Buffer based command transport can replace MMIO based mechanism.
It may be used to perform host-2-guc and guc-to-host communication.
Portions of this patch are based on work by:
Michel Thierry <michel.thierry@intel.com>
Robert Beckett <robert.beckett@intel.com>
Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
v2: use gem_object_pin_map (Chris)
don't use DEBUG_RATELIMITED (Chris)
don't track action stats (Chris)
simplify next fence (Chris)
use READ_ONCE (Chris)
move blob allocation to new function (Chris)
v3: use static owner id (Daniele)
v4: but keep channel initialization generic (Daniele)
and introduce owner_sub_id (Daniele)
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170526111326.87280-3-michal.wajdeczko@intel.com
