drivers/infiniband/hw/qib/qib_ud.c - LeafOS-Devices/android_kernel_samsung_gta4xl - Gitiles

 /*
  * 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 "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 qib_qp *sqp, struct qib_swqe *swqe)
 {
 	struct qib_ibport *ibp = to_iport(sqp->ibqp.device, sqp->port_num);
 	struct qib_pportdata *ppd;
 	struct qib_qp *qp;
 	struct ib_ah_attr *ah_attr;
 	unsigned long flags;
 	struct qib_sge_state ssge;
 	struct qib_sge *sge;
 	struct ib_wc wc;
 	u32 length;

 	qp = qib_lookup_qpn(ibp, swqe->wr.wr.ud.remote_qpn);
 	if (!qp) {
 		ibp->n_pkt_drops++;
 		return;
 	}
 	if (qp->ibqp.qp_type != sqp->ibqp.qp_type ||
 	    !(ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK)) {
 		ibp->n_pkt_drops++;
 		goto drop;
 	}

 	ah_attr = &to_iah(swqe->wr.wr.ud.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 | (ah_attr->src_path_bits &
 					  ((1 << ppd->lmc) - 1));
 			qib_bad_pqkey(ibp, IB_NOTICE_TRAP_BAD_PKEY, pkey1,
 				      ah_attr->sl,
 				      sqp->ibqp.qp_num, qp->ibqp.qp_num,
 				      cpu_to_be16(lid),
 				      cpu_to_be16(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->wr.wr.ud.remote_qkey < 0 ?
 			sqp->qkey : swqe->wr.wr.ud.remote_qkey;
 		if (unlikely(qkey != qp->qkey)) {
 			u16 lid;

 			lid = ppd->lid | (ah_attr->src_path_bits &
 					  ((1 << ppd->lmc) - 1));
 			qib_bad_pqkey(ibp, IB_NOTICE_TRAP_BAD_QKEY, qkey,
 				      ah_attr->sl,
 				      sqp->ibqp.qp_num, qp->ibqp.qp_num,
 				      cpu_to_be16(lid),
 				      cpu_to_be16(ah_attr->dlid));
 			goto drop;
 		}
 	}

 	/*
 	 * A GRH is expected to preceed 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 & QIB_R_REUSE_SGE)
 		qp->r_flags &= ~QIB_R_REUSE_SGE;
 	else {
 		int ret;

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

 	if (ah_attr->ah_flags & IB_AH_GRH) {
 		qib_copy_sge(&qp->r_sge, &ah_attr->grh,
 			     sizeof(struct ib_grh), 1);
 		wc.wc_flags |= IB_WC_GRH;
 	} else
 		qib_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;
 		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 >= QIB_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;
 	}
 	while (qp->r_sge.num_sge) {
 		atomic_dec(&qp->r_sge.sge.mr->refcount);
 		if (--qp->r_sge.num_sge)
 			qp->r_sge.sge = *qp->r_sge.sg_list++;
 	}
 	if (!test_and_clear_bit(QIB_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->wr.wr.ud.pkey_index : 0;
 	wc.slid = ppd->lid | (ah_attr->src_path_bits & ((1 << ppd->lmc) - 1));
 	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. */
 	qib_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
 		     swqe->wr.send_flags & IB_SEND_SOLICITED);
 	ibp->n_loop_pkts++;
 bail_unlock:
 	spin_unlock_irqrestore(&qp->r_lock, flags);
 drop:
 	if (atomic_dec_and_test(&qp->refcount))
 		wake_up(&qp->wait);
 }

 /**
  * qib_make_ud_req - construct a UD request packet
  * @qp: the QP
  *
  * Return 1 if constructed; otherwise, return 0.
  */
 int qib_make_ud_req(struct qib_qp *qp)
 {
 	struct qib_other_headers *ohdr;
 	struct ib_ah_attr *ah_attr;
 	struct qib_pportdata *ppd;
 	struct qib_ibport *ibp;
 	struct qib_swqe *wqe;
 	unsigned long flags;
 	u32 nwords;
 	u32 extra_bytes;
 	u32 bth0;
 	u16 lrh0;
 	u16 lid;
 	int ret = 0;
 	int next_cur;

 	spin_lock_irqsave(&qp->s_lock, flags);

