[patch v2 27/37] add rxe_resp.c

[rpearson-klaOcWyJdxkshyMvu7JE4pqQE7yCjDx5@public.gmane.org]

[-- Attachment #1: add-rxe_resp.c --]
[-- Type: text/plain, Size: 34383 bytes --]

QP response logic.

Signed-off-by: Bob Pearson <rpearson-klaOcWyJdxkshyMvu7JE4pqQE7yCjDx5@public.gmane.org>

---
 drivers/infiniband/hw/rxe/rxe_resp.c | 1366 +++++++++++++++++++++++++++++++++++
 1 file changed, 1366 insertions(+)

Index: infiniband/drivers/infiniband/hw/rxe/rxe_resp.c
===================================================================
--- /dev/null
+++ infiniband/drivers/infiniband/hw/rxe/rxe_resp.c
@@ -0,0 +1,1366 @@
+/*
+ * Copyright (c) 2009-2011 Mellanox Technologies Ltd. All rights reserved.
+ * Copyright (c) 2009-2011 System Fabric Works, Inc. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *	- Redistributions of source code must retain the above
+ *	  copyright notice, this list of conditions and the following
+ *	  disclaimer.
+ *
+ *	- Redistributions in binary form must reproduce the above
+ *	  copyright notice, this list of conditions and the following
+ *	  disclaimer in the documentation and/or other materials
+ *	  provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/*
+ * implements the qp responder
+ */
+
+#include <linux/skbuff.h>
+
+#include "rxe.h"
+#include "rxe_loc.h"
+#include "rxe_queue.h"
+
+enum resp_states {
+	RESPST_NONE,
+	RESPST_GET_REQ,
+	RESPST_CHK_PSN,
+	RESPST_CHK_OP_SEQ,
+	RESPST_CHK_OP_VALID,
+	RESPST_CHK_RESOURCE,
+	RESPST_CHK_LENGTH,
+	RESPST_CHK_RKEY,
+	RESPST_EXECUTE,
+	RESPST_READ_REPLY,
+	RESPST_COMPLETE,
+	RESPST_ACKNOWLEDGE,
+	RESPST_CLEANUP,
+	RESPST_DUPLICATE_REQUEST,
+	RESPST_ERR_MALFORMED_WQE,
+	RESPST_ERR_UNSUPPORTED_OPCODE,
+	RESPST_ERR_MISALIGNED_ATOMIC,
+	RESPST_ERR_PSN_OUT_OF_SEQ,
+	RESPST_ERR_MISSING_OPCODE_FIRST,
+	RESPST_ERR_MISSING_OPCODE_LAST_C,
+	RESPST_ERR_MISSING_OPCODE_LAST_D1E,
+	RESPST_ERR_TOO_MANY_RDMA_ATM_REQ,
+	RESPST_ERR_RNR,
+	RESPST_ERR_RKEY_VIOLATION,
+	RESPST_ERR_LENGTH,
+	RESPST_ERR_CQ_OVERFLOW,
+	RESPST_ERROR,
+	RESPST_RESET,
+	RESPST_DONE,
+	RESPST_EXIT,
+};
+
+static char *resp_state_name[] = {
+	[RESPST_NONE]				= "NONE",
+	[RESPST_GET_REQ]			= "GET_REQ",
+	[RESPST_CHK_PSN]			= "CHK_PSN",
+	[RESPST_CHK_OP_SEQ]			= "CHK_OP_SEQ",
+	[RESPST_CHK_OP_VALID]			= "CHK_OP_VALID",
+	[RESPST_CHK_RESOURCE]			= "CHK_RESOURCE",
+	[RESPST_CHK_LENGTH]			= "CHK_LENGTH",
+	[RESPST_CHK_RKEY]			= "CHK_RKEY",
+	[RESPST_EXECUTE]			= "EXECUTE",
+	[RESPST_READ_REPLY]			= "READ_REPLY",
+	[RESPST_COMPLETE]			= "COMPLETE",
+	[RESPST_ACKNOWLEDGE]			= "ACKNOWLEDGE",
+	[RESPST_CLEANUP]			= "CLEANUP",
+	[RESPST_DUPLICATE_REQUEST]		= "DUPLICATE_REQUEST",
+	[RESPST_ERR_MALFORMED_WQE]		= "ERR_MALFORMED_WQE",
+	[RESPST_ERR_UNSUPPORTED_OPCODE]		= "ERR_UNSUPPORTED_OPCODE",
+	[RESPST_ERR_MISALIGNED_ATOMIC]		= "ERR_MISALIGNED_ATOMIC",
+	[RESPST_ERR_PSN_OUT_OF_SEQ]		= "ERR_PSN_OUT_OF_SEQ",
+	[RESPST_ERR_MISSING_OPCODE_FIRST]	= "ERR_MISSING_OPCODE_FIRST",
+	[RESPST_ERR_MISSING_OPCODE_LAST_C]	= "ERR_MISSING_OPCODE_LAST_C",
+	[RESPST_ERR_MISSING_OPCODE_LAST_D1E]	= "ERR_MISSING_OPCODE_LAST_D1E",
+	[RESPST_ERR_TOO_MANY_RDMA_ATM_REQ]	= "ERR_TOO_MANY_RDMA_ATM_REQ",
+	[RESPST_ERR_RNR]			= "ERR_RNR",
+	[RESPST_ERR_RKEY_VIOLATION]		= "ERR_RKEY_VIOLATION",
+	[RESPST_ERR_LENGTH]			= "ERR_LENGTH",
+	[RESPST_ERR_CQ_OVERFLOW]		= "ERR_CQ_OVERFLOW",
+	[RESPST_ERROR]				= "ERROR",
+	[RESPST_RESET]				= "RESET",
+	[RESPST_DONE]				= "DONE",
+	[RESPST_EXIT]				= "EXIT",
+};
+
+/* rxe_recv calls here to add a request packet to the input queue */
+void rxe_resp_queue_pkt(struct rxe_dev *rxe, struct rxe_qp *qp,
+			struct sk_buff *skb)
+{
+	int must_sched;
+	struct rxe_pkt_info *pkt = SKB_TO_PKT(skb);
+
+	atomic_inc(&qp->req_skb_in);
+	atomic_inc(&rxe->req_skb_in);
+
+	skb_queue_tail(&qp->req_pkts, skb);
+
+	must_sched = (pkt->opcode == IB_OPCODE_RC_RDMA_READ_REQUEST)
+		    || (skb_queue_len(&qp->req_pkts) > 1);
+
+	rxe_run_task(&qp->resp.task, must_sched);
+}
+
+static inline enum resp_states get_req(struct rxe_qp *qp,
+				       struct rxe_pkt_info **pkt_p)
+{
+	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
+	struct sk_buff *skb;
+
+	if (qp->resp.state == QP_STATE_ERROR) {
+		skb = skb_dequeue(&qp->req_pkts);
