[RFC PATCH 01/16] PCI: Enhance pci_scan_root_bus() to support default IO/MEM resources

[Yijing Wang]

From: Yijing Wang <wangyijing0307 at gmail.com>

Pci_scan_root_bus(), pci_scan_bus() and pci_scan_bus_parented()
are very similar. But the latter two use the default
io/mem resources. Enhance pci_scan_root_bus() to support
default io/mem resources, then we could use
pci_scan_root_bus() instead of them, and clean them up.

Signed-off-by: Yijing Wang <wangyijing at huawei.com>
---
 drivers/pci/probe.c |   20 ++++++++++++++------
 1 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 5ed9930..fc99e88 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2069,15 +2069,23 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
 	struct pci_host_bridge_window *window;
 	bool found = false;
 	struct pci_bus *b;
+	LIST_HEAD(default_res);
 	int max;
 
-	list_for_each_entry(window, resources, list)
-		if (window->res->flags & IORESOURCE_BUS) {
-			found = true;
-			break;
-		}
+	if (!resources) {
+		pci_add_resource(&default_res, &ioport_resource);
+		pci_add_resource(&default_res, &iomem_resource);
+		pci_add_resource(&default_res, &busn_resource);
+	} else {
+		list_for_each_entry(window, resources, list)
+			if (window->res->flags & IORESOURCE_BUS) {
+				found = true;
+				break;
+			}
+	}
 
-	b = pci_create_root_bus(parent, bus, ops, sysdata, resources);
+	b = pci_create_root_bus(parent, bus, ops, sysdata, 
+			resources ? resources : &default_res);
 	if (!b)
 		return NULL;
 
-- 
1.7.1