diff --git a/drivers/infiniband/hw/hfi1/rc.c b/drivers/infiniband/hw/hfi1/rc.c
index 1c7c609..4e1abd3 100644
--- a/drivers/infiniband/hw/hfi1/rc.c
+++ b/drivers/infiniband/hw/hfi1/rc.c
@@ -51,28 +51,48 @@
 
 #include "hfi.h"
 #include "qp.h"
+#include "rc.h"
 #include "verbs_txreq.h"
 #include "trace.h"
 
-/* cut down ridiculously long IB macro names */
-#define OP(x) RC_OP(x)
-
-static struct rvt_swqe *do_rc_completion(struct rvt_qp *qp,
-					 struct rvt_swqe *wqe,
-					 struct hfi1_ibport *ibp);
-
-static u32 restart_sge(struct rvt_sge_state *ss, struct rvt_swqe *wqe,
-		       u32 psn, u32 pmtu)
+struct rvt_ack_entry *find_prev_entry(struct rvt_qp *qp, u32 psn, u8 *prev,
+				      u8 *prev_ack, bool *scheduled)
+	__must_hold(&qp->s_lock)
 {
-	u32 len;
+	struct rvt_ack_entry *e = NULL;
+	u8 i, p;
+	bool s = true;
 
-	len = delta_psn(psn, wqe->psn) * pmtu;
-	ss->sge = wqe->sg_list[0];
-	ss->sg_list = wqe->sg_list + 1;
-	ss->num_sge = wqe->wr.num_sge;
-	ss->total_len = wqe->length;
-	rvt_skip_sge(ss, len, false);
-	return wqe->length - len;
+	for (i = qp->r_head_ack_queue; ; i = p) {
+		if (i == qp->s_tail_ack_queue)
+			s = false;
+		if (i)
+			p = i - 1;
+		else
+			p = rvt_size_atomic(ib_to_rvt(qp->ibqp.device));
+		if (p == qp->r_head_ack_queue) {
+			e = NULL;
+			break;
+		}
+		e = &qp->s_ack_queue[p];
+		if (!e->opcode) {
+			e = NULL;
+			break;
+		}
+		if (cmp_psn(psn, e->psn) >= 0) {
+			if (p == qp->s_tail_ack_queue &&
+			    cmp_psn(psn, e->lpsn) <= 0)
+				s = false;
+			break;
+		}
+	}
+	if (prev)
+		*prev = p;
+	if (prev_ack)
+		*prev_ack = i;
+	if (scheduled)
+		*scheduled = s;
+	return e;
 }
 
 /**
@@ -126,7 +146,7 @@ static int make_rc_ack(struct hfi1_ibdev *dev, struct rvt_qp *qp,
 		 * response has been sent instead of only being
 		 * constructed.
 		 */
-		if (++qp->s_tail_ack_queue > HFI1_MAX_RDMA_ATOMIC)
+		if (++qp->s_tail_ack_queue > rvt_size_atomic(&dev->rdi))
 			qp->s_tail_ack_queue = 0;
 		/* FALLTHROUGH */
 	case OP(SEND_ONLY):
@@ -1225,9 +1245,9 @@ static inline void update_last_psn(struct rvt_qp *qp, u32 psn)
  * This is similar to hfi1_send_complete but has to check to be sure
  * that the SGEs are not being referenced if the SWQE is being resent.
  */
-static struct rvt_swqe *do_rc_completion(struct rvt_qp *qp,
-					 struct rvt_swqe *wqe,
-					 struct hfi1_ibport *ibp)
+struct rvt_swqe *do_rc_completion(struct rvt_qp *qp,
+				  struct rvt_swqe *wqe,
+				  struct hfi1_ibport *ibp)
 {
 	lockdep_assert_held(&qp->s_lock);
 	/*
@@ -1309,8 +1329,8 @@ static inline void update_last_psn(struct rvt_qp *qp, u32 psn)
  * May be called at interrupt level, with the QP s_lock held.
  * Returns 1 if OK, 0 if current operation should be aborted (NAK).
  */
-static int do_rc_ack(struct rvt_qp *qp, u32 aeth, u32 psn, int opcode,
-		     u64 val, struct hfi1_ctxtdata *rcd)
+int do_rc_ack(struct rvt_qp *qp, u32 aeth, u32 psn, int opcode,
+	      u64 val, struct hfi1_ctxtdata *rcd)
 {
 	struct hfi1_ibport *ibp;
 	enum ib_wc_status status;
@@ -1747,16 +1767,6 @@ static void rc_rcv_resp(struct hfi1_packet *packet)
 	return;
 }
 
