On Wed, Nov 09, 2016 at 10:12:59AM +1100, Benjamin Herrenschmidt wrote: > On Tue, 2016-11-08 at 11:49 +0000, Mark Rutland wrote: > > I believe that we could theoretically have multiple independent LPC/ISA > > busses, as is possible with PCI on !x86 systems. If the current ISA code > > assumes a singleton bus, I think that's something that needs to be fixed > > up more generically. > > > > I don't see why we should need any architecture-specific code here. Why > > can we not fix up the ISA bus code in drivers/of/address.c such that it > > handles multiple ISA bus instances, and translates all sub-device > > addresses relative to the specific bus instance? > > What in that code prevents that today ? It appears I was mistaken w.r.t. the singleton comment. We can already translate MMIO->MMIO addresses per-instance (in the presence of a ranges property). The big change would be to handle !MMIO translations, for which we'd need a runtime registry of ISA bus instance to find the relevant accessor ops and instance-specific data. Thanks, Mark. -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
