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v5.4
   1// SPDX-License-Identifier: GPL-2.0
   2#include <linux/kernel.h>
 
   3
   4#include <linux/string.h>
   5#include <linux/bitops.h>
   6#include <linux/smp.h>
   7#include <linux/sched.h>
   8#include <linux/sched/clock.h>
 
   9#include <linux/thread_info.h>
  10#include <linux/init.h>
  11#include <linux/uaccess.h>
 
 
 
  12
  13#include <asm/cpufeature.h>
  14#include <asm/pgtable.h>
  15#include <asm/msr.h>
  16#include <asm/bugs.h>
  17#include <asm/cpu.h>
  18#include <asm/intel-family.h>
  19#include <asm/microcode_intel.h>
  20#include <asm/hwcap2.h>
  21#include <asm/elf.h>
 
 
 
 
 
 
  22
  23#ifdef CONFIG_X86_64
  24#include <linux/topology.h>
  25#endif
  26
  27#include "cpu.h"
  28
  29#ifdef CONFIG_X86_LOCAL_APIC
  30#include <asm/mpspec.h>
  31#include <asm/apic.h>
  32#endif
  33
 
 
 
 
 
 
 
  34/*
  35 * Just in case our CPU detection goes bad, or you have a weird system,
  36 * allow a way to override the automatic disabling of MPX.
 
  37 */
  38static int forcempx;
  39
  40static int __init forcempx_setup(char *__unused)
  41{
  42	forcempx = 1;
  43
  44	return 1;
  45}
  46__setup("intel-skd-046-workaround=disable", forcempx_setup);
  47
  48void check_mpx_erratum(struct cpuinfo_x86 *c)
  49{
  50	if (forcempx)
  51		return;
  52	/*
  53	 * Turn off the MPX feature on CPUs where SMEP is not
  54	 * available or disabled.
  55	 *
  56	 * Works around Intel Erratum SKD046: "Branch Instructions
  57	 * May Initialize MPX Bound Registers Incorrectly".
  58	 *
  59	 * This might falsely disable MPX on systems without
  60	 * SMEP, like Atom processors without SMEP.  But there
  61	 * is no such hardware known at the moment.
  62	 */
  63	if (cpu_has(c, X86_FEATURE_MPX) && !cpu_has(c, X86_FEATURE_SMEP)) {
  64		setup_clear_cpu_cap(X86_FEATURE_MPX);
  65		pr_warn("x86/mpx: Disabling MPX since SMEP not present\n");
  66	}
  67}
  68
  69/*
  70 * Processors which have self-snooping capability can handle conflicting
  71 * memory type across CPUs by snooping its own cache. However, there exists
  72 * CPU models in which having conflicting memory types still leads to
  73 * unpredictable behavior, machine check errors, or hangs. Clear this
  74 * feature to prevent its use on machines with known erratas.
  75 */
  76static void check_memory_type_self_snoop_errata(struct cpuinfo_x86 *c)
  77{
  78	switch (c->x86_model) {
  79	case INTEL_FAM6_CORE_YONAH:
  80	case INTEL_FAM6_CORE2_MEROM:
  81	case INTEL_FAM6_CORE2_MEROM_L:
  82	case INTEL_FAM6_CORE2_PENRYN:
  83	case INTEL_FAM6_CORE2_DUNNINGTON:
  84	case INTEL_FAM6_NEHALEM:
  85	case INTEL_FAM6_NEHALEM_G:
  86	case INTEL_FAM6_NEHALEM_EP:
  87	case INTEL_FAM6_NEHALEM_EX:
  88	case INTEL_FAM6_WESTMERE:
  89	case INTEL_FAM6_WESTMERE_EP:
  90	case INTEL_FAM6_SANDYBRIDGE:
  91		setup_clear_cpu_cap(X86_FEATURE_SELFSNOOP);
  92	}
  93}
  94
  95static bool ring3mwait_disabled __read_mostly;
  96
  97static int __init ring3mwait_disable(char *__unused)
  98{
  99	ring3mwait_disabled = true;
 100	return 0;
 101}
 102__setup("ring3mwait=disable", ring3mwait_disable);
 103
 104static void probe_xeon_phi_r3mwait(struct cpuinfo_x86 *c)
 105{
 106	/*
 107	 * Ring 3 MONITOR/MWAIT feature cannot be detected without
 108	 * cpu model and family comparison.
 109	 */
 110	if (c->x86 != 6)
 111		return;
 112	switch (c->x86_model) {
 113	case INTEL_FAM6_XEON_PHI_KNL:
 114	case INTEL_FAM6_XEON_PHI_KNM:
 115		break;
 116	default:
 117		return;
 118	}
 119
 120	if (ring3mwait_disabled)
 121		return;
 122
 123	set_cpu_cap(c, X86_FEATURE_RING3MWAIT);
 124	this_cpu_or(msr_misc_features_shadow,
 125		    1UL << MSR_MISC_FEATURES_ENABLES_RING3MWAIT_BIT);
 126
 127	if (c == &boot_cpu_data)
 128		ELF_HWCAP2 |= HWCAP2_RING3MWAIT;
 129}
 130
 131/*
 132 * Early microcode releases for the Spectre v2 mitigation were broken.
 133 * Information taken from;
 134 * - https://newsroom.intel.com/wp-content/uploads/sites/11/2018/03/microcode-update-guidance.pdf
 135 * - https://kb.vmware.com/s/article/52345
 136 * - Microcode revisions observed in the wild
 137 * - Release note from 20180108 microcode release
 138 */
 139struct sku_microcode {
 140	u8 model;
 141	u8 stepping;
 142	u32 microcode;
 143};
 144static const struct sku_microcode spectre_bad_microcodes[] = {
 145	{ INTEL_FAM6_KABYLAKE,		0x0B,	0x80 },
 146	{ INTEL_FAM6_KABYLAKE,		0x0A,	0x80 },
 147	{ INTEL_FAM6_KABYLAKE,		0x09,	0x80 },
 148	{ INTEL_FAM6_KABYLAKE_L,	0x0A,	0x80 },
 149	{ INTEL_FAM6_KABYLAKE_L,	0x09,	0x80 },
 150	{ INTEL_FAM6_SKYLAKE_X,		0x03,	0x0100013e },
 151	{ INTEL_FAM6_SKYLAKE_X,		0x04,	0x0200003c },
 152	{ INTEL_FAM6_BROADWELL,		0x04,	0x28 },
 153	{ INTEL_FAM6_BROADWELL_G,	0x01,	0x1b },
 154	{ INTEL_FAM6_BROADWELL_D,	0x02,	0x14 },
 155	{ INTEL_FAM6_BROADWELL_D,	0x03,	0x07000011 },
 156	{ INTEL_FAM6_BROADWELL_X,	0x01,	0x0b000025 },
 157	{ INTEL_FAM6_HASWELL_L,		0x01,	0x21 },
 158	{ INTEL_FAM6_HASWELL_G,		0x01,	0x18 },
 159	{ INTEL_FAM6_HASWELL,		0x03,	0x23 },
 160	{ INTEL_FAM6_HASWELL_X,		0x02,	0x3b },
 161	{ INTEL_FAM6_HASWELL_X,		0x04,	0x10 },
 162	{ INTEL_FAM6_IVYBRIDGE_X,	0x04,	0x42a },
 163	/* Observed in the wild */
 164	{ INTEL_FAM6_SANDYBRIDGE_X,	0x06,	0x61b },
 165	{ INTEL_FAM6_SANDYBRIDGE_X,	0x07,	0x712 },
 166};
 167
 168static bool bad_spectre_microcode(struct cpuinfo_x86 *c)
 169{
 170	int i;
 171
 172	/*
 173	 * We know that the hypervisor lie to us on the microcode version so
 174	 * we may as well hope that it is running the correct version.
 175	 */
 176	if (cpu_has(c, X86_FEATURE_HYPERVISOR))
 177		return false;
 178
 179	if (c->x86 != 6)
 180		return false;
 181
 182	for (i = 0; i < ARRAY_SIZE(spectre_bad_microcodes); i++) {
 183		if (c->x86_model == spectre_bad_microcodes[i].model &&
 184		    c->x86_stepping == spectre_bad_microcodes[i].stepping)
 185			return (c->microcode <= spectre_bad_microcodes[i].microcode);
 186	}
 187	return false;
 188}
 189
 190static void early_init_intel(struct cpuinfo_x86 *c)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 191{
 192	u64 misc_enable;
 
 
 193
 194	/* Unmask CPUID levels if masked: */
 195	if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
 196		if (msr_clear_bit(MSR_IA32_MISC_ENABLE,
 197				  MSR_IA32_MISC_ENABLE_LIMIT_CPUID_BIT) > 0) {
 198			c->cpuid_level = cpuid_eax(0);
 199			get_cpu_cap(c);
 
 
 
