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) "microcode: " 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/mutex.h>
31 #include <linux/cpu.h>
35 #include <asm/microcode_intel.h>
36 #include <asm/cpu_device_id.h>
37 #include <asm/microcode_amd.h>
38 #include <asm/perf_event.h>
39 #include <asm/microcode.h>
40 #include <asm/processor.h>
41 #include <asm/cmdline.h>
43 #define MICROCODE_VERSION "2.01"
45 static struct microcode_ops *microcode_ops;
46 static bool dis_ucode_ldr;
51 * All non cpu-hotplug-callback call sites use:
53 * - microcode_mutex to synchronize with each other;
54 * - get/put_online_cpus() to synchronize with
55 * the cpu-hotplug-callback call sites.
57 * We guarantee that only a single cpu is being
58 * updated at any particular moment of time.
60 static DEFINE_MUTEX(microcode_mutex);
62 struct ucode_cpu_info ucode_cpu_info[NR_CPUS];
65 * Operations that are run on a target cpu:
69 struct cpu_signature *cpu_sig;
73 static bool __init check_loader_disabled_bsp(void)
75 static const char *__dis_opt_str = "dis_ucode_ldr";
78 const char *cmdline = (const char *)__pa_nodebug(boot_command_line);
79 const char *option = (const char *)__pa_nodebug(__dis_opt_str);
80 bool *res = (bool *)__pa_nodebug(&dis_ucode_ldr);
82 #else /* CONFIG_X86_64 */
83 const char *cmdline = boot_command_line;
84 const char *option = __dis_opt_str;
85 bool *res = &dis_ucode_ldr;
88 if (cmdline_find_option_bool(cmdline, option))
94 extern struct builtin_fw __start_builtin_fw[];
95 extern struct builtin_fw __end_builtin_fw[];
97 bool get_builtin_firmware(struct cpio_data *cd, const char *name)
99 #ifdef CONFIG_FW_LOADER
100 struct builtin_fw *b_fw;
102 for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
103 if (!strcmp(name, b_fw->name)) {
104 cd->size = b_fw->size;
105 cd->data = b_fw->data;
113 void __init load_ucode_bsp(void)
118 if (check_loader_disabled_bsp())
124 vendor = x86_cpuid_vendor();
125 family = x86_cpuid_family();
128 case X86_VENDOR_INTEL:
130 load_ucode_intel_bsp();
134 load_ucode_amd_bsp(family);
141 static bool check_loader_disabled_ap(void)
144 return *((bool *)__pa_nodebug(&dis_ucode_ldr));
146 return dis_ucode_ldr;
150 void load_ucode_ap(void)
154 if (check_loader_disabled_ap())
160 vendor = x86_cpuid_vendor();
161 family = x86_cpuid_family();
164 case X86_VENDOR_INTEL:
166 load_ucode_intel_ap();
177 static int __init save_microcode_in_initrd(void)
179 struct cpuinfo_x86 *c = &boot_cpu_data;
181 switch (c->x86_vendor) {
182 case X86_VENDOR_INTEL:
184 return save_microcode_in_initrd_intel();
188 return save_microcode_in_initrd_amd();
197 void reload_early_microcode(void)
201 vendor = x86_cpuid_vendor();
202 family = x86_cpuid_family();
205 case X86_VENDOR_INTEL:
207 reload_ucode_intel();
218 static void collect_cpu_info_local(void *arg)
220 struct cpu_info_ctx *ctx = arg;
222 ctx->err = microcode_ops->collect_cpu_info(smp_processor_id(),
226 static int collect_cpu_info_on_target(int cpu, struct cpu_signature *cpu_sig)
228 struct cpu_info_ctx ctx = { .cpu_sig = cpu_sig, .err = 0 };
231 ret = smp_call_function_single(cpu, collect_cpu_info_local, &ctx, 1);
238 static int collect_cpu_info(int cpu)
240 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
243 memset(uci, 0, sizeof(*uci));
245 ret = collect_cpu_info_on_target(cpu, &uci->cpu_sig);
252 struct apply_microcode_ctx {
256 static void apply_microcode_local(void *arg)
258 struct apply_microcode_ctx *ctx = arg;
260 ctx->err = microcode_ops->apply_microcode(smp_processor_id());
263 static int apply_microcode_on_target(int cpu)
265 struct apply_microcode_ctx ctx = { .err = 0 };
268 ret = smp_call_function_single(cpu, apply_microcode_local, &ctx, 1);
275 #ifdef CONFIG_MICROCODE_OLD_INTERFACE
276 static int do_microcode_update(const void __user *buf, size_t size)
281 for_each_online_cpu(cpu) {
282 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
283 enum ucode_state ustate;
288 ustate = microcode_ops->request_microcode_user(cpu, buf, size);
289 if (ustate == UCODE_ERROR) {
292 } else if (ustate == UCODE_OK)
293 apply_microcode_on_target(cpu);
299 static int microcode_open(struct inode *inode, struct file *file)
301 return capable(CAP_SYS_RAWIO) ? nonseekable_open(inode, file) : -EPERM;
