aboutsummaryrefslogtreecommitdiffstats
path: root/arch/i386/kernel/microcode.c
blob: d3fdf0057d82bec9adaccb5555dcdb5af6bf0135 (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
/*
 *	Intel CPU Microcode Update Driver for Linux
 *
 *	Copyright (C) 2000-2004 Tigran Aivazian
 *
 *	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/module.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/miscdevice.h>
#include <linux/spinlock.h>
#include <linux/mm.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@veritas.com>");
MODULE_LICENSE("GPL");

#define MICROCODE_VERSION 	"1.14"

#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 DECLARE_MUTEX(microcode_sem);

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

typedef enum mc_error_code {
	MC_SUCCESS 	= 0,
	MC_NOTFOUND 	= 1,
	MC_MARKED 	= 2,
	MC_ALLOCATED 	= 3,
} mc_error_code_t;

static struct ucode_cpu_info {
	unsigned int sig;
	unsigned int pf;
	unsigned int rev;
	unsigned int cksum;
	mc_error_code_t err;
	microcode_t *mc;
} ucode_cpu_info[NR_CPUS];
				
static int microcode_open (struct inode *unused1, struct file *unused2)
{
	return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
}

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

	uci->sig = uci->pf = uci->rev = uci->cksum = 0;
	uci->err = MC_NOTFOUND; 
	uci->mc = NULL;

	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);
		return;
	} else {
		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 void mark_microcode_update (int cpu_num, microcode_header_t *mc_header, int sig, int pf, int cksum)
{
	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;

	pr_debug("Microcode Found.\n");
	pr_debug("   Header Revision 0x%x\n", mc_header->hdrver);
	pr_debug("   Loader Revision 0x%x\n", mc_header->ldrver);
	pr_debug("   Revision 0x%x \n", mc_header->rev);
	pr_debug("   Date %x/%x/%x\n",
		((mc_header->date >> 24 ) & 0xff),
		((mc_header->date >> 16 ) & 0xff),
		(mc_header->date & 0xFFFF));
	pr_debug("   Signature 0x%x\n", sig);
	pr_debug("   Type 0x%x Family 0x%x Model 0x%x Stepping 0x%x\n",
		((sig >> 12) & 0x3),
		((sig >> 8) & 0xf),
		((sig >> 4) & 0xf),
		((sig & 0xf)));
	pr_debug("   Processor Flags 0x%x\n", pf);
	pr_debug("   Checksum 0x%x\n", cksum);

	if (mc_header->rev < uci->rev) {
		printk(KERN_ERR "microcode: CPU%d not 'upgrading' to earlier revision"
		       " 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
		goto out;
	} else if (mc_header->rev == uci->rev) {
		/* notify the caller of success on this cpu */
		uci->err = MC_SUCCESS;
		printk(KERN_ERR "microcode: CPU%d already at revision"
			" 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
		goto out;
	}

	pr_debug("microcode: CPU%d found a matching microcode update with "
		" revision 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
	uci->cksum = cksum;
	uci->pf = pf; /* keep the original mc pf for cksum calculation */
	uci->err = MC_MARKED; /* found the match */
out:
	return;
}

static int find_matching_ucodes (void) 
{
	int cursor = 0;
	int error = 0;

	while (cursor + MC_HEADER_SIZE < user_buffer_size) {
		microcode_header_t mc_header;
		void *newmc = NULL;
		int i, sum, cpu_num, allocated_flag, total_size, data_size, ext_table_size;

		if (copy_from_user(&mc_header, user_buffer + cursor, MC_HEADER_SIZE)) {
			printk(KERN_ERR "microcode: error! Can not read user data\n");
			error = -EFAULT;
			goto out;
		}

		total_size = get_totalsize(&mc_header);
		if ((cursor + total_size > user_buffer_size) || (total_size < DEFAULT_UCODE_TOTALSIZE)) {
			printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
			error = -EINVAL;
			goto out;
		}

		data_size = get_datasize(&mc_header);
		if ((data_size + MC_HEADER_SIZE > total_size) || (data_size < DEFAULT_UCODE_DATASIZE)) {
			printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
			error = -EINVAL;
			goto out;
		}

		if (mc_header.ldrver != 1 || mc_header.hdrver != 1) {
			printk(KERN_ERR "microcode: error! Unknown microcode update format\n");
			error = -EINVAL;
			goto out;
		}
		
		for (cpu_num = 0; cpu_num < num_online_cpus(); cpu_num++) {
			struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
			if (uci->err != MC_NOTFOUND) /* already found a match or not an online cpu*/
				continue;

			if (sigmatch(mc_header.sig, uci->sig, mc_header.pf, uci->pf))
				mark_microcode_update(cpu_num, &mc_header, mc_header.sig, mc_header.pf, mc_header.cksum);
		}

		ext_table_size = total_size - (MC_HEADER_SIZE + data_size);
		if (ext_table_size) {
			struct extended_sigtable ext_header;
			struct extended_signature ext_sig;
			int ext_sigcount;

			if ((ext_table_size < EXT_HEADER_SIZE) 
					|| ((ext_table_size - EXT_HEADER_SIZE) % EXT_SIGNATURE_SIZE)) {
				printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
				error = -EINVAL;
				goto out;
			}
			if (copy_from_user(&ext_header, user_buffer + cursor 
					+ MC_HEADER_SIZE + data_size, EXT_HEADER_SIZE)) {
				printk(KERN_ERR "microcode: error! Can not read user data\n");
				error = -EFAULT;
				goto out;
			}
			if (ext_table_size != exttable_size(&ext_header)) {
				printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
				error = -EFAULT;
				goto out;
			}

