xref: /openbmc/linux/arch/x86/kernel/cpu/common.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
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/mmu_context.h>
17 #include <asm/hypervisor.h>
18 #include <asm/processor.h>
19 #include <asm/sections.h>
20 #include <asm/topology.h>
21 #include <asm/cpumask.h>
22 #include <asm/pgtable.h>
23 #include <asm/atomic.h>
24 #include <asm/proto.h>
25 #include <asm/setup.h>
26 #include <asm/apic.h>
27 #include <asm/desc.h>
28 #include <asm/i387.h>
29 #include <asm/mtrr.h>
30 #include <asm/numa.h>
31 #include <asm/asm.h>
32 #include <asm/cpu.h>
33 #include <asm/mce.h>
34 #include <asm/msr.h>
35 #include <asm/pat.h>
36 #include <asm/smp.h>
37 
38 #ifdef CONFIG_X86_LOCAL_APIC
39 #include <asm/uv/uv.h>
40 #endif
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_initialized_mask;
48 cpumask_var_t cpu_callout_mask;
49 cpumask_var_t cpu_callin_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_sibling_setup_map;
66 cpumask_t cpu_callout_map;
67 cpumask_t cpu_initialized;
68 cpumask_t cpu_callin_map;
69 
70 #endif /* CONFIG_X86_32 */
71 
72 
73 static const 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 	 * 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 
178 		      : "=&r" (f1), "=&r" (f2)
179 		      : "ir" (flag));
180 
181 	return ((f1^f2) & flag) != 0;
182 }
183 
184 /* Probe for the CPUID instruction */
185 static int __cpuinit have_cpuid_p(void)
186 {
187 	return flag_is_changeable_p(X86_EFLAGS_ID);
188 }
189 
190 static void __cpuinit squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
191 {
192 	unsigned long lo, hi;
193 
194 	if (!cpu_has(c, X86_FEATURE_PN) || !disable_x86_serial_nr)
195 		return;
196 
197 	/* Disable processor serial number: */
198 
199 	rdmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
200 	lo |= 0x200000;
201 	wrmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
202 
203 	printk(KERN_NOTICE "CPU serial number disabled.\n");
204 	clear_cpu_cap(c, X86_FEATURE_PN);
205 
206 	/* Disabling the serial number may affect the cpuid level */
207 	c->cpuid_level = cpuid_eax(0);
208 }
209 
210 static int __init x86_serial_nr_setup(char *s)
211 {
212 	disable_x86_serial_nr = 0;
213 	return 1;
214 }
215 __setup("serialnumber", x86_serial_nr_setup);
216 #else
217 static inline int flag_is_changeable_p(u32 flag)
218 {
219 	return 1;
220 }
221 /* Probe for the CPUID instruction */
222 static inline int have_cpuid_p(void)
223 {
224 	return 1;
225 }
226 static inline void squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
227 {
228 }
229 #endif
230 
231 /*
232  * Some CPU features depend on higher CPUID levels, which may not always
233  * be available due to CPUID level capping or broken virtualization
234  * software.  Add those features to this table to auto-disable them.
235  */
236 struct cpuid_dependent_feature {
237 	u32 feature;
238 	u32 level;
239 };
240 
241 static const struct cpuid_dependent_feature __cpuinitconst
242 cpuid_dependent_features[] = {
243 	{ X86_FEATURE_MWAIT,		0x00000005 },
244 	{ X86_FEATURE_DCA,		0x00000009 },
245 	{ X86_FEATURE_XSAVE,		0x0000000d },
246 	{ 0, 0 }
247 };
248 
249 static void __cpuinit filter_cpuid_features(struct cpuinfo_x86 *c, bool warn)
250 {
251 	const struct cpuid_dependent_feature *df;
252 
253 	for (df = cpuid_dependent_features; df->feature; df++) {
254 
255 		if (!cpu_has(c, df->feature))
256 			continue;
257 		/*
258 		 * Note: cpuid_level is set to -1 if unavailable, but
259 		 * extended_extended_level is set to 0 if unavailable
260 		 * and the legitimate extended levels are all negative
261 		 * when signed; hence the weird messing around with
262 		 * signs here...
263 		 */
264 		if (!((s32)df->level < 0 ?
