/*
 * Copyright (c) 2006, 2007, 2008, 2009 QLogic Corporation. All rights reserved.
 * Copyright (c) 2005, 2006 PathScale, Inc. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

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

#include "qib.h"
#include "qib_mad.h"

/**
 * qib_ud_loopback - handle send on loopback QPs
 * @sqp: the sending QP
 * @swqe: the send work request
 *
 * This is called from qib_make_ud_req() to forward a WQE addressed
 * to the same HCA.
 * Note that the receive interrupt handler may be calling qib_ud_rcv()
 * while this is being called.
 */
static void qib_ud_loopback(struct rvt_qp *sqp, struct rvt_swqe *swqe)
{
        struct qib_ibport *ibp = to_iport(sqp->ibqp.device, sqp->port_num);
        struct qib_pportdata *ppd = ppd_from_ibp(ibp);
        struct qib_devdata *dd = ppd->dd;
        struct rvt_dev_info *rdi = &dd->verbs_dev.rdi;
        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(rdi, &ibp->rvp, swqe->ud_wr.remote_qpn);
        if (!qp) {
                ibp->rvp.n_pkt_drops++;
                goto drop;
        }

        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 pkey1;
                u16 pkey2;
                u16 lid;

                pkey1 = qib_get_pkey(ibp, sqp->s_pkey_index);
                pkey2 = qib_get_pkey(ibp, qp->s_pkey_index);
                if (unlikely(!qib_pkey_ok(pkey1, pkey2))) {
                        lid = ppd->lid | (rdma_ah_get_path_bits(ah_attr) &
                                          ((1 << ppd->lmc) - 1));
                        qib_bad_pkey(ibp, pkey1,
                                     rdma_ah_get_sl(ah_attr),
                                     sqp->ibqp.qp_num, qp->ibqp.qp_num,
                                     cpu_to_be16(lid),
                                     cpu_to_be16(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;
        }

        /*
         * 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;
                const struct ib_global_route *grd = rdma_ah_read_grh(ah_attr);

                qib_make_grh(ibp, &grh, grd, 0, 0);
                qib_copy_sge(&qp->r_sge, &grh,
                             sizeof(grh), 1);
                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;
                BUG_ON(len == 0);
                qib_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;
        }
        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;
        wc.pkey_index = qp->ibqp.qp_type == IB_QPT_GSI ?
                swqe->ud_wr.pkey_index : 0;
        wc.slid = ppd->lid | (rdma_ah_get_path_bits(ah_attr) &
                                ((1 << ppd->lmc) - 1));
        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();
}

/**
 * qib_make_ud_req - construct a UD request packet
 * @qp: the QP
 *
 * Assumes the s_lock is held.
 *
 * Return 1 if constructed; otherwise, return 0.
 */
int qib_make_ud_req(struct rvt_qp *qp, unsigned long *flags)
{
        struct qib_qp_priv *priv = qp->priv;
        struct ib_other_headers *ohdr;
        struct rdma_ah_attr *ah_attr;
        struct qib_pportdata *ppd;
        struct qib_ibport *ibp;
        struct rvt_swqe *wqe;
        u32 nwords;
        u32 extra_bytes;
        u32 bth0;
        u16 lrh0;
        u16 lid;
        int ret = 0;
        int next_cur;

        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 (atomic_read(&priv->s_dma_busy)) {
                        qp->s_flags |= RVT_S_WAIT_DMA;
                        goto bail;
                }
                wqe = rvt_get_swqe_ptr(qp, qp->s_last);
                qib_send_complete(qp, wqe, IB_WC_WR_FLUSH_ERR);
                goto done;
        }

