1 /* cpu_feature_enabled() cannot be used this early */
2 #define USE_EARLY_PGTABLE_L5
3
4 #include <linux/bootmem.h>
5 #include <linux/linkage.h>
6 #include <linux/bitops.h>
7 #include <linux/kernel.h>
8 #include <linux/export.h>
9 #include <linux/percpu.h>
10 #include <linux/string.h>
11 #include <linux/ctype.h>
12 #include <linux/delay.h>
13 #include <linux/sched/mm.h>
14 #include <linux/sched/clock.h>
15 #include <linux/sched/task.h>
16 #include <linux/init.h>
17 #include <linux/kprobes.h>
18 #include <linux/kgdb.h>
19 #include <linux/smp.h>
20 #include <linux/io.h>
21 #include <linux/syscore_ops.h>
22
23 #include <asm/stackprotector.h>
24 #include <asm/perf_event.h>
25 #include <asm/mmu_context.h>
26 #include <asm/archrandom.h>
27 #include <asm/hypervisor.h>
28 #include <asm/processor.h>
29 #include <asm/tlbflush.h>
30 #include <asm/debugreg.h>
31 #include <asm/sections.h>
32 #include <asm/vsyscall.h>
33 #include <linux/topology.h>
34 #include <linux/cpumask.h>
35 #include <asm/pgtable.h>
36 #include <linux/atomic.h>
37 #include <asm/proto.h>
38 #include <asm/setup.h>
39 #include <asm/apic.h>
40 #include <asm/desc.h>
41 #include <asm/fpu/internal.h>
42 #include <asm/mtrr.h>
43 #include <asm/hwcap2.h>
44 #include <linux/numa.h>
45 #include <asm/asm.h>
46 #include <asm/bugs.h>
47 #include <asm/cpu.h>
48 #include <asm/mce.h>
49 #include <asm/msr.h>
50 #include <asm/pat.h>
51 #include <asm/microcode.h>
52 #include <asm/microcode_intel.h>
53 #include <asm/intel-family.h>
54 #include <asm/cpu_device_id.h>
55
56 #ifdef CONFIG_X86_LOCAL_APIC
57 #include <asm/uv/uv.h>
58 #endif
59
60 #include "cpu.h"
61
62 u32 elf_hwcap2 __read_mostly;
63
64 /* all of these masks are initialized in setup_cpu_local_masks() */
65 cpumask_var_t cpu_initialized_mask;
66 cpumask_var_t cpu_callout_mask;
67 cpumask_var_t cpu_callin_mask;
68
69 /* representing cpus for which sibling maps can be computed */
70 cpumask_var_t cpu_sibling_setup_mask;
71
72 /* Number of siblings per CPU package */
73 int smp_num_siblings = 1;
74 EXPORT_SYMBOL(smp_num_siblings);
75
76 /* Last level cache ID of each logical CPU */
77 DEFINE_PER_CPU_READ_MOSTLY(u16, cpu_llc_id) = BAD_APICID;
78
79 /* correctly size the local cpu masks */
setup_cpu_local_masks(void)80 void __init setup_cpu_local_masks(void)
81 {
82 alloc_bootmem_cpumask_var(&cpu_initialized_mask);
83 alloc_bootmem_cpumask_var(&cpu_callin_mask);
84 alloc_bootmem_cpumask_var(&cpu_callout_mask);
85 alloc_bootmem_cpumask_var(&cpu_sibling_setup_mask);
86 }
87
default_init(struct cpuinfo_x86 * c)88 static void default_init(struct cpuinfo_x86 *c)
89 {
90 #ifdef CONFIG_X86_64
91 cpu_detect_cache_sizes(c);
92 #else
93 /* Not much we can do here... */
94 /* Check if at least it has cpuid */
95 if (c->cpuid_level == -1) {
96 /* No cpuid. It must be an ancient CPU */
97 if (c->x86 == 4)
98 strcpy(c->x86_model_id, "486");
99 else if (c->x86 == 3)
100 strcpy(c->x86_model_id, "386");
101 }
102 #endif
103 }
104
105 static const struct cpu_dev default_cpu = {
106 .c_init = default_init,
107 .c_vendor = "Unknown",
108 .c_x86_vendor = X86_VENDOR_UNKNOWN,
109 };
110
111 static const struct cpu_dev *this_cpu = &default_cpu;
112
113 DEFINE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page) = { .gdt = {
114 #ifdef CONFIG_X86_64
115 /*
116 * We need valid kernel segments for data and code in long mode too
117 * IRET will check the segment types kkeil 2000/10/28
118 * Also sysret mandates a special GDT layout
119 *
120 * TLS descriptors are currently at a different place compared to i386.
121 * Hopefully nobody expects them at a fixed place (Wine?)
122 */
123 [GDT_ENTRY_KERNEL32_CS] = GDT_ENTRY_INIT(0xc09b, 0, 0xfffff),
124 [GDT_ENTRY_KERNEL_CS] = GDT_ENTRY_INIT(0xa09b, 0, 0xfffff),
125 [GDT_ENTRY_KERNEL_DS] = GDT_ENTRY_INIT(0xc093, 0, 0xfffff),
126 [GDT_ENTRY_DEFAULT_USER32_CS] = GDT_ENTRY_INIT(0xc0fb, 0, 0xfffff),
127 [GDT_ENTRY_DEFAULT_USER_DS] = GDT_ENTRY_INIT(0xc0f3, 0, 0xfffff),
128 [GDT_ENTRY_DEFAULT_USER_CS] = GDT_ENTRY_INIT(0xa0fb, 0, 0xfffff),
129 #else
130 [GDT_ENTRY_KERNEL_CS] = GDT_ENTRY_INIT(0xc09a, 0, 0xfffff),
131 [GDT_ENTRY_KERNEL_DS] = GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
132 [GDT_ENTRY_DEFAULT_USER_CS] = GDT_ENTRY_INIT(0xc0fa, 0, 0xfffff),
133 [GDT_ENTRY_DEFAULT_USER_DS] = GDT_ENTRY_INIT(0xc0f2, 0, 0xfffff),
134 /*
135 * Segments used for calling PnP BIOS have byte granularity.
136 * They code segments and data segments have fixed 64k limits,
137 * the transfer segment sizes are set at run time.
138 */
139 /* 32-bit code */
140 [GDT_ENTRY_PNPBIOS_CS32] = GDT_ENTRY_INIT(0x409a, 0, 0xffff),
141 /* 16-bit code */
142 [GDT_ENTRY_PNPBIOS_CS16] = GDT_ENTRY_INIT(0x009a, 0, 0xffff),
143 /* 16-bit data */
144 [GDT_ENTRY_PNPBIOS_DS] = GDT_ENTRY_INIT(0x0092, 0, 0xffff),
145 /* 16-bit data */
146 [GDT_ENTRY_PNPBIOS_TS1] = GDT_ENTRY_INIT(0x0092, 0, 0),
147 /* 16-bit data */
148 [GDT_ENTRY_PNPBIOS_TS2] = GDT_ENTRY_INIT(0x0092, 0, 0),
149 /*
150 * The APM segments have byte granularity and their bases
151 * are set at run time. All have 64k limits.
152 */
153 /* 32-bit code */
154 [GDT_ENTRY_APMBIOS_BASE] = GDT_ENTRY_INIT(0x409a, 0, 0xffff),
155 /* 16-bit code */
156 [GDT_ENTRY_APMBIOS_BASE+1] = GDT_ENTRY_INIT(0x009a, 0, 0xffff),
157 /* data */
158 [GDT_ENTRY_APMBIOS_BASE+2] = GDT_ENTRY_INIT(0x4092, 0, 0xffff),
159
160 [GDT_ENTRY_ESPFIX_SS] = GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
161 [GDT_ENTRY_PERCPU] = GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
162 GDT_STACK_CANARY_INIT
163 #endif
164 } };
165 EXPORT_PER_CPU_SYMBOL_GPL(gdt_page);
166
x86_mpx_setup(char * s)167 static int __init x86_mpx_setup(char *s)
168 {
169 /* require an exact match without trailing characters */
170 if (strlen(s))
171 return 0;
172
173 /* do not emit a message if the feature is not present */
174 if (!boot_cpu_has(X86_FEATURE_MPX))
175 return 1;
176
177 setup_clear_cpu_cap(X86_FEATURE_MPX);
178 pr_info("nompx: Intel Memory Protection Extensions (MPX) disabled\n");
179 return 1;
180 }
181 __setup("nompx", x86_mpx_setup);
182
183 #ifdef CONFIG_X86_64
x86_nopcid_setup(char * s)184 static int __init x86_nopcid_setup(char *s)
185 {
186 /* nopcid doesn't accept parameters */
187 if (s)
188 return -EINVAL;
189
190 /* do not emit a message if the feature is not present */
191 if (!boot_cpu_has(X86_FEATURE_PCID))
192 return 0;
193
194 setup_clear_cpu_cap(X86_FEATURE_PCID);
195 pr_info("nopcid: PCID feature disabled\n");
196 return 0;
197 }
198 early_param("nopcid", x86_nopcid_setup);
199 #endif
200
x86_noinvpcid_setup(char * s)201 static int __init x86_noinvpcid_setup(char *s)
202 {
203 /* noinvpcid doesn't accept parameters */
204 if (s)
205 return -EINVAL;
206
207 /* do not emit a message if the feature is not present */
208 if (!boot_cpu_has(X86_FEATURE_INVPCID))
209 return 0;
210
211 setup_clear_cpu_cap(X86_FEATURE_INVPCID);
212 pr_info("noinvpcid: INVPCID feature disabled\n");
213 return 0;
214 }
215 early_param("noinvpcid", x86_noinvpcid_setup);
216
217 #ifdef CONFIG_X86_32
218 static int cachesize_override = -1;
219 static int disable_x86_serial_nr = 1;
220
cachesize_setup(char * str)221 static int __init cachesize_setup(char *str)
222 {
223 get_option(&str, &cachesize_override);
224 return 1;
225 }
226 __setup("cachesize=", cachesize_setup);
227
x86_sep_setup(char * s)228 static int __init x86_sep_setup(char *s)
229 {
230 setup_clear_cpu_cap(X86_FEATURE_SEP);
231 return 1;
232 }
233 __setup("nosep", x86_sep_setup);
234
235 /* Standard macro to see if a specific flag is changeable */
flag_is_changeable_p(u32 flag)236 static inline int flag_is_changeable_p(u32 flag)
237 {
238 u32 f1, f2;
239
240 /*
241 * Cyrix and IDT cpus allow disabling of CPUID
242 * so the code below may return different results
243 * when it is executed before and after enabling
244 * the CPUID. Add "volatile" to not allow gcc to
245 * optimize the subsequent calls to this function.