 
 200		}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 201	}
 202
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 203	if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
 204		(c->x86 == 0x6 && c->x86_model >= 0x0e))
 205		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
 206
 207	if (c->x86 >= 6 && !cpu_has(c, X86_FEATURE_IA64))
 208		c->microcode = intel_get_microcode_revision();
 209
 210	/* Now if any of them are set, check the blacklist and clear the lot */
 211	if ((cpu_has(c, X86_FEATURE_SPEC_CTRL) ||
 212	     cpu_has(c, X86_FEATURE_INTEL_STIBP) ||
 213	     cpu_has(c, X86_FEATURE_IBRS) || cpu_has(c, X86_FEATURE_IBPB) ||
 214	     cpu_has(c, X86_FEATURE_STIBP)) && bad_spectre_microcode(c)) {
 215		pr_warn("Intel Spectre v2 broken microcode detected; disabling Speculation Control\n");
 216		setup_clear_cpu_cap(X86_FEATURE_IBRS);
 217		setup_clear_cpu_cap(X86_FEATURE_IBPB);
 218		setup_clear_cpu_cap(X86_FEATURE_STIBP);
 219		setup_clear_cpu_cap(X86_FEATURE_SPEC_CTRL);
 220		setup_clear_cpu_cap(X86_FEATURE_MSR_SPEC_CTRL);
 221		setup_clear_cpu_cap(X86_FEATURE_INTEL_STIBP);
 222		setup_clear_cpu_cap(X86_FEATURE_SSBD);
 223		setup_clear_cpu_cap(X86_FEATURE_SPEC_CTRL_SSBD);
 224	}
 225
 226	/*
 227	 * Atom erratum AAE44/AAF40/AAG38/AAH41:
 228	 *
 229	 * A race condition between speculative fetches and invalidating
 230	 * a large page.  This is worked around in microcode, but we
 231	 * need the microcode to have already been loaded... so if it is
 232	 * not, recommend a BIOS update and disable large pages.
 233	 */
 234	if (c->x86 == 6 && c->x86_model == 0x1c && c->x86_stepping <= 2 &&
 235	    c->microcode < 0x20e) {
 236		pr_warn("Atom PSE erratum detected, BIOS microcode update recommended\n");
 237		clear_cpu_cap(c, X86_FEATURE_PSE);
 238	}
 239
 240#ifdef CONFIG_X86_64
 241	set_cpu_cap(c, X86_FEATURE_SYSENTER32);
 242#else
 243	/* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */
 244	if (c->x86 == 15 && c->x86_cache_alignment == 64)
 245		c->x86_cache_alignment = 128;
 246#endif
 247
 248	/* CPUID workaround for 0F33/0F34 CPU */
 249	if (c->x86 == 0xF && c->x86_model == 0x3
 250	    && (c->x86_stepping == 0x3 || c->x86_stepping == 0x4))
 251		c->x86_phys_bits = 36;
 252
 253	/*
 254	 * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
 255	 * with P/T states and does not stop in deep C-states.
 256	 *
 257	 * It is also reliable across cores and sockets. (but not across
 258	 * cabinets - we turn it off in that case explicitly.)
 259	 */
 260	if (c->x86_power & (1 << 8)) {
 261		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
 262		set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
 263	}
 264
 265	/* Penwell and Cloverview have the TSC which doesn't sleep on S3 */
 266	if (c->x86 == 6) {
 267		switch (c->x86_model) {
 268		case INTEL_FAM6_ATOM_SALTWELL_MID:
 269		case INTEL_FAM6_ATOM_SALTWELL_TABLET:
 270		case INTEL_FAM6_ATOM_SILVERMONT_MID:
 271		case INTEL_FAM6_ATOM_AIRMONT_NP:
 272			set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC_S3);
 273			break;
 274		default:
 275			break;
 276		}
 277	}
 278
 279	/*
 280	 * There is a known erratum on Pentium III and Core Solo
 281	 * and Core Duo CPUs.
 282	 * " Page with PAT set to WC while associated MTRR is UC
 283	 *   may consolidate to UC "
 284	 * Because of this erratum, it is better to stick with
 285	 * setting WC in MTRR rather than using PAT on these CPUs.
 286	 *
 287	 * Enable PAT WC only on P4, Core 2 or later CPUs.
 288	 */
 289	if (c->x86 == 6 && c->x86_model < 15)
 290		clear_cpu_cap(c, X86_FEATURE_PAT);
 291
 292	/*
 293	 * If fast string is not enabled in IA32_MISC_ENABLE for any reason,
 294	 * clear the fast string and enhanced fast string CPU capabilities.
 295	 */
 296	if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
 297		rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
 298		if (!(misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING)) {
 299			pr_info("Disabled fast string operations\n");
 300			setup_clear_cpu_cap(X86_FEATURE_REP_GOOD);
 301			setup_clear_cpu_cap(X86_FEATURE_ERMS);
 302		}
 303	}
 304
 305	/*
 306	 * Intel Quark Core DevMan_001.pdf section 6.4.11
 307	 * "The operating system also is required to invalidate (i.e., flush)
 308	 *  the TLB when any changes are made to any of the page table entries.
 309	 *  The operating system must reload CR3 to cause the TLB to be flushed"
 310	 *
 311	 * As a result, boot_cpu_has(X86_FEATURE_PGE) in arch/x86/include/asm/tlbflush.h
 312	 * should be false so that __flush_tlb_all() causes CR3 insted of CR4.PGE
 313	 * to be modified.
 314	 */
 315	if (c->x86 == 5 && c->x86_model == 9) {
 316		pr_info("Disabling PGE capability bit\n");
 317		setup_clear_cpu_cap(X86_FEATURE_PGE);
 318	}
 319
 320	if (c->cpuid_level >= 0x00000001) {
 321		u32 eax, ebx, ecx, edx;
 322
 323		cpuid(0x00000001, &eax, &ebx, &ecx, &edx);
 324		/*
 325		 * If HTT (EDX[28]) is set EBX[16:23] contain the number of
 326		 * apicids which are reserved per package. Store the resulting
 327		 * shift value for the package management code.
 328		 */
 329		if (edx & (1U << 28))
 330			c->x86_coreid_bits = get_count_order((ebx >> 16) & 0xff);
 331	}
 332
 333	check_mpx_erratum(c);
 334	check_memory_type_self_snoop_errata(c);
 335
 336	/*
 337	 * Get the number of SMT siblings early from the extended topology
 338	 * leaf, if available. Otherwise try the legacy SMT detection.
 339	 */
 340	if (detect_extended_topology_early(c) < 0)
 341		detect_ht_early(c);
 
 
 
 
 
 342}
 343
 344#ifdef CONFIG_X86_32
 345/*
 346 *	Early probe support logic for ppro memory erratum #50
 347 *
 348 *	This is called before we do cpu ident work
 349 */
 350
 351int ppro_with_ram_bug(void)
 352{
 353	/* Uses data from early_cpu_detect now */
 354	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
 355	    boot_cpu_data.x86 == 6 &&
 356	    boot_cpu_data.x86_model == 1 &&
 357	    boot_cpu_data.x86_stepping < 8) {
 358		pr_info("Pentium Pro with Errata#50 detected. Taking evasive action.\n");
 359		return 1;
 360	}
 361	return 0;
 362}
 363
 364static void intel_smp_check(struct cpuinfo_x86 *c)
 365{
 366	/* calling is from identify_secondary_cpu() ? */
 367	if (!c->cpu_index)
 368		return;
 369
 370	/*
 371	 * Mask B, Pentium, but not Pentium MMX
 372	 */
 373	if (c->x86 == 5 &&
 374	    c->x86_stepping >= 1 && c->x86_stepping <= 4 &&
 375	    c->x86_model <= 3) {
 376		/*
 377		 * Remember we have B step Pentia with bugs
 378		 */
 379		WARN_ONCE(1, "WARNING: SMP operation may be unreliable"
 380				    "with B stepping processors.\n");
 381	}
 382}
 383
 384static int forcepae;
 385static int __init forcepae_setup(char *__unused)
 386{
 387	forcepae = 1;
 388	return 1;
 389}
 390__setup("forcepae", forcepae_setup);
 391
 392static void intel_workarounds(struct cpuinfo_x86 *c)
 393{
 394#ifdef CONFIG_X86_F00F_BUG
 395	/*
 396	 * All models of Pentium and Pentium with MMX technology CPUs
 397	 * have the F0 0F bug, which lets nonprivileged users lock up the
 398	 * system. Announce that the fault handler will be checking for it.
 399	 * The Quark is also family 5, but does not have the same bug.
 400	 */
 401	clear_cpu_bug(c, X86_BUG_F00F);
 402	if (c->x86 == 5 && c->x86_model < 9) {
 403		static int f00f_workaround_enabled;
 404
 405		set_cpu_bug(c, X86_BUG_F00F);
 406		if (!f00f_workaround_enabled) {
 407			pr_notice("Intel Pentium with F0 0F bug - workaround enabled.\n");
 408			f00f_workaround_enabled = 1;
 409		}
 410	}
 411#endif
 412
 413	/*
 414	 * SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until
 415	 * model 3 mask 3
 416	 */
 417	if ((c->x86<<8 | c->x86_model<<4 | c->x86_stepping) < 0x633)
 418		clear_cpu_cap(c, X86_FEATURE_SEP);
 419
 420	/*
 421	 * PAE CPUID issue: many Pentium M report no PAE but may have a
 422	 * functionally usable PAE implementation.
 423	 * Forcefully enable PAE if kernel parameter "forcepae" is present.
