Add mapImage and unmapImage functions to DRIimage extension for mapping
and unmapping DRIimages for CPU access. The caller provides the region of
the image to map and is returned a pointer to the beginning of the region
and the stride (which could be different from the original).
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Reviewed-by: Eric Anholt <eric@anholt.net>