/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved.
 */
/*
 * Copyright (c) 2005 SilverStorm Technologies, 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.
 *
 */
/*
 * Sun elects to include this software in Sun product
 * under the OpenIB BSD license.
 *
 *
 * 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 OWNER 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.
 */

#include <sys/types.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/ib/clients/rds/rdsib_cm.h>
#include <sys/ib/clients/rds/rdsib_ib.h>
#include <sys/ib/clients/rds/rdsib_buf.h>
#include <sys/ib/clients/rds/rdsib_ep.h>
#include <sys/ib/clients/rds/rds_kstat.h>

static void rds_async_handler(void *clntp, ibt_hca_hdl_t hdl,
    ibt_async_code_t code, ibt_async_event_t *event);

static struct ibt_clnt_modinfo_s rds_ib_modinfo = {
        IBTI_V_CURR,
        IBT_NETWORK,
        rds_async_handler,
        NULL,
        "RDS"
};

/* performance tunables */
uint_t          rds_no_interrupts = 0;
uint_t          rds_poll_percent_full = 25;
uint_t          rds_wc_signal = IBT_NEXT_SOLICITED;
uint_t          rds_waittime_ms = 100; /* ms */

extern dev_info_t *rdsib_dev_info;
extern void rds_close_sessions();

static void
rdsib_validate_chan_sizes(ibt_hca_attr_t *hattrp)
{
        /* The SQ size should not be more than that supported by the HCA */
        if (((MaxDataSendBuffers + RDS_NUM_ACKS) > hattrp->hca_max_chan_sz) ||
            ((MaxDataSendBuffers + RDS_NUM_ACKS) > hattrp->hca_max_cq_sz)) {
                RDS_DPRINTF2("RDSIB", "MaxDataSendBuffers + %d is greater "
                    "than that supported by the HCA driver "
                    "(%d + %d > %d or %d), lowering it to a supported value.",
                    RDS_NUM_ACKS, MaxDataSendBuffers, RDS_NUM_ACKS,
                    hattrp->hca_max_chan_sz, hattrp->hca_max_cq_sz);

                MaxDataSendBuffers = (hattrp->hca_max_chan_sz >
                    hattrp->hca_max_cq_sz) ?
                    hattrp->hca_max_cq_sz - RDS_NUM_ACKS :
                    hattrp->hca_max_chan_sz - RDS_NUM_ACKS;
        }

        /* The RQ size should not be more than that supported by the HCA */
        if ((MaxDataRecvBuffers > hattrp->hca_max_chan_sz) ||
            (MaxDataRecvBuffers > hattrp->hca_max_cq_sz)) {
                RDS_DPRINTF2("RDSIB", "MaxDataRecvBuffers is greater than that "
                    "supported by the HCA driver (%d > %d or %d), lowering it "
                    "to a supported value.", MaxDataRecvBuffers,
                    hattrp->hca_max_chan_sz, hattrp->hca_max_cq_sz);

                MaxDataRecvBuffers = (hattrp->hca_max_chan_sz >
                    hattrp->hca_max_cq_sz) ? hattrp->hca_max_cq_sz :
                    hattrp->hca_max_chan_sz;
        }

        /* The SQ size should not be more than that supported by the HCA */
        if ((MaxCtrlSendBuffers > hattrp->hca_max_chan_sz) ||
            (MaxCtrlSendBuffers > hattrp->hca_max_cq_sz)) {
                RDS_DPRINTF2("RDSIB", "MaxCtrlSendBuffers is greater than that "
                    "supported by the HCA driver (%d > %d or %d), lowering it "
                    "to a supported value.", MaxCtrlSendBuffers,
                    hattrp->hca_max_chan_sz, hattrp->hca_max_cq_sz);

                MaxCtrlSendBuffers = (hattrp->hca_max_chan_sz >
                    hattrp->hca_max_cq_sz) ? hattrp->hca_max_cq_sz :
                    hattrp->hca_max_chan_sz;
        }

        /* The RQ size should not be more than that supported by the HCA */
        if ((MaxCtrlRecvBuffers > hattrp->hca_max_chan_sz) ||
            (MaxCtrlRecvBuffers > hattrp->hca_max_cq_sz)) {
                RDS_DPRINTF2("RDSIB", "MaxCtrlRecvBuffers is greater than that "
                    "supported by the HCA driver (%d > %d or %d), lowering it "
                    "to a supported value.", MaxCtrlRecvBuffers,
                    hattrp->hca_max_chan_sz, hattrp->hca_max_cq_sz);

                MaxCtrlRecvBuffers = (hattrp->hca_max_chan_sz >
                    hattrp->hca_max_cq_sz) ? hattrp->hca_max_cq_sz :
                    hattrp->hca_max_chan_sz;
        }

        /* The MaxRecvMemory should be less than that supported by the HCA */
        if ((NDataRX * RdsPktSize) > hattrp->hca_max_memr_len) {
                RDS_DPRINTF2("RDSIB", "MaxRecvMemory is greater than that "
                    "supported by the HCA driver (%d > %d), lowering it to %d",
                    NDataRX * RdsPktSize, hattrp->hca_max_memr_len,
                    hattrp->hca_max_memr_len);

                NDataRX = hattrp->hca_max_memr_len/RdsPktSize;
        }
}

/* Return hcap, given the hca guid */
rds_hca_t *
rds_lkup_hca(ib_guid_t hca_guid)
{
        rds_hca_t       *hcap;

        RDS_DPRINTF4("rds_lkup_hca", "Enter: statep: 0x%p "
            "guid: %llx", rdsib_statep, hca_guid);

        rw_enter(&rdsib_statep->rds_hca_lock, RW_READER);

        hcap = rdsib_statep->rds_hcalistp;
        while ((hcap != NULL) && (hcap->hca_guid != hca_guid)) {
                hcap = hcap->hca_nextp;
        }

        rw_exit(&rdsib_statep->rds_hca_lock);

        RDS_DPRINTF4("rds_lkup_hca", "return");

        return (hcap);
}

void rds_randomize_qps(rds_hca_t *hcap);

static rds_hca_t *
rdsib_init_hca(ib_guid_t hca_guid)
{
        rds_hca_t       *hcap;
        boolean_t       alloc = B_FALSE;
        int             ret;

        RDS_DPRINTF2("rdsib_init_hca", "enter: HCA 0x%llx", hca_guid);

        /* Do a HCA lookup */
        hcap = rds_lkup_hca(hca_guid);

        if (hcap != NULL && hcap->hca_hdl != NULL) {
                /*
                 * This can happen if we get IBT_HCA_ATTACH_EVENT on an HCA
                 * that we have already opened. Just return NULL so that
                 * we'll not end up reinitializing the HCA again.
                 */
                RDS_DPRINTF2("rdsib_init_hca", "HCA already initialized");
                return (NULL);
        }

        if (hcap == NULL) {
                RDS_DPRINTF2("rdsib_init_hca", "New HCA is added");
                hcap = (rds_hca_t *)kmem_zalloc(sizeof (rds_hca_t), KM_SLEEP);
                alloc = B_TRUE;
        }

        hcap->hca_guid = hca_guid;
        ret = ibt_open_hca(rdsib_statep->rds_ibhdl, hca_guid,
            &hcap->hca_hdl);
        if (ret != IBT_SUCCESS) {
                if (ret == IBT_HCA_IN_USE) {
                        RDS_DPRINTF2("rdsib_init_hca",
                            "ibt_open_hca: 0x%llx returned IBT_HCA_IN_USE",
                            hca_guid);
                } else {
                        RDS_DPRINTF2("rdsib_init_hca",
                            "ibt_open_hca: 0x%llx failed: %d", hca_guid, ret);
                }
                if (alloc == B_TRUE) {
                        kmem_free(hcap, sizeof (rds_hca_t));
                }
                return (NULL);
        }

        ret = ibt_query_hca(hcap->hca_hdl, &hcap->hca_attr);
        if (ret != IBT_SUCCESS) {
                RDS_DPRINTF2("rdsib_init_hca",
                    "Query HCA: 0x%llx failed:  %d", hca_guid, ret);
                ret = ibt_close_hca(hcap->hca_hdl);
                ASSERT(ret == IBT_SUCCESS);
                if (alloc == B_TRUE) {
                        kmem_free(hcap, sizeof (rds_hca_t));
                } else {
                        hcap->hca_hdl = NULL;
                }
                return (NULL);
        }

        ret = ibt_query_hca_ports(hcap->hca_hdl, 0,
            &hcap->hca_pinfop, &hcap->hca_nports, &hcap->hca_pinfo_sz);
        if (ret != IBT_SUCCESS) {
                RDS_DPRINTF2("rdsib_init_hca",
                    "Query HCA 0x%llx ports failed: %d", hca_guid,
                    ret);
                ret = ibt_close_hca(hcap->hca_hdl);
                hcap->hca_hdl = NULL;
                ASSERT(ret == IBT_SUCCESS);
                if (alloc == B_TRUE) {
                        kmem_free(hcap, sizeof (rds_hca_t));
                } else {
                        hcap->hca_hdl = NULL;
                }
                return (NULL);
        }

