xref: /linux/arch/x86/kernel/cpu/common.c (revision ee665ecca6d6775f65b1a4154c34f551f62cec52)
1 #include <linux/init.h>
2 #include <linux/kernel.h>
3 #include <linux/sched.h>
4 #include <linux/string.h>
5 #include <linux/bootmem.h>
6 #include <linux/bitops.h>
7 #include <linux/module.h>
8 #include <linux/kgdb.h>
9 #include <linux/topology.h>
10 #include <linux/delay.h>
11 #include <linux/smp.h>
12 #include <linux/percpu.h>
13 #include <asm/i387.h>
14 #include <asm/msr.h>
15 #include <asm/io.h>
16 #include <asm/linkage.h>
17 #include <asm/mmu_context.h>
18 #include <asm/mtrr.h>
19 #include <asm/mce.h>
20 #include <asm/pat.h>
21 #include <asm/asm.h>
22 #include <asm/numa.h>
23 #include <asm/smp.h>
24 #include <asm/cpu.h>
25 #include <asm/cpumask.h>
26 #include <asm/apic.h>
27 
28 #ifdef CONFIG_X86_LOCAL_APIC
29 #include <asm/uv/uv.h>
30 #endif
31 
32 #include <asm/pgtable.h>
33 #include <asm/processor.h>
34 #include <asm/desc.h>
35 #include <asm/atomic.h>
36 #include <asm/proto.h>
37 #include <asm/sections.h>
38 #include <asm/setup.h>
39 #include <asm/hypervisor.h>
40 #include <asm/stackprotector.h>
41 
42 #include "cpu.h"
43 
44 #ifdef CONFIG_X86_64
45 
46 /* all of these masks are initialized in setup_cpu_local_masks() */
47 cpumask_var_t cpu_callin_mask;
48 cpumask_var_t cpu_callout_mask;
49 cpumask_var_t cpu_initialized_mask;
50 
51 /* representing cpus for which sibling maps can be computed */
52 cpumask_var_t cpu_sibling_setup_mask;
53 
54 /* correctly size the local cpu masks */
55 void __init setup_cpu_local_masks(void)
56 {
57 	alloc_bootmem_cpumask_var(&cpu_initialized_mask);
58 	alloc_bootmem_cpumask_var(&cpu_callin_mask);
59 	alloc_bootmem_cpumask_var(&cpu_callout_mask);
60 	alloc_bootmem_cpumask_var(&cpu_sibling_setup_mask);
61 }
62 
63 #else /* CONFIG_X86_32 */
64 
65 cpumask_t cpu_callin_map;
66 cpumask_t cpu_callout_map;
67 cpumask_t cpu_initialized;
68 cpumask_t cpu_sibling_setup_map;
69 
70 #endif /* CONFIG_X86_32 */
71 
72 
73 static struct cpu_dev *this_cpu __cpuinitdata;
74 
75 DEFINE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page) = { .gdt = {
76 #ifdef CONFIG_X86_64
77 	/*
78 	 * We need valid kernel segments for data and code in long mode too
79 	 * IRET will check the segment types  kkeil 2000/10/28
80 	 * Also sysret mandates a special GDT layout
81 	 *
82 	 * The TLS descriptors are currently at a different place compared to i386.
83 	 * Hopefully nobody expects them at a fixed place (Wine?)
84 	 */
85 	[GDT_ENTRY_KERNEL32_CS] = { { { 0x0000ffff, 0x00cf9b00 } } },
86 	[GDT_ENTRY_KERNEL_CS] = { { { 0x0000ffff, 0x00af9b00 } } },
87 	[GDT_ENTRY_KERNEL_DS] = { { { 0x0000ffff, 0x00cf9300 } } },
88 	[GDT_ENTRY_DEFAULT_USER32_CS] = { { { 0x0000ffff, 0x00cffb00 } } },
89 	[GDT_ENTRY_DEFAULT_USER_DS] = { { { 0x0000ffff, 0x00cff300 } } },
90 	[GDT_ENTRY_DEFAULT_USER_CS] = { { { 0x0000ffff, 0x00affb00 } } },
91 #else
92 	[GDT_ENTRY_KERNEL_CS] = { { { 0x0000ffff, 0x00cf9a00 } } },
93 	[GDT_ENTRY_KERNEL_DS] = { { { 0x0000ffff, 0x00cf9200 } } },
94 	[GDT_ENTRY_DEFAULT_USER_CS] = { { { 0x0000ffff, 0x00cffa00 } } },
95 	[GDT_ENTRY_DEFAULT_USER_DS] = { { { 0x0000ffff, 0x00cff200 } } },
96 	/*
97 	 * Segments used for calling PnP BIOS have byte granularity.
98 	 * They code segments and data segments have fixed 64k limits,
99 	 * the transfer segment sizes are set at run time.
100 	 */
101 	/* 32-bit code */
102 	[GDT_ENTRY_PNPBIOS_CS32] = { { { 0x0000ffff, 0x00409a00 } } },
103 	/* 16-bit code */
104 	[GDT_ENTRY_PNPBIOS_CS16] = { { { 0x0000ffff, 0x00009a00 } } },
105 	/* 16-bit data */
106 	[GDT_ENTRY_PNPBIOS_DS] = { { { 0x0000ffff, 0x00009200 } } },
107 	/* 16-bit data */
108 	[GDT_ENTRY_PNPBIOS_TS1] = { { { 0x00000000, 0x00009200 } } },
109 	/* 16-bit data */
110 	[GDT_ENTRY_PNPBIOS_TS2] = { { { 0x00000000, 0x00009200 } } },
111 	/*
112 	 * The APM segments have byte granularity and their bases
113 	 * are set at run time.  All have 64k limits.
