[PATCH v1 0/4] arm64: dts: qcom: Make ADSP remote heaps no-map

[Jianping Li]

Several Qualcomm platforms declare the ADSP remote heap as a reusable
shared DMA pool. This allows the kernel to reuse the region for movable
allocations.

When FastRPC assigns the entire region to the DSP without first
allocating its pages from CMA, those pages remain available for HLOS
allocations despite HLOS access permissions having been revoked.
Subsequent kernel accesses can therefore cause synchronous external
aborts.

This issue has been reported on Talos during GPU stress testing and on
Kodiak during storage testing. A further report on a Kodiak-based
Motorola Edge 30 describes similar aborts during everyday use and
indicates that marking the heap no-map resolves the issue.

Following feedback on the Talos patch, this series updates the remaining
identified reusable ADSP remote heaps on Kodiak, Glymur, SM8250 and
SM8750. Each platform is handled in a separate patch to allow independent
review and backporting.

Replace reusable with no-map to prevent normal kernel allocations from
using these regions and exclude them from the kernel's standard memory
mapping. The existing allocation ranges, alignment and sizes are
unchanged.

The Talos fix was submitted separately [1]. Agatti is also excluded
because a separate fix has already been posted [2].

[1] https://lore.kernel.org/all/20261014083820.468-1-jianping.li@xxxxxxxxxxxxxxxx/
[2] https://lore.kernel.org/all/20261001085247.1897991-1-benjamin@xxxxxxxx/

Jianping Li (4):
  arm64: dts: qcom: kodiak: Make the ADSP remote heap no-map
  arm64: dts: qcom: glymur: Make the ADSP remote heap no-map
  arm64: dts: qcom: sm8250: Make the ADSP remote heap no-map
  arm64: dts: qcom: sm8750: Make the ADSP remote heap no-map

 arch/arm64/boot/dts/qcom/glymur.dtsi | 2 +-
 arch/arm64/boot/dts/qcom/kodiak.dtsi | 2 +-
 arch/arm64/boot/dts/qcom/sm8250.dtsi | 2 +-
 arch/arm64/boot/dts/qcom/sm8750.dtsi | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

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2.43.0