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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/edac/mce_amd_inj.c
Initial import
Diffstat (limited to 'drivers/edac/mce_amd_inj.c')
-rw-r--r--drivers/edac/mce_amd_inj.c262
1 files changed, 262 insertions, 0 deletions
diff --git a/drivers/edac/mce_amd_inj.c b/drivers/edac/mce_amd_inj.c
new file mode 100644
index 000000000..f7681b553
--- /dev/null
+++ b/drivers/edac/mce_amd_inj.c
@@ -0,0 +1,262 @@
+/*
+ * 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 <linux/cpu.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");
+
+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.inject_flags & MCJ_EXCEPTION)) {
+ amd_decode_mce(NULL, 0, &i_mce);
+ return;
+ }
+
+ get_online_cpus();
+ if (!cpu_online(cpu))
+ goto err;
+
+ /* 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;
+
+ 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 > 5) {
+ if (boot_cpu_data.x86 != 0x15 || val > 6) {
+ pr_err("Non-existent MCE bank: %llu\n", val);
+ return -EINVAL;
+ }
+ }
+
+ m->bank = val;
+ do_inject();
+
+ 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");
+
+static 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");