aboutsummaryrefslogtreecommitdiffstats
path: root/arch/i386/kernel/microcode.c
blob: 381252bae3d817c1509a7c3fcd98d304f831da29 (plain) (blame)
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
/*
 *	Intel CPU Microcode Update Driver for Linux
 *
 *	Copyright (C) 2000-2006 Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
 *		      2006	Shaohua Li <shaohua.li@intel.com>
 *
 *	This driver allows to upgrade microcode on Intel processors
 *	belonging to IA-32 family - PentiumPro, Pentium II, 
 *	Pentium III, Xeon, Pentium 4, etc.
 *
 *	Reference: Section 8.10 of Volume III, Intel Pentium 4 Manual, 
 *	Order Number 245472 or free download from:
 *		
 *	http://developer.intel.com/design/pentium4/manuals/245472.htm
 *
 *	For more information, go to http://www.urbanmyth.org/microcode
 *
 *	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.
 *
 *	1.0	16 Feb 2000, Tigran Aivazian <tigran@sco.com>
 *		Initial release.
 *	1.01	18 Feb 2000, Tigran Aivazian <tigran@sco.com>
 *		Added read() support + cleanups.
 *	1.02	21 Feb 2000, Tigran Aivazian <tigran@sco.com>
 *		Added 'device trimming' support. open(O_WRONLY) zeroes
 *		and frees the saved copy of applied microcode.
 *	1.03	29 Feb 2000, Tigran Aivazian <tigran@sco.com>
 *		Made to use devfs (/dev/cpu/microcode) + cleanups.
 *	1.04	06 Jun 2000, Simon Trimmer <simon@veritas.com>
 *		Added misc device support (now uses both devfs and misc).
 *		Added MICROCODE_IOCFREE ioctl to clear memory.
 *	1.05	09 Jun 2000, Simon Trimmer <simon@veritas.com>
 *		Messages for error cases (non Intel & no suitable microcode).
 *	1.06	03 Aug 2000, Tigran Aivazian <tigran@veritas.com>
 *		Removed ->release(). Removed exclusive open and status bitmap.
 *		Added microcode_rwsem to serialize read()/write()/ioctl().
 *		Removed global kernel lock usage.
 *	1.07	07 Sep 2000, Tigran Aivazian <tigran@veritas.com>
 *		Write 0 to 0x8B msr and then cpuid before reading revision,
 *		so that it works even if there were no update done by the
 *		BIOS. Otherwise, reading from 0x8B gives junk (which happened
 *		to be 0 on my machine which is why it worked even when I
 *		disabled update by the BIOS)
 *		Thanks to Eric W. Biederman <ebiederman@lnxi.com> for the fix.
 *	1.08	11 Dec 2000, Richard Schaal <richard.schaal@intel.com> and
 *			     Tigran Aivazian <tigran@veritas.com>
 *		Intel Pentium 4 processor support and bugfixes.
 *	1.09	30 Oct 2001, Tigran Aivazian <tigran@veritas.com>
 *		Bugfix for HT (Hyper-Threading) enabled processors
 *		whereby processor resources are shared by all logical processors
 *		in a single CPU package.
 *	1.10	28 Feb 2002 Asit K Mallick <asit.k.mallick@intel.com> and
 *		Tigran Aivazian <tigran@veritas.com>,
 *		Serialize updates as required on HT processors due to speculative
 *		nature of implementation.
 *	1.11	22 Mar 2002 Tigran Aivazian <tigran@veritas.com>
 *		Fix the panic when writing zero-length microcode chunk.
 *	1.12	29 Sep 2003 Nitin Kamble <nitin.a.kamble@intel.com>, 
 *		Jun Nakajima <jun.nakajima@intel.com>
 *		Support for the microcode updates in the new format.
 *	1.13	10 Oct 2003 Tigran Aivazian <tigran@veritas.com>
 *		Removed ->read() method and obsoleted MICROCODE_IOCFREE ioctl
 *		because we no longer hold a copy of applied microcode 
 *		in kernel memory.
 *	1.14	25 Jun 2004 Tigran Aivazian <tigran@veritas.com>
 *		Fix sigmatch() macro to handle old CPUs with pf == 0.
 *		Thanks to Stuart Swales for pointing out this bug.
 */

