Re: multi-domain PCI and sysfs

Alan Cox
2004-09-08T14:08:55Z

On Mer, 2004-09-08 at 07:01, Jon Smirl wrote:
> X on GL is going to eliminate all device access from X. Everything

Hardly.

> will be handled from the OpenGL layer. When everything is finished

Nope. It might change the access model for some user space applications.

> Where is the PCI segment base address stored in the PCI driver
> structures? I'm still having trouble with the fact that the PCI driver
> does not have a clear structure representing a PCI segment. Shouldn't
> there be a structure corresponding to a segment?

Who says PCI is a top level bus. You can have PCI bridges on a different
top level bus on some systems - totally independant. Not sure if you can
hot plug PCI root bridges on any parisc boxes but that would sure be
fun.

> >From what I understand right now the SN2 machine can not have two
> active VGA cards since it does not have two PCI segments. Without two
> segments there is no way to tell the legacy addresses apart.

Some of the NUMA x86 boxes have multiple I/O spaces too. So your I/O
address effectively includes a "system node" section.