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 *	This driver allows to upgrade microcode on Intel processors
  8 *	belonging to IA-32 family - PentiumPro, Pentium II,
  9 *	Pentium III, Xeon, Pentium 4, etc.
 10 *
 11 *	Reference: Section 8.11 of Volume 3a, IA-32 Intel? Architecture
 12 *	Software Developer's Manual
 13 *	Order Number 253668 or free download from:
 14 *
 15 *	http://developer.intel.com/Assets/PDF/manual/253668.pdf	
 16 *
 17 *	For more information, go to http://www.urbanmyth.org/microcode
 18 *
 19 *	This program is free software; you can redistribute it and/or
 20 *	modify it under the terms of the GNU General Public License
 21 *	as published by the Free Software Foundation; either version
 22 *	2 of the License, or (at your option) any later version.
 23 *
 24 *	1.0	16 Feb 2000, Tigran Aivazian <tigran@sco.com>
 25 *		Initial release.
 26 *	1.01	18 Feb 2000, Tigran Aivazian <tigran@sco.com>
 27 *		Added read() support + cleanups.
 28 *	1.02	21 Feb 2000, Tigran Aivazian <tigran@sco.com>
 29 *		Added 'device trimming' support. open(O_WRONLY) zeroes
 30 *		and frees the saved copy of applied microcode.
 31 *	1.03	29 Feb 2000, Tigran Aivazian <tigran@sco.com>
 32 *		Made to use devfs (/dev/cpu/microcode) + cleanups.
 33 *	1.04	06 Jun 2000, Simon Trimmer <simon@veritas.com>
 34 *		Added misc device support (now uses both devfs and misc).
 35 *		Added MICROCODE_IOCFREE ioctl to clear memory.
 36 *	1.05	09 Jun 2000, Simon Trimmer <simon@veritas.com>
 37 *		Messages for error cases (non Intel & no suitable microcode).
 38 *	1.06	03 Aug 2000, Tigran Aivazian <tigran@veritas.com>
 39 *		Removed ->release(). Removed exclusive open and status bitmap.
 40 *		Added microcode_rwsem to serialize read()/write()/ioctl().
 41 *		Removed global kernel lock usage.
 42 *	1.07	07 Sep 2000, Tigran Aivazian <tigran@veritas.com>
 43 *		Write 0 to 0x8B msr and then cpuid before reading revision,
 44 *		so that it works even if there were no update done by the
 45 *		BIOS. Otherwise, reading from 0x8B gives junk (which happened
 46 *		to be 0 on my machine which is why it worked even when I
 47 *		disabled update by the BIOS)
 48 *		Thanks to Eric W. Biederman <ebiederman@lnxi.com> for the fix.
 49 *	1.08	11 Dec 2000, Richard Schaal <richard.schaal@intel.com> and
 50 *			     Tigran Aivazian <tigran@veritas.com>
 51 *		Intel Pentium 4 processor support and bugfixes.
 52 *	1.09	30 Oct 2001, Tigran Aivazian <tigran@veritas.com>
 53 *		Bugfix for HT (Hyper-Threading) enabled processors
 54 *		whereby processor resources are shared by all logical processors
 55 *		in a single CPU package.
 56 *	1.10	28 Feb 2002 Asit K Mallick <asit.k.mallick@intel.com> and
 57 *		Tigran Aivazian <tigran@veritas.com>,
 58 *		Serialize updates as required on HT processors due to
 59 *		speculative nature of implementation.
 60 *	1.11	22 Mar 2002 Tigran Aivazian <tigran@veritas.com>
 61 *		Fix the panic when writing zero-length microcode chunk.
 62 *	1.12	29 Sep 2003 Nitin Kamble <nitin.a.kamble@intel.com>,
 63 *		Jun Nakajima <jun.nakajima@intel.com>
 64 *		Support for the microcode updates in the new format.
 65 *	1.13	10 Oct 2003 Tigran Aivazian <tigran@veritas.com>
 66 *		Removed ->read() method and obsoleted MICROCODE_IOCFREE ioctl
 67 *		because we no longer hold a copy of applied microcode
 68 *		in kernel memory.
 69 *	1.14	25 Jun 2004 Tigran Aivazian <tigran@veritas.com>
 70 *		Fix sigmatch() macro to handle old CPUs with pf == 0.
