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v4.17
   1#include <linux/bootmem.h>
   2#include <linux/linkage.h>
   3#include <linux/bitops.h>
   4#include <linux/kernel.h>
   5#include <linux/export.h>
   6#include <linux/percpu.h>
   7#include <linux/string.h>
   8#include <linux/ctype.h>
   9#include <linux/delay.h>
  10#include <linux/sched/mm.h>
  11#include <linux/sched/clock.h>
  12#include <linux/sched/task.h>
  13#include <linux/init.h>
  14#include <linux/kprobes.h>
  15#include <linux/kgdb.h>
  16#include <linux/smp.h>
  17#include <linux/io.h>
  18#include <linux/syscore_ops.h>
  19
  20#include <asm/stackprotector.h>
  21#include <asm/perf_event.h>
  22#include <asm/mmu_context.h>
  23#include <asm/archrandom.h>
  24#include <asm/hypervisor.h>
  25#include <asm/processor.h>
  26#include <asm/tlbflush.h>
  27#include <asm/debugreg.h>
  28#include <asm/sections.h>
  29#include <asm/vsyscall.h>
  30#include <linux/topology.h>
  31#include <linux/cpumask.h>
  32#include <asm/pgtable.h>
  33#include <linux/atomic.h>
  34#include <asm/proto.h>
  35#include <asm/setup.h>
  36#include <asm/apic.h>
  37#include <asm/desc.h>
  38#include <asm/fpu/internal.h>
  39#include <asm/mtrr.h>
  40#include <asm/hwcap2.h>
  41#include <linux/numa.h>
  42#include <asm/asm.h>
  43#include <asm/bugs.h>
  44#include <asm/cpu.h>
  45#include <asm/mce.h>
  46#include <asm/msr.h>
  47#include <asm/pat.h>
  48#include <asm/microcode.h>
  49#include <asm/microcode_intel.h>
  50#include <asm/intel-family.h>
  51#include <asm/cpu_device_id.h>
  52
  53#ifdef CONFIG_X86_LOCAL_APIC
  54#include <asm/uv/uv.h>
  55#endif
  56
  57#include "cpu.h"
  58
  59u32 elf_hwcap2 __read_mostly;
  60
  61/* all of these masks are initialized in setup_cpu_local_masks() */
  62cpumask_var_t cpu_initialized_mask;
  63cpumask_var_t cpu_callout_mask;
  64cpumask_var_t cpu_callin_mask;
  65
  66/* representing cpus for which sibling maps can be computed */
  67cpumask_var_t cpu_sibling_setup_mask;
  68
  69/* correctly size the local cpu masks */
  70void __init setup_cpu_local_masks(void)
  71{
  72	alloc_bootmem_cpumask_var(&cpu_initialized_mask);
  73	alloc_bootmem_cpumask_var(&cpu_callin_mask);
  74	alloc_bootmem_cpumask_var(&cpu_callout_mask);
  75	alloc_bootmem_cpumask_var(&cpu_sibling_setup_mask);
  76}
  77
  78static void default_init(struct cpuinfo_x86 *c)
  79{
  80#ifdef CONFIG_X86_64
  81	cpu_detect_cache_sizes(c);
  82#else
  83	/* Not much we can do here... */
  84	/* Check if at least it has cpuid */
  85	if (c->cpuid_level == -1) {
  86		/* No cpuid. It must be an ancient CPU */
  87		if (c->x86 == 4)
  88			strcpy(c->x86_model_id, "486");
  89		else if (c->x86 == 3)
  90			strcpy(c->x86_model_id, "386");
  91	}
  92#endif
  93}
  94
  95static const struct cpu_dev default_cpu = {
  96	.c_init		= default_init,
  97	.c_vendor	= "Unknown",
  98	.c_x86_vendor	= X86_VENDOR_UNKNOWN,
  99};
 100
 101static const struct cpu_dev *this_cpu = &default_cpu;
 102
 103DEFINE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page) = { .gdt = {
 104#ifdef CONFIG_X86_64
 105	/*
 106	 * We need valid kernel segments for data and code in long mode too
 107	 * IRET will check the segment types  kkeil 2000/10/28
 108	 * Also sysret mandates a special GDT layout
 109	 *
 110	 * TLS descriptors are currently at a different place compared to i386.
 111	 * Hopefully nobody expects them at a fixed place (Wine?)
 112	 */
 113	[GDT_ENTRY_KERNEL32_CS]		= GDT_ENTRY_INIT(0xc09b, 0, 0xfffff),
 114	[GDT_ENTRY_KERNEL_CS]		= GDT_ENTRY_INIT(0xa09b, 0, 0xfffff),
 115	[GDT_ENTRY_KERNEL_DS]		= GDT_ENTRY_INIT(0xc093, 0, 0xfffff),
 116	[GDT_ENTRY_DEFAULT_USER32_CS]	= GDT_ENTRY_INIT(0xc0fb, 0, 0xfffff),
 117	[GDT_ENTRY_DEFAULT_USER_DS]	= GDT_ENTRY_INIT(0xc0f3, 0, 0xfffff),
 118	[GDT_ENTRY_DEFAULT_USER_CS]	= GDT_ENTRY_INIT(0xa0fb, 0, 0xfffff),
 119#else
 120	[GDT_ENTRY_KERNEL_CS]		= GDT_ENTRY_INIT(0xc09a, 0, 0xfffff),
 121	[GDT_ENTRY_KERNEL_DS]		= GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
 122	[GDT_ENTRY_DEFAULT_USER_CS]	= GDT_ENTRY_INIT(0xc0fa, 0, 0xfffff),
 123	[GDT_ENTRY_DEFAULT_USER_DS]	= GDT_ENTRY_INIT(0xc0f2, 0, 0xfffff),
 124	/*
 125	 * Segments used for calling PnP BIOS have byte granularity.
 126	 * They code segments and data segments have fixed 64k limits,
 127	 * the transfer segment sizes are set at run time.
 128	 */
 129	/* 32-bit code */
 130	[GDT_ENTRY_PNPBIOS_CS32]	= GDT_ENTRY_INIT(0x409a, 0, 0xffff),
 131	/* 16-bit code */
 132	[GDT_ENTRY_PNPBIOS_CS16]	= GDT_ENTRY_INIT(0x009a, 0, 0xffff),
 133	/* 16-bit data */
 134	[GDT_ENTRY_PNPBIOS_DS]		= GDT_ENTRY_INIT(0x0092, 0, 0xffff),
 135	/* 16-bit data */
 136	[GDT_ENTRY_PNPBIOS_TS1]		= GDT_ENTRY_INIT(0x0092, 0, 0),
 137	/* 16-bit data */
 138	[GDT_ENTRY_PNPBIOS_TS2]		= GDT_ENTRY_INIT(0x0092, 0, 0),
 139	/*
 140	 * The APM segments have byte granularity and their bases
 141	 * are set at run time.  All have 64k limits.
 142	 */
 143	/* 32-bit code */
 144	[GDT_ENTRY_APMBIOS_BASE]	= GDT_ENTRY_INIT(0x409a, 0, 0xffff),
 145	/* 16-bit code */
 146	[GDT_ENTRY_APMBIOS_BASE+1]	= GDT_ENTRY_INIT(0x009a, 0, 0xffff),
 147	/* data */
 148	[GDT_ENTRY_APMBIOS_BASE+2]	= GDT_ENTRY_INIT(0x4092, 0, 0xffff),
 149
 150	[GDT_ENTRY_ESPFIX_SS]		= GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
 151	[GDT_ENTRY_PERCPU]		= GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
 152	GDT_STACK_CANARY_INIT
 153#endif
 154} };
 155EXPORT_PER_CPU_SYMBOL_GPL(gdt_page);
 156
 157static int __init x86_mpx_setup(char *s)
 158{
 159	/* require an exact match without trailing characters */
 160	if (strlen(s))
 161		return 0;
 162
 163	/* do not emit a message if the feature is not present */
 164	if (!boot_cpu_has(X86_FEATURE_MPX))
 165		return 1;
 166
 167	setup_clear_cpu_cap(X86_FEATURE_MPX);
 168	pr_info("nompx: Intel Memory Protection Extensions (MPX) disabled\n");
 169	return 1;
 170}
 171__setup("nompx", x86_mpx_setup);
 172
 173#ifdef CONFIG_X86_64
 174static int __init x86_nopcid_setup(char *s)
 175{
 176	/* nopcid doesn't accept parameters */
 177	if (s)
 178		return -EINVAL;
 179
 180	/* do not emit a message if the feature is not present */
 181	if (!boot_cpu_has(X86_FEATURE_PCID))
 182		return 0;
 183
 184	setup_clear_cpu_cap(X86_FEATURE_PCID);
 185	pr_info("nopcid: PCID feature disabled\n");
 186	return 0;
 187}
 188early_param("nopcid", x86_nopcid_setup);
 189#endif
 190
 191static int __init x86_noinvpcid_setup(char *s)
 192{
 193	/* noinvpcid doesn't accept parameters */
 194	if (s)
 195		return -EINVAL;
 196
 197	/* do not emit a message if the feature is not present */
 198	if (!boot_cpu_has(X86_FEATURE_INVPCID))
 199		return 0;
 200
 201	setup_clear_cpu_cap(X86_FEATURE_INVPCID);
 202	pr_info("noinvpcid: INVPCID feature disabled\n");
 203	return 0;
 204}
 205early_param("noinvpcid", x86_noinvpcid_setup);
 206
 207#ifdef CONFIG_X86_32
 208static int cachesize_override = -1;
 209static int disable_x86_serial_nr = 1;
 210
 211static int __init cachesize_setup(char *str)
 212{
 213	get_option(&str, &cachesize_override);
 214	return 1;
 215}
 216__setup("cachesize=", cachesize_setup);
 217
 
 
 
 
 
 
 
 
 218static int __init x86_sep_setup(char *s)
 219{
 220	setup_clear_cpu_cap(X86_FEATURE_SEP);
 221	return 1;
 222}
 223__setup("nosep", x86_sep_setup);
 224
 225/* Standard macro to see if a specific flag is changeable */
 226static inline int flag_is_changeable_p(u32 flag)
 227{
 228	u32 f1, f2;
 229
 230	/*
 231	 * Cyrix and IDT cpus allow disabling of CPUID
 232	 * so the code below may return different results
 233	 * when it is executed before and after enabling
 234	 * the CPUID. Add "volatile" to not allow gcc to
 235	 * optimize the subsequent calls to this function.
 236	 */
 237	asm volatile ("pushfl		\n\t"
 238		      "pushfl		\n\t"
 239		      "popl %0		\n\t"
 240		      "movl %0, %1	\n\t"
 241		      "xorl %2, %0	\n\t"
 242		      "pushl %0		\n\t"
 243		      "popfl		\n\t"
 244		      "pushfl		\n\t"
 245		      "popl %0		\n\t"
 246		      "popfl		\n\t"
 247
 248		      : "=&r" (f1), "=&r" (f2)
 249		      : "ir" (flag));
 250
 251	return ((f1^f2) & flag) != 0;
 252}
 253
 254/* Probe for the CPUID instruction */
 255int have_cpuid_p(void)
 256{
 257	return flag_is_changeable_p(X86_EFLAGS_ID);
 258}
 259
 260static void squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
 261{
 262	unsigned long lo, hi;
 263
 264	if (!cpu_has(c, X86_FEATURE_PN) || !disable_x86_serial_nr)
 265		return;
 266
 267	/* Disable processor serial number: */
 268
 269	rdmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
 270	lo |= 0x200000;
 271	wrmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
 272
 273	pr_notice("CPU serial number disabled.\n");
 274	clear_cpu_cap(c, X86_FEATURE_PN);
 275
 276	/* Disabling the serial number may affect the cpuid level */
 277	c->cpuid_level = cpuid_eax(0);
 278}
 279
 280static int __init x86_serial_nr_setup(char *s)
 281{
 282	disable_x86_serial_nr = 0;
 283	return 1;
 284}
 285__setup("serialnumber", x86_serial_nr_setup);
 286#else
 287static inline int flag_is_changeable_p(u32 flag)
 288{
 289	return 1;
 290}
 
 
 
 
 
 291static inline void squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
 292{
 293}
 294#endif
 295
 
 296static __init int setup_disable_smep(char *arg)
 297{
 298	setup_clear_cpu_cap(X86_FEATURE_SMEP);
 299	/* Check for things that depend on SMEP being enabled: */
 300	check_mpx_erratum(&boot_cpu_data);
 301	return 1;
 302}
 303__setup("nosmep", setup_disable_smep);
 304
 305static __always_inline void setup_smep(struct cpuinfo_x86 *c)
 306{
 307	if (cpu_has(c, X86_FEATURE_SMEP))
 308		cr4_set_bits(X86_CR4_SMEP);
 309}
 310
 311static __init int setup_disable_smap(char *arg)
 312{
 313	setup_clear_cpu_cap(X86_FEATURE_SMAP);
 314	return 1;
 315}
 316__setup("nosmap", setup_disable_smap);
 317
 318static __always_inline void setup_smap(struct cpuinfo_x86 *c)
 319{
 320	unsigned long eflags = native_save_fl();
 321
 322	/* This should have been cleared long ago */
 323	BUG_ON(eflags & X86_EFLAGS_AC);
 324
 325	if (cpu_has(c, X86_FEATURE_SMAP)) {
 326#ifdef CONFIG_X86_SMAP
 327		cr4_set_bits(X86_CR4_SMAP);
 328#else
 329		cr4_clear_bits(X86_CR4_SMAP);
 330#endif
 331	}
 332}
 333
 334static __always_inline void setup_umip(struct cpuinfo_x86 *c)
 335{
 336	/* Check the boot processor, plus build option for UMIP. */
 337	if (!cpu_feature_enabled(X86_FEATURE_UMIP))
 338		goto out;
 339
 340	/* Check the current processor's cpuid bits. */
 341	if (!cpu_has(c, X86_FEATURE_UMIP))
 342		goto out;
 343
 344	cr4_set_bits(X86_CR4_UMIP);
 345
 346	pr_info("x86/cpu: Activated the Intel User Mode Instruction Prevention (UMIP) CPU feature\n");
 347
 348	return;
 349
 350out:
 351	/*
 352	 * Make sure UMIP is disabled in case it was enabled in a
 353	 * previous boot (e.g., via kexec).
 354	 */
 355	cr4_clear_bits(X86_CR4_UMIP);
 356}
 357
 358/*
 359 * Protection Keys are not available in 32-bit mode.
 360 */
 361static bool pku_disabled;
 362
 363static __always_inline void setup_pku(struct cpuinfo_x86 *c)
 364{
 365	/* check the boot processor, plus compile options for PKU: */
 366	if (!cpu_feature_enabled(X86_FEATURE_PKU))
 367		return;
 368	/* checks the actual processor's cpuid bits: */
 369	if (!cpu_has(c, X86_FEATURE_PKU))
 370		return;
 371	if (pku_disabled)
 372		return;
 373
 374	cr4_set_bits(X86_CR4_PKE);
 375	/*
 376	 * Seting X86_CR4_PKE will cause the X86_FEATURE_OSPKE
 377	 * cpuid bit to be set.  We need to ensure that we
 378	 * update that bit in this CPU's "cpu_info".
 379	 */
 380	get_cpu_cap(c);
 381}
 382
 383#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
 384static __init int setup_disable_pku(char *arg)
 385{
 386	/*
 387	 * Do not clear the X86_FEATURE_PKU bit.  All of the
 388	 * runtime checks are against OSPKE so clearing the
 389	 * bit does nothing.
 390	 *
 391	 * This way, we will see "pku" in cpuinfo, but not
 392	 * "ospke", which is exactly what we want.  It shows
 393	 * that the CPU has PKU, but the OS has not enabled it.
 394	 * This happens to be exactly how a system would look
 395	 * if we disabled the config option.
 396	 */
 397	pr_info("x86: 'nopku' specified, disabling Memory Protection Keys\n");
 398	pku_disabled = true;
 399	return 1;
 400}
 401__setup("nopku", setup_disable_pku);
 402#endif /* CONFIG_X86_64 */
 403
 404/*
 405 * Some CPU features depend on higher CPUID levels, which may not always
 406 * be available due to CPUID level capping or broken virtualization
 407 * software.  Add those features to this table to auto-disable them.
 408 */
 409struct cpuid_dependent_feature {
 410	u32 feature;
 411	u32 level;
 412};
 413
 414static const struct cpuid_dependent_feature
 415cpuid_dependent_features[] = {
 416	{ X86_FEATURE_MWAIT,		0x00000005 },
 417	{ X86_FEATURE_DCA,		0x00000009 },
 418	{ X86_FEATURE_XSAVE,		0x0000000d },
 419	{ 0, 0 }
 420};
 421
 422static void filter_cpuid_features(struct cpuinfo_x86 *c, bool warn)
 423{
 424	const struct cpuid_dependent_feature *df;
 425
 426	for (df = cpuid_dependent_features; df->feature; df++) {
 427
 428		if (!cpu_has(c, df->feature))
 429			continue;
 430		/*
 431		 * Note: cpuid_level is set to -1 if unavailable, but
 432		 * extended_extended_level is set to 0 if unavailable
 433		 * and the legitimate extended levels are all negative
 434		 * when signed; hence the weird messing around with
 435		 * signs here...
 436		 */
 437		if (!((s32)df->level < 0 ?
 438		     (u32)df->level > (u32)c->extended_cpuid_level :
 439		     (s32)df->level > (s32)c->cpuid_level))
 440			continue;
 441
 442		clear_cpu_cap(c, df->feature);
 443		if (!warn)
 444			continue;
 445
 446		pr_warn("CPU: CPU feature " X86_CAP_FMT " disabled, no CPUID level 0x%x\n",
 447			x86_cap_flag(df->feature), df->level);
 
