Now we have weak functions like pcibios_root_bridge_prepare()
to setup pci host bridge, We could introduce pci_host_bridge_ops
which contain host bridge specific ops to setup pci_host_bridge.
Then host bridge driver could add pci_host_bridge_ops hooks
intead of weak function to setup pci_host_bridge.
This patch add following pci_host_bridge_ops hooks:

pci_host_bridge_ops {
	/* set root bus speed, some platform need this like powerpc */
	void (*phb_set_root_bus_speed)(struct pci_host_bridge *host);
	/* setup pci_host_bridge before pci_host_bridge be added to driver core */
	int (*phb_prepare)(struct pci_host_bridge *host);
	/* platform specific of scan hook to scan pci device */
	void (*phb_of_scan_bus)(struct pci_host_bridge *);
}
We could easily extend it to support different host bridge
specific operations.

Signed-off-by: Yijing Wang <redacted>
---
 drivers/pci/host-bridge.c |   12 ++++++++++--
 drivers/pci/probe.c       |   17 +++++++++++------
 include/linux/pci.h       |   12 ++++++++++--
 3 files changed, 31 insertions(+), 10 deletions(-)

diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c
index b42a4bb..4a2baa2 100644
--- a/drivers/pci/host-bridge.c
+++ b/drivers/pci/host-bridge.c

@@ -23,8 +23,8 @@ static void pci_release_host_bridge_dev(struct device *dev)
 }
 
 struct pci_host_bridge *pci_create_host_bridge(
-		struct device *parent, u32 db, 
-		struct list_head *resources, void *sysdata)
+		struct device *parent, u32 db, struct list_head *resources, 
+		void *sysdata, struct pci_host_bridge_ops *ops)
 {
 	int error;
 	int bus = PCI_BUSNUM(db);

@@ -56,6 +56,7 @@ struct pci_host_bridge *pci_create_host_bridge(
 		}
 	mutex_unlock(&phb_mutex);
 
+	host->ops = ops;
 	host->dev.parent = parent;
 	INIT_LIST_HEAD(&host->windows);
 	host->dev.release = pci_release_host_bridge_dev;

@@ -63,6 +64,13 @@ struct pci_host_bridge *pci_create_host_bridge(
 	dev_set_name(&host->dev, "pci%04x:%02x", host->domain, 
 			host->busnum);
 
+	if (host->ops && host->ops->phb_prepare) {
+		error = host->ops->phb_prepare(host);
+		if(error) {

--- a/include/linux/pci.h
+++ b/include/linux/pci.h

@@ -400,6 +400,13 @@ static inline int pci_channel_offline(struct pci_dev *pdev)
 	return (pdev->error_state != pci_channel_io_normal);
 }
 
+struct pci_host_bridge;
+struct pci_host_bridge_ops {
+	void (*phb_set_root_bus_speed)(struct pci_host_bridge *host);
+	int (*phb_prepare)(struct pci_host_bridge *host);
+	void (*phb_of_scan_bus)(struct pci_host_bridge *);