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/ctype.h>
9 #include <linux/delay.h>
10 #include <linux/sched.h>
11 #include <linux/init.h>
12 #include <linux/kprobes.h>
13 #include <linux/kgdb.h>
14 #include <linux/smp.h>
16 #include <linux/syscore_ops.h>
18 #include <asm/stackprotector.h>
19 #include <asm/perf_event.h>
20 #include <asm/mmu_context.h>
21 #include <asm/archrandom.h>
22 #include <asm/hypervisor.h>
23 #include <asm/processor.h>
24 #include <asm/tlbflush.h>
25 #include <asm/debugreg.h>
26 #include <asm/sections.h>
27 #include <asm/vsyscall.h>
28 #include <linux/topology.h>
29 #include <linux/cpumask.h>
30 #include <asm/pgtable.h>
31 #include <linux/atomic.h>
32 #include <asm/proto.h>
33 #include <asm/setup.h>
36 #include <asm/fpu/internal.h>
38 #include <linux/numa.h>
44 #include <asm/microcode.h>
45 #include <asm/microcode_intel.h>
47 #ifdef CONFIG_X86_LOCAL_APIC
48 #include <asm/uv/uv.h>
53 /* all of these masks are initialized in setup_cpu_local_masks() */
54 cpumask_var_t cpu_initialized_mask;
55 cpumask_var_t cpu_callout_mask;
56 cpumask_var_t cpu_callin_mask;
58 /* representing cpus for which sibling maps can be computed */
59 cpumask_var_t cpu_sibling_setup_mask;
61 /* correctly size the local cpu masks */
62 void __init setup_cpu_local_masks(void)
64 alloc_bootmem_cpumask_var(&cpu_initialized_mask);
65 alloc_bootmem_cpumask_var(&cpu_callin_mask);
66 alloc_bootmem_cpumask_var(&cpu_callout_mask);
67 alloc_bootmem_cpumask_var(&cpu_sibling_setup_mask);
70 static void default_init(struct cpuinfo_x86 *c)
73 cpu_detect_cache_sizes(c);
75 /* Not much we can do here... */
76 /* Check if at least it has cpuid */
77 if (c->cpuid_level == -1) {
78 /* No cpuid. It must be an ancient CPU */
80 strcpy(c->x86_model_id, "486");
82 strcpy(c->x86_model_id, "386");
87 static const struct cpu_dev default_cpu = {
88 .c_init = default_init,
89 .c_vendor = "Unknown",
90 .c_x86_vendor = X86_VENDOR_UNKNOWN,
93 static const struct cpu_dev *this_cpu = &default_cpu;
95 DEFINE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page) = { .gdt = {
98 * We need valid kernel segments for data and code in long mode too
99 * IRET will check the segment types kkeil 2000/10/28
100 * Also sysret mandates a special GDT layout
102 * TLS descriptors are currently at a different place compared to i386.
103 * Hopefully nobody expects them at a fixed place (Wine?)
105 [GDT_ENTRY_KERNEL32_CS] = GDT_ENTRY_INIT(0xc09b, 0, 0xfffff),
106 [GDT_ENTRY_KERNEL_CS] = GDT_ENTRY_INIT(0xa09b, 0, 0xfffff),
107 [GDT_ENTRY_KERNEL_DS] = GDT_ENTRY_INIT(0xc093, 0, 0xfffff),
108 [GDT_ENTRY_DEFAULT_USER32_CS] = GDT_ENTRY_INIT(0xc0fb, 0, 0xfffff),
109 [GDT_ENTRY_DEFAULT_USER_DS] = GDT_ENTRY_INIT(0xc0f3, 0, 0xfffff),
110 [GDT_ENTRY_DEFAULT_USER_CS] = GDT_ENTRY_INIT(0xa0fb, 0, 0xfffff),
112 [GDT_ENTRY_KERNEL_CS] = GDT_ENTRY_INIT(0xc09a, 0, 0xfffff),
113 [GDT_ENTRY_KERNEL_DS] = GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
114 [GDT_ENTRY_DEFAULT_USER_CS] = GDT_ENTRY_INIT(0xc0fa, 0, 0xfffff),
115 [GDT_ENTRY_DEFAULT_USER_DS] = GDT_ENTRY_INIT(0xc0f2, 0, 0xfffff),
117 * Segments used for calling PnP BIOS have byte granularity.
118 * They code segments and data segments have fixed 64k limits,
119 * the transfer segment sizes are set at run time.
122 [GDT_ENTRY_PNPBIOS_CS32] = GDT_ENTRY_INIT(0x409a, 0, 0xffff),
124 [GDT_ENTRY_PNPBIOS_CS16] = GDT_ENTRY_INIT(0x009a, 0, 0xffff),
126 [GDT_ENTRY_PNPBIOS_DS] = GDT_ENTRY_INIT(0x0092, 0, 0xffff),
128 [GDT_ENTRY_PNPBIOS_TS1] = GDT_ENTRY_INIT(0x0092, 0, 0),
130 [GDT_ENTRY_PNPBIOS_TS2] = GDT_ENTRY_INIT(0x0092, 0, 0),
132 * The APM segments have byte granularity and their bases
133 * are set at run time. All have 64k limits.