 448	}
 449}
 450
 451/*
 452 * Naming convention should be: <Name> [(<Codename>)]
 453 * This table only is used unless init_<vendor>() below doesn't set it;
 454 * in particular, if CPUID levels 0x80000002..4 are supported, this
 455 * isn't used
 456 */
 457
 458/* Look up CPU names by table lookup. */
 459static const char *table_lookup_model(struct cpuinfo_x86 *c)
 460{
 461#ifdef CONFIG_X86_32
 462	const struct legacy_cpu_model_info *info;
 463
 464	if (c->x86_model >= 16)
 465		return NULL;	/* Range check */
 466
 467	if (!this_cpu)
 468		return NULL;
 469
 470	info = this_cpu->legacy_models;
 471
 472	while (info->family) {
 473		if (info->family == c->x86)
 474			return info->model_names[c->x86_model];
 475		info++;
 476	}
 477#endif
 478	return NULL;		/* Not found */
 479}
 480
 481__u32 cpu_caps_cleared[NCAPINTS + NBUGINTS];
 482__u32 cpu_caps_set[NCAPINTS + NBUGINTS];
 483
 484void load_percpu_segment(int cpu)
 485{
 486#ifdef CONFIG_X86_32
 487	loadsegment(fs, __KERNEL_PERCPU);
 488#else
 489	__loadsegment_simple(gs, 0);
 490	wrmsrl(MSR_GS_BASE, cpu_kernelmode_gs_base(cpu));
 491#endif
 492	load_stack_canary_segment();
 493}
 494
 495#ifdef CONFIG_X86_32
 496/* The 32-bit entry code needs to find cpu_entry_area. */
 497DEFINE_PER_CPU(struct cpu_entry_area *, cpu_entry_area);
 498#endif
 499
 500#ifdef CONFIG_X86_64
 501/*
 502 * Special IST stacks which the CPU switches to when it calls
 503 * an IST-marked descriptor entry. Up to 7 stacks (hardware
 504 * limit), all of them are 4K, except the debug stack which
 505 * is 8K.
 506 */
 507static const unsigned int exception_stack_sizes[N_EXCEPTION_STACKS] = {
 508	  [0 ... N_EXCEPTION_STACKS - 1]	= EXCEPTION_STKSZ,
 509	  [DEBUG_STACK - 1]			= DEBUG_STKSZ
 510};
 511#endif
 512
 513/* Load the original GDT from the per-cpu structure */
 514void load_direct_gdt(int cpu)
 515{
 516	struct desc_ptr gdt_descr;
 517
 518	gdt_descr.address = (long)get_cpu_gdt_rw(cpu);
 519	gdt_descr.size = GDT_SIZE - 1;
 520	load_gdt(&gdt_descr);
 521}
 522EXPORT_SYMBOL_GPL(load_direct_gdt);
 523
 524/* Load a fixmap remapping of the per-cpu GDT */
 525void load_fixmap_gdt(int cpu)
 526{
 527	struct desc_ptr gdt_descr;
 528
 529	gdt_descr.address = (long)get_cpu_gdt_ro(cpu);
 530	gdt_descr.size = GDT_SIZE - 1;
 531	load_gdt(&gdt_descr);
 532}
 533EXPORT_SYMBOL_GPL(load_fixmap_gdt);
 534
 535/*
 536 * Current gdt points %fs at the "master" per-cpu area: after this,
 537 * it's on the real one.
 538 */
 539void switch_to_new_gdt(int cpu)
 540{
 541	/* Load the original GDT */
 542	load_direct_gdt(cpu);
 543	/* Reload the per-cpu base */
 
 544	load_percpu_segment(cpu);
 545}
 546
 547static const struct cpu_dev *cpu_devs[X86_VENDOR_NUM] = {};
 548
 549static void get_model_name(struct cpuinfo_x86 *c)
 550{
 551	unsigned int *v;
 552	char *p, *q, *s;
 553
 554	if (c->extended_cpuid_level < 0x80000004)
 555		return;
 556
 557	v = (unsigned int *)c->x86_model_id;
 558	cpuid(0x80000002, &v[0], &v[1], &v[2], &v[3]);
 559	cpuid(0x80000003, &v[4], &v[5], &v[6], &v[7]);
 560	cpuid(0x80000004, &v[8], &v[9], &v[10], &v[11]);
 561	c->x86_model_id[48] = 0;
 562
 563	/* Trim whitespace */
 564	p = q = s = &c->x86_model_id[0];
 565
 
 
 566	while (*p == ' ')
 567		p++;
 568
 569	while (*p) {
 570		/* Note the last non-whitespace index */
 571		if (!isspace(*p))
 572			s = q;
 573
 574		*q++ = *p++;
 575	}
 576
 577	*(s + 1) = '\0';
 578}
 579
 580void cpu_detect_cache_sizes(struct cpuinfo_x86 *c)
 581{
 582	unsigned int n, dummy, ebx, ecx, edx, l2size;
 583
 584	n = c->extended_cpuid_level;
 585
 586	if (n >= 0x80000005) {
 587		cpuid(0x80000005, &dummy, &ebx, &ecx, &edx);
 588		c->x86_cache_size = (ecx>>24) + (edx>>24);
 589#ifdef CONFIG_X86_64
 590		/* On K8 L1 TLB is inclusive, so don't count it */
 591		c->x86_tlbsize = 0;
 592#endif
 593	}
 594
 595	if (n < 0x80000006)	/* Some chips just has a large L1. */
 596		return;
 597
 598	cpuid(0x80000006, &dummy, &ebx, &ecx, &edx);
 599	l2size = ecx >> 16;
 600
 601#ifdef CONFIG_X86_64
 602	c->x86_tlbsize += ((ebx >> 16) & 0xfff) + (ebx & 0xfff);
 603#else
 604	/* do processor-specific cache resizing */
 605	if (this_cpu->legacy_cache_size)
 606		l2size = this_cpu->legacy_cache_size(c, l2size);
 607
 608	/* Allow user to override all this if necessary. */
 609	if (cachesize_override != -1)
 610		l2size = cachesize_override;
 611
 612	if (l2size == 0)
 613		return;		/* Again, no L2 cache is possible */
 614#endif
 615
 616	c->x86_cache_size = l2size;
 617}
 618
 619u16 __read_mostly tlb_lli_4k[NR_INFO];
 620u16 __read_mostly tlb_lli_2m[NR_INFO];
 621u16 __read_mostly tlb_lli_4m[NR_INFO];
 622u16 __read_mostly tlb_lld_4k[NR_INFO];
 623u16 __read_mostly tlb_lld_2m[NR_INFO];
 624u16 __read_mostly tlb_lld_4m[NR_INFO];
 625u16 __read_mostly tlb_lld_1g[NR_INFO];
 626
 627static void cpu_detect_tlb(struct cpuinfo_x86 *c)
 628{
 629	if (this_cpu->c_detect_tlb)
 630		this_cpu->c_detect_tlb(c);
 631
 632	pr_info("Last level iTLB entries: 4KB %d, 2MB %d, 4MB %d\n",
 633		tlb_lli_4k[ENTRIES], tlb_lli_2m[ENTRIES],
 634		tlb_lli_4m[ENTRIES]);
 635
 636	pr_info("Last level dTLB entries: 4KB %d, 2MB %d, 4MB %d, 1GB %d\n",
 637		tlb_lld_4k[ENTRIES], tlb_lld_2m[ENTRIES],
 638		tlb_lld_4m[ENTRIES], tlb_lld_1g[ENTRIES]);
 639}
 640
 641void detect_ht(struct cpuinfo_x86 *c)
 642{
 643#ifdef CONFIG_SMP
 644	u32 eax, ebx, ecx, edx;
 645	int index_msb, core_bits;
 646	static bool printed;
 647
 648	if (!cpu_has(c, X86_FEATURE_HT))
 649		return;
 650
 651	if (cpu_has(c, X86_FEATURE_CMP_LEGACY))
 652		goto out;
 653
 654	if (cpu_has(c, X86_FEATURE_XTOPOLOGY))
 655		return;
 656
 657	cpuid(1, &eax, &ebx, &ecx, &edx);
 658
 659	smp_num_siblings = (ebx & 0xff0000) >> 16;
 660
 661	if (smp_num_siblings == 1) {
 662		pr_info_once("CPU0: Hyper-Threading is disabled\n");
 663		goto out;
 664	}
 665
 666	if (smp_num_siblings <= 1)
 667		goto out;
 668
 669	index_msb = get_count_order(smp_num_siblings);
 670	c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, index_msb);
 671
 672	smp_num_siblings = smp_num_siblings / c->x86_max_cores;
 673
 674	index_msb = get_count_order(smp_num_siblings);
 675
 676	core_bits = get_count_order(c->x86_max_cores);
 677
 678	c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid, index_msb) &
 679				       ((1 << core_bits) - 1);
 680
 681out:
 682	if (!printed && (c->x86_max_cores * smp_num_siblings) > 1) {
 683		pr_info("CPU: Physical Processor ID: %d\n",
 684			c->phys_proc_id);
 685		pr_info("CPU: Processor Core ID: %d\n",
 686			c->cpu_core_id);
 687		printed = 1;
 688	}
 689#endif
 690}
 691
 692static void get_cpu_vendor(struct cpuinfo_x86 *c)
 693{
 694	char *v = c->x86_vendor_id;
 695	int i;
 696
 697	for (i = 0; i < X86_VENDOR_NUM; i++) {
 698		if (!cpu_devs[i])
 699			break;
 700
 701		if (!strcmp(v, cpu_devs[i]->c_ident[0]) ||
 702		    (cpu_devs[i]->c_ident[1] &&
 703		     !strcmp(v, cpu_devs[i]->c_ident[1]))) {
 704
 705			this_cpu = cpu_devs[i];
 706			c->x86_vendor = this_cpu->c_x86_vendor;
 707			return;
 708		}
 709	}
 710
 711	pr_err_once("CPU: vendor_id '%s' unknown, using generic init.\n" \
 712		    "CPU: Your system may be unstable.\n", v);
 
 713
 714	c->x86_vendor = X86_VENDOR_UNKNOWN;
 715	this_cpu = &default_cpu;
 716}
 717
 718void cpu_detect(struct cpuinfo_x86 *c)
 719{
 720	/* Get vendor name */
 721	cpuid(0x00000000, (unsigned int *)&c->cpuid_level,
 722	      (unsigned int *)&c->x86_vendor_id[0],
 723	      (unsigned int *)&c->x86_vendor_id[8],
 724	      (unsigned int *)&c->x86_vendor_id[4]);
 725
 726	c->x86 = 4;
 727	/* Intel-defined flags: level 0x00000001 */
 728	if (c->cpuid_level >= 0x00000001) {
 729		u32 junk, tfms, cap0, misc;
 730
 731		cpuid(0x00000001, &tfms, &misc, &junk, &cap0);
 732		c->x86		= x86_family(tfms);
 733		c->x86_model	= x86_model(tfms);
 734		c->x86_stepping	= x86_stepping(tfms);
 
 
 
 
 