 	if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_NEXT_SEND_OK)) {
 		if (!(ib_qib_state_ops[qp->state] & QIB_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 |= QIB_S_WAIT_DMA;
 			goto bail;
 		}
 		wqe = get_swqe_ptr(qp, qp->s_last);
 		qib_send_complete(qp, wqe, IB_WC_WR_FLUSH_ERR);
 		goto done;
 	}

 	if (qp->s_cur == qp->s_head)
 		goto bail;

 	wqe = 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 = &to_iah(wqe->wr.wr.ud.ah)->attr;
 	if (ah_attr->dlid >= QIB_MULTICAST_LID_BASE) {
 		if (ah_attr->dlid != QIB_PERMISSIVE_LID)
 			ibp->n_multicast_xmit++;
 		else
 			ibp->n_unicast_xmit++;
 	} else {
 		ibp->n_unicast_xmit++;
 		lid = ah_attr->dlid & ~((1 << ppd->lmc) - 1);
 		if (unlikely(lid == ppd->lid)) {
 			/*
 			 * 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(&qp->s_dma_busy)) {
 				qp->s_flags |= QIB_S_WAIT_DMA;
 				goto bail;
 			}
 			qp->s_cur = next_cur;
 			spin_unlock_irqrestore(&qp->s_lock, flags);
 			qib_ud_loopback(qp, wqe);
 			spin_lock_irqsave(&qp->s_lock, flags);
 			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 = ah_attr->static_rate;
 	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 += qib_make_grh(ibp, &qp->s_hdr.u.l.grh,
 					       &ah_attr->grh,
 					       qp->s_hdrwords, nwords);
 		lrh0 = QIB_LRH_GRH;
 		ohdr = &qp->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 = &qp->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 |= ah_attr->sl << 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[ah_attr->sl] << 12;
 	qp->s_hdr.lrh[0] = cpu_to_be16(lrh0);
 	qp->s_hdr.lrh[1] = cpu_to_be16(ah_attr->dlid);  /* DEST LID */
 	qp->s_hdr.lrh[2] = cpu_to_be16(qp->s_hdrwords + nwords + SIZE_OF_CRC);
 	lid = ppd->lid;
 	if (lid) {
 		lid |= ah_attr->src_path_bits & ((1 << ppd->lmc) - 1);
 		qp->s_hdr.lrh[3] = cpu_to_be16(lid);
 	} else
 		qp->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->wr.wr.ud.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] = ah_attr->dlid >= QIB_MULTICAST_LID_BASE &&
 		ah_attr->dlid != QIB_PERMISSIVE_LID ?
 		cpu_to_be32(QIB_MULTICAST_QPN) :
 		cpu_to_be32(wqe->wr.wr.ud.remote_qpn);
 	ohdr->bth[2] = cpu_to_be32(qp->s_next_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->wr.wr.ud.remote_qkey < 0 ?
 					 qp->qkey : wqe->wr.wr.ud.remote_qkey);
 	ohdr->u.ud.deth[1] = cpu_to_be32(qp->ibqp.qp_num);

 done:
 	ret = 1;
 	goto unlock;

 bail:
 	qp->s_flags &= ~QIB_S_BUSY;
 unlock:
 	spin_unlock_irqrestore(&qp->s_lock, flags);
 	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 qib_ib_header *hdr,
 		int has_grh, void *data, u32 tlen, struct qib_qp *qp)
 {
 	struct qib_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]) & QIB_QPN_MASK;

 	/* Get the number of bytes the message was padded by. */
 	pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
 	if (unlikely(tlen < (hdrsize + pad + 4))) {
 		/* Drop incomplete packets. */
 		ibp->n_pkt_drops++;
 		goto bail;
 	}
 	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)) {
 			ibp->n_pkt_drops++;
 			goto bail;
 		}
 		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_pqkey(ibp, IB_NOTICE_TRAP_BAD_PKEY,
 					      pkey1,
 					      (be16_to_cpu(hdr->lrh[0]) >> 4) &
 						0xF,
 					      src_qp, qp->ibqp.qp_num,
 					      hdr->lrh[3], hdr->lrh[1]);
 				goto bail;
 			}
 		}
 		if (unlikely(qkey != qp->qkey)) {
 			qib_bad_pqkey(ibp, IB_NOTICE_TRAP_BAD_QKEY, qkey,
 				      (be16_to_cpu(hdr->lrh[0]) >> 4) & 0xF,
 				      src_qp, qp->ibqp.qp_num,
 				      hdr->lrh[3], hdr->lrh[1]);
 			goto bail;
 		}
 		/* 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))) {
 			ibp->n_pkt_drops++;
 			goto bail;
 		}
 	} 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) {
 			ibp->n_pkt_drops++;
 			goto bail;
 		}
 		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) {
 			ibp->n_pkt_drops++;
 			goto bail;
 		}
 	}

