On Tue, Apr 30, 2019 at 04:24:21PM +0100, Catalin Marinas wrote: > My reading of the arm32 __dma_alloc() is that if the conditions are > right for the CMA allocator (allows blocking) and there is a default CMA > area or a per-device one, the call ends up in cma_alloc() without any > fallback if such allocation fails. Whether this is on purpose, I'm not > entirely sure. There are a couple of arm32 SoCs which call > dma_declare_contiguous() or dma_contiguous_reserve_area() and a few DT > files describing a specific CMA range (e.g. arch/arm/boot/dts/sun5i.dtsi > with a comment that address must be kept in the lower 256MB). > > If ZONE_DMA is set up correctly so that cma_alloc() is (or can be made) > interchangeable with alloc_pages(GFP_DMA) from a device DMA capability > perspective , I think it should be fine to have such fallback.
Indeed. I missed arm32 being different from everyone else, but we already addresses that in another thread. Sorry for misleading everyone. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