265 		     (u32)df->level > (u32)c->extended_cpuid_level :
266 		     (s32)df->level > (s32)c->cpuid_level))
267 			continue;
268 
269 		clear_cpu_cap(c, df->feature);
270 		if (!warn)
271 			continue;
272 
273 		printk(KERN_WARNING
274 		       "CPU: CPU feature %s disabled, no CPUID level 0x%x\n",
275 				x86_cap_flags[df->feature], df->level);
276 	}
277 }
278 
279 /*
280  * Naming convention should be: <Name> [(<Codename>)]
281  * This table only is used unless init_<vendor>() below doesn't set it;
282  * in particular, if CPUID levels 0x80000002..4 are supported, this
283  * isn't used
284  */
285 
286 /* Look up CPU names by table lookup. */
287 static const char *__cpuinit table_lookup_model(struct cpuinfo_x86 *c)
288 {
289 	const struct cpu_model_info *info;
290 
291 	if (c->x86_model >= 16)
292 		return NULL;	/* Range check */
293 
294 	if (!this_cpu)
295 		return NULL;
296 
297 	info = this_cpu->c_models;
298 
299 	while (info && info->family) {
300 		if (info->family == c->x86)
301 			return info->model_names[c->x86_model];
302 		info++;
303 	}
304 	return NULL;		/* Not found */
305 }
306 
307 __u32 cleared_cpu_caps[NCAPINTS] __cpuinitdata;
308 
309 void load_percpu_segment(int cpu)
310 {
311 #ifdef CONFIG_X86_32
312 	loadsegment(fs, __KERNEL_PERCPU);
313 #else
314 	loadsegment(gs, 0);
315 	wrmsrl(MSR_GS_BASE, (unsigned long)per_cpu(irq_stack_union.gs_base, cpu));
316 #endif
317 	load_stack_canary_segment();
318 }
319 
320 /*
321  * Current gdt points %fs at the "master" per-cpu area: after this,
322  * it's on the real one.
323  */
324 void switch_to_new_gdt(int cpu)
325 {
326 	struct desc_ptr gdt_descr;
327 
328 	gdt_descr.address = (long)get_cpu_gdt_table(cpu);
329 	gdt_descr.size = GDT_SIZE - 1;
330 	load_gdt(&gdt_descr);
331 	/* Reload the per-cpu base */
332 
333 	load_percpu_segment(cpu);
334 }
335 
336 static const struct cpu_dev *__cpuinitdata cpu_devs[X86_VENDOR_NUM] = {};
337 
338 static void __cpuinit default_init(struct cpuinfo_x86 *c)
339 {
340 #ifdef CONFIG_X86_64
341 	display_cacheinfo(c);
342 #else
343 	/* Not much we can do here... */
344 	/* Check if at least it has cpuid */
345 	if (c->cpuid_level == -1) {
346 		/* No cpuid. It must be an ancient CPU */
347 		if (c->x86 == 4)
348 			strcpy(c->x86_model_id, "486");
349 		else if (c->x86 == 3)
350 			strcpy(c->x86_model_id, "386");
351 	}
352 #endif
353 }
354 
355 static const struct cpu_dev __cpuinitconst default_cpu = {
356 	.c_init	= default_init,
357 	.c_vendor = "Unknown",
358 	.c_x86_vendor = X86_VENDOR_UNKNOWN,
359 };
360 
361 static void __cpuinit get_model_name(struct cpuinfo_x86 *c)
362 {
363 	unsigned int *v;
364 	char *p, *q;
365 
366 	if (c->extended_cpuid_level < 0x80000004)
367 		return;
368 
369 	v = (unsigned int *)c->x86_model_id;
370 	cpuid(0x80000002, &v[0], &v[1], &v[2], &v[3]);
371 	cpuid(0x80000003, &v[4], &v[5], &v[6], &v[7]);
372 	cpuid(0x80000004, &v[8], &v[9], &v[10], &v[11]);
373 	c->x86_model_id[48] = 0;
374 
375 	/*
376 	 * Intel chips right-justify this string for some dumb reason;
377 	 * undo that brain damage:
378 	 */
379 	p = q = &c->x86_model_id[0];
380 	while (*p == ' ')
381 		p++;
382 	if (p != q) {
383 		while (*p)
384 			*q++ = *p++;
385 		while (q <= &c->x86_model_id[48])
386 			*q++ = '\0';	/* Zero-pad the rest */
387 	}
388 }
389 
390 void __cpuinit display_cacheinfo(struct cpuinfo_x86 *c)
391 {
392 	unsigned int n, dummy, ebx, ecx, edx, l2size;
393 
394 	n = c->extended_cpuid_level;
395 
396 	if (n >= 0x80000005) {
397 		cpuid(0x80000005, &dummy, &ebx, &ecx, &edx);
398 		printk(KERN_INFO "CPU: L1 I Cache: %dK (%d bytes/line), D cache %dK (%d bytes/line)\n",
399 				edx>>24, edx&0xFF, ecx>>24, ecx&0xFF);
400 		c->x86_cache_size = (ecx>>24) + (edx>>24);
401 #ifdef CONFIG_X86_64
402 		/* On K8 L1 TLB is inclusive, so don't count it */
403 		c->x86_tlbsize = 0;
404 #endif
405 	}
406 
407 	if (n < 0x80000006)	/* Some chips just has a large L1. */
408 		return;
409 
410 	cpuid(0x80000006, &dummy, &ebx, &ecx, &edx);
411 	l2size = ecx >> 16;
412 
413 #ifdef CONFIG_X86_64
