Commit bc8e80d5 authored by Borislav Petkov's avatar Borislav Petkov Committed by Ingo Molnar

x86/mce: Merge mce_amd_inj into mce-inject

Reuse mce_amd_inj's debugfs interface so that mce-inject can
benefit from it too. The old functionality is still preserved under
CONFIG_X86_MCELOG_LEGACY.
Tested-by: default avatarYazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Acked-by: default avatarYazen Ghannam <yazen.ghannam@amd.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/20170613162835.30750-4-bp@alien8.deSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 17ef4af0
......@@ -1082,7 +1082,7 @@ config X86_MCE_THRESHOLD
def_bool y
config X86_MCE_INJECT
depends on X86_MCE && X86_LOCAL_APIC && X86_MCELOG_LEGACY
depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
tristate "Machine check injector support"
---help---
Provide support for injecting machine checks for testing purposes.
......
......@@ -257,8 +257,6 @@ drivers-$(CONFIG_PM) += arch/x86/power/
drivers-$(CONFIG_FB) += arch/x86/video/
drivers-$(CONFIG_RAS) += arch/x86/ras/
####
# boot loader support. Several targets are kept for legacy purposes
......
......@@ -901,8 +901,13 @@ static inline int mpx_disable_management(void)
}
#endif /* CONFIG_X86_INTEL_MPX */
#ifdef CONFIG_CPU_SUP_AMD
extern u16 amd_get_nb_id(int cpu);
extern u32 amd_get_nodes_per_socket(void);
#else
static inline u16 amd_get_nb_id(int cpu) { return 0; }
static inline u32 amd_get_nodes_per_socket(void) { return 0; }
#endif
static inline uint32_t hypervisor_cpuid_base(const char *sig, uint32_t leaves)
{
......
......@@ -10,23 +10,108 @@
* Authors:
* Andi Kleen
* Ying Huang
*
* The AMD part (from mce_amd_inj.c): a simple MCE injection facility
* for testing different aspects of the RAS code. This driver should be
* built as module so that it can be loaded on production kernels for
* testing purposes.
*
* This file may be distributed under the terms of the GNU General Public
* License version 2.
*
* Copyright (c) 2010-17: Borislav Petkov <bp@alien8.de>
* Advanced Micro Devices Inc.
*/
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/timer.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/cpu.h>
#include <linux/debugfs.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/preempt.h>
#include <linux/smp.h>
#include <linux/notifier.h>
#include <linux/gfp.h>
#include <linux/kdebug.h>
#include <linux/cpu.h>
#include <linux/kernel.h>
#include <linux/kobject.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/pci.h>
#include <linux/preempt.h>
#include <linux/sched.h>
#include <linux/gfp.h>
#include <asm/mce.h>
#include <linux/smp.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/uaccess.h>
#include <asm/amd_nb.h>
#include <asm/apic.h>
#include <asm/irq_vectors.h>
#include <asm/mce.h>
#include <asm/nmi.h>
#include <asm/smp.h>
#include "mce-internal.h"
/*
* Collect all the MCi_XXX settings
*/
static struct mce i_mce;
static struct dentry *dfs_inj;
static u8 n_banks;
#define MAX_FLAG_OPT_SIZE 3
#define NBCFG 0x44
enum injection_type {
SW_INJ = 0, /* SW injection, simply decode the error */
HW_INJ, /* Trigger a #MC */
DFR_INT_INJ, /* Trigger Deferred error interrupt */
THR_INT_INJ, /* Trigger threshold interrupt */
