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>
90 #include <asm/perf_event.h>
92 MODULE_DESCRIPTION("Microcode Update Driver");
93 MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
94 MODULE_LICENSE("GPL");
96 #define MICROCODE_VERSION "2.00"
98 static struct microcode_ops *microcode_ops;
103 * All non cpu-hotplug-callback call sites use:
105 * - microcode_mutex to synchronize with each other;
106 * - get/put_online_cpus() to synchronize with
107 * the cpu-hotplug-callback call sites.
109 * We guarantee that only a single cpu is being
110 * updated at any particular moment of time.
112 static DEFINE_MUTEX(microcode_mutex);
114 struct ucode_cpu_info ucode_cpu_info[NR_CPUS];
115 EXPORT_SYMBOL_GPL(ucode_cpu_info);
118 * Operations that are run on a target cpu:
121 struct cpu_info_ctx {
122 struct cpu_signature *cpu_sig;
126 static void collect_cpu_info_local(void *arg)
128 struct cpu_info_ctx *ctx = arg;
130 ctx->err = microcode_ops->collect_cpu_info(smp_processor_id(),
134 static int collect_cpu_info_on_target(int cpu, struct cpu_signature *cpu_sig)
136 struct cpu_info_ctx ctx = { .cpu_sig = cpu_sig, .err = 0 };
139 ret = smp_call_function_single(cpu, collect_cpu_info_local, &ctx, 1);
146 static int collect_cpu_info(int cpu)
148 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
151 memset(uci, 0, sizeof(*uci));
153 ret = collect_cpu_info_on_target(cpu, &uci->cpu_sig);
160 struct apply_microcode_ctx {
164 static void apply_microcode_local(void *arg)
166 struct apply_microcode_ctx *ctx = arg;
168 ctx->err = microcode_ops->apply_microcode(smp_processor_id());
171 static int apply_microcode_on_target(int cpu)
173 struct apply_microcode_ctx ctx = { .err = 0 };
176 ret = smp_call_function_single(cpu, apply_microcode_local, &ctx, 1);
183 #ifdef CONFIG_MICROCODE_OLD_INTERFACE
184 static int do_microcode_update(const void __user *buf, size_t size)
189 for_each_online_cpu(cpu) {
190 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
191 enum ucode_state ustate;
196 ustate = microcode_ops->request_microcode_user(cpu, buf, size);
197 if (ustate == UCODE_ERROR) {
200 } else if (ustate == UCODE_OK)
201 apply_microcode_on_target(cpu);
207 static int microcode_open(struct inode *inode, struct file *file)
209 return capable(CAP_SYS_RAWIO) ? nonseekable_open(inode, file) : -EPERM;
212 static ssize_t microcode_write(struct file *file, const char __user *buf,
213 size_t len, loff_t *ppos)
215 ssize_t ret = -EINVAL;
217 if ((len >> PAGE_SHIFT) > totalram_pages) {
218 pr_err("too much data (max %ld pages)\n", totalram_pages);
223 mutex_lock(µcode_mutex);
225 if (do_microcode_update(buf, len) == 0)
228 mutex_unlock(µcode_mutex);
234 static const struct file_operations microcode_fops = {
235 .owner = THIS_MODULE,
236 .write = microcode_write,
237 .open = microcode_open,
241 static struct miscdevice microcode_dev = {
242 .minor = MICROCODE_MINOR,
244 .nodename = "cpu/microcode",
245 .fops = µcode_fops,
248 static int __init microcode_dev_init(void)
252 error = misc_register(µcode_dev);
254 pr_err("can't misc_register on minor=%d\n", MICROCODE_MINOR);
261 static void __exit microcode_dev_exit(void)
263 misc_deregister(µcode_dev);