414 	c->x86_tlbsize += ((ebx >> 16) & 0xfff) + (ebx & 0xfff);
415 #else
416 	/* do processor-specific cache resizing */
417 	if (this_cpu->c_size_cache)
418 		l2size = this_cpu->c_size_cache(c, l2size);
419 
420 	/* Allow user to override all this if necessary. */
421 	if (cachesize_override != -1)
422 		l2size = cachesize_override;
423 
424 	if (l2size == 0)
425 		return;		/* Again, no L2 cache is possible */
426 #endif
427 
428 	c->x86_cache_size = l2size;
429 
430 	printk(KERN_INFO "CPU: L2 Cache: %dK (%d bytes/line)\n",
431 			l2size, ecx & 0xFF);
432 }
433 
434 void __cpuinit detect_ht(struct cpuinfo_x86 *c)
435 {
436 #ifdef CONFIG_X86_HT
437 	u32 eax, ebx, ecx, edx;
438 	int index_msb, core_bits;
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(KERN_INFO  "CPU: 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 ((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 	}
487 #endif
488 }
489 
490 static void __cpuinit get_cpu_vendor(struct cpuinfo_x86 *c)
491 {
492 	char *v = c->x86_vendor_id;
493 	static int printed;
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 	if (!printed) {
511 		printed++;
512 		printk(KERN_ERR
513 		    "CPU: vendor_id '%s' unknown, using generic init.\n", v);
514 
515 		printk(KERN_ERR "CPU: Your system may be unstable.\n");
516 	}
517 
518 	c->x86_vendor = X86_VENDOR_UNKNOWN;
519 	this_cpu = &default_cpu;
520 }
521 
522 void __cpuinit cpu_detect(struct cpuinfo_x86 *c)
523 {
524 	/* Get vendor name */
525 	cpuid(0x00000000, (unsigned int *)&c->cpuid_level,
526 	      (unsigned int *)&c->x86_vendor_id[0],
527 	      (unsigned int *)&c->x86_vendor_id[8],
528 	      (unsigned int *)&c->x86_vendor_id[4]);
529 
530 	c->x86 = 4;
531 	/* Intel-defined flags: level 0x00000001 */
532 	if (c->cpuid_level >= 0x00000001) {
533 		u32 junk, tfms, cap0, misc;
534 
535 		cpuid(0x00000001, &tfms, &misc, &junk, &cap0);
536 		c->x86 = (tfms >> 8) & 0xf;
537 		c->x86_model = (tfms >> 4) & 0xf;
538 		c->x86_mask = tfms & 0xf;
539 
540 		if (c->x86 == 0xf)
541 			c->x86 += (tfms >> 20) & 0xff;
542 		if (c->x86 >= 0x6)
543 			c->x86_model += ((tfms >> 16) & 0xf) << 4;
544 
545 		if (cap0 & (1<<19)) {
546 			c->x86_clflush_size = ((misc >> 8) & 0xff) * 8;
547 			c->x86_cache_alignment = c->x86_clflush_size;
548 		}
549 	}
550 }
551 
552 static void __cpuinit get_cpu_cap(struct cpuinfo_x86 *c)
553 {
554 	u32 tfms, xlvl;
555 	u32 ebx;
556 
557 	/* Intel-defined flags: level 0x00000001 */
558 	if (c->cpuid_level >= 0x00000001) {
559 		u32 capability, excap;
560 
561 		cpuid(0x00000001, &tfms, &ebx, &excap, &capability);
562 		c->x86_capability[0] = capability;
563 		c->x86_capability[4] = excap;
564 	}
565 
566 	/* AMD-defined flags: level 0x80000001 */
567 	xlvl = cpuid_eax(0x80000000);
568 	c->extended_cpuid_level = xlvl;
569 
570 	if ((xlvl & 0xffff0000) == 0x80000000) {
571 		if (xlvl >= 0x80000001) {
572 			c->x86_capability[1] = cpuid_edx(0x80000001);
573 			c->x86_capability[6] = cpuid_ecx(0x80000001);
574 		}
575 	}
576 
577 	if (c->extended_cpuid_level >= 0x80000008) {
578 		u32 eax = cpuid_eax(0x80000008);
579 
580 		c->x86_virt_bits = (eax >> 8) & 0xff;
581 		c->x86_phys_bits = eax & 0xff;
582 	}
583 #ifdef CONFIG_X86_32
584 	else if (cpu_has(c, X86_FEATURE_PAE) || cpu_has(c, X86_FEATURE_PSE36))
585 		c->x86_phys_bits = 36;
586 #endif
587 
588 	if (c->extended_cpuid_level >= 0x80000007)
589 		c->x86_power = cpuid_edx(0x80000007);
590 
591 }
592 
593 static void __cpuinit identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
594 {
595 #ifdef CONFIG_X86_32
596 	int i;
597 
598 	/*
599 	 * First of all, decide if this is a 486 or higher
600 	 * It's a 486 if we can modify the AC flag
601 	 */
602 	if (flag_is_changeable_p(X86_EFLAGS_AC))
603 		c->x86 = 4;
604 	else
605 		c->x86 = 3;
606 
607 	for (i = 0; i < X86_VENDOR_NUM; i++)
608 		if (cpu_devs[i] && cpu_devs[i]->c_identify) {
609 			c->x86_vendor_id[0] = 0;
610 			cpu_devs[i]->c_identify(c);
611 			if (c->x86_vendor_id[0]) {
612 				get_cpu_vendor(c);
613 				break;
614 			}
615 		}
616 #endif
617 }
618 
619 /*
620  * Do minimum CPU detection early.
