aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/kernel/microcode_intel_early.c
blob: 2e9e12871c2b51a9fe48068369f8dd4346a4db51 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
/*
 *	Intel CPU microcode early update for Linux
 *
 *	Copyright (C) 2012 Fenghua Yu <fenghua.yu@intel.com>
 *			   H Peter Anvin" <hpa@zytor.com>
 *
 *	This allows to early upgrade microcode on Intel processors
 *	belonging to IA-32 family - PentiumPro, Pentium II,
 *	Pentium III, Xeon, Pentium 4, etc.
 *
 *	Reference: Section 9.11 of Volume 3, IA-32 Intel Architecture
 *	Software Developer's Manual.
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License
 *	as published by the Free Software Foundation; either version
 *	2 of the License, or (at your option) any later version.
 */
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/earlycpio.h>
#include <linux/initrd.h>
#include <linux/cpu.h>
#include <asm/msr.h>
#include <asm/microcode_intel.h>
#include <asm/processor.h>
#include <asm/tlbflush.h>
#include <asm/setup.h>

unsigned long mc_saved_in_initrd[MAX_UCODE_COUNT];
struct mc_saved_data {
	unsigned int mc_saved_count;
	struct microcode_intel **mc_saved;
} mc_saved_data;

static enum ucode_state __cpuinit
generic_load_microcode_early(struct microcode_intel **mc_saved_p,
			     unsigned int mc_saved_count,
			     struct ucode_cpu_info *uci)
{
	struct microcode_intel *ucode_ptr, *new_mc = NULL;
	int new_rev = uci->cpu_sig.rev;
	enum ucode_state state = UCODE_OK;
	unsigned int mc_size;
	struct microcode_header_intel *mc_header;
	unsigned int csig = uci->cpu_sig.sig;
	unsigned int cpf = uci->cpu_sig.pf;
	int i;

	for (i = 0; i < mc_saved_count; i++) {
		ucode_ptr = mc_saved_p[i];

		mc_header = (struct microcode_header_intel *)ucode_ptr;
		mc_size = get_totalsize(mc_header);
		if (get_matching_microcode(csig, cpf, ucode_ptr, new_rev)) {
			new_rev = mc_header->rev;
			new_mc  = ucode_ptr;
		}
	}

	if (!new_mc) {
		state = UCODE_NFOUND;
		goto out;
	}

	uci->mc = (struct microcode_intel *)new_mc;
out:
	return state;
}

static void __cpuinit
microcode_pointer(struct microcode_intel **mc_saved,
		  unsigned long *mc_saved_in_initrd,
		  unsigned long initrd_start, int mc_saved_count)
{
	int i;

	for (i = 0; i < mc_saved_count; i++)
		mc_saved[i] = (struct microcode_intel *)
			      (mc_saved_in_initrd[i] + initrd_start);
}

#ifdef CONFIG_X86_32
static void __cpuinit
microcode_phys(struct microcode_intel **mc_saved_tmp,
	       struct mc_saved_data *mc_saved_data)
{
	int i;
	struct microcode_intel ***mc_saved;

	mc_saved = (struct microcode_intel ***)
		   __pa_nodebug(&mc_saved_data->mc_saved);
	for (i = 0; i < mc_saved_data->mc_saved_count; i++) {
		struct microcode_intel *p;

		p = *(struct microcode_intel **)
			__pa_nodebug(mc_saved_data->mc_saved + i);
		mc_saved_tmp[i] = (struct microcode_intel *)__pa_nodebug(p);
	}
}
#endif

static enum ucode_state __cpuinit
load_microcode(struct mc_saved_data *mc_saved_data,
	       unsigned long *mc_saved_in_initrd,
	       unsigned long initrd_start,
	       struct ucode_cpu_info *uci)
{
	struct microcode_intel *mc_saved_tmp[MAX_UCODE_COUNT];
	unsigned int count = mc_saved_data->mc_saved_count;

	if (!mc_saved_data->mc_saved) {
		microcode_pointer(mc_saved_tmp, mc_saved_in_initrd,
				  initrd_start, count);

		return generic_load_microcode_early(mc_saved_tmp, count, uci);
	} else {
#ifdef CONFIG_X86_32
		microcode_phys(mc_saved_tmp, mc_saved_data);
		return generic_load_microcode_early(mc_saved_tmp, count, uci);
#else
		return generic_load_microcode_early(mc_saved_data->mc_saved,
						    count, uci);
#endif
	}
}

