Currently, we scan the list of mappings each time we want to operate on
the vram_mapping struct.  Rather than repeatedly scanning these, look
them up once in the submission path, and then use _reference and
_unreference methods as necessary to manage this object.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>

This adds the etnaviv DRM driver and hooks it up in Makefiles
and Kconfig.
Signed-off-by: NChristian Gmeiner <christian.gmeiner@gmail.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>