xref: /linux/arch/x86/kernel/cpu/common.c (revision cc4589ebfae6f8dbb5cf880a0a67eedab3416492)
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 	setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT);
144 	return 1;
145 }
146 __setup("noxsave", x86_xsave_setup);
147 
148 static int __init x86_xsaveopt_setup(char *s)
149 {
150 	setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT);
151 	return 1;
152 }
153 __setup("noxsaveopt", x86_xsaveopt_setup);
154 
155 #ifdef CONFIG_X86_32
156 static int cachesize_override __cpuinitdata = -1;
157 static int disable_x86_serial_nr __cpuinitdata = 1;
158 
159 static int __init cachesize_setup(char *str)
160 {
161 	get_option(&str, &cachesize_override);
162 	return 1;
163 }
164 __setup("cachesize=", cachesize_setup);
165 
166 static int __init x86_fxsr_setup(char *s)
167 {
168 	setup_clear_cpu_cap(X86_FEATURE_FXSR);
169 	setup_clear_cpu_cap(X86_FEATURE_XMM);
170 	return 1;
171 }
172 __setup("nofxsr", x86_fxsr_setup);
173 
174 static int __init x86_sep_setup(char *s)
175 {
176 	setup_clear_cpu_cap(X86_FEATURE_SEP);
177 	return 1;
178 }
179 __setup("nosep", x86_sep_setup);
180 
181 /* Standard macro to see if a specific flag is changeable */
182 static inline int flag_is_changeable_p(u32 flag)
183 {
184 	u32 f1, f2;
185 
186 	/*
187 	 * Cyrix and IDT cpus allow disabling of CPUID
188 	 * so the code below may return different results
189 	 * when it is executed before and after enabling
190 	 * the CPUID. Add "volatile" to not allow gcc to
191 	 * optimize the subsequent calls to this function.
192 	 */
193 	asm volatile ("pushfl		\n\t"
194 		      "pushfl		\n\t"
195 		      "popl %0		\n\t"
196 		      "movl %0, %1	\n\t"
197 		      "xorl %2, %0	\n\t"
198 		      "pushl %0		\n\t"
199 		      "popfl		\n\t"
200 		      "pushfl		\n\t"
201 		      "popl %0		\n\t"
202 		      "popfl		\n\t"
203 
204 		      : "=&r" (f1), "=&r" (f2)
205 		      : "ir" (flag));
206 
207 	return ((f1^f2) & flag) != 0;
208 }
209 
210 /* Probe for the CPUID instruction */
211 static int __cpuinit have_cpuid_p(void)
212 {
213 	return flag_is_changeable_p(X86_EFLAGS_ID);
214 }
215 
216 static void __cpuinit squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
217 {
218 	unsigned long lo, hi;
219 
220 	if (!cpu_has(c, X86_FEATURE_PN) || !disable_x86_serial_nr)
221 		return;
222 
223 	/* Disable processor serial number: */
224 
225 	rdmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
226 	lo |= 0x200000;
227 	wrmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
228 
229 	printk(KERN_NOTICE "CPU serial number disabled.\n");
230 	clear_cpu_cap(c, X86_FEATURE_PN);
231 
232 	/* Disabling the serial number may affect the cpuid level */
233 	c->cpuid_level = cpuid_eax(0);
234 }
235 
236 static int __init x86_serial_nr_setup(char *s)
237 {
238 	disable_x86_serial_nr = 0;
239 	return 1;
240 }
241 __setup("serialnumber", x86_serial_nr_setup);
242 #else
243 static inline int flag_is_changeable_p(u32 flag)
244 {
245 	return 1;
246 }
247 /* Probe for the CPUID instruction */
248 static inline int have_cpuid_p(void)
249 {
250 	return 1;
251 }
252 static inline void squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
253 {
254 }
255 #endif
256 
257 /*
258  * Some CPU features depend on higher CPUID levels, which may not always
259  * be available due to CPUID level capping or broken virtualization
260  * software.  Add those features to this table to auto-disable them.
261  */
262 struct cpuid_dependent_feature {
263 	u32 feature;
264 	u32 level;
265 };
266 
267 static const struct cpuid_dependent_feature __cpuinitconst
268 cpuid_dependent_features[] = {
269 	{ X86_FEATURE_MWAIT,		0x00000005 },
270 	{ X86_FEATURE_DCA,		0x00000009 },
271 	{ X86_FEATURE_XSAVE,		0x0000000d },
272 	{ 0, 0 }
273 };
274 
275 static void __cpuinit filter_cpuid_features(struct cpuinfo_x86 *c, bool warn)
276 {
277 	const struct cpuid_dependent_feature *df;
278 
279 	for (df = cpuid_dependent_features; df->feature; df++) {
280 
281 		if (!cpu_has(c, df->feature))
282 			continue;
283 		/*
284 		 * Note: cpuid_level is set to -1 if unavailable, but
285 		 * extended_extended_level is set to 0 if unavailable
286 		 * and the legitimate extended levels are all negative
287 		 * when signed; hence the weird messing around with
288 		 * signs here...
289 		 */
290 		if (!((s32)df->level < 0 ?
