OpenCloudOS-Kernel/arch/x86/kernel/cpu/microcode/core.c

595 lines
13 KiB
C

/*
* CPU Microcode Update Driver for Linux
*
* Copyright (C) 2000-2006 Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
* 2006 Shaohua Li <shaohua.li@intel.com>
* 2013-2015 Borislav Petkov <bp@alien8.de>
*
* This driver allows to upgrade microcode on x86 processors.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/platform_device.h>
#include <linux/miscdevice.h>
#include <linux/capability.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/cpu.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/syscore_ops.h>
#include <asm/microcode.h>
#include <asm/processor.h>
#include <asm/cpu_device_id.h>
#include <asm/perf_event.h>
MODULE_DESCRIPTION("Microcode Update Driver");
MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
MODULE_LICENSE("GPL");
#define MICROCODE_VERSION "2.00"
static struct microcode_ops *microcode_ops;
bool dis_ucode_ldr;
module_param(dis_ucode_ldr, bool, 0);
/*
* Synchronization.
*
* All non cpu-hotplug-callback call sites use:
*
* - microcode_mutex to synchronize with each other;
* - get/put_online_cpus() to synchronize with
* the cpu-hotplug-callback call sites.
*
* We guarantee that only a single cpu is being
* updated at any particular moment of time.
*/
static DEFINE_MUTEX(microcode_mutex);
struct ucode_cpu_info ucode_cpu_info[NR_CPUS];
EXPORT_SYMBOL_GPL(ucode_cpu_info);
/*
* Operations that are run on a target cpu:
*/
struct cpu_info_ctx {
struct cpu_signature *cpu_sig;
int err;
};
static void collect_cpu_info_local(void *arg)
{
struct cpu_info_ctx *ctx = arg;
ctx->err = microcode_ops->collect_cpu_info(smp_processor_id(),
ctx->cpu_sig);
}
static int collect_cpu_info_on_target(int cpu, struct cpu_signature *cpu_sig)
{
struct cpu_info_ctx ctx = { .cpu_sig = cpu_sig, .err = 0 };
int ret;
ret = smp_call_function_single(cpu, collect_cpu_info_local, &ctx, 1);
if (!ret)
ret = ctx.err;
return ret;
}
static int collect_cpu_info(int cpu)
{
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
int ret;
memset(uci, 0, sizeof(*uci));
ret = collect_cpu_info_on_target(cpu, &uci->cpu_sig);
if (!ret)
uci->valid = 1;
return ret;
}
struct apply_microcode_ctx {
int err;
};
static void apply_microcode_local(void *arg)
{
struct apply_microcode_ctx *ctx = arg;
ctx->err = microcode_ops->apply_microcode(smp_processor_id());
}
static int apply_microcode_on_target(int cpu)
{
struct apply_microcode_ctx ctx = { .err = 0 };
int ret;
ret = smp_call_function_single(cpu, apply_microcode_local, &ctx, 1);
if (!ret)
ret = ctx.err;
return ret;
}
#ifdef CONFIG_MICROCODE_OLD_INTERFACE
static int do_microcode_update(const void __user *buf, size_t size)
{
int error = 0;
int cpu;
for_each_online_cpu(cpu) {
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
enum ucode_state ustate;
if (!uci->valid)
continue;
ustate = microcode_ops->request_microcode_user(cpu, buf, size);
if (ustate == UCODE_ERROR) {
error = -1;
break;
} else if (ustate == UCODE_OK)
apply_microcode_on_target(cpu);
}
return error;
}
static int microcode_open(struct inode *inode, struct file *file)
{
return capable(CAP_SYS_RAWIO) ? nonseekable_open(inode, file) : -EPERM;
}
static ssize_t microcode_write(struct file *file, const char __user *buf,
size_t len, loff_t *ppos)
{
ssize_t ret = -EINVAL;
if ((len >> PAGE_SHIFT) > totalram_pages) {
pr_err("too much data (max %ld pages)\n", totalram_pages);
return ret;
}
get_online_cpus();
mutex_lock(&microcode_mutex);
if (do_microcode_update(buf, len) == 0)
ret = (ssize_t)len;
if (ret > 0)
perf_check_microcode();
mutex_unlock(&microcode_mutex);
put_online_cpus();
return ret;
}
static const struct file_operations microcode_fops = {
.owner = THIS_MODULE,
.write = microcode_write,
.open = microcode_open,
.llseek = no_llseek,
};
static struct miscdevice microcode_dev = {
.minor = MICROCODE_MINOR,
.name = "microcode",
.nodename = "cpu/microcode",
.fops = &microcode_fops,
};
static int __init microcode_dev_init(void)
{
int error;
error = misc_register(&microcode_dev);
if (error) {
pr_err("can't misc_register on minor=%d\n", MICROCODE_MINOR);
return error;
}
return 0;
}
static void __exit microcode_dev_exit(void)
{
misc_deregister(&microcode_dev);
}
MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);
