[RFC 1/3] drm/driver: Add defaults for .gem_prime_export/import callbacks

[Noralf Trønnes]

The majority of drivers use drm_gem_prime_export() and
drm_gem_prime_import() for these callbacks so let's make them the
default.

Signed-off-by: Noralf Trønnes <noralf at tronnes.org>
---
 Documentation/gpu/todo.rst  |  7 +++++++
 drivers/gpu/drm/drm_prime.c | 10 ++++++++--
 include/drm/drm_drv.h       |  4 ++++
 3 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
index 77c2b3c25565..39748e22dea8 100644
--- a/Documentation/gpu/todo.rst
+++ b/Documentation/gpu/todo.rst
@@ -234,6 +234,13 @@ efficient.
 
 Contact: Daniel Vetter
 
+Defaults for .gem_prime_import and export
+-----------------------------------------
+
+Most drivers don't need to set drm_driver->gem_prime_import and
+->gem_prime_export now that drm_gem_prime_import() and drm_gem_prime_export()
+are the default.
+
 Core refactorings
 =================
 
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 3f0205fc0a1a..6721571749ff 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -559,7 +559,10 @@ static struct dma_buf *export_and_register_object(struct drm_device *dev,
 		return dmabuf;
 	}
 
-	dmabuf = dev->driver->gem_prime_export(dev, obj, flags);
+	if (dev->driver->gem_prime_export)
+		dmabuf = dev->driver->gem_prime_export(dev, obj, flags);
+	else
+		dmabuf = drm_gem_prime_export(dev, obj, flags);
 	if (IS_ERR(dmabuf)) {
 		/* normally the created dma-buf takes ownership of the ref,
 		 * but if that fails then drop the ref
@@ -792,7 +795,10 @@ int drm_gem_prime_fd_to_handle(struct drm_device *dev,
 
 	/* never seen this one, need to import */
 	mutex_lock(&dev->object_name_lock);
-	obj = dev->driver->gem_prime_import(dev, dma_buf);
+	if (dev->driver->gem_prime_import)
+		obj = dev->driver->gem_prime_import(dev, dma_buf);
+	else
+		obj = drm_gem_prime_import(dev, dma_buf);
 	if (IS_ERR(obj)) {
 		ret = PTR_ERR(obj);
 		goto out_unlock;
diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
index 8830e3de3a86..1162145f7f68 100644
--- a/include/drm/drm_drv.h
+++ b/include/drm/drm_drv.h
@@ -471,6 +471,8 @@ struct drm_driver {
 	 * @gem_prime_export:
 	 *
 	 * export GEM -> dmabuf
+	 *
+	 * This defaults to drm_gem_prime_export() if not set.
 	 */
 	struct dma_buf * (*gem_prime_export)(struct drm_device *dev,
 				struct drm_gem_object *obj, int flags);
@@ -478,6 +480,8 @@ struct drm_driver {
 	 * @gem_prime_import:
 	 *
 	 * import dmabuf -> GEM
+	 *
+	 * This defaults to drm_gem_prime_import() if not set.
 	 */
 	struct drm_gem_object * (*gem_prime_import)(struct drm_device *dev,
 				struct dma_buf *dma_buf);
-- 
2.15.1