edac_mce: Add an interface driver to report mce errors via edac

edac_mce module is an interface module that gets mcelog data and
forwards to any registered edac module that expects to receive data via
mce.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

arch/x86/kernel/cpu/mcheck/mce.c

@@ -36,6 +36,7 @@
 #include <linux/fs.h>
 #include <linux/mm.h>
 #include <linux/debugfs.h>
+#include <linux/edac_mce.h>
 
 #include <asm/processor.h>
 #include <asm/hw_irq.h>
@@ -168,6 +169,15 @@ void mce_log(struct mce *mce)
 	for (;;) {
 		entry = rcu_dereference_check_mce(mcelog.next);
 		for (;;) {
+			/*
+			 * If edac_mce is enabled, it will check the error type
+			 * and will process it, if it is a known error.
+			 * Otherwise, the error will be sent through mcelog
+			 * interface
+			 */
+			if (edac_mce_parse(mce))
+				return;
+
 			/*
 			 * When the buffer fills up discard new entries.
 			 * Assume that the earlier errors are the more

drivers/edac/Kconfig

@@ -69,6 +69,9 @@ config EDAC_MM_EDAC
 	  occurred so that a particular failing memory module can be
 	  replaced.  If unsure, select 'Y'.
 
+config EDAC_MCE
+	tristate
+
 config EDAC_AMD64
 	tristate "AMD64 (Opteron, Athlon64) K8, F10h, F11h"
 	depends on EDAC_MM_EDAC && K8_NB && X86_64 && PCI && EDAC_DECODE_MCE
@@ -169,9 +172,12 @@ config EDAC_I5400
 config EDAC_I7CORE
 	tristate "Intel i7 Core (Nehalem) processors"
 	depends on EDAC_MM_EDAC && PCI && X86
+	select EDAC_MCE
 	help
 	  Support for error detection and correction the Intel
-	  i7 Core (Nehalem) Integrated Memory Controller
+	  i7 Core (Nehalem) Integrated Memory Controller that exists on
+	  newer processors like i7 Core, i7 Core Extreme, Xeon 35xx
+	  and Xeon 55xx processors.
 
 config EDAC_I82860
 	tristate "Intel 82860"

drivers/edac/Makefile

@@ -8,6 +8,7 @@
 
 obj-$(CONFIG_EDAC)			:= edac_stub.o
 obj-$(CONFIG_EDAC_MM_EDAC)		+= edac_core.o
+obj-$(CONFIG_EDAC_MCE)			+= edac_mce.o
 
 edac_core-objs	:= edac_mc.o edac_device.o edac_mc_sysfs.o edac_pci_sysfs.o
 edac_core-objs	+= edac_module.o edac_device_sysfs.o

drivers/edac/edac_mce.c

@@ -0,0 +1,58 @@
+/* Provides edac interface to mcelog events
+ *
+ * This file may be distributed under the terms of the
+ * GNU General Public License version 2.
+ *
+ * Copyright (c) 2009 by:
+ *	 Mauro Carvalho Chehab <mchehab@redhat.com>
+ *
+ * Red Hat Inc. http://www.redhat.com
+ */
+
+#include <linux/module.h>
+#include <linux/edac_mce.h>
+#include <asm/mce.h>
+
+int edac_mce_enabled;
+EXPORT_SYMBOL_GPL(edac_mce_enabled);
+
+
+/*
+ * Extension interface
+ */
+
+static LIST_HEAD(edac_mce_list);
+static DEFINE_MUTEX(edac_mce_lock);
+
+int edac_mce_register(struct edac_mce *edac_mce)
+{
+	mutex_lock(&edac_mce_lock);
+	list_add_tail(&edac_mce->list, &edac_mce_list);
+	mutex_unlock(&edac_mce_lock);
+	return 0;
+}
+EXPORT_SYMBOL(edac_mce_register);
+
+void edac_mce_unregister(struct edac_mce *edac_mce)
+{
+	mutex_lock(&edac_mce_lock);
+	list_del(&edac_mce->list);
+	mutex_unlock(&edac_mce_lock);
+}
+EXPORT_SYMBOL(edac_mce_unregister);
+
+
+
+int edac_mce_queue(struct mce *mce)
+{
+	struct edac_mce *edac_mce;
+
+	list_for_each_entry(edac_mce, &edac_mce_list, list) {
+		if (edac_mce->check_error(edac_mce->priv, mce))
+			return 1;
+	}
+
+	/* Nobody queued the error */
+	return 0;
+}
+EXPORT_SYMBOL_GPL(edac_mce_queue);

include/linux/edac_mce.h

@@ -0,0 +1,31 @@
+/* Provides edac interface to mcelog events
+ *
+ * This file may be distributed under the terms of the
+ * GNU General Public License version 2.
+ *
+ * Copyright (c) 2009 by:
+ *	 Mauro Carvalho Chehab <mchehab@redhat.com>
+ *
+ * Red Hat Inc. http://www.redhat.com
+ */
+
+#if defined(CONFIG_EDAC_MCE) || \
+			(defined(CONFIG_EDAC_MCE_MODULE) && defined(MODULE))
+
+#include <asm/mce.h>
+#include <linux/list.h>
+
+struct edac_mce {
+	struct list_head list;
+
+	void *priv;
+	int (*check_error)(void *priv, struct mce *mce);
+};
+
+int edac_mce_register(struct edac_mce *edac_mce);
+void edac_mce_unregister(struct edac_mce *edac_mce);
+int edac_mce_parse(struct mce *mce);
+
+#else
+#define edac_mce_parse(mce) (0)
+#endif