IB/ipath: Fix lost UD send work request
[safe/jmp/linux-2.6] / drivers / infiniband / hw / ipath / ipath_ruc.c
index 9a456a7..af051f7 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2006 QLogic, Inc. All rights reserved.
+ * Copyright (c) 2006, 2007, 2008 QLogic Corporation. All rights reserved.
  * Copyright (c) 2005, 2006 PathScale, Inc. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * SOFTWARE.
  */
 
+#include <linux/spinlock.h>
+
 #include "ipath_verbs.h"
-#include "ips_common.h"
+#include "ipath_kernel.h"
 
 /*
  * Convert the AETH RNR timeout code into the number of milliseconds.
@@ -76,6 +78,7 @@ const u32 ib_ipath_rnr_table[32] = {
  * ipath_insert_rnr_queue - put QP on the RNR timeout list for the device
  * @qp: the QP
  *
+ * Called with the QP s_lock held and interrupts disabled.
  * XXX Use a simple list for now.  We might need a priority
  * queue if we have lots of QPs waiting for RNR timeouts
  * but that should be rare.
@@ -83,9 +86,9 @@ const u32 ib_ipath_rnr_table[32] = {
 void ipath_insert_rnr_queue(struct ipath_qp *qp)
 {
        struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
-       unsigned long flags;
 
-       spin_lock_irqsave(&dev->pending_lock, flags);
+       /* We already did a spin_lock_irqsave(), so just use spin_lock */
+       spin_lock(&dev->pending_lock);
        if (list_empty(&dev->rnrwait))
                list_add(&qp->timerwait, &dev->rnrwait);
        else {
@@ -96,14 +99,58 @@ void ipath_insert_rnr_queue(struct ipath_qp *qp)
                while (qp->s_rnr_timeout >= nqp->s_rnr_timeout) {
                        qp->s_rnr_timeout -= nqp->s_rnr_timeout;
                        l = l->next;
-                       if (l->next == &dev->rnrwait)
+                       if (l->next == &dev->rnrwait) {
+                               nqp = NULL;
                                break;
+                       }
                        nqp = list_entry(l->next, struct ipath_qp,
                                         timerwait);
                }
+               if (nqp)
+                       nqp->s_rnr_timeout -= qp->s_rnr_timeout;
                list_add(&qp->timerwait, l);
        }
-       spin_unlock_irqrestore(&dev->pending_lock, flags);
+       spin_unlock(&dev->pending_lock);
+}
+
+/**
+ * ipath_init_sge - Validate a RWQE and fill in the SGE state
+ * @qp: the QP
+ *
+ * Return 1 if OK.
+ */
+int ipath_init_sge(struct ipath_qp *qp, struct ipath_rwqe *wqe,
+                  u32 *lengthp, struct ipath_sge_state *ss)
+{
+       int i, j, ret;
+       struct ib_wc wc;
+
+       *lengthp = 0;
+       for (i = j = 0; i < wqe->num_sge; i++) {
+               if (wqe->sg_list[i].length == 0)
+                       continue;
+               /* Check LKEY */
+               if (!ipath_lkey_ok(qp, j ? &ss->sg_list[j - 1] : &ss->sge,
+                                  &wqe->sg_list[i], IB_ACCESS_LOCAL_WRITE))
+                       goto bad_lkey;
+               *lengthp += wqe->sg_list[i].length;
+               j++;
+       }
+       ss->num_sge = j;
+       ret = 1;
+       goto bail;
+
+bad_lkey:
+       memset(&wc, 0, sizeof(wc));
+       wc.wr_id = wqe->wr_id;
+       wc.status = IB_WC_LOC_PROT_ERR;
+       wc.opcode = IB_WC_RECV;
+       wc.qp = &qp->ibqp;
+       /* Signal solicited completion event. */
+       ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc, 1);
+       ret = 0;
+bail:
+       return ret;
 }
 
 /**
@@ -113,84 +160,96 @@ void ipath_insert_rnr_queue(struct ipath_qp *qp)
  *
  * Return 0 if no RWQE is available, otherwise return 1.
  *
- * Called at interrupt level with the QP r_rq.lock held.
+ * Can be called from interrupt level.
  */
 int ipath_get_rwqe(struct ipath_qp *qp, int wr_id_only)
 {
+       unsigned long flags;
        struct ipath_rq *rq;
+       struct ipath_rwq *wq;
        struct ipath_srq *srq;
        struct ipath_rwqe *wqe;
+       void (*handler)(struct ib_event *, void *);
+       u32 tail;
        int ret;
 
