ACPI/IORT: Make iort_get_device_domain IRQ domain agnostic

iort_get_device_domain() is PCI specific but it need not be,
since it can be used to retrieve IRQ domain nexus of any kind
by adding an irq_domain_bus_token input to it.

Make it PCI agnostic by also renaming the requestor ID input
to a more generic ID name.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>   # pci/msi.c
Cc: Will Deacon <will@kernel.org>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Link: https://lore.kernel.org/r/20200619082013.13661-3-lorenzo.pieralisi@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

drivers/acpi/arm64/iort.c

@@ -550,7 +550,6 @@ static struct acpi_iort_node *iort_find_dev_node(struct device *dev)
 		node = iort_get_iort_node(dev->fwnode);
 		if (node)
 			return node;
-
 		/*
 		 * if not, then it should be a platform device defined in
 		 * DSDT/SSDT (with Named Component node in IORT)
@@ -641,13 +640,13 @@ static int __maybe_unused iort_find_its_base(u32 its_id, phys_addr_t *base)
 /**
  * iort_dev_find_its_id() - Find the ITS identifier for a device
  * @dev: The device.
- * @req_id: Device's requester ID
+ * @id: Device's ID
  * @idx: Index of the ITS identifier list.
  * @its_id: ITS identifier.
  *
  * Returns: 0 on success, appropriate error value otherwise
  */
-static int iort_dev_find_its_id(struct device *dev, u32 req_id,
+static int iort_dev_find_its_id(struct device *dev, u32 id,
 				unsigned int idx, int *its_id)
 {
 	struct acpi_iort_its_group *its;
@@ -657,7 +656,7 @@ static int iort_dev_find_its_id(struct device *dev, u32 req_id,
 	if (!node)
 		return -ENXIO;
 
-	node = iort_node_map_id(node, req_id, NULL, IORT_MSI_TYPE);
+	node = iort_node_map_id(node, id, NULL, IORT_MSI_TYPE);
 	if (!node)
 		return -ENXIO;
 
@@ -680,19 +679,20 @@ static int iort_dev_find_its_id(struct device *dev, u32 req_id,
  *
  * Returns: the MSI domain for this device, NULL otherwise
  */
-struct irq_domain *iort_get_device_domain(struct device *dev, u32 req_id)
+struct irq_domain *iort_get_device_domain(struct device *dev, u32 id,
+					  enum irq_domain_bus_token bus_token)
 {
 	struct fwnode_handle *handle;
 	int its_id;
 
-	if (iort_dev_find_its_id(dev, req_id, 0, &its_id))
+	if (iort_dev_find_its_id(dev, id, 0, &its_id))
 		return NULL;
 
 	handle = iort_find_domain_token(its_id);
 	if (!handle)
 		return NULL;
 
-	return irq_find_matching_fwnode(handle, DOMAIN_BUS_PCI_MSI);
+	return irq_find_matching_fwnode(handle, bus_token);
 }
 
 static void iort_set_device_domain(struct device *dev,

drivers/pci/msi.c

@@ -1558,7 +1558,8 @@ struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev)
 	pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);
 	dom = of_msi_map_get_device_domain(&pdev->dev, rid);
 	if (!dom)
-		dom = iort_get_device_domain(&pdev->dev, rid);
+		dom = iort_get_device_domain(&pdev->dev, rid,
+					     DOMAIN_BUS_PCI_MSI);
 	return dom;
 }
 #endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */

include/linux/acpi_iort.h

@@ -29,7 +29,8 @@ struct fwnode_handle *iort_find_domain_token(int trans_id);
 #ifdef CONFIG_ACPI_IORT
 void acpi_iort_init(void);
 u32 iort_msi_map_rid(struct device *dev, u32 req_id);
-struct irq_domain *iort_get_device_domain(struct device *dev, u32 req_id);
+struct irq_domain *iort_get_device_domain(struct device *dev, u32 id,
+					  enum irq_domain_bus_token bus_token);
 void acpi_configure_pmsi_domain(struct device *dev);
 int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id);
 /* IOMMU interface */
@@ -40,8 +41,8 @@ int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head);
 static inline void acpi_iort_init(void) { }
 static inline u32 iort_msi_map_rid(struct device *dev, u32 req_id)
 { return req_id; }
-static inline struct irq_domain *iort_get_device_domain(struct device *dev,
-							u32 req_id)
+static inline struct irq_domain *iort_get_device_domain(
+	struct device *dev, u32 id, enum irq_domain_bus_token bus_token)
 { return NULL; }
 static inline void acpi_configure_pmsi_domain(struct device *dev) { }
 /* IOMMU interface */