drivers/edac: add new nmi rescan

Provides a way for NMI reported errors on x86 to notify the EDAC
subsystem pending ECC errors by writing to a software state variable.

Here's the reworked patch. I added an EDAC stub to the kernel so we can
have variables that are in the kernel even if EDAC is a module. I also
implemented the idea of using the chip driver to select error detection
mode via module parameter and eliminate the kernel compile option.
Please review/test. Thx!

Also, I only made changes to some of the chipset drivers since I am
unfamiliar with the other ones. We can add similar changes as we go.

Signed-off-by: Dave Jiang <djiang@mvista.com>
Signed-off-by: Douglas Thompson <dougthompson@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/edac.h b/include/linux/edac.h
new file mode 100644
index 0000000..c8b92d7
--- /dev/null
+++ b/include/linux/edac.h
@@ -0,0 +1,29 @@
+/*
+ * Generic EDAC defs
+ *
+ * Author: Dave Jiang <djiang@mvista.com>
+ *
+ * 2006-2007 (c) MontaVista Software, Inc. This file is licensed under
+ * the terms of the GNU General Public License version 2. This program
+ * is licensed "as is" without any warranty of any kind, whether express
+ * or implied.
+ *
+ */
+#ifndef _LINUX_EDAC_H_
+#define _LINUX_EDAC_H_
+
+#include <asm/atomic.h>
+
+#define EDAC_OPSTATE_INVAL	-1
+#define EDAC_OPSTATE_POLL	0
+#define EDAC_OPSTATE_NMI	1
+#define EDAC_OPSTATE_INT	2
+
+extern int edac_op_state;
+extern atomic_t edac_handlers;
+extern atomic_t edac_err_assert;
+
+extern int edac_handler_set(void);
+extern void edac_atomic_assert_error(void);
+
+#endif