 	/*
 	 * 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;
 		hdrsize += sizeof(u32);
 	} else if (opcode == IB_OPCODE_UD_SEND_ONLY) {
 		wc.ex.imm_data = 0;
 		wc.wc_flags = 0;
 	} else {
 		ibp->n_pkt_drops++;
 		goto bail;
 	}

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

 	/*
 	 * We need to serialize getting a receive work queue entry and
 	 * generating a completion for it against QPs sending to this QP
 	 * locally.
 	 */
 	spin_lock(&qp->r_lock);

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

 		ret = qib_get_rwqe(qp, 0);
 		if (ret < 0) {
 			qib_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
 			goto bail_unlock;
 		}
 		if (!ret) {
 			if (qp->ibqp.qp_num == 0)
 				ibp->n_vl15_dropped++;
 			goto bail_unlock;
 		}
 	}
 	/* Silently drop packets which are too big. */
 	if (unlikely(wc.byte_len > qp->r_len)) {
 		qp->r_flags |= QIB_R_REUSE_SGE;
 		ibp->n_pkt_drops++;
 		goto bail_unlock;
 	}
 	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
 		qib_skip_sge(&qp->r_sge, sizeof(struct ib_grh), 1);
 	qib_copy_sge(&qp->r_sge, data, wc.byte_len - sizeof(struct ib_grh), 1);
 	while (qp->r_sge.num_sge) {
 		atomic_dec(&qp->r_sge.sge.mr->refcount);
 		if (--qp->r_sge.num_sge)
 			qp->r_sge.sge = *qp->r_sge.sg_list++;
 	}
 	if (!test_and_clear_bit(QIB_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.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 >= QIB_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. */
 	qib_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
 		     (ohdr->bth[0] &
 			cpu_to_be32(IB_BTH_SOLICITED)) != 0);
 bail_unlock:
 	spin_unlock(&qp->r_lock);
 bail:;
 }
	/*
	* 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 "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 qib_qp sqp, struct qib_swqe swqe)
	{
	struct qib_ibport *ibp = to_iport(sqp->ibqp.device, sqp->port_num);
	struct qib_pportdata *ppd;
	struct qib_qp *qp;
	struct ib_ah_attr *ah_attr;
	unsigned long flags;
	struct qib_sge_state ssge;
	struct qib_sge *sge;
	struct ib_wc wc;
	u32 length;

	qp = qib_lookup_qpn(ibp, swqe->wr.wr.ud.remote_qpn);
	if (!qp) {
	ibp->n_pkt_drops++;
	return;
	}
	if (qp->ibqp.qp_type != sqp->ibqp.qp_type \|\|
	!(ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK)) {
	ibp->n_pkt_drops++;
	goto drop;
	}

	ah_attr = &to_iah(swqe->wr.wr.ud.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 \| (ah_attr->src_path_bits &
	((1 << ppd->lmc) - 1));
	qib_bad_pqkey(ibp, IB_NOTICE_TRAP_BAD_PKEY, pkey1,
	ah_attr->sl,
	sqp->ibqp.qp_num, qp->ibqp.qp_num,
	cpu_to_be16(lid),
	cpu_to_be16(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->wr.wr.ud.remote_qkey < 0 ?
	sqp->qkey : swqe->wr.wr.ud.remote_qkey;
	if (unlikely(qkey != qp->qkey)) {
	u16 lid;

	lid = ppd->lid \| (ah_attr->src_path_bits &
	((1 << ppd->lmc) - 1));
	qib_bad_pqkey(ibp, IB_NOTICE_TRAP_BAD_QKEY, qkey,
	ah_attr->sl,
	sqp->ibqp.qp_num, qp->ibqp.qp_num,
	cpu_to_be16(lid),
	cpu_to_be16(ah_attr->dlid));
	goto drop;
	}
	}

