On Tue, 2009-05-05 at 09:24 -0400, Gregory Haskins wrote: > > *) PIO is more direct than MMIO, but it poses other problems such as: > a) can have a small limited address space (x86 is 2^16) > b) is a narrow-band interface (one 8, 16, 32, 64 bit word at a time) > c) not available on all archs (PCI mentions ppc as problematic) and > is therefore recommended to avoid.
Side note: I don't know what PCI has to do with this, and "problematic" isn't the word I would use. ;) As far as I know, x86 is the only still-alive architecture that implements instructions for a separate IO space (not even ia64 does). -- Hollis Blanchard IBM Linux Technology Center -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
