> > The current PCI interface to the iommu doesn't allow you to explicitely > > ask an sg list to be force-merged into a single segment though that > > could be added via some platform hooks. That would probably work if > > that is the only DMA allocation you do on this TCE table. Those machines > > have a TCE table per PCI brigde and one bridge per slot, no ? > > You lost me at "PCI interface". :)
I mean the Linux PCI DMA mappings interfaces. > I don't currently know very much > about POWER at all, so you're going to have to bear with me a bit. As > far as I can tell, the PCI bridge on the card doesn't do anything except > convert regular PCI voltage to AGP voltage. I'm not at all familiar > with the TCE table, but it sounds like a more general version of an AGP > GART table. Is that a fair assessment? Somewhat ... > From skimming the kernel source briefly, it looks like this is only > supported on PPC64. Is that correct? If so, it sounds like something > PPC64-specific could be done to keep the performance up, but I think I > want to do something more general as well. I see no reason to exclude > support for PCI cards on x86, for example. I now understand why some > IHVs have complained that Linux can't allocate large (i.e., more than a > page) of physically contiguous memory. Of course, I've always > understood why it doesn't. (And never will! Muhahaha!) :) No, amost all 64 bits architectures have an iommu. Ben. ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click -- _______________________________________________ Dri-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/dri-devel
