Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma

Pull more rdma updates from Doug Ledford:
 "This is the second group of code for the 4.7 merge window.  It looks
  large, but only in one sense.  I'll get to that in a minute.  The list
  of changes here breaks down as follows:

   - Dynamic counter infrastructure in the IB drivers

     This is a sysfs based code to allow free form access to the
     hardware counters RDMA devices might support so drivers don't need
     to code this up repeatedly themselves

   - SendOnlyFullMember multicast support

   - IB router support

   - A couple misc fixes

   - The big item on the list: hfi1 driver updates, plus moving the hfi1
     driver out of staging

  There was a group of 15 patches in the hfi1 list that I thought I had
  in the first pull request but they weren't.  So that added to the
  length of the hfi1 section here.

  As far as these go, everything but the hfi1 is pretty straight
  forward.

  The hfi1 is, if you recall, the driver that Al had complaints about
  how it used the write/writev interfaces in an overloaded fashion.  The
  write portion of their interface behaved like the write handler in the
  IB stack proper and did bi-directional communications.  The writev
  interface, on the other hand, only accepts SDMA request structures.
  The completions for those structures are sent back via an entirely
  different event mechanism.

  With the security patch, we put security checks on the write
  interface, however, we also knew they would be going away soon.  Now,
  we've converted the write handler in the hfi1 driver to use ioctls
  from the IB reserved magic area for its bidirectional communications.
  With that change, Intel has addressed all of the items originally on
  their TODO when they went into staging (as well as many items added to
  the list later).

  As such, I moved them out, and since they were the last item in the
  staging/rdma directory, and I don't have immediate plans to use the
  staging area again, I removed the staging/rdma area.

  Because of the move out of staging, as well as a series of 5 patches
  in the hfi1 driver that removed code people thought should be done in
  a different way and was optional to begin with (a snoop debug
  interface, an eeprom driver for an eeprom connected directory to their
  hfi1 chip and not via an i2c bus, and a few other things like that),
  the line count, especially the removal count, is high"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma: (56 commits)
  staging/rdma: Remove the entire rdma subdirectory of staging
  IB/core: Make device counter infrastructure dynamic
  IB/hfi1: Fix pio map initialization
  IB/hfi1: Correct 8051 link parameter settings
  IB/hfi1: Update pkey table properly after link down or FM start
  IB/rdamvt: Fix rdmavt s_ack_queue sizing
  IB/rdmavt: Max atomic value should be a u8
  IB/hfi1: Fix hard lockup due to not using save/restore spin lock
  IB/hfi1: Add tracing support for send with invalidate opcode
  IB/hfi1, qib: Add ieth to the packet header definitions
  IB/hfi1: Move driver out of staging
  IB/hfi1: Do not free hfi1 cdev parent structure early
  IB/hfi1: Add trace message in user IOCTL handling
  IB/hfi1: Remove write(), use ioctl() for user cmds
  IB/hfi1: Add ioctl() interface for user commands
  IB/hfi1: Remove unused user command
  IB/hfi1: Remove snoop/diag interface
  IB/hfi1: Remove EPROM functionality from data device
  IB/hfi1: Remove UI char device
  IB/hfi1: Remove multiple device cdev
  ...

1 files changed, 2580 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/hfi1/rc.c b/drivers/infiniband/hw/hfi1/rc.c
new file mode 100644
index 000000000000..792f15eb8efe
--- /dev/null
+++ b/drivers/infiniband/hw/hfi1/rc.c
@@ -0,0 +1,2580 @@
+/*
+ * Copyright(c) 2015, 2016 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/io.h>
+#include <rdma/rdma_vt.h>
+#include <rdma/rdmavt_qp.h>
+
+#include "hfi.h"
+#include "qp.h"
+#include "verbs_txreq.h"
+#include "trace.h"
+
+/* cut down ridiculously long IB macro names */
+#define OP(x) IB_OPCODE_RC_##x
+
+/**
+ * hfi1_add_retry_timer - add/start a retry timer
+ * @qp - the QP
+ *
+ * add a retry timer on the QP
+ */
+static inline void hfi1_add_retry_timer(struct rvt_qp *qp)
+{
+	struct ib_qp *ibqp = &qp->ibqp;
+	struct rvt_dev_info *rdi = ib_to_rvt(ibqp->device);
+
+	qp->s_flags |= RVT_S_TIMER;
+	/* 4.096 usec. * (1 << qp->timeout) */
+	qp->s_timer.expires = jiffies + qp->timeout_jiffies +
+			      rdi->busy_jiffies;
+	add_timer(&qp->s_timer);
+}
+
+/**
+ * hfi1_add_rnr_timer - add/start an rnr timer
+ * @qp - the QP
+ * @to - timeout in usecs
+ *
+ * add an rnr timer on the QP
+ */
+void hfi1_add_rnr_timer(struct rvt_qp *qp, u32 to)
+{
+	struct hfi1_qp_priv *priv = qp->priv;
+
+	qp->s_flags |= RVT_S_WAIT_RNR;
+	qp->s_timer.expires = jiffies + usecs_to_jiffies(to);
+	add_timer(&priv->s_rnr_timer);
+}
+
+/**
+ * hfi1_mod_retry_timer - mod a retry timer
+ * @qp - the QP
+ *
+ * Modify a potentially already running retry
+ * timer
+ */
+static inline void hfi1_mod_retry_timer(struct rvt_qp *qp)
+{
+	struct ib_qp *ibqp = &qp->ibqp;
+	struct rvt_dev_info *rdi = ib_to_rvt(ibqp->device);
+
+	qp->s_flags |= RVT_S_TIMER;
+	/* 4.096 usec. * (1 << qp->timeout) */
+	mod_timer(&qp->s_timer, jiffies + qp->timeout_jiffies +
+		  rdi->busy_jiffies);
+}
+
+/**
+ * hfi1_stop_retry_timer - stop a retry timer
+ * @qp - the QP
+ *
+ * stop a retry timer and return if the timer
+ * had been pending.
+ */
+static inline int hfi1_stop_retry_timer(struct rvt_qp *qp)
+{
+	int rval = 0;
+
+	/* Remove QP from retry */
+	if (qp->s_flags & RVT_S_TIMER) {
+		qp->s_flags &= ~RVT_S_TIMER;
+		rval = del_timer(&qp->s_timer);
+	}
+	return rval;
+}
+
+/**
+ * hfi1_stop_rc_timers - stop all timers
+ * @qp - the QP
+ *
+ * stop any pending timers
+ */
+void hfi1_stop_rc_timers(struct rvt_qp *qp)
+{
+	struct hfi1_qp_priv *priv = qp->priv;
+
+	/* Remove QP from all timers */
+	if (qp->s_flags & (RVT_S_TIMER | RVT_S_WAIT_RNR)) {
+		qp->s_flags &= ~(RVT_S_TIMER | RVT_S_WAIT_RNR);
+		del_timer(&qp->s_timer);
+		del_timer(&priv->s_rnr_timer);
+	}
+}
+
+/**
+ * hfi1_stop_rnr_timer - stop an rnr timer
+ * @qp - the QP
+ *
+ * stop an rnr timer and return if the timer
+ * had been pending.
+ */
+static inline int hfi1_stop_rnr_timer(struct rvt_qp *qp)
+{
+	int rval = 0;
+	struct hfi1_qp_priv *priv = qp->priv;
+
+	/* Remove QP from rnr timer */
+	if (qp->s_flags & RVT_S_WAIT_RNR) {
+		qp->s_flags &= ~RVT_S_WAIT_RNR;
+		rval = del_timer(&priv->s_rnr_timer);
+	}
+	return rval;
+}
+
+/**
+ * hfi1_del_timers_sync - wait for any timeout routines to exit
+ * @qp - the QP
+ */
+void hfi1_del_timers_sync(struct rvt_qp *qp)
+{
+	struct hfi1_qp_priv *priv = qp->priv;
+
+	del_timer_sync(&qp->s_timer);
+	del_timer_sync(&priv->s_rnr_timer);
+}
+
+/* only opcode mask for adaptive pio */
+const u32 rc_only_opcode =
+	BIT(OP(SEND_ONLY) & 0x1f) |
+	BIT(OP(SEND_ONLY_WITH_IMMEDIATE & 0x1f)) |
+	BIT(OP(RDMA_WRITE_ONLY & 0x1f)) |
+	BIT(OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE & 0x1f)) |
+	BIT(OP(RDMA_READ_REQUEST & 0x1f)) |
+	BIT(OP(ACKNOWLEDGE & 0x1f)) |
+	BIT(OP(ATOMIC_ACKNOWLEDGE & 0x1f)) |
+	BIT(OP(COMPARE_SWAP & 0x1f)) |
+	BIT(OP(FETCH_ADD & 0x1f));
+
+static 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;
+	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;
+	hfi1_skip_sge(ss, len, 0);
+	return wqe->length - len;
+}
+
+/**
+ * make_rc_ack - construct a response packet (ACK, NAK, or RDMA read)
+ * @dev: the device for this QP
+ * @qp: a pointer to the QP
+ * @ohdr: a pointer to the IB header being constructed
+ * @ps: the xmit packet state
+ *
+ * Return 1 if constructed; otherwise, return 0.
+ * Note that we are in the responder's side of the QP context.
+ * Note the QP s_lock must be held.
+ */
+static int make_rc_ack(struct hfi1_ibdev *dev, struct rvt_qp *qp,
+		       struct hfi1_other_headers *ohdr,
+		       struct hfi1_pkt_state *ps)
+{
+	struct rvt_ack_entry *e;
+	u32 hwords;
+	u32 len;
+	u32 bth0;
+	u32 bth2;
+	int middle = 0;
+	u32 pmtu = qp->pmtu;
+	struct hfi1_qp_priv *priv = qp->priv;
+
+	/* Don't send an ACK if we aren't supposed to. */
+	if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK))
+		goto bail;
+
+	/* header size in 32-bit words LRH+BTH = (8+12)/4. */
+	hwords = 5;
+
+	switch (qp->s_ack_state) {
+	case OP(RDMA_READ_RESPONSE_LAST):
+	case OP(RDMA_READ_RESPONSE_ONLY):
+		e = &qp->s_ack_queue[qp->s_tail_ack_queue];
+		if (e->rdma_sge.mr) {
+			rvt_put_mr(e->rdma_sge.mr);
+			e->rdma_sge.mr = NULL;
+		}
+		/* FALLTHROUGH */
+	case OP(ATOMIC_ACKNOWLEDGE):
+		/*
+		 * We can increment the tail pointer now that the last
+		 * response has been sent instead of only being
+		 * constructed.
+		 */
+		if (++qp->s_tail_ack_queue > HFI1_MAX_RDMA_ATOMIC)
+			qp->s_tail_ack_queue = 0;
+		/* FALLTHROUGH */
+	case OP(SEND_ONLY):
+	case OP(ACKNOWLEDGE):
+		/* Check for no next entry in the queue. */
+		if (qp->r_head_ack_queue == qp->s_tail_ack_queue) {
+			if (qp->s_flags & RVT_S_ACK_PENDING)
+				goto normal;
+			goto bail;
+		}
+
+		e = &qp->s_ack_queue[qp->s_tail_ack_queue];
+		if (e->opcode == OP(RDMA_READ_REQUEST)) {
+			/*
+			 * If a RDMA read response is being resent and
+			 * we haven't seen the duplicate request yet,
+			 * then stop sending the remaining responses the
+			 * responder has seen until the requester re-sends it.