+		if (skb) {
+			/* drain request packet queue */
+			rxe_drop_ref(qp);
+			kfree_skb(skb);
+			atomic_dec(&qp->req_skb_in);
+			atomic_dec(&rxe->req_skb_in);
+			return RESPST_GET_REQ;
+		} else {
+			/* go drain recv wr queue */
+			return RESPST_CHK_RESOURCE;
+		}
+	}
+
+	skb = skb_peek(&qp->req_pkts);
+	if (!skb)
+		return RESPST_EXIT;
+
+	*pkt_p = SKB_TO_PKT(skb);
+
+	return (qp->resp.res) ? RESPST_READ_REPLY : RESPST_CHK_PSN;
+}
+
+static enum resp_states check_psn(struct rxe_qp *qp,
+				  struct rxe_pkt_info *pkt)
+{
+	int diff = psn_compare(pkt->psn, qp->resp.psn);
+
+	switch (qp_type(qp)) {
+	case IB_QPT_RC:
+		if (diff > 0) {
+			if (qp->resp.sent_psn_nak) {
+				return RESPST_CLEANUP;
+			} else {
+				qp->resp.sent_psn_nak = 1;
+				return RESPST_ERR_PSN_OUT_OF_SEQ;
+			}
+		} else if (diff < 0) {
+			return RESPST_DUPLICATE_REQUEST;
+		} else {
+			if (qp->resp.sent_psn_nak)
+				qp->resp.sent_psn_nak = 0;
+		}
+		break;
+
+	case IB_QPT_UC:
+		if (qp->resp.drop_msg || diff != 0) {
+			if (pkt->mask & RXE_START_MASK) {
+				qp->resp.drop_msg = 0;
+				return RESPST_CHK_OP_SEQ;
+			} else {
+				qp->resp.drop_msg = 1;
+				return RESPST_CLEANUP;
+			}
+		}
+		break;
+	default:
+		break;
+	}
+
+	return RESPST_CHK_OP_SEQ;
+}
+
+static enum resp_states check_op_seq(struct rxe_qp *qp,
+				     struct rxe_pkt_info *pkt)
+{
+	switch (qp_type(qp)) {
+	case IB_QPT_RC:
+		switch (qp->resp.opcode) {
+		case IB_OPCODE_RC_SEND_FIRST:
+		case IB_OPCODE_RC_SEND_MIDDLE:
+			switch (pkt->opcode) {
+			case IB_OPCODE_RC_SEND_MIDDLE:
+			case IB_OPCODE_RC_SEND_LAST:
+			case IB_OPCODE_RC_SEND_LAST_WITH_IMMEDIATE:
+			case IB_OPCODE_RC_SEND_LAST_INV:
+				return RESPST_CHK_OP_VALID;
+			default:
+				return RESPST_ERR_MISSING_OPCODE_LAST_C;
+			}
+
+		case IB_OPCODE_RC_RDMA_WRITE_FIRST:
+		case IB_OPCODE_RC_RDMA_WRITE_MIDDLE:
+			switch (pkt->opcode) {
+			case IB_OPCODE_RC_RDMA_WRITE_MIDDLE:
+			case IB_OPCODE_RC_RDMA_WRITE_LAST:
+			case IB_OPCODE_RC_RDMA_WRITE_LAST_WITH_IMMEDIATE:
+				return RESPST_CHK_OP_VALID;
+			default:
+				return RESPST_ERR_MISSING_OPCODE_LAST_C;
+			}
+
+		default:
+			switch (pkt->opcode) {
+			case IB_OPCODE_RC_SEND_MIDDLE:
+			case IB_OPCODE_RC_SEND_LAST:
+			case IB_OPCODE_RC_SEND_LAST_WITH_IMMEDIATE:
+			case IB_OPCODE_RC_SEND_LAST_INV:
+			case IB_OPCODE_RC_RDMA_WRITE_MIDDLE:
+			case IB_OPCODE_RC_RDMA_WRITE_LAST:
+			case IB_OPCODE_RC_RDMA_WRITE_LAST_WITH_IMMEDIATE:
+				return RESPST_ERR_MISSING_OPCODE_FIRST;
+			default:
+				return RESPST_CHK_OP_VALID;
+			}
+		}
+		break;
+
+	case IB_QPT_UC:
+		switch (qp->resp.opcode) {
+		case IB_OPCODE_UC_SEND_FIRST:
+		case IB_OPCODE_UC_SEND_MIDDLE:
+			switch (pkt->opcode) {
+			case IB_OPCODE_UC_SEND_MIDDLE:
+			case IB_OPCODE_UC_SEND_LAST:
+			case IB_OPCODE_UC_SEND_LAST_WITH_IMMEDIATE:
+				return RESPST_CHK_OP_VALID;
+			default:
+				return RESPST_ERR_MISSING_OPCODE_LAST_D1E;
+			}
+
+		case IB_OPCODE_UC_RDMA_WRITE_FIRST:
+		case IB_OPCODE_UC_RDMA_WRITE_MIDDLE:
+			switch (pkt->opcode) {
+			case IB_OPCODE_UC_RDMA_WRITE_MIDDLE:
+			case IB_OPCODE_UC_RDMA_WRITE_LAST:
+			case IB_OPCODE_UC_RDMA_WRITE_LAST_WITH_IMMEDIATE:
+				return RESPST_CHK_OP_VALID;
+			default:
+				return RESPST_ERR_MISSING_OPCODE_LAST_D1E;
+			}
+
+		default:
+			switch (pkt->opcode) {
+			case IB_OPCODE_UC_SEND_MIDDLE:
+			case IB_OPCODE_UC_SEND_LAST:
+			case IB_OPCODE_UC_SEND_LAST_WITH_IMMEDIATE:
+			case IB_OPCODE_UC_RDMA_WRITE_MIDDLE:
+			case IB_OPCODE_UC_RDMA_WRITE_LAST:
+			case IB_OPCODE_UC_RDMA_WRITE_LAST_WITH_IMMEDIATE:
+				qp->resp.drop_msg = 1;
+				return RESPST_CLEANUP;
+			default:
+				return RESPST_CHK_OP_VALID;
+			}
+		}
+		break;
+
+	default:
+		return RESPST_CHK_OP_VALID;
+	}
+}
+
+static enum resp_states check_op_valid(struct rxe_qp *qp,
+				       struct rxe_pkt_info *pkt)
+{
+	switch (qp_type(qp)) {
+	case IB_QPT_RC:
+		if (((pkt->mask & RXE_READ_MASK) &&
+		     !(qp->attr.qp_access_flags & IB_ACCESS_REMOTE_READ)) ||
+		    ((pkt->mask & RXE_WRITE_MASK) &&
+		     !(qp->attr.qp_access_flags & IB_ACCESS_REMOTE_WRITE)) ||
+		    ((pkt->mask & RXE_ATOMIC_MASK) &&
+		     !(qp->attr.qp_access_flags & IB_ACCESS_REMOTE_ATOMIC))) {
+			return RESPST_ERR_UNSUPPORTED_OPCODE;
+		}
