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>
18 #include <linux/syscore_ops.h>
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>
38 #include <asm/fpu/internal.h>
40 #include <asm/hwcap2.h>
41 #include <linux/numa.h>
48 #include <asm/microcode.h>
49 #include <asm/microcode_intel.h>
51 #ifdef CONFIG_X86_LOCAL_APIC
52 #include <asm/uv/uv.h>
57 u32 elf_hwcap2 __read_mostly;
59 /* all of these masks are initialized in setup_cpu_local_masks() */
60 cpumask_var_t cpu_initialized_mask;
61 cpumask_var_t cpu_callout_mask;
62 cpumask_var_t cpu_callin_mask;
64 /* representing cpus for which sibling maps can be computed */
65 cpumask_var_t cpu_sibling_setup_mask;
67 /* correctly size the local cpu masks */
68 void __init setup_cpu_local_masks(void)
70 alloc_bootmem_cpumask_var(&cpu_initialized_mask);
71 alloc_bootmem_cpumask_var(&cpu_callin_mask);
72 alloc_bootmem_cpumask_var(&cpu_callout_mask);
73 alloc_bootmem_cpumask_var(&cpu_sibling_setup_mask);
76 static void default_init(struct cpuinfo_x86 *c)
79 cpu_detect_cache_sizes(c);
81 /* Not much we can do here... */
82 /* Check if at least it has cpuid */
83 if (c->cpuid_level == -1) {
84 /* No cpuid. It must be an ancient CPU */
86 strcpy(c->x86_model_id, "486");
88 strcpy(c->x86_model_id, "386");
93 static const struct cpu_dev default_cpu = {
94 .c_init = default_init,
95 .c_vendor = "Unknown",
96 .c_x86_vendor = X86_VENDOR_UNKNOWN,
99 static const struct cpu_dev *this_cpu = &default_cpu;
101 DEFINE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page) = { .gdt = {
104 * We need valid kernel segments for data and code in long mode too
105 * IRET will check the segment types kkeil 2000/10/28
106 * Also sysret mandates a special GDT layout
108 * TLS descriptors are currently at a different place compared to i386.
109 * Hopefully nobody expects them at a fixed place (Wine?)
111 [GDT_ENTRY_KERNEL32_CS] = GDT_ENTRY_INIT(0xc09b, 0, 0xfffff),
112 [GDT_ENTRY_KERNEL_CS] = GDT_ENTRY_INIT(0xa09b, 0, 0xfffff),
113 [GDT_ENTRY_KERNEL_DS] = GDT_ENTRY_INIT(0xc093, 0, 0xfffff),
114 [GDT_ENTRY_DEFAULT_USER32_CS] = GDT_ENTRY_INIT(0xc0fb, 0, 0xfffff),
115 [GDT_ENTRY_DEFAULT_USER_DS] = GDT_ENTRY_INIT(0xc0f3, 0, 0xfffff),
116 [GDT_ENTRY_DEFAULT_USER_CS] = GDT_ENTRY_INIT(0xa0fb, 0, 0xfffff),
118 [GDT_ENTRY_KERNEL_CS] = GDT_ENTRY_INIT(0xc09a, 0, 0xfffff),
119 [GDT_ENTRY_KERNEL_DS] = GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
120 [GDT_ENTRY_DEFAULT_USER_CS] = GDT_ENTRY_INIT(0xc0fa, 0, 0xfffff),
121 [GDT_ENTRY_DEFAULT_USER_DS] = GDT_ENTRY_INIT(0xc0f2, 0, 0xfffff),
123 * Segments used for calling PnP BIOS have byte granularity.
124 * They code segments and data segments have fixed 64k limits,
125 * the transfer segment sizes are set at run time.
128 [GDT_ENTRY_PNPBIOS_CS32] = GDT_ENTRY_INIT(0x409a, 0, 0xffff),
130 [GDT_ENTRY_PNPBIOS_CS16] = GDT_ENTRY_INIT(0x009a, 0, 0xffff),
132 [GDT_ENTRY_PNPBIOS_DS] = GDT_ENTRY_INIT(0x0092, 0, 0xffff),
134 [GDT_ENTRY_PNPBIOS_TS1] = GDT_ENTRY_INIT(0x0092, 0, 0),
136 [GDT_ENTRY_PNPBIOS_TS2] = GDT_ENTRY_INIT(0x0092, 0, 0),
138 * The APM segments have byte granularity and their bases
139 * are set at run time. All have 64k limits.
142 [GDT_ENTRY_APMBIOS_BASE] = GDT_ENTRY_INIT(0x409a, 0, 0xffff),
144 [GDT_ENTRY_APMBIOS_BASE+1] = GDT_ENTRY_INIT(0x009a, 0, 0xffff),
146 [GDT_ENTRY_APMBIOS_BASE+2] = GDT_ENTRY_INIT(0x4092, 0, 0xffff),
148 [GDT_ENTRY_ESPFIX_SS] = GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
149 [GDT_ENTRY_PERCPU] = GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
150 GDT_STACK_CANARY_INIT
153 EXPORT_PER_CPU_SYMBOL_GPL(gdt_page);
155 static int __init x86_mpx_setup(char *s)
157 /* require an exact match without trailing characters */
161 /* do not emit a message if the feature is not present */
162 if (!boot_cpu_has(X86_FEATURE_MPX))
165 setup_clear_cpu_cap(X86_FEATURE_MPX);
166 pr_info("nompx: Intel Memory Protection Extensions (MPX) disabled\n");
169 __setup("nompx", x86_mpx_setup);
171 static int __init x86_noinvpcid_setup(char *s)
173 /* noinvpcid doesn't accept parameters */
177 /* do not emit a message if the feature is not present */
178 if (!boot_cpu_has(X86_FEATURE_INVPCID))
181 setup_clear_cpu_cap(X86_FEATURE_INVPCID);
182 pr_info("noinvpcid: INVPCID feature disabled\n");
185 early_param("noinvpcid", x86_noinvpcid_setup);
188 static int cachesize_override = -1;
189 static int disable_x86_serial_nr = 1;
191 static int __init cachesize_setup(char *str)
193 get_option(&str, &cachesize_override);
196 __setup("cachesize=", cachesize_setup);
198 static int __init x86_sep_setup(char *s)
200 setup_clear_cpu_cap(X86_FEATURE_SEP);
203 __setup("nosep", x86_sep_setup);
205 /* Standard macro to see if a specific flag is changeable */
206 static inline int flag_is_changeable_p(u32 flag)
211 * Cyrix and IDT cpus allow disabling of CPUID
212 * so the code below may return different results
213 * when it is executed before and after enabling
214 * the CPUID. Add "volatile" to not allow gcc to
215 * optimize the subsequent calls to this function.