 71 *		Thanks to Stuart Swales for pointing out this bug.
 72 */
 73
 74#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 75
 76#include <linux/platform_device.h>
 77#include <linux/miscdevice.h>
 78#include <linux/capability.h>
 79#include <linux/kernel.h>
 80#include <linux/module.h>
 81#include <linux/mutex.h>
 82#include <linux/cpu.h>
 83#include <linux/fs.h>
 84#include <linux/mm.h>
 85#include <linux/syscore_ops.h>
 86
 87#include <asm/microcode.h>
 88#include <asm/processor.h>
 89#include <asm/cpu_device_id.h>
 90#include <asm/perf_event.h>
 91
 92MODULE_DESCRIPTION("Microcode Update Driver");
 93MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
 94MODULE_LICENSE("GPL");
 95
 96#define MICROCODE_VERSION	"2.00"
 97
 98static struct microcode_ops	*microcode_ops;
 99
100/*
101 * Synchronization.
102 *
103 * All non cpu-hotplug-callback call sites use:
104 *
105 * - microcode_mutex to synchronize with each other;
106 * - get/put_online_cpus() to synchronize with
107 *   the cpu-hotplug-callback call sites.
108 *
109 * We guarantee that only a single cpu is being
110 * updated at any particular moment of time.
111 */
112static DEFINE_MUTEX(microcode_mutex);
113
114struct ucode_cpu_info		ucode_cpu_info[NR_CPUS];
115EXPORT_SYMBOL_GPL(ucode_cpu_info);
116
117/*
118 * Operations that are run on a target cpu:
119 */
120
121struct cpu_info_ctx {
122	struct cpu_signature	*cpu_sig;
123	int			err;
124};
125
126static void collect_cpu_info_local(void *arg)
127{
128	struct cpu_info_ctx *ctx = arg;
129
130	ctx->err = microcode_ops->collect_cpu_info(smp_processor_id(),
131						   ctx->cpu_sig);
132}
133
134static int collect_cpu_info_on_target(int cpu, struct cpu_signature *cpu_sig)
135{
136	struct cpu_info_ctx ctx = { .cpu_sig = cpu_sig, .err = 0 };
137	int ret;
138
139	ret = smp_call_function_single(cpu, collect_cpu_info_local, &ctx, 1);
140	if (!ret)
141		ret = ctx.err;
142
143	return ret;
144}
145
146static int collect_cpu_info(int cpu)
147{
148	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
149	int ret;
150
151	memset(uci, 0, sizeof(*uci));
152
153	ret = collect_cpu_info_on_target(cpu, &uci->cpu_sig);
154	if (!ret)
155		uci->valid = 1;
156
157	return ret;
158}
159
160struct apply_microcode_ctx {
161	int err;
162};
163
164static void apply_microcode_local(void *arg)
165{
166	struct apply_microcode_ctx *ctx = arg;
167
168	ctx->err = microcode_ops->apply_microcode(smp_processor_id());
169}
170
171static int apply_microcode_on_target(int cpu)
172{
173	struct apply_microcode_ctx ctx = { .err = 0 };
174	int ret;
175
176	ret = smp_call_function_single(cpu, apply_microcode_local, &ctx, 1);
177	if (!ret)
178		ret = ctx.err;
179
180	return ret;
181}
182
183#ifdef CONFIG_MICROCODE_OLD_INTERFACE
184static int do_microcode_update(const void __user *buf, size_t size)
185{
186	int error = 0;
187	int cpu;
188
189	for_each_online_cpu(cpu) {
190		struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
191		enum ucode_state ustate;
192
193		if (!uci->valid)
194			continue;
195
196		ustate = microcode_ops->request_microcode_user(cpu, buf, size);
197		if (ustate == UCODE_ERROR) {
198			error = -1;
199			break;
200		} else if (ustate == UCODE_OK)
201			apply_microcode_on_target(cpu);
202	}
203
204	return error;
205}
206
207static int microcode_open(struct inode *inode, struct file *file)
208{
209	return capable(CAP_SYS_RAWIO) ? nonseekable_open(inode, file) : -EPERM;
210}
211
212static ssize_t microcode_write(struct file *file, const char __user *buf,
213			       size_t len, loff_t *ppos)
214{
