staging/rdma/hfi1: Use rdmavt version of post_send

[mirror_ubuntu-artful-kernel.git] / drivers / staging / rdma / hfi1 / ud.c

/*
 *
 * 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
 *
 * Copyright(c) 2015 Intel Corporation.
 *
 * 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
 *
 * Copyright(c) 2015 Intel Corporation.
 *
 * 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 "qp.h"

/**
 * 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 rvt_qp *qp;
        struct ib_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 = hfi1_lookup_qpn(ibp, 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;
                u16 slid;
                u8 sc5 = ibp->sl_to_sc[ah_attr->sl];

                pkey = hfi1_get_pkey(ibp, sqp->s_pkey_index);
                slid = ppd->lid | (ah_attr->src_path_bits &
                                   ((1 << ppd->lmc) - 1));
                if (unlikely(ingress_pkey_check(ppd, pkey, sc5,
                                                qp->s_pkey_index, slid))) {
                        hfi1_bad_pqkey(ibp, OPA_TRAP_BAD_P_KEY, pkey,
                                       ah_attr->sl,
                                       sqp->ibqp.qp_num, qp->ibqp.qp_num,
                                       slid, ah_attr->dlid);
                        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)) {
                        u16 lid;

                        lid = ppd->lid | (ah_attr->src_path_bits &
                                          ((1 << ppd->lmc) - 1));
                        hfi1_bad_pqkey(ibp, OPA_TRAP_BAD_Q_KEY, qkey,
                                       ah_attr->sl,
                                       sqp->ibqp.qp_num, qp->ibqp.qp_num,
                                       lid,
                                       ah_attr->dlid);
                        goto drop;
                }
        }

        /*
         * 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 = hfi1_get_rwqe(qp, 0);
                if (ret < 0) {
                        hfi1_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 (ah_attr->ah_flags & IB_AH_GRH) {
                hfi1_copy_sge(&qp->r_sge, &ah_attr->grh,
                              sizeof(struct ib_grh), 1);
                wc.wc_flags |= IB_WC_GRH;
        } else
                hfi1_skip_sge(&qp->r_sge, sizeof(struct ib_grh), 1);
        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);
                hfi1_copy_sge(&qp->r_sge, sge->vaddr, len, 1);
                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;
        }
        hfi1_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 | (ah_attr->src_path_bits & ((1 << ppd->lmc) - 1));
        /* 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 = ah_attr->sl;
        wc.dlid_path_bits = ah_attr->dlid & ((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();
}

/**
 * hfi1_make_ud_req - construct a UD request packet
 * @qp: the QP
 *
 * Return 1 if constructed; otherwise, return 0.
 */
int hfi1_make_ud_req(struct rvt_qp *qp)
{
        struct hfi1_qp_priv *priv = qp->priv;
        struct hfi1_other_headers *ohdr;
        struct ib_ah_attr *ah_attr;
        struct hfi1_pportdata *ppd;
        struct hfi1_ibport *ibp;
        struct rvt_swqe *wqe;
        unsigned long flags;
        u32 nwords;
        u32 extra_bytes;
        u32 bth0;
        u16 lrh0;
        u16 lid;
        int ret = 0;
        int next_cur;
        u8 sc5;

        spin_lock_irqsave(&qp->s_lock, flags);

        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 == qp->s_head)
                        goto bail;
                /* If DMAs are in progress, we can't flush immediately. */
                if (atomic_read(&priv->s_iowait.sdma_busy)) {
                        qp->s_flags |= RVT_S_WAIT_DMA;
                        goto bail;
                }
                wqe = rvt_get_swqe_ptr(qp, qp->s_last);
                hfi1_send_complete(qp, wqe, IB_WC_WR_FLUSH_ERR);
                goto done;
        }