246 */
247 asm volatile ("pushfl \n\t"
248 "pushfl \n\t"
249 "popl %0 \n\t"
250 "movl %0, %1 \n\t"
251 "xorl %2, %0 \n\t"
252 "pushl %0 \n\t"
253 "popfl \n\t"
254 "pushfl \n\t"
255 "popl %0 \n\t"
256 "popfl \n\t"
257
258 : "=&r" (f1), "=&r" (f2)
259 : "ir" (flag));
260
261 return ((f1^f2) & flag) != 0;
262 }
263
264 /* Probe for the CPUID instruction */
have_cpuid_p(void)265 int have_cpuid_p(void)
266 {
267 return flag_is_changeable_p(X86_EFLAGS_ID);
268 }
269
squash_the_stupid_serial_number(struct cpuinfo_x86 * c)270 static void squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
271 {
272 unsigned long lo, hi;
273
274 if (!cpu_has(c, X86_FEATURE_PN) || !disable_x86_serial_nr)
275 return;
276
277 /* Disable processor serial number: */
278
279 rdmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
280 lo |= 0x200000;
281 wrmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
282
283 pr_notice("CPU serial number disabled.\n");
284 clear_cpu_cap(c, X86_FEATURE_PN);
285
286 /* Disabling the serial number may affect the cpuid level */
287 c->cpuid_level = cpuid_eax(0);
288 }
289
x86_serial_nr_setup(char * s)290 static int __init x86_serial_nr_setup(char *s)
291 {
292 disable_x86_serial_nr = 0;
293 return 1;
294 }
295 __setup("serialnumber", x86_serial_nr_setup);
296 #else
flag_is_changeable_p(u32 flag)297 static inline int flag_is_changeable_p(u32 flag)
298 {
299 return 1;
300 }
squash_the_stupid_serial_number(struct cpuinfo_x86 * c)301 static inline void squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
302 {
303 }
304 #endif
305
setup_disable_smep(char * arg)306 static __init int setup_disable_smep(char *arg)
307 {
308 setup_clear_cpu_cap(X86_FEATURE_SMEP);
309 /* Check for things that depend on SMEP being enabled: */
310 check_mpx_erratum(&boot_cpu_data);
311 return 1;
312 }
313 __setup("nosmep", setup_disable_smep);
314
setup_smep(struct cpuinfo_x86 * c)315 static __always_inline void setup_smep(struct cpuinfo_x86 *c)
316 {
317 if (cpu_has(c, X86_FEATURE_SMEP))
318 cr4_set_bits(X86_CR4_SMEP);
319 }
320
setup_disable_smap(char * arg)321 static __init int setup_disable_smap(char *arg)
322 {
323 setup_clear_cpu_cap(X86_FEATURE_SMAP);
324 return 1;
325 }
326 __setup("nosmap", setup_disable_smap);
327
setup_smap(struct cpuinfo_x86 * c)328 static __always_inline void setup_smap(struct cpuinfo_x86 *c)
329 {
330 unsigned long eflags = native_save_fl();
331
332 /* This should have been cleared long ago */
333 BUG_ON(eflags & X86_EFLAGS_AC);
334
335 if (cpu_has(c, X86_FEATURE_SMAP)) {
336 #ifdef CONFIG_X86_SMAP
337 cr4_set_bits(X86_CR4_SMAP);
338 #else
339 cr4_clear_bits(X86_CR4_SMAP);
340 #endif
341 }
342 }
343
setup_umip(struct cpuinfo_x86 * c)344 static __always_inline void setup_umip(struct cpuinfo_x86 *c)
345 {
346 /* Check the boot processor, plus build option for UMIP. */
347 if (!cpu_feature_enabled(X86_FEATURE_UMIP))
348 goto out;
349
350 /* Check the current processor's cpuid bits. */
351 if (!cpu_has(c, X86_FEATURE_UMIP))
352 goto out;
353
354 cr4_set_bits(X86_CR4_UMIP);
355
356 pr_info("x86/cpu: Activated the Intel User Mode Instruction Prevention (UMIP) CPU feature\n");
357
358 return;
359
360 out:
361 /*
362 * Make sure UMIP is disabled in case it was enabled in a
363 * previous boot (e.g., via kexec).
364 */
365 cr4_clear_bits(X86_CR4_UMIP);
366 }
367
368 /*
369 * Protection Keys are not available in 32-bit mode.
370 */
371 static bool pku_disabled;
372
setup_pku(struct cpuinfo_x86 * c)373 static __always_inline void setup_pku(struct cpuinfo_x86 *c)
374 {
375 /* check the boot processor, plus compile options for PKU: */
376 if (!cpu_feature_enabled(X86_FEATURE_PKU))
377 return;
378 /* checks the actual processor's cpuid bits: */
379 if (!cpu_has(c, X86_FEATURE_PKU))
380 return;
381 if (pku_disabled)
382 return;
383
384 cr4_set_bits(X86_CR4_PKE);
385 /*
386 * Seting X86_CR4_PKE will cause the X86_FEATURE_OSPKE
387 * cpuid bit to be set. We need to ensure that we
388 * update that bit in this CPU's "cpu_info".
389 */
390 get_cpu_cap(c);
391 }
392
393 #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
setup_disable_pku(char * arg)394 static __init int setup_disable_pku(char *arg)
395 {
396 /*
397 * Do not clear the X86_FEATURE_PKU bit. All of the
398 * runtime checks are against OSPKE so clearing the
399 * bit does nothing.
400 *
401 * This way, we will see "pku" in cpuinfo, but not
402 * "ospke", which is exactly what we want. It shows
403 * that the CPU has PKU, but the OS has not enabled it.
404 * This happens to be exactly how a system would look
405 * if we disabled the config option.
406 */
407 pr_info("x86: 'nopku' specified, disabling Memory Protection Keys\n");
408 pku_disabled = true;
409 return 1;
410 }
411 __setup("nopku", setup_disable_pku);
412 #endif /* CONFIG_X86_64 */
413
414 /*
415 * Some CPU features depend on higher CPUID levels, which may not always
416 * be available due to CPUID level capping or broken virtualization
417 * software. Add those features to this table to auto-disable them.
418 */
419 struct cpuid_dependent_feature {
420 u32 feature;
421 u32 level;
422 };
423
424 static const struct cpuid_dependent_feature
425 cpuid_dependent_features[] = {
426 { X86_FEATURE_MWAIT, 0x00000005 },
427 { X86_FEATURE_DCA, 0x00000009 },
428 { X86_FEATURE_XSAVE, 0x0000000d },
429 { 0, 0 }
430 };
431
filter_cpuid_features(struct cpuinfo_x86 * c,bool warn)432 static void filter_cpuid_features(struct cpuinfo_x86 *c, bool warn)
433 {
434 const struct cpuid_dependent_feature *df;
435
436 for (df = cpuid_dependent_features; df->feature; df++) {
437
438 if (!cpu_has(c, df->feature))
439 continue;
440 /*
441 * Note: cpuid_level is set to -1 if unavailable, but
442 * extended_extended_level is set to 0 if unavailable
443 * and the legitimate extended levels are all negative
444 * when signed; hence the weird messing around with
445 * signs here...
446 */
447 if (!((s32)df->level < 0 ?
