2 * Intel CPU Microcode Update Driver for Linux
4 * Copyright (C) 2000-2006 Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
5 * 2006 Shaohua Li <shaohua.li@intel.com>
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.
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:
15 * http://developer.intel.com/Assets/PDF/manual/253668.pdf
17 * For more information, go to http://www.urbanmyth.org/microcode
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.
24 * 1.0 16 Feb 2000, Tigran Aivazian <tigran@sco.com>
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
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.
74 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
85 #include <linux/syscore_ops.h>
87 #include <asm/microcode.h>
88 #include <asm/processor.h>
89 #include <asm/cpu_device_id.h>
91 MODULE_DESCRIPTION("Microcode Update Driver");
92 MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
93 MODULE_LICENSE("GPL");
95 #define MICROCODE_VERSION "2.00"
97 static struct microcode_ops *microcode_ops;
102 * All non cpu-hotplug-callback call sites use:
104 * - microcode_mutex to synchronize with each other;
105 * - get/put_online_cpus() to synchronize with
106 * the cpu-hotplug-callback call sites.
108 * We guarantee that only a single cpu is being
109 * updated at any particular moment of time.
111 static DEFINE_MUTEX(microcode_mutex);
113 struct ucode_cpu_info ucode_cpu_info[NR_CPUS];
114 EXPORT_SYMBOL_GPL(ucode_cpu_info);
117 * Operations that are run on a target cpu:
120 struct cpu_info_ctx {
121 struct cpu_signature *cpu_sig;
125 static void collect_cpu_info_local(void *arg)
127 struct cpu_info_ctx *ctx = arg;
129 ctx->err = microcode_ops->collect_cpu_info(smp_processor_id(),
133 static int collect_cpu_info_on_target(int cpu, struct cpu_signature *cpu_sig)
135 struct cpu_info_ctx ctx = { .cpu_sig = cpu_sig, .err = 0 };
138 ret = smp_call_function_single(cpu, collect_cpu_info_local, &ctx, 1);
145 static int collect_cpu_info(int cpu)
147 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
150 memset(uci, 0, sizeof(*uci));
152 ret = collect_cpu_info_on_target(cpu, &uci->cpu_sig);
159 struct apply_microcode_ctx {
163 static void apply_microcode_local(void *arg)
165 struct apply_microcode_ctx *ctx = arg;
167 ctx->err = microcode_ops->apply_microcode(smp_processor_id());
170 static int apply_microcode_on_target(int cpu)
172 struct apply_microcode_ctx ctx = { .err = 0 };
175 ret = smp_call_function_single(cpu, apply_microcode_local, &ctx, 1);
182 #ifdef CONFIG_MICROCODE_OLD_INTERFACE
183 static int do_microcode_update(const void __user *buf, size_t size)
188 for_each_online_cpu(cpu) {
189 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
190 enum ucode_state ustate;
195 ustate = microcode_ops->request_microcode_user(cpu, buf, size);
196 if (ustate == UCODE_ERROR) {
199 } else if (ustate == UCODE_OK)
200 apply_microcode_on_target(cpu);
206 static int microcode_open(struct inode *inode, struct file *file)
208 return capable(CAP_SYS_RAWIO) ? nonseekable_open(inode, file) : -EPERM;
211 static ssize_t microcode_write(struct file *file, const char __user *buf,
212 size_t len, loff_t *ppos)
214 ssize_t ret = -EINVAL;
216 if ((len >> PAGE_SHIFT) > totalram_pages) {
217 pr_err("too much data (max %ld pages)\n", totalram_pages);
222 mutex_lock(µcode_mutex);
224 if (do_microcode_update(buf, len) == 0)
227 mutex_unlock(µcode_mutex);
233 static const struct file_operations microcode_fops = {
234 .owner = THIS_MODULE,
235 .write = microcode_write,
236 .open = microcode_open,
240 static struct miscdevice microcode_dev = {
241 .minor = MICROCODE_MINOR,
243 .nodename = "cpu/microcode",
244 .fops = µcode_fops,
