xref: /openbmc/linux/arch/x86/kernel/cpu/microcode/intel.c (revision e4781421e883340b796da5a724bda7226817990b)
1 /*
2  * Intel CPU Microcode Update Driver for Linux
3  *
4  * Copyright (C) 2000-2006 Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
5  *		 2006 Shaohua Li <shaohua.li@intel.com>
6  *
7  * Intel CPU microcode early update for Linux
8  *
9  * Copyright (C) 2012 Fenghua Yu <fenghua.yu@intel.com>
10  *		      H Peter Anvin" <hpa@zytor.com>
11  *
12  * This program is free software; you can redistribute it and/or
13  * modify it under the terms of the GNU General Public License
14  * as published by the Free Software Foundation; either version
15  * 2 of the License, or (at your option) any later version.
16  */
17 
18 /*
19  * This needs to be before all headers so that pr_debug in printk.h doesn't turn
20  * printk calls into no_printk().
21  *
22  *#define DEBUG
23  */
24 #define pr_fmt(fmt) "microcode: " fmt
25 
26 #include <linux/earlycpio.h>
27 #include <linux/firmware.h>
28 #include <linux/uaccess.h>
29 #include <linux/vmalloc.h>
30 #include <linux/initrd.h>
31 #include <linux/kernel.h>
32 #include <linux/slab.h>
33 #include <linux/cpu.h>
34 #include <linux/mm.h>
35 
36 #include <asm/microcode_intel.h>
37 #include <asm/processor.h>
38 #include <asm/tlbflush.h>
39 #include <asm/setup.h>
40 #include <asm/msr.h>
41 
42 static const char ucode_path[] = "kernel/x86/microcode/GenuineIntel.bin";
43 
44 /* Current microcode patch used in early patching */
45 struct microcode_intel *intel_ucode_patch;
46 
47 static inline bool cpu_signatures_match(unsigned int s1, unsigned int p1,
48 					unsigned int s2, unsigned int p2)
49 {
50 	if (s1 != s2)
51 		return false;
52 
53 	/* Processor flags are either both 0 ... */
54 	if (!p1 && !p2)
55 		return true;
56 
57 	/* ... or they intersect. */
58 	return p1 & p2;
59 }
60 
61 /*
62  * Returns 1 if update has been found, 0 otherwise.
63  */
64 static int find_matching_signature(void *mc, unsigned int csig, int cpf)
65 {
66 	struct microcode_header_intel *mc_hdr = mc;
67 	struct extended_sigtable *ext_hdr;
68 	struct extended_signature *ext_sig;
69 	int i;
70 
71 	if (cpu_signatures_match(csig, cpf, mc_hdr->sig, mc_hdr->pf))
72 		return 1;
73 
74 	/* Look for ext. headers: */
75 	if (get_totalsize(mc_hdr) <= get_datasize(mc_hdr) + MC_HEADER_SIZE)
76 		return 0;
77 
78 	ext_hdr = mc + get_datasize(mc_hdr) + MC_HEADER_SIZE;
79 	ext_sig = (void *)ext_hdr + EXT_HEADER_SIZE;
80 
81 	for (i = 0; i < ext_hdr->count; i++) {
82 		if (cpu_signatures_match(csig, cpf, ext_sig->sig, ext_sig->pf))
83 			return 1;
84 		ext_sig++;
85 	}
86 	return 0;
87 }
88 
89 /*
90  * Returns 1 if update has been found, 0 otherwise.
91  */
92 static int has_newer_microcode(void *mc, unsigned int csig, int cpf, int new_rev)
93 {
94 	struct microcode_header_intel *mc_hdr = mc;
95 
96 	if (mc_hdr->rev <= new_rev)
97 		return 0;
98 
99 	return find_matching_signature(mc, csig, cpf);
100 }
101 
102 /*
103  * Given CPU signature and a microcode patch, this function finds if the
104  * microcode patch has matching family and model with the CPU.