291 		     (u32)df->level > (u32)c->extended_cpuid_level :
292 		     (s32)df->level > (s32)c->cpuid_level))
293 			continue;
294 
295 		clear_cpu_cap(c, df->feature);
296 		if (!warn)
297 			continue;
298 
299 		printk(KERN_WARNING
300 		       "CPU: CPU feature %s disabled, no CPUID level 0x%x\n",
301 				x86_cap_flags[df->feature], df->level);
302 	}
303 }
304 
305 /*
306  * Naming convention should be: <Name> [(<Codename>)]
307  * This table only is used unless init_<vendor>() below doesn't set it;
308  * in particular, if CPUID levels 0x80000002..4 are supported, this
309  * isn't used
310  */
311 
312 /* Look up CPU names by table lookup. */
313 static const char *__cpuinit table_lookup_model(struct cpuinfo_x86 *c)
314 {
315 	const struct cpu_model_info *info;
316 
317 	if (c->x86_model >= 16)
318 		return NULL;	/* Range check */
319 
320 	if (!this_cpu)
321 		return NULL;
322 
323 	info = this_cpu->c_models;
324 
325 	while (info && info->family) {
326 		if (info->family == c->x86)
327 			return info->model_names[c->x86_model];
328 		info++;
329 	}
330 	return NULL;		/* Not found */
331 }
332 
333 __u32 cpu_caps_cleared[NCAPINTS] __cpuinitdata;
334 __u32 cpu_caps_set[NCAPINTS] __cpuinitdata;
335 
336 void load_percpu_segment(int cpu)
337 {
338 #ifdef CONFIG_X86_32
339 	loadsegment(fs, __KERNEL_PERCPU);
340 #else
341 	loadsegment(gs, 0);
342 	wrmsrl(MSR_GS_BASE, (unsigned long)per_cpu(irq_stack_union.gs_base, cpu));
343 #endif
344 	load_stack_canary_segment();
345 }
346 
347 /*
348  * Current gdt points %fs at the "master" per-cpu area: after this,
349  * it's on the real one.
350  */
351 void switch_to_new_gdt(int cpu)
352 {
353 	struct desc_ptr gdt_descr;
354 
355 	gdt_descr.address = (long)get_cpu_gdt_table(cpu);
356 	gdt_descr.size = GDT_SIZE - 1;
357 	load_gdt(&gdt_descr);
358 	/* Reload the per-cpu base */
359 
360 	load_percpu_segment(cpu);
361 }
362 
363 static const struct cpu_dev *__cpuinitdata cpu_devs[X86_VENDOR_NUM] = {};
364 
365 static void __cpuinit get_model_name(struct cpuinfo_x86 *c)
366 {
367 	unsigned int *v;
368 	char *p, *q;
369 
370 	if (c->extended_cpuid_level < 0x80000004)
371 		return;
372 
373 	v = (unsigned int *)c->x86_model_id;
374 	cpuid(0x80000002, &v[0], &v[1], &v[2], &v[3]);
375 	cpuid(0x80000003, &v[4], &v[5], &v[6], &v[7]);
376 	cpuid(0x80000004, &v[8], &v[9], &v[10], &v[11]);
377 	c->x86_model_id[48] = 0;
378 
379 	/*
380 	 * Intel chips right-justify this string for some dumb reason;
381 	 * undo that brain damage:
382 	 */
383 	p = q = &c->x86_model_id[0];
384 	while (*p == ' ')
385 		p++;
386 	if (p != q) {
387 		while (*p)
388 			*q++ = *p++;
389 		while (q <= &c->x86_model_id[48])
390 			*q++ = '\0';	/* Zero-pad the rest */
391 	}
392 }
393 
394 void __cpuinit cpu_detect_cache_sizes(struct cpuinfo_x86 *c)
395 {
396 	unsigned int n, dummy, ebx, ecx, edx, l2size;
397 
398 	n = c->extended_cpuid_level;
399 
400 	if (n >= 0x80000005) {
401 		cpuid(0x80000005, &dummy, &ebx, &ecx, &edx);
402 		c->x86_cache_size = (ecx>>24) + (edx>>24);
403 #ifdef CONFIG_X86_64
404 		/* On K8 L1 TLB is inclusive, so don't count it */
405 		c->x86_tlbsize = 0;
406 #endif
407 	}
408 
409 	if (n < 0x80000006)	/* Some chips just has a large L1. */
410 		return;
411 
412 	cpuid(0x80000006, &dummy, &ebx, &ecx, &edx);
413 	l2size = ecx >> 16;
414 
415 #ifdef CONFIG_X86_64
416 	c->x86_tlbsize += ((ebx >> 16) & 0xfff) + (ebx & 0xfff);
417 #else
418 	/* do processor-specific cache resizing */
419 	if (this_cpu->c_size_cache)
420 		l2size = this_cpu->c_size_cache(c, l2size);
421 
422 	/* Allow user to override all this if necessary. */
423 	if (cachesize_override != -1)
424 		l2size = cachesize_override;
425 
426 	if (l2size == 0)
427 		return;		/* Again, no L2 cache is possible */
428 #endif
429 
430 	c->x86_cache_size = l2size;
431 }
432 
