text: /* SPDX-License-Identifier: BSD-3-Clause */
  /*
   * Authors: Roxana Nicolescu <nicolescu.roxana1996@gmail.com>
   *
   * Copyright (c) 2019, University Politehnica of Bucharest.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. Neither the name of the copyright holder nor the names of its
   *    contributors may be used to endorse or promote products derived from
   *    this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   *
   * THIS HEADER MAY NOT BE EXTRACTED OR MODIFIED IN ANY WAY.
   */
  #ifndef __BLKFRONT_XB_H__
  #define __BLKFRONT_XB_H__
  
  /**
   * Blkfront interface for xenstore operations.
   *
   * This header contains all the functions needed by the blkfront driver
   * in order to access Xenstore data.
   */
  
  #include "blkfront.h"
  
  /*
   * Get initial info from the xenstore.
   * Ex: backend path, handle, max-queues.
   *
   * Return 0 on success, a negative errno value on error.
   */
  int blkfront_xb_init(struct blkfront_dev *dev);
  
  /*
   * It deallocates the xendev structure members allocated during initialization.
   */
  void blkfront_xb_fini(struct blkfront_dev *dev);
  
  /**
   * Write nb of queues for further use to Xenstore.
   * Return 0 on success, a negative errno value on error.
   */
  int blkfront_xb_write_nb_queues(struct blkfront_dev *dev);
  
  /**
   * Write ring entries to Xenstore.
   * Device changes its state to Connected.
   * It waits until the backend is connected.
   *
   * Return 0 on success, a negative errno value on error.
   */
  int blkfront_xb_connect(struct blkfront_dev *dev);
  
  /**
   * Reinitialize the connection with the backend.
   * The following states are:
   *	Connected -> Closing -> Closed -> Initializing.
   * Delete ring entries
   *
   * Return 0 on success, a negative errno value on error.
   */
  int blkfront_xb_disconnect(struct blkfront_dev *dev);
  
  #endif /* __BLKFRONT_XB_H__ */
  