//#define DEBUG /* pr_debug */
#include <linux/capability.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/cpumask.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/miscdevice.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/mutex.h>
#include <linux/cpu.h>
#include <linux/firmware.h>
#include <linux/platform_device.h>

#include <asm/msr.h>
#include <asm/uaccess.h>
#include <asm/processor.h>

MODULE_DESCRIPTION("Intel CPU (IA-32) Microcode Update Driver");
MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
MODULE_LICENSE("GPL");

#define MICROCODE_VERSION 	"1.14a"

#define DEFAULT_UCODE_DATASIZE 	(2000) 	  /* 2000 bytes */
#define MC_HEADER_SIZE		(sizeof (microcode_header_t))  	  /* 48 bytes */
#define DEFAULT_UCODE_TOTALSIZE (DEFAULT_UCODE_DATASIZE + MC_HEADER_SIZE) /* 2048 bytes */
#define EXT_HEADER_SIZE		(sizeof (struct extended_sigtable)) /* 20 bytes */
#define EXT_SIGNATURE_SIZE	(sizeof (struct extended_signature)) /* 12 bytes */
#define DWSIZE			(sizeof (u32))
#define get_totalsize(mc) \
	(((microcode_t *)mc)->hdr.totalsize ? \
	 ((microcode_t *)mc)->hdr.totalsize : DEFAULT_UCODE_TOTALSIZE)
#define get_datasize(mc) \
	(((microcode_t *)mc)->hdr.datasize ? \
	 ((microcode_t *)mc)->hdr.datasize : DEFAULT_UCODE_DATASIZE)

#define sigmatch(s1, s2, p1, p2) \
	(((s1) == (s2)) && (((p1) & (p2)) || (((p1) == 0) && ((p2) == 0))))

#define exttable_size(et) ((et)->count * EXT_SIGNATURE_SIZE + EXT_HEADER_SIZE)

/* serialize access to the physical write to MSR 0x79 */
static DEFINE_SPINLOCK(microcode_update_lock);

/* no concurrent ->write()s are allowed on /dev/cpu/microcode */
static DEFINE_MUTEX(microcode_mutex);

static struct ucode_cpu_info {
	int valid;
	unsigned int sig;
	unsigned int pf;
	unsigned int rev;
	microcode_t *mc;
} ucode_cpu_info[NR_CPUS];

static void collect_cpu_info(int cpu_num)
{
	struct cpuinfo_x86 *c = cpu_data + cpu_num;
	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
	unsigned int val[2];

	/* We should bind the task to the CPU */
	BUG_ON(raw_smp_processor_id() != cpu_num);
	uci->pf = uci->rev = 0;
	uci->mc = NULL;
	uci->valid = 1;

	if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6 ||
	    	cpu_has(c, X86_FEATURE_IA64)) {
		printk(KERN_ERR "microcode: CPU%d not a capable Intel "
			"processor\n", cpu_num);
		uci->valid = 0;
		return;
	}

	uci->sig = cpuid_eax(0x00000001);

	if ((c->x86_model >= 5) || (c->x86 > 6)) {
		/* get processor flags from MSR 0x17 */
		rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
		uci->pf = 1 << ((val[1] >> 18) & 7);
	}

	wrmsr(MSR_IA32_UCODE_REV, 0, 0);
	/* see notes above for revision 1.07.  Apparent chip bug */
	sync_core();
	/* get the current revision from MSR 0x8B */
	rdmsr(MSR_IA32_UCODE_REV, val[0], uci->rev);
	pr_debug("microcode: collect_cpu_info : sig=0x%x, pf=0x%x, rev=0x%x\n",
			uci->sig, uci->pf, uci->rev);
}

static inline int microcode_update_match(int cpu_num,
	microcode_header_t *mc_header, int sig, int pf)
{
	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;

	if (!sigmatch(sig, uci->sig, pf, uci->pf)
		|| mc_header->rev <= uci->rev)
		return 0;
	return 1;
}

static int microcode_sanity_check(void *mc)
{
	microcode_header_t *mc_header = mc;
	struct extended_sigtable *ext_header = NULL;
	struct extended_signature *ext_sig;
	unsigned long total_size, data_size, ext_table_size;
	int sum, orig_sum, ext_sigcount = 0, i;

