[PATCH 4/4] iommu/arm-smmu-v3: Document nesting-related errata

[Robin Murphy]

Both MMU-600 and MMU-700 have similar errata around TLB invalidation
while both stages of translation are active, which will need some
consideration once nesting support is implemented. For now, though,
it's very easy to make our implicit lack of nesting support explicit
for those cases, so they're less likely to be missed in future.

Signed-off-by: Robin Murphy <robin.murphy at arm.com>
---
 Documentation/arm64/silicon-errata.rst      | 4 ++--
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 5 +++++
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/Documentation/arm64/silicon-errata.rst b/Documentation/arm64/silicon-errata.rst
index 84b58985a061..8a9e33d86dfd 100644
--- a/Documentation/arm64/silicon-errata.rst
+++ b/Documentation/arm64/silicon-errata.rst
@@ -140,9 +140,9 @@ stable kernels.
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | MMU-500         | #841119,826419  | N/A                         |
 +----------------+-----------------+-----------------+-----------------------------+
-| ARM            | MMU-600         | #1076982        | N/A                         |
+| ARM            | MMU-600         | #1076982,1209401| N/A                         |
 +----------------+-----------------+-----------------+-----------------------------+
-| ARM            | MMU-700         | #2812531        | N/A                         |
+| ARM            | MMU-700         | #2268618,2812531| N/A                         |
 +----------------+-----------------+-----------------+-----------------------------+
 +----------------+-----------------+-----------------+-----------------------------+
 | Broadcom       | Brahma-B53      | N/A             | ARM64_ERRATUM_845719        |
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index c4149cf51cb0..6dd4fae3660d 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -3460,11 +3460,16 @@ static void arm_smmu_device_iidr_probe(struct arm_smmu_device *smmu)
 			/* Arm erratum 1076982 */
 			if (variant == 0 && revision <= 2)
 				smmu->features &= ~ARM_SMMU_FEAT_SEV;
+			/* Arm erratum 1209401 */
+			if (variant < 2)
+				smmu->features &= ~ARM_SMMU_FEAT_NESTING;
 			break;
 		case IIDR_PRODUCTID_ARM_MMU_700:
 			/* Arm erratum 2812531 */
 			smmu->features &= ~ARM_SMMU_FEAT_BTM;
 			smmu->options |= ARM_SMMU_OPT_CMDQ_FORCE_SYNC;
+			/* Arm errata 2268618, 2812531 */
+			smmu->features &= ~ARM_SMMU_FEAT_NESTING;
 			break;
 		}
 		break;
-- 
2.39.2.101.g768bb238c484.dirty