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, 6 insertions, 1 deletions

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 48849ffdd672..c28c7b91910e 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -52,6 +52,7 @@ static void release_pcibus_dev(struct device *dev)
 	if (pci_bus->bridge)
 		put_device(pci_bus->bridge);
 	pci_bus_remove_resources(pci_bus);
+	pci_release_bus_of_node(pci_bus);
 	kfree(pci_bus);
 }
 
@@ -588,7 +589,7 @@ static struct pci_bus *pci_alloc_child_bus(struct pci_bus *parent,
 
 	child->self = bridge;
 	child->bridge = get_device(&bridge->dev);
-
+	pci_set_bus_of_node(child);
 	pci_set_bus_speed(child);
 
 	/* Set up default resource pointers and names.. */
@@ -1038,6 +1039,7 @@ static void pci_release_dev(struct device *dev)
 
 	pci_dev = to_pci_dev(dev);
 	pci_release_capabilities(pci_dev);
+	pci_release_of_node(pci_dev);
 	kfree(pci_dev);
 }
 
@@ -1157,6 +1159,8 @@ static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn)
 	dev->vendor = l & 0xffff;
 	dev->device = (l >> 16) & 0xffff;
 
+	pci_set_of_node(dev);
+
 	if (pci_setup_device(dev)) {
 		kfree(dev);
 		return NULL;
@@ -1409,6 +1413,7 @@ struct pci_bus * pci_create_bus(struct device *parent,
 		goto dev_reg_err;
 	b->bridge = get_device(dev);
 	device_enable_async_suspend(b->bridge);
+	pci_set_bus_of_node(b);
 
 	if (!parent)
 		set_dev_node(b->bridge, pcibus_to_node(b));