xref: /linux/arch/x86/kernel/cpu/common.c (revision 7ec7fb394298c212c30e063c57e0aa895efe9439)
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 #ifdef CONFIG_X86_LOCAL_APIC
25 #include <asm/mpspec.h>
26 #include <asm/apic.h>
27 #include <mach_apic.h>
28 #include <asm/genapic.h>
29 #endif
30 
31 #include <asm/pda.h>
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 
41 #include "cpu.h"
42 
43 static struct cpu_dev *this_cpu __cpuinitdata;
44 
45 #ifdef CONFIG_X86_64
46 /* We need valid kernel segments for data and code in long mode too
47  * IRET will check the segment types  kkeil 2000/10/28
48  * Also sysret mandates a special GDT layout
49  */
50 /* The TLS descriptors are currently at a different place compared to i386.
51    Hopefully nobody expects them at a fixed place (Wine?) */
52 DEFINE_PER_CPU(struct gdt_page, gdt_page) = { .gdt = {
53 	[GDT_ENTRY_KERNEL32_CS] = { { { 0x0000ffff, 0x00cf9b00 } } },
54 	[GDT_ENTRY_KERNEL_CS] = { { { 0x0000ffff, 0x00af9b00 } } },
55 	[GDT_ENTRY_KERNEL_DS] = { { { 0x0000ffff, 0x00cf9300 } } },
56 	[GDT_ENTRY_DEFAULT_USER32_CS] = { { { 0x0000ffff, 0x00cffb00 } } },
57 	[GDT_ENTRY_DEFAULT_USER_DS] = { { { 0x0000ffff, 0x00cff300 } } },
58 	[GDT_ENTRY_DEFAULT_USER_CS] = { { { 0x0000ffff, 0x00affb00 } } },
59 } };
60 #else
61 DEFINE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page) = { .gdt = {
62 	[GDT_ENTRY_KERNEL_CS] = { { { 0x0000ffff, 0x00cf9a00 } } },
63 	[GDT_ENTRY_KERNEL_DS] = { { { 0x0000ffff, 0x00cf9200 } } },
64 	[GDT_ENTRY_DEFAULT_USER_CS] = { { { 0x0000ffff, 0x00cffa00 } } },
65 	[GDT_ENTRY_DEFAULT_USER_DS] = { { { 0x0000ffff, 0x00cff200 } } },
66 	/*
67 	 * Segments used for calling PnP BIOS have byte granularity.
68 	 * They code segments and data segments have fixed 64k limits,
69 	 * the transfer segment sizes are set at run time.
70 	 */
71 	/* 32-bit code */
72 	[GDT_ENTRY_PNPBIOS_CS32] = { { { 0x0000ffff, 0x00409a00 } } },
73 	/* 16-bit code */
74 	[GDT_ENTRY_PNPBIOS_CS16] = { { { 0x0000ffff, 0x00009a00 } } },
75 	/* 16-bit data */
76 	[GDT_ENTRY_PNPBIOS_DS] = { { { 0x0000ffff, 0x00009200 } } },
77 	/* 16-bit data */
78 	[GDT_ENTRY_PNPBIOS_TS1] = { { { 0x00000000, 0x00009200 } } },
79 	/* 16-bit data */
80 	[GDT_ENTRY_PNPBIOS_TS2] = { { { 0x00000000, 0x00009200 } } },
81 	/*
82 	 * The APM segments have byte granularity and their bases
83 	 * are set at run time.  All have 64k limits.
84 	 */
85 	/* 32-bit code */
86 	[GDT_ENTRY_APMBIOS_BASE] = { { { 0x0000ffff, 0x00409a00 } } },
87 	/* 16-bit code */
88 	[GDT_ENTRY_APMBIOS_BASE+1] = { { { 0x0000ffff, 0x00009a00 } } },
89 	/* data */
90 	[GDT_ENTRY_APMBIOS_BASE+2] = { { { 0x0000ffff, 0x00409200 } } },
91 
92 	[GDT_ENTRY_ESPFIX_SS] = { { { 0x00000000, 0x00c09200 } } },
93 	[GDT_ENTRY_PERCPU] = { { { 0x00000000, 0x00000000 } } },
94 } };
95 #endif
96 EXPORT_PER_CPU_SYMBOL_GPL(gdt_page);
97 
98 #ifdef CONFIG_X86_32
99 static int cachesize_override __cpuinitdata = -1;
100 static int disable_x86_serial_nr __cpuinitdata = 1;
101 
102 static int __init cachesize_setup(char *str)
103 {
104 	get_option(&str, &cachesize_override);
105 	return 1;
106 }
107 __setup("cachesize=", cachesize_setup);
108 
109 static int __init x86_fxsr_setup(char *s)
110 {
111 	setup_clear_cpu_cap(X86_FEATURE_FXSR);
112 	setup_clear_cpu_cap(X86_FEATURE_XMM);
113 	return 1;
114 }
115 __setup("nofxsr", x86_fxsr_setup);
116 
117 static int __init x86_sep_setup(char *s)
118 {
119 	setup_clear_cpu_cap(X86_FEATURE_SEP);
120 	return 1;
121 }
122 __setup("nosep", x86_sep_setup);
123 
124 /* Standard macro to see if a specific flag is changeable */
125 static inline int flag_is_changeable_p(u32 flag)
126 {
127 	u32 f1, f2;
128 
129 	/*
130 	 * Cyrix and IDT cpus allow disabling of CPUID
131 	 * so the code below may return different results
132 	 * when it is executed before and after enabling
133 	 * the CPUID. Add "volatile" to not allow gcc to
134 	 * optimize the subsequent calls to this function.
