RFC Patch: https://lore.kernel.org/linux-iommu/20210806155523.50429-1-s...@svenpeter.dev/
Hi, After a very helpful discussion with Robin Murphy on the RFC, here's v2 that is slowly starting to look sane. I've been running this code for two weeks now and mainly tested it with usb storage devices connected to dwc3 and to xhci over pcie on the M1. Some background: On the Apple M1 the IOMMUs are hardwired to only support 16 KB pages. We'd still like to boot Linux with 4KB pages though because that's what most distros ship these days. This patch series adds support for that setup to the IOMMU DMA API. This is essentially done by always mapping the encapsulating IOMMU page and adjusting the returned iova offset. There are also changes to only allow DMA domains to make use of this and prevent UNMANAGED domains from encountering unexpected situations. For untrusted devices the allocation size is simply aligned to iovad->granule if they don't already go through the swiotlb path. I have not been able to test that part so far though since there's no Thunderbolt support for the M1 yet. The series is based on top of iommu/next (and without the last commit probably also on iommu/core). It won't apply cleanly on apple/dart since it already takes Robin's DMA domain cleanup series into account. Best, Sven Sven Peter (8): iommu/dma: Align size for untrusted devs to IOVA granule iommu/dma: Fail unaligned map requests for untrusted devs iommu/dma: Disable get_sgtable for granule > PAGE_SIZE iommu/dma: Support granule > PAGE_SIZE in dma_map_sg iommu/dma: Support PAGE_SIZE < iovad->granule allocations iommu: Move IOMMU pagesize check to attach_device iommu: Introduce __IOMMU_DOMAIN_LP iommu/dart: Remove force_bypass logic drivers/iommu/apple-dart.c | 14 +-- drivers/iommu/dma-iommu.c | 172 ++++++++++++++++++++++++++++++++----- drivers/iommu/iommu.c | 36 +++++++- drivers/iommu/iova.c | 7 +- include/linux/iommu.h | 8 +- 5 files changed, 197 insertions(+), 40 deletions(-) -- 2.25.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
