Hi all, looking at the recent ZONE_DEVICE related changes we still have a horrible maze of different code paths. I already suggested to depend on ARCH_HAS_PTE_SPECIAL for ZONE_DEVICE there, which all modern architectures have anyway. But the other odd special case is CONFIG_FS_DAX_LIMITED which is just used for the xpram driver. Does this driver still see use? If so can we make it behave like the other DAX drivers and require a pgmap? I think the biggest missing part would be to implement ARCH_HAS_PTE_DEVMAP for s390.