105  *
106  * %true - if there's a match
107  * %false - otherwise
108  */
109 static bool microcode_matches(struct microcode_header_intel *mc_header,
110 			      unsigned long sig)
111 {
112 	unsigned long total_size = get_totalsize(mc_header);
113 	unsigned long data_size = get_datasize(mc_header);
114 	struct extended_sigtable *ext_header;
115 	unsigned int fam_ucode, model_ucode;
116 	struct extended_signature *ext_sig;
117 	unsigned int fam, model;
118 	int ext_sigcount, i;
119 
120 	fam   = x86_family(sig);
121 	model = x86_model(sig);
122 
123 	fam_ucode   = x86_family(mc_header->sig);
124 	model_ucode = x86_model(mc_header->sig);
125 
126 	if (fam == fam_ucode && model == model_ucode)
127 		return true;
128 
129 	/* Look for ext. headers: */
130 	if (total_size <= data_size + MC_HEADER_SIZE)
131 		return false;
132 
133 	ext_header   = (void *) mc_header + data_size + MC_HEADER_SIZE;
134 	ext_sig      = (void *)ext_header + EXT_HEADER_SIZE;
135 	ext_sigcount = ext_header->count;
136 
137 	for (i = 0; i < ext_sigcount; i++) {
138 		fam_ucode   = x86_family(ext_sig->sig);
139 		model_ucode = x86_model(ext_sig->sig);
140 
141 		if (fam == fam_ucode && model == model_ucode)
142 			return true;
143 
144 		ext_sig++;
145 	}
146 	return false;
147 }
148 
149 static struct ucode_patch *__alloc_microcode_buf(void *data, unsigned int size)
150 {
151 	struct ucode_patch *p;
152 
153 	p = kzalloc(size, GFP_KERNEL);
154 	if (!p)
155 		return ERR_PTR(-ENOMEM);
156 
157 	p->data = kmemdup(data, size, GFP_KERNEL);
158 	if (!p->data) {
159 		kfree(p);
160 		return ERR_PTR(-ENOMEM);
161 	}
162 
163 	return p;
164 }
165 
166 static void save_microcode_patch(void *data, unsigned int size)
167 {
168 	struct microcode_header_intel *mc_hdr, *mc_saved_hdr;
169 	struct ucode_patch *iter, *tmp, *p;
170 	bool prev_found = false;
171 	unsigned int sig, pf;
172 
173 	mc_hdr = (struct microcode_header_intel *)data;
174 
175 	list_for_each_entry_safe(iter, tmp, &microcode_cache, plist) {
176 		mc_saved_hdr = (struct microcode_header_intel *)iter->data;
177 		sig	     = mc_saved_hdr->sig;
178 		pf	     = mc_saved_hdr->pf;
179 
180 		if (find_matching_signature(data, sig, pf)) {
181 			prev_found = true;
182 
183 			if (mc_hdr->rev <= mc_saved_hdr->rev)
184 				continue;
185 
186 			p = __alloc_microcode_buf(data, size);
187 			if (IS_ERR(p))
188 				pr_err("Error allocating buffer %p\n", data);
189 			else
190 				list_replace(&iter->plist, &p->plist);
191 		}
192 	}
193 
194 	/*
195 	 * There weren't any previous patches found in the list cache; save the
196 	 * newly found.
197 	 */
198 	if (!prev_found) {
199 		p = __alloc_microcode_buf(data, size);
200 		if (IS_ERR(p))
201 			pr_err("Error allocating buffer for %p\n", data);
202 		else
203 			list_add_tail(&p->plist, &microcode_cache);
204 	}
205 }
206 
207 static int microcode_sanity_check(void *mc, int print_err)
208 {
209 	unsigned long total_size, data_size, ext_table_size;
210 	struct microcode_header_intel *mc_header = mc;
211 	struct extended_sigtable *ext_header = NULL;
212 	u32 sum, orig_sum, ext_sigcount = 0, i;
213 	struct extended_signature *ext_sig;
214 
215 	total_size = get_totalsize(mc_header);
216 	data_size = get_datasize(mc_header);
217 
218 	if (data_size + MC_HEADER_SIZE > total_size) {
219 		if (print_err)
220 			pr_err("Error: bad microcode data file size.\n");
221 		return -EINVAL;
222 	}
223 
224 	if (mc_header->ldrver != 1 || mc_header->hdrver != 1) {
225 		if (print_err)
226 			pr_err("Error: invalid/unknown microcode update format.\n");
227 		return -EINVAL;
228 	}
229 
230 	ext_table_size = total_size - (MC_HEADER_SIZE + data_size);
231 	if (ext_table_size) {
232 		u32 ext_table_sum = 0;
233 		u32 *ext_tablep;
234 
235 		if ((ext_table_size < EXT_HEADER_SIZE)
236 		 || ((ext_table_size - EXT_HEADER_SIZE) % EXT_SIGNATURE_SIZE)) {
237 			if (print_err)
238 				pr_err("Error: truncated extended signature table.\n");
239 			return -EINVAL;
240 		}
241 
242 		ext_header = mc + MC_HEADER_SIZE + data_size;
243 		if (ext_table_size != exttable_size(ext_header)) {
244 			if (print_err)
245 				pr_err("Error: extended signature table size mismatch.\n");
246 			return -EFAULT;
247 		}
248 
249 		ext_sigcount = ext_header->count;
250 
251 		/*
252 		 * Check extended table checksum: the sum of all dwords that
253 		 * comprise a valid table must be 0.