	total_size = get_totalsize(mc_header);
	data_size = get_datasize(mc_header);
	if (data_size + MC_HEADER_SIZE > total_size) {
		printk(KERN_ERR "microcode: error! "
			"Bad data size in microcode data file\n");
		return -EINVAL;
	}

	if (mc_header->ldrver != 1 || mc_header->hdrver != 1) {
		printk(KERN_ERR "microcode: error! "
			"Unknown microcode update format\n");
		return -EINVAL;
	}
	ext_table_size = total_size - (MC_HEADER_SIZE + data_size);
	if (ext_table_size) {
		if ((ext_table_size < EXT_HEADER_SIZE)
		 || ((ext_table_size - EXT_HEADER_SIZE) % EXT_SIGNATURE_SIZE)) {
			printk(KERN_ERR "microcode: error! "
				"Small exttable size in microcode data file\n");
			return -EINVAL;
		}
		ext_header = mc + MC_HEADER_SIZE + data_size;
		if (ext_table_size != exttable_size(ext_header)) {
			printk(KERN_ERR "microcode: error! "
				"Bad exttable size in microcode data file\n");
			return -EFAULT;
		}
		ext_sigcount = ext_header->count;
	}

	/* check extended table checksum */
	if (ext_table_size) {
		int ext_table_sum = 0;
		int *ext_tablep = (int *)ext_header;

		i = ext_table_size / DWSIZE;
		while (i--)
			ext_table_sum += ext_tablep[i];
		if (ext_table_sum) {
			printk(KERN_WARNING "microcode: aborting, "
				"bad extended signature table checksum\n");
			return -EINVAL;
		}
	}

	/* calculate the checksum */
	orig_sum = 0;
	i = (MC_HEADER_SIZE + data_size) / DWSIZE;
	while (i--)
		orig_sum += ((int *)mc)[i];
	if (orig_sum) {
		printk(KERN_ERR "microcode: aborting, bad checksum\n");
		return -EINVAL;
	}
	if (!ext_table_size)
		return 0;
	/* check extended signature checksum */
	for (i = 0; i < ext_sigcount; i++) {
		ext_sig = (struct extended_signature *)((void *)ext_header
			+ EXT_HEADER_SIZE + EXT_SIGNATURE_SIZE * i);
		sum = orig_sum
			- (mc_header->sig + mc_header->pf + mc_header->cksum)
			+ (ext_sig->sig + ext_sig->pf + ext_sig->cksum);
		if (sum) {
			printk(KERN_ERR "microcode: aborting, bad checksum\n");
			return -EINVAL;
		}
	}
	return 0;
}

/*
 * return 0 - no update found
 * return 1 - found update
 * return < 0 - error
 */
static int get_maching_microcode(void *mc, int cpu)
{
	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
	microcode_header_t *mc_header = mc;
	struct extended_sigtable *ext_header;
	unsigned long total_size = get_totalsize(mc_header);
	int ext_sigcount, i;
	struct extended_signature *ext_sig;
	void *new_mc;

	if (microcode_update_match(cpu, mc_header,
			mc_header->sig, mc_header->pf))
		goto find;

	if (total_size <= get_datasize(mc_header) + MC_HEADER_SIZE)
		return 0;

	ext_header = (struct extended_sigtable *)(mc +
			get_datasize(mc_header) + MC_HEADER_SIZE);
	ext_sigcount = ext_header->count;
	ext_sig = (struct extended_signature *)((void *)ext_header
			+ EXT_HEADER_SIZE);
	for (i = 0; i < ext_sigcount; i++) {
		if (microcode_update_match(cpu, mc_header,
				ext_sig->sig, ext_sig->pf))
			goto find;
		ext_sig++;
	}
	return 0;
find:
	pr_debug("microcode: CPU %d found a matching microcode update with"
		" version 0x%x (current=0x%x)\n", cpu, mc_header->rev,uci->rev);
	new_mc = vmalloc(total_size);
	if (!new_mc) {
		printk(KERN_ERR "microcode: error! Can not allocate memory\n");
		return -ENOMEM;
	}