114 	 */
115 	/* 32-bit code */
116 	[GDT_ENTRY_APMBIOS_BASE] = { { { 0x0000ffff, 0x00409a00 } } },
117 	/* 16-bit code */
118 	[GDT_ENTRY_APMBIOS_BASE+1] = { { { 0x0000ffff, 0x00009a00 } } },
119 	/* data */
120 	[GDT_ENTRY_APMBIOS_BASE+2] = { { { 0x0000ffff, 0x00409200 } } },
121 
122 	[GDT_ENTRY_ESPFIX_SS] = { { { 0x00000000, 0x00c09200 } } },
123 	[GDT_ENTRY_PERCPU] = { { { 0x0000ffff, 0x00cf9200 } } },
124 	GDT_STACK_CANARY_INIT
125 #endif
126 } };
127 EXPORT_PER_CPU_SYMBOL_GPL(gdt_page);
128 
129 #ifdef CONFIG_X86_32
130 static int cachesize_override __cpuinitdata = -1;
131 static int disable_x86_serial_nr __cpuinitdata = 1;
132 
133 static int __init cachesize_setup(char *str)
134 {
135 	get_option(&str, &cachesize_override);
136 	return 1;
137 }
138 __setup("cachesize=", cachesize_setup);
139 
140 static int __init x86_fxsr_setup(char *s)
141 {
142 	setup_clear_cpu_cap(X86_FEATURE_FXSR);
143 	setup_clear_cpu_cap(X86_FEATURE_XMM);
144 	return 1;
145 }
146 __setup("nofxsr", x86_fxsr_setup);
147 
148 static int __init x86_sep_setup(char *s)
149 {
150 	setup_clear_cpu_cap(X86_FEATURE_SEP);
151 	return 1;
152 }
153 __setup("nosep", x86_sep_setup);
154 
155 /* Standard macro to see if a specific flag is changeable */
156 static inline int flag_is_changeable_p(u32 flag)
157 {
158 	u32 f1, f2;
159 
160 	/*
161 	 * Cyrix and IDT cpus allow disabling of CPUID
162 	 * so the code below may return different results
163 	 * when it is executed before and after enabling
164 	 * the CPUID. Add "volatile" to not allow gcc to
165 	 * optimize the subsequent calls to this function.
166 	 */
167 	asm volatile ("pushfl\n\t"
168 		      "pushfl\n\t"
169 		      "popl %0\n\t"
170 		      "movl %0,%1\n\t"
171 		      "xorl %2,%0\n\t"
172 		      "pushl %0\n\t"
173 		      "popfl\n\t"
174 		      "pushfl\n\t"
175 		      "popl %0\n\t"
176 		      "popfl\n\t"
177 		      : "=&r" (f1), "=&r" (f2)
178 		      : "ir" (flag));
179 
180 	return ((f1^f2) & flag) != 0;
181 }
182 
183 /* Probe for the CPUID instruction */
184 static int __cpuinit have_cpuid_p(void)
185 {
186 	return flag_is_changeable_p(X86_EFLAGS_ID);
187 }
188 
189 static void __cpuinit squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
190 {
191 	if (cpu_has(c, X86_FEATURE_PN) && disable_x86_serial_nr) {
192 		/* Disable processor serial number */
193 		unsigned long lo, hi;
194 		rdmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
195 		lo |= 0x200000;
196 		wrmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
197 		printk(KERN_NOTICE "CPU serial number disabled.\n");
198 		clear_cpu_cap(c, X86_FEATURE_PN);
199 
200 		/* Disabling the serial number may affect the cpuid level */
201 		c->cpuid_level = cpuid_eax(0);
202 	}
203 }
204 
205 static int __init x86_serial_nr_setup(char *s)
206 {
207 	disable_x86_serial_nr = 0;
208 	return 1;
209 }
210 __setup("serialnumber", x86_serial_nr_setup);
211 #else
212 static inline int flag_is_changeable_p(u32 flag)
213 {
214 	return 1;
215 }
216 /* Probe for the CPUID instruction */
217 static inline int have_cpuid_p(void)
218 {
219 	return 1;
220 }
221 static inline void squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
222 {
223 }
224 #endif
225 
226 /*
227  * Some CPU features depend on higher CPUID levels, which may not always
228  * be available due to CPUID level capping or broken virtualization
229  * software.  Add those features to this table to auto-disable them.
230  */
231 struct cpuid_dependent_feature {
232 	u32 feature;
233 	u32 level;
234 };
235 static const struct cpuid_dependent_feature __cpuinitconst
236 cpuid_dependent_features[] = {
237 	{ X86_FEATURE_MWAIT,		0x00000005 },
238 	{ X86_FEATURE_DCA,		0x00000009 },
239 	{ X86_FEATURE_XSAVE,		0x0000000d },
240 	{ 0, 0 }
241 };
242 
243 static void __cpuinit filter_cpuid_features(struct cpuinfo_x86 *c, bool warn)
244 {
245 	const struct cpuid_dependent_feature *df;
246 	for (df = cpuid_dependent_features; df->feature; df++) {
247 		/*
248 		 * Note: cpuid_level is set to -1 if unavailable, but
249 		 * extended_extended_level is set to 0 if unavailable
250 		 * and the legitimate extended levels are all negative
251 		 * when signed; hence the weird messing around with
252 		 * signs here...
253 		 */
254 		if (cpu_has(c, df->feature) &&
255 		    ((s32)df->level < 0 ?
