Merge branch 'iommu/pci/ats' into iommu/next

* iommu/pci/ats:
  arm64: dts: fvp: Enable PCIe ATS for Base RevC FVP
  iommu/of: Support ats-supported device-tree property
  dt-bindings: PCI: generic: Add ats-supported property

Documentation/devicetree/bindings/pci/host-generic-pci.yaml

@@ -110,6 +110,12 @@ properties:
   iommu-map-mask: true
   msi-parent: true
 
+  ats-supported:
+    description:
+      Indicates that a PCIe host controller supports ATS, and can handle Memory
+      Requests with Address Type (AT).
+    type: boolean
+
 required:
   - compatible
   - reg

arch/arm64/boot/dts/arm/fvp-base-revc.dts

@@ -243,6 +243,7 @@
 		iommu-map = <0x0 &smmu 0x0 0x10000>;
 
 		dma-coherent;
+		ats-supported;
 	};
 
 	smmu: iommu@2b400000 {

drivers/iommu/of_iommu.c

@@ -100,6 +100,14 @@ static int of_iommu_configure_device(struct device_node *master_np,
 		      of_iommu_configure_dev(master_np, dev);
 }
 
+static void of_pci_check_device_ats(struct device *dev, struct device_node *np)
+{
+	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+
+	if (fwspec && of_property_read_bool(np, "ats-supported"))
+		fwspec->flags |= IOMMU_FWSPEC_PCI_RC_ATS;
+}
+
 /*
  * Returns:
  *  0 on success, an iommu was configured
@@ -136,6 +144,7 @@ int of_iommu_configure(struct device *dev, struct device_node *master_np,
 		pci_request_acs();
 		err = pci_for_each_dma_alias(to_pci_dev(dev),
 					     of_pci_iommu_init, &info);
+		of_pci_check_device_ats(dev, master_np);
 	} else {
 		err = of_iommu_configure_device(master_np, dev, id);
 	}