215	ssize_t ret = -EINVAL;
216
217	if ((len >> PAGE_SHIFT) > totalram_pages) {
218		pr_err("too much data (max %ld pages)\n", totalram_pages);
219		return ret;
220	}
221
222	get_online_cpus();
223	mutex_lock(&microcode_mutex);
224
225	if (do_microcode_update(buf, len) == 0)
226		ret = (ssize_t)len;
227
228	if (ret > 0)
229		perf_check_microcode();
230
231	mutex_unlock(&microcode_mutex);
232	put_online_cpus();
233
234	return ret;
235}
236
237static const struct file_operations microcode_fops = {
238	.owner			= THIS_MODULE,
239	.write			= microcode_write,
240	.open			= microcode_open,
241	.llseek		= no_llseek,
242};
243
244static struct miscdevice microcode_dev = {
245	.minor			= MICROCODE_MINOR,
246	.name			= "microcode",
247	.nodename		= "cpu/microcode",
248	.fops			= &microcode_fops,
249};
250
251static int __init microcode_dev_init(void)
252{
253	int error;
254
255	error = misc_register(&microcode_dev);
256	if (error) {
257		pr_err("can't misc_register on minor=%d\n", MICROCODE_MINOR);
258		return error;
259	}
260
261	return 0;
262}
263
264static void __exit microcode_dev_exit(void)
265{
266	misc_deregister(&microcode_dev);
267}
268
269MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);
270MODULE_ALIAS("devname:cpu/microcode");
271#else
272#define microcode_dev_init()	0
273#define microcode_dev_exit()	do { } while (0)
274#endif
275
276/* fake device for request_firmware */
277static struct platform_device	*microcode_pdev;
278
279static int reload_for_cpu(int cpu)
280{
281	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
282	enum ucode_state ustate;
283	int err = 0;
284
285	if (!uci->valid)
286		return err;
287
288	ustate = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev, true);
289	if (ustate == UCODE_OK)
290		apply_microcode_on_target(cpu);
291	else
292		if (ustate == UCODE_ERROR)
293			err = -EINVAL;
294	return err;
295}
296
297static ssize_t reload_store(struct device *dev,
298			    struct device_attribute *attr,
299			    const char *buf, size_t size)
300{
301	unsigned long val;
302	int cpu;
303	ssize_t ret = 0, tmp_ret;
304
305	ret = kstrtoul(buf, 0, &val);
306	if (ret)
307		return ret;
308
309	if (val != 1)
310		return size;
311
312	get_online_cpus();
313	mutex_lock(&microcode_mutex);
314	for_each_online_cpu(cpu) {
315		tmp_ret = reload_for_cpu(cpu);
316		if (tmp_ret != 0)
317			pr_warn("Error reloading microcode on CPU %d\n", cpu);
318
319		/* save retval of the first encountered reload error */
320		if (!ret)
321			ret = tmp_ret;
322	}
323	if (!ret)
324		perf_check_microcode();
325	mutex_unlock(&microcode_mutex);
326	put_online_cpus();
327
328	if (!ret)
329		ret = size;
330
331	return ret;
332}
333
334static ssize_t version_show(struct device *dev,
335			struct device_attribute *attr, char *buf)
336{
337	struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
338
339	return sprintf(buf, "0x%x\n", uci->cpu_sig.rev);
340}
341
342static ssize_t pf_show(struct device *dev,
343			struct device_attribute *attr, char *buf)
344{
345	struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
346
347	return sprintf(buf, "0x%x\n", uci->cpu_sig.pf);
348}
349
350static DEVICE_ATTR(reload, 0200, NULL, reload_store);
351static DEVICE_ATTR(version, 0400, version_show, NULL);
352static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL);
353
354static struct attribute *mc_default_attrs[] = {
355	&dev_attr_version.attr,
356	&dev_attr_processor_flags.attr,
357	NULL
358};
359
360static struct attribute_group mc_attr_group = {
361	.attrs			= mc_default_attrs,
362	.name			= "microcode",
363};
