On Tue, Jun 09, 2020 at 11:22:24PM +0800, dillon min wrote: > Hi Vladimir, > > Thanks for reviewing. > > Hi Christoph Hellwig, > > I just want to know if kernel dma mapping/direct is focused on > platforms with MMU. > leave arch code to handle dma coherent memory management themself for > no-MMU platform. No, I'd really like to consolidate everything that isn't overly arch specific eventually. > > so, you just return error code in kernel/dma/mapping.c,direct.c > without CONFIG_MMU defined ? > which means dma-direct mapping doesn't support !CONFIG_MMU is not a > bug, but design as it's. > or, just return error code currently, will add dma direct mapping > support for !CONFIG_MMU in the > future? > > As Vladimir Murzin's suggestion has changes in kernel code, I need > your input to get > the design goal about dma-direct mapping, thanks. Can someone repost the whole patch?
