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>

1 files changed, 42 insertions, 0 deletions

diff --git a/drivers/edac/edac_stub.c b/drivers/edac/edac_stub.c
new file mode 100644
index 00000000000..91a038d2f65
--- /dev/null
+++ b/drivers/edac/edac_stub.c
@@ -0,0 +1,42 @@
+/*
+ * common EDAC components that must be in kernel
+ *
+ * Author: Dave Jiang <djiang@mvista.com>
+ *
+ * 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.
+ *
+ */
+#include <linux/module.h>
+#include <linux/edac.h>
+#include <asm/atomic.h>
+#include <asm/edac.h>
+
+int edac_op_state = EDAC_OPSTATE_INVAL;
+EXPORT_SYMBOL(edac_op_state);
+
+atomic_t edac_handlers = ATOMIC_INIT(0);
+EXPORT_SYMBOL(edac_handlers);
+
+atomic_t edac_err_assert = ATOMIC_INIT(0);
+EXPORT_SYMBOL(edac_err_assert);
+
+inline int edac_handler_set(void)
+{
+	if (edac_op_state == EDAC_OPSTATE_POLL)
+		return 0;
+
+	return atomic_read(&edac_handlers);
+}
+EXPORT_SYMBOL(edac_handler_set);
+
+/*
+ * handler for NMI type of interrupts to assert error
+ */
+inline void edac_atomic_assert_error(void)
+{
+	atomic_set(&edac_err_assert, 1);
+}
+EXPORT_SYMBOL(edac_atomic_assert_error);