2 * 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>
6 * 2013-2015 Borislav Petkov <bp@alien8.de>
8 * X86 CPU microcode early update for Linux:
10 * Copyright (C) 2012 Fenghua Yu <fenghua.yu@intel.com>
11 * H Peter Anvin" <hpa@zytor.com>
12 * (C) 2015 Borislav Petkov <bp@alien8.de>
14 * This driver allows to upgrade microcode on x86 processors.
16 * This program is free software; you can redistribute it and/or
17 * modify it under the terms of the GNU General Public License
18 * as published by the Free Software Foundation; either version
19 * 2 of the License, or (at your option) any later version.
22 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24 #include <linux/platform_device.h>
25 #include <linux/syscore_ops.h>
26 #include <linux/miscdevice.h>
27 #include <linux/capability.h>
28 #include <linux/firmware.h>
29 #include <linux/kernel.h>
30 #include <linux/module.h>
31 #include <linux/mutex.h>
32 #include <linux/cpu.h>
36 #include <asm/microcode_intel.h>
37 #include <asm/cpu_device_id.h>
38 #include <asm/microcode_amd.h>
39 #include <asm/perf_event.h>
40 #include <asm/microcode.h>
41 #include <asm/processor.h>
42 #include <asm/cmdline.h>
44 MODULE_DESCRIPTION("Microcode Update Driver");
45 MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
46 MODULE_LICENSE("GPL");
48 #define MICROCODE_VERSION "2.00"
50 static struct microcode_ops *microcode_ops;
53 module_param(dis_ucode_ldr, bool, 0);
58 * All non cpu-hotplug-callback call sites use:
60 * - microcode_mutex to synchronize with each other;
61 * - get/put_online_cpus() to synchronize with
62 * the cpu-hotplug-callback call sites.
64 * We guarantee that only a single cpu is being
65 * updated at any particular moment of time.
67 static DEFINE_MUTEX(microcode_mutex);
69 struct ucode_cpu_info ucode_cpu_info[NR_CPUS];
70 EXPORT_SYMBOL_GPL(ucode_cpu_info);
73 * Operations that are run on a target cpu:
77 struct cpu_signature *cpu_sig;
81 static bool __init check_loader_disabled_bsp(void)
84 const char *cmdline = (const char *)__pa_nodebug(boot_command_line);
85 const char *opt = "dis_ucode_ldr";
86 const char *option = (const char *)__pa_nodebug(opt);
87 bool *res = (bool *)__pa_nodebug(&dis_ucode_ldr);
89 #else /* CONFIG_X86_64 */
90 const char *cmdline = boot_command_line;
91 const char *option = "dis_ucode_ldr";
92 bool *res = &dis_ucode_ldr;
95 if (cmdline_find_option_bool(cmdline, option))
101 extern struct builtin_fw __start_builtin_fw[];
102 extern struct builtin_fw __end_builtin_fw[];
104 bool get_builtin_firmware(struct cpio_data *cd, const char *name)
106 #ifdef CONFIG_FW_LOADER
107 struct builtin_fw *b_fw;
109 for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
110 if (!strcmp(name, b_fw->name)) {
111 cd->size = b_fw->size;
112 cd->data = b_fw->data;
120 void __init load_ucode_bsp(void)
125 if (check_loader_disabled_bsp())
131 vendor = x86_vendor();
132 family = x86_family();
135 case X86_VENDOR_INTEL:
137 load_ucode_intel_bsp();
141 load_ucode_amd_bsp(family);
148 static bool check_loader_disabled_ap(void)
151 return *((bool *)__pa_nodebug(&dis_ucode_ldr));
153 return dis_ucode_ldr;
157 void load_ucode_ap(void)
161 if (check_loader_disabled_ap())
167 vendor = x86_vendor();
168 family = x86_family();
171 case X86_VENDOR_INTEL:
173 load_ucode_intel_ap();
184 int __init save_microcode_in_initrd(void)
186 struct cpuinfo_x86 *c = &boot_cpu_data;
188 switch (c->x86_vendor) {
189 case X86_VENDOR_INTEL:
191 save_microcode_in_initrd_intel();
195 save_microcode_in_initrd_amd();
204 void reload_early_microcode(void)
208 vendor = x86_vendor();
209 family = x86_family();
212 case X86_VENDOR_INTEL:
214 reload_ucode_intel();
225 static void collect_cpu_info_local(void *arg)
227 struct cpu_info_ctx *ctx = arg;
229 ctx->err = microcode_ops->collect_cpu_info(smp_processor_id(),
233 static int collect_cpu_info_on_target(int cpu, struct cpu_signature *cpu_sig)
235 struct cpu_info_ctx ctx = { .cpu_sig = cpu_sig, .err = 0 };
238 ret = smp_call_function_single(cpu, collect_cpu_info_local, &ctx, 1);
245 static int collect_cpu_info(int cpu)
247 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
250 memset(uci, 0, sizeof(*uci));
252 ret = collect_cpu_info_on_target(cpu, &uci->cpu_sig);
259 struct apply_microcode_ctx {
263 static void apply_microcode_local(void *arg)
265 struct apply_microcode_ctx *ctx = arg;
267 ctx->err = microcode_ops->apply_microcode(smp_processor_id());
270 static int apply_microcode_on_target(int cpu)
272 struct apply_microcode_ctx ctx = { .err = 0 };
275 ret = smp_call_function_single(cpu, apply_microcode_local, &ctx, 1);
282 #ifdef CONFIG_MICROCODE_OLD_INTERFACE
283 static int do_microcode_update(const void __user *buf, size_t size)
288 for_each_online_cpu(cpu) {
