/*
 * 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);
}