/*
 * Copyright (c) 2006, 2007, 2008 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 "ipath_verbs.h"
#include "ipath_kernel.h"

/* cut down ridiculously long IB macro names */
#define OP(x) IB_OPCODE_UC_##x

/**
 * ipath_make_uc_req - construct a request packet (SEND, RDMA write)
 * @qp: a pointer to the QP
 *
 * Return 1 if constructed; otherwise, return 0.
 */
int ipath_make_uc_req(struct ipath_qp *qp)
{
        struct ipath_other_headers *ohdr;
        struct ipath_swqe *wqe;
        unsigned long flags;
        u32 hwords;
        u32 bth0;
        u32 len;
        u32 pmtu = ib_mtu_enum_to_int(qp->path_mtu);
        int ret = 0;

        spin_lock_irqsave(&qp->s_lock, flags);

        if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_SEND_OK)) {
                if (!(ib_ipath_state_ops[qp->state] & IPATH_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(&qp->s_dma_busy)) {
                        qp->s_flags |= IPATH_S_WAIT_DMA;
                        goto bail;
                }
                wqe = get_swqe_ptr(qp, qp->s_last);
                ipath_send_complete(qp, wqe, IB_WC_WR_FLUSH_ERR);
                goto done;
        }

        ohdr = &qp->s_hdr.u.oth;
        if (qp->remote_ah_attr.ah_flags & IB_AH_GRH)
                ohdr = &qp->s_hdr.u.l.oth;

        /* header size in 32-bit words LRH+BTH = (8+12)/4. */
        hwords = 5;
        bth0 = 1 << 22; /* Set M bit */

        /* Get the next send request. */
        wqe = get_swqe_ptr(qp, qp->s_cur);
        qp->s_wqe = NULL;
        switch (qp->s_state) {
        default:
                if (!(ib_ipath_state_ops[qp->state] &
                    IPATH_PROCESS_NEXT_SEND_OK))
                        goto bail;
                /* Check if send work queue is empty. */
                if (qp->s_cur == qp->s_head)
                        goto bail;
                /*
                 * Start a new request.
                 */
                qp->s_psn = wqe->psn = qp->s_next_psn;
                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_len = len = wqe->length;
                switch (wqe->wr.opcode) {
                case IB_WR_SEND:
                case IB_WR_SEND_WITH_IMM:
                        if (len > pmtu) {
                                qp->s_state = OP(SEND_FIRST);
                                len = pmtu;
                                break;
                        }
                        if (wqe->wr.opcode == IB_WR_SEND)
                                qp->s_state = OP(SEND_ONLY);
                        else {
                                qp->s_state =
                                        OP(SEND_ONLY_WITH_IMMEDIATE);
                                /* Immediate data comes after the BTH */
                                ohdr->u.imm_data = wqe->wr.ex.imm_data;
                                hwords += 1;
                        }
                        if (wqe->wr.send_flags & IB_SEND_SOLICITED)
                                bth0 |= 1 << 23;
                        qp->s_wqe = wqe;
                        if (++qp->s_cur >= qp->s_size)
                                qp->s_cur = 0;
                        break;

                case IB_WR_RDMA_WRITE:
                case IB_WR_RDMA_WRITE_WITH_IMM:
                        ohdr->u.rc.reth.vaddr =
                                cpu_to_be64(wqe->wr.wr.rdma.remote_addr);
                        ohdr->u.rc.reth.rkey =
                                cpu_to_be32(wqe->wr.wr.rdma.rkey);
                        ohdr->u.rc.reth.length = cpu_to_be32(len);
                        hwords += sizeof(struct ib_reth) / 4;
                        if (len > pmtu) {
                                qp->s_state = OP(RDMA_WRITE_FIRST);
                                len = pmtu;
                                break;
                        }
                        if (wqe->wr.opcode == IB_WR_RDMA_WRITE)
                                qp->s_state = OP(RDMA_WRITE_ONLY);
                        else {
                                qp->s_state =
                                        OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE);
                                /* Immediate data comes after the RETH */
                                ohdr->u.rc.imm_data = wqe->wr.ex.imm_data;
                                hwords += 1;
                                if (wqe->wr.send_flags & IB_SEND_SOLICITED)
                                        bth0 |= 1 << 23;
                        }
                        qp->s_wqe = wqe;
                        if (++qp->s_cur >= qp->s_size)
                                qp->s_cur = 0;
                        break;

                default:
                        goto bail;
                }
                break;

