/*
 * Copyright(c) 2015 - 2018 Intel Corporation.
 *
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License 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.
 *
 * BSD LICENSE
 *
 * 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.
 *  - Neither the name of Intel Corporation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * 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 <linux/net.h>
#include <rdma/ib_smi.h>

#include "hfi.h"
#include "mad.h"
#include "verbs_txreq.h"
#include "qp.h"

/* We support only two types - 9B and 16B for now */
static const hfi1_make_req hfi1_make_ud_req_tbl[2] = {
        [HFI1_PKT_TYPE_9B] = &hfi1_make_ud_req_9B,
        [HFI1_PKT_TYPE_16B] = &hfi1_make_ud_req_16B
};

/**
 * ud_loopback - handle send on loopback QPs
 * @sqp: the sending QP
 * @swqe: the send work request
 *
 * This is called from hfi1_make_ud_req() to forward a WQE addressed
 * to the same HFI.
 * Note that the receive interrupt handler may be calling hfi1_ud_rcv()
 * while this is being called.
 */
static void ud_loopback(struct rvt_qp *sqp, struct rvt_swqe *swqe)
{
        struct hfi1_ibport *ibp = to_iport(sqp->ibqp.device, sqp->port_num);
        struct hfi1_pportdata *ppd;
        struct hfi1_qp_priv *priv = sqp->priv;
        struct rvt_qp *qp;
        struct rdma_ah_attr *ah_attr;
        unsigned long flags;
        struct rvt_sge_state ssge;
        struct rvt_sge *sge;
        struct ib_wc wc;
        u32 length;
        enum ib_qp_type sqptype, dqptype;

        rcu_read_lock();

        qp = rvt_lookup_qpn(ib_to_rvt(sqp->ibqp.device), &ibp->rvp,
                            swqe->ud_wr.remote_qpn);
        if (!qp) {
                ibp->rvp.n_pkt_drops++;
                rcu_read_unlock();
                return;
        }

        sqptype = sqp->ibqp.qp_type == IB_QPT_GSI ?
                        IB_QPT_UD : sqp->ibqp.qp_type;
        dqptype = qp->ibqp.qp_type == IB_QPT_GSI ?
                        IB_QPT_UD : qp->ibqp.qp_type;

        if (dqptype != sqptype ||
            !(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK)) {
                ibp->rvp.n_pkt_drops++;
                goto drop;
        }

        ah_attr = &ibah_to_rvtah(swqe->ud_wr.ah)->attr;
        ppd = ppd_from_ibp(ibp);

        if (qp->ibqp.qp_num > 1) {
                u16 pkey;
                u32 slid;
                u8 sc5 = ibp->sl_to_sc[rdma_ah_get_sl(ah_attr)];

                pkey = hfi1_get_pkey(ibp, sqp->s_pkey_index);
                slid = ppd->lid | (rdma_ah_get_path_bits(ah_attr) &
                                   ((1 << ppd->lmc) - 1));
                if (unlikely(ingress_pkey_check(ppd, pkey, sc5,
                                                qp->s_pkey_index,
                                                slid, false))) {
                        hfi1_bad_pkey(ibp, pkey,
                                      rdma_ah_get_sl(ah_attr),
                                      sqp->ibqp.qp_num, qp->ibqp.qp_num,
                                      slid, rdma_ah_get_dlid(ah_attr));
                        goto drop;
                }
        }

        /*
         * Check that the qkey matches (except for QP0, see 9.6.1.4.1).
         * Qkeys with the high order bit set mean use the
         * qkey from the QP context instead of the WR (see 10.2.5).
         */
        if (qp->ibqp.qp_num) {
                u32 qkey;

                qkey = (int)swqe->ud_wr.remote_qkey < 0 ?
                        sqp->qkey : swqe->ud_wr.remote_qkey;
                if (unlikely(qkey != qp->qkey))
                        goto drop; /* silently drop per IBTA spec */
        }

        /*
         * A GRH is expected to precede the data even if not
         * present on the wire.
         */
        length = swqe->length;
        memset(&wc, 0, sizeof(wc));
        wc.byte_len = length + sizeof(struct ib_grh);

        if (swqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
                wc.wc_flags = IB_WC_WITH_IMM;
                wc.ex.imm_data = swqe->wr.ex.imm_data;
        }

        spin_lock_irqsave(&qp->r_lock, flags);

        /*
         * Get the next work request entry to find where to put the data.
         */
        if (qp->r_flags & RVT_R_REUSE_SGE) {
                qp->r_flags &= ~RVT_R_REUSE_SGE;
        } else {
                int ret;

                ret = rvt_get_rwqe(qp, false);
                if (ret < 0) {
                        rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
                        goto bail_unlock;
                }
                if (!ret) {
                        if (qp->ibqp.qp_num == 0)
                                ibp->rvp.n_vl15_dropped++;
                        goto bail_unlock;
                }
        }
        /* Silently drop packets which are too big. */
        if (unlikely(wc.byte_len > qp->r_len)) {
                qp->r_flags |= RVT_R_REUSE_SGE;
                ibp->rvp.n_pkt_drops++;
                goto bail_unlock;
        }

        if (rdma_ah_get_ah_flags(ah_attr) & IB_AH_GRH) {
                struct ib_grh grh;
                struct ib_global_route grd = *(rdma_ah_read_grh(ah_attr));