448 (u32)df->level > (u32)c->extended_cpuid_level :
449 (s32)df->level > (s32)c->cpuid_level))
450 continue;
451
452 clear_cpu_cap(c, df->feature);
453 if (!warn)
454 continue;
455
456 pr_warn("CPU: CPU feature " X86_CAP_FMT " disabled, no CPUID level 0x%x\n",
457 x86_cap_flag(df->feature), df->level);
458 }
459 }
460
461 /*
462 * Naming convention should be: <Name> [(<Codename>)]
463 * This table only is used unless init_<vendor>() below doesn't set it;
464 * in particular, if CPUID levels 0x80000002..4 are supported, this
465 * isn't used
466 */
467
468 /* Look up CPU names by table lookup. */
table_lookup_model(struct cpuinfo_x86 * c)469 static const char *table_lookup_model(struct cpuinfo_x86 *c)
470 {
471 #ifdef CONFIG_X86_32
472 const struct legacy_cpu_model_info *info;
473
474 if (c->x86_model >= 16)
475 return NULL; /* Range check */
476
477 if (!this_cpu)
478 return NULL;
479
480 info = this_cpu->legacy_models;
481
482 while (info->family) {
483 if (info->family == c->x86)
484 return info->model_names[c->x86_model];
485 info++;
486 }
487 #endif
488 return NULL; /* Not found */
489 }
490
491 __u32 cpu_caps_cleared[NCAPINTS + NBUGINTS];
492 __u32 cpu_caps_set[NCAPINTS + NBUGINTS];
493
load_percpu_segment(int cpu)494 void load_percpu_segment(int cpu)
495 {
496 #ifdef CONFIG_X86_32
497 loadsegment(fs, __KERNEL_PERCPU);
498 #else
499 __loadsegment_simple(gs, 0);
500 wrmsrl(MSR_GS_BASE, cpu_kernelmode_gs_base(cpu));
501 #endif
502 load_stack_canary_segment();
503 }
504
505 #ifdef CONFIG_X86_32
506 /* The 32-bit entry code needs to find cpu_entry_area. */
507 DEFINE_PER_CPU(struct cpu_entry_area *, cpu_entry_area);
508 #endif
509
510 #ifdef CONFIG_X86_64
511 /*
512 * Special IST stacks which the CPU switches to when it calls
513 * an IST-marked descriptor entry. Up to 7 stacks (hardware
514 * limit), all of them are 4K, except the debug stack which
515 * is 8K.
516 */
517 static const unsigned int exception_stack_sizes[N_EXCEPTION_STACKS] = {
518 [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STKSZ,
519 [DEBUG_STACK - 1] = DEBUG_STKSZ
520 };
521 #endif
522
523 /* Load the original GDT from the per-cpu structure */
load_direct_gdt(int cpu)524 void load_direct_gdt(int cpu)
525 {
526 struct desc_ptr gdt_descr;
527
528 gdt_descr.address = (long)get_cpu_gdt_rw(cpu);
529 gdt_descr.size = GDT_SIZE - 1;
530 load_gdt(&gdt_descr);
531 }
532 EXPORT_SYMBOL_GPL(load_direct_gdt);
533
534 /* Load a fixmap remapping of the per-cpu GDT */
load_fixmap_gdt(int cpu)535 void load_fixmap_gdt(int cpu)
536 {
537 struct desc_ptr gdt_descr;
538
539 gdt_descr.address = (long)get_cpu_gdt_ro(cpu);
540 gdt_descr.size = GDT_SIZE - 1;
541 load_gdt(&gdt_descr);
542 }
543 EXPORT_SYMBOL_GPL(load_fixmap_gdt);
544
545 /*
546 * Current gdt points %fs at the "master" per-cpu area: after this,
547 * it's on the real one.
548 */
switch_to_new_gdt(int cpu)549 void switch_to_new_gdt(int cpu)
550 {
551 /* Load the original GDT */
552 load_direct_gdt(cpu);
553 /* Reload the per-cpu base */
554 load_percpu_segment(cpu);
555 }
556
557 static const struct cpu_dev *cpu_devs[X86_VENDOR_NUM] = {};
558
get_model_name(struct cpuinfo_x86 * c)559 static void get_model_name(struct cpuinfo_x86 *c)
560 {
561 unsigned int *v;
562 char *p, *q, *s;
563
564 if (c->extended_cpuid_level < 0x80000004)
565 return;
566
567 v = (unsigned int *)c->x86_model_id;
568 cpuid(0x80000002, &v[0], &v[1], &v[2], &v[3]);
569 cpuid(0x80000003, &v[4], &v[5], &v[6], &v[7]);
570 cpuid(0x80000004, &v[8], &v[9], &v[10], &v[11]);
571 c->x86_model_id[48] = 0;
572
573 /* Trim whitespace */
574 p = q = s = &c->x86_model_id[0];
575
576 while (*p == ' ')
577 p++;
578
579 while (*p) {
580 /* Note the last non-whitespace index */
581 if (!isspace(*p))
582 s = q;
583
584 *q++ = *p++;
585 }
586
587 *(s + 1) = '\0';
588 }
589
detect_num_cpu_cores(struct cpuinfo_x86 * c)590 void detect_num_cpu_cores(struct cpuinfo_x86 *c)
591 {
592 unsigned int eax, ebx, ecx, edx;
593
594 c->x86_max_cores = 1;
595 if (!IS_ENABLED(CONFIG_SMP) || c->cpuid_level < 4)
596 return;
597
598 cpuid_count(4, 0, &eax, &ebx, &ecx, &edx);
599 if (eax & 0x1f)
600 c->x86_max_cores = (eax >> 26) + 1;
601 }
602
cpu_detect_cache_sizes(struct cpuinfo_x86 * c)603 void cpu_detect_cache_sizes(struct cpuinfo_x86 *c)
604 {
605 unsigned int n, dummy, ebx, ecx, edx, l2size;
606
607 n = c->extended_cpuid_level;
608
609 if (n >= 0x80000005) {
610 cpuid(0x80000005, &dummy, &ebx, &ecx, &edx);
611 c->x86_cache_size = (ecx>>24) + (edx>>24);
612 #ifdef CONFIG_X86_64
613 /* On K8 L1 TLB is inclusive, so don't count it */
614 c->x86_tlbsize = 0;
615 #endif
616 }
617
618 if (n < 0x80000006) /* Some chips just has a large L1. */
619 return;
620
621 cpuid(0x80000006, &dummy, &ebx, &ecx, &edx);
622 l2size = ecx >> 16;
623
624 #ifdef CONFIG_X86_64
625 c->x86_tlbsize += ((ebx >> 16) & 0xfff) + (ebx & 0xfff);
626 #else
627 /* do processor-specific cache resizing */
628 if (this_cpu->legacy_cache_size)
629 l2size = this_cpu->legacy_cache_size(c, l2size);
630
631 /* Allow user to override all this if necessary. */
632 if (cachesize_override != -1)
633 l2size = cachesize_override;
634
635 if (l2size == 0)
636 return; /* Again, no L2 cache is possible */
637 #endif
638
639 c->x86_cache_size = l2size;
640 }
641
642 u16 __read_mostly tlb_lli_4k[NR_INFO];
643 u16 __read_mostly tlb_lli_2m[NR_INFO];
644 u16 __read_mostly tlb_lli_4m[NR_INFO];
645 u16 __read_mostly tlb_lld_4k[NR_INFO];
646 u16 __read_mostly tlb_lld_2m[NR_INFO];
647 u16 __read_mostly tlb_lld_4m[NR_INFO];
648 u16 __read_mostly tlb_lld_1g[NR_INFO];
649
cpu_detect_tlb(struct cpuinfo_x86 * c)650 static void cpu_detect_tlb(struct cpuinfo_x86 *c)
651 {
652 if (this_cpu->c_detect_tlb)
653 this_cpu->c_detect_tlb(c);
654
655 pr_info("Last level iTLB entries: 4KB %d, 2MB %d, 4MB %d\n",
656 tlb_lli_4k[ENTRIES], tlb_lli_2m[ENTRIES],
657 tlb_lli_4m[ENTRIES]);
658
659 pr_info("Last level dTLB entries: 4KB %d, 2MB %d, 4MB %d, 1GB %d\n",
660 tlb_lld_4k[ENTRIES], tlb_lld_2m[ENTRIES],
661 tlb_lld_4m[ENTRIES], tlb_lld_1g[ENTRIES]);
662 }
663
detect_ht_early(struct cpuinfo_x86 * c)664 int detect_ht_early(struct cpuinfo_x86 *c)
665 {
666 #ifdef CONFIG_SMP
667 u32 eax, ebx, ecx, edx;
668
669 if (!cpu_has(c, X86_FEATURE_HT))
670 return -1;
671
672 if (cpu_has(c, X86_FEATURE_CMP_LEGACY))
673 return -1;
674
675 if (cpu_has(c, X86_FEATURE_XTOPOLOGY))
676 return -1;
677
678 cpuid(1, &eax, &ebx, &ecx, &edx);
679
680 smp_num_siblings = (ebx & 0xff0000) >> 16;
681 if (smp_num_siblings == 1)
682 pr_info_once("CPU0: Hyper-Threading is disabled\n");
683 #endif
684 return 0;
685 }
686
detect_ht(struct cpuinfo_x86 * c)687 void detect_ht(struct cpuinfo_x86 *c)
688 {
689 #ifdef CONFIG_SMP
690 int index_msb, core_bits;
691
692 if (detect_ht_early(c) < 0)
693 return;
694
695 index_msb = get_count_order(smp_num_siblings);
696 c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, index_msb);
697
698 smp_num_siblings = smp_num_siblings / c->x86_max_cores;
699
700 index_msb = get_count_order(smp_num_siblings);
701
702 core_bits = get_count_order(c->x86_max_cores);
703
704 c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid, index_msb) &
705 ((1 << core_bits) - 1);
706 #endif
707 }
708
get_cpu_vendor(struct cpuinfo_x86 * c)709 static void get_cpu_vendor(struct cpuinfo_x86 *c)
710 {
711 char *v = c->x86_vendor_id;
712 int i;
713
714 for (i = 0; i < X86_VENDOR_NUM; i++) {
715 if (!cpu_devs[i])
716 break;
717
718 if (!strcmp(v, cpu_devs[i]->c_ident[0]) ||
719 (cpu_devs[i]->c_ident[1] &&
720 !strcmp(v, cpu_devs[i]->c_ident[1]))) {
721
722 this_cpu = cpu_devs[i];
723 c->x86_vendor = this_cpu->c_x86_vendor;
724 return;
725 }
726 }
727
728 pr_err_once("CPU: vendor_id '%s' unknown, using generic init.\n" \
729 "CPU: Your system may be unstable.\n", v);
730
731 c->x86_vendor = X86_VENDOR_UNKNOWN;
732 this_cpu = &default_cpu;
733 }
734
cpu_detect(struct cpuinfo_x86 * c)735 void cpu_detect(struct cpuinfo_x86 *c)
736 {
737 /* Get vendor name */
738 cpuid(0x00000000, (unsigned int *)&c->cpuid_level,
739 (unsigned int *)&c->x86_vendor_id[0],
740 (unsigned int *)&c->x86_vendor_id[8],
741 (unsigned int *)&c->x86_vendor_id[4]);
742
743 c->x86 = 4;
744 /* Intel-defined flags: level 0x00000001 */
745 if (c->cpuid_level >= 0x00000001) {
746 u32 junk, tfms, cap0, misc;
747
748 cpuid(0x00000001, &tfms, &misc, &junk, &cap0);
749 c->x86 = x86_family(tfms);
750 c->x86_model = x86_model(tfms);
751 c->x86_stepping = x86_stepping(tfms);
752
753 if (cap0 & (1<<19)) {
754 c->x86_clflush_size = ((misc >> 8) & 0xff) * 8;
755 c->x86_cache_alignment = c->x86_clflush_size;
756 }
757 }
758 }
759
apply_forced_caps(struct cpuinfo_x86 * c)760 static void apply_forced_caps(struct cpuinfo_x86 *c)
761 {
762 int i;
763
764 for (i = 0; i < NCAPINTS + NBUGINTS; i++) {
765 c->x86_capability[i] &= ~cpu_caps_cleared[i];
766 c->x86_capability[i] |= cpu_caps_set[i];
767 }
768 }
769
init_speculation_control(struct cpuinfo_x86 * c)770 static void init_speculation_control(struct cpuinfo_x86 *c)
771 {
772 /*
773 * The Intel SPEC_CTRL CPUID bit implies IBRS and IBPB support,
774 * and they also have a different bit for STIBP support. Also,
775 * a hypervisor might have set the individual AMD bits even on
776 * Intel CPUs, for finer-grained selection of what's available.