N_INJ_TYPES,
};
static const char * const flags_options[] = {
[SW_INJ] = "sw",
[HW_INJ] = "hw",
[DFR_INT_INJ] = "df",
[THR_INT_INJ] = "th",
NULL
};
/* Set default injection to SW_INJ */
static enum injection_type inj_type = SW_INJ;
#define MCE_INJECT_SET(reg) \
static int inj_##reg##_set(void *data, u64 val) \
{ \
struct mce *m = (struct mce *)data; \
\
m->reg = val; \
return 0; \
}
MCE_INJECT_SET(status);
MCE_INJECT_SET(misc);
MCE_INJECT_SET(addr);
MCE_INJECT_SET(synd);
#define MCE_INJECT_GET(reg) \
static int inj_##reg##_get(void *data, u64 *val) \
{ \
struct mce *m = (struct mce *)data; \
\
*val = m->reg; \
return 0; \
}
MCE_INJECT_GET(status);
MCE_INJECT_GET(misc);
MCE_INJECT_GET(addr);
MCE_INJECT_GET(synd);
DEFINE_SIMPLE_ATTRIBUTE(status_fops, inj_status_get, inj_status_set, "%llx\n");
DEFINE_SIMPLE_ATTRIBUTE(misc_fops, inj_misc_get, inj_misc_set, "%llx\n");
DEFINE_SIMPLE_ATTRIBUTE(addr_fops, inj_addr_get, inj_addr_set, "%llx\n");
DEFINE_SIMPLE_ATTRIBUTE(synd_fops, inj_synd_get, inj_synd_set, "%llx\n");
/* Update fake mce registers on current CPU. */
static void inject_mce(struct mce *m)
......@@ -143,7 +228,7 @@ static int raise_local(void)
return ret;
}
static void raise_mce(struct mce *m)
static void __maybe_unused raise_mce(struct mce *m)
{
int context = MCJ_CTX(m->inject_flags);
......@@ -198,6 +283,7 @@ static void raise_mce(struct mce *m)
}
}
#ifdef CONFIG_X86_MCELOG_LEGACY
/* Error injection interface */
static ssize_t mce_write(struct file *filp, const char __user *ubuf,
size_t usize, loff_t *off)
......@@ -232,21 +318,445 @@ static ssize_t mce_write(struct file *filp, const char __user *ubuf,
mutex_unlock(&mce_inject_mutex);
return usize;
}
#endif /* CONFIG_X86_MCELOG_LEGACY */
/*
* Caller needs to be make sure this cpu doesn't disappear
* from under us, i.e.: get_cpu/put_cpu.
*/
static int toggle_hw_mce_inject(unsigned int cpu, bool enable)
{
u32 l, h;
int err;
err = rdmsr_on_cpu(cpu, MSR_K7_HWCR, &l, &h);
if (err) {
pr_err("%s: error reading HWCR\n", __func__);
return err;
}
enable ? (l |= BIT(18)) : (l &= ~BIT(18));
err = wrmsr_on_cpu(cpu, MSR_K7_HWCR, l, h);
if (err)
pr_err("%s: error writing HWCR\n", __func__);
return err;
}
static int __set_inj(const char *buf)
{
int i;
for (i = 0; i < N_INJ_TYPES; i++) {
if (!strncmp(flags_options[i], buf, strlen(flags_options[i]))) {
inj_type = i;
return 0;
}
}
return -EINVAL;
}
static ssize_t flags_read(struct file *filp, char __user *ubuf,
size_t cnt, loff_t *ppos)
{
char buf[MAX_FLAG_OPT_SIZE];
int n;
n = sprintf(buf, "%s\n", flags_options[inj_type]);
return simple_read_from_buffer(ubuf, cnt, ppos, buf, n);
}
static ssize_t flags_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
char buf[MAX_FLAG_OPT_SIZE], *__buf;
int err;
if (cnt > MAX_FLAG_OPT_SIZE)
return -EINVAL;
if (copy_from_user(&buf, ubuf, cnt))
return -EFAULT;
buf[cnt - 1] = 0;
/* strip whitespace */
__buf = strstrip(buf);
err = __set_inj(__buf);
if (err) {
pr_err("%s: Invalid flags value: %s\n", __func__, __buf);
return err;
}
*ppos += cnt;
return cnt;
}
static const struct file_operations flags_fops = {
.read = flags_read,
.write = flags_write,
.llseek = generic_file_llseek,
};
/*
* On which CPU to inject?
