xref: /linux/arch/x86/kernel/cpu/common.c (revision 5a0e3ad6af8660be21ca98a971cd00f331318c05)
1 #include <linux/bootmem.h>
2 #include <linux/linkage.h>
3 #include <linux/bitops.h>
4 #include <linux/kernel.h>
5 #include <linux/module.h>
6 #include <linux/percpu.h>
7 #include <linux/string.h>
8 #include <linux/delay.h>
9 #include <linux/sched.h>
10 #include <linux/init.h>
11 #include <linux/kgdb.h>
12 #include <linux/smp.h>
13 #include <linux/io.h>
14 
15 #include <asm/stackprotector.h>
16 #include <asm/perf_event.h>
17 #include <asm/mmu_context.h>
18 #include <asm/hypervisor.h>
19 #include <asm/processor.h>
20 #include <asm/sections.h>
21 #include <linux/topology.h>
22 #include <linux/cpumask.h>
23 #include <asm/pgtable.h>
24 #include <asm/atomic.h>
25 #include <asm/proto.h>
26 #include <asm/setup.h>
27 #include <asm/apic.h>
28 #include <asm/desc.h>
29 #include <asm/i387.h>
30 #include <asm/mtrr.h>
31 #include <linux/numa.h>
32 #include <asm/asm.h>
33 #include <asm/cpu.h>
34 #include <asm/mce.h>
35 #include <asm/msr.h>
36 #include <asm/pat.h>
37 
38 #ifdef CONFIG_X86_LOCAL_APIC
39 #include <asm/uv/uv.h>
40 #endif
41 
42 #include "cpu.h"
43 
44 /* all of these masks are initialized in setup_cpu_local_masks() */
45 cpumask_var_t cpu_initialized_mask;
46 cpumask_var_t cpu_callout_mask;
47 cpumask_var_t cpu_callin_mask;
48 
49 /* representing cpus for which sibling maps can be computed */
50 cpumask_var_t cpu_sibling_setup_mask;
51 
52 /* correctly size the local cpu masks */
53 void __init setup_cpu_local_masks(void)
54 {
55 	alloc_bootmem_cpumask_var(&cpu_initialized_mask);
56 	alloc_bootmem_cpumask_var(&cpu_callin_mask);
57 	alloc_bootmem_cpumask_var(&cpu_callout_mask);
58 	alloc_bootmem_cpumask_var(&cpu_sibling_setup_mask);
59 }
60 
61 static void __cpuinit default_init(struct cpuinfo_x86 *c)
62 {
63 #ifdef CONFIG_X86_64
64 	cpu_detect_cache_sizes(c);
65 #else
66 	/* Not much we can do here... */
67 	/* Check if at least it has cpuid */
68 	if (c->cpuid_level == -1) {
69 		/* No cpuid. It must be an ancient CPU */
70 		if (c->x86 == 4)
71 			strcpy(c->x86_model_id, "486");
72 		else if (c->x86 == 3)
73 			strcpy(c->x86_model_id, "386");
74 	}
75 #endif
76 }
77 
78 static const struct cpu_dev __cpuinitconst default_cpu = {
79 	.c_init		= default_init,
80 	.c_vendor	= "Unknown",
81 	.c_x86_vendor	= X86_VENDOR_UNKNOWN,
82 };
83 
84 static const struct cpu_dev *this_cpu __cpuinitdata = &default_cpu;
85 
86 DEFINE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page) = { .gdt = {
87 #ifdef CONFIG_X86_64
88 	/*
89 	 * We need valid kernel segments for data and code in long mode too
90 	 * IRET will check the segment types  kkeil 2000/10/28
91 	 * Also sysret mandates a special GDT layout
92 	 *
93 	 * TLS descriptors are currently at a different place compared to i386.
94 	 * Hopefully nobody expects them at a fixed place (Wine?)
95 	 */
96 	[GDT_ENTRY_KERNEL32_CS]		= GDT_ENTRY_INIT(0xc09b, 0, 0xfffff),
97 	[GDT_ENTRY_KERNEL_CS]		= GDT_ENTRY_INIT(0xa09b, 0, 0xfffff),
98 	[GDT_ENTRY_KERNEL_DS]		= GDT_ENTRY_INIT(0xc093, 0, 0xfffff),
99 	[GDT_ENTRY_DEFAULT_USER32_CS]	= GDT_ENTRY_INIT(0xc0fb, 0, 0xfffff),
100 	[GDT_ENTRY_DEFAULT_USER_DS]	= GDT_ENTRY_INIT(0xc0f3, 0, 0xfffff),
101 	[GDT_ENTRY_DEFAULT_USER_CS]	= GDT_ENTRY_INIT(0xa0fb, 0, 0xfffff),
102 #else
103 	[GDT_ENTRY_KERNEL_CS]		= GDT_ENTRY_INIT(0xc09a, 0, 0xfffff),
104 	[GDT_ENTRY_KERNEL_DS]		= GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
105 	[GDT_ENTRY_DEFAULT_USER_CS]	= GDT_ENTRY_INIT(0xc0fa, 0, 0xfffff),
106 	[GDT_ENTRY_DEFAULT_USER_DS]	= GDT_ENTRY_INIT(0xc0f2, 0, 0xfffff),
107 	/*
108 	 * Segments used for calling PnP BIOS have byte granularity.
109 	 * They code segments and data segments have fixed 64k limits,
110 	 * the transfer segment sizes are set at run time.
111 	 */
112 	/* 32-bit code */
113 	[GDT_ENTRY_PNPBIOS_CS32]	= GDT_ENTRY_INIT(0x409a, 0, 0xffff),
114 	/* 16-bit code */
115 	[GDT_ENTRY_PNPBIOS_CS16]	= GDT_ENTRY_INIT(0x009a, 0, 0xffff),
116 	/* 16-bit data */
117 	[GDT_ENTRY_PNPBIOS_DS]		= GDT_ENTRY_INIT(0x0092, 0, 0xffff),
118 	/* 16-bit data */
119 	[GDT_ENTRY_PNPBIOS_TS1]		= GDT_ENTRY_INIT(0x0092, 0, 0),
120 	/* 16-bit data */
121 	[GDT_ENTRY_PNPBIOS_TS2]		= GDT_ENTRY_INIT(0x0092, 0, 0),
122 	/*
123 	 * The APM segments have byte granularity and their bases
124 	 * are set at run time.  All have 64k limits.