 735
 736		if (cap0 & (1<<19)) {
 737			c->x86_clflush_size = ((misc >> 8) & 0xff) * 8;
 738			c->x86_cache_alignment = c->x86_clflush_size;
 739		}
 740	}
 741}
 742
 743static void apply_forced_caps(struct cpuinfo_x86 *c)
 744{
 745	int i;
 746
 747	for (i = 0; i < NCAPINTS + NBUGINTS; i++) {
 748		c->x86_capability[i] &= ~cpu_caps_cleared[i];
 749		c->x86_capability[i] |= cpu_caps_set[i];
 750	}
 751}
 752
 753static void init_speculation_control(struct cpuinfo_x86 *c)
 754{
 755	/*
 756	 * The Intel SPEC_CTRL CPUID bit implies IBRS and IBPB support,
 757	 * and they also have a different bit for STIBP support. Also,
 758	 * a hypervisor might have set the individual AMD bits even on
 759	 * Intel CPUs, for finer-grained selection of what's available.
 760	 */
 761	if (cpu_has(c, X86_FEATURE_SPEC_CTRL)) {
 762		set_cpu_cap(c, X86_FEATURE_IBRS);
 763		set_cpu_cap(c, X86_FEATURE_IBPB);
 764		set_cpu_cap(c, X86_FEATURE_MSR_SPEC_CTRL);
 765	}
 766
 767	if (cpu_has(c, X86_FEATURE_INTEL_STIBP))
 768		set_cpu_cap(c, X86_FEATURE_STIBP);
 769
 770	if (cpu_has(c, X86_FEATURE_SPEC_CTRL_SSBD) ||
 771	    cpu_has(c, X86_FEATURE_VIRT_SSBD))
 772		set_cpu_cap(c, X86_FEATURE_SSBD);
 773
 774	if (cpu_has(c, X86_FEATURE_AMD_IBRS)) {
 775		set_cpu_cap(c, X86_FEATURE_IBRS);
 776		set_cpu_cap(c, X86_FEATURE_MSR_SPEC_CTRL);
 777	}
 778
 779	if (cpu_has(c, X86_FEATURE_AMD_IBPB))
 780		set_cpu_cap(c, X86_FEATURE_IBPB);
 781
 782	if (cpu_has(c, X86_FEATURE_AMD_STIBP)) {
 783		set_cpu_cap(c, X86_FEATURE_STIBP);
 784		set_cpu_cap(c, X86_FEATURE_MSR_SPEC_CTRL);
 785	}
 786}
 787
 788void get_cpu_cap(struct cpuinfo_x86 *c)
 789{
 790	u32 eax, ebx, ecx, edx;
 791
 792	/* Intel-defined flags: level 0x00000001 */
 793	if (c->cpuid_level >= 0x00000001) {
 794		cpuid(0x00000001, &eax, &ebx, &ecx, &edx);
 795
 796		c->x86_capability[CPUID_1_ECX] = ecx;
 797		c->x86_capability[CPUID_1_EDX] = edx;
 
 798	}
 799
 800	/* Thermal and Power Management Leaf: level 0x00000006 (eax) */
 801	if (c->cpuid_level >= 0x00000006)
 802		c->x86_capability[CPUID_6_EAX] = cpuid_eax(0x00000006);
 803
 804	/* Additional Intel-defined flags: level 0x00000007 */
 805	if (c->cpuid_level >= 0x00000007) {
 806		cpuid_count(0x00000007, 0, &eax, &ebx, &ecx, &edx);
 807		c->x86_capability[CPUID_7_0_EBX] = ebx;
 808		c->x86_capability[CPUID_7_ECX] = ecx;
 809		c->x86_capability[CPUID_7_EDX] = edx;
 810	}
 811
 812	/* Extended state features: level 0x0000000d */
 813	if (c->cpuid_level >= 0x0000000d) {
 814		cpuid_count(0x0000000d, 1, &eax, &ebx, &ecx, &edx);
 815
 816		c->x86_capability[CPUID_D_1_EAX] = eax;
 817	}
 818
 819	/* Additional Intel-defined flags: level 0x0000000F */
 820	if (c->cpuid_level >= 0x0000000F) {
 821
 822		/* QoS sub-leaf, EAX=0Fh, ECX=0 */
 823		cpuid_count(0x0000000F, 0, &eax, &ebx, &ecx, &edx);
 824		c->x86_capability[CPUID_F_0_EDX] = edx;
 825
 826		if (cpu_has(c, X86_FEATURE_CQM_LLC)) {
 827			/* will be overridden if occupancy monitoring exists */
 828			c->x86_cache_max_rmid = ebx;
 829
 830			/* QoS sub-leaf, EAX=0Fh, ECX=1 */
 831			cpuid_count(0x0000000F, 1, &eax, &ebx, &ecx, &edx);
 832			c->x86_capability[CPUID_F_1_EDX] = edx;
 833
 834			if ((cpu_has(c, X86_FEATURE_CQM_OCCUP_LLC)) ||
 835			      ((cpu_has(c, X86_FEATURE_CQM_MBM_TOTAL)) ||
 836			       (cpu_has(c, X86_FEATURE_CQM_MBM_LOCAL)))) {
 837				c->x86_cache_max_rmid = ecx;
 838				c->x86_cache_occ_scale = ebx;
 839			}
 840		} else {
 841			c->x86_cache_max_rmid = -1;
 842			c->x86_cache_occ_scale = -1;
 843		}
 844	}
 845
 846	/* AMD-defined flags: level 0x80000001 */
 847	eax = cpuid_eax(0x80000000);
 848	c->extended_cpuid_level = eax;
 849
 850	if ((eax & 0xffff0000) == 0x80000000) {
 851		if (eax >= 0x80000001) {
 852			cpuid(0x80000001, &eax, &ebx, &ecx, &edx);
 853
 854			c->x86_capability[CPUID_8000_0001_ECX] = ecx;
 855			c->x86_capability[CPUID_8000_0001_EDX] = edx;
 856		}
 857	}
 858
 859	if (c->extended_cpuid_level >= 0x80000007) {
 860		cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
 861
 862		c->x86_capability[CPUID_8000_0007_EBX] = ebx;
 863		c->x86_power = edx;
 864	}
 865
 866	if (c->extended_cpuid_level >= 0x80000008) {
 867		cpuid(0x80000008, &eax, &ebx, &ecx, &edx);
 868		c->x86_capability[CPUID_8000_0008_EBX] = ebx;
 869	}
 870
 871	if (c->extended_cpuid_level >= 0x8000000a)
 872		c->x86_capability[CPUID_8000_000A_EDX] = cpuid_edx(0x8000000a);
 873
 874	init_scattered_cpuid_features(c);
 875	init_speculation_control(c);
 876
 877	/*
 878	 * Clear/Set all flags overridden by options, after probe.
 879	 * This needs to happen each time we re-probe, which may happen
 880	 * several times during CPU initialization.
 881	 */
 882	apply_forced_caps(c);
 883}
 884
 885static void get_cpu_address_sizes(struct cpuinfo_x86 *c)
 886{
 887	u32 eax, ebx, ecx, edx;
 888
 889	if (c->extended_cpuid_level >= 0x80000008) {
 890		cpuid(0x80000008, &eax, &ebx, &ecx, &edx);
 891
 892		c->x86_virt_bits = (eax >> 8) & 0xff;
 893		c->x86_phys_bits = eax & 0xff;
 894	}
 895#ifdef CONFIG_X86_32
 896	else if (cpu_has(c, X86_FEATURE_PAE) || cpu_has(c, X86_FEATURE_PSE36))
 897		c->x86_phys_bits = 36;
 898#endif
 
 
 
 
 
 899}
 900
 901static void identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
 902{
 903#ifdef CONFIG_X86_32
 904	int i;
 905
 906	/*
 907	 * First of all, decide if this is a 486 or higher
 908	 * It's a 486 if we can modify the AC flag
 909	 */
 910	if (flag_is_changeable_p(X86_EFLAGS_AC))
 911		c->x86 = 4;
 912	else
 913		c->x86 = 3;
 914
 915	for (i = 0; i < X86_VENDOR_NUM; i++)
 916		if (cpu_devs[i] && cpu_devs[i]->c_identify) {
 917			c->x86_vendor_id[0] = 0;
 918			cpu_devs[i]->c_identify(c);
 919			if (c->x86_vendor_id[0]) {
 920				get_cpu_vendor(c);
 921				break;
 922			}
 923		}
 924#endif
 925}
 926
 927static const __initconst struct x86_cpu_id cpu_no_speculation[] = {
 928	{ X86_VENDOR_INTEL,	6, INTEL_FAM6_ATOM_CEDARVIEW,	X86_FEATURE_ANY },
 929	{ X86_VENDOR_INTEL,	6, INTEL_FAM6_ATOM_CLOVERVIEW,	X86_FEATURE_ANY },
 930	{ X86_VENDOR_INTEL,	6, INTEL_FAM6_ATOM_LINCROFT,	X86_FEATURE_ANY },
 931	{ X86_VENDOR_INTEL,	6, INTEL_FAM6_ATOM_PENWELL,	X86_FEATURE_ANY },
 932	{ X86_VENDOR_INTEL,	6, INTEL_FAM6_ATOM_PINEVIEW,	X86_FEATURE_ANY },
 933	{ X86_VENDOR_CENTAUR,	5 },
 934	{ X86_VENDOR_INTEL,	5 },
 935	{ X86_VENDOR_NSC,	5 },
 936	{ X86_VENDOR_ANY,	4 },
 937	{}
 938};
 939
 940static const __initconst struct x86_cpu_id cpu_no_meltdown[] = {
 941	{ X86_VENDOR_AMD },
 942	{}
 943};
 944
 945/* Only list CPUs which speculate but are non susceptible to SSB */
 946static const __initconst struct x86_cpu_id cpu_no_spec_store_bypass[] = {
 947	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_ATOM_SILVERMONT1	},
 948	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_ATOM_AIRMONT		},
 949	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_ATOM_SILVERMONT2	},
 950	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_ATOM_MERRIFIELD	},
 951	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_CORE_YONAH		},
 952	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_XEON_PHI_KNL		},
 953	{ X86_VENDOR_INTEL,	6,	INTEL_FAM6_XEON_PHI_KNM		},
 954	{ X86_VENDOR_AMD,	0x12,					},
 955	{ X86_VENDOR_AMD,	0x11,					},
 956	{ X86_VENDOR_AMD,	0x10,					},
 957	{ X86_VENDOR_AMD,	0xf,					},
 958	{}
 959};
 960
 961static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
 962{
 963	u64 ia32_cap = 0;
 964
 965	if (x86_match_cpu(cpu_no_speculation))
 966		return;
 967
 968	setup_force_cpu_bug(X86_BUG_SPECTRE_V1);
 969	setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
 970
 971	if (cpu_has(c, X86_FEATURE_ARCH_CAPABILITIES))
 972		rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap);
 973
 974	if (!x86_match_cpu(cpu_no_spec_store_bypass) &&
 975	   !(ia32_cap & ARCH_CAP_SSB_NO))
 976		setup_force_cpu_bug(X86_BUG_SPEC_STORE_BYPASS);
 977
 978	if (x86_match_cpu(cpu_no_meltdown))
 979		return;
 980
 981	/* Rogue Data Cache Load? No! */
 982	if (ia32_cap & ARCH_CAP_RDCL_NO)
 983		return;
 984
 985	setup_force_cpu_bug(X86_BUG_CPU_MELTDOWN);
 986}
 987
 988/*
 989 * Do minimum CPU detection early.
 990 * Fields really needed: vendor, cpuid_level, family, model, mask,
 991 * cache alignment.
 992 * The others are not touched to avoid unwanted side effects.
 993 *
 994 * WARNING: this function is only called on the boot CPU.  Don't add code
 995 * here that is supposed to run on all CPUs.
 996 */
 997static void __init early_identify_cpu(struct cpuinfo_x86 *c)
 998{
 999#ifdef CONFIG_X86_64
1000	c->x86_clflush_size = 64;
1001	c->x86_phys_bits = 36;
1002	c->x86_virt_bits = 48;
1003#else
1004	c->x86_clflush_size = 32;
1005	c->x86_phys_bits = 32;
1006	c->x86_virt_bits = 32;
1007#endif
1008	c->x86_cache_alignment = c->x86_clflush_size;
1009
1010	memset(&c->x86_capability, 0, sizeof c->x86_capability);
1011	c->extended_cpuid_level = 0;
1012
1013	/* cyrix could have cpuid enabled via c_identify()*/
1014	if (have_cpuid_p()) {
1015		cpu_detect(c);
1016		get_cpu_vendor(c);
1017		get_cpu_cap(c);
1018		get_cpu_address_sizes(c);
1019		setup_force_cpu_cap(X86_FEATURE_CPUID);
1020
1021		if (this_cpu->c_early_init)
1022			this_cpu->c_early_init(c);
1023
1024		c->cpu_index = 0;
1025		filter_cpuid_features(c, false);
 
1026
1027		if (this_cpu->c_bsp_init)
1028			this_cpu->c_bsp_init(c);
1029	} else {
1030		identify_cpu_without_cpuid(c);
1031		setup_clear_cpu_cap(X86_FEATURE_CPUID);
1032	}
1033
1034	setup_force_cpu_cap(X86_FEATURE_ALWAYS);
1035
1036	cpu_set_bug_bits(c);
1037
1038	fpu__init_system(c);
 
1039
1040#ifdef CONFIG_X86_32
1041	/*
1042	 * Regardless of whether PCID is enumerated, the SDM says
1043	 * that it can't be enabled in 32-bit mode.
1044	 */
1045	setup_clear_cpu_cap(X86_FEATURE_PCID);
1046#endif
 
 
 
