/*
   * Intel MIC Platform Software Stack (MPSS)
   *
   * Copyright(c) 2014 Intel Corporation.
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License, version 2, as
   * published by the Free Software Foundation.
   *
   * This program is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
   * General Public License for more details.
   *
   * Intel SCIF driver.
   *
   */
  #include "scif_peer_bus.h"
  
  #include "scif_main.h"
  #include "scif_map.h"
  
  /**
   * scif_invalidate_ep() - Set state for all connected endpoints
   * to disconnected and wake up all send/recv waitqueues
   */
  static void scif_invalidate_ep(int node)
  {
  	struct scif_endpt *ep;
  	struct list_head *pos, *tmpq;
  
  	flush_work(&scif_info.conn_work);
  	mutex_lock(&scif_info.connlock);
  	list_for_each_safe(pos, tmpq, &scif_info.disconnected) {
  		ep = list_entry(pos, struct scif_endpt, list);
  		if (ep->remote_dev->node == node) {
  			scif_unmap_all_windows(ep);
  			spin_lock(&ep->lock);
  			scif_cleanup_ep_qp(ep);
  			spin_unlock(&ep->lock);
  		}
  	}
  	list_for_each_safe(pos, tmpq, &scif_info.connected) {
  		ep = list_entry(pos, struct scif_endpt, list);
  		if (ep->remote_dev->node == node) {
  			list_del(pos);
  			spin_lock(&ep->lock);
  			ep->state = SCIFEP_DISCONNECTED;
  			list_add_tail(&ep->list, &scif_info.disconnected);
  			scif_cleanup_ep_qp(ep);
  			wake_up_interruptible(&ep->sendwq);
  			wake_up_interruptible(&ep->recvwq);
  			spin_unlock(&ep->lock);
  			scif_unmap_all_windows(ep);
  		}
  	}
  	mutex_unlock(&scif_info.connlock);
  }
  
  void scif_free_qp(struct scif_dev *scifdev)
  {
  	struct scif_qp *qp = scifdev->qpairs;
  
  	if (!qp)
  		return;
  	scif_unmap_single(qp->local_buf, scifdev, qp->inbound_q.size);
  	kfree(qp->inbound_q.rb_base);
  	scif_unmap_single(qp->local_qp, scifdev, sizeof(struct scif_qp));
  	kfree(scifdev->qpairs);
  	scifdev->qpairs = NULL;
  }
  
  static void scif_cleanup_qp(struct scif_dev *dev)
  {
  	struct scif_qp *qp = &dev->qpairs[0];
  
  	if (!qp)
  		return;
  	scif_iounmap((void *)qp->remote_qp, sizeof(struct scif_qp), dev);
  	scif_iounmap((void *)qp->outbound_q.rb_base,
  		     sizeof(struct scif_qp), dev);
  	qp->remote_qp = NULL;
  	qp->local_write = 0;
  	qp->inbound_q.current_write_offset = 0;
  	qp->inbound_q.current_read_offset = 0;
  	if (scifdev_is_p2p(dev))
  		scif_free_qp(dev);
  }
  
  void scif_send_acks(struct scif_dev *dev)
  {
  	struct scifmsg msg;
  
  	if (dev->node_remove_ack_pending) {
  		msg.uop = SCIF_NODE_REMOVE_ACK;
  		msg.src.node = scif_info.nodeid;
  		msg.dst.node = SCIF_MGMT_NODE;
  		msg.payload[0] = dev->node;
  		scif_nodeqp_send(&scif_dev[SCIF_MGMT_NODE], &msg);
  		dev->node_remove_ack_pending = false;
  	}
  	if (dev->exit_ack_pending) {
  		msg.uop = SCIF_EXIT_ACK;
  		msg.src.node = scif_info.nodeid;
  		msg.dst.node = dev->node;
  		scif_nodeqp_send(dev, &msg);
  		dev->exit_ack_pending = false;
  	}
  }
  