        /* Only one PD per HCA is allocated, so do it here */
        ret = ibt_alloc_pd(hcap->hca_hdl, IBT_PD_NO_FLAGS,
            &hcap->hca_pdhdl);
        if (ret != IBT_SUCCESS) {
                RDS_DPRINTF2("rdsib_init_hca",
                    "ibt_alloc_pd 0x%llx failed: %d", hca_guid, ret);
                (void) ibt_free_portinfo(hcap->hca_pinfop,
                    hcap->hca_pinfo_sz);
                ret = ibt_close_hca(hcap->hca_hdl);
                ASSERT(ret == IBT_SUCCESS);
                hcap->hca_hdl = NULL;
                if (alloc == B_TRUE) {
                        kmem_free(hcap, sizeof (rds_hca_t));
                } else {
                        hcap->hca_hdl = NULL;
                }
                return (NULL);
        }

        rdsib_validate_chan_sizes(&hcap->hca_attr);

        /* To minimize stale connections after ungraceful reboots */
        rds_randomize_qps(hcap);

        rw_enter(&rdsib_statep->rds_hca_lock, RW_WRITER);
        hcap->hca_state = RDS_HCA_STATE_OPEN;
        if (alloc == B_TRUE) {
                /* this is a new HCA, add it to the list */
                rdsib_statep->rds_nhcas++;
                hcap->hca_nextp = rdsib_statep->rds_hcalistp;
                rdsib_statep->rds_hcalistp = hcap;
        }
        rw_exit(&rdsib_statep->rds_hca_lock);

        RDS_DPRINTF2("rdsib_init_hca", "return: HCA 0x%llx", hca_guid);

        return (hcap);
}

/*
 * Called from attach
 */
int
rdsib_initialize_ib()
{
        ib_guid_t       *guidp;
        rds_hca_t       *hcap;
        uint_t          ix, hcaix, nhcas;
        int             ret;

        RDS_DPRINTF2("rdsib_initialize_ib", "enter: statep %p", rdsib_statep);

        ASSERT(rdsib_statep != NULL);
        if (rdsib_statep == NULL) {
                RDS_DPRINTF1("rdsib_initialize_ib",
                    "RDS Statep not initialized");
                return (-1);
        }

        /* How many hcas are there? */
        nhcas = ibt_get_hca_list(&guidp);
        if (nhcas == 0) {
                RDS_DPRINTF2("rdsib_initialize_ib", "No IB HCAs Available");
                return (-1);
        }

        RDS_DPRINTF3("rdsib_initialize_ib", "Number of HCAs: %d", nhcas);

        /* Register with IBTF */
        ret = ibt_attach(&rds_ib_modinfo, rdsib_dev_info, rdsib_statep,
            &rdsib_statep->rds_ibhdl);
        if (ret != IBT_SUCCESS) {
                RDS_DPRINTF2("rdsib_initialize_ib", "ibt_attach failed: %d",
                    ret);
                (void) ibt_free_hca_list(guidp, nhcas);
                return (-1);
        }

        /*
         * Open each HCA and gather its information. Don't care about HCAs
         * that cannot be opened. It is OK as long as atleast one HCA can be
         * opened.
         * Initialize a HCA only if all the information is available.
         */
        for (ix = 0, hcaix = 0; ix < nhcas; ix++) {
                RDS_DPRINTF3(LABEL, "Open HCA: 0x%llx", guidp[ix]);

                hcap = rdsib_init_hca(guidp[ix]);
                if (hcap != NULL) hcaix++;
        }

        /* free the HCA list, we are done with it */
        (void) ibt_free_hca_list(guidp, nhcas);

        if (hcaix == 0) {
                /* Failed to Initialize even one HCA */
                RDS_DPRINTF2("rdsib_initialize_ib", "No HCAs are initialized");
                (void) ibt_detach(rdsib_statep->rds_ibhdl);
                rdsib_statep->rds_ibhdl = NULL;
                return (-1);
        }

        if (hcaix < nhcas) {
                RDS_DPRINTF2("rdsib_open_ib", "HCAs %d/%d failed to initialize",
                    (nhcas - hcaix), nhcas);
        }

        RDS_DPRINTF2("rdsib_initialize_ib", "return: statep %p", rdsib_statep);

        return (0);
}

/*
 * Called from detach
 */
void
rdsib_deinitialize_ib()
{
        rds_hca_t       *hcap, *nextp;
        int             ret;

        RDS_DPRINTF2("rdsib_deinitialize_ib", "enter: statep %p", rdsib_statep);

        /* close and destroy all the sessions */
        rds_close_sessions(NULL);

        /* Release all HCA resources */
        rw_enter(&rdsib_statep->rds_hca_lock, RW_WRITER);
        RDS_DPRINTF2("rdsib_deinitialize_ib", "HCA List: %p, NHCA: %d",
            rdsib_statep->rds_hcalistp, rdsib_statep->rds_nhcas);
        hcap = rdsib_statep->rds_hcalistp;
        rdsib_statep->rds_hcalistp = NULL;
        rdsib_statep->rds_nhcas = 0;
        rw_exit(&rdsib_statep->rds_hca_lock);

        while (hcap != NULL) {
                nextp = hcap->hca_nextp;

                if (hcap->hca_hdl != NULL) {
                        ret = ibt_free_pd(hcap->hca_hdl, hcap->hca_pdhdl);
                        ASSERT(ret == IBT_SUCCESS);

                        (void) ibt_free_portinfo(hcap->hca_pinfop,
                            hcap->hca_pinfo_sz);

                        ret = ibt_close_hca(hcap->hca_hdl);
                        ASSERT(ret == IBT_SUCCESS);
                }

                kmem_free(hcap, sizeof (rds_hca_t));
                hcap = nextp;
        }

        /* Deregister with IBTF */
        if (rdsib_statep->rds_ibhdl != NULL) {
                (void) ibt_detach(rdsib_statep->rds_ibhdl);
                rdsib_statep->rds_ibhdl = NULL;
        }

        RDS_DPRINTF2("rdsib_deinitialize_ib", "return: statep %p",
            rdsib_statep);
}

/*
 * Called on open of first RDS socket
 */
int
rdsib_open_ib()
{
        int     ret;

        RDS_DPRINTF2("rdsib_open_ib", "enter: statep %p", rdsib_statep);

        /* Enable incoming connection requests */
        if (rdsib_statep->rds_srvhdl == NULL) {
                rdsib_statep->rds_srvhdl =
                    rds_register_service(rdsib_statep->rds_ibhdl);
                if (rdsib_statep->rds_srvhdl == NULL) {
                        RDS_DPRINTF2("rdsib_open_ib",
                            "Service registration failed");
                        return (-1);
                } else {
                        /* bind the service on all available ports */
                        ret = rds_bind_service(rdsib_statep);
                        if (ret != 0) {
                                RDS_DPRINTF2("rdsib_open_ib",
                                    "Bind service failed: %d", ret);
                        }
                }
        }

        RDS_DPRINTF2("rdsib_open_ib", "return: statep %p", rdsib_statep);

        return (0);
}

/*
 * Called when all ports are closed.
 */
void
rdsib_close_ib()
{
        int     ret;

        RDS_DPRINTF2("rdsib_close_ib", "enter: statep %p", rdsib_statep);

        /* Disable incoming connection requests */
        if (rdsib_statep->rds_srvhdl != NULL) {
                ret = ibt_unbind_all_services(rdsib_statep->rds_srvhdl);
                if (ret != 0) {
                        RDS_DPRINTF2("rdsib_close_ib",
                            "ibt_unbind_all_services failed: %d\n", ret);
                }
                ret = ibt_deregister_service(rdsib_statep->rds_ibhdl,
                    rdsib_statep->rds_srvhdl);
                if (ret != 0) {
                        RDS_DPRINTF2("rdsib_close_ib",
                            "ibt_deregister_service failed: %d\n", ret);
                } else {
                        rdsib_statep->rds_srvhdl = NULL;
                }
        }

