From: George Beshers <gbeshers@redhat.com>
Date: Thu, 31 Jul 2008 15:32:53 -0400
Subject: [IA64] Cache error recovery
Message-id: 20080731192658.4411.76538.sendpatchset@dhcp-100-2-194.bos.redhat.com
O-Subject: [RHEL5.3 PATCH 3/19] [IA64] Cache error recovery
Bugzilla: 455308
RH-Acked-by: Prarit Bhargava <prarit@redhat.com>

[patch] Cache error recovery

BZ#455308

Upstream: http://git.kernel.org/?p=linux/kernel/git/aegl/linux-2.6.git;a=commitdiff;h=396e8e76c5eda19184e7b14ba9f1dcd5c4ea8d7e

Similar to memory error recovery, when a cache error is consumed
by a user process terminate the user instead of crashing the system.

Signed-off-by: Russ Anderson (rja@sgi.com)
Acked-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

diff --git a/arch/ia64/kernel/mca_drv.c b/arch/ia64/kernel/mca_drv.c
index c216423..2896814 100644
--- a/arch/ia64/kernel/mca_drv.c
+++ b/arch/ia64/kernel/mca_drv.c
@@ -602,6 +602,8 @@ recover_from_platform_error(slidx_table_t *slidx, peidx_table_t *peidx,
 		default:
 			break;
 		}
+	} else if (psp->cc && !psp->bc) {	/* Cache error */
+		status = recover_from_read_error(slidx, peidx, pbci, sos);
 	}
 
 	return status;
@@ -645,13 +647,6 @@ recover_from_tlb_check(peidx_table_t *peidx)
  * Return value:
  *	1 on Success / 0 on Failure
  */
-/*
- *  Later we try to recover when below all conditions are satisfied.
- *   1. Only one processor error section is exist.
- *   2. BUS_CHECK is exist and the others are not exist.(Except TLB_CHECK)
- *   3. The entry of BUS_CHECK_INFO is 1.
- *   4. "External bus error" flag is set and the others are not set.
- */
 
 static int
 recover_from_processor_error(int platform, slidx_table_t *slidx,
@@ -687,36 +682,31 @@ recover_from_processor_error(int platform, slidx_table_t *slidx,
 	/*
 	 * The cache check and bus check bits have four possible states
 	 *   cc bc
-	 *    0  0	Weird record, not recovered
-	 *    1  0	Cache error, not recovered
-	 *    0  1	I/O error, attempt recovery
 	 *    1  1	Memory error, attempt recovery
+	 *    1  0	Cache error, attempt recovery
+	 *    0  1	I/O error, attempt recovery
+	 *    0  0	Other error type, not recovered
 	 */
-	if (psp->bc == 0 || pbci == NULL)
-		return fatal_mca("No bus check");
+	if (psp->cc == 0 && (psp->bc == 0 || pbci == NULL))
+		return fatal_mca("No cache or bus check");
 
 	/*
-	 * Sorry, we cannot handle so many.
+	 * Cannot handle more than one bus check.
 	 */
 	if (peidx_bus_check_num(peidx) > 1)
 		return fatal_mca("Too many bus checks");
-	/*
-	 * Well, here is only one bus error.
-	 */
+
 	if (pbci->ib)
 		return fatal_mca("Internal Bus error");
-	if (pbci->cc)
-		return fatal_mca("Cache-cache error");
 	if (pbci->eb && pbci->bsi > 0)
 		return fatal_mca("External bus check fatal status");
 
 	/*
-	 * This is a local MCA and estimated as recoverble external bus error.
-	 * (e.g. a load from poisoned memory)
-	 * This means "there are some platform errors".
+	 * This is a local MCA and estimated as a recoverable error.
 	 */
 	if (platform)
 		return recover_from_platform_error(slidx, peidx, pbci, sos);
+
 	/*
 	 * On account of strange SAL error record, we cannot recover.
 	 */