+			 */
+			len = e->rdma_sge.sge_length;
+			if (len && !e->rdma_sge.mr) {
+				qp->s_tail_ack_queue = qp->r_head_ack_queue;
+				goto bail;
+			}
+			/* Copy SGE state in case we need to resend */
+			ps->s_txreq->mr = e->rdma_sge.mr;
+			if (ps->s_txreq->mr)
+				rvt_get_mr(ps->s_txreq->mr);
+			qp->s_ack_rdma_sge.sge = e->rdma_sge;
+			qp->s_ack_rdma_sge.num_sge = 1;
+			qp->s_cur_sge = &qp->s_ack_rdma_sge;
+			if (len > pmtu) {
+				len = pmtu;
+				qp->s_ack_state = OP(RDMA_READ_RESPONSE_FIRST);
+			} else {
+				qp->s_ack_state = OP(RDMA_READ_RESPONSE_ONLY);
+				e->sent = 1;
+			}
+			ohdr->u.aeth = hfi1_compute_aeth(qp);
+			hwords++;
+			qp->s_ack_rdma_psn = e->psn;
+			bth2 = mask_psn(qp->s_ack_rdma_psn++);
+		} else {
+			/* COMPARE_SWAP or FETCH_ADD */
+			qp->s_cur_sge = NULL;
+			len = 0;
+			qp->s_ack_state = OP(ATOMIC_ACKNOWLEDGE);
+			ohdr->u.at.aeth = hfi1_compute_aeth(qp);
+			ohdr->u.at.atomic_ack_eth[0] =
+				cpu_to_be32(e->atomic_data >> 32);
+			ohdr->u.at.atomic_ack_eth[1] =
+				cpu_to_be32(e->atomic_data);
+			hwords += sizeof(ohdr->u.at) / sizeof(u32);
+			bth2 = mask_psn(e->psn);
+			e->sent = 1;
+		}
+		bth0 = qp->s_ack_state << 24;
+		break;
+
+	case OP(RDMA_READ_RESPONSE_FIRST):
+		qp->s_ack_state = OP(RDMA_READ_RESPONSE_MIDDLE);
+		/* FALLTHROUGH */
+	case OP(RDMA_READ_RESPONSE_MIDDLE):
+		qp->s_cur_sge = &qp->s_ack_rdma_sge;
+		ps->s_txreq->mr = qp->s_ack_rdma_sge.sge.mr;
+		if (ps->s_txreq->mr)
+			rvt_get_mr(ps->s_txreq->mr);
+		len = qp->s_ack_rdma_sge.sge.sge_length;
+		if (len > pmtu) {
+			len = pmtu;
+			middle = HFI1_CAP_IS_KSET(SDMA_AHG);
+		} else {
+			ohdr->u.aeth = hfi1_compute_aeth(qp);
+			hwords++;
+			qp->s_ack_state = OP(RDMA_READ_RESPONSE_LAST);
+			e = &qp->s_ack_queue[qp->s_tail_ack_queue];
+			e->sent = 1;
+		}
+		bth0 = qp->s_ack_state << 24;
+		bth2 = mask_psn(qp->s_ack_rdma_psn++);
+		break;
+
+	default:
+normal:
+		/*
+		 * Send a regular ACK.
+		 * Set the s_ack_state so we wait until after sending
+		 * the ACK before setting s_ack_state to ACKNOWLEDGE
+		 * (see above).
+		 */
+		qp->s_ack_state = OP(SEND_ONLY);
+		qp->s_flags &= ~RVT_S_ACK_PENDING;
+		qp->s_cur_sge = NULL;
+		if (qp->s_nak_state)
+			ohdr->u.aeth =
+				cpu_to_be32((qp->r_msn & HFI1_MSN_MASK) |
+					    (qp->s_nak_state <<
+					     HFI1_AETH_CREDIT_SHIFT));
+		else
+			ohdr->u.aeth = hfi1_compute_aeth(qp);
+		hwords++;
+		len = 0;
+		bth0 = OP(ACKNOWLEDGE) << 24;
+		bth2 = mask_psn(qp->s_ack_psn);
+	}
+	qp->s_rdma_ack_cnt++;
+	qp->s_hdrwords = hwords;
+	ps->s_txreq->sde = priv->s_sde;
+	qp->s_cur_size = len;
+	hfi1_make_ruc_header(qp, ohdr, bth0, bth2, middle, ps);
+	/* pbc */
+	ps->s_txreq->hdr_dwords = qp->s_hdrwords + 2;
+	return 1;
+
+bail:
+	qp->s_ack_state = OP(ACKNOWLEDGE);
+	/*
+	 * Ensure s_rdma_ack_cnt changes are committed prior to resetting
+	 * RVT_S_RESP_PENDING
+	 */
+	smp_wmb();
+	qp->s_flags &= ~(RVT_S_RESP_PENDING
+				| RVT_S_ACK_PENDING
+				| RVT_S_AHG_VALID);
+	return 0;
+}
+
+/**
+ * hfi1_make_rc_req - construct a request packet (SEND, RDMA r/w, ATOMIC)
+ * @qp: a pointer to the QP
+ *
+ * Assumes s_lock is held.
+ *
+ * Return 1 if constructed; otherwise, return 0.
+ */
+int hfi1_make_rc_req(struct rvt_qp *qp, struct hfi1_pkt_state *ps)
+{
+	struct hfi1_qp_priv *priv = qp->priv;
+	struct hfi1_ibdev *dev = to_idev(qp->ibqp.device);
+	struct hfi1_other_headers *ohdr;
+	struct rvt_sge_state *ss;
+	struct rvt_swqe *wqe;
+	/* header size in 32-bit words LRH+BTH = (8+12)/4. */
+	u32 hwords = 5;
+	u32 len;
+	u32 bth0 = 0;
+	u32 bth2;
+	u32 pmtu = qp->pmtu;
+	char newreq;
+	int middle = 0;
+	int delta;
+
+	ps->s_txreq = get_txreq(ps->dev, qp);
+	if (IS_ERR(ps->s_txreq))
+		goto bail_no_tx;
+
+	ohdr = &ps->s_txreq->phdr.hdr.u.oth;
+	if (qp->remote_ah_attr.ah_flags & IB_AH_GRH)
+		ohdr = &ps->s_txreq->phdr.hdr.u.l.oth;
+
+	/* Sending responses has higher priority over sending requests. */
+	if ((qp->s_flags & RVT_S_RESP_PENDING) &&
+	    make_rc_ack(dev, qp, ohdr, ps))
+		return 1;
+
+	if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_SEND_OK)) {
+		if (!(ib_rvt_state_ops[qp->state] & RVT_FLUSH_SEND))
+			goto bail;
+		/* We are in the error state, flush the work request. */
+		smp_read_barrier_depends(); /* see post_one_send() */
+		if (qp->s_last == ACCESS_ONCE(qp->s_head))
+			goto bail;
+		/* If DMAs are in progress, we can't flush immediately. */
+		if (iowait_sdma_pending(&priv->s_iowait)) {
+			qp->s_flags |= RVT_S_WAIT_DMA;
+			goto bail;
+		}
+		clear_ahg(qp);
+		wqe = rvt_get_swqe_ptr(qp, qp->s_last);
+		hfi1_send_complete(qp, wqe, qp->s_last != qp->s_acked ?
+			IB_WC_SUCCESS : IB_WC_WR_FLUSH_ERR);
+		/* will get called again */
+		goto done_free_tx;
+	}
+
+	if (qp->s_flags & (RVT_S_WAIT_RNR | RVT_S_WAIT_ACK))
+		goto bail;
+
+	if (cmp_psn(qp->s_psn, qp->s_sending_hpsn) <= 0) {
+		if (cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0) {
+			qp->s_flags |= RVT_S_WAIT_PSN;
+			goto bail;
+		}
+		qp->s_sending_psn = qp->s_psn;
+		qp->s_sending_hpsn = qp->s_psn - 1;
+	}
+
+	/* Send a request. */
+	wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
+	switch (qp->s_state) {
+	default:
+		if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_NEXT_SEND_OK))
+			goto bail;
+		/*
+		 * Resend an old request or start a new one.
+		 *
+		 * We keep track of the current SWQE so that
+		 * we don't reset the "furthest progress" state
+		 * if we need to back up.
+		 */
+		newreq = 0;
+		if (qp->s_cur == qp->s_tail) {
+			/* Check if send work queue is empty. */
+			if (qp->s_tail == qp->s_head) {
+				clear_ahg(qp);
+				goto bail;
+			}
+			/*
+			 * If a fence is requested, wait for previous
+			 * RDMA read and atomic operations to finish.
+			 */
+			if ((wqe->wr.send_flags & IB_SEND_FENCE) &&
+			    qp->s_num_rd_atomic) {
+				qp->s_flags |= RVT_S_WAIT_FENCE;
+				goto bail;
+			}
+			newreq = 1;
+			qp->s_psn = wqe->psn;
+		}
+		/*
+		 * Note that we have to be careful not to modify the
+		 * original work request since we may need to resend
+		 * it.
+		 */
+		len = wqe->length;
+		ss = &qp->s_sge;
+		bth2 = mask_psn(qp->s_psn);
+		switch (wqe->wr.opcode) {
+		case IB_WR_SEND:
+		case IB_WR_SEND_WITH_IMM:
+			/* If no credit, return. */
+			if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT) &&
+			    cmp_msn(wqe->ssn, qp->s_lsn + 1) > 0) {
+				qp->s_flags |= RVT_S_WAIT_SSN_CREDIT;
+				goto bail;
+			}
+			if (len > pmtu) {
+				qp->s_state = OP(SEND_FIRST);
+				len = pmtu;
+				break;
+			}
+			if (wqe->wr.opcode == IB_WR_SEND) {
+				qp->s_state = OP(SEND_ONLY);
+			} else {
+				qp->s_state = OP(SEND_ONLY_WITH_IMMEDIATE);
+				/* Immediate data comes after the BTH */
+				ohdr->u.imm_data = wqe->wr.ex.imm_data;
+				hwords += 1;
+			}
+			if (wqe->wr.send_flags & IB_SEND_SOLICITED)
+				bth0 |= IB_BTH_SOLICITED;
+			bth2 |= IB_BTH_REQ_ACK;
+			if (++qp->s_cur == qp->s_size)
+				qp->s_cur = 0;
+			break;
+
+		case IB_WR_RDMA_WRITE:
+			if (newreq && !(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
+				qp->s_lsn++;
+			/* FALLTHROUGH */
+		case IB_WR_RDMA_WRITE_WITH_IMM:
+			/* If no credit, return. */
+			if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT) &&
+			    cmp_msn(wqe->ssn, qp->s_lsn + 1) > 0) {
+				qp->s_flags |= RVT_S_WAIT_SSN_CREDIT;
+				goto bail;
+			}
+			ohdr->u.rc.reth.vaddr =
+				cpu_to_be64(wqe->rdma_wr.remote_addr);
+			ohdr->u.rc.reth.rkey =
+				cpu_to_be32(wqe->rdma_wr.rkey);
+			ohdr->u.rc.reth.length = cpu_to_be32(len);
+			hwords += sizeof(struct ib_reth) / sizeof(u32);
+			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 RETH */
+				ohdr->u.rc.imm_data = wqe->wr.ex.imm_data;
+				hwords += 1;
+				if (wqe->wr.send_flags & IB_SEND_SOLICITED)
+					bth0 |= IB_BTH_SOLICITED;
+			}
+			bth2 |= IB_BTH_REQ_ACK;
+			if (++qp->s_cur == qp->s_size)
+				qp->s_cur = 0;
+			break;
+
+		case IB_WR_RDMA_READ:
+			/*
+			 * Don't allow more operations to be started
+			 * than the QP limits allow.
+			 */
+			if (newreq) {
+				if (qp->s_num_rd_atomic >=
+				    qp->s_max_rd_atomic) {
+					qp->s_flags |= RVT_S_WAIT_RDMAR;
+					goto bail;
+				}
+				qp->s_num_rd_atomic++;
+				if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
+					qp->s_lsn++;
+			}
+			ohdr->u.rc.reth.vaddr =
+				cpu_to_be64(wqe->rdma_wr.remote_addr);
+			ohdr->u.rc.reth.rkey =
+				cpu_to_be32(wqe->rdma_wr.rkey);
+			ohdr->u.rc.reth.length = cpu_to_be32(len);
+			qp->s_state = OP(RDMA_READ_REQUEST);
+			hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
+			ss = NULL;
+			len = 0;
+			bth2 |= IB_BTH_REQ_ACK;
+			if (++qp->s_cur == qp->s_size)
+				qp->s_cur = 0;
+			break;
+
+		case IB_WR_ATOMIC_CMP_AND_SWP:
+		case IB_WR_ATOMIC_FETCH_AND_ADD:
+			/*
+			 * Don't allow more operations to be started
+			 * than the QP limits allow.