-       if (!qp->ibqp.srq) {
+       qp->r_sge.sg_list = qp->r_sg_list;
+
+       if (qp->ibqp.srq) {
+               srq = to_isrq(qp->ibqp.srq);
+               handler = srq->ibsrq.event_handler;
+               rq = &srq->rq;
+       } else {
+               srq = NULL;
+               handler = NULL;
                rq = &qp->r_rq;
-               if (unlikely(rq->tail == rq->head)) {
-                       ret = 0;
-                       goto bail;
-               }
-               wqe = get_rwqe_ptr(rq, rq->tail);
-               qp->r_wr_id = wqe->wr_id;
-               if (!wr_id_only) {
-                       qp->r_sge.sge = wqe->sg_list[0];
-                       qp->r_sge.sg_list = wqe->sg_list + 1;
-                       qp->r_sge.num_sge = wqe->num_sge;
-                       qp->r_len = wqe->length;
-               }
-               if (++rq->tail >= rq->size)
-                       rq->tail = 0;
-               ret = 1;
-               goto bail;
        }
 
-       srq = to_isrq(qp->ibqp.srq);
-       rq = &srq->rq;
-       spin_lock(&rq->lock);
-       if (unlikely(rq->tail == rq->head)) {
-               spin_unlock(&rq->lock);
+       spin_lock_irqsave(&rq->lock, flags);
+       if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK)) {
                ret = 0;
-               goto bail;
+               goto unlock;
        }
-       wqe = get_rwqe_ptr(rq, rq->tail);
+
+       wq = rq->wq;
+       tail = wq->tail;
+       /* Validate tail before using it since it is user writable. */
+       if (tail >= rq->size)
+               tail = 0;
+       do {
+               if (unlikely(tail == wq->head)) {
+                       ret = 0;
+                       goto unlock;
+               }
+               /* Make sure entry is read after head index is read. */
+               smp_rmb();
+               wqe = get_rwqe_ptr(rq, tail);
+               if (++tail >= rq->size)
+                       tail = 0;
+       } while (!wr_id_only && !ipath_init_sge(qp, wqe, &qp->r_len,
+                                               &qp->r_sge));
        qp->r_wr_id = wqe->wr_id;
-       if (!wr_id_only) {
-               qp->r_sge.sge = wqe->sg_list[0];
-               qp->r_sge.sg_list = wqe->sg_list + 1;
-               qp->r_sge.num_sge = wqe->num_sge;
-               qp->r_len = wqe->length;
-       }
-       if (++rq->tail >= rq->size)
-               rq->tail = 0;
-       if (srq->ibsrq.event_handler) {
-               struct ib_event ev;
+       wq->tail = tail;
+
+       ret = 1;
+       set_bit(IPATH_R_WRID_VALID, &qp->r_aflags);
+       if (handler) {
                u32 n;
 
-               if (rq->head < rq->tail)
-                       n = rq->size + rq->head - rq->tail;
+               /*
+                * validate head pointer value and compute
+                * the number of remaining WQEs.
+                */
+               n = wq->head;
+               if (n >= rq->size)
+                       n = 0;
+               if (n < tail)
+                       n += rq->size - tail;
                else
-                       n = rq->head - rq->tail;
+                       n -= tail;
                if (n < srq->limit) {
+                       struct ib_event ev;
+
                        srq->limit = 0;
-                       spin_unlock(&rq->lock);
+                       spin_unlock_irqrestore(&rq->lock, flags);
                        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);
-               } else
-                       spin_unlock(&rq->lock);
-       } else
-               spin_unlock(&rq->lock);
-       ret = 1;
-
+                       handler(&ev, srq->ibsrq.srq_context);
+                       goto bail;
+               }
+       }
+unlock:
+       spin_unlock_irqrestore(&rq->lock, flags);
 bail:
        return ret;
 }
 
 /**
  * ipath_ruc_loopback - handle UC and RC lookback requests
- * @sqp: the loopback QP
+ * @sqp: the sending QP
  *
- * This is called from ipath_do_uc_send() or ipath_do_rc_send() to
+ * This is called from ipath_do_send() to
  * forward a WQE addressed to the same HCA.
  * Note that although we are single threaded due to the tasklet, we still
  * have to protect against post_send().  We don't have to worry about
@@ -206,37 +265,64 @@ static void ipath_ruc_loopback(struct ipath_qp *sqp)
        unsigned long flags;
        struct ib_wc wc;
        u64 sdata;
+       atomic64_t *maddr;
+       enum ib_wc_status send_status;
 
+       /*
+        * Note that we check the responder QP state after
+        * checking the requester's state.
+        */
        qp = ipath_lookup_qpn(&dev->qp_table, sqp->remote_qpn);
-       if (!qp) {
-               dev->n_pkt_drops++;
-               return;
-       }
 
-again:
        spin_lock_irqsave(&sqp->s_lock, flags);
 
