On Fri, Feb 25, 2005 at 04:19:41PM -0500, Ralph Siemsen wrote: > Matt Porter wrote: > > > I didn't bother merging it upstream at one time. It wasn't clear > > if the driver had any value over just mmaping /dev/mem to bang > > on the couple gpio registers directly. [...] > > Will that work on the 440 where the devices sit above 4GB mark? Or must > one rely on there being an existing TLB mapping to bring them into > 32-bit space?
Ack...that's the one thing we are missing. :-/ I had forgotten that driver/char/mem.c calls remap_pfn_range() directly rather than io_remap_page_range(). Had it called the latter, we'd be OK since the "bigphys" fixup could take place. We can fix /dev/mem to call io_remap_page_range() when on ppc32 && 36-bit phys...other arches do similar tricks in that driver. If everybody is happy with mmaping /dev/mem then we can go try that route. -Matt