254 		 */
255 		ext_tablep = (u32 *)ext_header;
256 
257 		i = ext_table_size / sizeof(u32);
258 		while (i--)
259 			ext_table_sum += ext_tablep[i];
260 
261 		if (ext_table_sum) {
262 			if (print_err)
263 				pr_warn("Bad extended signature table checksum, aborting.\n");
264 			return -EINVAL;
265 		}
266 	}
267 
268 	/*
269 	 * Calculate the checksum of update data and header. The checksum of
270 	 * valid update data and header including the extended signature table
271 	 * must be 0.
272 	 */
273 	orig_sum = 0;
274 	i = (MC_HEADER_SIZE + data_size) / sizeof(u32);
275 	while (i--)
276 		orig_sum += ((u32 *)mc)[i];
277 
278 	if (orig_sum) {
279 		if (print_err)
280 			pr_err("Bad microcode data checksum, aborting.\n");
281 		return -EINVAL;
282 	}
283 
284 	if (!ext_table_size)
285 		return 0;
286 
287 	/*
288 	 * Check extended signature checksum: 0 => valid.
289 	 */
290 	for (i = 0; i < ext_sigcount; i++) {
291 		ext_sig = (void *)ext_header + EXT_HEADER_SIZE +
292 			  EXT_SIGNATURE_SIZE * i;
293 
294 		sum = (mc_header->sig + mc_header->pf + mc_header->cksum) -
295 		      (ext_sig->sig + ext_sig->pf + ext_sig->cksum);
296 		if (sum) {
297 			if (print_err)
298 				pr_err("Bad extended signature checksum, aborting.\n");
299 			return -EINVAL;
300 		}
301 	}
302 	return 0;
303 }
304 
305 /*
306  * Get microcode matching with BSP's model. Only CPUs with the same model as
307  * BSP can stay in the platform.
308  */
309 static struct microcode_intel *
310 scan_microcode(void *data, size_t size, struct ucode_cpu_info *uci, bool save)
311 {
312 	struct microcode_header_intel *mc_header;
313 	struct microcode_intel *patch = NULL;
314 	unsigned int mc_size;
315 
316 	while (size) {
317 		if (size < sizeof(struct microcode_header_intel))
318 			break;
319 
320 		mc_header = (struct microcode_header_intel *)data;
321 
322 		mc_size = get_totalsize(mc_header);
323 		if (!mc_size ||
324 		    mc_size > size ||
325 		    microcode_sanity_check(data, 0) < 0)
326 			break;
327 
328 		size -= mc_size;
329 
330 		if (!microcode_matches(mc_header, uci->cpu_sig.sig)) {
331 			data += mc_size;
332 			continue;
333 		}
334 
335 		if (save) {
336 			save_microcode_patch(data, mc_size);
337 			goto next;
338 		}
339 
340 
341 		if (!patch) {
342 			if (!has_newer_microcode(data,
343 						 uci->cpu_sig.sig,
344 						 uci->cpu_sig.pf,
345 						 uci->cpu_sig.rev))
346 				goto next;
347 
348 		} else {
349 			struct microcode_header_intel *phdr = &patch->hdr;
350 
351 			if (!has_newer_microcode(data,
352 						 phdr->sig,
353 						 phdr->pf,
354 						 phdr->rev))
355 				goto next;
356 		}
357 
358 		/* We have a newer patch, save it. */
359 		patch = data;
360 
361 next:
362 		data += mc_size;
363 	}
364 
365 	if (size)
366 		return NULL;
367 
368 	return patch;
369 }
370 
371 static void cpuid_1(void)
372 {
373 	/*
374 	 * According to the Intel SDM, Volume 3, 9.11.7:
375 	 *
376 	 *   CPUID returns a value in a model specific register in
377 	 *   addition to its usual register return values. The
378 	 *   semantics of CPUID cause it to deposit an update ID value
379 	 *   in the 64-bit model-specific register at address 08BH
380 	 *   (IA32_BIOS_SIGN_ID). If no update is present in the
381 	 *   processor, the value in the MSR remains unmodified.