-       if (!(ib_ipath_state_ops[sqp->state] & IPATH_PROCESS_SEND_OK)) {
-               spin_unlock_irqrestore(&sqp->s_lock, flags);
-               goto done;
-       }
+       /* Return if we are already busy processing a work request. */
+       if ((sqp->s_flags & (IPATH_S_BUSY | IPATH_S_ANY_WAIT)) ||
+           !(ib_ipath_state_ops[sqp->state] & IPATH_PROCESS_OR_FLUSH_SEND))
+               goto unlock;
 
-       /* Get the next send request. */
-       if (sqp->s_last == sqp->s_head) {
-               /* Send work queue is empty. */
-               spin_unlock_irqrestore(&sqp->s_lock, flags);
-               goto done;
+       sqp->s_flags |= IPATH_S_BUSY;
+
+again:
+       if (sqp->s_last == sqp->s_head)
+               goto clr_busy;
+       wqe = get_swqe_ptr(sqp, sqp->s_last);
+
+       /* Return if it is not OK to start a new work reqeust. */
+       if (!(ib_ipath_state_ops[sqp->state] & IPATH_PROCESS_NEXT_SEND_OK)) {
+               if (!(ib_ipath_state_ops[sqp->state] & IPATH_FLUSH_SEND))
+                       goto clr_busy;
+               /* We are in the error state, flush the work request. */
+               send_status = IB_WC_WR_FLUSH_ERR;
+               goto flush_send;
        }
 
        /*
         * We can rely on the entry not changing without the s_lock
         * being held until we update s_last.
+        * We increment s_cur to indicate s_last is in progress.
         */
-       wqe = get_swqe_ptr(sqp, sqp->s_last);
+       if (sqp->s_last == sqp->s_cur) {
+               if (++sqp->s_cur >= sqp->s_size)
+                       sqp->s_cur = 0;
+       }
        spin_unlock_irqrestore(&sqp->s_lock, flags);
 
-       wc.wc_flags = 0;
-       wc.imm_data = 0;
+       if (!qp || !(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK)) {
+               dev->n_pkt_drops++;
+               /*
+                * For RC, the requester would timeout and retry so
+                * shortcut the timeouts and just signal too many retries.
+                */
+               if (sqp->ibqp.qp_type == IB_QPT_RC)
+                       send_status = IB_WC_RETRY_EXC_ERR;
+               else
+                       send_status = IB_WC_SUCCESS;
+               goto serr;
+       }
+
+       memset(&wc, 0, sizeof wc);
+       send_status = IB_WC_SUCCESS;
 
        sqp->s_sge.sge = wqe->sg_list[0];
        sqp->s_sge.sg_list = wqe->sg_list + 1;
@@ -245,74 +331,41 @@ again:
        switch (wqe->wr.opcode) {
        case IB_WR_SEND_WITH_IMM:
                wc.wc_flags = IB_WC_WITH_IMM;
-               wc.imm_data = wqe->wr.imm_data;
+               wc.ex.imm_data = wqe->wr.ex.imm_data;
                /* FALLTHROUGH */
        case IB_WR_SEND:
-               spin_lock_irqsave(&qp->r_rq.lock, flags);
-               if (!ipath_get_rwqe(qp, 0)) {
-               rnr_nak:
-                       spin_unlock_irqrestore(&qp->r_rq.lock, flags);
-                       /* Handle RNR NAK */
-                       if (qp->ibqp.qp_type == IB_QPT_UC)
-                               goto send_comp;
-                       if (sqp->s_rnr_retry == 0) {
-                               wc.status = IB_WC_RNR_RETRY_EXC_ERR;
-                               goto err;
-                       }
-                       if (sqp->s_rnr_retry_cnt < 7)
-                               sqp->s_rnr_retry--;
-                       dev->n_rnr_naks++;
-                       sqp->s_rnr_timeout =
-                               ib_ipath_rnr_table[sqp->s_min_rnr_timer];
-                       ipath_insert_rnr_queue(sqp);
-                       goto done;
-               }
-               spin_unlock_irqrestore(&qp->r_rq.lock, flags);
+               if (!ipath_get_rwqe(qp, 0))
+                       goto rnr_nak;
                break;
 