247 static int __init microcode_dev_init(void)
251 error = misc_register(µcode_dev);
253 pr_err("can't misc_register on minor=%d\n", MICROCODE_MINOR);
260 static void __exit microcode_dev_exit(void)
262 misc_deregister(µcode_dev);
265 MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);
266 MODULE_ALIAS("devname:cpu/microcode");
268 #define microcode_dev_init() 0
269 #define microcode_dev_exit() do { } while (0)
272 /* fake device for request_firmware */
273 static struct platform_device *microcode_pdev;
275 static int reload_for_cpu(int cpu)
277 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
280 mutex_lock(µcode_mutex);
282 enum ucode_state ustate;
284 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev);
285 if (ustate == UCODE_OK)
286 apply_microcode_on_target(cpu);
288 if (ustate == UCODE_ERROR)
291 mutex_unlock(µcode_mutex);
296 static ssize_t reload_store(struct device *dev,
297 struct device_attribute *attr,
298 const char *buf, size_t size)
302 ssize_t ret = 0, tmp_ret;
304 ret = kstrtoul(buf, 0, &val);
312 for_each_online_cpu(cpu) {
313 tmp_ret = reload_for_cpu(cpu);
315 pr_warn("Error reloading microcode on CPU %d\n", cpu);
317 /* save retval of the first encountered reload error */
329 static ssize_t version_show(struct device *dev,
330 struct device_attribute *attr, char *buf)
332 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
334 return sprintf(buf, "0x%x\n", uci->cpu_sig.rev);
337 static ssize_t pf_show(struct device *dev,
338 struct device_attribute *attr, char *buf)
340 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
342 return sprintf(buf, "0x%x\n", uci->cpu_sig.pf);
345 static DEVICE_ATTR(reload, 0200, NULL, reload_store);
346 static DEVICE_ATTR(version, 0400, version_show, NULL);
347 static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL);
349 static struct attribute *mc_default_attrs[] = {
350 &dev_attr_version.attr,
351 &dev_attr_processor_flags.attr,
355 static struct attribute_group mc_attr_group = {
356 .attrs = mc_default_attrs,
360 static void microcode_fini_cpu(int cpu)
362 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
364 microcode_ops->microcode_fini_cpu(cpu);
368 static enum ucode_state microcode_resume_cpu(int cpu)
370 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
375 pr_debug("CPU%d updated upon resume\n", cpu);
376 apply_microcode_on_target(cpu);
381 static enum ucode_state microcode_init_cpu(int cpu)
383 enum ucode_state ustate;
385 if (collect_cpu_info(cpu))
388 /* --dimm. Trigger a delayed update? */
389 if (system_state != SYSTEM_RUNNING)
392 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev);
394 if (ustate == UCODE_OK) {
395 pr_debug("CPU%d updated upon init\n", cpu);
396 apply_microcode_on_target(cpu);
402 static enum ucode_state microcode_update_cpu(int cpu)
404 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
405 enum ucode_state ustate;
408 ustate = microcode_resume_cpu(cpu);
410 ustate = microcode_init_cpu(cpu);
415 static int mc_device_add(struct device *dev, struct subsys_interface *sif)
417 int err, cpu = dev->id;
419 if (!cpu_online(cpu))
422 pr_debug("CPU%d added\n", cpu);
424 err = sysfs_create_group(&dev->kobj, &mc_attr_group);
428 if (microcode_init_cpu(cpu) == UCODE_ERROR)
434 static int mc_device_remove(struct device *dev, struct subsys_interface *sif)
438 if (!cpu_online(cpu))
441 pr_debug("CPU%d removed\n", cpu);
442 microcode_fini_cpu(cpu);
443 sysfs_remove_group(&dev->kobj, &mc_attr_group);
447 static struct subsys_interface mc_cpu_interface = {
449 .subsys = &cpu_subsys,
450 .add_dev = mc_device_add,
451 .remove_dev = mc_device_remove,
455 * mc_bp_resume - Update boot CPU microcode during resume.
