Certain MMIO resources can be set to a write-combining cacheable
mode to increase performance. Typical resources that use this would
be graphics memory.
Change-Id: Icd96c720f86f7e2f19a6461bb23cb323124eb68e
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/2891
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>