+			 */
+			if (newreq) {
+				if (qp->s_num_rd_atomic >=
+				    qp->s_max_rd_atomic) {
+					qp->s_flags |= RVT_S_WAIT_RDMAR;
+					goto bail;
+				}
+				qp->s_num_rd_atomic++;
+				if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT))
+					qp->s_lsn++;
+			}
+			if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP) {
+				qp->s_state = OP(COMPARE_SWAP);
+				ohdr->u.atomic_eth.swap_data = cpu_to_be64(
+					wqe->atomic_wr.swap);
+				ohdr->u.atomic_eth.compare_data = cpu_to_be64(
+					wqe->atomic_wr.compare_add);
+			} else {
+				qp->s_state = OP(FETCH_ADD);
+				ohdr->u.atomic_eth.swap_data = cpu_to_be64(
+					wqe->atomic_wr.compare_add);
+				ohdr->u.atomic_eth.compare_data = 0;
+			}
+			ohdr->u.atomic_eth.vaddr[0] = cpu_to_be32(
+				wqe->atomic_wr.remote_addr >> 32);
+			ohdr->u.atomic_eth.vaddr[1] = cpu_to_be32(
+				wqe->atomic_wr.remote_addr);
+			ohdr->u.atomic_eth.rkey = cpu_to_be32(
+				wqe->atomic_wr.rkey);
+			hwords += sizeof(struct ib_atomic_eth) / sizeof(u32);
+			ss = NULL;
+			len = 0;
+			bth2 |= IB_BTH_REQ_ACK;
+			if (++qp->s_cur == qp->s_size)
+				qp->s_cur = 0;
+			break;
+
+		default:
+			goto bail;
+		}
+		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;
+		qp->s_len = wqe->length;
+		if (newreq) {
+			qp->s_tail++;
+			if (qp->s_tail >= qp->s_size)
+				qp->s_tail = 0;
+		}
+		if (wqe->wr.opcode == IB_WR_RDMA_READ)
+			qp->s_psn = wqe->lpsn + 1;
+		else
+			qp->s_psn++;
+		break;
+
+	case OP(RDMA_READ_RESPONSE_FIRST):
+		/*
+		 * qp->s_state is normally set to the opcode of the
+		 * last packet constructed for new requests and therefore
+		 * is never set to RDMA read response.
+		 * RDMA_READ_RESPONSE_FIRST is used by the ACK processing
+		 * thread to indicate a SEND needs to be restarted from an
+		 * earlier PSN without interfering with the sending thread.
+		 * See restart_rc().
+		 */
+		qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn, pmtu);
+		/* FALLTHROUGH */
+	case OP(SEND_FIRST):
+		qp->s_state = OP(SEND_MIDDLE);
+		/* FALLTHROUGH */
+	case OP(SEND_MIDDLE):
+		bth2 = mask_psn(qp->s_psn++);
+		ss = &qp->s_sge;
+		len = qp->s_len;
+		if (len > pmtu) {
+			len = pmtu;
+			middle = HFI1_CAP_IS_KSET(SDMA_AHG);
+			break;
+		}
+		if (wqe->wr.opcode == IB_WR_SEND) {
+			qp->s_state = OP(SEND_LAST);
+		} else {
+			qp->s_state = OP(SEND_LAST_WITH_IMMEDIATE);
+			/* Immediate data comes after the BTH */
+			ohdr->u.imm_data = wqe->wr.ex.imm_data;
+			hwords += 1;
+		}
+		if (wqe->wr.send_flags & IB_SEND_SOLICITED)
+			bth0 |= IB_BTH_SOLICITED;
+		bth2 |= IB_BTH_REQ_ACK;
+		qp->s_cur++;
+		if (qp->s_cur >= qp->s_size)
+			qp->s_cur = 0;
+		break;
+
+	case OP(RDMA_READ_RESPONSE_LAST):
+		/*
+		 * qp->s_state is normally set to the opcode of the
+		 * last packet constructed for new requests and therefore
+		 * is never set to RDMA read response.
+		 * RDMA_READ_RESPONSE_LAST is used by the ACK processing
+		 * thread to indicate a RDMA write needs to be restarted from
+		 * an earlier PSN without interfering with the sending thread.
+		 * See restart_rc().
+		 */
+		qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn, pmtu);
+		/* FALLTHROUGH */
+	case OP(RDMA_WRITE_FIRST):
+		qp->s_state = OP(RDMA_WRITE_MIDDLE);
+		/* FALLTHROUGH */
+	case OP(RDMA_WRITE_MIDDLE):
+		bth2 = mask_psn(qp->s_psn++);
+		ss = &qp->s_sge;
+		len = qp->s_len;
+		if (len > pmtu) {
+			len = pmtu;
+			middle = HFI1_CAP_IS_KSET(SDMA_AHG);
+			break;
+		}
+		if (wqe->wr.opcode == IB_WR_RDMA_WRITE) {
+			qp->s_state = OP(RDMA_WRITE_LAST);
+		} else {
+			qp->s_state = OP(RDMA_WRITE_LAST_WITH_IMMEDIATE);
+			/* Immediate data comes after the BTH */
+			ohdr->u.imm_data = wqe->wr.ex.imm_data;
+			hwords += 1;
+			if (wqe->wr.send_flags & IB_SEND_SOLICITED)
+				bth0 |= IB_BTH_SOLICITED;
+		}
+		bth2 |= IB_BTH_REQ_ACK;
+		qp->s_cur++;
+		if (qp->s_cur >= qp->s_size)
+			qp->s_cur = 0;
+		break;
+
+	case OP(RDMA_READ_RESPONSE_MIDDLE):
+		/*
+		 * qp->s_state is normally set to the opcode of the
+		 * last packet constructed for new requests and therefore
+		 * is never set to RDMA read response.
+		 * RDMA_READ_RESPONSE_MIDDLE is used by the ACK processing
+		 * thread to indicate a RDMA read needs to be restarted from
+		 * an earlier PSN without interfering with the sending thread.
+		 * See restart_rc().
+		 */
+		len = (delta_psn(qp->s_psn, wqe->psn)) * pmtu;
+		ohdr->u.rc.reth.vaddr =
+			cpu_to_be64(wqe->rdma_wr.remote_addr + len);
+		ohdr->u.rc.reth.rkey =
+			cpu_to_be32(wqe->rdma_wr.rkey);
+		ohdr->u.rc.reth.length = cpu_to_be32(wqe->length - len);
+		qp->s_state = OP(RDMA_READ_REQUEST);
+		hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
+		bth2 = mask_psn(qp->s_psn) | IB_BTH_REQ_ACK;
+		qp->s_psn = wqe->lpsn + 1;
+		ss = NULL;
+		len = 0;
+		qp->s_cur++;
+		if (qp->s_cur == qp->s_size)
+			qp->s_cur = 0;
+		break;
+	}
+	qp->s_sending_hpsn = bth2;
+	delta = delta_psn(bth2, wqe->psn);
+	if (delta && delta % HFI1_PSN_CREDIT == 0)
+		bth2 |= IB_BTH_REQ_ACK;
+	if (qp->s_flags & RVT_S_SEND_ONE) {
+		qp->s_flags &= ~RVT_S_SEND_ONE;
+		qp->s_flags |= RVT_S_WAIT_ACK;
+		bth2 |= IB_BTH_REQ_ACK;
+	}
+	qp->s_len -= len;
+	qp->s_hdrwords = hwords;
+	ps->s_txreq->sde = priv->s_sde;
+	qp->s_cur_sge = ss;
+	qp->s_cur_size = len;
+	hfi1_make_ruc_header(
+		qp,
+		ohdr,
+		bth0 | (qp->s_state << 24),
+		bth2,
+		middle,
+		ps);
+	/* pbc */
+	ps->s_txreq->hdr_dwords = qp->s_hdrwords + 2;
+	return 1;
+
+done_free_tx:
+	hfi1_put_txreq(ps->s_txreq);
+	ps->s_txreq = NULL;
+	return 1;
+
+bail:
+	hfi1_put_txreq(ps->s_txreq);
+
+bail_no_tx:
+	ps->s_txreq = NULL;
+	qp->s_flags &= ~RVT_S_BUSY;
+	qp->s_hdrwords = 0;
+	return 0;
+}
+
+/**
+ * hfi1_send_rc_ack - Construct an ACK packet and send it
+ * @qp: a pointer to the QP
+ *
+ * This is called from hfi1_rc_rcv() and handle_receive_interrupt().
+ * Note that RDMA reads and atomics are handled in the
+ * send side QP state and tasklet.
+ */
+void hfi1_send_rc_ack(struct hfi1_ctxtdata *rcd, struct rvt_qp *qp,
+		      int is_fecn)
+{
+	struct hfi1_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
+	struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
+	u64 pbc, pbc_flags = 0;
+	u16 lrh0;
+	u16 sc5;
+	u32 bth0;
+	u32 hwords;
+	u32 vl, plen;
+	struct send_context *sc;
+	struct pio_buf *pbuf;
+	struct hfi1_ib_header hdr;
+	struct hfi1_other_headers *ohdr;
+	unsigned long flags;
+
+	/* Don't send ACK or NAK if a RDMA read or atomic is pending. */
+	if (qp->s_flags & RVT_S_RESP_PENDING)
+		goto queue_ack;
+
+	/* Ensure s_rdma_ack_cnt changes are committed */
+	smp_read_barrier_depends();
+	if (qp->s_rdma_ack_cnt)
+		goto queue_ack;
+
+	/* Construct the header */
+	/* header size in 32-bit words LRH+BTH+AETH = (8+12+4)/4 */
+	hwords = 6;
+	if (unlikely(qp->remote_ah_attr.ah_flags & IB_AH_GRH)) {
+		hwords += hfi1_make_grh(ibp, &hdr.u.l.grh,
+				       &qp->remote_ah_attr.grh, hwords, 0);
+		ohdr = &hdr.u.l.oth;
+		lrh0 = HFI1_LRH_GRH;
+	} else {
+		ohdr = &hdr.u.oth;
+		lrh0 = HFI1_LRH_BTH;
+	}
+	/* read pkey_index w/o lock (its atomic) */
+	bth0 = hfi1_get_pkey(ibp, qp->s_pkey_index) | (OP(ACKNOWLEDGE) << 24);
+	if (qp->s_mig_state == IB_MIG_MIGRATED)
+		bth0 |= IB_BTH_MIG_REQ;
+	if (qp->r_nak_state)
+		ohdr->u.aeth = cpu_to_be32((qp->r_msn & HFI1_MSN_MASK) |
+					    (qp->r_nak_state <<
+					     HFI1_AETH_CREDIT_SHIFT));
+	else
+		ohdr->u.aeth = hfi1_compute_aeth(qp);
+	sc5 = ibp->sl_to_sc[qp->remote_ah_attr.sl];
+	/* set PBC_DC_INFO bit (aka SC[4]) in pbc_flags */
+	pbc_flags |= ((!!(sc5 & 0x10)) << PBC_DC_INFO_SHIFT);
+	lrh0 |= (sc5 & 0xf) << 12 | (qp->remote_ah_attr.sl & 0xf) << 4;
+	hdr.lrh[0] = cpu_to_be16(lrh0);
+	hdr.lrh[1] = cpu_to_be16(qp->remote_ah_attr.dlid);
+	hdr.lrh[2] = cpu_to_be16(hwords + SIZE_OF_CRC);
+	hdr.lrh[3] = cpu_to_be16(ppd->lid | qp->remote_ah_attr.src_path_bits);
+	ohdr->bth[0] = cpu_to_be32(bth0);
+	ohdr->bth[1] = cpu_to_be32(qp->remote_qpn);
+	ohdr->bth[1] |= cpu_to_be32((!!is_fecn) << HFI1_BECN_SHIFT);
+	ohdr->bth[2] = cpu_to_be32(mask_psn(qp->r_ack_psn));
+
+	/* Don't try to send ACKs if the link isn't ACTIVE */
+	if (driver_lstate(ppd) != IB_PORT_ACTIVE)
+		return;
+
+	sc = rcd->sc;
+	plen = 2 /* PBC */ + hwords;
+	vl = sc_to_vlt(ppd->dd, sc5);
+	pbc = create_pbc(ppd, pbc_flags, qp->srate_mbps, vl, plen);
+
+	pbuf = sc_buffer_alloc(sc, plen, NULL, NULL);
+	if (!pbuf) {
+		/*
+		 * We have no room to send at the moment.  Pass
+		 * responsibility for sending the ACK to the send tasklet
+		 * so that when enough buffer space becomes available,
+		 * the ACK is sent ahead of other outgoing packets.
