/*
 * Copyright (c) 2004 Topspin Communications.  All rights reserved.
 * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
 * Copyright (c) 2004 Voltaire, 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/string.h>
#include <linux/slab.h>

#include <rdma/ib_verbs.h>
#include <rdma/ib_mad.h>
#include <rdma/ib_smi.h>

#include "mthca_dev.h"
#include "mthca_cmd.h"

enum {
        MTHCA_VENDOR_CLASS1 = 0x9,
        MTHCA_VENDOR_CLASS2 = 0xa
};

static int mthca_update_rate(struct mthca_dev *dev, u8 port_num)
{
        struct ib_port_attr *tprops = NULL;
        int                  ret;

        tprops = kmalloc(sizeof *tprops, GFP_KERNEL);
        if (!tprops)
                return -ENOMEM;

        ret = ib_query_port(&dev->ib_dev, port_num, tprops);
        if (ret) {
                printk(KERN_WARNING "ib_query_port failed (%d) for %s port %d\n",
                       ret, dev->ib_dev.name, port_num);
                goto out;
        }

        dev->rate[port_num - 1] = tprops->active_speed *
                                  ib_width_enum_to_int(tprops->active_width);

out:
        kfree(tprops);
        return ret;
}

static void update_sm_ah(struct mthca_dev *dev,
                         u8 port_num, u16 lid, u8 sl)
{
        struct ib_ah *new_ah;
        struct rdma_ah_attr ah_attr;
        unsigned long flags;

        if (!dev->send_agent[port_num - 1][0])
                return;

        memset(&ah_attr, 0, sizeof ah_attr);
        ah_attr.type = rdma_ah_find_type(&dev->ib_dev, port_num);
        rdma_ah_set_dlid(&ah_attr, lid);
        rdma_ah_set_sl(&ah_attr, sl);
        rdma_ah_set_port_num(&ah_attr, port_num);

        new_ah = rdma_create_ah(dev->send_agent[port_num - 1][0]->qp->pd,
                                &ah_attr, 0);
        if (IS_ERR(new_ah))
                return;

        spin_lock_irqsave(&dev->sm_lock, flags);
        if (dev->sm_ah[port_num - 1])
                rdma_destroy_ah(dev->sm_ah[port_num - 1], 0);
        dev->sm_ah[port_num - 1] = new_ah;
        spin_unlock_irqrestore(&dev->sm_lock, flags);
}

/*
 * Snoop SM MADs for port info and P_Key table sets, so we can
 * synthesize LID change and P_Key change events.
 */
static void smp_snoop(struct ib_device *ibdev,
                      u8 port_num,
                      const struct ib_mad *mad,
                      u16 prev_lid)
{
        struct ib_event event;

        if ((mad->mad_hdr.mgmt_class  == IB_MGMT_CLASS_SUBN_LID_ROUTED ||
             mad->mad_hdr.mgmt_class  == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) &&
            mad->mad_hdr.method     == IB_MGMT_METHOD_SET) {
                if (mad->mad_hdr.attr_id == IB_SMP_ATTR_PORT_INFO) {
                        struct ib_port_info *pinfo =
                                (struct ib_port_info *) ((struct ib_smp *) mad)->data;
                        u16 lid = be16_to_cpu(pinfo->lid);

                        mthca_update_rate(to_mdev(ibdev), port_num);
                        update_sm_ah(to_mdev(ibdev), port_num,
                                     be16_to_cpu(pinfo->sm_lid),
                                     pinfo->neighbormtu_mastersmsl & 0xf);

                        event.device           = ibdev;
                        event.element.port_num = port_num;

                        if (pinfo->clientrereg_resv_subnetto & 0x80) {
                                event.event    = IB_EVENT_CLIENT_REREGISTER;
                                ib_dispatch_event(&event);
                        }

