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
];
63 EXPORT_SYMBOL_GPL(ucode_cpu_info
);
66 * Operations that are run on a target cpu:
70 struct cpu_signature
*cpu_sig
;
74 static bool __init
check_loader_disabled_bsp(void)
76 static const char *__dis_opt_str
= "dis_ucode_ldr";
79 const char *cmdline
= (const char *)__pa_nodebug(boot_command_line
);
80 const char *option
= (const char *)__pa_nodebug(__dis_opt_str
);
81 bool *res
= (bool *)__pa_nodebug(&dis_ucode_ldr
);
83 #else /* CONFIG_X86_64 */
84 const char *cmdline
= boot_command_line
;
85 const char *option
= __dis_opt_str
;
86 bool *res
= &dis_ucode_ldr
;
89 if (cmdline_find_option_bool(cmdline
, option
))
95 extern struct builtin_fw __start_builtin_fw
[];
96 extern struct builtin_fw __end_builtin_fw
[];
98 bool get_builtin_firmware(struct cpio_data
*cd
, const char *name
)
100 #ifdef CONFIG_FW_LOADER
101 struct builtin_fw
*b_fw
;
103 for (b_fw
= __start_builtin_fw
; b_fw
!= __end_builtin_fw
; b_fw
++) {
104 if (!strcmp(name
, b_fw
->name
)) {
105 cd
->size
= b_fw
->size
;
106 cd
->data
= b_fw
->data
;
114 void __init
load_ucode_bsp(void)
119 if (check_loader_disabled_bsp())
125 vendor
= x86_cpuid_vendor();
126 family
= x86_cpuid_family();
129 case X86_VENDOR_INTEL
:
131 load_ucode_intel_bsp();
135 load_ucode_amd_bsp(family
);
142 static bool check_loader_disabled_ap(void)
145 return *((bool *)__pa_nodebug(&dis_ucode_ldr
));
147 return dis_ucode_ldr
;
151 void load_ucode_ap(void)
155 if (check_loader_disabled_ap())
161 vendor
= x86_cpuid_vendor();
162 family
= x86_cpuid_family();
165 case X86_VENDOR_INTEL
:
167 load_ucode_intel_ap();
178 int __init
save_microcode_in_initrd(void)
180 struct cpuinfo_x86
*c
= &boot_cpu_data
;
182 switch (c
->x86_vendor
) {
183 case X86_VENDOR_INTEL
:
185 save_microcode_in_initrd_intel();
189 save_microcode_in_initrd_amd();
198 void reload_early_microcode(void)
202 vendor
= x86_cpuid_vendor();
203 family
= x86_cpuid_family();
206 case X86_VENDOR_INTEL
:
208 reload_ucode_intel();
219 static void collect_cpu_info_local(void *arg
)
221 struct cpu_info_ctx
*ctx
= arg
;
223 ctx
->err
= microcode_ops
->collect_cpu_info(smp_processor_id(),
227 static int collect_cpu_info_on_target(int cpu
, struct cpu_signature
*cpu_sig
)
229 struct cpu_info_ctx ctx
= { .cpu_sig
= cpu_sig
, .err
= 0 };
232 ret
= smp_call_function_single(cpu
, collect_cpu_info_local
, &ctx
, 1);
239 static int collect_cpu_info(int cpu
)
241 struct ucode_cpu_info
*uci
= ucode_cpu_info
+ cpu
;
244 memset(uci
, 0, sizeof(*uci
));
246 ret
= collect_cpu_info_on_target(cpu
, &uci
->cpu_sig
);
253 struct apply_microcode_ctx
{
257 static void apply_microcode_local(void *arg
)
259 struct apply_microcode_ctx
*ctx
= arg
;
261 ctx
->err
= microcode_ops
->apply_microcode(smp_processor_id());
264 static int apply_microcode_on_target(int cpu
)
266 struct apply_microcode_ctx ctx
= { .err
= 0 };
269 ret
= smp_call_function_single(cpu
, apply_microcode_local
, &ctx
, 1);
276 #ifdef CONFIG_MICROCODE_OLD_INTERFACE
277 static int do_microcode_update(const void __user
*buf
, size_t size
)
282 for_each_online_cpu(cpu
) {
283 struct ucode_cpu_info
*uci
= ucode_cpu_info
+ cpu
;
284 enum ucode_state ustate
;
289 ustate
= microcode_ops
->request_microcode_user(cpu
, buf
, size
);
290 if (ustate
== UCODE_ERROR
) {
293 } else if (ustate
== UCODE_OK
)
294 apply_microcode_on_target(cpu
);
300 static int microcode_open(struct inode
*inode
, struct file
*file
)
302 return capable(CAP_SYS_RAWIO
) ? nonseekable_open(inode
, file
) : -EPERM
;
305 static ssize_t
microcode_write(struct file
*file
, const char __user
*buf
,
306 size_t len
, loff_t
*ppos
)
308 ssize_t ret
= -EINVAL
;
310 if ((len
>> PAGE_SHIFT
) > totalram_pages
) {
311 pr_err("too much data (max %ld pages)\n", totalram_pages
);
316 mutex_lock(µcode_mutex
);
318 if (do_microcode_update(buf
, len
) == 0)
322 perf_check_microcode();
324 mutex_unlock(µcode_mutex
);
