>> -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.

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


-- 
Thanks!
Yijing

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