382 	 *
383 	 * Use native_cpuid -- this code runs very early and we don't
384 	 * want to mess with paravirt.
385 	 */
386 	unsigned int eax = 1, ebx, ecx = 0, edx;
387 
388 	native_cpuid(&eax, &ebx, &ecx, &edx);
389 }
390 
391 static int collect_cpu_info_early(struct ucode_cpu_info *uci)
392 {
393 	unsigned int val[2];
394 	unsigned int family, model;
395 	struct cpu_signature csig = { 0 };
396 	unsigned int eax, ebx, ecx, edx;
397 
398 	memset(uci, 0, sizeof(*uci));
399 
400 	eax = 0x00000001;
401 	ecx = 0;
402 	native_cpuid(&eax, &ebx, &ecx, &edx);
403 	csig.sig = eax;
404 
405 	family = x86_family(eax);
406 	model  = x86_model(eax);
407 
408 	if ((model >= 5) || (family > 6)) {
409 		/* get processor flags from MSR 0x17 */
410 		native_rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
411 		csig.pf = 1 << ((val[1] >> 18) & 7);
412 	}
413 	native_wrmsrl(MSR_IA32_UCODE_REV, 0);
414 
415 	/* As documented in the SDM: Do a CPUID 1 here */
416 	cpuid_1();
417 
418 	/* get the current revision from MSR 0x8B */
419 	native_rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
420 
421 	csig.rev = val[1];
422 
423 	uci->cpu_sig = csig;
424 	uci->valid = 1;
425 
426 	return 0;
427 }
428 
429 static void show_saved_mc(void)
430 {
431 #ifdef DEBUG
432 	int i = 0, j;
433 	unsigned int sig, pf, rev, total_size, data_size, date;
434 	struct ucode_cpu_info uci;
435 	struct ucode_patch *p;
436 
437 	if (list_empty(&microcode_cache)) {
438 		pr_debug("no microcode data saved.\n");
439 		return;
440 	}
441 
442 	collect_cpu_info_early(&uci);
443 
444 	sig	= uci.cpu_sig.sig;
445 	pf	= uci.cpu_sig.pf;
446 	rev	= uci.cpu_sig.rev;
447 	pr_debug("CPU: sig=0x%x, pf=0x%x, rev=0x%x\n", sig, pf, rev);
448 
449 	list_for_each_entry(p, &microcode_cache, plist) {
450 		struct microcode_header_intel *mc_saved_header;
451 		struct extended_sigtable *ext_header;
452 		struct extended_signature *ext_sig;
453 		int ext_sigcount;
454 
455 		mc_saved_header = (struct microcode_header_intel *)p->data;
456 
457 		sig	= mc_saved_header->sig;
458 		pf	= mc_saved_header->pf;
459 		rev	= mc_saved_header->rev;
460 		date	= mc_saved_header->date;
461 
462 		total_size	= get_totalsize(mc_saved_header);
463 		data_size	= get_datasize(mc_saved_header);
464 
465 		pr_debug("mc_saved[%d]: sig=0x%x, pf=0x%x, rev=0x%x, total size=0x%x, date = %04x-%02x-%02x\n",
466 			 i++, sig, pf, rev, total_size,
467 			 date & 0xffff,
468 			 date >> 24,
469 			 (date >> 16) & 0xff);
470 
471 		/* Look for ext. headers: */
472 		if (total_size <= data_size + MC_HEADER_SIZE)
473 			continue;
474 
475 		ext_header = (void *)mc_saved_header + data_size + MC_HEADER_SIZE;
476 		ext_sigcount = ext_header->count;
477 		ext_sig = (void *)ext_header + EXT_HEADER_SIZE;
478 
479 		for (j = 0; j < ext_sigcount; j++) {
480 			sig = ext_sig->sig;
481 			pf = ext_sig->pf;
482 
483 			pr_debug("\tExtended[%d]: sig=0x%x, pf=0x%x\n",
484 				 j, sig, pf);
485 
486 			ext_sig++;
487 		}
488 	}
489 #endif
490 }
491 
492 /*
493  * Save this microcode patch. It will be loaded early when a CPU is
494  * hot-added or resumes.
