Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 965 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/hfi1/ruc.c b/drivers/infiniband/hw/hfi1/ruc.c
new file mode 100644
index 000000000..62a3832a1
--- /dev/null
+++ b/drivers/infiniband/hw/hfi1/ruc.c
@@ -0,0 +1,965 @@
+/*
+ * Copyright(c) 2015 - 2018 Intel Corporation.
+ *
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * BSD LICENSE
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *  - Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  - Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *  - Neither the name of Intel Corporation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <linux/spinlock.h>
+
+#include "hfi.h"
+#include "mad.h"
+#include "qp.h"
+#include "verbs_txreq.h"
+#include "trace.h"
+
+static int gid_ok(union ib_gid *gid, __be64 gid_prefix, __be64 id)
+{
+	return (gid->global.interface_id == id &&
+		(gid->global.subnet_prefix == gid_prefix ||
+		 gid->global.subnet_prefix == IB_DEFAULT_GID_PREFIX));
+}
+
+/*
+ *
+ * This should be called with the QP r_lock held.
+ *
+ * The s_lock will be acquired around the hfi1_migrate_qp() call.
+ */
+int hfi1_ruc_check_hdr(struct hfi1_ibport *ibp, struct hfi1_packet *packet)
+{
+	__be64 guid;
+	unsigned long flags;
+	struct rvt_qp *qp = packet->qp;
+	u8 sc5 = ibp->sl_to_sc[rdma_ah_get_sl(&qp->remote_ah_attr)];
+	u32 dlid = packet->dlid;
+	u32 slid = packet->slid;
+	u32 sl = packet->sl;
+	bool migrated = packet->migrated;
+	u16 pkey = packet->pkey;
+
+	if (qp->s_mig_state == IB_MIG_ARMED && migrated) {
+		if (!packet->grh) {
+			if ((rdma_ah_get_ah_flags(&qp->alt_ah_attr) &
+			     IB_AH_GRH) &&
+			    (packet->etype != RHF_RCV_TYPE_BYPASS))
+				return 1;
+		} else {
+			const struct ib_global_route *grh;
+
+			if (!(rdma_ah_get_ah_flags(&qp->alt_ah_attr) &
+			      IB_AH_GRH))
+				return 1;
+			grh = rdma_ah_read_grh(&qp->alt_ah_attr);
+			guid = get_sguid(ibp, grh->sgid_index);
+			if (!gid_ok(&packet->grh->dgid, ibp->rvp.gid_prefix,
+				    guid))
+				return 1;
+			if (!gid_ok(
+				&packet->grh->sgid,
+				grh->dgid.global.subnet_prefix,
+				grh->dgid.global.interface_id))
+				return 1;
+		}
+		if (unlikely(rcv_pkey_check(ppd_from_ibp(ibp), pkey,
+					    sc5, slid))) {
+			hfi1_bad_pkey(ibp, pkey, sl, 0, qp->ibqp.qp_num,
+				      slid, dlid);
+			return 1;
+		}
+		/* Validate the SLID. See Ch. 9.6.1.5 and 17.2.8 */
+		if (slid != rdma_ah_get_dlid(&qp->alt_ah_attr) ||
+		    ppd_from_ibp(ibp)->port !=
+			rdma_ah_get_port_num(&qp->alt_ah_attr))
+			return 1;
+		spin_lock_irqsave(&qp->s_lock, flags);
+		hfi1_migrate_qp(qp);
+		spin_unlock_irqrestore(&qp->s_lock, flags);
+	} else {
+		if (!packet->grh) {
+			if ((rdma_ah_get_ah_flags(&qp->remote_ah_attr) &
+			     IB_AH_GRH) &&
+			    (packet->etype != RHF_RCV_TYPE_BYPASS))
+				return 1;
+		} else {
+			const struct ib_global_route *grh;
+
+			if (!(rdma_ah_get_ah_flags(&qp->remote_ah_attr) &
+						   IB_AH_GRH))
+				return 1;
+			grh = rdma_ah_read_grh(&qp->remote_ah_attr);
+			guid = get_sguid(ibp, grh->sgid_index);
+			if (!gid_ok(&packet->grh->dgid, ibp->rvp.gid_prefix,
+				    guid))
+				return 1;
+			if (!gid_ok(
+			     &packet->grh->sgid,
+			     grh->dgid.global.subnet_prefix,
+			     grh->dgid.global.interface_id))
+				return 1;
+		}
+		if (unlikely(rcv_pkey_check(ppd_from_ibp(ibp), pkey,
+					    sc5, slid))) {
+			hfi1_bad_pkey(ibp, pkey, sl, 0, qp->ibqp.qp_num,
+				      slid, dlid);
+			return 1;
+		}
+		/* Validate the SLID. See Ch. 9.6.1.5 */
+		if ((slid != rdma_ah_get_dlid(&qp->remote_ah_attr)) ||
+		    ppd_from_ibp(ibp)->port != qp->port_num)
+			return 1;
+		if (qp->s_mig_state == IB_MIG_REARM && !migrated)
+			qp->s_mig_state = IB_MIG_ARMED;
+	}
+
+	return 0;
+}
+
+/**
+ * ruc_loopback - handle UC and RC loopback requests
+ * @sqp: the sending QP
+ *
+ * This is called from hfi1_do_send() to
+ * forward a WQE addressed to the same HFI.
+ * Note that although we are single threaded due to the send engine, we still
+ * have to protect against post_send().  We don't have to worry about
+ * receive interrupts since this is a connected protocol and all packets
+ * will pass through here.
+ */
+static void ruc_loopback(struct rvt_qp *sqp)
+{
+	struct hfi1_ibport *ibp = to_iport(sqp->ibqp.device, sqp->port_num);
+	struct rvt_qp *qp;
+	struct rvt_swqe *wqe;
+	struct rvt_sge *sge;
+	unsigned long flags;
+	struct ib_wc wc;
+	u64 sdata;
+	atomic64_t *maddr;
+	enum ib_wc_status send_status;
+	bool release;
+	int ret;
+	bool copy_last = false;
+	int local_ops = 0;
+
+	rcu_read_lock();
+
+	/*
+	 * Note that we check the responder QP state after
+	 * checking the requester's state.
+	 */
+	qp = rvt_lookup_qpn(ib_to_rvt(sqp->ibqp.device), &ibp->rvp,
+			    sqp->remote_qpn);
+
+	spin_lock_irqsave(&sqp->s_lock, flags);
+
+	/* Return if we are already busy processing a work request. */
+	if ((sqp->s_flags & (RVT_S_BUSY | HFI1_S_ANY_WAIT)) ||
+	    !(ib_rvt_state_ops[sqp->state] & RVT_PROCESS_OR_FLUSH_SEND))
+		goto unlock;
+
+	sqp->s_flags |= RVT_S_BUSY;
+
+again:
+	if (sqp->s_last == READ_ONCE(sqp->s_head))
+		goto clr_busy;
+	wqe = rvt_get_swqe_ptr(sqp, sqp->s_last);
+
+	/* Return if it is not OK to start a new work request. */
+	if (!(ib_rvt_state_ops[sqp->state] & RVT_PROCESS_NEXT_SEND_OK)) {
+		if (!(ib_rvt_state_ops[sqp->state] & RVT_FLUSH_SEND))
+			goto clr_busy;
+		/* We are in the error state, flush the work request. */
+		send_status = IB_WC_WR_FLUSH_ERR;
+		goto flush_send;
+	}
+
+	/*
+	 * We can rely on the entry not changing without the s_lock
+	 * being held until we update s_last.
+	 * We increment s_cur to indicate s_last is in progress.
+	 */
+	if (sqp->s_last == sqp->s_cur) {
+		if (++sqp->s_cur >= sqp->s_size)
+			sqp->s_cur = 0;
+	}
+	spin_unlock_irqrestore(&sqp->s_lock, flags);
+
+	if (!qp || !(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK) ||
+	    qp->ibqp.qp_type != sqp->ibqp.qp_type) {
+		ibp->rvp.n_pkt_drops++;
+		/*
+		 * For RC, the requester would timeout and retry so
+		 * shortcut the timeouts and just signal too many retries.
+		 */
+		if (sqp->ibqp.qp_type == IB_QPT_RC)
+			send_status = IB_WC_RETRY_EXC_ERR;
+		else
+			send_status = IB_WC_SUCCESS;
+		goto serr;
+	}
+
+	memset(&wc, 0, sizeof(wc));
+	send_status = IB_WC_SUCCESS;
+
+	release = true;
+	sqp->s_sge.sge = wqe->sg_list[0];
+	sqp->s_sge.sg_list = wqe->sg_list + 1;
+	sqp->s_sge.num_sge = wqe->wr.num_sge;
+	sqp->s_len = wqe->length;
+	switch (wqe->wr.opcode) {
+	case IB_WR_REG_MR:
+		goto send_comp;
+
+	case IB_WR_LOCAL_INV:
+		if (!(wqe->wr.send_flags & RVT_SEND_COMPLETION_ONLY)) {
+			if (rvt_invalidate_rkey(sqp,
+						wqe->wr.ex.invalidate_rkey))
+				send_status = IB_WC_LOC_PROT_ERR;
+			local_ops = 1;
+		}
+		goto send_comp;
+
+	case IB_WR_SEND_WITH_INV:
+		if (!rvt_invalidate_rkey(qp, wqe->wr.ex.invalidate_rkey)) {
+			wc.wc_flags = IB_WC_WITH_INVALIDATE;
+			wc.ex.invalidate_rkey = wqe->wr.ex.invalidate_rkey;
+		}
+		goto send;
+
+	case IB_WR_SEND_WITH_IMM:
+		wc.wc_flags = IB_WC_WITH_IMM;
+		wc.ex.imm_data = wqe->wr.ex.imm_data;
+		/* FALLTHROUGH */
+	case IB_WR_SEND:
+send:
+		ret = rvt_get_rwqe(qp, false);
+		if (ret < 0)
+			goto op_err;
+		if (!ret)
+			goto rnr_nak;
+		if (wqe->length > qp->r_len)
+			goto inv_err;
+		break;
+
+	case IB_WR_RDMA_WRITE_WITH_IMM:
+		if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE)))
+			goto inv_err;
+		wc.wc_flags = IB_WC_WITH_IMM;
+		wc.ex.imm_data = wqe->wr.ex.imm_data;
+		ret = rvt_get_rwqe(qp, true);
+		if (ret < 0)
+			goto op_err;
+		if (!ret)
+			goto rnr_nak;
+		/* skip copy_last set and qp_access_flags recheck */
+		goto do_write;
+	case IB_WR_RDMA_WRITE:
+		copy_last = rvt_is_user_qp(qp);
+		if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE)))
+			goto inv_err;
+do_write:
+		if (wqe->length == 0)
+			break;
+		if (unlikely(!rvt_rkey_ok(qp, &qp->r_sge.sge, wqe->length,
+					  wqe->rdma_wr.remote_addr,
+					  wqe->rdma_wr.rkey,
+					  IB_ACCESS_REMOTE_WRITE)))
+			goto acc_err;
+		qp->r_sge.sg_list = NULL;
+		qp->r_sge.num_sge = 1;
+		qp->r_sge.total_len = wqe->length;
+		break;
+
+	case IB_WR_RDMA_READ:
+		if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_READ)))
+			goto inv_err;
+		if (unlikely(!rvt_rkey_ok(qp, &sqp->s_sge.sge, wqe->length,
+					  wqe->rdma_wr.remote_addr,
+					  wqe->rdma_wr.rkey,
+					  IB_ACCESS_REMOTE_READ)))
+			goto acc_err;
+		release = false;
+		sqp->s_sge.sg_list = NULL;
+		sqp->s_sge.num_sge = 1;
+		qp->r_sge.sge = wqe->sg_list[0];
+		qp->r_sge.sg_list = wqe->sg_list + 1;
+		qp->r_sge.num_sge = wqe->wr.num_sge;
+		qp->r_sge.total_len = wqe->length;
+		break;
+
+	case IB_WR_ATOMIC_CMP_AND_SWP:
+	case IB_WR_ATOMIC_FETCH_AND_ADD:
+		if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_ATOMIC)))
+			goto inv_err;
+		if (unlikely(!rvt_rkey_ok(qp, &qp->r_sge.sge, sizeof(u64),
+					  wqe->atomic_wr.remote_addr,
+					  wqe->atomic_wr.rkey,
+					  IB_ACCESS_REMOTE_ATOMIC)))
+			goto acc_err;
+		/* Perform atomic OP and save result. */
+		maddr = (atomic64_t *)qp->r_sge.sge.vaddr;
+		sdata = wqe->atomic_wr.compare_add;
+		*(u64 *)sqp->s_sge.sge.vaddr =
+			(wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) ?
+			(u64)atomic64_add_return(sdata, maddr) - sdata :
+			(u64)cmpxchg((u64 *)qp->r_sge.sge.vaddr,
+				      sdata, wqe->atomic_wr.swap);
+		rvt_put_mr(qp->r_sge.sge.mr);
+		qp->r_sge.num_sge = 0;
+		goto send_comp;
+
+	default:
+		send_status = IB_WC_LOC_QP_OP_ERR;
+		goto serr;
+	}
+
+	sge = &sqp->s_sge.sge;
+	while (sqp->s_len) {
+		u32 len = sqp->s_len;
+
+		if (len > sge->length)
+			len = sge->length;
+		if (len > sge->sge_length)
+			len = sge->sge_length;
+		WARN_ON_ONCE(len == 0);
+		hfi1_copy_sge(&qp->r_sge, sge->vaddr, len, release, copy_last);
+		sge->vaddr += len;
+		sge->length -= len;
+		sge->sge_length -= len;
+		if (sge->sge_length == 0) {
+			if (!release)
+				rvt_put_mr(sge->mr);
+			if (--sqp->s_sge.num_sge)
+				*sge = *sqp->s_sge.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;
+		}
+		sqp->s_len -= len;
+	}
+	if (release)
+		rvt_put_ss(&qp->r_sge);
+
+	if (!test_and_clear_bit(RVT_R_WRID_VALID, &qp->r_aflags))
+		goto send_comp;
+
+	if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM)
+		wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
+	else
+		wc.opcode = IB_WC_RECV;
+	wc.wr_id = qp->r_wr_id;
+	wc.status = IB_WC_SUCCESS;
+	wc.byte_len = wqe->length;
+	wc.qp = &qp->ibqp;
+	wc.src_qp = qp->remote_qpn;
+	wc.slid = rdma_ah_get_dlid(&qp->remote_ah_attr) & U16_MAX;
+	wc.sl = rdma_ah_get_sl(&qp->remote_ah_attr);
+	wc.port_num = 1;
+	/* Signal completion event if the solicited bit is set. */
+	rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.recv_cq), &wc,
+		     wqe->wr.send_flags & IB_SEND_SOLICITED);
+
+send_comp:
+	spin_lock_irqsave(&sqp->s_lock, flags);
+	ibp->rvp.n_loop_pkts++;
+flush_send:
+	sqp->s_rnr_retry = sqp->s_rnr_retry_cnt;
+	hfi1_send_complete(sqp, wqe, send_status);
+	if (local_ops) {
+		atomic_dec(&sqp->local_ops_pending);
+		local_ops = 0;
+	}
+	goto again;
+
+rnr_nak:
+	/* Handle RNR NAK */
+	if (qp->ibqp.qp_type == IB_QPT_UC)
+		goto send_comp;
+	ibp->rvp.n_rnr_naks++;
+	/*
+	 * Note: we don't need the s_lock held since the BUSY flag
+	 * makes this single threaded.
+	 */
+	if (sqp->s_rnr_retry == 0) {
+		send_status = IB_WC_RNR_RETRY_EXC_ERR;
+		goto serr;
+	}
+	if (sqp->s_rnr_retry_cnt < 7)
+		sqp->s_rnr_retry--;
+	spin_lock_irqsave(&sqp->s_lock, flags);
+	if (!(ib_rvt_state_ops[sqp->state] & RVT_PROCESS_RECV_OK))
+		goto clr_busy;
+	rvt_add_rnr_timer(sqp, qp->r_min_rnr_timer <<
+				IB_AETH_CREDIT_SHIFT);
+	goto clr_busy;
+
+op_err:
+	send_status = IB_WC_REM_OP_ERR;
+	wc.status = IB_WC_LOC_QP_OP_ERR;
+	goto err;
+
+inv_err:
+	send_status =
+		sqp->ibqp.qp_type == IB_QPT_RC ?
+			IB_WC_REM_INV_REQ_ERR :
+			IB_WC_SUCCESS;
+	wc.status = IB_WC_LOC_QP_OP_ERR;
+	goto err;
+
+acc_err:
+	send_status = IB_WC_REM_ACCESS_ERR;
+	wc.status = IB_WC_LOC_PROT_ERR;
+err:
+	/* responder goes to error state */
+	rvt_rc_error(qp, wc.status);
+
+serr:
+	spin_lock_irqsave(&sqp->s_lock, flags);
+	hfi1_send_complete(sqp, wqe, send_status);
+	if (sqp->ibqp.qp_type == IB_QPT_RC) {
+		int lastwqe = rvt_error_qp(sqp, IB_WC_WR_FLUSH_ERR);
+
+		sqp->s_flags &= ~RVT_S_BUSY;
+		spin_unlock_irqrestore(&sqp->s_lock, flags);
+		if (lastwqe) {
+			struct ib_event ev;
+
+			ev.device = sqp->ibqp.device;
+			ev.element.qp = &sqp->ibqp;
+			ev.event = IB_EVENT_QP_LAST_WQE_REACHED;
+			sqp->ibqp.event_handler(&ev, sqp->ibqp.qp_context);
+		}
+		goto done;
+	}
+clr_busy:
+	sqp->s_flags &= ~RVT_S_BUSY;
+unlock:
+	spin_unlock_irqrestore(&sqp->s_lock, flags);
+done:
+	rcu_read_unlock();
+}
+
+/**
+ * hfi1_make_grh - construct a GRH header
+ * @ibp: a pointer to the IB port
+ * @hdr: a pointer to the GRH header being constructed
+ * @grh: the global route address to send to
+ * @hwords: size of header after grh being sent in dwords
+ * @nwords: the number of 32 bit words of data being sent
+ *
+ * Return the size of the header in 32 bit words.
+ */
+u32 hfi1_make_grh(struct hfi1_ibport *ibp, struct ib_grh *hdr,
+		  const struct ib_global_route *grh, u32 hwords, u32 nwords)
+{
+	hdr->version_tclass_flow =
+		cpu_to_be32((IB_GRH_VERSION << IB_GRH_VERSION_SHIFT) |
+			    (grh->traffic_class << IB_GRH_TCLASS_SHIFT) |
+			    (grh->flow_label << IB_GRH_FLOW_SHIFT));
+	hdr->paylen = cpu_to_be16((hwords + nwords) << 2);
+	/* next_hdr is defined by C8-7 in ch. 8.4.1 */
+	hdr->next_hdr = IB_GRH_NEXT_HDR;
+	hdr->hop_limit = grh->hop_limit;
+	/* The SGID is 32-bit aligned. */
+	hdr->sgid.global.subnet_prefix = ibp->rvp.gid_prefix;
+	hdr->sgid.global.interface_id =
+		grh->sgid_index < HFI1_GUIDS_PER_PORT ?
+		get_sguid(ibp, grh->sgid_index) :
+		get_sguid(ibp, HFI1_PORT_GUID_INDEX);
+	hdr->dgid = grh->dgid;
+
+	/* GRH header size in 32-bit words. */
+	return sizeof(struct ib_grh) / sizeof(u32);
+}
+
+#define BTH2_OFFSET (offsetof(struct hfi1_sdma_header, \
+			      hdr.ibh.u.oth.bth[2]) / 4)
+
+/**
+ * build_ahg - create ahg in s_ahg
+ * @qp: a pointer to QP
+ * @npsn: the next PSN for the request/response
+ *
+ * This routine handles the AHG by allocating an ahg entry and causing the
+ * copy of the first middle.
+ *
+ * Subsequent middles use the copied entry, editing the
+ * PSN with 1 or 2 edits.
+ */
+static inline void build_ahg(struct rvt_qp *qp, u32 npsn)
+{
+	struct hfi1_qp_priv *priv = qp->priv;
+
+	if (unlikely(qp->s_flags & HFI1_S_AHG_CLEAR))
+		clear_ahg(qp);
+	if (!(qp->s_flags & HFI1_S_AHG_VALID)) {
+		/* first middle that needs copy  */
+		if (qp->s_ahgidx < 0)
+			qp->s_ahgidx = sdma_ahg_alloc(priv->s_sde);
+		if (qp->s_ahgidx >= 0) {
+			qp->s_ahgpsn = npsn;
+			priv->s_ahg->tx_flags |= SDMA_TXREQ_F_AHG_COPY;
+			/* save to protect a change in another thread */
+			priv->s_ahg->ahgidx = qp->s_ahgidx;
+			qp->s_flags |= HFI1_S_AHG_VALID;
+		}
+	} else {
+		/* subsequent middle after valid */
+		if (qp->s_ahgidx >= 0) {
+			priv->s_ahg->tx_flags |= SDMA_TXREQ_F_USE_AHG;
+			priv->s_ahg->ahgidx = qp->s_ahgidx;
+			priv->s_ahg->ahgcount++;
+			priv->s_ahg->ahgdesc[0] =
+				sdma_build_ahg_descriptor(
+					(__force u16)cpu_to_be16((u16)npsn),
+					BTH2_OFFSET,
+					16,
+					16);
+			if ((npsn & 0xffff0000) !=
+					(qp->s_ahgpsn & 0xffff0000)) {
+				priv->s_ahg->ahgcount++;
+				priv->s_ahg->ahgdesc[1] =
+					sdma_build_ahg_descriptor(
+						(__force u16)cpu_to_be16(
+							(u16)(npsn >> 16)),
+						BTH2_OFFSET,
+						0,
+						16);
+			}
+		}
+	}
+}
+
+static inline void hfi1_make_ruc_bth(struct rvt_qp *qp,
+				     struct ib_other_headers *ohdr,
+				     u32 bth0, u32 bth1, u32 bth2)
+{
+	bth1 |= qp->remote_qpn;
+	ohdr->bth[0] = cpu_to_be32(bth0);
+	ohdr->bth[1] = cpu_to_be32(bth1);
+	ohdr->bth[2] = cpu_to_be32(bth2);
+}
+
+/**
+ * hfi1_make_ruc_header_16B - build a 16B header
+ * @qp: the queue pair
+ * @ohdr: a pointer to the destination header memory
+ * @bth0: bth0 passed in from the RC/UC builder
+ * @bth2: bth2 passed in from the RC/UC builder
+ * @middle: non zero implies indicates ahg "could" be used
+ * @ps: the current packet state
+ *
+ * This routine may disarm ahg under these situations:
+ * - packet needs a GRH
+ * - BECN needed
+ * - migration state not IB_MIG_MIGRATED
+ */
+static inline void hfi1_make_ruc_header_16B(struct rvt_qp *qp,
+					    struct ib_other_headers *ohdr,
+					    u32 bth0, u32 bth2, int middle,
+					    struct hfi1_pkt_state *ps)
+{
+	struct hfi1_qp_priv *priv = qp->priv;
+	struct hfi1_ibport *ibp = ps->ibp;
+	struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
+	u32 bth1 = 0;
+	u32 slid;
+	u16 pkey = hfi1_get_pkey(ibp, qp->s_pkey_index);
+	u8 l4 = OPA_16B_L4_IB_LOCAL;
+	u8 extra_bytes = hfi1_get_16b_padding(
+				(ps->s_txreq->hdr_dwords << 2),
+				ps->s_txreq->s_cur_size);
+	u32 nwords = SIZE_OF_CRC + ((ps->s_txreq->s_cur_size +
+				 extra_bytes + SIZE_OF_LT) >> 2);
+	bool becn = false;
+
+	if (unlikely(rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH) &&
+	    hfi1_check_mcast(rdma_ah_get_dlid(&qp->remote_ah_attr))) {
+		struct ib_grh *grh;
+		struct ib_global_route *grd =
+			rdma_ah_retrieve_grh(&qp->remote_ah_attr);
+		/*
+		 * Ensure OPA GIDs are transformed to IB gids
+		 * before creating the GRH.
