many Pentium M report no PAE but may have a 455 * functionally usable PAE implementation. 456 * Forcefully enable PAE if kernel parameter "forcepae" is present. 457 */ 458 if (forcepae) { 459 pr_warn("PAE forced!\n"); 460 set_cpu_cap(c, X86_FEATURE_PAE); 461 add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_NOW_UNRELIABLE); 462 } 463 464 /* 465 * P4 Xeon erratum 037 workaround. 466 * Hardware prefetcher may cause stale data to be loaded into the cache. 467 */ 468 if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_stepping == 1)) { 469 if (msr_set_bit(MSR_IA32_MISC_ENABLE, 470 MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE_BIT) > 0) { 471 pr_info("CPU: C0 stepping P4 Xeon detected.\n"); 472 pr_info("CPU: Disabling hardware prefetching (Erratum 037)\n"); 473 } 474 } 475 476 /* 477 * See if we have a good local APIC by checking for buggy Pentia, 478 * i.e. all B steppings and the C2 stepping of P54C when using their 479 * integrated APIC (see 11AP erratum in "Pentium Processor 480 * Specification Update"). 481 */ 482 if (boot_cpu_has(X86_FEATURE_APIC) && (c->x86<<8 | c->x86_model<<4) == 0x520 && 483 (c->x86_stepping < 0x6 || c->x86_stepping == 0xb)) 484 set_cpu_bug(c, X86_BUG_11AP); 485 486 487 #ifdef CONFIG_X86_INTEL_USERCOPY 488 /* 489 * Set up the preferred alignment for movsl bulk memory moves 490 */ 491 switch (c->x86) { 492 case 4: /* 486: untested */ 493 break; 494 case 5: /* Old Pentia: untested */ 495 break; 496 case 6: /* PII/PIII only like movsl with 8-byte alignment */ 497 movsl_mask.mask = 7; 498 break; 499 case 15: /* P4 is OK down to 8-byte alignment */ 500 movsl_mask.mask = 7; 501 break; 502 } 503 #endif 504 505 intel_smp_check(c); 506 } 507 #else 508 static void intel_workarounds(struct cpuinfo_x86 *c) 509 { 510 } 511 #endif 512 513 static void srat_detect_node(struct cpuinfo_x86 *c) 514 { 515 #ifdef CONFIG_NUMA 516 unsigned node; 517 int cpu = smp_processor_id(); 518 519 /* Don't do the funky fallback heuristics the AMD version employs 520 for now. */ 521 node = numa_cpu_node(cpu); 522 if (node == NUMA_NO_NODE || !node_online(node)) { 523 /* reuse the value from init_cpu_to_node() */ 524 node = cpu_to_node(cpu); 525 } 526 numa_set_node(cpu, node); 527 #endif 528 } 529 530 #define MSR_IA32_TME_ACTIVATE 0x982 531 532 /* Helpers to access TME_ACTIVATE MSR */ 533 #define TME_ACTIVATE_LOCKED(x) (x & 0x1) 534 #define TME_ACTIVATE_ENABLED(x) (x & 0x2) 535 536 #define TME_ACTIVATE_POLICY(x) ((x >> 4) & 0xf) /* Bits 7:4 */ 537 #define TME_ACTIVATE_POLICY_AES_XTS_128 0 538 539 #define TME_ACTIVATE_KEYID_BITS(x) ((x >> 32) & 0xf) /* Bits 35:32 */ 540 541 #define TME_ACTIVATE_CRYPTO_ALGS(x) ((x >> 48) & 0xffff) /* Bits 63:48 */ 542 #define TME_ACTIVATE_CRYPTO_AES_XTS_128 1 543 544 /* Values for mktme_status (SW only construct) */ 545 #define MKTME_ENABLED 0 546 #define MKTME_DISABLED 1 547 #define MKTME_UNINITIALIZED 2 548 static int mktme_status = MKTME_UNINITIALIZED; 549 550 static void detect_tme(struct cpuinfo_x86 *c) 551 { 552 u64 tme_activate, tme_policy, tme_crypto_algs; 553 int keyid_bits = 0, nr_keyids = 0; 554 static u64 tme_activate_cpu0 = 0; 555 556 rdmsrl(MSR_IA32_TME_ACTIVATE, tme_activate); 557 558 if (mktme_status != MKTME_UNINITIALIZED) { 559 if (tme_activate != tme_activate_cpu0) { 560 /* Broken BIOS? */ 561 pr_err_once("x86/tme: configuration is inconsistent between CPUs\n"); 562 pr_err_once("x86/tme: MKTME is not usable\n"); 563 mktme_status = MKTME_DISABLED; 564 565 /* Proceed. We may need to exclude bits from x86_phys_bits. */ 566 } 567 } else { 568 tme_activate_cpu0 = tme_activate; 569 } 570 571 if (!TME_ACTIVATE_LOCKED(tme_activate) || !TME_ACTIVATE_ENABLED(tme_activate)) { 572 pr_info_once("x86/tme: not enabled by BIOS\n"); 573 mktme_status = MKTME_DISABLED; 574 return; 575 } 576 577 if (mktme_status != MKTME_UNINITIALIZED) 578 goto detect_keyid_bits; 579 580 pr_info("x86/tme: enabled by BIOS\n"); 581 582 tme_policy = TME_ACTIVATE_POLICY(tme_activate); 583 if (tme_policy != TME_ACTIVATE_POLICY_AES_XTS_128) 584 pr_warn("x86/tme: Unknown policy is active: %#llx\n", tme_policy); 585 586 tme_crypto_algs = TME_ACTIVATE_CRYPTO_ALGS(tme_activate); 587 if (!