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
  44enum 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 */
  56static enum split_lock_detect_state sld_state __ro_after_init = sld_off;
  57static 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 */
  64static 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 */
  73static 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
  92static bool ring3mwait_disabled __read_mostly;
  93
  94static int __init ring3mwait_disable(char *__unused)
  95{
  96	ring3mwait_disabled = true;
  97	return 1;
  98}
  99__setup("ring3mwait=disable", ring3mwait_disable);
 100
 101static 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 */
 136struct sku_microcode {
 137	u8 model;
 138	u8 stepping;
 139	u32 microcode;
 140};
 141static 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
 165static 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
 187int 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
 214	return 0;
 215}
 216EXPORT_SYMBOL_GPL(intel_cpu_collect_info);
 217
 218/*
 219 * Returns 1 if update has been found, 0 otherwise.
 220 */
 221int intel_find_matching_signature(void *mc, unsigned int csig, int cpf)
 222{
 223	struct microcode_header_intel *mc_hdr = mc;
 224	struct extended_sigtable *ext_hdr;
 225	struct extended_signature *ext_sig;
 226	int i;
 227
 228	if (intel_cpu_signatures_match(csig, cpf, mc_hdr->sig, mc_hdr->pf))
 229		return 1;
 230
 231	/* Look for ext. headers: */
 232	if (get_totalsize(mc_hdr) <= get_datasize(mc_hdr) + MC_HEADER_SIZE)
 233		return 0;
 234
 235	ext_hdr = mc + get_datasize(mc_hdr) + MC_HEADER_SIZE;
 236	ext_sig = (void *)ext_hdr + EXT_HEADER_SIZE;
 237
 238	for (i = 0; i < ext_hdr->count; i++) {
 239		if (intel_cpu_signatures_match(csig, cpf, ext_sig->sig, ext_sig->pf))
 240			return 1;
 241		ext_sig++;
 242	}
 243	return 0;
 244}
 245EXPORT_SYMBOL_GPL(intel_find_matching_signature);
 246
 247/**
 248 * intel_microcode_sanity_check() - Sanity check microcode file.
 249 * @mc: Pointer to the microcode file contents.
 250 * @print_err: Display failure reason if true, silent if false.
 251 * @hdr_type: Type of file, i.e. normal microcode file or In Field Scan file.
 252 *            Validate if the microcode header type matches with the type
 253 *            specified here.
 254 *
 255 * Validate certain header fields and verify if computed checksum matches
 256 * with the one specified in the header.
 257 *
 258 * Return: 0 if the file passes all the checks, -EINVAL if any of the checks
 259 * fail.
 260 */
 261int intel_microcode_sanity_check(void *mc, bool print_err, int hdr_type)
 262{
 263	unsigned long total_size, data_size, ext_table_size;
 264	struct microcode_header_intel *mc_header = mc;
 265	struct extended_sigtable *ext_header = NULL;
 266	u32 sum, orig_sum, ext_sigcount = 0, i;
 267	struct extended_signature *ext_sig;
 268
 269	total_size = get_totalsize(mc_header);
 270	data_size = get_datasize(mc_header);
 271
 272	if (data_size + MC_HEADER_SIZE > total_size) {
 273		if (print_err)
 274			pr_err("Error: bad microcode data file size.\n");
 275		return -EINVAL;
 276	}
 277
 278	if (mc_header->ldrver != 1 || mc_header->hdrver != hdr_type) {
 279		if (print_err)
 280			pr_err("Error: invalid/unknown microcode update format. Header type %d\n",
 281			       mc_header->hdrver);
 282		return -EINVAL;
 283	}
 284
 285	ext_table_size = total_size - (MC_HEADER_SIZE + data_size);
 286	if (ext_table_size) {
 287		u32 ext_table_sum = 0;
 288		u32 *ext_tablep;
 289
 290		if (ext_table_size < EXT_HEADER_SIZE ||
 291		    ((ext_table_size - EXT_HEADER_SIZE) % EXT_SIGNATURE_SIZE)) {
 292			if (print_err)
 293				pr_err("Error: truncated extended signature table.\n");
 294			return -EINVAL;
 295		}
 296
 297		ext_header = mc + MC_HEADER_SIZE + data_size;
 298		if (ext_table_size != exttable_size(ext_header)) {
 299			if (print_err)
 300				pr_err("Error: extended signature table size mismatch.\n");
 301			return -EFAULT;
 302		}
 303
 304		ext_sigcount = ext_header->count;
 305
 306		/*
 307		 * Check extended table checksum: the sum of all dwords that
 308		 * comprise a valid table must be 0.
 309		 */
 310		ext_tablep = (u32 *)ext_header;
 311
 312		i = ext_table_size / sizeof(u32);
 313		while (i--)
 314			ext_table_sum += ext_tablep[i];
 315
 316		if (ext_table_sum) {
 317			if (print_err)
 318				pr_warn("Bad extended signature table checksum, aborting.\n");
 319			return -EINVAL;
 320		}
 321	}
 322
 323	/*
 324	 * Calculate the checksum of update data and header. The checksum of
 325	 * valid update data and header including the extended signature table
 326	 * must be 0.
 327	 */
 328	orig_sum = 0;
 329	i = (MC_HEADER_SIZE + data_size) / sizeof(u32);
 330	while (i--)
 331		orig_sum += ((u32 *)mc)[i];
 332
 333	if (orig_sum) {
 334		if (print_err)
 335			pr_err("Bad microcode data checksum, aborting.\n");
 336		return -EINVAL;
 337	}
 338
 339	if (!ext_table_size)
 340		return 0;
 341
 342	/*
 343	 * Check extended signature checksum: 0 => valid.
 344	 */
 345	for (i = 0; i < ext_sigcount; i++) {
 346		ext_sig = (void *)ext_header + EXT_HEADER_SIZE +
 347			  EXT_SIGNATURE_SIZE * i;
 348
 349		sum = (mc_header->sig + mc_header->pf + mc_header->cksum) -
 350		      (ext_sig->sig + ext_sig->pf + ext_sig->cksum);
 351		if (sum) {
 352			if (print_err)
 353				pr_err("Bad extended signature checksum, aborting.\n");
 354			return -EINVAL;
 355		}
 356	}
 357	return 0;
 358}
 359EXPORT_SYMBOL_GPL(intel_microcode_sanity_check);
 360
 361static void early_init_intel(struct cpuinfo_x86 *c)
 362{
 363	u64 misc_enable;
 364
 365	/* Unmask CPUID levels if masked: */
 366	if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
 367		if (msr_clear_bit(MSR_IA32_MISC_ENABLE,
 368				  MSR_IA32_MISC_ENABLE_LIMIT_CPUID_BIT) > 0) {
 369			c->cpuid_level = cpuid_eax(0);
 370			get_cpu_cap(c);
 371		}
 372	}
 373
 374	if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
 375		(c->x86 == 0x6 && c->x86_model >= 0x0e))
 376		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
 377
 378	if (c->x86 >= 6 && !cpu_has(c, X86_FEATURE_IA64))
 379		c->microcode = intel_get_microcode_revision();
 380
 381	/* Now if any of them are set, check the blacklist and clear the lot */
 382	if ((cpu_has(c, X86_FEATURE_SPEC_CTRL) ||
 383	     cpu_has(c, X86_FEATURE_INTEL_STIBP) ||
 384	     cpu_has(c, X86_FEATURE_IBRS) || cpu_has(c, X86_FEATURE_IBPB) ||
 385	     cpu_has(c, X86_FEATURE_STIBP)) && bad_spectre_microcode(c)) {
 386		pr_warn("Intel Spectre v2 broken microcode detected; disabling Speculation Control\n");
 387		setup_clear_cpu_cap(X86_FEATURE_IBRS);
 388		setup_clear_cpu_cap(X86_FEATURE_IBPB);
 389		setup_clear_cpu_cap(X86_FEATURE_STIBP);
 390		setup_clear_cpu_cap(X86_FEATURE_SPEC_CTRL);
 391		setup_clear_cpu_cap(X86_FEATURE_MSR_SPEC_CTRL);
 392		setup_clear_cpu_cap(X86_FEATURE_INTEL_STIBP);
 393		setup_clear_cpu_cap(X86_FEATURE_SSBD);
 394		setup_clear_cpu_cap(X86_FEATURE_SPEC_CTRL_SSBD);
 395	}
 396
 397	/*
 398	 * Atom erratum AAE44/AAF40/AAG38/AAH41:
 399	 *
 400	 * A race condition between speculative fetches and invalidating
 401	 * a large page.  This is worked around in microcode, but we
 402	 * need the microcode to have already been loaded... so if it is
 403	 * not, recommend a BIOS update and disable large pages.
 404	 */
 405	if (c->x86 == 6 && c->x86_model == 0x1c && c->x86_stepping <= 2 &&
 406	    c->microcode < 0x20e) {
 407		pr_warn("Atom PSE erratum detected, BIOS microcode update recommended\n");
 408		clear_cpu_cap(c, X86_FEATURE_PSE);
 409	}
 410
 411#ifdef CONFIG_X86_64
 412	set_cpu_cap(c, X86_FEATURE_SYSENTER32);
 413#else
 414	/* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */
 415	if (c->x86 == 15 && c->x86_cache_alignment == 64)
 416		c->x86_cache_alignment = 128;
 417#endif
 418
 419	/* CPUID workaround for 0F33/0F34 CPU */
 420	if (c->x86 == 0xF && c->x86_model == 0x3
 421	    && (c->x86_stepping == 0x3 || c->x86_stepping == 0x4))
 422		c->x86_phys_bits = 36;
 423
 424	/*
 425	 * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
 426	 * with P/T states and does not stop in deep C-states.
 427	 *
 428	 * It is also reliable across cores and sockets. (but not across
 429	 * cabinets - we turn it off in that case explicitly.)
 430	 */
 431	if (c->x86_power & (1 << 8)) {
 432		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
 433		set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
 