266 MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);
267 MODULE_ALIAS("devname:cpu/microcode");
269 #define microcode_dev_init() 0
270 #define microcode_dev_exit() do { } while (0)
273 /* fake device for request_firmware */
274 static struct platform_device *microcode_pdev;
276 static int reload_for_cpu(int cpu)
278 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
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)
295 static ssize_t reload_store(struct device *dev,
296 struct device_attribute *attr,
297 const char *buf, size_t size)
301 ssize_t ret = 0, tmp_ret;
303 ret = kstrtoul(buf, 0, &val);
311 mutex_lock(µcode_mutex);
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 */
322 perf_check_microcode();
323 mutex_unlock(µcode_mutex);
332 static ssize_t version_show(struct device *dev,
333 struct device_attribute *attr, char *buf)
335 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
337 return sprintf(buf, "0x%x\n", uci->cpu_sig.rev);
340 static ssize_t pf_show(struct device *dev,
341 struct device_attribute *attr, char *buf)
343 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
345 return sprintf(buf, "0x%x\n", uci->cpu_sig.pf);
348 static DEVICE_ATTR(reload, 0200, NULL, reload_store);
349 static DEVICE_ATTR(version, 0400, version_show, NULL);
350 static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL);
352 static struct attribute *mc_default_attrs[] = {
353 &dev_attr_version.attr,
354 &dev_attr_processor_flags.attr,
358 static struct attribute_group mc_attr_group = {
359 .attrs = mc_default_attrs,
363 static void microcode_fini_cpu(int cpu)
365 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
367 microcode_ops->microcode_fini_cpu(cpu);
371 static enum ucode_state microcode_resume_cpu(int cpu)
373 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
378 pr_debug("CPU%d updated upon resume\n", cpu);
379 apply_microcode_on_target(cpu);
384 static enum ucode_state microcode_init_cpu(int cpu)
386 enum ucode_state ustate;
388 if (collect_cpu_info(cpu))
391 /* --dimm. Trigger a delayed update? */
392 if (system_state != SYSTEM_RUNNING)
395 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev);
397 if (ustate == UCODE_OK) {
398 pr_debug("CPU%d updated upon init\n", cpu);
399 apply_microcode_on_target(cpu);
405 static enum ucode_state microcode_update_cpu(int cpu)
407 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
408 enum ucode_state ustate;
411 ustate = microcode_resume_cpu(cpu);
413 ustate = microcode_init_cpu(cpu);
418 static int mc_device_add(struct device *dev, struct subsys_interface *sif)
420 int err, cpu = dev->id;
422 if (!cpu_online(cpu))
425 pr_debug("CPU%d added\n", cpu);
427 err = sysfs_create_group(&dev->kobj, &mc_attr_group);
431 if (microcode_init_cpu(cpu) == UCODE_ERROR)
437 static int mc_device_remove(struct device *dev, struct subsys_interface *sif)
441 if (!cpu_online(cpu))
444 pr_debug("CPU%d removed\n", cpu);
445 microcode_fini_cpu(cpu);
446 sysfs_remove_group(&dev->kobj, &mc_attr_group);
450 static struct subsys_interface mc_cpu_interface = {
452 .subsys = &cpu_subsys,
453 .add_dev = mc_device_add,
454 .remove_dev = mc_device_remove,
458 * mc_bp_resume - Update boot CPU microcode during resume.