217 asm volatile ("pushfl \n\t"
228 : "=&r" (f1), "=&r" (f2)
231 return ((f1^f2) & flag) != 0;
234 /* Probe for the CPUID instruction */
235 int have_cpuid_p(void)
237 return flag_is_changeable_p(X86_EFLAGS_ID);
240 static void squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
242 unsigned long lo, hi;
244 if (!cpu_has(c, X86_FEATURE_PN) || !disable_x86_serial_nr)
247 /* Disable processor serial number: */
249 rdmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
251 wrmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
253 pr_notice("CPU serial number disabled.\n");
254 clear_cpu_cap(c, X86_FEATURE_PN);
256 /* Disabling the serial number may affect the cpuid level */
257 c->cpuid_level = cpuid_eax(0);
260 static int __init x86_serial_nr_setup(char *s)
262 disable_x86_serial_nr = 0;
265 __setup("serialnumber", x86_serial_nr_setup);
267 static inline int flag_is_changeable_p(u32 flag)
271 static inline void squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
276 static __init int setup_disable_smep(char *arg)
278 setup_clear_cpu_cap(X86_FEATURE_SMEP);
279 /* Check for things that depend on SMEP being enabled: */
280 check_mpx_erratum(&boot_cpu_data);
283 __setup("nosmep", setup_disable_smep);
285 static __always_inline void setup_smep(struct cpuinfo_x86 *c)
287 if (cpu_has(c, X86_FEATURE_SMEP))
288 cr4_set_bits(X86_CR4_SMEP);
291 static __init int setup_disable_smap(char *arg)
293 setup_clear_cpu_cap(X86_FEATURE_SMAP);
296 __setup("nosmap", setup_disable_smap);
298 static __always_inline void setup_smap(struct cpuinfo_x86 *c)
300 unsigned long eflags = native_save_fl();
302 /* This should have been cleared long ago */
303 BUG_ON(eflags & X86_EFLAGS_AC);
305 if (cpu_has(c, X86_FEATURE_SMAP)) {
306 #ifdef CONFIG_X86_SMAP
307 cr4_set_bits(X86_CR4_SMAP);
309 cr4_clear_bits(X86_CR4_SMAP);
315 * Protection Keys are not available in 32-bit mode.
317 static bool pku_disabled;
319 static __always_inline void setup_pku(struct cpuinfo_x86 *c)
321 /* check the boot processor, plus compile options for PKU: */
322 if (!cpu_feature_enabled(X86_FEATURE_PKU))
324 /* checks the actual processor's cpuid bits: */
325 if (!cpu_has(c, X86_FEATURE_PKU))
330 cr4_set_bits(X86_CR4_PKE);
332 * Seting X86_CR4_PKE will cause the X86_FEATURE_OSPKE
333 * cpuid bit to be set. We need to ensure that we
334 * update that bit in this CPU's "cpu_info".
339 #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
340 static __init int setup_disable_pku(char *arg)
343 * Do not clear the X86_FEATURE_PKU bit. All of the
344 * runtime checks are against OSPKE so clearing the
347 * This way, we will see "pku" in cpuinfo, but not
348 * "ospke", which is exactly what we want. It shows
349 * that the CPU has PKU, but the OS has not enabled it.
350 * This happens to be exactly how a system would look
351 * if we disabled the config option.
353 pr_info("x86: 'nopku' specified, disabling Memory Protection Keys\n");
357 __setup("nopku", setup_disable_pku);
358 #endif /* CONFIG_X86_64 */
361 * Some CPU features depend on higher CPUID levels, which may not always
362 * be available due to CPUID level capping or broken virtualization
363 * software. Add those features to this table to auto-disable them.
365 struct cpuid_dependent_feature {
370 static const struct cpuid_dependent_feature
371 cpuid_dependent_features[] = {
372 { X86_FEATURE_MWAIT, 0x00000005 },
373 { X86_FEATURE_DCA, 0x00000009 },
374 { X86_FEATURE_XSAVE, 0x0000000d },
378 static void filter_cpuid_features(struct cpuinfo_x86 *c, bool warn)
380 const struct cpuid_dependent_feature *df;
382 for (df = cpuid_dependent_features; df->feature; df++) {
384 if (!cpu_has(c, df->feature))
387 * Note: cpuid_level is set to -1 if unavailable, but
388 * extended_extended_level is set to 0 if unavailable
389 * and the legitimate extended levels are all negative
390 * when signed; hence the weird messing around with
393 if (!((s32)df->level < 0 ?
394 (u32)df->level > (u32)c->extended_cpuid_level :
395 (s32)df->level > (s32)c->cpuid_level))
398 clear_cpu_cap(c, df->feature);
402 pr_warn("CPU: CPU feature " X86_CAP_FMT " disabled, no CPUID level 0x%x\n",
403 x86_cap_flag(df->feature), df->level);
408 * Naming convention should be: <Name> [(<Codename>)]
409 * This table only is used unless init_<vendor>() below doesn't set it;
410 * in particular, if CPUID levels 0x80000002..4 are supported, this
414 /* Look up CPU names by table lookup. */
415 static const char *table_lookup_model(struct cpuinfo_x86 *c)
418 const struct legacy_cpu_model_info *info;
420 if (c->x86_model >= 16)
421 return NULL; /* Range check */
426 info = this_cpu->legacy_models;
428 while (info->family) {
429 if (info->family == c->x86)
430 return info->model_names[c->x86_model];
434 return NULL; /* Not found */
437 __u32 cpu_caps_cleared[NCAPINTS];
438 __u32 cpu_caps_set[NCAPINTS];
440 void load_percpu_segment(int cpu)
443 loadsegment(fs, __KERNEL_PERCPU);
445 __loadsegment_simple(gs, 0);
446 wrmsrl(MSR_GS_BASE, (unsigned long)per_cpu(irq_stack_union.gs_base, cpu));
448 load_stack_canary_segment();
451 /* Setup the fixmap mapping only once per-processor */
452 static inline void setup_fixmap_gdt(int cpu)
455 /* On 64-bit systems, we use a read-only fixmap GDT. */
456 pgprot_t prot = PAGE_KERNEL_RO;
459 * On native 32-bit systems, the GDT cannot be read-only because
460 * our double fault handler uses a task gate, and entering through
461 * a task gate needs to change an available TSS to busy. If the GDT
462 * is read-only, that will triple fault.