static u8 get_x86_family(unsigned long sig)
{
	u8 x86;

	x86 = (sig >> 8) & 0xf;

	if (x86 == 0xf)
		x86 += (sig >> 20) & 0xff;

	return x86;
}

static u8 get_x86_model(unsigned long sig)
{
	u8 x86, x86_model;

	x86 = get_x86_family(sig);
	x86_model = (sig >> 4) & 0xf;

	if (x86 == 0x6 || x86 == 0xf)
		x86_model += ((sig >> 16) & 0xf) << 4;

	return x86_model;
}

/*
 * Given CPU signature and a microcode patch, this function finds if the
 * microcode patch has matching family and model with the CPU.
 */
static enum ucode_state
matching_model_microcode(struct microcode_header_intel *mc_header,
			unsigned long sig)
{
	u8 x86, x86_model;
	u8 x86_ucode, x86_model_ucode;
	struct extended_sigtable *ext_header;
	unsigned long total_size = get_totalsize(mc_header);
	unsigned long data_size = get_datasize(mc_header);
	int ext_sigcount, i;
	struct extended_signature *ext_sig;

	x86 = get_x86_family(sig);
	x86_model = get_x86_model(sig);

	x86_ucode = get_x86_family(mc_header->sig);
	x86_model_ucode = get_x86_model(mc_header->sig);

	if (x86 == x86_ucode && x86_model == x86_model_ucode)
		return UCODE_OK;

	/* Look for ext. headers: */
	if (total_size <= data_size + MC_HEADER_SIZE)
		return UCODE_NFOUND;

	ext_header = (struct extended_sigtable *)
		     mc_header + data_size + MC_HEADER_SIZE;
	ext_sigcount = ext_header->count;
	ext_sig = (void *)ext_header + EXT_HEADER_SIZE;

	for (i = 0; i < ext_sigcount; i++) {
		x86_ucode = get_x86_family(ext_sig->sig);
		x86_model_ucode = get_x86_model(ext_sig->sig);

		if (x86 == x86_ucode && x86_model == x86_model_ucode)
			return UCODE_OK;

		ext_sig++;
	}

	return UCODE_NFOUND;
}

static int
save_microcode(struct mc_saved_data *mc_saved_data,
	       struct microcode_intel **mc_saved_src,
	       unsigned int mc_saved_count)
{
	int i, j;
	struct microcode_intel **mc_saved_p;
	int ret;

	if (!mc_saved_count)
		return -EINVAL;

	/*
	 * Copy new microcode data.
	 */
	mc_saved_p = kmalloc(mc_saved_count*sizeof(struct microcode_intel *),
			     GFP_KERNEL);
	if (!mc_saved_p)
		return -ENOMEM;

	for (i = 0; i < mc_saved_count; i++) {
		struct microcode_intel *mc = mc_saved_src[i];
		struct microcode_header_intel *mc_header = &mc->hdr;
		unsigned long mc_size = get_totalsize(mc_header);
		mc_saved_p[i] = kmalloc(mc_size, GFP_KERNEL);
		if (!mc_saved_p[i]) {
			ret = -ENOMEM;
			goto err;
		}
		if (!mc_saved_src[i]) {
			ret = -EINVAL;
			goto err;
		}
		memcpy(mc_saved_p[i], mc, mc_size);
	}

	/*
	 * Point to newly saved microcode.
	 */
	mc_saved_data->mc_saved = mc_saved_p;
	mc_saved_data->mc_saved_count = mc_saved_count;

	return 0;

err:
	for (j = 0; j <= i; j++)
		kfree(mc_saved_p[j]);
	kfree(mc_saved_p);

	return ret;
}

/*
 * A microcode patch in ucode_ptr is saved into mc_saved
 * - if it has matching signature and newer revision compared to an existing
 *   patch mc_saved.
 * - or if it is a newly discovered microcode patch.
 *
 * The microcode patch should have matching model with CPU.
 */
static void _save_mc(struct microcode_intel **mc_saved, u8 *ucode_ptr,
		     unsigned int *mc_saved_count_p)
{
	int i;
	int found = 0;
	unsigned int mc_saved_count = *mc_saved_count_p;
	struct microcode_header_intel *mc_header;