	/* free previous update file */
	vfree(uci->mc);

	memcpy(new_mc, mc, total_size);
	uci->mc = new_mc;
	return 1;
}

static void apply_microcode(int cpu)
{
	unsigned long flags;
	unsigned int val[2];
	int cpu_num = raw_smp_processor_id();
	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;

	/* We should bind the task to the CPU */
	BUG_ON(cpu_num != cpu);

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

	/* serialize access to the physical write to MSR 0x79 */
	spin_lock_irqsave(&microcode_update_lock, flags);          

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

	/* see notes above for revision 1.07.  Apparent chip bug */
	sync_core();

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

	spin_unlock_irqrestore(&microcode_update_lock, flags);
	if (val[1] != uci->mc->hdr.rev) {
		printk(KERN_ERR "microcode: CPU%d updated from revision "
			"0x%x to 0x%x failed\n", cpu_num, uci->rev, val[1]);
		return;
	}
	pr_debug("microcode: CPU%d updated from revision "
	       "0x%x to 0x%x, date = %08x \n", 
	       cpu_num, uci->rev, val[1], uci->mc->hdr.date);
	uci->rev = val[1];
}

#ifdef CONFIG_MICROCODE_OLD_INTERFACE
static void __user *user_buffer;	/* user area microcode data buffer */
static unsigned int user_buffer_size;	/* it's size */

static long get_next_ucode(void **mc, long offset)
{
	microcode_header_t mc_header;
	unsigned long total_size;

	/* No more data */
	if (offset >= user_buffer_size)
		return 0;
	if (copy_from_user(&mc_header, user_buffer + offset, MC_HEADER_SIZE)) {
		printk(KERN_ERR "microcode: error! Can not read user data\n");
		return -EFAULT;
	}
	total_size = get_totalsize(&mc_header);
	if (offset + total_size > user_buffer_size) {
		printk(KERN_ERR "microcode: error! Bad total size in microcode "
				"data file\n");
		return -EINVAL;
	}
	*mc = vmalloc(total_size);
	if (!*mc)
		return -ENOMEM;
	if (copy_from_user(*mc, user_buffer + offset, total_size)) {
		printk(KERN_ERR "microcode: error! Can not read user data\n");
		vfree(*mc);
		return -EFAULT;
	}
	return offset + total_size;
}

static int do_microcode_update (void)
{
	long cursor = 0;
	int error = 0;
	void *new_mc;
	int cpu;
	cpumask_t old;

	old = current->cpus_allowed;

	while ((cursor = get_next_ucode(&new_mc, cursor)) > 0) {
		error = microcode_sanity_check(new_mc);
		if (error)
			goto out;
		/*
		 * It's possible the data file has multiple matching ucode,
		 * lets keep searching till the latest version
		 */
		for_each_online_cpu(cpu) {
			struct ucode_cpu_info *uci = ucode_cpu_info + cpu;

			if (!uci->valid)
				continue;
			set_cpus_allowed(current, cpumask_of_cpu(cpu));
			error = get_maching_microcode(new_mc, cpu);
			if (error < 0)
				goto out;
			if (error == 1)
				apply_microcode(cpu);
		}
		vfree(new_mc);
	}
out:
	if (cursor > 0)
		vfree(new_mc);
	if (cursor < 0)
		error = cursor;
	set_cpus_allowed(current, old);
	return error;
}

static int microcode_open (struct inode *unused1, struct file *unused2)
{
	return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
}

static ssize_t microcode_write (struct file *file, const char __user *buf, size_t len, loff_t *ppos)
{
	ssize_t ret;

	if ((len >> PAGE_SHIFT) > num_physpages) {
		printk(KERN_ERR "microcode: too much data (max %ld pages)\n", num_physpages);
		return -EINVAL;
	}

	lock_cpu_hotplug();
	mutex_lock(&microcode_mutex);

	user_buffer = (void __user *) buf;
	user_buffer_size = (int) len;

	ret = do_microcode_update();
	if (!ret)
		ret = (ssize_t)len;

	mutex_unlock(&microcode_mutex);
	unlock_cpu_hotplug();

	return ret;
}

static const struct file_operations microcode_fops = {
	.owner		= THIS_MODULE,
	.write		= microcode_write,
	.open		= microcode_open,
};

static struct miscdevice microcode_dev = {
	.minor		= MICROCODE_MINOR,
	.name		= "microcode",
	.fops		= &microcode_fops,
};

static int __init microcode_dev_init (void)
{
	int error;

	error = misc_register(&microcode_dev);
	if (error) {
		printk(KERN_ERR
			"microcode: can't misc_register on minor=%d\n",
			MICROCODE_MINOR);
		return error;
	}

	return 0;
}

static void __exit microcode_dev_exit (void)
{
	misc_deregister(&microcode_dev);
}

MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);
#else
#define microcode_dev_init() 0
#define microcode_dev_exit() do { } while(0)
#endif

static long get_next_ucode_from_buffer(void **mc, void *buf,
	unsigned long size, long offset)
{
	microcode_header_t *mc_header;
	unsigned long total_size;

	/* No more data */
	if (offset >= size)
		return 0;
	mc_header = (microcode_header_t *)(buf + offset);
	total_size = get_totalsize(mc_header);

	if (offset + total_size > size) {
		printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
		return -EINVAL;
	}

	*mc = vmalloc(total_size);
	if (!*mc) {
		printk(KERN_ERR "microcode: error! Can not allocate memory\n");
		return -ENOMEM;
	}
	memcpy(*mc, buf + offset, total_size);
	return offset + total_size;
}

/* fake device for request_firmware */
static struct platform_device *microcode_pdev;

static int cpu_request_microcode(int cpu)
{
	char name[30];
	struct cpuinfo_x86 *c = cpu_data + cpu;
	const struct firmware *firmware;
	void *buf;
	unsigned long size;
	long offset = 0;
	int error;
	void *mc;

	/* We should bind the task to the CPU */
	BUG_ON(cpu != raw_smp_processor_id());
	sprintf(name,"intel-ucode/%02x-%02x-%02x",
		c->x86, c->x86_model, c->x86_mask);
	error = request_firmware(&firmware, name, &microcode_pdev->dev);
	if (error) {
		pr_debug("ucode data file %s load failed\n", name);
		return error;
	}
	buf = (void *)firmware->data;
	size = firmware->size;
	while ((offset = get_next_ucode_from_buffer(&mc, buf, size, offset))
			> 0) {
		error = microcode_sanity_check(mc);
		if (error)
			break;
		error = get_maching_microcode(mc, cpu);
		if (error < 0)
			break;
		/*
		 * It's possible the data file has multiple matching ucode,
		 * lets keep searching till the latest version
		 */
		if (error == 1) {
			apply_microcode(cpu);
			error = 0;
		}
		vfree(mc);
	}
	if (offset > 0)
		vfree(mc);
	if (offset < 0)
		error = offset;
	release_firmware(firmware);

	return error;
}

static void microcode_init_cpu(int cpu)
{
	cpumask_t old;
	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;

	old = current->cpus_allowed;

	set_cpus_allowed(current, cpumask_of_cpu(cpu));
	mutex_lock(&microcode_mutex);
	collect_cpu_info(cpu);
	if (uci->valid && system_state == SYSTEM_RUNNING)
		cpu_request_microcode(cpu);
	mutex_unlock(&microcode_mutex);
	set_cpus_allowed(current, old);
}

static void microcode_fini_cpu(int cpu)
{
	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;

	mutex_lock(&microcode_mutex);
	uci->valid = 0;
	vfree(uci->mc);
	uci->mc = NULL;
	mutex_unlock(&microcode_mutex);
}

static ssize_t reload_store(struct sys_device *dev, const char *buf, size_t sz)
{
	struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
	char *end;
	unsigned long val = simple_strtoul(buf, &end, 0);
	int err = 0;
	int cpu = dev->id;

	if (end == buf)
		return -EINVAL;
	if (val == 1) {
		cpumask_t old;

		old = current->cpus_allowed;

		lock_cpu_hotplug();
		set_cpus_allowed(current, cpumask_of_cpu(cpu));

		mutex_lock(&microcode_mutex);
		if (uci->valid)
			err = cpu_request_microcode(cpu);
		mutex_unlock(&microcode_mutex);
		unlock_cpu_hotplug();
		set_cpus_allowed(current, old);
	}
	if (err)
		return err;
	return sz;
}

