Re: [PATCH RFC 04/13] arm64: dts: qcom: sm8650: move smmu sid 1 to new lpac device

[Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>]

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@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@1fc0000 {
>  			#reset-cells = <1>;
>  		};
>  
> +		lpac: lpac@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