1 files changed, 62 insertions, 25 deletions

diff --git a/drivers/gpu/drm/drm_gem_framebuffer_helper.c b/drivers/gpu/drm/drm_gem_framebuffer_helper.c
index 3a7ace19a902..86c1907c579a 100644
--- a/drivers/gpu/drm/drm_gem_framebuffer_helper.c
+++ b/drivers/gpu/drm/drm_gem_framebuffer_helper.c
@@ -54,19 +54,15 @@ struct drm_gem_object *drm_gem_fb_get_obj(struct drm_framebuffer *fb,
 }
 EXPORT_SYMBOL_GPL(drm_gem_fb_get_obj);
 
-static struct drm_framebuffer *
-drm_gem_fb_alloc(struct drm_device *dev,
+static int
+drm_gem_fb_init(struct drm_device *dev,
+		 struct drm_framebuffer *fb,
 		 const struct drm_mode_fb_cmd2 *mode_cmd,
 		 struct drm_gem_object **obj, unsigned int num_planes,
 		 const struct drm_framebuffer_funcs *funcs)
 {
-	struct drm_framebuffer *fb;
 	int ret, i;
 
-	fb = kzalloc(sizeof(*fb), GFP_KERNEL);
-	if (!fb)
-		return ERR_PTR(-ENOMEM);
-
 	drm_helper_mode_fill_fb_struct(dev, fb, mode_cmd);
 
 	for (i = 0; i < num_planes; i++)
@@ -76,10 +72,9 @@ drm_gem_fb_alloc(struct drm_device *dev,
 	if (ret) {
 		drm_err(dev, "Failed to init framebuffer: %d\n", ret);
 		kfree(fb);
-		return ERR_PTR(ret);
 	}
 
-	return fb;
+	return ret;
 }
 
 /**
@@ -123,10 +118,13 @@ int drm_gem_fb_create_handle(struct drm_framebuffer *fb, struct drm_file *file,
 EXPORT_SYMBOL(drm_gem_fb_create_handle);
 
 /**
- * drm_gem_fb_create_with_funcs() - Helper function for the
- *                                  &drm_mode_config_funcs.fb_create
- *                                  callback
+ * drm_gem_fb_init_with_funcs() - Helper function for implementing
+ *				  &drm_mode_config_funcs.fb_create
+ *				  callback in cases when the driver
+ *				  allocates a subclass of
+ *				  struct drm_framebuffer
  * @dev: DRM device
+ * @fb: framebuffer object
  * @file: DRM file that holds the GEM handle(s) backing the framebuffer
  * @mode_cmd: Metadata from the userspace framebuffer creation request
  * @funcs: vtable to be used for the new framebuffer object
@@ -134,23 +132,26 @@ EXPORT_SYMBOL(drm_gem_fb_create_handle);
  * This function can be used to set &drm_framebuffer_funcs for drivers that need
  * custom framebuffer callbacks. Use drm_gem_fb_create() if you don't need to
  * change &drm_framebuffer_funcs. The function does buffer size validation.
+ * The buffer size validation is for a general case, though, so users should
+ * pay attention to the checks being appropriate for them or, at least,
+ * non-conflicting.
  *
  * Returns:
- * Pointer to a &drm_framebuffer on success or an error pointer on failure.
+ * Zero or a negative error code.
  */
-struct drm_framebuffer *
-drm_gem_fb_create_with_funcs(struct drm_device *dev, struct drm_file *file,
-			     const struct drm_mode_fb_cmd2 *mode_cmd,
-			     const struct drm_framebuffer_funcs *funcs)
+int drm_gem_fb_init_with_funcs(struct drm_device *dev,
+			       struct drm_framebuffer *fb,
+			       struct drm_file *file,
+			       const struct drm_mode_fb_cmd2 *mode_cmd,
+			       const struct drm_framebuffer_funcs *funcs)
 {
 	const struct drm_format_info *info;
 	struct drm_gem_object *objs[4];
-	struct drm_framebuffer *fb;
 	int ret, i;
 
 	info = drm_get_format_info(dev, mode_cmd);
 	if (!info)
-		return ERR_PTR(-EINVAL);
+		return -EINVAL;
 
 	for (i = 0; i < info->num_planes; i++) {
 		unsigned int width = mode_cmd->width / (i ? info->hsub : 1);
@@ -175,19 +176,55 @@ drm_gem_fb_create_with_funcs(struct drm_device *dev, struct drm_file *file,
 		}
 	}
 
-	fb = drm_gem_fb_alloc(dev, mode_cmd, objs, i, funcs);
-	if (IS_ERR(fb)) {
-		ret = PTR_ERR(fb);
+	ret = drm_gem_fb_init(dev, fb, mode_cmd, objs, i, funcs);
+	if (ret)
 		goto err_gem_object_put;
-	}
 
-	return fb;
+	return 0;
 
 err_gem_object_put:
 	for (i--; i >= 0; i--)
 		drm_gem_object_put_unlocked(objs[i]);
 
-	return ERR_PTR(ret);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(drm_gem_fb_init_with_funcs);
+
+/**
+ * drm_gem_fb_create_with_funcs() - Helper function for the
+ *                                  &drm_mode_config_funcs.fb_create
+ *                                  callback
+ * @dev: DRM device
+ * @file: DRM file that holds the GEM handle(s) backing the framebuffer
+ * @mode_cmd: Metadata from the userspace framebuffer creation request
+ * @funcs: vtable to be used for the new framebuffer object
+ *
+ * This function can be used to set &drm_framebuffer_funcs for drivers that need
+ * custom framebuffer callbacks. Use drm_gem_fb_create() if you don't need to
+ * change &drm_framebuffer_funcs. The function does buffer size validation.
+ *
+ * Returns:
+ * Pointer to a &drm_framebuffer on success or an error pointer on failure.
+ */
+struct drm_framebuffer *
+drm_gem_fb_create_with_funcs(struct drm_device *dev, struct drm_file *file,
+			     const struct drm_mode_fb_cmd2 *mode_cmd,
+			     const struct drm_framebuffer_funcs *funcs)
+{
+	struct drm_framebuffer *fb;
+	int ret;
+
+	fb = kzalloc(sizeof(*fb), GFP_KERNEL);
+	if (!fb)
+		return ERR_PTR(-ENOMEM);
+
+	ret = drm_gem_fb_init_with_funcs(dev, fb, file, mode_cmd, funcs);
+	if (ret) {
+		kfree(fb);
+		return ERR_PTR(ret);
+	}
+
+	return fb;
 }
 EXPORT_SYMBOL_GPL(drm_gem_fb_create_with_funcs);