125 	 */
126 	/* 32-bit code */
127 	[GDT_ENTRY_APMBIOS_BASE]	= GDT_ENTRY_INIT(0x409a, 0, 0xffff),
128 	/* 16-bit code */
129 	[GDT_ENTRY_APMBIOS_BASE+1]	= GDT_ENTRY_INIT(0x009a, 0, 0xffff),
130 	/* data */
131 	[GDT_ENTRY_APMBIOS_BASE+2]	= GDT_ENTRY_INIT(0x4092, 0, 0xffff),
132 
133 	[GDT_ENTRY_ESPFIX_SS]		= GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
134 	[GDT_ENTRY_PERCPU]		= GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
135 	GDT_STACK_CANARY_INIT
136 #endif
137 } };
138 EXPORT_PER_CPU_SYMBOL_GPL(gdt_page);
139 
140 static int __init x86_xsave_setup(char *s)
141 {
142 	setup_clear_cpu_cap(X86_FEATURE_XSAVE);
143 	return 1;
144 }
145 __setup("noxsave", x86_xsave_setup);
146 
147 #ifdef CONFIG_X86_32
148 static int cachesize_override __cpuinitdata = -1;
149 static int disable_x86_serial_nr __cpuinitdata = 1;
150 
151 static int __init cachesize_setup(char *str)
152 {
153 	get_option(&str, &cachesize_override);
154 	return 1;
155 }
156 __setup("cachesize=", cachesize_setup);
157 
158 static int __init x86_fxsr_setup(char *s)
159 {
160 	setup_clear_cpu_cap(X86_FEATURE_FXSR);
161 	setup_clear_cpu_cap(X86_FEATURE_XMM);
162 	return 1;
163 }
164 __setup("nofxsr", x86_fxsr_setup);
165 
166 static int __init x86_sep_setup(char *s)
167 {
168 	setup_clear_cpu_cap(X86_FEATURE_SEP);
169 	return 1;
170 }
171 __setup("nosep", x86_sep_setup);
172 
173 /* Standard macro to see if a specific flag is changeable */
174 static inline int flag_is_changeable_p(u32 flag)
175 {
176 	u32 f1, f2;
177 
178 	/*
179 	 * Cyrix and IDT cpus allow disabling of CPUID
180 	 * so the code below may return different results
181 	 * when it is executed before and after enabling
182 	 * the CPUID. Add "volatile" to not allow gcc to
183 	 * optimize the subsequent calls to this function.
184 	 */
185 	asm volatile ("pushfl		\n\t"
186 		      "pushfl		\n\t"
187 		      "popl %0		\n\t"
188 		      "movl %0, %1	\n\t"
189 		      "xorl %2, %0	\n\t"
190 		      "pushl %0		\n\t"
191 		      "popfl		\n\t"
192 		      "pushfl		\n\t"
193 		      "popl %0		\n\t"
194 		      "popfl		\n\t"
195 
196 		      : "=&r" (f1), "=&r" (f2)
197 		      : "ir" (flag));
198 
199 	return ((f1^f2) & flag) != 0;
200 }
201 
202 /* Probe for the CPUID instruction */
203 static int __cpuinit have_cpuid_p(void)
204 {
205 	return flag_is_changeable_p(X86_EFLAGS_ID);
206 }
207 
208 static void __cpuinit squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
209 {
210 	unsigned long lo, hi;
211 
212 	if (!cpu_has(c, X86_FEATURE_PN) || !disable_x86_serial_nr)
213 		return;
214 
215 	/* Disable processor serial number: */
216 
217 	rdmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
218 	lo |= 0x200000;
219 	wrmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
220 
221 	printk(KERN_NOTICE "CPU serial number disabled.\n");
222 	clear_cpu_cap(c, X86_FEATURE_PN);
223 
224 	/* Disabling the serial number may affect the cpuid level */
225 	c->cpuid_level = cpuid_eax(0);
226 }
227 
228 static int __init x86_serial_nr_setup(char *s)
229 {
230 	disable_x86_serial_nr = 0;
231 	return 1;
232 }
233 __setup("serialnumber", x86_serial_nr_setup);
234 #else
235 static inline int flag_is_changeable_p(u32 flag)
236 {
237 	return 1;
238 }
239 /* Probe for the CPUID instruction */
240 static inline int have_cpuid_p(void)
241 {
242 	return 1;
243 }
244 static inline void squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
245 {
246 }
247 #endif
248 
249 /*
250  * Some CPU features depend on higher CPUID levels, which may not always
251  * be available due to CPUID level capping or broken virtualization
252  * software.  Add those features to this table to auto-disable them.
253  */
254 struct cpuid_dependent_feature {
255 	u32 feature;
256 	u32 level;
257 };
258 
259 static const struct cpuid_dependent_feature __cpuinitconst
260 cpuid_dependent_features[] = {
261 	{ X86_FEATURE_MWAIT,		0x00000005 },
262 	{ X86_FEATURE_DCA,		0x00000009 },
263 	{ X86_FEATURE_XSAVE,		0x0000000d },
264 	{ 0, 0 }
265 };
266 
267 static void __cpuinit filter_cpuid_features(struct cpuinfo_x86 *c, bool warn)
268 {
269 	const struct cpuid_dependent_feature *df;
270 
271 	for (df = cpuid_dependent_features; df->feature; df++) {
272 
273 		if (!cpu_has(c, df->feature))
274 			continue;
275 		/*
276 		 * Note: cpuid_level is set to -1 if unavailable, but
277 		 * extended_extended_level is set to 0 if unavailable
278 		 * and the legitimate extended levels are all negative
279 		 * when signed; hence the weird messing around with
280 		 * signs here...
