/*
 * Copyright (c) 2004, 2005 Mellanox Technologies Ltd.  All rights reserved.
 * Copyright (c) 2004, 2005 Infinicon Corporation.  All rights reserved.
 * Copyright (c) 2004, 2005 Intel Corporation.  All rights reserved.
 * Copyright (c) 2004, 2005 Topspin Corporation.  All rights reserved.
 * Copyright (c) 2004-2007 Voltaire Corporation.  All rights reserved.
 * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - 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.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */

#include <linux/slab.h>
#include <linux/string.h>

#include "agent.h"
#include "smi.h"
#include "mad_priv.h"

#define SPFX "ib_agent: "

struct ib_agent_port_private {
        struct list_head port_list;
        struct ib_mad_agent *agent[2];
};

static DEFINE_SPINLOCK(ib_agent_port_list_lock);
static LIST_HEAD(ib_agent_port_list);

static struct ib_agent_port_private *
__ib_get_agent_port(const struct ib_device *device, int port_num)
{
        struct ib_agent_port_private *entry;

        list_for_each_entry(entry, &ib_agent_port_list, port_list) {
                /* Need to check both agent[0] and agent[1], as an agent port
                 * may only have one of them
                 */
                if (entry->agent[0] &&
                    entry->agent[0]->device == device &&
                    entry->agent[0]->port_num == port_num)
                        return entry;

                if (entry->agent[1] &&
                    entry->agent[1]->device == device &&
                    entry->agent[1]->port_num == port_num)
                        return entry;
        }
        return NULL;
}

static struct ib_agent_port_private *
ib_get_agent_port(const struct ib_device *device, int port_num)
{
        struct ib_agent_port_private *entry;
        unsigned long flags;

        spin_lock_irqsave(&ib_agent_port_list_lock, flags);
        entry = __ib_get_agent_port(device, port_num);
        spin_unlock_irqrestore(&ib_agent_port_list_lock, flags);
        return entry;
}

void agent_send_response(const struct ib_mad_hdr *mad_hdr, const struct ib_grh *grh,
                         const struct ib_wc *wc, const struct ib_device *device,
                         int port_num, int qpn, size_t resp_mad_len, bool opa)
{
        struct ib_agent_port_private *port_priv;
        struct ib_mad_agent *agent;
        struct ib_mad_send_buf *send_buf;
        struct ib_ah *ah;
        struct ib_mad_send_wr_private *mad_send_wr;

        if (rdma_cap_ib_switch(device))
                port_priv = ib_get_agent_port(device, 0);
        else
                port_priv = ib_get_agent_port(device, port_num);

        if (!port_priv) {
                dev_err(&device->dev, "Unable to find port agent\n");
                return;
        }

        agent = port_priv->agent[qpn];
        ah = ib_create_ah_from_wc(agent->qp->pd, wc, grh, port_num);
        if (IS_ERR(ah)) {
                dev_err(&device->dev, "ib_create_ah_from_wc error %pe\n", ah);
                return;
        }

        if (opa && mad_hdr->base_version != OPA_MGMT_BASE_VERSION)
                resp_mad_len = IB_MGMT_MAD_SIZE;

        send_buf = ib_create_send_mad(agent, wc->src_qp, wc->pkey_index, 0,
                                      IB_MGMT_MAD_HDR,
                                      resp_mad_len - IB_MGMT_MAD_HDR,
                                      GFP_KERNEL,
                                      mad_hdr->base_version);
        if (IS_ERR(send_buf)) {
                dev_err(&device->dev, "ib_create_send_mad error\n");
                goto err1;
        }

        memcpy(send_buf->mad, mad_hdr, resp_mad_len);
        send_buf->ah = ah;

        if (rdma_cap_ib_switch(device)) {
                mad_send_wr = container_of(send_buf,
                                           struct ib_mad_send_wr_private,
                                           send_buf);
                mad_send_wr->send_wr.port_num = port_num;
        }

        if (ib_post_send_mad(send_buf, NULL)) {
                dev_err(&device->dev, "ib_post_send_mad error\n");
                goto err2;
        }
        return;
err2:
        ib_free_send_mad(send_buf);
err1:
        rdma_destroy_ah(ah, RDMA_DESTROY_AH_SLEEPABLE);
}

static void agent_send_handler(struct ib_mad_agent *mad_agent,
                               struct ib_mad_send_wc *mad_send_wc)
{
        rdma_destroy_ah(mad_send_wc->send_buf->ah, RDMA_DESTROY_AH_SLEEPABLE);
        ib_free_send_mad(mad_send_wc->send_buf);
}

int ib_agent_port_open(struct ib_device *device, int port_num)
{
        struct ib_agent_port_private *port_priv;
        unsigned long flags;
        int ret;

        /* Create new device info */
        port_priv = kzalloc_obj(*port_priv);
        if (!port_priv) {
                ret = -ENOMEM;
                goto error1;
        }

        if (rdma_cap_ib_smi(device, port_num)) {
                /* Obtain send only MAD agent for SMI QP */
                port_priv->agent[0] = ib_register_mad_agent(device, port_num,
                                                            IB_QPT_SMI, NULL, 0,
                                                            &agent_send_handler,
                                                            NULL, NULL, 0);
                if (IS_ERR(port_priv->agent[0])) {
                        ret = PTR_ERR(port_priv->agent[0]);
                        goto error2;
                }
        }

        if (rdma_cap_ib_cm(device, port_num)) {
                /* Obtain send only MAD agent for GSI QP */
                port_priv->agent[1] = ib_register_mad_agent(device, port_num,
                                                            IB_QPT_GSI, NULL, 0,
                                                            &agent_send_handler,
                                                            NULL, NULL, 0);
                if (IS_ERR(port_priv->agent[1])) {
                        ret = PTR_ERR(port_priv->agent[1]);
                        goto error3;
                }
        }

        spin_lock_irqsave(&ib_agent_port_list_lock, flags);
        list_add_tail(&port_priv->port_list, &ib_agent_port_list);
        spin_unlock_irqrestore(&ib_agent_port_list_lock, flags);

        return 0;

error3:
        if (port_priv->agent[0])
                ib_unregister_mad_agent(port_priv->agent[0]);
error2:
        kfree(port_priv);
error1:
        return ret;
}

int ib_agent_port_close(struct ib_device *device, int port_num)
{
        struct ib_agent_port_private *port_priv;
        unsigned long flags;

        spin_lock_irqsave(&ib_agent_port_list_lock, flags);
        port_priv = __ib_get_agent_port(device, port_num);
        if (port_priv == NULL) {
                spin_unlock_irqrestore(&ib_agent_port_list_lock, flags);
                dev_err(&device->dev, "Port %d not found\n", port_num);
                return -ENODEV;
        }
        list_del(&port_priv->port_list);
        spin_unlock_irqrestore(&ib_agent_port_list_lock, flags);

        if (port_priv->agent[1])
                ib_unregister_mad_agent(port_priv->agent[1]);
        if (port_priv->agent[0])
                ib_unregister_mad_agent(port_priv->agent[0]);

        kfree(port_priv);
        return 0;
}