The TCUs (Translation Control Units) and TBUs (Translation Buffer
Units) are key components of the MMU-500. Multiple TBUs are connected
to a single TCU over an interconnect. Each TBU contains a TLB that
caches page tables. The MMU-500 implements a TBU for each connected
master, and the TBU is designed, so that it is local to the master.
A common TBU DT schema is added to describe the TBUs.
The Qualcomm SDM845 and SC7280 platforms have an implementation of the
SMMU-500, that has multiple TBUs. A vendor-specific DT schema is added
to describe the resources for each TBU (register space, power-domains,
interconnects and clocks).
The TBU driver will manage the resources and allow the system to
operate the TBUs during a context fault to obtain details by doing
s1 inv, software + hardware page table walks etc. This is implemented
with ATOS/eCATs as the ATS feature is not supported. Being able to
query the TBUs is useful for debugging various hardware/software
issues on these platforms.
v8:
- Use ARM_SMMU_QCOM_DEBUG instead of a separate config option (Will)
- Replace mutex/spinlock handling with cleanup.h guard() (Konrad)
- Add missing power-domains in sdm845.dtsi (Konrad)
- Fix swapped labels in sc7280.dtsi (Konrad)
v7: https://lore.kernel.org/r/20240329210638.3647523-1-quic_c_gdjako@quicinc.com
- Pick Reviewed-by for the DT binding (Rob)
- Don't spam the log if the dts changes are not there (Konrad)
v6: https://lore.kernel.org/r/20240307190525.395291-1-quic_c_gdjako@quicinc.com/
- Use SoC-specific compatibles (Krzysztof)
- Use additionalProperties: false (Krzysztof)
- Wrap description text to 80 cols (Krzysztof)
v5: https://lore.kernel.org/r/20240226172218.69486-1-quic_c_gdjako@quicinc.com
- Drop the common TBU bindings and child nodes. These TBU functionalities
are only Qualcomm specific and not generic. In the unmodified ARM MMU-500
implementation there are no TBU-specific resources, so just make them
standalone DT nodes. (Robin)
- The "qcom,stream-id-range" DT property now takes a phandle to the smmu
and a stream ID range.
v4: https://lore.kernel.org/r/20240201210529.7728-1-quic_c_gdjako@quicinc.com/
- Create a common TBU schema. Move the vendor-specific properties into
a separate schema that references the common one. (Rob)
- Drop unused DT labels in example, fix regex. (Rob)
- Properly rebase on latest code.
v3: https://lore.kernel.org/r/20231220060236.18600-1-quic_c_gdjako@quicinc.com
- Having a TBU is not Qualcomm specific, so allow having TBU child
nodes with no specific constraints on properties. For some of the
vendor compatibles however, add a schema to describe specific
properties and allow validation. (Rob)
- Drop the useless reg-names DT property on TBUs. (Rob)
- Make the stream-id-range DT property a common one. (Rob)
- Fix the DT example. (Rob)
- Minor fixes on the TBU driver.
- Add support for SC7280 platforms.
v2: https://lore.kernel.org/r/20231118042730.2799-1-quic_c_gdjako@quicinc.com
- Improve DT binding description, add full example. (Konrad)
- Drop Qcom specific stuff from the generic binding. (Rob)
- Unconditionally try to populate subnodes. (Konrad)
- Improve TBU driver commit text, remove memory barriers. (Bjorn)
- Move TBU stuff into separate file. Make the driver builtin.
- TODO: Evaluate whether to keep TBU support as a separate driver
or just instantiate things from qcom_smmu_impl_init()
v1: https://lore.kernel.org/r/20231019021923.13939-1-quic_c_gdjako@quicinc.com
Georgi Djakov (7):
dt-bindings: iommu: Add Qualcomm TBU
iommu/arm-smmu-qcom-debug: Add support for TBUs
iommu/arm-smmu: Allow using a threaded handler for context interrupts
iommu/arm-smmu-qcom: Use a custom context fault handler for sdm845
arm64: dts: qcom: sdm845: Add DT nodes for the TBUs
iommu/arm-smmu-qcom: Use the custom fault handler on more platforms
arm64: dts: qcom: sc7280: Add DT nodes for the TBUs
.../devicetree/bindings/iommu/qcom,tbu.yaml | 69 +++
arch/arm64/boot/dts/qcom/sc7280.dtsi | 89 ++++
arch/arm64/boot/dts/qcom/sdm845.dtsi | 73 +++
drivers/iommu/Kconfig | 12 +-
.../iommu/arm/arm-smmu/arm-smmu-qcom-debug.c | 496 ++++++++++++++++++
drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 8 +
drivers/iommu/arm/arm-smmu/arm-smmu-qcom.h | 2 +
drivers/iommu/arm/arm-smmu/arm-smmu.c | 12 +-
drivers/iommu/arm/arm-smmu/arm-smmu.h | 3 +
9 files changed, 758 insertions(+), 6 deletions(-)
create mode 100644 Documentation/devicetree/bindings/iommu/qcom,tbu.yaml