        case IB_WR_RDMA_WRITE_WITH_IMM:
+               if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE)))
+                       goto inv_err;
                wc.wc_flags = IB_WC_WITH_IMM;
-               wc.imm_data = wqe->wr.imm_data;
-               spin_lock_irqsave(&qp->r_rq.lock, flags);
+               wc.ex.imm_data = wqe->wr.ex.imm_data;
                if (!ipath_get_rwqe(qp, 1))
                        goto rnr_nak;
-               spin_unlock_irqrestore(&qp->r_rq.lock, flags);
                /* FALLTHROUGH */
        case IB_WR_RDMA_WRITE:
+               if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE)))
+                       goto inv_err;
                if (wqe->length == 0)
                        break;
-               if (unlikely(!ipath_rkey_ok(dev, &qp->r_sge, wqe->length,
+               if (unlikely(!ipath_rkey_ok(qp, &qp->r_sge, wqe->length,
                                            wqe->wr.wr.rdma.remote_addr,
                                            wqe->wr.wr.rdma.rkey,
-                                           IB_ACCESS_REMOTE_WRITE))) {
-               acc_err:
-                       wc.status = IB_WC_REM_ACCESS_ERR;
-               err:
-                       wc.wr_id = wqe->wr.wr_id;
-                       wc.opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
-                       wc.vendor_err = 0;
-                       wc.byte_len = 0;
-                       wc.qp_num = sqp->ibqp.qp_num;
-                       wc.src_qp = sqp->remote_qpn;
-                       wc.pkey_index = 0;
-                       wc.slid = sqp->remote_ah_attr.dlid;
-                       wc.sl = sqp->remote_ah_attr.sl;
-                       wc.dlid_path_bits = 0;
-                       wc.port_num = 0;
-                       ipath_sqerror_qp(sqp, &wc);
-                       goto done;
-               }
+                                           IB_ACCESS_REMOTE_WRITE)))
+                       goto acc_err;
                break;
 
        case IB_WR_RDMA_READ:
-               if (unlikely(!ipath_rkey_ok(dev, &sqp->s_sge, wqe->length,
+               if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_READ)))
+                       goto inv_err;
+               if (unlikely(!ipath_rkey_ok(qp, &sqp->s_sge, wqe->length,
                                            wqe->wr.wr.rdma.remote_addr,
                                            wqe->wr.wr.rdma.rkey,
                                            IB_ACCESS_REMOTE_READ)))
                        goto acc_err;
-               if (unlikely(!(qp->qp_access_flags &
-                              IB_ACCESS_REMOTE_READ)))
-                       goto acc_err;
                qp->r_sge.sge = wqe->sg_list[0];
                qp->r_sge.sg_list = wqe->sg_list + 1;
                qp->r_sge.num_sge = wqe->wr.num_sge;
@@ -320,26 +373,26 @@ again:
 
        case IB_WR_ATOMIC_CMP_AND_SWP:
        case IB_WR_ATOMIC_FETCH_AND_ADD:
-               if (unlikely(!ipath_rkey_ok(dev, &qp->r_sge, sizeof(u64),
-                                           wqe->wr.wr.rdma.remote_addr,
-                                           wqe->wr.wr.rdma.rkey,
+               if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_ATOMIC)))
+                       goto inv_err;
+               if (unlikely(!ipath_rkey_ok(qp, &qp->r_sge, sizeof(u64),
+                                           wqe->wr.wr.atomic.remote_addr,
+                                           wqe->wr.wr.atomic.rkey,
                                            IB_ACCESS_REMOTE_ATOMIC)))
                        goto acc_err;
                /* Perform atomic OP and save result. */
-               sdata = wqe->wr.wr.atomic.swap;
-               spin_lock_irqsave(&dev->pending_lock, flags);
-               qp->r_atomic_data = *(u64 *) qp->r_sge.sge.vaddr;
-               if (wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)
-                       *(u64 *) qp->r_sge.sge.vaddr =
-                               qp->r_atomic_data + sdata;
-               else if (qp->r_atomic_data == wqe->wr.wr.atomic.compare_add)
-                       *(u64 *) qp->r_sge.sge.vaddr = sdata;
-               spin_unlock_irqrestore(&dev->pending_lock, flags);
-               *(u64 *) sqp->s_sge.sge.vaddr = qp->r_atomic_data;
+               maddr = (atomic64_t *) qp->r_sge.sge.vaddr;
+               sdata = wqe->wr.wr.atomic.compare_add;
+               *(u64 *) sqp->s_sge.sge.vaddr =
+                       (wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) ?
+                       (u64) atomic64_add_return(sdata, maddr) - sdata :
+                       (u64) cmpxchg((u64 *) qp->r_sge.sge.vaddr,
+                                     sdata, wqe->wr.wr.atomic.swap);
                goto send_comp;
 
        default:
-               goto done;
+               send_status = IB_WC_LOC_QP_OP_ERR;
+               goto serr;
        }
 
        sge = &sqp->s_sge.sge;
@@ -348,6 +401,8 @@ again:
 
                if (len > sge->length)
                        len = sge->length;
+               if (len > sge->sge_length)
+                       len = sge->sge_length;
                BUG_ON(len == 0);
                ipath_copy_sge(&qp->r_sge, sge->vaddr, len);
                sge->vaddr += len;
@@ -370,8 +425,7 @@ again:
                sqp->s_len -= len;
        }
 