+
+		if (!pkt->mask)
+			return RESPST_ERR_UNSUPPORTED_OPCODE;
+		break;
+
+	case IB_QPT_UC:
+		if ((pkt->mask & RXE_WRITE_MASK) &&
+		    !(qp->attr.qp_access_flags & IB_ACCESS_REMOTE_WRITE)) {
+			qp->resp.drop_msg = 1;
+			return RESPST_CLEANUP;
+		}
+
+		if (!pkt->mask) {
+			qp->resp.drop_msg = 1;
+			return RESPST_CLEANUP;
+		}
+		break;
+
+	case IB_QPT_UD:
+	case IB_QPT_SMI:
+	case IB_QPT_GSI:
+		if (!pkt->mask)
+			return RESPST_CLEANUP;
+		break;
+
+	default:
+		WARN_ON(1);
+		break;
+	}
+
+	return RESPST_CHK_RESOURCE;
+}
+
+static enum resp_states get_srq_wqe(struct rxe_qp *qp)
+{
+	struct rxe_srq *srq = qp->srq;
+	struct rxe_queue *q = srq->rq.queue;
+	struct rxe_recv_wqe *wqe;
+	struct ib_event ev;
+
+	if (srq->error)
+		return RESPST_ERR_RNR;
+
+	spin_lock_bh(&srq->rq.consumer_lock);
+
+	wqe = queue_head(q);
+	if (!wqe) {
+		spin_unlock_bh(&srq->rq.consumer_lock);
+		return RESPST_ERR_RNR;
+	}
+
+	/* note kernel and user space recv wqes have same size */
+	memcpy(&qp->resp.srq_wqe, wqe, sizeof(qp->resp.srq_wqe));
+
+	qp->resp.wqe = &qp->resp.srq_wqe.wqe;
+	advance_consumer(q);
+
+	if (srq->limit && srq->ibsrq.event_handler &&
+	    (queue_count(q) < srq->limit)) {
+		srq->limit = 0;
+		goto event;
+	}
+
+	spin_unlock_bh(&srq->rq.consumer_lock);
+	return RESPST_CHK_LENGTH;
+
+event:
+	spin_unlock_bh(&srq->rq.consumer_lock);
+	ev.device = qp->ibqp.device;
+	ev.element.srq = qp->ibqp.srq;
+	ev.event = IB_EVENT_SRQ_LIMIT_REACHED;
+	srq->ibsrq.event_handler(&ev, srq->ibsrq.srq_context);
+	return RESPST_CHK_LENGTH;
+}
+
+static enum resp_states check_resource(struct rxe_qp *qp,
+				       struct rxe_pkt_info *pkt)
+{
+	struct rxe_srq *srq = qp->srq;
+
+	if (qp->resp.state == QP_STATE_ERROR) {
+		if (qp->resp.wqe) {
+			qp->resp.status = IB_WC_WR_FLUSH_ERR;
+			return RESPST_COMPLETE;
+		} else if (!srq) {
+			qp->resp.wqe = queue_head(qp->rq.queue);
+			if (qp->resp.wqe) {
+				qp->resp.status = IB_WC_WR_FLUSH_ERR;
+				return RESPST_COMPLETE;
+			} else
+				return RESPST_EXIT;
+		} else
+			return RESPST_EXIT;
+	}
+
+	if (pkt->mask & RXE_READ_OR_ATOMIC) {
+		/* it is the requesters job to not send
+		   too many read/atomic ops, we just
+		   recycle the responder resource queue */
+		if (likely(qp->attr.max_rd_atomic > 0))
+			return RESPST_CHK_LENGTH;
+		else
+			return RESPST_ERR_TOO_MANY_RDMA_ATM_REQ;
+	}
+
+	if (pkt->mask & RXE_RWR_MASK) {
+		if (srq) {
+			return get_srq_wqe(qp);
+		} else {
+			qp->resp.wqe = queue_head(qp->rq.queue);
+			return (qp->resp.wqe) ? RESPST_CHK_LENGTH
+					      : RESPST_ERR_RNR;
+		}
+	}
+
+	return RESPST_CHK_LENGTH;
+}
+
+static enum resp_states check_length(struct rxe_qp *qp,
+				     struct rxe_pkt_info *pkt)
+{
+	switch (qp_type(qp)) {
+	case IB_QPT_RC:
+		return RESPST_CHK_RKEY;
+
+	case IB_QPT_UC:
+		return RESPST_CHK_RKEY;
+
+	default:
+		return RESPST_CHK_RKEY;
+	}
+}
+
+static enum resp_states check_rkey(struct rxe_qp *qp,
+				   struct rxe_pkt_info *pkt)
+{
+	struct rxe_mem *mem;
+	u64 va;
+	u32 rkey;
+	u32 resid;
+	u32 pktlen;
+	int mtu = qp->mtu;
+	enum resp_states state;
+	int access;
+
+	if (pkt->mask & (RXE_READ_MASK | RXE_WRITE_MASK)) {
+		if (pkt->mask & RXE_RETH_MASK) {
+			qp->resp.va = reth_va(pkt);
+			qp->resp.rkey = reth_rkey(pkt);
+			qp->resp.resid = reth_len(pkt);
+		}
+		access = (pkt->mask & RXE_READ_MASK) ? IB_ACCESS_REMOTE_READ
+						     : IB_ACCESS_REMOTE_WRITE;
+	} else if (pkt->mask & RXE_ATOMIC_MASK) {
+		qp->resp.va = atmeth_va(pkt);
+		qp->resp.rkey = atmeth_rkey(pkt);
+		qp->resp.resid = sizeof(u64);
+		access = IB_ACCESS_REMOTE_ATOMIC;
+	} else {
+		return RESPST_EXECUTE;
+	}
+
+	va	= qp->resp.va;
+	rkey	= qp->resp.rkey;
+	resid	= qp->resp.resid;
+	pktlen	= payload_size(pkt);
+
+	mem = lookup_mem(qp->pd, access, rkey, lookup_remote);
+	if (!mem) {
+		state = RESPST_ERR_RKEY_VIOLATION;
+		goto err1;
+	}
+
+	if (mem_check_range(mem, va, resid)) {
+		state = RESPST_ERR_RKEY_VIOLATION;
+		goto err2;
+	}
+
+	if (pkt->mask & RXE_WRITE_MASK)	 {
+		if (resid > mtu) {
+			if (pktlen != mtu || bth_pad(pkt)) {
+				state = RESPST_ERR_LENGTH;
+				goto err2;
+			}
+
+			resid = mtu;
+		} else {
+			if ((pktlen != resid)) {
+				state = RESPST_ERR_LENGTH;
+				goto err2;
