usb: dwc3: gadget: introduce cancelled_list

This list will host cancelled requests who still have TRBs being
processed.

Signed-off-by: Felipe Balbi <[e-mail]>

drivers/usb/dwc3/core.h

···
 /**
  * struct dwc3_ep - device side endpoint representation
  * @endpoint: usb endpoint
+ * @cancelled_list: list of cancelled requests for this endpoint
  * @pending_list: list of pending requests for this endpoint
  * @started_list: list of started requests on this endpoint
  * @wait_end_transfer: wait_queue_head_t for waiting on End Transfer complete
···
  */
 struct dwc3_ep {
 	struct usb_ep		endpoint;
+	struct list_head	cancelled_list;
 	struct list_head	pending_list;
 	struct list_head	started_list;
 

drivers/usb/dwc3/gadget.c

···
 
 	INIT_LIST_HEAD(&dep->pending_list);
 	INIT_LIST_HEAD(&dep->started_list);
+	INIT_LIST_HEAD(&dep->cancelled_list);
 
 	return 0;
 }

drivers/usb/dwc3/gadget.h

···
 	list_move_tail(&req->list, &dep->started_list);
 }
 
+/**
+ * dwc3_gadget_move_cancelled_request - move @req to the cancelled_list
+ * @req: the request to be moved
+ *
+ * Caller should take care of locking. This function will move @req from its
+ * current list to the endpoint's cancelled_list.
+ */
+static inline void dwc3_gadget_move_cancelled_request(struct dwc3_request *req)
+{
+	struct dwc3_ep		*dep = req->dep;
+
+	req->started = false;
+	list_move_tail(&req->list, &dep->cancelled_list);
+}
+
 void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
 		int status);