281 		 */
282 		if (!((s32)df->level < 0 ?
283 		     (u32)df->level > (u32)c->extended_cpuid_level :
284 		     (s32)df->level > (s32)c->cpuid_level))
285 			continue;
286 
287 		clear_cpu_cap(c, df->feature);
288 		if (!warn)
289 			continue;
290 
291 		printk(KERN_WARNING
292 		       "CPU: CPU feature %s disabled, no CPUID level 0x%x\n",
293 				x86_cap_flags[df->feature], df->level);
294 	}
295 }
296 
297 /*
298  * Naming convention should be: <Name> [(<Codename>)]
299  * This table only is used unless init_<vendor>() below doesn't set it;
300  * in particular, if CPUID levels 0x80000002..4 are supported, this
301  * isn't used
302  */
303 
304 /* Look up CPU names by table lookup. */
305 static const char *__cpuinit table_lookup_model(struct cpuinfo_x86 *c)
306 {
307 	const struct cpu_model_info *info;
308 
309 	if (c->x86_model >= 16)
310 		return NULL;	/* Range check */
311 
312 	if (!this_cpu)
313 		return NULL;
314 
315 	info = this_cpu->c_models;
316 
317 	while (info && info->family) {
318 		if (info->family == c->x86)
319 			return info->model_names[c->x86_model];
320 		info++;
321 	}
322 	return NULL;		/* Not found */
323 }
324 
325 __u32 cpu_caps_cleared[NCAPINTS] __cpuinitdata;
326 __u32 cpu_caps_set[NCAPINTS] __cpuinitdata;
327 
328 void load_percpu_segment(int cpu)
329 {
330 #ifdef CONFIG_X86_32
331 	loadsegment(fs, __KERNEL_PERCPU);
332 #else
333 	loadsegment(gs, 0);
334 	wrmsrl(MSR_GS_BASE, (unsigned long)per_cpu(irq_stack_union.gs_base, cpu));
335 #endif
336 	load_stack_canary_segment();
337 }
338 
339 /*
340  * Current gdt points %fs at the "master" per-cpu area: after this,
341  * it's on the real one.
342  */
343 void switch_to_new_gdt(int cpu)
344 {
345 	struct desc_ptr gdt_descr;
346 
347 	gdt_descr.address = (long)get_cpu_gdt_table(cpu);
348 	gdt_descr.size = GDT_SIZE - 1;
349 	load_gdt(&gdt_descr);
350 	/* Reload the per-cpu base */
351 
352 	load_percpu_segment(cpu);
353 }
354 
355 static const struct cpu_dev *__cpuinitdata cpu_devs[X86_VENDOR_NUM] = {};
356 
357 static void __cpuinit get_model_name(struct cpuinfo_x86 *c)
358 {
359 	unsigned int *v;
360 	char *p, *q;
361 
362 	if (c->extended_cpuid_level < 0x80000004)
363 		return;
364 
365 	v = (unsigned int *)c->x86_model_id;
366 	cpuid(0x80000002, &v[0], &v[1], &v[2], &v[3]);
367 	cpuid(0x80000003, &v[4], &v[5], &v[6], &v[7]);
368 	cpuid(0x80000004, &v[8], &v[9], &v[10], &v[11]);
369 	c->x86_model_id[48] = 0;
370 
371 	/*
372 	 * Intel chips right-justify this string for some dumb reason;
373 	 * undo that brain damage:
374 	 */
375 	p = q = &c->x86_model_id[0];
376 	while (*p == ' ')
377 		p++;
378 	if (p != q) {
379 		while (*p)
380 			*q++ = *p++;
381 		while (q <= &c->x86_model_id[48])
382 			*q++ = '\0';	/* Zero-pad the rest */
383 	}
384 }
385 
386 void __cpuinit cpu_detect_cache_sizes(struct cpuinfo_x86 *c)
387 {
388 	unsigned int n, dummy, ebx, ecx, edx, l2size;
389 
390 	n = c->extended_cpuid_level;
391 
392 	if (n >= 0x80000005) {
393 		cpuid(0x80000005, &dummy, &ebx, &ecx, &edx);
394 		c->x86_cache_size = (ecx>>24) + (edx>>24);
395 #ifdef CONFIG_X86_64
396 		/* On K8 L1 TLB is inclusive, so don't count it */
397 		c->x86_tlbsize = 0;
398 #endif
399 	}
400 
401 	if (n < 0x80000006)	/* Some chips just has a large L1. */
402 		return;
403 
404 	cpuid(0x80000006, &dummy, &ebx, &ecx, &edx);
405 	l2size = ecx >> 16;
406 
407 #ifdef CONFIG_X86_64
408 	c->x86_tlbsize += ((ebx >> 16) & 0xfff) + (ebx & 0xfff);
409 #else
410 	/* do processor-specific cache resizing */
411 	if (this_cpu->c_size_cache)
412 		l2size = this_cpu->c_size_cache(c, l2size);
413 
414 	/* Allow user to override all this if necessary. */
415 	if (cachesize_override != -1)
416 		l2size = cachesize_override;
417 
418 	if (l2size == 0)
419 		return;		/* Again, no L2 cache is possible */
420 #endif
421 
422 	c->x86_cache_size = l2size;
423 }
424 
425 void __cpuinit detect_ht(struct cpuinfo_x86 *c)
426 {
427 #ifdef CONFIG_X86_HT
428 	u32 eax, ebx, ecx, edx;
429 	int index_msb, core_bits;
430 	static bool printed;
431 
432 	if (!cpu_has(c, X86_FEATURE_HT))
433 		return;
434 
435 	if (cpu_has(c, X86_FEATURE_CMP_LEGACY))
436 		goto out;
437 
438 	if (cpu_has(c, X86_FEATURE_XTOPOLOGY))
439 		return;
440 
441 	cpuid(1, &eax, &ebx, &ecx, &edx);
442 
443 	smp_num_siblings = (ebx & 0xff0000) >> 16;
444 
445 	if (smp_num_siblings == 1) {
446 		printk_once(KERN_INFO "CPU0: Hyper-Threading is disabled\n");