464 * On Xen PV, the GDT must be read-only because the hypervisor requires
467 pgprot_t prot = boot_cpu_has(X86_FEATURE_XENPV) ?
468 PAGE_KERNEL_RO : PAGE_KERNEL;
471 __set_fixmap(get_cpu_gdt_ro_index(cpu), get_cpu_gdt_paddr(cpu), prot);
474 /* Load the original GDT from the per-cpu structure */
475 void load_direct_gdt(int cpu)
477 struct desc_ptr gdt_descr;
479 gdt_descr.address = (long)get_cpu_gdt_rw(cpu);
480 gdt_descr.size = GDT_SIZE - 1;
481 load_gdt(&gdt_descr);
483 EXPORT_SYMBOL_GPL(load_direct_gdt);
485 /* Load a fixmap remapping of the per-cpu GDT */
486 void load_fixmap_gdt(int cpu)
488 struct desc_ptr gdt_descr;
490 gdt_descr.address = (long)get_cpu_gdt_ro(cpu);
491 gdt_descr.size = GDT_SIZE - 1;
492 load_gdt(&gdt_descr);
494 EXPORT_SYMBOL_GPL(load_fixmap_gdt);
497 * Current gdt points %fs at the "master" per-cpu area: after this,
498 * it's on the real one.
500 void switch_to_new_gdt(int cpu)
502 /* Load the original GDT */
503 load_direct_gdt(cpu);
504 /* Reload the per-cpu base */
505 load_percpu_segment(cpu);
508 static const struct cpu_dev *cpu_devs[X86_VENDOR_NUM] = {};
510 static void get_model_name(struct cpuinfo_x86 *c)
515 if (c->extended_cpuid_level < 0x80000004)
518 v = (unsigned int *)c->x86_model_id;
519 cpuid(0x80000002, &v[0], &v[1], &v[2], &v[3]);
520 cpuid(0x80000003, &v[4], &v[5], &v[6], &v[7]);
521 cpuid(0x80000004, &v[8], &v[9], &v[10], &v[11]);
522 c->x86_model_id[48] = 0;
524 /* Trim whitespace */
525 p = q = s = &c->x86_model_id[0];
531 /* Note the last non-whitespace index */
541 void cpu_detect_cache_sizes(struct cpuinfo_x86 *c)
543 unsigned int n, dummy, ebx, ecx, edx, l2size;
545 n = c->extended_cpuid_level;
547 if (n >= 0x80000005) {
548 cpuid(0x80000005, &dummy, &ebx, &ecx, &edx);
549 c->x86_cache_size = (ecx>>24) + (edx>>24);
551 /* On K8 L1 TLB is inclusive, so don't count it */
556 if (n < 0x80000006) /* Some chips just has a large L1. */
559 cpuid(0x80000006, &dummy, &ebx, &ecx, &edx);
563 c->x86_tlbsize += ((ebx >> 16) & 0xfff) + (ebx & 0xfff);
565 /* do processor-specific cache resizing */
566 if (this_cpu->legacy_cache_size)
567 l2size = this_cpu->legacy_cache_size(c, l2size);
569 /* Allow user to override all this if necessary. */
570 if (cachesize_override != -1)
571 l2size = cachesize_override;
574 return; /* Again, no L2 cache is possible */
577 c->x86_cache_size = l2size;
580 u16 __read_mostly tlb_lli_4k[NR_INFO];
581 u16 __read_mostly tlb_lli_2m[NR_INFO];
582 u16 __read_mostly tlb_lli_4m[NR_INFO];
583 u16 __read_mostly tlb_lld_4k[NR_INFO];
584 u16 __read_mostly tlb_lld_2m[NR_INFO];
585 u16 __read_mostly tlb_lld_4m[NR_INFO];
586 u16 __read_mostly tlb_lld_1g[NR_INFO];
588 static void cpu_detect_tlb(struct cpuinfo_x86 *c)
590 if (this_cpu->c_detect_tlb)
591 this_cpu->c_detect_tlb(c);
593 pr_info("Last level iTLB entries: 4KB %d, 2MB %d, 4MB %d\n",
594 tlb_lli_4k[ENTRIES], tlb_lli_2m[ENTRIES],
595 tlb_lli_4m[ENTRIES]);
597 pr_info("Last level dTLB entries: 4KB %d, 2MB %d, 4MB %d, 1GB %d\n",
598 tlb_lld_4k[ENTRIES], tlb_lld_2m[ENTRIES],
599 tlb_lld_4m[ENTRIES], tlb_lld_1g[ENTRIES]);
602 void detect_ht(struct cpuinfo_x86 *c)
605 u32 eax, ebx, ecx, edx;
606 int index_msb, core_bits;
609 if (!cpu_has(c, X86_FEATURE_HT))
612 if (cpu_has(c, X86_FEATURE_CMP_LEGACY))
615 if (cpu_has(c, X86_FEATURE_XTOPOLOGY))
618 cpuid(1, &eax, &ebx, &ecx, &edx);
620 smp_num_siblings = (ebx & 0xff0000) >> 16;
622 if (smp_num_siblings == 1) {
623 pr_info_once("CPU0: Hyper-Threading is disabled\n");
627 if (smp_num_siblings <= 1)
630 index_msb = get_count_order(smp_num_siblings);
631 c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, index_msb);
633 smp_num_siblings = smp_num_siblings / c->x86_max_cores;
635 index_msb = get_count_order(smp_num_siblings);
637 core_bits = get_count_order(c->x86_max_cores);
639 c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid, index_msb) &
640 ((1 << core_bits) - 1);
643 if (!printed && (c->x86_max_cores * smp_num_siblings) > 1) {
644 pr_info("CPU: Physical Processor ID: %d\n",
646 pr_info("CPU: Processor Core ID: %d\n",
