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>

drivers/edac/Kconfig

@@ -39,7 +39,7 @@ config EDAC_DEBUG
 	  there're four debug levels (x=0,1,2,3 from low to high).
 	  Usually you should select 'N'.
 
- config EDAC_DECODE_MCE
+config EDAC_DECODE_MCE
 	tristate "Decode MCEs in human-readable form (only on AMD for now)"
 	depends on CPU_SUP_AMD && X86_MCE
 	default y
@@ -51,6 +51,16 @@ config EDAC_DEBUG
 	  which occur really early upon boot, before the module infrastructure
 	  has been initialized.
 
+config EDAC_MCE_INJ
+	tristate "Simple MCE injection interface over /sysfs"
+	depends on EDAC_DECODE_MCE
+	default n
+	help
+	  This is a simple interface to inject MCEs over /sysfs and test
+	  the MCE decoding code in EDAC.
+
+	  This is currently AMD-only.
+
 config EDAC_MM_EDAC
 	tristate "Main Memory EDAC (Error Detection And Correction) reporting"
 	help
@@ -72,7 +82,7 @@ config EDAC_AMD64
 	  Families of Memory Controllers (K8, F10h and F11h)
 
 config EDAC_AMD64_ERROR_INJECTION
-	bool "Sysfs Error Injection facilities"
+	bool "Sysfs HW Error injection facilities"
 	depends on EDAC_AMD64
 	help
 	  Recent Opterons (Family 10h and later) provide for Memory Error

drivers/edac/Makefile

@@ -17,6 +17,8 @@ ifdef CONFIG_PCI
 edac_core-objs	+= edac_pci.o edac_pci_sysfs.o
 endif
 
+obj-$(CONFIG_EDAC_MCE_INJ)		+= mce_amd_inj.o
+
 obj-$(CONFIG_EDAC_DECODE_MCE)		+= edac_mce_amd.o
 
 obj-$(CONFIG_EDAC_AMD76X)		+= amd76x_edac.o

drivers/edac/amd64_edac.h

@@ -486,7 +486,7 @@ extern const char *ext_msgs[32];
 extern const char *htlink_msgs[8];
 
 #ifdef CONFIG_EDAC_DEBUG
-#define NUM_DBG_ATTRS 9
+#define NUM_DBG_ATTRS 5
 #else
 #define NUM_DBG_ATTRS 0
 #endif

drivers/edac/amd64_edac_dbg.c

 #include "amd64_edac.h"
 
-/*
- * accept a hex value and store it into the virtual error register file, field:
- * nbeal and nbeah. Assume virtual error values have already been set for: NBSL,
- * NBSH and NBCFG. Then proceed to map the error values to a MC, CSROW and
- * CHANNEL
- */
-static ssize_t amd64_nbea_store(struct mem_ctl_info *mci, const char *data,
-				size_t count)
-{
-	struct amd64_pvt *pvt = mci->pvt_info;
-	u64 value;
-	int ret = 0;
-	struct mce m;
-
-	ret = strict_strtoull(data, 16, &value);
-	if (ret != -EINVAL) {
-		struct err_regs *regs = &pvt->ctl_error_info;
-
-		debugf0("received NBEA= 0x%llx\n", value);
-
-		/* place the value into the virtual error packet */
-		pvt->ctl_error_info.nbeal = (u32) value;
-		value >>= 32;
-		pvt->ctl_error_info.nbeah = (u32) value;
-
-		m.addr   = value;
-		m.status = regs->nbsl | ((u64)regs->nbsh << 32);
-
-		/* Process the Mapping request */
-		/* TODO: Add race prevention */
-		amd_decode_nb_mce(pvt->mc_node_id, &m, regs->nbcfg);
-
-		return count;
-	}
-	return ret;
+#define EDAC_DCT_ATTR_SHOW(reg)						\
+static ssize_t amd64_##reg##_show(struct mem_ctl_info *mci, char *data)	\
+{									\
+	struct amd64_pvt *pvt = mci->pvt_info;				\
+		return sprintf(data, "0x%016llx\n", (u64)pvt->reg);	\
 }
 
