On Fri, Nov 06, 2020 at 11:01:57AM +0100, Daniel Vetter wrote: > gpu drivers also tend to use vmf_insert_pfn* directly, so we can do > on-demand paging and move buffers around. From what I glanced for > lowest level we to the pte_mkspecial correctly (I think I convinced > myself that vm_insert_pfn does that), but for pud/pmd levels it seems > just yolo. > > remap_pfn_range seems to indeed split down to pte level always. Thats what it looked like to me too. > > From my reading, yes. See ioremap_try_huge_pmd(). > > The ioremap here shouldn't matter, since this is for kernel-internal > mappings. So that's all fine I think. Right, sorry to be unclear, we are talking about io_remap_pfn_range() which is for userspace mappings in VMAs Jason