Re: [PATCH v3 1/3] dt-bindings: reserved-memory: rmtfs: Allow guard pages

From: Krzysztof Kozlowski
Date: Sat Sep 23 2023 - 13:46:08 EST


On 21/09/2023 04:37, Bjorn Andersson wrote:
> On some Qualcomm platforms the firwmare, or hardware, does not
> gracefully handle memory protection of the rmtfs memory region when
> placed adjacent to other protected region. Some DeviceTree authors have
> worked around this issue by explicitly reserving the space around the
> region, but this prevents such author to use rely on the OS to place the
> region, through the use of "size" (instead of a fixed location).
>


Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>

> +
> + When this is set, the first and last 4kB should be left unused, and the
> + effective size of the region will thereby shrink with 8kB.

Maybe we should not reference the actual size (4 and 8 kB), but rather
page - "the first and last pages in mapping should be left unused ..." etc?



Best regards,
Krzysztof