433 void __cpuinit detect_ht(struct cpuinfo_x86 *c)
434 {
435 #ifdef CONFIG_X86_HT
436 	u32 eax, ebx, ecx, edx;
437 	int index_msb, core_bits;
438 	static bool printed;
439 
440 	if (!cpu_has(c, X86_FEATURE_HT))
441 		return;
442 
443 	if (cpu_has(c, X86_FEATURE_CMP_LEGACY))
444 		goto out;
445 
446 	if (cpu_has(c, X86_FEATURE_XTOPOLOGY))
447 		return;
448 
449 	cpuid(1, &eax, &ebx, &ecx, &edx);
450 
451 	smp_num_siblings = (ebx & 0xff0000) >> 16;
452 
453 	if (smp_num_siblings == 1) {
454 		printk_once(KERN_INFO "CPU0: Hyper-Threading is disabled\n");
455 		goto out;
456 	}
457 
458 	if (smp_num_siblings <= 1)
459 		goto out;
460 
461 	if (smp_num_siblings > nr_cpu_ids) {
462 		pr_warning("CPU: Unsupported number of siblings %d",
463 			   smp_num_siblings);
464 		smp_num_siblings = 1;
465 		return;
466 	}
467 
468 	index_msb = get_count_order(smp_num_siblings);
469 	c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, index_msb);
470 
471 	smp_num_siblings = smp_num_siblings / c->x86_max_cores;
472 
473 	index_msb = get_count_order(smp_num_siblings);
474 
475 	core_bits = get_count_order(c->x86_max_cores);
476 
477 	c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid, index_msb) &
478 				       ((1 << core_bits) - 1);
479 
480 out:
481 	if (!printed && (c->x86_max_cores * smp_num_siblings) > 1) {
482 		printk(KERN_INFO  "CPU: Physical Processor ID: %d\n",
483 		       c->phys_proc_id);
484 		printk(KERN_INFO  "CPU: Processor Core ID: %d\n",
485 		       c->cpu_core_id);
486 		printed = 1;
487 	}
488 #endif
489 }
490 
491 static void __cpuinit get_cpu_vendor(struct cpuinfo_x86 *c)
492 {
493 	char *v = c->x86_vendor_id;
494 	int i;
495 
496 	for (i = 0; i < X86_VENDOR_NUM; i++) {
497 		if (!cpu_devs[i])
498 			break;
499 
500 		if (!strcmp(v, cpu_devs[i]->c_ident[0]) ||
501 		    (cpu_devs[i]->c_ident[1] &&
502 		     !strcmp(v, cpu_devs[i]->c_ident[1]))) {
503 
504 			this_cpu = cpu_devs[i];
505 			c->x86_vendor = this_cpu->c_x86_vendor;
506 			return;
507 		}
508 	}
509 
510 	printk_once(KERN_ERR
511 			"CPU: vendor_id '%s' unknown, using generic init.\n" \
512 			"CPU: Your system may be unstable.\n", v);
513 
514 	c->x86_vendor = X86_VENDOR_UNKNOWN;
515 	this_cpu = &default_cpu;
516 }
517 
518 void __cpuinit cpu_detect(struct cpuinfo_x86 *c)
519 {
520 	/* Get vendor name */
521 	cpuid(0x00000000, (unsigned int *)&c->cpuid_level,
522 	      (unsigned int *)&c->x86_vendor_id[0],
523 	      (unsigned int *)&c->x86_vendor_id[8],
524 	      (unsigned int *)&c->x86_vendor_id[4]);
525 
526 	c->x86 = 4;
527 	/* Intel-defined flags: level 0x00000001 */
528 	if (c->cpuid_level >= 0x00000001) {
529 		u32 junk, tfms, cap0, misc;
530 
531 		cpuid(0x00000001, &tfms, &misc, &junk, &cap0);
532 		c->x86 = (tfms >> 8) & 0xf;
533 		c->x86_model = (tfms >> 4) & 0xf;
534 		c->x86_mask = tfms & 0xf;
535 
536 		if (c->x86 == 0xf)
537 			c->x86 += (tfms >> 20) & 0xff;
538 		if (c->x86 >= 0x6)
539 			c->x86_model += ((tfms >> 16) & 0xf) << 4;
540 
541 		if (cap0 & (1<<19)) {
542 			c->x86_clflush_size = ((misc >> 8) & 0xff) * 8;
543 			c->x86_cache_alignment = c->x86_clflush_size;
544 		}
545 	}
546 }
547 
548 static void __cpuinit get_cpu_cap(struct cpuinfo_x86 *c)
549 {
550 	u32 tfms, xlvl;
551 	u32 ebx;
552 
553 	/* Intel-defined flags: level 0x00000001 */
554 	if (c->cpuid_level >= 0x00000001) {
555 		u32 capability, excap;
556 
557 		cpuid(0x00000001, &tfms, &ebx, &excap, &capability);
558 		c->x86_capability[0] = capability;
559 		c->x86_capability[4] = excap;
560 	}
561 
562 	/* Additional Intel-defined flags: level 0x00000007 */
563 	if (c->cpuid_level >= 0x00000007) {
564 		u32 eax, ebx, ecx, edx;
565 
566 		cpuid_count(0x00000007, 0, &eax, &ebx, &ecx, &edx);
567 
568 		if (eax > 0)
569 			c->x86_capability[9] = ebx;
570 	}
571 
572 	/* AMD-defined flags: level 0x80000001 */