495  */
496 static void save_mc_for_early(u8 *mc, unsigned int size)
497 {
498 #ifdef CONFIG_HOTPLUG_CPU
499 	/* Synchronization during CPU hotplug. */
500 	static DEFINE_MUTEX(x86_cpu_microcode_mutex);
501 
502 	mutex_lock(&x86_cpu_microcode_mutex);
503 
504 	save_microcode_patch(mc, size);
505 	show_saved_mc();
506 
507 	mutex_unlock(&x86_cpu_microcode_mutex);
508 #endif
509 }
510 
511 static bool load_builtin_intel_microcode(struct cpio_data *cp)
512 {
513 	unsigned int eax = 1, ebx, ecx = 0, edx;
514 	char name[30];
515 
516 	if (IS_ENABLED(CONFIG_X86_32))
517 		return false;
518 
519 	native_cpuid(&eax, &ebx, &ecx, &edx);
520 
521 	sprintf(name, "intel-ucode/%02x-%02x-%02x",
522 		      x86_family(eax), x86_model(eax), x86_stepping(eax));
523 
524 	return get_builtin_firmware(cp, name);
525 }
526 
527 /*
528  * Print ucode update info.
529  */
530 static void
531 print_ucode_info(struct ucode_cpu_info *uci, unsigned int date)
532 {
533 	pr_info_once("microcode updated early to revision 0x%x, date = %04x-%02x-%02x\n",
534 		     uci->cpu_sig.rev,
535 		     date & 0xffff,
536 		     date >> 24,
537 		     (date >> 16) & 0xff);
538 }
539 
540 #ifdef CONFIG_X86_32
541 
542 static int delay_ucode_info;
543 static int current_mc_date;
544 
545 /*
546  * Print early updated ucode info after printk works. This is delayed info dump.
547  */
548 void show_ucode_info_early(void)
549 {
550 	struct ucode_cpu_info uci;
551 
552 	if (delay_ucode_info) {
553 		collect_cpu_info_early(&uci);
554 		print_ucode_info(&uci, current_mc_date);
555 		delay_ucode_info = 0;
556 	}
557 }
558 
559 /*
560  * At this point, we can not call printk() yet. Delay printing microcode info in
561  * show_ucode_info_early() until printk() works.
562  */
563 static void print_ucode(struct ucode_cpu_info *uci)
564 {
565 	struct microcode_intel *mc;
566 	int *delay_ucode_info_p;
567 	int *current_mc_date_p;
568 
569 	mc = uci->mc;
570 	if (!mc)
571 		return;
572 
573 	delay_ucode_info_p = (int *)__pa_nodebug(&delay_ucode_info);
574 	current_mc_date_p = (int *)__pa_nodebug(&current_mc_date);
575 
576 	*delay_ucode_info_p = 1;
577 	*current_mc_date_p = mc->hdr.date;
578 }
579 #else
580 
581 /*
582  * Flush global tlb. We only do this in x86_64 where paging has been enabled
583  * already and PGE should be enabled as well.