                /*
                 * For loopback packets with extended LIDs, the
                 * sgid_index in the GRH is 0 and the dgid is
                 * OPA GID of the sender. While creating a response
                 * to the loopback packet, IB core creates the new
                 * sgid_index from the DGID and that will be the
                 * OPA_GID_INDEX. The new dgid is from the sgid
                 * index and that will be in the IB GID format.
                 *
                 * We now have a case where the sent packet had a
                 * different sgid_index and dgid compared to the
                 * one that was received in response.
                 *
                 * Fix this inconsistency.
                 */
                if (priv->hdr_type == HFI1_PKT_TYPE_16B) {
                        if (grd.sgid_index == 0)
                                grd.sgid_index = OPA_GID_INDEX;

                        if (ib_is_opa_gid(&grd.dgid))
                                grd.dgid.global.interface_id =
                                cpu_to_be64(ppd->guids[HFI1_PORT_GUID_INDEX]);
                }

                hfi1_make_grh(ibp, &grh, &grd, 0, 0);
                rvt_copy_sge(qp, &qp->r_sge, &grh,
                             sizeof(grh), true, false);
                wc.wc_flags |= IB_WC_GRH;
        } else {
                rvt_skip_sge(&qp->r_sge, sizeof(struct ib_grh), true);
        }
        ssge.sg_list = swqe->sg_list + 1;
        ssge.sge = *swqe->sg_list;
        ssge.num_sge = swqe->wr.num_sge;
        sge = &ssge.sge;
        while (length) {
                u32 len = sge->length;

                if (len > length)
                        len = length;
                if (len > sge->sge_length)
                        len = sge->sge_length;
                WARN_ON_ONCE(len == 0);
                rvt_copy_sge(qp, &qp->r_sge, sge->vaddr, len, true, false);
                sge->vaddr += len;
                sge->length -= len;
                sge->sge_length -= len;
                if (sge->sge_length == 0) {
                        if (--ssge.num_sge)
                                *sge = *ssge.sg_list++;
                } else if (sge->length == 0 && sge->mr->lkey) {
                        if (++sge->n >= RVT_SEGSZ) {
                                if (++sge->m >= sge->mr->mapsz)
                                        break;
                                sge->n = 0;
                        }
                        sge->vaddr =
                                sge->mr->map[sge->m]->segs[sge->n].vaddr;
                        sge->length =
                                sge->mr->map[sge->m]->segs[sge->n].length;
                }
                length -= len;
        }
        rvt_put_ss(&qp->r_sge);
        if (!test_and_clear_bit(RVT_R_WRID_VALID, &qp->r_aflags))
                goto bail_unlock;
        wc.wr_id = qp->r_wr_id;
        wc.status = IB_WC_SUCCESS;
        wc.opcode = IB_WC_RECV;
        wc.qp = &qp->ibqp;
        wc.src_qp = sqp->ibqp.qp_num;
        if (qp->ibqp.qp_type == IB_QPT_GSI || qp->ibqp.qp_type == IB_QPT_SMI) {
                if (sqp->ibqp.qp_type == IB_QPT_GSI ||
                    sqp->ibqp.qp_type == IB_QPT_SMI)
                        wc.pkey_index = swqe->ud_wr.pkey_index;
                else
                        wc.pkey_index = sqp->s_pkey_index;
        } else {
                wc.pkey_index = 0;
        }
        wc.slid = (ppd->lid | (rdma_ah_get_path_bits(ah_attr) &
                                   ((1 << ppd->lmc) - 1))) & U16_MAX;
        /* Check for loopback when the port lid is not set */
        if (wc.slid == 0 && sqp->ibqp.qp_type == IB_QPT_GSI)
                wc.slid = be16_to_cpu(IB_LID_PERMISSIVE);
        wc.sl = rdma_ah_get_sl(ah_attr);
        wc.dlid_path_bits = rdma_ah_get_dlid(ah_attr) & ((1 << ppd->lmc) - 1);
        wc.port_num = qp->port_num;
        /* Signal completion event if the solicited bit is set. */
        rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.recv_cq), &wc,
                     swqe->wr.send_flags & IB_SEND_SOLICITED);
        ibp->rvp.n_loop_pkts++;
bail_unlock:
        spin_unlock_irqrestore(&qp->r_lock, flags);
drop:
        rcu_read_unlock();
}

static void hfi1_make_bth_deth(struct rvt_qp *qp, struct rvt_swqe *wqe,
                               struct ib_other_headers *ohdr,
                               u16 *pkey, u32 extra_bytes, bool bypass)
{
        u32 bth0;
        struct hfi1_ibport *ibp;

        ibp = to_iport(qp->ibqp.device, qp->port_num);
        if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
                ohdr->u.ud.imm_data = wqe->wr.ex.imm_data;
                bth0 = IB_OPCODE_UD_SEND_ONLY_WITH_IMMEDIATE << 24;
        } else {
                bth0 = IB_OPCODE_UD_SEND_ONLY << 24;
        }