 
 434	}
 435
 436	/* Penwell and Cloverview have the TSC which doesn't sleep on S3 */
 437	if (c->x86 == 6) {
 438		switch (c->x86_model) {
 439		case INTEL_FAM6_ATOM_SALTWELL_MID:
 440		case INTEL_FAM6_ATOM_SALTWELL_TABLET:
 441		case INTEL_FAM6_ATOM_SILVERMONT_MID:
 442		case INTEL_FAM6_ATOM_AIRMONT_NP:
 443			set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC_S3);
 444			break;
 445		default:
 446			break;
 447		}
 448	}
 449
 450	/*
 451	 * There is a known erratum on Pentium III and Core Solo
 452	 * and Core Duo CPUs.
 453	 * " Page with PAT set to WC while associated MTRR is UC
 454	 *   may consolidate to UC "
 455	 * Because of this erratum, it is better to stick with
 456	 * setting WC in MTRR rather than using PAT on these CPUs.
 457	 *
 458	 * Enable PAT WC only on P4, Core 2 or later CPUs.
 459	 */
 460	if (c->x86 == 6 && c->x86_model < 15)
 461		clear_cpu_cap(c, X86_FEATURE_PAT);
 462
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 463	/*
 464	 * If fast string is not enabled in IA32_MISC_ENABLE for any reason,
 465	 * clear the fast string and enhanced fast string CPU capabilities.
 466	 */
 467	if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
 468		rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
 469		if (!(misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING)) {
 470			pr_info("Disabled fast string operations\n");
 471			setup_clear_cpu_cap(X86_FEATURE_REP_GOOD);
 472			setup_clear_cpu_cap(X86_FEATURE_ERMS);
 473		}
 474	}
 475
 476	/*
 477	 * Intel Quark Core DevMan_001.pdf section 6.4.11
 478	 * "The operating system also is required to invalidate (i.e., flush)
 479	 *  the TLB when any changes are made to any of the page table entries.
 480	 *  The operating system must reload CR3 to cause the TLB to be flushed"
 481	 *
 482	 * As a result, boot_cpu_has(X86_FEATURE_PGE) in arch/x86/include/asm/tlbflush.h
 483	 * should be false so that __flush_tlb_all() causes CR3 instead of CR4.PGE
 484	 * to be modified.
 485	 */
 486	if (c->x86 == 5 && c->x86_model == 9) {
 487		pr_info("Disabling PGE capability bit\n");
 488		setup_clear_cpu_cap(X86_FEATURE_PGE);
 489	}
 490
 491	if (c->cpuid_level >= 0x00000001) {
 492		u32 eax, ebx, ecx, edx;
 493
 494		cpuid(0x00000001, &eax, &ebx, &ecx, &edx);
 495		/*
 496		 * If HTT (EDX[28]) is set EBX[16:23] contain the number of
 497		 * apicids which are reserved per package. Store the resulting
 498		 * shift value for the package management code.
 499		 */
 500		if (edx & (1U << 28))
 501			c->x86_coreid_bits = get_count_order((ebx >> 16) & 0xff);
 502	}
 503
 504	check_memory_type_self_snoop_errata(c);
 505
 506	/*
 507	 * Get the number of SMT siblings early from the extended topology
 508	 * leaf, if available. Otherwise try the legacy SMT detection.
 509	 */
 510	if (detect_extended_topology_early(c) < 0)
 511		detect_ht_early(c);
 512}
 513
 514static void bsp_init_intel(struct cpuinfo_x86 *c)
 515{
 516	resctrl_cpu_detect(c);
 517}
 518
 519#ifdef CONFIG_X86_32
 520/*
 521 *	Early probe support logic for ppro memory erratum #50
 522 *
 523 *	This is called before we do cpu ident work
 524 */
 525
 526int ppro_with_ram_bug(void)
 527{
 528	/* Uses data from early_cpu_detect now */
 529	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
 530	    boot_cpu_data.x86 == 6 &&
 531	    boot_cpu_data.x86_model == 1 &&
 532	    boot_cpu_data.x86_stepping < 8) {
 533		pr_info("Pentium Pro with Errata#50 detected. Taking evasive action.\n");
 534		return 1;
 535	}
 536	return 0;
 537}
 538
 539static void intel_smp_check(struct cpuinfo_x86 *c)
 540{
 541	/* calling is from identify_secondary_cpu() ? */
 542	if (!c->cpu_index)
 543		return;
 544
 545	/*
 546	 * Mask B, Pentium, but not Pentium MMX
 547	 */
 548	if (c->x86 == 5 &&
 549	    c->x86_stepping >= 1 && c->x86_stepping <= 4 &&
 550	    c->x86_model <= 3) {
 551		/*
 552		 * Remember we have B step Pentia with bugs
 553		 */
 554		WARN_ONCE(1, "WARNING: SMP operation may be unreliable"
 555				    "with B stepping processors.\n");
 556	}
 557}
 558
 559static int forcepae;
 560static int __init forcepae_setup(char *__unused)
 561{
 562	forcepae = 1;
 563	return 1;
 564}
 565__setup("forcepae", forcepae_setup);
 566
 567static void intel_workarounds(struct cpuinfo_x86 *c)
 568{
 569#ifdef CONFIG_X86_F00F_BUG
 570	/*
 571	 * All models of Pentium and Pentium with MMX technology CPUs
 572	 * have the F0 0F bug, which lets nonprivileged users lock up the
 573	 * system. Announce that the fault handler will be checking for it.
 574	 * The Quark is also family 5, but does not have the same bug.
 575	 */
 576	clear_cpu_bug(c, X86_BUG_F00F);
 577	if (c->x86 == 5 && c->x86_model < 9) {
 578		static int f00f_workaround_enabled;
 579
 580		set_cpu_bug(c, X86_BUG_F00F);
 581		if (!f00f_workaround_enabled) {
 582			pr_notice("Intel Pentium with F0 0F bug - workaround enabled.\n");
 583			f00f_workaround_enabled = 1;
 584		}
 585	}
 586#endif
 587
 588	/*
 589	 * SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until
 590	 * model 3 mask 3
 591	 */
 592	if ((c->x86<<8 | c->x86_model<<4 | c->x86_stepping) < 0x633)
 593		clear_cpu_cap(c, X86_FEATURE_SEP);
 594
 595	/*
 596	 * PAE CPUID issue: many Pentium M report no PAE but may have a
 597	 * functionally usable PAE implementation.
 598	 * Forcefully enable PAE if kernel parameter "forcepae" is present.
 599	 */
 600	if (forcepae) {
 601		pr_warn("PAE forced!\n");
 602		set_cpu_cap(c, X86_FEATURE_PAE);
 603		add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_NOW_UNRELIABLE);
 604	}
 605
 606	/*
 607	 * P4 Xeon erratum 037 workaround.
 608	 * Hardware prefetcher may cause stale data to be loaded into the cache.
 609	 */
 610	if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_stepping == 1)) {
 611		if (msr_set_bit(MSR_IA32_MISC_ENABLE,
 612				MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE_BIT) > 0) {
 
