Re: [PATCH 1/2] iommu/arm-smmu-qcom: Fix missing adreno_smmu's

Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> · Thu, 4 May 2023 21:24:08 +0300

On 04/05/2023 21:08, Rob Clark wrote:
On Thu, May 4, 2023 at 10:41 AM Konrad Dybcio <konrad.dybcio@xxxxxxxxxx> wrote:



On 2.05.2023 18:09, Rob Clark wrote:
From: Rob Clark <robdclark@xxxxxxxxxxxx>

When the special handling of qcom,adreno-smmu was moved into
qcom_smmu_create(), it was overlooked that we didn't have all the
required entries in qcom_smmu_impl_of_match.  So we stopped getting
adreno_smmu_priv on sc7180, breaking per-process pgtables.

Fixes: 30b912a03d91 ("iommu/arm-smmu-qcom: Move the qcom,adreno-smmu check into qcom_smmu_create")
Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
---
I believe the issue here is the lack of qcom,sc7180-smmu-v2 instead.

qcom,adreno-smmu does not have to imply the "qcom smmu v2" impl

Yes, but the ordering after "qcom,smmu-500" does.  Currently we just
need the one missing "qcom,sc7180-smmu-v2" but that seemed kind of
fragile to me, which is why I went with "qcom,adreno-smmu" as a
catch-all

I think, the order is not relevant when comparing compatible entries, 
see __of_match_node(). It uses scoring and the more specific compatible 
wins. This way, "qcom,adreno-smmu", "qcom,smmu-500" will always end up 
with the v2 ops instead smmu500. It was not included into the list 
intentionally, rather than being by omission.

Thus I'd also suggest adding "qcom,sc7180-smmu-v2" to the list, as we 
currently do for all SMMU_v2 devices.


BR,
-R


Konrad
  drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 5 +++++
  1 file changed, 5 insertions(+)

diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
index d1b296b95c86..88c89424485b 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
@@ -512,20 +512,25 @@ static const struct of_device_id __maybe_unused qcom_smmu_impl_of_match[] = {
       { .compatible = "qcom,sm6115-smmu-500", .data = &qcom_smmu_500_impl0_data},
       { .compatible = "qcom,sm6125-smmu-500", .data = &qcom_smmu_500_impl0_data },
       { .compatible = "qcom,sm6350-smmu-v2", .data = &qcom_smmu_v2_data },
       { .compatible = "qcom,sm6350-smmu-500", .data = &qcom_smmu_500_impl0_data },
       { .compatible = "qcom,sm6375-smmu-500", .data = &qcom_smmu_500_impl0_data },
       { .compatible = "qcom,sm8150-smmu-500", .data = &qcom_smmu_500_impl0_data },
       { .compatible = "qcom,sm8250-smmu-500", .data = &qcom_smmu_500_impl0_data },
       { .compatible = "qcom,sm8350-smmu-500", .data = &qcom_smmu_500_impl0_data },
       { .compatible = "qcom,sm8450-smmu-500", .data = &qcom_smmu_500_impl0_data },
       { .compatible = "qcom,smmu-500", .data = &qcom_smmu_500_impl0_data },
+     /*
+      * Should come after the qcom,smmu-500 fallback so smmu-500 variants of
+      * adreno-smmu get qcom_adreno_smmu_500_impl:
+      */
+     { .compatible = "qcom,adreno-smmu", .data = &qcom_smmu_v2_data },
       { }
  };

  #ifdef CONFIG_ACPI
  static struct acpi_platform_list qcom_acpi_platlist[] = {
       { "LENOVO", "CB-01   ", 0x8180, ACPI_SIG_IORT, equal, "QCOM SMMU" },
       { "QCOM  ", "QCOMEDK2", 0x8180, ACPI_SIG_IORT, equal, "QCOM SMMU" },
       { }
  };
  #endif

--
With best wishes
Dmitry