573 	xlvl = cpuid_eax(0x80000000);
574 	c->extended_cpuid_level = xlvl;
575 
576 	if ((xlvl & 0xffff0000) == 0x80000000) {
577 		if (xlvl >= 0x80000001) {
578 			c->x86_capability[1] = cpuid_edx(0x80000001);
579 			c->x86_capability[6] = cpuid_ecx(0x80000001);
580 		}
581 	}
582 
583 	if (c->extended_cpuid_level >= 0x80000008) {
584 		u32 eax = cpuid_eax(0x80000008);
585 
586 		c->x86_virt_bits = (eax >> 8) & 0xff;
587 		c->x86_phys_bits = eax & 0xff;
588 	}
589 #ifdef CONFIG_X86_32
590 	else if (cpu_has(c, X86_FEATURE_PAE) || cpu_has(c, X86_FEATURE_PSE36))
591 		c->x86_phys_bits = 36;
592 #endif
593 
594 	if (c->extended_cpuid_level >= 0x80000007)
595 		c->x86_power = cpuid_edx(0x80000007);
596 
597 	init_scattered_cpuid_features(c);
598 }
599 
600 static void __cpuinit identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
601 {
602 #ifdef CONFIG_X86_32
603 	int i;
604 
605 	/*
606 	 * First of all, decide if this is a 486 or higher
607 	 * It's a 486 if we can modify the AC flag
608 	 */
609 	if (flag_is_changeable_p(X86_EFLAGS_AC))
610 		c->x86 = 4;
611 	else
612 		c->x86 = 3;
613 
614 	for (i = 0; i < X86_VENDOR_NUM; i++)
615 		if (cpu_devs[i] && cpu_devs[i]->c_identify) {
616 			c->x86_vendor_id[0] = 0;
617 			cpu_devs[i]->c_identify(c);
618 			if (c->x86_vendor_id[0]) {
619 				get_cpu_vendor(c);
620 				break;
621 			}
622 		}
623 #endif
624 }
625 
626 /*
627  * Do minimum CPU detection early.
628  * Fields really needed: vendor, cpuid_level, family, model, mask,
629  * cache alignment.
630  * The others are not touched to avoid unwanted side effects.
631  *
632  * WARNING: this function is only called on the BP.  Don't add code here
633  * that is supposed to run on all CPUs.
634  */
635 static void __init early_identify_cpu(struct cpuinfo_x86 *c)
636 {
637 #ifdef CONFIG_X86_64
638 	c->x86_clflush_size = 64;
639 	c->x86_phys_bits = 36;
640 	c->x86_virt_bits = 48;
641 #else
642 	c->x86_clflush_size = 32;
643 	c->x86_phys_bits = 32;
644 	c->x86_virt_bits = 32;
645 #endif
646 	c->x86_cache_alignment = c->x86_clflush_size;
647 
648 	memset(&c->x86_capability, 0, sizeof c->x86_capability);
649 	c->extended_cpuid_level = 0;
650 
651 	if (!have_cpuid_p())
652 		identify_cpu_without_cpuid(c);
653 
654 	/* cyrix could have cpuid enabled via c_identify()*/
655 	if (!have_cpuid_p())
656 		return;
657 
658 	cpu_detect(c);
659 
660 	get_cpu_vendor(c);
661 
662 	get_cpu_cap(c);
663 
664 	if (this_cpu->c_early_init)
665 		this_cpu->c_early_init(c);
666 
667 #ifdef CONFIG_SMP
668 	c->cpu_index = boot_cpu_id;
669 #endif
670 	filter_cpuid_features(c, false);
671 }
672 
673 void __init early_cpu_init(void)
674 {
675 	const struct cpu_dev *const *cdev;
676 	int count = 0;
677 
678 #ifdef PROCESSOR_SELECT
679 	printk(KERN_INFO "KERNEL supported cpus:\n");
680 #endif
681 
682 	for (cdev = __x86_cpu_dev_start; cdev < __x86_cpu_dev_end; cdev++) {
683 		const struct cpu_dev *cpudev = *cdev;
684 
685 		if (count >= X86_VENDOR_NUM)
686 			break;
687 		cpu_devs[count] = cpudev;
688 		count++;
689 
690 #ifdef PROCESSOR_SELECT
691 		{
692 			unsigned int j;
693 
694 			for (j = 0; j < 2; j++) {
695 				if (!cpudev->c_ident[j])
696 					continue;
697 				printk(KERN_INFO "  %s %s\n", cpudev->c_vendor,
698 					cpudev->c_ident[j]);
699 			}
700 		}
701 #endif
702 	}
703 	early_identify_cpu(&boot_cpu_data);
704 }
705 
706 /*
707  * The NOPL instruction is supposed to exist on all CPUs with
708  * family >= 6; unfortunately, that's not true in practice because
709  * of early VIA chips and (more importantly) broken virtualizers that
710  * are not easy to detect.  In the latter case it doesn't even *fail*
711  * reliably, so probing for it doesn't even work.  Disable it completely
712  * unless we can find a reliable way to detect all the broken cases.