        RDS_DPRINTF2("rdsib_close_ib", "return: statep %p", rdsib_statep);
}

/* Return hcap, given the hca guid */
rds_hca_t *
rds_get_hcap(rds_state_t *statep, ib_guid_t hca_guid)
{
        rds_hca_t       *hcap;

        RDS_DPRINTF4("rds_get_hcap", "rds_get_hcap: Enter: statep: 0x%p "
            "guid: %llx", statep, hca_guid);

        rw_enter(&statep->rds_hca_lock, RW_READER);

        hcap = statep->rds_hcalistp;
        while ((hcap != NULL) && (hcap->hca_guid != hca_guid)) {
                hcap = hcap->hca_nextp;
        }

        /*
         * don't let anyone use this HCA until the RECV memory
         * is registered with this HCA
         */
        if ((hcap != NULL) &&
            (hcap->hca_state == RDS_HCA_STATE_MEM_REGISTERED)) {
                ASSERT(hcap->hca_mrhdl != NULL);
                rw_exit(&statep->rds_hca_lock);
                return (hcap);
        }

        RDS_DPRINTF2("rds_get_hcap",
            "HCA (0x%p, 0x%llx) is not initialized", hcap, hca_guid);
        rw_exit(&statep->rds_hca_lock);

        RDS_DPRINTF4("rds_get_hcap", "rds_get_hcap: return");

        return (NULL);
}

/* Return hcap, given a gid */
rds_hca_t *
rds_gid_to_hcap(rds_state_t *statep, ib_gid_t gid)
{
        rds_hca_t       *hcap;
        uint_t          ix;

        RDS_DPRINTF4("rds_gid_to_hcap", "Enter: statep: 0x%p gid: %llx:%llx",
            statep, gid.gid_prefix, gid.gid_guid);

        rw_enter(&statep->rds_hca_lock, RW_READER);

        hcap = statep->rds_hcalistp;
        while (hcap != NULL) {

                /*
                 * don't let anyone use this HCA until the RECV memory
                 * is registered with this HCA
                 */
                if (hcap->hca_state != RDS_HCA_STATE_MEM_REGISTERED) {
                        RDS_DPRINTF3("rds_gid_to_hcap",
                            "HCA (0x%p, 0x%llx) is not initialized",
                            hcap, gid.gid_guid);
                        hcap = hcap->hca_nextp;
                        continue;
                }

                for (ix = 0; ix < hcap->hca_nports; ix++) {
                        if ((hcap->hca_pinfop[ix].p_sgid_tbl[0].gid_prefix ==
                            gid.gid_prefix) &&
                            (hcap->hca_pinfop[ix].p_sgid_tbl[0].gid_guid ==
                            gid.gid_guid)) {
                                RDS_DPRINTF4("rds_gid_to_hcap",
                                    "gid found in hcap: 0x%p", hcap);
                                rw_exit(&statep->rds_hca_lock);
                                return (hcap);
                        }
                }
                hcap = hcap->hca_nextp;
        }

        rw_exit(&statep->rds_hca_lock);

        return (NULL);
}

/* This is called from the send CQ handler */
void
rds_send_acknowledgement(rds_ep_t *ep)
{
        int     ret;
        uint_t  ix;

        RDS_DPRINTF4("rds_send_acknowledgement", "Enter EP(%p)", ep);

        mutex_enter(&ep->ep_lock);

        ASSERT(ep->ep_rdmacnt != 0);

        /*
         * The previous ACK completed successfully, send the next one
         * if more messages were received after sending the last ACK
         */
        if (ep->ep_rbufid != *(uintptr_t *)(uintptr_t)ep->ep_ackds.ds_va) {
                *(uintptr_t *)(uintptr_t)ep->ep_ackds.ds_va = ep->ep_rbufid;
                mutex_exit(&ep->ep_lock);

                /* send acknowledgement */
                RDS_INCR_TXACKS();
                ret = ibt_post_send(ep->ep_chanhdl, &ep->ep_ackwr, 1, &ix);
                if (ret != IBT_SUCCESS) {
                        RDS_DPRINTF2("rds_send_acknowledgement",
                            "EP(%p): ibt_post_send for acknowledgement "
                            "failed: %d, SQ depth: %d",
                            ep, ret, ep->ep_sndpool.pool_nbusy);
                        mutex_enter(&ep->ep_lock);
                        ep->ep_rdmacnt--;
                        mutex_exit(&ep->ep_lock);
                }
        } else {
                /* ACKed all messages, no more to ACK */
                ep->ep_rdmacnt--;
                mutex_exit(&ep->ep_lock);
                return;
        }

        RDS_DPRINTF4("rds_send_acknowledgement", "Return EP(%p)", ep);
}

static int
rds_poll_ctrl_completions(ibt_cq_hdl_t cq, rds_ep_t *ep)
{
        ibt_wc_t        wc;
        uint_t          npolled;
        rds_buf_t       *bp;
        rds_ctrl_pkt_t  *cpkt;
        rds_qp_t        *recvqp;
        int             ret = IBT_SUCCESS;

        RDS_DPRINTF4("rds_poll_ctrl_completions", "Enter: EP(%p)", ep);

        bzero(&wc, sizeof (ibt_wc_t));
        ret = ibt_poll_cq(cq, &wc, 1, &npolled);
        if (ret != IBT_SUCCESS) {
                if (ret != IBT_CQ_EMPTY) {
                        RDS_DPRINTF2(LABEL, "EP(%p) CQ(%p): ibt_poll_cq "
                            "returned: %d", ep, cq, ret);
                } else {
                        RDS_DPRINTF5(LABEL, "EP(%p) CQ(%p): ibt_poll_cq "
                            "returned: IBT_CQ_EMPTY", ep, cq);
                }
                return (ret);
        }

        bp = (rds_buf_t *)(uintptr_t)wc.wc_id;

        if (wc.wc_status != IBT_WC_SUCCESS) {
                mutex_enter(&ep->ep_recvqp.qp_lock);
                ep->ep_recvqp.qp_level--;
                mutex_exit(&ep->ep_recvqp.qp_lock);

                /* Free the buffer */
                bp->buf_state = RDS_RCVBUF_FREE;
                rds_free_recv_buf(bp, 1);

                /* Receive completion failure */
                if (wc.wc_status != IBT_WC_WR_FLUSHED_ERR) {
                        RDS_DPRINTF2("rds_poll_ctrl_completions",
                            "EP(%p) CQ(%p) BP(%p): WC Error Status: %d",
                            ep, cq, wc.wc_id, wc.wc_status);
                }
                return (ret);
        }

        /* there is one less in the RQ */
        recvqp = &ep->ep_recvqp;
        mutex_enter(&recvqp->qp_lock);
        recvqp->qp_level--;
        if ((recvqp->qp_taskqpending == B_FALSE) &&
            (recvqp->qp_level <= recvqp->qp_lwm)) {
                /* Time to post more buffers into the RQ */
                recvqp->qp_taskqpending = B_TRUE;
                mutex_exit(&recvqp->qp_lock);

                ret = ddi_taskq_dispatch(rds_taskq,
                    rds_post_recv_buf, (void *)ep->ep_chanhdl, DDI_NOSLEEP);
                if (ret != DDI_SUCCESS) {
                        RDS_DPRINTF2(LABEL, "ddi_taskq_dispatch failed: %d",
                            ret);
                        mutex_enter(&recvqp->qp_lock);
                        recvqp->qp_taskqpending = B_FALSE;
                        mutex_exit(&recvqp->qp_lock);
                }
        } else {
                mutex_exit(&recvqp->qp_lock);
        }

        cpkt = (rds_ctrl_pkt_t *)(uintptr_t)bp->buf_ds.ds_va;
        rds_handle_control_message(ep->ep_sp, cpkt);

        bp->buf_state = RDS_RCVBUF_FREE;
        rds_free_recv_buf(bp, 1);

        RDS_DPRINTF4("rds_poll_ctrl_completions", "Return: EP(%p)", ep);

        return (ret);
}

#define RDS_POST_FEW_ATATIME    100
/* Post recv WRs into the RQ. Assumes the ep->refcnt is already incremented */
void
rds_post_recv_buf(void *arg)
{
        ibt_channel_hdl_t       chanhdl;
        rds_ep_t                *ep;
        rds_session_t           *sp;
        rds_qp_t                *recvqp;
        rds_bufpool_t           *gp;
        rds_buf_t               *bp, *bp1;
        ibt_recv_wr_t           *wrp, wr[RDS_POST_FEW_ATATIME];
        rds_hca_t               *hcap;
        uint_t                  npost, nspace, rcv_len;
        uint_t                  ix, jx, kx;
        int                     ret;

        chanhdl = (ibt_channel_hdl_t)arg;
        RDS_DPRINTF4("rds_post_recv_buf", "Enter: CHAN(%p)", chanhdl);
        RDS_INCR_POST_RCV_BUF_CALLS();

        ep = (rds_ep_t *)ibt_get_chan_private(chanhdl);
        ASSERT(ep != NULL);
        sp = ep->ep_sp;
        recvqp = &ep->ep_recvqp;