621  * Fields really needed: vendor, cpuid_level, family, model, mask,
622  * cache alignment.
623  * The others are not touched to avoid unwanted side effects.
624  *
625  * WARNING: this function is only called on the BP.  Don't add code here
626  * that is supposed to run on all CPUs.
627  */
628 static void __init early_identify_cpu(struct cpuinfo_x86 *c)
629 {
630 #ifdef CONFIG_X86_64
631 	c->x86_clflush_size = 64;
632 	c->x86_phys_bits = 36;
633 	c->x86_virt_bits = 48;
634 #else
635 	c->x86_clflush_size = 32;
636 	c->x86_phys_bits = 32;
637 	c->x86_virt_bits = 32;
638 #endif
639 	c->x86_cache_alignment = c->x86_clflush_size;
640 
641 	memset(&c->x86_capability, 0, sizeof c->x86_capability);
642 	c->extended_cpuid_level = 0;
643 
644 	if (!have_cpuid_p())
645 		identify_cpu_without_cpuid(c);
646 
647 	/* cyrix could have cpuid enabled via c_identify()*/
648 	if (!have_cpuid_p())
649 		return;
650 
651 	cpu_detect(c);
652 
653 	get_cpu_vendor(c);
654 
655 	get_cpu_cap(c);
656 
657 	if (this_cpu->c_early_init)
658 		this_cpu->c_early_init(c);
659 
660 #ifdef CONFIG_SMP
661 	c->cpu_index = boot_cpu_id;
662 #endif
663 	filter_cpuid_features(c, false);
664 }
665 
666 void __init early_cpu_init(void)
667 {
668 	const struct cpu_dev *const *cdev;
669 	int count = 0;
670 
671 	printk(KERN_INFO "KERNEL supported cpus:\n");
672 	for (cdev = __x86_cpu_dev_start; cdev < __x86_cpu_dev_end; cdev++) {
673 		const struct cpu_dev *cpudev = *cdev;
674 		unsigned int j;
675 
676 		if (count >= X86_VENDOR_NUM)
677 			break;
678 		cpu_devs[count] = cpudev;
679 		count++;
680 
681 		for (j = 0; j < 2; j++) {
682 			if (!cpudev->c_ident[j])
683 				continue;
684 			printk(KERN_INFO "  %s %s\n", cpudev->c_vendor,
685 				cpudev->c_ident[j]);
686 		}
687 	}
688 
689 	early_identify_cpu(&boot_cpu_data);
690 }
691 
692 /*
693  * The NOPL instruction is supposed to exist on all CPUs with
694  * family >= 6; unfortunately, that's not true in practice because
695  * of early VIA chips and (more importantly) broken virtualizers that
696  * are not easy to detect.  In the latter case it doesn't even *fail*
697  * reliably, so probing for it doesn't even work.  Disable it completely
698  * unless we can find a reliable way to detect all the broken cases.
699  */
700 static void __cpuinit detect_nopl(struct cpuinfo_x86 *c)
701 {
702 	clear_cpu_cap(c, X86_FEATURE_NOPL);
703 }
704 
705 static void __cpuinit generic_identify(struct cpuinfo_x86 *c)
706 {
707 	c->extended_cpuid_level = 0;
708 
709 	if (!have_cpuid_p())
710 		identify_cpu_without_cpuid(c);
711 
712 	/* cyrix could have cpuid enabled via c_identify()*/
713 	if (!have_cpuid_p())
714 		return;
715 
716 	cpu_detect(c);
717 
718 	get_cpu_vendor(c);
719 
720 	get_cpu_cap(c);
721 
722 	if (c->cpuid_level >= 0x00000001) {
723 		c->initial_apicid = (cpuid_ebx(1) >> 24) & 0xFF;
724 #ifdef CONFIG_X86_32
725 # ifdef CONFIG_X86_HT
726 		c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
727 # else
728 		c->apicid = c->initial_apicid;
729 # endif
730 #endif
731 
732 #ifdef CONFIG_X86_HT
733 		c->phys_proc_id = c->initial_apicid;
734 #endif
735 	}
736 
737 	get_model_name(c); /* Default name */
738 
739 	init_scattered_cpuid_features(c);
740 	detect_nopl(c);
741 }
742 
743 /*
744  * This does the hard work of actually picking apart the CPU stuff...