136 [GDT_ENTRY_APMBIOS_BASE] = GDT_ENTRY_INIT(0x409a, 0, 0xffff),
138 [GDT_ENTRY_APMBIOS_BASE+1] = GDT_ENTRY_INIT(0x009a, 0, 0xffff),
140 [GDT_ENTRY_APMBIOS_BASE+2] = GDT_ENTRY_INIT(0x4092, 0, 0xffff),
142 [GDT_ENTRY_ESPFIX_SS] = GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
143 [GDT_ENTRY_PERCPU] = GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
144 GDT_STACK_CANARY_INIT
147 EXPORT_PER_CPU_SYMBOL_GPL(gdt_page);
149 static int __init x86_mpx_setup(char *s)
151 /* require an exact match without trailing characters */
155 /* do not emit a message if the feature is not present */
156 if (!boot_cpu_has(X86_FEATURE_MPX))
159 setup_clear_cpu_cap(X86_FEATURE_MPX);
160 pr_info("nompx: Intel Memory Protection Extensions (MPX) disabled\n");
163 __setup("nompx", x86_mpx_setup);
165 static int __init x86_noinvpcid_setup(char *s)
167 /* noinvpcid doesn't accept parameters */
171 /* do not emit a message if the feature is not present */
172 if (!boot_cpu_has(X86_FEATURE_INVPCID))
175 setup_clear_cpu_cap(X86_FEATURE_INVPCID);
176 pr_info("noinvpcid: INVPCID feature disabled\n");
179 early_param("noinvpcid", x86_noinvpcid_setup);
182 static int cachesize_override = -1;
183 static int disable_x86_serial_nr = 1;
185 static int __init cachesize_setup(char *str)
187 get_option(&str, &cachesize_override);
190 __setup("cachesize=", cachesize_setup);
192 static int __init x86_sep_setup(char *s)
194 setup_clear_cpu_cap(X86_FEATURE_SEP);
197 __setup("nosep", x86_sep_setup);
199 /* Standard macro to see if a specific flag is changeable */
200 static inline int flag_is_changeable_p(u32 flag)
205 * Cyrix and IDT cpus allow disabling of CPUID
206 * so the code below may return different results
207 * when it is executed before and after enabling
208 * the CPUID. Add "volatile" to not allow gcc to
209 * optimize the subsequent calls to this function.
211 asm volatile ("pushfl \n\t"
222 : "=&r" (f1), "=&r" (f2)
225 return ((f1^f2) & flag) != 0;
228 /* Probe for the CPUID instruction */
229 int have_cpuid_p(void)
231 return flag_is_changeable_p(X86_EFLAGS_ID);
234 static void squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
236 unsigned long lo, hi;
238 if (!cpu_has(c, X86_FEATURE_PN) || !disable_x86_serial_nr)
241 /* Disable processor serial number: */
243 rdmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
245 wrmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
247 pr_notice("CPU serial number disabled.\n");
248 clear_cpu_cap(c, X86_FEATURE_PN);
250 /* Disabling the serial number may affect the cpuid level */
251 c->cpuid_level = cpuid_eax(0);
254 static int __init x86_serial_nr_setup(char *s)
256 disable_x86_serial_nr = 0;
259 __setup("serialnumber", x86_serial_nr_setup);
261 static inline int flag_is_changeable_p(u32 flag)
265 static inline void squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
270 static __init int setup_disable_smep(char *arg)
272 setup_clear_cpu_cap(X86_FEATURE_SMEP);
275 __setup("nosmep", setup_disable_smep);
277 static __always_inline void setup_smep(struct cpuinfo_x86 *c)
279 if (cpu_has(c, X86_FEATURE_SMEP))
280 cr4_set_bits(X86_CR4_SMEP);
283 static __init int setup_disable_smap(char *arg)
285 setup_clear_cpu_cap(X86_FEATURE_SMAP);
288 __setup("nosmap", setup_disable_smap);
290 static __always_inline void setup_smap(struct cpuinfo_x86 *c)
292 unsigned long eflags = native_save_fl();
294 /* This should have been cleared long ago */
295 BUG_ON(eflags & X86_EFLAGS_AC);
297 if (cpu_has(c, X86_FEATURE_SMAP)) {
298 #ifdef CONFIG_X86_SMAP
299 cr4_set_bits(X86_CR4_SMAP);
301 cr4_clear_bits(X86_CR4_SMAP);
307 * Some CPU features depend on higher CPUID levels, which may not always
308 * be available due to CPUID level capping or broken virtualization
309 * software. Add those features to this table to auto-disable them.
311 struct cpuid_dependent_feature {
316 static const struct cpuid_dependent_feature
317 cpuid_dependent_features[] = {
318 { X86_FEATURE_MWAIT, 0x00000005 },
319 { X86_FEATURE_DCA, 0x00000009 },
320 { X86_FEATURE_XSAVE, 0x0000000d },
324 static void filter_cpuid_features(struct cpuinfo_x86 *c, bool warn)
326 const struct cpuid_dependent_feature *df;
328 for (df = cpuid_dependent_features; df->feature; df++) {
330 if (!cpu_has(c, df->feature))
333 * Note: cpuid_level is set to -1 if unavailable, but
334 * extended_extended_level is set to 0 if unavailable
335 * and the legitimate extended levels are all negative
336 * when signed; hence the weird messing around with
339 if (!((s32)df->level < 0 ?