447 		goto out;
448 	}
449 
450 	if (smp_num_siblings <= 1)
451 		goto out;
452 
453 	if (smp_num_siblings > nr_cpu_ids) {
454 		pr_warning("CPU: Unsupported number of siblings %d",
455 			   smp_num_siblings);
456 		smp_num_siblings = 1;
457 		return;
458 	}
459 
460 	index_msb = get_count_order(smp_num_siblings);
461 	c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, index_msb);
462 
463 	smp_num_siblings = smp_num_siblings / c->x86_max_cores;
464 
465 	index_msb = get_count_order(smp_num_siblings);
466 
467 	core_bits = get_count_order(c->x86_max_cores);
468 
469 	c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid, index_msb) &
470 				       ((1 << core_bits) - 1);
471 
472 out:
473 	if (!printed && (c->x86_max_cores * smp_num_siblings) > 1) {
474 		printk(KERN_INFO  "CPU: Physical Processor ID: %d\n",
475 		       c->phys_proc_id);
476 		printk(KERN_INFO  "CPU: Processor Core ID: %d\n",
477 		       c->cpu_core_id);
478 		printed = 1;
479 	}
480 #endif
481 }
482 
483 static void __cpuinit get_cpu_vendor(struct cpuinfo_x86 *c)
484 {
485 	char *v = c->x86_vendor_id;
486 	int i;
487 
488 	for (i = 0; i < X86_VENDOR_NUM; i++) {
489 		if (!cpu_devs[i])
490 			break;
491 
492 		if (!strcmp(v, cpu_devs[i]->c_ident[0]) ||
493 		    (cpu_devs[i]->c_ident[1] &&
494 		     !strcmp(v, cpu_devs[i]->c_ident[1]))) {
495 
496 			this_cpu = cpu_devs[i];
497 			c->x86_vendor = this_cpu->c_x86_vendor;
498 			return;
499 		}
500 	}
501 
502 	printk_once(KERN_ERR
503 			"CPU: vendor_id '%s' unknown, using generic init.\n" \
504 			"CPU: Your system may be unstable.\n", v);
505 
506 	c->x86_vendor = X86_VENDOR_UNKNOWN;
507 	this_cpu = &default_cpu;
508 }
509 
510 void __cpuinit cpu_detect(struct cpuinfo_x86 *c)
511 {
512 	/* Get vendor name */
513 	cpuid(0x00000000, (unsigned int *)&c->cpuid_level,
514 	      (unsigned int *)&c->x86_vendor_id[0],
515 	      (unsigned int *)&c->x86_vendor_id[8],
516 	      (unsigned int *)&c->x86_vendor_id[4]);
517 
518 	c->x86 = 4;
519 	/* Intel-defined flags: level 0x00000001 */
520 	if (c->cpuid_level >= 0x00000001) {
521 		u32 junk, tfms, cap0, misc;
522 
523 		cpuid(0x00000001, &tfms, &misc, &junk, &cap0);
524 		c->x86 = (tfms >> 8) & 0xf;
525 		c->x86_model = (tfms >> 4) & 0xf;
526 		c->x86_mask = tfms & 0xf;
527 
528 		if (c->x86 == 0xf)
529 			c->x86 += (tfms >> 20) & 0xff;
530 		if (c->x86 >= 0x6)
531 			c->x86_model += ((tfms >> 16) & 0xf) << 4;
532 
533 		if (cap0 & (1<<19)) {
534 			c->x86_clflush_size = ((misc >> 8) & 0xff) * 8;
535 			c->x86_cache_alignment = c->x86_clflush_size;
536 		}
537 	}
538 }
539 
540 static void __cpuinit get_cpu_cap(struct cpuinfo_x86 *c)
541 {
542 	u32 tfms, xlvl;
543 	u32 ebx;
544 
545 	/* Intel-defined flags: level 0x00000001 */
546 	if (c->cpuid_level >= 0x00000001) {
547 		u32 capability, excap;
548 
549 		cpuid(0x00000001, &tfms, &ebx, &excap, &capability);
550 		c->x86_capability[0] = capability;
551 		c->x86_capability[4] = excap;
552 	}
553 
554 	/* AMD-defined flags: level 0x80000001 */
555 	xlvl = cpuid_eax(0x80000000);
556 	c->extended_cpuid_level = xlvl;
557 
558 	if ((xlvl & 0xffff0000) == 0x80000000) {
559 		if (xlvl >= 0x80000001) {
560 			c->x86_capability[1] = cpuid_edx(0x80000001);
561 			c->x86_capability[6] = cpuid_ecx(0x80000001);
562 		}
563 	}
564 
565 	if (c->extended_cpuid_level >= 0x80000008) {
566 		u32 eax = cpuid_eax(0x80000008);
567 
568 		c->x86_virt_bits = (eax >> 8) & 0xff;
569 		c->x86_phys_bits = eax & 0xff;
570 	}
571 #ifdef CONFIG_X86_32
572 	else if (cpu_has(c, X86_FEATURE_PAE) || cpu_has(c, X86_FEATURE_PSE36))
573 		c->x86_phys_bits = 36;
574 #endif
575 
576 	if (c->extended_cpuid_level >= 0x80000007)
577 		c->x86_power = cpuid_edx(0x80000007);
578 
579 }
580 
581 static void __cpuinit identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
582 {
583 #ifdef CONFIG_X86_32
584 	int i;
585 
586 	/*
587 	 * First of all, decide if this is a 486 or higher
588 	 * It's a 486 if we can modify the AC flag
589 	 */
590 	if (flag_is_changeable_p(X86_EFLAGS_AC))
591 		c->x86 = 4;
592 	else
593 		c->x86 = 3;
594 
595 	for (i = 0; i < X86_VENDOR_NUM; i++)
596 		if (cpu_devs[i] && cpu_devs[i]->c_identify) {
597 			c->x86_vendor_id[0] = 0;
598 			cpu_devs[i]->c_identify(c);
599 			if (c->x86_vendor_id[0]) {
600 				get_cpu_vendor(c);
601 				break;
602 			}
603 		}
604 #endif
605 }
606 
607 /*
608  * Do minimum CPU detection early.
