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 * 2013-2016 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>
42 #include <asm/setup.h>
44 #define DRIVER_VERSION "2.2"
46 static struct microcode_ops *microcode_ops;
47 static bool dis_ucode_ldr = true;
49 LIST_HEAD(microcode_cache);
54 * All non cpu-hotplug-callback call sites use:
56 * - microcode_mutex to synchronize with each other;
57 * - get/put_online_cpus() to synchronize with
58 * the cpu-hotplug-callback call sites.
60 * We guarantee that only a single cpu is being
61 * updated at any particular moment of time.
63 static DEFINE_MUTEX(microcode_mutex);
65 struct ucode_cpu_info ucode_cpu_info[NR_CPUS];
68 * Operations that are run on a target cpu:
72 struct cpu_signature *cpu_sig;
76 static bool __init check_loader_disabled_bsp(void)
78 static const char *__dis_opt_str = "dis_ucode_ldr";
82 const char *cmdline = (const char *)__pa_nodebug(boot_command_line);
83 const char *option = (const char *)__pa_nodebug(__dis_opt_str);
84 bool *res = (bool *)__pa_nodebug(&dis_ucode_ldr);
86 #else /* CONFIG_X86_64 */
87 const char *cmdline = boot_command_line;
88 const char *option = __dis_opt_str;
89 bool *res = &dis_ucode_ldr;
97 native_cpuid(&a, &b, &c, &d);
100 * CPUID(1).ECX[31]: reserved for hypervisor use. This is still not
101 * completely accurate as xen pv guests don't see that CPUID bit set but
102 * that's good enough as they don't land on the BSP path anyway.
107 if (cmdline_find_option_bool(cmdline, option) <= 0)
113 extern struct builtin_fw __start_builtin_fw[];
114 extern struct builtin_fw __end_builtin_fw[];
116 bool get_builtin_firmware(struct cpio_data *cd, const char *name)
118 #ifdef CONFIG_FW_LOADER
119 struct builtin_fw *b_fw;
121 for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
122 if (!strcmp(name, b_fw->name)) {
123 cd->size = b_fw->size;
124 cd->data = b_fw->data;
132 void __init load_ucode_bsp(void)
137 if (check_loader_disabled_bsp())
140 vendor = x86_cpuid_vendor();
141 family = x86_cpuid_family();
144 case X86_VENDOR_INTEL:
146 load_ucode_intel_bsp();
150 load_ucode_amd_bsp(family);
157 static bool check_loader_disabled_ap(void)
160 return *((bool *)__pa_nodebug(&dis_ucode_ldr));
162 return dis_ucode_ldr;
166 void load_ucode_ap(void)
170 if (check_loader_disabled_ap())
173 vendor = x86_cpuid_vendor();
174 family = x86_cpuid_family();
177 case X86_VENDOR_INTEL:
179 load_ucode_intel_ap();
183 load_ucode_amd_ap(family);
190 static int __init save_microcode_in_initrd(void)
192 struct cpuinfo_x86 *c = &boot_cpu_data;
194 switch (c->x86_vendor) {
195 case X86_VENDOR_INTEL:
197 return save_microcode_in_initrd_intel();
201 return save_microcode_in_initrd_amd(c->x86);
210 struct cpio_data find_microcode_in_initrd(const char *path, bool use_pa)
212 #ifdef CONFIG_BLK_DEV_INITRD
213 unsigned long start = 0;
217 struct boot_params *params;
220 params = (struct boot_params *)__pa_nodebug(&boot_params);
222 params = &boot_params;
224 size = params->hdr.ramdisk_size;
227 * Set start only if we have an initrd image. We cannot use initrd_start
228 * because it is not set that early yet.
231 start = params->hdr.ramdisk_image;
233 # else /* CONFIG_X86_64 */
234 size = (unsigned long)boot_params.ext_ramdisk_size << 32;
235 size |= boot_params.hdr.ramdisk_size;
238 start = (unsigned long)boot_params.ext_ramdisk_image << 32;
239 start |= boot_params.hdr.ramdisk_image;
241 start += PAGE_OFFSET;
246 * Fixup the start address: after reserve_initrd() runs, initrd_start
247 * has the virtual address of the beginning of the initrd. It also
248 * possibly relocates the ramdisk. In either case, initrd_start contains
249 * the updated address so use that instead.