 424	 */
 425	if (forcepae) {
 426		pr_warn("PAE forced!\n");
 427		set_cpu_cap(c, X86_FEATURE_PAE);
 428		add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_NOW_UNRELIABLE);
 429	}
 430
 431	/*
 432	 * P4 Xeon erratum 037 workaround.
 433	 * Hardware prefetcher may cause stale data to be loaded into the cache.
 434	 */
 435	if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_stepping == 1)) {
 436		if (msr_set_bit(MSR_IA32_MISC_ENABLE,
 437				MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE_BIT) > 0) {
 438			pr_info("CPU: C0 stepping P4 Xeon detected.\n");
 439			pr_info("CPU: Disabling hardware prefetching (Erratum 037)\n");
 440		}
 441	}
 442
 443	/*
 444	 * See if we have a good local APIC by checking for buggy Pentia,
 445	 * i.e. all B steppings and the C2 stepping of P54C when using their
 446	 * integrated APIC (see 11AP erratum in "Pentium Processor
 447	 * Specification Update").
 448	 */
 449	if (boot_cpu_has(X86_FEATURE_APIC) && (c->x86<<8 | c->x86_model<<4) == 0x520 &&
 450	    (c->x86_stepping < 0x6 || c->x86_stepping == 0xb))
 451		set_cpu_bug(c, X86_BUG_11AP);
 452
 453
 454#ifdef CONFIG_X86_INTEL_USERCOPY
 455	/*
 456	 * Set up the preferred alignment for movsl bulk memory moves
 457	 */
 458	switch (c->x86) {
 459	case 4:		/* 486: untested */
 460		break;
 461	case 5:		/* Old Pentia: untested */
 462		break;
 463	case 6:		/* PII/PIII only like movsl with 8-byte alignment */
 464		movsl_mask.mask = 7;
 465		break;
 466	case 15:	/* P4 is OK down to 8-byte alignment */
 467		movsl_mask.mask = 7;
 468		break;
 469	}
 470#endif
 471
 472	intel_smp_check(c);
 473}
 474#else
 475static void intel_workarounds(struct cpuinfo_x86 *c)
 476{
 477}
 478#endif
 479
 480static void srat_detect_node(struct cpuinfo_x86 *c)
 481{
 482#ifdef CONFIG_NUMA
 483	unsigned node;
 484	int cpu = smp_processor_id();
 485
 486	/* Don't do the funky fallback heuristics the AMD version employs
 487	   for now. */
 488	node = numa_cpu_node(cpu);
 489	if (node == NUMA_NO_NODE || !node_online(node)) {
 490		/* reuse the value from init_cpu_to_node() */
 491		node = cpu_to_node(cpu);
 492	}
 493	numa_set_node(cpu, node);
 494#endif
 495}
 496
 497static void detect_vmx_virtcap(struct cpuinfo_x86 *c)
 498{
 499	/* Intel VMX MSR indicated features */
 500#define X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW	0x00200000
 501#define X86_VMX_FEATURE_PROC_CTLS_VNMI		0x00400000
 502#define X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS	0x80000000
 503#define X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC	0x00000001
 504#define X86_VMX_FEATURE_PROC_CTLS2_EPT		0x00000002
 505#define X86_VMX_FEATURE_PROC_CTLS2_VPID		0x00000020
 506#define x86_VMX_FEATURE_EPT_CAP_AD		0x00200000
 507
 508	u32 vmx_msr_low, vmx_msr_high, msr_ctl, msr_ctl2;
 509	u32 msr_vpid_cap, msr_ept_cap;
 510
 511	clear_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
 512	clear_cpu_cap(c, X86_FEATURE_VNMI);
 513	clear_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
 514	clear_cpu_cap(c, X86_FEATURE_EPT);
 515	clear_cpu_cap(c, X86_FEATURE_VPID);
 516	clear_cpu_cap(c, X86_FEATURE_EPT_AD);
 517
 518	rdmsr(MSR_IA32_VMX_PROCBASED_CTLS, vmx_msr_low, vmx_msr_high);
 519	msr_ctl = vmx_msr_high | vmx_msr_low;
 520	if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW)
 521		set_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
 522	if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_VNMI)
 523		set_cpu_cap(c, X86_FEATURE_VNMI);
 524	if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS) {
 525		rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2,
 526		      vmx_msr_low, vmx_msr_high);
 527		msr_ctl2 = vmx_msr_high | vmx_msr_low;
 528		if ((msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC) &&
 529		    (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW))
 530			set_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
 531		if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_EPT) {
 532			set_cpu_cap(c, X86_FEATURE_EPT);
 533			rdmsr(MSR_IA32_VMX_EPT_VPID_CAP,
 534			      msr_ept_cap, msr_vpid_cap);
 535			if (msr_ept_cap & x86_VMX_FEATURE_EPT_CAP_AD)
 536				set_cpu_cap(c, X86_FEATURE_EPT_AD);
 537		}
 538		if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VPID)
 539			set_cpu_cap(c, X86_FEATURE_VPID);
 540	}
 541}
 542
 543#define MSR_IA32_TME_ACTIVATE		0x982
 544
 545/* Helpers to access TME_ACTIVATE MSR */
 546#define TME_ACTIVATE_LOCKED(x)		(x & 0x1)
 547#define TME_ACTIVATE_ENABLED(x)		(x & 0x2)
 548
 549#define TME_ACTIVATE_POLICY(x)		((x >> 4) & 0xf)	/* Bits 7:4 */
 550#define TME_ACTIVATE_POLICY_AES_XTS_128	0
 551
 552#define TME_ACTIVATE_KEYID_BITS(x)	((x >> 32) & 0xf)	/* Bits 35:32 */
 553
 554#define TME_ACTIVATE_CRYPTO_ALGS(x)	((x >> 48) & 0xffff)	/* Bits 63:48 */
 555#define TME_ACTIVATE_CRYPTO_AES_XTS_128	1
 556
 557/* Values for mktme_status (SW only construct) */
 558#define MKTME_ENABLED			0
 559#define MKTME_DISABLED			1
 560#define MKTME_UNINITIALIZED		2
 561static int mktme_status = MKTME_UNINITIALIZED;
 562
 563static void detect_tme(struct cpuinfo_x86 *c)
 564{
 565	u64 tme_activate, tme_policy, tme_crypto_algs;
 566	int keyid_bits = 0, nr_keyids = 0;
 567	static u64 tme_activate_cpu0 = 0;
 568
 569	rdmsrl(MSR_IA32_TME_ACTIVATE, tme_activate);
 570
 571	if (mktme_status != MKTME_UNINITIALIZED) {
 572		if (tme_activate != tme_activate_cpu0) {
 573			/* Broken BIOS? */
 574			pr_err_once("x86/tme: configuration is inconsistent between CPUs\n");
 575			pr_err_once("x86/tme: MKTME is not usable\n");
 576			mktme_status = MKTME_DISABLED;
 577
 578			/* Proceed. We may need to exclude bits from x86_phys_bits. */
 579		}
 580	} else {
 581		tme_activate_cpu0 = tme_activate;
 582	}
 583
 584	if (!TME_ACTIVATE_LOCKED(tme_activate) || !TME_ACTIVATE_ENABLED(tme_activate)) {
 585		pr_info_once("x86/tme: not enabled by BIOS\n");
 586		mktme_status = MKTME_DISABLED;
 587		return;
 588	}
 589
 590	if (mktme_status != MKTME_UNINITIALIZED)
 591		goto detect_keyid_bits;
 592
 593	pr_info("x86/tme: enabled by BIOS\n");
 594
 595	tme_policy = TME_ACTIVATE_POLICY(tme_activate);
 596	if (tme_policy != TME_ACTIVATE_POLICY_AES_XTS_128)
 597		pr_warn("x86/tme: Unknown policy is active: %#llx\n", tme_policy);
 598
 599	tme_crypto_algs = TME_ACTIVATE_CRYPTO_ALGS(tme_activate);
 600	if (!(tme_crypto_algs & TME_ACTIVATE_CRYPTO_AES_XTS_128)) {
 601		pr_err("x86/mktme: No known encryption algorithm is supported: %#llx\n",
 602				tme_crypto_algs);
 603		mktme_status = MKTME_DISABLED;
 604	}
 605detect_keyid_bits:
 606	keyid_bits = TME_ACTIVATE_KEYID_BITS(tme_activate);
 607	nr_keyids = (1UL << keyid_bits) - 1;
 608	if (nr_keyids) {
 609		pr_info_once("x86/mktme: enabled by BIOS\n");
 610		pr_info_once("x86/mktme: %d KeyIDs available\n", nr_keyids);
 611	} else {
 612		pr_info_once("x86/mktme: disabled by BIOS\n");
 613	}
 614
 615	if (mktme_status == MKTME_UNINITIALIZED) {
 616		/* MKTME is usable */
 617		mktme_status = MKTME_ENABLED;
 618	}
 619
 620	/*
 621	 * KeyID bits effectively lower the number of physical address
 622	 * bits.  Update cpuinfo_x86::x86_phys_bits accordingly.
 623	 */
 624	c->x86_phys_bits -= keyid_bits;
 625}
 626
 627static void init_cpuid_fault(struct cpuinfo_x86 *c)
 628{
 629	u64 msr;
 630
 631	if (!rdmsrl_safe(MSR_PLATFORM_INFO, &msr)) {
 632		if (msr & MSR_PLATFORM_INFO_CPUID_FAULT)
 633			set_cpu_cap(c, X86_FEATURE_CPUID_FAULT);
 634	}
 635}
 636
 637static void init_intel_misc_features(struct cpuinfo_x86 *c)
 638{
 639	u64 msr;
 640
 641	if (rdmsrl_safe(MSR_MISC_FEATURES_ENABLES, &msr))
 642		return;
 643
 644	/* Clear all MISC features */
 645	this_cpu_write(msr_misc_features_shadow, 0);
 646
 647	/* Check features and update capabilities and shadow control bits */
 648	init_cpuid_fault(c);
 649	probe_xeon_phi_r3mwait(c);
 650
 651	msr = this_cpu_read(msr_misc_features_shadow);
 652	wrmsrl(MSR_MISC_FEATURES_ENABLES, msr);
 653}
 654
 
