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-rw-r--r--Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt37
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+* ARM SMMUv3 Architecture Implementation
+
+The SMMUv3 architecture is a significant deparature from previous
+revisions, replacing the MMIO register interface with in-memory command
+and event queues and adding support for the ATS and PRI components of
+the PCIe specification.
+
+** SMMUv3 required properties:
+
+- compatible : Should include:
+
+ * "arm,smmu-v3" for any SMMUv3 compliant
+ implementation. This entry should be last in the
+ compatible list.
+
+- reg : Base address and size of the SMMU.
+
+- interrupts : Non-secure interrupt list describing the wired
+ interrupt sources corresponding to entries in
+ interrupt-names. If no wired interrupts are
+ present then this property may be omitted.
+
+- interrupt-names : When the interrupts property is present, should
+ include the following:
+ * "eventq" - Event Queue not empty
+ * "priq" - PRI Queue not empty
+ * "cmdq-sync" - CMD_SYNC complete
+ * "gerror" - Global Error activated
+
+** SMMUv3 optional properties:
+
+- dma-coherent : Present if DMA operations made by the SMMU (page
+ table walks, stream table accesses etc) are cache
+ coherent with the CPU.
+
+ NOTE: this only applies to the SMMU itself, not
+ masters connected upstream of the SMMU.