Le Wed, Apr 28, 2021 at 11:06:10AM +0100, Robin Murphy a écrit : > On 2021-04-28 09:42, Corentin Labbe wrote: > > Hello > > > > I work on the crypto offloader driver of cortina/gemini SL3516 SoC. > > I test it by filling a LUKS2 partition. > > I got a reproductible problem when handling skcipher requests. > > I use dma_map_sg() and when iterating other the result, sg_dma_address(sg) > > return 0. > > But sg_dma_len(sg) is still correct (4096 in my case). > > > > Below is a simplified view of my code: > > nr_sgs = dma_map_sg(ce->dev, areq->src, sg_nents(areq->src), DMA_TO_DEVICE); > > (nr_sgs = 1 in my case) > > sg = areq->src; > > if (!sg_dma_address(sg)) > > FAIL > > What is this check supposed to be for in the first place? 0 is a valid > DMA address, because it's also a valid physical address, and I recall > RAM at PA 0 on Hikey 960 flushing out some bugs in the past when we > tried to use 0 for DMA_MAPPING_ERROR. All the Gemini DTs appear to show > RAM starting at PA 0 too, so I'd have to guess that it's simply the case > that your DMA buffer happened to end up using that particular page. > > Robin. >
Yes, 0 is a valid DMA address. I just find it by going further and printing mem_map value and testing it against sg_page() return. So my original problem was not related to this. Sorry for the noise. Thanks _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
