QP response logic.

Signed-off-by: Kamal Heib <kam...@mellanox.com>
Signed-off-by: Amir Vadai <am...@mellanox.com>
---
 drivers/staging/rdma/rxe/rxe_resp.c | 1368 +++++++++++++++++++++++++++++++++++
 1 file changed, 1368 insertions(+)
 create mode 100644 drivers/staging/rdma/rxe/rxe_resp.c

diff --git a/drivers/staging/rdma/rxe/rxe_resp.c 
b/drivers/staging/rdma/rxe/rxe_resp.c
new file mode 100644
index 0000000..78304c6
--- /dev/null
+++ b/drivers/staging/rdma/rxe/rxe_resp.c
@@ -0,0 +1,1368 @@
+/*
+ * Copyright (c) 2015 Mellanox Technologies Ltd. All rights reserved.
+ * Copyright (c) 2015 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.
+ */
+
+#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);
+
+       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 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);
+                       return RESPST_GET_REQ;
+               }
+
+               /* 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;
+
+                       qp->resp.sent_psn_nak = 1;
+                       return RESPST_ERR_PSN_OUT_OF_SEQ;
+
+               } else if (diff < 0) {
+                       return RESPST_DUPLICATE_REQUEST;
+               }
+
+               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;
+                       }
+
+                       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);
+
+               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);
+
+       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, to_mem_obj, 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, to_mem_obj, 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,
+                                         struct rxe_pkt_info *ack,
+                                         int opcode,
+                                         int payload,
+                                         u32 psn,
+                                         u8 syndrome)
+{
+       struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
+       struct sk_buff *skb;
+       u32 crc = 0;
+       u32 *p;
+       int paylen;
+       int pad;
+       int err;
+
+       /*
+        * 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, ack);
+       if (!skb)
+               return NULL;
+
+       ack->qp = qp;
+       ack->opcode = opcode;
+       ack->mask |= rxe_opcode[opcode].mask;
+       ack->offset = pkt->offset;
+       ack->paylen = paylen;
+
+       /* fill in bth using the request packet headers */
+       memcpy(ack->hdr, pkt->hdr, pkt->offset + RXE_BTH_BYTES);
+
+       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);
+       bth_set_ack(ack, 0);
+       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);
+
+       err = rxe->ifc_ops->prepare(rxe, ack, skb, &crc);
+       if (err) {
+               kfree_skb(skb);
+               return NULL;
+       }
+
+       p = payload_addr(ack) + payload;
+       *p = ~crc;
+
+       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 ack_pkt;
+       struct sk_buff *skb;
+       int mtu = qp->mtu;
+       enum resp_states state;
+       int payload;
+       int opcode;
+       int err;
+       struct resp_res *res = qp->resp.res;
+
+       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, &ack_pkt, opcode, payload,
+                                res->cur_psn, AETH_ACK_UNLIMITED);
+       if (!skb)
+               return RESPST_ERR_RNR;
+
+       err = rxe_mem_copy(res->read.mr, res->read.va, payload_addr(&ack_pkt),
+                          payload, from_mem_obj, NULL);
+       if (err)
+               pr_err("Failed copying memory\n");
+
+       err = rxe_xmit_packet(rxe, qp, &ack_pkt, skb);
+       if (err) {
+               pr_err("Failed sending RDMA reply.\n");
+               kfree_skb(skb);
+               return RESPST_ERR_RNR;
+       }
+
+       res->read.va += payload;
+       res->read.resid -= payload;
+       res->cur_psn = (res->cur_psn + 1) & BTH_PSN_MASK;
+
+       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) {
+                       struct ib_grh grh;
+                       struct sk_buff *skb = PKT_TO_SKB(pkt);
+
+                       memset(&grh, 0, sizeof(struct ib_grh));
+                       if (skb->protocol == htons(ETH_P_IP)) {
+                               __u8 tos = ip_hdr(skb)->tos;
+                               struct in6_addr *s_addr =
+                                       (struct in6_addr *)&grh.sgid;
+                               struct in6_addr *d_addr =
+                                       (struct in6_addr *)&grh.dgid;
+
+                               grh.version_tclass_flow =