251 if (!use_pa && initrd_start)
252 start = initrd_start;
254 return find_cpio_data(path, (void *)start, size, NULL);
255 #else /* !CONFIG_BLK_DEV_INITRD */
256 return (struct cpio_data){ NULL, 0, "" };
260 void reload_early_microcode(void)
264 vendor = x86_cpuid_vendor();
265 family = x86_cpuid_family();
268 case X86_VENDOR_INTEL:
270 reload_ucode_intel();
281 static void collect_cpu_info_local(void *arg)
283 struct cpu_info_ctx *ctx = arg;
285 ctx->err = microcode_ops->collect_cpu_info(smp_processor_id(),
289 static int collect_cpu_info_on_target(int cpu, struct cpu_signature *cpu_sig)
291 struct cpu_info_ctx ctx = { .cpu_sig = cpu_sig, .err = 0 };
294 ret = smp_call_function_single(cpu, collect_cpu_info_local, &ctx, 1);
301 static int collect_cpu_info(int cpu)
303 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
306 memset(uci, 0, sizeof(*uci));
308 ret = collect_cpu_info_on_target(cpu, &uci->cpu_sig);
315 struct apply_microcode_ctx {
319 static void apply_microcode_local(void *arg)
321 struct apply_microcode_ctx *ctx = arg;
323 ctx->err = microcode_ops->apply_microcode(smp_processor_id());
326 static int apply_microcode_on_target(int cpu)
328 struct apply_microcode_ctx ctx = { .err = 0 };
331 ret = smp_call_function_single(cpu, apply_microcode_local, &ctx, 1);
338 #ifdef CONFIG_MICROCODE_OLD_INTERFACE
339 static int do_microcode_update(const void __user *buf, size_t size)
344 for_each_online_cpu(cpu) {
345 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
346 enum ucode_state ustate;
351 ustate = microcode_ops->request_microcode_user(cpu, buf, size);
352 if (ustate == UCODE_ERROR) {
355 } else if (ustate == UCODE_OK)
356 apply_microcode_on_target(cpu);
362 static int microcode_open(struct inode *inode, struct file *file)
364 return capable(CAP_SYS_RAWIO) ? nonseekable_open(inode, file) : -EPERM;
367 static ssize_t microcode_write(struct file *file, const char __user *buf,
368 size_t len, loff_t *ppos)
370 ssize_t ret = -EINVAL;
372 if ((len >> PAGE_SHIFT) > totalram_pages) {
373 pr_err("too much data (max %ld pages)\n", totalram_pages);
378 mutex_lock(µcode_mutex);
380 if (do_microcode_update(buf, len) == 0)
384 perf_check_microcode();
386 mutex_unlock(µcode_mutex);
392 static const struct file_operations microcode_fops = {
393 .owner = THIS_MODULE,
394 .write = microcode_write,
395 .open = microcode_open,
399 static struct miscdevice microcode_dev = {
400 .minor = MICROCODE_MINOR,
402 .nodename = "cpu/microcode",
403 .fops = µcode_fops,
406 static int __init microcode_dev_init(void)
410 error = misc_register(µcode_dev);
412 pr_err("can't misc_register on minor=%d\n", MICROCODE_MINOR);
419 static void __exit microcode_dev_exit(void)
421 misc_deregister(µcode_dev);
424 #define microcode_dev_init() 0
425 #define microcode_dev_exit() do { } while (0)
428 /* fake device for request_firmware */
429 static struct platform_device *microcode_pdev;
431 static int reload_for_cpu(int cpu)
433 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
434 enum ucode_state ustate;
440 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev, true);
441 if (ustate == UCODE_OK)
442 apply_microcode_on_target(cpu);
444 if (ustate == UCODE_ERROR)
449 static ssize_t reload_store(struct device *dev,
450 struct device_attribute *attr,
451 const char *buf, size_t size)
455 ssize_t ret = 0, tmp_ret;
457 ret = kstrtoul(buf, 0, &val);
465 mutex_lock(µcode_mutex);
466 for_each_online_cpu(cpu) {
467 tmp_ret = reload_for_cpu(cpu);
469 pr_warn("Error reloading microcode on CPU %d\n", cpu);
471 /* save retval of the first encountered reload error */
476 perf_check_microcode();
477 mutex_unlock(µcode_mutex);
486 static ssize_t version_show(struct device *dev,
487 struct device_attribute *attr, char *buf)
489 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
491 return sprintf(buf, "0x%x\n", uci->cpu_sig.rev);
494 static ssize_t pf_show(struct device *dev,
495 struct device_attribute *attr, char *buf)
497 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
499 return sprintf(buf, "0x%x\n", uci->cpu_sig.pf);
502 static DEVICE_ATTR(reload, 0200, NULL, reload_store);
503 static DEVICE_ATTR(version, 0400, version_show, NULL);
504 static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL);