-       if (wqe->wr.opcode == IB_WR_RDMA_WRITE ||
-           wqe->wr.opcode == IB_WR_RDMA_READ)
+       if (!test_and_clear_bit(IPATH_R_WRID_VALID, &qp->r_aflags))
                goto send_comp;
 
        if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM)
@@ -380,166 +434,135 @@ again:
                wc.opcode = IB_WC_RECV;
        wc.wr_id = qp->r_wr_id;
        wc.status = IB_WC_SUCCESS;
-       wc.vendor_err = 0;
        wc.byte_len = wqe->length;
-       wc.qp_num = qp->ibqp.qp_num;
+       wc.qp = &qp->ibqp;
        wc.src_qp = qp->remote_qpn;
-       /* XXX do we know which pkey matched? Only needed for GSI. */
-       wc.pkey_index = 0;
        wc.slid = qp->remote_ah_attr.dlid;
        wc.sl = qp->remote_ah_attr.sl;
-       wc.dlid_path_bits = 0;
+       wc.port_num = 1;
        /* Signal completion event if the solicited bit is set. */
        ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
                       wqe->wr.send_flags & IB_SEND_SOLICITED);
 
 send_comp:
+       spin_lock_irqsave(&sqp->s_lock, flags);
+flush_send:
        sqp->s_rnr_retry = sqp->s_rnr_retry_cnt;
+       ipath_send_complete(sqp, wqe, send_status);
+       goto again;
 
-       if (!test_bit(IPATH_S_SIGNAL_REQ_WR, &sqp->s_flags) ||
-           (wqe->wr.send_flags & IB_SEND_SIGNALED)) {
-               wc.wr_id = wqe->wr.wr_id;
-               wc.status = IB_WC_SUCCESS;
-               wc.opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
-               wc.vendor_err = 0;
-               wc.byte_len = wqe->length;
-               wc.qp_num = sqp->ibqp.qp_num;
-               wc.src_qp = 0;
-               wc.pkey_index = 0;
-               wc.slid = 0;
-               wc.sl = 0;
-               wc.dlid_path_bits = 0;
-               wc.port_num = 0;
-               ipath_cq_enter(to_icq(sqp->ibqp.send_cq), &wc, 0);
+rnr_nak:
+       /* Handle RNR NAK */
+       if (qp->ibqp.qp_type == IB_QPT_UC)
+               goto send_comp;
+       /*
+        * Note: we don't need the s_lock held since the BUSY flag
+        * makes this single threaded.
+        */
+       if (sqp->s_rnr_retry == 0) {
+               send_status = IB_WC_RNR_RETRY_EXC_ERR;
+               goto serr;
        }
-
-       /* Update s_last now that we are finished with the SWQE */
+       if (sqp->s_rnr_retry_cnt < 7)
+               sqp->s_rnr_retry--;
        spin_lock_irqsave(&sqp->s_lock, flags);
-       if (++sqp->s_last >= sqp->s_size)
-               sqp->s_last = 0;
-       spin_unlock_irqrestore(&sqp->s_lock, flags);
-       goto again;
+       if (!(ib_ipath_state_ops[sqp->state] & IPATH_PROCESS_RECV_OK))
+               goto clr_busy;
+       sqp->s_flags |= IPATH_S_WAITING;
+       dev->n_rnr_naks++;
+       sqp->s_rnr_timeout = ib_ipath_rnr_table[qp->r_min_rnr_timer];
+       ipath_insert_rnr_queue(sqp);
+       goto clr_busy;
+
+inv_err:
+       send_status = IB_WC_REM_INV_REQ_ERR;
+       wc.status = IB_WC_LOC_QP_OP_ERR;
+       goto err;
+
+acc_err:
+       send_status = IB_WC_REM_ACCESS_ERR;
+       wc.status = IB_WC_LOC_PROT_ERR;
+err:
+       /* responder goes to error state */
+       ipath_rc_error(qp, wc.status);
+
+serr:
+       spin_lock_irqsave(&sqp->s_lock, flags);
+       ipath_send_complete(sqp, wqe, send_status);
+       if (sqp->ibqp.qp_type == IB_QPT_RC) {
+               int lastwqe = ipath_error_qp(sqp, IB_WC_WR_FLUSH_ERR);
+
+               sqp->s_flags &= ~IPATH_S_BUSY;
+               spin_unlock_irqrestore(&sqp->s_lock, flags);
+               if (lastwqe) {
+                       struct ib_event ev;
 
+                       ev.device = sqp->ibqp.device;
+                       ev.element.qp = &sqp->ibqp;
+                       ev.event = IB_EVENT_QP_LAST_WQE_REACHED;
+                       sqp->ibqp.event_handler(&ev, sqp->ibqp.qp_context);
+               }
+               goto done;
+       }
+clr_busy:
+       sqp->s_flags &= ~IPATH_S_BUSY;
+unlock:
+       spin_unlock_irqrestore(&sqp->s_lock, flags);
 done:
-       if (atomic_dec_and_test(&qp->refcount))
+       if (qp && atomic_dec_and_test(&qp->refcount))
                wake_up(&qp->wait);
 }
 
