x86/ras: Move AMD MCE injector to arch/x86/ras/
This is an x86-specific module and would benefit from being
closer to the arch code. Move it there. Update copyright while
at it.
Signed-off-by: Borislav Petkov <bp@suse.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/1439396985-12812-14-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/x86/ras/mce_amd_inj.c b/arch/x86/ras/mce_amd_inj.c
new file mode 100644
index 0000000..17e35b5
--- /dev/null
+++ b/arch/x86/ras/mce_amd_inj.c
@@ -0,0 +1,375 @@
+/*
+ * 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 <asm/mce.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
+
+enum injection_type {
+ SW_INJ = 0, /* SW injection, simply decode the error */
+ HW_INJ, /* Trigger a #MC */
+ N_INJ_TYPES,
+};
+
+static const char * const flags_options[] = {
+ [SW_INJ] = "sw",
+ [HW_INJ] = "hw",
+ 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);
+
+#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 __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;
+ size_t ret;
+
+ if (cnt > MAX_FLAG_OPT_SIZE)
+ cnt = MAX_FLAG_OPT_SIZE;
+
+ ret = cnt;
+
+ 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 += ret;
+
+ return ret;
+}
+
+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 do_inject(void)
+{
+ u64 mcg_status = 0;
+ unsigned int cpu = i_mce.extcpu;
+ u8 b = i_mce.bank;
+
+ if (i_mce.misc)
+ i_mce.status |= MCI_STATUS_MISCV;
+
+ 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;
+
+ get_online_cpus();
+ if (!cpu_online(cpu))
+ goto err;
+
+ toggle_hw_mce_inject(cpu, true);
+
+ wrmsr_on_cpu(cpu, MSR_IA32_MCG_STATUS,
+ (u32)mcg_status, (u32)(mcg_status >> 32));
+
+ wrmsr_on_cpu(cpu, MSR_IA32_MCx_STATUS(b),
+ (u32)i_mce.status, (u32)(i_mce.status >> 32));
+
+ wrmsr_on_cpu(cpu, MSR_IA32_MCx_ADDR(b),
+ (u32)i_mce.addr, (u32)(i_mce.addr >> 32));
+
+ wrmsr_on_cpu(cpu, MSR_IA32_MCx_MISC(b),
+ (u32)i_mce.misc, (u32)(i_mce.misc >> 32));
+
+ toggle_hw_mce_inject(cpu, false);
+
+ 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"
+"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"
+"\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 = "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)
+{
+ 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 -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");