  /*
   * scif_cleanup_scifdev
   *
   * @dev: Remote SCIF device.
   * Uninitialize SCIF data structures for remote SCIF device.
   */
  void scif_cleanup_scifdev(struct scif_dev *dev)
  {
  	struct scif_hw_dev *sdev = dev->sdev;
  
  	if (!dev->sdev)
  		return;
  	if (scifdev_is_p2p(dev)) {
  		if (dev->cookie) {
  			sdev->hw_ops->free_irq(sdev, dev->cookie, dev);
  			dev->cookie = NULL;
  		}
  		scif_destroy_intr_wq(dev);
  	}
  	flush_work(&scif_info.misc_work);
  	scif_destroy_p2p(dev);
  	scif_invalidate_ep(dev->node);
  	scif_zap_mmaps(dev->node);
  	scif_cleanup_rma_for_zombies(dev->node);
  	flush_work(&scif_info.misc_work);
  	scif_send_acks(dev);
  	if (!dev->node && scif_info.card_initiated_exit) {
  		/*
  		 * Send an SCIF_EXIT message which is the last message from MIC
  		 * to the Host and wait for a SCIF_EXIT_ACK
  		 */
  		scif_send_exit(dev);
  		scif_info.card_initiated_exit = false;
  	}
  	scif_cleanup_qp(dev);
  }
  
  /*
   * scif_remove_node:
   *
   * @node: Node to remove
   */
  void scif_handle_remove_node(int node)
  {
  	struct scif_dev *scifdev = &scif_dev[node];
  
  	if (scif_peer_unregister_device(scifdev))
  		scif_send_acks(scifdev);
  }
  
  static int scif_send_rmnode_msg(int node, int remove_node)
  {
  	struct scifmsg notif_msg;
  	struct scif_dev *dev = &scif_dev[node];
  
  	notif_msg.uop = SCIF_NODE_REMOVE;
  	notif_msg.src.node = scif_info.nodeid;
  	notif_msg.dst.node = node;
  	notif_msg.payload[0] = remove_node;
  	return scif_nodeqp_send(dev, &notif_msg);
  }
  
  /**
   * scif_node_disconnect:
   *
   * @node_id[in]: source node id.
   * @mgmt_initiated: Disconnection initiated from the mgmt node
   *
   * Disconnect a node from the scif network.
   */
  void scif_disconnect_node(u32 node_id, bool mgmt_initiated)
  {
  	int ret;
  	int msg_cnt = 0;
  	u32 i = 0;
  	struct scif_dev *scifdev = &scif_dev[node_id];
  
  	if (!node_id)
  		return;
  
  	atomic_set(&scifdev->disconn_rescnt, 0);
  
  	/* Destroy p2p network */
  	for (i = 1; i <= scif_info.maxid; i++) {
  		if (i == node_id)
  			continue;
  		ret = scif_send_rmnode_msg(i, node_id);
  		if (!ret)
  			msg_cnt++;
  	}
  	/* Wait for the remote nodes to respond with SCIF_NODE_REMOVE_ACK */
  	ret = wait_event_timeout(scifdev->disconn_wq,
  				 (atomic_read(&scifdev->disconn_rescnt)
  				 == msg_cnt), SCIF_NODE_ALIVE_TIMEOUT);
  	/* Tell the card to clean up */
  	if (mgmt_initiated && _scifdev_alive(scifdev))
  		/*
  		 * Send an SCIF_EXIT message which is the last message from Host
  		 * to the MIC and wait for a SCIF_EXIT_ACK
  		 */
  		scif_send_exit(scifdev);
  	atomic_set(&scifdev->disconn_rescnt, 0);
  	/* Tell the mgmt node to clean up */
  	ret = scif_send_rmnode_msg(SCIF_MGMT_NODE, node_id);
  	if (!ret)
  		/* Wait for mgmt node to respond with SCIF_NODE_REMOVE_ACK */
  		wait_event_timeout(scifdev->disconn_wq,
  				   (atomic_read(&scifdev->disconn_rescnt) == 1),
  				   SCIF_NODE_ALIVE_TIMEOUT);
  }
  
  void scif_get_node_info(void)
  {
  	struct scifmsg msg;
  	DECLARE_COMPLETION_ONSTACK(node_info);
  
  	msg.uop = SCIF_GET_NODE_INFO;
  	msg.src.node = scif_info.nodeid;
  	msg.dst.node = SCIF_MGMT_NODE;
  	msg.payload[3] = (u64)&node_info;
  
  	if ((scif_nodeqp_send(&scif_dev[SCIF_MGMT_NODE], &msg)))
  		return;
  
  	/* Wait for a response with SCIF_GET_NODE_INFO */
  	wait_for_completion(&node_info);
  }