135 	 */
136 	asm volatile ("pushfl\n\t"
137 		      "pushfl\n\t"
138 		      "popl %0\n\t"
139 		      "movl %0,%1\n\t"
140 		      "xorl %2,%0\n\t"
141 		      "pushl %0\n\t"
142 		      "popfl\n\t"
143 		      "pushfl\n\t"
144 		      "popl %0\n\t"
145 		      "popfl\n\t"
146 		      : "=&r" (f1), "=&r" (f2)
147 		      : "ir" (flag));
148 
149 	return ((f1^f2) & flag) != 0;
150 }
151 
152 /* Probe for the CPUID instruction */
153 static int __cpuinit have_cpuid_p(void)
154 {
155 	return flag_is_changeable_p(X86_EFLAGS_ID);
156 }
157 
158 static void __cpuinit squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
159 {
160 	if (cpu_has(c, X86_FEATURE_PN) && disable_x86_serial_nr) {
161 		/* Disable processor serial number */
162 		unsigned long lo, hi;
163 		rdmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
164 		lo |= 0x200000;
165 		wrmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
166 		printk(KERN_NOTICE "CPU serial number disabled.\n");
167 		clear_cpu_cap(c, X86_FEATURE_PN);
168 
169 		/* Disabling the serial number may affect the cpuid level */
170 		c->cpuid_level = cpuid_eax(0);
171 	}
172 }
173 
174 static int __init x86_serial_nr_setup(char *s)
175 {
176 	disable_x86_serial_nr = 0;
177 	return 1;
178 }
179 __setup("serialnumber", x86_serial_nr_setup);
180 #else
181 static inline int flag_is_changeable_p(u32 flag)
182 {
183 	return 1;
184 }
185 /* Probe for the CPUID instruction */
186 static inline int have_cpuid_p(void)
187 {
188 	return 1;
189 }
190 static inline void squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
191 {
192 }
193 #endif
194 
195 /*
196  * Naming convention should be: <Name> [(<Codename>)]
197  * This table only is used unless init_<vendor>() below doesn't set it;
198  * in particular, if CPUID levels 0x80000002..4 are supported, this isn't used
199  *
200  */
201 
202 /* Look up CPU names by table lookup. */
203 static char __cpuinit *table_lookup_model(struct cpuinfo_x86 *c)
204 {
205 	struct cpu_model_info *info;
206 
207 	if (c->x86_model >= 16)
208 		return NULL;	/* Range check */
209 
210 	if (!this_cpu)
211 		return NULL;
212 
213 	info = this_cpu->c_models;
214 
215 	while (info && info->family) {
216 		if (info->family == c->x86)
217 			return info->model_names[c->x86_model];
218 		info++;
219 	}
220 	return NULL;		/* Not found */
221 }
222 
223 __u32 cleared_cpu_caps[NCAPINTS] __cpuinitdata;
224 
225 /* Current gdt points %fs at the "master" per-cpu area: after this,
226  * it's on the real one. */
227 void switch_to_new_gdt(void)
228 {
229 	struct desc_ptr gdt_descr;
230 
231 	gdt_descr.address = (long)get_cpu_gdt_table(smp_processor_id());
232 	gdt_descr.size = GDT_SIZE - 1;
233 	load_gdt(&gdt_descr);
234 #ifdef CONFIG_X86_32
235 	asm("mov %0, %%fs" : : "r" (__KERNEL_PERCPU) : "memory");
236 #endif
237 }
238 
239 static struct cpu_dev *cpu_devs[X86_VENDOR_NUM] = {};
240 
241 static void __cpuinit default_init(struct cpuinfo_x86 *c)
242 {
243 #ifdef CONFIG_X86_64
244 	display_cacheinfo(c);
245 #else
246 	/* Not much we can do here... */
247 	/* Check if at least it has cpuid */
248 	if (c->cpuid_level == -1) {
249 		/* No cpuid. It must be an ancient CPU */
250 		if (c->x86 == 4)
251 			strcpy(c->x86_model_id, "486");
252 		else if (c->x86 == 3)
253 			strcpy(c->x86_model_id, "386");
254 	}
255 #endif
256 }
257 
258 static struct cpu_dev __cpuinitdata default_cpu = {
259 	.c_init	= default_init,
260 	.c_vendor = "Unknown",
261 	.c_x86_vendor = X86_VENDOR_UNKNOWN,
262 };
263 
264 static void __cpuinit get_model_name(struct cpuinfo_x86 *c)
265 {
266 	unsigned int *v;
267 	char *p, *q;
268 