289 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
290 enum ucode_state ustate;
295 ustate = microcode_ops->request_microcode_user(cpu, buf, size);
296 if (ustate == UCODE_ERROR) {
299 } else if (ustate == UCODE_OK)
300 apply_microcode_on_target(cpu);
306 static int microcode_open(struct inode *inode, struct file *file)
308 return capable(CAP_SYS_RAWIO) ? nonseekable_open(inode, file) : -EPERM;
311 static ssize_t microcode_write(struct file *file, const char __user *buf,
312 size_t len, loff_t *ppos)
314 ssize_t ret = -EINVAL;
316 if ((len >> PAGE_SHIFT) > totalram_pages) {
317 pr_err("too much data (max %ld pages)\n", totalram_pages);
322 mutex_lock(µcode_mutex);
324 if (do_microcode_update(buf, len) == 0)
328 perf_check_microcode();
330 mutex_unlock(µcode_mutex);
336 static const struct file_operations microcode_fops = {
337 .owner = THIS_MODULE,
338 .write = microcode_write,
339 .open = microcode_open,
343 static struct miscdevice microcode_dev = {
344 .minor = MICROCODE_MINOR,
346 .nodename = "cpu/microcode",
347 .fops = µcode_fops,
350 static int __init microcode_dev_init(void)
354 error = misc_register(µcode_dev);
356 pr_err("can't misc_register on minor=%d\n", MICROCODE_MINOR);
363 static void __exit microcode_dev_exit(void)
365 misc_deregister(µcode_dev);
368 MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);
369 MODULE_ALIAS("devname:cpu/microcode");
371 #define microcode_dev_init() 0
372 #define microcode_dev_exit() do { } while (0)
375 /* fake device for request_firmware */
376 static struct platform_device *microcode_pdev;
378 static int reload_for_cpu(int cpu)
380 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
381 enum ucode_state ustate;
387 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev, true);
388 if (ustate == UCODE_OK)
389 apply_microcode_on_target(cpu);
391 if (ustate == UCODE_ERROR)
396 static ssize_t reload_store(struct device *dev,
397 struct device_attribute *attr,
398 const char *buf, size_t size)
402 ssize_t ret = 0, tmp_ret;
404 ret = kstrtoul(buf, 0, &val);
412 mutex_lock(µcode_mutex);
413 for_each_online_cpu(cpu) {
414 tmp_ret = reload_for_cpu(cpu);
416 pr_warn("Error reloading microcode on CPU %d\n", cpu);
418 /* save retval of the first encountered reload error */
423 perf_check_microcode();
424 mutex_unlock(µcode_mutex);
433 static ssize_t version_show(struct device *dev,
434 struct device_attribute *attr, char *buf)
436 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
438 return sprintf(buf, "0x%x\n", uci->cpu_sig.rev);
441 static ssize_t pf_show(struct device *dev,
442 struct device_attribute *attr, char *buf)
444 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
446 return sprintf(buf, "0x%x\n", uci->cpu_sig.pf);
449 static DEVICE_ATTR(reload, 0200, NULL, reload_store);
450 static DEVICE_ATTR(version, 0400, version_show, NULL);
451 static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL);
453 static struct attribute *mc_default_attrs[] = {
454 &dev_attr_version.attr,
455 &dev_attr_processor_flags.attr,
459 static struct attribute_group mc_attr_group = {
460 .attrs = mc_default_attrs,
464 static void microcode_fini_cpu(int cpu)
466 microcode_ops->microcode_fini_cpu(cpu);
469 static enum ucode_state microcode_resume_cpu(int cpu)
471 pr_debug("CPU%d updated upon resume\n", cpu);
473 if (apply_microcode_on_target(cpu))
479 static enum ucode_state microcode_init_cpu(int cpu, bool refresh_fw)
481 enum ucode_state ustate;
482 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
484 if (uci && uci->valid)
487 if (collect_cpu_info(cpu))
490 /* --dimm. Trigger a delayed update? */
491 if (system_state != SYSTEM_RUNNING)
494 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev,
497 if (ustate == UCODE_OK) {
498 pr_debug("CPU%d updated upon init\n", cpu);
499 apply_microcode_on_target(cpu);
505 static enum ucode_state microcode_update_cpu(int cpu)
507 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
510 return microcode_resume_cpu(cpu);
512 return microcode_init_cpu(cpu, false);
515 static int mc_device_add(struct device *dev, struct subsys_interface *sif)
517 int err, cpu = dev->id;
519 if (!cpu_online(cpu))
522 pr_debug("CPU%d added\n", cpu);
524 err = sysfs_create_group(&dev->kobj, &mc_attr_group);
528 if (microcode_init_cpu(cpu, true) == UCODE_ERROR)
534 static void mc_device_remove(struct device *dev, struct subsys_interface *sif)
538 if (!cpu_online(cpu))
541 pr_debug("CPU%d removed\n", cpu);
542 microcode_fini_cpu(cpu);
543 sysfs_remove_group(&dev->kobj, &mc_attr_group);
546 static struct subsys_interface mc_cpu_interface = {
548 .subsys = &cpu_subsys,
549 .add_dev = mc_device_add,
550 .remove_dev = mc_device_remove,
554 * mc_bp_resume - Update boot CPU microcode during resume.
