aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/microcode_core.c
blob: 87af68e0e1e1458a00d90d7e95e6755a4a332aa4 (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
/*
 *	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 8.11 of Volume 3a, IA-32 Intel? Architecture
 *	Software Developer's Manual
 *	Order Number 253668 or free download from:
 *
 *	http://developer.intel.com/Assets/PDF/manual/253668.pdf	
 *
 *	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 pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/platform_device.h>
#include <linux/miscdevice.h>
#include <linux/capability.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/cpu.h>
#include <linux/fs.h>
#include <linux/mm.h>

#include <asm/microcode.h>
#include <asm/processor.h>

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

#define MICROCODE_VERSION	"2.00"

static struct microcode_ops	*microcode_ops;

/*
 * Synchronization.
 *
 * All non cpu-hotplug-callback call sites use:
 *
 * - microcode_mutex to synchronize with each other;
 * - get/put_online_cpus() to synchronize with
 *   the cpu-hotplug-callback call sites.
 *
 * We guarantee that only a single cpu is being
 * updated at any particular moment of time.
 */
static DEFINE_MUTEX(microcode_mutex);

struct ucode_cpu_info		ucode_cpu_info[NR_CPUS];
EXPORT_SYMBOL_GPL(ucode_cpu_info);

/*
 * Operations that are run on a target cpu:
 */

struct cpu_info_ctx {
	struct cpu_signature	*cpu_sig;
	int			err;
};

static void collect_cpu_info_local(void *arg)
{
	struct cpu_info_ctx *ctx = arg;

	ctx->err = microcode_ops->collect_cpu_info(smp_processor_id(),
						   ctx->cpu_sig);
}

static int collect_cpu_info_on_target(int cpu, struct cpu_signature *cpu_sig)
{
	struct cpu_info_ctx ctx = { .cpu_sig = cpu_sig, .err = 0 };
	int ret;

	ret = smp_call_function_single(cpu, collect_cpu_info_local, &ctx, 1);
	if (!ret)
		ret = ctx.err;

	return ret;
}

static int collect_cpu_info(int cpu)
{
	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
	int ret;

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

	ret = collect_cpu_info_on_target(cpu, &uci->cpu_sig);
	if (!ret)
		uci->valid = 1;

	return ret;
}

struct apply_microcode_ctx {
	int err;
};

static void apply_microcode_local(void *arg)
{
	struct apply_microcode_ctx *ctx = arg;

	ctx->err = microcode_ops->apply_microcode(smp_processor_id());
}

static int apply_microcode_on_target(int cpu)
{
	struct apply_microcode_ctx ctx = { .err = 0 };
	int ret;

	ret = smp_call_function_single(cpu, apply_microcode_local, &ctx, 1);
	if (!ret)
		ret = ctx.err;

	return ret;
}

#ifdef CONFIG_MICROCODE_OLD_INTERFACE
static int do_microcode_update(const void __user *buf, size_t size)
{
	int error = 0;
	int cpu;

	for_each_online_cpu(cpu) {
		struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
		enum ucode_state ustate;

		if (!uci->valid)
			continue;

		ustate = microcode_ops->request_microcode_user(cpu, buf, size);
		if (ustate == UCODE_ERROR) {
			error = -1;
			break;
		} else if (ustate == UCODE_OK)
			apply_microcode_on_target(cpu);
	}

	return error;
}

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

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

	if ((len >> PAGE_SHIFT) > totalram_pages) {
		pr_err("too much data (max %ld pages)\n", totalram_pages);
		return ret;
	}

	get_online_cpus();
	mutex_lock(&microcode_mutex);

	if (do_microcode_update(buf, len) == 0)
		ret = (ssize_t)len;

	mutex_unlock(&microcode_mutex);
	put_online_cpus();

	return ret;
}

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

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

static int __init microcode_dev_init(void)
{
	int error;

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

	return 0;
}

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

MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);
MODULE_ALIAS("devname:cpu/microcode");
#else
#define microcode_dev_init()	0
#define microcode_dev_exit()	do { } while (0)
#endif

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

static int reload_for_cpu(int cpu)
{
	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
	int err = 0;

	mutex_lock(&microcode_mutex);
	if (uci->valid) {
		enum ucode_state ustate;

		ustate = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev);
		if (ustate == UCODE_OK)
			apply_microcode_on_target(cpu);
		else
			if (ustate == UCODE_ERROR)
				err = -EINVAL;
	}
	mutex_unlock(&microcode_mutex);

	return err;
}

static ssize_t reload_store(struct sys_device *dev,
			    struct sysdev_attribute *attr,
			    const char *buf, size_t size)
{
	unsigned long val;
	int cpu = dev->id;
	int ret = 0;
	char *end;

	val = simple_strtoul(buf, &end, 0);
	if (end == buf)
		return -EINVAL;

