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| author | Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> | 2023-03-08 10:56:48 +0300 |
|---|---|---|
| committer | Bjorn Andersson <andersson@kernel.org> | 2023-04-06 21:32:54 +0300 |
| commit | 6340b391e15094575911ab0d96bfff09deadafba (patch) | |
| tree | 5d3f5b6492cd0ab18aaec68c9126be92192760b0 /arch/arm64/boot/dts/qcom/sm8450.dtsi | |
| parent | d6573b4c202e75edd8b7ffbef6496613a1ef89df (diff) | |
| download | linux-6340b391e15094575911ab0d96bfff09deadafba.tar.xz | |
arm64: dts: qcom: Remove "iommus" property from PCIe nodes
Currently, most of the Qualcomm SoCs specify both "iommus" and "iommu-map"
properties for the PCIe nodes. First one passes the SMR mask to the iommu
driver and the latter specifies the SID for each PCIe device.
But with "iommus" property, the PCIe controller will be added to the
iommu group along with the devices. This makes no sense because the
controller will not initiate any DMA transaction on its own. And moreover,
it is not strictly required to pass the SMR mask to the iommu driver. If
the "iommus" property is not present, then the default mask of "0" would be
used which should work for all PCIe devices.
On the other side, if the SMR mask specified doesn't match the one expected
by the hypervisor, then all the PCIe transactions will end up triggering
"Unidentified Stream Fault" by the SMMU.
So to get rid of these hassles and also prohibit PCIe controllers from
adding to the iommu group, let's remove the "iommus" property from PCIe
nodes.
Reported-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/linux-arm-msm/20230227195535.GA749409-robh@kernel.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230308075648.134119-1-manivannan.sadhasivam@linaro.org
Diffstat (limited to 'arch/arm64/boot/dts/qcom/sm8450.dtsi')
| -rw-r--r-- | arch/arm64/boot/dts/qcom/sm8450.dtsi | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/arch/arm64/boot/dts/qcom/sm8450.dtsi b/arch/arm64/boot/dts/qcom/sm8450.dtsi index eebad05cd941..0bd205a11f2b 100644 --- a/arch/arm64/boot/dts/qcom/sm8450.dtsi +++ b/arch/arm64/boot/dts/qcom/sm8450.dtsi @@ -1786,7 +1786,6 @@ "aggre0", "aggre1"; - iommus = <&apps_smmu 0x1c00 0x7f>; iommu-map = <0x0 &apps_smmu 0x1c00 0x1>, <0x100 &apps_smmu 0x1c01 0x1>; @@ -1899,7 +1898,6 @@ "ddrss_sf_tbu", "aggre1"; - iommus = <&apps_smmu 0x1c80 0x7f>; iommu-map = <0x0 &apps_smmu 0x1c80 0x1>, <0x100 &apps_smmu 0x1c81 0x1>; |