269 	if (c->extended_cpuid_level < 0x80000004)
270 		return;
271 
272 	v = (unsigned int *) c->x86_model_id;
273 	cpuid(0x80000002, &v[0], &v[1], &v[2], &v[3]);
274 	cpuid(0x80000003, &v[4], &v[5], &v[6], &v[7]);
275 	cpuid(0x80000004, &v[8], &v[9], &v[10], &v[11]);
276 	c->x86_model_id[48] = 0;
277 
278 	/* Intel chips right-justify this string for some dumb reason;
279 	   undo that brain damage */
280 	p = q = &c->x86_model_id[0];
281 	while (*p == ' ')
282 	     p++;
283 	if (p != q) {
284 	     while (*p)
285 		  *q++ = *p++;
286 	     while (q <= &c->x86_model_id[48])
287 		  *q++ = '\0';	/* Zero-pad the rest */
288 	}
289 }
290 
291 void __cpuinit display_cacheinfo(struct cpuinfo_x86 *c)
292 {
293 	unsigned int n, dummy, ebx, ecx, edx, l2size;
294 
295 	n = c->extended_cpuid_level;
296 
297 	if (n >= 0x80000005) {
298 		cpuid(0x80000005, &dummy, &ebx, &ecx, &edx);
299 		printk(KERN_INFO "CPU: L1 I Cache: %dK (%d bytes/line), D cache %dK (%d bytes/line)\n",
300 				edx>>24, edx&0xFF, ecx>>24, ecx&0xFF);
301 		c->x86_cache_size = (ecx>>24) + (edx>>24);
302 #ifdef CONFIG_X86_64
303 		/* On K8 L1 TLB is inclusive, so don't count it */
304 		c->x86_tlbsize = 0;
305 #endif
306 	}
307 
308 	if (n < 0x80000006)	/* Some chips just has a large L1. */
309 		return;
310 
311 	cpuid(0x80000006, &dummy, &ebx, &ecx, &edx);
312 	l2size = ecx >> 16;
313 
314 #ifdef CONFIG_X86_64
315 	c->x86_tlbsize += ((ebx >> 16) & 0xfff) + (ebx & 0xfff);
316 #else
317 	/* do processor-specific cache resizing */
318 	if (this_cpu->c_size_cache)
319 		l2size = this_cpu->c_size_cache(c, l2size);
320 
321 	/* Allow user to override all this if necessary. */
322 	if (cachesize_override != -1)
323 		l2size = cachesize_override;
324 
325 	if (l2size == 0)
326 		return;		/* Again, no L2 cache is possible */
327 #endif
328 
329 	c->x86_cache_size = l2size;
330 
331 	printk(KERN_INFO "CPU: L2 Cache: %dK (%d bytes/line)\n",
332 			l2size, ecx & 0xFF);
333 }
334 
335 void __cpuinit detect_ht(struct cpuinfo_x86 *c)
336 {
337 #ifdef CONFIG_X86_HT
338 	u32 eax, ebx, ecx, edx;
339 	int index_msb, core_bits;
340 
341 	if (!cpu_has(c, X86_FEATURE_HT))
342 		return;
343 
344 	if (cpu_has(c, X86_FEATURE_CMP_LEGACY))
345 		goto out;
346 
347 	if (cpu_has(c, X86_FEATURE_XTOPOLOGY))
348 		return;
349 
350 	cpuid(1, &eax, &ebx, &ecx, &edx);
351 
352 	smp_num_siblings = (ebx & 0xff0000) >> 16;
353 
354 	if (smp_num_siblings == 1) {
355 		printk(KERN_INFO  "CPU: Hyper-Threading is disabled\n");
356 	} else if (smp_num_siblings > 1) {
357 
358 		if (smp_num_siblings > nr_cpu_ids) {
359 			printk(KERN_WARNING "CPU: Unsupported number of siblings %d",
360 					smp_num_siblings);
361 			smp_num_siblings = 1;
362 			return;
363 		}
364 
365 		index_msb = get_count_order(smp_num_siblings);
366 #ifdef CONFIG_X86_64
367 		c->phys_proc_id = phys_pkg_id(index_msb);
368 #else
369 		c->phys_proc_id = phys_pkg_id(c->initial_apicid, index_msb);
370 #endif
371 
372 		smp_num_siblings = smp_num_siblings / c->x86_max_cores;
373 
374 		index_msb = get_count_order(smp_num_siblings);
375 
376 		core_bits = get_count_order(c->x86_max_cores);
377 
378 #ifdef CONFIG_X86_64
379 		c->cpu_core_id = phys_pkg_id(index_msb) &
380 					       ((1 << core_bits) - 1);
381 #else
382 		c->cpu_core_id = phys_pkg_id(c->initial_apicid, index_msb) &
383 					       ((1 << core_bits) - 1);
384 #endif
385 	}
386 
387 out:
388 	if ((c->x86_max_cores * smp_num_siblings) > 1) {
389 		printk(KERN_INFO  "CPU: Physical Processor ID: %d\n",
390 		       c->phys_proc_id);
391 		printk(KERN_INFO  "CPU: Processor Core ID: %d\n",
392 		       c->cpu_core_id);
393 	}
394 #endif
395 }
396 
