[v5.4 stable] arm: stm32: Regression observed on "no-map" reserved memory region

[Rob Herring]

On Tue, Apr 20, 2021 at 10:12 AM Alexandre TORGUE
<alexandre.torgue at foss.st.com> wrote:
>
>
>
> On 4/20/21 4:45 PM, Rob Herring wrote:
> > On Tue, Apr 20, 2021 at 9:03 AM Alexandre TORGUE
> > <alexandre.torgue at foss.st.com> wrote:
> >>
> >> Hi,
> >
> > Greg or Sasha won't know what to do with this. Not sure who follows
> > the stable list either. Quentin sent the patch, but is not the author.
> > Given the patch in question is about consistency between EFI memory
> > map boot and DT memory map boot, copying EFI knowledgeable folks would
> > help (Ard B for starters).
>
> Ok thanks for the tips. I add Ard in the loop.

Sigh. If it was only Ard I was suggesting I would have done that
myself. Now everyone on the patch in question and relevant lists are
Cc'ed.

>
> Ard, let me know if other people have to be directly added or if I have
> to resend to another mailing list.
>
> thanks
> alex
>
> >
> >>
> >> Since v5.4.102 I observe a regression on stm32mp1 platform: "no-map"
> >> reserved-memory regions are no more "reserved" and make part of the
> >> kernel System RAM. This causes allocation failure for devices which try
> >> to take a reserved-memory region.
> >>
> >> It has been introduced by the following path:
> >>
> >> "fdt: Properly handle "no-map" field in the memory region
> >> [ Upstream commit 86588296acbfb1591e92ba60221e95677ecadb43 ]"
> >> which replace memblock_remove by memblock_mark_nomap in no-map case.
> >>
> >> Reverting this patch it's fine.
> >>
> >> I add part of my DT (something is maybe wrong inside):
> >>
> >> memory at c0000000 {
> >>          reg = <0xc0000000 0x20000000>;
> >> };
> >>
> >> reserved-memory {
> >>          #address-cells = <1>;
> >>          #size-cells = <1>;
> >>          ranges;
> >>
> >>          gpu_reserved: gpu at d4000000 {
> >>                  reg = <0xd4000000 0x4000000>;
> >>                  no-map;
> >>          };
> >> };
> >>
> >> Sorry if this issue has already been raised and discussed.
> >>
> >> Thanks
> >> alex