	mc_header = (struct microcode_header_intel *)ucode_ptr;
	for (i = 0; i < mc_saved_count; i++) {
		unsigned int sig, pf;
		unsigned int new_rev;
		struct microcode_header_intel *mc_saved_header =
			     (struct microcode_header_intel *)mc_saved[i];
		sig = mc_saved_header->sig;
		pf = mc_saved_header->pf;
		new_rev = mc_header->rev;

		if (get_matching_sig(sig, pf, ucode_ptr, new_rev)) {
			found = 1;
			if (update_match_revision(mc_header, new_rev)) {
				/*
				 * Found an older ucode saved before.
				 * Replace the older one with this newer
				 * one.
				 */
				mc_saved[i] =
					(struct microcode_intel *)ucode_ptr;
				break;
			}
		}
	}
	if (i >= mc_saved_count && !found)
		/*
		 * This ucode is first time discovered in ucode file.
		 * Save it to memory.
		 */
		mc_saved[mc_saved_count++] =
				 (struct microcode_intel *)ucode_ptr;

	*mc_saved_count_p = mc_saved_count;
}

/*
 * Get microcode matching with BSP's model. Only CPUs with the same model as
 * BSP can stay in the platform.
 */
static enum ucode_state __init
get_matching_model_microcode(int cpu, unsigned long start,
			     void *data, size_t size,
			     struct mc_saved_data *mc_saved_data,
			     unsigned long *mc_saved_in_initrd,
			     struct ucode_cpu_info *uci)
{
	u8 *ucode_ptr = data;
	unsigned int leftover = size;
	enum ucode_state state = UCODE_OK;
	unsigned int mc_size;
	struct microcode_header_intel *mc_header;
	struct microcode_intel *mc_saved_tmp[MAX_UCODE_COUNT];
	unsigned int mc_saved_count = mc_saved_data->mc_saved_count;
	int i;

	while (leftover) {
		mc_header = (struct microcode_header_intel *)ucode_ptr;

		mc_size = get_totalsize(mc_header);
		if (!mc_size || mc_size > leftover ||
			microcode_sanity_check(ucode_ptr, 0) < 0)
			break;

		leftover -= mc_size;

		/*
		 * Since APs with same family and model as the BSP may boot in
		 * the platform, we need to find and save microcode patches
		 * with the same family and model as the BSP.
		 */
		if (matching_model_microcode(mc_header, uci->cpu_sig.sig) !=
			 UCODE_OK) {
			ucode_ptr += mc_size;
			continue;
		}

		_save_mc(mc_saved_tmp, ucode_ptr, &mc_saved_count);

		ucode_ptr += mc_size;
	}

	if (leftover) {
		state = UCODE_ERROR;
		goto out;
	}

	if (mc_saved_count == 0) {
		state = UCODE_NFOUND;
		goto out;
	}

	for (i = 0; i < mc_saved_count; i++)
		mc_saved_in_initrd[i] = (unsigned long)mc_saved_tmp[i] - start;

	mc_saved_data->mc_saved_count = mc_saved_count;
out:
	return state;
}

#define native_rdmsr(msr, val1, val2)		\
do {						\
	u64 __val = native_read_msr((msr));	\
	(void)((val1) = (u32)__val);		\
	(void)((val2) = (u32)(__val >> 32));	\
} while (0)

#define native_wrmsr(msr, low, high)		\
	native_write_msr(msr, low, high);

static int __cpuinit collect_cpu_info_early(struct ucode_cpu_info *uci)
{
	unsigned int val[2];
	u8 x86, x86_model;
	struct cpu_signature csig;
	unsigned int eax, ebx, ecx, edx;

	csig.sig = 0;
	csig.pf = 0;
	csig.rev = 0;

	memset(uci, 0, sizeof(*uci));

	eax = 0x00000001;
	ecx = 0;
	native_cpuid(&eax, &ebx, &ecx, &edx);
	csig.sig = eax;

	x86 = get_x86_family(csig.sig);
	x86_model = get_x86_model(csig.sig);

	if ((x86_model >= 5) || (x86 > 6)) {
		/* get processor flags from MSR 0x17 */
		native_rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
		csig.pf = 1 << ((val[1] >> 18) & 7);
	}
	native_wrmsr(MSR_IA32_UCODE_REV, 0, 0);

