2 * CPU Microcode Update Driver for Linux
4 * Copyright (C) 2000-2006 Tigran Aivazian <aivazian.tigran@gmail.com>
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 struct cpu_signature
*cpu_sig
;
75 * Those patch levels cannot be updated to newer ones and thus should be final.
77 static u32 final_levels
[] = {
81 0, /* T-101 terminator */
85 * Check the current patch level on this CPU.
88 * - true: if update should stop
91 static bool amd_check_current_patch_level(void)
96 native_rdmsr(MSR_AMD64_PATCH_LEVEL
, lvl
, dummy
);
98 if (IS_ENABLED(CONFIG_X86_32
))
99 levels
= (u32
*)__pa_nodebug(&final_levels
);
101 levels
= final_levels
;
103 for (i
= 0; levels
[i
]; i
++) {
104 if (lvl
== levels
[i
])
110 static bool __init
check_loader_disabled_bsp(void)
112 static const char *__dis_opt_str
= "dis_ucode_ldr";
115 const char *cmdline
= (const char *)__pa_nodebug(boot_command_line
);
116 const char *option
= (const char *)__pa_nodebug(__dis_opt_str
);
117 bool *res
= (bool *)__pa_nodebug(&dis_ucode_ldr
);
119 #else /* CONFIG_X86_64 */
120 const char *cmdline
= boot_command_line
;
121 const char *option
= __dis_opt_str
;
122 bool *res
= &dis_ucode_ldr
;
129 * CPUID(1).ECX[31]: reserved for hypervisor use. This is still not
130 * completely accurate as xen pv guests don't see that CPUID bit set but
131 * that's good enough as they don't land on the BSP path anyway.
133 if (native_cpuid_ecx(1) & BIT(31))
136 if (x86_cpuid_vendor() == X86_VENDOR_AMD
) {
137 if (amd_check_current_patch_level())
141 if (cmdline_find_option_bool(cmdline
, option
) <= 0)
147 extern struct builtin_fw __start_builtin_fw
[];
148 extern struct builtin_fw __end_builtin_fw
[];
150 bool get_builtin_firmware(struct cpio_data
*cd
, const char *name
)
152 #ifdef CONFIG_FW_LOADER
153 struct builtin_fw
*b_fw
;
155 for (b_fw
= __start_builtin_fw
; b_fw
!= __end_builtin_fw
; b_fw
++) {
156 if (!strcmp(name
, b_fw
->name
)) {
157 cd
->size
= b_fw
->size
;
158 cd
->data
= b_fw
->data
;
166 void __init
load_ucode_bsp(void)
168 unsigned int cpuid_1_eax
;
170 if (check_loader_disabled_bsp())
173 cpuid_1_eax
= native_cpuid_eax(1);
175 switch (x86_cpuid_vendor()) {
176 case X86_VENDOR_INTEL
:
177 if (x86_family(cpuid_1_eax
) >= 6)
178 load_ucode_intel_bsp();
181 if (x86_family(cpuid_1_eax
) >= 0x10)
182 load_ucode_amd_bsp(cpuid_1_eax
);
189 static bool check_loader_disabled_ap(void)
192 return *((bool *)__pa_nodebug(&dis_ucode_ldr
));
194 return dis_ucode_ldr
;
198 void load_ucode_ap(void)
200 unsigned int cpuid_1_eax
;
202 if (check_loader_disabled_ap())
205 cpuid_1_eax
= native_cpuid_eax(1);
207 switch (x86_cpuid_vendor()) {
208 case X86_VENDOR_INTEL
:
209 if (x86_family(cpuid_1_eax
) >= 6)
210 load_ucode_intel_ap();
213 if (x86_family(cpuid_1_eax
) >= 0x10)
214 load_ucode_amd_ap(cpuid_1_eax
);
221 static int __init
save_microcode_in_initrd(void)
223 struct cpuinfo_x86
*c
= &boot_cpu_data
;
226 switch (c
->x86_vendor
) {
227 case X86_VENDOR_INTEL
:
229 ret
= save_microcode_in_initrd_intel();
233 return save_microcode_in_initrd_amd(cpuid_eax(1));
244 struct cpio_data
find_microcode_in_initrd(const char *path
, bool use_pa
)
246 #ifdef CONFIG_BLK_DEV_INITRD
247 unsigned long start
= 0;
251 struct boot_params
*params
;
254 params
= (struct boot_params
*)__pa_nodebug(&boot_params
);
256 params
= &boot_params
;
258 size
= params
->hdr
.ramdisk_size
;
261 * Set start only if we have an initrd image. We cannot use initrd_start
262 * because it is not set that early yet.