MODULE_ALIAS("devname:cpu/microcode");
#else
#define microcode_dev_init() 0
#define microcode_dev_exit() do { } while (0)
#endif
/* fake device for request_firmware */
static struct platform_device *microcode_pdev;
static int reload_for_cpu(int cpu)
{
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
enum ucode_state ustate;
int err = 0;
if (!uci->valid)
return err;
ustate = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev, true);
if (ustate == UCODE_OK)
apply_microcode_on_target(cpu);
else
if (ustate == UCODE_ERROR)
err = -EINVAL;
return err;
}
static ssize_t reload_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t size)
{
unsigned long val;
int cpu;
ssize_t ret = 0, tmp_ret;
ret = kstrtoul(buf, 0, &val);
if (ret)
return ret;
if (val != 1)
return size;
get_online_cpus();
mutex_lock(&microcode_mutex);
for_each_online_cpu(cpu) {
tmp_ret = reload_for_cpu(cpu);
if (tmp_ret != 0)
pr_warn("Error reloading microcode on CPU %d\n", cpu);
/* save retval of the first encountered reload error */
if (!ret)
ret = tmp_ret;
}
if (!ret)
perf_check_microcode();
mutex_unlock(&microcode_mutex);
put_online_cpus();
if (!ret)
ret = size;
return ret;
}
static ssize_t version_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
return sprintf(buf, "0x%x\n", uci->cpu_sig.rev);
}
static ssize_t pf_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
return sprintf(buf, "0x%x\n", uci->cpu_sig.pf);
}
static DEVICE_ATTR(reload, 0200, NULL, reload_store);
static DEVICE_ATTR(version, 0400, version_show, NULL);
static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL);
static struct attribute *mc_default_attrs[] = {
&dev_attr_version.attr,
&dev_attr_processor_flags.attr,
NULL
};
static struct attribute_group mc_attr_group = {
.attrs = mc_default_attrs,
.name = "microcode",
};
static void microcode_fini_cpu(int cpu)
{
microcode_ops->microcode_fini_cpu(cpu);
}
static enum ucode_state microcode_resume_cpu(int cpu)
{
pr_debug("CPU%d updated upon resume\n", cpu);
if (apply_microcode_on_target(cpu))
return UCODE_ERROR;
return UCODE_OK;
}
static enum ucode_state microcode_init_cpu(int cpu, bool refresh_fw)
{
enum ucode_state ustate;
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
if (uci && uci->valid)
return UCODE_OK;
if (collect_cpu_info(cpu))
return UCODE_ERROR;
/* --dimm. Trigger a delayed update? */
if (system_state != SYSTEM_RUNNING)
return UCODE_NFOUND;
ustate = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev,
refresh_fw);
if (ustate == UCODE_OK) {
pr_debug("CPU%d updated upon init\n", cpu);
apply_microcode_on_target(cpu);
}
return ustate;
}
static enum ucode_state microcode_update_cpu(int cpu)
{
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
if (uci->valid)
return microcode_resume_cpu(cpu);
return microcode_init_cpu(cpu, false);
}
static int mc_device_add(struct device *dev, struct subsys_interface *sif)
{
int err, cpu = dev->id;
if (!cpu_online(cpu))
return 0;
pr_debug("CPU%d added\n", cpu);
err = sysfs_create_group(&dev->kobj, &mc_attr_group);
if (err)
return err;
if (microcode_init_cpu(cpu, true) == UCODE_ERROR)
return -EINVAL;
return err;
}
static void mc_device_remove(struct device *dev, struct subsys_interface *sif)
{
int cpu = dev->id;
if (!cpu_online(cpu))
return;
pr_debug("CPU%d removed\n", cpu);
microcode_fini_cpu(cpu);
sysfs_remove_group(&dev->kobj, &mc_attr_group);
}
static struct subsys_interface mc_cpu_interface = {
.name = "microcode",
.subsys = &cpu_subsys,
.add_dev = mc_device_add,
.remove_dev = mc_device_remove,
};
/**
* mc_bp_resume - Update boot CPU microcode during resume.
*/
static void mc_bp_resume(void)
{
int cpu = smp_processor_id();
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
if (uci->valid && uci->mc)
microcode_ops->apply_microcode(cpu);
else if (!uci->mc)
reload_early_microcode();
}
static struct syscore_ops mc_syscore_ops = {
.resume = mc_bp_resume,
};
static int
mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned long)hcpu;
struct device *dev;
dev = get_cpu_device(cpu);
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_ONLINE:
microcode_update_cpu(cpu);
pr_debug("CPU%d added\n", cpu);
/*
* "break" is missing on purpose here because we want to fall
* through in order to create the sysfs group.
