| Message ID | 20231219-topic-8280_smmuv3-v2-1-c67bd3226687@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | Describe SC8280XP PCIe SMMU | expand |
On 09/03/2024 14:31, 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. > > Add a compatible for the instance found on Qualcomm SC8280XP. > > Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org> > --- > 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 This could be enum, because likely it will grow in the future, but there is no need to resend for this alone. Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Best regards, Krzysztof
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@linaro.org> > --- > 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-v3 > > reg: > maxItems: 1 >
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-v3 reg: maxItems: 1
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. Add a compatible for the instance found on Qualcomm SC8280XP. Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org> --- Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)