457 static void mc_bp_resume(void)
459 int cpu = smp_processor_id();
460 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
462 if (uci->valid && uci->mc)
463 microcode_ops->apply_microcode(cpu);
466 static struct syscore_ops mc_syscore_ops = {
467 .resume = mc_bp_resume,
471 mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
473 unsigned int cpu = (unsigned long)hcpu;
476 dev = get_cpu_device(cpu);
479 case CPU_ONLINE_FROZEN:
480 microcode_update_cpu(cpu);
481 case CPU_DOWN_FAILED:
482 case CPU_DOWN_FAILED_FROZEN:
483 pr_debug("CPU%d added\n", cpu);
484 if (sysfs_create_group(&dev->kobj, &mc_attr_group))
485 pr_err("Failed to create group for CPU%d\n", cpu);
487 case CPU_DOWN_PREPARE:
488 case CPU_DOWN_PREPARE_FROZEN:
489 /* Suspend is in progress, only remove the interface */
490 sysfs_remove_group(&dev->kobj, &mc_attr_group);
491 pr_debug("CPU%d removed\n", cpu);
495 * When a CPU goes offline, don't free up or invalidate the copy of
496 * the microcode in kernel memory, so that we can reuse it when the
497 * CPU comes back online without unnecessarily requesting the userspace
500 case CPU_UP_CANCELED_FROZEN:
501 /* The CPU refused to come up during a system resume */
502 microcode_fini_cpu(cpu);
508 static struct notifier_block __refdata mc_cpu_notifier = {
509 .notifier_call = mc_cpu_callback,
513 /* Autoload on Intel and AMD systems */
514 static const struct x86_cpu_id microcode_id[] = {
515 #ifdef CONFIG_MICROCODE_INTEL
516 { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, },
518 #ifdef CONFIG_MICROCODE_AMD
519 { X86_VENDOR_AMD, X86_FAMILY_ANY, X86_MODEL_ANY, },
523 MODULE_DEVICE_TABLE(x86cpu, microcode_id);
526 static struct attribute *cpu_root_microcode_attrs[] = {
527 &dev_attr_reload.attr,
531 static struct attribute_group cpu_root_microcode_group = {
533 .attrs = cpu_root_microcode_attrs,
536 static int __init microcode_init(void)
538 struct cpuinfo_x86 *c = &cpu_data(0);
541 if (c->x86_vendor == X86_VENDOR_INTEL)
542 microcode_ops = init_intel_microcode();
543 else if (c->x86_vendor == X86_VENDOR_AMD)
544 microcode_ops = init_amd_microcode();
546 pr_err("no support for this CPU vendor\n");
551 microcode_pdev = platform_device_register_simple("microcode", -1,
553 if (IS_ERR(microcode_pdev))
554 return PTR_ERR(microcode_pdev);
557 mutex_lock(µcode_mutex);
559 error = subsys_interface_register(&mc_cpu_interface);
561 mutex_unlock(µcode_mutex);
567 error = sysfs_create_group(&cpu_subsys.dev_root->kobj,
568 &cpu_root_microcode_group);
571 pr_err("Error creating microcode group!\n");
575 error = microcode_dev_init();
577 goto out_ucode_group;
579 register_syscore_ops(&mc_syscore_ops);
580 register_hotcpu_notifier(&mc_cpu_notifier);
582 pr_info("Microcode Update Driver: v" MICROCODE_VERSION
583 " <tigran@aivazian.fsnet.co.uk>, Peter Oruba\n");
588 sysfs_remove_group(&cpu_subsys.dev_root->kobj,
589 &cpu_root_microcode_group);
593 mutex_lock(µcode_mutex);
595 subsys_interface_unregister(&mc_cpu_interface);
597 mutex_unlock(µcode_mutex);
601 platform_device_unregister(microcode_pdev);
605 module_init(microcode_init);
607 static void __exit microcode_exit(void)
609 struct cpuinfo_x86 *c = &cpu_data(0);
611 microcode_dev_exit();
613 unregister_hotcpu_notifier(&mc_cpu_notifier);
614 unregister_syscore_ops(&mc_syscore_ops);
616 sysfs_remove_group(&cpu_subsys.dev_root->kobj,
617 &cpu_root_microcode_group);
620 mutex_lock(µcode_mutex);
622 subsys_interface_unregister(&mc_cpu_interface);
624 mutex_unlock(µcode_mutex);
627 platform_device_unregister(microcode_pdev);
629 microcode_ops = NULL;
631 if (c->x86_vendor == X86_VENDOR_AMD)
632 exit_amd_microcode();
634 pr_info("Microcode Update Driver: v" MICROCODE_VERSION " removed.\n");
636 module_exit(microcode_exit);