        case OP(SEND_FIRST):
                qp->s_state = OP(SEND_MIDDLE);
                /* FALLTHROUGH */
        case OP(SEND_MIDDLE):
                len = qp->s_len;
                if (len > pmtu) {
                        len = pmtu;
                        break;
                }
                if (wqe->wr.opcode == IB_WR_SEND)
                        qp->s_state = OP(SEND_LAST);
                else {
                        qp->s_state = OP(SEND_LAST_WITH_IMMEDIATE);
                        /* Immediate data comes after the BTH */
                        ohdr->u.imm_data = wqe->wr.ex.imm_data;
                        hwords += 1;
                }
                if (wqe->wr.send_flags & IB_SEND_SOLICITED)
                        bth0 |= 1 << 23;
                qp->s_wqe = wqe;
                if (++qp->s_cur >= qp->s_size)
                        qp->s_cur = 0;
                break;

        case OP(RDMA_WRITE_FIRST):
                qp->s_state = OP(RDMA_WRITE_MIDDLE);
                /* FALLTHROUGH */
        case OP(RDMA_WRITE_MIDDLE):
                len = qp->s_len;
                if (len > pmtu) {
                        len = pmtu;
                        break;
                }
                if (wqe->wr.opcode == IB_WR_RDMA_WRITE)
                        qp->s_state = OP(RDMA_WRITE_LAST);
                else {
                        qp->s_state =
                                OP(RDMA_WRITE_LAST_WITH_IMMEDIATE);
                        /* Immediate data comes after the BTH */
                        ohdr->u.imm_data = wqe->wr.ex.imm_data;
                        hwords += 1;
                        if (wqe->wr.send_flags & IB_SEND_SOLICITED)
                                bth0 |= 1 << 23;
                }
                qp->s_wqe = wqe;
                if (++qp->s_cur >= qp->s_size)
                        qp->s_cur = 0;
                break;
        }
        qp->s_len -= len;
        qp->s_hdrwords = hwords;
        qp->s_cur_sge = &qp->s_sge;
        qp->s_cur_size = len;
        ipath_make_ruc_header(to_idev(qp->ibqp.device),
                              qp, ohdr, bth0 | (qp->s_state << 24),
                              qp->s_next_psn++ & IPATH_PSN_MASK);
done:
        ret = 1;
        goto unlock;

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

/**
 * ipath_uc_rcv - handle an incoming UC packet
 * @dev: the device the packet came in on
 * @hdr: the header of the packet
 * @has_grh: true if the packet has a GRH
 * @data: the packet data
 * @tlen: the length of the packet
 * @qp: the QP for this packet.
 *
 * This is called from ipath_qp_rcv() to process an incoming UC packet
 * for the given QP.
 * Called at interrupt level.
 */
void ipath_uc_rcv(struct ipath_ibdev *dev, struct ipath_ib_header *hdr,
                  int has_grh, void *data, u32 tlen, struct ipath_qp *qp)
{
        struct ipath_other_headers *ohdr;
        int opcode;
        u32 hdrsize;
        u32 psn;
        u32 pad;
        struct ib_wc wc;
        u32 pmtu = ib_mtu_enum_to_int(qp->path_mtu);
        struct ib_reth *reth;
        int header_in_data;

        /* Validate the SLID. See Ch. 9.6.1.5 */
        if (unlikely(be16_to_cpu(hdr->lrh[3]) != qp->remote_ah_attr.dlid))
                goto done;

        /* Check for GRH */
        if (!has_grh) {
                ohdr = &hdr->u.oth;
                hdrsize = 8 + 12;       /* LRH + BTH */
                psn = be32_to_cpu(ohdr->bth[2]);
                header_in_data = 0;
        } else {
                ohdr = &hdr->u.l.oth;
                hdrsize = 8 + 40 + 12;  /* LRH + GRH + BTH */
                /*
                 * The header with GRH is 60 bytes and the
                 * core driver sets the eager header buffer
                 * size to 56 bytes so the last 4 bytes of
                 * the BTH header (PSN) is in the data buffer.
                 */
                header_in_data = dev->dd->ipath_rcvhdrentsize == 16;
                if (header_in_data) {
                        psn = be32_to_cpu(((__be32 *) data)[0]);
                        data += sizeof(__be32);
                } else
                        psn = be32_to_cpu(ohdr->bth[2]);
        }
        /*
         * 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;

        memset(&wc, 0, sizeof wc);

