On 2024-03-09 1:31 pm, Konrad Dybcio wrote:
The smmu-v3 binding currently doesn't differentiate the SoCs it's implemented on. This is a poor design choice that may bite in the future, should any quirks surface.
That doesn't seem entirely fair to say - the vast majority of bindings don't have separate compatibles for every known integration of the same implementation in different SoCs. And in this case we don't have per-implementation compatibles for quirks and errata because the implementation is architecturally discoverable from the SMMU_IIDR register.
We have the whole mess for QCom SMMUv2 because the effective *implementation* is a mix of hardware and hypervisor, whose behaviour does seem to vary on almost a per-SoC basis. I'm not at all keen to start repeating that here without very good reason, and that of "documenting" a device which we typically expect to not even be accessible isn't really convincing me...
Thanks, Robin.
Add a compatible for the instance found on Qualcomm SC8280XP. Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx> --- Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml index 75fcf4cb52d9..f284f7b0c1d8 100644 --- a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml +++ b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml @@ -20,7 +20,11 @@ properties: $nodename: pattern: "^iommu@[0-9a-f]*" compatible: - const: arm,smmu-v3 + oneOf: + - items: + - const: qcom,sc8280xp-smmu-v3 + - const: arm,smmu-v3 + - const: arm,smmu-v3reg:maxItems: 1