364
365static void microcode_fini_cpu(int cpu)
366{
367	microcode_ops->microcode_fini_cpu(cpu);
368}
369
370static enum ucode_state microcode_resume_cpu(int cpu)
371{
372	pr_debug("CPU%d updated upon resume\n", cpu);
373
374	if (apply_microcode_on_target(cpu))
375		return UCODE_ERROR;
376
377	return UCODE_OK;
378}
379
380static enum ucode_state microcode_init_cpu(int cpu, bool refresh_fw)
381{
382	enum ucode_state ustate;
383	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
384
385	if (uci && uci->valid)
386		return UCODE_OK;
387
388	if (collect_cpu_info(cpu))
389		return UCODE_ERROR;
390
391	/* --dimm. Trigger a delayed update? */
392	if (system_state != SYSTEM_RUNNING)
393		return UCODE_NFOUND;
394
395	ustate = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev,
396						     refresh_fw);
397
398	if (ustate == UCODE_OK) {
399		pr_debug("CPU%d updated upon init\n", cpu);
400		apply_microcode_on_target(cpu);
401	}
402
403	return ustate;
404}
405
406static enum ucode_state microcode_update_cpu(int cpu)
407{
408	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
409
410	if (uci->valid)
411		return microcode_resume_cpu(cpu);
412
413	return microcode_init_cpu(cpu, false);
414}
415
416static int mc_device_add(struct device *dev, struct subsys_interface *sif)
417{
418	int err, cpu = dev->id;
419
420	if (!cpu_online(cpu))
421		return 0;
422
423	pr_debug("CPU%d added\n", cpu);
424
425	err = sysfs_create_group(&dev->kobj, &mc_attr_group);
426	if (err)
427		return err;
428
429	if (microcode_init_cpu(cpu, true) == UCODE_ERROR)
430		return -EINVAL;
431
432	return err;
433}
434
435static int mc_device_remove(struct device *dev, struct subsys_interface *sif)
436{
437	int cpu = dev->id;
438
439	if (!cpu_online(cpu))
440		return 0;
441
442	pr_debug("CPU%d removed\n", cpu);
443	microcode_fini_cpu(cpu);
444	sysfs_remove_group(&dev->kobj, &mc_attr_group);
445	return 0;
446}
447
448static struct subsys_interface mc_cpu_interface = {
449	.name			= "microcode",
450	.subsys			= &cpu_subsys,
451	.add_dev		= mc_device_add,
452	.remove_dev		= mc_device_remove,
453};
454
455/**
456 * mc_bp_resume - Update boot CPU microcode during resume.
457 */
458static void mc_bp_resume(void)
459{
460	int cpu = smp_processor_id();
461	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
462
463	if (uci->valid && uci->mc)
464		microcode_ops->apply_microcode(cpu);
465}
466
467static struct syscore_ops mc_syscore_ops = {
468	.resume			= mc_bp_resume,
469};
470
471static int
472mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
473{
474	unsigned int cpu = (unsigned long)hcpu;
475	struct device *dev;
476
477	dev = get_cpu_device(cpu);
478
479	switch (action & ~CPU_TASKS_FROZEN) {
480	case CPU_ONLINE:
481		microcode_update_cpu(cpu);
482		pr_debug("CPU%d added\n", cpu);
483		/*
484		 * "break" is missing on purpose here because we want to fall
485		 * through in order to create the sysfs group.
486		 */
487
488	case CPU_DOWN_FAILED:
489		if (sysfs_create_group(&dev->kobj, &mc_attr_group))
490			pr_err("Failed to create group for CPU%d\n", cpu);
491		break;
492
493	case CPU_DOWN_PREPARE:
494		/* Suspend is in progress, only remove the interface */
495		sysfs_remove_group(&dev->kobj, &mc_attr_group);
496		pr_debug("CPU%d removed\n", cpu);
497		break;
498
499	/*
500	 * case CPU_DEAD:
501	 *
502	 * When a CPU goes offline, don't free up or invalidate the copy of
503	 * the microcode in kernel memory, so that we can reuse it when the
504	 * CPU comes back online without unnecessarily requesting the userspace
505	 * for it again.