653 static void get_cpu_vendor(struct cpuinfo_x86 *c)
655 char *v = c->x86_vendor_id;
658 for (i = 0; i < X86_VENDOR_NUM; i++) {
662 if (!strcmp(v, cpu_devs[i]->c_ident[0]) ||
663 (cpu_devs[i]->c_ident[1] &&
664 !strcmp(v, cpu_devs[i]->c_ident[1]))) {
666 this_cpu = cpu_devs[i];
667 c->x86_vendor = this_cpu->c_x86_vendor;
672 pr_err_once("CPU: vendor_id '%s' unknown, using generic init.\n" \
673 "CPU: Your system may be unstable.\n", v);
675 c->x86_vendor = X86_VENDOR_UNKNOWN;
676 this_cpu = &default_cpu;
679 void cpu_detect(struct cpuinfo_x86 *c)
681 /* Get vendor name */
682 cpuid(0x00000000, (unsigned int *)&c->cpuid_level,
683 (unsigned int *)&c->x86_vendor_id[0],
684 (unsigned int *)&c->x86_vendor_id[8],
685 (unsigned int *)&c->x86_vendor_id[4]);
688 /* Intel-defined flags: level 0x00000001 */
689 if (c->cpuid_level >= 0x00000001) {
690 u32 junk, tfms, cap0, misc;
692 cpuid(0x00000001, &tfms, &misc, &junk, &cap0);
693 c->x86 = x86_family(tfms);
694 c->x86_model = x86_model(tfms);
695 c->x86_mask = x86_stepping(tfms);
697 if (cap0 & (1<<19)) {
698 c->x86_clflush_size = ((misc >> 8) & 0xff) * 8;
699 c->x86_cache_alignment = c->x86_clflush_size;
704 static void apply_forced_caps(struct cpuinfo_x86 *c)
708 for (i = 0; i < NCAPINTS; i++) {
709 c->x86_capability[i] &= ~cpu_caps_cleared[i];
710 c->x86_capability[i] |= cpu_caps_set[i];
714 void get_cpu_cap(struct cpuinfo_x86 *c)
716 u32 eax, ebx, ecx, edx;
718 /* Intel-defined flags: level 0x00000001 */
719 if (c->cpuid_level >= 0x00000001) {
720 cpuid(0x00000001, &eax, &ebx, &ecx, &edx);
722 c->x86_capability[CPUID_1_ECX] = ecx;
723 c->x86_capability[CPUID_1_EDX] = edx;
726 /* Thermal and Power Management Leaf: level 0x00000006 (eax) */
727 if (c->cpuid_level >= 0x00000006)
728 c->x86_capability[CPUID_6_EAX] = cpuid_eax(0x00000006);
730 /* Additional Intel-defined flags: level 0x00000007 */
731 if (c->cpuid_level >= 0x00000007) {
732 cpuid_count(0x00000007, 0, &eax, &ebx, &ecx, &edx);
733 c->x86_capability[CPUID_7_0_EBX] = ebx;
734 c->x86_capability[CPUID_7_ECX] = ecx;
737 /* Extended state features: level 0x0000000d */
738 if (c->cpuid_level >= 0x0000000d) {
739 cpuid_count(0x0000000d, 1, &eax, &ebx, &ecx, &edx);
741 c->x86_capability[CPUID_D_1_EAX] = eax;
744 /* Additional Intel-defined flags: level 0x0000000F */
745 if (c->cpuid_level >= 0x0000000F) {
747 /* QoS sub-leaf, EAX=0Fh, ECX=0 */
748 cpuid_count(0x0000000F, 0, &eax, &ebx, &ecx, &edx);
749 c->x86_capability[CPUID_F_0_EDX] = edx;
751 if (cpu_has(c, X86_FEATURE_CQM_LLC)) {
752 /* will be overridden if occupancy monitoring exists */
753 c->x86_cache_max_rmid = ebx;
755 /* QoS sub-leaf, EAX=0Fh, ECX=1 */
756 cpuid_count(0x0000000F, 1, &eax, &ebx, &ecx, &edx);
757 c->x86_capability[CPUID_F_1_EDX] = edx;
759 if ((cpu_has(c, X86_FEATURE_CQM_OCCUP_LLC)) ||
760 ((cpu_has(c, X86_FEATURE_CQM_MBM_TOTAL)) ||
761 (cpu_has(c, X86_FEATURE_CQM_MBM_LOCAL)))) {
762 c->x86_cache_max_rmid = ecx;
763 c->x86_cache_occ_scale = ebx;
766 c->x86_cache_max_rmid = -1;
767 c->x86_cache_occ_scale = -1;
771 /* AMD-defined flags: level 0x80000001 */
772 eax = cpuid_eax(0x80000000);
773 c->extended_cpuid_level = eax;
775 if ((eax & 0xffff0000) == 0x80000000) {
776 if (eax >= 0x80000001) {
777 cpuid(0x80000001, &eax, &ebx, &ecx, &edx);
779 c->x86_capability[CPUID_8000_0001_ECX] = ecx;
780 c->x86_capability[CPUID_8000_0001_EDX] = edx;
784 if (c->extended_cpuid_level >= 0x80000007) {
785 cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
787 c->x86_capability[CPUID_8000_0007_EBX] = ebx;
791 if (c->extended_cpuid_level >= 0x80000008) {
792 cpuid(0x80000008, &eax, &ebx, &ecx, &edx);
794 c->x86_virt_bits = (eax >> 8) & 0xff;
795 c->x86_phys_bits = eax & 0xff;
796 c->x86_capability[CPUID_8000_0008_EBX] = ebx;
799 else if (cpu_has(c, X86_FEATURE_PAE) || cpu_has(c, X86_FEATURE_PSE36))
800 c->x86_phys_bits = 36;
803 if (c->extended_cpuid_level >= 0x8000000a)
804 c->x86_capability[CPUID_8000_000A_EDX] = cpuid_edx(0x8000000a);
806 init_scattered_cpuid_features(c);
809 * Clear/Set all flags overridden by options, after probe.
