drm/prime: Introduce drm_gem_prime_import_dev

The existing drm_gem_prime_import function uses the underlying
struct device of a drm_device for attaching to a dma_buf. Some drivers
(notably vgem) may not have an underlying device structure. Offer
an alternate function to attach using any available device structure.
Signed-off-by: Laura Abbott <labbott@redhat.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1493923548-20878-3-git-send-email-labbott@redhat.com

drivers/gpu/drm/drm_prime.c

@@ -595,15 +595,18 @@ int drm_gem_prime_handle_to_fd(struct drm_device *dev,
 EXPORT_SYMBOL(drm_gem_prime_handle_to_fd);
 
 /**
- * drm_gem_prime_import - helper library implementation of the import callback
+ * drm_gem_prime_import_dev - core implementation of the import callback
  * @dev: drm_device to import into
  * @dma_buf: dma-buf object to import
+ * @attach_dev: struct device to dma_buf attach
  *
- * This is the implementation of the gem_prime_import functions for GEM drivers
- * using the PRIME helpers.
+ * This is the core of drm_gem_prime_import. It's designed to be called by
+ * drivers who want to use a different device structure than dev->dev for
+ * attaching via dma_buf.
  */
-struct drm_gem_object *drm_gem_prime_import(struct drm_device *dev,
-					    struct dma_buf *dma_buf)
+struct drm_gem_object *drm_gem_prime_import_dev(struct drm_device *dev,
+					    struct dma_buf *dma_buf,
+					    struct device *attach_dev)
 {
 	struct dma_buf_attachment *attach;
 	struct sg_table *sgt;
@@ -625,7 +628,7 @@ struct drm_gem_object *drm_gem_prime_import(struct drm_device *dev,
 	if (!dev->driver->gem_prime_import_sg_table)
 		return ERR_PTR(-EINVAL);
 
-	attach = dma_buf_attach(dma_buf, dev->dev);
+	attach = dma_buf_attach(dma_buf, attach_dev);
 	if (IS_ERR(attach))
 		return ERR_CAST(attach);
 
@@ -655,6 +658,21 @@ struct drm_gem_object *drm_gem_prime_import(struct drm_device *dev,
 
 	return ERR_PTR(ret);
 }
+EXPORT_SYMBOL(drm_gem_prime_import_dev);
+
+/**
+ * drm_gem_prime_import - helper library implementation of the import callback
+ * @dev: drm_device to import into
+ * @dma_buf: dma-buf object to import
+ *
+ * This is the implementation of the gem_prime_import functions for GEM drivers
+ * using the PRIME helpers.
+ */
+struct drm_gem_object *drm_gem_prime_import(struct drm_device *dev,
+					    struct dma_buf *dma_buf)
+{
+	return drm_gem_prime_import_dev(dev, dma_buf, dev->dev);
+}
 EXPORT_SYMBOL(drm_gem_prime_import);
 
 /**

include/drm/drm_prime.h

@@ -65,6 +65,11 @@ int drm_gem_prime_handle_to_fd(struct drm_device *dev,
 			       int *prime_fd);
 struct drm_gem_object *drm_gem_prime_import(struct drm_device *dev,
 					    struct dma_buf *dma_buf);
+
+struct drm_gem_object *drm_gem_prime_import_dev(struct drm_device *dev,
+						struct dma_buf *dma_buf,
+						struct device *attach_dev);
+
 int drm_gem_prime_fd_to_handle(struct drm_device *dev,
 			       struct drm_file *file_priv, int prime_fd, uint32_t *handle);
 struct dma_buf *drm_gem_dmabuf_export(struct drm_device *dev,