static ssize_t version_show(struct sys_device *dev, char *buf)
{
	struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;

	return sprintf(buf, "0x%x\n", uci->rev);
}

static ssize_t pf_show(struct sys_device *dev, char *buf)
{
	struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;

	return sprintf(buf, "0x%x\n", uci->pf);
}

static SYSDEV_ATTR(reload, 0200, NULL, reload_store);
static SYSDEV_ATTR(version, 0400, version_show, NULL);
static SYSDEV_ATTR(processor_flags, 0400, pf_show, NULL);

static struct attribute *mc_default_attrs[] = {
	&attr_reload.attr,
	&attr_version.attr,
	&attr_processor_flags.attr,
	NULL
};

static struct attribute_group mc_attr_group = {
	.attrs = mc_default_attrs,
	.name = "microcode",
};

static int mc_sysdev_add(struct sys_device *sys_dev)
{
	int err, cpu = sys_dev->id;
	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;

	if (!cpu_online(cpu))
		return 0;

	pr_debug("Microcode:CPU %d added\n", cpu);
	memset(uci, 0, sizeof(*uci));

	err = sysfs_create_group(&sys_dev->kobj, &mc_attr_group);
	if (err)
		return err;

	microcode_init_cpu(cpu);
	return 0;
}

static int mc_sysdev_remove(struct sys_device *sys_dev)
{
	int cpu = sys_dev->id;

	if (!cpu_online(cpu))
		return 0;
	pr_debug("Microcode:CPU %d removed\n", cpu);
	microcode_fini_cpu(cpu);
	sysfs_remove_group(&sys_dev->kobj, &mc_attr_group);
	return 0;
}

static int mc_sysdev_resume(struct sys_device *dev)
{
	int cpu = dev->id;

	if (!cpu_online(cpu))
		return 0;
	pr_debug("Microcode:CPU %d resumed\n", cpu);
	/* only CPU 0 will apply ucode here */
	apply_microcode(0);
	return 0;
}

static struct sysdev_driver mc_sysdev_driver = {
	.add = mc_sysdev_add,
	.remove = mc_sysdev_remove,
	.resume = mc_sysdev_resume,
};

static __cpuinit int
mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
{
	unsigned int cpu = (unsigned long)hcpu;
	struct sys_device *sys_dev;

	sys_dev = get_cpu_sysdev(cpu);
	switch (action) {
	case CPU_ONLINE:
	case CPU_DOWN_FAILED:
		mc_sysdev_add(sys_dev);
		break;
	case CPU_DOWN_PREPARE:
		mc_sysdev_remove(sys_dev);
		break;
	}
	return NOTIFY_OK;
}

static struct notifier_block __cpuinitdata mc_cpu_notifier = {
	.notifier_call = mc_cpu_callback,
};

static int __init microcode_init (void)
{
	int error;

	error = microcode_dev_init();
	if (error)
		return error;
	microcode_pdev = platform_device_register_simple("microcode", -1,
							 NULL, 0);
	if (IS_ERR(microcode_pdev)) {
		microcode_dev_exit();
		return PTR_ERR(microcode_pdev);
	}

	lock_cpu_hotplug();
	error = sysdev_driver_register(&cpu_sysdev_class, &mc_sysdev_driver);
	unlock_cpu_hotplug();
	if (error) {
		microcode_dev_exit();
		platform_device_unregister(microcode_pdev);
		return error;
	}

	register_hotcpu_notifier(&mc_cpu_notifier);

	printk(KERN_INFO 
		"IA-32 Microcode Update Driver: v" MICROCODE_VERSION " <tigran@aivazian.fsnet.co.uk>\n");
	return 0;
}

static void __exit microcode_exit (void)
{
	microcode_dev_exit();

	unregister_hotcpu_notifier(&mc_cpu_notifier);

	lock_cpu_hotplug();
	sysdev_driver_unregister(&cpu_sysdev_class, &mc_sysdev_driver);
	unlock_cpu_hotplug();

	platform_device_unregister(microcode_pdev);
}

module_init(microcode_init)
module_exit(microcode_exit)