713  */
714 static void __cpuinit detect_nopl(struct cpuinfo_x86 *c)
715 {
716 	clear_cpu_cap(c, X86_FEATURE_NOPL);
717 }
718 
719 static void __cpuinit generic_identify(struct cpuinfo_x86 *c)
720 {
721 	c->extended_cpuid_level = 0;
722 
723 	if (!have_cpuid_p())
724 		identify_cpu_without_cpuid(c);
725 
726 	/* cyrix could have cpuid enabled via c_identify()*/
727 	if (!have_cpuid_p())
728 		return;
729 
730 	cpu_detect(c);
731 
732 	get_cpu_vendor(c);
733 
734 	get_cpu_cap(c);
735 
736 	if (c->cpuid_level >= 0x00000001) {
737 		c->initial_apicid = (cpuid_ebx(1) >> 24) & 0xFF;
738 #ifdef CONFIG_X86_32
739 # ifdef CONFIG_X86_HT
740 		c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
741 # else
742 		c->apicid = c->initial_apicid;
743 # endif
744 #endif
745 
746 #ifdef CONFIG_X86_HT
747 		c->phys_proc_id = c->initial_apicid;
748 #endif
749 	}
750 
751 	get_model_name(c); /* Default name */
752 
753 	detect_nopl(c);
754 }
755 
756 /*
757  * This does the hard work of actually picking apart the CPU stuff...
758  */
759 static void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
760 {
761 	int i;
762 
763 	c->loops_per_jiffy = loops_per_jiffy;
764 	c->x86_cache_size = -1;
765 	c->x86_vendor = X86_VENDOR_UNKNOWN;
766 	c->x86_model = c->x86_mask = 0;	/* So far unknown... */
767 	c->x86_vendor_id[0] = '\0'; /* Unset */
768 	c->x86_model_id[0] = '\0';  /* Unset */
769 	c->x86_max_cores = 1;
770 	c->x86_coreid_bits = 0;
771 #ifdef CONFIG_X86_64
772 	c->x86_clflush_size = 64;
773 	c->x86_phys_bits = 36;
774 	c->x86_virt_bits = 48;
775 #else
776 	c->cpuid_level = -1;	/* CPUID not detected */
777 	c->x86_clflush_size = 32;
778 	c->x86_phys_bits = 32;
779 	c->x86_virt_bits = 32;
780 #endif
781 	c->x86_cache_alignment = c->x86_clflush_size;
782 	memset(&c->x86_capability, 0, sizeof c->x86_capability);
783 
784 	generic_identify(c);
785 
786 	if (this_cpu->c_identify)
787 		this_cpu->c_identify(c);
788 
789 	/* Clear/Set all flags overriden by options, after probe */
790 	for (i = 0; i < NCAPINTS; i++) {
791 		c->x86_capability[i] &= ~cpu_caps_cleared[i];
792 		c->x86_capability[i] |= cpu_caps_set[i];
793 	}
794 
795 #ifdef CONFIG_X86_64
796 	c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
797 #endif
798 
799 	/*
800 	 * Vendor-specific initialization.  In this section we
801 	 * canonicalize the feature flags, meaning if there are
802 	 * features a certain CPU supports which CPUID doesn't
803 	 * tell us, CPUID claiming incorrect flags, or other bugs,
804 	 * we handle them here.
805 	 *
806 	 * At the end of this section, c->x86_capability better
807 	 * indicate the features this CPU genuinely supports!
808 	 */
809 	if (this_cpu->c_init)
810 		this_cpu->c_init(c);
811 
812 	/* Disable the PN if appropriate */
813 	squash_the_stupid_serial_number(c);
814 
815 	/*
816 	 * The vendor-specific functions might have changed features.
817 	 * Now we do "generic changes."
818 	 */
819 
820 	/* Filter out anything that depends on CPUID levels we don't have */
821 	filter_cpuid_features(c, true);
822 
823 	/* If the model name is still unset, do table lookup. */
824 	if (!c->x86_model_id[0]) {
825 		const char *p;
826 		p = table_lookup_model(c);
827 		if (p)
828 			strcpy(c->x86_model_id, p);
829 		else
830 			/* Last resort... */
831 			sprintf(c->x86_model_id, "%02x/%02x",
832 				c->x86, c->x86_model);
833 	}
834 
835 #ifdef CONFIG_X86_64
836 	detect_ht(c);
837 #endif
838 
839 	init_hypervisor(c);
840 
841 	/*
842 	 * Clear/Set all flags overriden by options, need do it
843 	 * before following smp all cpus cap AND.
844 	 */
845 	for (i = 0; i < NCAPINTS; i++) {
846 		c->x86_capability[i] &= ~cpu_caps_cleared[i];
847 		c->x86_capability[i] |= cpu_caps_set[i];
848 	}
849 
850 	/*
851 	 * On SMP, boot_cpu_data holds the common feature set between
852 	 * all CPUs; so make sure that we indicate which features are
853 	 * common between the CPUs.  The first time this routine gets
854 	 * executed, c == &boot_cpu_data.