        if (wqe->wr.send_flags & IB_SEND_SOLICITED)
                bth0 |= IB_BTH_SOLICITED;
        bth0 |= extra_bytes << 20;
        if (qp->ibqp.qp_type == IB_QPT_GSI || qp->ibqp.qp_type == IB_QPT_SMI)
                *pkey = hfi1_get_pkey(ibp, wqe->ud_wr.pkey_index);
        else
                *pkey = hfi1_get_pkey(ibp, qp->s_pkey_index);
        if (!bypass)
                bth0 |= *pkey;
        ohdr->bth[0] = cpu_to_be32(bth0);
        ohdr->bth[1] = cpu_to_be32(wqe->ud_wr.remote_qpn);
        ohdr->bth[2] = cpu_to_be32(mask_psn(wqe->psn));
        /*
         * Qkeys with the high order bit set mean use the
         * qkey from the QP context instead of the WR (see 10.2.5).
         */
        ohdr->u.ud.deth[0] = cpu_to_be32((int)wqe->ud_wr.remote_qkey < 0 ?
                                         qp->qkey : wqe->ud_wr.remote_qkey);
        ohdr->u.ud.deth[1] = cpu_to_be32(qp->ibqp.qp_num);
}

void hfi1_make_ud_req_9B(struct rvt_qp *qp, struct hfi1_pkt_state *ps,
                         struct rvt_swqe *wqe)
{
        u32 nwords, extra_bytes;
        u16 len, slid, dlid, pkey;
        u16 lrh0 = 0;
        u8 sc5;
        struct hfi1_qp_priv *priv = qp->priv;
        struct ib_other_headers *ohdr;
        struct rdma_ah_attr *ah_attr;
        struct hfi1_pportdata *ppd;
        struct hfi1_ibport *ibp;
        struct ib_grh *grh;

        ibp = to_iport(qp->ibqp.device, qp->port_num);
        ppd = ppd_from_ibp(ibp);
        ah_attr = &ibah_to_rvtah(wqe->ud_wr.ah)->attr;

        extra_bytes = -wqe->length & 3;
        nwords = ((wqe->length + extra_bytes) >> 2) + SIZE_OF_CRC;
        /* header size in dwords LRH+BTH+DETH = (8+12+8)/4. */
        ps->s_txreq->hdr_dwords = 7;
        if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM)
                ps->s_txreq->hdr_dwords++;

        if (rdma_ah_get_ah_flags(ah_attr) & IB_AH_GRH) {
                grh = &ps->s_txreq->phdr.hdr.ibh.u.l.grh;
                ps->s_txreq->hdr_dwords +=
                        hfi1_make_grh(ibp, grh, rdma_ah_read_grh(ah_attr),
                                      ps->s_txreq->hdr_dwords - LRH_9B_DWORDS,
                                      nwords);
                lrh0 = HFI1_LRH_GRH;
                ohdr = &ps->s_txreq->phdr.hdr.ibh.u.l.oth;
        } else {
                lrh0 = HFI1_LRH_BTH;
                ohdr = &ps->s_txreq->phdr.hdr.ibh.u.oth;
        }

        sc5 = ibp->sl_to_sc[rdma_ah_get_sl(ah_attr)];
        lrh0 |= (rdma_ah_get_sl(ah_attr) & 0xf) << 4;
        if (qp->ibqp.qp_type == IB_QPT_SMI) {
                lrh0 |= 0xF000; /* Set VL (see ch. 13.5.3.1) */
                priv->s_sc = 0xf;
        } else {
                lrh0 |= (sc5 & 0xf) << 12;
                priv->s_sc = sc5;
        }

        dlid = opa_get_lid(rdma_ah_get_dlid(ah_attr), 9B);
        if (dlid == be16_to_cpu(IB_LID_PERMISSIVE)) {
                slid = be16_to_cpu(IB_LID_PERMISSIVE);
        } else {
                u16 lid = (u16)ppd->lid;

                if (lid) {
                        lid |= rdma_ah_get_path_bits(ah_attr) &
                                ((1 << ppd->lmc) - 1);
                        slid = lid;
                } else {
                        slid = be16_to_cpu(IB_LID_PERMISSIVE);
                }
        }
        hfi1_make_bth_deth(qp, wqe, ohdr, &pkey, extra_bytes, false);
        len = ps->s_txreq->hdr_dwords + nwords;

        /* Setup the packet */
        ps->s_txreq->phdr.hdr.hdr_type = HFI1_PKT_TYPE_9B;
        hfi1_make_ib_hdr(&ps->s_txreq->phdr.hdr.ibh,
                         lrh0, len, dlid, slid);
}

void hfi1_make_ud_req_16B(struct rvt_qp *qp, struct hfi1_pkt_state *ps,
                          struct rvt_swqe *wqe)
{
        struct hfi1_qp_priv *priv = qp->priv;
        struct ib_other_headers *ohdr;
        struct rdma_ah_attr *ah_attr;
        struct hfi1_pportdata *ppd;
        struct hfi1_ibport *ibp;
        u32 dlid, slid, nwords, extra_bytes;
        u32 dest_qp = wqe->ud_wr.remote_qpn;
        u32 src_qp = qp->ibqp.qp_num;
        u16 len, pkey;
        u8 l4, sc5;
        bool is_mgmt = false;

        ibp = to_iport(qp->ibqp.device, qp->port_num);
        ppd = ppd_from_ibp(ibp);
        ah_attr = &ibah_to_rvtah(wqe->ud_wr.ah)->attr;

        /*
         * Build 16B Management Packet if either the destination
         * or source queue pair number is 0 or 1.
         */
        if (dest_qp == 0 || src_qp == 0 || dest_qp == 1 || src_qp == 1) {
                /* header size in dwords 16B LRH+L4_FM = (16+8)/4. */
                ps->s_txreq->hdr_dwords = 6;
                is_mgmt = true;
        } else {
                /* header size in dwords 16B LRH+BTH+DETH = (16+12+8)/4. */
                ps->s_txreq->hdr_dwords = 9;
                if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM)
                        ps->s_txreq->hdr_dwords++;
        }