777 */
778 if (cpu_has(c, X86_FEATURE_SPEC_CTRL)) {
779 set_cpu_cap(c, X86_FEATURE_IBRS);
780 set_cpu_cap(c, X86_FEATURE_IBPB);
781 set_cpu_cap(c, X86_FEATURE_MSR_SPEC_CTRL);
782 }
783
784 if (cpu_has(c, X86_FEATURE_INTEL_STIBP))
785 set_cpu_cap(c, X86_FEATURE_STIBP);
786
787 if (cpu_has(c, X86_FEATURE_SPEC_CTRL_SSBD) ||
788 cpu_has(c, X86_FEATURE_VIRT_SSBD))
789 set_cpu_cap(c, X86_FEATURE_SSBD);
790
791 if (cpu_has(c, X86_FEATURE_AMD_IBRS)) {
792 set_cpu_cap(c, X86_FEATURE_IBRS);
793 set_cpu_cap(c, X86_FEATURE_MSR_SPEC_CTRL);
794 }
795
796 if (cpu_has(c, X86_FEATURE_AMD_IBPB))
797 set_cpu_cap(c, X86_FEATURE_IBPB);
798
799 if (cpu_has(c, X86_FEATURE_AMD_STIBP)) {
800 set_cpu_cap(c, X86_FEATURE_STIBP);
801 set_cpu_cap(c, X86_FEATURE_MSR_SPEC_CTRL);
802 }
803
804 if (cpu_has(c, X86_FEATURE_AMD_SSBD)) {
805 set_cpu_cap(c, X86_FEATURE_SSBD);
806 set_cpu_cap(c, X86_FEATURE_MSR_SPEC_CTRL);
807 clear_cpu_cap(c, X86_FEATURE_VIRT_SSBD);
808 }
809 }
810
get_cpu_cap(struct cpuinfo_x86 * c)811 void get_cpu_cap(struct cpuinfo_x86 *c)
812 {
813 u32 eax, ebx, ecx, edx;
814
815 /* Intel-defined flags: level 0x00000001 */
816 if (c->cpuid_level >= 0x00000001) {
817 cpuid(0x00000001, &eax, &ebx, &ecx, &edx);
818
819 c->x86_capability[CPUID_1_ECX] = ecx;
820 c->x86_capability[CPUID_1_EDX] = edx;
821 }
822
823 /* Thermal and Power Management Leaf: level 0x00000006 (eax) */
824 if (c->cpuid_level >= 0x00000006)
825 c->x86_capability[CPUID_6_EAX] = cpuid_eax(0x00000006);
826
827 /* Additional Intel-defined flags: level 0x00000007 */
828 if (c->cpuid_level >= 0x00000007) {
829 cpuid_count(0x00000007, 0, &eax, &ebx, &ecx, &edx);
830 c->x86_capability[CPUID_7_0_EBX] = ebx;
831 c->x86_capability[CPUID_7_ECX] = ecx;
832 c->x86_capability[CPUID_7_EDX] = edx;
833 }
834
835 /* Extended state features: level 0x0000000d */
836 if (c->cpuid_level >= 0x0000000d) {
837 cpuid_count(0x0000000d, 1, &eax, &ebx, &ecx, &edx);
838
839 c->x86_capability[CPUID_D_1_EAX] = eax;
840 }
841
842 /* Additional Intel-defined flags: level 0x0000000F */
843 if (c->cpuid_level >= 0x0000000F) {
844
845 /* QoS sub-leaf, EAX=0Fh, ECX=0 */
846 cpuid_count(0x0000000F, 0, &eax, &ebx, &ecx, &edx);
847 c->x86_capability[CPUID_F_0_EDX] = edx;
848
849 if (cpu_has(c, X86_FEATURE_CQM_LLC)) {
850 /* will be overridden if occupancy monitoring exists */
851 c->x86_cache_max_rmid = ebx;
852
853 /* QoS sub-leaf, EAX=0Fh, ECX=1 */
854 cpuid_count(0x0000000F, 1, &eax, &ebx, &ecx, &edx);
855 c->x86_capability[CPUID_F_1_EDX] = edx;
856
857 if ((cpu_has(c, X86_FEATURE_CQM_OCCUP_LLC)) ||
858 ((cpu_has(c, X86_FEATURE_CQM_MBM_TOTAL)) ||
859 (cpu_has(c, X86_FEATURE_CQM_MBM_LOCAL)))) {
860 c->x86_cache_max_rmid = ecx;
861 c->x86_cache_occ_scale = ebx;
862 }
863 } else {
864 c->x86_cache_max_rmid = -1;
865 c->x86_cache_occ_scale = -1;
866 }
867 }
868
869 /* AMD-defined flags: level 0x80000001 */
870 eax = cpuid_eax(0x80000000);
871 c->extended_cpuid_level = eax;
872
873 if ((eax & 0xffff0000) == 0x80000000) {
874 if (eax >= 0x80000001) {
875 cpuid(0x80000001, &eax, &ebx, &ecx, &edx);
876
877 c->x86_capability[CPUID_8000_0001_ECX] = ecx;
878 c->x86_capability[CPUID_8000_0001_EDX] = edx;
879 }
880 }
881
882 if (c->extended_cpuid_level >= 0x80000007) {
883 cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
884
885 c->x86_capability[CPUID_8000_0007_EBX] = ebx;
886 c->x86_power = edx;
887 }
888
889 if (c->extended_cpuid_level >= 0x80000008) {
890 cpuid(0x80000008, &eax, &ebx, &ecx, &edx);
891 c->x86_capability[CPUID_8000_0008_EBX] = ebx;
892 }
893
894 if (c->extended_cpuid_level >= 0x8000000a)
895 c->x86_capability[CPUID_8000_000A_EDX] = cpuid_edx(0x8000000a);
896
897 init_scattered_cpuid_features(c);
898 init_speculation_control(c);
899
900 /*
901 * Clear/Set all flags overridden by options, after probe.
902 * This needs to happen each time we re-probe, which may happen
903 * several times during CPU initialization.