	/* As documented in the SDM: Do a CPUID 1 here */
	sync_core();

	/* get the current revision from MSR 0x8B */
	native_rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);

	csig.rev = val[1];

	uci->cpu_sig = csig;
	uci->valid = 1;

	return 0;
}

#ifdef DEBUG
static void __ref show_saved_mc(void)
{
	int i, j;
	unsigned int sig, pf, rev, total_size, data_size, date;
	struct ucode_cpu_info uci;

	if (mc_saved_data.mc_saved_count == 0) {
		pr_debug("no micorcode data saved.\n");
		return;
	}
	pr_debug("Total microcode saved: %d\n", mc_saved_data.mc_saved_count);

	collect_cpu_info_early(&uci);

	sig = uci.cpu_sig.sig;
	pf = uci.cpu_sig.pf;
	rev = uci.cpu_sig.rev;
	pr_debug("CPU%d: sig=0x%x, pf=0x%x, rev=0x%x\n",
		 smp_processor_id(), sig, pf, rev);

	for (i = 0; i < mc_saved_data.mc_saved_count; i++) {
		struct microcode_header_intel *mc_saved_header;
		struct extended_sigtable *ext_header;
		int ext_sigcount;
		struct extended_signature *ext_sig;

		mc_saved_header = (struct microcode_header_intel *)
				  mc_saved_data.mc_saved[i];
		sig = mc_saved_header->sig;
		pf = mc_saved_header->pf;
		rev = mc_saved_header->rev;
		total_size = get_totalsize(mc_saved_header);
		data_size = get_datasize(mc_saved_header);
		date = mc_saved_header->date;

		pr_debug("mc_saved[%d]: sig=0x%x, pf=0x%x, rev=0x%x, toal size=0x%x, date = %04x-%02x-%02x\n",
			 i, sig, pf, rev, total_size,
			 date & 0xffff,
			 date >> 24,
			 (date >> 16) & 0xff);

		/* Look for ext. headers: */
		if (total_size <= data_size + MC_HEADER_SIZE)
			continue;

		ext_header = (struct extended_sigtable *)
			     mc_saved_header + data_size + MC_HEADER_SIZE;
		ext_sigcount = ext_header->count;
		ext_sig = (void *)ext_header + EXT_HEADER_SIZE;

		for (j = 0; j < ext_sigcount; j++) {
			sig = ext_sig->sig;
			pf = ext_sig->pf;

			pr_debug("\tExtended[%d]: sig=0x%x, pf=0x%x\n",
				 j, sig, pf);

			ext_sig++;
		}

	}
}
#else
static inline void show_saved_mc(void)
{
}
#endif

#if defined(CONFIG_MICROCODE_INTEL_EARLY) && defined(CONFIG_HOTPLUG_CPU)
static DEFINE_MUTEX(x86_cpu_microcode_mutex);
/*
 * Save this mc into mc_saved_data. So it will be loaded early when a CPU is
 * hot added or resumes.
 *
 * Please make sure this mc should be a valid microcode patch before calling
 * this function.
 */
int save_mc_for_early(u8 *mc)
{
	struct microcode_intel *mc_saved_tmp[MAX_UCODE_COUNT];
	unsigned int mc_saved_count_init;
	unsigned int mc_saved_count;
	struct microcode_intel **mc_saved;
	int ret = 0;
	int i;

	/*
	 * Hold hotplug lock so mc_saved_data is not accessed by a CPU in
	 * hotplug.
	 */
	mutex_lock(&x86_cpu_microcode_mutex);

	mc_saved_count_init = mc_saved_data.mc_saved_count;
	mc_saved_count = mc_saved_data.mc_saved_count;
	mc_saved = mc_saved_data.mc_saved;

	if (mc_saved && mc_saved_count)
		memcpy(mc_saved_tmp, mc_saved,
		       mc_saved_count * sizeof(struct mirocode_intel *));
	/*
	 * Save the microcode patch mc in mc_save_tmp structure if it's a newer
	 * version.
	 */

	_save_mc(mc_saved_tmp, mc, &mc_saved_count);

	/*
	 * Save the mc_save_tmp in global mc_saved_data.
	 */
	ret = save_microcode(&mc_saved_data, mc_saved_tmp, mc_saved_count);
	if (ret) {
		pr_err("Can not save microcode patch.\n");
		goto out;
	}

	show_saved_mc();