 
 
 655static void init_intel(struct cpuinfo_x86 *c)
 656{
 657	early_init_intel(c);
 658
 659	intel_workarounds(c);
 660
 661	/*
 662	 * Detect the extended topology information if available. This
 663	 * will reinitialise the initial_apicid which will be used
 664	 * in init_intel_cacheinfo()
 665	 */
 666	detect_extended_topology(c);
 667
 668	if (!cpu_has(c, X86_FEATURE_XTOPOLOGY)) {
 669		/*
 670		 * let's use the legacy cpuid vector 0x1 and 0x4 for topology
 671		 * detection.
 672		 */
 673		detect_num_cpu_cores(c);
 674#ifdef CONFIG_X86_32
 675		detect_ht(c);
 676#endif
 677	}
 678
 679	init_intel_cacheinfo(c);
 680
 681	if (c->cpuid_level > 9) {
 682		unsigned eax = cpuid_eax(10);
 683		/* Check for version and the number of counters */
 684		if ((eax & 0xff) && (((eax>>8) & 0xff) > 1))
 685			set_cpu_cap(c, X86_FEATURE_ARCH_PERFMON);
 686	}
 687
 688	if (cpu_has(c, X86_FEATURE_XMM2))
 689		set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
 690
 691	if (boot_cpu_has(X86_FEATURE_DS)) {
 692		unsigned int l1, l2;
 693
 694		rdmsr(MSR_IA32_MISC_ENABLE, l1, l2);
 695		if (!(l1 & (1<<11)))
 696			set_cpu_cap(c, X86_FEATURE_BTS);
 697		if (!(l1 & (1<<12)))
 698			set_cpu_cap(c, X86_FEATURE_PEBS);
 699	}
 700
 701	if (c->x86 == 6 && boot_cpu_has(X86_FEATURE_CLFLUSH) &&
 702	    (c->x86_model == 29 || c->x86_model == 46 || c->x86_model == 47))
 703		set_cpu_bug(c, X86_BUG_CLFLUSH_MONITOR);
 704
 705	if (c->x86 == 6 && boot_cpu_has(X86_FEATURE_MWAIT) &&
 706		((c->x86_model == INTEL_FAM6_ATOM_GOLDMONT)))
 707		set_cpu_bug(c, X86_BUG_MONITOR);
 708
 709#ifdef CONFIG_X86_64
 710	if (c->x86 == 15)
 711		c->x86_cache_alignment = c->x86_clflush_size * 2;
 712	if (c->x86 == 6)
 713		set_cpu_cap(c, X86_FEATURE_REP_GOOD);
 714#else
 715	/*
 716	 * Names for the Pentium II/Celeron processors
 717	 * detectable only by also checking the cache size.
 718	 * Dixon is NOT a Celeron.
 719	 */
 720	if (c->x86 == 6) {
 721		unsigned int l2 = c->x86_cache_size;
 722		char *p = NULL;
 723
 724		switch (c->x86_model) {
 725		case 5:
 726			if (l2 == 0)
 727				p = "Celeron (Covington)";
 728			else if (l2 == 256)
 729				p = "Mobile Pentium II (Dixon)";
 730			break;
 731
 732		case 6:
 733			if (l2 == 128)
 734				p = "Celeron (Mendocino)";
 735			else if (c->x86_stepping == 0 || c->x86_stepping == 5)
 736				p = "Celeron-A";
 737			break;
 738
 739		case 8:
 740			if (l2 == 128)
 741				p = "Celeron (Coppermine)";
 742			break;
 743		}
 744
 745		if (p)
 746			strcpy(c->x86_model_id, p);
 747	}
 748
 749	if (c->x86 == 15)
 750		set_cpu_cap(c, X86_FEATURE_P4);
 751	if (c->x86 == 6)
 752		set_cpu_cap(c, X86_FEATURE_P3);
 753#endif
 754
 755	/* Work around errata */
 756	srat_detect_node(c);
 757
 758	if (cpu_has(c, X86_FEATURE_VMX))
 759		detect_vmx_virtcap(c);
 760
 761	if (cpu_has(c, X86_FEATURE_TME))
 762		detect_tme(c);
 763
 764	init_intel_misc_features(c);
 765
 766	if (tsx_ctrl_state == TSX_CTRL_ENABLE)
 767		tsx_enable();
 768	if (tsx_ctrl_state == TSX_CTRL_DISABLE)
 769		tsx_disable();
 770}
 771
 772#ifdef CONFIG_X86_32
 773static unsigned int intel_size_cache(struct cpuinfo_x86 *c, unsigned int size)
 774{
 775	/*
 776	 * Intel PIII Tualatin. This comes in two flavours.
 777	 * One has 256kb of cache, the other 512. We have no way
 778	 * to determine which, so we use a boottime override
 779	 * for the 512kb model, and assume 256 otherwise.
 780	 */
 781	if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
 782		size = 256;
 783
 784	/*
 785	 * Intel Quark SoC X1000 contains a 4-way set associative
 786	 * 16K cache with a 16 byte cache line and 256 lines per tag
 787	 */
 788	if ((c->x86 == 5) && (c->x86_model == 9))
 789		size = 16;
 790	return size;
 791}
 792#endif
 793
 794#define TLB_INST_4K	0x01
 795#define TLB_INST_4M	0x02
 796#define TLB_INST_2M_4M	0x03
 797
 798#define TLB_INST_ALL	0x05
 799#define TLB_INST_1G	0x06
 800
 801#define TLB_DATA_4K	0x11
 802#define TLB_DATA_4M	0x12
 803#define TLB_DATA_2M_4M	0x13
 804#define TLB_DATA_4K_4M	0x14
 805
 806#define TLB_DATA_1G	0x16
 807
 808#define TLB_DATA0_4K	0x21
 809#define TLB_DATA0_4M	0x22
 810#define TLB_DATA0_2M_4M	0x23
 811
 812#define STLB_4K		0x41
 813#define STLB_4K_2M	0x42
 814
 815static const struct _tlb_table intel_tlb_table[] = {
 816	{ 0x01, TLB_INST_4K,		32,	" TLB_INST 4 KByte pages, 4-way set associative" },
 817	{ 0x02, TLB_INST_4M,		2,	" TLB_INST 4 MByte pages, full associative" },
 818	{ 0x03, TLB_DATA_4K,		64,	" TLB_DATA 4 KByte pages, 4-way set associative" },
 819	{ 0x04, TLB_DATA_4M,		8,	" TLB_DATA 4 MByte pages, 4-way set associative" },
 820	{ 0x05, TLB_DATA_4M,		32,	" TLB_DATA 4 MByte pages, 4-way set associative" },
 821	{ 0x0b, TLB_INST_4M,		4,	" TLB_INST 4 MByte pages, 4-way set associative" },
 822	{ 0x4f, TLB_INST_4K,		32,	" TLB_INST 4 KByte pages */" },
 823	{ 0x50, TLB_INST_ALL,		64,	" TLB_INST 4 KByte and 2-MByte or 4-MByte pages" },
 824	{ 0x51, TLB_INST_ALL,		128,	" TLB_INST 4 KByte and 2-MByte or 4-MByte pages" },
 825	{ 0x52, TLB_INST_ALL,		256,	" TLB_INST 4 KByte and 2-MByte or 4-MByte pages" },
 826	{ 0x55, TLB_INST_2M_4M,		7,	" TLB_INST 2-MByte or 4-MByte pages, fully associative" },
 827	{ 0x56, TLB_DATA0_4M,		16,	" TLB_DATA0 4 MByte pages, 4-way set associative" },
 828	{ 0x57, TLB_DATA0_4K,		16,	" TLB_DATA0 4 KByte pages, 4-way associative" },
 829	{ 0x59, TLB_DATA0_4K,		16,	" TLB_DATA0 4 KByte pages, fully associative" },
 830	{ 0x5a, TLB_DATA0_2M_4M,	32,	" TLB_DATA0 2-MByte or 4 MByte pages, 4-way set associative" },
 831	{ 0x5b, TLB_DATA_4K_4M,		64,	" TLB_DATA 4 KByte and 4 MByte pages" },
 832	{ 0x5c, TLB_DATA_4K_4M,		128,	" TLB_DATA 4 KByte and 4 MByte pages" },
 833	{ 0x5d, TLB_DATA_4K_4M,		256,	" TLB_DATA 4 KByte and 4 MByte pages" },
 834	{ 0x61, TLB_INST_4K,		48,	" TLB_INST 4 KByte pages, full associative" },
 835	{ 0x63, TLB_DATA_1G,		4,	" TLB_DATA 1 GByte pages, 4-way set associative" },
 836	{ 0x6b, TLB_DATA_4K,		256,	" TLB_DATA 4 KByte pages, 8-way associative" },
 837	{ 0x6c, TLB_DATA_2M_4M,		128,	" TLB_DATA 2 MByte or 4 MByte pages, 8-way associative" },
 838	{ 0x6d, TLB_DATA_1G,		16,	" TLB_DATA 1 GByte pages, fully associative" },
 839	{ 0x76, TLB_INST_2M_4M,		8,	" TLB_INST 2-MByte or 4-MByte pages, fully associative" },
 840	{ 0xb0, TLB_INST_4K,		128,	" TLB_INST 4 KByte pages, 4-way set associative" },
 841	{ 0xb1, TLB_INST_2M_4M,		4,	" TLB_INST 2M pages, 4-way, 8 entries or 4M pages, 4-way entries" },
 842	{ 0xb2, TLB_INST_4K,		64,	" TLB_INST 4KByte pages, 4-way set associative" },
 843	{ 0xb3, TLB_DATA_4K,		128,	" TLB_DATA 4 KByte pages, 4-way set associative" },
 844	{ 0xb4, TLB_DATA_4K,		256,	" TLB_DATA 4 KByte pages, 4-way associative" },
 845	{ 0xb5, TLB_INST_4K,		64,	" TLB_INST 4 KByte pages, 8-way set associative" },
 846	{ 0xb6, TLB_INST_4K,		128,	" TLB_INST 4 KByte pages, 8-way set associative" },
 847	{ 0xba, TLB_DATA_4K,		64,	" TLB_DATA 4 KByte pages, 4-way associative" },
 848	{ 0xc0, TLB_DATA_4K_4M,		8,	" TLB_DATA 4 KByte and 4 MByte pages, 4-way associative" },
 849	{ 0xc1, STLB_4K_2M,		1024,	" STLB 4 KByte and 2 MByte pages, 8-way associative" },
 850	{ 0xc2, TLB_DATA_2M_4M,		16,	" DTLB 2 MByte/4MByte pages, 4-way associative" },
 851	{ 0xca, STLB_4K,		512,	" STLB 4 KByte pages, 4-way associative" },
 852	{ 0x00, 0, 0 }
 853};
 854
 855static void intel_tlb_lookup(const unsigned char desc)
 856{
 857	unsigned char k;
 858	if (desc == 0)
 859		return;
 860
 861	/* look up this descriptor in the table */
 862	for (k = 0; intel_tlb_table[k].descriptor != desc && \
 863			intel_tlb_table[k].descriptor != 0; k++)
 864		;
 865
 866	if (intel_tlb_table[k].tlb_type == 0)
 867		return;
 868
 869	switch (intel_tlb_table[k].tlb_type) {
 870	case STLB_4K:
 871		if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
 872			tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
 873		if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
 874			tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
 875		break;
 876	case STLB_4K_2M:
 877		if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
 878			tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
 879		if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
 880			tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
 881		if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries)
 882			tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries;
 883		if (tlb_lld_2m[ENTRIES] < intel_tlb_table[k].entries)
 884			tlb_lld_2m[ENTRIES] = intel_tlb_table[k].entries;
 885		if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
 886			tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
 887		if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
 888			tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
 889		break;
 890	case TLB_INST_ALL:
 891		if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
 892			tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
 893		if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries)
 894			tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries;
 895		if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
 896			tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
 897		break;
 898	case TLB_INST_4K:
 899		if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
 900			tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
 901		break;
 902	case TLB_INST_4M:
 903		if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
 904			tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
 905		break;
 906	case TLB_INST_2M_4M:
 907		if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries)
 908			tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries;
 909		if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
 910			tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
 911		break;
 912	case TLB_DATA_4K:
 913	case TLB_DATA0_4K:
 914		if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
 915			tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
 916		break;
 917	case TLB_DATA_4M:
 918	case TLB_DATA0_4M:
 919		if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
 920			tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
 921		break;
 922	case TLB_DATA_2M_4M:
 923	case TLB_DATA0_2M_4M:
 924		if (tlb_lld_2m[ENTRIES] < intel_tlb_table[k].entries)
 925			tlb_lld_2m[ENTRIES] = intel_tlb_table[k].entries;
 926		if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
 927			tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
 928		break;
 929	case TLB_DATA_4K_4M:
 930		if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
 931			tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
 932		if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
 933			tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
 934		break;
 935	case TLB_DATA_1G:
 936		if (tlb_lld_1g[ENTRIES] < intel_tlb_table[k].entries)
 937			tlb_lld_1g[ENTRIES] = intel_tlb_table[k].entries;
 938		break;
 939	}
 940}
 941
 942static void intel_detect_tlb(struct cpuinfo_x86 *c)
 943{
 944	int i, j, n;
 945	unsigned int regs[4];
 946	unsigned char *desc = (unsigned char *)regs;
 947
 948	if (c->cpuid_level < 2)
 949		return;
 950
 951	/* Number of times to iterate */
 952	n = cpuid_eax(2) & 0xFF;
 953
 954	for (i = 0 ; i < n ; i++) {
 955		cpuid(2, &regs[0], &regs[1], &regs[2], &regs[3]);
 956
 957		/* If bit 31 is set, this is an unknown format */
 958		for (j = 0 ; j < 3 ; j++)
 959			if (regs[j] & (1 << 31))
 960				regs[j] = 0;
 961
 962		/* Byte 0 is level count, not a descriptor */
 963		for (j = 1 ; j < 16 ; j++)
 964			intel_tlb_lookup(desc[j]);
 965	}
 966}
 967
 968static const struct cpu_dev intel_cpu_dev = {
 969	.c_vendor	= "Intel",
 970	.c_ident	= { "GenuineIntel" },
 971#ifdef CONFIG_X86_32
 972	.legacy_models = {
 973		{ .family = 4, .model_names =
 974		  {
 975			  [0] = "486 DX-25/33",
 976			  [1] = "486 DX-50",
 977			  [2] = "486 SX",
 978			  [3] = "486 DX/2",
 979			  [4] = "486 SL",
 980			  [5] = "486 SX/2",
 981			  [7] = "486 DX/2-WB",
 982			  [8] = "486 DX/4",
 983			  [9] = "486 DX/4-WB"
 984		  }
 985		},
 986		{ .family = 5, .model_names =
 987		  {
 988			  [0] = "Pentium 60/66 A-step",
 989			  [1] = "Pentium 60/66",
 990			  [2] = "Pentium 75 - 200",
 991			  [3] = "OverDrive PODP5V83",
 992			  [4] = "Pentium MMX",
 993			  [7] = "Mobile Pentium 75 - 200",
 994			  [8] = "Mobile Pentium MMX",
 995			  [9] = "Quark SoC X1000",
 996		  }
 997		},
 998		{ .family = 6, .model_names =
 999		  {
1000			  [0] = "Pentium Pro A-step",
1001			  [1] = "Pentium Pro",
1002			  [3] = "Pentium II (Klamath)",
1003			  [4] = "Pentium II (Deschutes)",
1004			  [5] = "Pentium II (Deschutes)",
1005			  [6] = "Mobile Pentium II",
1006			  [7] = "Pentium III (Katmai)",
1007			  [8] = "Pentium III (Coppermine)",
1008			  [10] = "Pentium III (Cascades)",
1009			  [11] = "Pentium III (Tualatin)",
1010		  }
1011		},
1012		{ .family = 15, .model_names =
1013		  {
1014			  [0] = "Pentium 4 (Unknown)",
1015			  [1] = "Pentium 4 (Willamette)",
1016			  [2] = "Pentium 4 (Northwood)",
1017			  [4] = "Pentium 4 (Foster)",
1018			  [5] = "Pentium 4 (Foster)",
1019		  }
1020		},
1021	},
1022	.legacy_cache_size = intel_size_cache,
1023#endif
1024	.c_detect_tlb	= intel_detect_tlb,
1025	.c_early_init   = early_init_intel,
 