+		 */
+		goto queue_ack;
+	}
+
+	trace_ack_output_ibhdr(dd_from_ibdev(qp->ibqp.device), &hdr);
+
+	/* write the pbc and data */
+	ppd->dd->pio_inline_send(ppd->dd, pbuf, pbc, &hdr, hwords);
+
+	return;
+
+queue_ack:
+	this_cpu_inc(*ibp->rvp.rc_qacks);
+	spin_lock_irqsave(&qp->s_lock, flags);
+	qp->s_flags |= RVT_S_ACK_PENDING | RVT_S_RESP_PENDING;
+	qp->s_nak_state = qp->r_nak_state;
+	qp->s_ack_psn = qp->r_ack_psn;
+	if (is_fecn)
+		qp->s_flags |= RVT_S_ECN;
+
+	/* Schedule the send tasklet. */
+	hfi1_schedule_send(qp);
+	spin_unlock_irqrestore(&qp->s_lock, flags);
+}
+
+/**
+ * reset_psn - reset the QP state to send starting from PSN
+ * @qp: the QP
+ * @psn: the packet sequence number to restart at
+ *
+ * This is called from hfi1_rc_rcv() to process an incoming RC ACK
+ * for the given QP.
+ * Called at interrupt level with the QP s_lock held.
+ */
+static void reset_psn(struct rvt_qp *qp, u32 psn)
+{
+	u32 n = qp->s_acked;
+	struct rvt_swqe *wqe = rvt_get_swqe_ptr(qp, n);
+	u32 opcode;
+
+	qp->s_cur = n;
+
+	/*
+	 * If we are starting the request from the beginning,
+	 * let the normal send code handle initialization.
+	 */
+	if (cmp_psn(psn, wqe->psn) <= 0) {
+		qp->s_state = OP(SEND_LAST);
+		goto done;
+	}
+
+	/* Find the work request opcode corresponding to the given PSN. */
+	opcode = wqe->wr.opcode;
+	for (;;) {
+		int diff;
+
+		if (++n == qp->s_size)
+			n = 0;
+		if (n == qp->s_tail)
+			break;
+		wqe = rvt_get_swqe_ptr(qp, n);
+		diff = cmp_psn(psn, wqe->psn);
+		if (diff < 0)
+			break;
+		qp->s_cur = n;
+		/*
+		 * If we are starting the request from the beginning,
+		 * let the normal send code handle initialization.
+		 */
+		if (diff == 0) {
+			qp->s_state = OP(SEND_LAST);
+			goto done;
+		}
+		opcode = wqe->wr.opcode;
+	}
+
+	/*
+	 * Set the state to restart in the middle of a request.
+	 * Don't change the s_sge, s_cur_sge, or s_cur_size.
+	 * See hfi1_make_rc_req().
+	 */
+	switch (opcode) {
+	case IB_WR_SEND:
+	case IB_WR_SEND_WITH_IMM:
+		qp->s_state = OP(RDMA_READ_RESPONSE_FIRST);
+		break;
+
+	case IB_WR_RDMA_WRITE:
+	case IB_WR_RDMA_WRITE_WITH_IMM:
+		qp->s_state = OP(RDMA_READ_RESPONSE_LAST);
+		break;
+
+	case IB_WR_RDMA_READ:
+		qp->s_state = OP(RDMA_READ_RESPONSE_MIDDLE);
+		break;
+
+	default:
+		/*
+		 * This case shouldn't happen since its only
+		 * one PSN per req.
+		 */
+		qp->s_state = OP(SEND_LAST);
+	}
+done:
+	qp->s_psn = psn;
+	/*
+	 * Set RVT_S_WAIT_PSN as rc_complete() may start the timer
+	 * asynchronously before the send tasklet can get scheduled.
+	 * Doing it in hfi1_make_rc_req() is too late.
+	 */
+	if ((cmp_psn(qp->s_psn, qp->s_sending_hpsn) <= 0) &&
+	    (cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0))
+		qp->s_flags |= RVT_S_WAIT_PSN;
+	qp->s_flags &= ~RVT_S_AHG_VALID;
+}
+
+/*
+ * Back up requester to resend the last un-ACKed request.
+ * The QP r_lock and s_lock should be held and interrupts disabled.
+ */
+static void restart_rc(struct rvt_qp *qp, u32 psn, int wait)
+{
+	struct rvt_swqe *wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
+	struct hfi1_ibport *ibp;
+
+	if (qp->s_retry == 0) {
+		if (qp->s_mig_state == IB_MIG_ARMED) {
+			hfi1_migrate_qp(qp);
+			qp->s_retry = qp->s_retry_cnt;
+		} else if (qp->s_last == qp->s_acked) {
+			hfi1_send_complete(qp, wqe, IB_WC_RETRY_EXC_ERR);
+			rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
+			return;
+		} else { /* need to handle delayed completion */
+			return;
+		}
+	} else {
+		qp->s_retry--;
+	}
+
+	ibp = to_iport(qp->ibqp.device, qp->port_num);
+	if (wqe->wr.opcode == IB_WR_RDMA_READ)
+		ibp->rvp.n_rc_resends++;
+	else
+		ibp->rvp.n_rc_resends += delta_psn(qp->s_psn, psn);
+
+	qp->s_flags &= ~(RVT_S_WAIT_FENCE | RVT_S_WAIT_RDMAR |
+			 RVT_S_WAIT_SSN_CREDIT | RVT_S_WAIT_PSN |
+			 RVT_S_WAIT_ACK);
+	if (wait)
+		qp->s_flags |= RVT_S_SEND_ONE;
+	reset_psn(qp, psn);
+}
+
+/*
+ * This is called from s_timer for missing responses.
+ */
+void hfi1_rc_timeout(unsigned long arg)
+{
+	struct rvt_qp *qp = (struct rvt_qp *)arg;
+	struct hfi1_ibport *ibp;
+	unsigned long flags;
+
+	spin_lock_irqsave(&qp->r_lock, flags);
+	spin_lock(&qp->s_lock);
+	if (qp->s_flags & RVT_S_TIMER) {
+		ibp = to_iport(qp->ibqp.device, qp->port_num);
+		ibp->rvp.n_rc_timeouts++;
+		qp->s_flags &= ~RVT_S_TIMER;
+		del_timer(&qp->s_timer);
+		trace_hfi1_rc_timeout(qp, qp->s_last_psn + 1);
+		restart_rc(qp, qp->s_last_psn + 1, 1);
+		hfi1_schedule_send(qp);
+	}
+	spin_unlock(&qp->s_lock);
+	spin_unlock_irqrestore(&qp->r_lock, flags);
+}
+
+/*
+ * This is called from s_timer for RNR timeouts.
+ */
+void hfi1_rc_rnr_retry(unsigned long arg)
+{
+	struct rvt_qp *qp = (struct rvt_qp *)arg;
+	unsigned long flags;
+
+	spin_lock_irqsave(&qp->s_lock, flags);
+	hfi1_stop_rnr_timer(qp);
+	hfi1_schedule_send(qp);
+	spin_unlock_irqrestore(&qp->s_lock, flags);
+}
+
+/*
+ * Set qp->s_sending_psn to the next PSN after the given one.
+ * This would be psn+1 except when RDMA reads are present.
+ */
+static void reset_sending_psn(struct rvt_qp *qp, u32 psn)
+{
+	struct rvt_swqe *wqe;
+	u32 n = qp->s_last;
+
+	/* Find the work request corresponding to the given PSN. */
+	for (;;) {
+		wqe = rvt_get_swqe_ptr(qp, n);
+		if (cmp_psn(psn, wqe->lpsn) <= 0) {
+			if (wqe->wr.opcode == IB_WR_RDMA_READ)
+				qp->s_sending_psn = wqe->lpsn + 1;
+			else
+				qp->s_sending_psn = psn + 1;
+			break;
+		}
+		if (++n == qp->s_size)
+			n = 0;
+		if (n == qp->s_tail)
+			break;
+	}
+}
+
+/*
+ * This should be called with the QP s_lock held and interrupts disabled.
+ */
+void hfi1_rc_send_complete(struct rvt_qp *qp, struct hfi1_ib_header *hdr)
+{
+	struct hfi1_other_headers *ohdr;
+	struct rvt_swqe *wqe;
+	struct ib_wc wc;
+	unsigned i;
+	u32 opcode;
+	u32 psn;
+
+	if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_OR_FLUSH_SEND))
+		return;
+
+	/* Find out where the BTH is */
+	if ((be16_to_cpu(hdr->lrh[0]) & 3) == HFI1_LRH_BTH)
+		ohdr = &hdr->u.oth;
+	else
+		ohdr = &hdr->u.l.oth;
+
+	opcode = be32_to_cpu(ohdr->bth[0]) >> 24;
+	if (opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
+	    opcode <= OP(ATOMIC_ACKNOWLEDGE)) {
+		WARN_ON(!qp->s_rdma_ack_cnt);
+		qp->s_rdma_ack_cnt--;
+		return;
+	}
+
+	psn = be32_to_cpu(ohdr->bth[2]);
+	reset_sending_psn(qp, psn);
+
+	/*
+	 * Start timer after a packet requesting an ACK has been sent and
+	 * there are still requests that haven't been acked.
+	 */
+	if ((psn & IB_BTH_REQ_ACK) && qp->s_acked != qp->s_tail &&
+	    !(qp->s_flags &
+		(RVT_S_TIMER | RVT_S_WAIT_RNR | RVT_S_WAIT_PSN)) &&
+		(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK))
+		hfi1_add_retry_timer(qp);
+
+	while (qp->s_last != qp->s_acked) {
+		u32 s_last;
+
+		wqe = rvt_get_swqe_ptr(qp, qp->s_last);
+		if (cmp_psn(wqe->lpsn, qp->s_sending_psn) >= 0 &&
+		    cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0)
+			break;
+		s_last = qp->s_last;
+		if (++s_last >= qp->s_size)
+			s_last = 0;
+		qp->s_last = s_last;
+		/* see post_send() */
+		barrier();
+		for (i = 0; i < wqe->wr.num_sge; i++) {
+			struct rvt_sge *sge = &wqe->sg_list[i];
+
+			rvt_put_mr(sge->mr);
+		}
+		/* Post a send completion queue entry if requested. */
+		if (!(qp->s_flags & RVT_S_SIGNAL_REQ_WR) ||
+		    (wqe->wr.send_flags & IB_SEND_SIGNALED)) {
+			memset(&wc, 0, sizeof(wc));
+			wc.wr_id = wqe->wr.wr_id;
+			wc.status = IB_WC_SUCCESS;
+			wc.opcode = ib_hfi1_wc_opcode[wqe->wr.opcode];
+			wc.byte_len = wqe->length;
+			wc.qp = &qp->ibqp;
+			rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.send_cq), &wc, 0);
+		}
+	}
+	/*
+	 * If we were waiting for sends to complete before re-sending,
+	 * and they are now complete, restart sending.
+	 */
+	trace_hfi1_rc_sendcomplete(qp, psn);
+	if (qp->s_flags & RVT_S_WAIT_PSN &&
+	    cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) > 0) {
+		qp->s_flags &= ~RVT_S_WAIT_PSN;
+		qp->s_sending_psn = qp->s_psn;
+		qp->s_sending_hpsn = qp->s_psn - 1;
+		hfi1_schedule_send(qp);
+	}
+}
+
+static inline void update_last_psn(struct rvt_qp *qp, u32 psn)
+{
+	qp->s_last_psn = psn;
+}
+
+/*
+ * Generate a SWQE completion.
+ * 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 ib_wc wc;
+	unsigned i;
+
+	/*
+	 * Don't decrement refcount and don't generate a
+	 * completion if the SWQE is being resent until the send
+	 * is finished.
