On Thu, Mar 12, 2020 at 11:14:22AM +0100, Christian König wrote: > > > The page pointer is set to NULL and only the DMA address, > > > length and offset values are valid. > > NAK. The only valid way to fill DMA address in scatterlists is > > dma_map_sg / dma_map_sg_attr. > > How can we then map PCIe BARs into an scatterlist which are not backed by > struct pages? You can't. scatterlists by definition map memory backed by a struct page. If you want to map something else struct scatterlist is the wrong structure and you need to use something else (which you should anyway as struct scatterlist is a bad design patter, and the above is only one of the many issues with it).
