[PATCH v5 02/27] mm, cma: support multiple contiguous ranges, if requested

[Frank van der Linden]

On Mon, Apr 7, 2025 at 4:50 AM Geert Uytterhoeven <geert at linux-m68k.org> wrote:
>
> Thanks for your patch, which is now commit c009da4258f9885c
> ("mm, cma: support multiple contiguous ranges, if requested")
> in v6.15-rc1.
>
> After this patch, the printed base address becomes zero on several
> Renesas arm32/arm64 platforms:
>
>   - Koelsch (R-Car M2-W):
>
>       -cma: Reserved 64 MiB at 0x7c000000 on node -1
>       +cma: Reserved 64 MiB at 0x00000000
>
>    - Salvator-XS (R-Car H3 ES2.0):
>
>       -cma: Reserved 128 MiB at 0x0000000078000000 on node -1
>       +cma: Reserved 128 MiB at 0x0000000000000000
>
>   - Gray Hawk Single (R-Car V4H):
>
>       -cma: Reserved 128 MiB at 0x00000000b8000000 on node -1
>       +cma: Reserved 128 MiB at 0x0000000000000000
>
> None of these have actual RAM at address zero.  As I haven't noticed
> any other impact on system operation, I do not know if this is purely
> a cosmetic issue, or if it can cause real problems.
>
> Thanks!
>
> Gr{oetje,eeting}s,
>
>                         Geert

Hi Geert,

Thanks for the report! This is just a reporting issue with my change,
it's working fine otherwise. I refactored the code slightly, and the
!fixed && !multi case will now report base 0, because it doesn't 'see'
the actual allocated base. Let me send a follow-up patch.

Thanks again,

- Frank