256 		     (u32)df->level > (u32)c->extended_cpuid_level :
257 		     (s32)df->level > (s32)c->cpuid_level)) {
258 			clear_cpu_cap(c, df->feature);
259 			if (warn)
260 				printk(KERN_WARNING
261 				       "CPU: CPU feature %s disabled "
262 				       "due to lack of CPUID level 0x%x\n",
263 				       x86_cap_flags[df->feature],
264 				       df->level);
265 		}
266 	}
267 }
268 
269 /*
270  * Naming convention should be: <Name> [(<Codename>)]
271  * This table only is used unless init_<vendor>() below doesn't set it;
272  * in particular, if CPUID levels 0x80000002..4 are supported, this isn't used
273  *
274  */
275 
276 /* Look up CPU names by table lookup. */
277 static char __cpuinit *table_lookup_model(struct cpuinfo_x86 *c)
278 {
279 	struct cpu_model_info *info;
280 
281 	if (c->x86_model >= 16)
282 		return NULL;	/* Range check */
283 
284 	if (!this_cpu)
285 		return NULL;
286 
287 	info = this_cpu->c_models;
288 
289 	while (info && info->family) {
290 		if (info->family == c->x86)
291 			return info->model_names[c->x86_model];
292 		info++;
293 	}
294 	return NULL;		/* Not found */
295 }
296 
297 __u32 cleared_cpu_caps[NCAPINTS] __cpuinitdata;
298 
299 void load_percpu_segment(int cpu)
300 {
301 #ifdef CONFIG_X86_32
302 	loadsegment(fs, __KERNEL_PERCPU);
303 #else
304 	loadsegment(gs, 0);
305 	wrmsrl(MSR_GS_BASE, (unsigned long)per_cpu(irq_stack_union.gs_base, cpu));
306 #endif
307 	load_stack_canary_segment();
308 }
309 
310 /* Current gdt points %fs at the "master" per-cpu area: after this,
311  * it's on the real one. */
312 void switch_to_new_gdt(int cpu)
313 {
314 	struct desc_ptr gdt_descr;
315 
316 	gdt_descr.address = (long)get_cpu_gdt_table(cpu);
317 	gdt_descr.size = GDT_SIZE - 1;
318 	load_gdt(&gdt_descr);
319 	/* Reload the per-cpu base */
320 
321 	load_percpu_segment(cpu);
322 }
323 
324 static struct cpu_dev *cpu_devs[X86_VENDOR_NUM] = {};
325 
326 static void __cpuinit default_init(struct cpuinfo_x86 *c)
327 {
328 #ifdef CONFIG_X86_64
329 	display_cacheinfo(c);
330 #else
331 	/* Not much we can do here... */
332 	/* Check if at least it has cpuid */
333 	if (c->cpuid_level == -1) {
334 		/* No cpuid. It must be an ancient CPU */
335 		if (c->x86 == 4)
336 			strcpy(c->x86_model_id, "486");
337 		else if (c->x86 == 3)
338 			strcpy(c->x86_model_id, "386");
339 	}
340 #endif
341 }
342 
343 static struct cpu_dev __cpuinitdata default_cpu = {
344 	.c_init	= default_init,
345 	.c_vendor = "Unknown",
346 	.c_x86_vendor = X86_VENDOR_UNKNOWN,
347 };
348 
349 static void __cpuinit get_model_name(struct cpuinfo_x86 *c)
350 {
351 	unsigned int *v;
352 	char *p, *q;
353 
354 	if (c->extended_cpuid_level < 0x80000004)
355 		return;
356 
357 	v = (unsigned int *) c->x86_model_id;
358 	cpuid(0x80000002, &v[0], &v[1], &v[2], &v[3]);
359 	cpuid(0x80000003, &v[4], &v[5], &v[6], &v[7]);
360 	cpuid(0x80000004, &v[8], &v[9], &v[10], &v[11]);
361 	c->x86_model_id[48] = 0;
362 
363 	/* Intel chips right-justify this string for some dumb reason;
364 	   undo that brain damage */
365 	p = q = &c->x86_model_id[0];
366 	while (*p == ' ')
367 	     p++;
368 	if (p != q) {
369 	     while (*p)
370 		  *q++ = *p++;
371 	     while (q <= &c->x86_model_id[48])
372 		  *q++ = '\0';	/* Zero-pad the rest */
373 	}
374 }
375 
376 void __cpuinit display_cacheinfo(struct cpuinfo_x86 *c)
377 {
378 	unsigned int n, dummy, ebx, ecx, edx, l2size;
379 
380 	n = c->extended_cpuid_level;
381 
382 	if (n >= 0x80000005) {
383 		cpuid(0x80000005, &dummy, &ebx, &ecx, &edx);
384 		printk(KERN_INFO "CPU: L1 I Cache: %dK (%d bytes/line), D cache %dK (%d bytes/line)\n",
385 				edx>>24, edx&0xFF, ecx>>24, ecx&0xFF);
386 		c->x86_cache_size = (ecx>>24) + (edx>>24);
387 #ifdef CONFIG_X86_64
388 		/* On K8 L1 TLB is inclusive, so don't count it */
389 		c->x86_tlbsize = 0;
390 #endif
391 	}
392 
393 	if (n < 0x80000006)	/* Some chips just has a large L1. */
394 		return;
395 
396 	cpuid(0x80000006, &dummy, &ebx, &ecx, &edx);
397 	l2size = ecx >> 16;
398 
399 #ifdef CONFIG_X86_64
400 	c->x86_tlbsize += ((ebx >> 16) & 0xfff) + (ebx & 0xfff);
401 #else
402 	/* do processor-specific cache resizing */
403 	if (this_cpu->c_size_cache)
404 		l2size = this_cpu->c_size_cache(c, l2size);
405 
406 	/* Allow user to override all this if necessary. */
407 	if (cachesize_override != -1)
408 		l2size = cachesize_override;
409 
410 	if (l2size == 0)
411 		return;		/* Again, no L2 cache is possible */
412 #endif
413 
414 	c->x86_cache_size = l2size;
415 
416 	printk(KERN_INFO "CPU: L2 Cache: %dK (%d bytes/line)\n",
417 			l2size, ecx & 0xFF);
418 }
419 
420 void __cpuinit detect_ht(struct cpuinfo_x86 *c)
421 {
422 #ifdef CONFIG_X86_HT
423 	u32 eax, ebx, ecx, edx;