        /* 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;
        if (rdma_ah_get_dlid(ah_attr) >= be16_to_cpu(IB_MULTICAST_LID_BASE)) {
                if (rdma_ah_get_dlid(ah_attr) !=
                                be16_to_cpu(IB_LID_PERMISSIVE))
                        this_cpu_inc(ibp->pmastats->n_multicast_xmit);
                else
                        this_cpu_inc(ibp->pmastats->n_unicast_xmit);
        } else {
                this_cpu_inc(ibp->pmastats->n_unicast_xmit);
                lid = rdma_ah_get_dlid(ah_attr) & ~((1 << ppd->lmc) - 1);
                if (unlikely(lid == ppd->lid)) {
                        unsigned long tflags = *flags;
                        /*
                         * If DMAs are in progress, we can't generate
                         * a completion for the loopback packet since
                         * it would be out of order.
                         * XXX Instead of waiting, we could queue a
                         * zero length descriptor so we get a callback.
                         */
                        if (atomic_read(&priv->s_dma_busy)) {
                                qp->s_flags |= RVT_S_WAIT_DMA;
                                goto bail;
                        }
                        qp->s_cur = next_cur;
                        spin_unlock_irqrestore(&qp->s_lock, tflags);
                        qib_ud_loopback(qp, wqe);
                        spin_lock_irqsave(&qp->s_lock, tflags);
                        *flags = tflags;
                        qib_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 = rdma_ah_get_static_rate(ah_attr);
        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 (rdma_ah_get_ah_flags(ah_attr) & IB_AH_GRH) {
                /* Header size in 32-bit words. */
                qp->s_hdrwords += qib_make_grh(ibp, &priv->s_hdr->u.l.grh,
                                               rdma_ah_read_grh(ah_attr),
                                               qp->s_hdrwords, nwords);
                lrh0 = QIB_LRH_GRH;
                ohdr = &priv->s_hdr->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 = QIB_LRH_BTH;
                ohdr = &priv->s_hdr->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;
        lrh0 |= rdma_ah_get_sl(ah_attr) << 4;
        if (qp->ibqp.qp_type == IB_QPT_SMI)
                lrh0 |= 0xF000; /* Set VL (see ch. 13.5.3.1) */
        else
                lrh0 |= ibp->sl_to_vl[rdma_ah_get_sl(ah_attr)] << 12;
        priv->s_hdr->lrh[0] = cpu_to_be16(lrh0);
        priv->s_hdr->lrh[1] =
                        cpu_to_be16(rdma_ah_get_dlid(ah_attr));  /* DEST LID */
        priv->s_hdr->lrh[2] =
                        cpu_to_be16(qp->s_hdrwords + nwords + SIZE_OF_CRC);
        lid = ppd->lid;
        if (lid) {
                lid |= rdma_ah_get_path_bits(ah_attr) &
                        ((1 << ppd->lmc) - 1);
                priv->s_hdr->lrh[3] = cpu_to_be16(lid);
        } else
                priv->s_hdr->lrh[3] = IB_LID_PERMISSIVE;
        if (wqe->wr.send_flags & IB_SEND_SOLICITED)
                bth0 |= IB_BTH_SOLICITED;
        bth0 |= extra_bytes << 20;
        bth0 |= qp->ibqp.qp_type == IB_QPT_SMI ? QIB_DEFAULT_P_KEY :
                qib_get_pkey(ibp, qp->ibqp.qp_type == IB_QPT_GSI ?
                             wqe->ud_wr.pkey_index : qp->s_pkey_index);
        ohdr->bth[0] = cpu_to_be32(bth0);
        /*
         * Use the multicast QP if the destination LID is a multicast LID.
         */
        ohdr->bth[1] = rdma_ah_get_dlid(ah_attr) >=
                        be16_to_cpu(IB_MULTICAST_LID_BASE) &&
                rdma_ah_get_dlid(ah_attr) != be16_to_cpu(IB_LID_PERMISSIVE) ?
                cpu_to_be32(QIB_MULTICAST_QPN) :
                cpu_to_be32(wqe->ud_wr.remote_qpn);
        ohdr->bth[2] = cpu_to_be32(wqe->psn & QIB_PSN_MASK);
        /*
         * 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);

done:
        return 1;
bail:
        qp->s_flags &= ~RVT_S_BUSY;
        return ret;
}

static unsigned qib_lookup_pkey(struct qib_ibport *ibp, u16 pkey)
{
        struct qib_pportdata *ppd = ppd_from_ibp(ibp);
        struct qib_devdata *dd = ppd->dd;
        unsigned ctxt = ppd->hw_pidx;
        unsigned i;

