Re: [PATCH] Introduce PCI <-> CPU address conversion [1/2]

From: Matthew Wilcox
Date: Thu Oct 14 2004 - 19:41:26 EST


On Thu, Oct 14, 2004 at 05:37:51PM -0500, Colin Ngam wrote:
> On SGI's Altix system, the sysdata for the device is very much different than
> the sysdata for the bus.

That's fascinating, because ia64 is one of the architectures that relies
on sysdata being the same in both the bus and the device:

#define PCI_CONTROLLER(busdev) ((struct pci_controller *) busdev->sysdata)

In various places, we have
struct pci_controller *controller = PCI_CONTROLLER(dev);
and
if (PCI_CONTROLLER(bus)->iommu)

So what the hell does Altix do? Which sysdata can be used to get to the
pci_controller? This seems like a horrible mistake to me.

--
"Next the statesmen will invent cheap lies, putting the blame upon
the nation that is attacked, and every man will be glad of those
conscience-soothing falsities, and will diligently study them, and refuse
to examine any refutations of them; and thus he will by and by convince
himself that the war is just, and will thank God for the better sleep
he enjoys after this process of grotesque self-deception." -- Mark Twain
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