+	 */
+	if (cmp_psn(wqe->lpsn, qp->s_sending_psn) < 0 ||
+	    cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) > 0) {
+		u32 s_last;
+
+		for (i = 0; i < wqe->wr.num_sge; i++) {
+			struct rvt_sge *sge = &wqe->sg_list[i];
+
+			rvt_put_mr(sge->mr);
+		}
+		s_last = qp->s_last;
+		if (++s_last >= qp->s_size)
+			s_last = 0;
+		qp->s_last = s_last;
+		/* see post_send() */
+		barrier();
+		/* Post a send completion queue entry if requested. */
+		if (!(qp->s_flags & RVT_S_SIGNAL_REQ_WR) ||
+		    (wqe->wr.send_flags & IB_SEND_SIGNALED)) {
+			memset(&wc, 0, sizeof(wc));
+			wc.wr_id = wqe->wr.wr_id;
+			wc.status = IB_WC_SUCCESS;
+			wc.opcode = ib_hfi1_wc_opcode[wqe->wr.opcode];
+			wc.byte_len = wqe->length;
+			wc.qp = &qp->ibqp;
+			rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.send_cq), &wc, 0);
+		}
+	} else {
+		struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
+
+		this_cpu_inc(*ibp->rvp.rc_delayed_comp);
+		/*
+		 * If send progress not running attempt to progress
+		 * SDMA queue.
+		 */
+		if (ppd->dd->flags & HFI1_HAS_SEND_DMA) {
+			struct sdma_engine *engine;
+			u8 sc5;
+
+			/* For now use sc to find engine */
+			sc5 = ibp->sl_to_sc[qp->remote_ah_attr.sl];
+			engine = qp_to_sdma_engine(qp, sc5);
+			sdma_engine_progress_schedule(engine);
+		}
+	}
+
+	qp->s_retry = qp->s_retry_cnt;
+	update_last_psn(qp, wqe->lpsn);
+
+	/*
+	 * If we are completing a request which is in the process of
+	 * being resent, we can stop re-sending it since we know the
+	 * responder has already seen it.
+	 */
+	if (qp->s_acked == qp->s_cur) {
+		if (++qp->s_cur >= qp->s_size)
+			qp->s_cur = 0;
+		qp->s_acked = qp->s_cur;
+		wqe = rvt_get_swqe_ptr(qp, qp->s_cur);
+		if (qp->s_acked != qp->s_tail) {
+			qp->s_state = OP(SEND_LAST);
+			qp->s_psn = wqe->psn;
+		}
+	} else {
+		if (++qp->s_acked >= qp->s_size)
+			qp->s_acked = 0;
+		if (qp->state == IB_QPS_SQD && qp->s_acked == qp->s_cur)
+			qp->s_draining = 0;
+		wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
+	}
+	return wqe;
+}
+
+/**
+ * do_rc_ack - process an incoming RC ACK
+ * @qp: the QP the ACK came in on
+ * @psn: the packet sequence number of the ACK
+ * @opcode: the opcode of the request that resulted in the ACK
+ *
+ * This is called from rc_rcv_resp() to process an incoming RC ACK
+ * for the given QP.
+ * 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)
+{
+	struct hfi1_ibport *ibp;
+	enum ib_wc_status status;
+	struct rvt_swqe *wqe;
+	int ret = 0;
+	u32 ack_psn;
+	int diff;
+	unsigned long to;
+
+	/*
+	 * Note that NAKs implicitly ACK outstanding SEND and RDMA write
+	 * requests and implicitly NAK RDMA read and atomic requests issued
+	 * before the NAK'ed request.  The MSN won't include the NAK'ed
+	 * request but will include an ACK'ed request(s).
+	 */
+	ack_psn = psn;
+	if (aeth >> 29)
+		ack_psn--;
+	wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
+	ibp = to_iport(qp->ibqp.device, qp->port_num);
+
+	/*
+	 * The MSN might be for a later WQE than the PSN indicates so
+	 * only complete WQEs that the PSN finishes.
+	 */
+	while ((diff = delta_psn(ack_psn, wqe->lpsn)) >= 0) {
+		/*
+		 * RDMA_READ_RESPONSE_ONLY is a special case since
+		 * we want to generate completion events for everything
+		 * before the RDMA read, copy the data, then generate
+		 * the completion for the read.
+		 */
+		if (wqe->wr.opcode == IB_WR_RDMA_READ &&
+		    opcode == OP(RDMA_READ_RESPONSE_ONLY) &&
+		    diff == 0) {
+			ret = 1;
+			goto bail_stop;
+		}
+		/*
+		 * If this request is a RDMA read or atomic, and the ACK is
+		 * for a later operation, this ACK NAKs the RDMA read or
+		 * atomic.  In other words, only a RDMA_READ_LAST or ONLY
+		 * can ACK a RDMA read and likewise for atomic ops.  Note
+		 * that the NAK case can only happen if relaxed ordering is
+		 * used and requests are sent after an RDMA read or atomic
+		 * is sent but before the response is received.
+		 */
+		if ((wqe->wr.opcode == IB_WR_RDMA_READ &&
+		     (opcode != OP(RDMA_READ_RESPONSE_LAST) || diff != 0)) ||
+		    ((wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
+		      wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) &&
+		     (opcode != OP(ATOMIC_ACKNOWLEDGE) || diff != 0))) {
+			/* Retry this request. */
+			if (!(qp->r_flags & RVT_R_RDMAR_SEQ)) {
+				qp->r_flags |= RVT_R_RDMAR_SEQ;
+				restart_rc(qp, qp->s_last_psn + 1, 0);
+				if (list_empty(&qp->rspwait)) {
+					qp->r_flags |= RVT_R_RSP_SEND;
+					atomic_inc(&qp->refcount);
+					list_add_tail(&qp->rspwait,
+						      &rcd->qp_wait_list);
+				}
+			}
+			/*
+			 * No need to process the ACK/NAK since we are
+			 * restarting an earlier request.
+			 */
+			goto bail_stop;
+		}
+		if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
+		    wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) {
+			u64 *vaddr = wqe->sg_list[0].vaddr;
+			*vaddr = val;
+		}
+		if (qp->s_num_rd_atomic &&
+		    (wqe->wr.opcode == IB_WR_RDMA_READ ||
+		     wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
+		     wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)) {
+			qp->s_num_rd_atomic--;
+			/* Restart sending task if fence is complete */
+			if ((qp->s_flags & RVT_S_WAIT_FENCE) &&
+			    !qp->s_num_rd_atomic) {
+				qp->s_flags &= ~(RVT_S_WAIT_FENCE |
+						 RVT_S_WAIT_ACK);
+				hfi1_schedule_send(qp);
+			} else if (qp->s_flags & RVT_S_WAIT_RDMAR) {
+				qp->s_flags &= ~(RVT_S_WAIT_RDMAR |
+						 RVT_S_WAIT_ACK);
+				hfi1_schedule_send(qp);
+			}
+		}
+		wqe = do_rc_completion(qp, wqe, ibp);
+		if (qp->s_acked == qp->s_tail)
+			break;
+	}
+
+	switch (aeth >> 29) {
+	case 0:         /* ACK */
+		this_cpu_inc(*ibp->rvp.rc_acks);
+		if (qp->s_acked != qp->s_tail) {
+			/*
+			 * We are expecting more ACKs so
+			 * mod the retry timer.
+			 */
+			hfi1_mod_retry_timer(qp);
+			/*
+			 * We can stop re-sending the earlier packets and
+			 * continue with the next packet the receiver wants.
+			 */
+			if (cmp_psn(qp->s_psn, psn) <= 0)
+				reset_psn(qp, psn + 1);
+		} else {
+			/* No more acks - kill all timers */
+			hfi1_stop_rc_timers(qp);
+			if (cmp_psn(qp->s_psn, psn) <= 0) {
+				qp->s_state = OP(SEND_LAST);
+				qp->s_psn = psn + 1;
+			}
+		}
+		if (qp->s_flags & RVT_S_WAIT_ACK) {
+			qp->s_flags &= ~RVT_S_WAIT_ACK;
+			hfi1_schedule_send(qp);
+		}
+		hfi1_get_credit(qp, aeth);
+		qp->s_rnr_retry = qp->s_rnr_retry_cnt;
+		qp->s_retry = qp->s_retry_cnt;
+		update_last_psn(qp, psn);
+		return 1;
+
+	case 1:         /* RNR NAK */
+		ibp->rvp.n_rnr_naks++;
+		if (qp->s_acked == qp->s_tail)
+			goto bail_stop;
+		if (qp->s_flags & RVT_S_WAIT_RNR)
+			goto bail_stop;
+		if (qp->s_rnr_retry == 0) {
+			status = IB_WC_RNR_RETRY_EXC_ERR;
+			goto class_b;
+		}
+		if (qp->s_rnr_retry_cnt < 7)
+			qp->s_rnr_retry--;
+
+		/* The last valid PSN is the previous PSN. */
+		update_last_psn(qp, psn - 1);
+
+		ibp->rvp.n_rc_resends += delta_psn(qp->s_psn, psn);
+
+		reset_psn(qp, psn);
+
+		qp->s_flags &= ~(RVT_S_WAIT_SSN_CREDIT | RVT_S_WAIT_ACK);
+		hfi1_stop_rc_timers(qp);
+		to =
+			ib_hfi1_rnr_table[(aeth >> HFI1_AETH_CREDIT_SHIFT) &
+					   HFI1_AETH_CREDIT_MASK];
+		hfi1_add_rnr_timer(qp, to);
+		return 0;
+
+	case 3:         /* NAK */
+		if (qp->s_acked == qp->s_tail)
+			goto bail_stop;
+		/* The last valid PSN is the previous PSN. */
+		update_last_psn(qp, psn - 1);
+		switch ((aeth >> HFI1_AETH_CREDIT_SHIFT) &
+			HFI1_AETH_CREDIT_MASK) {
+		case 0: /* PSN sequence error */
+			ibp->rvp.n_seq_naks++;
+			/*
+			 * Back up to the responder's expected PSN.
+			 * Note that we might get a NAK in the middle of an
+			 * RDMA READ response which terminates the RDMA
+			 * READ.
+			 */
+			restart_rc(qp, psn, 0);
+			hfi1_schedule_send(qp);
+			break;
+
+		case 1: /* Invalid Request */
+			status = IB_WC_REM_INV_REQ_ERR;
+			ibp->rvp.n_other_naks++;
+			goto class_b;
+
+		case 2: /* Remote Access Error */
+			status = IB_WC_REM_ACCESS_ERR;
+			ibp->rvp.n_other_naks++;
+			goto class_b;
+
+		case 3: /* Remote Operation Error */
+			status = IB_WC_REM_OP_ERR;
+			ibp->rvp.n_other_naks++;
+class_b:
+			if (qp->s_last == qp->s_acked) {
+				hfi1_send_complete(qp, wqe, status);
+				rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
+			}
+			break;
+
+		default:
+			/* Ignore other reserved NAK error codes */
+			goto reserved;
+		}
+		qp->s_retry = qp->s_retry_cnt;
+		qp->s_rnr_retry = qp->s_rnr_retry_cnt;
+		goto bail_stop;
+
+	default:                /* 2: reserved */
+reserved:
+		/* Ignore reserved NAK codes. */
+		goto bail_stop;
+	}
+	/* cannot be reached  */
+bail_stop:
+	hfi1_stop_rc_timers(qp);
+	return ret;
+}
+
+/*
+ * We have seen an out of sequence RDMA read middle or last packet.
+ * This ACKs SENDs and RDMA writes up to the first RDMA read or atomic SWQE.
+ */
+static void rdma_seq_err(struct rvt_qp *qp, struct hfi1_ibport *ibp, u32 psn,
+			 struct hfi1_ctxtdata *rcd)
+{
+	struct rvt_swqe *wqe;
+
+	/* Remove QP from retry timer */
+	hfi1_stop_rc_timers(qp);
+
+	wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
+
+	while (cmp_psn(psn, wqe->lpsn) > 0) {
+		if (wqe->wr.opcode == IB_WR_RDMA_READ ||
+		    wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
+		    wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)
+			break;
+		wqe = do_rc_completion(qp, wqe, ibp);
+	}
+
+	ibp->rvp.n_rdma_seq++;
+	qp->r_flags |= RVT_R_RDMAR_SEQ;
+	restart_rc(qp, qp->s_last_psn + 1, 0);
+	if (list_empty(&qp->rspwait)) {
+		qp->r_flags |= RVT_R_RSP_SEND;
+		atomic_inc(&qp->refcount);
+		list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
+	}
+}
+
+/**
+ * rc_rcv_resp - process an incoming RC response packet
+ * @ibp: the port this packet came in on
+ * @ohdr: the other headers for this packet
+ * @data: the packet data
+ * @tlen: the packet length
+ * @qp: the QP for this packet
+ * @opcode: the opcode for this packet
+ * @psn: the packet sequence number for this packet
+ * @hdrsize: the header length
+ * @pmtu: the path MTU
+ *
+ * This is called from hfi1_rc_rcv() to process an incoming RC response
+ * packet for the given QP.
