+/*----------------------------------------------------------------------*/
+
+/* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
+
+struct kiocb_priv {
+ struct usb_request *req;
+ struct ep_data *epdata;
+ void *buf;
+ char __user *ubuf;
+ unsigned actual;
+};
+
+static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
+{
+ struct kiocb_priv *priv = iocb->private;
+ struct ep_data *epdata;
+ int value;
+
+ local_irq_disable();
+ epdata = priv->epdata;
+ // spin_lock(&epdata->dev->lock);
+ kiocbSetCancelled(iocb);
+ if (likely(epdata && epdata->ep && priv->req))
+ value = usb_ep_dequeue (epdata->ep, priv->req);
+ else
+ value = -EINVAL;
+ // spin_unlock(&epdata->dev->lock);
+ local_irq_enable();
+
+ aio_put_req(iocb);
+ return value;
+}
+
+static ssize_t ep_aio_read_retry(struct kiocb *iocb)
+{
+ struct kiocb_priv *priv = iocb->private;
+ ssize_t status = priv->actual;
+
+ /* we "retry" to get the right mm context for this: */
+ status = copy_to_user(priv->ubuf, priv->buf, priv->actual);
+ if (unlikely(0 != status))
+ status = -EFAULT;
+ else
+ status = priv->actual;
+ kfree(priv->buf);
+ kfree(priv);
+ aio_put_req(iocb);
+ return status;
+}
+
+static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
+{
+ struct kiocb *iocb = req->context;
+ struct kiocb_priv *priv = iocb->private;
+ struct ep_data *epdata = priv->epdata;
+
+ /* lock against disconnect (and ideally, cancel) */
+ spin_lock(&epdata->dev->lock);
+ priv->req = NULL;
+ priv->epdata = NULL;
+ if (NULL == iocb->ki_retry
+ || unlikely(0 == req->actual)
+ || unlikely(kiocbIsCancelled(iocb))) {
+ kfree(req->buf);
+ kfree(priv);
+ iocb->private = NULL;
+ /* aio_complete() reports bytes-transferred _and_ faults */
+ if (unlikely(kiocbIsCancelled(iocb)))
+ aio_put_req(iocb);
+ else
+ aio_complete(iocb,
+ req->actual ? req->actual : req->status,
+ req->status);
+ } else {
+ /* retry() won't report both; so we hide some faults */
+ if (unlikely(0 != req->status))
+ DBG(epdata->dev, "%s fault %d len %d\n",
+ ep->name, req->status, req->actual);
+
+ priv->buf = req->buf;
+ priv->actual = req->actual;
+ kick_iocb(iocb);
+ }
+ spin_unlock(&epdata->dev->lock);
+
+ usb_ep_free_request(ep, req);
+ put_ep(epdata);
+}
+
+static ssize_t
+ep_aio_rwtail(
+ struct kiocb *iocb,
+ char *buf,
+ size_t len,
+ struct ep_data *epdata,
+ char __user *ubuf
+)
+{
+ struct kiocb_priv *priv = (void *) &iocb->private;
+ struct usb_request *req;
+ ssize_t value;
+
+ priv = kmalloc(sizeof *priv, GFP_KERNEL);
+ if (!priv) {
+ value = -ENOMEM;
+fail:
+ kfree(buf);
+ return value;
+ }
+ iocb->private = priv;
+ priv->ubuf = ubuf;
+
+ value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
+ if (unlikely(value < 0)) {
+ kfree(priv);
+ goto fail;
+ }
+
+ iocb->ki_cancel = ep_aio_cancel;
+ get_ep(epdata);
+ priv->epdata = epdata;
+ priv->actual = 0;
+
+ /* each kiocb is coupled to one usb_request, but we can't
+ * allocate or submit those if the host disconnected.
+ */
+ spin_lock_irq(&epdata->dev->lock);
+ if (likely(epdata->ep)) {
+ req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
+ if (likely(req)) {
+ priv->req = req;
+ req->buf = buf;
+ req->length = len;
+ req->complete = ep_aio_complete;
+ req->context = iocb;
+ value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
+ if (unlikely(0 != value))
+ usb_ep_free_request(epdata->ep, req);
+ } else
+ value = -EAGAIN;
+ } else
+ value = -ENODEV;
+ spin_unlock_irq(&epdata->dev->lock);
+
+ up(&epdata->lock);
+
+ if (unlikely(value)) {
+ kfree(priv);
+ put_ep(epdata);
+ } else
+ value = -EIOCBQUEUED;
+ return value;
+}
+
+static ssize_t
+ep_aio_read(struct kiocb *iocb, char __user *ubuf, size_t len, loff_t o)
+{
+ struct ep_data *epdata = iocb->ki_filp->private_data;
+ char *buf;
+
+ if (unlikely(epdata->desc.bEndpointAddress & USB_DIR_IN))
+ return -EINVAL;
+ buf = kmalloc(len, GFP_KERNEL);
+ if (unlikely(!buf))
+ return -ENOMEM;
+ iocb->ki_retry = ep_aio_read_retry;
+ return ep_aio_rwtail(iocb, buf, len, epdata, ubuf);
+}
+
+static ssize_t
+ep_aio_write(struct kiocb *iocb, const char __user *ubuf, size_t len, loff_t o)
+{
+ struct ep_data *epdata = iocb->ki_filp->private_data;
+ char *buf;
+
+ if (unlikely(!(epdata->desc.bEndpointAddress & USB_DIR_IN)))
+ return -EINVAL;
+ buf = kmalloc(len, GFP_KERNEL);
+ if (unlikely(!buf))
+ return -ENOMEM;
+ if (unlikely(copy_from_user(buf, ubuf, len) != 0)) {
+ kfree(buf);
+ return -EFAULT;
+ }
+ return ep_aio_rwtail(iocb, buf, len, epdata, NULL);
+}
+
+/*----------------------------------------------------------------------*/
+