+                                       cpu_to_be32((IPVERSION << 28) |
+                                                   (tos << 24));
+                               grh.paylen = ip_hdr(skb)->tot_len;
+                               grh.hop_limit = ip_hdr(skb)->ttl;
+                               grh.next_hdr = ip_hdr(skb)->protocol;
+                               ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
+                                                      s_addr);
+                               ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
+                                                      d_addr);
+                       } else if (skb->protocol == htons(ETH_P_IPV6)) {
+                               memcpy(&grh, ipv6_hdr(skb), sizeof(grh));
+                       }
+
+                       err = send_data_in(qp, &grh, sizeof(grh));
+                       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;
+       wc->qp                  = &qp->ibqp;
+
+       /* 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 rxe_pkt_info ack_pkt;
+       struct sk_buff *skb;
+       struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
+
+       skb = prepare_ack_packet(qp, pkt, &ack_pkt, IB_OPCODE_RC_ACKNOWLEDGE,
+                                0, psn, syndrome);
+       if (!skb) {
+               err = -ENOMEM;
+               goto err1;
+       }
+
+       err = rxe_xmit_packet(rxe, qp, &ack_pkt, skb);
+       if (err) {
+               pr_err("Failed sending ack. This flow is not handled - skb 
ignored\n");
+               kfree_skb(skb);
+       }
+
+err1:
+       return err;
+}
+
+static int send_atomic_ack(struct rxe_qp *qp, struct rxe_pkt_info *pkt,
+                          u8 syndrome)
+{
+       int rc = 0;
+       struct rxe_pkt_info ack_pkt;
+       struct sk_buff *skb;
+       struct sk_buff *skb_copy;
+       struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
+       struct resp_res *res;
+
+       skb = prepare_ack_packet(qp, pkt, &ack_pkt,
+                                IB_OPCODE_RC_ATOMIC_ACKNOWLEDGE, 0, pkt->psn,
+                                syndrome);
+       if (!skb) {
+               rc = -ENOMEM;
+               goto out;
+       }
+
+       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 */
+       else
+               pr_warn("Could not clone atomic response\n");
+
+       rc = rxe_xmit_packet(rxe, qp, &ack_pkt, skb_copy);
+       if (rc) {
+               pr_err("Failed sending atomic ack. This flow is not handled - 
skb ignored\n");
+               rxe_drop_ref(qp);
+               kfree_skb(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;
+
+       if (pkt) {
+               skb = skb_dequeue(&qp->req_pkts);
+               rxe_drop_ref(qp);
+               kfree_skb(skb);
+       }
+
+       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;
+
+       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) {
+                       /* Resource 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 */
+                       } 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. */
+                       rc = rxe_xmit_packet(to_rdev(qp->ibqp.device), qp,
+                                            pkt, skb_copy);
+                       if (rc) {
+                               pr_err("Failed resending result. This flow is 
not handled - skb ignored\n");
+                               kfree_skb(skb_copy);
+                               rc = RESPST_CLEANUP;
+                               goto out;
+                       }
+               }
+
+               /* Resource 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_CLEANUP;
+       }
+}
+
+int rxe_responder(void *arg)
+{
+       struct rxe_qp *qp = (struct rxe_qp *)arg;
+       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;
+                       }
+
+                       goto done;
+
+               case RESPST_EXIT:
+                       if (qp->resp.goto_error) {
+                               state = RESPST_ERROR;
+                               break;
+                       }
+
+                       goto exit;
+
+               case RESPST_RESET: {
+                       struct sk_buff *skb;
+
+                       while ((skb = skb_dequeue(&qp->req_pkts))) {
+                               rxe_drop_ref(qp);
+                               kfree_skb(skb);
+                       }
+
+                       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;
+}
-- 
1.8.3.1

--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to