+ * Called at interrupt level.
+ */
+static void rc_rcv_resp(struct hfi1_ibport *ibp,
+			struct hfi1_other_headers *ohdr,
+			void *data, u32 tlen, struct rvt_qp *qp,
+			u32 opcode, u32 psn, u32 hdrsize, u32 pmtu,
+			struct hfi1_ctxtdata *rcd)
+{
+	struct rvt_swqe *wqe;
+	enum ib_wc_status status;
+	unsigned long flags;
+	int diff;
+	u32 pad;
+	u32 aeth;
+	u64 val;
+
+	spin_lock_irqsave(&qp->s_lock, flags);
+
+	trace_hfi1_rc_ack(qp, psn);
+
+	/* Ignore invalid responses. */
+	smp_read_barrier_depends(); /* see post_one_send */
+	if (cmp_psn(psn, ACCESS_ONCE(qp->s_next_psn)) >= 0)
+		goto ack_done;
+
+	/* Ignore duplicate responses. */
+	diff = cmp_psn(psn, qp->s_last_psn);
+	if (unlikely(diff <= 0)) {
+		/* Update credits for "ghost" ACKs */
+		if (diff == 0 && opcode == OP(ACKNOWLEDGE)) {
+			aeth = be32_to_cpu(ohdr->u.aeth);
+			if ((aeth >> 29) == 0)
+				hfi1_get_credit(qp, aeth);
+		}
+		goto ack_done;
+	}
+
+	/*
+	 * Skip everything other than the PSN we expect, if we are waiting
+	 * for a reply to a restarted RDMA read or atomic op.
+	 */
+	if (qp->r_flags & RVT_R_RDMAR_SEQ) {
+		if (cmp_psn(psn, qp->s_last_psn + 1) != 0)
+			goto ack_done;
+		qp->r_flags &= ~RVT_R_RDMAR_SEQ;
+	}
+
+	if (unlikely(qp->s_acked == qp->s_tail))
+		goto ack_done;
+	wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
+	status = IB_WC_SUCCESS;
+
+	switch (opcode) {
+	case OP(ACKNOWLEDGE):
+	case OP(ATOMIC_ACKNOWLEDGE):
+	case OP(RDMA_READ_RESPONSE_FIRST):
+		aeth = be32_to_cpu(ohdr->u.aeth);
+		if (opcode == OP(ATOMIC_ACKNOWLEDGE)) {
+			__be32 *p = ohdr->u.at.atomic_ack_eth;
+
+			val = ((u64)be32_to_cpu(p[0]) << 32) |
+				be32_to_cpu(p[1]);
+		} else {
+			val = 0;
+		}
+		if (!do_rc_ack(qp, aeth, psn, opcode, val, rcd) ||
+		    opcode != OP(RDMA_READ_RESPONSE_FIRST))
+			goto ack_done;
+		wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
+		if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
+			goto ack_op_err;
+		/*
+		 * If this is a response to a resent RDMA read, we
+		 * have to be careful to copy the data to the right
+		 * location.
+		 */
+		qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
+						  wqe, psn, pmtu);
+		goto read_middle;
+
+	case OP(RDMA_READ_RESPONSE_MIDDLE):
+		/* no AETH, no ACK */
+		if (unlikely(cmp_psn(psn, qp->s_last_psn + 1)))
+			goto ack_seq_err;
+		if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
+			goto ack_op_err;
+read_middle:
+		if (unlikely(tlen != (hdrsize + pmtu + 4)))
+			goto ack_len_err;
+		if (unlikely(pmtu >= qp->s_rdma_read_len))
+			goto ack_len_err;
+
+		/*
+		 * We got a response so update the timeout.
+		 * 4.096 usec. * (1 << qp->timeout)
+		 */
+		qp->s_flags |= RVT_S_TIMER;
+		mod_timer(&qp->s_timer, jiffies + qp->timeout_jiffies);
+		if (qp->s_flags & RVT_S_WAIT_ACK) {
+			qp->s_flags &= ~RVT_S_WAIT_ACK;
+			hfi1_schedule_send(qp);
+		}
+
+		if (opcode == OP(RDMA_READ_RESPONSE_MIDDLE))
+			qp->s_retry = qp->s_retry_cnt;
+
+		/*
+		 * Update the RDMA receive state but do the copy w/o
+		 * holding the locks and blocking interrupts.
+		 */
+		qp->s_rdma_read_len -= pmtu;
+		update_last_psn(qp, psn);
+		spin_unlock_irqrestore(&qp->s_lock, flags);
+		hfi1_copy_sge(&qp->s_rdma_read_sge, data, pmtu, 0, 0);
+		goto bail;
+
+	case OP(RDMA_READ_RESPONSE_ONLY):
+		aeth = be32_to_cpu(ohdr->u.aeth);
+		if (!do_rc_ack(qp, aeth, psn, opcode, 0, rcd))
+			goto ack_done;
+		/* Get the number of bytes the message was padded by. */
+		pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
+		/*
+		 * Check that the data size is >= 0 && <= pmtu.
+		 * Remember to account for ICRC (4).
+		 */
+		if (unlikely(tlen < (hdrsize + pad + 4)))
+			goto ack_len_err;
+		/*
+		 * If this is a response to a resent RDMA read, we
+		 * have to be careful to copy the data to the right
+		 * location.
+		 */
+		wqe = rvt_get_swqe_ptr(qp, qp->s_acked);
+		qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge,
+						  wqe, psn, pmtu);
+		goto read_last;
+
+	case OP(RDMA_READ_RESPONSE_LAST):
+		/* ACKs READ req. */
+		if (unlikely(cmp_psn(psn, qp->s_last_psn + 1)))
+			goto ack_seq_err;
+		if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ))
+			goto ack_op_err;
+		/* Get the number of bytes the message was padded by. */
+		pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
+		/*
+		 * Check that the data size is >= 1 && <= pmtu.
+		 * Remember to account for ICRC (4).
+		 */
+		if (unlikely(tlen <= (hdrsize + pad + 4)))
+			goto ack_len_err;
+read_last:
+		tlen -= hdrsize + pad + 4;
+		if (unlikely(tlen != qp->s_rdma_read_len))
+			goto ack_len_err;
+		aeth = be32_to_cpu(ohdr->u.aeth);
+		hfi1_copy_sge(&qp->s_rdma_read_sge, data, tlen, 0, 0);
+		WARN_ON(qp->s_rdma_read_sge.num_sge);
+		(void)do_rc_ack(qp, aeth, psn,
+				 OP(RDMA_READ_RESPONSE_LAST), 0, rcd);
+		goto ack_done;
+	}
+
+ack_op_err:
+	status = IB_WC_LOC_QP_OP_ERR;
+	goto ack_err;
+
+ack_seq_err:
+	rdma_seq_err(qp, ibp, psn, rcd);
+	goto ack_done;
+
+ack_len_err:
+	status = IB_WC_LOC_LEN_ERR;
+ack_err:
+	if (qp->s_last == qp->s_acked) {
+		hfi1_send_complete(qp, wqe, status);
+		rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
+	}
+ack_done:
+	spin_unlock_irqrestore(&qp->s_lock, flags);
+bail:
+	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;
+		atomic_inc(&qp->refcount);
+		list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
+	}
+}
+
+static inline void rc_cancel_ack(struct rvt_qp *qp)
+{
+	struct hfi1_qp_priv *priv = qp->priv;
+
+	priv->r_adefered = 0;
+	if (list_empty(&qp->rspwait))
+		return;
+	list_del_init(&qp->rspwait);
+	qp->r_flags &= ~RVT_R_RSP_NAK;
+	if (atomic_dec_and_test(&qp->refcount))
+		wake_up(&qp->wait);
+}
+
+/**
+ * rc_rcv_error - process an incoming duplicate or error RC packet
+ * @ohdr: the other headers for this packet
+ * @data: the packet data
+ * @qp: the QP for this packet
+ * @opcode: the opcode for this packet
+ * @psn: the packet sequence number for this packet
+ * @diff: the difference between the PSN and the expected PSN
+ *
+ * This is called from hfi1_rc_rcv() to process an unexpected
+ * incoming RC packet for the given QP.
+ * Called at interrupt level.
+ * Return 1 if no more processing is needed; otherwise return 0 to
+ * schedule a response to be sent.
+ */
+static noinline int rc_rcv_error(struct hfi1_other_headers *ohdr, void *data,
+				 struct rvt_qp *qp, u32 opcode, u32 psn,
+				 int diff, struct hfi1_ctxtdata *rcd)
+{
+	struct hfi1_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
+	struct rvt_ack_entry *e;
+	unsigned long flags;
+	u8 i, prev;
+	int old_req;
+
+	trace_hfi1_rc_rcv_error(qp, psn);
+	if (diff > 0) {
+		/*
+		 * Packet sequence error.
+		 * A NAK will ACK earlier sends and RDMA writes.
+		 * Don't queue the NAK if we already sent one.
+		 */
+		if (!qp->r_nak_state) {
+			ibp->rvp.n_rc_seqnak++;
+			qp->r_nak_state = IB_NAK_PSN_ERROR;
+			/* Use the expected PSN. */
+			qp->r_ack_psn = qp->r_psn;
+			/*
+			 * Wait to send the sequence NAK until all packets
+			 * in the receive queue have been processed.
+			 * Otherwise, we end up propagating congestion.
+			 */
+			rc_defered_ack(rcd, qp);
+		}
+		goto done;
+	}
+
+	/*
+	 * Handle a duplicate request.  Don't re-execute SEND, RDMA
+	 * write or atomic op.  Don't NAK errors, just silently drop
+	 * the duplicate request.  Note that r_sge, r_len, and
+	 * r_rcv_len may be in use so don't modify them.
+	 *
+	 * We are supposed to ACK the earliest duplicate PSN but we
+	 * can coalesce an outstanding duplicate ACK.  We have to
+	 * send the earliest so that RDMA reads can be restarted at
+	 * the requester's expected PSN.
+	 *
+	 * First, find where this duplicate PSN falls within the
+	 * ACKs previously sent.
+	 * old_req is true if there is an older response that is scheduled
+	 * to be sent before sending this one.
+	 */
+	e = NULL;
+	old_req = 1;
+	ibp->rvp.n_rc_dupreq++;
+
+	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;
+		}
+	}
+	switch (opcode) {
+	case OP(RDMA_READ_REQUEST): {
+		struct ib_reth *reth;
+		u32 offset;
+		u32 len;
+
+		/*
+		 * If we didn't find the RDMA read request in the ack queue,
+		 * we can ignore this request.
+		 */
+		if (!e || e->opcode != OP(RDMA_READ_REQUEST))
+			goto unlock_done;
+		/* RETH comes after BTH */
+		reth = &ohdr->u.rc.reth;
+		/*
+		 * Address range must be a subset of the original
+		 * request and start on pmtu boundaries.
+		 * We reuse the old ack_queue slot since the requester
+		 * should not back up and request an earlier PSN for the
+		 * same request.
+		 */
+		offset = delta_psn(psn, e->psn) * qp->pmtu;
+		len = be32_to_cpu(reth->length);
+		if (unlikely(offset + len != e->rdma_sge.sge_length))
+			goto unlock_done;
+		if (e->rdma_sge.mr) {
+			rvt_put_mr(e->rdma_sge.mr);
+			e->rdma_sge.mr = NULL;
+		}
+		if (len != 0) {
+			u32 rkey = be32_to_cpu(reth->rkey);
+			u64 vaddr = be64_to_cpu(reth->vaddr);
+			int ok;
+
+			ok = rvt_rkey_ok(qp, &e->rdma_sge, len, vaddr, rkey,
+					 IB_ACCESS_REMOTE_READ);
+			if (unlikely(!ok))
+				goto unlock_done;
+		} else {
+			e->rdma_sge.vaddr = NULL;
+			e->rdma_sge.length = 0;
+			e->rdma_sge.sge_length = 0;
+		}
+		e->psn = psn;
+		if (old_req)
+			goto unlock_done;
+		qp->s_tail_ack_queue = prev;
+		break;
+	}
+
+	case OP(COMPARE_SWAP):
+	case OP(FETCH_ADD): {
+		/*
+		 * If we didn't find the atomic request in the ack queue
+		 * or the send tasklet is already backed up to send an
+		 * earlier entry, we can ignore this request.