	/*
	* A GRH is expected to preceed 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 & QIB_R_REUSE_SGE)
	qp->r_flags &= ~QIB_R_REUSE_SGE;
	else {
	int ret;

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

	if (ah_attr->ah_flags & IB_AH_GRH) {
	qib_copy_sge(&qp->r_sge, &ah_attr->grh,
	sizeof(struct ib_grh), 1);
	wc.wc_flags \|= IB_WC_GRH;
	} else
	qib_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;
	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 >= QIB_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;
	}
	while (qp->r_sge.num_sge) {
	atomic_dec(&qp->r_sge.sge.mr->refcount);
	if (--qp->r_sge.num_sge)
	qp->r_sge.sge = *qp->r_sge.sg_list++;
	}
	if (!test_and_clear_bit(QIB_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->wr.wr.ud.pkey_index : 0;
	wc.slid = ppd->lid \| (ah_attr->src_path_bits & ((1 << ppd->lmc) - 1));
	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. */
	qib_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
	swqe->wr.send_flags & IB_SEND_SOLICITED);
	ibp->n_loop_pkts++;
	bail_unlock:
	spin_unlock_irqrestore(&qp->r_lock, flags);
	drop:
	if (atomic_dec_and_test(&qp->refcount))
	wake_up(&qp->wait);
	}

	/**
	* qib_make_ud_req - construct a UD request packet
	* @qp: the QP
	*
	* Return 1 if constructed; otherwise, return 0.
	*/
	int qib_make_ud_req(struct qib_qp *qp)
	{
	struct qib_other_headers *ohdr;
	struct ib_ah_attr *ah_attr;
	struct qib_pportdata *ppd;
	struct qib_ibport *ibp;
	struct qib_swqe *wqe;
	unsigned long flags;
	u32 nwords;
	u32 extra_bytes;
	u32 bth0;
	u16 lrh0;
	u16 lid;
	int ret = 0;
	int next_cur;

	spin_lock_irqsave(&qp->s_lock, flags);

	if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_NEXT_SEND_OK)) {
	if (!(ib_qib_state_ops[qp->state] & QIB_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 \|= QIB_S_WAIT_DMA;
	goto bail;
	}
	wqe = get_swqe_ptr(qp, qp->s_last);
	qib_send_complete(qp, wqe, IB_WC_WR_FLUSH_ERR);
	goto done;
	}

	if (qp->s_cur == qp->s_head)
	goto bail;

	wqe = 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 = &to_iah(wqe->wr.wr.ud.ah)->attr;
	if (ah_attr->dlid >= QIB_MULTICAST_LID_BASE) {
	if (ah_attr->dlid != QIB_PERMISSIVE_LID)
	ibp->n_multicast_xmit++;
	else
	ibp->n_unicast_xmit++;
	} else {
	ibp->n_unicast_xmit++;
	lid = ah_attr->dlid & ~((1 << ppd->lmc) - 1);
	if (unlikely(lid == ppd->lid)) {
	/*
	* 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(&qp->s_dma_busy)) {
	qp->s_flags \|= QIB_S_WAIT_DMA;
	goto bail;
	}
	qp->s_cur = next_cur;
	spin_unlock_irqrestore(&qp->s_lock, flags);
	qib_ud_loopback(qp, wqe);
	spin_lock_irqsave(&qp->s_lock, flags);
	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 = ah_attr->static_rate;
	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 += qib_make_grh(ibp, &qp->s_hdr.u.l.grh,
	&ah_attr->grh,
	qp->s_hdrwords, nwords);
	lrh0 = QIB_LRH_GRH;
	ohdr = &qp->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 = &qp->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 \|= ah_attr->sl << 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[ah_attr->sl] << 12;
	qp->s_hdr.lrh[0] = cpu_to_be16(lrh0);
	qp->s_hdr.lrh[1] = cpu_to_be16(ah_attr->dlid); /* DEST LID */
	qp->s_hdr.lrh[2] = cpu_to_be16(qp->s_hdrwords + nwords + SIZE_OF_CRC);
	lid = ppd->lid;
	if (lid) {
	lid \|= ah_attr->src_path_bits & ((1 << ppd->lmc) - 1);
	qp->s_hdr.lrh[3] = cpu_to_be16(lid);
	} else
	qp->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->wr.wr.ud.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] = ah_attr->dlid >= QIB_MULTICAST_LID_BASE &&
	ah_attr->dlid != QIB_PERMISSIVE_LID ?
	cpu_to_be32(QIB_MULTICAST_QPN) :
	cpu_to_be32(wqe->wr.wr.ud.remote_qpn);
	ohdr->bth[2] = cpu_to_be32(qp->s_next_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->wr.wr.ud.remote_qkey < 0 ?
	qp->qkey : wqe->wr.wr.ud.remote_qkey);
	ohdr->u.ud.deth[1] = cpu_to_be32(qp->ibqp.qp_num);

