diff options
| author | Ashish Mhetre <amhetre@nvidia.com> | 2026-07-26 08:19:04 +0000 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2026-07-28 09:49:47 +0000 |
| commit | 06b15ddcfbc04ddd1cf6b339cf80779a68cf9efe (patch) | |
| tree | f677272fe15c485c14967fed4b7d8d17d138a957 | |
| parent | d501d66815eeb0e6641ce61e7eeb2beea19eadf5 (diff) | |
iommu/arm-smmu-v3: Enable CFGI/TLBI-repeat workaround on Tegra264
Nvidia Tegra264 SMMU is affected by an erratum where a TLB entry can
survive an invalidation that races with concurrent traffic targeting
the same entry. The hardware-recommended software workaround is to
issue every CFGI/TLBI command (each followed by CMD_SYNC) twice, and
that infrastructure is already in place behind
arm_smmu_erratum_repeat_tlbi_cfgi_key.
Neither IDR nor IIDR flags this Tegra264-specific bug, so hardware
detection is not possible. Tegra264 is device-tree-only (no ACPI/IORT
support) and already has a dedicated "nvidia,tegra264-smmu" compatible,
so DT-probe is the only viable detection path.
Enable the workaround on instances matching the existing
"nvidia,tegra264-smmu" compatible by calling static_branch_enable() on
arm_smmu_erratum_repeat_tlbi_cfgi_key. Document the erratum in
Documentation/arch/arm64/silicon-errata.rst.
Signed-off-by: Ashish Mhetre <amhetre@nvidia.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Will Deacon <will@kernel.org>
| -rw-r--r-- | Documentation/arch/arm64/silicon-errata.rst | 2 | ||||
| -rw-r--r-- | drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 4 |
2 files changed, 5 insertions, 1 deletions
diff --git a/Documentation/arch/arm64/silicon-errata.rst b/Documentation/arch/arm64/silicon-errata.rst index 014aa1c215a1..076b3947d259 100644 --- a/Documentation/arch/arm64/silicon-errata.rst +++ b/Documentation/arch/arm64/silicon-errata.rst @@ -312,6 +312,8 @@ stable kernels. | | | T241-MPAM-4, | | | | | T241-MPAM-6 | | +----------------+-----------------+-----------------+-----------------------------+ +| NVIDIA | T264 SMMU | T264-SMMU-3 | N/A | ++----------------+-----------------+-----------------+-----------------------------+ +----------------+-----------------+-----------------+-----------------------------+ | Freescale/NXP | LS2080A/LS1043A | A-008585 | FSL_ERRATUM_A008585 | +----------------+-----------------+-----------------+-----------------------------+ 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 a78e85f4b457..3a9cbd7d8a00 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -5386,8 +5386,10 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev, if (of_dma_is_coherent(dev->of_node)) smmu->features |= ARM_SMMU_FEAT_COHERENCY; - if (of_device_is_compatible(dev->of_node, "nvidia,tegra264-smmu")) + if (of_device_is_compatible(dev->of_node, "nvidia,tegra264-smmu")) { tegra_cmdqv_dt_probe(dev->of_node, smmu); + static_branch_enable(&arm_smmu_erratum_repeat_tlbi_cfgi_key); + } return ret; } |