1026	.c_init		= init_intel,
1027	.c_x86_vendor	= X86_VENDOR_INTEL,
1028};
1029
1030cpu_dev_register(intel_cpu_dev);
v6.9.4
   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.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
 187#define MSR_IA32_TME_ACTIVATE		0x982
 188
 189/* Helpers to access TME_ACTIVATE MSR */
 190#define TME_ACTIVATE_LOCKED(x)		(x & 0x1)
 191#define TME_ACTIVATE_ENABLED(x)		(x & 0x2)
 192
 193#define TME_ACTIVATE_POLICY(x)		((x >> 4) & 0xf)	/* Bits 7:4 */
 194#define TME_ACTIVATE_POLICY_AES_XTS_128	0
 195
 196#define TME_ACTIVATE_KEYID_BITS(x)	((x >> 32) & 0xf)	/* Bits 35:32 */
 197
 198#define TME_ACTIVATE_CRYPTO_ALGS(x)	((x >> 48) & 0xffff)	/* Bits 63:48 */
 199#define TME_ACTIVATE_CRYPTO_AES_XTS_128	1
 200
 201/* Values for mktme_status (SW only construct) */
 202#define MKTME_ENABLED			0
 203#define MKTME_DISABLED			1
 204#define MKTME_UNINITIALIZED		2
 205static int mktme_status = MKTME_UNINITIALIZED;
 206
 207static void detect_tme_early(struct cpuinfo_x86 *c)
 208{
 209	u64 tme_activate, tme_policy, tme_crypto_algs;
 210	int keyid_bits = 0, nr_keyids = 0;
 211	static u64 tme_activate_cpu0 = 0;
 212
 213	rdmsrl(MSR_IA32_TME_ACTIVATE, tme_activate);
 214
 215	if (mktme_status != MKTME_UNINITIALIZED) {
 216		if (tme_activate != tme_activate_cpu0) {
 217			/* Broken BIOS? */
 218			pr_err_once("x86/tme: configuration is inconsistent between CPUs\n");
 219			pr_err_once("x86/tme: MKTME is not usable\n");
 220			mktme_status = MKTME_DISABLED;
 221
 222			/* Proceed. We may need to exclude bits from x86_phys_bits. */
 223		}
 224	} else {
 225		tme_activate_cpu0 = tme_activate;
 226	}
 227
 228	if (!TME_ACTIVATE_LOCKED(tme_activate) || !TME_ACTIVATE_ENABLED(tme_activate)) {
 229		pr_info_once("x86/tme: not enabled by BIOS\n");
 230		mktme_status = MKTME_DISABLED;
 231		return;
 232	}
 233
 234	if (mktme_status != MKTME_UNINITIALIZED)
 235		goto detect_keyid_bits;
 236
 237	pr_info("x86/tme: enabled by BIOS\n");
 238
 239	tme_policy = TME_ACTIVATE_POLICY(tme_activate);
 240	if (tme_policy != TME_ACTIVATE_POLICY_AES_XTS_128)
 241		pr_warn("x86/tme: Unknown policy is active: %#llx\n", tme_policy);
 242
 243	tme_crypto_algs = TME_ACTIVATE_CRYPTO_ALGS(tme_activate);
 244	if (!(tme_crypto_algs & TME_ACTIVATE_CRYPTO_AES_XTS_128)) {
 245		pr_err("x86/mktme: No known encryption algorithm is supported: %#llx\n",
 246				tme_crypto_algs);
 247		mktme_status = MKTME_DISABLED;
 248	}
 249detect_keyid_bits:
 250	keyid_bits = TME_ACTIVATE_KEYID_BITS(tme_activate);
 251	nr_keyids = (1UL << keyid_bits) - 1;
 252	if (nr_keyids) {
 253		pr_info_once("x86/mktme: enabled by BIOS\n");
 254		pr_info_once("x86/mktme: %d KeyIDs available\n", nr_keyids);
 255	} else {
 256		pr_info_once("x86/mktme: disabled by BIOS\n");
 257	}
 258
 259	if (mktme_status == MKTME_UNINITIALIZED) {
 260		/* MKTME is usable */
 261		mktme_status = MKTME_ENABLED;
 262	}
 263
 264	/*
 265	 * KeyID bits effectively lower the number of physical address
 266	 * bits.  Update cpuinfo_x86::x86_phys_bits accordingly.
 267	 */
 268	c->x86_phys_bits -= keyid_bits;
 269}
 270
 271void intel_unlock_cpuid_leafs(struct cpuinfo_x86 *c)
 272{
 273	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
 274		return;
 275
 276	if (c->x86 < 6 || (c->x86 == 6 && c->x86_model < 0xd))
 277		return;
 278
 279	/*
 280	 * The BIOS can have limited CPUID to leaf 2, which breaks feature
 281	 * enumeration. Unlock it and update the maximum leaf info.
 282	 */
 283	if (msr_clear_bit(MSR_IA32_MISC_ENABLE, MSR_IA32_MISC_ENABLE_LIMIT_CPUID_BIT) > 0)
 284		c->cpuid_level = cpuid_eax(0);
 285}
 286
 287static void early_init_intel(struct cpuinfo_x86 *c)
 288{
 289	u64 misc_enable;
 290
 291	if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
 292		(c->x86 == 0x6 && c->x86_model >= 0x0e))
 293		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
 294
 295	if (c->x86 >= 6 && !cpu_has(c, X86_FEATURE_IA64))
 296		c->microcode = intel_get_microcode_revision();
 297
 298	/* Now if any of them are set, check the blacklist and clear the lot */
 299	if ((cpu_has(c, X86_FEATURE_SPEC_CTRL) ||
 300	     cpu_has(c, X86_FEATURE_INTEL_STIBP) ||
 301	     cpu_has(c, X86_FEATURE_IBRS) || cpu_has(c, X86_FEATURE_IBPB) ||
 302	     cpu_has(c, X86_FEATURE_STIBP)) && bad_spectre_microcode(c)) {
 303		pr_warn("Intel Spectre v2 broken microcode detected; disabling Speculation Control\n");
 304		setup_clear_cpu_cap(X86_FEATURE_IBRS);
 305		setup_clear_cpu_cap(X86_FEATURE_IBPB);
 306		setup_clear_cpu_cap(X86_FEATURE_STIBP);
 307		setup_clear_cpu_cap(X86_FEATURE_SPEC_CTRL);
 308		setup_clear_cpu_cap(X86_FEATURE_MSR_SPEC_CTRL);
 309		setup_clear_cpu_cap(X86_FEATURE_INTEL_STIBP);
 310		setup_clear_cpu_cap(X86_FEATURE_SSBD);
 311		setup_clear_cpu_cap(X86_FEATURE_SPEC_CTRL_SSBD);
 312	}
 313
 314	/*
 315	 * Atom erratum AAE44/AAF40/AAG38/AAH41:
 316	 *
 317	 * A race condition between speculative fetches and invalidating
 318	 * a large page.  This is worked around in microcode, but we
 319	 * need the microcode to have already been loaded... so if it is
 320	 * not, recommend a BIOS update and disable large pages.
 321	 */
 322	if (c->x86 == 6 && c->x86_model == 0x1c && c->x86_stepping <= 2 &&
 323	    c->microcode < 0x20e) {
 324		pr_warn("Atom PSE erratum detected, BIOS microcode update recommended\n");
 325		clear_cpu_cap(c, X86_FEATURE_PSE);
 326	}
 327
 328#ifdef CONFIG_X86_64
 329	set_cpu_cap(c, X86_FEATURE_SYSENTER32);
 330#else
 331	/* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */
 332	if (c->x86 == 15 && c->x86_cache_alignment == 64)
 333		c->x86_cache_alignment = 128;
 334#endif
 335
 336	/* CPUID workaround for 0F33/0F34 CPU */
 337	if (c->x86 == 0xF && c->x86_model == 0x3
 338	    && (c->x86_stepping == 0x3 || c->x86_stepping == 0x4))
 339		c->x86_phys_bits = 36;
 340
 341	/*
 342	 * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
 343	 * with P/T states and does not stop in deep C-states.
 344	 *
 345	 * It is also reliable across cores and sockets. (but not across
 346	 * cabinets - we turn it off in that case explicitly.)
 347	 */
 348	if (c->x86_power & (1 << 8)) {
 349		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
 350		set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
 351	}
 352
 353	/* Penwell and Cloverview have the TSC which doesn't sleep on S3 */
 354	if (c->x86 == 6) {
 355		switch (c->x86_model) {
 356		case INTEL_FAM6_ATOM_SALTWELL_MID:
 357		case INTEL_FAM6_ATOM_SALTWELL_TABLET:
 358		case INTEL_FAM6_ATOM_SILVERMONT_MID:
 359		case INTEL_FAM6_ATOM_AIRMONT_NP:
 360			set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC_S3);
 361			break;
 362		default:
 363			break;
 364		}
 365	}
 366
 367	/*
 368	 * There is a known erratum on Pentium III and Core Solo
 369	 * and Core Duo CPUs.
 370	 * " Page with PAT set to WC while associated MTRR is UC
 371	 *   may consolidate to UC "
 372	 * Because of this erratum, it is better to stick with
 373	 * setting WC in MTRR rather than using PAT on these CPUs.
 374	 *
 375	 * Enable PAT WC only on P4, Core 2 or later CPUs.
 376	 */
 377	if (c->x86 == 6 && c->x86_model < 15)
 378		clear_cpu_cap(c, X86_FEATURE_PAT);
 379
 380	/*
 381	 * If fast string is not enabled in IA32_MISC_ENABLE for any reason,
 382	 * clear the fast string and enhanced fast string CPU capabilities.
 383	 */
 384	if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
 385		rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
 386		if (!(misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING)) {
 387			pr_info("Disabled fast string operations\n");
 388			setup_clear_cpu_cap(X86_FEATURE_REP_GOOD);
 389			setup_clear_cpu_cap(X86_FEATURE_ERMS);
 390		}
 391	}
 392
 393	/*
 394	 * Intel Quark Core DevMan_001.pdf section 6.4.11
 395	 * "The operating system also is required to invalidate (i.e., flush)
 396	 *  the TLB when any changes are made to any of the page table entries.
 397	 *  The operating system must reload CR3 to cause the TLB to be flushed"
 398	 *
 399	 * As a result, boot_cpu_has(X86_FEATURE_PGE) in arch/x86/include/asm/tlbflush.h
 400	 * should be false so that __flush_tlb_all() causes CR3 instead of CR4.PGE
 401	 * to be modified.
 402	 */
 403	if (c->x86 == 5 && c->x86_model == 9) {
 404		pr_info("Disabling PGE capability bit\n");