745  */
746 static void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
747 {
748 	int i;
749 
750 	c->loops_per_jiffy = loops_per_jiffy;
751 	c->x86_cache_size = -1;
752 	c->x86_vendor = X86_VENDOR_UNKNOWN;
753 	c->x86_model = c->x86_mask = 0;	/* So far unknown... */
754 	c->x86_vendor_id[0] = '\0'; /* Unset */
755 	c->x86_model_id[0] = '\0';  /* Unset */
756 	c->x86_max_cores = 1;
757 	c->x86_coreid_bits = 0;
758 #ifdef CONFIG_X86_64
759 	c->x86_clflush_size = 64;
760 	c->x86_phys_bits = 36;
761 	c->x86_virt_bits = 48;
762 #else
763 	c->cpuid_level = -1;	/* CPUID not detected */
764 	c->x86_clflush_size = 32;
765 	c->x86_phys_bits = 32;
766 	c->x86_virt_bits = 32;
767 #endif
768 	c->x86_cache_alignment = c->x86_clflush_size;
769 	memset(&c->x86_capability, 0, sizeof c->x86_capability);
770 
771 	generic_identify(c);
772 
773 	if (this_cpu->c_identify)
774 		this_cpu->c_identify(c);
775 
776 #ifdef CONFIG_X86_64
777 	c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
778 #endif
779 
780 	/*
781 	 * Vendor-specific initialization.  In this section we
782 	 * canonicalize the feature flags, meaning if there are
783 	 * features a certain CPU supports which CPUID doesn't
784 	 * tell us, CPUID claiming incorrect flags, or other bugs,
785 	 * we handle them here.
786 	 *
787 	 * At the end of this section, c->x86_capability better
788 	 * indicate the features this CPU genuinely supports!
789 	 */
790 	if (this_cpu->c_init)
791 		this_cpu->c_init(c);
792 
793 	/* Disable the PN if appropriate */
794 	squash_the_stupid_serial_number(c);
795 
796 	/*
797 	 * The vendor-specific functions might have changed features.
798 	 * Now we do "generic changes."
799 	 */
800 
801 	/* Filter out anything that depends on CPUID levels we don't have */
802 	filter_cpuid_features(c, true);
803 
804 	/* If the model name is still unset, do table lookup. */
805 	if (!c->x86_model_id[0]) {
806 		const char *p;
807 		p = table_lookup_model(c);
808 		if (p)
809 			strcpy(c->x86_model_id, p);
810 		else
811 			/* Last resort... */
812 			sprintf(c->x86_model_id, "%02x/%02x",
813 				c->x86, c->x86_model);
814 	}
815 
816 #ifdef CONFIG_X86_64
817 	detect_ht(c);
818 #endif
819 
820 	init_hypervisor(c);
821 	/*
822 	 * On SMP, boot_cpu_data holds the common feature set between
823 	 * all CPUs; so make sure that we indicate which features are
824 	 * common between the CPUs.  The first time this routine gets
825 	 * executed, c == &boot_cpu_data.