609  * Fields really needed: vendor, cpuid_level, family, model, mask,
610  * cache alignment.
611  * The others are not touched to avoid unwanted side effects.
612  *
613  * WARNING: this function is only called on the BP.  Don't add code here
614  * that is supposed to run on all CPUs.
615  */
616 static void __init early_identify_cpu(struct cpuinfo_x86 *c)
617 {
618 #ifdef CONFIG_X86_64
619 	c->x86_clflush_size = 64;
620 	c->x86_phys_bits = 36;
621 	c->x86_virt_bits = 48;
622 #else
623 	c->x86_clflush_size = 32;
624 	c->x86_phys_bits = 32;
625 	c->x86_virt_bits = 32;
626 #endif
627 	c->x86_cache_alignment = c->x86_clflush_size;
628 
629 	memset(&c->x86_capability, 0, sizeof c->x86_capability);
630 	c->extended_cpuid_level = 0;
631 
632 	if (!have_cpuid_p())
633 		identify_cpu_without_cpuid(c);
634 
635 	/* cyrix could have cpuid enabled via c_identify()*/
636 	if (!have_cpuid_p())
637 		return;
638 
639 	cpu_detect(c);
640 
641 	get_cpu_vendor(c);
642 
643 	get_cpu_cap(c);
644 
645 	if (this_cpu->c_early_init)
646 		this_cpu->c_early_init(c);
647 
648 #ifdef CONFIG_SMP
649 	c->cpu_index = boot_cpu_id;
650 #endif
651 	filter_cpuid_features(c, false);
652 }
653 
654 void __init early_cpu_init(void)
655 {
656 	const struct cpu_dev *const *cdev;
657 	int count = 0;
658 
659 #ifdef PROCESSOR_SELECT
660 	printk(KERN_INFO "KERNEL supported cpus:\n");
661 #endif
662 
663 	for (cdev = __x86_cpu_dev_start; cdev < __x86_cpu_dev_end; cdev++) {
664 		const struct cpu_dev *cpudev = *cdev;
665 
666 		if (count >= X86_VENDOR_NUM)
667 			break;
668 		cpu_devs[count] = cpudev;
669 		count++;
670 
671 #ifdef PROCESSOR_SELECT
672 		{
673 			unsigned int j;
674 
675 			for (j = 0; j < 2; j++) {
676 				if (!cpudev->c_ident[j])
677 					continue;
678 				printk(KERN_INFO "  %s %s\n", cpudev->c_vendor,
679 					cpudev->c_ident[j]);
680 			}
681 		}
682 #endif
683 	}
684 	early_identify_cpu(&boot_cpu_data);
685 }
686 
687 /*
688  * The NOPL instruction is supposed to exist on all CPUs with
689  * family >= 6; unfortunately, that's not true in practice because
690  * of early VIA chips and (more importantly) broken virtualizers that
691  * are not easy to detect.  In the latter case it doesn't even *fail*
692  * reliably, so probing for it doesn't even work.  Disable it completely
693  * unless we can find a reliable way to detect all the broken cases.
694  */
695 static void __cpuinit detect_nopl(struct cpuinfo_x86 *c)
696 {
697 	clear_cpu_cap(c, X86_FEATURE_NOPL);
698 }
699 
700 static void __cpuinit generic_identify(struct cpuinfo_x86 *c)
701 {
702 	c->extended_cpuid_level = 0;
703 
704 	if (!have_cpuid_p())
705 		identify_cpu_without_cpuid(c);
706 
707 	/* cyrix could have cpuid enabled via c_identify()*/
708 	if (!have_cpuid_p())
709 		return;
710 
711 	cpu_detect(c);
712 
713 	get_cpu_vendor(c);
714 
715 	get_cpu_cap(c);
716 
717 	if (c->cpuid_level >= 0x00000001) {
718 		c->initial_apicid = (cpuid_ebx(1) >> 24) & 0xFF;
719 #ifdef CONFIG_X86_32
720 # ifdef CONFIG_X86_HT
721 		c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
722 # else
723 		c->apicid = c->initial_apicid;
724 # endif
725 #endif
726 
727 #ifdef CONFIG_X86_HT
728 		c->phys_proc_id = c->initial_apicid;
729 #endif
730 	}
731 
732 	get_model_name(c); /* Default name */
733 
734 	init_scattered_cpuid_features(c);
735 	detect_nopl(c);
736 }
737 
738 /*
739  * This does the hard work of actually picking apart the CPU stuff...
740  */
741 static void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
742 {
743 	int i;
744 
745 	c->loops_per_jiffy = loops_per_jiffy;
746 	c->x86_cache_size = -1;
747 	c->x86_vendor = X86_VENDOR_UNKNOWN;
748 	c->x86_model = c->x86_mask = 0;	/* So far unknown... */
749 	c->x86_vendor_id[0] = '\0'; /* Unset */
750 	c->x86_model_id[0] = '\0';  /* Unset */
751 	c->x86_max_cores = 1;
752 	c->x86_coreid_bits = 0;
753 #ifdef CONFIG_X86_64
754 	c->x86_clflush_size = 64;
755 	c->x86_phys_bits = 36;
756 	c->x86_virt_bits = 48;
757 #else
758 	c->cpuid_level = -1;	/* CPUID not detected */
759 	c->x86_clflush_size = 32;
760 	c->x86_phys_bits = 32;
761 	c->x86_virt_bits = 32;
762 #endif
763 	c->x86_cache_alignment = c->x86_clflush_size;
764 	memset(&c->x86_capability, 0, sizeof c->x86_capability);
765 
766 	generic_identify(c);
767 
768 	if (this_cpu->c_identify)
769 		this_cpu->c_identify(c);
770 
771 	/* Clear/Set all flags overriden by options, after probe */
772 	for (i = 0; i < NCAPINTS; i++) {
773 		c->x86_capability[i] &= ~cpu_caps_cleared[i];
774 		c->x86_capability[i] |= cpu_caps_set[i];
775 	}
776 
777 #ifdef CONFIG_X86_64
778 	c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
779 #endif
780 
781 	/*
782 	 * Vendor-specific initialization.  In this section we
783 	 * canonicalize the feature flags, meaning if there are
784 	 * features a certain CPU supports which CPUID doesn't
785 	 * tell us, CPUID claiming incorrect flags, or other bugs,
786 	 * we handle them here.
