EDAC, MCE: Rework MCE injection

Add sysfs injection facilities for testing of the MCE decoding code.
Remove large parts of amd64_edac_dbg.c, as a result, which did only
NB MCE injection anyway and the new injection code supports that
functionality already.

Add an injection module so that MCE decoding code in production kernels
like those in RHEL and SLES can be tested.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>

1 files changed, 171 insertions, 0 deletions

diff --git a/drivers/edac/mce_amd_inj.c b/drivers/edac/mce_amd_inj.c
new file mode 100644
index 0000000..0e4f2dc
--- /dev/null
+++ b/drivers/edac/mce_amd_inj.c
@@ -0,0 +1,171 @@
+/*
+ * A simple MCE injection facility for testing the MCE decoding 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:  Borislav Petkov <borislav.petkov@amd.com>
+ *			Advanced Micro Devices Inc.
+ */
+
+#include <linux/kobject.h>
+#include <linux/sysdev.h>
+#include <linux/edac.h>
+#include <asm/mce.h>
+
+#include "edac_mce_amd.h"
+
+struct edac_mce_attr {
+	struct attribute attr;
+	ssize_t (*show) (struct kobject *kobj, struct edac_mce_attr *attr, char *buf);
+	ssize_t (*store)(struct kobject *kobj, struct edac_mce_attr *attr,
+			 const char *buf, size_t count);
+};
+
+#define EDAC_MCE_ATTR(_name, _mode, _show, _store)			\
+static struct edac_mce_attr mce_attr_##_name = __ATTR(_name, _mode, _show, _store)
+
+static struct kobject *mce_kobj;
+
+/*
+ * Collect all the MCi_XXX settings
+ */
+static struct mce i_mce;
+
+#define MCE_INJECT_STORE(reg)						\
+static ssize_t edac_inject_##reg##_store(struct kobject *kobj,		\
+					 struct edac_mce_attr *attr,	\
+					 const char *data, size_t count)\
+{									\
+	int ret = 0;							\
+	unsigned long value;						\
+									\
+	ret = strict_strtoul(data, 16, &value);				\
+	if (ret < 0)							\
+		printk(KERN_ERR "Error writing MCE " #reg " field.\n");	\
+									\
+	i_mce.reg = value;						\
+									\
+	return count;							\
+}
+
+MCE_INJECT_STORE(status);
+MCE_INJECT_STORE(misc);
+MCE_INJECT_STORE(addr);
+
+#define MCE_INJECT_SHOW(reg)						\
+static ssize_t edac_inject_##reg##_show(struct kobject *kobj,		\
+					struct edac_mce_attr *attr,	\
+					char *buf)			\
+{									\
+	return sprintf(buf, "0x%016llx\n", i_mce.reg);			\
+}
+
+MCE_INJECT_SHOW(status);
+MCE_INJECT_SHOW(misc);
+MCE_INJECT_SHOW(addr);
+
+EDAC_MCE_ATTR(status, 0644, edac_inject_status_show, edac_inject_status_store);
+EDAC_MCE_ATTR(misc, 0644, edac_inject_misc_show, edac_inject_misc_store);
+EDAC_MCE_ATTR(addr, 0644, edac_inject_addr_show, edac_inject_addr_store);
+
+/*
+ * This denotes into which bank we're injecting and triggers
+ * the injection, at the same time.
+ */
+static ssize_t edac_inject_bank_store(struct kobject *kobj,
+				      struct edac_mce_attr *attr,
+				      const char *data, size_t count)
+{
+	int ret = 0;
+	unsigned long value;
+
+	ret = strict_strtoul(data, 10, &value);
+	if (ret < 0) {
+		printk(KERN_ERR "Invalid bank value!\n");
+		return -EINVAL;
+	}
+
+	if (value > 5) {
+		printk(KERN_ERR "Non-existant MCE bank: %lu\n", value);
+		return -EINVAL;
+	}
+
+	i_mce.bank = value;
+
+	amd_decode_mce(NULL, 0, &i_mce);
+
+	return count;
+}
+
+static ssize_t edac_inject_bank_show(struct kobject *kobj,
+				     struct edac_mce_attr *attr, char *buf)
+{
+	return sprintf(buf, "%d\n", i_mce.bank);
+}
+
+EDAC_MCE_ATTR(bank, 0644, edac_inject_bank_show, edac_inject_bank_store);
+
+static struct edac_mce_attr *sysfs_attrs[] = { &mce_attr_status, &mce_attr_misc,
+					       &mce_attr_addr, &mce_attr_bank
+};
+
+static int __init edac_init_mce_inject(void)
+{
+	struct sysdev_class *edac_class = NULL;
+	int i, err = 0;
+
+	edac_class = edac_get_sysfs_class();
+	if (!edac_class)
+		return -EINVAL;
+
+	mce_kobj = kobject_create_and_add("mce", &edac_class->kset.kobj);
+	if (!mce_kobj) {
+		printk(KERN_ERR "Error creating a mce kset.\n");
+		err = -ENOMEM;
+		goto err_mce_kobj;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(sysfs_attrs); i++) {
+		err = sysfs_create_file(mce_kobj, &sysfs_attrs[i]->attr);
+		if (err) {
+			printk(KERN_ERR "Error creating %s in sysfs.\n",
+					sysfs_attrs[i]->attr.name);
+			goto err_sysfs_create;
+		}
+	}
+	return 0;
+
+err_sysfs_create:
+	while (i-- >= 0)
+		sysfs_remove_file(mce_kobj, &sysfs_attrs[i]->attr);
+
+	kobject_del(mce_kobj);
+
+err_mce_kobj:
+	edac_put_sysfs_class();
+
+	return err;
+}
+
+static void __exit edac_exit_mce_inject(void)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(sysfs_attrs); i++)
+		sysfs_remove_file(mce_kobj, &sysfs_attrs[i]->attr);
+
+	kobject_del(mce_kobj);
+
+	edac_put_sysfs_class();
+}
+
+module_init(edac_init_mce_inject);
+module_exit(edac_exit_mce_inject);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Borislav Petkov <borislav.petkov@amd.com>");
+MODULE_AUTHOR("AMD Inc.");
+MODULE_DESCRIPTION("MCE injection facility for testing MCE decoding");