- specified there. Otherwise, if the EFI memory map reports that
- the entire granule supports WB, we should use that (granules
- that are partially reserved or occupied by firmware do not appear
- in kern_memmap). Otherwise, we should use a UC mapping.
+ specified there.
+
+ If the EFI memory map reports that the entire granule supports
+ WB, we should use that (granules that are partially reserved
+ or occupied by firmware do not appear in kern_memmap).
+
+ If the granule contains non-WB memory, but we can cover the
+ region safely with kernel page table mappings, we can use
+ ioremap_page_range() as most other architectures do.
+
+ Failing all of the above, we have to fall back to a UC mapping.