855 	 */
856 	if (c != &boot_cpu_data) {
857 		/* AND the already accumulated flags with these */
858 		for (i = 0; i < NCAPINTS; i++)
859 			boot_cpu_data.x86_capability[i] &= c->x86_capability[i];
860 	}
861 
862 	/* Init Machine Check Exception if available. */
863 	mcheck_cpu_init(c);
864 
865 	select_idle_routine(c);
866 
867 #if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
868 	numa_add_cpu(smp_processor_id());
869 #endif
870 }
871 
872 #ifdef CONFIG_X86_64
873 static void vgetcpu_set_mode(void)
874 {
875 	if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP))
876 		vgetcpu_mode = VGETCPU_RDTSCP;
877 	else
878 		vgetcpu_mode = VGETCPU_LSL;
879 }
880 #endif
881 
882 void __init identify_boot_cpu(void)
883 {
884 	identify_cpu(&boot_cpu_data);
885 	init_c1e_mask();
886 #ifdef CONFIG_X86_32
887 	sysenter_setup();
888 	enable_sep_cpu();
889 #else
890 	vgetcpu_set_mode();
891 #endif
892 	init_hw_perf_events();
893 }
894 
895 void __cpuinit identify_secondary_cpu(struct cpuinfo_x86 *c)
896 {
897 	BUG_ON(c == &boot_cpu_data);
898 	identify_cpu(c);
899 #ifdef CONFIG_X86_32
900 	enable_sep_cpu();
901 #endif
902 	mtrr_ap_init();
903 }
904 
905 struct msr_range {
906 	unsigned	min;
907 	unsigned	max;
908 };
909 
910 static const struct msr_range msr_range_array[] __cpuinitconst = {
911 	{ 0x00000000, 0x00000418},
912 	{ 0xc0000000, 0xc000040b},
913 	{ 0xc0010000, 0xc0010142},
914 	{ 0xc0011000, 0xc001103b},
915 };
916 
917 static void __cpuinit print_cpu_msr(void)
918 {
919 	unsigned index_min, index_max;
920 	unsigned index;
921 	u64 val;
922 	int i;
923 
924 	for (i = 0; i < ARRAY_SIZE(msr_range_array); i++) {
925 		index_min = msr_range_array[i].min;
926 		index_max = msr_range_array[i].max;
927 
928 		for (index = index_min; index < index_max; index++) {
929 			if (rdmsrl_amd_safe(index, &val))
930 				continue;
931 			printk(KERN_INFO " MSR%08x: %016llx\n", index, val);
932 		}
933 	}
934 }
935 
936 static int show_msr __cpuinitdata;
937 
938 static __init int setup_show_msr(char *arg)
939 {
940 	int num;
941 
942 	get_option(&arg, &num);
943 
944 	if (num > 0)
945 		show_msr = num;
946 	return 1;
947 }
948 __setup("show_msr=", setup_show_msr);
949 
950 static __init int setup_noclflush(char *arg)
951 {
952 	setup_clear_cpu_cap(X86_FEATURE_CLFLSH);
953 	return 1;
954 }
955 __setup("noclflush", setup_noclflush);
956 
957 void __cpuinit print_cpu_info(struct cpuinfo_x86 *c)
958 {
959 	const char *vendor = NULL;
960 
961 	if (c->x86_vendor < X86_VENDOR_NUM) {
962 		vendor = this_cpu->c_vendor;
963 	} else {
964 		if (c->cpuid_level >= 0)
965 			vendor = c->x86_vendor_id;
966 	}
967 
968 	if (vendor && !strstr(c->x86_model_id, vendor))
969 		printk(KERN_CONT "%s ", vendor);
970 
971 	if (c->x86_model_id[0])
972 		printk(KERN_CONT "%s", c->x86_model_id);
973 	else
974 		printk(KERN_CONT "%d86", c->x86);
975 
976 	if (c->x86_mask || c->cpuid_level >= 0)
977 		printk(KERN_CONT " stepping %02x\n", c->x86_mask);
978 	else
979 		printk(KERN_CONT "\n");
980 
981 #ifdef CONFIG_SMP
982 	if (c->cpu_index < show_msr)
983 		print_cpu_msr();
984 #else
985 	if (show_msr)
986 		print_cpu_msr();
987 #endif
988 }
989 
990 static __init int setup_disablecpuid(char *arg)
991 {
992 	int bit;
993 
994 	if (get_option(&arg, &bit) && bit < NCAPINTS*32)
995 		setup_clear_cpu_cap(bit);
996 	else
997 		return 0;
998 
999 	return 1;
1000 }
1001 __setup("clearcpuid=", setup_disablecpuid);
1002 
1003 #ifdef CONFIG_X86_64
1004 struct desc_ptr idt_descr = { NR_VECTORS * 16 - 1, (unsigned long) idt_table };
1005 
1006 DEFINE_PER_CPU_FIRST(union irq_stack_union,
1007 		     irq_stack_union) __aligned(PAGE_SIZE);
1008 
1009 /*
1010  * The following four percpu variables are hot.  Align current_task to
1011  * cacheline size such that all four fall in the same cacheline.