340 (u32)df->level > (u32)c->extended_cpuid_level :
341 (s32)df->level > (s32)c->cpuid_level))
344 clear_cpu_cap(c, df->feature);
348 pr_warn("CPU: CPU feature " X86_CAP_FMT " disabled, no CPUID level 0x%x\n",
349 x86_cap_flag(df->feature), df->level);
354 * Naming convention should be: <Name> [(<Codename>)]
355 * This table only is used unless init_<vendor>() below doesn't set it;
356 * in particular, if CPUID levels 0x80000002..4 are supported, this
360 /* Look up CPU names by table lookup. */
361 static const char *table_lookup_model(struct cpuinfo_x86 *c)
364 const struct legacy_cpu_model_info *info;
366 if (c->x86_model >= 16)
367 return NULL; /* Range check */
372 info = this_cpu->legacy_models;
374 while (info->family) {
375 if (info->family == c->x86)
376 return info->model_names[c->x86_model];
380 return NULL; /* Not found */
383 __u32 cpu_caps_cleared[NCAPINTS];
384 __u32 cpu_caps_set[NCAPINTS];
386 void load_percpu_segment(int cpu)
389 loadsegment(fs, __KERNEL_PERCPU);
392 wrmsrl(MSR_GS_BASE, (unsigned long)per_cpu(irq_stack_union.gs_base, cpu));
394 load_stack_canary_segment();
398 * Current gdt points %fs at the "master" per-cpu area: after this,
399 * it's on the real one.
401 void switch_to_new_gdt(int cpu)
403 struct desc_ptr gdt_descr;
405 gdt_descr.address = (long)get_cpu_gdt_table(cpu);
406 gdt_descr.size = GDT_SIZE - 1;
407 load_gdt(&gdt_descr);
408 /* Reload the per-cpu base */
410 load_percpu_segment(cpu);
413 static const struct cpu_dev *cpu_devs[X86_VENDOR_NUM] = {};
415 static void get_model_name(struct cpuinfo_x86 *c)
420 if (c->extended_cpuid_level < 0x80000004)
423 v = (unsigned int *)c->x86_model_id;
424 cpuid(0x80000002, &v[0], &v[1], &v[2], &v[3]);
425 cpuid(0x80000003, &v[4], &v[5], &v[6], &v[7]);
426 cpuid(0x80000004, &v[8], &v[9], &v[10], &v[11]);
427 c->x86_model_id[48] = 0;
429 /* Trim whitespace */
430 p = q = s = &c->x86_model_id[0];
436 /* Note the last non-whitespace index */
446 void cpu_detect_cache_sizes(struct cpuinfo_x86 *c)
448 unsigned int n, dummy, ebx, ecx, edx, l2size;
450 n = c->extended_cpuid_level;
452 if (n >= 0x80000005) {
453 cpuid(0x80000005, &dummy, &ebx, &ecx, &edx);
454 c->x86_cache_size = (ecx>>24) + (edx>>24);
456 /* On K8 L1 TLB is inclusive, so don't count it */
461 if (n < 0x80000006) /* Some chips just has a large L1. */
464 cpuid(0x80000006, &dummy, &ebx, &ecx, &edx);
468 c->x86_tlbsize += ((ebx >> 16) & 0xfff) + (ebx & 0xfff);
470 /* do processor-specific cache resizing */
471 if (this_cpu->legacy_cache_size)
472 l2size = this_cpu->legacy_cache_size(c, l2size);
474 /* Allow user to override all this if necessary. */
475 if (cachesize_override != -1)
476 l2size = cachesize_override;
479 return; /* Again, no L2 cache is possible */
482 c->x86_cache_size = l2size;
485 u16 __read_mostly tlb_lli_4k[NR_INFO];
486 u16 __read_mostly tlb_lli_2m[NR_INFO];
487 u16 __read_mostly tlb_lli_4m[NR_INFO];
488 u16 __read_mostly tlb_lld_4k[NR_INFO];
489 u16 __read_mostly tlb_lld_2m[NR_INFO];
490 u16 __read_mostly tlb_lld_4m[NR_INFO];
491 u16 __read_mostly tlb_lld_1g[NR_INFO];
493 static void cpu_detect_tlb(struct cpuinfo_x86 *c)
495 if (this_cpu->c_detect_tlb)
496 this_cpu->c_detect_tlb(c);
498 pr_info("Last level iTLB entries: 4KB %d, 2MB %d, 4MB %d\n",
499 tlb_lli_4k[ENTRIES], tlb_lli_2m[ENTRIES],
500 tlb_lli_4m[ENTRIES]);
502 pr_info("Last level dTLB entries: 4KB %d, 2MB %d, 4MB %d, 1GB %d\n",
503 tlb_lld_4k[ENTRIES], tlb_lld_2m[ENTRIES],
504 tlb_lld_4m[ENTRIES], tlb_lld_1g[ENTRIES]);
507 void detect_ht(struct cpuinfo_x86 *c)
510 u32 eax, ebx, ecx, edx;
511 int index_msb, core_bits;
514 if (!cpu_has(c, X86_FEATURE_HT))
517 if (cpu_has(c, X86_FEATURE_CMP_LEGACY))
520 if (cpu_has(c, X86_FEATURE_XTOPOLOGY))
523 cpuid(1, &eax, &ebx, &ecx, &edx);
525 smp_num_siblings = (ebx & 0xff0000) >> 16;
527 if (smp_num_siblings == 1) {
528 pr_info_once("CPU0: Hyper-Threading is disabled\n");
532 if (smp_num_siblings <= 1)
535 index_msb = get_count_order(smp_num_siblings);
536 c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, index_msb);
538 smp_num_siblings = smp_num_siblings / c->x86_max_cores;
540 index_msb = get_count_order(smp_num_siblings);
542 core_bits = get_count_order(c->x86_max_cores);