1047}
1048
1049void __init early_cpu_init(void)
1050{
1051	const struct cpu_dev *const *cdev;
1052	int count = 0;
1053
1054#ifdef CONFIG_PROCESSOR_SELECT
1055	pr_info("KERNEL supported cpus:\n");
1056#endif
1057
1058	for (cdev = __x86_cpu_dev_start; cdev < __x86_cpu_dev_end; cdev++) {
1059		const struct cpu_dev *cpudev = *cdev;
1060
1061		if (count >= X86_VENDOR_NUM)
1062			break;
1063		cpu_devs[count] = cpudev;
1064		count++;
1065
1066#ifdef CONFIG_PROCESSOR_SELECT
1067		{
1068			unsigned int j;
1069
1070			for (j = 0; j < 2; j++) {
1071				if (!cpudev->c_ident[j])
1072					continue;
1073				pr_info("  %s %s\n", cpudev->c_vendor,
1074					cpudev->c_ident[j]);
1075			}
1076		}
1077#endif
1078	}
1079	early_identify_cpu(&boot_cpu_data);
1080}
1081
1082/*
1083 * The NOPL instruction is supposed to exist on all CPUs of family >= 6;
1084 * unfortunately, that's not true in practice because of early VIA
1085 * chips and (more importantly) broken virtualizers that are not easy
1086 * to detect. In the latter case it doesn't even *fail* reliably, so
1087 * probing for it doesn't even work. Disable it completely on 32-bit
1088 * unless we can find a reliable way to detect all the broken cases.
1089 * Enable it explicitly on 64-bit for non-constant inputs of cpu_has().
1090 */
1091static void detect_nopl(struct cpuinfo_x86 *c)
1092{
1093#ifdef CONFIG_X86_32
1094	clear_cpu_cap(c, X86_FEATURE_NOPL);
1095#else
1096	set_cpu_cap(c, X86_FEATURE_NOPL);
1097#endif
1098}
1099
1100static void detect_null_seg_behavior(struct cpuinfo_x86 *c)
1101{
1102#ifdef CONFIG_X86_64
1103	/*
1104	 * Empirically, writing zero to a segment selector on AMD does
1105	 * not clear the base, whereas writing zero to a segment
1106	 * selector on Intel does clear the base.  Intel's behavior
1107	 * allows slightly faster context switches in the common case
1108	 * where GS is unused by the prev and next threads.
1109	 *
1110	 * Since neither vendor documents this anywhere that I can see,
1111	 * detect it directly instead of hardcoding the choice by
1112	 * vendor.
1113	 *
1114	 * I've designated AMD's behavior as the "bug" because it's
1115	 * counterintuitive and less friendly.
1116	 */
1117
1118	unsigned long old_base, tmp;
1119	rdmsrl(MSR_FS_BASE, old_base);
1120	wrmsrl(MSR_FS_BASE, 1);
1121	loadsegment(fs, 0);
1122	rdmsrl(MSR_FS_BASE, tmp);
1123	if (tmp != 0)
1124		set_cpu_bug(c, X86_BUG_NULL_SEG);
1125	wrmsrl(MSR_FS_BASE, old_base);
1126#endif
1127}
1128
1129static void generic_identify(struct cpuinfo_x86 *c)
1130{
1131	c->extended_cpuid_level = 0;
1132
1133	if (!have_cpuid_p())
1134		identify_cpu_without_cpuid(c);
1135
1136	/* cyrix could have cpuid enabled via c_identify()*/
1137	if (!have_cpuid_p())
1138		return;
1139
1140	cpu_detect(c);
1141
1142	get_cpu_vendor(c);
1143
1144	get_cpu_cap(c);
1145
1146	get_cpu_address_sizes(c);
1147
1148	if (c->cpuid_level >= 0x00000001) {
1149		c->initial_apicid = (cpuid_ebx(1) >> 24) & 0xFF;
1150#ifdef CONFIG_X86_32
1151# ifdef CONFIG_SMP
1152		c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
1153# else
1154		c->apicid = c->initial_apicid;
1155# endif
1156#endif
1157		c->phys_proc_id = c->initial_apicid;
1158	}
1159
1160	get_model_name(c); /* Default name */
1161
1162	detect_nopl(c);
1163
1164	detect_null_seg_behavior(c);
1165
1166	/*
1167	 * ESPFIX is a strange bug.  All real CPUs have it.  Paravirt
1168	 * systems that run Linux at CPL > 0 may or may not have the
1169	 * issue, but, even if they have the issue, there's absolutely
1170	 * nothing we can do about it because we can't use the real IRET
1171	 * instruction.
1172	 *
1173	 * NB: For the time being, only 32-bit kernels support
1174	 * X86_BUG_ESPFIX as such.  64-bit kernels directly choose
1175	 * whether to apply espfix using paravirt hooks.  If any
1176	 * non-paravirt system ever shows up that does *not* have the
1177	 * ESPFIX issue, we can change this.
1178	 */
1179#ifdef CONFIG_X86_32
1180# ifdef CONFIG_PARAVIRT
1181	do {
1182		extern void native_iret(void);
1183		if (pv_cpu_ops.iret == native_iret)
1184			set_cpu_bug(c, X86_BUG_ESPFIX);
1185	} while (0);
1186# else
1187	set_cpu_bug(c, X86_BUG_ESPFIX);
1188# endif
1189#endif
1190}
1191
1192static void x86_init_cache_qos(struct cpuinfo_x86 *c)
1193{
1194	/*
1195	 * The heavy lifting of max_rmid and cache_occ_scale are handled
1196	 * in get_cpu_cap().  Here we just set the max_rmid for the boot_cpu
1197	 * in case CQM bits really aren't there in this CPU.
1198	 */
1199	if (c != &boot_cpu_data) {
1200		boot_cpu_data.x86_cache_max_rmid =
1201			min(boot_cpu_data.x86_cache_max_rmid,
1202			    c->x86_cache_max_rmid);
1203	}
1204}
1205
1206/*
1207 * Validate that ACPI/mptables have the same information about the
1208 * effective APIC id and update the package map.
1209 */
1210static void validate_apic_and_package_id(struct cpuinfo_x86 *c)
1211{
1212#ifdef CONFIG_SMP
1213	unsigned int apicid, cpu = smp_processor_id();
1214
1215	apicid = apic->cpu_present_to_apicid(cpu);
1216
1217	if (apicid != c->apicid) {
1218		pr_err(FW_BUG "CPU%u: APIC id mismatch. Firmware: %x APIC: %x\n",
1219		       cpu, apicid, c->initial_apicid);
1220	}
1221	BUG_ON(topology_update_package_map(c->phys_proc_id, cpu));
1222#else
1223	c->logical_proc_id = 0;
1224#endif
1225}
1226
1227/*
1228 * This does the hard work of actually picking apart the CPU stuff...
1229 */
1230static void identify_cpu(struct cpuinfo_x86 *c)
1231{
1232	int i;
1233
1234	c->loops_per_jiffy = loops_per_jiffy;
1235	c->x86_cache_size = 0;
1236	c->x86_vendor = X86_VENDOR_UNKNOWN;
1237	c->x86_model = c->x86_stepping = 0;	/* So far unknown... */
1238	c->x86_vendor_id[0] = '\0'; /* Unset */
1239	c->x86_model_id[0] = '\0';  /* Unset */
1240	c->x86_max_cores = 1;
1241	c->x86_coreid_bits = 0;
1242	c->cu_id = 0xff;
1243#ifdef CONFIG_X86_64
1244	c->x86_clflush_size = 64;
1245	c->x86_phys_bits = 36;
1246	c->x86_virt_bits = 48;
1247#else
1248	c->cpuid_level = -1;	/* CPUID not detected */
1249	c->x86_clflush_size = 32;
1250	c->x86_phys_bits = 32;
1251	c->x86_virt_bits = 32;
1252#endif
1253	c->x86_cache_alignment = c->x86_clflush_size;
1254	memset(&c->x86_capability, 0, sizeof c->x86_capability);
1255
1256	generic_identify(c);
1257
1258	if (this_cpu->c_identify)
1259		this_cpu->c_identify(c);
1260
1261	/* Clear/Set all flags overridden by options, after probe */
1262	apply_forced_caps(c);
 
 
 
1263
1264#ifdef CONFIG_X86_64
1265	c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
1266#endif
1267
1268	/*
1269	 * Vendor-specific initialization.  In this section we
1270	 * canonicalize the feature flags, meaning if there are
1271	 * features a certain CPU supports which CPUID doesn't
1272	 * tell us, CPUID claiming incorrect flags, or other bugs,
1273	 * we handle them here.
1274	 *
1275	 * At the end of this section, c->x86_capability better
1276	 * indicate the features this CPU genuinely supports!
1277	 */
1278	if (this_cpu->c_init)
1279		this_cpu->c_init(c);
1280
1281	/* Disable the PN if appropriate */
1282	squash_the_stupid_serial_number(c);
1283
1284	/* Set up SMEP/SMAP/UMIP */
1285	setup_smep(c);
1286	setup_smap(c);
1287	setup_umip(c);
1288
1289	/*
1290	 * The vendor-specific functions might have changed features.
1291	 * Now we do "generic changes."
1292	 */
1293
1294	/* Filter out anything that depends on CPUID levels we don't have */
1295	filter_cpuid_features(c, true);
1296
1297	/* If the model name is still unset, do table lookup. */
1298	if (!c->x86_model_id[0]) {
1299		const char *p;
1300		p = table_lookup_model(c);
1301		if (p)
1302			strcpy(c->x86_model_id, p);
1303		else
1304			/* Last resort... */
1305			sprintf(c->x86_model_id, "%02x/%02x",
1306				c->x86, c->x86_model);
1307	}
1308
1309#ifdef CONFIG_X86_64
1310	detect_ht(c);
1311#endif
1312
1313	x86_init_rdrand(c);
1314	x86_init_cache_qos(c);
1315	setup_pku(c);
1316
1317	/*
1318	 * Clear/Set all flags overridden by options, need do it
1319	 * before following smp all cpus cap AND.
1320	 */
1321	apply_forced_caps(c);
 
 
 
1322
1323	/*
1324	 * On SMP, boot_cpu_data holds the common feature set between
1325	 * all CPUs; so make sure that we indicate which features are
1326	 * common between the CPUs.  The first time this routine gets
1327	 * executed, c == &boot_cpu_data.
1328	 */
1329	if (c != &boot_cpu_data) {
1330		/* AND the already accumulated flags with these */
1331		for (i = 0; i < NCAPINTS; i++)
1332			boot_cpu_data.x86_capability[i] &= c->x86_capability[i];
1333
1334		/* OR, i.e. replicate the bug flags */
1335		for (i = NCAPINTS; i < NCAPINTS + NBUGINTS; i++)
1336			c->x86_capability[i] |= boot_cpu_data.x86_capability[i];
1337	}
1338
1339	/* Init Machine Check Exception if available. */
1340	mcheck_cpu_init(c);
1341
1342	select_idle_routine(c);
1343
1344#ifdef CONFIG_NUMA
1345	numa_add_cpu(smp_processor_id());
1346#endif
1347}
1348
1349/*
1350 * Set up the CPU state needed to execute SYSENTER/SYSEXIT instructions
1351 * on 32-bit kernels:
1352 */
1353#ifdef CONFIG_X86_32
1354void enable_sep_cpu(void)
1355{
1356	struct tss_struct *tss;
1357	int cpu;
1358
1359	if (!boot_cpu_has(X86_FEATURE_SEP))
1360		return;
1361
1362	cpu = get_cpu();
1363	tss = &per_cpu(cpu_tss_rw, cpu);
1364
1365	/*
1366	 * We cache MSR_IA32_SYSENTER_CS's value in the TSS's ss1 field --
1367	 * see the big comment in struct x86_hw_tss's definition.
1368	 */
1369
1370	tss->x86_tss.ss1 = __KERNEL_CS;
1371	wrmsr(MSR_IA32_SYSENTER_CS, tss->x86_tss.ss1, 0);
1372	wrmsr(MSR_IA32_SYSENTER_ESP, (unsigned long)(cpu_entry_stack(cpu) + 1), 0);
1373	wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long)entry_SYSENTER_32, 0);
1374
1375	put_cpu();
1376}
1377#endif
1378
1379void __init identify_boot_cpu(void)
1380{
1381	identify_cpu(&boot_cpu_data);
 
1382#ifdef CONFIG_X86_32
1383	sysenter_setup();
1384	enable_sep_cpu();
 
 
1385#endif
1386	cpu_detect_tlb(&boot_cpu_data);
1387}
1388
1389void identify_secondary_cpu(struct cpuinfo_x86 *c)
1390{
1391	BUG_ON(c == &boot_cpu_data);
1392	identify_cpu(c);
1393#ifdef CONFIG_X86_32
1394	enable_sep_cpu();
1395#endif
1396	mtrr_ap_init();
1397	validate_apic_and_package_id(c);
1398	x86_spec_ctrl_setup_ap();
1399}
1400
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1401static __init int setup_noclflush(char *arg)
1402{
1403	setup_clear_cpu_cap(X86_FEATURE_CLFLUSH);
1404	setup_clear_cpu_cap(X86_FEATURE_CLFLUSHOPT);
1405	return 1;
1406}
1407__setup("noclflush", setup_noclflush);
1408
1409void print_cpu_info(struct cpuinfo_x86 *c)
1410{
1411	const char *vendor = NULL;
1412
1413	if (c->x86_vendor < X86_VENDOR_NUM) {
1414		vendor = this_cpu->c_vendor;
1415	} else {
1416		if (c->cpuid_level >= 0)
1417			vendor = c->x86_vendor_id;
1418	}
1419
1420	if (vendor && !strstr(c->x86_model_id, vendor))
1421		pr_cont("%s ", vendor);
1422
1423	if (c->x86_model_id[0])
1424		pr_cont("%s", c->x86_model_id);
1425	else
1426		pr_cont("%d86", c->x86);
1427
1428	pr_cont(" (family: 0x%x, model: 0x%x", c->x86, c->x86_model);
1429
1430	if (c->x86_stepping || c->cpuid_level >= 0)
1431		pr_cont(", stepping: 0x%x)\n", c->x86_stepping);
1432	else
1433		pr_cont(")\n");
 
 
 
 
 
 
 
 
1434}
1435
1436/*
1437 * clearcpuid= was already parsed in fpu__init_parse_early_param.
1438 * But we need to keep a dummy __setup around otherwise it would
1439 * show up as an environment variable for init.
1440 */
1441static __init int setup_clearcpuid(char *arg)
1442{
 
 
 
 
 
 
 
1443	return 1;
1444}
1445__setup("clearcpuid=", setup_clearcpuid);
1446
1447#ifdef CONFIG_X86_64
 
 
1448DEFINE_PER_CPU_FIRST(union irq_stack_union,
1449		     irq_stack_union) __aligned(PAGE_SIZE) __visible;
1450EXPORT_PER_CPU_SYMBOL_GPL(irq_stack_union);
1451
1452/*
1453 * The following percpu variables are hot.  Align current_task to
1454 * cacheline size such that they fall in the same cacheline.
1455 */
1456DEFINE_PER_CPU(struct task_struct *, current_task) ____cacheline_aligned =
1457	&init_task;
1458EXPORT_PER_CPU_SYMBOL(current_task);
1459
 
 
 
 
1460DEFINE_PER_CPU(char *, irq_stack_ptr) =
1461	init_per_cpu_var(irq_stack_union.irq_stack) + IRQ_STACK_SIZE;
1462
1463DEFINE_PER_CPU(unsigned int, irq_count) __visible = -1;
1464
1465DEFINE_PER_CPU(int, __preempt_count) = INIT_PREEMPT_COUNT;
1466EXPORT_PER_CPU_SYMBOL(__preempt_count);
 
 
 
 
 
 
 
 
 
 
 
1467
1468/* May not be marked __init: used by software suspend */
1469void syscall_init(void)
1470{
1471	extern char _entry_trampoline[];
1472	extern char entry_SYSCALL_64_trampoline[];
1473
1474	int cpu = smp_processor_id();
1475	unsigned long SYSCALL64_entry_trampoline =
1476		(unsigned long)get_cpu_entry_area(cpu)->entry_trampoline +
1477		(entry_SYSCALL_64_trampoline - _entry_trampoline);
1478
1479	wrmsr(MSR_STAR, 0, (__USER32_CS << 16) | __KERNEL_CS);
1480	if (static_cpu_has(X86_FEATURE_PTI))
1481		wrmsrl(MSR_LSTAR, SYSCALL64_entry_trampoline);
1482	else
1483		wrmsrl(MSR_LSTAR, (unsigned long)entry_SYSCALL_64);
1484
1485#ifdef CONFIG_IA32_EMULATION
1486	wrmsrl(MSR_CSTAR, (unsigned long)entry_SYSCALL_compat);
1487	/*
1488	 * This only works on Intel CPUs.
1489	 * On AMD CPUs these MSRs are 32-bit, CPU truncates MSR_IA32_SYSENTER_EIP.
1490	 * This does not cause SYSENTER to jump to the wrong location, because
1491	 * AMD doesn't allow SYSENTER in long mode (either 32- or 64-bit).
1492	 */
1493	wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS);
1494	wrmsrl_safe(MSR_IA32_SYSENTER_ESP, (unsigned long)(cpu_entry_stack(cpu) + 1));
1495	wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)entry_SYSENTER_compat);
1496#else
1497	wrmsrl(MSR_CSTAR, (unsigned long)ignore_sysret);
1498	wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)GDT_ENTRY_INVALID_SEG);
1499	wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL);
1500	wrmsrl_safe(MSR_IA32_SYSENTER_EIP, 0ULL);
1501#endif
1502
1503	/* Flags to clear on syscall */
1504	wrmsrl(MSR_SYSCALL_MASK,
1505	       X86_EFLAGS_TF|X86_EFLAGS_DF|X86_EFLAGS_IF|
1506	       X86_EFLAGS_IOPL|X86_EFLAGS_AC|X86_EFLAGS_NT);
1507}
1508
 