        /* SW provides space for CRC and LT for bypass packets. */
        extra_bytes = hfi1_get_16b_padding((ps->s_txreq->hdr_dwords << 2),
                                           wqe->length);
        nwords = ((wqe->length + extra_bytes + SIZE_OF_LT) >> 2) + SIZE_OF_CRC;

        if ((rdma_ah_get_ah_flags(ah_attr) & IB_AH_GRH) &&
            hfi1_check_mcast(rdma_ah_get_dlid(ah_attr))) {
                struct ib_grh *grh;
                struct ib_global_route *grd = rdma_ah_retrieve_grh(ah_attr);
                /*
                 * Ensure OPA GIDs are transformed to IB gids
                 * before creating the GRH.
                 */
                if (grd->sgid_index == OPA_GID_INDEX) {
                        dd_dev_warn(ppd->dd, "Bad sgid_index. sgid_index: %d\n",
                                    grd->sgid_index);
                        grd->sgid_index = 0;
                }
                grh = &ps->s_txreq->phdr.hdr.opah.u.l.grh;
                ps->s_txreq->hdr_dwords += hfi1_make_grh(
                        ibp, grh, grd,
                        ps->s_txreq->hdr_dwords - LRH_16B_DWORDS,
                        nwords);
                ohdr = &ps->s_txreq->phdr.hdr.opah.u.l.oth;
                l4 = OPA_16B_L4_IB_GLOBAL;
        } else {
                ohdr = &ps->s_txreq->phdr.hdr.opah.u.oth;
                l4 = OPA_16B_L4_IB_LOCAL;
        }

        sc5 = ibp->sl_to_sc[rdma_ah_get_sl(ah_attr)];
        if (qp->ibqp.qp_type == IB_QPT_SMI)
                priv->s_sc = 0xf;
        else
                priv->s_sc = sc5;

        dlid = opa_get_lid(rdma_ah_get_dlid(ah_attr), 16B);
        if (!ppd->lid)
                slid = be32_to_cpu(OPA_LID_PERMISSIVE);
        else
                slid = ppd->lid | (rdma_ah_get_path_bits(ah_attr) &
                           ((1 << ppd->lmc) - 1));

        if (is_mgmt) {
                l4 = OPA_16B_L4_FM;
                pkey = hfi1_get_pkey(ibp, wqe->ud_wr.pkey_index);
                hfi1_16B_set_qpn(&ps->s_txreq->phdr.hdr.opah.u.mgmt,
                                 dest_qp, src_qp);
        } else {
                hfi1_make_bth_deth(qp, wqe, ohdr, &pkey, extra_bytes, true);
        }
        /* Convert dwords to flits */
        len = (ps->s_txreq->hdr_dwords + nwords) >> 1;

        /* Setup the packet */
        ps->s_txreq->phdr.hdr.hdr_type = HFI1_PKT_TYPE_16B;
        hfi1_make_16b_hdr(&ps->s_txreq->phdr.hdr.opah,
                          slid, dlid, len, pkey, 0, 0, l4, priv->s_sc);
}

/**
 * hfi1_make_ud_req - construct a UD request packet
 * @qp: the QP
 *
 * Assume s_lock is held.
 *
 * Return 1 if constructed; otherwise, return 0.
 */
int hfi1_make_ud_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps)
{
        struct hfi1_qp_priv *priv = qp->priv;
        struct rdma_ah_attr *ah_attr;
        struct hfi1_pportdata *ppd;
        struct hfi1_ibport *ibp;
        struct rvt_swqe *wqe;
        int next_cur;
        u32 lid;

        ps->s_txreq = get_txreq(ps->dev, qp);
        if (!ps->s_txreq)
                goto bail_no_tx;

        if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_NEXT_SEND_OK)) {
                if (!(ib_rvt_state_ops[qp->state] & RVT_FLUSH_SEND))
                        goto bail;
                /* We are in the error state, flush the work request. */
                if (qp->s_last == READ_ONCE(qp->s_head))
                        goto bail;
                /* If DMAs are in progress, we can't flush immediately. */
                if (iowait_sdma_pending(&priv->s_iowait)) {
                        qp->s_flags |= RVT_S_WAIT_DMA;
                        goto bail;
                }
                wqe = rvt_get_swqe_ptr(qp, qp->s_last);
                rvt_send_complete(qp, wqe, IB_WC_WR_FLUSH_ERR);
                goto done_free_tx;
        }

        /* see post_one_send() */
        if (qp->s_cur == READ_ONCE(qp->s_head))
                goto bail;

        wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
        next_cur = qp->s_cur + 1;
        if (next_cur >= qp->s_size)
                next_cur = 0;

