PCI configuration question

[Liu Tao]

Hello all,

In the LinuxBIOS-AMD64 document the author explains the "pci" keyword
> The first occurrence of the pci keyword tells LinuxBIOS where the

bridge device start,
> relative to PCI configuration space used by the bridge. The

following occurences of
> the pci keyword describe the provided devices.

then gives an example
> northbridge amd/amdk8 "mc1"
>          pci 0:19.0
>          pci 0:19.0
>          pci 0:19.0
>          pci 0:19.1
>          pci 0:19.2
>          pci 0:19.3
>  end

I'm not clear why the example repeate "pci 0:19.0" three times?
I noticed in chip.c the chip_enumerate() function checks the same path
>    identical_paths = (i > 0) && (path_eq(&chip->path[i - 1].path, 

&chip->path[i].path));
but I can't find out the real intent.

Another question maybe related to the former one is, in "device" structure
what does the "link[MAX_LINKS]" and "links" member describe?
Does "link[MAX_LINKS]" describes the secondary or subordinate bus of a 
bridge device?
Why MAX_LINKS is defined to 3?

Thanks in advance.