(tme_crypto_algs & TME_ACTIVATE_CRYPTO_AES_XTS_128)) { 588 pr_err("x86/mktme: No known encryption algorithm is supported: %#llx\n", 589 tme_crypto_algs); 590 mktme_status = MKTME_DISABLED; 591 } 592 detect_keyid_bits: 593 keyid_bits = TME_ACTIVATE_KEYID_BITS(tme_activate); 594 nr_keyids = (1UL << keyid_bits) - 1; 595 if (nr_keyids) { 596 pr_info_once("x86/mktme: enabled by BIOS\n"); 597 pr_info_once("x86/mktme: %d KeyIDs available\n", nr_keyids); 598 } else { 599 pr_info_once("x86/mktme: disabled by BIOS\n"); 600 } 601 602 if (mktme_status == MKTME_UNINITIALIZED) { 603 /* MKTME is usable */ 604 mktme_status = MKTME_ENABLED; 605 } 606 607 /* 608 * KeyID bits effectively lower the number of physical address 609 * bits. Update cpuinfo_x86::x86_phys_bits accordingly. 610 */ 611 c->x86_phys_bits -= keyid_bits; 612 } 613 614 static void init_cpuid_fault(struct cpuinfo_x86 *c) 615 { 616 u64 msr; 617 618 if (!rdmsrl_safe(MSR_PLATFORM_INFO, &msr)) { 619 if (msr & MSR_PLATFORM_INFO_CPUID_FAULT) 620 set_cpu_cap(c, X86_FEATURE_CPUID_FAULT); 621 } 622 } 623 624 static void init_intel_misc_features(struct cpuinfo_x86 *c) 625 { 626 u64 msr; 627 628 if (rdmsrl_safe(MSR_MISC_FEATURES_ENABLES, &msr)) 629 return; 630 631 /* Clear all MISC features */ 632 this_cpu_write(msr_misc_features_shadow, 0); 633 634 /* Check features and update capabilities and shadow control bits */ 635 init_cpuid_fault(c); 636 probe_xeon_phi_r3mwait(c); 637 638 msr = this_cpu_read(msr_misc_features_shadow); 639 wrmsrl(MSR_MISC_FEATURES_ENABLES, msr); 640 } 641 642 static void split_lock_init(void); 643 static void bus_lock_init(void); 644 645 static void init_intel(struct cpuinfo_x86 *c) 646 { 647 early_init_intel(c); 648 649 intel_workarounds(c); 650 651 /* 652 * Detect the extended topology information if available. This 653 * will reinitialise the initial_apicid which will be used 654 * in init_intel_cacheinfo() 655 */ 656 detect_extended_topology(c); 657 658 if (!cpu_has(c, X86_FEATURE_XTOPOLOGY)) { 659 /* 660 * let's use the legacy cpuid vector 0x1 and 0x4 for topology 661 * detection. 662 */ 663 detect_num_cpu_cores(c); 664 #ifdef CONFIG_X86_32 665 detect_ht(c); 666 #endif 667 } 668 669 init_intel_cacheinfo(c); 670 671 if (c->cpuid_level > 9) { 672 unsigned eax = cpuid_eax(10); 673 /* Check for version and the number of counters */ 674 if ((eax & 0xff) && (((eax>>8) & 0xff) > 1)) 675 set_cpu_cap(c, X86_FEATURE_ARCH_PERFMON); 676 } 677 678 if (cpu_has(c, X86_FEATURE_XMM2)) 679 set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC); 680 681 if (boot_cpu_has(X86_FEATURE_DS)) { 682 unsigned int l1, l2; 683 684 rdmsr(MSR_IA32_MISC_ENABLE, l1, l2); 685 if (!(l1 & (1<<11))) 686 set_cpu_cap(c, X86_FEATURE_BTS); 687 if (!(l1 & (1<<12))) 688 set_cpu_cap(c, X86_FEATURE_PEBS); 689 } 690 691 if (c->x86 == 6 && boot_cpu_has(X86_FEATURE_CLFLUSH) && 692 (c->x86_model == 29 || c->x86_model == 46 || c->x86_model == 47)) 693 set_cpu_bug(c, X86_BUG_CLFLUSH_MONITOR); 694 695 if (c->x86 == 6 && boot_cpu_has(X86_FEATURE_MWAIT) && 696 ((c->x86_model == INTEL_FAM6_ATOM_GOLDMONT))) 697 set_cpu_bug(c, X86_BUG_MONITOR); 698 699 #ifdef CONFIG_X86_64 700 if (c->x86 == 15) 701 c->x86_cache_alignment = c->x86_clflush_size * 2; 702 if (c->x86 == 6) 703 set_cpu_cap(c, X86_FEATURE_REP_GOOD); 704 #else 705 /* 706 * Names for the Pentium II/Celeron processors 707 * detectable only by also checking the cache size. 708 * Dixon is NOT a Celeron. 