	/*
	 * Free old saved microcod data.
	 */
	if (mc_saved) {
		for (i = 0; i < mc_saved_count_init; i++)
			kfree(mc_saved[i]);
		kfree(mc_saved);
	}

out:
	mutex_unlock(&x86_cpu_microcode_mutex);

	return ret;
}
EXPORT_SYMBOL_GPL(save_mc_for_early);
#endif

static __initdata char ucode_name[] = "kernel/x86/microcode/GenuineIntel.bin";
static __init enum ucode_state
scan_microcode(unsigned long start, unsigned long end,
		struct mc_saved_data *mc_saved_data,
		unsigned long *mc_saved_in_initrd,
		struct ucode_cpu_info *uci)
{
	unsigned int size = end - start + 1;
	struct cpio_data cd;
	long offset = 0;
#ifdef CONFIG_X86_32
	char *p = (char *)__pa_nodebug(ucode_name);
#else
	char *p = ucode_name;
#endif

	cd.data = NULL;
	cd.size = 0;

	cd = find_cpio_data(p, (void *)start, size, &offset);
	if (!cd.data)
		return UCODE_ERROR;


	return get_matching_model_microcode(0, start, cd.data, cd.size,
					    mc_saved_data, mc_saved_in_initrd,
					    uci);
}

/*
 * Print ucode update info.
 */
static void __cpuinit
print_ucode_info(struct ucode_cpu_info *uci, unsigned int date)
{
	int cpu = smp_processor_id();

	pr_info("CPU%d microcode updated early to revision 0x%x, date = %04x-%02x-%02x\n",
		cpu,
		uci->cpu_sig.rev,
		date & 0xffff,
		date >> 24,
		(date >> 16) & 0xff);
}

#ifdef CONFIG_X86_32

static int delay_ucode_info;
static int current_mc_date;

/*
 * Print early updated ucode info after printk works. This is delayed info dump.
 */
void __cpuinit show_ucode_info_early(void)
{
	struct ucode_cpu_info uci;

	if (delay_ucode_info) {
		collect_cpu_info_early(&uci);
		print_ucode_info(&uci, current_mc_date);
		delay_ucode_info = 0;
	}
}

/*
 * At this point, we can not call printk() yet. Keep microcode patch number in
 * mc_saved_data.mc_saved and delay printing microcode info in
 * show_ucode_info_early() until printk() works.
 */
static void __cpuinit print_ucode(struct ucode_cpu_info *uci)
{
	struct microcode_intel *mc_intel;
	int *delay_ucode_info_p;
	int *current_mc_date_p;

	mc_intel = uci->mc;
	if (mc_intel == NULL)
		return;

	delay_ucode_info_p = (int *)__pa_nodebug(&delay_ucode_info);
	current_mc_date_p = (int *)__pa_nodebug(&current_mc_date);

	*delay_ucode_info_p = 1;
	*current_mc_date_p = mc_intel->hdr.date;
}
#else

/*
 * Flush global tlb. We only do this in x86_64 where paging has been enabled
 * already and PGE should be enabled as well.
 */
static inline void __cpuinit flush_tlb_early(void)
{
	__native_flush_tlb_global_irq_disabled();
}

static inline void __cpuinit print_ucode(struct ucode_cpu_info *uci)
{
	struct microcode_intel *mc_intel;

	mc_intel = uci->mc;
	if (mc_intel == NULL)
		return;

	print_ucode_info(uci, mc_intel->hdr.date);
}
#endif

static int __cpuinit apply_microcode_early(struct mc_saved_data *mc_saved_data,
					   struct ucode_cpu_info *uci)
{
	struct microcode_intel *mc_intel;
	unsigned int val[2];

	mc_intel = uci->mc;
	if (mc_intel == NULL)
		return 0;

	/* write microcode via MSR 0x79 */
	native_wrmsr(MSR_IA32_UCODE_WRITE,
	      (unsigned long) mc_intel->bits,
	      (unsigned long) mc_intel->bits >> 16 >> 16);
	native_wrmsr(MSR_IA32_UCODE_REV, 0, 0);

	/* As documented in the SDM: Do a CPUID 1 here */
	sync_core();