*/
case CPU_DOWN_FAILED:
if (sysfs_create_group(&dev->kobj, &mc_attr_group))
pr_err("Failed to create group for CPU%d\n", cpu);
break;
case CPU_DOWN_PREPARE:
/* Suspend is in progress, only remove the interface */
sysfs_remove_group(&dev->kobj, &mc_attr_group);
pr_debug("CPU%d removed\n", cpu);
break;
/*
* case CPU_DEAD:
*
* When a CPU goes offline, don't free up or invalidate the copy of
* the microcode in kernel memory, so that we can reuse it when the
* CPU comes back online without unnecessarily requesting the userspace
* for it again.
*/
}
/* The CPU refused to come up during a system resume */
if (action == CPU_UP_CANCELED_FROZEN)
microcode_fini_cpu(cpu);
return NOTIFY_OK;
}
static struct notifier_block mc_cpu_notifier = {
.notifier_call = mc_cpu_callback,
};
#ifdef MODULE
/* Autoload on Intel and AMD systems */
static const struct x86_cpu_id __initconst microcode_id[] = {
#ifdef CONFIG_MICROCODE_INTEL
{ X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, },
#endif
#ifdef CONFIG_MICROCODE_AMD
{ X86_VENDOR_AMD, X86_FAMILY_ANY, X86_MODEL_ANY, },
#endif
{}
};
MODULE_DEVICE_TABLE(x86cpu, microcode_id);
#endif
static struct attribute *cpu_root_microcode_attrs[] = {
&dev_attr_reload.attr,
NULL
};
static struct attribute_group cpu_root_microcode_group = {
.name = "microcode",
.attrs = cpu_root_microcode_attrs,
};
static int __init microcode_init(void)
{
struct cpuinfo_x86 *c = &cpu_data(0);
int error;
if (paravirt_enabled() || dis_ucode_ldr)
return -EINVAL;
if (c->x86_vendor == X86_VENDOR_INTEL)
microcode_ops = init_intel_microcode();
else if (c->x86_vendor == X86_VENDOR_AMD)
microcode_ops = init_amd_microcode();
else
pr_err("no support for this CPU vendor\n");
if (!microcode_ops)
return -ENODEV;
microcode_pdev = platform_device_register_simple("microcode", -1,
NULL, 0);
if (IS_ERR(microcode_pdev))
return PTR_ERR(microcode_pdev);
get_online_cpus();
mutex_lock(&microcode_mutex);
error = subsys_interface_register(&mc_cpu_interface);
if (!error)
perf_check_microcode();
mutex_unlock(&microcode_mutex);
put_online_cpus();
if (error)
goto out_pdev;
error = sysfs_create_group(&cpu_subsys.dev_root->kobj,
&cpu_root_microcode_group);
if (error) {
pr_err("Error creating microcode group!\n");
goto out_driver;
}
error = microcode_dev_init();
if (error)
goto out_ucode_group;
register_syscore_ops(&mc_syscore_ops);
register_hotcpu_notifier(&mc_cpu_notifier);
pr_info("Microcode Update Driver: v" MICROCODE_VERSION
" <tigran@aivazian.fsnet.co.uk>, Peter Oruba\n");
return 0;
out_ucode_group:
sysfs_remove_group(&cpu_subsys.dev_root->kobj,
&cpu_root_microcode_group);
out_driver:
get_online_cpus();
mutex_lock(&microcode_mutex);
subsys_interface_unregister(&mc_cpu_interface);
mutex_unlock(&microcode_mutex);
put_online_cpus();
out_pdev:
platform_device_unregister(microcode_pdev);
return error;
}
module_init(microcode_init);
static void __exit microcode_exit(void)
{
struct cpuinfo_x86 *c = &cpu_data(0);
microcode_dev_exit();
unregister_hotcpu_notifier(&mc_cpu_notifier);
unregister_syscore_ops(&mc_syscore_ops);
sysfs_remove_group(&cpu_subsys.dev_root->kobj,
&cpu_root_microcode_group);
get_online_cpus();
mutex_lock(&microcode_mutex);
subsys_interface_unregister(&mc_cpu_interface);
mutex_unlock(&microcode_mutex);
put_online_cpus();
platform_device_unregister(microcode_pdev);
microcode_ops = NULL;
if (c->x86_vendor == X86_VENDOR_AMD)
exit_amd_microcode();
pr_info("Microcode Update Driver: v" MICROCODE_VERSION " removed.\n");
}
module_exit(microcode_exit);