pci/of: Match PCI devices to OF nodes dynamically

powerpc has two different ways of matching PCI devices to their
corresponding OF node (if any) for historical reasons. The ppc64 one
does a scan looking for matching bus/dev/fn, while the ppc32 one does a
scan looking only for matching dev/fn on each level in order to be
agnostic to busses being renumbered (which Linux does on some
platforms).

This removes both and instead moves the matching code to the PCI core
itself. It's the most logical place to do it: when a pci_dev is created,
we know the parent and thus can do a single level scan for the matching
device_node (if any).

The benefit is that all archs now get the matching for free. There's one
hook the arch might want to provide to match a PHB bus to its device
node. A default weak implementation is provided that looks for the
parent device device node, but it's not entirely reliable on powerpc for
various reasons so powerpc provides its own.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Michal Simek <monstr@monstr.eu>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 3 insertions, 6 deletions

diff --git a/arch/powerpc/kernel/pci_of_scan.c b/arch/powerpc/kernel/pci_of_scan.c
index 1e89a72fd030..fe0a5ad6f73e 100644
--- a/arch/powerpc/kernel/pci_of_scan.c
+++ b/arch/powerpc/kernel/pci_of_scan.c
@@ -202,9 +202,9 @@ EXPORT_SYMBOL(of_create_pci_dev);
  * this routine in turn call of_scan_bus() recusively to scan for more child
  * devices.
  */
-void __devinit of_scan_pci_bridge(struct device_node *node,
-                                  struct pci_dev *dev)
+void __devinit of_scan_pci_bridge(struct pci_dev *dev)
 {
+        struct device_node *node = dev->dev.of_node;
         struct pci_bus *bus;
         const u32 *busrange, *ranges;
         int len, i, mode;
@@ -238,7 +238,6 @@ void __devinit of_scan_pci_bridge(struct device_node *node,
         bus->primary = dev->bus->number;
         bus->subordinate = busrange[1];
         bus->bridge_ctl = 0;
-        bus->dev.of_node = of_node_get(node);
 
         /* parse ranges property */
         /* PCI #address-cells == 3 and #size-cells == 2 always */
@@ -335,9 +334,7 @@ static void __devinit __of_scan_bus(struct device_node *node,
         list_for_each_entry(dev, &bus->devices, bus_list) {
                 if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE ||
                     dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) {
-                        struct device_node *child = pci_device_to_OF_node(dev);
-                        if (child)
-                                of_scan_pci_bridge(child, dev);
+                        of_scan_pci_bridge(dev);
                 }
         }
 }