+			}
+			if ((bth_pad(pkt) != (0x3 & (-resid)))) {
+				/* This case may not be exactly that
+				 * but nothing else fits. */
+				state = RESPST_ERR_LENGTH;
+				goto err2;
+			}
+		}
+	}
+
+	WARN_ON(qp->resp.mr != NULL);
+
+	qp->resp.mr = mem;
+	return RESPST_EXECUTE;
+
+err2:
+	rxe_drop_ref(mem);
+err1:
+	return state;
+}
+
+static enum resp_states send_data_in(struct rxe_qp *qp, void *data_addr,
+				     int data_len)
+{
+	int err;
+	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
+
+	err = copy_data(rxe, qp->pd, IB_ACCESS_LOCAL_WRITE, &qp->resp.wqe->dma,
+			data_addr, data_len, direction_in, NULL);
+	if (unlikely(err))
+		return (err == -ENOSPC) ? RESPST_ERR_LENGTH
+					: RESPST_ERR_MALFORMED_WQE;
+
+	return RESPST_NONE;
+}
+
+static enum resp_states write_data_in(struct rxe_qp *qp,
+				      struct rxe_pkt_info *pkt)
+{
+	enum resp_states rc = RESPST_NONE;
+	int	err;
+	int data_len = payload_size(pkt);
+
+	err = rxe_mem_copy(qp->resp.mr, qp->resp.va, payload_addr(pkt),
+			   data_len, direction_in, NULL);
+	if (err) {
+		rc = RESPST_ERR_RKEY_VIOLATION;
+		goto out;
+	}
+
+	qp->resp.va += data_len;
+	qp->resp.resid -= data_len;
+
+out:
+	return rc;
+}
+
+/* Guarantee atomicity of atomic operations at the machine level. */
+static DEFINE_SPINLOCK(atomic_ops_lock);
+
+static enum resp_states process_atomic(struct rxe_qp *qp,
+				       struct rxe_pkt_info *pkt)
+{
+	u64 iova = atmeth_va(pkt);
+	u64 *vaddr;
+	enum resp_states ret;
+	struct rxe_mem *mr = qp->resp.mr;
+
+	if (mr->state != RXE_MEM_STATE_VALID) {
+		ret = RESPST_ERR_RKEY_VIOLATION;
+		goto out;
+	}
+
+	vaddr = iova_to_vaddr(mr, iova, sizeof(u64));
+
+	/* check vaddr is 8 bytes aligned. */
+	if (!vaddr || (uintptr_t)vaddr & 7) {
+		ret = RESPST_ERR_MISALIGNED_ATOMIC;
+		goto out;
+	}
+
+	spin_lock_bh(&atomic_ops_lock);
+
+	qp->resp.atomic_orig = *vaddr;
+
+	if (pkt->opcode == IB_OPCODE_RC_COMPARE_SWAP ||
+	    pkt->opcode == IB_OPCODE_RD_COMPARE_SWAP) {
+		if (*vaddr == atmeth_comp(pkt))
+			*vaddr = atmeth_swap_add(pkt);
+	} else {
+		*vaddr += atmeth_swap_add(pkt);
+	}
+
+	spin_unlock_bh(&atomic_ops_lock);
+
+	ret = RESPST_NONE;
+out:
+	return ret;
+}
+
+static struct sk_buff *prepare_ack_packet(struct rxe_qp *qp,
+					  struct rxe_pkt_info *pkt,
+					  int opcode,
+					  int payload,
+					  u32 psn,
+					  u8 syndrome)
+{
+	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
+	struct sk_buff *skb;
+	struct rxe_pkt_info *ack;
+	int paylen;
+	int pad;
+
+	/*
+	 * allocate packet
+	 */
+	pad = (-payload) & 0x3;
+	paylen = rxe_opcode[opcode].length + payload + pad + RXE_ICRC_SIZE;
+
+	skb = rxe->ifc_ops->init_packet(rxe, &qp->pri_av, paylen);
+	if (!skb)
+		return NULL;
+
+	atomic_inc(&qp->resp_skb_out);
+	atomic_inc(&rxe->resp_skb_out);
+
+	ack = SKB_TO_PKT(skb);
+	ack->qp = qp;
+	ack->opcode = opcode;
+	ack->mask |= rxe_opcode[opcode].mask;
+	ack->offset = pkt->offset;
+	ack->paylen = paylen;
+
+	/* fill in lrh/grh/bth using the request packet headers */
+	memcpy(ack->hdr, pkt->hdr, pkt->offset + RXE_BTH_BYTES);
+
+	/* swap addresses in lrh */
+	if (ack->mask & RXE_LRH_MASK) {
+		__lrh_set_dlid(ack->hdr, __lrh_slid(pkt->hdr));
+		__lrh_set_slid(ack->hdr, __lrh_dlid(pkt->hdr));
+	}
+
+	/* swap addresses in grh */
+	if (ack->mask & RXE_GRH_MASK) {
+		grh_set_paylen(ack, paylen);
+		grh_set_dgid(ack, grh_sgid(pkt)->global.subnet_prefix,
+			grh_sgid(pkt)->global.interface_id);
+		grh_set_sgid(ack, grh_dgid(pkt)->global.subnet_prefix,
+			grh_dgid(pkt)->global.interface_id);
+	}
+
+	bth_set_opcode(ack, opcode);
+	bth_set_qpn(ack, qp->attr.dest_qp_num);
+	bth_set_pad(ack, pad);
+	bth_set_se(ack, 0);
+	bth_set_psn(ack, psn);
+	ack->psn = psn;
+
+	if (ack->mask & RXE_AETH_MASK) {
+		aeth_set_syn(ack, syndrome);
+		aeth_set_msn(ack, qp->resp.msn);
+	}
+
+	if (ack->mask & RXE_ATMACK_MASK)
+		atmack_set_orig(ack, qp->resp.atomic_orig);
+
+	return skb;
+}
+
+/* RDMA read response. If res is not NULL, then we have a current RDMA request
+ * being processed or replayed. */
+static enum resp_states read_reply(struct rxe_qp *qp,
+				   struct rxe_pkt_info *req_pkt)
+{
+	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
+	struct rxe_pkt_info *pkt;
+	int mtu = qp->mtu;