 
1509/*
1510 * Copies of the original ist values from the tss are only accessed during
1511 * debugging, no special alignment required.
1512 */
1513DEFINE_PER_CPU(struct orig_ist, orig_ist);
1514
1515static DEFINE_PER_CPU(unsigned long, debug_stack_addr);
1516DEFINE_PER_CPU(int, debug_stack_usage);
1517
1518int is_debug_stack(unsigned long addr)
1519{
1520	return __this_cpu_read(debug_stack_usage) ||
1521		(addr <= __this_cpu_read(debug_stack_addr) &&
1522		 addr > (__this_cpu_read(debug_stack_addr) - DEBUG_STKSZ));
1523}
1524NOKPROBE_SYMBOL(is_debug_stack);
1525
1526DEFINE_PER_CPU(u32, debug_idt_ctr);
1527
1528void debug_stack_set_zero(void)
1529{
1530	this_cpu_inc(debug_idt_ctr);
1531	load_current_idt();
1532}
1533NOKPROBE_SYMBOL(debug_stack_set_zero);
1534
1535void debug_stack_reset(void)
1536{
1537	if (WARN_ON(!this_cpu_read(debug_idt_ctr)))
1538		return;
1539	if (this_cpu_dec_return(debug_idt_ctr) == 0)
1540		load_current_idt();
1541}
1542NOKPROBE_SYMBOL(debug_stack_reset);
1543
1544#else	/* CONFIG_X86_64 */
1545
1546DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task;
1547EXPORT_PER_CPU_SYMBOL(current_task);
1548DEFINE_PER_CPU(int, __preempt_count) = INIT_PREEMPT_COUNT;
1549EXPORT_PER_CPU_SYMBOL(__preempt_count);
1550
1551/*
1552 * On x86_32, vm86 modifies tss.sp0, so sp0 isn't a reliable way to find
1553 * the top of the kernel stack.  Use an extra percpu variable to track the
1554 * top of the kernel stack directly.
1555 */
1556DEFINE_PER_CPU(unsigned long, cpu_current_top_of_stack) =
1557	(unsigned long)&init_thread_union + THREAD_SIZE;
1558EXPORT_PER_CPU_SYMBOL(cpu_current_top_of_stack);
1559
1560#ifdef CONFIG_CC_STACKPROTECTOR
1561DEFINE_PER_CPU_ALIGNED(struct stack_canary, stack_canary);
1562#endif
1563
 
 
 
 
 
 
 
 
 
1564#endif	/* CONFIG_X86_64 */
1565
1566/*
1567 * Clear all 6 debug registers:
1568 */
1569static void clear_all_debug_regs(void)
1570{
1571	int i;
1572
1573	for (i = 0; i < 8; i++) {
1574		/* Ignore db4, db5 */
1575		if ((i == 4) || (i == 5))
1576			continue;
1577
1578		set_debugreg(0, i);
1579	}
1580}
1581
1582#ifdef CONFIG_KGDB
1583/*
1584 * Restore debug regs if using kgdbwait and you have a kernel debugger
1585 * connection established.
1586 */
1587static void dbg_restore_debug_regs(void)
1588{
1589	if (unlikely(kgdb_connected && arch_kgdb_ops.correct_hw_break))
1590		arch_kgdb_ops.correct_hw_break();
1591}
1592#else /* ! CONFIG_KGDB */
1593#define dbg_restore_debug_regs()
1594#endif /* ! CONFIG_KGDB */
1595
1596static void wait_for_master_cpu(int cpu)
1597{
1598#ifdef CONFIG_SMP
1599	/*
1600	 * wait for ACK from master CPU before continuing
1601	 * with AP initialization
1602	 */
1603	WARN_ON(cpumask_test_and_set_cpu(cpu, cpu_initialized_mask));
1604	while (!cpumask_test_cpu(cpu, cpu_callout_mask))
1605		cpu_relax();
1606#endif
1607}
1608
1609/*
1610 * cpu_init() initializes state that is per-CPU. Some data is already
1611 * initialized (naturally) in the bootstrap process, such as the GDT
1612 * and IDT. We reload them nevertheless, this function acts as a
1613 * 'CPU state barrier', nothing should get across.
1614 * A lot of state is already set up in PDA init for 64 bit
1615 */
1616#ifdef CONFIG_X86_64
1617
1618void cpu_init(void)
1619{
1620	struct orig_ist *oist;
1621	struct task_struct *me;
1622	struct tss_struct *t;
1623	unsigned long v;
1624	int cpu = raw_smp_processor_id();
1625	int i;
1626
1627	wait_for_master_cpu(cpu);
1628
1629	/*
1630	 * Initialize the CR4 shadow before doing anything that could
1631	 * try to read it.
1632	 */
1633	cr4_init_shadow();
1634
1635	if (cpu)
1636		load_ucode_ap();
1637
1638	t = &per_cpu(cpu_tss_rw, cpu);
1639	oist = &per_cpu(orig_ist, cpu);
1640
1641#ifdef CONFIG_NUMA
1642	if (this_cpu_read(numa_node) == 0 &&
1643	    early_cpu_to_node(cpu) != NUMA_NO_NODE)
1644		set_numa_node(early_cpu_to_node(cpu));
1645#endif
1646
1647	me = current;
1648
 
 
 
1649	pr_debug("Initializing CPU#%d\n", cpu);
1650
1651	cr4_clear_bits(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1652
1653	/*
1654	 * Initialize the per-CPU GDT with the boot GDT,
1655	 * and set up the GDT descriptor:
1656	 */
1657
1658	switch_to_new_gdt(cpu);
1659	loadsegment(fs, 0);
1660
1661	load_current_idt();
1662
1663	memset(me->thread.tls_array, 0, GDT_ENTRY_TLS_ENTRIES * 8);
1664	syscall_init();
1665
1666	wrmsrl(MSR_FS_BASE, 0);
1667	wrmsrl(MSR_KERNEL_GS_BASE, 0);
1668	barrier();
1669
1670	x86_configure_nx();
1671	x2apic_setup();
 
1672
1673	/*
1674	 * set up and load the per-CPU TSS
1675	 */
1676	if (!oist->ist[0]) {
1677		char *estacks = get_cpu_entry_area(cpu)->exception_stacks;
1678
1679		for (v = 0; v < N_EXCEPTION_STACKS; v++) {
1680			estacks += exception_stack_sizes[v];
1681			oist->ist[v] = t->x86_tss.ist[v] =
1682					(unsigned long)estacks;
1683			if (v == DEBUG_STACK-1)
1684				per_cpu(debug_stack_addr, cpu) = (unsigned long)estacks;
1685		}
1686	}
1687
1688	t->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET;
1689
1690	/*
1691	 * <= is required because the CPU will access up to
1692	 * 8 bits beyond the end of the IO permission bitmap.
1693	 */
1694	for (i = 0; i <= IO_BITMAP_LONGS; i++)
1695		t->io_bitmap[i] = ~0UL;
1696
1697	mmgrab(&init_mm);
1698	me->active_mm = &init_mm;
1699	BUG_ON(me->mm);
1700	initialize_tlbstate_and_flush();
1701	enter_lazy_tlb(&init_mm, me);
1702
1703	/*
1704	 * Initialize the TSS.  sp0 points to the entry trampoline stack
1705	 * regardless of what task is running.
1706	 */
1707	set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss);
1708	load_TR_desc();
1709	load_sp0((unsigned long)(cpu_entry_stack(cpu) + 1));
1710
1711	load_mm_ldt(&init_mm);
1712
1713	clear_all_debug_regs();
1714	dbg_restore_debug_regs();
1715
1716	fpu__init_cpu();
 
 
 
1717
1718	if (is_uv_system())
1719		uv_cpu_init();
1720
1721	load_fixmap_gdt(cpu);
1722}
1723
1724#else
1725
1726void cpu_init(void)
1727{
1728	int cpu = smp_processor_id();
1729	struct task_struct *curr = current;
1730	struct tss_struct *t = &per_cpu(cpu_tss_rw, cpu);
1731
1732	wait_for_master_cpu(cpu);
1733
1734	/*
1735	 * Initialize the CR4 shadow before doing anything that could
1736	 * try to read it.
1737	 */
1738	cr4_init_shadow();
1739
1740	show_ucode_info_early();
1741
1742	pr_info("Initializing CPU#%d\n", cpu);
1743
1744	if (cpu_feature_enabled(X86_FEATURE_VME) ||
1745	    boot_cpu_has(X86_FEATURE_TSC) ||
1746	    boot_cpu_has(X86_FEATURE_DE))
1747		cr4_clear_bits(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1748
1749	load_current_idt();
1750	switch_to_new_gdt(cpu);
1751
1752	/*
1753	 * Set up and load the per-CPU TSS and LDT
1754	 */
1755	mmgrab(&init_mm);
1756	curr->active_mm = &init_mm;
1757	BUG_ON(curr->mm);
1758	initialize_tlbstate_and_flush();
1759	enter_lazy_tlb(&init_mm, curr);
1760
1761	/*
1762	 * Initialize the TSS.  Don't bother initializing sp0, as the initial
1763	 * task never enters user mode.
1764	 */
1765	set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss);
1766	load_TR_desc();
 
1767
1768	load_mm_ldt(&init_mm);
1769
1770	t->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET;
1771
1772#ifdef CONFIG_DOUBLEFAULT
1773	/* Set up doublefault TSS pointer in the GDT */
1774	__set_tss_desc(cpu, GDT_ENTRY_DOUBLEFAULT_TSS, &doublefault_tss);
1775#endif
1776
1777	clear_all_debug_regs();
1778	dbg_restore_debug_regs();
1779
1780	fpu__init_cpu();
1781
1782	load_fixmap_gdt(cpu);
1783}
1784#endif
1785
1786static void bsp_resume(void)
1787{
1788	if (this_cpu->c_bsp_resume)
1789		this_cpu->c_bsp_resume(&boot_cpu_data);
1790}
1791
1792static struct syscore_ops cpu_syscore_ops = {
1793	.resume		= bsp_resume,
1794};
1795
1796static int __init init_cpu_syscore(void)
1797{
1798	register_syscore_ops(&cpu_syscore_ops);
1799	return 0;
1800}
1801core_initcall(init_cpu_syscore);
1802
1803/*
1804 * The microcode loader calls this upon late microcode load to recheck features,
1805 * only when microcode has been updated. Caller holds microcode_mutex and CPU
1806 * hotplug lock.
1807 */
1808void microcode_check(void)
1809{
1810	struct cpuinfo_x86 info;
1811
1812	perf_check_microcode();
1813
1814	/* Reload CPUID max function as it might've changed. */
1815	info.cpuid_level = cpuid_eax(0);
1816
1817	/*
1818	 * Copy all capability leafs to pick up the synthetic ones so that
1819	 * memcmp() below doesn't fail on that. The ones coming from CPUID will
1820	 * get overwritten in get_cpu_cap().
1821	 */
1822	memcpy(&info.x86_capability, &boot_cpu_data.x86_capability, sizeof(info.x86_capability));
1823
1824	get_cpu_cap(&info);
1825
1826	if (!memcmp(&info.x86_capability, &boot_cpu_data.x86_capability, sizeof(info.x86_capability)))
1827		return;
1828
1829	pr_warn("x86/CPU: CPU features have changed after loading microcode, but might not take effect.\n");
1830	pr_warn("x86/CPU: Please consider either early loading through initrd/built-in or a potential BIOS update.\n");
1831}
v3.1
   1#include <linux/bootmem.h>
   2#include <linux/linkage.h>
   3#include <linux/bitops.h>
   4#include <linux/kernel.h>
   5#include <linux/module.h>
   6#include <linux/percpu.h>
   7#include <linux/string.h>
 
   8#include <linux/delay.h>
   9#include <linux/sched.h>
 
 
  10#include <linux/init.h>
 
  11#include <linux/kgdb.h>
  12#include <linux/smp.h>
  13#include <linux/io.h>
 
  14
  15#include <asm/stackprotector.h>
  16#include <asm/perf_event.h>
  17#include <asm/mmu_context.h>
 
  18#include <asm/hypervisor.h>
  19#include <asm/processor.h>
 
 
  20#include <asm/sections.h>
 
  21#include <linux/topology.h>
  22#include <linux/cpumask.h>
  23#include <asm/pgtable.h>
  24#include <linux/atomic.h>
  25#include <asm/proto.h>
  26#include <asm/setup.h>
  27#include <asm/apic.h>
  28#include <asm/desc.h>
  29#include <asm/i387.h>
  30#include <asm/mtrr.h>
 
  31#include <linux/numa.h>
  32#include <asm/asm.h>
 
  33#include <asm/cpu.h>
  34#include <asm/mce.h>
  35#include <asm/msr.h>
  36#include <asm/pat.h>
 
 
 
 
  37
  38#ifdef CONFIG_X86_LOCAL_APIC
  39#include <asm/uv/uv.h>
  40#endif
  41
  42#include "cpu.h"
  43
 
