blob: 319dd65f98a25530d3a55cb6ea1cf61f6c2004bc [file] [log] [blame]
/*
* CPU Microcode Update Driver for Linux
*
* Copyright (C) 2000-2006 Tigran Aivazian <aivazian.tigran@gmail.com>
* 2006 Shaohua Li <shaohua.li@intel.com>
* 2013-2016 Borislav Petkov <bp@alien8.de>
*
* X86 CPU microcode early update for Linux:
*
* Copyright (C) 2012 Fenghua Yu <fenghua.yu@intel.com>
* H Peter Anvin" <hpa@zytor.com>
* (C) 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) "microcode: " fmt
#include <linux/platform_device.h>
#include <linux/syscore_ops.h>
#include <linux/miscdevice.h>
#include <linux/capability.h>
#include <linux/firmware.h>
#include <linux/kernel.h>
#include <linux/mutex.h>
#include <linux/cpu.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <asm/microcode_intel.h>
#include <asm/cpu_device_id.h>
#include <asm/microcode_amd.h>
#include <asm/perf_event.h>
#include <asm/microcode.h>
#include <asm/processor.h>
#include <asm/cmdline.h>
#include <asm/setup.h>
#define DRIVER_VERSION "2.2"
static struct microcode_ops *microcode_ops;
static bool dis_ucode_ldr = true;
bool initrd_gone;
LIST_HEAD(microcode_cache);
/*
* 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];
struct cpu_info_ctx {
struct cpu_signature *cpu_sig;
int err;
};
/*
* Those patch levels cannot be updated to newer ones and thus should be final.
*/
static u32 final_levels[] = {
0x01000098,
0x0100009f,
0x010000af,
0, /* T-101 terminator */
};
/*
* Check the current patch level on this CPU.
*
* Returns:
* - true: if update should stop
* - false: otherwise
*/
static bool amd_check_current_patch_level(void)
{
u32 lvl, dummy, i;
u32 *levels;
native_rdmsr(MSR_AMD64_PATCH_LEVEL, lvl, dummy);
if (IS_ENABLED(CONFIG_X86_32))
levels = (u32 *)__pa_nodebug(&final_levels);
else
levels = final_levels;
for (i = 0; levels[i]; i++) {
if (lvl == levels[i])
return true;
}
return false;
}
static bool __init check_loader_disabled_bsp(void)
{
static const char *__dis_opt_str = "dis_ucode_ldr";
#ifdef CONFIG_X86_32
const char *cmdline = (const char *)__pa_nodebug(boot_command_line);
const char *option = (const char *)__pa_nodebug(__dis_opt_str);
bool *res = (bool *)__pa_nodebug(&dis_ucode_ldr);
#else /* CONFIG_X86_64 */
const char *cmdline = boot_command_line;
const char *option = __dis_opt_str;
bool *res = &dis_ucode_ldr;
#endif
/*
* CPUID(1).ECX[31]: reserved for hypervisor use. This is still not
* completely accurate as xen pv guests don't see that CPUID bit set but
* that's good enough as they don't land on the BSP path anyway.
*/
if (native_cpuid_ecx(1) & BIT(31))
return *res;
if (x86_cpuid_vendor() == X86_VENDOR_AMD) {
if (amd_check_current_patch_level())
return *res;
}
if (cmdline_find_option_bool(cmdline, option) <= 0)
*res = false;
return *res;
}
extern struct builtin_fw __start_builtin_fw[];
extern struct builtin_fw __end_builtin_fw[];
bool get_builtin_firmware(struct cpio_data *cd, const char *name)
{
#ifdef CONFIG_FW_LOADER
struct builtin_fw *b_fw;
for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
if (!strcmp(name, b_fw->name)) {
cd->size = b_fw->size;
cd->data = b_fw->data;
return true;
}
}
#endif
return false;
}
void __init load_ucode_bsp(void)
{
unsigned int cpuid_1_eax;
bool intel = true;
if (!have_cpuid_p())
return;
cpuid_1_eax = native_cpuid_eax(1);
switch (x86_cpuid_vendor()) {
case X86_VENDOR_INTEL:
if (x86_family(cpuid_1_eax) < 6)
return;
break;
case X86_VENDOR_AMD:
if (x86_family(cpuid_1_eax) < 0x10)
return;
intel = false;
break;
default:
return;
}
if (check_loader_disabled_bsp())
return;
if (intel)
load_ucode_intel_bsp();
else
load_ucode_amd_bsp(cpuid_1_eax);
}
static bool check_loader_disabled_ap(void)
{
#ifdef CONFIG_X86_32
return *((bool *)__pa_nodebug(&dis_ucode_ldr));
#else
return dis_ucode_ldr;
#endif
}
void load_ucode_ap(void)
{
unsigned int cpuid_1_eax;
if (check_loader_disabled_ap())
return;
cpuid_1_eax = native_cpuid_eax(1);
switch (x86_cpuid_vendor()) {
case X86_VENDOR_INTEL:
if (x86_family(cpuid_1_eax) >= 6)
load_ucode_intel_ap();
break;
case X86_VENDOR_AMD:
if (x86_family(cpuid_1_eax) >= 0x10)
load_ucode_amd_ap(cpuid_1_eax);
break;
default:
break;
}
}
static int __init save_microcode_in_initrd(void)
{
struct cpuinfo_x86 *c = &boot_cpu_data;
int ret = -EINVAL;
switch (c->x86_vendor) {
case X86_VENDOR_INTEL:
if (c->x86 >= 6)
ret = save_microcode_in_initrd_intel();
break;
case X86_VENDOR_AMD:
if (c->x86 >= 0x10)
ret = save_microcode_in_initrd_amd(cpuid_eax(1));
break;
default:
break;
}
initrd_gone = true;
return ret;
}
struct cpio_data find_microcode_in_initrd(const char *path, bool use_pa)
{
#ifdef CONFIG_BLK_DEV_INITRD
unsigned long start = 0;
size_t size;
#ifdef CONFIG_X86_32
struct boot_params *params;
if (use_pa)
params = (struct boot_params *)__pa_nodebug(&boot_params);
else
params = &boot_params;
size = params->hdr.ramdisk_size;
/*
* Set start only if we have an initrd image. We cannot use initrd_start
* because it is not set that early yet.