506	 */
507	}
508
509	/* The CPU refused to come up during a system resume */
510	if (action == CPU_UP_CANCELED_FROZEN)
511		microcode_fini_cpu(cpu);
512
513	return NOTIFY_OK;
514}
515
516static struct notifier_block __refdata mc_cpu_notifier = {
517	.notifier_call	= mc_cpu_callback,
518};
519
520#ifdef MODULE
521/* Autoload on Intel and AMD systems */
522static const struct x86_cpu_id __initconst microcode_id[] = {
523#ifdef CONFIG_MICROCODE_INTEL
524	{ X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, },
525#endif
526#ifdef CONFIG_MICROCODE_AMD
527	{ X86_VENDOR_AMD, X86_FAMILY_ANY, X86_MODEL_ANY, },
528#endif
529	{}
530};
531MODULE_DEVICE_TABLE(x86cpu, microcode_id);
532#endif
533
534static struct attribute *cpu_root_microcode_attrs[] = {
535	&dev_attr_reload.attr,
536	NULL
537};
538
539static struct attribute_group cpu_root_microcode_group = {
540	.name  = "microcode",
541	.attrs = cpu_root_microcode_attrs,
542};
543
544static int __init microcode_init(void)
545{
546	struct cpuinfo_x86 *c = &cpu_data(0);
547	int error;
548
549	if (c->x86_vendor == X86_VENDOR_INTEL)
550		microcode_ops = init_intel_microcode();
551	else if (c->x86_vendor == X86_VENDOR_AMD)
552		microcode_ops = init_amd_microcode();
553	else
554		pr_err("no support for this CPU vendor\n");
555
556	if (!microcode_ops)
557		return -ENODEV;
558
559	microcode_pdev = platform_device_register_simple("microcode", -1,
560							 NULL, 0);
561	if (IS_ERR(microcode_pdev))
562		return PTR_ERR(microcode_pdev);
563
564	get_online_cpus();
565	mutex_lock(&microcode_mutex);
566
567	error = subsys_interface_register(&mc_cpu_interface);
568	if (!error)
569		perf_check_microcode();
570	mutex_unlock(&microcode_mutex);
571	put_online_cpus();
572
573	if (error)
574		goto out_pdev;
575
576	error = sysfs_create_group(&cpu_subsys.dev_root->kobj,
577				   &cpu_root_microcode_group);
578
579	if (error) {
580		pr_err("Error creating microcode group!\n");
581		goto out_driver;
582	}
583
584	error = microcode_dev_init();
585	if (error)
586		goto out_ucode_group;
587
588	register_syscore_ops(&mc_syscore_ops);
589	register_hotcpu_notifier(&mc_cpu_notifier);
590
591	pr_info("Microcode Update Driver: v" MICROCODE_VERSION
592		" <tigran@aivazian.fsnet.co.uk>, Peter Oruba\n");
593
594	return 0;
595
596 out_ucode_group:
597	sysfs_remove_group(&cpu_subsys.dev_root->kobj,
598			   &cpu_root_microcode_group);
599
600 out_driver:
601	get_online_cpus();
602	mutex_lock(&microcode_mutex);
603
604	subsys_interface_unregister(&mc_cpu_interface);
605
606	mutex_unlock(&microcode_mutex);
607	put_online_cpus();
608
609 out_pdev:
610	platform_device_unregister(microcode_pdev);
611	return error;
612
613}
614module_init(microcode_init);
615
616static void __exit microcode_exit(void)
617{
618	struct cpuinfo_x86 *c = &cpu_data(0);
619
620	microcode_dev_exit();
621
622	unregister_hotcpu_notifier(&mc_cpu_notifier);
623	unregister_syscore_ops(&mc_syscore_ops);
624
625	sysfs_remove_group(&cpu_subsys.dev_root->kobj,
626			   &cpu_root_microcode_group);
627
628	get_online_cpus();
629	mutex_lock(&microcode_mutex);
630
631	subsys_interface_unregister(&mc_cpu_interface);
632
633	mutex_unlock(&microcode_mutex);
634	put_online_cpus();
635
636	platform_device_unregister(microcode_pdev);
637
638	microcode_ops = NULL;
639
640	if (c->x86_vendor == X86_VENDOR_AMD)
641		exit_amd_microcode();
642
643	pr_info("Microcode Update Driver: v" MICROCODE_VERSION " removed.\n");
644}
645module_exit(microcode_exit);