PCI: of: Simplify devm_of_pci_get_host_bridge_resources() interface

Previously pci_parse_request_of_pci_ranges() supplied the default bus range
to devm_of_pci_get_host_bridge_resources(), but that function is static and
has no other callers, so there's no reason to complicate its interface by
passing the default bus range.

Drop the busno and bus_max parameters and use 0x0 and 0xff directly in
devm_of_pci_get_host_bridge_resources().

Link: https://lore.kernel.org/r/20250113231557.441289-4-helgaas@kernel.org
[bhelgaas: dev_warn() for invalid end of bus-range]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Author: bjorn-helgaas

drivers/pci/of.c

@@ -302,8 +302,6 @@ EXPORT_SYMBOL_GPL(of_pci_check_probe_only);
  * devm_of_pci_get_host_bridge_resources() - Resource-managed parsing of PCI
  *                                           host bridge resources from DT
  * @dev: host bridge device
- * @busno: bus number associated with the bridge root bus
- * @bus_max: maximum number of buses for this bridge
  * @resources: list where the range of resources will be added after DT parsing
  * @ib_resources: list where the range of inbound resources (with addresses
  *                from 'dma-ranges') will be added after DT parsing
@@ -319,7 +317,6 @@ EXPORT_SYMBOL_GPL(of_pci_check_probe_only);
  * value if it failed.
  */
 static int devm_of_pci_get_host_bridge_resources(struct device *dev,
-			unsigned char busno, unsigned char bus_max,
 			struct list_head *resources,
 			struct list_head *ib_resources,
 			resource_size_t *io_base)
@@ -343,12 +340,15 @@ static int devm_of_pci_get_host_bridge_resources(struct device *dev,
 
 	err = of_pci_parse_bus_range(dev_node, bus_range);
 	if (err) {
-		bus_range->start = busno;
-		bus_range->end = bus_max;
+		bus_range->start = 0;
+		bus_range->end = 0xff;
 		bus_range->flags = IORESOURCE_BUS;
 	} else {
-		if (bus_range->end > bus_range->start + bus_max)
-			bus_range->end = bus_range->start + bus_max;
+		if (bus_range->end > 0xff) {
+			dev_warn(dev, "  Invalid end bus number in %pR, defaulting to 0xff\n",
+				 bus_range);
+			bus_range->end = 0xff;
+		}
 	}
 	pci_add_resource(resources, bus_range);
 
@@ -595,7 +595,7 @@ static int pci_parse_request_of_pci_ranges(struct device *dev,
 	INIT_LIST_HEAD(&bridge->windows);
 	INIT_LIST_HEAD(&bridge->dma_ranges);
 
-	err = devm_of_pci_get_host_bridge_resources(dev, 0, 0xff, &bridge->windows,
+	err = devm_of_pci_get_host_bridge_resources(dev, &bridge->windows,
 						    &bridge->dma_ranges, &iobase);
 	if (err)
 		return err;