584  */
585 static inline void flush_tlb_early(void)
586 {
587 	__native_flush_tlb_global_irq_disabled();
588 }
589 
590 static inline void print_ucode(struct ucode_cpu_info *uci)
591 {
592 	struct microcode_intel *mc;
593 
594 	mc = uci->mc;
595 	if (!mc)
596 		return;
597 
598 	print_ucode_info(uci, mc->hdr.date);
599 }
600 #endif
601 
602 static int apply_microcode_early(struct ucode_cpu_info *uci, bool early)
603 {
604 	struct microcode_intel *mc;
605 	unsigned int val[2];
606 
607 	mc = uci->mc;
608 	if (!mc)
609 		return 0;
610 
611 	/* write microcode via MSR 0x79 */
612 	native_wrmsrl(MSR_IA32_UCODE_WRITE, (unsigned long)mc->bits);
613 	native_wrmsrl(MSR_IA32_UCODE_REV, 0);
614 
615 	/* As documented in the SDM: Do a CPUID 1 here */
616 	cpuid_1();
617 
618 	/* get the current revision from MSR 0x8B */
619 	native_rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
620 	if (val[1] != mc->hdr.rev)
621 		return -1;
622 
623 #ifdef CONFIG_X86_64
624 	/* Flush global tlb. This is precaution. */
625 	flush_tlb_early();
626 #endif
627 	uci->cpu_sig.rev = val[1];
628 
629 	if (early)
630 		print_ucode(uci);
631 	else
632 		print_ucode_info(uci, mc->hdr.date);
633 
634 	return 0;
635 }
636 
637 int __init save_microcode_in_initrd_intel(void)
638 {
639 	struct ucode_cpu_info uci;
640 	struct cpio_data cp;
641 
642 	/*
643 	 * AP loading didn't find any microcode patch, no need to save anything.
644 	 */
645 	if (!intel_ucode_patch || IS_ERR(intel_ucode_patch))
646 		return 0;
647 
648 	if (!load_builtin_intel_microcode(&cp))
649 		cp = find_microcode_in_initrd(ucode_path, false);
650 
651 	if (!(cp.data && cp.size))
652 		return 0;
653 
654 	collect_cpu_info_early(&uci);
655 
656 	scan_microcode(cp.data, cp.size, &uci, true);
657 
658 	show_saved_mc();
659 
660 	return 0;
661 }
662 
663 
664 /*
665  * @res_patch, output: a pointer to the patch we found.
666  */
667 static struct microcode_intel *__load_ucode_intel(struct ucode_cpu_info *uci)
668 {
669 	static const char *path;
670 	struct cpio_data cp;
671 	bool use_pa;
672 
673 	if (IS_ENABLED(CONFIG_X86_32)) {
674 		path	  = (const char *)__pa_nodebug(ucode_path);
675 		use_pa	  = true;
676 	} else {
677 		path	  = ucode_path;
678 		use_pa	  = false;
679 	}
680 
681 	/* try built-in microcode first */
682 	if (!load_builtin_intel_microcode(&cp))
683 		cp = find_microcode_in_initrd(path, use_pa);
684 
685 	if (!(cp.data && cp.size))
686 		return NULL;
687 
688 	collect_cpu_info_early(uci);
689 
690 	return scan_microcode(cp.data, cp.size, uci, false);
691 }
692 
693 void __init load_ucode_intel_bsp(void)
694 {
695 	struct microcode_intel *patch;
696 	struct ucode_cpu_info uci;
697 
698 	patch = __load_ucode_intel(&uci);
699 	if (!patch)
700 		return;
701 
702 	uci.mc = patch;
703 
704 	apply_microcode_early(&uci, true);
705 }
706 
707 void load_ucode_intel_ap(void)
708 {
709 	struct microcode_intel *patch, **iup;
710 	struct ucode_cpu_info uci;
711 
712 	if (IS_ENABLED(CONFIG_X86_32))
713 		iup = (struct microcode_intel **) __pa_nodebug(&intel_ucode_patch);
714 	else
715 		iup = &intel_ucode_patch;
716 
717 reget:
718 	if (!*iup) {
719 		patch = __load_ucode_intel(&uci);
720 		if (!patch)
721 			return;
722 
723 		*iup = patch;
724 	}
725 
726 	uci.mc = *iup;
727 
728 	if (apply_microcode_early(&uci, true)) {
729 		/* Mixed-silicon system? Try to refetch the proper patch: */
730 		*iup = NULL;
731 
732 		goto reget;
733 	}
734 }
735 