*/
MCE_INJECT_GET(extcpu);
static int inj_extcpu_set(void *data, u64 val)
{
struct mce *m = (struct mce *)data;
if (val >= nr_cpu_ids || !cpu_online(val)) {
pr_err("%s: Invalid CPU: %llu\n", __func__, val);
return -EINVAL;
}
m->extcpu = val;
return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(extcpu_fops, inj_extcpu_get, inj_extcpu_set, "%llu\n");
static void trigger_mce(void *info)
{
asm volatile("int $18");
}
static void trigger_dfr_int(void *info)
{
asm volatile("int %0" :: "i" (DEFERRED_ERROR_VECTOR));
}
static void trigger_thr_int(void *info)
{
asm volatile("int %0" :: "i" (THRESHOLD_APIC_VECTOR));
}
static u32 get_nbc_for_node(int node_id)
{
struct cpuinfo_x86 *c = &boot_cpu_data;
u32 cores_per_node;
cores_per_node = (c->x86_max_cores * smp_num_siblings) / amd_get_nodes_per_socket();
return cores_per_node * node_id;
}
static void toggle_nb_mca_mst_cpu(u16 nid)
{
struct amd_northbridge *nb;
struct pci_dev *F3;
u32 val;
int err;
nb = node_to_amd_nb(nid);
if (!nb)
return;
F3 = nb->misc;
if (!F3)
return;
err = pci_read_config_dword(F3, NBCFG, &val);
if (err) {
pr_err("%s: Error reading F%dx%03x.\n",
__func__, PCI_FUNC(F3->devfn), NBCFG);
return;
}
if (val & BIT(27))
return;
pr_err("%s: Set D18F3x44[NbMcaToMstCpuEn] which BIOS hasn't done.\n",
__func__);
val |= BIT(27);
err = pci_write_config_dword(F3, NBCFG, val);
if (err)
pr_err("%s: Error writing F%dx%03x.\n",
__func__, PCI_FUNC(F3->devfn), NBCFG);
}
static int inject_init(void)
static void prepare_msrs(void *info)
{
struct mce m = *(struct mce *)info;
u8 b = m.bank;
wrmsrl(MSR_IA32_MCG_STATUS, m.mcgstatus);
if (boot_cpu_has(X86_FEATURE_SMCA)) {
if (m.inject_flags == DFR_INT_INJ) {
wrmsrl(MSR_AMD64_SMCA_MCx_DESTAT(b), m.status);
wrmsrl(MSR_AMD64_SMCA_MCx_DEADDR(b), m.addr);
} else {
wrmsrl(MSR_AMD64_SMCA_MCx_STATUS(b), m.status);
wrmsrl(MSR_AMD64_SMCA_MCx_ADDR(b), m.addr);
}
wrmsrl(MSR_AMD64_SMCA_MCx_MISC(b), m.misc);
wrmsrl(MSR_AMD64_SMCA_MCx_SYND(b), m.synd);
} else {
wrmsrl(MSR_IA32_MCx_STATUS(b), m.status);
wrmsrl(MSR_IA32_MCx_ADDR(b), m.addr);
wrmsrl(MSR_IA32_MCx_MISC(b), m.misc);
}
}
static void do_inject(void)
{
u64 mcg_status = 0;
unsigned int cpu = i_mce.extcpu;
u8 b = i_mce.bank;
rdtscll(i_mce.tsc);
if (i_mce.misc)
i_mce.status |= MCI_STATUS_MISCV;
if (i_mce.synd)
i_mce.status |= MCI_STATUS_SYNDV;
if (inj_type == SW_INJ) {
mce_inject_log(&i_mce);
return;
}
/* prep MCE global settings for the injection */
mcg_status = MCG_STATUS_MCIP | MCG_STATUS_EIPV;
if (!(i_mce.status & MCI_STATUS_PCC))
mcg_status |= MCG_STATUS_RIPV;
/*
* Ensure necessary status bits for deferred errors:
* - MCx_STATUS[Deferred]: make sure it is a deferred error
* - MCx_STATUS[UC] cleared: deferred errors are _not_ UC
*/
if (inj_type == DFR_INT_INJ) {
i_mce.status |= MCI_STATUS_DEFERRED;
i_mce.status |= (i_mce.status & ~MCI_STATUS_UC);
}
/*
* For multi node CPUs, logging and reporting of bank 4 errors happens
* only on the node base core. Refer to D18F3x44[NbMcaToMstCpuEn] for
* Fam10h and later BKDGs.
*/
if (static_cpu_has(X86_FEATURE_AMD_DCM) &&
b == 4 &&
boot_cpu_data.x86 < 0x17) {
toggle_nb_mca_mst_cpu(amd_get_nb_id(cpu));
cpu = get_nbc_for_node(amd_get_nb_id(cpu));
}
get_online_cpus();
if (!cpu_online(cpu))
goto err;
toggle_hw_mce_inject(cpu, true);
i_mce.mcgstatus = mcg_status;
i_mce.inject_flags = inj_type;
smp_call_function_single(cpu, prepare_msrs, &i_mce, 0);
toggle_hw_mce_inject(cpu, false);
switch (inj_type) {
case DFR_INT_INJ:
smp_call_function_single(cpu, trigger_dfr_int, NULL, 0);
break;
case THR_INT_INJ:
smp_call_function_single(cpu, trigger_thr_int, NULL, 0);
break;
default:
smp_call_function_single(cpu, trigger_mce, NULL, 0);
}
err:
put_online_cpus();
}
/*
* This denotes into which bank we're injecting and triggers
* the injection, at the same time.
