PCI: Add devm_request_pci_bus_resources()

Several host bridge drivers iterate through the list of bridge windows to
request resources.  Several others don't request the window resources at
all.

Add a devm_request_pci_bus_resources() interface to make it easier for
drivers to request all the window resources.  Export to GPL modules (from
Arnd Bergmann <arnd@arndb.de>).

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index dd7cdbe..6293ce0 100644
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -91,6 +91,35 @@
 	}
 }
 
+int devm_request_pci_bus_resources(struct device *dev,
+				   struct list_head *resources)
+{
+	struct resource_entry *win;
+	struct resource *parent, *res;
+	int err;
+
+	resource_list_for_each_entry(win, resources) {
+		res = win->res;
+		switch (resource_type(res)) {
+		case IORESOURCE_IO:
+			parent = &ioport_resource;
+			break;
+		case IORESOURCE_MEM:
+			parent = &iomem_resource;
+			break;
+		default:
+			continue;
+		}
+
+		err = devm_request_resource(dev, parent, res);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_request_pci_bus_resources);
+
 static struct pci_bus_region pci_32_bit = {0, 0xffffffffULL};
 #ifdef CONFIG_PCI_BUS_ADDR_T_64BIT
 static struct pci_bus_region pci_64_bit = {0,
@@ -397,4 +426,3 @@
 		put_device(&bus->dev);
 }
 EXPORT_SYMBOL(pci_bus_put);
-