736 static struct microcode_intel *find_patch(struct ucode_cpu_info *uci)
737 {
738 	struct microcode_header_intel *phdr;
739 	struct ucode_patch *iter, *tmp;
740 
741 	list_for_each_entry_safe(iter, tmp, &microcode_cache, plist) {
742 
743 		phdr = (struct microcode_header_intel *)iter->data;
744 
745 		if (phdr->rev <= uci->cpu_sig.rev)
746 			continue;
747 
748 		if (!find_matching_signature(phdr,
749 					     uci->cpu_sig.sig,
750 					     uci->cpu_sig.pf))
751 			continue;
752 
753 		return iter->data;
754 	}
755 	return NULL;
756 }
757 
758 void reload_ucode_intel(void)
759 {
760 	struct microcode_intel *p;
761 	struct ucode_cpu_info uci;
762 
763 	collect_cpu_info_early(&uci);
764 
765 	p = find_patch(&uci);
766 	if (!p)
767 		return;
768 
769 	uci.mc = p;
770 
771 	apply_microcode_early(&uci, false);
772 }
773 
774 static int collect_cpu_info(int cpu_num, struct cpu_signature *csig)
775 {
776 	static struct cpu_signature prev;
777 	struct cpuinfo_x86 *c = &cpu_data(cpu_num);
778 	unsigned int val[2];
779 
780 	memset(csig, 0, sizeof(*csig));
781 
782 	csig->sig = cpuid_eax(0x00000001);
783 
784 	if ((c->x86_model >= 5) || (c->x86 > 6)) {
785 		/* get processor flags from MSR 0x17 */
786 		rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
787 		csig->pf = 1 << ((val[1] >> 18) & 7);
788 	}
789 
790 	csig->rev = c->microcode;
791 
792 	/* No extra locking on prev, races are harmless. */
793 	if (csig->sig != prev.sig || csig->pf != prev.pf || csig->rev != prev.rev) {
794 		pr_info("sig=0x%x, pf=0x%x, revision=0x%x\n",
795 			csig->sig, csig->pf, csig->rev);
796 		prev = *csig;
797 	}
798 
799 	return 0;
800 }
801 
802 static int apply_microcode_intel(int cpu)
803 {
804 	struct microcode_intel *mc;
805 	struct ucode_cpu_info *uci;
806 	struct cpuinfo_x86 *c;
807 	unsigned int val[2];
808 	static int prev_rev;
809 
810 	/* We should bind the task to the CPU */
811 	if (WARN_ON(raw_smp_processor_id() != cpu))
812 		return -1;
813 
814 	uci = ucode_cpu_info + cpu;
815 	mc = uci->mc;
816 	if (!mc) {
817 		/* Look for a newer patch in our cache: */
818 		mc = find_patch(uci);
819 		if (!mc)
820 			return 0;
821 	}
822 
823 	/* write microcode via MSR 0x79 */
824 	wrmsrl(MSR_IA32_UCODE_WRITE, (unsigned long)mc->bits);
825 	wrmsrl(MSR_IA32_UCODE_REV, 0);
826 
827 	/* As documented in the SDM: Do a CPUID 1 here */
828 	cpuid_1();
829 
830 	/* get the current revision from MSR 0x8B */
831 	rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
832 
833 	if (val[1] != mc->hdr.rev) {
834 		pr_err("CPU%d update to revision 0x%x failed\n",
835 		       cpu, mc->hdr.rev);
836 		return -1;
837 	}
838 
839 	if (val[1] != prev_rev) {
840 		pr_info("updated to revision 0x%x, date = %04x-%02x-%02x\n",
841 			val[1],
842 			mc->hdr.date & 0xffff,
843 			mc->hdr.date >> 24,
844 			(mc->hdr.date >> 16) & 0xff);
845 		prev_rev = val[1];
846 	}
847 
848 	c = &cpu_data(cpu);
849 
850 	uci->cpu_sig.rev = val[1];
851 	c->microcode = val[1];
852 
853 	return 0;
854 }
855 
856 static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size,
857 				int (*get_ucode_data)(void *, const void *, size_t))
858 {
859 	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
860 	u8 *ucode_ptr = data, *new_mc = NULL, *mc = NULL;
861 	int new_rev = uci->cpu_sig.rev;
862 	unsigned int leftover = size;
863 	unsigned int curr_mc_size = 0;
864 	unsigned int csig, cpf;
865 
866 	while (leftover) {
867 		struct microcode_header_intel mc_header;
868 		unsigned int mc_size;
869 
