[PATCH retry] intel-iommu:make identity_map default for crash dump

[Dave Young]

kdump kernel sometimes will get DMAR faults which
is caused by random in-flight dma from 1st kernel

Here make the identity_mapping as default for this case

Signed-off-by: Dave Young <dyoung at redhat.com>
---
 drivers/iommu/intel-iommu.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

--- linux-2.6.orig/drivers/iommu/intel-iommu.c	2011-11-01 13:06:18.667505962 +0800
+++ linux-2.6/drivers/iommu/intel-iommu.c	2011-11-01 17:07:50.789137864 +0800
@@ -40,6 +40,7 @@
 #include <linux/tboot.h>
 #include <linux/dmi.h>
 #include <linux/pci-ats.h>
+#include <linux/crash_dump.h>
 #include <asm/cacheflush.h>
 #include <asm/iommu.h>
 
@@ -2488,7 +2489,7 @@ static int __init init_dmars(void)
 		}
 	}
 
-	if (iommu_pass_through)
+	if (iommu_pass_through || is_kdump_kernel())
 		iommu_identity_mapping |= IDENTMAP_ALL;
 
 #ifdef CONFIG_INTEL_IOMMU_BROKEN_GFX_WA