-/* display back what the last NBEA (MCA NB Address (MC4_ADDR)) was written */
-static ssize_t amd64_nbea_show(struct mem_ctl_info *mci, char *data)
-{
-	struct amd64_pvt *pvt = mci->pvt_info;
-	u64 value;
-
-	value = pvt->ctl_error_info.nbeah;
-	value <<= 32;
-	value |= pvt->ctl_error_info.nbeal;
-
-	return sprintf(data, "%llx\n", value);
-}
-
-/* store the NBSL (MCA NB Status Low (MC4_STATUS)) value user desires */
-static ssize_t amd64_nbsl_store(struct mem_ctl_info *mci, const char *data,
-				size_t count)
-{
-	struct amd64_pvt *pvt = mci->pvt_info;
-	unsigned long value;
-	int ret = 0;
-
-	ret = strict_strtoul(data, 16, &value);
-	if (ret != -EINVAL) {
-		debugf0("received NBSL= 0x%lx\n", value);
-
-		pvt->ctl_error_info.nbsl = (u32) value;
-
-		return count;
-	}
-	return ret;
-}
-
-/* display back what the last NBSL value written */
-static ssize_t amd64_nbsl_show(struct mem_ctl_info *mci, char *data)
-{
-	struct amd64_pvt *pvt = mci->pvt_info;
-	u32 value;
-
-	value = pvt->ctl_error_info.nbsl;
-
-	return sprintf(data, "%x\n", value);
-}
-
-/* store the NBSH (MCA NB Status High) value user desires */
-static ssize_t amd64_nbsh_store(struct mem_ctl_info *mci, const char *data,
-				size_t count)
-{
-	struct amd64_pvt *pvt = mci->pvt_info;
-	unsigned long value;
-	int ret = 0;
-
-	ret = strict_strtoul(data, 16, &value);
-	if (ret != -EINVAL) {
-		debugf0("received NBSH= 0x%lx\n", value);
-
-		pvt->ctl_error_info.nbsh = (u32) value;
-
-		return count;
-	}
-	return ret;
-}
-
-/* display back what the last NBSH value written */
-static ssize_t amd64_nbsh_show(struct mem_ctl_info *mci, char *data)
-{
-	struct amd64_pvt *pvt = mci->pvt_info;
-	u32 value;
-
-	value = pvt->ctl_error_info.nbsh;
-
-	return sprintf(data, "%x\n", value);
-}
-
-/* accept and store the NBCFG (MCA NB Configuration) value user desires */
-static ssize_t amd64_nbcfg_store(struct mem_ctl_info *mci,
-					const char *data, size_t count)
-{
-	struct amd64_pvt *pvt = mci->pvt_info;
-	unsigned long value;
-	int ret = 0;
-
-	ret = strict_strtoul(data, 16, &value);
-	if (ret != -EINVAL) {
-		debugf0("received NBCFG= 0x%lx\n", value);
-
-		pvt->ctl_error_info.nbcfg = (u32) value;
-
-		return count;
-	}
-	return ret;
-}
-
-/* various show routines for the controls of a MCI */
-static ssize_t amd64_nbcfg_show(struct mem_ctl_info *mci, char *data)
-{
-	struct amd64_pvt *pvt = mci->pvt_info;
-
-	return sprintf(data, "%x\n", pvt->ctl_error_info.nbcfg);
-}
-
-
-static ssize_t amd64_dhar_show(struct mem_ctl_info *mci, char *data)
-{
-	struct amd64_pvt *pvt = mci->pvt_info;
-
-	return sprintf(data, "%x\n", pvt->dhar);
-}
-
-
-static ssize_t amd64_dbam_show(struct mem_ctl_info *mci, char *data)
-{
-	struct amd64_pvt *pvt = mci->pvt_info;
-
-	return sprintf(data, "%x\n", pvt->dbam0);
-}
-
-
-static ssize_t amd64_topmem_show(struct mem_ctl_info *mci, char *data)
-{
-	struct amd64_pvt *pvt = mci->pvt_info;
-
-	return sprintf(data, "%llx\n", pvt->top_mem);
-}
-
-
-static ssize_t amd64_topmem2_show(struct mem_ctl_info *mci, char *data)
-{
-	struct amd64_pvt *pvt = mci->pvt_info;
-
-	return sprintf(data, "%llx\n", pvt->top_mem2);
-}
+EDAC_DCT_ATTR_SHOW(dhar);
+EDAC_DCT_ATTR_SHOW(dbam0);
+EDAC_DCT_ATTR_SHOW(top_mem);
+EDAC_DCT_ATTR_SHOW(top_mem2);
 
 static ssize_t amd64_hole_show(struct mem_ctl_info *mci, char *data)
 {
@@ -186,38 +29,6 @@ static ssize_t amd64_hole_show(struct mem_ctl_info *mci, char *data)
  */
 struct mcidev_sysfs_attribute amd64_dbg_attrs[] = {
 