904 */
905 apply_forced_caps(c);
906 }
907
get_cpu_address_sizes(struct cpuinfo_x86 * c)908 void get_cpu_address_sizes(struct cpuinfo_x86 *c)
909 {
910 u32 eax, ebx, ecx, edx;
911
912 if (c->extended_cpuid_level >= 0x80000008) {
913 cpuid(0x80000008, &eax, &ebx, &ecx, &edx);
914
915 c->x86_virt_bits = (eax >> 8) & 0xff;
916 c->x86_phys_bits = eax & 0xff;
917 }
918 #ifdef CONFIG_X86_32
919 else if (cpu_has(c, X86_FEATURE_PAE) || cpu_has(c, X86_FEATURE_PSE36))
920 c->x86_phys_bits = 36;
921 #endif
922 c->x86_cache_bits = c->x86_phys_bits;
923 }
924
identify_cpu_without_cpuid(struct cpuinfo_x86 * c)925 static void identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
926 {
927 #ifdef CONFIG_X86_32
928 int i;
929
930 /*
931 * First of all, decide if this is a 486 or higher
932 * It's a 486 if we can modify the AC flag
933 */
934 if (flag_is_changeable_p(X86_EFLAGS_AC))
935 c->x86 = 4;
936 else
937 c->x86 = 3;
938
939 for (i = 0; i < X86_VENDOR_NUM; i++)
940 if (cpu_devs[i] && cpu_devs[i]->c_identify) {
941 c->x86_vendor_id[0] = 0;
942 cpu_devs[i]->c_identify(c);
943 if (c->x86_vendor_id[0]) {
944 get_cpu_vendor(c);
945 break;
946 }
947 }
948 #endif
949 }
950
951 static const __initconst struct x86_cpu_id cpu_no_speculation[] = {
952 { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_CEDARVIEW, X86_FEATURE_ANY },
953 { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_CLOVERVIEW, X86_FEATURE_ANY },
954 { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_LINCROFT, X86_FEATURE_ANY },
955 { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_PENWELL, X86_FEATURE_ANY },
956 { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_PINEVIEW, X86_FEATURE_ANY },
957 { X86_VENDOR_CENTAUR, 5 },
958 { X86_VENDOR_INTEL, 5 },
959 { X86_VENDOR_NSC, 5 },
960 { X86_VENDOR_ANY, 4 },
961 {}
962 };
963
964 static const __initconst struct x86_cpu_id cpu_no_meltdown[] = {
965 { X86_VENDOR_AMD },
966 {}
967 };
968
969 /* Only list CPUs which speculate but are non susceptible to SSB */
970 static const __initconst struct x86_cpu_id cpu_no_spec_store_bypass[] = {
971 { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SILVERMONT1 },
972 { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_AIRMONT },
973 { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SILVERMONT2 },
974 { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_MERRIFIELD },
975 { X86_VENDOR_INTEL, 6, INTEL_FAM6_CORE_YONAH },
976 { X86_VENDOR_INTEL, 6, INTEL_FAM6_XEON_PHI_KNL },
977 { X86_VENDOR_INTEL, 6, INTEL_FAM6_XEON_PHI_KNM },
978 { X86_VENDOR_AMD, 0x12, },
979 { X86_VENDOR_AMD, 0x11, },
980 { X86_VENDOR_AMD, 0x10, },
981 { X86_VENDOR_AMD, 0xf, },
982 {}
983 };
984
985 static const __initconst struct x86_cpu_id cpu_no_l1tf[] = {
986 /* in addition to cpu_no_speculation */
987 { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SILVERMONT1 },
988 { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SILVERMONT2 },
989 { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_AIRMONT },
990 { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_MERRIFIELD },
991 { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_MOOREFIELD },
992 { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_GOLDMONT },
993 { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_DENVERTON },
994 { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_GEMINI_LAKE },
995 { X86_VENDOR_INTEL, 6, INTEL_FAM6_XEON_PHI_KNL },
996 { X86_VENDOR_INTEL, 6, INTEL_FAM6_XEON_PHI_KNM },
997 {}
998 };
999
cpu_set_bug_bits(struct cpuinfo_x86 * c)1000 static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
1001 {
1002 u64 ia32_cap = 0;
1003
1004 if (x86_match_cpu(cpu_no_speculation))
1005 return;
1006
1007 setup_force_cpu_bug(X86_BUG_SPECTRE_V1);
1008 setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
1009
1010 if (cpu_has(c, X86_FEATURE_ARCH_CAPABILITIES))
1011 rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap);
1012
1013 if (!x86_match_cpu(cpu_no_spec_store_bypass) &&
1014 !(ia32_cap & ARCH_CAP_SSB_NO) &&
1015 !cpu_has(c, X86_FEATURE_AMD_SSB_NO))
1016 setup_force_cpu_bug(X86_BUG_SPEC_STORE_BYPASS);
1017
1018 if (ia32_cap & ARCH_CAP_IBRS_ALL)
1019 setup_force_cpu_cap(X86_FEATURE_IBRS_ENHANCED);
1020
1021 if (x86_match_cpu(cpu_no_meltdown))
1022 return;
1023
1024 /* Rogue Data Cache Load? No! */
1025 if (ia32_cap & ARCH_CAP_RDCL_NO)
1026 return;
1027
1028 setup_force_cpu_bug(X86_BUG_CPU_MELTDOWN);
1029
1030 if (x86_match_cpu(cpu_no_l1tf))
1031 return;
1032
1033 setup_force_cpu_bug(X86_BUG_L1TF);
1034 }
1035
1036 /*
1037 * The NOPL instruction is supposed to exist on all CPUs of family >= 6;
1038 * unfortunately, that's not true in practice because of early VIA
1039 * chips and (more importantly) broken virtualizers that are not easy
1040 * to detect. In the latter case it doesn't even *fail* reliably, so
1041 * probing for it doesn't even work. Disable it completely on 32-bit
1042 * unless we can find a reliable way to detect all the broken cases.
1043 * Enable it explicitly on 64-bit for non-constant inputs of cpu_has().
1044 */
detect_nopl(void)1045 static void detect_nopl(void)
1046 {
1047 #ifdef CONFIG_X86_32
1048 setup_clear_cpu_cap(X86_FEATURE_NOPL);
1049 #else
1050 setup_force_cpu_cap(X86_FEATURE_NOPL);
1051 #endif
1052 }
1053
1054 /*
1055 * Do minimum CPU detection early.
1056 * Fields really needed: vendor, cpuid_level, family, model, mask,
1057 * cache alignment.
1058 * The others are not touched to avoid unwanted side effects.
1059 *
1060 * WARNING: this function is only called on the boot CPU. Don't add code
1061 * here that is supposed to run on all CPUs.
1062 */
early_identify_cpu(struct cpuinfo_x86 * c)1063 static void __init early_identify_cpu(struct cpuinfo_x86 *c)
1064 {
1065 #ifdef CONFIG_X86_64
1066 c->x86_clflush_size = 64;
1067 c->x86_phys_bits = 36;
1068 c->x86_virt_bits = 48;
1069 #else
1070 c->x86_clflush_size = 32;
1071 c->x86_phys_bits = 32;
1072 c->x86_virt_bits = 32;
1073 #endif
1074 c->x86_cache_alignment = c->x86_clflush_size;
1075
1076 memset(&c->x86_capability, 0, sizeof c->x86_capability);
1077 c->extended_cpuid_level = 0;
1078
1079 /* cyrix could have cpuid enabled via c_identify()*/
1080 if (have_cpuid_p()) {
1081 cpu_detect(c);
1082 get_cpu_vendor(c);
1083 get_cpu_cap(c);
1084 get_cpu_address_sizes(c);
1085 setup_force_cpu_cap(X86_FEATURE_CPUID);
1086
1087 if (this_cpu->c_early_init)
1088 this_cpu->c_early_init(c);
1089
1090 c->cpu_index = 0;
1091 filter_cpuid_features(c, false);
1092
1093 if (this_cpu->c_bsp_init)
1094 this_cpu->c_bsp_init(c);
1095 } else {
1096 identify_cpu_without_cpuid(c);
1097 setup_clear_cpu_cap(X86_FEATURE_CPUID);
1098 }
1099
1100 setup_force_cpu_cap(X86_FEATURE_ALWAYS);
1101
1102 cpu_set_bug_bits(c);
1103
1104 fpu__init_system(c);
1105
1106 #ifdef CONFIG_X86_32
1107 /*
1108 * Regardless of whether PCID is enumerated, the SDM says
1109 * that it can't be enabled in 32-bit mode.
1110 */
1111 setup_clear_cpu_cap(X86_FEATURE_PCID);
1112 #endif
1113
1114 /*
1115 * Later in the boot process pgtable_l5_enabled() relies on
1116 * cpu_feature_enabled(X86_FEATURE_LA57). If 5-level paging is not
1117 * enabled by this point we need to clear the feature bit to avoid
1118 * false-positives at the later stage.
1119 *
1120 * pgtable_l5_enabled() can be false here for several reasons:
1121 * - 5-level paging is disabled compile-time;
1122 * - it's 32-bit kernel;
1123 * - machine doesn't support 5-level paging;
1124 * - user specified 'no5lvl' in kernel command line.
1125 */
1126 if (!pgtable_l5_enabled())
1127 setup_clear_cpu_cap(X86_FEATURE_LA57);
1128
1129 detect_nopl();
1130 }
1131
early_cpu_init(void)1132 void __init early_cpu_init(void)
1133 {
1134 const struct cpu_dev *const *cdev;
1135 int count = 0;
1136
1137 #ifdef CONFIG_PROCESSOR_SELECT
1138 pr_info("KERNEL supported cpus:\n");
1139 #endif
1140
1141 for (cdev = __x86_cpu_dev_start; cdev < __x86_cpu_dev_end; cdev++) {
1142 const struct cpu_dev *cpudev = *cdev;
1143
1144 if (count >= X86_VENDOR_NUM)
1145 break;
1146 cpu_devs[count] = cpudev;
1147 count++;
1148
1149 #ifdef CONFIG_PROCESSOR_SELECT
1150 {
1151 unsigned int j;
1152
1153 for (j = 0; j < 2; j++) {
1154 if (!cpudev->c_ident[j])
1155 continue;
1156 pr_info(" %s %s\n", cpudev->c_vendor,
1157 cpudev->c_ident[j]);
1158 }
1159 }
1160 #endif
1161 }
1162 early_identify_cpu(&boot_cpu_data);
1163 }
1164
detect_null_seg_behavior(struct cpuinfo_x86 * c)1165 static void detect_null_seg_behavior(struct cpuinfo_x86 *c)
1166 {
1167 #ifdef CONFIG_X86_64
1168 /*
1169 * Empirically, writing zero to a segment selector on AMD does
1170 * not clear the base, whereas writing zero to a segment
1171 * selector on Intel does clear the base. Intel's behavior
1172 * allows slightly faster context switches in the common case
1173 * where GS is unused by the prev and next threads.