+static void want_buffer(struct ipath_devdata *dd, struct ipath_qp *qp)
+{
+       if (!(dd->ipath_flags & IPATH_HAS_SEND_DMA) ||
+           qp->ibqp.qp_type == IB_QPT_SMI) {
+               unsigned long flags;
+
+               spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
+               dd->ipath_sendctrl |= INFINIPATH_S_PIOINTBUFAVAIL;
+               ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
+                                dd->ipath_sendctrl);
+               ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
+               spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);
+       }
+}
+
 /**
  * ipath_no_bufs_available - tell the layer driver we need buffers
  * @qp: the QP that caused the problem
  * @dev: the device we ran out of buffers on
  *
  * Called when we run out of PIO buffers.
+ * If we are now in the error state, return zero to flush the
+ * send work request.
  */
-void ipath_no_bufs_available(struct ipath_qp *qp, struct ipath_ibdev *dev)
+static int ipath_no_bufs_available(struct ipath_qp *qp,
+                                   struct ipath_ibdev *dev)
 {
        unsigned long flags;
+       int ret = 1;
 
-       spin_lock_irqsave(&dev->pending_lock, flags);
-       if (list_empty(&qp->piowait))
-               list_add_tail(&qp->piowait, &dev->piowait);
-       spin_unlock_irqrestore(&dev->pending_lock, flags);
        /*
-        * Note that as soon as ipath_layer_want_buffer() is called and
+        * Note that as soon as want_buffer() is called and
         * possibly before it returns, ipath_ib_piobufavail()
-        * could be called.  If we are still in the tasklet function,
-        * tasklet_hi_schedule() will not call us until the next time
-        * tasklet_hi_schedule() is called.
-        * We clear the tasklet flag now since we are committing to return
-        * from the tasklet function.
+        * could be called. Therefore, put QP on the piowait list before
+        * enabling the PIO avail interrupt.
         */
-       clear_bit(IPATH_S_BUSY, &qp->s_flags);
-       tasklet_unlock(&qp->s_task);
-       ipath_layer_want_buffer(dev->dd);
-       dev->n_piowait++;
-}
-
-/**
- * ipath_post_ruc_send - post RC and UC sends
- * @qp: the QP to post on
- * @wr: the work request to send
- */
-int ipath_post_ruc_send(struct ipath_qp *qp, struct ib_send_wr *wr)
-{
-       struct ipath_swqe *wqe;
-       unsigned long flags;
-       u32 next;
-       int i, j;
-       int acc;
-       int ret;
-
-       /*
-        * Don't allow RDMA reads or atomic operations on UC or
-        * undefined operations.
-        * Make sure buffer is large enough to hold the result for atomics.
-        */
-       if (qp->ibqp.qp_type == IB_QPT_UC) {
-               if ((unsigned) wr->opcode >= IB_WR_RDMA_READ) {
-                       ret = -EINVAL;
-                       goto bail;
-               }
-       } else if ((unsigned) wr->opcode > IB_WR_ATOMIC_FETCH_AND_ADD) {
-               ret = -EINVAL;
-               goto bail;
-       } else if (wr->opcode >= IB_WR_ATOMIC_CMP_AND_SWP &&
-                  (wr->num_sge == 0 ||
-                   wr->sg_list[0].length < sizeof(u64) ||
-                   wr->sg_list[0].addr & (sizeof(u64) - 1))) {
-               ret = -EINVAL;
-               goto bail;
-       }
-       /* IB spec says that num_sge == 0 is OK. */
-       if (wr->num_sge > qp->s_max_sge) {
-               ret = -ENOMEM;
-               goto bail;
-       }
        spin_lock_irqsave(&qp->s_lock, flags);
-       next = qp->s_head + 1;
-       if (next >= qp->s_size)
-               next = 0;
-       if (next == qp->s_last) {
-               spin_unlock_irqrestore(&qp->s_lock, flags);
-               ret = -EINVAL;
-               goto bail;
-       }
-
-       wqe = get_swqe_ptr(qp, qp->s_head);
-       wqe->wr = *wr;
-       wqe->ssn = qp->s_ssn++;
-       wqe->sg_list[0].mr = NULL;
-       wqe->sg_list[0].vaddr = NULL;
-       wqe->sg_list[0].length = 0;
-       wqe->sg_list[0].sge_length = 0;
-       wqe->length = 0;
-       acc = wr->opcode >= IB_WR_RDMA_READ ? IB_ACCESS_LOCAL_WRITE : 0;
-       for (i = 0, j = 0; i < wr->num_sge; i++) {
-               if (to_ipd(qp->ibqp.pd)->user && wr->sg_list[i].lkey == 0) {
-                       spin_unlock_irqrestore(&qp->s_lock, flags);
-                       ret = -EINVAL;
-                       goto bail;
-               }
-               if (wr->sg_list[i].length == 0)
-                       continue;
-               if (!ipath_lkey_ok(&to_idev(qp->ibqp.device)->lk_table,
-                                  &wqe->sg_list[j], &wr->sg_list[i],
-                                  acc)) {
-                       spin_unlock_irqrestore(&qp->s_lock, flags);
-                       ret = -EINVAL;
-                       goto bail;
-               }
-               wqe->length += wr->sg_list[i].length;
-               j++;
-       }
-       wqe->wr.num_sge = j;
-       qp->s_head = next;
+       if (ib_ipath_state_ops[qp->state] & IPATH_PROCESS_SEND_OK) {
+               dev->n_piowait++;
+               qp->s_flags |= IPATH_S_WAITING;
+               qp->s_flags &= ~IPATH_S_BUSY;
+               spin_lock(&dev->pending_lock);
+               if (list_empty(&qp->piowait))
+                       list_add_tail(&qp->piowait, &dev->piowait);
+               spin_unlock(&dev->pending_lock);
+       } else
+               ret = 0;
        spin_unlock_irqrestore(&qp->s_lock, flags);
-
-       ipath_do_ruc_send((unsigned long) qp);
-
-       ret = 0;
-
-bail:
+       if (ret)
+               want_buffer(dev->dd, qp);
        return ret;
 }
 
