On Tue, Dec 01, 2020 at 12:36:58PM +0900, Sergey Senozhatsky wrote: > Not that I have any sound experience in this area, but the helper > probably won't hurt. Do you also plan to add vmap() to that helper > or dma_alloc_noncontiguous()/sg_alloc_table_from_pages() only? Yes, I think adding the vmap is useful, and it probably makes sense to do that unconditionally. I'd also include the fallback to dma_alloc_pages when the noncontig version isn't supported in the helper.