On Mon, Feb 6, 2012 at 10:48 AM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote:
>> +struct resource iobusn_resource = {
>> + .name = "PCI busn",
>> + .start = 0,
>> + .end = 0xffffff,
>> + .flags = IORESOURCE_BUS,
>> +};
>
> I'm not sure this should be global. iomem_resource and
> ioport_resource *are* really global, because they refer to processor
> address space that is the same for everybody. But PCI bus numbers are
> specific to PCI. Some machines don't have PCI at all, and there are
> different bus architectures to which this doesn't apply.
that does not hurt them.
>
> The 0-0xffffff range is misleading because it includes both the domain
> and the bus number, and it's meaningless to allocate ranges that cross
> domain boundaries. For example, [bus 0x0000f0-0x000120] includes bus
> numbers from domain 0000 and domain 0001, which doesn't make any sense
> because a bus can only be in one domain.
allocation code will make sure it will be cross the boundary for domain.
>
> I think it would make more sense to keep this bus number resource in a
> per-host bridge structure. Then we wouldn't need to include the
> domain number at all because the host bridge determines the domain.
not sure. insert the all busn_res of all peer root buses into one
global iobusn_resource
looks more simple.
Yinghai
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