 613			pr_info("CPU: C0 stepping P4 Xeon detected.\n");
 614			pr_info("CPU: Disabling hardware prefetching (Erratum 037)\n");
 615		}
 616	}
 617
 618	/*
 619	 * See if we have a good local APIC by checking for buggy Pentia,
 620	 * i.e. all B steppings and the C2 stepping of P54C when using their
 621	 * integrated APIC (see 11AP erratum in "Pentium Processor
 622	 * Specification Update").
 623	 */
 624	if (boot_cpu_has(X86_FEATURE_APIC) && (c->x86<<8 | c->x86_model<<4) == 0x520 &&
 625	    (c->x86_stepping < 0x6 || c->x86_stepping == 0xb))
 626		set_cpu_bug(c, X86_BUG_11AP);
 627
 628
 629#ifdef CONFIG_X86_INTEL_USERCOPY
 630	/*
 631	 * Set up the preferred alignment for movsl bulk memory moves
 632	 */
 633	switch (c->x86) {
 634	case 4:		/* 486: untested */
 635		break;
 636	case 5:		/* Old Pentia: untested */
 637		break;
 638	case 6:		/* PII/PIII only like movsl with 8-byte alignment */
 639		movsl_mask.mask = 7;
 640		break;
 641	case 15:	/* P4 is OK down to 8-byte alignment */
 642		movsl_mask.mask = 7;
 643		break;
 644	}
 645#endif
 646
 647	intel_smp_check(c);
 648}
 649#else
 650static void intel_workarounds(struct cpuinfo_x86 *c)
 651{
 652}
 653#endif
 654
 655static void srat_detect_node(struct cpuinfo_x86 *c)
 656{
 657#ifdef CONFIG_NUMA
 658	unsigned node;
 659	int cpu = smp_processor_id();
 660
 661	/* Don't do the funky fallback heuristics the AMD version employs
 662	   for now. */
 663	node = numa_cpu_node(cpu);
 664	if (node == NUMA_NO_NODE || !node_online(node)) {
 665		/* reuse the value from init_cpu_to_node() */
 666		node = cpu_to_node(cpu);
 667	}
 668	numa_set_node(cpu, node);
 669#endif
 670}
 671
 672#define MSR_IA32_TME_ACTIVATE		0x982
 673
 674/* Helpers to access TME_ACTIVATE MSR */
 675#define TME_ACTIVATE_LOCKED(x)		(x & 0x1)
 676#define TME_ACTIVATE_ENABLED(x)		(x & 0x2)
 677
 678#define TME_ACTIVATE_POLICY(x)		((x >> 4) & 0xf)	/* Bits 7:4 */
 679#define TME_ACTIVATE_POLICY_AES_XTS_128	0
 680
 681#define TME_ACTIVATE_KEYID_BITS(x)	((x >> 32) & 0xf)	/* Bits 35:32 */
 682
 683#define TME_ACTIVATE_CRYPTO_ALGS(x)	((x >> 48) & 0xffff)	/* Bits 63:48 */
 684#define TME_ACTIVATE_CRYPTO_AES_XTS_128	1
 685
 686/* Values for mktme_status (SW only construct) */
 687#define MKTME_ENABLED			0
 688#define MKTME_DISABLED			1
 689#define MKTME_UNINITIALIZED		2
 690static int mktme_status = MKTME_UNINITIALIZED;
 691
 692static void detect_tme(struct cpuinfo_x86 *c)
 693{
 694	u64 tme_activate, tme_policy, tme_crypto_algs;
 695	int keyid_bits = 0, nr_keyids = 0;
 696	static u64 tme_activate_cpu0 = 0;
 697
 698	rdmsrl(MSR_IA32_TME_ACTIVATE, tme_activate);
 699
 700	if (mktme_status != MKTME_UNINITIALIZED) {
 701		if (tme_activate != tme_activate_cpu0) {
 702			/* Broken BIOS? */
 703			pr_err_once("x86/tme: configuration is inconsistent between CPUs\n");
 704			pr_err_once("x86/tme: MKTME is not usable\n");
 705			mktme_status = MKTME_DISABLED;
 706
 707			/* Proceed. We may need to exclude bits from x86_phys_bits. */
 708		}
 709	} else {
 710		tme_activate_cpu0 = tme_activate;
 711	}
 712
 713	if (!TME_ACTIVATE_LOCKED(tme_activate) || !TME_ACTIVATE_ENABLED(tme_activate)) {
 714		pr_info_once("x86/tme: not enabled by BIOS\n");
 715		mktme_status = MKTME_DISABLED;
 716		return;
 717	}
 718
 719	if (mktme_status != MKTME_UNINITIALIZED)
 720		goto detect_keyid_bits;
 721
 722	pr_info("x86/tme: enabled by BIOS\n");
 723
 724	tme_policy = TME_ACTIVATE_POLICY(tme_activate);
 725	if (tme_policy != TME_ACTIVATE_POLICY_AES_XTS_128)
 726		pr_warn("x86/tme: Unknown policy is active: %#llx\n", tme_policy);
 727
 728	tme_crypto_algs = TME_ACTIVATE_CRYPTO_ALGS(tme_activate);
 729	if (!(tme_crypto_algs & TME_ACTIVATE_CRYPTO_AES_XTS_128)) {
 730		pr_err("x86/mktme: No known encryption algorithm is supported: %#llx\n",
 731				tme_crypto_algs);
 732		mktme_status = MKTME_DISABLED;
 733	}
 734detect_keyid_bits:
 735	keyid_bits = TME_ACTIVATE_KEYID_BITS(tme_activate);
 736	nr_keyids = (1UL << keyid_bits) - 1;
 737	if (nr_keyids) {
 738		pr_info_once("x86/mktme: enabled by BIOS\n");
 739		pr_info_once("x86/mktme: %d KeyIDs available\n", nr_keyids);
 740	} else {
 741		pr_info_once("x86/mktme: disabled by BIOS\n");
 742	}
 743
 744	if (mktme_status == MKTME_UNINITIALIZED) {
 745		/* MKTME is usable */
 746		mktme_status = MKTME_ENABLED;
 747	}
 748
 749	/*
 750	 * KeyID bits effectively lower the number of physical address
 751	 * bits.  Update cpuinfo_x86::x86_phys_bits accordingly.
 752	 */
 753	c->x86_phys_bits -= keyid_bits;
 