        /* Construct the header. */
        ibp = to_iport(qp->ibqp.device, qp->port_num);
        ppd = ppd_from_ibp(ibp);
        ah_attr = &ibah_to_rvtah(wqe->ud_wr.ah)->attr;
        priv->hdr_type = hfi1_get_hdr_type(ppd->lid, ah_attr);
        if ((!hfi1_check_mcast(rdma_ah_get_dlid(ah_attr))) ||
            (rdma_ah_get_dlid(ah_attr) == be32_to_cpu(OPA_LID_PERMISSIVE))) {
                lid = rdma_ah_get_dlid(ah_attr) & ~((1 << ppd->lmc) - 1);
                if (unlikely(!loopback &&
                             ((lid == ppd->lid) ||
                              ((lid == be32_to_cpu(OPA_LID_PERMISSIVE)) &&
                               (qp->ibqp.qp_type == IB_QPT_GSI))))) {
                        unsigned long tflags = ps->flags;
                        /*
                         * If DMAs are in progress, we can't generate
                         * a completion for the loopback packet since
                         * it would be out of order.
                         * Instead of waiting, we could queue a
                         * zero length descriptor so we get a callback.
                         */
                        if (iowait_sdma_pending(&priv->s_iowait)) {
                                qp->s_flags |= RVT_S_WAIT_DMA;
                                goto bail;
                        }
                        qp->s_cur = next_cur;
                        spin_unlock_irqrestore(&qp->s_lock, tflags);
                        ud_loopback(qp, wqe);
                        spin_lock_irqsave(&qp->s_lock, tflags);
                        ps->flags = tflags;
                        rvt_send_complete(qp, wqe, IB_WC_SUCCESS);
                        goto done_free_tx;
                }
        }

        qp->s_cur = next_cur;
        ps->s_txreq->s_cur_size = wqe->length;
        ps->s_txreq->ss = &qp->s_sge;
        qp->s_srate = rdma_ah_get_static_rate(ah_attr);
        qp->srate_mbps = ib_rate_to_mbps(qp->s_srate);
        qp->s_wqe = wqe;
        qp->s_sge.sge = wqe->sg_list[0];
        qp->s_sge.sg_list = wqe->sg_list + 1;
        qp->s_sge.num_sge = wqe->wr.num_sge;
        qp->s_sge.total_len = wqe->length;

        /* Make the appropriate header */
        hfi1_make_ud_req_tbl[priv->hdr_type](qp, ps, qp->s_wqe);
        priv->s_sde = qp_to_sdma_engine(qp, priv->s_sc);
        ps->s_txreq->sde = priv->s_sde;
        priv->s_sendcontext = qp_to_send_context(qp, priv->s_sc);
        ps->s_txreq->psc = priv->s_sendcontext;
        /* disarm any ahg */
        priv->s_ahg->ahgcount = 0;
        priv->s_ahg->ahgidx = 0;
        priv->s_ahg->tx_flags = 0;

        return 1;

done_free_tx:
        hfi1_put_txreq(ps->s_txreq);
        ps->s_txreq = NULL;
        return 1;

bail:
        hfi1_put_txreq(ps->s_txreq);

bail_no_tx:
        ps->s_txreq = NULL;
        qp->s_flags &= ~RVT_S_BUSY;
        return 0;
}

/*
 * Hardware can't check this so we do it here.
 *
 * This is a slightly different algorithm than the standard pkey check.  It
 * special cases the management keys and allows for 0x7fff and 0xffff to be in
 * the table at the same time.
 *
 * @returns the index found or -1 if not found
 */
int hfi1_lookup_pkey_idx(struct hfi1_ibport *ibp, u16 pkey)
{
        struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
        unsigned i;

        if (pkey == FULL_MGMT_P_KEY || pkey == LIM_MGMT_P_KEY) {
                unsigned lim_idx = -1;

                for (i = 0; i < ARRAY_SIZE(ppd->pkeys); ++i) {
                        /* here we look for an exact match */
                        if (ppd->pkeys[i] == pkey)
                                return i;
                        if (ppd->pkeys[i] == LIM_MGMT_P_KEY)
                                lim_idx = i;
                }

                /* did not find 0xffff return 0x7fff idx if found */
                if (pkey == FULL_MGMT_P_KEY)
                        return lim_idx;

                /* no match...  */
                return -1;
        }

        pkey &= 0x7fff; /* remove limited/full membership bit */

        for (i = 0; i < ARRAY_SIZE(ppd->pkeys); ++i)
                if ((ppd->pkeys[i] & 0x7fff) == pkey)
                        return i;

        /*
         * Should not get here, this means hardware failed to validate pkeys.
         */
        return -1;
}

void return_cnp_16B(struct hfi1_ibport *ibp, struct rvt_qp *qp,
                    u32 remote_qpn, u16 pkey, u32 slid, u32 dlid,
                    u8 sc5, const struct ib_grh *old_grh)
{
        u64 pbc, pbc_flags = 0;
        u32 bth0, plen, vl, hwords = 7;
        u16 len;
        u8 l4;
        struct hfi1_16b_header hdr;
        struct ib_other_headers *ohdr;
        struct pio_buf *pbuf;
        struct send_context *ctxt = qp_to_send_context(qp, sc5);
        struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
        u32 nwords;

        /* Populate length */
        nwords = ((hfi1_get_16b_padding(hwords << 2, 0) +
                   SIZE_OF_LT) >> 2) + SIZE_OF_CRC;
        if (old_grh) {
                struct ib_grh *grh = &hdr.u.l.grh;

                grh->version_tclass_flow = old_grh->version_tclass_flow;
                grh->paylen = cpu_to_be16(
                        (hwords - LRH_16B_DWORDS + nwords) << 2);
                grh->hop_limit = 0xff;
                grh->sgid = old_grh->dgid;
                grh->dgid = old_grh->sgid;
                ohdr = &hdr.u.l.oth;
                l4 = OPA_16B_L4_IB_GLOBAL;
                hwords += sizeof(struct ib_grh) / sizeof(u32);
        } else {
                ohdr = &hdr.u.oth;
                l4 = OPA_16B_L4_IB_LOCAL;
        }