-	{
-		.attr = {
-			.name = "nbea_ctl",
-			.mode = (S_IRUGO | S_IWUSR)
-		},
-		.show = amd64_nbea_show,
-		.store = amd64_nbea_store,
-	},
-	{
-		.attr = {
-			.name = "nbsl_ctl",
-			.mode = (S_IRUGO | S_IWUSR)
-		},
-		.show = amd64_nbsl_show,
-		.store = amd64_nbsl_store,
-	},
-	{
-		.attr = {
-			.name = "nbsh_ctl",
-			.mode = (S_IRUGO | S_IWUSR)
-		},
-		.show = amd64_nbsh_show,
-		.store = amd64_nbsh_store,
-	},
-	{
-		.attr = {
-			.name = "nbcfg_ctl",
-			.mode = (S_IRUGO | S_IWUSR)
-		},
-		.show = amd64_nbcfg_show,
-		.store = amd64_nbcfg_store,
-	},
 	{
 		.attr = {
 			.name = "dhar",
@@ -231,7 +42,7 @@ struct mcidev_sysfs_attribute amd64_dbg_attrs[] = {
 			.name = "dbam",
 			.mode = (S_IRUGO)
 		},
-		.show = amd64_dbam_show,
+		.show = amd64_dbam0_show,
 		.store = NULL,
 	},
 	{
@@ -239,7 +50,7 @@ struct mcidev_sysfs_attribute amd64_dbg_attrs[] = {
 			.name = "topmem",
 			.mode = (S_IRUGO)
 		},
-		.show = amd64_topmem_show,
+		.show = amd64_top_mem_show,
 		.store = NULL,
 	},
 	{
@@ -247,7 +58,7 @@ struct mcidev_sysfs_attribute amd64_dbg_attrs[] = {
 			.name = "topmem2",
 			.mode = (S_IRUGO)
 		},
-		.show = amd64_topmem2_show,
+		.show = amd64_top_mem2_show,
 		.store = NULL,
 	},
 	{

drivers/edac/edac_mce_amd.c

@@ -324,8 +324,7 @@ static inline void amd_decode_err_code(u16 ec)
 		pr_emerg(HW_ERR "Huh? Unknown MCE error 0x%x\n", ec);
 }
 
-static int amd_decode_mce(struct notifier_block *nb, unsigned long val,
-			   void *data)
+int amd_decode_mce(struct notifier_block *nb, unsigned long val, void *data)
 {
 	struct mce *m = (struct mce *)data;
 	int node, ecc;
@@ -379,6 +378,7 @@ static int amd_decode_mce(struct notifier_block *nb, unsigned long val,
 
 	return NOTIFY_STOP;
 }
+EXPORT_SYMBOL_GPL(amd_decode_mce);
 
 static struct notifier_block amd_mce_dec_nb = {
 	.notifier_call	= amd_decode_mce,

drivers/edac/edac_mce_amd.h

 #ifndef _EDAC_MCE_AMD_H
 #define _EDAC_MCE_AMD_H
 
+#include <linux/notifier.h>
+
 #include <asm/mce.h>
 
 #define ERROR_CODE(x)			((x) & 0xffff)
@@ -61,10 +63,10 @@ struct err_regs {
 	u32 nbeal;
 };
 
-
 void amd_report_gart_errors(bool);
 void amd_register_ecc_decoder(void (*f)(int, struct mce *, u32));
 void amd_unregister_ecc_decoder(void (*f)(int, struct mce *, u32));
 void amd_decode_nb_mce(int, struct mce *, u32);
+int amd_decode_mce(struct notifier_block *nb, unsigned long val, void *data);
 
 #endif /* _EDAC_MCE_AMD_H */

drivers/edac/mce_amd_inj.c

+/*
+ * 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");