*/
static int inj_bank_set(void *data, u64 val)
{
struct mce *m = (struct mce *)data;
if (val >= n_banks) {
pr_err("Non-existent MCE bank: %llu\n", val);
return -EINVAL;
}
m->bank = val;
do_inject();
return 0;
}
MCE_INJECT_GET(bank);
DEFINE_SIMPLE_ATTRIBUTE(bank_fops, inj_bank_get, inj_bank_set, "%llu\n");
static const char readme_msg[] =
"Description of the files and their usages:\n"
"\n"
"Note1: i refers to the bank number below.\n"
"Note2: See respective BKDGs for the exact bit definitions of the files below\n"
"as they mirror the hardware registers.\n"
"\n"
"status:\t Set MCi_STATUS: the bits in that MSR control the error type and\n"
"\t attributes of the error which caused the MCE.\n"
"\n"
"misc:\t Set MCi_MISC: provide auxiliary info about the error. It is mostly\n"
"\t used for error thresholding purposes and its validity is indicated by\n"
"\t MCi_STATUS[MiscV].\n"
"\n"
"synd:\t Set MCi_SYND: provide syndrome info about the error. Only valid on\n"
"\t Scalable MCA systems, and its validity is indicated by MCi_STATUS[SyndV].\n"
"\n"
"addr:\t Error address value to be written to MCi_ADDR. Log address information\n"
"\t associated with the error.\n"
"\n"
"cpu:\t The CPU to inject the error on.\n"
"\n"
"bank:\t Specify the bank you want to inject the error into: the number of\n"
"\t banks in a processor varies and is family/model-specific, therefore, the\n"
"\t supplied value is sanity-checked. Setting the bank value also triggers the\n"
"\t injection.\n"
"\n"
"flags:\t Injection type to be performed. Writing to this file will trigger a\n"
"\t real machine check, an APIC interrupt or invoke the error decoder routines\n"
"\t for AMD processors.\n"
"\n"
"\t Allowed error injection types:\n"
"\t - \"sw\": Software error injection. Decode error to a human-readable \n"
"\t format only. Safe to use.\n"
"\t - \"hw\": Hardware error injection. Causes the #MC exception handler to \n"
"\t handle the error. Be warned: might cause system panic if MCi_STATUS[PCC] \n"
"\t is set. Therefore, consider setting (debugfs_mountpoint)/mce/fake_panic \n"
"\t before injecting.\n"
"\t - \"df\": Trigger APIC interrupt for Deferred error. Causes deferred \n"
"\t error APIC interrupt handler to handle the error if the feature is \n"
"\t is present in hardware. \n"
"\t - \"th\": Trigger APIC interrupt for Threshold errors. Causes threshold \n"
"\t APIC interrupt handler to handle the error. \n"
"\n";
static ssize_t
inj_readme_read(struct file *filp, char __user *ubuf,
size_t cnt, loff_t *ppos)
{
return simple_read_from_buffer(ubuf, cnt, ppos,
readme_msg, strlen(readme_msg));
}
static const struct file_operations readme_fops = {
.read = inj_readme_read,
};
static struct dfs_node {
char *name;
struct dentry *d;
const struct file_operations *fops;
umode_t perm;
} dfs_fls[] = {
{ .name = "status", .fops = &status_fops, .perm = S_IRUSR | S_IWUSR },
{ .name = "misc", .fops = &misc_fops, .perm = S_IRUSR | S_IWUSR },
{ .name = "addr", .fops = &addr_fops, .perm = S_IRUSR | S_IWUSR },
{ .name = "synd", .fops = &synd_fops, .perm = S_IRUSR | S_IWUSR },
{ .name = "bank", .fops = &bank_fops, .perm = S_IRUSR | S_IWUSR },
{ .name = "flags", .fops = &flags_fops, .perm = S_IRUSR | S_IWUSR },
{ .name = "cpu", .fops = &extcpu_fops, .perm = S_IRUSR | S_IWUSR },
{ .name = "README", .fops = &readme_fops, .perm = S_IRUSR | S_IRGRP | S_IROTH },
};
static int __init debugfs_init(void)
{
unsigned int i;
u64 cap;
rdmsrl(MSR_IA32_MCG_CAP, cap);
n_banks = cap & MCG_BANKCNT_MASK;
dfs_inj = debugfs_create_dir("mce-inject", NULL);
if (!dfs_inj)
return -EINVAL;
for (i = 0; i < ARRAY_SIZE(dfs_fls); i++) {
dfs_fls[i].d = debugfs_create_file(dfs_fls[i].name,
dfs_fls[i].perm,
dfs_inj,
&i_mce,
dfs_fls[i].fops);
if (!dfs_fls[i].d)
goto err_dfs_add;
}
return 0;
err_dfs_add:
while (i-- > 0)
debugfs_remove(dfs_fls[i].d);
debugfs_remove(dfs_inj);
dfs_inj = NULL;
return -ENODEV;
}
static int __init inject_init(void)
{
int err;
if (!alloc_cpumask_var(&mce_inject_cpumask, GFP_KERNEL))
return -ENOMEM;
#ifdef CONFIG_X86_MCELOG_LEGACY
register_mce_write_callback(mce_write);
#endif
register_nmi_handler(NMI_LOCAL, mce_raise_notify, 0, "mce_notify");
err = debugfs_init();
if (err) {
free_cpumask_var(mce_inject_cpumask);
return err;
}
pr_info("Machine check injector initialized\n");
register_mce_write_callback(mce_write);
register_nmi_handler(NMI_LOCAL, mce_raise_notify, 0,
"mce_notify");
return 0;
}
module_init(inject_init);
/*
* Cannot tolerate unloading currently because we cannot
* guarantee all openers of mce_chrdev will get a reference to us.