709 */ 710 if (c->x86 == 6) { 711 unsigned int l2 = c->x86_cache_size; 712 char *p = NULL; 713 714 switch (c->x86_model) { 715 case 5: 716 if (l2 == 0) 717 p = "Celeron (Covington)"; 718 else if (l2 == 256) 719 p = "Mobile Pentium II (Dixon)"; 720 break; 721 722 case 6: 723 if (l2 == 128) 724 p = "Celeron (Mendocino)"; 725 else if (c->x86_stepping == 0 || c->x86_stepping == 5) 726 p = "Celeron-A"; 727 break; 728 729 case 8: 730 if (l2 == 128) 731 p = "Celeron (Coppermine)"; 732 break; 733 } 734 735 if (p) 736 strcpy(c->x86_model_id, p); 737 } 738 739 if (c->x86 == 15) 740 set_cpu_cap(c, X86_FEATURE_P4); 741 if (c->x86 == 6) 742 set_cpu_cap(c, X86_FEATURE_P3); 743 #endif 744 745 /* Work around errata */ 746 srat_detect_node(c); 747 748 init_ia32_feat_ctl(c); 749 750 if (cpu_has(c, X86_FEATURE_TME)) 751 detect_tme(c); 752 753 init_intel_misc_features(c); 754 755 split_lock_init(); 756 bus_lock_init(); 757 758 intel_init_thermal(c); 759 } 760 761 #ifdef CONFIG_X86_32 762 static unsigned int intel_size_cache(struct cpuinfo_x86 *c, unsigned int size) 763 { 764 /* 765 * Intel PIII Tualatin. This comes in two flavours. 766 * One has 256kb of cache, the other 512. We have no way 767 * to determine which, so we use a boottime override 768 * for the 512kb model, and assume 256 otherwise. 769 */ 770 if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0)) 771 size = 256; 772 773 /* 774 * Intel Quark SoC X1000 contains a 4-way set associative 775 * 16K cache with a 16 byte cache line and 256 lines per tag 776 */ 777 if ((c->x86 == 5) && (c->x86_model == 9)) 778 size = 16; 779 return size; 780 } 781 #endif 782 783 #define TLB_INST_4K 0x01 784 #define TLB_INST_4M 0x02 785 #define TLB_INST_2M_4M 0x03 786 787 #define TLB_INST_ALL 0x05 788 #define TLB_INST_1G 0x06 789 790 #define TLB_DATA_4K 0x11 791 #define TLB_DATA_4M 0x12 792 #define TLB_DATA_2M_4M 0x13 793 #define TLB_DATA_4K_4M 0x14 794 795 #define TLB_DATA_1G 0x16 796 797 #define TLB_DATA0_4K 0x21 798 #define TLB_DATA0_4M 0x22 799 #define TLB_DATA0_2M_4M 0x23 800 801 #define STLB_4K 0x41 802 #define STLB_4K_2M 0x42 803 804 static const struct _tlb_table intel_tlb_table[] = { 805 { 0x01, TLB_INST_4K, 32, " TLB_INST 4 KByte pages, 4-way set associative" }, 806 { 0x02, TLB_INST_4M, 2, " TLB_INST 4 MByte pages, full associative" }, 807 { 0x03, TLB_DATA_4K, 64, " TLB_DATA 4 KByte pages, 4-way set associative" }, 808 { 0x04, TLB_DATA_4M, 8, " TLB_DATA 4 MByte pages, 4-way set associative" }, 809 { 0x05, TLB_DATA_4M, 32, " TLB_DATA 4 MByte pages, 4-way set associative" }, 810 { 0x0b, TLB_INST_4M, 4, " TLB_INST 4 MByte pages, 4-way set associative" }, 811 { 0x4f, TLB_INST_4K, 32, " TLB_INST 4 KByte pages" }, 812 { 0x50, TLB_INST_ALL, 64, " TLB_INST 4 KByte and 2-MByte or 4-MByte pages" }, 813 { 0x51, TLB_INST_ALL, 128, " TLB_INST 4 KByte and 2-MByte or 4-MByte pages" }, 814 { 0x52, TLB_INST_ALL, 256, " TLB_INST 4 KByte and 2-MByte or 4-MByte pages" }, 815 { 0x55, TLB_INST_2M_4M, 7, " TLB_INST 2-MByte or 4-MByte pages, fully associative" }, 816 { 0x56, TLB_DATA0_4M, 16, " TLB_DATA0 4 MByte pages, 4-way set associative" }, 817 { 0x57, TLB_DATA0_4K, 16, " TLB_DATA0 4 KByte pages, 4-way associative" }, 818 { 0x59, TLB_DATA0_4K, 16, " TLB_DATA0 4 KByte pages, fully associative" }, 819 { 0x5a, TLB_DATA0_2M_4M, 32, " TLB_DATA0 2-MByte or 4 MByte pages, 4-way set associative" }, 820 { 0x5b, TLB_DATA_4K_4M, 64, " TLB_DATA 4 KByte and 4 MByte pages" }, 821 { 0x5c, TLB_DATA_4K_4M, 128, " TLB_DATA 4 KByte and 4 MByte pages" }, 822 { 0x5d, TLB_DATA_4K_4M, 