RE: [PATCH v10 10/13] iommu/arm-smmu-v3: Check for SVA features
From: Krishna Reddy <vdumpa@nvidia.com>
Date: 2020-12-14 23:23:30
Also in:
linux-iommu, linux-mm
quoted
The Tegra Next Generation SOC uses arm-smmu-v3, but it doesn't have support for BTM. Do you have plan to get your earlier patch to handle invalidate notifications into upstream sometime soon? Can the dependency on BTM be relaxed with the patch? PATCH v9 13/13] iommu/arm-smmu-v3: Hook up ATC invalidation to mm ops https://www.spinics.net/lists/arm-kernel/msg825099.html
This patch (which should be in 5.11) only takes care of sending ATC invalidations to PCIe endpoints. With this, BTM is still required to invalidate SMMU TLBs. However we could enable command-queue invalidation when ARM_SMMU_FEAT_BTM isn't set. Invalidations are still a relatively rare event so it may not be outrageously slow. I can add a patch to my tree if you have hardware to test.
Thanks! We can test the patch on emulation platform. -KR _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel