drivers/infiniband/hw/ipath/ipath_uc.c - kernel/msm-4.9 - Gitiles

 /*
  * Copyright (c) 2006 QLogic, Inc. 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

 static void complete_last_send(struct ipath_qp *qp, struct ipath_swqe *wqe,
 			       struct ib_wc *wc)
 {
 	if (++qp->s_last == qp->s_size)
 		qp->s_last = 0;
 	if (!test_bit(IPATH_S_SIGNAL_REQ_WR, &qp->s_flags) ||
 	    (wqe->wr.send_flags & IB_SEND_SIGNALED)) {
 		wc->wr_id = wqe->wr.wr_id;
 		wc->status = IB_WC_SUCCESS;
 		wc->opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
 		wc->vendor_err = 0;
 		wc->byte_len = wqe->length;
 		wc->qp_num = qp->ibqp.qp_num;
 		wc->src_qp = qp->remote_qpn;
 		wc->pkey_index = 0;
 		wc->slid = qp->remote_ah_attr.dlid;
 		wc->sl = qp->remote_ah_attr.sl;
 		wc->dlid_path_bits = 0;
 		wc->port_num = 0;
 		ipath_cq_enter(to_icq(qp->ibqp.send_cq), wc, 0);
 	}
 	wqe = get_swqe_ptr(qp, qp->s_last);
 }

 /**
  * ipath_make_uc_req - construct a request packet (SEND, RDMA write)
  * @qp: a pointer to the QP
  * @ohdr: a pointer to the IB header being constructed
  * @pmtu: the path MTU
  * @bth0p: pointer to the BTH opcode word
  * @bth2p: pointer to the BTH PSN word
  *
  * Return 1 if constructed; otherwise, return 0.
  * Note the QP s_lock must be held and interrupts disabled.
  */
 int ipath_make_uc_req(struct ipath_qp *qp,
 		      struct ipath_other_headers *ohdr,
 		      u32 pmtu, u32 *bth0p, u32 *bth2p)
 {
 	struct ipath_swqe *wqe;
 	u32 hwords;
 	u32 bth0;
 	u32 len;
 	struct ib_wc wc;

 	if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_SEND_OK))
 		goto done;

 	/* header size in 32-bit words LRH+BTH = (8+12)/4. */
 	hwords = 5;
 	bth0 = 0;

 	/* Get the next send request. */
 	wqe = get_swqe_ptr(qp, qp->s_last);
 	switch (qp->s_state) {
 	default:
 		/*
 		 * Signal the completion of the last send
 		 * (if there is one).
 		 */
 		if (qp->s_last != qp->s_tail)
 			complete_last_send(qp, wqe, &wc);

 		/* Check if send work queue is empty. */
 		if (qp->s_tail == qp->s_head)
 			goto done;
 		/*
 		 * 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.imm_data;
 				hwords += 1;
 			}
 			if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 				bth0 |= 1 << 23;
 			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.imm_data;
 				hwords += 1;
 				if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 					bth0 |= 1 << 23;
 			}
 			break;

 		default:
 			goto done;
 		}
 		if (++qp->s_tail >= qp->s_size)
 			qp->s_tail = 0;
 		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.imm_data;
 			hwords += 1;
 		}
 		if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 			bth0 |= 1 << 23;
 		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.imm_data;
 			hwords += 1;
 			if (wqe->wr.send_flags & IB_SEND_SOLICITED)
 				bth0 |= 1 << 23;
 		}
 		break;
 	}
 	qp->s_len -= len;
 	qp->s_hdrwords = hwords;
 	qp->s_cur_sge = &qp->s_sge;
 	qp->s_cur_size = len;
 	*bth0p = bth0 | (qp->s_state << 24);
 	*bth2p = qp->s_next_psn++ & IPATH_PSN_MASK;
 	return 1;

 done:
 	return 0;
 }

 /**
  * 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;

 	wc.imm_data = 0;
 	wc.wc_flags = 0;

