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, 3 insertions, 0 deletions

diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c
index eae1ca1caebd..81a28d6662e4 100644
--- a/drivers/edac/edac_mc.c
+++ b/drivers/edac/edac_mc.c
@@ -27,6 +27,7 @@
 #include <linux/list.h>
 #include <linux/sysdev.h>
 #include <linux/ctype.h>
+#include <linux/edac.h>
 #include <asm/uaccess.h>
 #include <asm/page.h>
 #include <asm/edac.h>
@@ -241,6 +242,7 @@ static int add_mc_to_global_list (struct mem_ctl_info *mci)
         }
 
         list_add_tail_rcu(&mci->link, insert_before);
+        atomic_inc(&edac_handlers);
         return 0;
 
 fail0:
@@ -267,6 +269,7 @@ static void complete_mc_list_del(struct rcu_head *head)
 
 static void del_mc_from_global_list(struct mem_ctl_info *mci)
 {
+        atomic_dec(&edac_handlers);
         list_del_rcu(&mci->link);
         init_completion(&mci->complete);
         call_rcu(&mci->rcu, complete_mc_list_del);