On Fri, Jul 26, 2019 at 02:15:14PM +0900, Tomasz Figa wrote: > Could you try dma_get_sgtable() with the SCP struct device and then > dma_map_sg() with the P1 struct device? Please don't do that. dma_get_sgtable is a pretty broken API (see the common near the arm implementation) and we should not add more users of it. If you want a piece of memory that can be mapped to multiple devices allocate it using alloc_pages and then just map it to each device.