826 	 */
827 	if (c != &boot_cpu_data) {
828 		/* AND the already accumulated flags with these */
829 		for (i = 0; i < NCAPINTS; i++)
830 			boot_cpu_data.x86_capability[i] &= c->x86_capability[i];
831 	}
832 
833 	/* Clear all flags overriden by options */
834 	for (i = 0; i < NCAPINTS; i++)
835 		c->x86_capability[i] &= ~cleared_cpu_caps[i];
836 
837 #ifdef CONFIG_X86_MCE
838 	/* Init Machine Check Exception if available. */
839 	mcheck_init(c);
840 #endif
841 
842 	select_idle_routine(c);
843 
844 #if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
845 	numa_add_cpu(smp_processor_id());
846 #endif
847 }
848 
849 #ifdef CONFIG_X86_64
850 static void vgetcpu_set_mode(void)
851 {
852 	if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP))
853 		vgetcpu_mode = VGETCPU_RDTSCP;
854 	else
855 		vgetcpu_mode = VGETCPU_LSL;
856 }
857 #endif
858 
859 void __init identify_boot_cpu(void)
860 {
861 	identify_cpu(&boot_cpu_data);
862 #ifdef CONFIG_X86_32
863 	sysenter_setup();
864 	enable_sep_cpu();
865 #else
866 	vgetcpu_set_mode();
867 #endif
868 }
869 
870 void __cpuinit identify_secondary_cpu(struct cpuinfo_x86 *c)
871 {
872 	BUG_ON(c == &boot_cpu_data);
873 	identify_cpu(c);
874 #ifdef CONFIG_X86_32
875 	enable_sep_cpu();
876 #endif
877 	mtrr_ap_init();
878 }
879 
880 struct msr_range {
881 	unsigned	min;
882 	unsigned	max;
883 };
884 
885 static const struct msr_range msr_range_array[] __cpuinitconst = {
886 	{ 0x00000000, 0x00000418},
887 	{ 0xc0000000, 0xc000040b},
888 	{ 0xc0010000, 0xc0010142},
889 	{ 0xc0011000, 0xc001103b},
890 };
891 
892 static void __cpuinit print_cpu_msr(void)
893 {
894 	unsigned index_min, index_max;
895 	unsigned index;
896 	u64 val;
897 	int i;
898 
899 	for (i = 0; i < ARRAY_SIZE(msr_range_array); i++) {
900 		index_min = msr_range_array[i].min;
901 		index_max = msr_range_array[i].max;
902 
903 		for (index = index_min; index < index_max; index++) {
904 			if (rdmsrl_amd_safe(index, &val))
905 				continue;
906 			printk(KERN_INFO " MSR%08x: %016llx\n", index, val);
907 		}
908 	}
909 }
910 
911 static int show_msr __cpuinitdata;
912 
913 static __init int setup_show_msr(char *arg)
914 {
915 	int num;
916 
917 	get_option(&arg, &num);
918 
919 	if (num > 0)
920 		show_msr = num;
921 	return 1;
922 }
923 __setup("show_msr=", setup_show_msr);
924 
925 static __init int setup_noclflush(char *arg)
926 {
927 	setup_clear_cpu_cap(X86_FEATURE_CLFLSH);
928 	return 1;
929 }
930 __setup("noclflush", setup_noclflush);
931 
932 void __cpuinit print_cpu_info(struct cpuinfo_x86 *c)
933 {
934 	const char *vendor = NULL;
935 
936 	if (c->x86_vendor < X86_VENDOR_NUM) {
937 		vendor = this_cpu->c_vendor;
938 	} else {
939 		if (c->cpuid_level >= 0)
940 			vendor = c->x86_vendor_id;
941 	}
942 
943 	if (vendor && !strstr(c->x86_model_id, vendor))
944 		printk(KERN_CONT "%s ", vendor);
945 
946 	if (c->x86_model_id[0])
947 		printk(KERN_CONT "%s", c->x86_model_id);
948 	else
949 		printk(KERN_CONT "%d86", c->x86);
950 
951 	if (c->x86_mask || c->cpuid_level >= 0)
952 		printk(KERN_CONT " stepping %02x\n", c->x86_mask);
953 	else
954 		printk(KERN_CONT "\n");
955 
956 #ifdef CONFIG_SMP
957 	if (c->cpu_index < show_msr)
958 		print_cpu_msr();
959 #else
960 	if (show_msr)
961 		print_cpu_msr();
962 #endif
963 }
964 
965 static __init int setup_disablecpuid(char *arg)
966 {
967 	int bit;
968 
969 	if (get_option(&arg, &bit) && bit < NCAPINTS*32)
970 		setup_clear_cpu_cap(bit);
971 	else
972 		return 0;
973 
974 	return 1;
975 }
976 __setup("clearcpuid=", setup_disablecpuid);
977 
978 #ifdef CONFIG_X86_64
979 struct desc_ptr idt_descr = { 256 * 16 - 1, (unsigned long) idt_table };
980 
981 DEFINE_PER_CPU_FIRST(union irq_stack_union,
982 		     irq_stack_union) __aligned(PAGE_SIZE);
983 
984 DEFINE_PER_CPU(char *, irq_stack_ptr) =
985 	init_per_cpu_var(irq_stack_union.irq_stack) + IRQ_STACK_SIZE - 64;
986 
987 DEFINE_PER_CPU(unsigned long, kernel_stack) =
988 	(unsigned long)&init_thread_union - KERNEL_STACK_OFFSET + THREAD_SIZE;
989 EXPORT_PER_CPU_SYMBOL(kernel_stack);
990 
991 DEFINE_PER_CPU(unsigned int, irq_count) = -1;
992 
993 /*
994  * Special IST stacks which the CPU switches to when it calls
995  * an IST-marked descriptor entry. Up to 7 stacks (hardware
996  * limit), all of them are 4K, except the debug stack which
997  * is 8K.