 
  44/* all of these masks are initialized in setup_cpu_local_masks() */
  45cpumask_var_t cpu_initialized_mask;
  46cpumask_var_t cpu_callout_mask;
  47cpumask_var_t cpu_callin_mask;
  48
  49/* representing cpus for which sibling maps can be computed */
  50cpumask_var_t cpu_sibling_setup_mask;
  51
  52/* correctly size the local cpu masks */
  53void __init setup_cpu_local_masks(void)
  54{
  55	alloc_bootmem_cpumask_var(&cpu_initialized_mask);
  56	alloc_bootmem_cpumask_var(&cpu_callin_mask);
  57	alloc_bootmem_cpumask_var(&cpu_callout_mask);
  58	alloc_bootmem_cpumask_var(&cpu_sibling_setup_mask);
  59}
  60
  61static void __cpuinit default_init(struct cpuinfo_x86 *c)
  62{
  63#ifdef CONFIG_X86_64
  64	cpu_detect_cache_sizes(c);
  65#else
  66	/* Not much we can do here... */
  67	/* Check if at least it has cpuid */
  68	if (c->cpuid_level == -1) {
  69		/* No cpuid. It must be an ancient CPU */
  70		if (c->x86 == 4)
  71			strcpy(c->x86_model_id, "486");
  72		else if (c->x86 == 3)
  73			strcpy(c->x86_model_id, "386");
  74	}
  75#endif
  76}
  77
  78static const struct cpu_dev __cpuinitconst default_cpu = {
  79	.c_init		= default_init,
  80	.c_vendor	= "Unknown",
  81	.c_x86_vendor	= X86_VENDOR_UNKNOWN,
  82};
  83
  84static const struct cpu_dev *this_cpu __cpuinitdata = &default_cpu;
  85
  86DEFINE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page) = { .gdt = {
  87#ifdef CONFIG_X86_64
  88	/*
  89	 * We need valid kernel segments for data and code in long mode too
  90	 * IRET will check the segment types  kkeil 2000/10/28
  91	 * Also sysret mandates a special GDT layout
  92	 *
  93	 * TLS descriptors are currently at a different place compared to i386.
  94	 * Hopefully nobody expects them at a fixed place (Wine?)
  95	 */
  96	[GDT_ENTRY_KERNEL32_CS]		= GDT_ENTRY_INIT(0xc09b, 0, 0xfffff),
  97	[GDT_ENTRY_KERNEL_CS]		= GDT_ENTRY_INIT(0xa09b, 0, 0xfffff),
  98	[GDT_ENTRY_KERNEL_DS]		= GDT_ENTRY_INIT(0xc093, 0, 0xfffff),
  99	[GDT_ENTRY_DEFAULT_USER32_CS]	= GDT_ENTRY_INIT(0xc0fb, 0, 0xfffff),
 100	[GDT_ENTRY_DEFAULT_USER_DS]	= GDT_ENTRY_INIT(0xc0f3, 0, 0xfffff),
 101	[GDT_ENTRY_DEFAULT_USER_CS]	= GDT_ENTRY_INIT(0xa0fb, 0, 0xfffff),
 102#else
 103	[GDT_ENTRY_KERNEL_CS]		= GDT_ENTRY_INIT(0xc09a, 0, 0xfffff),
 104	[GDT_ENTRY_KERNEL_DS]		= GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
 105	[GDT_ENTRY_DEFAULT_USER_CS]	= GDT_ENTRY_INIT(0xc0fa, 0, 0xfffff),
 106	[GDT_ENTRY_DEFAULT_USER_DS]	= GDT_ENTRY_INIT(0xc0f2, 0, 0xfffff),
 107	/*
 108	 * Segments used for calling PnP BIOS have byte granularity.
 109	 * They code segments and data segments have fixed 64k limits,
 110	 * the transfer segment sizes are set at run time.
 111	 */
 112	/* 32-bit code */
 113	[GDT_ENTRY_PNPBIOS_CS32]	= GDT_ENTRY_INIT(0x409a, 0, 0xffff),
 114	/* 16-bit code */
 115	[GDT_ENTRY_PNPBIOS_CS16]	= GDT_ENTRY_INIT(0x009a, 0, 0xffff),
 116	/* 16-bit data */
 117	[GDT_ENTRY_PNPBIOS_DS]		= GDT_ENTRY_INIT(0x0092, 0, 0xffff),
 118	/* 16-bit data */
 119	[GDT_ENTRY_PNPBIOS_TS1]		= GDT_ENTRY_INIT(0x0092, 0, 0),
 120	/* 16-bit data */
 121	[GDT_ENTRY_PNPBIOS_TS2]		= GDT_ENTRY_INIT(0x0092, 0, 0),
 122	/*
 123	 * The APM segments have byte granularity and their bases
 124	 * are set at run time.  All have 64k limits.
 125	 */
 126	/* 32-bit code */
 127	[GDT_ENTRY_APMBIOS_BASE]	= GDT_ENTRY_INIT(0x409a, 0, 0xffff),
 128	/* 16-bit code */
 129	[GDT_ENTRY_APMBIOS_BASE+1]	= GDT_ENTRY_INIT(0x009a, 0, 0xffff),
 130	/* data */
 131	[GDT_ENTRY_APMBIOS_BASE+2]	= GDT_ENTRY_INIT(0x4092, 0, 0xffff),
 132
 133	[GDT_ENTRY_ESPFIX_SS]		= GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
 134	[GDT_ENTRY_PERCPU]		= GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
 135	GDT_STACK_CANARY_INIT
 136#endif
 137} };
 138EXPORT_PER_CPU_SYMBOL_GPL(gdt_page);
 139
 140static int __init x86_xsave_setup(char *s)
 141{
 142	setup_clear_cpu_cap(X86_FEATURE_XSAVE);
 143	setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT);
 
 
 
 
 
 
 
 
 144	return 1;
 145}
 146__setup("noxsave", x86_xsave_setup);
 147
 148static int __init x86_xsaveopt_setup(char *s)
 
 149{
 150	setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT);
 151	return 1;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 152}
 153__setup("noxsaveopt", x86_xsaveopt_setup);
 154
 155#ifdef CONFIG_X86_32
 156static int cachesize_override __cpuinitdata = -1;
 157static int disable_x86_serial_nr __cpuinitdata = 1;
 158
 159static int __init cachesize_setup(char *str)
 160{
 161	get_option(&str, &cachesize_override);
 162	return 1;
 163}
 164__setup("cachesize=", cachesize_setup);
 165
 166static int __init x86_fxsr_setup(char *s)
 167{
 168	setup_clear_cpu_cap(X86_FEATURE_FXSR);
 169	setup_clear_cpu_cap(X86_FEATURE_XMM);
 170	return 1;
 171}
 172__setup("nofxsr", x86_fxsr_setup);
 173
 174static int __init x86_sep_setup(char *s)
 175{
 176	setup_clear_cpu_cap(X86_FEATURE_SEP);
 177	return 1;
 178}
 179__setup("nosep", x86_sep_setup);
 180
 181/* Standard macro to see if a specific flag is changeable */
 182static inline int flag_is_changeable_p(u32 flag)
 183{
 184	u32 f1, f2;
 185
 186	/*
 187	 * Cyrix and IDT cpus allow disabling of CPUID
 188	 * so the code below may return different results
 189	 * when it is executed before and after enabling
 190	 * the CPUID. Add "volatile" to not allow gcc to
 191	 * optimize the subsequent calls to this function.
 192	 */
 193	asm volatile ("pushfl		\n\t"
 194		      "pushfl		\n\t"
 195		      "popl %0		\n\t"
 196		      "movl %0, %1	\n\t"
 197		      "xorl %2, %0	\n\t"
 198		      "pushl %0		\n\t"
 199		      "popfl		\n\t"
 200		      "pushfl		\n\t"
 201		      "popl %0		\n\t"
 202		      "popfl		\n\t"
 203
 204		      : "=&r" (f1), "=&r" (f2)
 205		      : "ir" (flag));
 206
 207	return ((f1^f2) & flag) != 0;
 208}
 209
 210/* Probe for the CPUID instruction */
 211static int __cpuinit have_cpuid_p(void)
 212{
 213	return flag_is_changeable_p(X86_EFLAGS_ID);
 214}
 215
 216static void __cpuinit squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
 217{
 218	unsigned long lo, hi;
 219
 220	if (!cpu_has(c, X86_FEATURE_PN) || !disable_x86_serial_nr)
 221		return;
 222
 223	/* Disable processor serial number: */
 224
 225	rdmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
 226	lo |= 0x200000;
 227	wrmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
 228
 229	printk(KERN_NOTICE "CPU serial number disabled.\n");
 230	clear_cpu_cap(c, X86_FEATURE_PN);
 231
 232	/* Disabling the serial number may affect the cpuid level */
 233	c->cpuid_level = cpuid_eax(0);
 234}
 235
 236static int __init x86_serial_nr_setup(char *s)
 237{
 238	disable_x86_serial_nr = 0;
 239	return 1;
 240}
 241__setup("serialnumber", x86_serial_nr_setup);
 242#else
 243static inline int flag_is_changeable_p(u32 flag)
 244{
 245	return 1;
 246}
 247/* Probe for the CPUID instruction */
 248static inline int have_cpuid_p(void)
 249{
 250	return 1;
 251}
 252static inline void squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
 253{
 254}
 255#endif
 256
 257static int disable_smep __cpuinitdata;
 258static __init int setup_disable_smep(char *arg)
 259{
 260	disable_smep = 1;
 
 
 261	return 1;
 262}
 263__setup("nosmep", setup_disable_smep);
 264
 265static __cpuinit void setup_smep(struct cpuinfo_x86 *c)
 
 
 
 
 
 
 266{
 267	if (cpu_has(c, X86_FEATURE_SMEP)) {
 268		if (unlikely(disable_smep)) {
 269			setup_clear_cpu_cap(X86_FEATURE_SMEP);
 270			clear_in_cr4(X86_CR4_SMEP);
 271		} else
 272			set_in_cr4(X86_CR4_SMEP);
 
 
 
 
 
 
 
 
 
 
 
 
 273	}
 274}
 275
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 276/*
 277 * Some CPU features depend on higher CPUID levels, which may not always
 278 * be available due to CPUID level capping or broken virtualization
 279 * software.  Add those features to this table to auto-disable them.
 280 */
 281struct cpuid_dependent_feature {
 282	u32 feature;
 283	u32 level;
 284};
 285
 286static const struct cpuid_dependent_feature __cpuinitconst
 287cpuid_dependent_features[] = {
 288	{ X86_FEATURE_MWAIT,		0x00000005 },
 289	{ X86_FEATURE_DCA,		0x00000009 },
 290	{ X86_FEATURE_XSAVE,		0x0000000d },
 291	{ 0, 0 }
 292};
 293
 294static void __cpuinit filter_cpuid_features(struct cpuinfo_x86 *c, bool warn)
 295{
 296	const struct cpuid_dependent_feature *df;
 297
 298	for (df = cpuid_dependent_features; df->feature; df++) {
 299
 300		if (!cpu_has(c, df->feature))
 301			continue;
 302		/*
 303		 * Note: cpuid_level is set to -1 if unavailable, but
 304		 * extended_extended_level is set to 0 if unavailable
 305		 * and the legitimate extended levels are all negative
 306		 * when signed; hence the weird messing around with
 307		 * signs here...
 308		 */
 309		if (!((s32)df->level < 0 ?
 310		     (u32)df->level > (u32)c->extended_cpuid_level :
 311		     (s32)df->level > (s32)c->cpuid_level))
 312			continue;
 313
 314		clear_cpu_cap(c, df->feature);
 315		if (!warn)
 316			continue;
 317
 318		printk(KERN_WARNING
 319		       "CPU: CPU feature %s disabled, no CPUID level 0x%x\n",
 320				x86_cap_flags[df->feature], df->level);
 321	}
 322}
 323
 324/*
 325 * Naming convention should be: <Name> [(<Codename>)]
 326 * This table only is used unless init_<vendor>() below doesn't set it;
 327 * in particular, if CPUID levels 0x80000002..4 are supported, this
 328 * isn't used
 329 */
 330
 331/* Look up CPU names by table lookup. */
 332static const char *__cpuinit table_lookup_model(struct cpuinfo_x86 *c)
 333{
 334	const struct cpu_model_info *info;
 
 335
 336	if (c->x86_model >= 16)
 337		return NULL;	/* Range check */
 338
 339	if (!this_cpu)
 340		return NULL;
 341
 342	info = this_cpu->c_models;
 343
 344	while (info && info->family) {
 345		if (info->family == c->x86)
 346			return info->model_names[c->x86_model];
 347		info++;
 348	}
 
 349	return NULL;		/* Not found */
 350}
 351
 352__u32 cpu_caps_cleared[NCAPINTS] __cpuinitdata;
 353__u32 cpu_caps_set[NCAPINTS] __cpuinitdata;
 354
 355void load_percpu_segment(int cpu)
 356{
 357#ifdef CONFIG_X86_32
 358	loadsegment(fs, __KERNEL_PERCPU);
 359#else
 360	loadsegment(gs, 0);
 361	wrmsrl(MSR_GS_BASE, (unsigned long)per_cpu(irq_stack_union.gs_base, cpu));
 362#endif
 363	load_stack_canary_segment();
 364}
 365
 
 
 
 
 
 
 366/*
 367 * Current gdt points %fs at the "master" per-cpu area: after this,
 368 * it's on the real one.
 
 
 369 */
 370void switch_to_new_gdt(int cpu)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 371{
 372	struct desc_ptr gdt_descr;
 373
 374	gdt_descr.address = (long)get_cpu_gdt_table(cpu);
 375	gdt_descr.size = GDT_SIZE - 1;
 376	load_gdt(&gdt_descr);
 
 
 
 
 
 
 
 
 
 
 
 377	/* Reload the per-cpu base */
 378
 379	load_percpu_segment(cpu);
 380}
 381
 382static const struct cpu_dev *__cpuinitdata cpu_devs[X86_VENDOR_NUM] = {};
 383
 384static void __cpuinit get_model_name(struct cpuinfo_x86 *c)
 385{
 386	unsigned int *v;
 387	char *p, *q;
 388
 389	if (c->extended_cpuid_level < 0x80000004)
 390		return;
 391
 392	v = (unsigned int *)c->x86_model_id;
 393	cpuid(0x80000002, &v[0], &v[1], &v[2], &v[3]);
 394	cpuid(0x80000003, &v[4], &v[5], &v[6], &v[7]);
 395	cpuid(0x80000004, &v[8], &v[9], &v[10], &v[11]);
 396	c->x86_model_id[48] = 0;
 397
 398	/*
 399	 * Intel chips right-justify this string for some dumb reason;
 400	 * undo that brain damage:
 401	 */
 402	p = q = &c->x86_model_id[0];
 403	while (*p == ' ')
 404		p++;
 405	if (p != q) {
 406		while (*p)
 407			*q++ = *p++;
 408		while (q <= &c->x86_model_id[48])
 409			*q++ = '\0';	/* Zero-pad the rest */
 
 
 410	}
 
 
 411}
 412
 413void __cpuinit cpu_detect_cache_sizes(struct cpuinfo_x86 *c)
 414{
 415	unsigned int n, dummy, ebx, ecx, edx, l2size;
 416
 417	n = c->extended_cpuid_level;
 418
 419	if (n >= 0x80000005) {
 420		cpuid(0x80000005, &dummy, &ebx, &ecx, &edx);
 421		c->x86_cache_size = (ecx>>24) + (edx>>24);
 422#ifdef CONFIG_X86_64
 423		/* On K8 L1 TLB is inclusive, so don't count it */
 424		c->x86_tlbsize = 0;
 425#endif
 426	}
 427
 428	if (n < 0x80000006)	/* Some chips just has a large L1. */
 429		return;
 430
 431	cpuid(0x80000006, &dummy, &ebx, &ecx, &edx);
 432	l2size = ecx >> 16;
 433
 434#ifdef CONFIG_X86_64
 435	c->x86_tlbsize += ((ebx >> 16) & 0xfff) + (ebx & 0xfff);
 436#else
 437	/* do processor-specific cache resizing */
 438	if (this_cpu->c_size_cache)
 439		l2size = this_cpu->c_size_cache(c, l2size);
 440
 441	/* Allow user to override all this if necessary. */
 442	if (cachesize_override != -1)
 443		l2size = cachesize_override;
 444
 445	if (l2size == 0)
 446		return;		/* Again, no L2 cache is possible */
 447#endif
 448
 449	c->x86_cache_size = l2size;
 450}
 451
 452void __cpuinit detect_ht(struct cpuinfo_x86 *c)
 
 
 
 
 
 
 