 	/* 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_reuse_sge) {
 			qp->r_reuse_sge = 0;
 			qp->r_sge = qp->s_rdma_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_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_reuse_sge = 1;
 			dev->n_pkt_drops++;
 			goto done;
 		}
 		qp->r_rcv_len += pmtu;
 		if (unlikely(qp->r_rcv_len > qp->r_len)) {
 			qp->r_reuse_sge = 1;
 			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.imm_data = *(__be32 *) data;
 			data += sizeof(__be32);
 		} else {
 			/* Immediate data comes after BTH */
 			wc.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_reuse_sge = 1;
 			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_reuse_sge = 1;
 			dev->n_pkt_drops++;
 			goto done;
 		}
 		/* XXX Need to free SGEs */
 	last_imm:
 		ipath_copy_sge(&qp->r_sge, data, tlen);
 		wc.wr_id = qp->r_wr_id;
 		wc.status = IB_WC_SUCCESS;
 		wc.opcode = IB_WC_RECV;
 		wc.vendor_err = 0;
 		wc.qp_num = qp->ibqp.qp_num;
 		wc.src_qp = qp->remote_qpn;
 		wc.pkey_index = 0;
 		wc.slid = qp->remote_ah_attr.dlid;
 		wc.sl = qp->remote_ah_attr.sl;
 		wc.dlid_path_bits = 0;
 		wc.port_num = 0;
 		/* Signal completion event if the solicited bit is set. */
 		ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
 			       (ohdr->bth[0] &
 				__constant_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:
 		/* 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_reuse_sge)
 			qp->r_reuse_sge = 0;
 		else if (!ipath_get_rwqe(qp, 1)) {
 			dev->n_pkt_drops++;
 			goto done;
 		}
 		if (header_in_data) {
 			wc.imm_data = *(__be32 *) data;
 			data += sizeof(__be32);
 		} else {
 			/* Immediate data comes after BTH */
 			wc.imm_data = ohdr->u.imm_data;
 		}
 		hdrsize += 4;
 		wc.wc_flags = IB_WC_WITH_IMM;
 		wc.byte_len = 0;
 		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;
 }
	/*
	* Copyright (c) 2006 QLogic, Inc. 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

	static void complete_last_send(struct ipath_qp qp, struct ipath_swqe wqe,
	struct ib_wc *wc)
	{
	if (++qp->s_last == qp->s_size)
	qp->s_last = 0;
	if (!test_bit(IPATH_S_SIGNAL_REQ_WR, &qp->s_flags) \|\|
	(wqe->wr.send_flags & IB_SEND_SIGNALED)) {
	wc->wr_id = wqe->wr.wr_id;
	wc->status = IB_WC_SUCCESS;
	wc->opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
	wc->vendor_err = 0;
	wc->byte_len = wqe->length;
	wc->qp_num = qp->ibqp.qp_num;
	wc->src_qp = qp->remote_qpn;
	wc->pkey_index = 0;
	wc->slid = qp->remote_ah_attr.dlid;
	wc->sl = qp->remote_ah_attr.sl;
	wc->dlid_path_bits = 0;
	wc->port_num = 0;
	ipath_cq_enter(to_icq(qp->ibqp.send_cq), wc, 0);
	}
	wqe = get_swqe_ptr(qp, qp->s_last);
	}

	/**
	* ipath_make_uc_req - construct a request packet (SEND, RDMA write)
	* @qp: a pointer to the QP
	* @ohdr: a pointer to the IB header being constructed
	* @pmtu: the path MTU
	* @bth0p: pointer to the BTH opcode word
	* @bth2p: pointer to the BTH PSN word
	*
	* Return 1 if constructed; otherwise, return 0.
	* Note the QP s_lock must be held and interrupts disabled.
	*/
	int ipath_make_uc_req(struct ipath_qp *qp,
	struct ipath_other_headers *ohdr,
	u32 pmtu, u32 bth0p, u32 bth2p)
	{
	struct ipath_swqe *wqe;
	u32 hwords;
	u32 bth0;
	u32 len;
	struct ib_wc wc;

	if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_SEND_OK))
	goto done;