810 * This needs to happen each time we re-probe, which may happen
811 * several times during CPU initialization.
813 apply_forced_caps(c);
816 static void identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
822 * First of all, decide if this is a 486 or higher
823 * It's a 486 if we can modify the AC flag
825 if (flag_is_changeable_p(X86_EFLAGS_AC))
830 for (i = 0; i < X86_VENDOR_NUM; i++)
831 if (cpu_devs[i] && cpu_devs[i]->c_identify) {
832 c->x86_vendor_id[0] = 0;
833 cpu_devs[i]->c_identify(c);
834 if (c->x86_vendor_id[0]) {
843 * Do minimum CPU detection early.
844 * Fields really needed: vendor, cpuid_level, family, model, mask,
846 * The others are not touched to avoid unwanted side effects.
848 * WARNING: this function is only called on the BP. Don't add code here
849 * that is supposed to run on all CPUs.
851 static void __init early_identify_cpu(struct cpuinfo_x86 *c)
854 c->x86_clflush_size = 64;
855 c->x86_phys_bits = 36;
856 c->x86_virt_bits = 48;
858 c->x86_clflush_size = 32;
859 c->x86_phys_bits = 32;
860 c->x86_virt_bits = 32;
862 c->x86_cache_alignment = c->x86_clflush_size;
864 memset(&c->x86_capability, 0, sizeof c->x86_capability);
865 c->extended_cpuid_level = 0;
867 /* cyrix could have cpuid enabled via c_identify()*/
868 if (have_cpuid_p()) {
872 setup_force_cpu_cap(X86_FEATURE_CPUID);
874 if (this_cpu->c_early_init)
875 this_cpu->c_early_init(c);
878 filter_cpuid_features(c, false);
880 if (this_cpu->c_bsp_init)
881 this_cpu->c_bsp_init(c);
883 identify_cpu_without_cpuid(c);
884 setup_clear_cpu_cap(X86_FEATURE_CPUID);
887 setup_force_cpu_cap(X86_FEATURE_ALWAYS);
891 void __init early_cpu_init(void)
893 const struct cpu_dev *const *cdev;
896 #ifdef CONFIG_PROCESSOR_SELECT
897 pr_info("KERNEL supported cpus:\n");
900 for (cdev = __x86_cpu_dev_start; cdev < __x86_cpu_dev_end; cdev++) {
901 const struct cpu_dev *cpudev = *cdev;
903 if (count >= X86_VENDOR_NUM)
905 cpu_devs[count] = cpudev;
908 #ifdef CONFIG_PROCESSOR_SELECT
912 for (j = 0; j < 2; j++) {
913 if (!cpudev->c_ident[j])
915 pr_info(" %s %s\n", cpudev->c_vendor,
921 early_identify_cpu(&boot_cpu_data);
925 * The NOPL instruction is supposed to exist on all CPUs of family >= 6;
926 * unfortunately, that's not true in practice because of early VIA
927 * chips and (more importantly) broken virtualizers that are not easy
928 * to detect. In the latter case it doesn't even *fail* reliably, so
929 * probing for it doesn't even work. Disable it completely on 32-bit
930 * unless we can find a reliable way to detect all the broken cases.
931 * Enable it explicitly on 64-bit for non-constant inputs of cpu_has().
933 static void detect_nopl(struct cpuinfo_x86 *c)
936 clear_cpu_cap(c, X86_FEATURE_NOPL);
938 set_cpu_cap(c, X86_FEATURE_NOPL);
942 static void detect_null_seg_behavior(struct cpuinfo_x86 *c)
946 * Empirically, writing zero to a segment selector on AMD does
947 * not clear the base, whereas writing zero to a segment
948 * selector on Intel does clear the base. Intel's behavior
949 * allows slightly faster context switches in the common case
950 * where GS is unused by the prev and next threads.
952 * Since neither vendor documents this anywhere that I can see,
953 * detect it directly instead of hardcoding the choice by
956 * I've designated AMD's behavior as the "bug" because it's
957 * counterintuitive and less friendly.
960 unsigned long old_base, tmp;
961 rdmsrl(MSR_FS_BASE, old_base);
962 wrmsrl(MSR_FS_BASE, 1);
964 rdmsrl(MSR_FS_BASE, tmp);
966 set_cpu_bug(c, X86_BUG_NULL_SEG);
967 wrmsrl(MSR_FS_BASE, old_base);
971 static void generic_identify(struct cpuinfo_x86 *c)
973 c->extended_cpuid_level = 0;
976 identify_cpu_without_cpuid(c);
978 /* cyrix could have cpuid enabled via c_identify()*/
988 if (c->cpuid_level >= 0x00000001) {
989 c->initial_apicid = (cpuid_ebx(1) >> 24) & 0xFF;
992 c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
994 c->apicid = c->initial_apicid;
997 c->phys_proc_id = c->initial_apicid;
1000 get_model_name(c); /* Default name */
1004 detect_null_seg_behavior(c);
1007 * ESPFIX is a strange bug. All real CPUs have it. Paravirt
1008 * systems that run Linux at CPL > 0 may or may not have the
1009 * issue, but, even if they have the issue, there's absolutely
1010 * nothing we can do about it because we can't use the real IRET
1013 * NB: For the time being, only 32-bit kernels support
1014 * X86_BUG_ESPFIX as such. 64-bit kernels directly choose
1015 * whether to apply espfix using paravirt hooks. If any
1016 * non-paravirt system ever shows up that does *not* have the
1017 * ESPFIX issue, we can change this.
1019 #ifdef CONFIG_X86_32
1020 # ifdef CONFIG_PARAVIRT
1022 extern void native_iret(void);
1023 if (pv_cpu_ops.iret == native_iret)
1024 set_cpu_bug(c, X86_BUG_ESPFIX);
1027 set_cpu_bug(c, X86_BUG_ESPFIX);
1032 static void x86_init_cache_qos(struct cpuinfo_x86 *c)
1035 * The heavy lifting of max_rmid and cache_occ_scale are handled
1036 * in get_cpu_cap(). Here we just set the max_rmid for the boot_cpu
1037 * in case CQM bits really aren't there in this CPU.