1012  */
1013 DEFINE_PER_CPU(struct task_struct *, current_task) ____cacheline_aligned =
1014 	&init_task;
1015 EXPORT_PER_CPU_SYMBOL(current_task);
1016 
1017 DEFINE_PER_CPU(unsigned long, kernel_stack) =
1018 	(unsigned long)&init_thread_union - KERNEL_STACK_OFFSET + THREAD_SIZE;
1019 EXPORT_PER_CPU_SYMBOL(kernel_stack);
1020 
1021 DEFINE_PER_CPU(char *, irq_stack_ptr) =
1022 	init_per_cpu_var(irq_stack_union.irq_stack) + IRQ_STACK_SIZE - 64;
1023 
1024 DEFINE_PER_CPU(unsigned int, irq_count) = -1;
1025 
1026 /*
1027  * Special IST stacks which the CPU switches to when it calls
1028  * an IST-marked descriptor entry. Up to 7 stacks (hardware
1029  * limit), all of them are 4K, except the debug stack which
1030  * is 8K.
1031  */
1032 static const unsigned int exception_stack_sizes[N_EXCEPTION_STACKS] = {
1033 	  [0 ... N_EXCEPTION_STACKS - 1]	= EXCEPTION_STKSZ,
1034 	  [DEBUG_STACK - 1]			= DEBUG_STKSZ
1035 };
1036 
1037 static DEFINE_PER_CPU_PAGE_ALIGNED(char, exception_stacks
1038 	[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ]);
1039 
1040 /* May not be marked __init: used by software suspend */
1041 void syscall_init(void)
1042 {
1043 	/*
1044 	 * LSTAR and STAR live in a bit strange symbiosis.
1045 	 * They both write to the same internal register. STAR allows to
1046 	 * set CS/DS but only a 32bit target. LSTAR sets the 64bit rip.
1047 	 */
1048 	wrmsrl(MSR_STAR,  ((u64)__USER32_CS)<<48  | ((u64)__KERNEL_CS)<<32);
1049 	wrmsrl(MSR_LSTAR, system_call);
1050 	wrmsrl(MSR_CSTAR, ignore_sysret);
1051 
1052 #ifdef CONFIG_IA32_EMULATION
1053 	syscall32_cpu_init();
1054 #endif
1055 
1056 	/* Flags to clear on syscall */
1057 	wrmsrl(MSR_SYSCALL_MASK,
1058 	       X86_EFLAGS_TF|X86_EFLAGS_DF|X86_EFLAGS_IF|X86_EFLAGS_IOPL);
1059 }
1060 
1061 unsigned long kernel_eflags;
1062 
1063 /*
1064  * Copies of the original ist values from the tss are only accessed during
1065  * debugging, no special alignment required.
1066  */
1067 DEFINE_PER_CPU(struct orig_ist, orig_ist);
1068 
1069 #else	/* CONFIG_X86_64 */
1070 
1071 DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task;
1072 EXPORT_PER_CPU_SYMBOL(current_task);
1073 
1074 #ifdef CONFIG_CC_STACKPROTECTOR
1075 DEFINE_PER_CPU_ALIGNED(struct stack_canary, stack_canary);
1076 #endif
1077 
1078 /* Make sure %fs and %gs are initialized properly in idle threads */
1079 struct pt_regs * __cpuinit idle_regs(struct pt_regs *regs)
1080 {
1081 	memset(regs, 0, sizeof(struct pt_regs));
1082 	regs->fs = __KERNEL_PERCPU;
1083 	regs->gs = __KERNEL_STACK_CANARY;
1084 
1085 	return regs;
1086 }
1087 #endif	/* CONFIG_X86_64 */
1088 
1089 /*
1090  * Clear all 6 debug registers:
1091  */
1092 static void clear_all_debug_regs(void)
1093 {
1094 	int i;
1095 
1096 	for (i = 0; i < 8; i++) {
1097 		/* Ignore db4, db5 */
1098 		if ((i == 4) || (i == 5))
1099 			continue;
1100 
1101 		set_debugreg(0, i);
1102 	}
1103 }
1104 
1105 #ifdef CONFIG_KGDB
1106 /*
1107  * Restore debug regs if using kgdbwait and you have a kernel debugger
1108  * connection established.
1109  */
1110 static void dbg_restore_debug_regs(void)
1111 {
1112 	if (unlikely(kgdb_connected && arch_kgdb_ops.correct_hw_break))
1113 		arch_kgdb_ops.correct_hw_break();
1114 }
1115 #else /* ! CONFIG_KGDB */
1116 #define dbg_restore_debug_regs()
1117 #endif /* ! CONFIG_KGDB */
1118 
1119 /*
1120  * cpu_init() initializes state that is per-CPU. Some data is already
1121  * initialized (naturally) in the bootstrap process, such as the GDT
1122  * and IDT. We reload them nevertheless, this function acts as a
1123  * 'CPU state barrier', nothing should get across.