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

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

        /*
         * Should not get here, this means hardware failed to validate pkeys.
         * Punt and return index 0.
         */
        return 0;
}

/**
 * qib_ud_rcv - receive an incoming UD packet
 * @ibp: the port the packet came in on
 * @hdr: the packet header
 * @has_grh: true if the packet has a GRH
 * @data: the packet data
 * @tlen: the packet length
 * @qp: the QP the packet came on
 *
 * This is called from qib_qp_rcv() to process an incoming UD packet
 * for the given QP.
 * Called at interrupt level.
 */
void qib_ud_rcv(struct qib_ibport *ibp, struct ib_header *hdr,
                int has_grh, void *data, u32 tlen, struct rvt_qp *qp)
{
        struct ib_other_headers *ohdr;
        int opcode;
        u32 hdrsize;
        u32 pad;
        struct ib_wc wc;
        u32 qkey;
        u32 src_qp;
        u16 dlid;

        /* Check for GRH */
        if (!has_grh) {
                ohdr = &hdr->u.oth;
                hdrsize = 8 + 12 + 8;   /* LRH + BTH + DETH */
        } else {
                ohdr = &hdr->u.l.oth;
                hdrsize = 8 + 40 + 12 + 8; /* LRH + GRH + BTH + DETH */
        }
        qkey = be32_to_cpu(ohdr->u.ud.deth[0]);
        src_qp = be32_to_cpu(ohdr->u.ud.deth[1]) & RVT_QPN_MASK;

        /*
         * 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) {
                        u16 pkey1, pkey2;

                        pkey1 = be32_to_cpu(ohdr->bth[0]);
                        pkey2 = qib_get_pkey(ibp, qp->s_pkey_index);
                        if (unlikely(!qib_pkey_ok(pkey1, pkey2))) {
                                qib_bad_pkey(ibp,
                                             pkey1,
                                             (be16_to_cpu(hdr->lrh[0]) >> 4) &
                                                0xF,
                                             src_qp, qp->ibqp.qp_num,
                                             hdr->lrh[3], hdr->lrh[1]);
                                return;
                        }
                }
                if (unlikely(qkey != qp->qkey))
                        return;

                /* Drop invalid MAD packets (see 13.5.3.1). */
                if (unlikely(qp->ibqp.qp_num == 1 &&
                             (tlen != 256 ||
                              (be16_to_cpu(hdr->lrh[0]) >> 12) == 15)))
                        goto drop;
        } else {
                struct ib_smp *smp;

                /* Drop invalid MAD packets (see 13.5.3.1). */
                if (tlen != 256 || (be16_to_cpu(hdr->lrh[0]) >> 12) != 15)
                        goto drop;
                smp = (struct ib_smp *) data;
                if ((hdr->lrh[1] == IB_LID_PERMISSIVE ||
                     hdr->lrh[3] == IB_LID_PERMISSIVE) &&
                    smp->mgmt_class != IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE)
                        goto drop;
        }

        /*
         * 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;
        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 = 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 (has_grh) {
                qib_copy_sge(&qp->r_sge, &hdr->u.l.grh,
                             sizeof(struct ib_grh), 1);
                wc.wc_flags |= IB_WC_GRH;
        } else
                rvt_skip_sge(&qp->r_sge, sizeof(struct ib_grh), true);
        qib_copy_sge(&qp->r_sge, data, wc.byte_len - sizeof(struct ib_grh), 1);
        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;
        wc.pkey_index = qp->ibqp.qp_type == IB_QPT_GSI ?
                qib_lookup_pkey(ibp, be32_to_cpu(ohdr->bth[0])) : 0;
        wc.slid = be16_to_cpu(hdr->lrh[3]);
        wc.sl = (be16_to_cpu(hdr->lrh[0]) >> 4) & 0xF;
        dlid = be16_to_cpu(hdr->lrh[1]);
        /*
         * 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,
                     ib_bth_is_solicited(ohdr));
        return;

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