                        if (prev_lid != lid) {
                                event.event    = IB_EVENT_LID_CHANGE;
                                ib_dispatch_event(&event);
                        }
                }

                if (mad->mad_hdr.attr_id == IB_SMP_ATTR_PKEY_TABLE) {
                        event.device           = ibdev;
                        event.event            = IB_EVENT_PKEY_CHANGE;
                        event.element.port_num = port_num;
                        ib_dispatch_event(&event);
                }
        }
}

static void node_desc_override(struct ib_device *dev,
                               struct ib_mad *mad)
{
        if ((mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_LID_ROUTED ||
             mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) &&
            mad->mad_hdr.method == IB_MGMT_METHOD_GET_RESP &&
            mad->mad_hdr.attr_id == IB_SMP_ATTR_NODE_DESC) {
                mutex_lock(&to_mdev(dev)->cap_mask_mutex);
                memcpy(((struct ib_smp *) mad)->data, dev->node_desc,
                       IB_DEVICE_NODE_DESC_MAX);
                mutex_unlock(&to_mdev(dev)->cap_mask_mutex);
        }
}

static void forward_trap(struct mthca_dev *dev,
                         u8 port_num,
                         const struct ib_mad *mad)
{
        int qpn = mad->mad_hdr.mgmt_class != IB_MGMT_CLASS_SUBN_LID_ROUTED;
        struct ib_mad_send_buf *send_buf;
        struct ib_mad_agent *agent = dev->send_agent[port_num - 1][qpn];
        int ret;
        unsigned long flags;

        if (agent) {
                send_buf = ib_create_send_mad(agent, qpn, 0, 0, IB_MGMT_MAD_HDR,
                                              IB_MGMT_MAD_DATA, GFP_ATOMIC,
                                              IB_MGMT_BASE_VERSION);
                if (IS_ERR(send_buf))
                        return;
                /*
                 * We rely here on the fact that MLX QPs don't use the
                 * address handle after the send is posted (this is
                 * wrong following the IB spec strictly, but we know
                 * it's OK for our devices).
                 */
                spin_lock_irqsave(&dev->sm_lock, flags);
                memcpy(send_buf->mad, mad, sizeof *mad);
                if ((send_buf->ah = dev->sm_ah[port_num - 1]))
                        ret = ib_post_send_mad(send_buf, NULL);
                else
                        ret = -EINVAL;
                spin_unlock_irqrestore(&dev->sm_lock, flags);

                if (ret)
                        ib_free_send_mad(send_buf);
        }
}

int mthca_process_mad(struct ib_device *ibdev,
                      int mad_flags,
                      u8 port_num,
                      const struct ib_wc *in_wc,
                      const struct ib_grh *in_grh,
                      const struct ib_mad_hdr *in, size_t in_mad_size,
                      struct ib_mad_hdr *out, size_t *out_mad_size,
                      u16 *out_mad_pkey_index)
{
        int err;
        u16 slid = in_wc ? ib_lid_cpu16(in_wc->slid) : be16_to_cpu(IB_LID_PERMISSIVE);
        u16 prev_lid = 0;
        struct ib_port_attr pattr;
        const struct ib_mad *in_mad = (const struct ib_mad *)in;
        struct ib_mad *out_mad = (struct ib_mad *)out;

        if (WARN_ON_ONCE(in_mad_size != sizeof(*in_mad) ||
                         *out_mad_size != sizeof(*out_mad)))
                return IB_MAD_RESULT_FAILURE;

        /* Forward locally generated traps to the SM */
        if (in_mad->mad_hdr.method == IB_MGMT_METHOD_TRAP &&
            slid == 0) {
                forward_trap(to_mdev(ibdev), port_num, in_mad);
                return IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_CONSUMED;
        }

        /*
         * Only handle SM gets, sets and trap represses for SM class
         *
         * Only handle PMA and Mellanox vendor-specific class gets and
         * sets for other classes.
         */
        if (in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_LID_ROUTED ||
            in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) {
                if (in_mad->mad_hdr.method   != IB_MGMT_METHOD_GET &&
                    in_mad->mad_hdr.method   != IB_MGMT_METHOD_SET &&
                    in_mad->mad_hdr.method   != IB_MGMT_METHOD_TRAP_REPRESS)
                        return IB_MAD_RESULT_SUCCESS;

