quoted

-static struct resource busn_resource = {
+struct resource busn_resource = {
 	.name	= "PCI busn",
 	.start	= 0,
 	.end	= 255,
 	.flags	= IORESOURCE_BUS,
 };
+EXPORT_SYMBOL(busn_resource);

I don't think this is a good idea.  We support multiple PCI domains, and
each domain has its own 0-255 bus number range.  This busn_resource is
only for domain 0 and probably should be handled in arch code instead of
the PCI core.

Right now, I think it's possible to call pci_scan_bus_parented() or
pci_scan_bus() several times for buses in different domains, and they would
all share the same busn_resource, which would cause corruption.

So it's already broken, but I don't want to make it harder to fix by
exporting this stuff.

Hi Bjorn, busn_resource may would not be shared by multi domains,

We insert bus number resource like:

pci_add_resource(&resources, &busn_resource);	
	pci_bus_insert_busn_res(root_bus, start, bus_max);	//start is the root bus number provided by arch pci host driver, bus max here == 255
		get_pci_domain_busn_res(domain)	//for root bus	//try to get a domain specific pci_domain_busn_res, if not exist, create it.
			request_resource_conflict(domain_specific_busn_res, res)   //request busn res(start, bus_max) from the pci_domain_busn_res.

So every domain has its own pci_domain_busn_res , different domain would not share the same bus number resource.

Do I understand correct ?

Thanks!
Yijing.

quoted

 
 /* Ugh.  Need to stop exporting this to modules. */
 LIST_HEAD(pci_root_buses);
-- 
1.7.1

.

-- 
Thanks!
Yijing