M7350/kernel/Documentation/devicetree/bindings/gpu/adreno-iommu.txt
2024-09-09 08:57:42 +00:00

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Qualcomm Technologies, Inc. GPU IOMMU
Required properties:
Required properties:
- compatible : one of:
- "qcom,kgsl-smmu-v1"
- "qcom,kgsl-smmu-v2"
- reg : Base address and size of the SMMU.
- clocks : List of clocks to be used during SMMU register access. See
Documentation/devicetree/bindings/clock/clock-bindings.txt
for information about the format. For each clock specified
here, there must be a corresponding entry in clock-names
(see below).
- clock-names : List of clock names corresponding to the clocks specified in
the "clocks" property (above). See
Documentation/devicetree/bindings/clock/clock-bindings.txt
for more info.
- qcom,protect : The GPU register region which must be protected by a CP
protected mode. On some targets this region must cover
the entire SMMU register space, on others there
is a separate aperture for CP to program context banks.
Optional properties:
- qcom,micro-mmu-control : Some targets provide an implementation defined
register for blocking translation requests during GPU side
programming. This property specifies the offset of this
register within the iommu register space.
- qcom,retention : A boolean specifying if retention is supported on this target
- qcom,global_pt : A boolean specifying if global pagetable should be used.
When not set we use per process pagetables
- qcom,hyp_secure_alloc : A bool specifying if the hypervisor is used on this target
for secure buffer allocation
- qcom,secure_align_mask: A mask for determining how secure buffers need to
be aligned
- qcom,coherent-htw: A boolean specifying if coherent hardware table walks should
be enabled.
- List of sub nodes, one for each of the translation context banks supported.
The driver uses the names of these nodes to determine how they are used,
currently supported names are:
- gfx3d_user : Used for the 'normal' GPU address space.
- gfx3d_secure : Used for the content protection address space.
Each sub node has the following required properties:
- compatible : "qcom,smmu-kgsl-cb"
- iommus : Specifies the SID's used by this context bank, this needs to be
<kgsl_smmu SID> pair, kgsl_smmu is the string parsed by iommu
driver to match this context bank with the kgsl_smmu device
defined in iommu device tree. On targets where the msm iommu
driver is used rather than the arm smmu driver, this property
may be absent.
- qcom,gpu-offset : Offset into the GPU register space for accessing
this context bank. On some targets the iommu registers are not
part of the GPU's register space, and a separate register aperture
is used. Otherwise the same register offsets may be used for CPU
or GPU side programming.
Example:
msm_iommu: qcom,kgsl-iommu {
compatible = "qcom,kgsl-smmu-v2";
reg = <0xb40000 0x20000>;
qcom,protect = <0x40000 0x20000>;
clocks = <&clock_mmss clk_gpu_ahb_clk>,
<&clock_gcc clk_gcc_mmss_bimc_gfx_clk>,
<&clock_mmss clk_mmss_mmagic_ahb_clk>,
<&clock_mmss clk_mmss_mmagic_cfg_ahb_clk>;
clock-names = "gpu_ahb_clk", "bimc_gfx_clk", "mmagic_ahb_clk", "mmagic_cfg_ahb_clk";
qcom,secure_align_mask = <0xfff>;
qcom,retention;
qcom,global_pt;
gfx3d_user: gfx3d_user {
compatible = "qcom,smmu-kgsl-cb";
iommus = <&kgsl_smmu 0>,
<&kgsl_smmu 1>;
qcom,gpu-offset = <0x48000>;
};
gfx3d_secure: gfx3d_secure {
compatible = "qcom,smmu-kgsl-cb";
iommus = <&kgsl_smmu 2>;
};
};