870 		if (leftover < sizeof(mc_header)) {
871 			pr_err("error! Truncated header in microcode data file\n");
872 			break;
873 		}
874 
875 		if (get_ucode_data(&mc_header, ucode_ptr, sizeof(mc_header)))
876 			break;
877 
878 		mc_size = get_totalsize(&mc_header);
879 		if (!mc_size || mc_size > leftover) {
880 			pr_err("error! Bad data in microcode data file\n");
881 			break;
882 		}
883 
884 		/* For performance reasons, reuse mc area when possible */
885 		if (!mc || mc_size > curr_mc_size) {
886 			vfree(mc);
887 			mc = vmalloc(mc_size);
888 			if (!mc)
889 				break;
890 			curr_mc_size = mc_size;
891 		}
892 
893 		if (get_ucode_data(mc, ucode_ptr, mc_size) ||
894 		    microcode_sanity_check(mc, 1) < 0) {
895 			break;
896 		}
897 
898 		csig = uci->cpu_sig.sig;
899 		cpf = uci->cpu_sig.pf;
900 		if (has_newer_microcode(mc, csig, cpf, new_rev)) {
901 			vfree(new_mc);
902 			new_rev = mc_header.rev;
903 			new_mc  = mc;
904 			mc = NULL;	/* trigger new vmalloc */
905 		}
906 
907 		ucode_ptr += mc_size;
908 		leftover  -= mc_size;
909 	}
910 
911 	vfree(mc);
912 
913 	if (leftover) {
914 		vfree(new_mc);
915 		return UCODE_ERROR;
916 	}
917 
918 	if (!new_mc)
919 		return UCODE_NFOUND;
920 
921 	vfree(uci->mc);
922 	uci->mc = (struct microcode_intel *)new_mc;
923 
924 	/*
925 	 * If early loading microcode is supported, save this mc into
926 	 * permanent memory. So it will be loaded early when a CPU is hot added
927 	 * or resumes.
928 	 */
929 	save_mc_for_early(new_mc, curr_mc_size);
930 
931 	pr_debug("CPU%d found a matching microcode update with version 0x%x (current=0x%x)\n",
932 		 cpu, new_rev, uci->cpu_sig.rev);
933 
934 	return UCODE_OK;
935 }
936 
937 static int get_ucode_fw(void *to, const void *from, size_t n)
938 {
939 	memcpy(to, from, n);
940 	return 0;
941 }
942 
943 static enum ucode_state request_microcode_fw(int cpu, struct device *device,
944 					     bool refresh_fw)
945 {
946 	char name[30];
947 	struct cpuinfo_x86 *c = &cpu_data(cpu);
948 	const struct firmware *firmware;
949 	enum ucode_state ret;
950 
951 	sprintf(name, "intel-ucode/%02x-%02x-%02x",
952 		c->x86, c->x86_model, c->x86_mask);
953 
954 	if (request_firmware_direct(&firmware, name, device)) {
955 		pr_debug("data file %s load failed\n", name);
956 		return UCODE_NFOUND;
957 	}
958 
959 	ret = generic_load_microcode(cpu, (void *)firmware->data,
960 				     firmware->size, &get_ucode_fw);
961 
962 	release_firmware(firmware);
963 
964 	return ret;
965 }
966 
967 static int get_ucode_user(void *to, const void *from, size_t n)
968 {
969 	return copy_from_user(to, from, n);
970 }
971 
972 static enum ucode_state
973 request_microcode_user(int cpu, const void __user *buf, size_t size)
974 {
975 	return generic_load_microcode(cpu, (void *)buf, size, &get_ucode_user);
976 }
977 
978 static struct microcode_ops microcode_intel_ops = {
979 	.request_microcode_user		  = request_microcode_user,
980 	.request_microcode_fw             = request_microcode_fw,
981 	.collect_cpu_info                 = collect_cpu_info,
982 	.apply_microcode                  = apply_microcode_intel,
983 };
984 
985 struct microcode_ops * __init init_intel_microcode(void)
986 {
987 	struct cpuinfo_x86 *c = &boot_cpu_data;
988 
989 	if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6 ||
990 	    cpu_has(c, X86_FEATURE_IA64)) {
991 		pr_err("Intel CPU family 0x%x not supported\n", c->x86);
992 		return NULL;
993 	}
994 
995 	return &microcode_intel_ops;
996 }
997