 
 453{
 454#ifdef CONFIG_X86_HT
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 455	u32 eax, ebx, ecx, edx;
 456	int index_msb, core_bits;
 457	static bool printed;
 458
 459	if (!cpu_has(c, X86_FEATURE_HT))
 460		return;
 461
 462	if (cpu_has(c, X86_FEATURE_CMP_LEGACY))
 463		goto out;
 464
 465	if (cpu_has(c, X86_FEATURE_XTOPOLOGY))
 466		return;
 467
 468	cpuid(1, &eax, &ebx, &ecx, &edx);
 469
 470	smp_num_siblings = (ebx & 0xff0000) >> 16;
 471
 472	if (smp_num_siblings == 1) {
 473		printk_once(KERN_INFO "CPU0: Hyper-Threading is disabled\n");
 474		goto out;
 475	}
 476
 477	if (smp_num_siblings <= 1)
 478		goto out;
 479
 480	index_msb = get_count_order(smp_num_siblings);
 481	c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, index_msb);
 482
 483	smp_num_siblings = smp_num_siblings / c->x86_max_cores;
 484
 485	index_msb = get_count_order(smp_num_siblings);
 486
 487	core_bits = get_count_order(c->x86_max_cores);
 488
 489	c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid, index_msb) &
 490				       ((1 << core_bits) - 1);
 491
 492out:
 493	if (!printed && (c->x86_max_cores * smp_num_siblings) > 1) {
 494		printk(KERN_INFO  "CPU: Physical Processor ID: %d\n",
 495		       c->phys_proc_id);
 496		printk(KERN_INFO  "CPU: Processor Core ID: %d\n",
 497		       c->cpu_core_id);
 498		printed = 1;
 499	}
 500#endif
 501}
 502
 503static void __cpuinit get_cpu_vendor(struct cpuinfo_x86 *c)
 504{
 505	char *v = c->x86_vendor_id;
 506	int i;
 507
 508	for (i = 0; i < X86_VENDOR_NUM; i++) {
 509		if (!cpu_devs[i])
 510			break;
 511
 512		if (!strcmp(v, cpu_devs[i]->c_ident[0]) ||
 513		    (cpu_devs[i]->c_ident[1] &&
 514		     !strcmp(v, cpu_devs[i]->c_ident[1]))) {
 515
 516			this_cpu = cpu_devs[i];
 517			c->x86_vendor = this_cpu->c_x86_vendor;
 518			return;
 519		}
 520	}
 521
 522	printk_once(KERN_ERR
 523			"CPU: vendor_id '%s' unknown, using generic init.\n" \
 524			"CPU: Your system may be unstable.\n", v);
 525
 526	c->x86_vendor = X86_VENDOR_UNKNOWN;
 527	this_cpu = &default_cpu;
 528}
 529
 530void __cpuinit cpu_detect(struct cpuinfo_x86 *c)
 531{
 532	/* Get vendor name */
 533	cpuid(0x00000000, (unsigned int *)&c->cpuid_level,
 534	      (unsigned int *)&c->x86_vendor_id[0],
 535	      (unsigned int *)&c->x86_vendor_id[8],
 536	      (unsigned int *)&c->x86_vendor_id[4]);
 537
 538	c->x86 = 4;
 539	/* Intel-defined flags: level 0x00000001 */
 540	if (c->cpuid_level >= 0x00000001) {
 541		u32 junk, tfms, cap0, misc;
 542
 543		cpuid(0x00000001, &tfms, &misc, &junk, &cap0);
 544		c->x86 = (tfms >> 8) & 0xf;
 545		c->x86_model = (tfms >> 4) & 0xf;
 546		c->x86_mask = tfms & 0xf;
 547
 548		if (c->x86 == 0xf)
 549			c->x86 += (tfms >> 20) & 0xff;
 550		if (c->x86 >= 0x6)
 551			c->x86_model += ((tfms >> 16) & 0xf) << 4;
 552
 553		if (cap0 & (1<<19)) {
 554			c->x86_clflush_size = ((misc >> 8) & 0xff) * 8;
 555			c->x86_cache_alignment = c->x86_clflush_size;
 556		}
 557	}
 558}
 559
 560void __cpuinit get_cpu_cap(struct cpuinfo_x86 *c)
 561{
 562	u32 tfms, xlvl;
 563	u32 ebx;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 564
 565	/* Intel-defined flags: level 0x00000001 */
 566	if (c->cpuid_level >= 0x00000001) {
 567		u32 capability, excap;
 568
 569		cpuid(0x00000001, &tfms, &ebx, &excap, &capability);
 570		c->x86_capability[0] = capability;
 571		c->x86_capability[4] = excap;
 572	}
 573
 
 
 
 
 574	/* Additional Intel-defined flags: level 0x00000007 */
 575	if (c->cpuid_level >= 0x00000007) {
 576		u32 eax, ebx, ecx, edx;
 
 
 
 
 
 
 
 
 577
 578		cpuid_count(0x00000007, 0, &eax, &ebx, &ecx, &edx);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 579
 580		c->x86_capability[9] = ebx;
 
 
 
 
 
 
 
 
 
 581	}
 582
 583	/* AMD-defined flags: level 0x80000001 */
 584	xlvl = cpuid_eax(0x80000000);
 585	c->extended_cpuid_level = xlvl;
 586
 587	if ((xlvl & 0xffff0000) == 0x80000000) {
 588		if (xlvl >= 0x80000001) {
 589			c->x86_capability[1] = cpuid_edx(0x80000001);
 590			c->x86_capability[6] = cpuid_ecx(0x80000001);
 
 
 591		}
 592	}
 593
 
 
 
 
 
 
 
 594	if (c->extended_cpuid_level >= 0x80000008) {
 595		u32 eax = cpuid_eax(0x80000008);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 596
 597		c->x86_virt_bits = (eax >> 8) & 0xff;
 598		c->x86_phys_bits = eax & 0xff;
 599	}
 600#ifdef CONFIG_X86_32
 601	else if (cpu_has(c, X86_FEATURE_PAE) || cpu_has(c, X86_FEATURE_PSE36))
 602		c->x86_phys_bits = 36;
 603#endif
 604
 605	if (c->extended_cpuid_level >= 0x80000007)
 606		c->x86_power = cpuid_edx(0x80000007);
 607
 608	init_scattered_cpuid_features(c);
 609}
 610
 611static void __cpuinit identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
 612{
 613#ifdef CONFIG_X86_32
 614	int i;
 615
 616	/*
 617	 * First of all, decide if this is a 486 or higher
 618	 * It's a 486 if we can modify the AC flag
 619	 */
 620	if (flag_is_changeable_p(X86_EFLAGS_AC))
 621		c->x86 = 4;
 622	else
 623		c->x86 = 3;
 624
 625	for (i = 0; i < X86_VENDOR_NUM; i++)
 626		if (cpu_devs[i] && cpu_devs[i]->c_identify) {
 627			c->x86_vendor_id[0] = 0;
 628			cpu_devs[i]->c_identify(c);
 629			if (c->x86_vendor_id[0]) {
 630				get_cpu_vendor(c);
 631				break;
 632			}
 633		}
 634#endif
 635}
 636
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 637/*
 638 * Do minimum CPU detection early.
 639 * Fields really needed: vendor, cpuid_level, family, model, mask,
 640 * cache alignment.
 641 * The others are not touched to avoid unwanted side effects.
 642 *
 643 * WARNING: this function is only called on the BP.  Don't add code here
 644 * that is supposed to run on all CPUs.
 645 */
 646static void __init early_identify_cpu(struct cpuinfo_x86 *c)
 647{
 648#ifdef CONFIG_X86_64
 649	c->x86_clflush_size = 64;
 650	c->x86_phys_bits = 36;
 651	c->x86_virt_bits = 48;
 652#else
 653	c->x86_clflush_size = 32;
 654	c->x86_phys_bits = 32;
 655	c->x86_virt_bits = 32;
 656#endif
 657	c->x86_cache_alignment = c->x86_clflush_size;
 658
 659	memset(&c->x86_capability, 0, sizeof c->x86_capability);
 660	c->extended_cpuid_level = 0;
 661
 662	if (!have_cpuid_p())
 663		identify_cpu_without_cpuid(c);
 
 
 
 
 
 
 
 
 664
 665	/* cyrix could have cpuid enabled via c_identify()*/
 666	if (!have_cpuid_p())
 667		return;
 668
 669	cpu_detect(c);
 
 
 
 
 
 670
 671	get_cpu_vendor(c);
 672
 673	get_cpu_cap(c);
 674
 675	if (this_cpu->c_early_init)
 676		this_cpu->c_early_init(c);
 677
 678#ifdef CONFIG_SMP
 679	c->cpu_index = 0;
 
 
 
 
 680#endif
 681	filter_cpuid_features(c, false);
 682
 683	setup_smep(c);
 684}
 685
 686void __init early_cpu_init(void)
 687{
 688	const struct cpu_dev *const *cdev;
 689	int count = 0;
 690
 691#ifdef CONFIG_PROCESSOR_SELECT
 692	printk(KERN_INFO "KERNEL supported cpus:\n");
 693#endif
 694
 695	for (cdev = __x86_cpu_dev_start; cdev < __x86_cpu_dev_end; cdev++) {
 696		const struct cpu_dev *cpudev = *cdev;
 697
 698		if (count >= X86_VENDOR_NUM)
 699			break;
 700		cpu_devs[count] = cpudev;
 701		count++;
 702
 703#ifdef CONFIG_PROCESSOR_SELECT
 704		{
 705			unsigned int j;
 706
 707			for (j = 0; j < 2; j++) {
 708				if (!cpudev->c_ident[j])
 709					continue;
 710				printk(KERN_INFO "  %s %s\n", cpudev->c_vendor,
 711					cpudev->c_ident[j]);
 712			}
 713		}
 714#endif
 715	}
 716	early_identify_cpu(&boot_cpu_data);
 717}
 718
 719/*
 720 * The NOPL instruction is supposed to exist on all CPUs of family >= 6;
 721 * unfortunately, that's not true in practice because of early VIA
 722 * chips and (more importantly) broken virtualizers that are not easy
 723 * to detect. In the latter case it doesn't even *fail* reliably, so
 724 * probing for it doesn't even work. Disable it completely on 32-bit
 725 * unless we can find a reliable way to detect all the broken cases.
 726 * Enable it explicitly on 64-bit for non-constant inputs of cpu_has().
 727 */
 728static void __cpuinit detect_nopl(struct cpuinfo_x86 *c)
 729{
 730#ifdef CONFIG_X86_32
 731	clear_cpu_cap(c, X86_FEATURE_NOPL);
 732#else
 733	set_cpu_cap(c, X86_FEATURE_NOPL);
 734#endif
 735}
 736
 737static void __cpuinit generic_identify(struct cpuinfo_x86 *c)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 738{
 739	c->extended_cpuid_level = 0;
 740
 741	if (!have_cpuid_p())
 742		identify_cpu_without_cpuid(c);
 743
 744	/* cyrix could have cpuid enabled via c_identify()*/
 745	if (!have_cpuid_p())
 746		return;
 747
 748	cpu_detect(c);
 749
 750	get_cpu_vendor(c);
 751
 752	get_cpu_cap(c);
 753
 
 
 754	if (c->cpuid_level >= 0x00000001) {
 755		c->initial_apicid = (cpuid_ebx(1) >> 24) & 0xFF;
 756#ifdef CONFIG_X86_32
 757# ifdef CONFIG_X86_HT
 758		c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
 759# else
 760		c->apicid = c->initial_apicid;
 761# endif
 762#endif
 
 
 763
 764#ifdef CONFIG_X86_HT
 765		c->phys_proc_id = c->initial_apicid;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 766#endif
 
 
 
 
 
 
 
 
 
 
 
 
 
 767	}
 
 768
 769	setup_smep(c);
 
 
 
 
 
 
 
 770
 771	get_model_name(c); /* Default name */
 772
 773	detect_nopl(c);
 
 
 
 
 
 
 
 774}
 775
 776/*
 777 * This does the hard work of actually picking apart the CPU stuff...
 778 */
 779static void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
 780{
 781	int i;
 782
 783	c->loops_per_jiffy = loops_per_jiffy;
 784	c->x86_cache_size = -1;
 785	c->x86_vendor = X86_VENDOR_UNKNOWN;
 786	c->x86_model = c->x86_mask = 0;	/* So far unknown... */
 787	c->x86_vendor_id[0] = '\0'; /* Unset */
 788	c->x86_model_id[0] = '\0';  /* Unset */
 789	c->x86_max_cores = 1;
 790	c->x86_coreid_bits = 0;
 
 791#ifdef CONFIG_X86_64
 792	c->x86_clflush_size = 64;
 793	c->x86_phys_bits = 36;
 794	c->x86_virt_bits = 48;
 795#else
 796	c->cpuid_level = -1;	/* CPUID not detected */
 797	c->x86_clflush_size = 32;
 798	c->x86_phys_bits = 32;
 799	c->x86_virt_bits = 32;
 800#endif
 801	c->x86_cache_alignment = c->x86_clflush_size;
 802	memset(&c->x86_capability, 0, sizeof c->x86_capability);
 803
 804	generic_identify(c);
 805
 806	if (this_cpu->c_identify)
 807		this_cpu->c_identify(c);
 808
 809	/* Clear/Set all flags overriden by options, after probe */
 810	for (i = 0; i < NCAPINTS; i++) {
 811		c->x86_capability[i] &= ~cpu_caps_cleared[i];
 812		c->x86_capability[i] |= cpu_caps_set[i];
 813	}
 814
 815#ifdef CONFIG_X86_64
 816	c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
 817#endif
 818
 819	/*
 820	 * Vendor-specific initialization.  In this section we
 821	 * canonicalize the feature flags, meaning if there are
 822	 * features a certain CPU supports which CPUID doesn't
 823	 * tell us, CPUID claiming incorrect flags, or other bugs,
 824	 * we handle them here.
 825	 *
 826	 * At the end of this section, c->x86_capability better
 827	 * indicate the features this CPU genuinely supports!
 828	 */
 829	if (this_cpu->c_init)
 830		this_cpu->c_init(c);
 831
 832	/* Disable the PN if appropriate */
 833	squash_the_stupid_serial_number(c);
 834
 
 
 
 
 
 835	/*
 836	 * The vendor-specific functions might have changed features.
 837	 * Now we do "generic changes."
 838	 */
 839
 840	/* Filter out anything that depends on CPUID levels we don't have */
 841	filter_cpuid_features(c, true);
 842
 843	/* If the model name is still unset, do table lookup. */
 844	if (!c->x86_model_id[0]) {
 845		const char *p;
 846		p = table_lookup_model(c);
 847		if (p)
 848			strcpy(c->x86_model_id, p);
 849		else
 850			/* Last resort... */
 851			sprintf(c->x86_model_id, "%02x/%02x",
 852				c->x86, c->x86_model);
 853	}
 854
 855#ifdef CONFIG_X86_64
 856	detect_ht(c);
 857#endif
 858
 859	init_hypervisor(c);
 
