On 24.11.16 13:58:30, Ard Biesheuvel wrote: > On 24 November 2016 at 13:51, Robert Richter <robert.richter@xxxxxxxxxx> wrote: > > On 24.11.16 13:44:31, Ard Biesheuvel wrote: > >> On 24 November 2016 at 13:42, Robert Richter <robert.richter@xxxxxxxxxx> wrote: > >> > On 23.11.16 21:25:06, Ard Biesheuvel wrote: > >> >> Why? MEMREMAP_WB is used often, among other things for mapping > >> >> firmware tables, which are marked as NOMAP, so in these cases, the > >> >> linear address is not mapped. > >> > > >> > If fw tables are mapped wb, that is wrong and needs a separate fix. > >> > > >> > >> Why is that wrong? > > > > The whole issue with mapping acpi tables is not marking them cachable, > > what wb does. > > What 'issue'? > > > Otherwise we could just use linear mapping for those mem > > ranges. > > > > 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(). Are there other concerns with this patch? 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