397 static void __cpuinit get_cpu_vendor(struct cpuinfo_x86 *c)
398 {
399 	char *v = c->x86_vendor_id;
400 	int i;
401 	static int printed;
402 
403 	for (i = 0; i < X86_VENDOR_NUM; i++) {
404 		if (!cpu_devs[i])
405 			break;
406 
407 		if (!strcmp(v, cpu_devs[i]->c_ident[0]) ||
408 		    (cpu_devs[i]->c_ident[1] &&
409 		     !strcmp(v, cpu_devs[i]->c_ident[1]))) {
410 			this_cpu = cpu_devs[i];
411 			c->x86_vendor = this_cpu->c_x86_vendor;
412 			return;
413 		}
414 	}
415 
416 	if (!printed) {
417 		printed++;
418 		printk(KERN_ERR "CPU: vendor_id '%s' unknown, using generic init.\n", v);
419 		printk(KERN_ERR "CPU: Your system may be unstable.\n");
420 	}
421 
422 	c->x86_vendor = X86_VENDOR_UNKNOWN;
423 	this_cpu = &default_cpu;
424 }
425 
426 void __cpuinit cpu_detect(struct cpuinfo_x86 *c)
427 {
428 	/* Get vendor name */
429 	cpuid(0x00000000, (unsigned int *)&c->cpuid_level,
430 	      (unsigned int *)&c->x86_vendor_id[0],
431 	      (unsigned int *)&c->x86_vendor_id[8],
432 	      (unsigned int *)&c->x86_vendor_id[4]);
433 
434 	c->x86 = 4;
435 	/* Intel-defined flags: level 0x00000001 */
436 	if (c->cpuid_level >= 0x00000001) {
437 		u32 junk, tfms, cap0, misc;
438 		cpuid(0x00000001, &tfms, &misc, &junk, &cap0);
439 		c->x86 = (tfms >> 8) & 0xf;
440 		c->x86_model = (tfms >> 4) & 0xf;
441 		c->x86_mask = tfms & 0xf;
442 		if (c->x86 == 0xf)
443 			c->x86 += (tfms >> 20) & 0xff;
444 		if (c->x86 >= 0x6)
445 			c->x86_model += ((tfms >> 16) & 0xf) << 4;
446 		if (cap0 & (1<<19)) {
447 			c->x86_clflush_size = ((misc >> 8) & 0xff) * 8;
448 			c->x86_cache_alignment = c->x86_clflush_size;
449 		}
450 	}
451 }
452 
453 static void __cpuinit get_cpu_cap(struct cpuinfo_x86 *c)
454 {
455 	u32 tfms, xlvl;
456 	u32 ebx;
457 
458 	/* Intel-defined flags: level 0x00000001 */
459 	if (c->cpuid_level >= 0x00000001) {
460 		u32 capability, excap;
461 		cpuid(0x00000001, &tfms, &ebx, &excap, &capability);
462 		c->x86_capability[0] = capability;
463 		c->x86_capability[4] = excap;
464 	}
465 
466 	/* AMD-defined flags: level 0x80000001 */
467 	xlvl = cpuid_eax(0x80000000);
468 	c->extended_cpuid_level = xlvl;
469 	if ((xlvl & 0xffff0000) == 0x80000000) {
470 		if (xlvl >= 0x80000001) {
471 			c->x86_capability[1] = cpuid_edx(0x80000001);
472 			c->x86_capability[6] = cpuid_ecx(0x80000001);
473 		}
474 	}
475 
476 #ifdef CONFIG_X86_64
477 	if (c->extended_cpuid_level >= 0x80000008) {
478 		u32 eax = cpuid_eax(0x80000008);
479 
480 		c->x86_virt_bits = (eax >> 8) & 0xff;
481 		c->x86_phys_bits = eax & 0xff;
482 	}
483 #endif
484 
485 	if (c->extended_cpuid_level >= 0x80000007)
486 		c->x86_power = cpuid_edx(0x80000007);
487 
488 }
489 
490 static void __cpuinit identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
491 {
492 #ifdef CONFIG_X86_32
493 	int i;
494 
495 	/*
496 	 * First of all, decide if this is a 486 or higher
497 	 * It's a 486 if we can modify the AC flag
498 	 */
499 	if (flag_is_changeable_p(X86_EFLAGS_AC))
500 		c->x86 = 4;
501 	else
502 		c->x86 = 3;
503 
504 	for (i = 0; i < X86_VENDOR_NUM; i++)
505 		if (cpu_devs[i] && cpu_devs[i]->c_identify) {
506 			c->x86_vendor_id[0] = 0;
507 			cpu_devs[i]->c_identify(c);
508 			if (c->x86_vendor_id[0]) {
509 				get_cpu_vendor(c);
510 				break;
511 			}
512 		}
513 #endif
514 }
515 
516 /*
517  * Do minimum CPU detection early.
518  * Fields really needed: vendor, cpuid_level, family, model, mask,
519  * cache alignment.
520  * The others are not touched to avoid unwanted side effects.
521  *
522  * WARNING: this function is only called on the BP.  Don't add code here
523  * that is supposed to run on all CPUs.