1039 if (c != &boot_cpu_data) {
1040 boot_cpu_data.x86_cache_max_rmid =
1041 min(boot_cpu_data.x86_cache_max_rmid,
1042 c->x86_cache_max_rmid);
1047 * Validate that ACPI/mptables have the same information about the
1048 * effective APIC id and update the package map.
1050 static void validate_apic_and_package_id(struct cpuinfo_x86 *c)
1053 unsigned int apicid, cpu = smp_processor_id();
1055 apicid = apic->cpu_present_to_apicid(cpu);
1057 if (apicid != c->apicid) {
1058 pr_err(FW_BUG "CPU%u: APIC id mismatch. Firmware: %x APIC: %x\n",
1059 cpu, apicid, c->initial_apicid);
1061 BUG_ON(topology_update_package_map(c->phys_proc_id, cpu));
1063 c->logical_proc_id = 0;
1068 * This does the hard work of actually picking apart the CPU stuff...
1070 static void identify_cpu(struct cpuinfo_x86 *c)
1074 c->loops_per_jiffy = loops_per_jiffy;
1075 c->x86_cache_size = -1;
1076 c->x86_vendor = X86_VENDOR_UNKNOWN;
1077 c->x86_model = c->x86_mask = 0; /* So far unknown... */
1078 c->x86_vendor_id[0] = '\0'; /* Unset */
1079 c->x86_model_id[0] = '\0'; /* Unset */
1080 c->x86_max_cores = 1;
1081 c->x86_coreid_bits = 0;
1083 #ifdef CONFIG_X86_64
1084 c->x86_clflush_size = 64;
1085 c->x86_phys_bits = 36;
1086 c->x86_virt_bits = 48;
1088 c->cpuid_level = -1; /* CPUID not detected */
1089 c->x86_clflush_size = 32;
1090 c->x86_phys_bits = 32;
1091 c->x86_virt_bits = 32;
1093 c->x86_cache_alignment = c->x86_clflush_size;
1094 memset(&c->x86_capability, 0, sizeof c->x86_capability);
1096 generic_identify(c);
1098 if (this_cpu->c_identify)
1099 this_cpu->c_identify(c);
1101 /* Clear/Set all flags overridden by options, after probe */
1102 apply_forced_caps(c);
1104 #ifdef CONFIG_X86_64
1105 c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
1109 * Vendor-specific initialization. In this section we
1110 * canonicalize the feature flags, meaning if there are
1111 * features a certain CPU supports which CPUID doesn't
1112 * tell us, CPUID claiming incorrect flags, or other bugs,
1113 * we handle them here.
1115 * At the end of this section, c->x86_capability better
1116 * indicate the features this CPU genuinely supports!
1118 if (this_cpu->c_init)
1119 this_cpu->c_init(c);
1121 /* Disable the PN if appropriate */
1122 squash_the_stupid_serial_number(c);
1124 /* Set up SMEP/SMAP */
1129 * The vendor-specific functions might have changed features.
1130 * Now we do "generic changes."
1133 /* Filter out anything that depends on CPUID levels we don't have */
1134 filter_cpuid_features(c, true);
1136 /* If the model name is still unset, do table lookup. */
1137 if (!c->x86_model_id[0]) {
1139 p = table_lookup_model(c);
1141 strcpy(c->x86_model_id, p);
1143 /* Last resort... */
1144 sprintf(c->x86_model_id, "%02x/%02x",
1145 c->x86, c->x86_model);
1148 #ifdef CONFIG_X86_64
1153 x86_init_cache_qos(c);
1157 * Clear/Set all flags overridden by options, need do it
1158 * before following smp all cpus cap AND.
1160 apply_forced_caps(c);
1163 * On SMP, boot_cpu_data holds the common feature set between
1164 * all CPUs; so make sure that we indicate which features are
1165 * common between the CPUs. The first time this routine gets
1166 * executed, c == &boot_cpu_data.
1168 if (c != &boot_cpu_data) {
1169 /* AND the already accumulated flags with these */
1170 for (i = 0; i < NCAPINTS; i++)
1171 boot_cpu_data.x86_capability[i] &= c->x86_capability[i];
1173 /* OR, i.e. replicate the bug flags */
1174 for (i = NCAPINTS; i < NCAPINTS + NBUGINTS; i++)
1175 c->x86_capability[i] |= boot_cpu_data.x86_capability[i];
1178 /* Init Machine Check Exception if available. */
1181 select_idle_routine(c);
1184 numa_add_cpu(smp_processor_id());
1189 * Set up the CPU state needed to execute SYSENTER/SYSEXIT instructions
1190 * on 32-bit kernels:
1192 #ifdef CONFIG_X86_32
1193 void enable_sep_cpu(void)
1195 struct tss_struct *tss;
1198 if (!boot_cpu_has(X86_FEATURE_SEP))
1202 tss = &per_cpu(cpu_tss, cpu);
1205 * We cache MSR_IA32_SYSENTER_CS's value in the TSS's ss1 field --
1206 * see the big comment in struct x86_hw_tss's definition.
