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;
51 LIST_HEAD(microcode_cache);
56 * All non cpu-hotplug-callback call sites use:
58 * - microcode_mutex to synchronize with each other;
59 * - get/put_online_cpus() to synchronize with
60 * the cpu-hotplug-callback call sites.
62 * We guarantee that only a single cpu is being
63 * updated at any particular moment of time.
65 static DEFINE_MUTEX(microcode_mutex);
67 struct ucode_cpu_info ucode_cpu_info[NR_CPUS];
70 * Operations that are run on a target cpu:
74 struct cpu_signature *cpu_sig;
78 static bool __init check_loader_disabled_bsp(void)
80 static const char *__dis_opt_str = "dis_ucode_ldr";
84 const char *cmdline = (const char *)__pa_nodebug(boot_command_line);
85 const char *option = (const char *)__pa_nodebug(__dis_opt_str);
86 bool *res = (bool *)__pa_nodebug(&dis_ucode_ldr);
88 #else /* CONFIG_X86_64 */
89 const char *cmdline = boot_command_line;
90 const char *option = __dis_opt_str;
91 bool *res = &dis_ucode_ldr;
99 native_cpuid(&a, &b, &c, &d);
102 * CPUID(1).ECX[31]: reserved for hypervisor use. This is still not
103 * completely accurate as xen pv guests don't see that CPUID bit set but
104 * that's good enough as they don't land on the BSP path anyway.
109 if (cmdline_find_option_bool(cmdline, option) <= 0)
115 extern struct builtin_fw __start_builtin_fw[];
116 extern struct builtin_fw __end_builtin_fw[];
118 bool get_builtin_firmware(struct cpio_data *cd, const char *name)
120 #ifdef CONFIG_FW_LOADER
121 struct builtin_fw *b_fw;
123 for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
124 if (!strcmp(name, b_fw->name)) {
125 cd->size = b_fw->size;
126 cd->data = b_fw->data;
134 void __init load_ucode_bsp(void)
139 if (check_loader_disabled_bsp())
142 vendor = x86_cpuid_vendor();
143 family = x86_cpuid_family();
146 case X86_VENDOR_INTEL:
148 load_ucode_intel_bsp();
152 load_ucode_amd_bsp(family);
159 static bool check_loader_disabled_ap(void)
162 return *((bool *)__pa_nodebug(&dis_ucode_ldr));
164 return dis_ucode_ldr;
168 void load_ucode_ap(void)
172 if (check_loader_disabled_ap())
175 vendor = x86_cpuid_vendor();
176 family = x86_cpuid_family();
179 case X86_VENDOR_INTEL:
181 load_ucode_intel_ap();
185 load_ucode_amd_ap(family);
192 static int __init save_microcode_in_initrd(void)
194 struct cpuinfo_x86 *c = &boot_cpu_data;
197 switch (c->x86_vendor) {
198 case X86_VENDOR_INTEL:
200 ret = save_microcode_in_initrd_intel();
204 ret = save_microcode_in_initrd_amd(c->x86);
215 struct cpio_data find_microcode_in_initrd(const char *path, bool use_pa)
217 #ifdef CONFIG_BLK_DEV_INITRD
218 unsigned long start = 0;
222 struct boot_params *params;
225 params = (struct boot_params *)__pa_nodebug(&boot_params);
227 params = &boot_params;
229 size = params->hdr.ramdisk_size;
232 * Set start only if we have an initrd image. We cannot use initrd_start
233 * because it is not set that early yet.
236 start = params->hdr.ramdisk_image;
238 # else /* CONFIG_X86_64 */
239 size = (unsigned long)boot_params.ext_ramdisk_size << 32;
240 size |= boot_params.hdr.ramdisk_size;
243 start = (unsigned long)boot_params.ext_ramdisk_image << 32;
244 start |= boot_params.hdr.ramdisk_image;
246 start += PAGE_OFFSET;
251 * Fixup the start address: after reserve_initrd() runs, initrd_start
252 * has the virtual address of the beginning of the initrd. It also
253 * possibly relocates the ramdisk. In either case, initrd_start contains
254 * the updated address so use that instead.
