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From:   Easwar Hariharan <eahariha@linux.microsoft.com>
To:     stable@vger.kernel.org
Cc:     easwar.hariharan@microsoft.com,
        Robin Murphy <robin.murphy@arm.com>,
        Nicolin Chen <nicolinc@nvidia.com>,
        Will Deacon <will@kernel.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Joerg Roedel <joro@8bytes.org>,
        Sasha Levin <sashal@kernel.org>,
        Tomas Krcka <krckatom@amazon.de>,
        Yicong Yang <yangyicong@hisilicon.com>,
        linux-arm-kernel@lists.infradead.org (moderated list:ARM64 PORT
        (AARCH64 ARCHITECTURE)),
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        iommu@lists.linux-foundation.org (open list:IOMMU DRIVERS),
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Subject: [PATCH v2 6.1 4/4] iommu/arm-smmu-v3: Document nesting-related errata
Date:   Wed,  2 Aug 2023 17:09:11 +0000
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From: Robin Murphy <robin.murphy@arm.com>

commit 0bfbfc526c70606bf0fad302e4821087cbecfaf4 upstream

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@arm.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/696da78d32bb4491f898f11b0bb4d850a8aa7c6a.1683731256.git.robin.murphy@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Easwar Hariharan <eahariha@linux.microsoft.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 322df8abbc0e..83a75e16e54d 100644
--- a/Documentation/arm64/silicon-errata.rst
+++ b/Documentation/arm64/silicon-errata.rst
@@ -122,9 +122,9 @@ 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 7cec4a457d91..340ef116d574 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -3487,11 +3487,16 @@ 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;
-- 
2.25.1