	/* get the current revision from MSR 0x8B */
	native_rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
	if (val[1] != mc_intel->hdr.rev)
		return -1;

#ifdef CONFIG_X86_64
	/* Flush global tlb. This is precaution. */
	flush_tlb_early();
#endif
	uci->cpu_sig.rev = val[1];

	print_ucode(uci);

	return 0;
}

/*
 * This function converts microcode patch offsets previously stored in
 * mc_saved_in_initrd to pointers and stores the pointers in mc_saved_data.
 */
int __init save_microcode_in_initrd(void)
{
	unsigned int count = mc_saved_data.mc_saved_count;
	struct microcode_intel *mc_saved[MAX_UCODE_COUNT];
	int ret = 0;

	if (count == 0)
		return ret;

	microcode_pointer(mc_saved, mc_saved_in_initrd, initrd_start, count);
	ret = save_microcode(&mc_saved_data, mc_saved, count);
	if (ret)
		pr_err("Can not save microcod patches from initrd");

	show_saved_mc();

	return ret;
}

static void __init
_load_ucode_intel_bsp(struct mc_saved_data *mc_saved_data,
		      unsigned long *mc_saved_in_initrd,
		      unsigned long initrd_start_early,
		      unsigned long initrd_end_early,
		      struct ucode_cpu_info *uci)
{
	collect_cpu_info_early(uci);
	scan_microcode(initrd_start_early, initrd_end_early, mc_saved_data,
		       mc_saved_in_initrd, uci);
	load_microcode(mc_saved_data, mc_saved_in_initrd,
		       initrd_start_early, uci);
	apply_microcode_early(mc_saved_data, uci);
}

void __init
load_ucode_intel_bsp(void)
{
	u64 ramdisk_image, ramdisk_size;
	unsigned long initrd_start_early, initrd_end_early;
	struct ucode_cpu_info uci;
#ifdef CONFIG_X86_32
	struct boot_params *boot_params_p;

	boot_params_p = (struct boot_params *)__pa_nodebug(&boot_params);
	ramdisk_image = boot_params_p->hdr.ramdisk_image;
	ramdisk_size  = boot_params_p->hdr.ramdisk_size;
	initrd_start_early = ramdisk_image;
	initrd_end_early = initrd_start_early + ramdisk_size;

	_load_ucode_intel_bsp(
		(struct mc_saved_data *)__pa_nodebug(&mc_saved_data),
		(unsigned long *)__pa_nodebug(&mc_saved_in_initrd),
		initrd_start_early, initrd_end_early, &uci);
#else
	ramdisk_image = boot_params.hdr.ramdisk_image;
	ramdisk_size  = boot_params.hdr.ramdisk_size;
	initrd_start_early = ramdisk_image + PAGE_OFFSET;
	initrd_end_early = initrd_start_early + ramdisk_size;

	_load_ucode_intel_bsp(&mc_saved_data, mc_saved_in_initrd,
			      initrd_start_early, initrd_end_early, &uci);
#endif
}

void __cpuinit load_ucode_intel_ap(void)
{
	struct mc_saved_data *mc_saved_data_p;
	struct ucode_cpu_info uci;
	unsigned long *mc_saved_in_initrd_p;
	unsigned long initrd_start_addr;
#ifdef CONFIG_X86_32
	unsigned long *initrd_start_p;

	mc_saved_in_initrd_p =
		(unsigned long *)__pa_nodebug(mc_saved_in_initrd);
	mc_saved_data_p = (struct mc_saved_data *)__pa_nodebug(&mc_saved_data);
	initrd_start_p = (unsigned long *)__pa_nodebug(&initrd_start);
	initrd_start_addr = (unsigned long)__pa_nodebug(*initrd_start_p);
#else
	mc_saved_data_p = &mc_saved_data;
	mc_saved_in_initrd_p = mc_saved_in_initrd;
	initrd_start_addr = initrd_start;
#endif

	/*
	 * If there is no valid ucode previously saved in memory, no need to
	 * update ucode on this AP.
	 */
	if (mc_saved_data_p->mc_saved_count == 0)
		return;

	collect_cpu_info_early(&uci);
	load_microcode(mc_saved_data_p, mc_saved_in_initrd_p,
		       initrd_start_addr, &uci);
	apply_microcode_early(mc_saved_data_p, &uci);
}