256 * initrd_gone is for the hotplug case where we've thrown out initrd
261 return (struct cpio_data){ NULL, 0, "" };
263 start = initrd_start;
266 return find_cpio_data(path, (void *)start, size, NULL);
267 #else /* !CONFIG_BLK_DEV_INITRD */
268 return (struct cpio_data){ NULL, 0, "" };
272 void reload_early_microcode(void)
276 vendor = x86_cpuid_vendor();
277 family = x86_cpuid_family();
280 case X86_VENDOR_INTEL:
282 reload_ucode_intel();
293 static void collect_cpu_info_local(void *arg)
295 struct cpu_info_ctx *ctx = arg;
297 ctx->err = microcode_ops->collect_cpu_info(smp_processor_id(),
301 static int collect_cpu_info_on_target(int cpu, struct cpu_signature *cpu_sig)
303 struct cpu_info_ctx ctx = { .cpu_sig = cpu_sig, .err = 0 };
306 ret = smp_call_function_single(cpu, collect_cpu_info_local, &ctx, 1);
313 static int collect_cpu_info(int cpu)
315 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
318 memset(uci, 0, sizeof(*uci));
320 ret = collect_cpu_info_on_target(cpu, &uci->cpu_sig);
327 struct apply_microcode_ctx {
331 static void apply_microcode_local(void *arg)
333 struct apply_microcode_ctx *ctx = arg;
335 ctx->err = microcode_ops->apply_microcode(smp_processor_id());
338 static int apply_microcode_on_target(int cpu)
340 struct apply_microcode_ctx ctx = { .err = 0 };
343 ret = smp_call_function_single(cpu, apply_microcode_local, &ctx, 1);
350 #ifdef CONFIG_MICROCODE_OLD_INTERFACE
351 static int do_microcode_update(const void __user *buf, size_t size)
356 for_each_online_cpu(cpu) {
357 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
358 enum ucode_state ustate;
363 ustate = microcode_ops->request_microcode_user(cpu, buf, size);
364 if (ustate == UCODE_ERROR) {
367 } else if (ustate == UCODE_OK)
368 apply_microcode_on_target(cpu);
374 static int microcode_open(struct inode *inode, struct file *file)
376 return capable(CAP_SYS_RAWIO) ? nonseekable_open(inode, file) : -EPERM;
379 static ssize_t microcode_write(struct file *file, const char __user *buf,
380 size_t len, loff_t *ppos)
382 ssize_t ret = -EINVAL;
384 if ((len >> PAGE_SHIFT) > totalram_pages) {
385 pr_err("too much data (max %ld pages)\n", totalram_pages);
390 mutex_lock(µcode_mutex);
392 if (do_microcode_update(buf, len) == 0)
396 perf_check_microcode();
398 mutex_unlock(µcode_mutex);
404 static const struct file_operations microcode_fops = {
405 .owner = THIS_MODULE,
406 .write = microcode_write,
407 .open = microcode_open,
411 static struct miscdevice microcode_dev = {
412 .minor = MICROCODE_MINOR,
414 .nodename = "cpu/microcode",
415 .fops = µcode_fops,
418 static int __init microcode_dev_init(void)
422 error = misc_register(µcode_dev);
424 pr_err("can't misc_register on minor=%d\n", MICROCODE_MINOR);
431 static void __exit microcode_dev_exit(void)
433 misc_deregister(µcode_dev);
436 #define microcode_dev_init() 0
437 #define microcode_dev_exit() do { } while (0)
440 /* fake device for request_firmware */
441 static struct platform_device *microcode_pdev;
443 static int reload_for_cpu(int cpu)
445 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
446 enum ucode_state ustate;
452 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev, true);
453 if (ustate == UCODE_OK)
454 apply_microcode_on_target(cpu);
456 if (ustate == UCODE_ERROR)
461 static ssize_t reload_store(struct device *dev,
462 struct device_attribute *attr,
463 const char *buf, size_t size)
467 ssize_t ret = 0, tmp_ret;
469 ret = kstrtoul(buf, 0, &val);
477 mutex_lock(µcode_mutex);
478 for_each_online_cpu(cpu) {
479 tmp_ret = reload_for_cpu(cpu);
481 pr_warn("Error reloading microcode on CPU %d\n", cpu);
483 /* save retval of the first encountered reload error */
488 perf_check_microcode();
489 mutex_unlock(µcode_mutex);
498 static ssize_t version_show(struct device *dev,
499 struct device_attribute *attr, char *buf)
501 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
503 return sprintf(buf, "0x%x\n", uci->cpu_sig.rev);
506 static ssize_t pf_show(struct device *dev,
507 struct device_attribute *attr, char *buf)
509 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
511 return sprintf(buf, "0x%x\n", uci->cpu_sig.pf);
514 static DEVICE_ATTR(reload, 0200, NULL, reload_store);
515 static DEVICE_ATTR(version, 0400, version_show, NULL);