256, " TLB_DATA 4 KByte and 4 MByte pages" }, 823 { 0x61, TLB_INST_4K, 48, " TLB_INST 4 KByte pages, full associative" }, 824 { 0x63, TLB_DATA_1G, 4, " TLB_DATA 1 GByte pages, 4-way set associative" }, 825 { 0x6b, TLB_DATA_4K, 256, " TLB_DATA 4 KByte pages, 8-way associative" }, 826 { 0x6c, TLB_DATA_2M_4M, 128, " TLB_DATA 2 MByte or 4 MByte pages, 8-way associative" }, 827 { 0x6d, TLB_DATA_1G, 16, " TLB_DATA 1 GByte pages, fully associative" }, 828 { 0x76, TLB_INST_2M_4M, 8, " TLB_INST 2-MByte or 4-MByte pages, fully associative" }, 829 { 0xb0, TLB_INST_4K, 128, " TLB_INST 4 KByte pages, 4-way set associative" }, 830 { 0xb1, TLB_INST_2M_4M, 4, " TLB_INST 2M pages, 4-way, 8 entries or 4M pages, 4-way entries" }, 831 { 0xb2, TLB_INST_4K, 64, " TLB_INST 4KByte pages, 4-way set associative" }, 832 { 0xb3, TLB_DATA_4K, 128, " TLB_DATA 4 KByte pages, 4-way set associative" }, 833 { 0xb4, TLB_DATA_4K, 256, " TLB_DATA 4 KByte pages, 4-way associative" }, 834 { 0xb5, TLB_INST_4K, 64, " TLB_INST 4 KByte pages, 8-way set associative" }, 835 { 0xb6, TLB_INST_4K, 128, " TLB_INST 4 KByte pages, 8-way set associative" }, 836 { 0xba, TLB_DATA_4K, 64, " TLB_DATA 4 KByte pages, 4-way associative" }, 837 { 0xc0, TLB_DATA_4K_4M, 8, " TLB_DATA 4 KByte and 4 MByte pages, 4-way associative" }, 838 { 0xc1, STLB_4K_2M, 1024, " STLB 4 KByte and 2 MByte pages, 8-way associative" }, 839 { 0xc2, TLB_DATA_2M_4M, 16, " TLB_DATA 2 MByte/4MByte pages, 4-way associative" }, 840 { 0xca, STLB_4K, 512, " STLB 4 KByte pages, 4-way associative" }, 841 { 0x00, 0, 0 } 842 }; 843 844 static void intel_tlb_lookup(const unsigned char desc) 845 { 846 unsigned char k; 847 if (desc == 0) 848 return; 849 850 /* look up this descriptor in the table */ 851 for (k = 0; intel_tlb_table[k].descriptor != desc && 852 intel_tlb_table[k].descriptor != 0; k++) 853 ; 854 855 if (intel_tlb_table[k].tlb_type == 0) 856 return; 857 858 switch (intel_tlb_table[k].tlb_type) { 859 case STLB_4K: 860 if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries) 861 tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries; 862 if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries) 863 tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries; 864 break; 865 case STLB_4K_2M: 866 if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries) 867 tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries; 868 if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries) 869 tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries; 870 if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries) 871 tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries; 872 if (tlb_lld_2m[ENTRIES] < intel_tlb_table[k].entries) 873 tlb_lld_2m[ENTRIES] = intel_tlb_table[k].entries; 874 if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries) 875 tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries; 876 if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries) 877 tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries; 878 break; 879 case TLB_INST_ALL: 880 if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries) 881 tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries; 882 if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries) 883 tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries; 884 if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries) 885 tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries; 886 break; 887 case TLB_INST_4K: 888 if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries) 889 tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries; 890 break; 891 case TLB_INST_4M: 892 if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries) 893 tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries; 894 break; 895 case TLB_INST_2M_4M: 896 if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries) 897 tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries; 898 if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries) 899 tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries; 900 break; 901 case TLB_DATA_4K: 902 case TLB_DATA0_4K: 903 if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries) 904 tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries; 905 break; 906 case TLB_DATA_4M: 907 case TLB_DATA0_4M: 908 if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries) 909 tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries; 910 break; 911 case TLB_DATA_2M_4M: 912 case TLB_DATA0_2M_4M: 913 if (tlb_lld_2m[ENTRIES] < intel_tlb_table[k].entries) 914 tlb_lld_2m[ENTRIES] = intel_tlb_table[k].entries; 915 if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries) 916 tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries; 917 break; 918 case TLB_DATA_4K_4M: 919 if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries) 920 tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries; 921 if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries) 922 tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries; 923 break; 924 case TLB_DATA_1G: 925 if (tlb_lld_1g[ENTRIES] < intel_tlb_table[k].entries) 926 tlb_lld_1g[ENTRIES] = intel_tlb_table[k].entries; 927 break; 928 } 929 } 930 931 static void intel_detect_tlb(struct cpuinfo_x86 *c) 932 { 933 int i, j, n; 934 unsigned int regs[4]; 935 unsigned char *desc = (unsigned char *)regs; 936 937 if (c->cpuid_level < 2) 938 return; 939 940 /* Number of times to iterate */ 941 n = cpuid_eax(2) & 0xFF; 942 943 for (i = 0 ; i < n ; i++) { 944 cpuid(2, ®s[0], ®s[1], ®s[2], ®s[3]); 945 946 /* If bit 31 is set, this is an unknown format */ 947 for (j = 0 ; j < 3 ; j++) 948 if (regs[j] & (1 << 31)) 949 regs[j] = 0; 950 951 /* Byte 0 is level count, not a descriptor */ 952 for (j = 1 ; j < 16 ; j++) 953 intel_tlb_lookup(desc[j]); 954 } 955 } 956 957 static const struct cpu_dev intel_cpu_dev = { 958 .c_vendor = "Intel", 959 .c_ident = { "GenuineIntel" }, 960 #ifdef CONFIG_X86_32 961 .legacy_models = { 962 { .family = 4, .model_names = 963 { 964 [0] = "486 DX-25/33", 965 [1] = "486 DX-50", 966 [2] = "486 SX", 967 [3] = "486 DX/2", 968 [4] = "486 SL", 969 [5] = "486 SX/2", 970 [7] = "486 DX/2-WB", 971 [8] = "486 DX/4", 972 [9] = "486 DX/4-WB" 973 } 974 }, 975 { .family = 5, .model_names = 976 { 977 [0] = "Pentium 60/66 A-step", 978 [1] = "Pentium 60/66", 979 [2] = "Pentium 75 - 200", 980 [3] = "OverDrive PODP5V83", 981 [4] = "Pentium MMX", 982 [7] = "Mobile Pentium 75 - 200", 983 [8] = "Mobile Pentium MMX", 984 [9] = "Quark SoC X1000", 985 } 986 }, 987 { .family = 6, .model_names = 988 { 989 [0] = "Pentium Pro A-step", 990 [1] = "Pentium Pro", 991 [3] = "Pentium II (Klamath)", 992 [4] = "Pentium II (Deschutes)", 993 [5] = "Pentium II (Deschutes)", 994 [6] = "Mobile Pentium II", 995 [7] = "Pentium III (Katmai)", 996 [8] = "Pentium III (Coppermine)", 997 [10] = "Pentium III (Cascades)", 998 [11] = "Pentium III (Tualatin)", 999 } 1000 }, 1001 { .family = 15, .model_names = 1002 { 1003 [0] = "Pentium 4 (Unknown)", 1004 [1] = "Pentium 4 (Willamette)", 1005 [2] = "Pentium 4 (Northwood)", 1006 [4] = "Pentium 4 (Foster)", 1007 [5] = "Pentium 4 (Foster)", 1008 } 1009 }, 1010 }, 1011 .legacy_cache_size = intel_size_cache, 1012 #endif 1013 .c_detect_tlb = intel_detect_tlb, 1014 .c_early_init = early_init_intel, 1015 .c_bsp_init = bsp_init_intel, 1016 .c_init = init_intel, 1017 .c_x86_vendor = X86_VENDOR_INTEL, 1018 }; 1019 1020 cpu_dev_register(intel_cpu_dev); 