787 	 *
788 	 * At the end of this section, c->x86_capability better
789 	 * indicate the features this CPU genuinely supports!
790 	 */
791 	if (this_cpu->c_init)
792 		this_cpu->c_init(c);
793 
794 	/* Disable the PN if appropriate */
795 	squash_the_stupid_serial_number(c);
796 
797 	/*
798 	 * The vendor-specific functions might have changed features.
799 	 * Now we do "generic changes."
800 	 */
801 
802 	/* Filter out anything that depends on CPUID levels we don't have */
803 	filter_cpuid_features(c, true);
804 
805 	/* If the model name is still unset, do table lookup. */
806 	if (!c->x86_model_id[0]) {
807 		const char *p;
808 		p = table_lookup_model(c);
809 		if (p)
810 			strcpy(c->x86_model_id, p);
811 		else
812 			/* Last resort... */
813 			sprintf(c->x86_model_id, "%02x/%02x",
814 				c->x86, c->x86_model);
815 	}
816 
817 #ifdef CONFIG_X86_64
818 	detect_ht(c);
819 #endif
820 
821 	init_hypervisor(c);
822 
823 	/*
824 	 * Clear/Set all flags overriden by options, need do it
825 	 * before following smp all cpus cap AND.
826 	 */
827 	for (i = 0; i < NCAPINTS; i++) {
828 		c->x86_capability[i] &= ~cpu_caps_cleared[i];
829 		c->x86_capability[i] |= cpu_caps_set[i];
830 	}
831 
832 	/*
833 	 * On SMP, boot_cpu_data holds the common feature set between
834 	 * all CPUs; so make sure that we indicate which features are
835 	 * common between the CPUs.  The first time this routine gets
836 	 * executed, c == &boot_cpu_data.
837 	 */
838 	if (c != &boot_cpu_data) {
839 		/* AND the already accumulated flags with these */
840 		for (i = 0; i < NCAPINTS; i++)
841 			boot_cpu_data.x86_capability[i] &= c->x86_capability[i];
842 	}
843 
844 	/* Init Machine Check Exception if available. */
845 	mcheck_cpu_init(c);
846 
847 	select_idle_routine(c);
848 
849 #if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
850 	numa_add_cpu(smp_processor_id());
851 #endif
852 }
853 
854 #ifdef CONFIG_X86_64
855 static void vgetcpu_set_mode(void)
856 {
857 	if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP))
858 		vgetcpu_mode = VGETCPU_RDTSCP;
859 	else
860 		vgetcpu_mode = VGETCPU_LSL;
861 }
862 #endif
863 
864 void __init identify_boot_cpu(void)
865 {
866 	identify_cpu(&boot_cpu_data);
867 	init_c1e_mask();
868 #ifdef CONFIG_X86_32
869 	sysenter_setup();
870 	enable_sep_cpu();
871 #else
872 	vgetcpu_set_mode();
873 #endif
874 	init_hw_perf_events();
875 }
876 
877 void __cpuinit identify_secondary_cpu(struct cpuinfo_x86 *c)
878 {
879 	BUG_ON(c == &boot_cpu_data);
880 	identify_cpu(c);
881 #ifdef CONFIG_X86_32
882 	enable_sep_cpu();
883 #endif
884 	mtrr_ap_init();
885 }
886 
887 struct msr_range {
888 	unsigned	min;
889 	unsigned	max;
890 };
891 
892 static const struct msr_range msr_range_array[] __cpuinitconst = {
893 	{ 0x00000000, 0x00000418},
894 	{ 0xc0000000, 0xc000040b},
895 	{ 0xc0010000, 0xc0010142},
896 	{ 0xc0011000, 0xc001103b},
897 };
898 
899 static void __cpuinit print_cpu_msr(void)
900 {
901 	unsigned index_min, index_max;
902 	unsigned index;
903 	u64 val;
904 	int i;
905 
906 	for (i = 0; i < ARRAY_SIZE(msr_range_array); i++) {
907 		index_min = msr_range_array[i].min;
908 		index_max = msr_range_array[i].max;
909 
910 		for (index = index_min; index < index_max; index++) {
911 			if (rdmsrl_amd_safe(index, &val))
912 				continue;
913 			printk(KERN_INFO " MSR%08x: %016llx\n", index, val);
914 		}
915 	}
916 }
917 
918 static int show_msr __cpuinitdata;
919 
920 static __init int setup_show_msr(char *arg)
921 {
922 	int num;
923 
924 	get_option(&arg, &num);
925 
926 	if (num > 0)
927 		show_msr = num;
928 	return 1;
929 }
930 __setup("show_msr=", setup_show_msr);
931 
932 static __init int setup_noclflush(char *arg)
933 {
934 	setup_clear_cpu_cap(X86_FEATURE_CLFLSH);
935 	return 1;
936 }
937 __setup("noclflush", setup_noclflush);
938 
939 void __cpuinit print_cpu_info(struct cpuinfo_x86 *c)
940 {
941 	const char *vendor = NULL;
942 
943 	if (c->x86_vendor < X86_VENDOR_NUM) {
944 		vendor = this_cpu->c_vendor;
945 	} else {
946 		if (c->cpuid_level >= 0)
947 			vendor = c->x86_vendor_id;
948 	}
949 
950 	if (vendor && !strstr(c->x86_model_id, vendor))
951 		printk(KERN_CONT "%s ", vendor);
952 
953 	if (c->x86_model_id[0])
954 		printk(KERN_CONT "%s", c->x86_model_id);
955 	else
956 		printk(KERN_CONT "%d86", c->x86);
957 
958 	if (c->x86_mask || c->cpuid_level >= 0)
959 		printk(KERN_CONT " stepping %02x\n", c->x86_mask);
960 	else
961 		printk(KERN_CONT "\n");
962 
963 #ifdef CONFIG_SMP
964 	if (c->cpu_index < show_msr)
965 		print_cpu_msr();
966 #else
967 	if (show_msr)
968 		print_cpu_msr();
969 #endif
970 }
971 
972 static __init int setup_disablecpuid(char *arg)
973 {
974 	int bit;
975 
976 	if (get_option(&arg, &bit) && bit < NCAPINTS*32)
977 		setup_clear_cpu_cap(bit);
978 	else
979 		return 0;
980 
981 	return 1;
982 }
983 __setup("clearcpuid=", setup_disablecpuid);
984 
985 #ifdef CONFIG_X86_64
986 struct desc_ptr idt_descr = { NR_VECTORS * 16 - 1, (unsigned long) idt_table };
987 
988 DEFINE_PER_CPU_FIRST(union irq_stack_union,
989 		     irq_stack_union) __aligned(PAGE_SIZE);
990 
991 /*
992  * The following four percpu variables are hot.  Align current_task to
993  * cacheline size such that all four fall in the same cacheline.