1174 *
1175 * Since neither vendor documents this anywhere that I can see,
1176 * detect it directly instead of hardcoding the choice by
1177 * vendor.
1178 *
1179 * I've designated AMD's behavior as the "bug" because it's
1180 * counterintuitive and less friendly.
1181 */
1182
1183 unsigned long old_base, tmp;
1184 rdmsrl(MSR_FS_BASE, old_base);
1185 wrmsrl(MSR_FS_BASE, 1);
1186 loadsegment(fs, 0);
1187 rdmsrl(MSR_FS_BASE, tmp);
1188 if (tmp != 0)
1189 set_cpu_bug(c, X86_BUG_NULL_SEG);
1190 wrmsrl(MSR_FS_BASE, old_base);
1191 #endif
1192 }
1193
generic_identify(struct cpuinfo_x86 * c)1194 static void generic_identify(struct cpuinfo_x86 *c)
1195 {
1196 c->extended_cpuid_level = 0;
1197
1198 if (!have_cpuid_p())
1199 identify_cpu_without_cpuid(c);
1200
1201 /* cyrix could have cpuid enabled via c_identify()*/
1202 if (!have_cpuid_p())
1203 return;
1204
1205 cpu_detect(c);
1206
1207 get_cpu_vendor(c);
1208
1209 get_cpu_cap(c);
1210
1211 get_cpu_address_sizes(c);
1212
1213 if (c->cpuid_level >= 0x00000001) {
1214 c->initial_apicid = (cpuid_ebx(1) >> 24) & 0xFF;
1215 #ifdef CONFIG_X86_32
1216 # ifdef CONFIG_SMP
1217 c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
1218 # else
1219 c->apicid = c->initial_apicid;
1220 # endif
1221 #endif
1222 c->phys_proc_id = c->initial_apicid;
1223 }
1224
1225 get_model_name(c); /* Default name */
1226
1227 detect_null_seg_behavior(c);
1228
1229 /*
1230 * ESPFIX is a strange bug. All real CPUs have it. Paravirt
1231 * systems that run Linux at CPL > 0 may or may not have the
1232 * issue, but, even if they have the issue, there's absolutely
1233 * nothing we can do about it because we can't use the real IRET
1234 * instruction.
1235 *
1236 * NB: For the time being, only 32-bit kernels support
1237 * X86_BUG_ESPFIX as such. 64-bit kernels directly choose
1238 * whether to apply espfix using paravirt hooks. If any
1239 * non-paravirt system ever shows up that does *not* have the
1240 * ESPFIX issue, we can change this.
1241 */
1242 #ifdef CONFIG_X86_32
1243 # ifdef CONFIG_PARAVIRT
1244 do {
1245 extern void native_iret(void);
1246 if (pv_cpu_ops.iret == native_iret)
1247 set_cpu_bug(c, X86_BUG_ESPFIX);
1248 } while (0);
1249 # else
1250 set_cpu_bug(c, X86_BUG_ESPFIX);
1251 # endif
1252 #endif
1253 }
1254
x86_init_cache_qos(struct cpuinfo_x86 * c)1255 static void x86_init_cache_qos(struct cpuinfo_x86 *c)
1256 {
1257 /*
1258 * The heavy lifting of max_rmid and cache_occ_scale are handled
1259 * in get_cpu_cap(). Here we just set the max_rmid for the boot_cpu
1260 * in case CQM bits really aren't there in this CPU.
1261 */
1262 if (c != &boot_cpu_data) {
1263 boot_cpu_data.x86_cache_max_rmid =
1264 min(boot_cpu_data.x86_cache_max_rmid,
1265 c->x86_cache_max_rmid);
1266 }
1267 }
1268
1269 /*
1270 * Validate that ACPI/mptables have the same information about the
1271 * effective APIC id and update the package map.
1272 */
validate_apic_and_package_id(struct cpuinfo_x86 * c)1273 static void validate_apic_and_package_id(struct cpuinfo_x86 *c)
1274 {
1275 #ifdef CONFIG_SMP
1276 unsigned int apicid, cpu = smp_processor_id();
1277
1278 apicid = apic->cpu_present_to_apicid(cpu);
1279
1280 if (apicid != c->apicid) {
1281 pr_err(FW_BUG "CPU%u: APIC id mismatch. Firmware: %x APIC: %x\n",
1282 cpu, apicid, c->initial_apicid);
1283 }
1284 BUG_ON(topology_update_package_map(c->phys_proc_id, cpu));
1285 #else
1286 c->logical_proc_id = 0;
1287 #endif
1288 }
1289
1290 /*
1291 * This does the hard work of actually picking apart the CPU stuff...
1292 */
identify_cpu(struct cpuinfo_x86 * c)1293 static void identify_cpu(struct cpuinfo_x86 *c)
1294 {
1295 int i;
1296
1297 c->loops_per_jiffy = loops_per_jiffy;
1298 c->x86_cache_size = 0;
1299 c->x86_vendor = X86_VENDOR_UNKNOWN;
1300 c->x86_model = c->x86_stepping = 0; /* So far unknown... */
1301 c->x86_vendor_id[0] = '\0'; /* Unset */
1302 c->x86_model_id[0] = '\0'; /* Unset */
1303 c->x86_max_cores = 1;
1304 c->x86_coreid_bits = 0;
1305 c->cu_id = 0xff;
1306 #ifdef CONFIG_X86_64
1307 c->x86_clflush_size = 64;
1308 c->x86_phys_bits = 36;
1309 c->x86_virt_bits = 48;
1310 #else
1311 c->cpuid_level = -1; /* CPUID not detected */
1312 c->x86_clflush_size = 32;
1313 c->x86_phys_bits = 32;
1314 c->x86_virt_bits = 32;
1315 #endif
1316 c->x86_cache_alignment = c->x86_clflush_size;
1317 memset(&c->x86_capability, 0, sizeof c->x86_capability);
1318
1319 generic_identify(c);
1320
1321 if (this_cpu->c_identify)
1322 this_cpu->c_identify(c);
1323
1324 /* Clear/Set all flags overridden by options, after probe */
1325 apply_forced_caps(c);
1326
1327 #ifdef CONFIG_X86_64
1328 c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
1329 #endif
1330
1331 /*
1332 * Vendor-specific initialization. In this section we
1333 * canonicalize the feature flags, meaning if there are
1334 * features a certain CPU supports which CPUID doesn't
1335 * tell us, CPUID claiming incorrect flags, or other bugs,
1336 * we handle them here.
1337 *
1338 * At the end of this section, c->x86_capability better
1339 * indicate the features this CPU genuinely supports!
1340 */
1341 if (this_cpu->c_init)
1342 this_cpu->c_init(c);
1343
1344 /* Disable the PN if appropriate */
1345 squash_the_stupid_serial_number(c);
1346
1347 /* Set up SMEP/SMAP/UMIP */
1348 setup_smep(c);
1349 setup_smap(c);
1350 setup_umip(c);
1351
1352 /*
1353 * The vendor-specific functions might have changed features.
1354 * Now we do "generic changes."
1355 */
1356
1357 /* Filter out anything that depends on CPUID levels we don't have */
1358 filter_cpuid_features(c, true);
1359
1360 /* If the model name is still unset, do table lookup. */
1361 if (!c->x86_model_id[0]) {
1362 const char *p;
1363 p = table_lookup_model(c);
1364 if (p)
1365 strcpy(c->x86_model_id, p);
1366 else
1367 /* Last resort... */
1368 sprintf(c->x86_model_id, "%02x/%02x",
1369 c->x86, c->x86_model);
1370 }
1371
1372 #ifdef CONFIG_X86_64
1373 detect_ht(c);
1374 #endif
1375
1376 x86_init_rdrand(c);
1377 x86_init_cache_qos(c);
1378 setup_pku(c);
1379
1380 /*
1381 * Clear/Set all flags overridden by options, need do it
1382 * before following smp all cpus cap AND.
1383 */
1384 apply_forced_caps(c);
1385
1386 /*
1387 * On SMP, boot_cpu_data holds the common feature set between
1388 * all CPUs; so make sure that we indicate which features are
1389 * common between the CPUs. The first time this routine gets
1390 * executed, c == &boot_cpu_data.
1391 */
1392 if (c != &boot_cpu_data) {
1393 /* AND the already accumulated flags with these */
1394 for (i = 0; i < NCAPINTS; i++)
1395 boot_cpu_data.x86_capability[i] &= c->x86_capability[i];
1396
1397 /* OR, i.e. replicate the bug flags */
1398 for (i = NCAPINTS; i < NCAPINTS + NBUGINTS; i++)
1399 c->x86_capability[i] |= boot_cpu_data.x86_capability[i];
1400 }
1401
1402 /* Init Machine Check Exception if available. */
1403 mcheck_cpu_init(c);
1404
1405 select_idle_routine(c);
1406
1407 #ifdef CONFIG_NUMA
1408 numa_add_cpu(smp_processor_id());
1409 #endif
1410 }
1411
1412 /*
1413 * Set up the CPU state needed to execute SYSENTER/SYSEXIT instructions
1414 * on 32-bit kernels:
1415 */
1416 #ifdef CONFIG_X86_32
enable_sep_cpu(void)1417 void enable_sep_cpu(void)
1418 {
1419 struct tss_struct *tss;
1420 int cpu;
1421
1422 if (!boot_cpu_has(X86_FEATURE_SEP))
1423 return;
1424
1425 cpu = get_cpu();
1426 tss = &per_cpu(cpu_tss_rw, cpu);
1427
1428 /*
1429 * We cache MSR_IA32_SYSENTER_CS's value in the TSS's ss1 field --
1430 * see the big comment in struct x86_hw_tss's definition.
