Re: [RFC] PCI bridge driver rewrite

Jesse Barnes
2005-03-01T00:38:15Z

On Monday, February 28, 2005 4:13 pm, Adam Belay wrote:
> On Mon, 2005-02-28 at 15:38 -0800, Jesse Barnes wrote:
> > On Monday, February 28, 2005 3:27 pm, Adam Belay wrote:
> > > How can we specify which bus to target?
> >
> > Maybe we could have a list of legacy (ISA?) devices for drivers like
> > vgacon to attach to? The bus info could be stuffed into the legacy
> > device structure itself so that the platform code would know what to do.
>
> Are these devices actually legacy, or PCI with compatibility interfaces?

So far I've only tried VGA cards, like radeons and r128s.

> I think a "struct isa_device" would be be useful. Would a pointer to
> the "struct pci_bus" do the trick?

Yeah, that would work for me.

> I was just wondering if we have to reserve a memory range for this?

Sure, each bus can have that address range reserved. The ia64 specific
HAVE_PCI_LEGACY code (in arch/ia64/sn/pci/pci_dma.c I think) might illuminate
things a bit. Basically, each bus has legacy base addresses, we could
reserve 64k for port space and 1M for memory.

Jesse