544 c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid, index_msb) &
545 ((1 << core_bits) - 1);
548 if (!printed && (c->x86_max_cores * smp_num_siblings) > 1) {
549 pr_info("CPU: Physical Processor ID: %d\n",
551 pr_info("CPU: Processor Core ID: %d\n",
558 static void get_cpu_vendor(struct cpuinfo_x86 *c)
560 char *v = c->x86_vendor_id;
563 for (i = 0; i < X86_VENDOR_NUM; i++) {
567 if (!strcmp(v, cpu_devs[i]->c_ident[0]) ||
568 (cpu_devs[i]->c_ident[1] &&
569 !strcmp(v, cpu_devs[i]->c_ident[1]))) {
571 this_cpu = cpu_devs[i];
572 c->x86_vendor = this_cpu->c_x86_vendor;
577 pr_err_once("CPU: vendor_id '%s' unknown, using generic init.\n" \
578 "CPU: Your system may be unstable.\n", v);
580 c->x86_vendor = X86_VENDOR_UNKNOWN;
581 this_cpu = &default_cpu;
584 void cpu_detect(struct cpuinfo_x86 *c)
586 /* Get vendor name */
587 cpuid(0x00000000, (unsigned int *)&c->cpuid_level,
588 (unsigned int *)&c->x86_vendor_id[0],
589 (unsigned int *)&c->x86_vendor_id[8],
590 (unsigned int *)&c->x86_vendor_id[4]);
593 /* Intel-defined flags: level 0x00000001 */
594 if (c->cpuid_level >= 0x00000001) {
595 u32 junk, tfms, cap0, misc;
597 cpuid(0x00000001, &tfms, &misc, &junk, &cap0);
598 c->x86 = x86_family(tfms);
599 c->x86_model = x86_model(tfms);
600 c->x86_mask = x86_stepping(tfms);
602 if (cap0 & (1<<19)) {
603 c->x86_clflush_size = ((misc >> 8) & 0xff) * 8;
604 c->x86_cache_alignment = c->x86_clflush_size;
609 void get_cpu_cap(struct cpuinfo_x86 *c)
611 u32 eax, ebx, ecx, edx;
613 /* Intel-defined flags: level 0x00000001 */
614 if (c->cpuid_level >= 0x00000001) {
615 cpuid(0x00000001, &eax, &ebx, &ecx, &edx);
617 c->x86_capability[CPUID_1_ECX] = ecx;
618 c->x86_capability[CPUID_1_EDX] = edx;
621 /* Additional Intel-defined flags: level 0x00000007 */
622 if (c->cpuid_level >= 0x00000007) {
623 cpuid_count(0x00000007, 0, &eax, &ebx, &ecx, &edx);
625 c->x86_capability[CPUID_7_0_EBX] = ebx;
627 c->x86_capability[CPUID_6_EAX] = cpuid_eax(0x00000006);
630 /* Extended state features: level 0x0000000d */
631 if (c->cpuid_level >= 0x0000000d) {
632 cpuid_count(0x0000000d, 1, &eax, &ebx, &ecx, &edx);
634 c->x86_capability[CPUID_D_1_EAX] = eax;
637 /* Additional Intel-defined flags: level 0x0000000F */
638 if (c->cpuid_level >= 0x0000000F) {
640 /* QoS sub-leaf, EAX=0Fh, ECX=0 */
641 cpuid_count(0x0000000F, 0, &eax, &ebx, &ecx, &edx);
642 c->x86_capability[CPUID_F_0_EDX] = edx;
644 if (cpu_has(c, X86_FEATURE_CQM_LLC)) {
645 /* will be overridden if occupancy monitoring exists */
646 c->x86_cache_max_rmid = ebx;
648 /* QoS sub-leaf, EAX=0Fh, ECX=1 */
649 cpuid_count(0x0000000F, 1, &eax, &ebx, &ecx, &edx);
650 c->x86_capability[CPUID_F_1_EDX] = edx;
652 if (cpu_has(c, X86_FEATURE_CQM_OCCUP_LLC)) {
653 c->x86_cache_max_rmid = ecx;
654 c->x86_cache_occ_scale = ebx;
657 c->x86_cache_max_rmid = -1;
658 c->x86_cache_occ_scale = -1;
662 /* AMD-defined flags: level 0x80000001 */
663 eax = cpuid_eax(0x80000000);
664 c->extended_cpuid_level = eax;
666 if ((eax & 0xffff0000) == 0x80000000) {
667 if (eax >= 0x80000001) {
668 cpuid(0x80000001, &eax, &ebx, &ecx, &edx);
670 c->x86_capability[CPUID_8000_0001_ECX] = ecx;
671 c->x86_capability[CPUID_8000_0001_EDX] = edx;
675 if (c->extended_cpuid_level >= 0x80000008) {
676 cpuid(0x80000008, &eax, &ebx, &ecx, &edx);
678 c->x86_virt_bits = (eax >> 8) & 0xff;
679 c->x86_phys_bits = eax & 0xff;
680 c->x86_capability[CPUID_8000_0008_EBX] = ebx;
683 else if (cpu_has(c, X86_FEATURE_PAE) || cpu_has(c, X86_FEATURE_PSE36))
684 c->x86_phys_bits = 36;
687 if (c->extended_cpuid_level >= 0x80000007)
688 c->x86_power = cpuid_edx(0x80000007);
690 if (c->extended_cpuid_level >= 0x8000000a)
691 c->x86_capability[CPUID_8000_000A_EDX] = cpuid_edx(0x8000000a);
693 init_scattered_cpuid_features(c);
696 static void identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
702 * First of all, decide if this is a 486 or higher
703 * It's a 486 if we can modify the AC flag
705 if (flag_is_changeable_p(X86_EFLAGS_AC))
710 for (i = 0; i < X86_VENDOR_NUM; i++)
711 if (cpu_devs[i] && cpu_devs[i]->c_identify) {
712 c->x86_vendor_id[0] = 0;
713 cpu_devs[i]->c_identify(c);
714 if (c->x86_vendor_id[0]) {
723 * Do minimum CPU detection early.
