pgprot_writecombine & shub 1.x

Jesse Barnes
2005-01-11T20:00:02Z

SGI sn2 systems based on SHub 1.x chipsets don't support the write combine
attribute on PIO space, only regular memory space. This is a problem because
drivers often expect to map PIO space with certain memory attributes (e.g.
the PCI mmap code, drm, fbmem, acorn video). None of the calls to
pgprot_writecombine are in performance critical paths, so would making
pgprot_writecombine into a machine vector would be ok? Comments?

Thanks,
Jesse