@@ -566,47 +589,84 @@ u32 ipath_make_grh(struct ipath_ibdev *dev, struct ib_grh *hdr,
        hdr->hop_limit = grh->hop_limit;
        /* The SGID is 32-bit aligned. */
        hdr->sgid.global.subnet_prefix = dev->gid_prefix;
-       hdr->sgid.global.interface_id = ipath_layer_get_guid(dev->dd);
+       hdr->sgid.global.interface_id = dev->dd->ipath_guid;
        hdr->dgid = grh->dgid;
 
        /* GRH header size in 32-bit words. */
        return sizeof(struct ib_grh) / sizeof(u32);
 }
 
+void ipath_make_ruc_header(struct ipath_ibdev *dev, struct ipath_qp *qp,
+                          struct ipath_other_headers *ohdr,
+                          u32 bth0, u32 bth2)
+{
+       u16 lrh0;
+       u32 nwords;
+       u32 extra_bytes;
+
+       /* Construct the header. */
+       extra_bytes = -qp->s_cur_size & 3;
+       nwords = (qp->s_cur_size + extra_bytes) >> 2;
+       lrh0 = IPATH_LRH_BTH;
+       if (unlikely(qp->remote_ah_attr.ah_flags & IB_AH_GRH)) {
+               qp->s_hdrwords += ipath_make_grh(dev, &qp->s_hdr.u.l.grh,
+                                                &qp->remote_ah_attr.grh,
+                                                qp->s_hdrwords, nwords);
+               lrh0 = IPATH_LRH_GRH;
+       }
+       lrh0 |= qp->remote_ah_attr.sl << 4;
+       qp->s_hdr.lrh[0] = cpu_to_be16(lrh0);
+       qp->s_hdr.lrh[1] = cpu_to_be16(qp->remote_ah_attr.dlid);
+       qp->s_hdr.lrh[2] = cpu_to_be16(qp->s_hdrwords + nwords + SIZE_OF_CRC);
+       qp->s_hdr.lrh[3] = cpu_to_be16(dev->dd->ipath_lid);
+       bth0 |= ipath_get_pkey(dev->dd, qp->s_pkey_index);
+       bth0 |= extra_bytes << 20;
+       ohdr->bth[0] = cpu_to_be32(bth0 | (1 << 22));
+       ohdr->bth[1] = cpu_to_be32(qp->remote_qpn);
+       ohdr->bth[2] = cpu_to_be32(bth2);
+}
+
 /**
- * ipath_do_ruc_send - perform a send on an RC or UC QP
+ * ipath_do_send - perform a send on a QP
  * @data: contains a pointer to the QP
  *
  * Process entries in the send work queue until credit or queue is
  * exhausted.  Only allow one CPU to send a packet per QP (tasklet).
- * Otherwise, after we drop the QP s_lock, two threads could send
- * packets out of order.
+ * Otherwise, two threads could send packets out of order.
  */
-void ipath_do_ruc_send(unsigned long data)
+void ipath_do_send(unsigned long data)
 {
        struct ipath_qp *qp = (struct ipath_qp *)data;
        struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
+       int (*make_req)(struct ipath_qp *qp);
        unsigned long flags;
-       u16 lrh0;
-       u32 nwords;
-       u32 extra_bytes;
-       u32 bth0;
-       u32 bth2;
-       u32 pmtu = ib_mtu_enum_to_int(qp->path_mtu);
-       struct ipath_other_headers *ohdr;
 