 405		setup_clear_cpu_cap(X86_FEATURE_PGE);
 406	}
 407
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 408	check_memory_type_self_snoop_errata(c);
 409
 410	/*
 411	 * Adjust the number of physical bits early because it affects the
 412	 * valid bits of the MTRR mask registers.
 413	 */
 414	if (cpu_has(c, X86_FEATURE_TME))
 415		detect_tme_early(c);
 416}
 417
 418static void bsp_init_intel(struct cpuinfo_x86 *c)
 419{
 420	resctrl_cpu_detect(c);
 421}
 422
 423#ifdef CONFIG_X86_32
 424/*
 425 *	Early probe support logic for ppro memory erratum #50
 426 *
 427 *	This is called before we do cpu ident work
 428 */
 429
 430int ppro_with_ram_bug(void)
 431{
 432	/* Uses data from early_cpu_detect now */
 433	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
 434	    boot_cpu_data.x86 == 6 &&
 435	    boot_cpu_data.x86_model == 1 &&
 436	    boot_cpu_data.x86_stepping < 8) {
 437		pr_info("Pentium Pro with Errata#50 detected. Taking evasive action.\n");
 438		return 1;
 439	}
 440	return 0;
 441}
 442
 443static void intel_smp_check(struct cpuinfo_x86 *c)
 444{
 445	/* calling is from identify_secondary_cpu() ? */
 446	if (!c->cpu_index)
 447		return;
 448
 449	/*
 450	 * Mask B, Pentium, but not Pentium MMX
 451	 */
 452	if (c->x86 == 5 &&
 453	    c->x86_stepping >= 1 && c->x86_stepping <= 4 &&
 454	    c->x86_model <= 3) {
 455		/*
 456		 * Remember we have B step Pentia with bugs
 457		 */
 458		WARN_ONCE(1, "WARNING: SMP operation may be unreliable"
 459				    "with B stepping processors.\n");
 460	}
 461}
 462
 463static int forcepae;
 464static int __init forcepae_setup(char *__unused)
 465{
 466	forcepae = 1;
 467	return 1;
 468}
 469__setup("forcepae", forcepae_setup);
 470
 471static void intel_workarounds(struct cpuinfo_x86 *c)
 472{
 473#ifdef CONFIG_X86_F00F_BUG
 474	/*
 475	 * All models of Pentium and Pentium with MMX technology CPUs
 476	 * have the F0 0F bug, which lets nonprivileged users lock up the
 477	 * system. Announce that the fault handler will be checking for it.
 478	 * The Quark is also family 5, but does not have the same bug.
 479	 */
 480	clear_cpu_bug(c, X86_BUG_F00F);
 481	if (c->x86 == 5 && c->x86_model < 9) {
 482		static int f00f_workaround_enabled;
 483
 484		set_cpu_bug(c, X86_BUG_F00F);
 485		if (!f00f_workaround_enabled) {
 486			pr_notice("Intel Pentium with F0 0F bug - workaround enabled.\n");
 487			f00f_workaround_enabled = 1;
 488		}
 489	}
 490#endif
 491
 492	/*
 493	 * SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until
 494	 * model 3 mask 3
 495	 */
 496	if ((c->x86<<8 | c->x86_model<<4 | c->x86_stepping) < 0x633)
 497		clear_cpu_cap(c, X86_FEATURE_SEP);
 498
 499	/*
 500	 * PAE CPUID issue: many Pentium M report no PAE but may have a
 501	 * functionally usable PAE implementation.
 502	 * Forcefully enable PAE if kernel parameter "forcepae" is present.
 503	 */
 504	if (forcepae) {
 505		pr_warn("PAE forced!\n");
 506		set_cpu_cap(c, X86_FEATURE_PAE);
 507		add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_NOW_UNRELIABLE);
 508	}
 509
 510	/*
 511	 * P4 Xeon erratum 037 workaround.
 512	 * Hardware prefetcher may cause stale data to be loaded into the cache.
 513	 */
 514	if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_stepping == 1)) {
 515		if (msr_set_bit(MSR_IA32_MISC_ENABLE,
 516				MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE_BIT) > 0) {
 517			pr_info("CPU: C0 stepping P4 Xeon detected.\n");
 518			pr_info("CPU: Disabling hardware prefetching (Erratum 037)\n");
 519		}
 520	}
 521
 522	/*
 523	 * See if we have a good local APIC by checking for buggy Pentia,
 524	 * i.e. all B steppings and the C2 stepping of P54C when using their
 525	 * integrated APIC (see 11AP erratum in "Pentium Processor
 526	 * Specification Update").
 527	 */
 528	if (boot_cpu_has(X86_FEATURE_APIC) && (c->x86<<8 | c->x86_model<<4) == 0x520 &&
 529	    (c->x86_stepping < 0x6 || c->x86_stepping == 0xb))
 530		set_cpu_bug(c, X86_BUG_11AP);
 531
 532
 533#ifdef CONFIG_X86_INTEL_USERCOPY
 534	/*
 535	 * Set up the preferred alignment for movsl bulk memory moves
 536	 */
 537	switch (c->x86) {
 538	case 4:		/* 486: untested */
 539		break;
 540	case 5:		/* Old Pentia: untested */
 541		break;
 542	case 6:		/* PII/PIII only like movsl with 8-byte alignment */
 543		movsl_mask.mask = 7;
 544		break;
 545	case 15:	/* P4 is OK down to 8-byte alignment */
 546		movsl_mask.mask = 7;
 547		break;
 548	}
 549#endif
 550
 551	intel_smp_check(c);
 552}
 553#else
 554static void intel_workarounds(struct cpuinfo_x86 *c)
 555{
 556}
 557#endif
 558
 559static void srat_detect_node(struct cpuinfo_x86 *c)
 560{
 561#ifdef CONFIG_NUMA
 562	unsigned node;
 563	int cpu = smp_processor_id();
 564
 565	/* Don't do the funky fallback heuristics the AMD version employs
 566	   for now. */
 567	node = numa_cpu_node(cpu);
 568	if (node == NUMA_NO_NODE || !node_online(node)) {
 569		/* reuse the value from init_cpu_to_node() */
 570		node = cpu_to_node(cpu);
 571	}
 572	numa_set_node(cpu, node);
 573#endif
 574}
 575
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 576static void init_cpuid_fault(struct cpuinfo_x86 *c)
 577{
 578	u64 msr;
 579
 580	if (!rdmsrl_safe(MSR_PLATFORM_INFO, &msr)) {
 581		if (msr & MSR_PLATFORM_INFO_CPUID_FAULT)
 582			set_cpu_cap(c, X86_FEATURE_CPUID_FAULT);
 583	}
 584}
 585
 586static void init_intel_misc_features(struct cpuinfo_x86 *c)
 587{
 588	u64 msr;
 589
 590	if (rdmsrl_safe(MSR_MISC_FEATURES_ENABLES, &msr))
 591		return;
 592
 593	/* Clear all MISC features */
 594	this_cpu_write(msr_misc_features_shadow, 0);
 595
 596	/* Check features and update capabilities and shadow control bits */
 597	init_cpuid_fault(c);
 598	probe_xeon_phi_r3mwait(c);
 599
 600	msr = this_cpu_read(msr_misc_features_shadow);
 601	wrmsrl(MSR_MISC_FEATURES_ENABLES, msr);
 602}
 603
 604static void split_lock_init(void);
 605static void bus_lock_init(void);
 606
 607static void init_intel(struct cpuinfo_x86 *c)
 608{
 609	early_init_intel(c);
 610
 611	intel_workarounds(c);
 612
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 613	init_intel_cacheinfo(c);
 614
 615	if (c->cpuid_level > 9) {
 616		unsigned eax = cpuid_eax(10);
 617		/* Check for version and the number of counters */
 618		if ((eax & 0xff) && (((eax>>8) & 0xff) > 1))
 619			set_cpu_cap(c, X86_FEATURE_ARCH_PERFMON);
 620	}
 621
 622	if (cpu_has(c, X86_FEATURE_XMM2))
 623		set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
 624
 625	if (boot_cpu_has(X86_FEATURE_DS)) {
 626		unsigned int l1, l2;
 627
 628		rdmsr(MSR_IA32_MISC_ENABLE, l1, l2);
 629		if (!(l1 & MSR_IA32_MISC_ENABLE_BTS_UNAVAIL))
 630			set_cpu_cap(c, X86_FEATURE_BTS);
 631		if (!(l1 & MSR_IA32_MISC_ENABLE_PEBS_UNAVAIL))
 632			set_cpu_cap(c, X86_FEATURE_PEBS);
 633	}
 634
 635	if (c->x86 == 6 && boot_cpu_has(X86_FEATURE_CLFLUSH) &&
 636	    (c->x86_model == 29 || c->x86_model == 46 || c->x86_model == 47))
 637		set_cpu_bug(c, X86_BUG_CLFLUSH_MONITOR);
 638
 639	if (c->x86 == 6 && boot_cpu_has(X86_FEATURE_MWAIT) &&
 640		((c->x86_model == INTEL_FAM6_ATOM_GOLDMONT)))
 641		set_cpu_bug(c, X86_BUG_MONITOR);
 642
 643#ifdef CONFIG_X86_64
 644	if (c->x86 == 15)
 645		c->x86_cache_alignment = c->x86_clflush_size * 2;
 646	if (c->x86 == 6)
 647		set_cpu_cap(c, X86_FEATURE_REP_GOOD);
 648#else
 649	/*
 650	 * Names for the Pentium II/Celeron processors
 651	 * detectable only by also checking the cache size.
 652	 * Dixon is NOT a Celeron.
 653	 */
 654	if (c->x86 == 6) {
 655		unsigned int l2 = c->x86_cache_size;
 656		char *p = NULL;
 657
 658		switch (c->x86_model) {
 659		case 5:
 660			if (l2 == 0)
 661				p = "Celeron (Covington)";
 662			else if (l2 == 256)
 663				p = "Mobile Pentium II (Dixon)";
 664			break;
 665
 666		case 6:
 667			if (l2 == 128)
 668				p = "Celeron (Mendocino)";
 669			else if (c->x86_stepping == 0 || c->x86_stepping == 5)
 670				p = "Celeron-A";
 671			break;
 672
 673		case 8:
 674			if (l2 == 128)
 675				p = "Celeron (Coppermine)";
 676			break;
 677		}
 678
 679		if (p)
 680			strcpy(c->x86_model_id, p);
 681	}
 682
 683	if (c->x86 == 15)
 684		set_cpu_cap(c, X86_FEATURE_P4);
 685	if (c->x86 == 6)
 686		set_cpu_cap(c, X86_FEATURE_P3);
 687#endif
 688
 689	/* Work around errata */
 690	srat_detect_node(c);
 691
 692	init_ia32_feat_ctl(c);
 