304 static ssize_t microcode_write(struct file *file, const char __user *buf,
305 size_t len, loff_t *ppos)
307 ssize_t ret = -EINVAL;
309 if ((len >> PAGE_SHIFT) > totalram_pages) {
310 pr_err("too much data (max %ld pages)\n", totalram_pages);
315 mutex_lock(µcode_mutex);
317 if (do_microcode_update(buf, len) == 0)
321 perf_check_microcode();
323 mutex_unlock(µcode_mutex);
329 static const struct file_operations microcode_fops = {
330 .owner = THIS_MODULE,
331 .write = microcode_write,
332 .open = microcode_open,
336 static struct miscdevice microcode_dev = {
337 .minor = MICROCODE_MINOR,
339 .nodename = "cpu/microcode",
340 .fops = µcode_fops,
343 static int __init microcode_dev_init(void)
347 error = misc_register(µcode_dev);
349 pr_err("can't misc_register on minor=%d\n", MICROCODE_MINOR);
356 static void __exit microcode_dev_exit(void)
358 misc_deregister(µcode_dev);
361 #define microcode_dev_init() 0
362 #define microcode_dev_exit() do { } while (0)
365 /* fake device for request_firmware */
366 static struct platform_device *microcode_pdev;
368 static int reload_for_cpu(int cpu)
370 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
371 enum ucode_state ustate;
377 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev, true);
378 if (ustate == UCODE_OK)
379 apply_microcode_on_target(cpu);
381 if (ustate == UCODE_ERROR)
386 static ssize_t reload_store(struct device *dev,
387 struct device_attribute *attr,
388 const char *buf, size_t size)
392 ssize_t ret = 0, tmp_ret;
394 ret = kstrtoul(buf, 0, &val);
402 mutex_lock(µcode_mutex);
403 for_each_online_cpu(cpu) {
404 tmp_ret = reload_for_cpu(cpu);
406 pr_warn("Error reloading microcode on CPU %d\n", cpu);
408 /* save retval of the first encountered reload error */
413 perf_check_microcode();
414 mutex_unlock(µcode_mutex);
423 static ssize_t version_show(struct device *dev,
424 struct device_attribute *attr, char *buf)
426 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
428 return sprintf(buf, "0x%x\n", uci->cpu_sig.rev);
431 static ssize_t pf_show(struct device *dev,
432 struct device_attribute *attr, char *buf)
434 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
436 return sprintf(buf, "0x%x\n", uci->cpu_sig.pf);
439 static DEVICE_ATTR(reload, 0200, NULL, reload_store);
440 static DEVICE_ATTR(version, 0400, version_show, NULL);
441 static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL);
443 static struct attribute *mc_default_attrs[] = {
444 &dev_attr_version.attr,
445 &dev_attr_processor_flags.attr,
449 static struct attribute_group mc_attr_group = {
450 .attrs = mc_default_attrs,
454 static void microcode_fini_cpu(int cpu)
456 microcode_ops->microcode_fini_cpu(cpu);
459 static enum ucode_state microcode_resume_cpu(int cpu)
461 pr_debug("CPU%d updated upon resume\n", cpu);
463 if (apply_microcode_on_target(cpu))
469 static enum ucode_state microcode_init_cpu(int cpu, bool refresh_fw)
471 enum ucode_state ustate;
472 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
477 if (collect_cpu_info(cpu))
480 /* --dimm. Trigger a delayed update? */
481 if (system_state != SYSTEM_RUNNING)
484 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev,
487 if (ustate == UCODE_OK) {
488 pr_debug("CPU%d updated upon init\n", cpu);
489 apply_microcode_on_target(cpu);
495 static enum ucode_state microcode_update_cpu(int cpu)
497 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
500 return microcode_resume_cpu(cpu);
502 return microcode_init_cpu(cpu, false);
505 static int mc_device_add(struct device *dev, struct subsys_interface *sif)
507 int err, cpu = dev->id;
509 if (!cpu_online(cpu))
512 pr_debug("CPU%d added\n", cpu);
514 err = sysfs_create_group(&dev->kobj, &mc_attr_group);
518 if (microcode_init_cpu(cpu, true) == UCODE_ERROR)
524 static void mc_device_remove(struct device *dev, struct subsys_interface *sif)
528 if (!cpu_online(cpu))
531 pr_debug("CPU%d removed\n", cpu);
532 microcode_fini_cpu(cpu);
533 sysfs_remove_group(&dev->kobj, &mc_attr_group);
536 static struct subsys_interface mc_cpu_interface = {
538 .subsys = &cpu_subsys,
539 .add_dev = mc_device_add,
540 .remove_dev = mc_device_remove,
544 * mc_bp_resume - Update boot CPU microcode during resume.
