Ard, > > >> On 24 November 2016 at 13:51, Robert Richter <robert.richter@xxxxxxxxxx> wrote: > > >> > On 24.11.16 13:44:31, Ard Biesheuvel wrote: > > >> Regions containing firmware tables are owned by the firmware, and it > > >> is the firmware that tells us which memory attributes we are allowed > > >> to use. If those attributes include WB, it is perfectly legal to use a > > >> cacheable mapping. That does *not* mean they should be covered by the > > >> linear mapping. The linear mapping is read-write-non-exec, for > > >> instance, and we may prefer to use a read-only mapping and/or > > >> executable mapping. > > > > > > Ok, I am going to fix try_ram_remap(). I revisited the code and it is working well already since: e7cd190385d1 arm64: mark reserved memblock regions explicitly in iomem Now, try_ram_remap() is only called if the region to be mapped is entirely in IORESOURCE_SYSTEM_RAM. This is only true for normal mem ranges and not NOMAP mem. region_intersects() then returns REGION_INTERSECTS and calls try_ram_remap(). For the NOMAP memory case REGION_DISJOINT would be returned and thus arch_memremap_wb() being called directly. Before the e7cd190385d1 change try_ram_remap() was called also for nomap regions. So we can leave memremap() as it is and just apply this patch unmodified. What do you think? Please ack. I am going to prepare the pfn_is_ram() change in addition to this patch, but that should not be required for this fix to work correcly. Thanks, -Robert -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
