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The > dma_flags (SG_DMA_BUS_ADDRESS, SG_DMA_SWIOTLB) are dropped. > > The flags describe the DMA side of an entry, which is the side > importers may use. Copy them as well. > > This is not a bug fix. No importer reads the flags today. Their only > readers are dma-iommu, dma-direct and iommu_map_sg(), which are not > supposed to see an importer's copy at all. The warn mode added in the > next patch keeps its marker in dma_flags and lets importers that do > get there continue. They should then see the same flags as without > DMABUF_DEBUG. > > Assisted-by: LLM > Signed-off-by: Karl Mehltretter > --- > > Notes: > Built alone on x86_64 with NEED_SG_DMA_FLAGS=y (dma-buf.o, W=1). The > KUnit test in patch 3 checks the flags in the copy. It passes on x86_64 > under QEMU in strict and in warn mode. > > drivers/dma-buf/dma-buf.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c > index 4c9add51f9ef..b3d311acb883 100644 > --- a/drivers/dma-buf/dma-buf.c > +++ b/drivers/dma-buf/dma-buf.c > @@ -904,6 +904,10 @@ static int dma_buf_wrap_sg_table(struct sg_table **sg_table) > sg_assign_page(to_sg, NULL); > sg_dma_address(to_sg) = sg_dma_address(from_sg); > sg_dma_len(to_sg) = sg_dma_len(from_sg); > +#ifdef CONFIG_NEED_SG_DMA_FLAGS > + /* the flags describe the DMA side, e.g. SG_DMA_BUS_ADDRESS */ > + to_sg->dma_flags = from_sg->dma_flags; We should probably have a WARN_ON_ONCE(sg_dma_is_swiotlb(from_sg)) here as well since some importers/exporters doesn't realize that this combination will usually not work. Apart from that looks good to me. Regards, Christian. > +#endif > to_sg = sg_next(to_sg); > } >