-static inline void rc_defered_ack(struct hfi1_ctxtdata *rcd,
-				  struct rvt_qp *qp)
-{
-	if (list_empty(&qp->rspwait)) {
-		qp->r_flags |= RVT_R_RSP_NAK;
-		rvt_get_qp(qp);
-		list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
-	}
-}
-
 static inline void rc_cancel_ack(struct rvt_qp *qp)
 {
 	qp->r_adefered = 0;
@@ -1789,8 +1799,9 @@ static noinline int rc_rcv_error(struct ib_other_headers *ohdr, void *data,
 	struct hfi1_ibport *ibp = rcd_to_iport(rcd);
 	struct rvt_ack_entry *e;
 	unsigned long flags;
-	u8 i, prev;
-	int old_req;
+	u8 prev;
+	u8 mra; /* most recent ACK */
+	bool old_req;
 
 	trace_hfi1_rcv_error(qp, psn);
 	if (diff > 0) {
@@ -1836,29 +1847,8 @@ static noinline int rc_rcv_error(struct ib_other_headers *ohdr, void *data,
 
 	spin_lock_irqsave(&qp->s_lock, flags);
 
-	for (i = qp->r_head_ack_queue; ; i = prev) {
-		if (i == qp->s_tail_ack_queue)
-			old_req = 0;
-		if (i)
-			prev = i - 1;
-		else
-			prev = HFI1_MAX_RDMA_ATOMIC;
-		if (prev == qp->r_head_ack_queue) {
-			e = NULL;
-			break;
-		}
-		e = &qp->s_ack_queue[prev];
-		if (!e->opcode) {
-			e = NULL;
-			break;
-		}
-		if (cmp_psn(psn, e->psn) >= 0) {
-			if (prev == qp->s_tail_ack_queue &&
-			    cmp_psn(psn, e->lpsn) <= 0)
-				old_req = 0;
-			break;
-		}
-	}
+	e = find_prev_entry(qp, psn, &prev, &mra, &old_req);
+
 	switch (opcode) {
 	case OP(RDMA_READ_REQUEST): {
 		struct ib_reth *reth;
@@ -1933,7 +1923,7 @@ static noinline int rc_rcv_error(struct ib_other_headers *ohdr, void *data,
 		 * Resend the most recent ACK if this request is
 		 * after all the previous RDMA reads and atomics.
 		 */
-		if (i == qp->r_head_ack_queue) {
+		if (mra == qp->r_head_ack_queue) {
 			spin_unlock_irqrestore(&qp->s_lock, flags);
 			qp->r_nak_state = 0;
 			qp->r_ack_psn = qp->r_psn - 1;
@@ -1944,7 +1934,7 @@ static noinline int rc_rcv_error(struct ib_other_headers *ohdr, void *data,
 		 * Resend the RDMA read or atomic op which
 		 * ACKs this duplicate request.
 		 */
-		qp->s_tail_ack_queue = i;
+		qp->s_tail_ack_queue = mra;
 		break;
 	}
 	qp->s_ack_state = OP(ACKNOWLEDGE);
@@ -1961,17 +1951,6 @@ static noinline int rc_rcv_error(struct ib_other_headers *ohdr, void *data,
 	return 0;
 }
 
-static inline void update_ack_queue(struct rvt_qp *qp, unsigned n)
-{
-	unsigned next;
-
-	next = n + 1;
-	if (next > HFI1_MAX_RDMA_ATOMIC)
-		next = 0;
-	qp->s_tail_ack_queue = next;
-	qp->s_ack_state = OP(ACKNOWLEDGE);
-}
-
 static void log_cca_event(struct hfi1_pportdata *ppd, u8 sl, u32 rlid,
 			  u32 lqpn, u32 rqpn, u8 svc_type)
 {
@@ -2327,7 +2306,7 @@ void hfi1_rc_rcv(struct hfi1_packet *packet)
 			goto nack_inv;
 		next = qp->r_head_ack_queue + 1;
 		/* s_ack_queue is size HFI1_MAX_RDMA_ATOMIC+1 so use > not >= */
-		if (next > HFI1_MAX_RDMA_ATOMIC)
+		if (next > rvt_size_atomic(ib_to_rvt(qp->ibqp.device)))
 			next = 0;
 		spin_lock_irqsave(&qp->s_lock, flags);
 		if (unlikely(next == qp->s_tail_ack_queue)) {
@@ -2404,7 +2383,7 @@ void hfi1_rc_rcv(struct hfi1_packet *packet)
 			     !opfn))
 			goto nack_inv;
 		next = qp->r_head_ack_queue + 1;
-		if (next > HFI1_MAX_RDMA_ATOMIC)
+		if (next > rvt_size_atomic(ib_to_rvt(qp->ibqp.device)))
 			next = 0;
 		spin_lock_irqsave(&qp->s_lock, flags);
 		if (unlikely(next == qp->s_tail_ack_queue)) {
diff --git a/drivers/infiniband/hw/hfi1/rc.h b/drivers/infiniband/hw/hfi1/rc.h
new file mode 100644
index 0000000..ca39ee9
--- /dev/null
+++ b/drivers/infiniband/hw/hfi1/rc.h
@@ -0,0 +1,92 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
+/*
+ * Copyright(c) 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.
+ *
+ */
+
+#ifndef HFI1_RC_H
+#define HFI1_RC_H
+
+/* cut down ridiculously long IB macro names */
+#define OP(x) IB_OPCODE_RC_##x
+
+static inline void update_ack_queue(struct rvt_qp *qp, unsigned int n)
+{
+	unsigned int next;
+
+	next = n + 1;
+	if (next > rvt_size_atomic(ib_to_rvt(qp->ibqp.device)))
+		next = 0;
+	qp->s_tail_ack_queue = next;
+	qp->s_ack_state = OP(ACKNOWLEDGE);
+}
+
+static inline void rc_defered_ack(struct hfi1_ctxtdata *rcd,
+				  struct rvt_qp *qp)
+{
+	if (list_empty(&qp->rspwait)) {
+		qp->r_flags |= RVT_R_RSP_NAK;
+		rvt_get_qp(qp);
+		list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
+	}
+}
+
+static inline u32 restart_sge(struct rvt_sge_state *ss, struct rvt_swqe *wqe,
+			      u32 psn, u32 pmtu)
+{
+	u32 len;
+
+	len = delta_psn(psn, wqe->psn) * pmtu;
+	return rvt_restart_sge(ss, wqe, len);
+}
+
+struct rvt_ack_entry *find_prev_entry(struct rvt_qp *qp, u32 psn, u8 *prev,
+				      u8 *prev_ack, bool *scheduled);
+int do_rc_ack(struct rvt_qp *qp, u32 aeth, u32 psn, int opcode, u64 val,
+	      struct hfi1_ctxtdata *rcd);
+struct rvt_swqe *do_rc_completion(struct rvt_qp *qp, struct rvt_swqe *wqe,
+				  struct hfi1_ibport *ibp);
+
+#endif /* HFI1_RC_H */
diff --git a/drivers/infiniband/hw/qib/qib_rc.c b/drivers/infiniband/hw/qib/qib_rc.c
index f35fdeb..b701804 100644
--- a/drivers/infiniband/hw/qib/qib_rc.c
+++ b/drivers/infiniband/hw/qib/qib_rc.c
@@ -45,12 +45,7 @@ static u32 restart_sge(struct rvt_sge_state *ss, struct rvt_swqe *wqe,
 	u32 len;
 
