On 26/02/2025 22:52, Luca Fancellu wrote:
>
>
> Currently the early stage of the Arm boot maps the DTB using
> early_fdt_map() using PAGE_HYPERVISOR_RO which is cacheable
> read-only memory, later during DTB relocation the function
> copy_from_paddr() is used to map pages in the same range on
> the fixmap but using PAGE_HYPERVISOR_WC which is non-cacheable
> read-write memory.
>
> The Arm specifications, ARM DDI0487L.a, section B2.11 "Mismatched
> memory attributes" discourage using mismatched attributes for
> aliases of the same location.
>
> Given that there is nothing preventing the relocation since the region
> is already mapped, fix that by open-coding copy_from_paddr inside
> relocate_fdt, without mapping on the fixmap.
>
> Signed-off-by: Luca Fancellu <luca.fance...@arm.com>
Reviewed-by: Michal Orzel <michal.or...@amd.com>
~Michal
