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");