+		 */
+		if (!e || e->opcode != (u8)opcode || old_req)
+			goto unlock_done;
+		qp->s_tail_ack_queue = prev;
+		break;
+	}
+
+	default:
+		/*
+		 * Ignore this operation if it doesn't request an ACK
+		 * or an earlier RDMA read or atomic is going to be resent.
+		 */
+		if (!(psn & IB_BTH_REQ_ACK) || old_req)
+			goto unlock_done;
+		/*
+		 * Resend the most recent ACK if this request is
+		 * after all the previous RDMA reads and atomics.
+		 */
+		if (i == 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;
+			goto send_ack;
+		}
+
+		/*
+		 * Resend the RDMA read or atomic op which
+		 * ACKs this duplicate request.
+		 */
+		qp->s_tail_ack_queue = i;
+		break;
+	}
+	qp->s_ack_state = OP(ACKNOWLEDGE);
+	qp->s_flags |= RVT_S_RESP_PENDING;
+	qp->r_nak_state = 0;
+	hfi1_schedule_send(qp);
+
+unlock_done:
+	spin_unlock_irqrestore(&qp->s_lock, flags);
+done:
+	return 1;
+
+send_ack:
+	return 0;
+}
+
+void hfi1_rc_error(struct rvt_qp *qp, enum ib_wc_status err)
+{
+	unsigned long flags;
+	int lastwqe;
+
+	spin_lock_irqsave(&qp->s_lock, flags);
+	lastwqe = rvt_error_qp(qp, err);
+	spin_unlock_irqrestore(&qp->s_lock, flags);
+
+	if (lastwqe) {
+		struct ib_event ev;
+
+		ev.device = qp->ibqp.device;
+		ev.element.qp = &qp->ibqp;
+		ev.event = IB_EVENT_QP_LAST_WQE_REACHED;
+		qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
+	}
+}
+
+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)
+{
+	struct opa_hfi1_cong_log_event_internal *cc_event;
+	unsigned long flags;
+
+	if (sl >= OPA_MAX_SLS)
+		return;
+
+	spin_lock_irqsave(&ppd->cc_log_lock, flags);
+
+	ppd->threshold_cong_event_map[sl / 8] |= 1 << (sl % 8);
+	ppd->threshold_event_counter++;
+
+	cc_event = &ppd->cc_events[ppd->cc_log_idx++];
+	if (ppd->cc_log_idx == OPA_CONG_LOG_ELEMS)
+		ppd->cc_log_idx = 0;
+	cc_event->lqpn = lqpn & RVT_QPN_MASK;
+	cc_event->rqpn = rqpn & RVT_QPN_MASK;
+	cc_event->sl = sl;
+	cc_event->svc_type = svc_type;
+	cc_event->rlid = rlid;
+	/* keep timestamp in units of 1.024 usec */
+	cc_event->timestamp = ktime_to_ns(ktime_get()) / 1024;
+
+	spin_unlock_irqrestore(&ppd->cc_log_lock, flags);
+}
+
+void process_becn(struct hfi1_pportdata *ppd, u8 sl, u16 rlid, u32 lqpn,
+		  u32 rqpn, u8 svc_type)
+{
+	struct cca_timer *cca_timer;
+	u16 ccti, ccti_incr, ccti_timer, ccti_limit;
+	u8 trigger_threshold;
+	struct cc_state *cc_state;
+	unsigned long flags;
+
+	if (sl >= OPA_MAX_SLS)
+		return;
+
+	cc_state = get_cc_state(ppd);
+
+	if (!cc_state)
+		return;
+
+	/*
+	 * 1) increase CCTI (for this SL)
+	 * 2) select IPG (i.e., call set_link_ipg())
+	 * 3) start timer
+	 */
+	ccti_limit = cc_state->cct.ccti_limit;
+	ccti_incr = cc_state->cong_setting.entries[sl].ccti_increase;
+	ccti_timer = cc_state->cong_setting.entries[sl].ccti_timer;
+	trigger_threshold =
+		cc_state->cong_setting.entries[sl].trigger_threshold;
+
+	spin_lock_irqsave(&ppd->cca_timer_lock, flags);
+
+	cca_timer = &ppd->cca_timer[sl];
+	if (cca_timer->ccti < ccti_limit) {
+		if (cca_timer->ccti + ccti_incr <= ccti_limit)
+			cca_timer->ccti += ccti_incr;
+		else
+			cca_timer->ccti = ccti_limit;
+		set_link_ipg(ppd);
+	}
+
+	ccti = cca_timer->ccti;
+
+	if (!hrtimer_active(&cca_timer->hrtimer)) {
+		/* ccti_timer is in units of 1.024 usec */
+		unsigned long nsec = 1024 * ccti_timer;
+
+		hrtimer_start(&cca_timer->hrtimer, ns_to_ktime(nsec),
+			      HRTIMER_MODE_REL);
+	}
+
+	spin_unlock_irqrestore(&ppd->cca_timer_lock, flags);
+
+	if ((trigger_threshold != 0) && (ccti >= trigger_threshold))
+		log_cca_event(ppd, sl, rlid, lqpn, rqpn, svc_type);
+}
+
+/**
+ * hfi1_rc_rcv - process an incoming RC packet
+ * @rcd: the context pointer
+ * @hdr: the header of this packet
+ * @rcv_flags: flags relevant to rcv processing
+ * @data: the packet data
+ * @tlen: the packet length
+ * @qp: the QP for this packet
+ *
+ * This is called from qp_rcv() to process an incoming RC packet
+ * for the given QP.
+ * May be called at interrupt level.
+ */
+void hfi1_rc_rcv(struct hfi1_packet *packet)
+{
+	struct hfi1_ctxtdata *rcd = packet->rcd;
+	struct hfi1_ib_header *hdr = packet->hdr;
+	u32 rcv_flags = packet->rcv_flags;
+	void *data = packet->ebuf;
+	u32 tlen = packet->tlen;
+	struct rvt_qp *qp = packet->qp;
+	struct hfi1_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
+	struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
+	struct hfi1_other_headers *ohdr = packet->ohdr;
+	u32 bth0, opcode;
+	u32 hdrsize = packet->hlen;
+	u32 psn;
+	u32 pad;
+	struct ib_wc wc;
+	u32 pmtu = qp->pmtu;
+	int diff;
+	struct ib_reth *reth;
+	unsigned long flags;
+	u32 bth1;
+	int ret, is_fecn = 0;
+	int copy_last = 0;
+
+	bth0 = be32_to_cpu(ohdr->bth[0]);
+	if (hfi1_ruc_check_hdr(ibp, hdr, rcv_flags & HFI1_HAS_GRH, qp, bth0))
+		return;
+
+	bth1 = be32_to_cpu(ohdr->bth[1]);
+	if (unlikely(bth1 & (HFI1_BECN_SMASK | HFI1_FECN_SMASK))) {
+		if (bth1 & HFI1_BECN_SMASK) {
+			u16 rlid = qp->remote_ah_attr.dlid;
+			u32 lqpn, rqpn;
+
+			lqpn = qp->ibqp.qp_num;
+			rqpn = qp->remote_qpn;
+			process_becn(
+				ppd,
+				qp->remote_ah_attr.sl,
+				rlid, lqpn, rqpn,
+				IB_CC_SVCTYPE_RC);
+		}
+		is_fecn = bth1 & HFI1_FECN_SMASK;
+	}
+
+	psn = be32_to_cpu(ohdr->bth[2]);
+	opcode = (bth0 >> 24) & 0xff;
+
+	/*
+	 * Process responses (ACKs) before anything else.  Note that the
+	 * packet sequence number will be for something in the send work
+	 * queue rather than the expected receive packet sequence number.
+	 * In other words, this QP is the requester.
+	 */
+	if (opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
+	    opcode <= OP(ATOMIC_ACKNOWLEDGE)) {
+		rc_rcv_resp(ibp, ohdr, data, tlen, qp, opcode, psn,
+			    hdrsize, pmtu, rcd);
+		if (is_fecn)
+			goto send_ack;
+		return;
+	}
+
+	/* Compute 24 bits worth of difference. */
+	diff = delta_psn(psn, qp->r_psn);
+	if (unlikely(diff)) {
+		if (rc_rcv_error(ohdr, data, qp, opcode, psn, diff, rcd))
+			return;
+		goto send_ack;
+	}
+
+	/* 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 nack_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 nack_inv;
+
+	default:
+		if (opcode == OP(SEND_MIDDLE) ||
+		    opcode == OP(SEND_LAST) ||
+		    opcode == OP(SEND_LAST_WITH_IMMEDIATE) ||
+		    opcode == OP(RDMA_WRITE_MIDDLE) ||
+		    opcode == OP(RDMA_WRITE_LAST) ||
+		    opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE))
+			goto nack_inv;
+		/*
+		 * Note that it is up to the requester to not send a new
+		 * RDMA read or atomic operation before receiving an ACK
+		 * for the previous operation.
+		 */
+		break;
+	}
+
+	if (qp->state == IB_QPS_RTR && !(qp->r_flags & RVT_R_COMM_EST))
+		qp_comm_est(qp);
+
+	/* OK, process the packet. */
+	switch (opcode) {
+	case OP(SEND_FIRST):
+		ret = hfi1_rvt_get_rwqe(qp, 0);
+		if (ret < 0)
+			goto nack_op_err;
+		if (!ret)
+			goto rnr_nak;
+		qp->r_rcv_len = 0;
+		/* FALLTHROUGH */
+	case OP(SEND_MIDDLE):
+	case OP(RDMA_WRITE_MIDDLE):
+send_middle:
+		/* Check for invalid length PMTU or posted rwqe len. */
+		if (unlikely(tlen != (hdrsize + pmtu + 4)))
+			goto nack_inv;
+		qp->r_rcv_len += pmtu;
+		if (unlikely(qp->r_rcv_len > qp->r_len))
+			goto nack_inv;
+		hfi1_copy_sge(&qp->r_sge, data, pmtu, 1, 0);
+		break;
+
+	case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE):
+		/* consume RWQE */
+		ret = hfi1_rvt_get_rwqe(qp, 1);
+		if (ret < 0)
+			goto nack_op_err;
+		if (!ret)
+			goto rnr_nak;
+		goto send_last_imm;
+
+	case OP(SEND_ONLY):
+	case OP(SEND_ONLY_WITH_IMMEDIATE):
+		ret = hfi1_rvt_get_rwqe(qp, 0);
+		if (ret < 0)
+			goto nack_op_err;
+		if (!ret)
+			goto rnr_nak;
+		qp->r_rcv_len = 0;
+		if (opcode == OP(SEND_ONLY))
+			goto no_immediate_data;
+		/* FALLTHROUGH for SEND_ONLY_WITH_IMMEDIATE */
+	case OP(SEND_LAST_WITH_IMMEDIATE):
+send_last_imm:
+		wc.ex.imm_data = ohdr->u.imm_data;
+		wc.wc_flags = IB_WC_WITH_IMM;
+		goto send_last;
+	case OP(RDMA_WRITE_LAST):
+		copy_last = ibpd_to_rvtpd(qp->ibqp.pd)->user;
+		/* fall through */
+	case OP(SEND_LAST):
+no_immediate_data:
+		wc.wc_flags = 0;
+		wc.ex.imm_data = 0;
+send_last:
+		/* Get the number of bytes the message was padded by. */
+		pad = (bth0 >> 20) & 3;
+		/* Check for invalid length. */
+		/* LAST len should be >= 1 */
+		if (unlikely(tlen < (hdrsize + pad + 4)))
+			goto nack_inv;
+		/* 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))
+			goto nack_inv;
+		hfi1_copy_sge(&qp->r_sge, data, tlen, 1, copy_last);
+		rvt_put_ss(&qp->r_sge);
+		qp->r_msn++;
+		if (!test_and_clear_bit(RVT_R_WRID_VALID, &qp->r_aflags))
+			break;
+		wc.wr_id = qp->r_wr_id;
+		wc.status = IB_WC_SUCCESS;
+		if (opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE) ||
+		    opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE))
+			wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
+		else
+			wc.opcode = IB_WC_RECV;
+		wc.qp = &qp->ibqp;
+		wc.src_qp = qp->remote_qpn;
+		wc.slid = qp->remote_ah_attr.dlid;
+		/*
+		 * It seems that IB mandates the presence of an SL in a
+		 * work completion only for the UD transport (see section
+		 * 11.4.2 of IBTA Vol. 1).
