Messages in this thread | | | Date | Wed, 14 Feb 2024 18:36:38 -0700 | From | Keith Busch <> | Subject | Re: [PATCH v1 2/2] nvme-pci: Fix iommu map (via swiotlb) failures when PAGE_SIZE=64KB |
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On Tue, Feb 13, 2024 at 10:09:19PM -0800, Nicolin Chen wrote: > On Tue, Feb 13, 2024 at 04:31:04PM -0700, Keith Busch wrote: > > On Tue, Feb 13, 2024 at 01:53:57PM -0800, Nicolin Chen wrote: > > > @@ -2967,7 +2967,7 @@ static struct nvme_dev *nvme_pci_alloc_dev(struct pci_dev *pdev, > > > dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(48)); > > > else > > > dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); > > > - dma_set_min_align_mask(&pdev->dev, NVME_CTRL_PAGE_SIZE - 1); > > > + dma_set_min_align_mask(&pdev->dev, PAGE_SIZE - 1); > > > dma_set_max_seg_size(&pdev->dev, 0xffffffff); > > > > I recall we had to do this for POWER because they have 64k pages, but > > page aligned addresses IOMMU map to 4k, so we needed to allow the lower > > dma alignment to efficiently use it. > > Thanks for the input! > > In that case, we might have to rely on iovad->granule from the > attached iommu_domain:
I explored a bit more, and there is some PPC weirdness that lead to NVME_CTRL_PAGE_SIZE, I don't find the dma min align mask used in that path. It looks like swiotlb is the only user for this, so your original patch may be just fine.
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