506 static struct attribute *mc_default_attrs[] = {
507 &dev_attr_version.attr,
508 &dev_attr_processor_flags.attr,
512 static struct attribute_group mc_attr_group = {
513 .attrs = mc_default_attrs,
517 static void microcode_fini_cpu(int cpu)
519 if (microcode_ops->microcode_fini_cpu)
520 microcode_ops->microcode_fini_cpu(cpu);
523 static enum ucode_state microcode_resume_cpu(int cpu)
525 if (apply_microcode_on_target(cpu))
528 pr_debug("CPU%d updated upon resume\n", cpu);
533 static enum ucode_state microcode_init_cpu(int cpu, bool refresh_fw)
535 enum ucode_state ustate;
536 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
541 if (collect_cpu_info(cpu))
544 /* --dimm. Trigger a delayed update? */
545 if (system_state != SYSTEM_RUNNING)
548 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev,
551 if (ustate == UCODE_OK) {
552 pr_debug("CPU%d updated upon init\n", cpu);
553 apply_microcode_on_target(cpu);
559 static enum ucode_state microcode_update_cpu(int cpu)
561 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
563 /* Refresh CPU microcode revision after resume. */
564 collect_cpu_info(cpu);
567 return microcode_resume_cpu(cpu);
569 return microcode_init_cpu(cpu, false);
572 static int mc_device_add(struct device *dev, struct subsys_interface *sif)
574 int err, cpu = dev->id;
576 if (!cpu_online(cpu))
579 pr_debug("CPU%d added\n", cpu);
581 err = sysfs_create_group(&dev->kobj, &mc_attr_group);
585 if (microcode_init_cpu(cpu, true) == UCODE_ERROR)
591 static void mc_device_remove(struct device *dev, struct subsys_interface *sif)
595 if (!cpu_online(cpu))
598 pr_debug("CPU%d removed\n", cpu);
599 microcode_fini_cpu(cpu);
600 sysfs_remove_group(&dev->kobj, &mc_attr_group);
603 static struct subsys_interface mc_cpu_interface = {
605 .subsys = &cpu_subsys,
606 .add_dev = mc_device_add,
607 .remove_dev = mc_device_remove,
611 * mc_bp_resume - Update boot CPU microcode during resume.
613 static void mc_bp_resume(void)
615 int cpu = smp_processor_id();
616 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
618 if (uci->valid && uci->mc)
619 microcode_ops->apply_microcode(cpu);
621 reload_early_microcode();
624 static struct syscore_ops mc_syscore_ops = {
625 .resume = mc_bp_resume,
628 static int mc_cpu_online(unsigned int cpu)
632 dev = get_cpu_device(cpu);
633 microcode_update_cpu(cpu);
634 pr_debug("CPU%d added\n", cpu);
636 if (sysfs_create_group(&dev->kobj, &mc_attr_group))
637 pr_err("Failed to create group for CPU%d\n", cpu);
641 static int mc_cpu_down_prep(unsigned int cpu)
645 dev = get_cpu_device(cpu);
646 /* Suspend is in progress, only remove the interface */
647 sysfs_remove_group(&dev->kobj, &mc_attr_group);
648 pr_debug("CPU%d removed\n", cpu);
653 static struct attribute *cpu_root_microcode_attrs[] = {
654 &dev_attr_reload.attr,
658 static struct attribute_group cpu_root_microcode_group = {
660 .attrs = cpu_root_microcode_attrs,
663 int __init microcode_init(void)
665 struct cpuinfo_x86 *c = &boot_cpu_data;
671 if (c->x86_vendor == X86_VENDOR_INTEL)
672 microcode_ops = init_intel_microcode();
673 else if (c->x86_vendor == X86_VENDOR_AMD)
674 microcode_ops = init_amd_microcode();
676 pr_err("no support for this CPU vendor\n");
681 microcode_pdev = platform_device_register_simple("microcode", -1,
683 if (IS_ERR(microcode_pdev))
684 return PTR_ERR(microcode_pdev);
687 mutex_lock(µcode_mutex);
689 error = subsys_interface_register(&mc_cpu_interface);
691 perf_check_microcode();
692 mutex_unlock(µcode_mutex);
698 error = sysfs_create_group(&cpu_subsys.dev_root->kobj,
699 &cpu_root_microcode_group);
702 pr_err("Error creating microcode group!\n");
706 error = microcode_dev_init();
708 goto out_ucode_group;
710 register_syscore_ops(&mc_syscore_ops);
711 cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/microcode:online",
712 mc_cpu_online, mc_cpu_down_prep);
714 pr_info("Microcode Update Driver: v%s.", DRIVER_VERSION);
719 sysfs_remove_group(&cpu_subsys.dev_root->kobj,
720 &cpu_root_microcode_group);
724 mutex_lock(µcode_mutex);
726 subsys_interface_unregister(&mc_cpu_interface);
728 mutex_unlock(µcode_mutex);
732 platform_device_unregister(microcode_pdev);
736 fs_initcall(save_microcode_in_initrd);
737 late_initcall(microcode_init);