 754}
 755
 756static void init_cpuid_fault(struct cpuinfo_x86 *c)
 757{
 758	u64 msr;
 759
 760	if (!rdmsrl_safe(MSR_PLATFORM_INFO, &msr)) {
 761		if (msr & MSR_PLATFORM_INFO_CPUID_FAULT)
 762			set_cpu_cap(c, X86_FEATURE_CPUID_FAULT);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 763	}
 764}
 765
 766static void init_intel_misc_features(struct cpuinfo_x86 *c)
 767{
 768	u64 msr;
 769
 770	if (rdmsrl_safe(MSR_MISC_FEATURES_ENABLES, &msr))
 771		return;
 772
 773	/* Clear all MISC features */
 774	this_cpu_write(msr_misc_features_shadow, 0);
 775
 776	/* Check features and update capabilities and shadow control bits */
 777	init_cpuid_fault(c);
 778	probe_xeon_phi_r3mwait(c);
 779
 780	msr = this_cpu_read(msr_misc_features_shadow);
 781	wrmsrl(MSR_MISC_FEATURES_ENABLES, msr);
 782}
 783
 784static void split_lock_init(void);
 785static void bus_lock_init(void);
 786
 787static void init_intel(struct cpuinfo_x86 *c)
 788{
 
 
 789	early_init_intel(c);
 790
 791	intel_workarounds(c);
 792
 793	/*
 794	 * Detect the extended topology information if available. This
 795	 * will reinitialise the initial_apicid which will be used
 796	 * in init_intel_cacheinfo()
 797	 */
 798	detect_extended_topology(c);
 799
 800	if (!cpu_has(c, X86_FEATURE_XTOPOLOGY)) {
 801		/*
 802		 * let's use the legacy cpuid vector 0x1 and 0x4 for topology
 803		 * detection.
 804		 */
 805		detect_num_cpu_cores(c);
 806#ifdef CONFIG_X86_32
 807		detect_ht(c);
 808#endif
 809	}
 810
 811	init_intel_cacheinfo(c);
 812
 813	if (c->cpuid_level > 9) {
 814		unsigned eax = cpuid_eax(10);
 815		/* Check for version and the number of counters */
 816		if ((eax & 0xff) && (((eax>>8) & 0xff) > 1))
 817			set_cpu_cap(c, X86_FEATURE_ARCH_PERFMON);
 818	}
 819
 820	if (cpu_has(c, X86_FEATURE_XMM2))
 821		set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
 822
 823	if (boot_cpu_has(X86_FEATURE_DS)) {
 824		unsigned int l1, l2;
 825
 826		rdmsr(MSR_IA32_MISC_ENABLE, l1, l2);
 827		if (!(l1 & MSR_IA32_MISC_ENABLE_BTS_UNAVAIL))
 828			set_cpu_cap(c, X86_FEATURE_BTS);
 829		if (!(l1 & MSR_IA32_MISC_ENABLE_PEBS_UNAVAIL))
 830			set_cpu_cap(c, X86_FEATURE_PEBS);
 831	}
 832
 833	if (c->x86 == 6 && boot_cpu_has(X86_FEATURE_CLFLUSH) &&
 834	    (c->x86_model == 29 || c->x86_model == 46 || c->x86_model == 47))
 835		set_cpu_bug(c, X86_BUG_CLFLUSH_MONITOR);
 836
 837	if (c->x86 == 6 && boot_cpu_has(X86_FEATURE_MWAIT) &&
 838		((c->x86_model == INTEL_FAM6_ATOM_GOLDMONT)))
 839		set_cpu_bug(c, X86_BUG_MONITOR);
 840
 841#ifdef CONFIG_X86_64
 842	if (c->x86 == 15)
 843		c->x86_cache_alignment = c->x86_clflush_size * 2;
 844	if (c->x86 == 6)
 845		set_cpu_cap(c, X86_FEATURE_REP_GOOD);
 846#else
 847	/*
 848	 * Names for the Pentium II/Celeron processors
 849	 * detectable only by also checking the cache size.
 850	 * Dixon is NOT a Celeron.
 851	 */
 852	if (c->x86 == 6) {
 853		unsigned int l2 = c->x86_cache_size;
 854		char *p = NULL;
 855
 856		switch (c->x86_model) {
 857		case 5:
 858			if (l2 == 0)
 859				p = "Celeron (Covington)";
 860			else if (l2 == 256)
 861				p = "Mobile Pentium II (Dixon)";
 862			break;
 863
 864		case 6:
 865			if (l2 == 128)
 866				p = "Celeron (Mendocino)";
 867			else if (c->x86_stepping == 0 || c->x86_stepping == 5)
 868				p = "Celeron-A";
 869			break;
 870
 871		case 8:
 872			if (l2 == 128)
 873				p = "Celeron (Coppermine)";
 874			break;
 875		}
 876
 877		if (p)
 878			strcpy(c->x86_model_id, p);
 879	}
 880
 881	if (c->x86 == 15)
 882		set_cpu_cap(c, X86_FEATURE_P4);
 883	if (c->x86 == 6)
 884		set_cpu_cap(c, X86_FEATURE_P3);
 885#endif
 886
 