*/
#ifndef CONFIG_X86_MCELOG_LEGACY
static void __exit inject_exit(void)
{
debugfs_remove_recursive(dfs_inj);
dfs_inj = NULL;
memset(&dfs_fls, 0, sizeof(dfs_fls));
unregister_nmi_handler(NMI_LOCAL, "mce_notify");
free_cpumask_var(mce_inject_cpumask);
}
module_exit(inject_exit);
#endif
MODULE_LICENSE("GPL");
config MCE_AMD_INJ
tristate "Simple MCE injection interface for AMD processors"
depends on RAS && X86_MCE && DEBUG_FS && AMD_NB
default n
help
This is a simple debugfs interface to inject MCEs and test different
aspects of the MCE handling code.
WARNING: Do not even assume this interface is staying stable!
config RAS_CEC
bool "Correctable Errors Collector"
depends on X86_MCE && MEMORY_FAILURE && DEBUG_FS
......@@ -20,4 +10,3 @@ config RAS_CEC
Bear in mind that this is absolutely useless if your platform doesn't
have ECC DIMMs and doesn't have DRAM ECC checking enabled in the BIOS.
obj-$(CONFIG_MCE_AMD_INJ) += mce_amd_inj.o
/*
* A simple MCE injection facility for testing different aspects of the RAS
* code. This driver should be built as module so that it can be loaded
* on production kernels for testing purposes.
*
* This file may be distributed under the terms of the GNU General Public
* License version 2.
*
* Copyright (c) 2010-15: Borislav Petkov <bp@alien8.de>
* Advanced Micro Devices Inc.
*/
#include <linux/kobject.h>
#include <linux/debugfs.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/cpu.h>
#include <linux/string.h>
#include <linux/uaccess.h>
#include <linux/pci.h>
#include <asm/mce.h>
#include <asm/smp.h>
#include <asm/amd_nb.h>
#include <asm/irq_vectors.h>
#include "../kernel/cpu/mcheck/mce-internal.h"
/*
* Collect all the MCi_XXX settings
*/
static struct mce i_mce;
static struct dentry *dfs_inj;
static u8 n_banks;
#define MAX_FLAG_OPT_SIZE 3
#define NBCFG 0x44
enum injection_type {
SW_INJ = 0, /* SW injection, simply decode the error */
HW_INJ, /* Trigger a #MC */
DFR_INT_INJ, /* Trigger Deferred error interrupt */
THR_INT_INJ, /* Trigger threshold interrupt */
N_INJ_TYPES,
};
static const char * const flags_options[] = {
[SW_INJ] = "sw",
[HW_INJ] = "hw",
[DFR_INT_INJ] = "df",
[THR_INT_INJ] = "th",
NULL
};
/* Set default injection to SW_INJ */
static enum injection_type inj_type = SW_INJ;
#define MCE_INJECT_SET(reg) \
static int inj_##reg##_set(void *data, u64 val) \
{ \
struct mce *m = (struct mce *)data; \
\
m->reg = val; \
return 0; \
}
MCE_INJECT_SET(status);
MCE_INJECT_SET(misc);
MCE_INJECT_SET(addr);
MCE_INJECT_SET(synd);
#define MCE_INJECT_GET(reg) \
static int inj_##reg##_get(void *data, u64 *val) \
{ \
struct mce *m = (struct mce *)data; \
\
*val = m->reg; \
return 0; \
}
MCE_INJECT_GET(status);
MCE_INJECT_GET(misc);
MCE_INJECT_GET(addr);
MCE_INJECT_GET(synd);
DEFINE_SIMPLE_ATTRIBUTE(status_fops, inj_status_get, inj_status_set, "%llx\n");
DEFINE_SIMPLE_ATTRIBUTE(misc_fops, inj_misc_get, inj_misc_set, "%llx\n");
DEFINE_SIMPLE_ATTRIBUTE(addr_fops, inj_addr_get, inj_addr_set, "%llx\n");
DEFINE_SIMPLE_ATTRIBUTE(synd_fops, inj_synd_get, inj_synd_set, "%llx\n");
/*
* Caller needs to be make sure this cpu doesn't disappear
* from under us, i.e.: get_cpu/put_cpu.
