+static struct arpc *arpc_alloc(void *payload, u16 size, u8 type)
+{
+ struct arpc *rpc;
+
+ if (size + sizeof(*rpc->req) > ARPC_OUT_SIZE_MAX)
+ return NULL;
+
+ rpc = kzalloc(sizeof(*rpc), GFP_KERNEL);
+ if (!rpc)
+ return NULL;
+
+ INIT_LIST_HEAD(&rpc->list);
+ rpc->req = kzalloc(sizeof(*rpc->req) + size, GFP_KERNEL);
+ if (!rpc->req)
+ goto err_free_rpc;
+
+ rpc->resp = kzalloc(sizeof(*rpc->resp), GFP_KERNEL);
+ if (!rpc->resp)
+ goto err_free_req;
+
+ rpc->req->type = type;
+ rpc->req->size = cpu_to_le16(sizeof(rpc->req) + size);
+ memcpy(rpc->req->data, payload, size);
+
+ init_completion(&rpc->response_received);
+
+ return rpc;
+
+err_free_req:
+ kfree(rpc->req);
+err_free_rpc:
+ kfree(rpc);
+
+ return NULL;
+}
+
+static void arpc_free(struct arpc *rpc)
+{
+ kfree(rpc->req);
+ kfree(rpc->resp);
+ kfree(rpc);
+}
+
+static struct arpc *arpc_find(struct es2_ap_dev *es2, __le16 id)
+{
+ struct arpc *rpc;
+
+ list_for_each_entry(rpc, &es2->arpcs, list) {
+ if (rpc->req->id == id)
+ return rpc;
+ }
+
+ return NULL;
+}
+
+static void arpc_add(struct es2_ap_dev *es2, struct arpc *rpc)
+{
+ rpc->active = true;
+ rpc->req->id = cpu_to_le16(es2->arpc_id_cycle++);
+ list_add_tail(&rpc->list, &es2->arpcs);
+}
+
+static void arpc_del(struct es2_ap_dev *es2, struct arpc *rpc)
+{
+ if (rpc->active) {
+ rpc->active = false;
+ list_del(&rpc->list);
+ }
+}
+
+static int arpc_send(struct es2_ap_dev *es2, struct arpc *rpc, int timeout)
+{
+ struct usb_device *udev = es2->usb_dev;
+ int retval;
+
+ retval = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+ GB_APB_REQUEST_ARPC_RUN,
+ USB_DIR_OUT | USB_TYPE_VENDOR |
+ USB_RECIP_INTERFACE,
+ 0, 0,
+ rpc->req, le16_to_cpu(rpc->req->size),
+ ES2_USB_CTRL_TIMEOUT);
+ if (retval != le16_to_cpu(rpc->req->size)) {
+ dev_err(&udev->dev,
+ "failed to send ARPC request %d: %d\n",
+ rpc->req->type, retval);
+ if (retval > 0)
+ retval = -EIO;
+ return retval;
+ }
+
+ return 0;
+}
+
+static int arpc_sync(struct es2_ap_dev *es2, u8 type, void *payload,
+ size_t size, int *result, unsigned int timeout)
+{
+ struct arpc *rpc;
+ unsigned long flags;
+ int retval;
+
+ if (result)
+ *result = 0;
+
+ rpc = arpc_alloc(payload, size, type);
+ if (!rpc)
+ return -ENOMEM;
+
+ spin_lock_irqsave(&es2->arpc_lock, flags);
+ arpc_add(es2, rpc);
+ spin_unlock_irqrestore(&es2->arpc_lock, flags);
+
+ retval = arpc_send(es2, rpc, timeout);
+ if (retval)
+ goto out_arpc_del;
+
+ retval = wait_for_completion_interruptible_timeout(
+ &rpc->response_received,
+ msecs_to_jiffies(timeout));
+ if (retval <= 0) {
+ if (!retval)
+ retval = -ETIMEDOUT;
+ goto out_arpc_del;
+ }
+
+ if (rpc->resp->result) {
+ retval = -EREMOTEIO;
+ if (result)
+ *result = rpc->resp->result;
+ } else {
+ retval = 0;
+ }
+
+out_arpc_del:
+ spin_lock_irqsave(&es2->arpc_lock, flags);
+ arpc_del(es2, rpc);
+ spin_unlock_irqrestore(&es2->arpc_lock, flags);
+ arpc_free(rpc);
+
+ if (retval < 0 && retval != -EREMOTEIO) {
+ dev_err(&es2->usb_dev->dev,
+ "failed to execute ARPC: %d\n", retval);
+ }
+
+ return retval;
+}
+
+static void arpc_in_callback(struct urb *urb)
+{
+ struct es2_ap_dev *es2 = urb->context;
+ struct device *dev = &urb->dev->dev;
+ int status = check_urb_status(urb);
+ struct arpc *rpc;
+ struct arpc_response_message *resp;
+ unsigned long flags;
+ int retval;
+
+ if (status) {
+ if ((status == -EAGAIN) || (status == -EPROTO))
+ goto exit;
+
+ /* The urb is being unlinked */
+ if (status == -ENOENT || status == -ESHUTDOWN)
+ return;
+
+ dev_err(dev, "arpc in-urb error %d (dropped)\n", status);
+ return;
+ }
+
+ if (urb->actual_length < sizeof(*resp)) {
+ dev_err(dev, "short aprc response received\n");
+ goto exit;
+ }
+
+ resp = urb->transfer_buffer;
+ spin_lock_irqsave(&es2->arpc_lock, flags);
+ rpc = arpc_find(es2, resp->id);
+ if (!rpc) {
+ dev_err(dev, "invalid arpc response id received: %u\n",
+ le16_to_cpu(resp->id));
+ spin_unlock_irqrestore(&es2->arpc_lock, flags);
+ goto exit;
+ }
+
+ arpc_del(es2, rpc);
+ memcpy(rpc->resp, resp, sizeof(*resp));
+ complete(&rpc->response_received);
+ spin_unlock_irqrestore(&es2->arpc_lock, flags);
+
+exit:
+ /* put our urb back in the request pool */
+ retval = usb_submit_urb(urb, GFP_ATOMIC);
+ if (retval)
+ dev_err(dev, "failed to resubmit arpc in-urb: %d\n", retval);
+}
+