        if (qp->s_cur == 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;
        if (ah_attr->dlid < be16_to_cpu(IB_MULTICAST_LID_BASE) ||
            ah_attr->dlid == be16_to_cpu(IB_LID_PERMISSIVE)) {
                lid = ah_attr->dlid & ~((1 << ppd->lmc) - 1);
                if (unlikely(!loopback && (lid == ppd->lid ||
                    (lid == be16_to_cpu(IB_LID_PERMISSIVE) &&
                     qp->ibqp.qp_type == IB_QPT_GSI)))) {
                        /*
                         * 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 (atomic_read(&priv->s_iowait.sdma_busy)) {
                                qp->s_flags |= RVT_S_WAIT_DMA;
                                goto bail;
                        }
                        qp->s_cur = next_cur;
                        spin_unlock_irqrestore(&qp->s_lock, flags);
                        ud_loopback(qp, wqe);
                        spin_lock_irqsave(&qp->s_lock, flags);
                        hfi1_send_complete(qp, wqe, IB_WC_SUCCESS);
                        goto done;
                }
        }

        qp->s_cur = next_cur;
        extra_bytes = -wqe->length & 3;
        nwords = (wqe->length + extra_bytes) >> 2;

        /* header size in 32-bit words LRH+BTH+DETH = (8+12+8)/4. */
        qp->s_hdrwords = 7;
        qp->s_cur_size = wqe->length;
        qp->s_cur_sge = &qp->s_sge;
        qp->s_srate = ah_attr->static_rate;
        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;

        if (ah_attr->ah_flags & IB_AH_GRH) {
                /* Header size in 32-bit words. */
                qp->s_hdrwords += hfi1_make_grh(ibp, &priv->s_hdr->ibh.u.l.grh,
                                               &ah_attr->grh,
                                               qp->s_hdrwords, nwords);
                lrh0 = HFI1_LRH_GRH;
                ohdr = &priv->s_hdr->ibh.u.l.oth;
                /*
                 * Don't worry about sending to locally attached multicast
                 * QPs.  It is unspecified by the spec. what happens.
                 */
        } else {
                /* Header size in 32-bit words. */
                lrh0 = HFI1_LRH_BTH;
                ohdr = &priv->s_hdr->ibh.u.oth;
        }
        if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
                qp->s_hdrwords++;
                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;
        sc5 = ibp->sl_to_sc[ah_attr->sl];
        lrh0 |= (ah_attr->sl & 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;
        }
        priv->s_sde = qp_to_sdma_engine(qp, priv->s_sc);
        priv->s_hdr->ibh.lrh[0] = cpu_to_be16(lrh0);
        priv->s_hdr->ibh.lrh[1] = cpu_to_be16(ah_attr->dlid);  /* DEST LID */
        priv->s_hdr->ibh.lrh[2] =
                cpu_to_be16(qp->s_hdrwords + nwords + SIZE_OF_CRC);
        if (ah_attr->dlid == be16_to_cpu(IB_LID_PERMISSIVE))
                priv->s_hdr->ibh.lrh[3] = IB_LID_PERMISSIVE;
        else {
                lid = ppd->lid;
                if (lid) {
                        lid |= ah_attr->src_path_bits & ((1 << ppd->lmc) - 1);
                        priv->s_hdr->ibh.lrh[3] = cpu_to_be16(lid);
                } else
                        priv->s_hdr->ibh.lrh[3] = IB_LID_PERMISSIVE;
        }
        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)
                bth0 |= hfi1_get_pkey(ibp, wqe->ud_wr.pkey_index);
        else
                bth0 |= hfi1_get_pkey(ibp, qp->s_pkey_index);
        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(qp->s_next_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);
        /* disarm any ahg */
        priv->s_hdr->ahgcount = 0;
        priv->s_hdr->ahgidx = 0;
        priv->s_hdr->tx_flags = 0;
        priv->s_hdr->sde = NULL;

done:
        ret = 1;
        goto unlock;

bail:
        qp->s_flags &= ~RVT_S_BUSY;
unlock:
        spin_unlock_irqrestore(&qp->s_lock, flags);
        return ret;
}