 
 860
 861	/*
 862	 * Clear/Set all flags overriden by options, need do it
 863	 * before following smp all cpus cap AND.
 864	 */
 865	for (i = 0; i < NCAPINTS; i++) {
 866		c->x86_capability[i] &= ~cpu_caps_cleared[i];
 867		c->x86_capability[i] |= cpu_caps_set[i];
 868	}
 869
 870	/*
 871	 * On SMP, boot_cpu_data holds the common feature set between
 872	 * all CPUs; so make sure that we indicate which features are
 873	 * common between the CPUs.  The first time this routine gets
 874	 * executed, c == &boot_cpu_data.
 875	 */
 876	if (c != &boot_cpu_data) {
 877		/* AND the already accumulated flags with these */
 878		for (i = 0; i < NCAPINTS; i++)
 879			boot_cpu_data.x86_capability[i] &= c->x86_capability[i];
 
 
 
 
 880	}
 881
 882	/* Init Machine Check Exception if available. */
 883	mcheck_cpu_init(c);
 884
 885	select_idle_routine(c);
 886
 887#ifdef CONFIG_NUMA
 888	numa_add_cpu(smp_processor_id());
 889#endif
 890}
 891
 892#ifdef CONFIG_X86_64
 893static void vgetcpu_set_mode(void)
 
 
 
 
 894{
 895	if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP))
 896		vgetcpu_mode = VGETCPU_RDTSCP;
 897	else
 898		vgetcpu_mode = VGETCPU_LSL;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 899}
 900#endif
 901
 902void __init identify_boot_cpu(void)
 903{
 904	identify_cpu(&boot_cpu_data);
 905	init_amd_e400_c1e_mask();
 906#ifdef CONFIG_X86_32
 907	sysenter_setup();
 908	enable_sep_cpu();
 909#else
 910	vgetcpu_set_mode();
 911#endif
 
 912}
 913
 914void __cpuinit identify_secondary_cpu(struct cpuinfo_x86 *c)
 915{
 916	BUG_ON(c == &boot_cpu_data);
 917	identify_cpu(c);
 918#ifdef CONFIG_X86_32
 919	enable_sep_cpu();
 920#endif
 921	mtrr_ap_init();
 
 
 922}
 923
 924struct msr_range {
 925	unsigned	min;
 926	unsigned	max;
 927};
 928
 929static const struct msr_range msr_range_array[] __cpuinitconst = {
 930	{ 0x00000000, 0x00000418},
 931	{ 0xc0000000, 0xc000040b},
 932	{ 0xc0010000, 0xc0010142},
 933	{ 0xc0011000, 0xc001103b},
 934};
 935
 936static void __cpuinit print_cpu_msr(void)
 937{
 938	unsigned index_min, index_max;
 939	unsigned index;
 940	u64 val;
 941	int i;
 942
 943	for (i = 0; i < ARRAY_SIZE(msr_range_array); i++) {
 944		index_min = msr_range_array[i].min;
 945		index_max = msr_range_array[i].max;
 946
 947		for (index = index_min; index < index_max; index++) {
 948			if (rdmsrl_amd_safe(index, &val))
 949				continue;
 950			printk(KERN_INFO " MSR%08x: %016llx\n", index, val);
 951		}
 952	}
 953}
 954
 955static int show_msr __cpuinitdata;
 956
 957static __init int setup_show_msr(char *arg)
 958{
 959	int num;
 960
 961	get_option(&arg, &num);
 962
 963	if (num > 0)
 964		show_msr = num;
 965	return 1;
 966}
 967__setup("show_msr=", setup_show_msr);
 968
 969static __init int setup_noclflush(char *arg)
 970{
 971	setup_clear_cpu_cap(X86_FEATURE_CLFLSH);
 
 972	return 1;
 973}
 974__setup("noclflush", setup_noclflush);
 975
 976void __cpuinit print_cpu_info(struct cpuinfo_x86 *c)
 977{
 978	const char *vendor = NULL;
 979
 980	if (c->x86_vendor < X86_VENDOR_NUM) {
 981		vendor = this_cpu->c_vendor;
 982	} else {
 983		if (c->cpuid_level >= 0)
 984			vendor = c->x86_vendor_id;
 985	}
 986
 987	if (vendor && !strstr(c->x86_model_id, vendor))
 988		printk(KERN_CONT "%s ", vendor);
 989
 990	if (c->x86_model_id[0])
 991		printk(KERN_CONT "%s", c->x86_model_id);
 992	else
 993		printk(KERN_CONT "%d86", c->x86);
 
 
 994
 995	if (c->x86_mask || c->cpuid_level >= 0)
 996		printk(KERN_CONT " stepping %02x\n", c->x86_mask);
 997	else
 998		printk(KERN_CONT "\n");
 999
1000#ifdef CONFIG_SMP
1001	if (c->cpu_index < show_msr)
1002		print_cpu_msr();
1003#else
1004	if (show_msr)
1005		print_cpu_msr();
1006#endif
1007}
1008
1009static __init int setup_disablecpuid(char *arg)
 
 
 
 
 
1010{
1011	int bit;
1012
1013	if (get_option(&arg, &bit) && bit < NCAPINTS*32)
1014		setup_clear_cpu_cap(bit);
1015	else
1016		return 0;
1017
1018	return 1;
1019}
1020__setup("clearcpuid=", setup_disablecpuid);
1021
1022#ifdef CONFIG_X86_64
1023struct desc_ptr idt_descr = { NR_VECTORS * 16 - 1, (unsigned long) idt_table };
1024
1025DEFINE_PER_CPU_FIRST(union irq_stack_union,
1026		     irq_stack_union) __aligned(PAGE_SIZE);
 
1027
1028/*
1029 * The following four percpu variables are hot.  Align current_task to
1030 * cacheline size such that all four fall in the same cacheline.
1031 */
1032DEFINE_PER_CPU(struct task_struct *, current_task) ____cacheline_aligned =
1033	&init_task;
1034EXPORT_PER_CPU_SYMBOL(current_task);
1035
1036DEFINE_PER_CPU(unsigned long, kernel_stack) =
1037	(unsigned long)&init_thread_union - KERNEL_STACK_OFFSET + THREAD_SIZE;
1038EXPORT_PER_CPU_SYMBOL(kernel_stack);
1039
1040DEFINE_PER_CPU(char *, irq_stack_ptr) =
1041	init_per_cpu_var(irq_stack_union.irq_stack) + IRQ_STACK_SIZE - 64;
1042
1043DEFINE_PER_CPU(unsigned int, irq_count) = -1;
1044
1045/*
1046 * Special IST stacks which the CPU switches to when it calls
1047 * an IST-marked descriptor entry. Up to 7 stacks (hardware
1048 * limit), all of them are 4K, except the debug stack which
1049 * is 8K.
1050 */
1051static const unsigned int exception_stack_sizes[N_EXCEPTION_STACKS] = {
1052	  [0 ... N_EXCEPTION_STACKS - 1]	= EXCEPTION_STKSZ,
1053	  [DEBUG_STACK - 1]			= DEBUG_STKSZ
1054};
1055
1056static DEFINE_PER_CPU_PAGE_ALIGNED(char, exception_stacks
1057	[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ]);
1058
1059/* May not be marked __init: used by software suspend */
1060void syscall_init(void)
1061{
1062	/*
1063	 * LSTAR and STAR live in a bit strange symbiosis.
1064	 * They both write to the same internal register. STAR allows to
1065	 * set CS/DS but only a 32bit target. LSTAR sets the 64bit rip.
1066	 */
1067	wrmsrl(MSR_STAR,  ((u64)__USER32_CS)<<48  | ((u64)__KERNEL_CS)<<32);
1068	wrmsrl(MSR_LSTAR, system_call);
1069	wrmsrl(MSR_CSTAR, ignore_sysret);
 
 
 
 
 
1070
1071#ifdef CONFIG_IA32_EMULATION
1072	syscall32_cpu_init();
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1073#endif
1074
1075	/* Flags to clear on syscall */
1076	wrmsrl(MSR_SYSCALL_MASK,
1077	       X86_EFLAGS_TF|X86_EFLAGS_DF|X86_EFLAGS_IF|X86_EFLAGS_IOPL);
 
1078}
1079
1080unsigned long kernel_eflags;
1081
1082/*
1083 * Copies of the original ist values from the tss are only accessed during
1084 * debugging, no special alignment required.
1085 */
1086DEFINE_PER_CPU(struct orig_ist, orig_ist);
1087
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1088#else	/* CONFIG_X86_64 */
1089
1090DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task;
1091EXPORT_PER_CPU_SYMBOL(current_task);
 
 
 
 
 
 
 
 
 
 
 
1092
1093#ifdef CONFIG_CC_STACKPROTECTOR
1094DEFINE_PER_CPU_ALIGNED(struct stack_canary, stack_canary);
1095#endif
1096
1097/* Make sure %fs and %gs are initialized properly in idle threads */
1098struct pt_regs * __cpuinit idle_regs(struct pt_regs *regs)
1099{
1100	memset(regs, 0, sizeof(struct pt_regs));
1101	regs->fs = __KERNEL_PERCPU;
1102	regs->gs = __KERNEL_STACK_CANARY;
1103
1104	return regs;
1105}
1106#endif	/* CONFIG_X86_64 */
1107
1108/*
1109 * Clear all 6 debug registers:
1110 */
1111static void clear_all_debug_regs(void)
1112{
1113	int i;
1114
1115	for (i = 0; i < 8; i++) {
1116		/* Ignore db4, db5 */
1117		if ((i == 4) || (i == 5))
1118			continue;
1119
1120		set_debugreg(0, i);
1121	}
1122}
1123
1124#ifdef CONFIG_KGDB
1125/*
1126 * Restore debug regs if using kgdbwait and you have a kernel debugger
1127 * connection established.
1128 */
1129static void dbg_restore_debug_regs(void)
1130{
1131	if (unlikely(kgdb_connected && arch_kgdb_ops.correct_hw_break))
1132		arch_kgdb_ops.correct_hw_break();
1133}
1134#else /* ! CONFIG_KGDB */
1135#define dbg_restore_debug_regs()
1136#endif /* ! CONFIG_KGDB */
1137
 
 
 
 
 
 
 
 
 
 
 
 
 
1138/*
1139 * cpu_init() initializes state that is per-CPU. Some data is already
1140 * initialized (naturally) in the bootstrap process, such as the GDT
1141 * and IDT. We reload them nevertheless, this function acts as a
1142 * 'CPU state barrier', nothing should get across.
1143 * A lot of state is already set up in PDA init for 64 bit
1144 */
1145#ifdef CONFIG_X86_64
1146
1147void __cpuinit cpu_init(void)
1148{
1149	struct orig_ist *oist;
1150	struct task_struct *me;
1151	struct tss_struct *t;
1152	unsigned long v;
1153	int cpu;
1154	int i;
1155
1156	cpu = stack_smp_processor_id();
1157	t = &per_cpu(init_tss, cpu);
 
 
 
 
 
 
 
 
 
 
1158	oist = &per_cpu(orig_ist, cpu);
1159
1160#ifdef CONFIG_NUMA
1161	if (cpu != 0 && percpu_read(numa_node) == 0 &&
1162	    early_cpu_to_node(cpu) != NUMA_NO_NODE)
1163		set_numa_node(early_cpu_to_node(cpu));
1164#endif
1165
1166	me = current;
1167
1168	if (cpumask_test_and_set_cpu(cpu, cpu_initialized_mask))
1169		panic("CPU#%d already initialized!\n", cpu);
1170
1171	pr_debug("Initializing CPU#%d\n", cpu);
1172
1173	clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1174
1175	/*
1176	 * Initialize the per-CPU GDT with the boot GDT,
1177	 * and set up the GDT descriptor:
1178	 */
1179
1180	switch_to_new_gdt(cpu);
1181	loadsegment(fs, 0);
1182
1183	load_idt((const struct desc_ptr *)&idt_descr);
1184
1185	memset(me->thread.tls_array, 0, GDT_ENTRY_TLS_ENTRIES * 8);
1186	syscall_init();
1187
1188	wrmsrl(MSR_FS_BASE, 0);
1189	wrmsrl(MSR_KERNEL_GS_BASE, 0);
1190	barrier();
1191
1192	x86_configure_nx();
1193	if (cpu != 0)
1194		enable_x2apic();
1195
1196	/*
1197	 * set up and load the per-CPU TSS
1198	 */
1199	if (!oist->ist[0]) {
1200		char *estacks = per_cpu(exception_stacks, cpu);
1201
1202		for (v = 0; v < N_EXCEPTION_STACKS; v++) {
1203			estacks += exception_stack_sizes[v];
1204			oist->ist[v] = t->x86_tss.ist[v] =
1205					(unsigned long)estacks;
 
 
1206		}
1207	}
1208
1209	t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
1210
1211	/*
1212	 * <= is required because the CPU will access up to
1213	 * 8 bits beyond the end of the IO permission bitmap.
1214	 */
1215	for (i = 0; i <= IO_BITMAP_LONGS; i++)
1216		t->io_bitmap[i] = ~0UL;
1217
1218	atomic_inc(&init_mm.mm_count);
1219	me->active_mm = &init_mm;
1220	BUG_ON(me->mm);
 
1221	enter_lazy_tlb(&init_mm, me);
1222
1223	load_sp0(t, &current->thread);
1224	set_tss_desc(cpu, t);
 
 
 
1225	load_TR_desc();
1226	load_LDT(&init_mm.context);
 
 
1227
1228	clear_all_debug_regs();
1229	dbg_restore_debug_regs();
1230
1231	fpu_init();
1232	xsave_init();
1233
1234	raw_local_save_flags(kernel_eflags);
1235
1236	if (is_uv_system())
1237		uv_cpu_init();
 
 
1238}
1239
1240#else
1241
1242void __cpuinit cpu_init(void)
1243{
1244	int cpu = smp_processor_id();
1245	struct task_struct *curr = current;
1246	struct tss_struct *t = &per_cpu(init_tss, cpu);
1247	struct thread_struct *thread = &curr->thread;
 
1248
1249	if (cpumask_test_and_set_cpu(cpu, cpu_initialized_mask)) {
1250		printk(KERN_WARNING "CPU#%d already initialized!\n", cpu);
1251		for (;;)
1252			local_irq_enable();
1253	}
 
 
1254
1255	printk(KERN_INFO "Initializing CPU#%d\n", cpu);
1256
1257	if (cpu_has_vme || cpu_has_tsc || cpu_has_de)
1258		clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
 
 
1259
1260	load_idt(&idt_descr);
1261	switch_to_new_gdt(cpu);
1262
1263	/*
1264	 * Set up and load the per-CPU TSS and LDT
1265	 */
1266	atomic_inc(&init_mm.mm_count);
1267	curr->active_mm = &init_mm;
1268	BUG_ON(curr->mm);
 
1269	enter_lazy_tlb(&init_mm, curr);
1270
1271	load_sp0(t, thread);
1272	set_tss_desc(cpu, t);
 
 
 
1273	load_TR_desc();
1274	load_LDT(&init_mm.context);
1275
1276	t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
 
 
1277
1278#ifdef CONFIG_DOUBLEFAULT
1279	/* Set up doublefault TSS pointer in the GDT */
1280	__set_tss_desc(cpu, GDT_ENTRY_DOUBLEFAULT_TSS, &doublefault_tss);
1281#endif
1282
1283	clear_all_debug_regs();
1284	dbg_restore_debug_regs();
1285
1286	fpu_init();
1287	xsave_init();
 
1288}
1289#endif