drm/gem: Add drm_gem_dumb_map_offset()

Add a common drm_driver.dumb_map_offset function for GEM backed drivers.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1500837417-40580-2-git-send-email-noralf@tronnes.org

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 5df028a6dd9f26eafd24fa17973f481fccd8a69b..a8d396bed6a46fa683ffb5f47ace8a828e75c2ef 100644 (file)
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -310,6 +310,41 @@ drm_gem_handle_delete(struct drm_file *filp, u32 handle)
 }
 EXPORT_SYMBOL(drm_gem_handle_delete);
 
+/**
+ * drm_gem_dumb_map_offset - return the fake mmap offset for a gem object
+ * @file: drm file-private structure containing the gem object
+ * @dev: corresponding drm_device
+ * @handle: gem object handle
+ * @offset: return location for the fake mmap offset
+ *
+ * This implements the &drm_driver.dumb_map_offset kms driver callback for
+ * drivers which use gem to manage their backing storage.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
+                           u32 handle, u64 *offset)
+{
+       struct drm_gem_object *obj;
+       int ret;
+
+       obj = drm_gem_object_lookup(file, handle);
+       if (!obj)
+               return -ENOENT;
+
+       ret = drm_gem_create_mmap_offset(obj);
+       if (ret)
+               goto out;
+
+       *offset = drm_vma_node_offset_addr(&obj->vma_node);
+out:
+       drm_gem_object_put_unlocked(obj);
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(drm_gem_dumb_map_offset);
+
 /**
  * drm_gem_dumb_destroy - dumb fb callback helper for gem based drivers
  * @file: drm file-private structure to remove the dumb handle from

diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index 4a9d231b42941e7dd2bd563484f5c16427ad04dc..9c55c2acaa2b366dc5b93f068f66575aa3177a64 100644 (file)
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -302,6 +302,8 @@ void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
                bool dirty, bool accessed);
 
 struct drm_gem_object *drm_gem_object_lookup(struct drm_file *filp, u32 handle);
+int drm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
+                           u32 handle, u64 *offset);
 int drm_gem_dumb_destroy(struct drm_file *file,
                         struct drm_device *dev,
                         uint32_t handle);