+		 */
+		if (grd->sgid_index == OPA_GID_INDEX)
+			grd->sgid_index = 0;
+		grh = &ps->s_txreq->phdr.hdr.opah.u.l.grh;
+		l4 = OPA_16B_L4_IB_GLOBAL;
+		ps->s_txreq->hdr_dwords +=
+			hfi1_make_grh(ibp, grh, grd,
+				      ps->s_txreq->hdr_dwords - LRH_16B_DWORDS,
+				      nwords);
+		middle = 0;
+	}
+
+	if (qp->s_mig_state == IB_MIG_MIGRATED)
+		bth1 |= OPA_BTH_MIG_REQ;
+	else
+		middle = 0;
+
+	if (qp->s_flags & RVT_S_ECN) {
+		qp->s_flags &= ~RVT_S_ECN;
+		/* we recently received a FECN, so return a BECN */
+		becn = true;
+		middle = 0;
+	}
+	if (middle)
+		build_ahg(qp, bth2);
+	else
+		qp->s_flags &= ~HFI1_S_AHG_VALID;
+
+	bth0 |= pkey;
+	bth0 |= extra_bytes << 20;
+	hfi1_make_ruc_bth(qp, ohdr, bth0, bth1, bth2);
+
+	if (!ppd->lid)
+		slid = be32_to_cpu(OPA_LID_PERMISSIVE);
+	else
+		slid = ppd->lid |
+			(rdma_ah_get_path_bits(&qp->remote_ah_attr) &
+			((1 << ppd->lmc) - 1));
+
+	hfi1_make_16b_hdr(&ps->s_txreq->phdr.hdr.opah,
+			  slid,
+			  opa_get_lid(rdma_ah_get_dlid(&qp->remote_ah_attr),
+				      16B),
+			  (ps->s_txreq->hdr_dwords + nwords) >> 1,
+			  pkey, becn, 0, l4, priv->s_sc);
+}
+
+/**
+ * hfi1_make_ruc_header_9B - build a 9B header
+ * @qp: the queue pair
+ * @ohdr: a pointer to the destination header memory
+ * @bth0: bth0 passed in from the RC/UC builder
+ * @bth2: bth2 passed in from the RC/UC builder
+ * @middle: non zero implies indicates ahg "could" be used
+ * @ps: the current packet state
+ *
+ * This routine may disarm ahg under these situations:
+ * - packet needs a GRH
+ * - BECN needed
+ * - migration state not IB_MIG_MIGRATED
+ */
+static inline void hfi1_make_ruc_header_9B(struct rvt_qp *qp,
+					   struct ib_other_headers *ohdr,
+					   u32 bth0, u32 bth2, int middle,
+					   struct hfi1_pkt_state *ps)
+{
+	struct hfi1_qp_priv *priv = qp->priv;
+	struct hfi1_ibport *ibp = ps->ibp;
+	u32 bth1 = 0;
+	u16 pkey = hfi1_get_pkey(ibp, qp->s_pkey_index);
+	u16 lrh0 = HFI1_LRH_BTH;
+	u8 extra_bytes = -ps->s_txreq->s_cur_size & 3;
+	u32 nwords = SIZE_OF_CRC + ((ps->s_txreq->s_cur_size +
+					 extra_bytes) >> 2);
+
+	if (unlikely(rdma_ah_get_ah_flags(&qp->remote_ah_attr) & IB_AH_GRH)) {
+		struct ib_grh *grh = &ps->s_txreq->phdr.hdr.ibh.u.l.grh;
+
+		lrh0 = HFI1_LRH_GRH;
+		ps->s_txreq->hdr_dwords +=
+			hfi1_make_grh(ibp, grh,
+				      rdma_ah_read_grh(&qp->remote_ah_attr),
+				      ps->s_txreq->hdr_dwords - LRH_9B_DWORDS,
+				      nwords);
+		middle = 0;
+	}
+	lrh0 |= (priv->s_sc & 0xf) << 12 |
+		(rdma_ah_get_sl(&qp->remote_ah_attr) & 0xf) << 4;
+
+	if (qp->s_mig_state == IB_MIG_MIGRATED)
+		bth0 |= IB_BTH_MIG_REQ;
+	else
+		middle = 0;
+
+	if (qp->s_flags & RVT_S_ECN) {
+		qp->s_flags &= ~RVT_S_ECN;
+		/* we recently received a FECN, so return a BECN */
+		bth1 |= (IB_BECN_MASK << IB_BECN_SHIFT);
+		middle = 0;
+	}
+	if (middle)
+		build_ahg(qp, bth2);
+	else
+		qp->s_flags &= ~HFI1_S_AHG_VALID;
+
+	bth0 |= pkey;
+	bth0 |= extra_bytes << 20;
+	hfi1_make_ruc_bth(qp, ohdr, bth0, bth1, bth2);
+	hfi1_make_ib_hdr(&ps->s_txreq->phdr.hdr.ibh,
+			 lrh0,
+			 ps->s_txreq->hdr_dwords + nwords,
+			 opa_get_lid(rdma_ah_get_dlid(&qp->remote_ah_attr), 9B),
+			 ppd_from_ibp(ibp)->lid |
+				rdma_ah_get_path_bits(&qp->remote_ah_attr));
+}
+
+typedef void (*hfi1_make_ruc_hdr)(struct rvt_qp *qp,
+				  struct ib_other_headers *ohdr,
+				  u32 bth0, u32 bth2, int middle,
+				  struct hfi1_pkt_state *ps);
+
+/* We support only two types - 9B and 16B for now */
+static const hfi1_make_ruc_hdr hfi1_ruc_header_tbl[2] = {
+	[HFI1_PKT_TYPE_9B] = &hfi1_make_ruc_header_9B,
+	[HFI1_PKT_TYPE_16B] = &hfi1_make_ruc_header_16B
+};
+
+void hfi1_make_ruc_header(struct rvt_qp *qp, struct ib_other_headers *ohdr,
+			  u32 bth0, u32 bth2, int middle,
+			  struct hfi1_pkt_state *ps)
+{
+	struct hfi1_qp_priv *priv = qp->priv;
+
+	/*
+	 * reset s_ahg/AHG fields
+	 *
+	 * This insures that the ahgentry/ahgcount
+	 * are at a non-AHG default to protect
+	 * build_verbs_tx_desc() from using
+	 * an include ahgidx.
+	 *
+	 * build_ahg() will modify as appropriate
+	 * to use the AHG feature.
+	 */
+	priv->s_ahg->tx_flags = 0;
+	priv->s_ahg->ahgcount = 0;
+	priv->s_ahg->ahgidx = 0;
+
+	/* Make the appropriate header */
+	hfi1_ruc_header_tbl[priv->hdr_type](qp, ohdr, bth0, bth2, middle, ps);
+}
+
+/* when sending, force a reschedule every one of these periods */
+#define SEND_RESCHED_TIMEOUT (5 * HZ)  /* 5s in jiffies */
+
+/**
+ * schedule_send_yield - test for a yield required for QP send engine
+ * @timeout: Final time for timeout slice for jiffies
+ * @qp: a pointer to QP
+ * @ps: a pointer to a structure with commonly lookup values for
+ *      the the send engine progress
+ *
+ * This routine checks if the time slice for the QP has expired
+ * for RC QPs, if so an additional work entry is queued. At this
+ * point, other QPs have an opportunity to be scheduled. It
+ * returns true if a yield is required, otherwise, false
+ * is returned.
+ */
+static bool schedule_send_yield(struct rvt_qp *qp,
+				struct hfi1_pkt_state *ps)
+{
+	ps->pkts_sent = true;
+
+	if (unlikely(time_after(jiffies, ps->timeout))) {
+		if (!ps->in_thread ||
+		    workqueue_congested(ps->cpu, ps->ppd->hfi1_wq)) {
+			spin_lock_irqsave(&qp->s_lock, ps->flags);
+			qp->s_flags &= ~RVT_S_BUSY;
+			hfi1_schedule_send(qp);
+			spin_unlock_irqrestore(&qp->s_lock, ps->flags);
+			this_cpu_inc(*ps->ppd->dd->send_schedule);
+			trace_hfi1_rc_expired_time_slice(qp, true);
+			return true;
+		}
+
+		cond_resched();
+		this_cpu_inc(*ps->ppd->dd->send_schedule);
+		ps->timeout = jiffies + ps->timeout_int;
+	}
+
+	trace_hfi1_rc_expired_time_slice(qp, false);
+	return false;
+}
+
+void hfi1_do_send_from_rvt(struct rvt_qp *qp)
+{
+	hfi1_do_send(qp, false);
+}
+
+void _hfi1_do_send(struct work_struct *work)
+{
+	struct iowait *wait = container_of(work, struct iowait, iowork);
+	struct rvt_qp *qp = iowait_to_qp(wait);
+
+	hfi1_do_send(qp, true);
+}
+
+/**
+ * hfi1_do_send - perform a send on a QP
+ * @work: contains a pointer to the QP
+ * @in_thread: true if in a workqueue thread
+ *
+ * Process entries in the send work queue until credit or queue is
+ * exhausted.  Only allow one CPU to send a packet per QP.