			ext_sigcount = ext_header.count;
			
			for (i = 0; i < ext_sigcount; i++) {
				if (copy_from_user(&ext_sig, user_buffer + cursor + MC_HEADER_SIZE + data_size + EXT_HEADER_SIZE 
						+ EXT_SIGNATURE_SIZE * i, EXT_SIGNATURE_SIZE)) {
					printk(KERN_ERR "microcode: error! Can not read user data\n");
					error = -EFAULT;
					goto out;
				}
				for (cpu_num = 0; cpu_num < num_online_cpus(); cpu_num++) {
					struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
					if (uci->err != MC_NOTFOUND) /* already found a match or not an online cpu*/
						continue;
					if (sigmatch(ext_sig.sig, uci->sig, ext_sig.pf, uci->pf)) {
						mark_microcode_update(cpu_num, &mc_header, ext_sig.sig, ext_sig.pf, ext_sig.cksum);
					}
				}
			}
		}
		/* now check if any cpu has matched */
		for (cpu_num = 0, allocated_flag = 0, sum = 0; cpu_num < num_online_cpus(); cpu_num++) {
			if (ucode_cpu_info[cpu_num].err == MC_MARKED) { 
				struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
				if (!allocated_flag) {
					allocated_flag = 1;
					newmc = vmalloc(total_size);
					if (!newmc) {
						printk(KERN_ERR "microcode: error! Can not allocate memory\n");
						error = -ENOMEM;
						goto out;
					}
					if (copy_from_user(newmc + MC_HEADER_SIZE, 
								user_buffer + cursor + MC_HEADER_SIZE, 
								total_size - MC_HEADER_SIZE)) {
						printk(KERN_ERR "microcode: error! Can not read user data\n");
						vfree(newmc);
						error = -EFAULT;
						goto out;
					}
					memcpy(newmc, &mc_header, MC_HEADER_SIZE);
					/* check extended table checksum */
					if (ext_table_size) {
						int ext_table_sum = 0;
						int * ext_tablep = (((void *) newmc) + MC_HEADER_SIZE + data_size);
						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");
							vfree(newmc);
							error = -EINVAL;
							goto out;
						}
					}

					/* calculate the checksum */
					i = (MC_HEADER_SIZE + data_size) / DWSIZE;
					while (i--) sum += ((int *)newmc)[i];
					sum -= (mc_header.sig + mc_header.pf + mc_header.cksum);
				}
				ucode_cpu_info[cpu_num].mc = newmc;
				ucode_cpu_info[cpu_num].err = MC_ALLOCATED; /* mc updated */
				if (sum + uci->sig + uci->pf + uci->cksum != 0) {
					printk(KERN_ERR "microcode: CPU%d aborting, bad checksum\n", cpu_num);
					error = -EINVAL;
					goto out;
				}
			}
		}
		cursor += total_size; /* goto the next update patch */
	} /* end of while */
out:
	return error;
}

static void do_update_one (void * unused)
{
	unsigned long flags;
	unsigned int val[2];
	int cpu_num = smp_processor_id();
	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;

	if (uci->mc == NULL) {
		printk(KERN_INFO "microcode: No new microcode data for CPU%d\n", cpu_num);
		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]);

	/* notify the caller of success on this cpu */
	uci->err = MC_SUCCESS;
	spin_unlock_irqrestore(&microcode_update_lock, flags);
	printk(KERN_INFO "microcode: CPU%d updated from revision "
	       "0x%x to 0x%x, date = %08x \n", 
	       cpu_num, uci->rev, val[1], uci->mc->hdr.date);
	return;
}

static int do_microcode_update (void)
{
	int i, error;

	if (on_each_cpu(collect_cpu_info, NULL, 1, 1) != 0) {
		printk(KERN_ERR "microcode: Error! Could not run on all processors\n");
		error = -EIO;
		goto out;
	}

	if ((error = find_matching_ucodes())) {
		printk(KERN_ERR "microcode: Error in the microcode data\n");
		goto out_free;
	}

	if (on_each_cpu(do_update_one, NULL, 1, 1) != 0) {
		printk(KERN_ERR "microcode: Error! Could not run on all processors\n");
		error = -EIO;
	}

out_free:
	for (i = 0; i < num_online_cpus(); i++) {
		if (ucode_cpu_info[i].mc) {
			int j;
			void *tmp = ucode_cpu_info[i].mc;
			vfree(tmp);
			for (j = i; j < num_online_cpus(); j++) {
				if (ucode_cpu_info[j].mc == tmp)
					ucode_cpu_info[j].mc = NULL;
			}
		}
	}
out:
	return error;
}

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

	if (len < DEFAULT_UCODE_TOTALSIZE) {
		printk(KERN_ERR "microcode: not enough data\n"); 
		return -EINVAL;
	}

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

	down(&microcode_sem);

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

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

	up(&microcode_sem);

	return ret;
}

static int microcode_ioctl (struct inode *inode, struct file *file, 
		unsigned int cmd, unsigned long arg)
{
	switch (cmd) {
		/* 
		 *  XXX: will be removed after microcode_ctl 
		 *  is updated to ignore failure of this ioctl()
		 */
		case MICROCODE_IOCFREE:
			return 0;
		default:
			return -EINVAL;
	}
	return -EINVAL;
}

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

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

static int __init microcode_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;
	}

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

static void __exit microcode_exit (void)
{
	misc_deregister(&microcode_dev);
	printk(KERN_INFO "IA-32 Microcode Update Driver v" MICROCODE_VERSION " unregistered\n");
}

module_init(microcode_init)
module_exit(microcode_exit)
MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);