/*
 * 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(struct hfi1_ibport *ibp, struct rvt_qp *qp, u32 remote_qpn,
                u32 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 hfi1_ib_header hdr;
        struct hfi1_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 - 2 + 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 << HFI1_BECN_SHIFT));
        ohdr->bth[2] = 0; /* PSN 0 */

        hdr.lrh[0] = cpu_to_be16(lrh0);
        hdr.lrh[1] = cpu_to_be16(dlid);
        hdr.lrh[2] = cpu_to_be16(hwords + SIZE_OF_CRC);
        hdr.lrh[3] = cpu_to_be16(slid);

        plen = 2 /* PBC */ + hwords;
        pbc_flags |= (!!(sc5 & 0x10)) << 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 0.90, section 9.10.26
 * ("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, trap, or trap repress.
         * Our response depends, in part, on which type of
         * SMP we're processing.
         *
         * If this is not an SMA request, or trap repress:
         *   - accept MAD if the port is running an SM
         *   - pkey == FULL_MGMT_P_KEY =>
         *       reply with unsupported method (i.e., just mark
         *       the smp's status field here, and let it be
         *       processed normally)
         *   - pkey != LIM_MGMT_P_KEY =>
         *       increment port recv constraint errors, drop MAD
         * If this is an SMA request or trap repress:
         *   - pkey != FULL_MGMT_P_KEY =>
         *       increment port recv constraint errors, drop MAD
         */
        switch (smp->method) {
        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;
        case IB_MGMT_METHOD_SEND:
        case IB_MGMT_METHOD_TRAP:
        case IB_MGMT_METHOD_GET_RESP:
        case IB_MGMT_METHOD_REPORT_RESP:
                if (ibp->rvp.port_cap_flags & IB_PORT_SM)
                        return 0;
                if (pkey == FULL_MGMT_P_KEY) {
                        smp->status |= IB_SMP_UNSUP_METHOD;
                        return 0;
                }
                if (pkey != LIM_MGMT_P_KEY) {
                        ingress_pkey_table_fail(ppd, pkey, slid);
                        return 1;
                }
                break;
        default:
                break;
        }
        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)
{
        struct hfi1_other_headers *ohdr = packet->ohdr;
        int opcode;
        u32 hdrsize = packet->hlen;
        u32 pad;
        struct ib_wc wc;
        u32 qkey;
        u32 src_qp;
        u16 dlid, pkey;
        int mgmt_pkey_idx = -1;
        struct hfi1_ibport *ibp = &packet->rcd->ppd->ibport_data;
        struct hfi1_ib_header *hdr = packet->hdr;
        u32 rcv_flags = packet->rcv_flags;
        void *data = packet->ebuf;
        u32 tlen = packet->tlen;
        struct rvt_qp *qp = packet->qp;
        bool has_grh = rcv_flags & HFI1_HAS_GRH;
        bool sc4_bit = has_sc4_bit(packet);
        u8 sc;
        u32 bth1;
        int is_mcast;
        struct ib_grh *grh = NULL;

        qkey = be32_to_cpu(ohdr->u.ud.deth[0]);
        src_qp = be32_to_cpu(ohdr->u.ud.deth[1]) & HFI1_QPN_MASK;
        dlid = be16_to_cpu(hdr->lrh[1]);
        is_mcast = (dlid > be16_to_cpu(IB_MULTICAST_LID_BASE)) &&
                        (dlid != be16_to_cpu(IB_LID_PERMISSIVE));
        bth1 = be32_to_cpu(ohdr->bth[1]);
        if (unlikely(bth1 & HFI1_BECN_SMASK)) {
                /*
                 * In pre-B0 h/w the CNP_OPCODE is handled via an
                 * error path.
                 */
                struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
                u32 lqpn =  be32_to_cpu(ohdr->bth[1]) & HFI1_QPN_MASK;
                u8 sl, sc5;

                sc5 = (be16_to_cpu(hdr->lrh[0]) >> 12) & 0xf;
                sc5 |= sc4_bit;
                sl = ibp->sc_to_sl[sc5];

                process_becn(ppd, sl, 0, lqpn, 0, IB_CC_SVCTYPE_UD);
        }

        /*
         * The opcode is in the low byte when its in network order
         * (top byte when in host order).
         */
        opcode = be32_to_cpu(ohdr->bth[0]) >> 24;
        opcode &= 0xff;

        pkey = (u16)be32_to_cpu(ohdr->bth[0]);

        if (!is_mcast && (opcode != IB_OPCODE_CNP) && bth1 & HFI1_FECN_SMASK) {
                u16 slid = be16_to_cpu(hdr->lrh[3]);
                u8 sc5;

                sc5 = (be16_to_cpu(hdr->lrh[0]) >> 12) & 0xf;
                sc5 |= sc4_bit;

                return_cnp(ibp, qp, src_qp, pkey, dlid, slid, sc5, grh);
        }
        /*
         * Get the number of bytes the message was padded by
         * and drop incomplete packets.
         */
        pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
        if (unlikely(tlen < (hdrsize + pad + 4)))
                goto drop;

        tlen -= hdrsize + pad + 4;

