Hi Yijing,

On Wed, Jan 21, 2015 at 12:29:55AM +0000, Yijing Wang wrote:

v1->v2:
	Split pci_host_bridge_list into a new patch, remove .phb_probe_mode
	and rework powerpc .phb_of_scan_bus() for simpilicty suggested by
	Arnd. Refresh some patch description log, and add a new patch to fix
	build warning in ia64.

This series is based on Bjorn's pci-next branch.

Patch 1-4 ripped out pci_bus_add_devices() from pci scan interfaces
for better pci scan flow.

Patch 5-11 make a generic pci_host_bridge to hold pci_host_bridge
related informations, and introduce a pci_host_bridge_ops to 
support platform host drivers provide its own pci_host_bridge 
related operations to setup pci_host_bridge during pci enumeration.

Patch 12-28 apply the new pci scan interfaces to platform pci host
bridge drivers.

Now in kernel, we scan pci bus use the following ways:
1. pci_scan_bus. 
	parent = NULL, default io/mem/bus resources
	call pci_bus_add_devices()

2. pci_scan_bus_parented() + pci_bus_add_devices()
	default io/mem/bus resources, only used by xen

3. pci_scan_root_bus() + pci_bus_add_devices()

4. pci_create_root_bus() + pci_scan_child_bus() + pci_bus_add_devices()

5. pci_create_root_bus() + xx_of_scan_bus()  +  pci_bus_add_devices()

And we have a lot of arch specific pci_domain_nr() and other platform
specific weak function like pcibios_root_bridge_prepare().

After applied this series, we have following scan interfaces:

1. pci_scan_bus_legacy() 
	parent = NULL, default io/mem/bus resources.
	for legacy pci scan

2. pci_scan_root_bus()
	for callers provide its own parent and io/mem/bus resources
	but no platform specific pci_host_bridge operations

3. pci_scan_root_bridge()
	for callers provide its own parent and io/mem/bus resources
	and pci_host_bridge_ops.

Besides, above pci scan interfaces all need addtionally call pci_bus_add_devices()
to set match_driver true and try to attach drivers.

Also we could eliminate all arch specific pci_domain_nr() after applied this series.

I tested this series on x86 (with or without ACPI).
Comments and tests are warmly welcome!

Can you push a public branch out rebased against mainline for us to pull
and test please ?

Thanks !
Lorenzo