drm/nouveau: implement prime helper unpin function

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Acked-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/nouveau/nouveau_drm.c

@@ -702,6 +702,7 @@ driver = {
 	.gem_prime_export = drm_gem_prime_export,
 	.gem_prime_import = drm_gem_prime_import,
 	.gem_prime_pin = nouveau_gem_prime_pin,
+	.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,
 	.gem_prime_vmap = nouveau_gem_prime_vmap,

drivers/gpu/drm/nouveau/nouveau_gem.h

@@ -36,6 +36,7 @@ extern int nouveau_gem_ioctl_info(struct drm_device *, void *,
 				  struct drm_file *);
 
 extern int nouveau_gem_prime_pin(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(
 	struct drm_device *, size_t size, struct sg_table *);

drivers/gpu/drm/nouveau/nouveau_prime.c

@@ -84,7 +84,7 @@ struct drm_gem_object *nouveau_gem_prime_import_sg_table(struct drm_device *dev,
 int nouveau_gem_prime_pin(struct drm_gem_object *obj)
 {
 	struct nouveau_bo *nvbo = nouveau_gem_object(obj);
-	int ret = 0;
+	int ret;
 
 	/* pin buffer into GTT */
 	ret = nouveau_bo_pin(nvbo, TTM_PL_FLAG_TT);
@@ -93,3 +93,10 @@ int nouveau_gem_prime_pin(struct drm_gem_object *obj)
 
 	return 0;
 }
+
+void nouveau_gem_prime_unpin(struct drm_gem_object *obj)
+{
+	struct nouveau_bo *nvbo = nouveau_gem_object(obj);
+
+	nouveau_bo_unpin(nvbo);
+}