drm/atomic: integrate modeset lock with private objects

Follow the same pattern of locking as with other state objects. This
avoids boilerplate in the driver.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20181022123122.30468-1-boris.brezillon@bootlin.com

1 files changed, 15 insertions, 4 deletions

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 9ac26437051b..008224f376fe 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -676,6 +676,7 @@ static void drm_atomic_plane_print_state(struct drm_printer *p,
 
 /**
  * drm_atomic_private_obj_init - initialize private object
+ * @dev: DRM device this object will be attached to
  * @obj: private object
  * @state: initial private object state
  * @funcs: pointer to the struct of function pointers that identify the object
@@ -685,14 +686,18 @@ static void drm_atomic_plane_print_state(struct drm_printer *p,
  * driver private object that needs its own atomic state.
  */
 void
-drm_atomic_private_obj_init(struct drm_private_obj *obj,
+drm_atomic_private_obj_init(struct drm_device *dev,
+			    struct drm_private_obj *obj,
 			    struct drm_private_state *state,
 			    const struct drm_private_state_funcs *funcs)
 {
 	memset(obj, 0, sizeof(*obj));
 
+	drm_modeset_lock_init(&obj->lock);
+
 	obj->state = state;
 	obj->funcs = funcs;
+	list_add_tail(&obj->head, &dev->mode_config.privobj_list);
 }
 EXPORT_SYMBOL(drm_atomic_private_obj_init);
 
@@ -705,7 +710,9 @@ EXPORT_SYMBOL(drm_atomic_private_obj_init);
 void
 drm_atomic_private_obj_fini(struct drm_private_obj *obj)
 {
+	list_del(&obj->head);
 	obj->funcs->atomic_destroy_state(obj, obj->state);
+	drm_modeset_lock_fini(&obj->lock);
 }
 EXPORT_SYMBOL(drm_atomic_private_obj_fini);
 
@@ -715,8 +722,8 @@ EXPORT_SYMBOL(drm_atomic_private_obj_fini);
  * @obj: private object to get the state for
  *
  * This function returns the private object state for the given private object,
- * allocating the state if needed. It does not grab any locks as the caller is
- * expected to care of any required locking.
+ * allocating the state if needed. It will also grab the relevant private
+ * object lock to make sure that the state is consistent.
  *
  * RETURNS:
  *
@@ -726,7 +733,7 @@ struct drm_private_state *
 drm_atomic_get_private_obj_state(struct drm_atomic_state *state,
 				 struct drm_private_obj *obj)
 {
-	int index, num_objs, i;
+	int index, num_objs, i, ret;
 	size_t size;
 	struct __drm_private_objs_state *arr;
 	struct drm_private_state *obj_state;
@@ -735,6 +742,10 @@ drm_atomic_get_private_obj_state(struct drm_atomic_state *state,
 		if (obj == state->private_objs[i].ptr)
 			return state->private_objs[i].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);