424 	int index_msb, core_bits;
425 
426 	if (!cpu_has(c, X86_FEATURE_HT))
427 		return;
428 
429 	if (cpu_has(c, X86_FEATURE_CMP_LEGACY))
430 		goto out;
431 
432 	if (cpu_has(c, X86_FEATURE_XTOPOLOGY))
433 		return;
434 
435 	cpuid(1, &eax, &ebx, &ecx, &edx);
436 
437 	smp_num_siblings = (ebx & 0xff0000) >> 16;
438 
439 	if (smp_num_siblings == 1) {
440 		printk(KERN_INFO  "CPU: Hyper-Threading is disabled\n");
441 	} else if (smp_num_siblings > 1) {
442 
443 		if (smp_num_siblings > nr_cpu_ids) {
444 			printk(KERN_WARNING "CPU: Unsupported number of siblings %d",
445 					smp_num_siblings);
446 			smp_num_siblings = 1;
447 			return;
448 		}
449 
450 		index_msb = get_count_order(smp_num_siblings);
451 		c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, index_msb);
452 
453 		smp_num_siblings = smp_num_siblings / c->x86_max_cores;
454 
455 		index_msb = get_count_order(smp_num_siblings);
456 
457 		core_bits = get_count_order(c->x86_max_cores);
458 
459 		c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid, index_msb) &
460 					       ((1 << core_bits) - 1);
461 	}
462 
463 out:
464 	if ((c->x86_max_cores * smp_num_siblings) > 1) {
465 		printk(KERN_INFO  "CPU: Physical Processor ID: %d\n",
466 		       c->phys_proc_id);
467 		printk(KERN_INFO  "CPU: Processor Core ID: %d\n",
468 		       c->cpu_core_id);
469 	}
470 #endif
471 }
472 
473 static void __cpuinit get_cpu_vendor(struct cpuinfo_x86 *c)
474 {
475 	char *v = c->x86_vendor_id;
476 	int i;
477 	static int printed;
478 
479 	for (i = 0; i < X86_VENDOR_NUM; i++) {
480 		if (!cpu_devs[i])
481 			break;
482 
483 		if (!strcmp(v, cpu_devs[i]->c_ident[0]) ||
484 		    (cpu_devs[i]->c_ident[1] &&
485 		     !strcmp(v, cpu_devs[i]->c_ident[1]))) {
486 			this_cpu = cpu_devs[i];
487 			c->x86_vendor = this_cpu->c_x86_vendor;
488 			return;
489 		}
490 	}
491 
492 	if (!printed) {
493 		printed++;
494 		printk(KERN_ERR "CPU: vendor_id '%s' unknown, using generic init.\n", v);
495 		printk(KERN_ERR "CPU: Your system may be unstable.\n");
496 	}
497 
498 	c->x86_vendor = X86_VENDOR_UNKNOWN;
499 	this_cpu = &default_cpu;
500 }
501 
502 void __cpuinit cpu_detect(struct cpuinfo_x86 *c)
503 {
504 	/* Get vendor name */
505 	cpuid(0x00000000, (unsigned int *)&c->cpuid_level,
506 	      (unsigned int *)&c->x86_vendor_id[0],
507 	      (unsigned int *)&c->x86_vendor_id[8],
508 	      (unsigned int *)&c->x86_vendor_id[4]);
509 
510 	c->x86 = 4;
511 	/* Intel-defined flags: level 0x00000001 */
512 	if (c->cpuid_level >= 0x00000001) {
513 		u32 junk, tfms, cap0, misc;
514 		cpuid(0x00000001, &tfms, &misc, &junk, &cap0);
515 		c->x86 = (tfms >> 8) & 0xf;
516 		c->x86_model = (tfms >> 4) & 0xf;
517 		c->x86_mask = tfms & 0xf;
518 		if (c->x86 == 0xf)
519 			c->x86 += (tfms >> 20) & 0xff;
520 		if (c->x86 >= 0x6)
521 			c->x86_model += ((tfms >> 16) & 0xf) << 4;
522 		if (cap0 & (1<<19)) {
523 			c->x86_clflush_size = ((misc >> 8) & 0xff) * 8;
524 			c->x86_cache_alignment = c->x86_clflush_size;
525 		}
526 	}
527 }
528 
529 static void __cpuinit get_cpu_cap(struct cpuinfo_x86 *c)
530 {
531 	u32 tfms, xlvl;
532 	u32 ebx;
533 
534 	/* Intel-defined flags: level 0x00000001 */
535 	if (c->cpuid_level >= 0x00000001) {
536 		u32 capability, excap;
537 		cpuid(0x00000001, &tfms, &ebx, &excap, &capability);
538 		c->x86_capability[0] = capability;
539 		c->x86_capability[4] = excap;
540 	}
541 
542 	/* AMD-defined flags: level 0x80000001 */
543 	xlvl = cpuid_eax(0x80000000);
544 	c->extended_cpuid_level = xlvl;
545 	if ((xlvl & 0xffff0000) == 0x80000000) {
546 		if (xlvl >= 0x80000001) {
547 			c->x86_capability[1] = cpuid_edx(0x80000001);
548 			c->x86_capability[6] = cpuid_ecx(0x80000001);
549 		}
550 	}
551 
552 #ifdef CONFIG_X86_64
553 	if (c->extended_cpuid_level >= 0x80000008) {
554 		u32 eax = cpuid_eax(0x80000008);
555 
556 		c->x86_virt_bits = (eax >> 8) & 0xff;
557 		c->x86_phys_bits = eax & 0xff;
558 	}
559 #endif
560 
561 	if (c->extended_cpuid_level >= 0x80000007)
562 		c->x86_power = cpuid_edx(0x80000007);
563 
564 }
565 
566 static void __cpuinit identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
567 {
568 #ifdef CONFIG_X86_32
569 	int i;
570 
571 	/*
572 	 * First of all, decide if this is a 486 or higher
573 	 * It's a 486 if we can modify the AC flag
574 	 */
575 	if (flag_is_changeable_p(X86_EFLAGS_AC))
576 		c->x86 = 4;
577 	else
578 		c->x86 = 3;
579 
580 	for (i = 0; i < X86_VENDOR_NUM; i++)
581 		if (cpu_devs[i] && cpu_devs[i]->c_identify) {
582 			c->x86_vendor_id[0] = 0;
583 			cpu_devs[i]->c_identify(c);
584 			if (c->x86_vendor_id[0]) {
585 				get_cpu_vendor(c);
586 				break;
587 			}
588 		}
589 #endif
590 }
591 
592 /*
593  * Do minimum CPU detection early.