524  */
525 static void __init early_identify_cpu(struct cpuinfo_x86 *c)
526 {
527 #ifdef CONFIG_X86_64
528 	c->x86_clflush_size = 64;
529 #else
530 	c->x86_clflush_size = 32;
531 #endif
532 	c->x86_cache_alignment = c->x86_clflush_size;
533 
534 	memset(&c->x86_capability, 0, sizeof c->x86_capability);
535 	c->extended_cpuid_level = 0;
536 
537 	if (!have_cpuid_p())
538 		identify_cpu_without_cpuid(c);
539 
540 	/* cyrix could have cpuid enabled via c_identify()*/
541 	if (!have_cpuid_p())
542 		return;
543 
544 	cpu_detect(c);
545 
546 	get_cpu_vendor(c);
547 
548 	get_cpu_cap(c);
549 
550 	if (this_cpu->c_early_init)
551 		this_cpu->c_early_init(c);
552 
553 	validate_pat_support(c);
554 
555 #ifdef CONFIG_SMP
556 	c->cpu_index = boot_cpu_id;
557 #endif
558 }
559 
560 void __init early_cpu_init(void)
561 {
562 	struct cpu_dev **cdev;
563 	int count = 0;
564 
565 	printk("KERNEL supported cpus:\n");
566 	for (cdev = __x86_cpu_dev_start; cdev < __x86_cpu_dev_end; cdev++) {
567 		struct cpu_dev *cpudev = *cdev;
568 		unsigned int j;
569 
570 		if (count >= X86_VENDOR_NUM)
571 			break;
572 		cpu_devs[count] = cpudev;
573 		count++;
574 
575 		for (j = 0; j < 2; j++) {
576 			if (!cpudev->c_ident[j])
577 				continue;
578 			printk("  %s %s\n", cpudev->c_vendor,
579 				cpudev->c_ident[j]);
580 		}
581 	}
582 
583 	early_identify_cpu(&boot_cpu_data);
584 }
585 
586 /*
587  * The NOPL instruction is supposed to exist on all CPUs with
588  * family >= 6; unfortunately, that's not true in practice because
589  * of early VIA chips and (more importantly) broken virtualizers that
590  * are not easy to detect.  In the latter case it doesn't even *fail*
591  * reliably, so probing for it doesn't even work.  Disable it completely
592  * unless we can find a reliable way to detect all the broken cases.
593  */
594 static void __cpuinit detect_nopl(struct cpuinfo_x86 *c)
595 {
596 	clear_cpu_cap(c, X86_FEATURE_NOPL);
597 }
598 
599 static void __cpuinit generic_identify(struct cpuinfo_x86 *c)
600 {
601 	c->extended_cpuid_level = 0;
602 
603 	if (!have_cpuid_p())
604 		identify_cpu_without_cpuid(c);
605 
606 	/* cyrix could have cpuid enabled via c_identify()*/
607 	if (!have_cpuid_p())
608 		return;
609 
610 	cpu_detect(c);
611 
612 	get_cpu_vendor(c);
613 
614 	get_cpu_cap(c);
615 
616 	if (c->cpuid_level >= 0x00000001) {
617 		c->initial_apicid = (cpuid_ebx(1) >> 24) & 0xFF;
618 #ifdef CONFIG_X86_32
619 # ifdef CONFIG_X86_HT
620 		c->apicid = phys_pkg_id(c->initial_apicid, 0);
621 # else
622 		c->apicid = c->initial_apicid;
623 # endif
624 #endif
625 
626 #ifdef CONFIG_X86_HT
627 		c->phys_proc_id = c->initial_apicid;
628 #endif
629 	}
630 
631 	get_model_name(c); /* Default name */
632 
633 	init_scattered_cpuid_features(c);
634 	detect_nopl(c);
635 }
636 
637 /*
638  * This does the hard work of actually picking apart the CPU stuff...
639  */
640 static void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
641 {
642 	int i;
643 
644 	c->loops_per_jiffy = loops_per_jiffy;
645 	c->x86_cache_size = -1;
646 	c->x86_vendor = X86_VENDOR_UNKNOWN;
647 	c->x86_model = c->x86_mask = 0;	/* So far unknown... */
648 	c->x86_vendor_id[0] = '\0'; /* Unset */
649 	c->x86_model_id[0] = '\0';  /* Unset */
650 	c->x86_max_cores = 1;
651 	c->x86_coreid_bits = 0;
652 #ifdef CONFIG_X86_64
653 	c->x86_clflush_size = 64;
654 #else
655 	c->cpuid_level = -1;	/* CPUID not detected */
656 	c->x86_clflush_size = 32;
657 #endif
658 	c->x86_cache_alignment = c->x86_clflush_size;
659 	memset(&c->x86_capability, 0, sizeof c->x86_capability);
660 
661 	generic_identify(c);
662 
663 	if (this_cpu->c_identify)
664 		this_cpu->c_identify(c);
665 
666 #ifdef CONFIG_X86_64
667 	c->apicid = phys_pkg_id(0);
668 #endif
669 
670 	/*
671 	 * Vendor-specific initialization.  In this section we
672 	 * canonicalize the feature flags, meaning if there are
673 	 * features a certain CPU supports which CPUID doesn't
674 	 * tell us, CPUID claiming incorrect flags, or other bugs,
675 	 * we handle them here.
676 	 *
677 	 * At the end of this section, c->x86_capability better
678 	 * indicate the features this CPU genuinely supports!
679 	 */
680 	if (this_cpu->c_init)
681 		this_cpu->c_init(c);
682 
683 	/* Disable the PN if appropriate */
684 	squash_the_stupid_serial_number(c);
685 
686 	/*
687 	 * The vendor-specific functions might have changed features.  Now
688 	 * we do "generic changes."
689 	 */
690 
691 	/* If the model name is still unset, do table lookup. */
692 	if (!c->x86_model_id[0]) {
693 		char *p;
694 		p = table_lookup_model(c);
695 		if (p)
696 			strcpy(c->x86_model_id, p);
697 		else
698 			/* Last resort... */
699 			sprintf(c->x86_model_id, "%02x/%02x",
700 				c->x86, c->x86_model);
701 	}
702 
703 #ifdef CONFIG_X86_64
704 	detect_ht(c);
705 #endif
706 
707 	init_hypervisor(c);
708 	/*
709 	 * On SMP, boot_cpu_data holds the common feature set between
710 	 * all CPUs; so make sure that we indicate which features are
711 	 * common between the CPUs.  The first time this routine gets
712 	 * executed, c == &boot_cpu_data.