        /* BIT 16 to 19 is TVER. Bit 20 to 22 is pad cnt */
        bth0 = (IB_OPCODE_CNP << 24) | (1 << 16) |
               (hfi1_get_16b_padding(hwords << 2, 0) << 20);
        ohdr->bth[0] = cpu_to_be32(bth0);

        ohdr->bth[1] = cpu_to_be32(remote_qpn);
        ohdr->bth[2] = 0; /* PSN 0 */

        /* Convert dwords to flits */
        len = (hwords + nwords) >> 1;
        hfi1_make_16b_hdr(&hdr, slid, dlid, len, pkey, 1, 0, l4, sc5);

        plen = 2 /* PBC */ + hwords + nwords;
        pbc_flags |= PBC_PACKET_BYPASS | PBC_INSERT_BYPASS_ICRC;
        vl = sc_to_vlt(ppd->dd, sc5);
        pbc = create_pbc(ppd, pbc_flags, qp->srate_mbps, vl, plen);
        if (ctxt) {
                pbuf = sc_buffer_alloc(ctxt, plen, NULL, NULL);
                if (pbuf)
                        ppd->dd->pio_inline_send(ppd->dd, pbuf, pbc,
                                                 &hdr, hwords);
        }
}

void return_cnp(struct hfi1_ibport *ibp, struct rvt_qp *qp, u32 remote_qpn,
                u16 pkey, u32 slid, u32 dlid, u8 sc5,
                const struct ib_grh *old_grh)
{
        u64 pbc, pbc_flags = 0;
        u32 bth0, plen, vl, hwords = 5;
        u16 lrh0;
        u8 sl = ibp->sc_to_sl[sc5];
        struct ib_header hdr;
        struct ib_other_headers *ohdr;
        struct pio_buf *pbuf;
        struct send_context *ctxt = qp_to_send_context(qp, sc5);
        struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);

        if (old_grh) {
                struct ib_grh *grh = &hdr.u.l.grh;

                grh->version_tclass_flow = old_grh->version_tclass_flow;
                grh->paylen = cpu_to_be16(
                        (hwords - LRH_9B_DWORDS + SIZE_OF_CRC) << 2);
                grh->hop_limit = 0xff;
                grh->sgid = old_grh->dgid;
                grh->dgid = old_grh->sgid;
                ohdr = &hdr.u.l.oth;
                lrh0 = HFI1_LRH_GRH;
                hwords += sizeof(struct ib_grh) / sizeof(u32);
        } else {
                ohdr = &hdr.u.oth;
                lrh0 = HFI1_LRH_BTH;
        }

        lrh0 |= (sc5 & 0xf) << 12 | sl << 4;

        bth0 = pkey | (IB_OPCODE_CNP << 24);
        ohdr->bth[0] = cpu_to_be32(bth0);

        ohdr->bth[1] = cpu_to_be32(remote_qpn | (1 << IB_BECN_SHIFT));
        ohdr->bth[2] = 0; /* PSN 0 */

        hfi1_make_ib_hdr(&hdr, lrh0, hwords + SIZE_OF_CRC, dlid, slid);
        plen = 2 /* PBC */ + hwords;
        pbc_flags |= (ib_is_sc5(sc5) << PBC_DC_INFO_SHIFT);
        vl = sc_to_vlt(ppd->dd, sc5);
        pbc = create_pbc(ppd, pbc_flags, qp->srate_mbps, vl, plen);
        if (ctxt) {
                pbuf = sc_buffer_alloc(ctxt, plen, NULL, NULL);
                if (pbuf)
                        ppd->dd->pio_inline_send(ppd->dd, pbuf, pbc,
                                                 &hdr, hwords);
        }
}

/*
 * opa_smp_check() - Do the regular pkey checking, and the additional
 * checks for SMPs specified in OPAv1 rev 1.0, 9/19/2016 update, section
 * 9.10.25 ("SMA Packet Checks").
 *
 * Note that:
 *   - Checks are done using the pkey directly from the packet's BTH,
 *     and specifically _not_ the pkey that we attach to the completion,
 *     which may be different.
 *   - These checks are specifically for "non-local" SMPs (i.e., SMPs
 *     which originated on another node). SMPs which are sent from, and
 *     destined to this node are checked in opa_local_smp_check().
 *
 * At the point where opa_smp_check() is called, we know:
 *   - destination QP is QP0
 *
 * opa_smp_check() returns 0 if all checks succeed, 1 otherwise.
 */
static int opa_smp_check(struct hfi1_ibport *ibp, u16 pkey, u8 sc5,
                         struct rvt_qp *qp, u16 slid, struct opa_smp *smp)
{
        struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);

        /*
         * I don't think it's possible for us to get here with sc != 0xf,
         * but check it to be certain.
         */
        if (sc5 != 0xf)
                return 1;

        if (rcv_pkey_check(ppd, pkey, sc5, slid))
                return 1;

        /*
         * At this point we know (and so don't need to check again) that
         * the pkey is either LIM_MGMT_P_KEY, or FULL_MGMT_P_KEY
         * (see ingress_pkey_check).
         */
        if (smp->mgmt_class != IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE &&
            smp->mgmt_class != IB_MGMT_CLASS_SUBN_LID_ROUTED) {
                ingress_pkey_table_fail(ppd, pkey, slid);
                return 1;
        }