594  * Fields really needed: vendor, cpuid_level, family, model, mask,
595  * cache alignment.
596  * The others are not touched to avoid unwanted side effects.
597  *
598  * WARNING: this function is only called on the BP.  Don't add code here
599  * that is supposed to run on all CPUs.
600  */
601 static void __init early_identify_cpu(struct cpuinfo_x86 *c)
602 {
603 #ifdef CONFIG_X86_64
604 	c->x86_clflush_size = 64;
605 #else
606 	c->x86_clflush_size = 32;
607 #endif
608 	c->x86_cache_alignment = c->x86_clflush_size;
609 
610 	memset(&c->x86_capability, 0, sizeof c->x86_capability);
611 	c->extended_cpuid_level = 0;
612 
613 	if (!have_cpuid_p())
614 		identify_cpu_without_cpuid(c);
615 
616 	/* cyrix could have cpuid enabled via c_identify()*/
617 	if (!have_cpuid_p())
618 		return;
619 
620 	cpu_detect(c);
621 
622 	get_cpu_vendor(c);
623 
624 	get_cpu_cap(c);
625 
626 	if (this_cpu->c_early_init)
627 		this_cpu->c_early_init(c);
628 
629 #ifdef CONFIG_SMP
630 	c->cpu_index = boot_cpu_id;
631 #endif
632 	filter_cpuid_features(c, false);
633 }
634 
635 void __init early_cpu_init(void)
636 {
637 	struct cpu_dev **cdev;
638 	int count = 0;
639 
640 	printk("KERNEL supported cpus:\n");
641 	for (cdev = __x86_cpu_dev_start; cdev < __x86_cpu_dev_end; cdev++) {
642 		struct cpu_dev *cpudev = *cdev;
643 		unsigned int j;
644 
645 		if (count >= X86_VENDOR_NUM)
646 			break;
647 		cpu_devs[count] = cpudev;
648 		count++;
649 
650 		for (j = 0; j < 2; j++) {
651 			if (!cpudev->c_ident[j])
652 				continue;
653 			printk("  %s %s\n", cpudev->c_vendor,
654 				cpudev->c_ident[j]);
655 		}
656 	}
657 
658 	early_identify_cpu(&boot_cpu_data);
659 }
660 
661 /*
662  * The NOPL instruction is supposed to exist on all CPUs with
663  * family >= 6; unfortunately, that's not true in practice because
664  * of early VIA chips and (more importantly) broken virtualizers that
665  * are not easy to detect.  In the latter case it doesn't even *fail*
666  * reliably, so probing for it doesn't even work.  Disable it completely
667  * unless we can find a reliable way to detect all the broken cases.
668  */
669 static void __cpuinit detect_nopl(struct cpuinfo_x86 *c)
670 {
671 	clear_cpu_cap(c, X86_FEATURE_NOPL);
672 }
673 
674 static void __cpuinit generic_identify(struct cpuinfo_x86 *c)
675 {
676 	c->extended_cpuid_level = 0;
677 
678 	if (!have_cpuid_p())
679 		identify_cpu_without_cpuid(c);
680 
681 	/* cyrix could have cpuid enabled via c_identify()*/
682 	if (!have_cpuid_p())
683 		return;
684 
685 	cpu_detect(c);
686 
687 	get_cpu_vendor(c);
688 
689 	get_cpu_cap(c);
690 
691 	if (c->cpuid_level >= 0x00000001) {
692 		c->initial_apicid = (cpuid_ebx(1) >> 24) & 0xFF;
693 #ifdef CONFIG_X86_32
694 # ifdef CONFIG_X86_HT
695 		c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
696 # else
697 		c->apicid = c->initial_apicid;
698 # endif
699 #endif
700 
701 #ifdef CONFIG_X86_HT
702 		c->phys_proc_id = c->initial_apicid;
703 #endif
704 	}
705 
706 	get_model_name(c); /* Default name */
707 
708 	init_scattered_cpuid_features(c);
709 	detect_nopl(c);
710 }
711 
712 /*
713  * This does the hard work of actually picking apart the CPU stuff...