        RDS_DPRINTF5("rds_post_recv_buf", "EP(%p)", ep);

        /* get the hcap for the HCA hosting this channel */
        hcap = rds_lkup_hca(ep->ep_hca_guid);
        if (hcap == NULL) {
                RDS_DPRINTF2("rds_post_recv_buf", "HCA (0x%llx) not found",
                    ep->ep_hca_guid);
                return;
        }

        /* Make sure the session is still connected */
        rw_enter(&sp->session_lock, RW_READER);
        if ((sp->session_state != RDS_SESSION_STATE_INIT) &&
            (sp->session_state != RDS_SESSION_STATE_CONNECTED) &&
            (sp->session_state != RDS_SESSION_STATE_HCA_CLOSING)) {
                RDS_DPRINTF2("rds_post_recv_buf", "EP(%p): Session is not "
                    "in active state (%d)", ep, sp->session_state);
                rw_exit(&sp->session_lock);
                return;
        }
        rw_exit(&sp->session_lock);

        /* how many can be posted */
        mutex_enter(&recvqp->qp_lock);
        nspace = recvqp->qp_depth - recvqp->qp_level;
        if (nspace == 0) {
                RDS_DPRINTF2("rds_post_recv_buf", "RQ is FULL");
                recvqp->qp_taskqpending = B_FALSE;
                mutex_exit(&recvqp->qp_lock);
                return;
        }
        mutex_exit(&recvqp->qp_lock);

        if (ep->ep_type == RDS_EP_TYPE_DATA) {
                gp = &rds_dpool;
                rcv_len = RdsPktSize;
        } else {
                gp = &rds_cpool;
                rcv_len = RDS_CTRLPKT_SIZE;
        }

        bp = rds_get_buf(gp, nspace, &jx);
        if (bp == NULL) {
                RDS_DPRINTF2(LABEL, "EP(%p): No Recv buffers available", ep);
                /* try again later */
                ret = ddi_taskq_dispatch(rds_taskq, rds_post_recv_buf,
                    (void *)chanhdl, DDI_NOSLEEP);
                if (ret != DDI_SUCCESS) {
                        RDS_DPRINTF2(LABEL, "ddi_taskq_dispatch failed: %d",
                            ret);
                        mutex_enter(&recvqp->qp_lock);
                        recvqp->qp_taskqpending = B_FALSE;
                        mutex_exit(&recvqp->qp_lock);
                }
                return;
        }

        if (jx != nspace) {
                RDS_DPRINTF2(LABEL, "EP(%p): Recv buffers "
                    "needed: %d available: %d", ep, nspace, jx);
                nspace = jx;
        }

        bp1 = bp;
        for (ix = 0; ix < nspace; ix++) {
                bp1->buf_ep = ep;
                ASSERT(bp1->buf_state == RDS_RCVBUF_FREE);
                bp1->buf_state = RDS_RCVBUF_POSTED;
                bp1->buf_ds.ds_key = hcap->hca_lkey;
                bp1->buf_ds.ds_len = rcv_len;
                bp1 = bp1->buf_nextp;
        }

#if 0
        wrp = kmem_zalloc(RDS_POST_FEW_ATATIME * sizeof (ibt_recv_wr_t),
            KM_SLEEP);
#else
        wrp = &wr[0];
#endif

        npost = nspace;
        while (npost) {
                jx = (npost > RDS_POST_FEW_ATATIME) ?
                    RDS_POST_FEW_ATATIME : npost;
                for (ix = 0; ix < jx; ix++) {
                        wrp[ix].wr_id = (uintptr_t)bp;
                        wrp[ix].wr_nds = 1;
                        wrp[ix].wr_sgl = &bp->buf_ds;
                        bp = bp->buf_nextp;
                }

                ret = ibt_post_recv(chanhdl, wrp, jx, &kx);
                if ((ret != IBT_SUCCESS) || (kx != jx)) {
                        RDS_DPRINTF2(LABEL, "ibt_post_recv for %d WRs failed: "
                            "%d", npost, ret);
                        npost -= kx;
                        break;
                }

                npost -= jx;
        }

        mutex_enter(&recvqp->qp_lock);
        if (npost != 0) {
                RDS_DPRINTF2("rds_post_recv_buf",
                    "EP(%p) Failed to post %d WRs", ep, npost);
                recvqp->qp_level += (nspace - npost);
        } else {
                recvqp->qp_level += nspace;
        }

        /*
         * sometimes, the recv WRs can get consumed as soon as they are
         * posted. In that case, taskq thread to post more WRs to the RQ will
         * not be scheduled as the taskqpending flag is still set.
         */
        if (recvqp->qp_level == 0) {
                mutex_exit(&recvqp->qp_lock);
                ret = ddi_taskq_dispatch(rds_taskq,
                    rds_post_recv_buf, (void *)chanhdl, DDI_NOSLEEP);
                if (ret != DDI_SUCCESS) {
                        RDS_DPRINTF2("rds_post_recv_buf",
                            "ddi_taskq_dispatch failed: %d", ret);
                        mutex_enter(&recvqp->qp_lock);
                        recvqp->qp_taskqpending = B_FALSE;
                        mutex_exit(&recvqp->qp_lock);
                }
        } else {
                recvqp->qp_taskqpending = B_FALSE;
                mutex_exit(&recvqp->qp_lock);
        }

#if 0
        kmem_free(wrp, RDS_POST_FEW_ATATIME * sizeof (ibt_recv_wr_t));
#endif

        RDS_DPRINTF4("rds_post_recv_buf", "Return: EP(%p)", ep);
}

static int
rds_poll_data_completions(ibt_cq_hdl_t cq, rds_ep_t *ep)
{
        ibt_wc_t        wc;
        rds_buf_t       *bp;
        rds_data_hdr_t  *pktp;
        rds_qp_t        *recvqp;
        uint_t          npolled;
        int             ret = IBT_SUCCESS;


        RDS_DPRINTF4("rds_poll_data_completions", "Enter: EP(%p)", ep);

        bzero(&wc, sizeof (ibt_wc_t));
        ret = ibt_poll_cq(cq, &wc, 1, &npolled);
        if (ret != IBT_SUCCESS) {
                if (ret != IBT_CQ_EMPTY) {
                        RDS_DPRINTF2(LABEL, "EP(%p) CQ(%p): ibt_poll_cq "
                            "returned: %d", ep, cq, ret);
                } else {
                        RDS_DPRINTF5(LABEL, "EP(%p) CQ(%p): ibt_poll_cq "
                            "returned: IBT_CQ_EMPTY", ep, cq);
                }
                return (ret);
        }

        bp = (rds_buf_t *)(uintptr_t)wc.wc_id;
        ASSERT(bp->buf_state == RDS_RCVBUF_POSTED);
        bp->buf_state = RDS_RCVBUF_ONSOCKQ;
        bp->buf_nextp = NULL;

        if (wc.wc_status != IBT_WC_SUCCESS) {
                mutex_enter(&ep->ep_recvqp.qp_lock);
                ep->ep_recvqp.qp_level--;
                mutex_exit(&ep->ep_recvqp.qp_lock);

                /* free the buffer */
                bp->buf_state = RDS_RCVBUF_FREE;
                rds_free_recv_buf(bp, 1);

                /* Receive completion failure */
                if (wc.wc_status != IBT_WC_WR_FLUSHED_ERR) {
                        RDS_DPRINTF2("rds_poll_data_completions",
                            "EP(%p) CQ(%p) BP(%p): WC Error Status: %d",
                            ep, cq, wc.wc_id, wc.wc_status);
                        RDS_INCR_RXERRS();
                }
                return (ret);
        }