*/
static int toggle_hw_mce_inject(unsigned int cpu, bool enable)
{
u32 l, h;
int err;
err = rdmsr_on_cpu(cpu, MSR_K7_HWCR, &l, &h);
if (err) {
pr_err("%s: error reading HWCR\n", __func__);
return err;
}
enable ? (l |= BIT(18)) : (l &= ~BIT(18));
err = wrmsr_on_cpu(cpu, MSR_K7_HWCR, l, h);
if (err)
pr_err("%s: error writing HWCR\n", __func__);
return err;
}
static int __set_inj(const char *buf)
{
int i;
for (i = 0; i < N_INJ_TYPES; i++) {
if (!strncmp(flags_options[i], buf, strlen(flags_options[i]))) {
inj_type = i;
return 0;
}
}
return -EINVAL;
}
static ssize_t flags_read(struct file *filp, char __user *ubuf,
size_t cnt, loff_t *ppos)
{
char buf[MAX_FLAG_OPT_SIZE];
int n;
n = sprintf(buf, "%s\n", flags_options[inj_type]);
return simple_read_from_buffer(ubuf, cnt, ppos, buf, n);
}
static ssize_t flags_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
char buf[MAX_FLAG_OPT_SIZE], *__buf;
int err;
if (cnt > MAX_FLAG_OPT_SIZE)
return -EINVAL;
if (copy_from_user(&buf, ubuf, cnt))
return -EFAULT;
buf[cnt - 1] = 0;
/* strip whitespace */
__buf = strstrip(buf);
err = __set_inj(__buf);
if (err) {
pr_err("%s: Invalid flags value: %s\n", __func__, __buf);
return err;
}
*ppos += cnt;
return cnt;
}
static const struct file_operations flags_fops = {
.read = flags_read,
.write = flags_write,
.llseek = generic_file_llseek,
};
/*
* On which CPU to inject?
*/
MCE_INJECT_GET(extcpu);
static int inj_extcpu_set(void *data, u64 val)
{
struct mce *m = (struct mce *)data;
if (val >= nr_cpu_ids || !cpu_online(val)) {
pr_err("%s: Invalid CPU: %llu\n", __func__, val);
return -EINVAL;
}
m->extcpu = val;
return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(extcpu_fops, inj_extcpu_get, inj_extcpu_set, "%llu\n");
static void trigger_mce(void *info)
{
asm volatile("int $18");
}
static void trigger_dfr_int(void *info)
{
asm volatile("int %0" :: "i" (DEFERRED_ERROR_VECTOR));
}
static void trigger_thr_int(void *info)
{
asm volatile("int %0" :: "i" (THRESHOLD_APIC_VECTOR));
}
static u32 get_nbc_for_node(int node_id)
{
struct cpuinfo_x86 *c = &boot_cpu_data;
u32 cores_per_node;
cores_per_node = (c->x86_max_cores * smp_num_siblings) / amd_get_nodes_per_socket();
return cores_per_node * node_id;
}
static void toggle_nb_mca_mst_cpu(u16 nid)
{
struct pci_dev *F3 = node_to_amd_nb(nid)->misc;
u32 val;
int err;
if (!F3)
return;
err = pci_read_config_dword(F3, NBCFG, &val);
if (err) {
pr_err("%s: Error reading F%dx%03x.\n",
__func__, PCI_FUNC(F3->devfn), NBCFG);
return;
}
if (val & BIT(27))
return;