994  */
995 DEFINE_PER_CPU(struct task_struct *, current_task) ____cacheline_aligned =
996 	&init_task;
997 EXPORT_PER_CPU_SYMBOL(current_task);
998 
999 DEFINE_PER_CPU(unsigned long, kernel_stack) =
1000 	(unsigned long)&init_thread_union - KERNEL_STACK_OFFSET + THREAD_SIZE;
1001 EXPORT_PER_CPU_SYMBOL(kernel_stack);
1002 
1003 DEFINE_PER_CPU(char *, irq_stack_ptr) =
1004 	init_per_cpu_var(irq_stack_union.irq_stack) + IRQ_STACK_SIZE - 64;
1005 
1006 DEFINE_PER_CPU(unsigned int, irq_count) = -1;
1007 
1008 /*
1009  * Special IST stacks which the CPU switches to when it calls
1010  * an IST-marked descriptor entry. Up to 7 stacks (hardware
1011  * limit), all of them are 4K, except the debug stack which
1012  * is 8K.
1013  */
1014 static const unsigned int exception_stack_sizes[N_EXCEPTION_STACKS] = {
1015 	  [0 ... N_EXCEPTION_STACKS - 1]	= EXCEPTION_STKSZ,
1016 	  [DEBUG_STACK - 1]			= DEBUG_STKSZ
1017 };
1018 
1019 static DEFINE_PER_CPU_PAGE_ALIGNED(char, exception_stacks
1020 	[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ]);
1021 
1022 /* May not be marked __init: used by software suspend */
1023 void syscall_init(void)
1024 {
1025 	/*
1026 	 * LSTAR and STAR live in a bit strange symbiosis.
1027 	 * They both write to the same internal register. STAR allows to
1028 	 * set CS/DS but only a 32bit target. LSTAR sets the 64bit rip.
1029 	 */
1030 	wrmsrl(MSR_STAR,  ((u64)__USER32_CS)<<48  | ((u64)__KERNEL_CS)<<32);
1031 	wrmsrl(MSR_LSTAR, system_call);
1032 	wrmsrl(MSR_CSTAR, ignore_sysret);
1033 
1034 #ifdef CONFIG_IA32_EMULATION
1035 	syscall32_cpu_init();
1036 #endif
1037 
1038 	/* Flags to clear on syscall */
1039 	wrmsrl(MSR_SYSCALL_MASK,
1040 	       X86_EFLAGS_TF|X86_EFLAGS_DF|X86_EFLAGS_IF|X86_EFLAGS_IOPL);
1041 }
1042 
1043 unsigned long kernel_eflags;
1044 
1045 /*
1046  * Copies of the original ist values from the tss are only accessed during
1047  * debugging, no special alignment required.
1048  */
1049 DEFINE_PER_CPU(struct orig_ist, orig_ist);
1050 
1051 #else	/* CONFIG_X86_64 */
1052 
1053 DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task;
1054 EXPORT_PER_CPU_SYMBOL(current_task);
1055 
1056 #ifdef CONFIG_CC_STACKPROTECTOR
1057 DEFINE_PER_CPU_ALIGNED(struct stack_canary, stack_canary);
1058 #endif
1059 
1060 /* Make sure %fs and %gs are initialized properly in idle threads */
1061 struct pt_regs * __cpuinit idle_regs(struct pt_regs *regs)
1062 {
1063 	memset(regs, 0, sizeof(struct pt_regs));
1064 	regs->fs = __KERNEL_PERCPU;
1065 	regs->gs = __KERNEL_STACK_CANARY;
1066 
1067 	return regs;
1068 }
1069 #endif	/* CONFIG_X86_64 */
1070 
1071 /*
1072  * Clear all 6 debug registers:
1073  */
1074 static void clear_all_debug_regs(void)
1075 {
1076 	int i;
1077 
1078 	for (i = 0; i < 8; i++) {
1079 		/* Ignore db4, db5 */
1080 		if ((i == 4) || (i == 5))
1081 			continue;
1082 
1083 		set_debugreg(0, i);
1084 	}
1085 }
1086 
1087 /*
1088  * cpu_init() initializes state that is per-CPU. Some data is already
1089  * initialized (naturally) in the bootstrap process, such as the GDT
1090  * and IDT. We reload them nevertheless, this function acts as a
1091  * 'CPU state barrier', nothing should get across.