713 	 */
714 	if (c != &boot_cpu_data) {
715 		/* AND the already accumulated flags with these */
716 		for (i = 0; i < NCAPINTS; i++)
717 			boot_cpu_data.x86_capability[i] &= c->x86_capability[i];
718 	}
719 
720 	/* Clear all flags overriden by options */
721 	for (i = 0; i < NCAPINTS; i++)
722 		c->x86_capability[i] &= ~cleared_cpu_caps[i];
723 
724 #ifdef CONFIG_X86_MCE
725 	/* Init Machine Check Exception if available. */
726 	mcheck_init(c);
727 #endif
728 
729 	select_idle_routine(c);
730 
731 #if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
732 	numa_add_cpu(smp_processor_id());
733 #endif
734 }
735 
736 #ifdef CONFIG_X86_64
737 static void vgetcpu_set_mode(void)
738 {
739 	if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP))
740 		vgetcpu_mode = VGETCPU_RDTSCP;
741 	else
742 		vgetcpu_mode = VGETCPU_LSL;
743 }
744 #endif
745 
746 void __init identify_boot_cpu(void)
747 {
748 	identify_cpu(&boot_cpu_data);
749 #ifdef CONFIG_X86_32
750 	sysenter_setup();
751 	enable_sep_cpu();
752 #else
753 	vgetcpu_set_mode();
754 #endif
755 }
756 
757 void __cpuinit identify_secondary_cpu(struct cpuinfo_x86 *c)
758 {
759 	BUG_ON(c == &boot_cpu_data);
760 	identify_cpu(c);
761 #ifdef CONFIG_X86_32
762 	enable_sep_cpu();
763 #endif
764 	mtrr_ap_init();
765 }
766 
767 struct msr_range {
768 	unsigned min;
769 	unsigned max;
770 };
771 
772 static struct msr_range msr_range_array[] __cpuinitdata = {
773 	{ 0x00000000, 0x00000418},
774 	{ 0xc0000000, 0xc000040b},
775 	{ 0xc0010000, 0xc0010142},
776 	{ 0xc0011000, 0xc001103b},
777 };
778 
779 static void __cpuinit print_cpu_msr(void)
780 {
781 	unsigned index;
782 	u64 val;
783 	int i;
784 	unsigned index_min, index_max;
785 
786 	for (i = 0; i < ARRAY_SIZE(msr_range_array); i++) {
787 		index_min = msr_range_array[i].min;
788 		index_max = msr_range_array[i].max;
789 		for (index = index_min; index < index_max; index++) {
790 			if (rdmsrl_amd_safe(index, &val))
791 				continue;
792 			printk(KERN_INFO " MSR%08x: %016llx\n", index, val);
793 		}
794 	}
795 }
796 
797 static int show_msr __cpuinitdata;
798 static __init int setup_show_msr(char *arg)
799 {
800 	int num;
801 
802 	get_option(&arg, &num);
803 
804 	if (num > 0)
805 		show_msr = num;
806 	return 1;
807 }
808 __setup("show_msr=", setup_show_msr);
809 
810 static __init int setup_noclflush(char *arg)
811 {
812 	setup_clear_cpu_cap(X86_FEATURE_CLFLSH);
813 	return 1;
814 }
815 __setup("noclflush", setup_noclflush);
816 
817 void __cpuinit print_cpu_info(struct cpuinfo_x86 *c)
818 {
819 	char *vendor = NULL;
820 
821 	if (c->x86_vendor < X86_VENDOR_NUM)
822 		vendor = this_cpu->c_vendor;
823 	else if (c->cpuid_level >= 0)
824 		vendor = c->x86_vendor_id;
825 
826 	if (vendor && !strstr(c->x86_model_id, vendor))
827 		printk(KERN_CONT "%s ", vendor);
828 
829 	if (c->x86_model_id[0])
830 		printk(KERN_CONT "%s", c->x86_model_id);
831 	else
832 		printk(KERN_CONT "%d86", c->x86);
833 
834 	if (c->x86_mask || c->cpuid_level >= 0)
835 		printk(KERN_CONT " stepping %02x\n", c->x86_mask);
836 	else
837 		printk(KERN_CONT "\n");
838 
839 #ifdef CONFIG_SMP
840 	if (c->cpu_index < show_msr)
841 		print_cpu_msr();
842 #else
843 	if (show_msr)
844 		print_cpu_msr();
845 #endif
846 }
847 
848 static __init int setup_disablecpuid(char *arg)
849 {
850 	int bit;
851 	if (get_option(&arg, &bit) && bit < NCAPINTS*32)
852 		setup_clear_cpu_cap(bit);
853 	else
854 		return 0;
855 	return 1;
856 }
857 __setup("clearcpuid=", setup_disablecpuid);
858 
859 cpumask_t cpu_initialized __cpuinitdata = CPU_MASK_NONE;
860 
861 #ifdef CONFIG_X86_64
862 struct x8664_pda **_cpu_pda __read_mostly;
863 EXPORT_SYMBOL(_cpu_pda);
864 
865 struct desc_ptr idt_descr = { 256 * 16 - 1, (unsigned long) idt_table };
866 
867 static char boot_cpu_stack[IRQSTACKSIZE] __page_aligned_bss;
868 
869 void __cpuinit pda_init(int cpu)
870 {
871 	struct x8664_pda *pda = cpu_pda(cpu);
872 
873 	/* Setup up data that may be needed in __get_free_pages early */
874 	loadsegment(fs, 0);
875 	loadsegment(gs, 0);
876 	/* Memory clobbers used to order PDA accessed */
877 	mb();
878 	wrmsrl(MSR_GS_BASE, pda);
879 	mb();
880 
881 	pda->cpunumber = cpu;
882 	pda->irqcount = -1;
883 	pda->kernelstack = (unsigned long)stack_thread_info() -
884 				 PDA_STACKOFFSET + THREAD_SIZE;
885 	pda->active_mm = &init_mm;
886 	pda->mmu_state = 0;
887 