1209 tss->x86_tss.ss1 = __KERNEL_CS;
1210 wrmsr(MSR_IA32_SYSENTER_CS, tss->x86_tss.ss1, 0);
1212 wrmsr(MSR_IA32_SYSENTER_ESP,
1213 (unsigned long)tss + offsetofend(struct tss_struct, SYSENTER_stack),
1216 wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long)entry_SYSENTER_32, 0);
1222 void __init identify_boot_cpu(void)
1224 identify_cpu(&boot_cpu_data);
1225 #ifdef CONFIG_X86_32
1229 cpu_detect_tlb(&boot_cpu_data);
1232 void identify_secondary_cpu(struct cpuinfo_x86 *c)
1234 BUG_ON(c == &boot_cpu_data);
1236 #ifdef CONFIG_X86_32
1240 validate_apic_and_package_id(c);
1243 static __init int setup_noclflush(char *arg)
1245 setup_clear_cpu_cap(X86_FEATURE_CLFLUSH);
1246 setup_clear_cpu_cap(X86_FEATURE_CLFLUSHOPT);
1249 __setup("noclflush", setup_noclflush);
1251 void print_cpu_info(struct cpuinfo_x86 *c)
1253 const char *vendor = NULL;
1255 if (c->x86_vendor < X86_VENDOR_NUM) {
1256 vendor = this_cpu->c_vendor;
1258 if (c->cpuid_level >= 0)
1259 vendor = c->x86_vendor_id;
1262 if (vendor && !strstr(c->x86_model_id, vendor))
1263 pr_cont("%s ", vendor);
1265 if (c->x86_model_id[0])
1266 pr_cont("%s", c->x86_model_id);
1268 pr_cont("%d86", c->x86);
1270 pr_cont(" (family: 0x%x, model: 0x%x", c->x86, c->x86_model);
1272 if (c->x86_mask || c->cpuid_level >= 0)
1273 pr_cont(", stepping: 0x%x)\n", c->x86_mask);
1278 static __init int setup_disablecpuid(char *arg)
1282 if (get_option(&arg, &bit) && bit >= 0 && bit < NCAPINTS * 32)
1283 setup_clear_cpu_cap(bit);
1289 __setup("clearcpuid=", setup_disablecpuid);
1291 #ifdef CONFIG_X86_64
1292 struct desc_ptr idt_descr __ro_after_init = {
1293 .size = NR_VECTORS * 16 - 1,
1294 .address = (unsigned long) idt_table,
1296 const struct desc_ptr debug_idt_descr = {
1297 .size = NR_VECTORS * 16 - 1,
1298 .address = (unsigned long) debug_idt_table,
1301 DEFINE_PER_CPU_FIRST(union irq_stack_union,
1302 irq_stack_union) __aligned(PAGE_SIZE) __visible;
1305 * The following percpu variables are hot. Align current_task to
1306 * cacheline size such that they fall in the same cacheline.
1308 DEFINE_PER_CPU(struct task_struct *, current_task) ____cacheline_aligned =
1310 EXPORT_PER_CPU_SYMBOL(current_task);
1312 DEFINE_PER_CPU(char *, irq_stack_ptr) =
1313 init_per_cpu_var(irq_stack_union.irq_stack) + IRQ_STACK_SIZE;
1315 DEFINE_PER_CPU(unsigned int, irq_count) __visible = -1;
1317 DEFINE_PER_CPU(int, __preempt_count) = INIT_PREEMPT_COUNT;
1318 EXPORT_PER_CPU_SYMBOL(__preempt_count);
1321 * Special IST stacks which the CPU switches to when it calls
1322 * an IST-marked descriptor entry. Up to 7 stacks (hardware
1323 * limit), all of them are 4K, except the debug stack which
1326 static const unsigned int exception_stack_sizes[N_EXCEPTION_STACKS] = {
1327 [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STKSZ,
1328 [DEBUG_STACK - 1] = DEBUG_STKSZ
1331 static DEFINE_PER_CPU_PAGE_ALIGNED(char, exception_stacks
1332 [(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ]);
1334 /* May not be marked __init: used by software suspend */
1335 void syscall_init(void)
1337 wrmsr(MSR_STAR, 0, (__USER32_CS << 16) | __KERNEL_CS);
1338 wrmsrl(MSR_LSTAR, (unsigned long)entry_SYSCALL_64);
1340 #ifdef CONFIG_IA32_EMULATION
1341 wrmsrl(MSR_CSTAR, (unsigned long)entry_SYSCALL_compat);
1343 * This only works on Intel CPUs.
1344 * On AMD CPUs these MSRs are 32-bit, CPU truncates MSR_IA32_SYSENTER_EIP.
1345 * This does not cause SYSENTER to jump to the wrong location, because
1346 * AMD doesn't allow SYSENTER in long mode (either 32- or 64-bit).
1348 wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS);
1349 wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL);
1350 wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)entry_SYSENTER_compat);
1352 wrmsrl(MSR_CSTAR, (unsigned long)ignore_sysret);
1353 wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)GDT_ENTRY_INVALID_SEG);
1354 wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL);
1355 wrmsrl_safe(MSR_IA32_SYSENTER_EIP, 0ULL);
1358 /* Flags to clear on syscall */
1359 wrmsrl(MSR_SYSCALL_MASK,
1360 X86_EFLAGS_TF|X86_EFLAGS_DF|X86_EFLAGS_IF|
1361 X86_EFLAGS_IOPL|X86_EFLAGS_AC|X86_EFLAGS_NT);
1365 * Copies of the original ist values from the tss are only accessed during
1366 * debugging, no special alignment required.
1368 DEFINE_PER_CPU(struct orig_ist, orig_ist);
1370 static DEFINE_PER_CPU(unsigned long, debug_stack_addr);
1371 DEFINE_PER_CPU(int, debug_stack_usage);
1373 int is_debug_stack(unsigned long addr)
1375 return __this_cpu_read(debug_stack_usage) ||
1376 (addr <= __this_cpu_read(debug_stack_addr) &&
1377 addr > (__this_cpu_read(debug_stack_addr) - DEBUG_STKSZ));
1379 NOKPROBE_SYMBOL(is_debug_stack);
1381 DEFINE_PER_CPU(u32, debug_idt_ctr);
1383 void debug_stack_set_zero(void)
1385 this_cpu_inc(debug_idt_ctr);
1388 NOKPROBE_SYMBOL(debug_stack_set_zero);
1390 void debug_stack_reset(void)
1392 if (WARN_ON(!this_cpu_read(debug_idt_ctr)))
1394 if (this_cpu_dec_return(debug_idt_ctr) == 0)
1397 NOKPROBE_SYMBOL(debug_stack_reset);
1399 #else /* CONFIG_X86_64 */
1401 DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task;
1402 EXPORT_PER_CPU_SYMBOL(current_task);
1403 DEFINE_PER_CPU(int, __preempt_count) = INIT_PREEMPT_COUNT;
1404 EXPORT_PER_CPU_SYMBOL(__preempt_count);
1407 * On x86_32, vm86 modifies tss.sp0, so sp0 isn't a reliable way to find
1408 * the top of the kernel stack. Use an extra percpu variable to track the
1409 * top of the kernel stack directly.