714  */
715 static void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
716 {
717 	int i;
718 
719 	c->loops_per_jiffy = loops_per_jiffy;
720 	c->x86_cache_size = -1;
721 	c->x86_vendor = X86_VENDOR_UNKNOWN;
722 	c->x86_model = c->x86_mask = 0;	/* So far unknown... */
723 	c->x86_vendor_id[0] = '\0'; /* Unset */
724 	c->x86_model_id[0] = '\0';  /* Unset */
725 	c->x86_max_cores = 1;
726 	c->x86_coreid_bits = 0;
727 #ifdef CONFIG_X86_64
728 	c->x86_clflush_size = 64;
729 #else
730 	c->cpuid_level = -1;	/* CPUID not detected */
731 	c->x86_clflush_size = 32;
732 #endif
733 	c->x86_cache_alignment = c->x86_clflush_size;
734 	memset(&c->x86_capability, 0, sizeof c->x86_capability);
735 
736 	generic_identify(c);
737 
738 	if (this_cpu->c_identify)
739 		this_cpu->c_identify(c);
740 
741 #ifdef CONFIG_X86_64
742 	c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
743 #endif
744 
745 	/*
746 	 * Vendor-specific initialization.  In this section we
747 	 * canonicalize the feature flags, meaning if there are
748 	 * features a certain CPU supports which CPUID doesn't
749 	 * tell us, CPUID claiming incorrect flags, or other bugs,
750 	 * we handle them here.
751 	 *
752 	 * At the end of this section, c->x86_capability better
753 	 * indicate the features this CPU genuinely supports!
754 	 */
755 	if (this_cpu->c_init)
756 		this_cpu->c_init(c);
757 
758 	/* Disable the PN if appropriate */
759 	squash_the_stupid_serial_number(c);
760 
761 	/*
762 	 * The vendor-specific functions might have changed features.  Now
763 	 * we do "generic changes."
764 	 */
765 
766 	/* Filter out anything that depends on CPUID levels we don't have */
767 	filter_cpuid_features(c, true);
768 
769 	/* If the model name is still unset, do table lookup. */
770 	if (!c->x86_model_id[0]) {
771 		char *p;
772 		p = table_lookup_model(c);
773 		if (p)
774 			strcpy(c->x86_model_id, p);
775 		else
776 			/* Last resort... */
777 			sprintf(c->x86_model_id, "%02x/%02x",
778 				c->x86, c->x86_model);
779 	}
780 
781 #ifdef CONFIG_X86_64
782 	detect_ht(c);
783 #endif
784 
785 	init_hypervisor(c);
786 	/*
787 	 * On SMP, boot_cpu_data holds the common feature set between
788 	 * all CPUs; so make sure that we indicate which features are
789 	 * common between the CPUs.  The first time this routine gets
790 	 * executed, c == &boot_cpu_data.
791 	 */
792 	if (c != &boot_cpu_data) {
793 		/* AND the already accumulated flags with these */
794 		for (i = 0; i < NCAPINTS; i++)
795 			boot_cpu_data.x86_capability[i] &= c->x86_capability[i];
796 	}
797 
798 	/* Clear all flags overriden by options */
799 	for (i = 0; i < NCAPINTS; i++)
800 		c->x86_capability[i] &= ~cleared_cpu_caps[i];
801 
802 #ifdef CONFIG_X86_MCE
803 	/* Init Machine Check Exception if available. */
804 	mcheck_init(c);
805 #endif
806 
807 	select_idle_routine(c);
808 
809 #if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
810 	numa_add_cpu(smp_processor_id());
811 #endif
812 }
813 
814 #ifdef CONFIG_X86_64
815 static void vgetcpu_set_mode(void)
816 {
817 	if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP))
818 		vgetcpu_mode = VGETCPU_RDTSCP;
819 	else
820 		vgetcpu_mode = VGETCPU_LSL;
821 }
822 #endif
823 
824 void __init identify_boot_cpu(void)
825 {
826 	identify_cpu(&boot_cpu_data);
827 #ifdef CONFIG_X86_32
828 	sysenter_setup();
829 	enable_sep_cpu();
830 #else
831 	vgetcpu_set_mode();
832 #endif
833 }
834 
835 void __cpuinit identify_secondary_cpu(struct cpuinfo_x86 *c)
836 {
837 	BUG_ON(c == &boot_cpu_data);
838 	identify_cpu(c);
839 #ifdef CONFIG_X86_32
840 	enable_sep_cpu();
841 #endif
842 	mtrr_ap_init();
843 }
844 
845 struct msr_range {
846 	unsigned min;
847 	unsigned max;
848 };
849 
850 static struct msr_range msr_range_array[] __cpuinitdata = {
851 	{ 0x00000000, 0x00000418},
852 	{ 0xc0000000, 0xc000040b},
853 	{ 0xc0010000, 0xc0010142},
854 	{ 0xc0011000, 0xc001103b},
855 };
856 
857 static void __cpuinit print_cpu_msr(void)
858 {
859 	unsigned index;
860 	u64 val;
861 	int i;
862 	unsigned index_min, index_max;
863 
864 	for (i = 0; i < ARRAY_SIZE(msr_range_array); i++) {