1124  * A lot of state is already set up in PDA init for 64 bit
1125  */
1126 #ifdef CONFIG_X86_64
1127 
1128 void __cpuinit cpu_init(void)
1129 {
1130 	struct orig_ist *oist;
1131 	struct task_struct *me;
1132 	struct tss_struct *t;
1133 	unsigned long v;
1134 	int cpu;
1135 	int i;
1136 
1137 	cpu = stack_smp_processor_id();
1138 	t = &per_cpu(init_tss, cpu);
1139 	oist = &per_cpu(orig_ist, cpu);
1140 
1141 #ifdef CONFIG_NUMA
1142 	if (cpu != 0 && percpu_read(numa_node) == 0 &&
1143 	    early_cpu_to_node(cpu) != NUMA_NO_NODE)
1144 		set_numa_node(early_cpu_to_node(cpu));
1145 #endif
1146 
1147 	me = current;
1148 
1149 	if (cpumask_test_and_set_cpu(cpu, cpu_initialized_mask))
1150 		panic("CPU#%d already initialized!\n", cpu);
1151 
1152 	pr_debug("Initializing CPU#%d\n", cpu);
1153 
1154 	clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1155 
1156 	/*
1157 	 * Initialize the per-CPU GDT with the boot GDT,
1158 	 * and set up the GDT descriptor:
1159 	 */
1160 
1161 	switch_to_new_gdt(cpu);
1162 	loadsegment(fs, 0);
1163 
1164 	load_idt((const struct desc_ptr *)&idt_descr);
1165 
1166 	memset(me->thread.tls_array, 0, GDT_ENTRY_TLS_ENTRIES * 8);
1167 	syscall_init();
1168 
1169 	wrmsrl(MSR_FS_BASE, 0);
1170 	wrmsrl(MSR_KERNEL_GS_BASE, 0);
1171 	barrier();
1172 
1173 	x86_configure_nx();
1174 	if (cpu != 0)
1175 		enable_x2apic();
1176 
1177 	/*
1178 	 * set up and load the per-CPU TSS
1179 	 */
1180 	if (!oist->ist[0]) {
1181 		char *estacks = per_cpu(exception_stacks, cpu);
1182 
1183 		for (v = 0; v < N_EXCEPTION_STACKS; v++) {
1184 			estacks += exception_stack_sizes[v];
1185 			oist->ist[v] = t->x86_tss.ist[v] =
1186 					(unsigned long)estacks;
1187 		}
1188 	}
1189 
1190 	t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
1191 
1192 	/*
1193 	 * <= is required because the CPU will access up to
1194 	 * 8 bits beyond the end of the IO permission bitmap.
1195 	 */
1196 	for (i = 0; i <= IO_BITMAP_LONGS; i++)
1197 		t->io_bitmap[i] = ~0UL;
1198 
1199 	atomic_inc(&init_mm.mm_count);
1200 	me->active_mm = &init_mm;
1201 	BUG_ON(me->mm);
1202 	enter_lazy_tlb(&init_mm, me);
1203 
1204 	load_sp0(t, &current->thread);
1205 	set_tss_desc(cpu, t);
1206 	load_TR_desc();
1207 	load_LDT(&init_mm.context);
1208 
1209 	clear_all_debug_regs();
1210 	dbg_restore_debug_regs();
1211 
1212 	fpu_init();
1213 	xsave_init();
1214 
1215 	raw_local_save_flags(kernel_eflags);
1216 
1217 	if (is_uv_system())
1218 		uv_cpu_init();
1219 }
1220 
1221 #else
1222 
1223 void __cpuinit cpu_init(void)
1224 {
1225 	int cpu = smp_processor_id();
1226 	struct task_struct *curr = current;
1227 	struct tss_struct *t = &per_cpu(init_tss, cpu);
1228 	struct thread_struct *thread = &curr->thread;
1229 
1230 	if (cpumask_test_and_set_cpu(cpu, cpu_initialized_mask)) {
1231 		printk(KERN_WARNING "CPU#%d already initialized!\n", cpu);
1232 		for (;;)
1233 			local_irq_enable();
1234 	}
1235 
1236 	printk(KERN_INFO "Initializing CPU#%d\n", cpu);
1237 
1238 	if (cpu_has_vme || cpu_has_tsc || cpu_has_de)
1239 		clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1240 
1241 	load_idt(&idt_descr);
1242 	switch_to_new_gdt(cpu);
1243 
1244 	/*
1245 	 * Set up and load the per-CPU TSS and LDT
1246 	 */
1247 	atomic_inc(&init_mm.mm_count);
1248 	curr->active_mm = &init_mm;
1249 	BUG_ON(curr->mm);
1250 	enter_lazy_tlb(&init_mm, curr);
1251 
1252 	load_sp0(t, thread);
1253 	set_tss_desc(cpu, t);
1254 	load_TR_desc();
1255 	load_LDT(&init_mm.context);
1256 
1257 	t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
1258 
1259 #ifdef CONFIG_DOUBLEFAULT
1260 	/* Set up doublefault TSS pointer in the GDT */
1261 	__set_tss_desc(cpu, GDT_ENTRY_DOUBLEFAULT_TSS, &doublefault_tss);
1262 #endif
1263 
1264 	clear_all_debug_regs();
1265 	dbg_restore_debug_regs();
1266 
1267 	/*
1268 	 * Force FPU initialization:
1269 	 */
1270 	current_thread_info()->status = 0;
1271 	clear_used_math();
1272 	mxcsr_feature_mask_init();
1273 
1274 	fpu_init();
1275 	xsave_init();
1276 }
1277 #endif
1278