                /*
                 * Don't process SMInfo queries or vendor-specific
                 * MADs -- the SMA can't handle them.
                 */
                if (in_mad->mad_hdr.attr_id == IB_SMP_ATTR_SM_INFO ||
                    ((in_mad->mad_hdr.attr_id & IB_SMP_ATTR_VENDOR_MASK) ==
                     IB_SMP_ATTR_VENDOR_MASK))
                        return IB_MAD_RESULT_SUCCESS;
        } else if (in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_PERF_MGMT ||
                   in_mad->mad_hdr.mgmt_class == MTHCA_VENDOR_CLASS1     ||
                   in_mad->mad_hdr.mgmt_class == MTHCA_VENDOR_CLASS2) {
                if (in_mad->mad_hdr.method  != IB_MGMT_METHOD_GET &&
                    in_mad->mad_hdr.method  != IB_MGMT_METHOD_SET)
                        return IB_MAD_RESULT_SUCCESS;
        } else
                return IB_MAD_RESULT_SUCCESS;
        if ((in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_LID_ROUTED ||
             in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) &&
            in_mad->mad_hdr.method == IB_MGMT_METHOD_SET &&
            in_mad->mad_hdr.attr_id == IB_SMP_ATTR_PORT_INFO &&
            !ib_query_port(ibdev, port_num, &pattr))
                prev_lid = ib_lid_cpu16(pattr.lid);

        err = mthca_MAD_IFC(to_mdev(ibdev),
                            mad_flags & IB_MAD_IGNORE_MKEY,
                            mad_flags & IB_MAD_IGNORE_BKEY,
                            port_num, in_wc, in_grh, in_mad, out_mad);
        if (err == -EBADMSG)
                return IB_MAD_RESULT_SUCCESS;
        else if (err) {
                mthca_err(to_mdev(ibdev), "MAD_IFC returned %d\n", err);
                return IB_MAD_RESULT_FAILURE;
        }

        if (!out_mad->mad_hdr.status) {
                smp_snoop(ibdev, port_num, in_mad, prev_lid);
                node_desc_override(ibdev, out_mad);
        }

        /* set return bit in status of directed route responses */
        if (in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE)
                out_mad->mad_hdr.status |= cpu_to_be16(1 << 15);

        if (in_mad->mad_hdr.method == IB_MGMT_METHOD_TRAP_REPRESS)
                /* no response for trap repress */
                return IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_CONSUMED;

        return IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_REPLY;
}

static void send_handler(struct ib_mad_agent *agent,
                         struct ib_mad_send_wc *mad_send_wc)
{
        ib_free_send_mad(mad_send_wc->send_buf);
}

int mthca_create_agents(struct mthca_dev *dev)
{
        struct ib_mad_agent *agent;
        int p, q;
        int ret;

        spin_lock_init(&dev->sm_lock);

        for (p = 0; p < dev->limits.num_ports; ++p)
                for (q = 0; q <= 1; ++q) {
                        agent = ib_register_mad_agent(&dev->ib_dev, p + 1,
                                                      q ? IB_QPT_GSI : IB_QPT_SMI,
                                                      NULL, 0, send_handler,
                                                      NULL, NULL, 0);
                        if (IS_ERR(agent)) {
                                ret = PTR_ERR(agent);
                                goto err;
                        }
                        dev->send_agent[p][q] = agent;
                }

        for (p = 1; p <= dev->limits.num_ports; ++p) {
                ret = mthca_update_rate(dev, p);
                if (ret) {
                        mthca_err(dev, "Failed to obtain port %d rate."
                                  " aborting.\n", p);
                        goto err;
                }
        }

        return 0;

err:
        for (p = 0; p < dev->limits.num_ports; ++p)
                for (q = 0; q <= 1; ++q)
                        if (dev->send_agent[p][q])
                                ib_unregister_mad_agent(dev->send_agent[p][q]);

        return ret;
}

void mthca_free_agents(struct mthca_dev *dev)
{
        struct ib_mad_agent *agent;
        int p, q;

        for (p = 0; p < dev->limits.num_ports; ++p) {
                for (q = 0; q <= 1; ++q) {
                        agent = dev->send_agent[p][q];
                        dev->send_agent[p][q] = NULL;
                        ib_unregister_mad_agent(agent);
                }

                if (dev->sm_ah[p])
                        rdma_destroy_ah(dev->sm_ah[p],
                                        RDMA_DESTROY_AH_SLEEPABLE);
        }
}