        /* Compare the PSN verses the expected PSN. */
        if (unlikely(ipath_cmp24(psn, qp->r_psn) != 0)) {
                /*
                 * Handle a sequence error.
                 * Silently drop any current message.
                 */
                qp->r_psn = psn;
        inv:
                qp->r_state = OP(SEND_LAST);
                switch (opcode) {
                case OP(SEND_FIRST):
                case OP(SEND_ONLY):
                case OP(SEND_ONLY_WITH_IMMEDIATE):
                        goto send_first;

                case OP(RDMA_WRITE_FIRST):
                case OP(RDMA_WRITE_ONLY):
                case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE):
                        goto rdma_first;

                default:
                        dev->n_pkt_drops++;
                        goto done;
                }
        }

        /* Check for opcode sequence errors. */
        switch (qp->r_state) {
        case OP(SEND_FIRST):
        case OP(SEND_MIDDLE):
                if (opcode == OP(SEND_MIDDLE) ||
                    opcode == OP(SEND_LAST) ||
                    opcode == OP(SEND_LAST_WITH_IMMEDIATE))
                        break;
                goto inv;

        case OP(RDMA_WRITE_FIRST):
        case OP(RDMA_WRITE_MIDDLE):
                if (opcode == OP(RDMA_WRITE_MIDDLE) ||
                    opcode == OP(RDMA_WRITE_LAST) ||
                    opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
                        break;
                goto inv;

        default:
                if (opcode == OP(SEND_FIRST) ||
                    opcode == OP(SEND_ONLY) ||
                    opcode == OP(SEND_ONLY_WITH_IMMEDIATE) ||
                    opcode == OP(RDMA_WRITE_FIRST) ||
                    opcode == OP(RDMA_WRITE_ONLY) ||
                    opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE))
                        break;
                goto inv;
        }

        /* OK, process the packet. */
        switch (opcode) {
        case OP(SEND_FIRST):
        case OP(SEND_ONLY):
        case OP(SEND_ONLY_WITH_IMMEDIATE):
        send_first:
                if (qp->r_flags & IPATH_R_REUSE_SGE) {
                        qp->r_flags &= ~IPATH_R_REUSE_SGE;
                        qp->r_sge = qp->s_rdma_read_sge;
                } else if (!ipath_get_rwqe(qp, 0)) {
                        dev->n_pkt_drops++;
                        goto done;
                }
                /* Save the WQE so we can reuse it in case of an error. */
                qp->s_rdma_read_sge = qp->r_sge;
                qp->r_rcv_len = 0;
                if (opcode == OP(SEND_ONLY))
                        goto send_last;
                else if (opcode == OP(SEND_ONLY_WITH_IMMEDIATE))
                        goto send_last_imm;
                /* FALLTHROUGH */
        case OP(SEND_MIDDLE):
                /* Check for invalid length PMTU or posted rwqe len. */
                if (unlikely(tlen != (hdrsize + pmtu + 4))) {
                        qp->r_flags |= IPATH_R_REUSE_SGE;
                        dev->n_pkt_drops++;
                        goto done;
                }
                qp->r_rcv_len += pmtu;
                if (unlikely(qp->r_rcv_len > qp->r_len)) {
                        qp->r_flags |= IPATH_R_REUSE_SGE;
                        dev->n_pkt_drops++;
                        goto done;
                }
                ipath_copy_sge(&qp->r_sge, data, pmtu);
                break;

        case OP(SEND_LAST_WITH_IMMEDIATE):
        send_last_imm:
                if (header_in_data) {
                        wc.ex.imm_data = *(__be32 *) data;
                        data += sizeof(__be32);
                } else {
                        /* Immediate data comes after BTH */
                        wc.ex.imm_data = ohdr->u.imm_data;
                }
                hdrsize += 4;
                wc.wc_flags = IB_WC_WITH_IMM;
                /* FALLTHROUGH */
        case OP(SEND_LAST):
        send_last:
                /* Get the number of bytes the message was padded by. */
                pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
                /* Check for invalid length. */
                /* XXX LAST len should be >= 1 */
                if (unlikely(tlen < (hdrsize + pad + 4))) {
                        qp->r_flags |= IPATH_R_REUSE_SGE;
                        dev->n_pkt_drops++;
                        goto done;
                }
                /* Don't count the CRC. */
                tlen -= (hdrsize + pad + 4);
                wc.byte_len = tlen + qp->r_rcv_len;
                if (unlikely(wc.byte_len > qp->r_len)) {
                        qp->r_flags |= IPATH_R_REUSE_SGE;
                        dev->n_pkt_drops++;
                        goto done;
                }
                wc.opcode = IB_WC_RECV;
        last_imm:
                ipath_copy_sge(&qp->r_sge, data, tlen);
                wc.wr_id = qp->r_wr_id;
                wc.status = IB_WC_SUCCESS;
                wc.qp = &qp->ibqp;
                wc.src_qp = qp->remote_qpn;
                wc.slid = qp->remote_ah_attr.dlid;
                wc.sl = qp->remote_ah_attr.sl;
                /* Signal completion event if the solicited bit is set. */
                ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
                               (ohdr->bth[0] &
                                cpu_to_be32(1 << 23)) != 0);
                break;

