drm_atomic_get_private_obj_state() allocates a new private object
state by duplicating the current one and inserts it into the atomic
commit as a single operation.

However, a later change will need to insert a private object state
into a commit without going through the full allocation and
duplication path in drm_atomic_get_private_obj_state().

Extract the state insertion logic, including the array reallocation,
into a new static drm_atomic_commit_set_private_obj_state() helper,
and convert drm_atomic_get_private_obj_state() to use it.

Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
 drivers/gpu/drm/drm_atomic.c | 57 ++++++++++++++++++++++++++++----------------
 1 file changed, 37 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index f006de9b7263..d4dcab2d851c 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1097,10 +1097,41 @@ drm_atomic_private_obj_fini(struct drm_private_obj *obj)
 	obj->funcs->atomic_destroy_state(obj, obj->state);
 	drm_modeset_lock_fini(&obj->lock);
 }
 EXPORT_SYMBOL(drm_atomic_private_obj_fini);
 
+static int drm_atomic_commit_set_private_obj_state(struct drm_atomic_commit *commit,
+						   struct drm_private_obj *obj,
+						   struct drm_private_state *obj_state)
+{
+	struct __drm_private_objs_state *arr;
+	int index, num_objs;
+	size_t size;
+
+	drm_modeset_lock_assert_held(&obj->lock);
+
+	num_objs = commit->num_private_objs + 1;
+	size = sizeof(*commit->private_objs) * num_objs;
+	arr = krealloc(commit->private_objs, size, GFP_KERNEL);
+	if (!arr)
+		return -ENOMEM;
+
+	commit->private_objs = arr;
+	index = commit->num_private_objs;
+	memset(&commit->private_objs[index], 0, sizeof(*commit->private_objs));
+
+	commit->private_objs[index].state_to_destroy = obj_state;
+	commit->private_objs[index].old_state = obj->state;
+	commit->private_objs[index].new_state = obj_state;
+	commit->private_objs[index].ptr = obj;
+	obj_state->state = commit;
+
+	commit->num_private_objs = num_objs;
+
+	return 0;
+}
+
 /**
  * drm_atomic_get_private_obj_state - get private object state
  * @state: global atomic state
  * @obj: private object to get the state for
  *
@@ -1113,13 +1144,11 @@ EXPORT_SYMBOL(drm_atomic_private_obj_fini);
  */
 struct drm_private_state *
 drm_atomic_get_private_obj_state(struct drm_atomic_commit *state,
 				 struct drm_private_obj *obj)
 {
-	int index, num_objs, ret;
-	size_t size;
-	struct __drm_private_objs_state *arr;
+	int ret;
 	struct drm_private_state *obj_state;
 
 	WARN_ON(!state->acquire_ctx);
 	drm_WARN_ON(state->dev, state->checked);
 
@@ -1129,31 +1158,19 @@ drm_atomic_get_private_obj_state(struct drm_atomic_commit *state,
 
 	ret = drm_modeset_lock(&obj->lock, state->acquire_ctx);
 	if (ret)
 		return ERR_PTR(ret);
 
-	num_objs = state->num_private_objs + 1;
-	size = sizeof(*state->private_objs) * num_objs;
-	arr = krealloc(state->private_objs, size, GFP_KERNEL);
-	if (!arr)
-		return ERR_PTR(-ENOMEM);
-
-	state->private_objs = arr;
-	index = state->num_private_objs;
-	memset(&state->private_objs[index], 0, sizeof(*state->private_objs));
-
 	obj_state = obj->funcs->atomic_duplicate_state(obj);
 	if (!obj_state)
 		return ERR_PTR(-ENOMEM);
 
-	state->private_objs[index].state_to_destroy = obj_state;
-	state->private_objs[index].old_state = obj->state;
-	state->private_objs[index].new_state = obj_state;
-	state->private_objs[index].ptr = obj;
-	obj_state->state = state;
-
-	state->num_private_objs = num_objs;
+	ret = drm_atomic_commit_set_private_obj_state(state, obj, obj_state);
+	if (ret) {
+		obj->funcs->atomic_destroy_state(obj, obj_state);
+		return ERR_PTR(ret);
+	}
 
 	drm_dbg_atomic(state->dev,
 		       "Added new private object %p state %p to %p\n",
 		       obj, obj_state, state);
 

-- 
2.54.0