+	enum resp_states state;
+	int payload;
+	struct sk_buff *skb;
+	int opcode;
+	int err;
+	struct resp_res *res = qp->resp.res;
+	unsigned char *buf;
+
+	if (!res) {
+		/* This is the first time we process that request. Get a
+		 * resource */
+		res = &qp->resp.resources[qp->resp.res_head];
+
+		free_rd_atomic_resource(qp, res);
+		rxe_advance_resp_resource(qp);
+
+		res->type		= RXE_READ_MASK;
+
+		res->read.va		= qp->resp.va;
+		res->read.va_org	= qp->resp.va;
+
+		res->first_psn		= req_pkt->psn;
+		res->last_psn		= req_pkt->psn +
+					  (reth_len(req_pkt) + mtu - 1)/mtu - 1;
+		res->cur_psn		= req_pkt->psn;
+
+		res->read.resid		= qp->resp.resid;
+		res->read.length	= qp->resp.resid;
+		res->read.rkey		= qp->resp.rkey;
+
+		/* note res inherits the reference to mr from qp */
+		res->read.mr		= qp->resp.mr;
+		qp->resp.mr		= NULL;
+
+		qp->resp.res		= res;
+		res->state		= rdatm_res_state_new;
+	}
+
+	if (res->state == rdatm_res_state_new) {
+		if (res->read.resid <= mtu)
+			opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_ONLY;
+		else
+			opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST;
+	} else {
+		if (res->read.resid > mtu)
+			opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE;
+		else
+			opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST;
+	}
+
+	res->state = rdatm_res_state_next;
+
+	payload = min_t(int, res->read.resid, mtu);
+
+	skb = prepare_ack_packet(qp, req_pkt, opcode, payload,
+				 res->cur_psn, AETH_ACK_UNLIMITED);
+	if (!skb)
+		return RESPST_ERR_RNR;
+
+	pkt = SKB_TO_PKT(skb);
+
+	err = rxe_mem_copy(res->read.mr, res->read.va, payload_addr(pkt),
+			   payload, direction_out, NULL);
+	if (err)
+		pr_warn("rxe_mem_copy failed TODO ???\n");
+
+	res->read.va += payload;
+	res->read.resid -= payload;
+	res->cur_psn = (res->cur_psn + 1) & BTH_PSN_MASK;
+
+	buf = payload_addr(pkt) + payload;
+	while (payload & 0x3) {
+		*buf++ = 0;
+		payload++;
+	}
+
+	if (!rxe_crc_disable)
+		*buf = rxe_icrc_pkt(pkt);
+
+	arbiter_skb_queue(rxe, qp, skb);
+
+	if (res->read.resid > 0) {
+		state = RESPST_DONE;
+	} else {
+		qp->resp.res = NULL;
+		qp->resp.opcode = -1;
+		qp->resp.psn = res->cur_psn;
+		state = RESPST_CLEANUP;
+	}
+
+	return state;
+}
+
+/* Executes a new request. A retried request never reach that function (send
+ * and writes are discarded, and reads and atomics are retried elsewhere. */
+static enum resp_states execute(struct rxe_qp *qp, struct rxe_pkt_info *pkt)
+{
+	enum resp_states err;
+
+	if (pkt->mask & RXE_SEND_MASK) {
+		if (qp_type(qp) == IB_QPT_UD ||
+		    qp_type(qp) == IB_QPT_SMI ||
+		    qp_type(qp) == IB_QPT_GSI) {
+			/* Copy the GRH */
+			err = send_data_in(qp, pkt->hdr, RXE_GRH_BYTES);
+			if (err)
+				return err;
+		}
+
+		err = send_data_in(qp, payload_addr(pkt), payload_size(pkt));
+		if (err)
+			return err;
+	} else if (pkt->mask & RXE_WRITE_MASK) {
+		err = write_data_in(qp, pkt);
+		if (err)
+			return err;
+	} else if (pkt->mask & RXE_READ_MASK) {
+		/* For RDMA Read we can increment the msn now. See C9-148. */
+		qp->resp.msn++;
+		return RESPST_READ_REPLY;
+	} else if (pkt->mask & RXE_ATOMIC_MASK) {
+		err = process_atomic(qp, pkt);
+		if (err)
+			return err;
+	} else
+		/* Unreachable */
+		WARN_ON(1);
+
+	/* We successfully processed this new request. */
+	qp->resp.msn++;
+
+	/* next expected psn, read handles this separately */
+	qp->resp.psn = (pkt->psn + 1) & BTH_PSN_MASK;
+
+	qp->resp.opcode = pkt->opcode;
+	qp->resp.status = IB_WC_SUCCESS;
+
+	if (pkt->mask & RXE_COMP_MASK)
+		return RESPST_COMPLETE;
+	else if (qp_type(qp) == IB_QPT_RC)
+		return RESPST_ACKNOWLEDGE;
+	else
+		return RESPST_CLEANUP;
+}
+
+static enum resp_states do_complete(struct rxe_qp *qp,
+				    struct rxe_pkt_info *pkt)
+{
+	struct rxe_cqe cqe;
+	struct ib_wc *wc = &cqe.ibwc;
+	struct ib_uverbs_wc *uwc = &cqe.uibwc;
+	struct rxe_recv_wqe *wqe = qp->resp.wqe;
+
+	if (unlikely(!wqe))
+		return RESPST_CLEANUP;
+
+	memset(&cqe, 0, sizeof(cqe));
+
+	wc->wr_id		= wqe->wr_id;
+	wc->status		= qp->resp.status;
+
+	/* fields after status are not required for errors */
+	if (wc->status == IB_WC_SUCCESS) {
+		wc->opcode = (pkt->mask & RXE_IMMDT_MASK &&
+				pkt->mask & RXE_READ_MASK) ?