888 	if (cpu == 0) {
889 		/* others are initialized in smpboot.c */
890 		pda->pcurrent = &init_task;
891 		pda->irqstackptr = boot_cpu_stack;
892 		pda->irqstackptr += IRQSTACKSIZE - 64;
893 	} else {
894 		if (!pda->irqstackptr) {
895 			pda->irqstackptr = (char *)
896 				__get_free_pages(GFP_ATOMIC, IRQSTACK_ORDER);
897 			if (!pda->irqstackptr)
898 				panic("cannot allocate irqstack for cpu %d",
899 				      cpu);
900 			pda->irqstackptr += IRQSTACKSIZE - 64;
901 		}
902 
903 		if (pda->nodenumber == 0 && cpu_to_node(cpu) != NUMA_NO_NODE)
904 			pda->nodenumber = cpu_to_node(cpu);
905 	}
906 }
907 
908 static char boot_exception_stacks[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ +
909 				  DEBUG_STKSZ] __page_aligned_bss;
910 
911 extern asmlinkage void ignore_sysret(void);
912 
913 /* May not be marked __init: used by software suspend */
914 void syscall_init(void)
915 {
916 	/*
917 	 * LSTAR and STAR live in a bit strange symbiosis.
918 	 * They both write to the same internal register. STAR allows to
919 	 * set CS/DS but only a 32bit target. LSTAR sets the 64bit rip.
920 	 */
921 	wrmsrl(MSR_STAR,  ((u64)__USER32_CS)<<48  | ((u64)__KERNEL_CS)<<32);
922 	wrmsrl(MSR_LSTAR, system_call);
923 	wrmsrl(MSR_CSTAR, ignore_sysret);
924 
925 #ifdef CONFIG_IA32_EMULATION
926 	syscall32_cpu_init();
927 #endif
928 
929 	/* Flags to clear on syscall */
930 	wrmsrl(MSR_SYSCALL_MASK,
931 	       X86_EFLAGS_TF|X86_EFLAGS_DF|X86_EFLAGS_IF|X86_EFLAGS_IOPL);
932 }
933 
934 unsigned long kernel_eflags;
935 
936 /*
937  * Copies of the original ist values from the tss are only accessed during
938  * debugging, no special alignment required.
939  */
940 DEFINE_PER_CPU(struct orig_ist, orig_ist);
941 
942 #else
943 
944 /* Make sure %fs is initialized properly in idle threads */
945 struct pt_regs * __cpuinit idle_regs(struct pt_regs *regs)
946 {
947 	memset(regs, 0, sizeof(struct pt_regs));
948 	regs->fs = __KERNEL_PERCPU;
949 	return regs;
950 }
951 #endif
952 
953 /*
954  * cpu_init() initializes state that is per-CPU. Some data is already
955  * initialized (naturally) in the bootstrap process, such as the GDT
956  * and IDT. We reload them nevertheless, this function acts as a
957  * 'CPU state barrier', nothing should get across.
958  * A lot of state is already set up in PDA init for 64 bit
959  */
960 #ifdef CONFIG_X86_64
961 void __cpuinit cpu_init(void)
962 {
963 	int cpu = stack_smp_processor_id();
964 	struct tss_struct *t = &per_cpu(init_tss, cpu);
965 	struct orig_ist *orig_ist = &per_cpu(orig_ist, cpu);
966 	unsigned long v;
967 	char *estacks = NULL;
968 	struct task_struct *me;
969 	int i;
970 
971 	/* CPU 0 is initialised in head64.c */
972 	if (cpu != 0)
973 		pda_init(cpu);
974 	else
975 		estacks = boot_exception_stacks;
976 
977 	me = current;
978 
979 	if (cpu_test_and_set(cpu, cpu_initialized))
980 		panic("CPU#%d already initialized!\n", cpu);
981 
982 	printk(KERN_INFO "Initializing CPU#%d\n", cpu);
983 
984 	clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
985 
986 	/*
987 	 * Initialize the per-CPU GDT with the boot GDT,
988 	 * and set up the GDT descriptor:
989 	 */
990 
991 	switch_to_new_gdt();
992 	load_idt((const struct desc_ptr *)&idt_descr);
993 
994 	memset(me->thread.tls_array, 0, GDT_ENTRY_TLS_ENTRIES * 8);
995 	syscall_init();
996 
997 	wrmsrl(MSR_FS_BASE, 0);
998 	wrmsrl(MSR_KERNEL_GS_BASE, 0);
999 	barrier();
1000 
1001 	check_efer();
1002 	if (cpu != 0 && x2apic)
1003 		enable_x2apic();
1004 
1005 	/*
1006 	 * set up and load the per-CPU TSS
1007 	 */
1008 	if (!orig_ist->ist[0]) {
1009 		static const unsigned int order[N_EXCEPTION_STACKS] = {
1010 		  [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STACK_ORDER,
1011 		  [DEBUG_STACK - 1] = DEBUG_STACK_ORDER
1012 		};
1013 		for (v = 0; v < N_EXCEPTION_STACKS; v++) {
1014 			if (cpu) {
1015 				estacks = (char *)__get_free_pages(GFP_ATOMIC, order[v]);
1016 				if (!estacks)
1017 					panic("Cannot allocate exception "
1018 					      "stack %ld %d\n", v, cpu);
1019 			}
1020 			estacks += PAGE_SIZE << order[v];
1021 			orig_ist->ist[v] = t->x86_tss.ist[v] =
1022 					(unsigned long)estacks;
1023 		}
1024 	}
1025 
1026 	t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
1027 	/*
1028 	 * <= is required because the CPU will access up to
1029 	 * 8 bits beyond the end of the IO permission bitmap.