        /*
         * SMPs fall into one of four (disjoint) categories:
         * SMA request, SMA response, SMA trap, or SMA trap repress.
         * Our response depends, in part, on which type of SMP we're
         * processing.
         *
         * If this is an SMA response, skip the check here.
         *
         * If this is an SMA request or SMA trap repress:
         *   - pkey != FULL_MGMT_P_KEY =>
         *       increment port recv constraint errors, drop MAD
         *
         * Otherwise:
         *    - accept if the port is running an SM
         *    - drop MAD if it's an SMA trap
         *    - pkey == FULL_MGMT_P_KEY =>
         *        reply with unsupported method
         *    - pkey != FULL_MGMT_P_KEY =>
         *        increment port recv constraint errors, drop MAD
         */
        switch (smp->method) {
        case IB_MGMT_METHOD_GET_RESP:
        case IB_MGMT_METHOD_REPORT_RESP:
                break;
        case IB_MGMT_METHOD_GET:
        case IB_MGMT_METHOD_SET:
        case IB_MGMT_METHOD_REPORT:
        case IB_MGMT_METHOD_TRAP_REPRESS:
                if (pkey != FULL_MGMT_P_KEY) {
                        ingress_pkey_table_fail(ppd, pkey, slid);
                        return 1;
                }
                break;
        default:
                if (ibp->rvp.port_cap_flags & IB_PORT_SM)
                        return 0;
                if (smp->method == IB_MGMT_METHOD_TRAP)
                        return 1;
                if (pkey == FULL_MGMT_P_KEY) {
                        smp->status |= IB_SMP_UNSUP_METHOD;
                        return 0;
                }
                ingress_pkey_table_fail(ppd, pkey, slid);
                return 1;
        }
        return 0;
}

/**
 * hfi1_ud_rcv - receive an incoming UD packet
 * @ibp: the port the packet came in on
 * @hdr: the packet header
 * @rcv_flags: flags relevant to rcv processing
 * @data: the packet data
 * @tlen: the packet length
 * @qp: the QP the packet came on
 *
 * This is called from qp_rcv() to process an incoming UD packet
 * for the given QP.
 * Called at interrupt level.
 */
void hfi1_ud_rcv(struct hfi1_packet *packet)
{
        u32 hdrsize = packet->hlen;
        struct ib_wc wc;
        u32 src_qp;
        u16 pkey;
        int mgmt_pkey_idx = -1;
        struct hfi1_ibport *ibp = rcd_to_iport(packet->rcd);
        struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
        void *data = packet->payload;
        u32 tlen = packet->tlen;
        struct rvt_qp *qp = packet->qp;
        u8 sc5 = packet->sc;
        u8 sl_from_sc;
        u8 opcode = packet->opcode;
        u8 sl = packet->sl;
        u32 dlid = packet->dlid;
        u32 slid = packet->slid;
        u8 extra_bytes;
        u8 l4 = 0;
        bool dlid_is_permissive;
        bool slid_is_permissive;
        bool solicited = false;

        extra_bytes = packet->pad + packet->extra_byte + (SIZE_OF_CRC << 2);

        if (packet->etype == RHF_RCV_TYPE_BYPASS) {
                u32 permissive_lid =
                        opa_get_lid(be32_to_cpu(OPA_LID_PERMISSIVE), 16B);

                l4 = hfi1_16B_get_l4(packet->hdr);
                pkey = hfi1_16B_get_pkey(packet->hdr);
                dlid_is_permissive = (dlid == permissive_lid);
                slid_is_permissive = (slid == permissive_lid);
        } else {
                pkey = ib_bth_get_pkey(packet->ohdr);
                dlid_is_permissive = (dlid == be16_to_cpu(IB_LID_PERMISSIVE));
                slid_is_permissive = (slid == be16_to_cpu(IB_LID_PERMISSIVE));
        }
        sl_from_sc = ibp->sc_to_sl[sc5];

        if (likely(l4 != OPA_16B_L4_FM)) {
                src_qp = ib_get_sqpn(packet->ohdr);
                solicited = ib_bth_is_solicited(packet->ohdr);
        } else {
                src_qp = hfi1_16B_get_src_qpn(packet->mgmt);
        }

        process_ecn(qp, packet, (opcode != IB_OPCODE_CNP));
        /*
         * Get the number of bytes the message was padded by
         * and drop incomplete packets.
         */
        if (unlikely(tlen < (hdrsize + extra_bytes)))
                goto drop;

        tlen -= hdrsize + extra_bytes;

        /*
         * Check that the permissive LID is only used on QP0
         * and the QKEY matches (see 9.6.1.4.1 and 9.6.1.5.1).
         */
        if (qp->ibqp.qp_num) {
                if (unlikely(dlid_is_permissive || slid_is_permissive))
                        goto drop;
                if (qp->ibqp.qp_num > 1) {
                        if (unlikely(rcv_pkey_check(ppd, pkey, sc5, slid))) {
                                /*
                                 * Traps will not be sent for packets dropped
                                 * by the HW. This is fine, as sending trap
                                 * for invalid pkeys is optional according to
                                 * IB spec (release 1.3, section 10.9.4)
                                 */
                                hfi1_bad_pkey(ibp,
                                              pkey, sl,
                                              src_qp, qp->ibqp.qp_num,
                                              slid, dlid);
                                return;
                        }
                } else {
                        /* GSI packet */
                        mgmt_pkey_idx = hfi1_lookup_pkey_idx(ibp, pkey);
                        if (mgmt_pkey_idx < 0)
                                goto drop;
                }
                if (unlikely(l4 != OPA_16B_L4_FM &&
                             ib_get_qkey(packet->ohdr) != qp->qkey))
                        return; /* Silent drop */