1021 1022 #undef pr_fmt 1023 #define pr_fmt(fmt) "x86/split lock detection: " fmt 1024 1025 static const struct { 1026 const char *option; 1027 enum split_lock_detect_state state; 1028 } sld_options[] __initconst = { 1029 { "off", sld_off }, 1030 { "warn", sld_warn }, 1031 { "fatal", sld_fatal }, 1032 { "ratelimit:", sld_ratelimit }, 1033 }; 1034 1035 static struct ratelimit_state bld_ratelimit; 1036 1037 static DEFINE_SEMAPHORE(buslock_sem); 1038 1039 static inline bool match_option(const char *arg, int arglen, const char *opt) 1040 { 1041 int len = strlen(opt), ratelimit; 1042 1043 if (strncmp(arg, opt, len)) 1044 return false; 1045 1046 /* 1047 * Min ratelimit is 1 bus lock/sec. 1048 * Max ratelimit is 1000 bus locks/sec. 1049 */ 1050 if (sscanf(arg, "ratelimit:%d", &ratelimit) == 1 && 1051 ratelimit > 0 && ratelimit <= 1000) { 1052 ratelimit_state_init(&bld_ratelimit, HZ, ratelimit); 1053 ratelimit_set_flags(&bld_ratelimit, RATELIMIT_MSG_ON_RELEASE); 1054 return true; 1055 } 1056 1057 return len == arglen; 1058 } 1059 1060 static bool split_lock_verify_msr(bool on) 1061 { 1062 u64 ctrl, tmp; 1063 1064 if (rdmsrl_safe(MSR_TEST_CTRL, &ctrl)) 1065 return false; 1066 if (on) 1067 ctrl |= MSR_TEST_CTRL_SPLIT_LOCK_DETECT; 1068 else 1069 ctrl &= ~MSR_TEST_CTRL_SPLIT_LOCK_DETECT; 1070 if (wrmsrl_safe(MSR_TEST_CTRL, ctrl)) 1071 return false; 1072 rdmsrl(MSR_TEST_CTRL, tmp); 1073 return ctrl == tmp; 1074 } 1075 1076 static void __init sld_state_setup(void) 1077 { 1078 enum split_lock_detect_state state = sld_warn; 1079 char arg[20]; 1080 int i, ret; 1081 1082 if (!boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT) && 1083 !boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) 1084 return; 1085 1086 ret = cmdline_find_option(boot_command_line, "split_lock_detect", 1087 arg, sizeof(arg)); 1088 if (ret >= 0) { 1089 for (i = 0; i < ARRAY_SIZE(sld_options); i++) { 1090 if (match_option(arg, ret, sld_options[i].option)) { 1091 state = sld_options[i].state; 1092 break; 1093 } 1094 } 1095 } 1096 sld_state = state; 1097 } 1098 1099 static void __init __split_lock_setup(void) 1100 { 1101 if (!split_lock_verify_msr(false)) { 1102 pr_info("MSR access failed: Disabled\n"); 1103 return; 1104 } 1105 1106 rdmsrl(MSR_TEST_CTRL, msr_test_ctrl_cache); 1107 1108 if (!split_lock_verify_msr(true)) { 1109 pr_info("MSR access failed: Disabled\n"); 1110 return; 1111 } 1112 1113 /* Restore the MSR to its cached value. */ 1114 wrmsrl(MSR_TEST_CTRL, msr_test_ctrl_cache); 1115 1116 setup_force_cpu_cap(X86_FEATURE_SPLIT_LOCK_DETECT); 1117 } 1118 1119 /* 1120 * MSR_TEST_CTRL is per core, but we treat it like a per CPU MSR. Locking 1121 * is not implemented as one thread could undo the setting of the other 1122 * thread immediately after dropping the lock anyway. 1123 */ 1124 static void sld_update_msr(bool on) 1125 { 1126 u64 test_ctrl_val = msr_test_ctrl_cache; 1127 1128 if (on) 1129 test_ctrl_val |= MSR_TEST_CTRL_SPLIT_LOCK_DETECT; 1130 1131 wrmsrl(MSR_TEST_CTRL, test_ctrl_val); 1132 } 1133 1134 static void split_lock_init(void) 1135 { 1136 /* 1137 * #DB for bus lock handles ratelimit and #AC for split lock is 1138 * disabled. 1139 */ 1140 if (sld_state == sld_ratelimit) { 1141 split_lock_verify_msr(false); 1142 return; 1143 } 1144 1145 if (cpu_model_supports_sld) 1146 split_lock_verify_msr(sld_state != sld_off); 1147 } 1148 1149 static void __split_lock_reenable(struct work_struct *work) 1150 { 1151 sld_update_msr(true); 1152 up(&buslock_sem); 1153 } 1154 1155 /* 1156 * If a CPU goes offline with pending delayed work to re-enable split lock 1157 * detection then the delayed work will be executed on some other CPU. That 1158 * handles releasing the buslock_sem, but because it executes on a 1159 * different CPU probably won't re-enable split lock detection. This is a 1160 * problem on HT systems since the sibling CPU on the same core may then be 1161 * left running with split lock detection disabled. 