516 static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL);
518 static struct attribute *mc_default_attrs[] = {
519 &dev_attr_version.attr,
520 &dev_attr_processor_flags.attr,
524 static struct attribute_group mc_attr_group = {
525 .attrs = mc_default_attrs,
529 static void microcode_fini_cpu(int cpu)
531 if (microcode_ops->microcode_fini_cpu)
532 microcode_ops->microcode_fini_cpu(cpu);
535 static enum ucode_state microcode_resume_cpu(int cpu)
537 if (apply_microcode_on_target(cpu))
540 pr_debug("CPU%d updated upon resume\n", cpu);
545 static enum ucode_state microcode_init_cpu(int cpu, bool refresh_fw)
547 enum ucode_state ustate;
548 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
553 if (collect_cpu_info(cpu))
556 /* --dimm. Trigger a delayed update? */
557 if (system_state != SYSTEM_RUNNING)
560 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev,
563 if (ustate == UCODE_OK) {
564 pr_debug("CPU%d updated upon init\n", cpu);
565 apply_microcode_on_target(cpu);
571 static enum ucode_state microcode_update_cpu(int cpu)
573 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
575 /* Refresh CPU microcode revision after resume. */
576 collect_cpu_info(cpu);
579 return microcode_resume_cpu(cpu);
581 return microcode_init_cpu(cpu, false);
584 static int mc_device_add(struct device *dev, struct subsys_interface *sif)
586 int err, cpu = dev->id;
588 if (!cpu_online(cpu))
591 pr_debug("CPU%d added\n", cpu);
593 err = sysfs_create_group(&dev->kobj, &mc_attr_group);
597 if (microcode_init_cpu(cpu, true) == UCODE_ERROR)
603 static void mc_device_remove(struct device *dev, struct subsys_interface *sif)
607 if (!cpu_online(cpu))
610 pr_debug("CPU%d removed\n", cpu);
611 microcode_fini_cpu(cpu);
612 sysfs_remove_group(&dev->kobj, &mc_attr_group);
615 static struct subsys_interface mc_cpu_interface = {
617 .subsys = &cpu_subsys,
618 .add_dev = mc_device_add,
619 .remove_dev = mc_device_remove,
623 * mc_bp_resume - Update boot CPU microcode during resume.
625 static void mc_bp_resume(void)
627 int cpu = smp_processor_id();
628 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
630 if (uci->valid && uci->mc)
631 microcode_ops->apply_microcode(cpu);
633 reload_early_microcode();
636 static struct syscore_ops mc_syscore_ops = {
637 .resume = mc_bp_resume,
640 static int mc_cpu_online(unsigned int cpu)
644 dev = get_cpu_device(cpu);
645 microcode_update_cpu(cpu);
646 pr_debug("CPU%d added\n", cpu);
648 if (sysfs_create_group(&dev->kobj, &mc_attr_group))
649 pr_err("Failed to create group for CPU%d\n", cpu);
653 static int mc_cpu_down_prep(unsigned int cpu)
657 dev = get_cpu_device(cpu);
658 /* Suspend is in progress, only remove the interface */
659 sysfs_remove_group(&dev->kobj, &mc_attr_group);
660 pr_debug("CPU%d removed\n", cpu);
665 static struct attribute *cpu_root_microcode_attrs[] = {
666 &dev_attr_reload.attr,
670 static struct attribute_group cpu_root_microcode_group = {
672 .attrs = cpu_root_microcode_attrs,
675 int __init microcode_init(void)
677 struct cpuinfo_x86 *c = &boot_cpu_data;
683 if (c->x86_vendor == X86_VENDOR_INTEL)
684 microcode_ops = init_intel_microcode();
685 else if (c->x86_vendor == X86_VENDOR_AMD)
686 microcode_ops = init_amd_microcode();
688 pr_err("no support for this CPU vendor\n");
693 microcode_pdev = platform_device_register_simple("microcode", -1,
695 if (IS_ERR(microcode_pdev))
696 return PTR_ERR(microcode_pdev);
699 mutex_lock(µcode_mutex);
701 error = subsys_interface_register(&mc_cpu_interface);
703 perf_check_microcode();
704 mutex_unlock(µcode_mutex);
710 error = sysfs_create_group(&cpu_subsys.dev_root->kobj,
711 &cpu_root_microcode_group);
714 pr_err("Error creating microcode group!\n");
718 error = microcode_dev_init();
720 goto out_ucode_group;
722 register_syscore_ops(&mc_syscore_ops);
723 cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/microcode:online",
724 mc_cpu_online, mc_cpu_down_prep);
726 pr_info("Microcode Update Driver: v%s.", DRIVER_VERSION);
731 sysfs_remove_group(&cpu_subsys.dev_root->kobj,
732 &cpu_root_microcode_group);
736 mutex_lock(µcode_mutex);
738 subsys_interface_unregister(&mc_cpu_interface);
740 mutex_unlock(µcode_mutex);
744 platform_device_unregister(microcode_pdev);
748 fs_initcall(save_microcode_in_initrd);
749 late_initcall(microcode_init);