Re: LongTrail PCI resource assignment

[Benjamin Herrenschmidt <bh40@calva.net>]

On Wed, Mar 22, 2000, Michel Lanners <mlan@mcp.cpu.lu> wrote:


>Can't we replace this with a seed to the resource tree, defined per host
>bridge
>in arch-specific code? On PowerMacs, there's a function that scans for known
>host bridges; that code could (either dynamically or based on hardcoded
>knowledge) put the available IO window into some resource of the host bridge
>pci_dev struct. The tree of IO resources could then be built from there.

Note that in the Uni-N case, all 3 sub-busses have the same bus number
(0). There's apparenty no dev_fn conflicts between the devices on the
various nodes (but each sub node does _not_ have a specific range of
dev_fn, they are somewhat mixed).

For config accesses, we can still rely on my current hack which does a
reverse lookup of the PCI device in the OF device-tree, walks up the tree
to find on which Uni-N entry it is attached, and use the proper config
access registers (all not-found devices are routed to the external PCI,
just in case).

Ben.


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