1162 * 1163 * Unconditionally re-enable detection here. 1164 */ 1165 static int splitlock_cpu_offline(unsigned int cpu) 1166 { 1167 sld_update_msr(true); 1168 1169 return 0; 1170 } 1171 1172 static DECLARE_DELAYED_WORK(split_lock_reenable, __split_lock_reenable); 1173 1174 static void split_lock_warn(unsigned long ip) 1175 { 1176 int cpu; 1177 1178 if (!current->reported_split_lock) 1179 pr_warn_ratelimited("#AC: %s/%d took a split_lock trap at address: 0x%lx\n", 1180 current->comm, current->pid, ip); 1181 current->reported_split_lock = 1; 1182 1183 /* misery factor #1, sleep 10ms before trying to execute split lock */ 1184 if (msleep_interruptible(10) > 0) 1185 return; 1186 /* Misery factor #2, only allow one buslocked disabled core at a time */ 1187 if (down_interruptible(&buslock_sem) == -EINTR) 1188 return; 1189 cpu = get_cpu(); 1190 schedule_delayed_work_on(cpu, &split_lock_reenable, 2); 1191 1192 /* Disable split lock detection on this CPU to make progress */ 1193 sld_update_msr(false); 1194 put_cpu(); 1195 } 1196 1197 bool handle_guest_split_lock(unsigned long ip) 1198 { 1199 if (sld_state == sld_warn) { 1200 split_lock_warn(ip); 1201 return true; 1202 } 1203 1204 pr_warn_once("#AC: %s/%d %s split_lock trap at address: 0x%lx\n", 1205 current->comm, current->pid, 1206 sld_state == sld_fatal ? "fatal" : "bogus", ip); 1207 1208 current->thread.error_code = 0; 1209 current->thread.trap_nr = X86_TRAP_AC; 1210 force_sig_fault(SIGBUS, BUS_ADRALN, NULL); 1211 return false; 1212 } 1213 EXPORT_SYMBOL_GPL(handle_guest_split_lock); 1214 1215 static void bus_lock_init(void) 1216 { 1217 u64 val; 1218 1219 /* 1220 * Warn and fatal are handled by #AC for split lock if #AC for 1221 * split lock is supported. 1222 */ 1223 if (!boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT) || 1224 (boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT) && 1225 (sld_state == sld_warn || sld_state == sld_fatal)) || 1226 sld_state == sld_off) 1227 return; 1228 1229 /* 1230 * Enable #DB for bus lock. All bus locks are handled in #DB except 1231 * split locks are handled in #AC in the fatal case. 1232 */ 1233 rdmsrl(MSR_IA32_DEBUGCTLMSR, val); 1234 val |= DEBUGCTLMSR_BUS_LOCK_DETECT; 1235 wrmsrl(MSR_IA32_DEBUGCTLMSR, val); 1236 } 1237 1238 bool handle_user_split_lock(struct pt_regs *regs, long error_code) 1239 { 1240 if ((regs->flags & X86_EFLAGS_AC) || sld_state == sld_fatal) 1241 return false; 1242 split_lock_warn(regs->ip); 1243 return true; 1244 } 1245 1246 void handle_bus_lock(struct pt_regs *regs) 1247 { 1248 switch (sld_state) { 1249 case sld_off: 1250 break; 1251 case sld_ratelimit: 1252 /* Enforce no more than bld_ratelimit bus locks/sec. */ 1253 while (!__ratelimit(&bld_ratelimit)) 1254 msleep(20); 1255 /* Warn on the bus lock. */ 1256 fallthrough; 1257 case sld_warn: 1258 pr_warn_ratelimited("#DB: %s/%d took a bus_lock trap at address: 0x%lx\n", 1259 current->comm, current->pid, regs->ip); 1260 break; 1261 case sld_fatal: 1262 force_sig_fault(SIGBUS, BUS_ADRALN, NULL); 1263 break; 1264 } 1265 } 1266 1267 /* 1268 * Bits in the IA32_CORE_CAPABILITIES are not architectural, so they should 1269 * only be trusted if it is confirmed that a CPU model implements a 1270 * specific feature at a particular bit position. 1271 * 1272 * The possible driver data field values: 1273 * 1274 * - 0: CPU models that are known to have the per-core split-lock detection 1275 * feature even though they do not enumerate IA32_CORE_CAPABILITIES. 