998  */
999 static const unsigned int exception_stack_sizes[N_EXCEPTION_STACKS] = {
1000 	  [0 ... N_EXCEPTION_STACKS - 1]	= EXCEPTION_STKSZ,
1001 	  [DEBUG_STACK - 1]			= DEBUG_STKSZ
1002 };
1003 
1004 static DEFINE_PER_CPU_PAGE_ALIGNED(char, exception_stacks
1005 	[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ])
1006 	__aligned(PAGE_SIZE);
1007 
1008 /* May not be marked __init: used by software suspend */
1009 void syscall_init(void)
1010 {
1011 	/*
1012 	 * LSTAR and STAR live in a bit strange symbiosis.
1013 	 * They both write to the same internal register. STAR allows to
1014 	 * set CS/DS but only a 32bit target. LSTAR sets the 64bit rip.
1015 	 */
1016 	wrmsrl(MSR_STAR,  ((u64)__USER32_CS)<<48  | ((u64)__KERNEL_CS)<<32);
1017 	wrmsrl(MSR_LSTAR, system_call);
1018 	wrmsrl(MSR_CSTAR, ignore_sysret);
1019 
1020 #ifdef CONFIG_IA32_EMULATION
1021 	syscall32_cpu_init();
1022 #endif
1023 
1024 	/* Flags to clear on syscall */
1025 	wrmsrl(MSR_SYSCALL_MASK,
1026 	       X86_EFLAGS_TF|X86_EFLAGS_DF|X86_EFLAGS_IF|X86_EFLAGS_IOPL);
1027 }
1028 
1029 unsigned long kernel_eflags;
1030 
1031 /*
1032  * Copies of the original ist values from the tss are only accessed during
1033  * debugging, no special alignment required.
1034  */
1035 DEFINE_PER_CPU(struct orig_ist, orig_ist);
1036 
1037 #else	/* CONFIG_X86_64 */
1038 
1039 #ifdef CONFIG_CC_STACKPROTECTOR
1040 DEFINE_PER_CPU(unsigned long, stack_canary);
1041 #endif
1042 
1043 /* Make sure %fs and %gs are initialized properly in idle threads */
1044 struct pt_regs * __cpuinit idle_regs(struct pt_regs *regs)
1045 {
1046 	memset(regs, 0, sizeof(struct pt_regs));
1047 	regs->fs = __KERNEL_PERCPU;
1048 	regs->gs = __KERNEL_STACK_CANARY;
1049 
1050 	return regs;
1051 }
1052 #endif	/* CONFIG_X86_64 */
1053 
1054 /*
1055  * Clear all 6 debug registers:
1056  */
1057 static void clear_all_debug_regs(void)
1058 {
1059 	int i;
1060 
1061 	for (i = 0; i < 8; i++) {
1062 		/* Ignore db4, db5 */
1063 		if ((i == 4) || (i == 5))
1064 			continue;
1065 
1066 		set_debugreg(0, i);
1067 	}
1068 }
1069 
1070 /*
1071  * cpu_init() initializes state that is per-CPU. Some data is already
1072  * initialized (naturally) in the bootstrap process, such as the GDT
1073  * and IDT. We reload them nevertheless, this function acts as a
1074  * 'CPU state barrier', nothing should get across.
1075  * A lot of state is already set up in PDA init for 64 bit
1076  */
1077 #ifdef CONFIG_X86_64
1078 
1079 void __cpuinit cpu_init(void)
1080 {
1081 	struct orig_ist *orig_ist;
1082 	struct task_struct *me;
1083 	struct tss_struct *t;
1084 	unsigned long v;
1085 	int cpu;
1086 	int i;
1087 
1088 	cpu = stack_smp_processor_id();
1089 	t = &per_cpu(init_tss, cpu);
1090 	orig_ist = &per_cpu(orig_ist, cpu);
1091 
1092 #ifdef CONFIG_NUMA
1093 	if (cpu != 0 && percpu_read(node_number) == 0 &&
1094 	    cpu_to_node(cpu) != NUMA_NO_NODE)
1095 		percpu_write(node_number, cpu_to_node(cpu));
1096 #endif
1097 
1098 	me = current;
1099 
1100 	if (cpumask_test_and_set_cpu(cpu, cpu_initialized_mask))
1101 		panic("CPU#%d already initialized!\n", cpu);
1102 
1103 	printk(KERN_INFO "Initializing CPU#%d\n", cpu);
1104 
1105 	clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1106 
1107 	/*
1108 	 * Initialize the per-CPU GDT with the boot GDT,
1109 	 * and set up the GDT descriptor:
1110 	 */
1111 
1112 	switch_to_new_gdt(cpu);
1113 	loadsegment(fs, 0);
1114 
1115 	load_idt((const struct desc_ptr *)&idt_descr);
1116 
1117 	memset(me->thread.tls_array, 0, GDT_ENTRY_TLS_ENTRIES * 8);
1118 	syscall_init();
1119 
1120 	wrmsrl(MSR_FS_BASE, 0);
1121 	wrmsrl(MSR_KERNEL_GS_BASE, 0);
1122 	barrier();
1123 
1124 	check_efer();
1125 	if (cpu != 0)
1126 		enable_x2apic();
1127 
1128 	/*
1129 	 * set up and load the per-CPU TSS
1130 	 */
1131 	if (!orig_ist->ist[0]) {
1132 		char *estacks = per_cpu(exception_stacks, cpu);
1133 
1134 		for (v = 0; v < N_EXCEPTION_STACKS; v++) {
1135 			estacks += exception_stack_sizes[v];
1136 			orig_ist->ist[v] = t->x86_tss.ist[v] =
1137 					(unsigned long)estacks;
1138 		}
1139 	}
1140 
1141 	t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
1142 
1143 	/*
1144 	 * <= is required because the CPU will access up to
1145 	 * 8 bits beyond the end of the IO permission bitmap.