                /* Drop invalid MAD packets (see 13.5.3.1). */
                if (unlikely(qp->ibqp.qp_num == 1 &&
                             (tlen > 2048 || (sc5 == 0xF))))
                        goto drop;
        } else {
                /* Received on QP0, and so by definition, this is an SMP */
                struct opa_smp *smp = (struct opa_smp *)data;

                if (opa_smp_check(ibp, pkey, sc5, qp, slid, smp))
                        goto drop;

                if (tlen > 2048)
                        goto drop;
                if ((dlid_is_permissive || slid_is_permissive) &&
                    smp->mgmt_class != IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE)
                        goto drop;

                /* look up SMI pkey */
                mgmt_pkey_idx = hfi1_lookup_pkey_idx(ibp, pkey);
                if (mgmt_pkey_idx < 0)
                        goto drop;
        }

        if (qp->ibqp.qp_num > 1 &&
            opcode == IB_OPCODE_UD_SEND_ONLY_WITH_IMMEDIATE) {
                wc.ex.imm_data = packet->ohdr->u.ud.imm_data;
                wc.wc_flags = IB_WC_WITH_IMM;
                tlen -= sizeof(u32);
        } else if (opcode == IB_OPCODE_UD_SEND_ONLY) {
                wc.ex.imm_data = 0;
                wc.wc_flags = 0;
        } else {
                goto drop;
        }

        /*
         * A GRH is expected to precede the data even if not
         * present on the wire.
         */
        wc.byte_len = tlen + sizeof(struct ib_grh);

        /*
         * Get the next work request entry to find where to put the data.
         */
        if (qp->r_flags & RVT_R_REUSE_SGE) {

                qp->r_flags &= ~RVT_R_REUSE_SGE;
        } else {
                int ret;

                ret = rvt_get_rwqe(qp, false);
                if (ret < 0) {
                        rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
                        return;
                }
                if (!ret) {
                        if (qp->ibqp.qp_num == 0)
                                ibp->rvp.n_vl15_dropped++;
                        return;
                }
        }
        /* Silently drop packets which are too big. */
        if (unlikely(wc.byte_len > qp->r_len)) {
                qp->r_flags |= RVT_R_REUSE_SGE;
                goto drop;
        }
        if (packet->grh) {
                rvt_copy_sge(qp, &qp->r_sge, packet->grh,
                             sizeof(struct ib_grh), true, false);
                wc.wc_flags |= IB_WC_GRH;
        } else if (packet->etype == RHF_RCV_TYPE_BYPASS) {
                struct ib_grh grh;
                /*
                 * Assuming we only created 16B on the send side
                 * if we want to use large LIDs, since GRH was stripped
                 * out when creating 16B, add back the GRH here.
                 */
                hfi1_make_ext_grh(packet, &grh, slid, dlid);
                rvt_copy_sge(qp, &qp->r_sge, &grh,
                             sizeof(struct ib_grh), true, false);
                wc.wc_flags |= IB_WC_GRH;
        } else {
                rvt_skip_sge(&qp->r_sge, sizeof(struct ib_grh), true);
        }
        rvt_copy_sge(qp, &qp->r_sge, data, wc.byte_len - sizeof(struct ib_grh),
                     true, false);
        rvt_put_ss(&qp->r_sge);
        if (!test_and_clear_bit(RVT_R_WRID_VALID, &qp->r_aflags))
                return;
        wc.wr_id = qp->r_wr_id;
        wc.status = IB_WC_SUCCESS;
        wc.opcode = IB_WC_RECV;
        wc.vendor_err = 0;
        wc.qp = &qp->ibqp;
        wc.src_qp = src_qp;

        if (qp->ibqp.qp_type == IB_QPT_GSI ||
            qp->ibqp.qp_type == IB_QPT_SMI) {
                if (mgmt_pkey_idx < 0) {
                        if (net_ratelimit()) {
                                struct hfi1_devdata *dd = ppd->dd;

                                dd_dev_err(dd, "QP type %d mgmt_pkey_idx < 0 and packet not dropped???\n",
                                           qp->ibqp.qp_type);
                                mgmt_pkey_idx = 0;
                        }
                }
                wc.pkey_index = (unsigned)mgmt_pkey_idx;
        } else {
                wc.pkey_index = 0;
        }
        if (slid_is_permissive)
                slid = be32_to_cpu(OPA_LID_PERMISSIVE);
        wc.slid = slid & U16_MAX;
        wc.sl = sl_from_sc;

        /*
         * Save the LMC lower bits if the destination LID is a unicast LID.
         */
        wc.dlid_path_bits = hfi1_check_mcast(dlid) ? 0 :
                dlid & ((1 << ppd_from_ibp(ibp)->lmc) - 1);
        wc.port_num = qp->port_num;
        /* Signal completion event if the solicited bit is set. */
        rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.recv_cq), &wc, solicited);
        return;

drop:
        ibp->rvp.n_pkt_drops++;
}