546 static void mc_bp_resume(void)
548 int cpu = smp_processor_id();
549 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
551 if (uci->valid && uci->mc)
552 microcode_ops->apply_microcode(cpu);
554 reload_early_microcode();
557 static struct syscore_ops mc_syscore_ops = {
558 .resume = mc_bp_resume,
562 mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
564 unsigned int cpu = (unsigned long)hcpu;
567 dev = get_cpu_device(cpu);
569 switch (action & ~CPU_TASKS_FROZEN) {
571 microcode_update_cpu(cpu);
572 pr_debug("CPU%d added\n", cpu);
574 * "break" is missing on purpose here because we want to fall
575 * through in order to create the sysfs group.
578 case CPU_DOWN_FAILED:
579 if (sysfs_create_group(&dev->kobj, &mc_attr_group))
580 pr_err("Failed to create group for CPU%d\n", cpu);
583 case CPU_DOWN_PREPARE:
584 /* Suspend is in progress, only remove the interface */
585 sysfs_remove_group(&dev->kobj, &mc_attr_group);
586 pr_debug("CPU%d removed\n", cpu);
592 * When a CPU goes offline, don't free up or invalidate the copy of
593 * the microcode in kernel memory, so that we can reuse it when the
594 * CPU comes back online without unnecessarily requesting the userspace
599 /* The CPU refused to come up during a system resume */
600 if (action == CPU_UP_CANCELED_FROZEN)
601 microcode_fini_cpu(cpu);
606 static struct notifier_block mc_cpu_notifier = {
607 .notifier_call = mc_cpu_callback,
610 static struct attribute *cpu_root_microcode_attrs[] = {
611 &dev_attr_reload.attr,
615 static struct attribute_group cpu_root_microcode_group = {
617 .attrs = cpu_root_microcode_attrs,
620 int __init microcode_init(void)
622 struct cpuinfo_x86 *c = &boot_cpu_data;
628 if (c->x86_vendor == X86_VENDOR_INTEL)
629 microcode_ops = init_intel_microcode();
630 else if (c->x86_vendor == X86_VENDOR_AMD)
631 microcode_ops = init_amd_microcode();
633 pr_err("no support for this CPU vendor\n");
638 microcode_pdev = platform_device_register_simple("microcode", -1,
640 if (IS_ERR(microcode_pdev))
641 return PTR_ERR(microcode_pdev);
644 mutex_lock(µcode_mutex);
646 error = subsys_interface_register(&mc_cpu_interface);
648 perf_check_microcode();
649 mutex_unlock(µcode_mutex);
655 error = sysfs_create_group(&cpu_subsys.dev_root->kobj,
656 &cpu_root_microcode_group);
659 pr_err("Error creating microcode group!\n");
663 error = microcode_dev_init();
665 goto out_ucode_group;
667 register_syscore_ops(&mc_syscore_ops);
668 register_hotcpu_notifier(&mc_cpu_notifier);
670 pr_info("Microcode Update Driver: v" MICROCODE_VERSION
671 " <tigran@aivazian.fsnet.co.uk>, Peter Oruba\n");
676 sysfs_remove_group(&cpu_subsys.dev_root->kobj,
677 &cpu_root_microcode_group);
681 mutex_lock(µcode_mutex);
683 subsys_interface_unregister(&mc_cpu_interface);
685 mutex_unlock(µcode_mutex);
689 platform_device_unregister(microcode_pdev);
693 fs_initcall(save_microcode_in_initrd);
694 late_initcall(microcode_init);