 
 
 
 
 
 
 
 
 
 
 887	/* Work around errata */
 888	srat_detect_node(c);
 889
 890	init_ia32_feat_ctl(c);
 891
 892	if (cpu_has(c, X86_FEATURE_TME))
 893		detect_tme(c);
 894
 895	init_intel_misc_features(c);
 896
 897	split_lock_init();
 898	bus_lock_init();
 899
 900	intel_init_thermal(c);
 
 
 
 
 
 
 
 
 
 
 
 
 
 901}
 902
 903#ifdef CONFIG_X86_32
 904static unsigned int intel_size_cache(struct cpuinfo_x86 *c, unsigned int size)
 905{
 906	/*
 907	 * Intel PIII Tualatin. This comes in two flavours.
 908	 * One has 256kb of cache, the other 512. We have no way
 909	 * to determine which, so we use a boottime override
 910	 * for the 512kb model, and assume 256 otherwise.
 911	 */
 912	if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
 913		size = 256;
 914
 915	/*
 916	 * Intel Quark SoC X1000 contains a 4-way set associative
 917	 * 16K cache with a 16 byte cache line and 256 lines per tag
 918	 */
 919	if ((c->x86 == 5) && (c->x86_model == 9))
 920		size = 16;
 921	return size;
 922}
 923#endif
 924
 925#define TLB_INST_4K	0x01
 926#define TLB_INST_4M	0x02
 927#define TLB_INST_2M_4M	0x03
 928
 929#define TLB_INST_ALL	0x05
 930#define TLB_INST_1G	0x06
 931
 932#define TLB_DATA_4K	0x11
 933#define TLB_DATA_4M	0x12
 934#define TLB_DATA_2M_4M	0x13
 935#define TLB_DATA_4K_4M	0x14
 936
 937#define TLB_DATA_1G	0x16
 938
 939#define TLB_DATA0_4K	0x21
 940#define TLB_DATA0_4M	0x22
 941#define TLB_DATA0_2M_4M	0x23
 942
 943#define STLB_4K		0x41
 944#define STLB_4K_2M	0x42
 945
 946static const struct _tlb_table intel_tlb_table[] = {
 947	{ 0x01, TLB_INST_4K,		32,	" TLB_INST 4 KByte pages, 4-way set associative" },
 948	{ 0x02, TLB_INST_4M,		2,	" TLB_INST 4 MByte pages, full associative" },
 949	{ 0x03, TLB_DATA_4K,		64,	" TLB_DATA 4 KByte pages, 4-way set associative" },
 950	{ 0x04, TLB_DATA_4M,		8,	" TLB_DATA 4 MByte pages, 4-way set associative" },
 951	{ 0x05, TLB_DATA_4M,		32,	" TLB_DATA 4 MByte pages, 4-way set associative" },
 952	{ 0x0b, TLB_INST_4M,		4,	" TLB_INST 4 MByte pages, 4-way set associative" },
 953	{ 0x4f, TLB_INST_4K,		32,	" TLB_INST 4 KByte pages" },
 954	{ 0x50, TLB_INST_ALL,		64,	" TLB_INST 4 KByte and 2-MByte or 4-MByte pages" },
 955	{ 0x51, TLB_INST_ALL,		128,	" TLB_INST 4 KByte and 2-MByte or 4-MByte pages" },
 956	{ 0x52, TLB_INST_ALL,		256,	" TLB_INST 4 KByte and 2-MByte or 4-MByte pages" },
 957	{ 0x55, TLB_INST_2M_4M,		7,	" TLB_INST 2-MByte or 4-MByte pages, fully associative" },
 958	{ 0x56, TLB_DATA0_4M,		16,	" TLB_DATA0 4 MByte pages, 4-way set associative" },
 959	{ 0x57, TLB_DATA0_4K,		16,	" TLB_DATA0 4 KByte pages, 4-way associative" },
 960	{ 0x59, TLB_DATA0_4K,		16,	" TLB_DATA0 4 KByte pages, fully associative" },
 961	{ 0x5a, TLB_DATA0_2M_4M,	32,	" TLB_DATA0 2-MByte or 4 MByte pages, 4-way set associative" },
 962	{ 0x5b, TLB_DATA_4K_4M,		64,	" TLB_DATA 4 KByte and 4 MByte pages" },
 963	{ 0x5c, TLB_DATA_4K_4M,		128,	" TLB_DATA 4 KByte and 4 MByte pages" },
 964	{ 0x5d, TLB_DATA_4K_4M,		256,	" TLB_DATA 4 KByte and 4 MByte pages" },
 965	{ 0x61, TLB_INST_4K,		48,	" TLB_INST 4 KByte pages, full associative" },
 966	{ 0x63, TLB_DATA_1G,		4,	" TLB_DATA 1 GByte pages, 4-way set associative" },
 967	{ 0x6b, TLB_DATA_4K,		256,	" TLB_DATA 4 KByte pages, 8-way associative" },
 968	{ 0x6c, TLB_DATA_2M_4M,		128,	" TLB_DATA 2 MByte or 4 MByte pages, 8-way associative" },
 969	{ 0x6d, TLB_DATA_1G,		16,	" TLB_DATA 1 GByte pages, fully associative" },
 970	{ 0x76, TLB_INST_2M_4M,		8,	" TLB_INST 2-MByte or 4-MByte pages, fully associative" },
 971	{ 0xb0, TLB_INST_4K,		128,	" TLB_INST 4 KByte pages, 4-way set associative" },
 972	{ 0xb1, TLB_INST_2M_4M,		4,	" TLB_INST 2M pages, 4-way, 8 entries or 4M pages, 4-way entries" },
 973	{ 0xb2, TLB_INST_4K,		64,	" TLB_INST 4KByte pages, 4-way set associative" },
 974	{ 0xb3, TLB_DATA_4K,		128,	" TLB_DATA 4 KByte pages, 4-way set associative" },
 975	{ 0xb4, TLB_DATA_4K,		256,	" TLB_DATA 4 KByte pages, 4-way associative" },
 976	{ 0xb5, TLB_INST_4K,		64,	" TLB_INST 4 KByte pages, 8-way set associative" },
 977	{ 0xb6, TLB_INST_4K,		128,	" TLB_INST 4 KByte pages, 8-way set associative" },
 978	{ 0xba, TLB_DATA_4K,		64,	" TLB_DATA 4 KByte pages, 4-way associative" },
 979	{ 0xc0, TLB_DATA_4K_4M,		8,	" TLB_DATA 4 KByte and 4 MByte pages, 4-way associative" },
 980	{ 0xc1, STLB_4K_2M,		1024,	" STLB 4 KByte and 2 MByte pages, 8-way associative" },
 981	{ 0xc2, TLB_DATA_2M_4M,		16,	" TLB_DATA 2 MByte/4MByte pages, 4-way associative" },
 982	{ 0xca, STLB_4K,		512,	" STLB 4 KByte pages, 4-way associative" },
 983	{ 0x00, 0, 0 }
 984};
 985
 986static void intel_tlb_lookup(const unsigned char desc)
 987{
 988	unsigned char k;
 989	if (desc == 0)
 990		return;
 991
 992	/* look up this descriptor in the table */
 993	for (k = 0; intel_tlb_table[k].descriptor != desc &&
 994	     intel_tlb_table[k].descriptor != 0; k++)
 995		;
 996
 997	if (intel_tlb_table[k].tlb_type == 0)
 998		return;
 999
1000	switch (intel_tlb_table[k].tlb_type) {
1001	case STLB_4K:
1002		if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
1003			tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
1004		if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
1005			tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
1006		break;
1007	case STLB_4K_2M:
1008		if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
1009			tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
1010		if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
1011			tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
1012		if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries)
1013			tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries;
1014		if (tlb_lld_2m[ENTRIES] < intel_tlb_table[k].entries)
1015			tlb_lld_2m[ENTRIES] = intel_tlb_table[k].entries;
1016		if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
1017			tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
1018		if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
1019			tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
1020		break;
1021	case TLB_INST_ALL:
1022		if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
1023			tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
1024		if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries)
1025			tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries;
1026		if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
1027			tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
1028		break;
1029	case TLB_INST_4K:
1030		if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
1031			tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
1032		break;
1033	case TLB_INST_4M:
1034		if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
1035			tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
1036		break;
1037	case TLB_INST_2M_4M:
1038		if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries)
1039			tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries;
1040		if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
1041			tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
1042		break;
1043	case TLB_DATA_4K:
1044	case TLB_DATA0_4K:
1045		if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
1046			tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
1047		break;
1048	case TLB_DATA_4M:
1049	case TLB_DATA0_4M:
1050		if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
1051			tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
1052		break;
1053	case TLB_DATA_2M_4M:
1054	case TLB_DATA0_2M_4M:
1055		if (tlb_lld_2m[ENTRIES] < intel_tlb_table[k].entries)
1056			tlb_lld_2m[ENTRIES] = intel_tlb_table[k].entries;
1057		if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
1058			tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
1059		break;
1060	case TLB_DATA_4K_4M:
1061		if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
1062			tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
1063		if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
1064			tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
1065		break;
1066	case TLB_DATA_1G:
1067		if (tlb_lld_1g[ENTRIES] < intel_tlb_table[k].entries)
1068			tlb_lld_1g[ENTRIES] = intel_tlb_table[k].entries;
1069		break;
1070	}
1071}
1072
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1073static void intel_detect_tlb(struct cpuinfo_x86 *c)
1074{
1075	int i, j, n;
1076	unsigned int regs[4];
1077	unsigned char *desc = (unsigned char *)regs;
1078
1079	if (c->cpuid_level < 2)
1080		return;
1081
1082	/* Number of times to iterate */
1083	n = cpuid_eax(2) & 0xFF;
1084
1085	for (i = 0 ; i < n ; i++) {
1086		cpuid(2, &regs[0], &regs[1], &regs[2], &regs[3]);
1087
1088		/* If bit 31 is set, this is an unknown format */
1089		for (j = 0 ; j < 3 ; j++)
1090			if (regs[j] & (1 << 31))
1091				regs[j] = 0;
1092
1093		/* Byte 0 is level count, not a descriptor */
1094		for (j = 1 ; j < 16 ; j++)
1095			intel_tlb_lookup(desc[j]);
1096	}
 