pr_err("%s: Set D18F3x44[NbMcaToMstCpuEn] which BIOS hasn't done.\n",
__func__);
val |= BIT(27);
err = pci_write_config_dword(F3, NBCFG, val);
if (err)
pr_err("%s: Error writing F%dx%03x.\n",
__func__, PCI_FUNC(F3->devfn), NBCFG);
}
static void prepare_msrs(void *info)
{
struct mce m = *(struct mce *)info;
u8 b = m.bank;
wrmsrl(MSR_IA32_MCG_STATUS, m.mcgstatus);
if (boot_cpu_has(X86_FEATURE_SMCA)) {
if (m.inject_flags == DFR_INT_INJ) {
wrmsrl(MSR_AMD64_SMCA_MCx_DESTAT(b), m.status);
wrmsrl(MSR_AMD64_SMCA_MCx_DEADDR(b), m.addr);
} else {
wrmsrl(MSR_AMD64_SMCA_MCx_STATUS(b), m.status);
wrmsrl(MSR_AMD64_SMCA_MCx_ADDR(b), m.addr);
}
wrmsrl(MSR_AMD64_SMCA_MCx_MISC(b), m.misc);
wrmsrl(MSR_AMD64_SMCA_MCx_SYND(b), m.synd);
} else {
wrmsrl(MSR_IA32_MCx_STATUS(b), m.status);
wrmsrl(MSR_IA32_MCx_ADDR(b), m.addr);
wrmsrl(MSR_IA32_MCx_MISC(b), m.misc);
}
}
static void do_inject(void)
{
u64 mcg_status = 0;
unsigned int cpu = i_mce.extcpu;
u8 b = i_mce.bank;
rdtscll(i_mce.tsc);
if (i_mce.misc)
i_mce.status |= MCI_STATUS_MISCV;
if (i_mce.synd)
i_mce.status |= MCI_STATUS_SYNDV;
if (inj_type == SW_INJ) {
mce_inject_log(&i_mce);
return;
}
/* prep MCE global settings for the injection */
mcg_status = MCG_STATUS_MCIP | MCG_STATUS_EIPV;
if (!(i_mce.status & MCI_STATUS_PCC))
mcg_status |= MCG_STATUS_RIPV;
/*
* Ensure necessary status bits for deferred errors:
* - MCx_STATUS[Deferred]: make sure it is a deferred error
* - MCx_STATUS[UC] cleared: deferred errors are _not_ UC
*/
if (inj_type == DFR_INT_INJ) {
i_mce.status |= MCI_STATUS_DEFERRED;
i_mce.status |= (i_mce.status & ~MCI_STATUS_UC);
}
/*
* For multi node CPUs, logging and reporting of bank 4 errors happens
* only on the node base core. Refer to D18F3x44[NbMcaToMstCpuEn] for
* Fam10h and later BKDGs.
*/
if (static_cpu_has(X86_FEATURE_AMD_DCM) &&
b == 4 &&
boot_cpu_data.x86 < 0x17) {
toggle_nb_mca_mst_cpu(amd_get_nb_id(cpu));
cpu = get_nbc_for_node(amd_get_nb_id(cpu));
}
get_online_cpus();
if (!cpu_online(cpu))
goto err;
toggle_hw_mce_inject(cpu, true);
i_mce.mcgstatus = mcg_status;
i_mce.inject_flags = inj_type;
smp_call_function_single(cpu, prepare_msrs, &i_mce, 0);
toggle_hw_mce_inject(cpu, false);
switch (inj_type) {
case DFR_INT_INJ:
smp_call_function_single(cpu, trigger_dfr_int, NULL, 0);
break;
case THR_INT_INJ:
smp_call_function_single(cpu, trigger_thr_int, NULL, 0);
break;
default:
smp_call_function_single(cpu, trigger_mce, NULL, 0);
}
err:
put_online_cpus();
}
/*
* This denotes into which bank we're injecting and triggers
* the injection, at the same time.