1411 DEFINE_PER_CPU(unsigned long, cpu_current_top_of_stack) =
1412 (unsigned long)&init_thread_union + THREAD_SIZE;
1413 EXPORT_PER_CPU_SYMBOL(cpu_current_top_of_stack);
1415 #ifdef CONFIG_CC_STACKPROTECTOR
1416 DEFINE_PER_CPU_ALIGNED(struct stack_canary, stack_canary);
1419 #endif /* CONFIG_X86_64 */
1422 * Clear all 6 debug registers:
1424 static void clear_all_debug_regs(void)
1428 for (i = 0; i < 8; i++) {
1429 /* Ignore db4, db5 */
1430 if ((i == 4) || (i == 5))
1439 * Restore debug regs if using kgdbwait and you have a kernel debugger
1440 * connection established.
1442 static void dbg_restore_debug_regs(void)
1444 if (unlikely(kgdb_connected && arch_kgdb_ops.correct_hw_break))
1445 arch_kgdb_ops.correct_hw_break();
1447 #else /* ! CONFIG_KGDB */
1448 #define dbg_restore_debug_regs()
1449 #endif /* ! CONFIG_KGDB */
1451 static void wait_for_master_cpu(int cpu)
1455 * wait for ACK from master CPU before continuing
1456 * with AP initialization
1458 WARN_ON(cpumask_test_and_set_cpu(cpu, cpu_initialized_mask));
1459 while (!cpumask_test_cpu(cpu, cpu_callout_mask))
1465 * cpu_init() initializes state that is per-CPU. Some data is already
1466 * initialized (naturally) in the bootstrap process, such as the GDT
1467 * and IDT. We reload them nevertheless, this function acts as a
1468 * 'CPU state barrier', nothing should get across.
1469 * A lot of state is already set up in PDA init for 64 bit
1471 #ifdef CONFIG_X86_64
1475 struct orig_ist *oist;
1476 struct task_struct *me;
1477 struct tss_struct *t;
1479 int cpu = raw_smp_processor_id();
1482 wait_for_master_cpu(cpu);
1485 * Initialize the CR4 shadow before doing anything that could
1493 t = &per_cpu(cpu_tss, cpu);
1494 oist = &per_cpu(orig_ist, cpu);
1497 if (this_cpu_read(numa_node) == 0 &&
1498 early_cpu_to_node(cpu) != NUMA_NO_NODE)
1499 set_numa_node(early_cpu_to_node(cpu));
1504 pr_debug("Initializing CPU#%d\n", cpu);
1506 cr4_clear_bits(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1509 * Initialize the per-CPU GDT with the boot GDT,
1510 * and set up the GDT descriptor:
1513 switch_to_new_gdt(cpu);
1518 memset(me->thread.tls_array, 0, GDT_ENTRY_TLS_ENTRIES * 8);
1521 wrmsrl(MSR_FS_BASE, 0);
1522 wrmsrl(MSR_KERNEL_GS_BASE, 0);
1529 * set up and load the per-CPU TSS
1531 if (!oist->ist[0]) {
1532 char *estacks = per_cpu(exception_stacks, cpu);
1534 for (v = 0; v < N_EXCEPTION_STACKS; v++) {
1535 estacks += exception_stack_sizes[v];
1536 oist->ist[v] = t->x86_tss.ist[v] =
1537 (unsigned long)estacks;
1538 if (v == DEBUG_STACK-1)
1539 per_cpu(debug_stack_addr, cpu) = (unsigned long)estacks;
1543 t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
1546 * <= is required because the CPU will access up to
1547 * 8 bits beyond the end of the IO permission bitmap.
1549 for (i = 0; i <= IO_BITMAP_LONGS; i++)
1550 t->io_bitmap[i] = ~0UL;
1553 me->active_mm = &init_mm;
1555 enter_lazy_tlb(&init_mm, me);
1557 load_sp0(t, ¤t->thread);
1558 set_tss_desc(cpu, t);
1560 load_mm_ldt(&init_mm);
1562 clear_all_debug_regs();
1563 dbg_restore_debug_regs();
1570 setup_fixmap_gdt(cpu);
1571 load_fixmap_gdt(cpu);
1578 int cpu = smp_processor_id();
1579 struct task_struct *curr = current;
1580 struct tss_struct *t = &per_cpu(cpu_tss, cpu);
1581 struct thread_struct *thread = &curr->thread;
1583 wait_for_master_cpu(cpu);
1586 * Initialize the CR4 shadow before doing anything that could
1591 show_ucode_info_early();
1593 pr_info("Initializing CPU#%d\n", cpu);
1595 if (cpu_feature_enabled(X86_FEATURE_VME) ||
1596 boot_cpu_has(X86_FEATURE_TSC) ||
1597 boot_cpu_has(X86_FEATURE_DE))
1598 cr4_clear_bits(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1601 switch_to_new_gdt(cpu);
1604 * Set up and load the per-CPU TSS and LDT
1607 curr->active_mm = &init_mm;
1609 enter_lazy_tlb(&init_mm, curr);
1611 load_sp0(t, thread);
1612 set_tss_desc(cpu, t);
1614 load_mm_ldt(&init_mm);
1616 t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
1618 #ifdef CONFIG_DOUBLEFAULT
1619 /* Set up doublefault TSS pointer in the GDT */
1620 __set_tss_desc(cpu, GDT_ENTRY_DOUBLEFAULT_TSS, &doublefault_tss);
1623 clear_all_debug_regs();
1624 dbg_restore_debug_regs();
1628 setup_fixmap_gdt(cpu);
1629 load_fixmap_gdt(cpu);
1633 static void bsp_resume(void)
1635 if (this_cpu->c_bsp_resume)
1636 this_cpu->c_bsp_resume(&boot_cpu_data);
1639 static struct syscore_ops cpu_syscore_ops = {
1640 .resume = bsp_resume,
1643 static int __init init_cpu_syscore(void)
1645 register_syscore_ops(&cpu_syscore_ops);
1648 core_initcall(init_cpu_syscore);