[RFC PATCH 6/6] iommu/arm-smmu: Update bindings document for smmu-inst-as-data DT option
From: Anup Patel
Date: Wed Jan 27 2016 - 00:22:20 EST
This patch adds info about 'smmu-inst-as-data' DT option in ARM
SMMUv1/SMMUv2 driver bindings document.
Signed-off-by: Anup Patel <anup.patel@xxxxxxxxxxxx>
Reviewed-by: Ray Jui <rjui@xxxxxxxxxxxx>
Reviewed-by: Vikram Prakash <vikramp@xxxxxxxxxxxx>
Reviewed-by: Scott Branden <sbranden@xxxxxxxxxxxx>
Documentation/devicetree/bindings/iommu/arm,smmu.txt | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
index 7180745..4c4d03e 100644
@@ -49,6 +49,14 @@ conditions.
NOTE: this only applies to the SMMU itself, not
masters connected upstream of the SMMU.
+- smmu-inst-as-data : Treat privilege/unprivilege instruction fetch as
+ data read for SMMUv2. The SMMU driver by default provides
+ unprivilege read-write permission in page table entries.
+ For SMMUv2, privilege instruction fetch from MMU masters
+ will cause a context fault for unprivilege read-write
+ pages. To allow both privilege and unprivilege instruction
+ fetch, we have to forcefully treat it as data read.
- calxeda,smmu-secure-config-access : Enable proper handling of buggy
implementations that always use secure access to
SMMU configuration registers. In this case non-secure