265 start
= params
->hdr
.ramdisk_image
;
267 # else /* CONFIG_X86_64 */
268 size
= (unsigned long)boot_params
.ext_ramdisk_size
<< 32;
269 size
|= boot_params
.hdr
.ramdisk_size
;
272 start
= (unsigned long)boot_params
.ext_ramdisk_image
<< 32;
273 start
|= boot_params
.hdr
.ramdisk_image
;
275 start
+= PAGE_OFFSET
;
280 * Fixup the start address: after reserve_initrd() runs, initrd_start
281 * has the virtual address of the beginning of the initrd. It also
282 * possibly relocates the ramdisk. In either case, initrd_start contains
283 * the updated address so use that instead.
285 * initrd_gone is for the hotplug case where we've thrown out initrd
290 return (struct cpio_data
){ NULL
, 0, "" };
292 start
= initrd_start
;
295 * The picture with physical addresses is a bit different: we
296 * need to get the *physical* address to which the ramdisk was
297 * relocated, i.e., relocated_ramdisk (not initrd_start) and
298 * since we're running from physical addresses, we need to access
299 * relocated_ramdisk through its *physical* address too.
301 u64
*rr
= (u64
*)__pa_nodebug(&relocated_ramdisk
);
306 return find_cpio_data(path
, (void *)start
, size
, NULL
);
307 #else /* !CONFIG_BLK_DEV_INITRD */
308 return (struct cpio_data
){ NULL
, 0, "" };
312 void reload_early_microcode(void)
316 vendor
= x86_cpuid_vendor();
317 family
= x86_cpuid_family();
320 case X86_VENDOR_INTEL
:
322 reload_ucode_intel();
333 static void collect_cpu_info_local(void *arg
)
335 struct cpu_info_ctx
*ctx
= arg
;
337 ctx
->err
= microcode_ops
->collect_cpu_info(smp_processor_id(),
341 static int collect_cpu_info_on_target(int cpu
, struct cpu_signature
*cpu_sig
)
343 struct cpu_info_ctx ctx
= { .cpu_sig
= cpu_sig
, .err
= 0 };
346 ret
= smp_call_function_single(cpu
, collect_cpu_info_local
, &ctx
, 1);
353 static int collect_cpu_info(int cpu
)
355 struct ucode_cpu_info
*uci
= ucode_cpu_info
+ cpu
;
358 memset(uci
, 0, sizeof(*uci
));
360 ret
= collect_cpu_info_on_target(cpu
, &uci
->cpu_sig
);
367 struct apply_microcode_ctx
{
371 static void apply_microcode_local(void *arg
)
373 struct apply_microcode_ctx
*ctx
= arg
;
375 ctx
->err
= microcode_ops
->apply_microcode(smp_processor_id());
378 static int apply_microcode_on_target(int cpu
)
380 struct apply_microcode_ctx ctx
= { .err
= 0 };
383 ret
= smp_call_function_single(cpu
, apply_microcode_local
, &ctx
, 1);
390 #ifdef CONFIG_MICROCODE_OLD_INTERFACE
391 static int do_microcode_update(const void __user
*buf
, size_t size
)
396 for_each_online_cpu(cpu
) {
397 struct ucode_cpu_info
*uci
= ucode_cpu_info
+ cpu
;
398 enum ucode_state ustate
;
403 ustate
= microcode_ops
->request_microcode_user(cpu
, buf
, size
);
404 if (ustate
== UCODE_ERROR
) {
407 } else if (ustate
== UCODE_OK
)
408 apply_microcode_on_target(cpu
);
414 static int microcode_open(struct inode
*inode
, struct file
*file
)
416 return capable(CAP_SYS_RAWIO
) ? nonseekable_open(inode
, file
) : -EPERM
;
419 static ssize_t
microcode_write(struct file
*file
, const char __user
*buf
,
420 size_t len
, loff_t
*ppos
)
422 ssize_t ret
= -EINVAL
;
424 if ((len
>> PAGE_SHIFT
) > totalram_pages
) {
425 pr_err("too much data (max %ld pages)\n", totalram_pages
);
430 mutex_lock(µcode_mutex
);
432 if (do_microcode_update(buf
, len
) == 0)
436 perf_check_microcode();
438 mutex_unlock(µcode_mutex
);
444 static const struct file_operations microcode_fops
= {
445 .owner
= THIS_MODULE
,
446 .write
= microcode_write
,
447 .open
= microcode_open
,
451 static struct miscdevice microcode_dev
= {
452 .minor
= MICROCODE_MINOR
,
454 .nodename
= "cpu/microcode",
455 .fops
= µcode_fops
,
458 static int __init
microcode_dev_init(void)
462 error
= misc_register(µcode_dev
);