1097}
1098
1099static const struct cpu_dev intel_cpu_dev = {
1100	.c_vendor	= "Intel",
1101	.c_ident	= { "GenuineIntel" },
1102#ifdef CONFIG_X86_32
1103	.legacy_models = {
1104		{ .family = 4, .model_names =
1105		  {
1106			  [0] = "486 DX-25/33",
1107			  [1] = "486 DX-50",
1108			  [2] = "486 SX",
1109			  [3] = "486 DX/2",
1110			  [4] = "486 SL",
1111			  [5] = "486 SX/2",
1112			  [7] = "486 DX/2-WB",
1113			  [8] = "486 DX/4",
1114			  [9] = "486 DX/4-WB"
1115		  }
1116		},
1117		{ .family = 5, .model_names =
1118		  {
1119			  [0] = "Pentium 60/66 A-step",
1120			  [1] = "Pentium 60/66",
1121			  [2] = "Pentium 75 - 200",
1122			  [3] = "OverDrive PODP5V83",
1123			  [4] = "Pentium MMX",
1124			  [7] = "Mobile Pentium 75 - 200",
1125			  [8] = "Mobile Pentium MMX",
1126			  [9] = "Quark SoC X1000",
1127		  }
1128		},
1129		{ .family = 6, .model_names =
1130		  {
1131			  [0] = "Pentium Pro A-step",
1132			  [1] = "Pentium Pro",
1133			  [3] = "Pentium II (Klamath)",
1134			  [4] = "Pentium II (Deschutes)",
1135			  [5] = "Pentium II (Deschutes)",
1136			  [6] = "Mobile Pentium II",
1137			  [7] = "Pentium III (Katmai)",
1138			  [8] = "Pentium III (Coppermine)",
1139			  [10] = "Pentium III (Cascades)",
1140			  [11] = "Pentium III (Tualatin)",
1141		  }
1142		},
1143		{ .family = 15, .model_names =
1144		  {
1145			  [0] = "Pentium 4 (Unknown)",
1146			  [1] = "Pentium 4 (Willamette)",
1147			  [2] = "Pentium 4 (Northwood)",
1148			  [4] = "Pentium 4 (Foster)",
1149			  [5] = "Pentium 4 (Foster)",
1150		  }
1151		},
1152	},
1153	.legacy_cache_size = intel_size_cache,
1154#endif
1155	.c_detect_tlb	= intel_detect_tlb,
1156	.c_early_init   = early_init_intel,
1157	.c_bsp_init	= bsp_init_intel,
1158	.c_init		= init_intel,
1159	.c_x86_vendor	= X86_VENDOR_INTEL,
1160};
1161
1162cpu_dev_register(intel_cpu_dev);
1163
1164#undef pr_fmt
1165#define pr_fmt(fmt) "x86/split lock detection: " fmt
1166
1167static const struct {
1168	const char			*option;
1169	enum split_lock_detect_state	state;
1170} sld_options[] __initconst = {
1171	{ "off",	sld_off   },
1172	{ "warn",	sld_warn  },
1173	{ "fatal",	sld_fatal },
1174	{ "ratelimit:", sld_ratelimit },
1175};
1176
1177static struct ratelimit_state bld_ratelimit;
1178
1179static unsigned int sysctl_sld_mitigate = 1;
1180static DEFINE_SEMAPHORE(buslock_sem);
1181
1182#ifdef CONFIG_PROC_SYSCTL
1183static struct ctl_table sld_sysctls[] = {
1184	{
1185		.procname       = "split_lock_mitigate",
1186		.data           = &sysctl_sld_mitigate,
1187		.maxlen         = sizeof(unsigned int),
1188		.mode           = 0644,
1189		.proc_handler	= proc_douintvec_minmax,
1190		.extra1         = SYSCTL_ZERO,
1191		.extra2         = SYSCTL_ONE,
1192	},
1193	{}
1194};
1195
1196static int __init sld_mitigate_sysctl_init(void)
1197{
1198	register_sysctl_init("kernel", sld_sysctls);
1199	return 0;
1200}
1201
1202late_initcall(sld_mitigate_sysctl_init);
1203#endif
1204
1205static inline bool match_option(const char *arg, int arglen, const char *opt)
1206{
1207	int len = strlen(opt), ratelimit;
1208
1209	if (strncmp(arg, opt, len))
1210		return false;
1211
1212	/*
1213	 * Min ratelimit is 1 bus lock/sec.
1214	 * Max ratelimit is 1000 bus locks/sec.
1215	 */
1216	if (sscanf(arg, "ratelimit:%d", &ratelimit) == 1 &&
1217	    ratelimit > 0 && ratelimit <= 1000) {
1218		ratelimit_state_init(&bld_ratelimit, HZ, ratelimit);
1219		ratelimit_set_flags(&bld_ratelimit, RATELIMIT_MSG_ON_RELEASE);
1220		return true;
1221	}
1222
1223	return len == arglen;
1224}
1225
1226static bool split_lock_verify_msr(bool on)
1227{
1228	u64 ctrl, tmp;
1229
1230	if (rdmsrl_safe(MSR_TEST_CTRL, &ctrl))
1231		return false;
1232	if (on)
1233		ctrl |= MSR_TEST_CTRL_SPLIT_LOCK_DETECT;
1234	else
1235		ctrl &= ~MSR_TEST_CTRL_SPLIT_LOCK_DETECT;
1236	if (wrmsrl_safe(MSR_TEST_CTRL, ctrl))
1237		return false;
1238	rdmsrl(MSR_TEST_CTRL, tmp);
1239	return ctrl == tmp;
1240}
1241
1242static void __init sld_state_setup(void)
1243{
1244	enum split_lock_detect_state state = sld_warn;
1245	char arg[20];
1246	int i, ret;
1247
1248	if (!boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT) &&
1249	    !boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT))
1250		return;
1251
1252	ret = cmdline_find_option(boot_command_line, "split_lock_detect",
1253				  arg, sizeof(arg));
1254	if (ret >= 0) {
1255		for (i = 0; i < ARRAY_SIZE(sld_options); i++) {
1256			if (match_option(arg, ret, sld_options[i].option)) {
1257				state = sld_options[i].state;
1258				break;
1259			}
1260		}
1261	}
1262	sld_state = state;
1263}
1264
1265static void __init __split_lock_setup(void)
1266{
1267	if (!split_lock_verify_msr(false)) {