        /* there is one less in the RQ */
        recvqp = &ep->ep_recvqp;
        mutex_enter(&recvqp->qp_lock);
        recvqp->qp_level--;
        if ((recvqp->qp_taskqpending == B_FALSE) &&
            (recvqp->qp_level <= recvqp->qp_lwm)) {
                /* Time to post more buffers into the RQ */
                recvqp->qp_taskqpending = B_TRUE;
                mutex_exit(&recvqp->qp_lock);

                ret = ddi_taskq_dispatch(rds_taskq,
                    rds_post_recv_buf, (void *)ep->ep_chanhdl, DDI_NOSLEEP);
                if (ret != DDI_SUCCESS) {
                        RDS_DPRINTF2(LABEL, "ddi_taskq_dispatch failed: %d",
                            ret);
                        mutex_enter(&recvqp->qp_lock);
                        recvqp->qp_taskqpending = B_FALSE;
                        mutex_exit(&recvqp->qp_lock);
                }
        } else {
                mutex_exit(&recvqp->qp_lock);
        }

        pktp = (rds_data_hdr_t *)(uintptr_t)bp->buf_ds.ds_va;
        ASSERT(pktp->dh_datalen != 0);

        RDS_DPRINTF5(LABEL, "Message Received: sendIP: 0x%x recvIP: 0x%x "
            "sendport: %d recvport: %d npkts: %d pktno: %d", ep->ep_remip,
            ep->ep_myip, pktp->dh_sendport, pktp->dh_recvport,
            pktp->dh_npkts, pktp->dh_psn);

        RDS_DPRINTF3(LABEL, "BP(%p): npkts: %d psn: %d", bp,
            pktp->dh_npkts, pktp->dh_psn);

        if (pktp->dh_npkts == 1) {
                /* single pkt or last packet */
                if (pktp->dh_psn != 0) {
                        /* last packet of a segmented message */
                        ASSERT(ep->ep_seglbp != NULL);
                        ep->ep_seglbp->buf_nextp = bp;
                        ep->ep_seglbp = bp;
                        rds_received_msg(ep, ep->ep_segfbp);
                        ep->ep_segfbp = NULL;
                        ep->ep_seglbp = NULL;
                } else {
                        /* single packet */
                        rds_received_msg(ep, bp);
                }
        } else {
                /* multi-pkt msg */
                if (pktp->dh_psn == 0) {
                        /* first packet */
                        ASSERT(ep->ep_segfbp == NULL);
                        ep->ep_segfbp = bp;
                        ep->ep_seglbp = bp;
                } else {
                        /* intermediate packet */
                        ASSERT(ep->ep_segfbp != NULL);
                        ep->ep_seglbp->buf_nextp = bp;
                        ep->ep_seglbp = bp;
                }
        }

        RDS_DPRINTF4("rds_poll_data_completions", "Return: EP(%p)", ep);

        return (ret);
}

void
rds_recvcq_handler(ibt_cq_hdl_t cq, void *arg)
{
        rds_ep_t        *ep;
        int             ret = IBT_SUCCESS;
        int             (*func)(ibt_cq_hdl_t, rds_ep_t *);

        ep = (rds_ep_t *)arg;

        RDS_DPRINTF4("rds_recvcq_handler", "enter: EP(%p)", ep);

        if (ep->ep_type == RDS_EP_TYPE_DATA) {
                func = rds_poll_data_completions;
        } else {
                func = rds_poll_ctrl_completions;
        }

        do {
                ret = func(cq, ep);
        } while (ret != IBT_CQ_EMPTY);

        /* enable the CQ */
        ret = ibt_enable_cq_notify(cq, rds_wc_signal);
        if (ret != IBT_SUCCESS) {
                RDS_DPRINTF2(LABEL, "EP(%p) CQ(%p): ibt_enable_cq_notify "
                    "failed: %d", ep, cq, ret);
                return;
        }

        do {
                ret = func(cq, ep);
        } while (ret != IBT_CQ_EMPTY);

        RDS_DPRINTF4("rds_recvcq_handler", "Return: EP(%p)", ep);
}

void
rds_poll_send_completions(ibt_cq_hdl_t cq, rds_ep_t *ep, boolean_t lock)
{
        ibt_wc_t        wc[RDS_NUM_DATA_SEND_WCS];
        uint_t          npolled, nret, send_error = 0;
        rds_buf_t       *headp, *tailp, *bp;
        int             ret, ix;

        RDS_DPRINTF4("rds_poll_send_completions", "Enter EP(%p)", ep);

        headp = NULL;
        tailp = NULL;
        npolled = 0;
        do {
                ret = ibt_poll_cq(cq, wc, RDS_NUM_DATA_SEND_WCS, &nret);
                if (ret != IBT_SUCCESS) {
                        if (ret != IBT_CQ_EMPTY) {
                                RDS_DPRINTF2(LABEL, "EP(%p) CQ(%p): "
                                    "ibt_poll_cq returned: %d", ep, cq, ret);
                        } else {
                                RDS_DPRINTF5(LABEL, "EP(%p) CQ(%p): "
                                    "ibt_poll_cq returned: IBT_CQ_EMPTY",
                                    ep, cq);
                        }

                        break;
                }

                for (ix = 0; ix < nret; ix++) {
                        if (wc[ix].wc_status == IBT_WC_SUCCESS) {
                                if (wc[ix].wc_type == IBT_WRC_RDMAW) {
                                        rds_send_acknowledgement(ep);
                                        continue;
                                }

                                bp = (rds_buf_t *)(uintptr_t)wc[ix].wc_id;
                                ASSERT(bp->buf_state == RDS_SNDBUF_PENDING);
                                bp->buf_state = RDS_SNDBUF_FREE;
                        } else if (wc[ix].wc_status == IBT_WC_WR_FLUSHED_ERR) {
                                RDS_INCR_TXERRS();
                                RDS_DPRINTF5("rds_poll_send_completions",
                                    "EP(%p): WC ID: %p ERROR: %d", ep,
                                    wc[ix].wc_id, wc[ix].wc_status);

                                send_error = 1;

                                if (wc[ix].wc_id == RDS_RDMAW_WRID) {
                                        mutex_enter(&ep->ep_lock);
                                        ep->ep_rdmacnt--;
                                        mutex_exit(&ep->ep_lock);
                                        continue;
                                }

                                bp = (rds_buf_t *)(uintptr_t)wc[ix].wc_id;
                                ASSERT(bp->buf_state == RDS_SNDBUF_PENDING);
                                bp->buf_state = RDS_SNDBUF_FREE;
                        } else {
                                RDS_INCR_TXERRS();
                                RDS_DPRINTF2("rds_poll_send_completions",
                                    "EP(%p): WC ID: %p ERROR: %d", ep,
                                    wc[ix].wc_id, wc[ix].wc_status);
                                if (send_error == 0) {
                                        rds_session_t   *sp = ep->ep_sp;

                                        /* don't let anyone send anymore */
                                        rw_enter(&sp->session_lock, RW_WRITER);
                                        if (sp->session_state !=
                                            RDS_SESSION_STATE_ERROR) {
                                                sp->session_state =
                                                    RDS_SESSION_STATE_ERROR;
                                                /* Make this the active end */
                                                sp->session_type =
                                                    RDS_SESSION_ACTIVE;
                                        }
                                        rw_exit(&sp->session_lock);
                                }

                                send_error = 1;

                                if (wc[ix].wc_id == RDS_RDMAW_WRID) {
                                        mutex_enter(&ep->ep_lock);
                                        ep->ep_rdmacnt--;
                                        mutex_exit(&ep->ep_lock);
                                        continue;
                                }

                                bp = (rds_buf_t *)(uintptr_t)wc[ix].wc_id;
                                ASSERT(bp->buf_state == RDS_SNDBUF_PENDING);
                                bp->buf_state = RDS_SNDBUF_FREE;
                        }

                        bp->buf_nextp = NULL;
                        if (headp) {
                                tailp->buf_nextp = bp;
                                tailp = bp;
                        } else {
                                headp = bp;
                                tailp = bp;
                        }

                        npolled++;
                }

                if (rds_no_interrupts && (npolled > 100)) {
                        break;
                }

                if (rds_no_interrupts == 1) {
                        break;
                }
        } while (ret != IBT_CQ_EMPTY);

        RDS_DPRINTF5("rds_poll_send_completions", "Npolled: %d send_error: %d",
            npolled, send_error);

        /* put the buffers to the pool */
        if (npolled != 0) {
                rds_free_send_buf(ep, headp, tailp, npolled, lock);
        }

        if (send_error != 0) {
                rds_handle_send_error(ep);
        }

        RDS_DPRINTF4("rds_poll_send_completions", "Return EP(%p)", ep);
}

void
rds_sendcq_handler(ibt_cq_hdl_t cq, void *arg)
{
        rds_ep_t        *ep;
        int             ret;

        ep = (rds_ep_t *)arg;

        RDS_DPRINTF4("rds_sendcq_handler", "Enter: EP(%p)", ep);

