PCI: rcar: Convert PCI scan API to pci_scan_root_bus_bridge()

The introduction of pci_scan_root_bus_bridge() provides a PCI core API to
scan a PCI root bus backed by an already initialized struct pci_host_bridge
object, which simplifies the bus scan interface and makes the PCI scan root
bus interface easier to generalize as members are added to the struct
pci_host_bridge.

Convert PCI rcar host code to pci_scan_root_bus_bridge() to improve the PCI
root bus scanning interface.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Simon Horman <horms@verge.net.au>

drivers/pci/host/pcie-rcar.c

@@ -450,28 +450,32 @@ static void rcar_pcie_force_speedup(struct rcar_pcie *pcie)
 static int rcar_pcie_enable(struct rcar_pcie *pcie)
 {
 	struct device *dev = pcie->dev;
+	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
 	struct pci_bus *bus, *child;
-	LIST_HEAD(res);
+	int ret;
 
 	/* Try setting 5 GT/s link speed */
 	rcar_pcie_force_speedup(pcie);
 
-	rcar_pcie_setup(&res, pcie);
+	rcar_pcie_setup(&bridge->windows, pcie);
 
 	pci_add_flags(PCI_REASSIGN_ALL_RSRC | PCI_REASSIGN_ALL_BUS);
 
+	bridge->dev.parent = dev;
+	bridge->sysdata = pcie;
+	bridge->busnr = pcie->root_bus_nr;
+	bridge->ops = &rcar_pcie_ops;
 	if (IS_ENABLED(CONFIG_PCI_MSI))
-		bus = pci_scan_root_bus_msi(dev, pcie->root_bus_nr,
-				&rcar_pcie_ops, pcie, &res, &pcie->msi.chip);
-	else
-		bus = pci_scan_root_bus(dev, pcie->root_bus_nr,
-				&rcar_pcie_ops, pcie, &res);
+		bridge->msi = &pcie->msi.chip;
 
-	if (!bus) {
-		dev_err(dev, "Scanning rootbus failed");
-		return -ENODEV;
+	ret = pci_scan_root_bus_bridge(bridge);
+	if (ret < 0) {
+		kfree(bridge);
+		return ret;
 	}
 
+	bus = bridge->bus;
+
 	pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
 
 	pci_bus_size_bridges(bus);
@@ -1127,11 +1131,14 @@ static int rcar_pcie_probe(struct platform_device *pdev)
 	unsigned int data;
 	int err;
 	int (*hw_init_fn)(struct rcar_pcie *);
+	struct pci_host_bridge *bridge;
 
-	pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
-	if (!pcie)
+	bridge = pci_alloc_host_bridge(sizeof(*pcie));
+	if (!bridge)
 		return -ENOMEM;
 
+	pcie = pci_host_bridge_priv(bridge);
+
 	pcie->dev = dev;
 
 	INIT_LIST_HEAD(&pcie->resources);
@@ -1141,12 +1148,12 @@ static int rcar_pcie_probe(struct platform_device *pdev)
 	err = rcar_pcie_get_resources(pcie);
 	if (err < 0) {
 		dev_err(dev, "failed to request resources: %d\n", err);
-		return err;
+		goto err_free_bridge;
 	}
 
 	err = rcar_pcie_parse_map_dma_ranges(pcie, dev->of_node);
 	if (err)
-		return err;
+		goto err_free_bridge;
 
 	pm_runtime_enable(dev);
 	err = pm_runtime_get_sync(dev);
@@ -1183,6 +1190,9 @@ static int rcar_pcie_probe(struct platform_device *pdev)
 
 	return 0;
 
+err_free_bridge:
+	pci_free_host_bridge(bridge);
+
 err_pm_put:
 	pm_runtime_put(dev);