[PATCH RFC 04/13] arm64: dts: qcom: sm8650: move smmu sid 1 to new lpac device
Konrad Dybcio
konrad.dybcio at oss.qualcomm.com
Mon Jul 6 01:40:43 PDT 2026
On 7/5/26 9:13 PM, Anna Maniscalco wrote:
> Previously both SID 0 and 1 where associated with the same domain.
>
> When LPAC is not used this is needed so firmware can acces memory when
> initializing using the same page table as GFX.
>
> To use LPAC however we need to move SID 1 to a different device.
>
> Signed-off-by: Anna Maniscalco <anna.maniscalco2000 at gmail.com>
> ---
> arch/arm64/boot/dts/qcom/sm8650.dtsi | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/boot/dts/qcom/sm8650.dtsi b/arch/arm64/boot/dts/qcom/sm8650.dtsi
> index 1604bc8cff37..44e5f9d4b335 100644
> --- a/arch/arm64/boot/dts/qcom/sm8650.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sm8650.dtsi
> @@ -4133,6 +4133,13 @@ tcsr: clock-controller at 1fc0000 {
> #reset-cells = <1>;
> };
>
> + lpac: lpac at 3d00000 {
> + compatible = "qcom,lpac";
> + reg = <0x0 0x03d00000 0x0 0x61000>;
> +
> + iommus = <&adreno_smmu 1 0x0>;
> + };
I think this could work better as a subnode of the GPU (or perhaps
if there's no "actual" separate address space, maybe just iommu-maps?
for something also making use of the latter, see patches 1-5 of:
https://lore.kernel.org/all/20260610-glymur-v8-0-1c79b9d51fc0@oss.qualcomm.com/
Konrad
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