*/
if (size)
start = params->hdr.ramdisk_image;
# else /* CONFIG_X86_64 */
size = (unsigned long)boot_params.ext_ramdisk_size << 32;
size |= boot_params.hdr.ramdisk_size;
if (size) {
start = (unsigned long)boot_params.ext_ramdisk_image << 32;
start |= boot_params.hdr.ramdisk_image;
start += PAGE_OFFSET;
}
# endif
/*
* Fixup the start address: after reserve_initrd() runs, initrd_start
* has the virtual address of the beginning of the initrd. It also
* possibly relocates the ramdisk. In either case, initrd_start contains
* the updated address so use that instead.
*
* initrd_gone is for the hotplug case where we've thrown out initrd
* already.
*/
if (!use_pa) {
if (initrd_gone)
return (struct cpio_data){ NULL, 0, "" };
if (initrd_start)
start = initrd_start;
} else {
/*
* The picture with physical addresses is a bit different: we
* need to get the *physical* address to which the ramdisk was
* relocated, i.e., relocated_ramdisk (not initrd_start) and
* since we're running from physical addresses, we need to access
* relocated_ramdisk through its *physical* address too.
*/
u64 *rr = (u64 *)__pa_nodebug(&relocated_ramdisk);
if (*rr)
start = *rr;
}
return find_cpio_data(path, (void *)start, size, NULL);
#else /* !CONFIG_BLK_DEV_INITRD */
return (struct cpio_data){ NULL, 0, "" };
#endif
}
void reload_early_microcode(void)
{
int vendor, family;
vendor = x86_cpuid_vendor();
family = x86_cpuid_family();
switch (vendor) {
case X86_VENDOR_INTEL:
if (family >= 6)
reload_ucode_intel();
break;
case X86_VENDOR_AMD:
if (family >= 0x10)
reload_ucode_amd();
break;
default:
break;
}
}
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);
}
#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_WO(reload);
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 const struct attribute_group mc_attr_group = {
.attrs = mc_default_attrs,
.name = "microcode",
};
static void microcode_fini_cpu(int cpu)
{
if (microcode_ops->microcode_fini_cpu)
microcode_ops->microcode_fini_cpu(cpu);
}
static enum ucode_state microcode_resume_cpu(int cpu)
{
if (apply_microcode_on_target(cpu))
return UCODE_ERROR;
pr_debug("CPU%d updated upon resume\n", cpu);
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->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;
/* Refresh CPU microcode revision after resume. */
collect_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_online(unsigned int cpu)
{
struct device *dev;
dev = get_cpu_device(cpu);
microcode_update_cpu(cpu);
pr_debug("CPU%d added\n", cpu);
if (sysfs_create_group(&dev->kobj, &mc_attr_group))
pr_err("Failed to create group for CPU%d\n", cpu);
return 0;
}
static int mc_cpu_down_prep(unsigned int cpu)
{
struct device *dev;
dev = get_cpu_device(cpu);
/* Suspend is in progress, only remove the interface */
sysfs_remove_group(&dev->kobj, &mc_attr_group);
pr_debug("CPU%d removed\n", cpu);
return 0;
}
static struct attribute *cpu_root_microcode_attrs[] = {
&dev_attr_reload.attr,
NULL
};
static const struct attribute_group cpu_root_microcode_group = {
.name = "microcode",
.attrs = cpu_root_microcode_attrs,
};
int __init microcode_init(void)
{
struct cpuinfo_x86 *c = &boot_cpu_data;
int error;
if (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);
cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/microcode:online",
mc_cpu_online, mc_cpu_down_prep);
pr_info("Microcode Update Driver: v%s.", DRIVER_VERSION);
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;
}
fs_initcall(save_microcode_in_initrd);
late_initcall(microcode_init);