556 static void mc_bp_resume(void)
558 int cpu = smp_processor_id();
559 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
561 if (uci->valid && uci->mc)
562 microcode_ops->apply_microcode(cpu);
564 reload_early_microcode();
567 static struct syscore_ops mc_syscore_ops = {
568 .resume = mc_bp_resume,
572 mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
574 unsigned int cpu = (unsigned long)hcpu;
577 dev = get_cpu_device(cpu);
579 switch (action & ~CPU_TASKS_FROZEN) {
581 microcode_update_cpu(cpu);
582 pr_debug("CPU%d added\n", cpu);
584 * "break" is missing on purpose here because we want to fall
585 * through in order to create the sysfs group.
588 case CPU_DOWN_FAILED:
589 if (sysfs_create_group(&dev->kobj, &mc_attr_group))
590 pr_err("Failed to create group for CPU%d\n", cpu);
593 case CPU_DOWN_PREPARE:
594 /* Suspend is in progress, only remove the interface */
595 sysfs_remove_group(&dev->kobj, &mc_attr_group);
596 pr_debug("CPU%d removed\n", cpu);
602 * When a CPU goes offline, don't free up or invalidate the copy of
603 * the microcode in kernel memory, so that we can reuse it when the
604 * CPU comes back online without unnecessarily requesting the userspace
609 /* The CPU refused to come up during a system resume */
610 if (action == CPU_UP_CANCELED_FROZEN)
611 microcode_fini_cpu(cpu);
616 static struct notifier_block mc_cpu_notifier = {
617 .notifier_call = mc_cpu_callback,
621 /* Autoload on Intel and AMD systems */
622 static const struct x86_cpu_id __initconst microcode_id[] = {
623 #ifdef CONFIG_MICROCODE_INTEL
624 { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, },
626 #ifdef CONFIG_MICROCODE_AMD
627 { X86_VENDOR_AMD, X86_FAMILY_ANY, X86_MODEL_ANY, },
631 MODULE_DEVICE_TABLE(x86cpu, microcode_id);
634 static struct attribute *cpu_root_microcode_attrs[] = {
635 &dev_attr_reload.attr,
639 static struct attribute_group cpu_root_microcode_group = {
641 .attrs = cpu_root_microcode_attrs,
644 int __init microcode_init(void)
646 struct cpuinfo_x86 *c = &boot_cpu_data;
649 if (paravirt_enabled() || dis_ucode_ldr)
652 if (c->x86_vendor == X86_VENDOR_INTEL)
653 microcode_ops = init_intel_microcode();
654 else if (c->x86_vendor == X86_VENDOR_AMD)
655 microcode_ops = init_amd_microcode();
657 pr_err("no support for this CPU vendor\n");
662 microcode_pdev = platform_device_register_simple("microcode", -1,
664 if (IS_ERR(microcode_pdev))
665 return PTR_ERR(microcode_pdev);
668 mutex_lock(µcode_mutex);
670 error = subsys_interface_register(&mc_cpu_interface);
672 perf_check_microcode();
673 mutex_unlock(µcode_mutex);
679 error = sysfs_create_group(&cpu_subsys.dev_root->kobj,
680 &cpu_root_microcode_group);
683 pr_err("Error creating microcode group!\n");
687 error = microcode_dev_init();
689 goto out_ucode_group;
691 register_syscore_ops(&mc_syscore_ops);
692 register_hotcpu_notifier(&mc_cpu_notifier);
694 pr_info("Microcode Update Driver: v" MICROCODE_VERSION
695 " <tigran@aivazian.fsnet.co.uk>, Peter Oruba\n");
700 sysfs_remove_group(&cpu_subsys.dev_root->kobj,
701 &cpu_root_microcode_group);
705 mutex_lock(µcode_mutex);
707 subsys_interface_unregister(&mc_cpu_interface);
709 mutex_unlock(µcode_mutex);
713 platform_device_unregister(microcode_pdev);