	if (val == 1) {
		get_online_cpus();
		if (cpu_online(cpu))
			ret = reload_for_cpu(cpu);
		put_online_cpus();
	}

	if (!ret)
		ret = size;

	return ret;
}

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

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

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

	return sprintf(buf, "0x%x\n", uci->cpu_sig.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 void microcode_fini_cpu(int cpu)
{
	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;

	microcode_ops->microcode_fini_cpu(cpu);
	uci->valid = 0;
}

static enum ucode_state microcode_resume_cpu(int cpu)
{
	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;

	if (!uci->mc)
		return UCODE_NFOUND;

	pr_debug("CPU%d updated upon resume\n", cpu);
	apply_microcode_on_target(cpu);

	return UCODE_OK;
}

static enum ucode_state microcode_init_cpu(int cpu)
{
	enum ucode_state ustate;

	if (collect_cpu_info(cpu))
		return UCODE_ERROR;

	/* --dimm. Trigger a delayed update? */
	if (system_state != SYSTEM_RUNNING)
		return UCODE_NFOUND;

	ustate = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev);

	if (ustate == UCODE_OK) {
		pr_debug("CPU%d updated upon init\n", cpu);
		apply_microcode_on_target(cpu);
	}

	return ustate;
}

static enum ucode_state microcode_update_cpu(int cpu)
{
	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
	enum ucode_state ustate;

	if (uci->valid)
		ustate = microcode_resume_cpu(cpu);
	else
		ustate = microcode_init_cpu(cpu);

	return ustate;
}

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

	if (!cpu_online(cpu))
		return 0;

	pr_debug("CPU%d added\n", cpu);

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

	if (microcode_init_cpu(cpu) == UCODE_ERROR) {
		sysfs_remove_group(&sys_dev->kobj, &mc_attr_group);
		return -EINVAL;
	}

	return err;
}

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

	if (!cpu_online(cpu))
		return 0;

	pr_debug("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;
	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;

	if (!cpu_online(cpu))
		return 0;

	/*
	 * All non-bootup cpus are still disabled,
	 * so only CPU 0 will apply ucode here.
	 *
	 * Moreover, there can be no concurrent
	 * updates from any other places at this point.
	 */
	WARN_ON(cpu != 0);

	if (uci->valid && uci->mc)
		microcode_ops->apply_microcode(cpu);

	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_ONLINE_FROZEN:
		microcode_update_cpu(cpu);
	case CPU_DOWN_FAILED:
	case CPU_DOWN_FAILED_FROZEN:
		pr_debug("CPU%d added\n", cpu);
		if (sysfs_create_group(&sys_dev->kobj, &mc_attr_group))
			pr_err("Failed to create group for CPU%d\n", cpu);
		break;
	case CPU_DOWN_PREPARE:
	case CPU_DOWN_PREPARE_FROZEN:
		/* Suspend is in progress, only remove the interface */
		sysfs_remove_group(&sys_dev->kobj, &mc_attr_group);
		pr_debug("CPU%d removed\n", cpu);
		break;
	case CPU_DEAD:
	case CPU_UP_CANCELED_FROZEN:
		/* The CPU refused to come up during a system resume */
		microcode_fini_cpu(cpu);
		break;
	}
	return NOTIFY_OK;
}

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

static int __init microcode_init(void)
{
	struct cpuinfo_x86 *c = &cpu_data(0);
	int error;

	if (c->x86_vendor == X86_VENDOR_INTEL)
		microcode_ops = init_intel_microcode();
	else if (c->x86_vendor == X86_VENDOR_AMD)
		microcode_ops = init_amd_microcode();

	if (!microcode_ops) {
		pr_err("no support for this CPU vendor\n");
		return -ENODEV;
	}

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

	get_online_cpus();
	mutex_lock(&microcode_mutex);

	error = sysdev_driver_register(&cpu_sysdev_class, &mc_sysdev_driver);

	mutex_unlock(&microcode_mutex);
	put_online_cpus();

	if (error) {
		platform_device_unregister(microcode_pdev);
		return error;
	}

	error = microcode_dev_init();
	if (error)
		return error;

	register_hotcpu_notifier(&mc_cpu_notifier);

	pr_info("Microcode Update Driver: v" MICROCODE_VERSION
		" <tigran@aivazian.fsnet.co.uk>, Peter Oruba\n");

	return 0;
}
module_init(microcode_init);

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

	unregister_hotcpu_notifier(&mc_cpu_notifier);

	get_online_cpus();
	mutex_lock(&microcode_mutex);

	sysdev_driver_unregister(&cpu_sysdev_class, &mc_sysdev_driver);

	mutex_unlock(&microcode_mutex);
	put_online_cpus();

	platform_device_unregister(microcode_pdev);

	microcode_ops = NULL;

	pr_info("Microcode Update Driver: v" MICROCODE_VERSION " removed.\n");
}
module_exit(microcode_exit);