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| author | Robin Murphy <robin.murphy@arm.com> | 2017-03-31 14:03:33 +0300 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2017-04-06 18:06:43 +0300 |
| commit | 56fbf600dd8e2f32a5317437fe310b56719f7d2b (patch) | |
| tree | 625b33270215c8ac908a8904cdb44d5573f731f3 /Documentation/devicetree/bindings/iommu | |
| parent | 8513c89300696a68963cc504c21d034c6369e183 (diff) | |
| download | linux-56fbf600dd8e2f32a5317437fe310b56719f7d2b.tar.xz | |
iommu/arm-smmu: Add global SMR masking property
The current SMR masking support using a 2-cell iommu-specifier is
primarily intended to handle individual masters with large and/or
complex Stream ID assignments; it quickly gets a bit clunky in other SMR
use-cases where we just want to consistently mask out the same part of
every Stream ID (e.g. for MMU-500 configurations where the appended TBU
number gets in the way unnecessarily). Let's add a new property to allow
a single global mask value to better fit the latter situation.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Nipun Gupta <nipun.gupta@nxp.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'Documentation/devicetree/bindings/iommu')
| -rw-r--r-- | Documentation/devicetree/bindings/iommu/arm,smmu.txt | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt b/Documentation/devicetree/bindings/iommu/arm,smmu.txt index 6cdf32d037fc..8a6ffce12af5 100644 --- a/Documentation/devicetree/bindings/iommu/arm,smmu.txt +++ b/Documentation/devicetree/bindings/iommu/arm,smmu.txt @@ -60,6 +60,17 @@ conditions. aliases of secure registers have to be used during SMMU configuration. +- stream-match-mask : For SMMUs supporting stream matching and using + #iommu-cells = <1>, specifies a mask of bits to ignore + when matching stream IDs (e.g. this may be programmed + into the SMRn.MASK field of every stream match register + used). For cases where it is desirable to ignore some + portion of every Stream ID (e.g. for certain MMU-500 + configurations given globally unique input IDs). This + property is not valid for SMMUs using stream indexing, + or using stream matching with #iommu-cells = <2>, and + may be ignored if present in such cases. + ** Deprecated properties: - mmu-masters (deprecated in favour of the generic "iommus" binding) : @@ -109,3 +120,20 @@ conditions. master3 { iommus = <&smmu2 1 0x30>; }; + + + /* ARM MMU-500 with 10-bit stream ID input configuration */ + smmu3: iommu { + compatible = "arm,mmu-500", "arm,smmu-v2"; + ... + #iommu-cells = <1>; + /* always ignore appended 5-bit TBU number */ + stream-match-mask = 0x7c00; + }; + + bus { + /* bus whose child devices emit one unique 10-bit stream + ID each, but may master through multiple SMMU TBUs */ + iommu-map = <0 &smmu3 0 0x400>; + ... + }; |