        /* enable the CQ */
        ret = ibt_enable_cq_notify(cq, IBT_NEXT_COMPLETION);
        if (ret != IBT_SUCCESS) {
                RDS_DPRINTF2(LABEL, "EP(%p) CQ(%p): ibt_enable_cq_notify "
                    "failed: %d", ep, cq, ret);
                return;
        }

        rds_poll_send_completions(cq, ep, B_FALSE);

        RDS_DPRINTF4("rds_sendcq_handler", "Return: EP(%p)", ep);
}

void
rds_ep_free_rc_channel(rds_ep_t *ep)
{
        int ret;

        RDS_DPRINTF2("rds_ep_free_rc_channel", "EP(%p) - Enter", ep);

        ASSERT(mutex_owned(&ep->ep_lock));

        /* free the QP */
        if (ep->ep_chanhdl != NULL) {
                /* wait until the RQ is empty */
                (void) ibt_flush_channel(ep->ep_chanhdl);
                (void) rds_is_recvq_empty(ep, B_TRUE);
                ret = ibt_free_channel(ep->ep_chanhdl);
                if (ret != IBT_SUCCESS) {
                        RDS_DPRINTF2("rds_ep_free_rc_channel", "EP(%p) "
                            "ibt_free_channel returned: %d", ep, ret);
                }
                ep->ep_chanhdl = NULL;
        } else {
                RDS_DPRINTF2("rds_ep_free_rc_channel",
                    "EP(%p) Channel is ALREADY FREE", ep);
        }

        /* free the Send CQ */
        if (ep->ep_sendcq != NULL) {
                ret = ibt_free_cq(ep->ep_sendcq);
                if (ret != IBT_SUCCESS) {
                        RDS_DPRINTF2("rds_ep_free_rc_channel",
                            "EP(%p) - for sendcq, ibt_free_cq returned %d",
                            ep, ret);
                }
                ep->ep_sendcq = NULL;
        } else {
                RDS_DPRINTF2("rds_ep_free_rc_channel",
                    "EP(%p) SendCQ is ALREADY FREE", ep);
        }

        /* free the Recv CQ */
        if (ep->ep_recvcq != NULL) {
                ret = ibt_free_cq(ep->ep_recvcq);
                if (ret != IBT_SUCCESS) {
                        RDS_DPRINTF2("rds_ep_free_rc_channel",
                            "EP(%p) - for recvcq, ibt_free_cq returned %d",
                            ep, ret);
                }
                ep->ep_recvcq = NULL;
        } else {
                RDS_DPRINTF2("rds_ep_free_rc_channel",
                    "EP(%p) RecvCQ is ALREADY FREE", ep);
        }

        RDS_DPRINTF2("rds_ep_free_rc_channel", "EP(%p) - Return", ep);
}

/* Allocate resources for RC channel */
ibt_channel_hdl_t
rds_ep_alloc_rc_channel(rds_ep_t *ep, uint8_t hca_port)
{
        int                             ret = IBT_SUCCESS;
        ibt_cq_attr_t                   scqattr, rcqattr;
        ibt_rc_chan_alloc_args_t        chanargs;
        ibt_channel_hdl_t               chanhdl;
        rds_session_t                   *sp;
        rds_hca_t                       *hcap;

        RDS_DPRINTF4("rds_ep_alloc_rc_channel", "Enter: 0x%p port: %d",
            ep, hca_port);

        /* Update the EP with the right IP address and HCA guid */
        sp = ep->ep_sp;
        ASSERT(sp != NULL);
        rw_enter(&sp->session_lock, RW_READER);
        mutex_enter(&ep->ep_lock);
        ep->ep_myip = sp->session_myip;
        ep->ep_remip = sp->session_remip;
        hcap = rds_gid_to_hcap(rdsib_statep, sp->session_lgid);
        ep->ep_hca_guid = hcap->hca_guid;
        mutex_exit(&ep->ep_lock);
        rw_exit(&sp->session_lock);

        /* reset taskqpending flag here */
        ep->ep_recvqp.qp_taskqpending = B_FALSE;

        if (ep->ep_type == RDS_EP_TYPE_CTRL) {
                scqattr.cq_size = MaxCtrlSendBuffers;
                scqattr.cq_sched = NULL;
                scqattr.cq_flags = IBT_CQ_NO_FLAGS;

                rcqattr.cq_size = MaxCtrlRecvBuffers;
                rcqattr.cq_sched = NULL;
                rcqattr.cq_flags = IBT_CQ_NO_FLAGS;

                chanargs.rc_sizes.cs_sq = MaxCtrlSendBuffers;
                chanargs.rc_sizes.cs_rq = MaxCtrlRecvBuffers;
                chanargs.rc_sizes.cs_sq_sgl = 1;
                chanargs.rc_sizes.cs_rq_sgl = 1;
        } else {
                scqattr.cq_size = MaxDataSendBuffers + RDS_NUM_ACKS;
                scqattr.cq_sched = NULL;
                scqattr.cq_flags = IBT_CQ_NO_FLAGS;

                rcqattr.cq_size = MaxDataRecvBuffers;
                rcqattr.cq_sched = NULL;
                rcqattr.cq_flags = IBT_CQ_NO_FLAGS;

                chanargs.rc_sizes.cs_sq = MaxDataSendBuffers + RDS_NUM_ACKS;
                chanargs.rc_sizes.cs_rq = MaxDataRecvBuffers;
                chanargs.rc_sizes.cs_sq_sgl = 1;
                chanargs.rc_sizes.cs_rq_sgl = 1;
        }

        mutex_enter(&ep->ep_lock);
        if (ep->ep_sendcq == NULL) {
                /* returned size is always greater than the requested size */
                ret = ibt_alloc_cq(hcap->hca_hdl, &scqattr,
                    &ep->ep_sendcq, NULL);
                if (ret != IBT_SUCCESS) {
                        RDS_DPRINTF2(LABEL, "ibt_alloc_cq for sendCQ "
                            "failed, size = %d: %d", scqattr.cq_size, ret);
                        mutex_exit(&ep->ep_lock);
                        return (NULL);
                }

                (void) ibt_set_cq_handler(ep->ep_sendcq, rds_sendcq_handler,
                    ep);

                if (rds_no_interrupts == 0) {
                        ret = ibt_enable_cq_notify(ep->ep_sendcq,
                            IBT_NEXT_COMPLETION);
                        if (ret != IBT_SUCCESS) {
                                RDS_DPRINTF2(LABEL,
                                    "ibt_enable_cq_notify failed: %d", ret);
                                (void) ibt_free_cq(ep->ep_sendcq);
                                ep->ep_sendcq = NULL;
                                mutex_exit(&ep->ep_lock);
                                return (NULL);
                        }
                }
        }

        if (ep->ep_recvcq == NULL) {
                /* returned size is always greater than the requested size */
                ret = ibt_alloc_cq(hcap->hca_hdl, &rcqattr,
                    &ep->ep_recvcq, NULL);
                if (ret != IBT_SUCCESS) {
                        RDS_DPRINTF2(LABEL, "ibt_alloc_cq for recvCQ "
                            "failed, size = %d: %d", rcqattr.cq_size, ret);
                        (void) ibt_free_cq(ep->ep_sendcq);
                        ep->ep_sendcq = NULL;
                        mutex_exit(&ep->ep_lock);
                        return (NULL);
                }

                (void) ibt_set_cq_handler(ep->ep_recvcq, rds_recvcq_handler,
                    ep);

                ret = ibt_enable_cq_notify(ep->ep_recvcq, rds_wc_signal);
                if (ret != IBT_SUCCESS) {
                        RDS_DPRINTF2(LABEL,
                            "ibt_enable_cq_notify failed: %d", ret);
                        (void) ibt_free_cq(ep->ep_recvcq);
                        ep->ep_recvcq = NULL;
                        (void) ibt_free_cq(ep->ep_sendcq);
                        ep->ep_sendcq = NULL;
                        mutex_exit(&ep->ep_lock);
                        return (NULL);
                }
        }

        chanargs.rc_flags = IBT_ALL_SIGNALED;
        chanargs.rc_control = IBT_CEP_RDMA_RD | IBT_CEP_RDMA_WR |
            IBT_CEP_ATOMIC;
        chanargs.rc_hca_port_num = hca_port;
        chanargs.rc_scq = ep->ep_sendcq;
        chanargs.rc_rcq = ep->ep_recvcq;
        chanargs.rc_pd = hcap->hca_pdhdl;
        chanargs.rc_srq = NULL;

        ret = ibt_alloc_rc_channel(hcap->hca_hdl,
            IBT_ACHAN_NO_FLAGS, &chanargs, &chanhdl, NULL);
        if (ret != IBT_SUCCESS) {
                RDS_DPRINTF2(LABEL, "ibt_alloc_rc_channel fail: %d",
                    ret);
                (void) ibt_free_cq(ep->ep_recvcq);
                ep->ep_recvcq = NULL;
                (void) ibt_free_cq(ep->ep_sendcq);
                ep->ep_sendcq = NULL;
                mutex_exit(&ep->ep_lock);
                return (NULL);
        }
        mutex_exit(&ep->ep_lock);