+					IB_WC_RECV_RDMA_WITH_IMM : IB_WC_RECV;
+		wc->vendor_err = 0;
+		wc->byte_len = wqe->dma.length - wqe->dma.resid;
+
+		/* fields after byte_len are offset
+		   between kernel and user space */
+		if (qp->rcq->is_user) {
+			uwc->wc_flags		= IB_WC_GRH;
+
+			if (pkt->mask & RXE_IMMDT_MASK) {
+				uwc->wc_flags |= IB_WC_WITH_IMM;
+				uwc->ex.imm_data =
+					(__u32 __force)immdt_imm(pkt);
+			}
+
+			if (pkt->mask & RXE_IETH_MASK) {
+				uwc->wc_flags |= IB_WC_WITH_INVALIDATE;
+				uwc->ex.invalidate_rkey = ieth_rkey(pkt);
+			}
+
+			uwc->qp_num		= qp->ibqp.qp_num;
+
+			if (pkt->mask & RXE_DETH_MASK)
+				uwc->src_qp = deth_sqp(pkt);
+
+			uwc->port_num		= qp->attr.port_num;
+		} else {
+			wc->wc_flags		= IB_WC_GRH;
+
+			if (pkt->mask & RXE_IMMDT_MASK) {
+				wc->wc_flags |= IB_WC_WITH_IMM;
+				wc->ex.imm_data = immdt_imm(pkt);
+			}
+
+			if (pkt->mask & RXE_IETH_MASK) {
+				wc->wc_flags |= IB_WC_WITH_INVALIDATE;
+				wc->ex.invalidate_rkey = ieth_rkey(pkt);
+			}
+
+			wc->qp			= &qp->ibqp;
+
+			if (pkt->mask & RXE_DETH_MASK)
+				wc->src_qp = deth_sqp(pkt);
+
+			wc->port_num		= qp->attr.port_num;
+		}
+	}
+
+	/* have copy for srq and reference for !srq */
+	if (!qp->srq)
+		advance_consumer(qp->rq.queue);
+
+	qp->resp.wqe = NULL;
+
+	if (rxe_cq_post(qp->rcq, &cqe, pkt ? bth_se(pkt) : 1))
+		return RESPST_ERR_CQ_OVERFLOW;
+
+	if (qp->resp.state == QP_STATE_ERROR)
+		return RESPST_CHK_RESOURCE;
+
+	if (!pkt)
+		return RESPST_DONE;
+	else if (qp_type(qp) == IB_QPT_RC)
+		return RESPST_ACKNOWLEDGE;
+	else
+		return RESPST_CLEANUP;
+}
+
+static int send_ack(struct rxe_qp *qp, struct rxe_pkt_info *pkt,
+		    u8 syndrome, u32 psn)
+{
+	int err = 0;
+	struct sk_buff *skb;
+	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
+	struct rxe_pkt_info *ack;
+	u32 *buf;
+
+	skb = prepare_ack_packet(qp, pkt, IB_OPCODE_RC_ACKNOWLEDGE,
+				 0, psn, syndrome);
+	if (skb == NULL) {
+		err = -ENOMEM;
+		goto err1;
+	}
+
+	/* CRC */
+	ack = SKB_TO_PKT(skb);
+	buf = payload_addr(ack);
+
+	if (!rxe_crc_disable)
+		*buf = rxe_icrc_pkt(ack);
+
+	arbiter_skb_queue(rxe, qp, skb);
+
+err1:
+	return err;
+}
+
+static int send_atomic_ack(struct rxe_qp *qp, struct rxe_pkt_info *pkt,
+			   u8 syndrome)
+{
+	int rc = 0;
+	struct sk_buff *skb;
+	struct sk_buff *skb_copy;
+	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
+	struct rxe_pkt_info *ack;
+	struct resp_res *res;
+	u32 *buf;
+
+	skb = prepare_ack_packet(qp, pkt, IB_OPCODE_RC_ATOMIC_ACKNOWLEDGE,
+				 0, pkt->psn, syndrome);
+	if (skb == NULL) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	ack = SKB_TO_PKT(skb);
+	buf = payload_addr(ack);
+
+	if (!rxe_crc_disable)
+		*buf = rxe_icrc_pkt(ack);
+
+	res = &qp->resp.resources[qp->resp.res_head];
+	free_rd_atomic_resource(qp, res);
+	rxe_advance_resp_resource(qp);
+
+	res->type = RXE_ATOMIC_MASK;
+	res->atomic.skb = skb;
+	res->first_psn = qp->resp.psn;
+	res->last_psn = qp->resp.psn;
+	res->cur_psn = qp->resp.psn;
+
+	skb_copy = skb_clone(skb, GFP_ATOMIC);
+	if (skb_copy) {
+		rxe_add_ref(qp); /* for the new SKB */
+		atomic_inc(&qp->resp_skb_out);
+		atomic_inc(&rxe->resp_skb_out);
+	} else {
+		pr_warn("Could not clone atomic response\n");
+	}
+
+	arbiter_skb_queue(rxe, qp, skb_copy);
+
+out:
+	return rc;
+}
+
+static enum resp_states acknowledge(struct rxe_qp *qp,
+				    struct rxe_pkt_info *pkt)
+{
+	if (qp_type(qp) != IB_QPT_RC)
+		return RESPST_CLEANUP;
+
+	if (qp->resp.aeth_syndrome != AETH_ACK_UNLIMITED)
+		send_ack(qp, pkt, qp->resp.aeth_syndrome, pkt->psn);
+	else if (pkt->mask & RXE_ATOMIC_MASK)
+		send_atomic_ack(qp, pkt, AETH_ACK_UNLIMITED);
+	else if (bth_ack(pkt))
+		send_ack(qp, pkt, AETH_ACK_UNLIMITED, pkt->psn);
+
+	return RESPST_CLEANUP;
+}
+
+static enum resp_states cleanup(struct rxe_qp *qp,
+				struct rxe_pkt_info *pkt)
+{
+	struct sk_buff *skb;
+	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
+
+	if (pkt) {
+		skb = skb_dequeue(&qp->req_pkts);
+		rxe_drop_ref(qp);
+		kfree_skb(skb);
+		atomic_dec(&qp->req_skb_in);
+		atomic_dec(&rxe->req_skb_in);
+	}
+
+	if (qp->resp.mr) {
+		rxe_drop_ref(qp->resp.mr);
+		qp->resp.mr = NULL;
+	}
+
+	return RESPST_DONE;
+}
+
+static struct resp_res *find_resource(struct rxe_qp *qp, u32 psn)
+{
+	int i;
+
+	for (i = 0; i < qp->attr.max_rd_atomic; i++) {
+		struct resp_res *res = &qp->resp.resources[i];
+		if (res->type == 0)
+			continue;
+
+		if (psn_compare(psn, res->first_psn) >= 0 &&
+		    psn_compare(psn, res->last_psn) <= 0) {
+			return res;
+		}
+	}
+
+	return NULL;
+}
+
+static enum resp_states duplicate_request(struct rxe_qp *qp,
+					  struct rxe_pkt_info *pkt)
+{
+	enum resp_states rc;
+	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
+
+	if (pkt->mask & RXE_SEND_MASK ||
+	    pkt->mask & RXE_WRITE_MASK) {
+		/* SEND. Ack again and cleanup. C9-105. */
+		if (bth_ack(pkt))
+			send_ack(qp, pkt, AETH_ACK_UNLIMITED, qp->resp.psn - 1);
+		rc = RESPST_CLEANUP;
+		goto out;
+	} else if (pkt->mask & RXE_READ_MASK) {
+		struct resp_res *res;
+
+		res = find_resource(qp, pkt->psn);
+		if (!res) {
+			/* Ressource not found. Class D error.
+			   Drop the request. */
+			rc = RESPST_CLEANUP;
+			goto out;
+		} else {
+			/* Ensure this new request is the same as the previous
+			 * one or a subset of it. */
+			u64 iova = reth_va(pkt);
+			u32 resid = reth_len(pkt);
+
+			if (iova < res->read.va_org ||
+			    resid > res->read.length ||
+			    (iova + resid) > (res->read.va_org +
+					      res->read.length)) {
+				rc = RESPST_CLEANUP;
+				goto out;
+			}
+
+			if (reth_rkey(pkt) != res->read.rkey) {
+				rc = RESPST_CLEANUP;
+				goto out;
+			}
+
+			res->cur_psn = pkt->psn;
+			res->state = (pkt->psn == res->first_psn) ?
+					rdatm_res_state_new :
+					rdatm_res_state_replay;
+
+			/* Reset the resource, except length. */
+			res->read.va_org = iova;
+			res->read.va = iova;
+			res->read.resid = resid;
+
+			/* Replay the RDMA read reply. */
+			qp->resp.res = res;
+			rc = RESPST_READ_REPLY;
+			goto out;
+		}
+	} else {
+		struct resp_res *res;
+
+		WARN_ON((pkt->mask & RXE_ATOMIC_MASK) == 0);
+
+		/* Find the operation in our list of responder resources. */
+		res = find_resource(qp, pkt->psn);
+		if (res) {
+			struct sk_buff *skb_copy;
+
+			skb_copy = skb_clone(res->atomic.skb, GFP_ATOMIC);
+			if (skb_copy) {
+				rxe_add_ref(qp); /* for the new SKB */
+				atomic_inc(&qp->resp_skb_out);
+				atomic_inc(&rxe->resp_skb_out);
+			} else {
+				pr_warn("Couldn't clone atomic resp\n");
+				rc = RESPST_CLEANUP;
+				goto out;
+			}
+			bth_set_psn(SKB_TO_PKT(skb_copy),
+				    qp->resp.psn - 1);
+			/* Resend the result. */
+			arbiter_skb_queue(to_rdev(qp->ibqp.device), qp,
+					  skb_copy);
+		}
+
+		/* Ressource not found. Class D error. Drop the request. */
+		rc = RESPST_CLEANUP;
+		goto out;
+	}
+out:
+	return rc;
+}
+
+/* Process a class A or C. Both are treated the same in this implementation. */
+static void do_class_ac_error(struct rxe_qp *qp, u8 syndrome,
+			      enum ib_wc_status status)
+{
+	qp->resp.aeth_syndrome	= syndrome;
+	qp->resp.status		= status;
+
+	/* indicate that we should go through the ERROR state */
+	qp->resp.goto_error	= 1;
+}
+
+static enum resp_states do_class_d1e_error(struct rxe_qp *qp)
+{
+	/* UC */
+	if (qp->srq) {
+		/* Class E */
+		qp->resp.drop_msg = 1;
+		if (qp->resp.wqe) {
+			qp->resp.status = IB_WC_REM_INV_REQ_ERR;
+			return RESPST_COMPLETE;
+		} else {
+			return RESPST_CLEANUP;
+		}
+	} else {
+		/* Class D1. This packet may be the start of a
+		   new message and could be valid. The previous
+		   message is invalid and ignored. reset the
+		   recv wr to its original state */
+		if (qp->resp.wqe) {
+			qp->resp.wqe->dma.resid = qp->resp.wqe->dma.length;
+			qp->resp.wqe->dma.cur_sge = 0;
+			qp->resp.wqe->dma.sge_offset = 0;
+			qp->resp.opcode = -1;
+		}
+
+		if (qp->resp.mr) {
+			rxe_drop_ref(qp->resp.mr);
+			qp->resp.mr = NULL;
+		}
+
+		return RESPST_CHK_OP_SEQ;
+	}
+}
+
+int rxe_responder(void *arg)
+{
+	struct rxe_qp *qp = (struct rxe_qp *)arg;
+	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
+	enum resp_states state;
+	struct rxe_pkt_info *pkt = NULL;
+	int ret = 0;
+
+	qp->resp.aeth_syndrome = AETH_ACK_UNLIMITED;
+
+	if (!qp->valid) {
+		ret = -EINVAL;
+		goto done;
+	}
+
+	switch (qp->resp.state) {