1431 */
1432
1433 tss->x86_tss.ss1 = __KERNEL_CS;
1434 wrmsr(MSR_IA32_SYSENTER_CS, tss->x86_tss.ss1, 0);
1435 wrmsr(MSR_IA32_SYSENTER_ESP, (unsigned long)(cpu_entry_stack(cpu) + 1), 0);
1436 wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long)entry_SYSENTER_32, 0);
1437
1438 put_cpu();
1439 }
1440 #endif
1441
identify_boot_cpu(void)1442 void __init identify_boot_cpu(void)
1443 {
1444 identify_cpu(&boot_cpu_data);
1445 #ifdef CONFIG_X86_32
1446 sysenter_setup();
1447 enable_sep_cpu();
1448 #endif
1449 cpu_detect_tlb(&boot_cpu_data);
1450 }
1451
identify_secondary_cpu(struct cpuinfo_x86 * c)1452 void identify_secondary_cpu(struct cpuinfo_x86 *c)
1453 {
1454 BUG_ON(c == &boot_cpu_data);
1455 identify_cpu(c);
1456 #ifdef CONFIG_X86_32
1457 enable_sep_cpu();
1458 #endif
1459 mtrr_ap_init();
1460 validate_apic_and_package_id(c);
1461 x86_spec_ctrl_setup_ap();
1462 }
1463
setup_noclflush(char * arg)1464 static __init int setup_noclflush(char *arg)
1465 {
1466 setup_clear_cpu_cap(X86_FEATURE_CLFLUSH);
1467 setup_clear_cpu_cap(X86_FEATURE_CLFLUSHOPT);
1468 return 1;
1469 }
1470 __setup("noclflush", setup_noclflush);
1471
print_cpu_info(struct cpuinfo_x86 * c)1472 void print_cpu_info(struct cpuinfo_x86 *c)
1473 {
1474 const char *vendor = NULL;
1475
1476 if (c->x86_vendor < X86_VENDOR_NUM) {
1477 vendor = this_cpu->c_vendor;
1478 } else {
1479 if (c->cpuid_level >= 0)
1480 vendor = c->x86_vendor_id;
1481 }
1482
1483 if (vendor && !strstr(c->x86_model_id, vendor))
1484 pr_cont("%s ", vendor);
1485
1486 if (c->x86_model_id[0])
1487 pr_cont("%s", c->x86_model_id);
1488 else
1489 pr_cont("%d86", c->x86);
1490
1491 pr_cont(" (family: 0x%x, model: 0x%x", c->x86, c->x86_model);
1492
1493 if (c->x86_stepping || c->cpuid_level >= 0)
1494 pr_cont(", stepping: 0x%x)\n", c->x86_stepping);
1495 else
1496 pr_cont(")\n");
1497 }
1498
1499 /*
1500 * clearcpuid= was already parsed in fpu__init_parse_early_param.
1501 * But we need to keep a dummy __setup around otherwise it would
1502 * show up as an environment variable for init.
1503 */
setup_clearcpuid(char * arg)1504 static __init int setup_clearcpuid(char *arg)
1505 {
1506 return 1;
1507 }
1508 __setup("clearcpuid=", setup_clearcpuid);
1509
1510 #ifdef CONFIG_X86_64
1511 DEFINE_PER_CPU_FIRST(union irq_stack_union,
1512 irq_stack_union) __aligned(PAGE_SIZE) __visible;
1513 EXPORT_PER_CPU_SYMBOL_GPL(irq_stack_union);
1514
1515 /*
1516 * The following percpu variables are hot. Align current_task to
1517 * cacheline size such that they fall in the same cacheline.
1518 */
1519 DEFINE_PER_CPU(struct task_struct *, current_task) ____cacheline_aligned =
1520 &init_task;
1521 EXPORT_PER_CPU_SYMBOL(current_task);
1522
1523 DEFINE_PER_CPU(char *, irq_stack_ptr) =
1524 init_per_cpu_var(irq_stack_union.irq_stack) + IRQ_STACK_SIZE;
1525
1526 DEFINE_PER_CPU(unsigned int, irq_count) __visible = -1;
1527
1528 DEFINE_PER_CPU(int, __preempt_count) = INIT_PREEMPT_COUNT;
1529 EXPORT_PER_CPU_SYMBOL(__preempt_count);
1530
1531 /* May not be marked __init: used by software suspend */
syscall_init(void)1532 void syscall_init(void)
1533 {
1534 extern char _entry_trampoline[];
1535 extern char entry_SYSCALL_64_trampoline[];
1536
1537 int cpu = smp_processor_id();
1538 unsigned long SYSCALL64_entry_trampoline =
1539 (unsigned long)get_cpu_entry_area(cpu)->entry_trampoline +
1540 (entry_SYSCALL_64_trampoline - _entry_trampoline);
1541
1542 wrmsr(MSR_STAR, 0, (__USER32_CS << 16) | __KERNEL_CS);
1543 if (static_cpu_has(X86_FEATURE_PTI))
1544 wrmsrl(MSR_LSTAR, SYSCALL64_entry_trampoline);
1545 else
1546 wrmsrl(MSR_LSTAR, (unsigned long)entry_SYSCALL_64);
1547
1548 #ifdef CONFIG_IA32_EMULATION
1549 wrmsrl(MSR_CSTAR, (unsigned long)entry_SYSCALL_compat);
1550 /*
1551 * This only works on Intel CPUs.
1552 * On AMD CPUs these MSRs are 32-bit, CPU truncates MSR_IA32_SYSENTER_EIP.
1553 * This does not cause SYSENTER to jump to the wrong location, because
1554 * AMD doesn't allow SYSENTER in long mode (either 32- or 64-bit).
1555 */
1556 wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS);
1557 wrmsrl_safe(MSR_IA32_SYSENTER_ESP, (unsigned long)(cpu_entry_stack(cpu) + 1));
1558 wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)entry_SYSENTER_compat);
1559 #else
1560 wrmsrl(MSR_CSTAR, (unsigned long)ignore_sysret);
1561 wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)GDT_ENTRY_INVALID_SEG);
1562 wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL);
1563 wrmsrl_safe(MSR_IA32_SYSENTER_EIP, 0ULL);
1564 #endif
1565
1566 /* Flags to clear on syscall */
1567 wrmsrl(MSR_SYSCALL_MASK,
1568 X86_EFLAGS_TF|X86_EFLAGS_DF|X86_EFLAGS_IF|
1569 X86_EFLAGS_IOPL|X86_EFLAGS_AC|X86_EFLAGS_NT);
1570 }
1571
1572 /*
1573 * Copies of the original ist values from the tss are only accessed during
1574 * debugging, no special alignment required.
1575 */
1576 DEFINE_PER_CPU(struct orig_ist, orig_ist);
1577
1578 static DEFINE_PER_CPU(unsigned long, debug_stack_addr);
1579 DEFINE_PER_CPU(int, debug_stack_usage);
1580
is_debug_stack(unsigned long addr)1581 int is_debug_stack(unsigned long addr)
1582 {
1583 return __this_cpu_read(debug_stack_usage) ||
1584 (addr <= __this_cpu_read(debug_stack_addr) &&
1585 addr > (__this_cpu_read(debug_stack_addr) - DEBUG_STKSZ));
1586 }
1587 NOKPROBE_SYMBOL(is_debug_stack);
1588
1589 DEFINE_PER_CPU(u32, debug_idt_ctr);
1590
debug_stack_set_zero(void)1591 void debug_stack_set_zero(void)
1592 {
1593 this_cpu_inc(debug_idt_ctr);
1594 load_current_idt();
1595 }
1596 NOKPROBE_SYMBOL(debug_stack_set_zero);
1597
debug_stack_reset(void)1598 void debug_stack_reset(void)
1599 {
1600 if (WARN_ON(!this_cpu_read(debug_idt_ctr)))
1601 return;
1602 if (this_cpu_dec_return(debug_idt_ctr) == 0)
1603 load_current_idt();
1604 }
1605 NOKPROBE_SYMBOL(debug_stack_reset);
1606
1607 #else /* CONFIG_X86_64 */
1608
1609 DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task;
1610 EXPORT_PER_CPU_SYMBOL(current_task);
1611 DEFINE_PER_CPU(int, __preempt_count) = INIT_PREEMPT_COUNT;
1612 EXPORT_PER_CPU_SYMBOL(__preempt_count);
1613
1614 /*
1615 * On x86_32, vm86 modifies tss.sp0, so sp0 isn't a reliable way to find
1616 * the top of the kernel stack. Use an extra percpu variable to track the
1617 * top of the kernel stack directly.