724 * Fields really needed: vendor, cpuid_level, family, model, mask,
726 * The others are not touched to avoid unwanted side effects.
728 * WARNING: this function is only called on the BP. Don't add code here
729 * that is supposed to run on all CPUs.
731 static void __init early_identify_cpu(struct cpuinfo_x86 *c)
734 c->x86_clflush_size = 64;
735 c->x86_phys_bits = 36;
736 c->x86_virt_bits = 48;
738 c->x86_clflush_size = 32;
739 c->x86_phys_bits = 32;
740 c->x86_virt_bits = 32;
742 c->x86_cache_alignment = c->x86_clflush_size;
744 memset(&c->x86_capability, 0, sizeof c->x86_capability);
745 c->extended_cpuid_level = 0;
748 identify_cpu_without_cpuid(c);
750 /* cyrix could have cpuid enabled via c_identify()*/
758 if (this_cpu->c_early_init)
759 this_cpu->c_early_init(c);
762 filter_cpuid_features(c, false);
764 if (this_cpu->c_bsp_init)
765 this_cpu->c_bsp_init(c);
767 setup_force_cpu_cap(X86_FEATURE_ALWAYS);
771 void __init early_cpu_init(void)
773 const struct cpu_dev *const *cdev;
776 #ifdef CONFIG_PROCESSOR_SELECT
777 pr_info("KERNEL supported cpus:\n");
780 for (cdev = __x86_cpu_dev_start; cdev < __x86_cpu_dev_end; cdev++) {
781 const struct cpu_dev *cpudev = *cdev;
783 if (count >= X86_VENDOR_NUM)
785 cpu_devs[count] = cpudev;
788 #ifdef CONFIG_PROCESSOR_SELECT
792 for (j = 0; j < 2; j++) {
793 if (!cpudev->c_ident[j])
795 pr_info(" %s %s\n", cpudev->c_vendor,
801 early_identify_cpu(&boot_cpu_data);
805 * The NOPL instruction is supposed to exist on all CPUs of family >= 6;
806 * unfortunately, that's not true in practice because of early VIA
807 * chips and (more importantly) broken virtualizers that are not easy
808 * to detect. In the latter case it doesn't even *fail* reliably, so
809 * probing for it doesn't even work. Disable it completely on 32-bit
810 * unless we can find a reliable way to detect all the broken cases.
811 * Enable it explicitly on 64-bit for non-constant inputs of cpu_has().
813 static void detect_nopl(struct cpuinfo_x86 *c)
816 clear_cpu_cap(c, X86_FEATURE_NOPL);
818 set_cpu_cap(c, X86_FEATURE_NOPL);
822 static void generic_identify(struct cpuinfo_x86 *c)
824 c->extended_cpuid_level = 0;
827 identify_cpu_without_cpuid(c);
829 /* cyrix could have cpuid enabled via c_identify()*/
839 if (c->cpuid_level >= 0x00000001) {
840 c->initial_apicid = (cpuid_ebx(1) >> 24) & 0xFF;
843 c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
845 c->apicid = c->initial_apicid;
848 c->phys_proc_id = c->initial_apicid;
851 get_model_name(c); /* Default name */
856 static void x86_init_cache_qos(struct cpuinfo_x86 *c)
859 * The heavy lifting of max_rmid and cache_occ_scale are handled
860 * in get_cpu_cap(). Here we just set the max_rmid for the boot_cpu
861 * in case CQM bits really aren't there in this CPU.
863 if (c != &boot_cpu_data) {
864 boot_cpu_data.x86_cache_max_rmid =
865 min(boot_cpu_data.x86_cache_max_rmid,
866 c->x86_cache_max_rmid);
871 * This does the hard work of actually picking apart the CPU stuff...
873 static void identify_cpu(struct cpuinfo_x86 *c)
877 c->loops_per_jiffy = loops_per_jiffy;
878 c->x86_cache_size = -1;
879 c->x86_vendor = X86_VENDOR_UNKNOWN;
880 c->x86_model = c->x86_mask = 0; /* So far unknown... */
881 c->x86_vendor_id[0] = '\0'; /* Unset */
882 c->x86_model_id[0] = '\0'; /* Unset */
883 c->x86_max_cores = 1;
884 c->x86_coreid_bits = 0;
886 c->x86_clflush_size = 64;
887 c->x86_phys_bits = 36;
888 c->x86_virt_bits = 48;
890 c->cpuid_level = -1; /* CPUID not detected */
891 c->x86_clflush_size = 32;
892 c->x86_phys_bits = 32;
893 c->x86_virt_bits = 32;
895 c->x86_cache_alignment = c->x86_clflush_size;
896 memset(&c->x86_capability, 0, sizeof c->x86_capability);
900 if (this_cpu->c_identify)
901 this_cpu->c_identify(c);
903 /* Clear/Set all flags overriden by options, after probe */
904 for (i = 0; i < NCAPINTS; i++) {
905 c->x86_capability[i] &= ~cpu_caps_cleared[i];
906 c->x86_capability[i] |= cpu_caps_set[i];
910 c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
914 * Vendor-specific initialization. In this section we
915 * canonicalize the feature flags, meaning if there are
916 * features a certain CPU supports which CPUID doesn't
917 * tell us, CPUID claiming incorrect flags, or other bugs,
918 * we handle them here.