        /* Chan private should contain the ep */
        (void) ibt_set_chan_private(chanhdl, ep);

        RDS_DPRINTF4("rds_ep_alloc_rc_channel", "Return: 0x%p", chanhdl);

        return (chanhdl);
}


#if 0

/* Return node guid given a port gid */
ib_guid_t
rds_gid_to_node_guid(ib_gid_t gid)
{
        ibt_node_info_t nodeinfo;
        int             ret;

        RDS_DPRINTF4("rds_gid_to_node_guid", "Enter: gid: %llx:%llx",
            gid.gid_prefix, gid.gid_guid);

        ret = ibt_gid_to_node_info(gid, &nodeinfo);
        if (ret != IBT_SUCCESS) {
                RDS_DPRINTF2(LABEL, "ibt_gid_node_info for gid: %llx:%llx "
                    "failed", gid.gid_prefix, gid.gid_guid);
                return (0LL);
        }

        RDS_DPRINTF4("rds_gid_to_node_guid", "Return: Node guid: %llx",
            nodeinfo.n_node_guid);

        return (nodeinfo.n_node_guid);
}

#endif

static void
rds_handle_portup_event(rds_state_t *statep, ibt_hca_hdl_t hdl,
    ibt_async_event_t *event)
{
        rds_hca_t               *hcap;
        ibt_hca_portinfo_t      *newpinfop, *oldpinfop;
        uint_t                  newsize, oldsize, nport;
        ib_gid_t                gid;
        int                     ret;

        RDS_DPRINTF2("rds_handle_portup_event",
            "Enter: GUID: 0x%llx Statep: %p", event->ev_hca_guid, statep);

        rw_enter(&statep->rds_hca_lock, RW_WRITER);

        hcap = statep->rds_hcalistp;
        while ((hcap != NULL) && (hcap->hca_guid != event->ev_hca_guid)) {
                hcap = hcap->hca_nextp;
        }

        if (hcap == NULL) {
                RDS_DPRINTF2("rds_handle_portup_event", "HCA: 0x%llx is "
                    "not in our list", event->ev_hca_guid);
                rw_exit(&statep->rds_hca_lock);
                return;
        }

        ret = ibt_query_hca_ports(hdl, 0, &newpinfop, &nport, &newsize);
        if (ret != IBT_SUCCESS) {
                RDS_DPRINTF2(LABEL, "ibt_query_hca_ports failed: %d", ret);
                rw_exit(&statep->rds_hca_lock);
                return;
        }

        oldpinfop = hcap->hca_pinfop;
        oldsize = hcap->hca_pinfo_sz;
        hcap->hca_pinfop = newpinfop;
        hcap->hca_pinfo_sz = newsize;

        (void) ibt_free_portinfo(oldpinfop, oldsize);

        /* If RDS service is not registered then no bind is needed */
        if (statep->rds_srvhdl == NULL) {
                RDS_DPRINTF2("rds_handle_portup_event",
                    "RDS Service is not registered, so no action needed");
                rw_exit(&statep->rds_hca_lock);
                return;
        }

        /*
         * If the service was previously bound on this port and
         * if this port has changed state down and now up, we do not
         * need to bind the service again. The bind is expected to
         * persist across state changes. If the service was never bound
         * before then we bind it this time.
         */
        if (hcap->hca_bindhdl[event->ev_port - 1] == NULL) {

                /* structure copy */
                gid = newpinfop[event->ev_port - 1].p_sgid_tbl[0];

                /* bind RDS service on the port, pass statep as cm_private */
                ret = ibt_bind_service(statep->rds_srvhdl, gid, NULL, statep,
                    &hcap->hca_bindhdl[event->ev_port - 1]);
                if (ret != IBT_SUCCESS) {
                        RDS_DPRINTF2("rds_handle_portup_event",
                            "Bind service for HCA: 0x%llx Port: %d "
                            "gid %llx:%llx returned: %d", event->ev_hca_guid,
                            event->ev_port, gid.gid_prefix, gid.gid_guid, ret);
                }
        }

        rw_exit(&statep->rds_hca_lock);

        RDS_DPRINTF2("rds_handle_portup_event", "Return: GUID: 0x%llx",
            event->ev_hca_guid);
}

static void
rdsib_add_hca(ib_guid_t hca_guid)
{
        rds_hca_t       *hcap;
        ibt_mr_attr_t   mem_attr;
        ibt_mr_desc_t   mem_desc;
        int             ret;

        RDS_DPRINTF2("rdsib_add_hca", "Enter: GUID: 0x%llx", hca_guid);

        hcap = rdsib_init_hca(hca_guid);
        if (hcap == NULL)
                return;

        /* register the recv memory with this hca */
        mutex_enter(&rds_dpool.pool_lock);
        if (rds_dpool.pool_memp == NULL) {
                /* no memory to register */
                RDS_DPRINTF2("rdsib_add_hca", "No memory to register");
                mutex_exit(&rds_dpool.pool_lock);
                return;
        }

        mem_attr.mr_vaddr = (ib_vaddr_t)(uintptr_t)rds_dpool.pool_memp;
        mem_attr.mr_len = rds_dpool.pool_memsize;
        mem_attr.mr_as = NULL;
        mem_attr.mr_flags = IBT_MR_ENABLE_LOCAL_WRITE;

        ret = ibt_register_mr(hcap->hca_hdl, hcap->hca_pdhdl, &mem_attr,
            &hcap->hca_mrhdl, &mem_desc);

        mutex_exit(&rds_dpool.pool_lock);

        if (ret != IBT_SUCCESS) {
                RDS_DPRINTF2("rdsib_add_hca", "ibt_register_mr failed: %d",
                    ret);
        } else {
                rw_enter(&rdsib_statep->rds_hca_lock, RW_WRITER);
                hcap->hca_state = RDS_HCA_STATE_MEM_REGISTERED;
                hcap->hca_lkey = mem_desc.md_lkey;
                hcap->hca_rkey = mem_desc.md_rkey;
                rw_exit(&rdsib_statep->rds_hca_lock);
        }

        RDS_DPRINTF2("rdsib_add_hca", "Retrun: GUID: 0x%llx", hca_guid);
}

void rds_close_this_session(rds_session_t *sp, uint8_t wait);
int rds_post_control_message(rds_session_t *sp, uint8_t code, in_port_t port);

static void
rdsib_del_hca(rds_state_t *statep, ib_guid_t hca_guid)
{
        rds_session_t   *sp;
        rds_hca_t       *hcap;
        rds_hca_state_t saved_state;
        int             ret, ix;

        RDS_DPRINTF2("rdsib_del_hca", "Enter: GUID: 0x%llx", hca_guid);

        /*
         * This should be a write lock as we don't want anyone to get access
         * to the hcap while we are modifing its contents
         */
        rw_enter(&statep->rds_hca_lock, RW_WRITER);

        hcap = statep->rds_hcalistp;
        while ((hcap != NULL) && (hcap->hca_guid != hca_guid)) {
                hcap = hcap->hca_nextp;
        }

        /* Prevent initiating any new activity on this HCA */
        ASSERT(hcap != NULL);
        saved_state = hcap->hca_state;
        hcap->hca_state = RDS_HCA_STATE_STOPPING;

        rw_exit(&statep->rds_hca_lock);

        /*
         * stop the outgoing traffic and close any active sessions on this hca.
         * Any pending messages in the SQ will be allowed to complete.
         */
        rw_enter(&statep->rds_sessionlock, RW_READER);
        sp = statep->rds_sessionlistp;
        while (sp) {
                if (sp->session_hca_guid != hca_guid) {
                        sp = sp->session_nextp;
                        continue;
                }

                rw_enter(&sp->session_lock, RW_WRITER);
                RDS_DPRINTF2("rdsib_del_hca", "SP(%p) State: %d", sp,
                    sp->session_state);
                /*
                 * We are changing the session state in advance. This prevents
                 * further messages to be posted to the SQ. We then
                 * send a control message to the remote and tell it close
                 * the session.
                 */
                sp->session_state = RDS_SESSION_STATE_HCA_CLOSING;
                RDS_DPRINTF3("rds_handle_cm_conn_closed", "SP(%p) State "
                    "RDS_SESSION_STATE_PASSIVE_CLOSING", sp);
                rw_exit(&sp->session_lock);