*/
static int inj_bank_set(void *data, u64 val)
{
struct mce *m = (struct mce *)data;
if (val >= n_banks) {
pr_err("Non-existent MCE bank: %llu\n", val);
return -EINVAL;
}
m->bank = val;
do_inject();
return 0;
}
MCE_INJECT_GET(bank);
DEFINE_SIMPLE_ATTRIBUTE(bank_fops, inj_bank_get, inj_bank_set, "%llu\n");
static const char readme_msg[] =
"Description of the files and their usages:\n"
"\n"
"Note1: i refers to the bank number below.\n"
"Note2: See respective BKDGs for the exact bit definitions of the files below\n"
"as they mirror the hardware registers.\n"
"\n"
"status:\t Set MCi_STATUS: the bits in that MSR control the error type and\n"
"\t attributes of the error which caused the MCE.\n"
"\n"
"misc:\t Set MCi_MISC: provide auxiliary info about the error. It is mostly\n"
"\t used for error thresholding purposes and its validity is indicated by\n"
"\t MCi_STATUS[MiscV].\n"
"\n"
"synd:\t Set MCi_SYND: provide syndrome info about the error. Only valid on\n"
"\t Scalable MCA systems, and its validity is indicated by MCi_STATUS[SyndV].\n"
"\n"
"addr:\t Error address value to be written to MCi_ADDR. Log address information\n"
"\t associated with the error.\n"
"\n"
"cpu:\t The CPU to inject the error on.\n"
"\n"
"bank:\t Specify the bank you want to inject the error into: the number of\n"
"\t banks in a processor varies and is family/model-specific, therefore, the\n"
"\t supplied value is sanity-checked. Setting the bank value also triggers the\n"
"\t injection.\n"
"\n"
"flags:\t Injection type to be performed. Writing to this file will trigger a\n"
"\t real machine check, an APIC interrupt or invoke the error decoder routines\n"
"\t for AMD processors.\n"
"\n"
"\t Allowed error injection types:\n"
"\t - \"sw\": Software error injection. Decode error to a human-readable \n"
"\t format only. Safe to use.\n"
"\t - \"hw\": Hardware error injection. Causes the #MC exception handler to \n"
"\t handle the error. Be warned: might cause system panic if MCi_STATUS[PCC] \n"
"\t is set. Therefore, consider setting (debugfs_mountpoint)/mce/fake_panic \n"
"\t before injecting.\n"
"\t - \"df\": Trigger APIC interrupt for Deferred error. Causes deferred \n"
"\t error APIC interrupt handler to handle the error if the feature is \n"
"\t is present in hardware. \n"
"\t - \"th\": Trigger APIC interrupt for Threshold errors. Causes threshold \n"
"\t APIC interrupt handler to handle the error. \n"
"\n";
static ssize_t
inj_readme_read(struct file *filp, char __user *ubuf,
size_t cnt, loff_t *ppos)
{
return simple_read_from_buffer(ubuf, cnt, ppos,
readme_msg, strlen(readme_msg));
}
static const struct file_operations readme_fops = {
.read = inj_readme_read,
};
static struct dfs_node {
char *name;
struct dentry *d;
const struct file_operations *fops;
umode_t perm;
} dfs_fls[] = {
{ .name = "status", .fops = &status_fops, .perm = S_IRUSR | S_IWUSR },
{ .name = "misc", .fops = &misc_fops, .perm = S_IRUSR | S_IWUSR },
{ .name = "addr", .fops = &addr_fops, .perm = S_IRUSR | S_IWUSR },
{ .name = "synd", .fops = &synd_fops, .perm = S_IRUSR | S_IWUSR },
{ .name = "bank", .fops = &bank_fops, .perm = S_IRUSR | S_IWUSR },
{ .name = "flags", .fops = &flags_fops, .perm = S_IRUSR | S_IWUSR },
{ .name = "cpu", .fops = &extcpu_fops, .perm = S_IRUSR | S_IWUSR },
{ .name = "README", .fops = &readme_fops, .perm = S_IRUSR | S_IRGRP | S_IROTH },
};
static int __init init_mce_inject(void)
{
unsigned int i;
u64 cap;
rdmsrl(MSR_IA32_MCG_CAP, cap);
n_banks = cap & MCG_BANKCNT_MASK;
dfs_inj = debugfs_create_dir("mce-inject", NULL);
if (!dfs_inj)
return -EINVAL;
for (i = 0; i < ARRAY_SIZE(dfs_fls); i++) {
dfs_fls[i].d = debugfs_create_file(dfs_fls[i].name,
dfs_fls[i].perm,
dfs_inj,
&i_mce,
dfs_fls[i].fops);
if (!dfs_fls[i].d)
goto err_dfs_add;
}
return 0;
err_dfs_add:
while (i-- > 0)
debugfs_remove(dfs_fls[i].d);
debugfs_remove(dfs_inj);
dfs_inj = NULL;
return -ENODEV;
}
static void __exit exit_mce_inject(void)
{
debugfs_remove_recursive(dfs_inj);
dfs_inj = NULL;
memset(&dfs_fls, 0, sizeof(dfs_fls));
}
module_init(init_mce_inject);
module_exit(exit_mce_inject);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Borislav Petkov <bp@alien8.de>");
MODULE_AUTHOR("AMD Inc.");
MODULE_DESCRIPTION("MCE injection facility for RAS testing");
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