        case OP(RDMA_WRITE_FIRST):
        case OP(RDMA_WRITE_ONLY):
        case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE): /* consume RWQE */
        rdma_first:
                /* RETH comes after BTH */
                if (!header_in_data)
                        reth = &ohdr->u.rc.reth;
                else {
                        reth = (struct ib_reth *)data;
                        data += sizeof(*reth);
                }
                hdrsize += sizeof(*reth);
                qp->r_len = be32_to_cpu(reth->length);
                qp->r_rcv_len = 0;
                if (qp->r_len != 0) {
                        u32 rkey = be32_to_cpu(reth->rkey);
                        u64 vaddr = be64_to_cpu(reth->vaddr);
                        int ok;

                        /* Check rkey */
                        ok = ipath_rkey_ok(qp, &qp->r_sge, qp->r_len,
                                           vaddr, rkey,
                                           IB_ACCESS_REMOTE_WRITE);
                        if (unlikely(!ok)) {
                                dev->n_pkt_drops++;
                                goto done;
                        }
                } else {
                        qp->r_sge.sg_list = NULL;
                        qp->r_sge.sge.mr = NULL;
                        qp->r_sge.sge.vaddr = NULL;
                        qp->r_sge.sge.length = 0;
                        qp->r_sge.sge.sge_length = 0;
                }
                if (unlikely(!(qp->qp_access_flags &
                               IB_ACCESS_REMOTE_WRITE))) {
                        dev->n_pkt_drops++;
                        goto done;
                }
                if (opcode == OP(RDMA_WRITE_ONLY))
                        goto rdma_last;
                else if (opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE))
                        goto rdma_last_imm;
                /* FALLTHROUGH */
        case OP(RDMA_WRITE_MIDDLE):
                /* Check for invalid length PMTU or posted rwqe len. */
                if (unlikely(tlen != (hdrsize + pmtu + 4))) {
                        dev->n_pkt_drops++;
                        goto done;
                }
                qp->r_rcv_len += pmtu;
                if (unlikely(qp->r_rcv_len > qp->r_len)) {
                        dev->n_pkt_drops++;
                        goto done;
                }
                ipath_copy_sge(&qp->r_sge, data, pmtu);
                break;

        case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE):
        rdma_last_imm:
                if (header_in_data) {
                        wc.ex.imm_data = *(__be32 *) data;
                        data += sizeof(__be32);
                } else {
                        /* Immediate data comes after BTH */
                        wc.ex.imm_data = ohdr->u.imm_data;
                }
                hdrsize += 4;
                wc.wc_flags = IB_WC_WITH_IMM;

                /* Get the number of bytes the message was padded by. */
                pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
                /* Check for invalid length. */
                /* XXX LAST len should be >= 1 */
                if (unlikely(tlen < (hdrsize + pad + 4))) {
                        dev->n_pkt_drops++;
                        goto done;
                }
                /* Don't count the CRC. */
                tlen -= (hdrsize + pad + 4);
                if (unlikely(tlen + qp->r_rcv_len != qp->r_len)) {
                        dev->n_pkt_drops++;
                        goto done;
                }
                if (qp->r_flags & IPATH_R_REUSE_SGE)
                        qp->r_flags &= ~IPATH_R_REUSE_SGE;
                else if (!ipath_get_rwqe(qp, 1)) {
                        dev->n_pkt_drops++;
                        goto done;
                }
                wc.byte_len = qp->r_len;
                wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
                goto last_imm;

        case OP(RDMA_WRITE_LAST):
        rdma_last:
                /* Get the number of bytes the message was padded by. */
                pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
                /* Check for invalid length. */
                /* XXX LAST len should be >= 1 */
                if (unlikely(tlen < (hdrsize + pad + 4))) {
                        dev->n_pkt_drops++;
                        goto done;
                }
                /* Don't count the CRC. */
                tlen -= (hdrsize + pad + 4);
                if (unlikely(tlen + qp->r_rcv_len != qp->r_len)) {
                        dev->n_pkt_drops++;
                        goto done;
                }
                ipath_copy_sge(&qp->r_sge, data, tlen);
                break;

        default:
                /* Drop packet for unknown opcodes. */
                dev->n_pkt_drops++;
                goto done;
        }
        qp->r_psn++;
        qp->r_state = opcode;
done:
        return;
}