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+* ARM System MMU Architecture Implementation
+
+ARM SoCs may contain an implementation of the ARM System Memory
+Management Unit Architecture, which can be used to provide 1 or 2 stages
+of address translation to bus masters external to the CPU.
+
+The SMMU may also raise interrupts in response to various fault
+conditions.
+
+** System MMU required properties:
+
+- compatible    : Should be one of:
+
+                        "arm,smmu-v1"
+                        "arm,smmu-v2"
+                        "arm,mmu-400"
+                        "arm,mmu-401"
+                        "arm,mmu-500"
+                        "cavium,smmu-v2"
+
+                  depending on the particular implementation and/or the
+                  version of the architecture implemented.
+
+- reg           : Base address and size of the SMMU.
+
+- #global-interrupts : The number of global interrupts exposed by the
+                       device.
+
+- interrupts    : Interrupt list, with the first #global-irqs entries
+                  corresponding to the global interrupts and any
+                  following entries corresponding to context interrupts,
+                  specified in order of their indexing by the SMMU.
+
+                  For SMMUv2 implementations, there must be exactly one
+                  interrupt per context bank. In the case of a single,
+                  combined interrupt, it must be listed multiple times.
+
+- #iommu-cells  : See Documentation/devicetree/bindings/iommu/iommu.txt
+                  for details. With a value of 1, each IOMMU specifier
+                  represents a distinct stream ID emitted by that device
+                  into the relevant SMMU.
+
+                  SMMUs with stream matching support and complex masters
+                  may use a value of 2, where the second cell of the
+                  IOMMU specifier represents an SMR mask to combine with
+                  the ID in the first cell.  Care must be taken to ensure
+                  the set of matched IDs does not result in conflicts.
+
+** System MMU optional properties:
+
+- dma-coherent  : Present if page table walks made by the SMMU are
+                  cache coherent with the CPU.
+
+                  NOTE: this only applies to the SMMU itself, not
+                  masters connected upstream of the SMMU.
+
+- calxeda,smmu-secure-config-access : Enable proper handling of buggy
+                  implementations that always use secure access to
+                  SMMU configuration registers. In this case non-secure
+                  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) :
+                  A list of phandles to device nodes representing bus
+                  masters for which the SMMU can provide a translation
+                  and their corresponding Stream IDs. Each device node
+                  linked from this list must have a "#stream-id-cells"
+                  property, indicating the number of Stream ID
+                  arguments associated with its phandle.
+
+** Examples:
+
+        /* SMMU with stream matching or stream indexing */
+        smmu1: iommu {
+                compatible = "arm,smmu-v1";
+                reg = <0xba5e0000 0x10000>;
+                #global-interrupts = <2>;
+                interrupts = <0 32 4>,
+                             <0 33 4>,
+                             <0 34 4>, /* This is the first context interrupt */
+                             <0 35 4>,
+                             <0 36 4>,
+                             <0 37 4>;
+                #iommu-cells = <1>;
+        };
+
+        /* device with two stream IDs, 0 and 7 */
+        master1 {
+                iommus = <&smmu1 0>,
+                         <&smmu1 7>;
+        };
+
+
+        /* SMMU with stream matching */
+        smmu2: iommu {
+                ...
+                #iommu-cells = <2>;
+        };
+
+        /* device with stream IDs 0 and 7 */
+        master2 {
+                iommus = <&smmu2 0 0>,
+                         <&smmu2 7 0>;
+        };
+
+        /* device with stream IDs 1, 17, 33 and 49 */
+        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>;
+                ...
+        };