865 		index_min = msr_range_array[i].min;
866 		index_max = msr_range_array[i].max;
867 		for (index = index_min; index < index_max; index++) {
868 			if (rdmsrl_amd_safe(index, &val))
869 				continue;
870 			printk(KERN_INFO " MSR%08x: %016llx\n", index, val);
871 		}
872 	}
873 }
874 
875 static int show_msr __cpuinitdata;
876 static __init int setup_show_msr(char *arg)
877 {
878 	int num;
879 
880 	get_option(&arg, &num);
881 
882 	if (num > 0)
883 		show_msr = num;
884 	return 1;
885 }
886 __setup("show_msr=", setup_show_msr);
887 
888 static __init int setup_noclflush(char *arg)
889 {
890 	setup_clear_cpu_cap(X86_FEATURE_CLFLSH);
891 	return 1;
892 }
893 __setup("noclflush", setup_noclflush);
894 
895 void __cpuinit print_cpu_info(struct cpuinfo_x86 *c)
896 {
897 	char *vendor = NULL;
898 
899 	if (c->x86_vendor < X86_VENDOR_NUM)
900 		vendor = this_cpu->c_vendor;
901 	else if (c->cpuid_level >= 0)
902 		vendor = c->x86_vendor_id;
903 
904 	if (vendor && !strstr(c->x86_model_id, vendor))
905 		printk(KERN_CONT "%s ", vendor);
906 
907 	if (c->x86_model_id[0])
908 		printk(KERN_CONT "%s", c->x86_model_id);
909 	else
910 		printk(KERN_CONT "%d86", c->x86);
911 
912 	if (c->x86_mask || c->cpuid_level >= 0)
913 		printk(KERN_CONT " stepping %02x\n", c->x86_mask);
914 	else
915 		printk(KERN_CONT "\n");
916 
917 #ifdef CONFIG_SMP
918 	if (c->cpu_index < show_msr)
919 		print_cpu_msr();
920 #else
921 	if (show_msr)
922 		print_cpu_msr();
923 #endif
924 }
925 
926 static __init int setup_disablecpuid(char *arg)
927 {
928 	int bit;
929 	if (get_option(&arg, &bit) && bit < NCAPINTS*32)
930 		setup_clear_cpu_cap(bit);
931 	else
932 		return 0;
933 	return 1;
934 }
935 __setup("clearcpuid=", setup_disablecpuid);
936 
937 #ifdef CONFIG_X86_64
938 struct desc_ptr idt_descr = { 256 * 16 - 1, (unsigned long) idt_table };
939 
940 DEFINE_PER_CPU_FIRST(union irq_stack_union,
941 		     irq_stack_union) __aligned(PAGE_SIZE);
942 DEFINE_PER_CPU(char *, irq_stack_ptr) =
943 	init_per_cpu_var(irq_stack_union.irq_stack) + IRQ_STACK_SIZE - 64;
944 
945 DEFINE_PER_CPU(unsigned long, kernel_stack) =
946 	(unsigned long)&init_thread_union - KERNEL_STACK_OFFSET + THREAD_SIZE;
947 EXPORT_PER_CPU_SYMBOL(kernel_stack);
948 
949 DEFINE_PER_CPU(unsigned int, irq_count) = -1;
950 
951 static DEFINE_PER_CPU_PAGE_ALIGNED(char, exception_stacks
952 	[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ])
953 	__aligned(PAGE_SIZE);
954 
955 extern asmlinkage void ignore_sysret(void);
956 
957 /* May not be marked __init: used by software suspend */
958 void syscall_init(void)
959 {
960 	/*
961 	 * LSTAR and STAR live in a bit strange symbiosis.
962 	 * They both write to the same internal register. STAR allows to
963 	 * set CS/DS but only a 32bit target. LSTAR sets the 64bit rip.
964 	 */
965 	wrmsrl(MSR_STAR,  ((u64)__USER32_CS)<<48  | ((u64)__KERNEL_CS)<<32);
966 	wrmsrl(MSR_LSTAR, system_call);
967 	wrmsrl(MSR_CSTAR, ignore_sysret);
968 
969 #ifdef CONFIG_IA32_EMULATION
970 	syscall32_cpu_init();
971 #endif
972 
973 	/* Flags to clear on syscall */
974 	wrmsrl(MSR_SYSCALL_MASK,
975 	       X86_EFLAGS_TF|X86_EFLAGS_DF|X86_EFLAGS_IF|X86_EFLAGS_IOPL);
976 }
977 
978 unsigned long kernel_eflags;
979 
980 /*
981  * Copies of the original ist values from the tss are only accessed during
982  * debugging, no special alignment required.
983  */
984 DEFINE_PER_CPU(struct orig_ist, orig_ist);
985 
986 #else	/* x86_64 */
987 
988 #ifdef CONFIG_CC_STACKPROTECTOR
989 DEFINE_PER_CPU(unsigned long, stack_canary);
990 #endif
991 
992 /* Make sure %fs and %gs are initialized properly in idle threads */
993 struct pt_regs * __cpuinit idle_regs(struct pt_regs *regs)
994 {
995 	memset(regs, 0, sizeof(struct pt_regs));
996 	regs->fs = __KERNEL_PERCPU;
997 	regs->gs = __KERNEL_STACK_CANARY;
998 	return regs;
999 }
1000 #endif	/* x86_64 */
1001 
1002 /*
1003  * cpu_init() initializes state that is per-CPU. Some data is already
1004  * initialized (naturally) in the bootstrap process, such as the GDT
1005  * and IDT. We reload them nevertheless, this function acts as a
1006  * 'CPU state barrier', nothing should get across.