	/* header size in 32-bit words LRH+BTH = (8+12)/4. */
	hwords = 5;
	bth0 = 0;

	/* Get the next send request. */
	wqe = get_swqe_ptr(qp, qp->s_last);
	switch (qp->s_state) {
	default:
	/*
	* Signal the completion of the last send
	* (if there is one).
	*/
	if (qp->s_last != qp->s_tail)
	complete_last_send(qp, wqe, &wc);

	/* Check if send work queue is empty. */
	if (qp->s_tail == qp->s_head)
	goto done;
	/*
	* 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.imm_data;
	hwords += 1;
	}
	if (wqe->wr.send_flags & IB_SEND_SOLICITED)
	bth0 \|= 1 << 23;
	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.imm_data;
	hwords += 1;
	if (wqe->wr.send_flags & IB_SEND_SOLICITED)
	bth0 \|= 1 << 23;
	}
	break;

	default:
	goto done;
	}
	if (++qp->s_tail >= qp->s_size)
	qp->s_tail = 0;
	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.imm_data;
	hwords += 1;
	}
	if (wqe->wr.send_flags & IB_SEND_SOLICITED)
	bth0 \|= 1 << 23;
	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.imm_data;
	hwords += 1;
	if (wqe->wr.send_flags & IB_SEND_SOLICITED)
	bth0 \|= 1 << 23;
	}
	break;
	}
	qp->s_len -= len;
	qp->s_hdrwords = hwords;
	qp->s_cur_sge = &qp->s_sge;
	qp->s_cur_size = len;
	*bth0p = bth0 \| (qp->s_state << 24);
	*bth2p = qp->s_next_psn++ & IPATH_PSN_MASK;
	return 1;

	done:
	return 0;
	}

	/**
	* 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;

	wc.imm_data = 0;
	wc.wc_flags = 0;

	/* 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_reuse_sge) {
	qp->r_reuse_sge = 0;
	qp->r_sge = qp->s_rdma_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_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_reuse_sge = 1;
	dev->n_pkt_drops++;
	goto done;
	}
	qp->r_rcv_len += pmtu;
	if (unlikely(qp->r_rcv_len > qp->r_len)) {
	qp->r_reuse_sge = 1;
	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.imm_data = (__be32 ) data;
	data += sizeof(__be32);
	} else {
	/* Immediate data comes after BTH */
	wc.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_reuse_sge = 1;
	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_reuse_sge = 1;
	dev->n_pkt_drops++;
	goto done;
	}
	/* XXX Need to free SGEs */
	last_imm:
	ipath_copy_sge(&qp->r_sge, data, tlen);
	wc.wr_id = qp->r_wr_id;
	wc.status = IB_WC_SUCCESS;
	wc.opcode = IB_WC_RECV;
	wc.vendor_err = 0;
	wc.qp_num = qp->ibqp.qp_num;
	wc.src_qp = qp->remote_qpn;
	wc.pkey_index = 0;
	wc.slid = qp->remote_ah_attr.dlid;
	wc.sl = qp->remote_ah_attr.sl;
	wc.dlid_path_bits = 0;
	wc.port_num = 0;
	/* Signal completion event if the solicited bit is set. */
	ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
	(ohdr->bth[0] &
	__constant_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:
	/* 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_reuse_sge)
	qp->r_reuse_sge = 0;
	else if (!ipath_get_rwqe(qp, 1)) {
	dev->n_pkt_drops++;
	goto done;
	}
	if (header_in_data) {
	wc.imm_data = (__be32 ) data;
	data += sizeof(__be32);
	} else {
	/* Immediate data comes after BTH */
	wc.imm_data = ohdr->u.imm_data;
	}
	hdrsize += 4;
	wc.wc_flags = IB_WC_WITH_IMM;
	wc.byte_len = 0;
	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;
	}