[PATCH] Fix bug in iommu_context_addr: Always get pointer to lower extended-context-table

["Nan Xiao" <xiaonan19830818-9uewiaClKEY@public.gmane.org>]

Hi David & Joerg,

In iommu_context_addr() function, we always use lower extended-context-table
even though upper-half of the extended root-entry is present.

Signed-off-by: Nan Xiao <nan-IAhD+5PxXTI3bvoXafbxaA@public.gmane.org>
---
 drivers/iommu/intel-iommu.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 0649b94..4213598 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -759,10 +759,11 @@ static inline struct context_entry *iommu_context_addr(struct intel_iommu *iommu
 		if (devfn >= 0x80) {
 			devfn -= 0x80;
 			entry = &root->hi;
-		}
+		} else
+			entry = &root->lo;
 		devfn *= 2;
-	}
-	entry = &root->lo;
+	} else
+		entry = &root->lo;
 	if (*entry & 1)
 		context = phys_to_virt(*entry & VTD_PAGE_MASK);
 	else {
-- 
2.4.3

Best Regards
Nan Xiao