1146 	 */
1147 	for (i = 0; i <= IO_BITMAP_LONGS; i++)
1148 		t->io_bitmap[i] = ~0UL;
1149 
1150 	atomic_inc(&init_mm.mm_count);
1151 	me->active_mm = &init_mm;
1152 	BUG_ON(me->mm);
1153 	enter_lazy_tlb(&init_mm, me);
1154 
1155 	load_sp0(t, &current->thread);
1156 	set_tss_desc(cpu, t);
1157 	load_TR_desc();
1158 	load_LDT(&init_mm.context);
1159 
1160 #ifdef CONFIG_KGDB
1161 	/*
1162 	 * If the kgdb is connected no debug regs should be altered.  This
1163 	 * is only applicable when KGDB and a KGDB I/O module are built
1164 	 * into the kernel and you are using early debugging with
1165 	 * kgdbwait. KGDB will control the kernel HW breakpoint registers.
1166 	 */
1167 	if (kgdb_connected && arch_kgdb_ops.correct_hw_break)
1168 		arch_kgdb_ops.correct_hw_break();
1169 	else
1170 #endif
1171 		clear_all_debug_regs();
1172 
1173 	fpu_init();
1174 
1175 	raw_local_save_flags(kernel_eflags);
1176 
1177 	if (is_uv_system())
1178 		uv_cpu_init();
1179 }
1180 
1181 #else
1182 
1183 void __cpuinit cpu_init(void)
1184 {
1185 	int cpu = smp_processor_id();
1186 	struct task_struct *curr = current;
1187 	struct tss_struct *t = &per_cpu(init_tss, cpu);
1188 	struct thread_struct *thread = &curr->thread;
1189 
1190 	if (cpumask_test_and_set_cpu(cpu, cpu_initialized_mask)) {
1191 		printk(KERN_WARNING "CPU#%d already initialized!\n", cpu);
1192 		for (;;)
1193 			local_irq_enable();
1194 	}
1195 
1196 	printk(KERN_INFO "Initializing CPU#%d\n", cpu);
1197 
1198 	if (cpu_has_vme || cpu_has_tsc || cpu_has_de)
1199 		clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
1200 
1201 	load_idt(&idt_descr);
1202 	switch_to_new_gdt(cpu);
1203 
1204 	/*
1205 	 * Set up and load the per-CPU TSS and LDT
1206 	 */
1207 	atomic_inc(&init_mm.mm_count);
1208 	curr->active_mm = &init_mm;
1209 	BUG_ON(curr->mm);
1210 	enter_lazy_tlb(&init_mm, curr);
1211 
1212 	load_sp0(t, thread);
1213 	set_tss_desc(cpu, t);
1214 	load_TR_desc();
1215 	load_LDT(&init_mm.context);
1216 
1217 #ifdef CONFIG_DOUBLEFAULT
1218 	/* Set up doublefault TSS pointer in the GDT */
1219 	__set_tss_desc(cpu, GDT_ENTRY_DOUBLEFAULT_TSS, &doublefault_tss);
1220 #endif
1221 
1222 	clear_all_debug_regs();
1223 
1224 	/*
1225 	 * Force FPU initialization:
1226 	 */
1227 	if (cpu_has_xsave)
1228 		current_thread_info()->status = TS_XSAVE;
1229 	else
1230 		current_thread_info()->status = 0;
1231 	clear_used_math();
1232 	mxcsr_feature_mask_init();
1233 
1234 	/*
1235 	 * Boot processor to setup the FP and extended state context info.
1236 	 */
1237 	if (smp_processor_id() == boot_cpu_id)
1238 		init_thread_xstate();
1239 
1240 	xsave_init();
1241 }
1242 #endif
1243