 
 
 
 693
 694	init_intel_misc_features(c);
 695
 696	split_lock_init();
 697	bus_lock_init();
 698
 699	intel_init_thermal(c);
 700}
 701
 702#ifdef CONFIG_X86_32
 703static unsigned int intel_size_cache(struct cpuinfo_x86 *c, unsigned int size)
 704{
 705	/*
 706	 * Intel PIII Tualatin. This comes in two flavours.
 707	 * One has 256kb of cache, the other 512. We have no way
 708	 * to determine which, so we use a boottime override
 709	 * for the 512kb model, and assume 256 otherwise.
 710	 */
 711	if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
 712		size = 256;
 713
 714	/*
 715	 * Intel Quark SoC X1000 contains a 4-way set associative
 716	 * 16K cache with a 16 byte cache line and 256 lines per tag
 717	 */
 718	if ((c->x86 == 5) && (c->x86_model == 9))
 719		size = 16;
 720	return size;
 721}
 722#endif
 723
 724#define TLB_INST_4K	0x01
 725#define TLB_INST_4M	0x02
 726#define TLB_INST_2M_4M	0x03
 727
 728#define TLB_INST_ALL	0x05
 729#define TLB_INST_1G	0x06
 730
 731#define TLB_DATA_4K	0x11
 732#define TLB_DATA_4M	0x12
 733#define TLB_DATA_2M_4M	0x13
 734#define TLB_DATA_4K_4M	0x14
 735
 736#define TLB_DATA_1G	0x16
 737
 738#define TLB_DATA0_4K	0x21
 739#define TLB_DATA0_4M	0x22
 740#define TLB_DATA0_2M_4M	0x23
 741
 742#define STLB_4K		0x41
 743#define STLB_4K_2M	0x42
 744
 745static const struct _tlb_table intel_tlb_table[] = {
 746	{ 0x01, TLB_INST_4K,		32,	" TLB_INST 4 KByte pages, 4-way set associative" },
 747	{ 0x02, TLB_INST_4M,		2,	" TLB_INST 4 MByte pages, full associative" },
 748	{ 0x03, TLB_DATA_4K,		64,	" TLB_DATA 4 KByte pages, 4-way set associative" },
 749	{ 0x04, TLB_DATA_4M,		8,	" TLB_DATA 4 MByte pages, 4-way set associative" },
 750	{ 0x05, TLB_DATA_4M,		32,	" TLB_DATA 4 MByte pages, 4-way set associative" },
 751	{ 0x0b, TLB_INST_4M,		4,	" TLB_INST 4 MByte pages, 4-way set associative" },
 752	{ 0x4f, TLB_INST_4K,		32,	" TLB_INST 4 KByte pages" },
 753	{ 0x50, TLB_INST_ALL,		64,	" TLB_INST 4 KByte and 2-MByte or 4-MByte pages" },
 754	{ 0x51, TLB_INST_ALL,		128,	" TLB_INST 4 KByte and 2-MByte or 4-MByte pages" },
 755	{ 0x52, TLB_INST_ALL,		256,	" TLB_INST 4 KByte and 2-MByte or 4-MByte pages" },
 756	{ 0x55, TLB_INST_2M_4M,		7,	" TLB_INST 2-MByte or 4-MByte pages, fully associative" },
 757	{ 0x56, TLB_DATA0_4M,		16,	" TLB_DATA0 4 MByte pages, 4-way set associative" },
 758	{ 0x57, TLB_DATA0_4K,		16,	" TLB_DATA0 4 KByte pages, 4-way associative" },
 759	{ 0x59, TLB_DATA0_4K,		16,	" TLB_DATA0 4 KByte pages, fully associative" },
 760	{ 0x5a, TLB_DATA0_2M_4M,	32,	" TLB_DATA0 2-MByte or 4 MByte pages, 4-way set associative" },
 761	{ 0x5b, TLB_DATA_4K_4M,		64,	" TLB_DATA 4 KByte and 4 MByte pages" },
 762	{ 0x5c, TLB_DATA_4K_4M,		128,	" TLB_DATA 4 KByte and 4 MByte pages" },
 763	{ 0x5d, TLB_DATA_4K_4M,		256,	" TLB_DATA 4 KByte and 4 MByte pages" },
 764	{ 0x61, TLB_INST_4K,		48,	" TLB_INST 4 KByte pages, full associative" },
 765	{ 0x63, TLB_DATA_1G,		4,	" TLB_DATA 1 GByte pages, 4-way set associative" },
 766	{ 0x6b, TLB_DATA_4K,		256,	" TLB_DATA 4 KByte pages, 8-way associative" },
 767	{ 0x6c, TLB_DATA_2M_4M,		128,	" TLB_DATA 2 MByte or 4 MByte pages, 8-way associative" },
 768	{ 0x6d, TLB_DATA_1G,		16,	" TLB_DATA 1 GByte pages, fully associative" },
 769	{ 0x76, TLB_INST_2M_4M,		8,	" TLB_INST 2-MByte or 4-MByte pages, fully associative" },
 770	{ 0xb0, TLB_INST_4K,		128,	" TLB_INST 4 KByte pages, 4-way set associative" },
 771	{ 0xb1, TLB_INST_2M_4M,		4,	" TLB_INST 2M pages, 4-way, 8 entries or 4M pages, 4-way entries" },
 772	{ 0xb2, TLB_INST_4K,		64,	" TLB_INST 4KByte pages, 4-way set associative" },
 773	{ 0xb3, TLB_DATA_4K,		128,	" TLB_DATA 4 KByte pages, 4-way set associative" },
 774	{ 0xb4, TLB_DATA_4K,		256,	" TLB_DATA 4 KByte pages, 4-way associative" },
 775	{ 0xb5, TLB_INST_4K,		64,	" TLB_INST 4 KByte pages, 8-way set associative" },
 776	{ 0xb6, TLB_INST_4K,		128,	" TLB_INST 4 KByte pages, 8-way set associative" },
 777	{ 0xba, TLB_DATA_4K,		64,	" TLB_DATA 4 KByte pages, 4-way associative" },
 778	{ 0xc0, TLB_DATA_4K_4M,		8,	" TLB_DATA 4 KByte and 4 MByte pages, 4-way associative" },
 779	{ 0xc1, STLB_4K_2M,		1024,	" STLB 4 KByte and 2 MByte pages, 8-way associative" },
 780	{ 0xc2, TLB_DATA_2M_4M,		16,	" TLB_DATA 2 MByte/4MByte pages, 4-way associative" },
 781	{ 0xca, STLB_4K,		512,	" STLB 4 KByte pages, 4-way associative" },
 782	{ 0x00, 0, 0 }
 783};
 784
 785static void intel_tlb_lookup(const unsigned char desc)
 786{
 787	unsigned char k;
 788	if (desc == 0)
 789		return;
 790
 791	/* look up this descriptor in the table */
 792	for (k = 0; intel_tlb_table[k].descriptor != desc &&
 793	     intel_tlb_table[k].descriptor != 0; k++)
 794		;
 795
 796	if (intel_tlb_table[k].tlb_type == 0)
 797		return;
 798
 799	switch (intel_tlb_table[k].tlb_type) {
 800	case STLB_4K:
 801		if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
 802			tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
 803		if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
 804			tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
 805		break;
 806	case STLB_4K_2M:
 807		if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
 808			tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
 809		if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
 810			tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
 811		if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries)
 812			tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries;
 813		if (tlb_lld_2m[ENTRIES] < intel_tlb_table[k].entries)
 814			tlb_lld_2m[ENTRIES] = intel_tlb_table[k].entries;
 815		if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
 816			tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
 817		if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
 818			tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
 819		break;
 820	case TLB_INST_ALL:
 821		if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
 822			tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
 823		if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries)
 824			tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries;
 825		if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
 826			tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
 827		break;
 828	case TLB_INST_4K:
 829		if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
 830			tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
 831		break;
 832	case TLB_INST_4M:
 833		if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
 834			tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
 835		break;
 836	case TLB_INST_2M_4M:
 837		if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries)
 838			tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries;
 839		if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
 840			tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
 841		break;
 842	case TLB_DATA_4K:
 843	case TLB_DATA0_4K:
 844		if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
 845			tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
 846		break;
 847	case TLB_DATA_4M:
 848	case TLB_DATA0_4M:
 849		if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
 850			tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
 851		break;
 852	case TLB_DATA_2M_4M:
 853	case TLB_DATA0_2M_4M:
 854		if (tlb_lld_2m[ENTRIES] < intel_tlb_table[k].entries)
 855			tlb_lld_2m[ENTRIES] = intel_tlb_table[k].entries;
 856		if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
 857			tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
 858		break;
 859	case TLB_DATA_4K_4M:
 860		if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
 861			tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
 862		if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
 863			tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
 864		break;
 865	case TLB_DATA_1G:
 866		if (tlb_lld_1g[ENTRIES] < intel_tlb_table[k].entries)
 867			tlb_lld_1g[ENTRIES] = intel_tlb_table[k].entries;
 868		break;
 869	}
 870}
 871
 872static void intel_detect_tlb(struct cpuinfo_x86 *c)
 873{
 874	int i, j, n;
 875	unsigned int regs[4];
 876	unsigned char *desc = (unsigned char *)regs;
 877
 878	if (c->cpuid_level < 2)
 879		return;
 880
 881	/* Number of times to iterate */
 882	n = cpuid_eax(2) & 0xFF;
 883
 884	for (i = 0 ; i < n ; i++) {
 885		cpuid(2, &regs[0], &regs[1], &regs[2], &regs[3]);
 886
 887		/* If bit 31 is set, this is an unknown format */
 888		for (j = 0 ; j < 3 ; j++)
 889			if (regs[j] & (1 << 31))
 890				regs[j] = 0;
 891
 892		/* Byte 0 is level count, not a descriptor */
 893		for (j = 1 ; j < 16 ; j++)
 894			intel_tlb_lookup(desc[j]);
 895	}
 896}
 897
 898static const struct cpu_dev intel_cpu_dev = {
 899	.c_vendor	= "Intel",
 900	.c_ident	= { "GenuineIntel" },
 901#ifdef CONFIG_X86_32
 902	.legacy_models = {
 903		{ .family = 4, .model_names =
 904		  {
 905			  [0] = "486 DX-25/33",
 906			  [1] = "486 DX-50",
 907			  [2] = "486 SX",
 908			  [3] = "486 DX/2",
 909			  [4] = "486 SL",
 910			  [5] = "486 SX/2",
 911			  [7] = "486 DX/2-WB",
 912			  [8] = "486 DX/4",
 913			  [9] = "486 DX/4-WB"
 914		  }
 915		},
 916		{ .family = 5, .model_names =
 917		  {
 918			  [0] = "Pentium 60/66 A-step",
 919			  [1] = "Pentium 60/66",
 920			  [2] = "Pentium 75 - 200",
 921			  [3] = "OverDrive PODP5V83",
 922			  [4] = "Pentium MMX",
 923			  [7] = "Mobile Pentium 75 - 200",
 924			  [8] = "Mobile Pentium MMX",
 925			  [9] = "Quark SoC X1000",
 926		  }
 927		},
 928		{ .family = 6, .model_names =
 929		  {
 930			  [0] = "Pentium Pro A-step",
 931			  [1] = "Pentium Pro",
 932			  [3] = "Pentium II (Klamath)",
 933			  [4] = "Pentium II (Deschutes)",
 934			  [5] = "Pentium II (Deschutes)",
 935			  [6] = "Mobile Pentium II",
 936			  [7] = "Pentium III (Katmai)",
 937			  [8] = "Pentium III (Coppermine)",
 938			  [10] = "Pentium III (Cascades)",
 939			  [11] = "Pentium III (Tualatin)",
 940		  }
 941		},
 942		{ .family = 15, .model_names =
 943		  {
 944			  [0] = "Pentium 4 (Unknown)",
 945			  [1] = "Pentium 4 (Willamette)",
 946			  [2] = "Pentium 4 (Northwood)",
 947			  [4] = "Pentium 4 (Foster)",
 948			  [5] = "Pentium 4 (Foster)",
 949		  }
 950		},
 951	},
 952	.legacy_cache_size = intel_size_cache,
 953#endif
 954	.c_detect_tlb	= intel_detect_tlb,
 955	.c_early_init   = early_init_intel,
 956	.c_bsp_init	= bsp_init_intel,
 957	.c_init		= init_intel,
 958	.c_x86_vendor	= X86_VENDOR_INTEL,
 959};
 960
 961cpu_dev_register(intel_cpu_dev);
 962
 963#undef pr_fmt
 964#define pr_fmt(fmt) "x86/split lock detection: " fmt
 965
 966static const struct {
 967	const char			*option;
 968	enum split_lock_detect_state	state;
 969} sld_options[] __initconst = {
 970	{ "off",	sld_off   },
 971	{ "warn",	sld_warn  },
 972	{ "fatal",	sld_fatal },
 973	{ "ratelimit:", sld_ratelimit },
 974};
 975
 976static struct ratelimit_state bld_ratelimit;
 977
 978static unsigned int sysctl_sld_mitigate = 1;
 979static DEFINE_SEMAPHORE(buslock_sem, 1);
 980
 981#ifdef CONFIG_PROC_SYSCTL