1276 * 1277 * - 1: CPU models which may enumerate IA32_CORE_CAPABILITIES and if so use 1278 * bit 5 to enumerate the per-core split-lock detection feature. 1279 */ 1280 static const struct x86_cpu_id split_lock_cpu_ids[] __initconst = { 1281 X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_X, 0), 1282 X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_L, 0), 1283 X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_D, 0), 1284 X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT, 1), 1285 X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT_D, 1), 1286 X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT_L, 1), 1287 X86_MATCH_INTEL_FAM6_MODEL(TIGERLAKE_L, 1), 1288 X86_MATCH_INTEL_FAM6_MODEL(TIGERLAKE, 1), 1289 X86_MATCH_INTEL_FAM6_MODEL(SAPPHIRERAPIDS_X, 1), 1290 X86_MATCH_INTEL_FAM6_MODEL(ALDERLAKE, 1), 1291 X86_MATCH_INTEL_FAM6_MODEL(ALDERLAKE_L, 1), 1292 X86_MATCH_INTEL_FAM6_MODEL(RAPTORLAKE, 1), 1293 {} 1294 }; 1295 1296 static void __init split_lock_setup(struct cpuinfo_x86 *c) 1297 { 1298 const struct x86_cpu_id *m; 1299 u64 ia32_core_caps; 1300 1301 if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) 1302 return; 1303 1304 m = x86_match_cpu(split_lock_cpu_ids); 1305 if (!m) 1306 return; 1307 1308 switch (m->driver_data) { 1309 case 0: 1310 break; 1311 case 1: 1312 if (!cpu_has(c, X86_FEATURE_CORE_CAPABILITIES)) 1313 return; 1314 rdmsrl(MSR_IA32_CORE_CAPS, ia32_core_caps); 1315 if (!(ia32_core_caps & MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT)) 1316 return; 1317 break; 1318 default: 1319 return; 1320 } 1321 1322 cpu_model_supports_sld = true; 1323 __split_lock_setup(); 1324 } 1325 1326 static void sld_state_show(void) 1327 { 1328 if (!boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT) && 1329 !boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) 1330 return; 1331 1332 switch (sld_state) { 1333 case sld_off: 1334 pr_info("disabled\n"); 1335 break; 1336 case sld_warn: 1337 if (boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) { 1338 pr_info("#AC: crashing the kernel on kernel split_locks and warning on user-space split_locks\n"); 1339 if (cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, 1340 "x86/splitlock", NULL, splitlock_cpu_offline) < 0) 1341 pr_warn("No splitlock CPU offline handler\n"); 1342 } else if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) { 1343 pr_info("#DB: warning on user-space bus_locks\n"); 1344 } 1345 break; 1346 case sld_fatal: 1347 if (boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) { 1348 pr_info("#AC: crashing the kernel on kernel split_locks and sending SIGBUS on user-space split_locks\n"); 1349 } else if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) { 1350 pr_info("#DB: sending SIGBUS on user-space bus_locks%s\n", 1351 boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT) ? 1352 " from non-WB" : ""); 1353 } 1354 break; 1355 case sld_ratelimit: 1356 if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) 1357 pr_info("#DB: setting system wide bus lock rate limit to %u/sec\n", bld_ratelimit.burst); 1358 break; 1359 } 1360 } 1361 1362 void __init sld_setup(struct cpuinfo_x86 *c) 1363 { 1364 split_lock_setup(c); 1365 sld_state_setup(); 1366 sld_state_show(); 1367 } 1368 1369 #define X86_HYBRID_CPU_TYPE_ID_SHIFT 24 1370 1371 /** 1372 * get_this_hybrid_cpu_type() - Get the type of this hybrid CPU 1373 * 1374 * Returns the CPU type [31:24] (i.e., Atom or Core) of a CPU in 1375 * a hybrid processor. If the processor is not hybrid, returns 0. 1376 */ 1377 u8 get_this_hybrid_cpu_type(void) 1378 { 1379 if (!cpu_feature_enabled(X86_FEATURE_HYBRID_CPU)) 1380 return 0; 1381 1382 return cpuid_eax(0x0000001a) >> X86_HYBRID_CPU_TYPE_ID_SHIFT; 1383 } 1384