[PATCH v5 0/6] RISC-V DT related fixes for reserved memory & UEFI

[Atish Patra]

On Tue, Apr 7, 2020 at 10:35 AM Atish Patra <atishp at atishpatra.org> wrote:
>
> On Mon, Apr 6, 2020 at 11:51 PM Ard Biesheuvel
> <ard.biesheuvel at linaro.org> wrote:
> >
> > On Tue, 7 Apr 2020 at 08:46, Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
> > >
> > > On 4/6/20 11:01 PM, Ard Biesheuvel wrote:
> > > > On Mon, 6 Apr 2020 at 22:45, Atish Patra <atish.patra at wdc.com> wrote:
> > > >>
> > > >> This series adds few DT related fixes required for Linux EFI stub to work
> > > >> on RISC-V.
> > > >>
> > > >
> > > > I'm not sure how this is supposed to work, since DT reserved memory
> > > > regions are not used by EFI. If you want to reserve memory on a UEFI
> > > > system, you have to reserve it in the UEFI memory map from firmware.
> > > > The DT reserved-memory node is taken into account too late, the
> > > > /memreserve/ entries are ignored entirely.
> > >
> > > Hello Ard,
> > >
> > > thanks for reviewing.
> > >
> > > What do you mean by "The DT reserved-memory node is taken into account
> > > too late"?
> > >
> > > Cf. commit 7be64b885a36 ("cmd: bootefi: Parse reserved-memory node from DT")
> > >
> >
> > What I mean is that the EFI stub in Linux uses memory allocation
> > functions, expecting the firmware to ensure that those allocations do
> > not conflict with memory descriptions and reservations in DT. So if
> > the firmware wants to express this redundantly, by passing
> > reservations in both reserved-memory and in the EFI memory map, that
> > is probably fine.
> >
> > Also, I must sheepishly admit that I only realize now that this patch
> > set is against u-boot not Linux :-)
> >
> :)
>
> > So if fixed reserved-memory regions are only being used to seed the
> > reserved regions in the EFI memory map, you can safely ignore me.
>
> Yeah. That's the purpose. Having reserved memory nodes in the final DT
> used by linux
> also ensures that proper Linux adds a reserved memory block or removes
> it from memblock
> entries depending on "no-map" property.
>
> > Apologies for the noise.
>
>
>
> --
> Regards,
> Atish

Any other comments on the series ? It would be great if this series
could be merged before
v2020.07 release.

-- 
Regards,
Atish