On Fri, Aug 03, 2018 at 09:16:39AM +0200, Ard Biesheuvel wrote: > On 3 August 2018 at 08:35, Mikulas Patocka <mpato...@redhat.com> wrote: > > > > > > On Thu, 2 Aug 2018, Matt Sealey wrote: > > > >> The easiest explanation for this would be that the memory isn?t mapped > >> correctly. You can?t use PCIe memory spaces with anything other than > >> Device-nGnRE or stricter mappings. That?s just differences between the > >> AMBA and PCIe (posted/unposted) memory models. > > Whoa hold on there. > > Are you saying we cannot have PCIe BAR windows with memory semantics on ARM? > > Most accelerated graphics drivers rely heavily on the ability to map > the VRAM normal-non-cacheable (ioremap_wc, basically), and treat it as > ordinary memory.
Yeah, I'd expect framebuffers to be mapped as normal NC. That should be fine for prefetchable BARs, no? Will