	done:
	ret = 1;
	goto unlock;

	bail:
	qp->s_flags &= ~QIB_S_BUSY;
	unlock:
	spin_unlock_irqrestore(&qp->s_lock, flags);
	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 qib_ib_header hdr,
	int has_grh, void data, u32 tlen, struct qib_qp qp)
	{
	struct qib_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]) & QIB_QPN_MASK;

	/* Get the number of bytes the message was padded by. */
	pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
	if (unlikely(tlen < (hdrsize + pad + 4))) {
	/* Drop incomplete packets. */
	ibp->n_pkt_drops++;
	goto bail;
	}
	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)) {
	ibp->n_pkt_drops++;
	goto bail;
	}
	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_pqkey(ibp, IB_NOTICE_TRAP_BAD_PKEY,
	pkey1,
	(be16_to_cpu(hdr->lrh[0]) >> 4) &
	0xF,
	src_qp, qp->ibqp.qp_num,
	hdr->lrh[3], hdr->lrh[1]);
	goto bail;
	}
	}
	if (unlikely(qkey != qp->qkey)) {
	qib_bad_pqkey(ibp, IB_NOTICE_TRAP_BAD_QKEY, qkey,
	(be16_to_cpu(hdr->lrh[0]) >> 4) & 0xF,
	src_qp, qp->ibqp.qp_num,
	hdr->lrh[3], hdr->lrh[1]);
	goto bail;
	}
	/* 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))) {
	ibp->n_pkt_drops++;
	goto bail;
	}
	} 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) {
	ibp->n_pkt_drops++;
	goto bail;
	}
	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) {
	ibp->n_pkt_drops++;
	goto bail;
	}
	}

	/*
	* 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;
	hdrsize += sizeof(u32);
	} else if (opcode == IB_OPCODE_UD_SEND_ONLY) {
	wc.ex.imm_data = 0;
	wc.wc_flags = 0;
	} else {
	ibp->n_pkt_drops++;
	goto bail;
	}

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

	/*
	* We need to serialize getting a receive work queue entry and
	* generating a completion for it against QPs sending to this QP
	* locally.
	*/
	spin_lock(&qp->r_lock);

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

	ret = qib_get_rwqe(qp, 0);
	if (ret < 0) {
	qib_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
	goto bail_unlock;
	}
	if (!ret) {
	if (qp->ibqp.qp_num == 0)
	ibp->n_vl15_dropped++;
	goto bail_unlock;
	}
	}
	/* Silently drop packets which are too big. */
	if (unlikely(wc.byte_len > qp->r_len)) {
	qp->r_flags \|= QIB_R_REUSE_SGE;
	ibp->n_pkt_drops++;
	goto bail_unlock;
	}
	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
	qib_skip_sge(&qp->r_sge, sizeof(struct ib_grh), 1);
	qib_copy_sge(&qp->r_sge, data, wc.byte_len - sizeof(struct ib_grh), 1);
	while (qp->r_sge.num_sge) {
	atomic_dec(&qp->r_sge.sge.mr->refcount);
	if (--qp->r_sge.num_sge)
	qp->r_sge.sge = *qp->r_sge.sg_list++;
	}
	if (!test_and_clear_bit(QIB_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.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 >= QIB_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. */
	qib_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
	(ohdr->bth[0] &
	cpu_to_be32(IB_BTH_SOLICITED)) != 0);
	bail_unlock:
	spin_unlock(&qp->r_lock);
	bail:;
	}