464 pr_err("can't misc_register on minor=%d\n", MICROCODE_MINOR
);
471 static void __exit
microcode_dev_exit(void)
473 misc_deregister(µcode_dev
);
476 #define microcode_dev_init() 0
477 #define microcode_dev_exit() do { } while (0)
480 /* fake device for request_firmware */
481 static struct platform_device
*microcode_pdev
;
483 static int reload_for_cpu(int cpu
)
485 struct ucode_cpu_info
*uci
= ucode_cpu_info
+ cpu
;
486 enum ucode_state ustate
;
492 ustate
= microcode_ops
->request_microcode_fw(cpu
, µcode_pdev
->dev
, true);
493 if (ustate
== UCODE_OK
)
494 apply_microcode_on_target(cpu
);
496 if (ustate
== UCODE_ERROR
)
501 static ssize_t
reload_store(struct device
*dev
,
502 struct device_attribute
*attr
,
503 const char *buf
, size_t size
)
507 ssize_t ret
= 0, tmp_ret
;
509 ret
= kstrtoul(buf
, 0, &val
);
517 mutex_lock(µcode_mutex
);
518 for_each_online_cpu(cpu
) {
519 tmp_ret
= reload_for_cpu(cpu
);
521 pr_warn("Error reloading microcode on CPU %d\n", cpu
);
523 /* save retval of the first encountered reload error */
528 perf_check_microcode();
529 mutex_unlock(µcode_mutex
);
538 static ssize_t
version_show(struct device
*dev
,
539 struct device_attribute
*attr
, char *buf
)
541 struct ucode_cpu_info
*uci
= ucode_cpu_info
+ dev
->id
;
543 return sprintf(buf
, "0x%x\n", uci
->cpu_sig
.rev
);
546 static ssize_t
pf_show(struct device
*dev
,
547 struct device_attribute
*attr
, char *buf
)
549 struct ucode_cpu_info
*uci
= ucode_cpu_info
+ dev
->id
;
551 return sprintf(buf
, "0x%x\n", uci
->cpu_sig
.pf
);
554 static DEVICE_ATTR(reload
, 0200, NULL
, reload_store
);
555 static DEVICE_ATTR(version
, 0400, version_show
, NULL
);
556 static DEVICE_ATTR(processor_flags
, 0400, pf_show
, NULL
);
558 static struct attribute
*mc_default_attrs
[] = {
559 &dev_attr_version
.attr
,
560 &dev_attr_processor_flags
.attr
,
564 static const struct attribute_group mc_attr_group
= {
565 .attrs
= mc_default_attrs
,
569 static void microcode_fini_cpu(int cpu
)
571 if (microcode_ops
->microcode_fini_cpu
)
572 microcode_ops
->microcode_fini_cpu(cpu
);
575 static enum ucode_state
microcode_resume_cpu(int cpu
)
577 if (apply_microcode_on_target(cpu
))
580 pr_debug("CPU%d updated upon resume\n", cpu
);
585 static enum ucode_state
microcode_init_cpu(int cpu
, bool refresh_fw
)
587 enum ucode_state ustate
;
588 struct ucode_cpu_info
*uci
= ucode_cpu_info
+ cpu
;
593 if (collect_cpu_info(cpu
))
596 /* --dimm. Trigger a delayed update? */
597 if (system_state
!= SYSTEM_RUNNING
)
600 ustate
= microcode_ops
->request_microcode_fw(cpu
, µcode_pdev
->dev
,
603 if (ustate
== UCODE_OK
) {
604 pr_debug("CPU%d updated upon init\n", cpu
);
605 apply_microcode_on_target(cpu
);
611 static enum ucode_state
microcode_update_cpu(int cpu
)
613 struct ucode_cpu_info
*uci
= ucode_cpu_info
+ cpu
;
615 /* Refresh CPU microcode revision after resume. */
616 collect_cpu_info(cpu
);
619 return microcode_resume_cpu(cpu
);
621 return microcode_init_cpu(cpu
, false);
624 static int mc_device_add(struct device
*dev
, struct subsys_interface
*sif
)
626 int err
, cpu
= dev
->id
;
628 if (!cpu_online(cpu
))
631 pr_debug("CPU%d added\n", cpu
);
633 err
= sysfs_create_group(&dev
->kobj
, &mc_attr_group
);
637 if (microcode_init_cpu(cpu
, true) == UCODE_ERROR
)
643 static void mc_device_remove(struct device
*dev
, struct subsys_interface
*sif
)
647 if (!cpu_online(cpu
))
650 pr_debug("CPU%d removed\n", cpu
);
651 microcode_fini_cpu(cpu
);
652 sysfs_remove_group(&dev
->kobj
, &mc_attr_group
);
655 static struct subsys_interface mc_cpu_interface
= {
657 .subsys
= &cpu_subsys
,
658 .add_dev
= mc_device_add
,
659 .remove_dev
= mc_device_remove
,
663 * mc_bp_resume - Update boot CPU microcode during resume.
