PCI/MSI: Make the pci_msi_map_rid_ctlr_node() interface firmware agnostic

To support booting with OF and ACPI seamlessly, GIC ITS parent code
requires the PCI/MSI irqdomain layer to implement a function to retrieve
an MSI controller fwnode and map an RID in a firmware agnostic way
(ie pci_msi_map_rid_ctlr_node()).

Convert pci_msi_map_rid_ctlr_node() to an OF agnostic interface
(fwnode_handle based) and update the GIC ITS MSI parent code to reflect
the pci_msi_map_rid_ctlr_node() change.

Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260115-gicv5-host-acpi-v3-2-c13a9a150388@kernel.org
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: Lorenzo Pieralisi

drivers/irqchip/irq-gic-its-msi-parent.c

@@ -104,7 +104,7 @@ static int its_pci_msi_prepare(struct irq_domain *domain, struct device *dev,
 static int its_v5_pci_msi_prepare(struct irq_domain *domain, struct device *dev,
 				  int nvec, msi_alloc_info_t *info)
 {
-	struct device_node *msi_node = NULL;
+	struct fwnode_handle *msi_node = NULL;
 	struct msi_domain_info *msi_info;
 	struct pci_dev *pdev;
 	phys_addr_t pa;
@@ -116,15 +116,15 @@ static int its_v5_pci_msi_prepare(struct irq_domain *domain, struct device *dev,
 
 	pdev = to_pci_dev(dev);
 
-	rid = pci_msi_map_rid_ctlr_node(pdev, &msi_node);
+	rid = pci_msi_map_rid_ctlr_node(domain->parent, pdev, &msi_node);
 	if (!msi_node)
 		return -ENODEV;
 
-	ret = its_translate_frame_address(msi_node, &pa);
+	ret = its_translate_frame_address(to_of_node(msi_node), &pa);
 	if (ret)
 		return -ENODEV;
 
-	of_node_put(msi_node);
+	fwnode_handle_put(msi_node);
 
 	/* ITS specific DeviceID */
 	info->scratchpad[0].ul = rid;

drivers/pci/msi/irqdomain.c

@@ -376,23 +376,34 @@ u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev)
 }
 
 /**
- * pci_msi_map_rid_ctlr_node - Get the MSI controller node and MSI requester id (RID)
+ * pci_msi_map_rid_ctlr_node - Get the MSI controller fwnode_handle and MSI requester id (RID)
+ * @domain:	The interrupt domain
  * @pdev:	The PCI device
- * @node:	Pointer to store the MSI controller device node
+ * @node:	Pointer to store the MSI controller fwnode_handle
  *
- * Use the firmware data to find the MSI controller node for @pdev.
+ * Use the firmware data to find the MSI controller fwnode_handle for @pdev.
  * If found map the RID and initialize @node with it. @node value must
  * be set to NULL on entry.
  *
  * Returns: The RID.
  */
-u32 pci_msi_map_rid_ctlr_node(struct pci_dev *pdev, struct device_node **node)
+u32 pci_msi_map_rid_ctlr_node(struct irq_domain *domain, struct pci_dev *pdev,
+			      struct fwnode_handle **node)
 {
 	u32 rid = pci_dev_id(pdev);
 
 	pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);
 
-	return of_msi_xlate(&pdev->dev, node, rid);
+	/* Check whether the domain fwnode is an OF node */
+	if (irq_domain_get_of_node(domain)) {
+		struct device_node *msi_ctlr_node = NULL;
+
+		rid = of_msi_xlate(&pdev->dev, &msi_ctlr_node, rid);
+		if (msi_ctlr_node)
+			*node = of_fwnode_handle(msi_ctlr_node);
+	}
+
+	return rid;
 }
 
 /**

include/linux/msi.h

@@ -702,7 +702,8 @@ void __pci_write_msi_msg(struct msi_desc *entry, struct msi_msg *msg);
 void pci_msi_mask_irq(struct irq_data *data);
 void pci_msi_unmask_irq(struct irq_data *data);
 u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev);
-u32 pci_msi_map_rid_ctlr_node(struct pci_dev *pdev, struct device_node **node);
+u32 pci_msi_map_rid_ctlr_node(struct irq_domain *domain, struct pci_dev *pdev,
+			      struct fwnode_handle **node);
 struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev);
 void pci_msix_prepare_desc(struct irq_domain *domain, msi_alloc_info_t *arg,
 			   struct msi_desc *desc);