1092  * A lot of state is already set up in PDA init for 64 bit
1093  */
1094 #ifdef CONFIG_X86_64
1095 
1096 void __cpuinit cpu_init(void)
1097 {
1098 	struct orig_ist *oist;
1099 	struct task_struct *me;
1100 	struct tss_struct *t;
1101 	unsigned long v;
1102 	int cpu;
1103 	int i;
1104 
1105 	cpu = stack_smp_processor_id();
1106 	t = &per_cpu(init_tss, cpu);
1107 	oist = &per_cpu(orig_ist, cpu);
1108 
1109 #ifdef CONFIG_NUMA
1110 	if (cpu != 0 && percpu_read(node_number) == 0 &&
1111 	    cpu_to_node(cpu) != NUMA_NO_NODE)
1112 		percpu_write(node_number, cpu_to_node(cpu));
1113 #endif
1114 
1115 	me = current;
1116 
1117 	if (cpumask_test_and_set_cpu(cpu, cpu_initialized_mask))
1118 		panic("CPU#%d already initialized!\n", cpu);
1119 
1120 	pr_debug("Initializing CPU#%d\n", cpu);
1121 
1122 	clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1123 
1124 	/*
1125 	 * Initialize the per-CPU GDT with the boot GDT,
1126 	 * and set up the GDT descriptor:
1127 	 */
1128 
1129 	switch_to_new_gdt(cpu);
1130 	loadsegment(fs, 0);
1131 
1132 	load_idt((const struct desc_ptr *)&idt_descr);
1133 
1134 	memset(me->thread.tls_array, 0, GDT_ENTRY_TLS_ENTRIES * 8);
1135 	syscall_init();
1136 
1137 	wrmsrl(MSR_FS_BASE, 0);
1138 	wrmsrl(MSR_KERNEL_GS_BASE, 0);
1139 	barrier();
1140 
1141 	x86_configure_nx();
1142 	if (cpu != 0)
1143 		enable_x2apic();
1144 
1145 	/*
1146 	 * set up and load the per-CPU TSS
1147 	 */
1148 	if (!oist->ist[0]) {
1149 		char *estacks = per_cpu(exception_stacks, cpu);
1150 
1151 		for (v = 0; v < N_EXCEPTION_STACKS; v++) {
1152 			estacks += exception_stack_sizes[v];
1153 			oist->ist[v] = t->x86_tss.ist[v] =
1154 					(unsigned long)estacks;
1155 		}
1156 	}
1157 
1158 	t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
1159 
1160 	/*
1161 	 * <= is required because the CPU will access up to
1162 	 * 8 bits beyond the end of the IO permission bitmap.
1163 	 */
1164 	for (i = 0; i <= IO_BITMAP_LONGS; i++)
1165 		t->io_bitmap[i] = ~0UL;
1166 
1167 	atomic_inc(&init_mm.mm_count);
1168 	me->active_mm = &init_mm;
1169 	BUG_ON(me->mm);
1170 	enter_lazy_tlb(&init_mm, me);
1171 
1172 	load_sp0(t, &current->thread);
1173 	set_tss_desc(cpu, t);
1174 	load_TR_desc();
1175 	load_LDT(&init_mm.context);
1176 
1177 #ifdef CONFIG_KGDB
1178 	/*
1179 	 * If the kgdb is connected no debug regs should be altered.  This
1180 	 * is only applicable when KGDB and a KGDB I/O module are built
1181 	 * into the kernel and you are using early debugging with
1182 	 * kgdbwait. KGDB will control the kernel HW breakpoint registers.
1183 	 */
1184 	if (kgdb_connected && arch_kgdb_ops.correct_hw_break)
1185 		arch_kgdb_ops.correct_hw_break();
1186 	else
1187 #endif
1188 		clear_all_debug_regs();
1189 
1190 	fpu_init();
1191 
1192 	raw_local_save_flags(kernel_eflags);
1193 
1194 	if (is_uv_system())
1195 		uv_cpu_init();
1196 }
1197 
1198 #else
1199 
1200 void __cpuinit cpu_init(void)
1201 {
1202 	int cpu = smp_processor_id();
1203 	struct task_struct *curr = current;
1204 	struct tss_struct *t = &per_cpu(init_tss, cpu);
1205 	struct thread_struct *thread = &curr->thread;
1206 
1207 	if (cpumask_test_and_set_cpu(cpu, cpu_initialized_mask)) {
1208 		printk(KERN_WARNING "CPU#%d already initialized!\n", cpu);
1209 		for (;;)
1210 			local_irq_enable();
1211 	}
1212 
1213 	printk(KERN_INFO "Initializing CPU#%d\n", cpu);
1214 
1215 	if (cpu_has_vme || cpu_has_tsc || cpu_has_de)
1216 		clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1217 
1218 	load_idt(&idt_descr);
1219 	switch_to_new_gdt(cpu);
1220 
1221 	/*
1222 	 * Set up and load the per-CPU TSS and LDT
1223 	 */
1224 	atomic_inc(&init_mm.mm_count);
1225 	curr->active_mm = &init_mm;
1226 	BUG_ON(curr->mm);
1227 	enter_lazy_tlb(&init_mm, curr);
1228 
1229 	load_sp0(t, thread);
1230 	set_tss_desc(cpu, t);
1231 	load_TR_desc();
1232 	load_LDT(&init_mm.context);
1233 
1234 	t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
1235 
1236 #ifdef CONFIG_DOUBLEFAULT
1237 	/* Set up doublefault TSS pointer in the GDT */
1238 	__set_tss_desc(cpu, GDT_ENTRY_DOUBLEFAULT_TSS, &doublefault_tss);
1239 #endif
1240 
1241 	clear_all_debug_regs();
1242 
1243 	/*
1244 	 * Force FPU initialization:
1245 	 */
1246 	if (cpu_has_xsave)
1247 		current_thread_info()->status = TS_XSAVE;
1248 	else
1249 		current_thread_info()->status = 0;
1250 	clear_used_math();
1251 	mxcsr_feature_mask_init();
1252 
1253 	/*
1254 	 * Boot processor to setup the FP and extended state context info.
1255 	 */
1256 	if (smp_processor_id() == boot_cpu_id)
1257 		init_thread_xstate();
1258 
1259 	xsave_init();
1260 }
1261 #endif
1262