+		 *
+		 * However, the way the SL is chosen below is consistent
+		 * with the way that IB/qib works and is trying avoid
+		 * introducing incompatibilities.
+		 *
+		 * See also OPA Vol. 1, section 9.7.6, and table 9-17.
+		 */
+		wc.sl = qp->remote_ah_attr.sl;
+		/* zero fields that are N/A */
+		wc.vendor_err = 0;
+		wc.pkey_index = 0;
+		wc.dlid_path_bits = 0;
+		wc.port_num = 0;
+		/* Signal completion event if the solicited bit is set. */
+		rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.recv_cq), &wc,
+			     (bth0 & IB_BTH_SOLICITED) != 0);
+		break;
+
+	case OP(RDMA_WRITE_ONLY):
+		copy_last = 1;
+		/* fall through */
+	case OP(RDMA_WRITE_FIRST):
+	case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE):
+		if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE)))
+			goto nack_inv;
+		/* consume RWQE */
+		reth = &ohdr->u.rc.reth;
+		qp->r_len = be32_to_cpu(reth->length);
+		qp->r_rcv_len = 0;
+		qp->r_sge.sg_list = NULL;
+		if (qp->r_len != 0) {
+			u32 rkey = be32_to_cpu(reth->rkey);
+			u64 vaddr = be64_to_cpu(reth->vaddr);
+			int ok;
+
+			/* Check rkey & NAK */
+			ok = rvt_rkey_ok(qp, &qp->r_sge.sge, qp->r_len, vaddr,
+					 rkey, IB_ACCESS_REMOTE_WRITE);
+			if (unlikely(!ok))
+				goto nack_acc;
+			qp->r_sge.num_sge = 1;
+		} else {
+			qp->r_sge.num_sge = 0;
+			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 (opcode == OP(RDMA_WRITE_FIRST))
+			goto send_middle;
+		else if (opcode == OP(RDMA_WRITE_ONLY))
+			goto no_immediate_data;
+		ret = hfi1_rvt_get_rwqe(qp, 1);
+		if (ret < 0)
+			goto nack_op_err;
+		if (!ret)
+			goto rnr_nak;
+		wc.ex.imm_data = ohdr->u.rc.imm_data;
+		wc.wc_flags = IB_WC_WITH_IMM;
+		goto send_last;
+
+	case OP(RDMA_READ_REQUEST): {
+		struct rvt_ack_entry *e;
+		u32 len;
+		u8 next;
+
+		if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_READ)))
+			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)
+			next = 0;
+		spin_lock_irqsave(&qp->s_lock, flags);
+		if (unlikely(next == qp->s_tail_ack_queue)) {
+			if (!qp->s_ack_queue[next].sent)
+				goto nack_inv_unlck;
+			update_ack_queue(qp, next);
+		}
+		e = &qp->s_ack_queue[qp->r_head_ack_queue];
+		if (e->opcode == OP(RDMA_READ_REQUEST) && e->rdma_sge.mr) {
+			rvt_put_mr(e->rdma_sge.mr);
+			e->rdma_sge.mr = NULL;
+		}
+		reth = &ohdr->u.rc.reth;
+		len = be32_to_cpu(reth->length);
+		if (len) {
+			u32 rkey = be32_to_cpu(reth->rkey);
+			u64 vaddr = be64_to_cpu(reth->vaddr);
+			int ok;
+
+			/* Check rkey & NAK */
+			ok = rvt_rkey_ok(qp, &e->rdma_sge, len, vaddr,
+					 rkey, IB_ACCESS_REMOTE_READ);
+			if (unlikely(!ok))
+				goto nack_acc_unlck;
+			/*
+			 * Update the next expected PSN.  We add 1 later
+			 * below, so only add the remainder here.
+			 */
+			if (len > pmtu)
+				qp->r_psn += (len - 1) / pmtu;
+		} else {
+			e->rdma_sge.mr = NULL;
+			e->rdma_sge.vaddr = NULL;
+			e->rdma_sge.length = 0;
+			e->rdma_sge.sge_length = 0;
+		}
+		e->opcode = opcode;
+		e->sent = 0;
+		e->psn = psn;
+		e->lpsn = qp->r_psn;
+		/*
+		 * We need to increment the MSN here instead of when we
+		 * finish sending the result since a duplicate request would
+		 * increment it more than once.
+		 */
+		qp->r_msn++;
+		qp->r_psn++;
+		qp->r_state = opcode;
+		qp->r_nak_state = 0;
+		qp->r_head_ack_queue = next;
+
+		/* Schedule the send tasklet. */
+		qp->s_flags |= RVT_S_RESP_PENDING;
+		hfi1_schedule_send(qp);
+
+		spin_unlock_irqrestore(&qp->s_lock, flags);
+		if (is_fecn)
+			goto send_ack;
+		return;
+	}
+
+	case OP(COMPARE_SWAP):
+	case OP(FETCH_ADD): {
+		struct ib_atomic_eth *ateth;
+		struct rvt_ack_entry *e;
+		u64 vaddr;
+		atomic64_t *maddr;
+		u64 sdata;
+		u32 rkey;
+		u8 next;
+
+		if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_ATOMIC)))
+			goto nack_inv;
+		next = qp->r_head_ack_queue + 1;
+		if (next > HFI1_MAX_RDMA_ATOMIC)
+			next = 0;
+		spin_lock_irqsave(&qp->s_lock, flags);
+		if (unlikely(next == qp->s_tail_ack_queue)) {
+			if (!qp->s_ack_queue[next].sent)
+				goto nack_inv_unlck;
+			update_ack_queue(qp, next);
+		}
+		e = &qp->s_ack_queue[qp->r_head_ack_queue];
+		if (e->opcode == OP(RDMA_READ_REQUEST) && e->rdma_sge.mr) {
+			rvt_put_mr(e->rdma_sge.mr);
+			e->rdma_sge.mr = NULL;
+		}
+		ateth = &ohdr->u.atomic_eth;
+		vaddr = ((u64)be32_to_cpu(ateth->vaddr[0]) << 32) |
+			be32_to_cpu(ateth->vaddr[1]);
+		if (unlikely(vaddr & (sizeof(u64) - 1)))
+			goto nack_inv_unlck;
+		rkey = be32_to_cpu(ateth->rkey);
+		/* Check rkey & NAK */
+		if (unlikely(!rvt_rkey_ok(qp, &qp->r_sge.sge, sizeof(u64),
+					  vaddr, rkey,
+					  IB_ACCESS_REMOTE_ATOMIC)))
+			goto nack_acc_unlck;
+		/* Perform atomic OP and save result. */
+		maddr = (atomic64_t *)qp->r_sge.sge.vaddr;
+		sdata = be64_to_cpu(ateth->swap_data);
+		e->atomic_data = (opcode == OP(FETCH_ADD)) ?
+			(u64)atomic64_add_return(sdata, maddr) - sdata :
+			(u64)cmpxchg((u64 *)qp->r_sge.sge.vaddr,
+				      be64_to_cpu(ateth->compare_data),
+				      sdata);
+		rvt_put_mr(qp->r_sge.sge.mr);
+		qp->r_sge.num_sge = 0;
+		e->opcode = opcode;
+		e->sent = 0;
+		e->psn = psn;
+		e->lpsn = psn;
+		qp->r_msn++;
+		qp->r_psn++;
+		qp->r_state = opcode;
+		qp->r_nak_state = 0;
+		qp->r_head_ack_queue = next;
+
+		/* Schedule the send tasklet. */
+		qp->s_flags |= RVT_S_RESP_PENDING;
+		hfi1_schedule_send(qp);
+
+		spin_unlock_irqrestore(&qp->s_lock, flags);
+		if (is_fecn)
+			goto send_ack;
+		return;
+	}
+
+	default:
+		/* NAK unknown opcodes. */
+		goto nack_inv;
+	}
+	qp->r_psn++;
+	qp->r_state = opcode;
+	qp->r_ack_psn = psn;
+	qp->r_nak_state = 0;
+	/* Send an ACK if requested or required. */
+	if (psn & IB_BTH_REQ_ACK) {
+		struct hfi1_qp_priv *priv = qp->priv;
+
+		if (packet->numpkt == 0) {
+			rc_cancel_ack(qp);
+			goto send_ack;
+		}
+		if (priv->r_adefered >= HFI1_PSN_CREDIT) {
+			rc_cancel_ack(qp);
+			goto send_ack;
+		}
+		if (unlikely(is_fecn)) {
+			rc_cancel_ack(qp);
+			goto send_ack;
+		}
+		priv->r_adefered++;
+		rc_defered_ack(rcd, qp);
+	}
+	return;
+
+rnr_nak:
+	qp->r_nak_state = qp->r_min_rnr_timer | IB_RNR_NAK;
+	qp->r_ack_psn = qp->r_psn;
+	/* Queue RNR NAK for later */
+	rc_defered_ack(rcd, qp);
+	return;
+
+nack_op_err:
+	hfi1_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
+	qp->r_nak_state = IB_NAK_REMOTE_OPERATIONAL_ERROR;
+	qp->r_ack_psn = qp->r_psn;
+	/* Queue NAK for later */
+	rc_defered_ack(rcd, qp);
+	return;
+
+nack_inv_unlck:
+	spin_unlock_irqrestore(&qp->s_lock, flags);
+nack_inv:
+	hfi1_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
+	qp->r_nak_state = IB_NAK_INVALID_REQUEST;
+	qp->r_ack_psn = qp->r_psn;
+	/* Queue NAK for later */
+	rc_defered_ack(rcd, qp);
+	return;
+
+nack_acc_unlck:
+	spin_unlock_irqrestore(&qp->s_lock, flags);
+nack_acc:
+	hfi1_rc_error(qp, IB_WC_LOC_PROT_ERR);
+	qp->r_nak_state = IB_NAK_REMOTE_ACCESS_ERROR;
+	qp->r_ack_psn = qp->r_psn;
+send_ack:
+	hfi1_send_rc_ack(rcd, qp, is_fecn);
+}
+
+void hfi1_rc_hdrerr(
+	struct hfi1_ctxtdata *rcd,
+	struct hfi1_ib_header *hdr,
+	u32 rcv_flags,
+	struct rvt_qp *qp)
+{
+	int has_grh = rcv_flags & HFI1_HAS_GRH;
+	struct hfi1_other_headers *ohdr;
+	struct hfi1_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
+	int diff;
+	u32 opcode;
+	u32 psn, bth0;
+
+	/* Check for GRH */
+	ohdr = &hdr->u.oth;
+	if (has_grh)
+		ohdr = &hdr->u.l.oth;
+
+	bth0 = be32_to_cpu(ohdr->bth[0]);
+	if (hfi1_ruc_check_hdr(ibp, hdr, has_grh, qp, bth0))
+		return;
+
+	psn = be32_to_cpu(ohdr->bth[2]);
+	opcode = (bth0 >> 24) & 0xff;
+
+	/* Only deal with RDMA Writes for now */
+	if (opcode < IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST) {
+		diff = delta_psn(psn, qp->r_psn);
+		if (!qp->r_nak_state && diff >= 0) {
+			ibp->rvp.n_rc_seqnak++;
+			qp->r_nak_state = IB_NAK_PSN_ERROR;
+			/* Use the expected PSN. */
+			qp->r_ack_psn = qp->r_psn;
+			/*
+			 * Wait to send the sequence
+			 * NAK until all packets
+			 * in the receive queue have
+			 * been processed.
+			 * Otherwise, we end up
+			 * propagating congestion.
+			 */
+			rc_defered_ack(rcd, qp);
+		} /* Out of sequence NAK */
+	} /* QP Request NAKs */
+}