 982static struct ctl_table sld_sysctls[] = {
 983	{
 984		.procname       = "split_lock_mitigate",
 985		.data           = &sysctl_sld_mitigate,
 986		.maxlen         = sizeof(unsigned int),
 987		.mode           = 0644,
 988		.proc_handler	= proc_douintvec_minmax,
 989		.extra1         = SYSCTL_ZERO,
 990		.extra2         = SYSCTL_ONE,
 991	},
 992};
 993
 994static int __init sld_mitigate_sysctl_init(void)
 995{
 996	register_sysctl_init("kernel", sld_sysctls);
 997	return 0;
 998}
 999
1000late_initcall(sld_mitigate_sysctl_init);
1001#endif
1002
1003static inline bool match_option(const char *arg, int arglen, const char *opt)
1004{
1005	int len = strlen(opt), ratelimit;
1006
1007	if (strncmp(arg, opt, len))
1008		return false;
1009
1010	/*
1011	 * Min ratelimit is 1 bus lock/sec.
1012	 * Max ratelimit is 1000 bus locks/sec.
1013	 */
1014	if (sscanf(arg, "ratelimit:%d", &ratelimit) == 1 &&
1015	    ratelimit > 0 && ratelimit <= 1000) {
1016		ratelimit_state_init(&bld_ratelimit, HZ, ratelimit);
1017		ratelimit_set_flags(&bld_ratelimit, RATELIMIT_MSG_ON_RELEASE);
1018		return true;
1019	}
1020
1021	return len == arglen;
1022}
1023
1024static bool split_lock_verify_msr(bool on)
1025{
1026	u64 ctrl, tmp;
1027
1028	if (rdmsrl_safe(MSR_TEST_CTRL, &ctrl))
1029		return false;
1030	if (on)
1031		ctrl |= MSR_TEST_CTRL_SPLIT_LOCK_DETECT;
1032	else
1033		ctrl &= ~MSR_TEST_CTRL_SPLIT_LOCK_DETECT;
1034	if (wrmsrl_safe(MSR_TEST_CTRL, ctrl))
1035		return false;
1036	rdmsrl(MSR_TEST_CTRL, tmp);
1037	return ctrl == tmp;
1038}
1039
1040static void __init sld_state_setup(void)
1041{
1042	enum split_lock_detect_state state = sld_warn;
1043	char arg[20];
1044	int i, ret;
1045
1046	if (!boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT) &&
1047	    !boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT))
1048		return;
1049
1050	ret = cmdline_find_option(boot_command_line, "split_lock_detect",
1051				  arg, sizeof(arg));
1052	if (ret >= 0) {
1053		for (i = 0; i < ARRAY_SIZE(sld_options); i++) {
1054			if (match_option(arg, ret, sld_options[i].option)) {
1055				state = sld_options[i].state;
1056				break;
1057			}
1058		}
1059	}
1060	sld_state = state;
1061}
1062
1063static void __init __split_lock_setup(void)
1064{
1065	if (!split_lock_verify_msr(false)) {
1066		pr_info("MSR access failed: Disabled\n");
1067		return;
1068	}
1069
1070	rdmsrl(MSR_TEST_CTRL, msr_test_ctrl_cache);
1071
1072	if (!split_lock_verify_msr(true)) {
1073		pr_info("MSR access failed: Disabled\n");
1074		return;
1075	}
1076
1077	/* Restore the MSR to its cached value. */
1078	wrmsrl(MSR_TEST_CTRL, msr_test_ctrl_cache);
1079
1080	setup_force_cpu_cap(X86_FEATURE_SPLIT_LOCK_DETECT);
1081}
1082
1083/*
1084 * MSR_TEST_CTRL is per core, but we treat it like a per CPU MSR. Locking
1085 * is not implemented as one thread could undo the setting of the other
1086 * thread immediately after dropping the lock anyway.
1087 */
1088static void sld_update_msr(bool on)
1089{
1090	u64 test_ctrl_val = msr_test_ctrl_cache;
1091
1092	if (on)
1093		test_ctrl_val |= MSR_TEST_CTRL_SPLIT_LOCK_DETECT;
1094
1095	wrmsrl(MSR_TEST_CTRL, test_ctrl_val);
1096}
1097
1098static void split_lock_init(void)
1099{
1100	/*
1101	 * #DB for bus lock handles ratelimit and #AC for split lock is
1102	 * disabled.
1103	 */
1104	if (sld_state == sld_ratelimit) {
1105		split_lock_verify_msr(false);
1106		return;
1107	}
1108
1109	if (cpu_model_supports_sld)
1110		split_lock_verify_msr(sld_state != sld_off);
1111}
1112
1113static void __split_lock_reenable_unlock(struct work_struct *work)
1114{
1115	sld_update_msr(true);
1116	up(&buslock_sem);
1117}
1118
1119static DECLARE_DELAYED_WORK(sl_reenable_unlock, __split_lock_reenable_unlock);
1120
1121static void __split_lock_reenable(struct work_struct *work)
1122{
1123	sld_update_msr(true);
1124}
1125static DECLARE_DELAYED_WORK(sl_reenable, __split_lock_reenable);
1126
1127/*
1128 * If a CPU goes offline with pending delayed work to re-enable split lock
1129 * detection then the delayed work will be executed on some other CPU. That
1130 * handles releasing the buslock_sem, but because it executes on a
1131 * different CPU probably won't re-enable split lock detection. This is a
1132 * problem on HT systems since the sibling CPU on the same core may then be
1133 * left running with split lock detection disabled.
1134 *
1135 * Unconditionally re-enable detection here.
1136 */
1137static int splitlock_cpu_offline(unsigned int cpu)
1138{
1139	sld_update_msr(true);
1140
1141	return 0;
1142}
1143
1144static void split_lock_warn(unsigned long ip)
1145{
1146	struct delayed_work *work;
1147	int cpu;
1148
1149	if (!current->reported_split_lock)
1150		pr_warn_ratelimited("#AC: %s/%d took a split_lock trap at address: 0x%lx\n",
1151				    current->comm, current->pid, ip);
1152	current->reported_split_lock = 1;
1153
1154	if (sysctl_sld_mitigate) {
1155		/*
1156		 * misery factor #1:
1157		 * sleep 10ms before trying to execute split lock.
1158		 */
1159		if (msleep_interruptible(10) > 0)
1160			return;
1161		/*
1162		 * Misery factor #2:
1163		 * only allow one buslocked disabled core at a time.
1164		 */
1165		if (down_interruptible(&buslock_sem) == -EINTR)
1166			return;
1167		work = &sl_reenable_unlock;
1168	} else {
1169		work = &sl_reenable;
1170	}
1171
1172	cpu = get_cpu();
1173	schedule_delayed_work_on(cpu, work, 2);
1174
1175	/* Disable split lock detection on this CPU to make progress */
1176	sld_update_msr(false);
1177	put_cpu();
1178}
1179
1180bool handle_guest_split_lock(unsigned long ip)
1181{
1182	if (sld_state == sld_warn) {
1183		split_lock_warn(ip);
1184		return true;
1185	}
1186
1187	pr_warn_once("#AC: %s/%d %s split_lock trap at address: 0x%lx\n",
1188		     current->comm, current->pid,
1189		     sld_state == sld_fatal ? "fatal" : "bogus", ip);
1190
1191	current->thread.error_code = 0;
1192	current->thread.trap_nr = X86_TRAP_AC;
1193	force_sig_fault(SIGBUS, BUS_ADRALN, NULL);
1194	return false;
1195}
1196EXPORT_SYMBOL_GPL(handle_guest_split_lock);
1197
1198static void bus_lock_init(void)
1199{
1200	u64 val;
1201
1202	if (!boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT))
1203		return;
1204
1205	rdmsrl(MSR_IA32_DEBUGCTLMSR, val);
1206
1207	if ((boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT) &&
1208	    (sld_state == sld_warn || sld_state == sld_fatal)) ||
1209	    sld_state == sld_off) {
1210		/*
1211		 * Warn and fatal are handled by #AC for split lock if #AC for
1212		 * split lock is supported.
1213		 */
1214		val &= ~DEBUGCTLMSR_BUS_LOCK_DETECT;
1215	} else {
1216		val |= DEBUGCTLMSR_BUS_LOCK_DETECT;
1217	}
1218
1219	wrmsrl(MSR_IA32_DEBUGCTLMSR, val);
1220}
1221
1222bool handle_user_split_lock(struct pt_regs *regs, long error_code)
1223{
1224	if ((regs->flags & X86_EFLAGS_AC) || sld_state == sld_fatal)
1225		return false;
1226	split_lock_warn(regs->ip);
1227	return true;
1228}
1229
1230void handle_bus_lock(struct pt_regs *regs)
1231{
1232	switch (sld_state) {
1233	case sld_off:
1234		break;
1235	case sld_ratelimit:
1236		/* Enforce no more than bld_ratelimit bus locks/sec. */
1237		while (!__ratelimit(&bld_ratelimit))
1238			msleep(20);
1239		/* Warn on the bus lock. */
1240		fallthrough;
1241	case sld_warn:
1242		pr_warn_ratelimited("#DB: %s/%d took a bus_lock trap at address: 0x%lx\n",
1243				    current->comm, current->pid, regs->ip);
1244		break;
1245	case sld_fatal:
1246		force_sig_fault(SIGBUS, BUS_ADRALN, NULL);
1247		break;
1248	}
1249}
1250
1251/*
1252 * CPU models that are known to have the per-core split-lock detection
1253 * feature even though they do not enumerate IA32_CORE_CAPABILITIES.
1254 */
1255static const struct x86_cpu_id split_lock_cpu_ids[] __initconst = {
1256	X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_X,	0),
1257	X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_L,	0),
1258	X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_D,	0),
1259	{}
1260};
1261
1262static void __init split_lock_setup(struct cpuinfo_x86 *c)
1263{
1264	const struct x86_cpu_id *m;
1265	u64 ia32_core_caps;
1266
1267	if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
1268		return;
1269
1270	/* Check for CPUs that have support but do not enumerate it: */
1271	m = x86_match_cpu(split_lock_cpu_ids);
1272	if (m)
1273		goto supported;
1274
1275	if (!cpu_has(c, X86_FEATURE_CORE_CAPABILITIES))
1276		return;
1277
1278	/*
1279	 * Not all bits in MSR_IA32_CORE_CAPS are architectural, but
1280	 * MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT is.  All CPUs that set
1281	 * it have split lock detection.
1282	 */
1283	rdmsrl(MSR_IA32_CORE_CAPS, ia32_core_caps);
1284	if (ia32_core_caps & MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT)
1285		goto supported;
1286
1287	/* CPU is not in the model list and does not have the MSR bit: */
1288	return;
1289
1290supported:
1291	cpu_model_supports_sld = true;
1292	__split_lock_setup();
1293}
1294
1295static void sld_state_show(void)
1296{
1297	if (!boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT) &&
1298	    !boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT))
1299		return;
1300
1301	switch (sld_state) {
1302	case sld_off:
1303		pr_info("disabled\n");
1304		break;
1305	case sld_warn:
1306		if (boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) {
1307			pr_info("#AC: crashing the kernel on kernel split_locks and warning on user-space split_locks\n");
1308			if (cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
1309					      "x86/splitlock", NULL, splitlock_cpu_offline) < 0)
1310				pr_warn("No splitlock CPU offline handler\n");
1311		} else if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) {
1312			pr_info("#DB: warning on user-space bus_locks\n");
1313		}
1314		break;
1315	case sld_fatal:
1316		if (boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) {
1317			pr_info("#AC: crashing the kernel on kernel split_locks and sending SIGBUS on user-space split_locks\n");
1318		} else if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) {
1319			pr_info("#DB: sending SIGBUS on user-space bus_locks%s\n",
1320				boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT) ?
1321				" from non-WB" : "");
1322		}
1323		break;
1324	case sld_ratelimit:
1325		if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT))
1326			pr_info("#DB: setting system wide bus lock rate limit to %u/sec\n", bld_ratelimit.burst);
1327		break;
1328	}
1329}
1330
1331void __init sld_setup(struct cpuinfo_x86 *c)
1332{
1333	split_lock_setup(c);
1334	sld_state_setup();
1335	sld_state_show();
1336}
1337
1338#define X86_HYBRID_CPU_TYPE_ID_SHIFT	24
1339
1340/**
1341 * get_this_hybrid_cpu_type() - Get the type of this hybrid CPU
1342 *
1343 * Returns the CPU type [31:24] (i.e., Atom or Core) of a CPU in
1344 * a hybrid processor. If the processor is not hybrid, returns 0.
1345 */
1346u8 get_this_hybrid_cpu_type(void)
1347{
1348	if (!cpu_feature_enabled(X86_FEATURE_HYBRID_CPU))
1349		return 0;
1350
1351	return cpuid_eax(0x0000001a) >> X86_HYBRID_CPU_TYPE_ID_SHIFT;
1352}