1007  * A lot of state is already set up in PDA init for 64 bit
1008  */
1009 #ifdef CONFIG_X86_64
1010 void __cpuinit cpu_init(void)
1011 {
1012 	int cpu = stack_smp_processor_id();
1013 	struct tss_struct *t = &per_cpu(init_tss, cpu);
1014 	struct orig_ist *orig_ist = &per_cpu(orig_ist, cpu);
1015 	unsigned long v;
1016 	struct task_struct *me;
1017 	int i;
1018 
1019 #ifdef CONFIG_NUMA
1020 	if (cpu != 0 && percpu_read(node_number) == 0 &&
1021 	    cpu_to_node(cpu) != NUMA_NO_NODE)
1022 		percpu_write(node_number, cpu_to_node(cpu));
1023 #endif
1024 
1025 	me = current;
1026 
1027 	if (cpumask_test_and_set_cpu(cpu, cpu_initialized_mask))
1028 		panic("CPU#%d already initialized!\n", cpu);
1029 
1030 	printk(KERN_INFO "Initializing CPU#%d\n", cpu);
1031 
1032 	clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1033 
1034 	/*
1035 	 * Initialize the per-CPU GDT with the boot GDT,
1036 	 * and set up the GDT descriptor:
1037 	 */
1038 
1039 	switch_to_new_gdt(cpu);
1040 	loadsegment(fs, 0);
1041 
1042 	load_idt((const struct desc_ptr *)&idt_descr);
1043 
1044 	memset(me->thread.tls_array, 0, GDT_ENTRY_TLS_ENTRIES * 8);
1045 	syscall_init();
1046 
1047 	wrmsrl(MSR_FS_BASE, 0);
1048 	wrmsrl(MSR_KERNEL_GS_BASE, 0);
1049 	barrier();
1050 
1051 	check_efer();
1052 	if (cpu != 0)
1053 		enable_x2apic();
1054 
1055 	/*
1056 	 * set up and load the per-CPU TSS
1057 	 */
1058 	if (!orig_ist->ist[0]) {
1059 		static const unsigned int sizes[N_EXCEPTION_STACKS] = {
1060 		  [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STKSZ,
1061 		  [DEBUG_STACK - 1] = DEBUG_STKSZ
1062 		};
1063 		char *estacks = per_cpu(exception_stacks, cpu);
1064 		for (v = 0; v < N_EXCEPTION_STACKS; v++) {
1065 			estacks += sizes[v];
1066 			orig_ist->ist[v] = t->x86_tss.ist[v] =
1067 					(unsigned long)estacks;
1068 		}
1069 	}
1070 
1071 	t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
1072 	/*
1073 	 * <= is required because the CPU will access up to
1074 	 * 8 bits beyond the end of the IO permission bitmap.
1075 	 */
1076 	for (i = 0; i <= IO_BITMAP_LONGS; i++)
1077 		t->io_bitmap[i] = ~0UL;
1078 
1079 	atomic_inc(&init_mm.mm_count);
1080 	me->active_mm = &init_mm;
1081 	if (me->mm)
1082 		BUG();
1083 	enter_lazy_tlb(&init_mm, me);
1084 
1085 	load_sp0(t, &current->thread);
1086 	set_tss_desc(cpu, t);
1087 	load_TR_desc();
1088 	load_LDT(&init_mm.context);
1089 
1090 #ifdef CONFIG_KGDB
1091 	/*
1092 	 * If the kgdb is connected no debug regs should be altered.  This
1093 	 * is only applicable when KGDB and a KGDB I/O module are built
1094 	 * into the kernel and you are using early debugging with
1095 	 * kgdbwait. KGDB will control the kernel HW breakpoint registers.
1096 	 */
1097 	if (kgdb_connected && arch_kgdb_ops.correct_hw_break)
1098 		arch_kgdb_ops.correct_hw_break();
1099 	else
1100 #endif
1101 	{
1102 		/*
1103 		 * Clear all 6 debug registers:
1104 		 */
1105 		set_debugreg(0UL, 0);
1106 		set_debugreg(0UL, 1);
1107 		set_debugreg(0UL, 2);
1108 		set_debugreg(0UL, 3);
1109 		set_debugreg(0UL, 6);
1110 		set_debugreg(0UL, 7);
1111 	}
1112 
1113 	fpu_init();
1114 
1115 	raw_local_save_flags(kernel_eflags);
1116 
1117 	if (is_uv_system())
1118 		uv_cpu_init();
1119 }
1120 
1121 #else
1122 
1123 void __cpuinit cpu_init(void)
1124 {
1125 	int cpu = smp_processor_id();
1126 	struct task_struct *curr = current;
1127 	struct tss_struct *t = &per_cpu(init_tss, cpu);
1128 	struct thread_struct *thread = &curr->thread;
1129 
1130 	if (cpumask_test_and_set_cpu(cpu, cpu_initialized_mask)) {
1131 		printk(KERN_WARNING "CPU#%d already initialized!\n", cpu);
1132 		for (;;) local_irq_enable();
1133 	}
1134 
1135 	printk(KERN_INFO "Initializing CPU#%d\n", cpu);
1136 
1137 	if (cpu_has_vme || cpu_has_tsc || cpu_has_de)
1138 		clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1139 
1140 	load_idt(&idt_descr);
1141 	switch_to_new_gdt(cpu);
1142 
1143 	/*
1144 	 * Set up and load the per-CPU TSS and LDT
1145 	 */
1146 	atomic_inc(&init_mm.mm_count);
1147 	curr->active_mm = &init_mm;
1148 	if (curr->mm)
1149 		BUG();
1150 	enter_lazy_tlb(&init_mm, curr);
1151 
1152 	load_sp0(t, thread);
1153 	set_tss_desc(cpu, t);
1154 	load_TR_desc();
1155 	load_LDT(&init_mm.context);
1156 
1157 #ifdef CONFIG_DOUBLEFAULT
1158 	/* Set up doublefault TSS pointer in the GDT */
1159 	__set_tss_desc(cpu, GDT_ENTRY_DOUBLEFAULT_TSS, &doublefault_tss);
1160 #endif
1161 
1162 	/* Clear all 6 debug registers: */
1163 	set_debugreg(0, 0);
1164 	set_debugreg(0, 1);
1165 	set_debugreg(0, 2);
1166 	set_debugreg(0, 3);
1167 	set_debugreg(0, 6);
1168 	set_debugreg(0, 7);
1169 
1170 	/*
1171 	 * Force FPU initialization:
1172 	 */
1173 	if (cpu_has_xsave)
1174 		current_thread_info()->status = TS_XSAVE;
1175 	else
1176 		current_thread_info()->status = 0;
1177 	clear_used_math();
1178 	mxcsr_feature_mask_init();
1179 
1180 	/*
1181 	 * Boot processor to setup the FP and extended state context info.
1182 	 */
1183 	if (smp_processor_id() == boot_cpu_id)
1184 		init_thread_xstate();
1185 
1186 	xsave_init();
1187 }
1188 
1189 
1190 #endif
1191