920 * At the end of this section, c->x86_capability better
921 * indicate the features this CPU genuinely supports!
923 if (this_cpu->c_init)
926 /* Disable the PN if appropriate */
927 squash_the_stupid_serial_number(c);
929 /* Set up SMEP/SMAP */
934 * The vendor-specific functions might have changed features.
935 * Now we do "generic changes."
938 /* Filter out anything that depends on CPUID levels we don't have */
939 filter_cpuid_features(c, true);
941 /* If the model name is still unset, do table lookup. */
942 if (!c->x86_model_id[0]) {
944 p = table_lookup_model(c);
946 strcpy(c->x86_model_id, p);
949 sprintf(c->x86_model_id, "%02x/%02x",
950 c->x86, c->x86_model);
959 x86_init_cache_qos(c);
962 * Clear/Set all flags overriden by options, need do it
963 * before following smp all cpus cap AND.
965 for (i = 0; i < NCAPINTS; i++) {
966 c->x86_capability[i] &= ~cpu_caps_cleared[i];
967 c->x86_capability[i] |= cpu_caps_set[i];
971 * On SMP, boot_cpu_data holds the common feature set between
972 * all CPUs; so make sure that we indicate which features are
973 * common between the CPUs. The first time this routine gets
974 * executed, c == &boot_cpu_data.
976 if (c != &boot_cpu_data) {
977 /* AND the already accumulated flags with these */
978 for (i = 0; i < NCAPINTS; i++)
979 boot_cpu_data.x86_capability[i] &= c->x86_capability[i];
981 /* OR, i.e. replicate the bug flags */
982 for (i = NCAPINTS; i < NCAPINTS + NBUGINTS; i++)
983 c->x86_capability[i] |= boot_cpu_data.x86_capability[i];
986 /* Init Machine Check Exception if available. */
989 select_idle_routine(c);
992 numa_add_cpu(smp_processor_id());
997 * Set up the CPU state needed to execute SYSENTER/SYSEXIT instructions
1000 #ifdef CONFIG_X86_32
1001 void enable_sep_cpu(void)
1003 struct tss_struct *tss;
1007 tss = &per_cpu(cpu_tss, cpu);
1009 if (!boot_cpu_has(X86_FEATURE_SEP))
1013 * We cache MSR_IA32_SYSENTER_CS's value in the TSS's ss1 field --
1014 * see the big comment in struct x86_hw_tss's definition.
1017 tss->x86_tss.ss1 = __KERNEL_CS;
1018 wrmsr(MSR_IA32_SYSENTER_CS, tss->x86_tss.ss1, 0);
1020 wrmsr(MSR_IA32_SYSENTER_ESP,
1021 (unsigned long)tss + offsetofend(struct tss_struct, SYSENTER_stack),
1024 wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long)entry_SYSENTER_32, 0);
1031 void __init identify_boot_cpu(void)
1033 identify_cpu(&boot_cpu_data);
1034 init_amd_e400_c1e_mask();
1035 #ifdef CONFIG_X86_32
1039 cpu_detect_tlb(&boot_cpu_data);
1042 void identify_secondary_cpu(struct cpuinfo_x86 *c)
1044 BUG_ON(c == &boot_cpu_data);
1046 #ifdef CONFIG_X86_32
1057 static const struct msr_range msr_range_array[] = {
1058 { 0x00000000, 0x00000418},
1059 { 0xc0000000, 0xc000040b},
1060 { 0xc0010000, 0xc0010142},
1061 { 0xc0011000, 0xc001103b},
1064 static void __print_cpu_msr(void)
1066 unsigned index_min, index_max;
1071 for (i = 0; i < ARRAY_SIZE(msr_range_array); i++) {
1072 index_min = msr_range_array[i].min;
1073 index_max = msr_range_array[i].max;
1075 for (index = index_min; index < index_max; index++) {
1076 if (rdmsrl_safe(index, &val))
1078 pr_info(" MSR%08x: %016llx\n", index, val);
1083 static int show_msr;
1085 static __init int setup_show_msr(char *arg)
1089 get_option(&arg, &num);
1095 __setup("show_msr=", setup_show_msr);
1097 static __init int setup_noclflush(char *arg)
1099 setup_clear_cpu_cap(X86_FEATURE_CLFLUSH);
1100 setup_clear_cpu_cap(X86_FEATURE_CLFLUSHOPT);
1103 __setup("noclflush", setup_noclflush);
1105 void print_cpu_info(struct cpuinfo_x86 *c)
1107 const char *vendor = NULL;
1109 if (c->x86_vendor < X86_VENDOR_NUM) {
1110 vendor = this_cpu->c_vendor;
1112 if (c->cpuid_level >= 0)
1113 vendor = c->x86_vendor_id;
1116 if (vendor && !strstr(c->x86_model_id, vendor))
1117 pr_cont("%s ", vendor);
1119 if (c->x86_model_id[0])
1120 pr_cont("%s", c->x86_model_id);
1122 pr_cont("%d86", c->x86);
1124 pr_cont(" (family: 0x%x, model: 0x%x", c->x86, c->x86_model);
1126 if (c->x86_mask || c->cpuid_level >= 0)
1127 pr_cont(", stepping: 0x%x)\n", c->x86_mask);
1134 void print_cpu_msr(struct cpuinfo_x86 *c)
1136 if (c->cpu_index < show_msr)
1140 static __init int setup_disablecpuid(char *arg)
1144 if (get_option(&arg, &bit) && bit < NCAPINTS*32)
1145 setup_clear_cpu_cap(bit);
1151 __setup("clearcpuid=", setup_disablecpuid);
1153 #ifdef CONFIG_X86_64
1154 struct desc_ptr idt_descr = { NR_VECTORS * 16 - 1, (unsigned long) idt_table };
1155 struct desc_ptr debug_idt_descr = { NR_VECTORS * 16 - 1,
1156 (unsigned long) debug_idt_table };
1158 DEFINE_PER_CPU_FIRST(union irq_stack_union,
1159 irq_stack_union) __aligned(PAGE_SIZE) __visible;
1162 * The following percpu variables are hot. Align current_task to
1163 * cacheline size such that they fall in the same cacheline.