        /*
         * 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(hdr->lrh[1] == IB_LID_PERMISSIVE ||
                             hdr->lrh[3] == IB_LID_PERMISSIVE))
                        goto drop;
                if (qp->ibqp.qp_num > 1) {
                        struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
                        u16 slid;
                        u8 sc5;

                        sc5 = (be16_to_cpu(hdr->lrh[0]) >> 12) & 0xf;
                        sc5 |= sc4_bit;

                        slid = be16_to_cpu(hdr->lrh[3]);
                        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_pqkey(ibp, OPA_TRAP_BAD_P_KEY,
                                               pkey,
                                               (be16_to_cpu(hdr->lrh[0]) >> 4) &
                                                0xF,
                                               src_qp, qp->ibqp.qp_num,
                                               be16_to_cpu(hdr->lrh[3]),
                                               be16_to_cpu(hdr->lrh[1]));
                                return;
                        }
                } else {
                        /* GSI packet */
                        mgmt_pkey_idx = hfi1_lookup_pkey_idx(ibp, pkey);
                        if (mgmt_pkey_idx < 0)
                                goto drop;

                }
                if (unlikely(qkey != qp->qkey)) {
                        hfi1_bad_pqkey(ibp, OPA_TRAP_BAD_Q_KEY, qkey,
                                       (be16_to_cpu(hdr->lrh[0]) >> 4) & 0xF,
                                       src_qp, qp->ibqp.qp_num,
                                       be16_to_cpu(hdr->lrh[3]),
                                       be16_to_cpu(hdr->lrh[1]));
                        return;
                }
                /* Drop invalid MAD packets (see 13.5.3.1). */
                if (unlikely(qp->ibqp.qp_num == 1 &&
                             (tlen > 2048 ||
                              (be16_to_cpu(hdr->lrh[0]) >> 12) == 15)))
                        goto drop;
        } else {
                /* Received on QP0, and so by definition, this is an SMP */
                struct opa_smp *smp = (struct opa_smp *)data;
                u16 slid = be16_to_cpu(hdr->lrh[3]);
                u8 sc5;

                sc5 = (be16_to_cpu(hdr->lrh[0]) >> 12) & 0xf;
                sc5 |= sc4_bit;

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

                if (tlen > 2048)
                        goto drop;
                if ((hdr->lrh[1] == IB_LID_PERMISSIVE ||
                     hdr->lrh[3] == IB_LID_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 = 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 = hfi1_get_rwqe(qp, 0);
                if (ret < 0) {
                        hfi1_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 (has_grh) {
                hfi1_copy_sge(&qp->r_sge, &hdr->u.l.grh,
                              sizeof(struct ib_grh), 1);
                wc.wc_flags |= IB_WC_GRH;
        } else
                hfi1_skip_sge(&qp->r_sge, sizeof(struct ib_grh), 1);
        hfi1_copy_sge(&qp->r_sge, data, wc.byte_len - sizeof(struct ib_grh), 1);
        hfi1_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_pportdata *ppd = ppd_from_ibp(ibp);
                                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;

        wc.slid = be16_to_cpu(hdr->lrh[3]);
        sc = (be16_to_cpu(hdr->lrh[0]) >> 12) & 0xf;
        sc |= sc4_bit;
        wc.sl = ibp->sc_to_sl[sc];

        /*
         * Save the LMC lower bits if the destination LID is a unicast LID.
         */
        wc.dlid_path_bits = dlid >= be16_to_cpu(IB_MULTICAST_LID_BASE) ? 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,
                     (ohdr->bth[0] &
                      cpu_to_be32(IB_BTH_SOLICITED)) != 0);
        return;

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