+ * Otherwise, two threads could send packets out of order.
+ */
+void hfi1_do_send(struct rvt_qp *qp, bool in_thread)
+{
+	struct hfi1_pkt_state ps;
+	struct hfi1_qp_priv *priv = qp->priv;
+	int (*make_req)(struct rvt_qp *qp, struct hfi1_pkt_state *ps);
+
+	ps.dev = to_idev(qp->ibqp.device);
+	ps.ibp = to_iport(qp->ibqp.device, qp->port_num);
+	ps.ppd = ppd_from_ibp(ps.ibp);
+	ps.in_thread = in_thread;
+
+	trace_hfi1_rc_do_send(qp, in_thread);
+
+	switch (qp->ibqp.qp_type) {
+	case IB_QPT_RC:
+		if (!loopback && ((rdma_ah_get_dlid(&qp->remote_ah_attr) &
+				   ~((1 << ps.ppd->lmc) - 1)) ==
+				  ps.ppd->lid)) {
+			ruc_loopback(qp);
+			return;
+		}
+		make_req = hfi1_make_rc_req;
+		ps.timeout_int = qp->timeout_jiffies;
+		break;
+	case IB_QPT_UC:
+		if (!loopback && ((rdma_ah_get_dlid(&qp->remote_ah_attr) &
+				   ~((1 << ps.ppd->lmc) - 1)) ==
+				  ps.ppd->lid)) {
+			ruc_loopback(qp);
+			return;
+		}
+		make_req = hfi1_make_uc_req;
+		ps.timeout_int = SEND_RESCHED_TIMEOUT;
+		break;
+	default:
+		make_req = hfi1_make_ud_req;
+		ps.timeout_int = SEND_RESCHED_TIMEOUT;
+	}
+
+	spin_lock_irqsave(&qp->s_lock, ps.flags);
+
+	/* Return if we are already busy processing a work request. */
+	if (!hfi1_send_ok(qp)) {
+		spin_unlock_irqrestore(&qp->s_lock, ps.flags);
+		return;
+	}
+
+	qp->s_flags |= RVT_S_BUSY;
+
+	ps.timeout_int = ps.timeout_int / 8;
+	ps.timeout = jiffies + ps.timeout_int;
+	ps.cpu = priv->s_sde ? priv->s_sde->cpu :
+			cpumask_first(cpumask_of_node(ps.ppd->dd->node));
+	ps.pkts_sent = false;
+
+	/* insure a pre-built packet is handled  */
+	ps.s_txreq = get_waiting_verbs_txreq(qp);
+	do {
+		/* Check for a constructed packet to be sent. */
+		if (ps.s_txreq) {
+			spin_unlock_irqrestore(&qp->s_lock, ps.flags);
+			/*
+			 * If the packet cannot be sent now, return and
+			 * the send engine will be woken up later.
+			 */
+			if (hfi1_verbs_send(qp, &ps))
+				return;
+			/* allow other tasks to run */
+			if (schedule_send_yield(qp, &ps))
+				return;
+
+			spin_lock_irqsave(&qp->s_lock, ps.flags);
+		}
+	} while (make_req(qp, &ps));
+	iowait_starve_clear(ps.pkts_sent, &priv->s_iowait);
+	spin_unlock_irqrestore(&qp->s_lock, ps.flags);
+}
+
+/*
+ * This should be called with s_lock held.
+ */
+void hfi1_send_complete(struct rvt_qp *qp, struct rvt_swqe *wqe,
+			enum ib_wc_status status)
+{
+	u32 old_last, last;
+
+	if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_OR_FLUSH_SEND))
+		return;
+
+	last = qp->s_last;
+	old_last = last;
+	trace_hfi1_qp_send_completion(qp, wqe, last);
+	if (++last >= qp->s_size)
+		last = 0;
+	trace_hfi1_qp_send_completion(qp, wqe, last);
+	qp->s_last = last;
+	/* See post_send() */
+	barrier();
+	rvt_put_swqe(wqe);
+	if (qp->ibqp.qp_type == IB_QPT_UD ||
+	    qp->ibqp.qp_type == IB_QPT_SMI ||
+	    qp->ibqp.qp_type == IB_QPT_GSI)
+		atomic_dec(&ibah_to_rvtah(wqe->ud_wr.ah)->refcount);
+
+	rvt_qp_swqe_complete(qp,
+			     wqe,
+			     ib_hfi1_wc_opcode[wqe->wr.opcode],
+			     status);
+
+	if (qp->s_acked == old_last)
+		qp->s_acked = last;
+	if (qp->s_cur == old_last)
+		qp->s_cur = last;
+	if (qp->s_tail == old_last)
+		qp->s_tail = last;
+	if (qp->state == IB_QPS_SQD && last == qp->s_cur)
+		qp->s_draining = 0;
+}