1165 DEFINE_PER_CPU(struct task_struct *, current_task) ____cacheline_aligned =
1167 EXPORT_PER_CPU_SYMBOL(current_task);
1169 DEFINE_PER_CPU(char *, irq_stack_ptr) =
1170 init_per_cpu_var(irq_stack_union.irq_stack) + IRQ_STACK_SIZE - 64;
1172 DEFINE_PER_CPU(unsigned int, irq_count) __visible = -1;
1174 DEFINE_PER_CPU(int, __preempt_count) = INIT_PREEMPT_COUNT;
1175 EXPORT_PER_CPU_SYMBOL(__preempt_count);
1178 * Special IST stacks which the CPU switches to when it calls
1179 * an IST-marked descriptor entry. Up to 7 stacks (hardware
1180 * limit), all of them are 4K, except the debug stack which
1183 static const unsigned int exception_stack_sizes[N_EXCEPTION_STACKS] = {
1184 [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STKSZ,
1185 [DEBUG_STACK - 1] = DEBUG_STKSZ
1188 static DEFINE_PER_CPU_PAGE_ALIGNED(char, exception_stacks
1189 [(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ]);
1191 /* May not be marked __init: used by software suspend */
1192 void syscall_init(void)
1195 * LSTAR and STAR live in a bit strange symbiosis.
1196 * They both write to the same internal register. STAR allows to
1197 * set CS/DS but only a 32bit target. LSTAR sets the 64bit rip.
1199 wrmsr(MSR_STAR, 0, (__USER32_CS << 16) | __KERNEL_CS);
1200 wrmsrl(MSR_LSTAR, (unsigned long)entry_SYSCALL_64);
1202 #ifdef CONFIG_IA32_EMULATION
1203 wrmsrl(MSR_CSTAR, (unsigned long)entry_SYSCALL_compat);
1205 * This only works on Intel CPUs.
1206 * On AMD CPUs these MSRs are 32-bit, CPU truncates MSR_IA32_SYSENTER_EIP.
1207 * This does not cause SYSENTER to jump to the wrong location, because
1208 * AMD doesn't allow SYSENTER in long mode (either 32- or 64-bit).
1210 wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS);
1211 wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL);
1212 wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)entry_SYSENTER_compat);
1214 wrmsrl(MSR_CSTAR, (unsigned long)ignore_sysret);
1215 wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)GDT_ENTRY_INVALID_SEG);
1216 wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL);
1217 wrmsrl_safe(MSR_IA32_SYSENTER_EIP, 0ULL);
1220 /* Flags to clear on syscall */
1221 wrmsrl(MSR_SYSCALL_MASK,
1222 X86_EFLAGS_TF|X86_EFLAGS_DF|X86_EFLAGS_IF|
1223 X86_EFLAGS_IOPL|X86_EFLAGS_AC|X86_EFLAGS_NT);
1227 * Copies of the original ist values from the tss are only accessed during
1228 * debugging, no special alignment required.
1230 DEFINE_PER_CPU(struct orig_ist, orig_ist);
1232 static DEFINE_PER_CPU(unsigned long, debug_stack_addr);
1233 DEFINE_PER_CPU(int, debug_stack_usage);
1235 int is_debug_stack(unsigned long addr)
1237 return __this_cpu_read(debug_stack_usage) ||
1238 (addr <= __this_cpu_read(debug_stack_addr) &&
1239 addr > (__this_cpu_read(debug_stack_addr) - DEBUG_STKSZ));
1241 NOKPROBE_SYMBOL(is_debug_stack);
1243 DEFINE_PER_CPU(u32, debug_idt_ctr);
1245 void debug_stack_set_zero(void)
1247 this_cpu_inc(debug_idt_ctr);
1250 NOKPROBE_SYMBOL(debug_stack_set_zero);
1252 void debug_stack_reset(void)
1254 if (WARN_ON(!this_cpu_read(debug_idt_ctr)))
1256 if (this_cpu_dec_return(debug_idt_ctr) == 0)
1259 NOKPROBE_SYMBOL(debug_stack_reset);
1261 #else /* CONFIG_X86_64 */
1263 DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task;
1264 EXPORT_PER_CPU_SYMBOL(current_task);
1265 DEFINE_PER_CPU(int, __preempt_count) = INIT_PREEMPT_COUNT;
1266 EXPORT_PER_CPU_SYMBOL(__preempt_count);
1269 * On x86_32, vm86 modifies tss.sp0, so sp0 isn't a reliable way to find
1270 * the top of the kernel stack. Use an extra percpu variable to track the
1271 * top of the kernel stack directly.
1273 DEFINE_PER_CPU(unsigned long, cpu_current_top_of_stack) =
1274 (unsigned long)&init_thread_union + THREAD_SIZE;
1275 EXPORT_PER_CPU_SYMBOL(cpu_current_top_of_stack);
1277 #ifdef CONFIG_CC_STACKPROTECTOR
1278 DEFINE_PER_CPU_ALIGNED(struct stack_canary, stack_canary);
1281 #endif /* CONFIG_X86_64 */
1284 * Clear all 6 debug registers:
1286 static void clear_all_debug_regs(void)
1290 for (i = 0; i < 8; i++) {
1291 /* Ignore db4, db5 */
1292 if ((i == 4) || (i == 5))
1301 * Restore debug regs if using kgdbwait and you have a kernel debugger
1302 * connection established.