 	len = ((psn - wqe->psn) & QIB_PSN_MASK) * pmtu;
-	ss->sge = wqe->sg_list[0];
-	ss->sg_list = wqe->sg_list + 1;
-	ss->num_sge = wqe->wr.num_sge;
-	ss->total_len = wqe->length;
-	rvt_skip_sge(ss, len, false);
-	return wqe->length - len;
+	return rvt_restart_sge(ss, wqe, len);
 }
 
 /**
diff --git a/drivers/infiniband/sw/rdmavt/rc.c b/drivers/infiniband/sw/rdmavt/rc.c
index 6131cc5..a6f6edd 100644
--- a/drivers/infiniband/sw/rdmavt/rc.c
+++ b/drivers/infiniband/sw/rdmavt/rc.c
@@ -187,3 +187,22 @@ void rvt_get_credit(struct rvt_qp *qp, u32 aeth)
 	}
 }
 EXPORT_SYMBOL(rvt_get_credit);
+
+/**
+ * rvt_restart_sge - rewind the sge state for a wqe
+ * @ss: the sge state pointer
+ * @wqe: the wqe to rewind
+ * @len: the data length from the start of the wqe in bytes
+ *
+ * Returns the remaining data length.
+ */
+u32 rvt_restart_sge(struct rvt_sge_state *ss, struct rvt_swqe *wqe, u32 len)
+{
+	ss->sge = wqe->sg_list[0];
+	ss->sg_list = wqe->sg_list + 1;
+	ss->num_sge = wqe->wr.num_sge;
+	ss->total_len = wqe->length;
+	rvt_skip_sge(ss, len, false);
+	return wqe->length - len;
+}
+EXPORT_SYMBOL(rvt_restart_sge);
diff --git a/include/rdma/rdma_vt.h b/include/rdma/rdma_vt.h
index 6e259f9..d187621 100644
--- a/include/rdma/rdma_vt.h
+++ b/include/rdma/rdma_vt.h
@@ -486,6 +486,11 @@ static inline unsigned int rvt_max_atomic(struct rvt_dev_info *rdi)
 	return rdi->dparms.max_rdma_atomic + 1;
 }
 
+static inline unsigned int rvt_size_atomic(struct rvt_dev_info *rdi)
+{
+	return rdi->dparms.max_rdma_atomic;
+}
+
 /*
  * Return the indexed PKEY from the port PKEY table.
  */
diff --git a/include/rdma/rdmavt_qp.h b/include/rdma/rdmavt_qp.h
index 927f6d5..7e32aa4 100644
--- a/include/rdma/rdmavt_qp.h
+++ b/include/rdma/rdmavt_qp.h
@@ -628,6 +628,9 @@ static inline int rvt_cmp_msn(u32 a, u32 b)
  */
 void rvt_get_credit(struct rvt_qp *qp, u32 aeth);
 
+/* rvt_restart_sge - rewind the sge state for a wqe */
+u32 rvt_restart_sge(struct rvt_sge_state *ss, struct rvt_swqe *wqe, u32 len);
+
 /**
  * @qp - the qp pair
  * @len - the length