1030 	 */
1031 	for (i = 0; i <= IO_BITMAP_LONGS; i++)
1032 		t->io_bitmap[i] = ~0UL;
1033 
1034 	atomic_inc(&init_mm.mm_count);
1035 	me->active_mm = &init_mm;
1036 	if (me->mm)
1037 		BUG();
1038 	enter_lazy_tlb(&init_mm, me);
1039 
1040 	load_sp0(t, &current->thread);
1041 	set_tss_desc(cpu, t);
1042 	load_TR_desc();
1043 	load_LDT(&init_mm.context);
1044 
1045 #ifdef CONFIG_KGDB
1046 	/*
1047 	 * If the kgdb is connected no debug regs should be altered.  This
1048 	 * is only applicable when KGDB and a KGDB I/O module are built
1049 	 * into the kernel and you are using early debugging with
1050 	 * kgdbwait. KGDB will control the kernel HW breakpoint registers.
1051 	 */
1052 	if (kgdb_connected && arch_kgdb_ops.correct_hw_break)
1053 		arch_kgdb_ops.correct_hw_break();
1054 	else {
1055 #endif
1056 	/*
1057 	 * Clear all 6 debug registers:
1058 	 */
1059 
1060 	set_debugreg(0UL, 0);
1061 	set_debugreg(0UL, 1);
1062 	set_debugreg(0UL, 2);
1063 	set_debugreg(0UL, 3);
1064 	set_debugreg(0UL, 6);
1065 	set_debugreg(0UL, 7);
1066 #ifdef CONFIG_KGDB
1067 	/* If the kgdb is connected no debug regs should be altered. */
1068 	}
1069 #endif
1070 
1071 	fpu_init();
1072 
1073 	raw_local_save_flags(kernel_eflags);
1074 
1075 	if (is_uv_system())
1076 		uv_cpu_init();
1077 }
1078 
1079 #else
1080 
1081 void __cpuinit cpu_init(void)
1082 {
1083 	int cpu = smp_processor_id();
1084 	struct task_struct *curr = current;
1085 	struct tss_struct *t = &per_cpu(init_tss, cpu);
1086 	struct thread_struct *thread = &curr->thread;
1087 
1088 	if (cpu_test_and_set(cpu, cpu_initialized)) {
1089 		printk(KERN_WARNING "CPU#%d already initialized!\n", cpu);
1090 		for (;;) local_irq_enable();
1091 	}
1092 
1093 	printk(KERN_INFO "Initializing CPU#%d\n", cpu);
1094 
1095 	if (cpu_has_vme || cpu_has_tsc || cpu_has_de)
1096 		clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1097 
1098 	load_idt(&idt_descr);
1099 	switch_to_new_gdt();
1100 
1101 	/*
1102 	 * Set up and load the per-CPU TSS and LDT
1103 	 */
1104 	atomic_inc(&init_mm.mm_count);
1105 	curr->active_mm = &init_mm;
1106 	if (curr->mm)
1107 		BUG();
1108 	enter_lazy_tlb(&init_mm, curr);
1109 
1110 	load_sp0(t, thread);
1111 	set_tss_desc(cpu, t);
1112 	load_TR_desc();
1113 	load_LDT(&init_mm.context);
1114 
1115 #ifdef CONFIG_DOUBLEFAULT
1116 	/* Set up doublefault TSS pointer in the GDT */
1117 	__set_tss_desc(cpu, GDT_ENTRY_DOUBLEFAULT_TSS, &doublefault_tss);
1118 #endif
1119 
1120 	/* Clear %gs. */
1121 	asm volatile ("mov %0, %%gs" : : "r" (0));
1122 
1123 	/* Clear all 6 debug registers: */
1124 	set_debugreg(0, 0);
1125 	set_debugreg(0, 1);
1126 	set_debugreg(0, 2);
1127 	set_debugreg(0, 3);
1128 	set_debugreg(0, 6);
1129 	set_debugreg(0, 7);
1130 
1131 	/*
1132 	 * Force FPU initialization:
1133 	 */
1134 	if (cpu_has_xsave)
1135 		current_thread_info()->status = TS_XSAVE;
1136 	else
1137 		current_thread_info()->status = 0;
1138 	clear_used_math();
1139 	mxcsr_feature_mask_init();
1140 
1141 	/*
1142 	 * Boot processor to setup the FP and extended state context info.
1143 	 */
1144 	if (smp_processor_id() == boot_cpu_id)
1145 		init_thread_xstate();
1146 
1147 	xsave_init();
1148 }
1149 
1150 
1151 #endif
1152