                /*
                 * wait until the sendq is empty then tell the remote to
                 * close this session. This enables for graceful shutdown of
                 * the session
                 */
                (void) rds_is_sendq_empty(&sp->session_dataep, 2);
                (void) rds_post_control_message(sp,
                    RDS_CTRL_CODE_CLOSE_SESSION, 0);

                sp = sp->session_nextp;
        }

        /* wait until all the sessions are off this HCA */
        sp = statep->rds_sessionlistp;
        while (sp) {
                if (sp->session_hca_guid != hca_guid) {
                        sp = sp->session_nextp;
                        continue;
                }

                rw_enter(&sp->session_lock, RW_READER);
                RDS_DPRINTF2("rdsib_del_hca", "SP(%p) State: %d", sp,
                    sp->session_state);

                while ((sp->session_state == RDS_SESSION_STATE_HCA_CLOSING) ||
                    (sp->session_state == RDS_SESSION_STATE_ERROR) ||
                    (sp->session_state == RDS_SESSION_STATE_PASSIVE_CLOSING) ||
                    (sp->session_state == RDS_SESSION_STATE_CLOSED)) {
                        rw_exit(&sp->session_lock);
                        delay(drv_usectohz(1000000));
                        rw_enter(&sp->session_lock, RW_READER);
                        RDS_DPRINTF2("rdsib_del_hca", "SP(%p) State: %d", sp,
                            sp->session_state);
                }

                rw_exit(&sp->session_lock);

                sp = sp->session_nextp;
        }
        rw_exit(&statep->rds_sessionlock);

        /*
         * if rdsib_close_ib was called before this, then that would have
         * unbound the service on all ports. In that case, the HCA structs
         * will contain stale bindhdls. Hence, we do not call unbind unless
         * the service is still registered.
         */
        if (statep->rds_srvhdl != NULL) {
                /* unbind RDS service on all ports on this HCA */
                for (ix = 0; ix < hcap->hca_nports; ix++) {
                        if (hcap->hca_bindhdl[ix] == NULL) {
                                continue;
                        }

                        RDS_DPRINTF2("rdsib_del_hca",
                            "Unbinding Service: port: %d, bindhdl: %p",
                            ix + 1, hcap->hca_bindhdl[ix]);
                        (void) ibt_unbind_service(rdsib_statep->rds_srvhdl,
                            hcap->hca_bindhdl[ix]);
                        hcap->hca_bindhdl[ix] = NULL;
                }
        }

        RDS_DPRINTF2("rdsib_del_hca", "HCA(%p) State: %d", hcap,
            hcap->hca_state);

        switch (saved_state) {
        case RDS_HCA_STATE_MEM_REGISTERED:
                ASSERT(hcap->hca_mrhdl != NULL);
                ret = ibt_deregister_mr(hcap->hca_hdl, hcap->hca_mrhdl);
                if (ret != IBT_SUCCESS) {
                        RDS_DPRINTF2("rdsib_del_hca",
                            "ibt_deregister_mr failed: %d", ret);
                        return;
                }
                hcap->hca_mrhdl = NULL;
                /* FALLTHRU */
        case RDS_HCA_STATE_OPEN:
                ASSERT(hcap->hca_hdl != NULL);
                ASSERT(hcap->hca_pdhdl != NULL);


                ret = ibt_free_pd(hcap->hca_hdl, hcap->hca_pdhdl);
                if (ret != IBT_SUCCESS) {
                        RDS_DPRINTF2("rdsib_del_hca",
                            "ibt_free_pd failed: %d", ret);
                }

                (void) ibt_free_portinfo(hcap->hca_pinfop, hcap->hca_pinfo_sz);

                ret = ibt_close_hca(hcap->hca_hdl);
                if (ret != IBT_SUCCESS) {
                        RDS_DPRINTF2("rdsib_del_hca",
                            "ibt_close_hca failed: %d", ret);
                }

                hcap->hca_hdl = NULL;
                hcap->hca_pdhdl = NULL;
                hcap->hca_lkey = 0;
                hcap->hca_rkey = 0;
        }

        /*
         * This should be a write lock as we don't want anyone to get access
         * to the hcap while we are modifing its contents
         */
        rw_enter(&statep->rds_hca_lock, RW_WRITER);
        hcap->hca_state = RDS_HCA_STATE_REMOVED;
        rw_exit(&statep->rds_hca_lock);

        RDS_DPRINTF2("rdsib_del_hca", "Return: GUID: 0x%llx", hca_guid);
}

static void
rds_async_handler(void *clntp, ibt_hca_hdl_t hdl, ibt_async_code_t code,
    ibt_async_event_t *event)
{
        rds_state_t             *statep = (rds_state_t *)clntp;

        RDS_DPRINTF2("rds_async_handler", "Async code: %d", code);

        switch (code) {
        case IBT_EVENT_PORT_UP:
                rds_handle_portup_event(statep, hdl, event);
                break;
        case IBT_HCA_ATTACH_EVENT:
                /*
                 * NOTE: In some error recovery paths, it is possible to
                 * receive IBT_HCA_ATTACH_EVENTs on already known HCAs.
                 */
                (void) rdsib_add_hca(event->ev_hca_guid);
                break;
        case IBT_HCA_DETACH_EVENT:
                (void) rdsib_del_hca(statep, event->ev_hca_guid);
                break;

        default:
                RDS_DPRINTF2(LABEL, "Async event: %d not handled", code);
        }

        RDS_DPRINTF2("rds_async_handler", "Return: code: %d", code);
}

/*
 * This routine exists to minimize stale connections across ungraceful
 * reboots of nodes in a cluster.
 */
void
rds_randomize_qps(rds_hca_t *hcap)
{
        ibt_cq_attr_t                   cqattr;
        ibt_rc_chan_alloc_args_t        chanargs;
        ibt_channel_hdl_t               qp1, qp2;
        ibt_cq_hdl_t                    cq_hdl;
        hrtime_t                        nsec;
        uint8_t                         i, j, rand1, rand2;
        int                             ret;

        bzero(&cqattr, sizeof (ibt_cq_attr_t));
        cqattr.cq_size = 1;
        cqattr.cq_sched = NULL;
        cqattr.cq_flags = IBT_CQ_NO_FLAGS;
        ret = ibt_alloc_cq(hcap->hca_hdl, &cqattr, &cq_hdl, NULL);
        if (ret != IBT_SUCCESS) {
                RDS_DPRINTF2("rds_randomize_qps",
                    "ibt_alloc_cq failed: %d", ret);
                return;
        }

        bzero(&chanargs, sizeof (ibt_rc_chan_alloc_args_t));
        chanargs.rc_flags = IBT_ALL_SIGNALED;
        chanargs.rc_control = IBT_CEP_RDMA_RD | IBT_CEP_RDMA_WR |
            IBT_CEP_ATOMIC;
        chanargs.rc_hca_port_num = 1;
        chanargs.rc_scq = cq_hdl;
        chanargs.rc_rcq = cq_hdl;
        chanargs.rc_pd = hcap->hca_pdhdl;
        chanargs.rc_srq = NULL;

        nsec = gethrtime();
        rand1 = (nsec & 0xF);
        rand2 = (nsec >> 4) & 0xF;
        RDS_DPRINTF2("rds_randomize_qps", "rand1: %d rand2: %d",
            rand1, rand2);

        for (i = 0; i < rand1 + 3; i++) {
                if (ibt_alloc_rc_channel(hcap->hca_hdl,
                    IBT_ACHAN_NO_FLAGS, &chanargs, &qp1, NULL) !=
                    IBT_SUCCESS) {
                        RDS_DPRINTF2("rds_randomize_qps",
                            "Bailing at i: %d", i);
                        (void) ibt_free_cq(cq_hdl);
                        return;
                }
                for (j = 0; j < rand2 + 3; j++) {
                        if (ibt_alloc_rc_channel(hcap->hca_hdl,
                            IBT_ACHAN_NO_FLAGS, &chanargs, &qp2,
                            NULL) != IBT_SUCCESS) {
                                RDS_DPRINTF2("rds_randomize_qps",
                                    "Bailing at i: %d j: %d", i, j);
                                (void) ibt_free_channel(qp1);
                                (void) ibt_free_cq(cq_hdl);
                                return;
                        }
                        (void) ibt_free_channel(qp2);
                }
                (void) ibt_free_channel(qp1);
        }

        (void) ibt_free_cq(cq_hdl);
}