+	case QP_STATE_RESET:
+		state = RESPST_RESET;
+		break;
+
+	default:
+		state = RESPST_GET_REQ;
+		break;
+	}
+
+	while (1) {
+		pr_debug("state = %s\n", resp_state_name[state]);
+		switch (state) {
+		case RESPST_GET_REQ:
+			state = get_req(qp, &pkt);
+			break;
+		case RESPST_CHK_PSN:
+			state = check_psn(qp, pkt);
+			break;
+		case RESPST_CHK_OP_SEQ:
+			state = check_op_seq(qp, pkt);
+			break;
+		case RESPST_CHK_OP_VALID:
+			state = check_op_valid(qp, pkt);
+			break;
+		case RESPST_CHK_RESOURCE:
+			state = check_resource(qp, pkt);
+			break;
+		case RESPST_CHK_LENGTH:
+			state = check_length(qp, pkt);
+			break;
+		case RESPST_CHK_RKEY:
+			state = check_rkey(qp, pkt);
+			break;
+		case RESPST_EXECUTE:
+			state = execute(qp, pkt);
+			break;
+		case RESPST_COMPLETE:
+			state = do_complete(qp, pkt);
+			break;
+		case RESPST_READ_REPLY:
+			state = read_reply(qp, pkt);
+			break;
+		case RESPST_ACKNOWLEDGE:
+			state = acknowledge(qp, pkt);
+			break;
+		case RESPST_CLEANUP:
+			state = cleanup(qp, pkt);
+			break;
+		case RESPST_DUPLICATE_REQUEST:
+			state = duplicate_request(qp, pkt);
+			break;
+		case RESPST_ERR_PSN_OUT_OF_SEQ:
+			/* RC only - Class B. Drop packet. */
+			send_ack(qp, pkt, AETH_NAK_PSN_SEQ_ERROR, qp->resp.psn);
+			state = RESPST_CLEANUP;
+			break;
+
+		case RESPST_ERR_TOO_MANY_RDMA_ATM_REQ:
+		case RESPST_ERR_MISSING_OPCODE_FIRST:
+		case RESPST_ERR_MISSING_OPCODE_LAST_C:
+		case RESPST_ERR_UNSUPPORTED_OPCODE:
+		case RESPST_ERR_MISALIGNED_ATOMIC:
+			/* RC Only - Class C. */
+			do_class_ac_error(qp, AETH_NAK_INVALID_REQ,
+					  IB_WC_REM_INV_REQ_ERR);
+			state = RESPST_COMPLETE;
+			break;
+
+		case RESPST_ERR_MISSING_OPCODE_LAST_D1E:
+			state = do_class_d1e_error(qp);
+			break;
+		case RESPST_ERR_RNR:
+			if (qp_type(qp) == IB_QPT_RC) {
+				/* RC - class B */
+				send_ack(qp, pkt, AETH_RNR_NAK |
+					 (~AETH_TYPE_MASK &
+					 qp->attr.min_rnr_timer),
+					 pkt->psn);
+			} else {
+				/* UD/UC - class D */
+				qp->resp.drop_msg = 1;
+			}
+			state = RESPST_CLEANUP;
+			break;
+
+		case RESPST_ERR_RKEY_VIOLATION:
+			if (qp_type(qp) == IB_QPT_RC) {
+				/* Class C */
+				do_class_ac_error(qp, AETH_NAK_REM_ACC_ERR,
+						  IB_WC_REM_ACCESS_ERR);
+				state = RESPST_COMPLETE;
+			} else {
+				qp->resp.drop_msg = 1;
+				if (qp->srq) {
+					/* UC/SRQ Class D */
+					qp->resp.status = IB_WC_REM_ACCESS_ERR;
+					state = RESPST_COMPLETE;
+				} else {
+					/* UC/non-SRQ Class E. */
+					state = RESPST_CLEANUP;
+				}
+			}
+			break;
+
+		case RESPST_ERR_LENGTH:
+			if (qp_type(qp) == IB_QPT_RC) {
+				/* Class C */
+				do_class_ac_error(qp, AETH_NAK_INVALID_REQ,
+						  IB_WC_REM_INV_REQ_ERR);
+				state = RESPST_COMPLETE;
+			} else if (qp->srq) {
+				/* UC/UD - class E */
+				qp->resp.status = IB_WC_REM_INV_REQ_ERR;
+				state = RESPST_COMPLETE;
+			} else {
+				/* UC/UD - class D */
+				qp->resp.drop_msg = 1;
+				state = RESPST_CLEANUP;
+			}
+			break;
+
+		case RESPST_ERR_MALFORMED_WQE:
+			/* All, Class A. */
+			do_class_ac_error(qp, AETH_NAK_REM_OP_ERR,
+					  IB_WC_LOC_QP_OP_ERR);
+			state = RESPST_COMPLETE;
+			break;
+
+		case RESPST_ERR_CQ_OVERFLOW:
+			/* All - Class G */
+			state = RESPST_ERROR;
+			break;
+
+		case RESPST_DONE:
+			if (qp->resp.goto_error) {
+				state = RESPST_ERROR;
+				break;
+			} else
+				goto done;
+
+		case RESPST_EXIT:
+			if (qp->resp.goto_error) {
+				state = RESPST_ERROR;
+				break;
+			} else
+				goto exit;
+
+		case RESPST_RESET: {
+			struct sk_buff *skb;
+
+			while ((skb = skb_dequeue(&qp->req_pkts))) {
+				rxe_drop_ref(qp);
+				kfree_skb(skb);
+				atomic_dec(&qp->req_skb_in);
+				atomic_dec(&rxe->req_skb_in);
+			}
+
+			while (!qp->srq && qp->rq.queue &&
+			       queue_head(qp->rq.queue))
+				advance_consumer(qp->rq.queue);
+
+			qp->resp.wqe = NULL;
+			goto exit;
+		}
+
+		case RESPST_ERROR:
+			qp->resp.goto_error = 0;
+			pr_warn("qp#%d moved to error state\n", qp_num(qp));
+			rxe_qp_error(qp);
+			goto exit;
+
+		default:
+			WARN_ON(1);
+		}
+	}
+
+exit:
+	ret = -EAGAIN;
+done:
+	return ret;
+}


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