1268		pr_info("MSR access failed: Disabled\n");
1269		return;
1270	}
1271
1272	rdmsrl(MSR_TEST_CTRL, msr_test_ctrl_cache);
1273
1274	if (!split_lock_verify_msr(true)) {
1275		pr_info("MSR access failed: Disabled\n");
1276		return;
1277	}
1278
1279	/* Restore the MSR to its cached value. */
1280	wrmsrl(MSR_TEST_CTRL, msr_test_ctrl_cache);
1281
1282	setup_force_cpu_cap(X86_FEATURE_SPLIT_LOCK_DETECT);
1283}
1284
1285/*
1286 * MSR_TEST_CTRL is per core, but we treat it like a per CPU MSR. Locking
1287 * is not implemented as one thread could undo the setting of the other
1288 * thread immediately after dropping the lock anyway.
1289 */
1290static void sld_update_msr(bool on)
1291{
1292	u64 test_ctrl_val = msr_test_ctrl_cache;
1293
1294	if (on)
1295		test_ctrl_val |= MSR_TEST_CTRL_SPLIT_LOCK_DETECT;
1296
1297	wrmsrl(MSR_TEST_CTRL, test_ctrl_val);
1298}
1299
1300static void split_lock_init(void)
1301{
1302	/*
1303	 * #DB for bus lock handles ratelimit and #AC for split lock is
1304	 * disabled.
1305	 */
1306	if (sld_state == sld_ratelimit) {
1307		split_lock_verify_msr(false);
1308		return;
1309	}
1310
1311	if (cpu_model_supports_sld)
1312		split_lock_verify_msr(sld_state != sld_off);
1313}
1314
1315static void __split_lock_reenable_unlock(struct work_struct *work)
1316{
1317	sld_update_msr(true);
1318	up(&buslock_sem);
1319}
1320
1321static DECLARE_DELAYED_WORK(sl_reenable_unlock, __split_lock_reenable_unlock);
1322
1323static void __split_lock_reenable(struct work_struct *work)
1324{
1325	sld_update_msr(true);
1326}
1327static DECLARE_DELAYED_WORK(sl_reenable, __split_lock_reenable);
1328
1329/*
1330 * If a CPU goes offline with pending delayed work to re-enable split lock
1331 * detection then the delayed work will be executed on some other CPU. That
1332 * handles releasing the buslock_sem, but because it executes on a
1333 * different CPU probably won't re-enable split lock detection. This is a
1334 * problem on HT systems since the sibling CPU on the same core may then be
1335 * left running with split lock detection disabled.
1336 *
1337 * Unconditionally re-enable detection here.
1338 */
1339static int splitlock_cpu_offline(unsigned int cpu)
1340{
1341	sld_update_msr(true);
1342
1343	return 0;
1344}
1345
1346static void split_lock_warn(unsigned long ip)
1347{
1348	struct delayed_work *work;
1349	int cpu;
1350
1351	if (!current->reported_split_lock)
1352		pr_warn_ratelimited("#AC: %s/%d took a split_lock trap at address: 0x%lx\n",
1353				    current->comm, current->pid, ip);
1354	current->reported_split_lock = 1;
1355
1356	if (sysctl_sld_mitigate) {
1357		/*
1358		 * misery factor #1:
1359		 * sleep 10ms before trying to execute split lock.
1360		 */
1361		if (msleep_interruptible(10) > 0)
1362			return;
1363		/*
1364		 * Misery factor #2:
1365		 * only allow one buslocked disabled core at a time.
1366		 */
1367		if (down_interruptible(&buslock_sem) == -EINTR)
1368			return;
1369		work = &sl_reenable_unlock;
1370	} else {
1371		work = &sl_reenable;
1372	}
1373
1374	cpu = get_cpu();
1375	schedule_delayed_work_on(cpu, work, 2);
1376
1377	/* Disable split lock detection on this CPU to make progress */
1378	sld_update_msr(false);
1379	put_cpu();
1380}
1381
1382bool handle_guest_split_lock(unsigned long ip)
1383{
1384	if (sld_state == sld_warn) {
1385		split_lock_warn(ip);
1386		return true;
1387	}
1388
1389	pr_warn_once("#AC: %s/%d %s split_lock trap at address: 0x%lx\n",
1390		     current->comm, current->pid,
1391		     sld_state == sld_fatal ? "fatal" : "bogus", ip);
1392
1393	current->thread.error_code = 0;
1394	current->thread.trap_nr = X86_TRAP_AC;
1395	force_sig_fault(SIGBUS, BUS_ADRALN, NULL);
1396	return false;
1397}
1398EXPORT_SYMBOL_GPL(handle_guest_split_lock);
1399
1400static void bus_lock_init(void)
1401{
1402	u64 val;
1403
1404	if (!boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT))
1405		return;
1406
1407	rdmsrl(MSR_IA32_DEBUGCTLMSR, val);
1408
1409	if ((boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT) &&
1410	    (sld_state == sld_warn || sld_state == sld_fatal)) ||
1411	    sld_state == sld_off) {
1412		/*
1413		 * Warn and fatal are handled by #AC for split lock if #AC for
1414		 * split lock is supported.
1415		 */
1416		val &= ~DEBUGCTLMSR_BUS_LOCK_DETECT;
1417	} else {
1418		val |= DEBUGCTLMSR_BUS_LOCK_DETECT;
1419	}
1420
1421	wrmsrl(MSR_IA32_DEBUGCTLMSR, val);
1422}
1423
1424bool handle_user_split_lock(struct pt_regs *regs, long error_code)
1425{
1426	if ((regs->flags & X86_EFLAGS_AC) || sld_state == sld_fatal)
1427		return false;
1428	split_lock_warn(regs->ip);
1429	return true;
1430}
1431
1432void handle_bus_lock(struct pt_regs *regs)
1433{
1434	switch (sld_state) {
1435	case sld_off:
1436		break;
1437	case sld_ratelimit:
1438		/* Enforce no more than bld_ratelimit bus locks/sec. */
1439		while (!__ratelimit(&bld_ratelimit))
1440			msleep(20);
1441		/* Warn on the bus lock. */
1442		fallthrough;
1443	case sld_warn:
1444		pr_warn_ratelimited("#DB: %s/%d took a bus_lock trap at address: 0x%lx\n",
1445				    current->comm, current->pid, regs->ip);
1446		break;
1447	case sld_fatal:
1448		force_sig_fault(SIGBUS, BUS_ADRALN, NULL);
1449		break;
1450	}
1451}
1452
1453/*
1454 * Bits in the IA32_CORE_CAPABILITIES are not architectural, so they should
1455 * only be trusted if it is confirmed that a CPU model implements a
1456 * specific feature at a particular bit position.
1457 *
1458 * The possible driver data field values:
1459 *
1460 * - 0: CPU models that are known to have the per-core split-lock detection
1461 *	feature even though they do not enumerate IA32_CORE_CAPABILITIES.
1462 *
1463 * - 1: CPU models which may enumerate IA32_CORE_CAPABILITIES and if so use
1464 *      bit 5 to enumerate the per-core split-lock detection feature.
1465 */
1466static const struct x86_cpu_id split_lock_cpu_ids[] __initconst = {
1467	X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_X,		0),
1468	X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_L,		0),
1469	X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_D,		0),
1470	X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT,	1),
1471	X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT_D,	1),
1472	X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT_L,	1),
1473	X86_MATCH_INTEL_FAM6_MODEL(TIGERLAKE_L,		1),
1474	X86_MATCH_INTEL_FAM6_MODEL(TIGERLAKE,		1),
1475	X86_MATCH_INTEL_FAM6_MODEL(SAPPHIRERAPIDS_X,	1),
1476	X86_MATCH_INTEL_FAM6_MODEL(ALDERLAKE,		1),
1477	X86_MATCH_INTEL_FAM6_MODEL(ALDERLAKE_L,		1),
1478	X86_MATCH_INTEL_FAM6_MODEL(RAPTORLAKE,		1),
1479	{}
1480};
1481
1482static void __init split_lock_setup(struct cpuinfo_x86 *c)
1483{
1484	const struct x86_cpu_id *m;
1485	u64 ia32_core_caps;
1486
1487	if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
1488		return;
1489
1490	m = x86_match_cpu(split_lock_cpu_ids);
1491	if (!m)
1492		return;
1493
1494	switch (m->driver_data) {
1495	case 0:
1496		break;
1497	case 1:
1498		if (!cpu_has(c, X86_FEATURE_CORE_CAPABILITIES))
1499			return;
1500		rdmsrl(MSR_IA32_CORE_CAPS, ia32_core_caps);
1501		if (!(ia32_core_caps & MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT))
1502			return;
1503		break;
1504	default:
1505		return;
1506	}
1507
1508	cpu_model_supports_sld = true;
1509	__split_lock_setup();
1510}
1511
1512static void sld_state_show(void)
1513{
1514	if (!boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT) &&
1515	    !boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT))
1516		return;
1517
1518	switch (sld_state) {
1519	case sld_off:
1520		pr_info("disabled\n");
1521		break;
1522	case sld_warn:
1523		if (boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) {
1524			pr_info("#AC: crashing the kernel on kernel split_locks and warning on user-space split_locks\n");
1525			if (cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
1526					      "x86/splitlock", NULL, splitlock_cpu_offline) < 0)
1527				pr_warn("No splitlock CPU offline handler\n");
1528		} else if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) {
1529			pr_info("#DB: warning on user-space bus_locks\n");
1530		}
1531		break;
1532	case sld_fatal:
1533		if (boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) {
1534			pr_info("#AC: crashing the kernel on kernel split_locks and sending SIGBUS on user-space split_locks\n");
1535		} else if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) {
1536			pr_info("#DB: sending SIGBUS on user-space bus_locks%s\n",
1537				boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT) ?
1538				" from non-WB" : "");
1539		}
1540		break;
1541	case sld_ratelimit:
1542		if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT))
1543			pr_info("#DB: setting system wide bus lock rate limit to %u/sec\n", bld_ratelimit.burst);
1544		break;
1545	}
1546}
1547
1548void __init sld_setup(struct cpuinfo_x86 *c)
1549{
1550	split_lock_setup(c);
1551	sld_state_setup();
1552	sld_state_show();
1553}
1554
1555#define X86_HYBRID_CPU_TYPE_ID_SHIFT	24
1556
1557/**
1558 * get_this_hybrid_cpu_type() - Get the type of this hybrid CPU
1559 *
1560 * Returns the CPU type [31:24] (i.e., Atom or Core) of a CPU in
1561 * a hybrid processor. If the processor is not hybrid, returns 0.
1562 */
1563u8 get_this_hybrid_cpu_type(void)
1564{
1565	if (!cpu_feature_enabled(X86_FEATURE_HYBRID_CPU))
1566		return 0;
1567
1568	return cpuid_eax(0x0000001a) >> X86_HYBRID_CPU_TYPE_ID_SHIFT;
1569}