1618 */
1619 DEFINE_PER_CPU(unsigned long, cpu_current_top_of_stack) =
1620 (unsigned long)&init_thread_union + THREAD_SIZE;
1621 EXPORT_PER_CPU_SYMBOL(cpu_current_top_of_stack);
1622
1623 #ifdef CONFIG_STACKPROTECTOR
1624 DEFINE_PER_CPU_ALIGNED(struct stack_canary, stack_canary);
1625 #endif
1626
1627 #endif /* CONFIG_X86_64 */
1628
1629 /*
1630 * Clear all 6 debug registers:
1631 */
clear_all_debug_regs(void)1632 static void clear_all_debug_regs(void)
1633 {
1634 int i;
1635
1636 for (i = 0; i < 8; i++) {
1637 /* Ignore db4, db5 */
1638 if ((i == 4) || (i == 5))
1639 continue;
1640
1641 set_debugreg(0, i);
1642 }
1643 }
1644
1645 #ifdef CONFIG_KGDB
1646 /*
1647 * Restore debug regs if using kgdbwait and you have a kernel debugger
1648 * connection established.
1649 */
dbg_restore_debug_regs(void)1650 static void dbg_restore_debug_regs(void)
1651 {
1652 if (unlikely(kgdb_connected && arch_kgdb_ops.correct_hw_break))
1653 arch_kgdb_ops.correct_hw_break();
1654 }
1655 #else /* ! CONFIG_KGDB */
1656 #define dbg_restore_debug_regs()
1657 #endif /* ! CONFIG_KGDB */
1658
wait_for_master_cpu(int cpu)1659 static void wait_for_master_cpu(int cpu)
1660 {
1661 #ifdef CONFIG_SMP
1662 /*
1663 * wait for ACK from master CPU before continuing
1664 * with AP initialization
1665 */
1666 WARN_ON(cpumask_test_and_set_cpu(cpu, cpu_initialized_mask));
1667 while (!cpumask_test_cpu(cpu, cpu_callout_mask))
1668 cpu_relax();
1669 #endif
1670 }
1671
1672 /*
1673 * cpu_init() initializes state that is per-CPU. Some data is already
1674 * initialized (naturally) in the bootstrap process, such as the GDT
1675 * and IDT. We reload them nevertheless, this function acts as a
1676 * 'CPU state barrier', nothing should get across.
1677 * A lot of state is already set up in PDA init for 64 bit
1678 */
1679 #ifdef CONFIG_X86_64
1680
cpu_init(void)1681 void cpu_init(void)
1682 {
1683 struct orig_ist *oist;
1684 struct task_struct *me;
1685 struct tss_struct *t;
1686 unsigned long v;
1687 int cpu = raw_smp_processor_id();
1688 int i;
1689
1690 wait_for_master_cpu(cpu);
1691
1692 /*
1693 * Initialize the CR4 shadow before doing anything that could
1694 * try to read it.
1695 */
1696 cr4_init_shadow();
1697
1698 if (cpu)
1699 load_ucode_ap();
1700
1701 t = &per_cpu(cpu_tss_rw, cpu);
1702 oist = &per_cpu(orig_ist, cpu);
1703
1704 #ifdef CONFIG_NUMA
1705 if (this_cpu_read(numa_node) == 0 &&
1706 early_cpu_to_node(cpu) != NUMA_NO_NODE)
1707 set_numa_node(early_cpu_to_node(cpu));
1708 #endif
1709
1710 me = current;
1711
1712 pr_debug("Initializing CPU#%d\n", cpu);
1713
1714 cr4_clear_bits(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1715
1716 /*
1717 * Initialize the per-CPU GDT with the boot GDT,
1718 * and set up the GDT descriptor:
1719 */
1720
1721 switch_to_new_gdt(cpu);
1722 loadsegment(fs, 0);
1723
1724 load_current_idt();
1725
1726 memset(me->thread.tls_array, 0, GDT_ENTRY_TLS_ENTRIES * 8);
1727 syscall_init();
1728
1729 wrmsrl(MSR_FS_BASE, 0);
1730 wrmsrl(MSR_KERNEL_GS_BASE, 0);
1731 barrier();
1732
1733 x86_configure_nx();
1734 x2apic_setup();
1735
1736 /*
1737 * set up and load the per-CPU TSS
1738 */
1739 if (!oist->ist[0]) {
1740 char *estacks = get_cpu_entry_area(cpu)->exception_stacks;
1741
1742 for (v = 0; v < N_EXCEPTION_STACKS; v++) {
1743 estacks += exception_stack_sizes[v];
1744 oist->ist[v] = t->x86_tss.ist[v] =
1745 (unsigned long)estacks;
1746 if (v == DEBUG_STACK-1)
1747 per_cpu(debug_stack_addr, cpu) = (unsigned long)estacks;
1748 }
1749 }
1750
1751 t->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET;
1752
1753 /*
1754 * <= is required because the CPU will access up to
1755 * 8 bits beyond the end of the IO permission bitmap.
1756 */
1757 for (i = 0; i <= IO_BITMAP_LONGS; i++)
1758 t->io_bitmap[i] = ~0UL;
1759
1760 mmgrab(&init_mm);
1761 me->active_mm = &init_mm;
1762 BUG_ON(me->mm);
1763 initialize_tlbstate_and_flush();
1764 enter_lazy_tlb(&init_mm, me);
1765
1766 /*
1767 * Initialize the TSS. sp0 points to the entry trampoline stack
1768 * regardless of what task is running.
1769 */
1770 set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss);
1771 load_TR_desc();
1772 load_sp0((unsigned long)(cpu_entry_stack(cpu) + 1));
1773
1774 load_mm_ldt(&init_mm);
1775
1776 clear_all_debug_regs();
1777 dbg_restore_debug_regs();
1778
1779 fpu__init_cpu();
1780
1781 if (is_uv_system())
1782 uv_cpu_init();
1783
1784 load_fixmap_gdt(cpu);
1785 }
1786
1787 #else
1788
cpu_init(void)1789 void cpu_init(void)
1790 {
1791 int cpu = smp_processor_id();
1792 struct task_struct *curr = current;
1793 struct tss_struct *t = &per_cpu(cpu_tss_rw, cpu);
1794
1795 wait_for_master_cpu(cpu);
1796
1797 /*
1798 * Initialize the CR4 shadow before doing anything that could
1799 * try to read it.
1800 */
1801 cr4_init_shadow();
1802
1803 show_ucode_info_early();
1804
1805 pr_info("Initializing CPU#%d\n", cpu);
1806
1807 if (cpu_feature_enabled(X86_FEATURE_VME) ||
1808 boot_cpu_has(X86_FEATURE_TSC) ||
1809 boot_cpu_has(X86_FEATURE_DE))
1810 cr4_clear_bits(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1811
1812 load_current_idt();
1813 switch_to_new_gdt(cpu);
1814
1815 /*
1816 * Set up and load the per-CPU TSS and LDT
1817 */
1818 mmgrab(&init_mm);
1819 curr->active_mm = &init_mm;
1820 BUG_ON(curr->mm);
1821 initialize_tlbstate_and_flush();
1822 enter_lazy_tlb(&init_mm, curr);
1823
1824 /*
1825 * Initialize the TSS. sp0 points to the entry trampoline stack
1826 * regardless of what task is running.
1827 */
1828 set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss);
1829 load_TR_desc();
1830 load_sp0((unsigned long)(cpu_entry_stack(cpu) + 1));
1831
1832 load_mm_ldt(&init_mm);
1833
1834 t->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET;
1835
1836 #ifdef CONFIG_DOUBLEFAULT
1837 /* Set up doublefault TSS pointer in the GDT */
1838 __set_tss_desc(cpu, GDT_ENTRY_DOUBLEFAULT_TSS, &doublefault_tss);
1839 #endif
1840
1841 clear_all_debug_regs();
1842 dbg_restore_debug_regs();
1843
1844 fpu__init_cpu();
1845
1846 load_fixmap_gdt(cpu);
1847 }
1848 #endif
1849
bsp_resume(void)1850 static void bsp_resume(void)
1851 {
1852 if (this_cpu->c_bsp_resume)
1853 this_cpu->c_bsp_resume(&boot_cpu_data);
1854 }
1855
1856 static struct syscore_ops cpu_syscore_ops = {
1857 .resume = bsp_resume,
1858 };
1859
init_cpu_syscore(void)1860 static int __init init_cpu_syscore(void)
1861 {
1862 register_syscore_ops(&cpu_syscore_ops);
1863 return 0;
1864 }
1865 core_initcall(init_cpu_syscore);
1866
1867 /*
1868 * The microcode loader calls this upon late microcode load to recheck features,
1869 * only when microcode has been updated. Caller holds microcode_mutex and CPU
1870 * hotplug lock.
1871 */
microcode_check(void)1872 void microcode_check(void)
1873 {
1874 struct cpuinfo_x86 info;
1875
1876 perf_check_microcode();
1877
1878 /* Reload CPUID max function as it might've changed. */
1879 info.cpuid_level = cpuid_eax(0);
1880
1881 /*
1882 * Copy all capability leafs to pick up the synthetic ones so that
1883 * memcmp() below doesn't fail on that. The ones coming from CPUID will
1884 * get overwritten in get_cpu_cap().
1885 */
1886 memcpy(&info.x86_capability, &boot_cpu_data.x86_capability, sizeof(info.x86_capability));
1887
1888 get_cpu_cap(&info);
1889
1890 if (!memcmp(&info.x86_capability, &boot_cpu_data.x86_capability, sizeof(info.x86_capability)))
1891 return;
1892
1893 pr_warn("x86/CPU: CPU features have changed after loading microcode, but might not take effect.\n");
1894 pr_warn("x86/CPU: Please consider either early loading through initrd/built-in or a potential BIOS update.\n");
1895 }
1896