1304 static void dbg_restore_debug_regs(void)
1306 if (unlikely(kgdb_connected && arch_kgdb_ops.correct_hw_break))
1307 arch_kgdb_ops.correct_hw_break();
1309 #else /* ! CONFIG_KGDB */
1310 #define dbg_restore_debug_regs()
1311 #endif /* ! CONFIG_KGDB */
1313 static void wait_for_master_cpu(int cpu)
1317 * wait for ACK from master CPU before continuing
1318 * with AP initialization
1320 WARN_ON(cpumask_test_and_set_cpu(cpu, cpu_initialized_mask));
1321 while (!cpumask_test_cpu(cpu, cpu_callout_mask))
1327 * cpu_init() initializes state that is per-CPU. Some data is already
1328 * initialized (naturally) in the bootstrap process, such as the GDT
1329 * and IDT. We reload them nevertheless, this function acts as a
1330 * 'CPU state barrier', nothing should get across.
1331 * A lot of state is already set up in PDA init for 64 bit
1333 #ifdef CONFIG_X86_64
1337 struct orig_ist *oist;
1338 struct task_struct *me;
1339 struct tss_struct *t;
1341 int cpu = stack_smp_processor_id();
1344 wait_for_master_cpu(cpu);
1347 * Initialize the CR4 shadow before doing anything that could
1353 * Load microcode on this cpu if a valid microcode is available.
1354 * This is early microcode loading procedure.
1358 t = &per_cpu(cpu_tss, cpu);
1359 oist = &per_cpu(orig_ist, cpu);
1362 if (this_cpu_read(numa_node) == 0 &&
1363 early_cpu_to_node(cpu) != NUMA_NO_NODE)
1364 set_numa_node(early_cpu_to_node(cpu));
1369 pr_debug("Initializing CPU#%d\n", cpu);
1371 cr4_clear_bits(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1374 * Initialize the per-CPU GDT with the boot GDT,
1375 * and set up the GDT descriptor:
1378 switch_to_new_gdt(cpu);
1383 memset(me->thread.tls_array, 0, GDT_ENTRY_TLS_ENTRIES * 8);
1386 wrmsrl(MSR_FS_BASE, 0);
1387 wrmsrl(MSR_KERNEL_GS_BASE, 0);
1394 * set up and load the per-CPU TSS
1396 if (!oist->ist[0]) {
1397 char *estacks = per_cpu(exception_stacks, cpu);
1399 for (v = 0; v < N_EXCEPTION_STACKS; v++) {
1400 estacks += exception_stack_sizes[v];
1401 oist->ist[v] = t->x86_tss.ist[v] =
1402 (unsigned long)estacks;
1403 if (v == DEBUG_STACK-1)
1404 per_cpu(debug_stack_addr, cpu) = (unsigned long)estacks;
1408 t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
1411 * <= is required because the CPU will access up to
1412 * 8 bits beyond the end of the IO permission bitmap.
1414 for (i = 0; i <= IO_BITMAP_LONGS; i++)
1415 t->io_bitmap[i] = ~0UL;
1417 atomic_inc(&init_mm.mm_count);
1418 me->active_mm = &init_mm;
1420 enter_lazy_tlb(&init_mm, me);
1422 load_sp0(t, ¤t->thread);
1423 set_tss_desc(cpu, t);
1425 load_mm_ldt(&init_mm);
1427 clear_all_debug_regs();
1428 dbg_restore_debug_regs();
1440 int cpu = smp_processor_id();
1441 struct task_struct *curr = current;
1442 struct tss_struct *t = &per_cpu(cpu_tss, cpu);
1443 struct thread_struct *thread = &curr->thread;
1445 wait_for_master_cpu(cpu);
1448 * Initialize the CR4 shadow before doing anything that could
1453 show_ucode_info_early();
1455 pr_info("Initializing CPU#%d\n", cpu);
1457 if (cpu_feature_enabled(X86_FEATURE_VME) ||
1459 boot_cpu_has(X86_FEATURE_DE))
1460 cr4_clear_bits(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1463 switch_to_new_gdt(cpu);
1466 * Set up and load the per-CPU TSS and LDT
1468 atomic_inc(&init_mm.mm_count);
1469 curr->active_mm = &init_mm;
1471 enter_lazy_tlb(&init_mm, curr);
1473 load_sp0(t, thread);
1474 set_tss_desc(cpu, t);
1476 load_mm_ldt(&init_mm);
1478 t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
1480 #ifdef CONFIG_DOUBLEFAULT
1481 /* Set up doublefault TSS pointer in the GDT */
1482 __set_tss_desc(cpu, GDT_ENTRY_DOUBLEFAULT_TSS, &doublefault_tss);
1485 clear_all_debug_regs();
1486 dbg_restore_debug_regs();
1492 static void bsp_resume(void)
1494 if (this_cpu->c_bsp_resume)
1495 this_cpu->c_bsp_resume(&boot_cpu_data);
1498 static struct syscore_ops cpu_syscore_ops = {
1499 .resume = bsp_resume,
1502 static int __init init_cpu_syscore(void)
1504 register_syscore_ops(&cpu_syscore_ops);
1507 core_initcall(init_cpu_syscore);