drm/nouveau: Fill out gem_object->resv

That way we can ditch our gem_prime_res_obj implementation. Since ttm
absolutely needs the right reservation object all the boilerplate is
already there and we just have to wire it up correctly.

Note that gem/prime doesn't care when we do this, as long as we do it
before the bo is registered and someone can call the handle2fd ioctl
on it.

Aside: ttm_buffer_object.ttm_resv could probably be ditched in favour
of always passing a non-NULL resv to ttm_bo_init(). At least for gem
drivers that would avoid having two of these, on in ttm_buffer_object
and the other in drm_gem_object, one just there for confusion.
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: nouveau@lists.freedesktop.org
Reviewed-by: Ben Skeggs <bskeggs@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190725132655.11951-3-daniel.vetter@ffwll.ch

drivers/gpu/drm/nouveau/nouveau_bo.c

@@ -299,6 +299,8 @@ nouveau_bo_new(struct nouveau_cli *cli, u64 size, int align,
 			  type, &nvbo->placement,
 			  align >> PAGE_SHIFT, false, acc_size, sg,
 			  robj, nouveau_bo_del_ttm);
+	nvbo->gem.resv = nvbo->bo.resv;
+
 	if (ret) {
 		/* ttm will call nouveau_bo_del_ttm if it fails.. */
 		return ret;

drivers/gpu/drm/nouveau/nouveau_drm.c

@@ -1131,7 +1131,6 @@ driver_stub = {
 	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
 	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
 	.gem_prime_pin = nouveau_gem_prime_pin,
-	.gem_prime_res_obj = nouveau_gem_prime_res_obj,
 	.gem_prime_unpin = nouveau_gem_prime_unpin,
 	.gem_prime_get_sg_table = nouveau_gem_prime_get_sg_table,
 	.gem_prime_import_sg_table = nouveau_gem_prime_import_sg_table,

drivers/gpu/drm/nouveau/nouveau_gem.h

@@ -33,7 +33,6 @@ extern int nouveau_gem_ioctl_info(struct drm_device *, void *,
 				  struct drm_file *);
 
 extern int nouveau_gem_prime_pin(struct drm_gem_object *);
-struct reservation_object *nouveau_gem_prime_res_obj(struct drm_gem_object *);
 extern void nouveau_gem_prime_unpin(struct drm_gem_object *);
 extern struct sg_table *nouveau_gem_prime_get_sg_table(struct drm_gem_object *);
 extern struct drm_gem_object *nouveau_gem_prime_import_sg_table(

drivers/gpu/drm/nouveau/nouveau_prime.c

@@ -107,10 +107,3 @@ void nouveau_gem_prime_unpin(struct drm_gem_object *obj)
 
 	nouveau_bo_unpin(nvbo);
 }
-
-struct reservation_object *nouveau_gem_prime_res_obj(struct drm_gem_object *obj)
-{
-	struct nouveau_bo *nvbo = nouveau_gem_object(obj);
-
-	return nvbo->bo.resv;
-}