330 static const struct file_operations microcode_fops
= {
331 .owner
= THIS_MODULE
,
332 .write
= microcode_write
,
333 .open
= microcode_open
,
337 static struct miscdevice microcode_dev
= {
338 .minor
= MICROCODE_MINOR
,
340 .nodename
= "cpu/microcode",
341 .fops
= µcode_fops
,
344 static int __init
microcode_dev_init(void)
348 error
= misc_register(µcode_dev
);
350 pr_err("can't misc_register on minor=%d\n", MICROCODE_MINOR
);
357 static void __exit
microcode_dev_exit(void)
359 misc_deregister(µcode_dev
);
362 #define microcode_dev_init() 0
363 #define microcode_dev_exit() do { } while (0)
366 /* fake device for request_firmware */
367 static struct platform_device
*microcode_pdev
;
369 static int reload_for_cpu(int cpu
)
371 struct ucode_cpu_info
*uci
= ucode_cpu_info
+ cpu
;
372 enum ucode_state ustate
;
378 ustate
= microcode_ops
->request_microcode_fw(cpu
, µcode_pdev
->dev
, true);
379 if (ustate
== UCODE_OK
)
380 apply_microcode_on_target(cpu
);
382 if (ustate
== UCODE_ERROR
)
387 static ssize_t
reload_store(struct device
*dev
,
388 struct device_attribute
*attr
,
389 const char *buf
, size_t size
)
393 ssize_t ret
= 0, tmp_ret
;
395 ret
= kstrtoul(buf
, 0, &val
);
403 mutex_lock(µcode_mutex
);
404 for_each_online_cpu(cpu
) {
405 tmp_ret
= reload_for_cpu(cpu
);
407 pr_warn("Error reloading microcode on CPU %d\n", cpu
);
409 /* save retval of the first encountered reload error */
414 perf_check_microcode();
415 mutex_unlock(µcode_mutex
);
424 static ssize_t
version_show(struct device
*dev
,
425 struct device_attribute
*attr
, char *buf
)
427 struct ucode_cpu_info
*uci
= ucode_cpu_info
+ dev
->id
;
429 return sprintf(buf
, "0x%x\n", uci
->cpu_sig
.rev
);
432 static ssize_t
pf_show(struct device
*dev
,
433 struct device_attribute
*attr
, char *buf
)
435 struct ucode_cpu_info
*uci
= ucode_cpu_info
+ dev
->id
;
437 return sprintf(buf
, "0x%x\n", uci
->cpu_sig
.pf
);
440 static DEVICE_ATTR(reload
, 0200, NULL
, reload_store
);
441 static DEVICE_ATTR(version
, 0400, version_show
, NULL
);
442 static DEVICE_ATTR(processor_flags
, 0400, pf_show
, NULL
);
444 static struct attribute
*mc_default_attrs
[] = {
445 &dev_attr_version
.attr
,
446 &dev_attr_processor_flags
.attr
,
450 static struct attribute_group mc_attr_group
= {
451 .attrs
= mc_default_attrs
,
455 static void microcode_fini_cpu(int cpu
)
457 microcode_ops
->microcode_fini_cpu(cpu
);
460 static enum ucode_state
microcode_resume_cpu(int cpu
)
462 pr_debug("CPU%d updated upon resume\n", cpu
);
464 if (apply_microcode_on_target(cpu
))
470 static enum ucode_state
microcode_init_cpu(int cpu
, bool refresh_fw
)
472 enum ucode_state ustate
;
473 struct ucode_cpu_info
*uci
= ucode_cpu_info
+ cpu
;
478 if (collect_cpu_info(cpu
))
481 /* --dimm. Trigger a delayed update? */
482 if (system_state
!= SYSTEM_RUNNING
)
485 ustate
= microcode_ops
->request_microcode_fw(cpu
, µcode_pdev
->dev
,
488 if (ustate
== UCODE_OK
) {
489 pr_debug("CPU%d updated upon init\n", cpu
);
490 apply_microcode_on_target(cpu
);
496 static enum ucode_state
microcode_update_cpu(int cpu
)
498 struct ucode_cpu_info
*uci
= ucode_cpu_info
+ cpu
;
501 return microcode_resume_cpu(cpu
);
503 return microcode_init_cpu(cpu
, false);
506 static int mc_device_add(struct device
*dev
, struct subsys_interface
*sif
)
508 int err
, cpu
= dev
->id
;
510 if (!cpu_online(cpu
))
513 pr_debug("CPU%d added\n", cpu
);
515 err
= sysfs_create_group(&dev
->kobj
, &mc_attr_group
);
519 if (microcode_init_cpu(cpu
, true) == UCODE_ERROR
)
525 static void mc_device_remove(struct device
*dev
, struct subsys_interface
*sif
)
529 if (!cpu_online(cpu
))
532 pr_debug("CPU%d removed\n", cpu
);
533 microcode_fini_cpu(cpu
);
534 sysfs_remove_group(&dev
->kobj
, &mc_attr_group
);
537 static struct subsys_interface mc_cpu_interface
= {
539 .subsys
= &cpu_subsys
,
540 .add_dev
= mc_device_add
,
541 .remove_dev
= mc_device_remove
,
545 * mc_bp_resume - Update boot CPU microcode during resume.