665 static void mc_bp_resume(void)
667 int cpu
= smp_processor_id();
668 struct ucode_cpu_info
*uci
= ucode_cpu_info
+ cpu
;
670 if (uci
->valid
&& uci
->mc
)
671 microcode_ops
->apply_microcode(cpu
);
673 reload_early_microcode();
676 static struct syscore_ops mc_syscore_ops
= {
677 .resume
= mc_bp_resume
,
680 static int mc_cpu_online(unsigned int cpu
)
684 dev
= get_cpu_device(cpu
);
685 microcode_update_cpu(cpu
);
686 pr_debug("CPU%d added\n", cpu
);
688 if (sysfs_create_group(&dev
->kobj
, &mc_attr_group
))
689 pr_err("Failed to create group for CPU%d\n", cpu
);
693 static int mc_cpu_down_prep(unsigned int cpu
)
697 dev
= get_cpu_device(cpu
);
698 /* Suspend is in progress, only remove the interface */
699 sysfs_remove_group(&dev
->kobj
, &mc_attr_group
);
700 pr_debug("CPU%d removed\n", cpu
);
705 static struct attribute
*cpu_root_microcode_attrs
[] = {
706 &dev_attr_reload
.attr
,
710 static const struct attribute_group cpu_root_microcode_group
= {
712 .attrs
= cpu_root_microcode_attrs
,
715 int __init
microcode_init(void)
717 struct cpuinfo_x86
*c
= &boot_cpu_data
;
723 if (c
->x86_vendor
== X86_VENDOR_INTEL
)
724 microcode_ops
= init_intel_microcode();
725 else if (c
->x86_vendor
== X86_VENDOR_AMD
)
726 microcode_ops
= init_amd_microcode();
728 pr_err("no support for this CPU vendor\n");
733 microcode_pdev
= platform_device_register_simple("microcode", -1,
735 if (IS_ERR(microcode_pdev
))
736 return PTR_ERR(microcode_pdev
);
739 mutex_lock(µcode_mutex
);
741 error
= subsys_interface_register(&mc_cpu_interface
);
743 perf_check_microcode();
744 mutex_unlock(µcode_mutex
);
750 error
= sysfs_create_group(&cpu_subsys
.dev_root
->kobj
,
751 &cpu_root_microcode_group
);
754 pr_err("Error creating microcode group!\n");
758 error
= microcode_dev_init();
760 goto out_ucode_group
;
762 register_syscore_ops(&mc_syscore_ops
);
763 cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN
, "x86/microcode:online",
764 mc_cpu_online
, mc_cpu_down_prep
);
766 pr_info("Microcode Update Driver: v%s.", DRIVER_VERSION
);
771 sysfs_remove_group(&cpu_subsys
.dev_root
->kobj
,
772 &cpu_root_microcode_group
);
776 mutex_lock(µcode_mutex
);
778 subsys_interface_unregister(&mc_cpu_interface
);
780 mutex_unlock(µcode_mutex
);
784 platform_device_unregister(microcode_pdev
);
788 fs_initcall(save_microcode_in_initrd
);
789 late_initcall(microcode_init
);