Re: [Patch v2] iommu: arm-smmu: disable large page mappings for Nvidia arm-smmu

[Jon Hunter]

Hi Will,

On 22/04/2022 11:55, Will Deacon wrote:
> On Thu, 21 Apr 2022 13:45:04 +0530, Ashish Mhetre wrote:
> > Tegra194 and Tegra234 SoCs have the erratum that causes walk cache
> > entries to not be invalidated correctly. The problem is that the walk
> > cache index generated for IOVA is not same across translation and
> > invalidation requests. This is leading to page faults when PMD entry is
> > released during unmap and populated with new PTE table during subsequent
> > map request. Disabling large page mappings avoids the release of PMD
> > entry and avoid translations seeing stale PMD entry in walk cache.
> > Fix this by limiting the page mappings to PAGE_SIZE for Tegra194 and
> > Tegra234 devices. This is recommended fix from Tegra hardware design
> > team.
> >
> > [...]
>
> Applied to will (for-joerg/arm-smmu/fixes), thanks!
>
> [1/1] iommu: arm-smmu: disable large page mappings for Nvidia arm-smmu
>        https://git.kernel.org/will/c/4a25f2ea0e03

Thanks for applying. Sorry to be late to the party, but feel free
to add my ...

Reviewed-by: Jon Hunter <jonathanh@xxxxxxxxxx>

Also any chance we could tag for stable? Probably the most
appropriate fixes-tag would be ...

Fixes: aab5a1c88276 ("iommu/arm-smmu: add NVIDIA implementation for ARM MMU-500 usage")

Thanks!
Jon

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nvpublic