460 static void mc_bp_resume(void)
462 int cpu = smp_processor_id();
463 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
465 if (uci->valid && uci->mc)
466 microcode_ops->apply_microcode(cpu);
469 static struct syscore_ops mc_syscore_ops = {
470 .resume = mc_bp_resume,
474 mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
476 unsigned int cpu = (unsigned long)hcpu;
479 dev = get_cpu_device(cpu);
482 case CPU_ONLINE_FROZEN:
483 microcode_update_cpu(cpu);
484 case CPU_DOWN_FAILED:
485 case CPU_DOWN_FAILED_FROZEN:
486 pr_debug("CPU%d added\n", cpu);
487 if (sysfs_create_group(&dev->kobj, &mc_attr_group))
488 pr_err("Failed to create group for CPU%d\n", cpu);
490 case CPU_DOWN_PREPARE:
491 case CPU_DOWN_PREPARE_FROZEN:
492 /* Suspend is in progress, only remove the interface */
493 sysfs_remove_group(&dev->kobj, &mc_attr_group);
494 pr_debug("CPU%d removed\n", cpu);
498 * When a CPU goes offline, don't free up or invalidate the copy of
499 * the microcode in kernel memory, so that we can reuse it when the
500 * CPU comes back online without unnecessarily requesting the userspace
503 case CPU_UP_CANCELED_FROZEN:
504 /* The CPU refused to come up during a system resume */
505 microcode_fini_cpu(cpu);
511 static struct notifier_block __refdata mc_cpu_notifier = {
512 .notifier_call = mc_cpu_callback,
516 /* Autoload on Intel and AMD systems */
517 static const struct x86_cpu_id __initconst microcode_id[] = {
518 #ifdef CONFIG_MICROCODE_INTEL
519 { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, },
521 #ifdef CONFIG_MICROCODE_AMD
522 { X86_VENDOR_AMD, X86_FAMILY_ANY, X86_MODEL_ANY, },
526 MODULE_DEVICE_TABLE(x86cpu, microcode_id);
529 static struct attribute *cpu_root_microcode_attrs[] = {
530 &dev_attr_reload.attr,
534 static struct attribute_group cpu_root_microcode_group = {
536 .attrs = cpu_root_microcode_attrs,
539 static int __init microcode_init(void)
541 struct cpuinfo_x86 *c = &cpu_data(0);
544 if (c->x86_vendor == X86_VENDOR_INTEL)
545 microcode_ops = init_intel_microcode();
546 else if (c->x86_vendor == X86_VENDOR_AMD)
547 microcode_ops = init_amd_microcode();
549 pr_err("no support for this CPU vendor\n");
554 microcode_pdev = platform_device_register_simple("microcode", -1,
556 if (IS_ERR(microcode_pdev))
557 return PTR_ERR(microcode_pdev);
560 mutex_lock(µcode_mutex);
562 error = subsys_interface_register(&mc_cpu_interface);
564 perf_check_microcode();
565 mutex_unlock(µcode_mutex);
571 error = sysfs_create_group(&cpu_subsys.dev_root->kobj,
572 &cpu_root_microcode_group);
575 pr_err("Error creating microcode group!\n");
579 error = microcode_dev_init();
581 goto out_ucode_group;
583 register_syscore_ops(&mc_syscore_ops);
584 register_hotcpu_notifier(&mc_cpu_notifier);
586 pr_info("Microcode Update Driver: v" MICROCODE_VERSION
587 " <tigran@aivazian.fsnet.co.uk>, Peter Oruba\n");
592 sysfs_remove_group(&cpu_subsys.dev_root->kobj,
593 &cpu_root_microcode_group);
597 mutex_lock(µcode_mutex);
599 subsys_interface_unregister(&mc_cpu_interface);
601 mutex_unlock(µcode_mutex);
605 platform_device_unregister(microcode_pdev);
609 module_init(microcode_init);
611 static void __exit microcode_exit(void)
613 struct cpuinfo_x86 *c = &cpu_data(0);
615 microcode_dev_exit();
617 unregister_hotcpu_notifier(&mc_cpu_notifier);
618 unregister_syscore_ops(&mc_syscore_ops);
620 sysfs_remove_group(&cpu_subsys.dev_root->kobj,
621 &cpu_root_microcode_group);
624 mutex_lock(µcode_mutex);
626 subsys_interface_unregister(&mc_cpu_interface);
628 mutex_unlock(µcode_mutex);
631 platform_device_unregister(microcode_pdev);
633 microcode_ops = NULL;
635 if (c->x86_vendor == X86_VENDOR_AMD)
636 exit_amd_microcode();
638 pr_info("Microcode Update Driver: v" MICROCODE_VERSION " removed.\n");
640 module_exit(microcode_exit);