547 static void mc_bp_resume(void)
549 int cpu
= smp_processor_id();
550 struct ucode_cpu_info
*uci
= ucode_cpu_info
+ cpu
;
552 if (uci
->valid
&& uci
->mc
)
553 microcode_ops
->apply_microcode(cpu
);
555 reload_early_microcode();
558 static struct syscore_ops mc_syscore_ops
= {
559 .resume
= mc_bp_resume
,
563 mc_cpu_callback(struct notifier_block
*nb
, unsigned long action
, void *hcpu
)
565 unsigned int cpu
= (unsigned long)hcpu
;
568 dev
= get_cpu_device(cpu
);
570 switch (action
& ~CPU_TASKS_FROZEN
) {
572 microcode_update_cpu(cpu
);
573 pr_debug("CPU%d added\n", cpu
);
575 * "break" is missing on purpose here because we want to fall
576 * through in order to create the sysfs group.
579 case CPU_DOWN_FAILED
:
580 if (sysfs_create_group(&dev
->kobj
, &mc_attr_group
))
581 pr_err("Failed to create group for CPU%d\n", cpu
);
584 case CPU_DOWN_PREPARE
:
585 /* Suspend is in progress, only remove the interface */
586 sysfs_remove_group(&dev
->kobj
, &mc_attr_group
);
587 pr_debug("CPU%d removed\n", cpu
);
593 * When a CPU goes offline, don't free up or invalidate the copy of
594 * the microcode in kernel memory, so that we can reuse it when the
595 * CPU comes back online without unnecessarily requesting the userspace
600 /* The CPU refused to come up during a system resume */
601 if (action
== CPU_UP_CANCELED_FROZEN
)
602 microcode_fini_cpu(cpu
);
607 static struct notifier_block mc_cpu_notifier
= {
608 .notifier_call
= mc_cpu_callback
,
611 static struct attribute
*cpu_root_microcode_attrs
[] = {
612 &dev_attr_reload
.attr
,
616 static struct attribute_group cpu_root_microcode_group
= {
618 .attrs
= cpu_root_microcode_attrs
,
621 int __init
microcode_init(void)
623 struct cpuinfo_x86
*c
= &boot_cpu_data
;
629 if (c
->x86_vendor
== X86_VENDOR_INTEL
)
630 microcode_ops
= init_intel_microcode();
631 else if (c
->x86_vendor
== X86_VENDOR_AMD
)
632 microcode_ops
= init_amd_microcode();
634 pr_err("no support for this CPU vendor\n");
639 microcode_pdev
= platform_device_register_simple("microcode", -1,
641 if (IS_ERR(microcode_pdev
))
642 return PTR_ERR(microcode_pdev
);
645 mutex_lock(µcode_mutex
);
647 error
= subsys_interface_register(&mc_cpu_interface
);
649 perf_check_microcode();
650 mutex_unlock(µcode_mutex
);
656 error
= sysfs_create_group(&cpu_subsys
.dev_root
->kobj
,
657 &cpu_root_microcode_group
);
660 pr_err("Error creating microcode group!\n");
664 error
= microcode_dev_init();
666 goto out_ucode_group
;
668 register_syscore_ops(&mc_syscore_ops
);
669 register_hotcpu_notifier(&mc_cpu_notifier
);
671 pr_info("Microcode Update Driver: v" MICROCODE_VERSION
672 " <tigran@aivazian.fsnet.co.uk>, Peter Oruba\n");
677 sysfs_remove_group(&cpu_subsys
.dev_root
->kobj
,
678 &cpu_root_microcode_group
);
682 mutex_lock(µcode_mutex
);
684 subsys_interface_unregister(&mc_cpu_interface
);
686 mutex_unlock(µcode_mutex
);
690 platform_device_unregister(microcode_pdev
);
694 late_initcall(microcode_init
);