1 files changed, 42 insertions, 16 deletions

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 3dc7acd56b1d..4589ab4bb1ec 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -830,36 +830,62 @@ void *__devm_drm_dev_alloc(struct device *parent,
 EXPORT_SYMBOL(__devm_drm_dev_alloc);
 
 /**
- * drm_dev_alloc - Allocate new DRM device
- * @driver: DRM driver to allocate device for
+ * __drm_dev_alloc - Allocation of a &drm_device instance
  * @parent: Parent device object
+ * @driver: DRM driver
+ * @size: the size of the struct which contains struct drm_device
+ * @offset: the offset of the &drm_device within the container.
  *
- * This is the deprecated version of devm_drm_dev_alloc(), which does not support
- * subclassing through embedding the struct &drm_device in a driver private
- * structure, and which does not support automatic cleanup through devres.
+ * This should *NOT* be by any drivers, but is a dedicated interface for the
+ * corresponding Rust abstraction.
  *
- * RETURNS:
- * Pointer to new DRM device, or ERR_PTR on failure.
+ * This is the same as devm_drm_dev_alloc(), but without the corresponding
+ * resource management through the parent device, but not the same as
+ * drm_dev_alloc(), since the latter is the deprecated version, which does not
+ * support subclassing.
+ *
+ * Returns: A pointer to new DRM device, or an ERR_PTR on failure.
  */
-struct drm_device *drm_dev_alloc(const struct drm_driver *driver,
-				 struct device *parent)
+void *__drm_dev_alloc(struct device *parent,
+		      const struct drm_driver *driver,
+		      size_t size, size_t offset)
 {
-	struct drm_device *dev;
+	void *container;
+	struct drm_device *drm;
 	int ret;
 
-	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
-	if (!dev)
+	container = kzalloc(size, GFP_KERNEL);
+	if (!container)
 		return ERR_PTR(-ENOMEM);
 
-	ret = drm_dev_init(dev, driver, parent);
+	drm = container + offset;
+	ret = drm_dev_init(drm, driver, parent);
 	if (ret) {
-		kfree(dev);
+		kfree(container);
 		return ERR_PTR(ret);
 	}
+	drmm_add_final_kfree(drm, container);
 
-	drmm_add_final_kfree(dev, dev);
+	return container;
+}
+EXPORT_SYMBOL(__drm_dev_alloc);
 
-	return dev;
+/**
+ * drm_dev_alloc - Allocate new DRM device
+ * @driver: DRM driver to allocate device for
+ * @parent: Parent device object
+ *
+ * This is the deprecated version of devm_drm_dev_alloc(), which does not support
+ * subclassing through embedding the struct &drm_device in a driver private
+ * structure, and which does not support automatic cleanup through devres.
+ *
+ * RETURNS:
+ * Pointer to new DRM device, or ERR_PTR on failure.
+ */
+struct drm_device *drm_dev_alloc(const struct drm_driver *driver,
+				 struct device *parent)
+{
+	return __drm_dev_alloc(parent, driver, sizeof(struct drm_device), 0);
 }
 EXPORT_SYMBOL(drm_dev_alloc);