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/*
* 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) 2010-14: 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 <asm/mce.h>
#include "mce_amd.h"
/*
* Collect all the MCi_XXX settings
*/
static struct mce i_mce;
static struct dentry *dfs_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);
#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);
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");
/*
* 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 flags_get(void *data, u64 *val)
{
struct mce *m = (struct mce *)data;
*val = m->inject_flags;
return 0;
}
static int flags_set(void *data, u64 val)
{
struct mce *m = (struct mce *)data;
m->inject_flags = (u8)val;
return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(flags_fops, flags_get, flags_set, "%llu\n");
/*
* 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");
/*
* 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 > 5) {
if (boot_cpu_data.x86 != 0x15 || val > 6) {
pr_err("Non-existent MCE bank: %llu\n", val);
return -EINVAL;
}
}
m->bank = val;
amd_decode_mce(NULL, 0, m);
return 0;
}
static int inj_bank_get(void *data, u64 *val)
{
struct mce *m = (struct mce *)data;
*val = m->bank;
return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(bank_fops, inj_bank_get, inj_bank_set, "%llu\n");
struct dfs_node {
char *name;
struct dentry *d;
const struct file_operations *fops;
} dfs_fls[] = {
{ .name = "status", .fops = &status_fops },
{ .name = "misc", .fops = &misc_fops },
{ .name = "addr", .fops = &addr_fops },
{ .name = "bank", .fops = &bank_fops },
{ .name = "flags", .fops = &flags_fops },
{ .name = "cpu", .fops = &extcpu_fops },
};
static int __init init_mce_inject(void)
{
int i;
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,
S_IRUSR | S_IWUSR,
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 -ENOMEM;
}
static void __exit exit_mce_inject(void)
{
int i;
for (i = 0; i < ARRAY_SIZE(dfs_fls); i++)
debugfs_remove(dfs_fls[i].d);
memset(&dfs_fls, 0, sizeof(dfs_fls));
debugfs_remove(dfs_inj);
dfs_inj = NULL;
}
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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