-       if (test_and_set_bit(IPATH_S_BUSY, &qp->s_flags))
+       if ((qp->ibqp.qp_type == IB_QPT_RC ||
+            qp->ibqp.qp_type == IB_QPT_UC) &&
+           qp->remote_ah_attr.dlid == dev->dd->ipath_lid) {
+               ipath_ruc_loopback(qp);
                goto bail;
+       }
 
-       if (unlikely(qp->remote_ah_attr.dlid ==
-                    ipath_layer_get_lid(dev->dd))) {
-               ipath_ruc_loopback(qp);
-               goto clear;
+       if (qp->ibqp.qp_type == IB_QPT_RC)
+              make_req = ipath_make_rc_req;
+       else if (qp->ibqp.qp_type == IB_QPT_UC)
+              make_req = ipath_make_uc_req;
+       else
+              make_req = ipath_make_ud_req;
+
+       spin_lock_irqsave(&qp->s_lock, flags);
+
+       /* Return if we are already busy processing a work request. */
+       if ((qp->s_flags & (IPATH_S_BUSY | IPATH_S_ANY_WAIT)) ||
+           !(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_OR_FLUSH_SEND)) {
+               spin_unlock_irqrestore(&qp->s_lock, flags);
+               goto bail;
        }
 
-       ohdr = &qp->s_hdr.u.oth;
-       if (qp->remote_ah_attr.ah_flags & IB_AH_GRH)
-               ohdr = &qp->s_hdr.u.l.oth;
+       qp->s_flags |= IPATH_S_BUSY;
+
+       spin_unlock_irqrestore(&qp->s_lock, flags);
 
 again:
        /* Check for a constructed packet to be sent. */
@@ -615,69 +675,58 @@ again:
                 * If no PIO bufs are available, return.  An interrupt will
                 * call ipath_ib_piobufavail() when one is available.
                 */
-               if (ipath_verbs_send(dev->dd, qp->s_hdrwords,
-                                    (u32 *) &qp->s_hdr, qp->s_cur_size,
-                                    qp->s_cur_sge)) {
-                       ipath_no_bufs_available(qp, dev);
-                       goto bail;
+               if (ipath_verbs_send(qp, &qp->s_hdr, qp->s_hdrwords,
+                                    qp->s_cur_sge, qp->s_cur_size)) {
+                       if (ipath_no_bufs_available(qp, dev))
+                               goto bail;
                }
                dev->n_unicast_xmit++;
                /* Record that we sent the packet and s_hdr is empty. */
                qp->s_hdrwords = 0;
        }
 
-       /*
-        * The lock is needed to synchronize between setting
-        * qp->s_ack_state, resend timer, and post_send().
-        */
-       spin_lock_irqsave(&qp->s_lock, flags);
+       if (make_req(qp))
+               goto again;
 
-       /* Sending responses has higher priority over sending requests. */
-       if (qp->s_ack_state != IB_OPCODE_RC_ACKNOWLEDGE &&
-           (bth0 = ipath_make_rc_ack(qp, ohdr, pmtu)) != 0)
-               bth2 = qp->s_ack_psn++ & IPS_PSN_MASK;
-       else if (!((qp->ibqp.qp_type == IB_QPT_RC) ?
-                  ipath_make_rc_req(qp, ohdr, pmtu, &bth0, &bth2) :
-                  ipath_make_uc_req(qp, ohdr, pmtu, &bth0, &bth2))) {
-               /*
-                * Clear the busy bit before unlocking to avoid races with
-                * adding new work queue items and then failing to process
-                * them.
-                */
-               clear_bit(IPATH_S_BUSY, &qp->s_flags);
-               spin_unlock_irqrestore(&qp->s_lock, flags);
-               goto bail;
-       }
+bail:;
+}
 
-       spin_unlock_irqrestore(&qp->s_lock, flags);
+/*
+ * This should be called with s_lock held.
+ */
+void ipath_send_complete(struct ipath_qp *qp, struct ipath_swqe *wqe,
+                        enum ib_wc_status status)
+{
+       u32 old_last, last;
 
-       /* Construct the header. */
-       extra_bytes = (4 - qp->s_cur_size) & 3;
-       nwords = (qp->s_cur_size + extra_bytes) >> 2;
-       lrh0 = IPS_LRH_BTH;
-       if (unlikely(qp->remote_ah_attr.ah_flags & IB_AH_GRH)) {
-               qp->s_hdrwords += ipath_make_grh(dev, &qp->s_hdr.u.l.grh,
-                                                &qp->remote_ah_attr.grh,
-                                                qp->s_hdrwords, nwords);
-               lrh0 = IPS_LRH_GRH;
-       }
-       lrh0 |= qp->remote_ah_attr.sl << 4;
-       qp->s_hdr.lrh[0] = cpu_to_be16(lrh0);
-       qp->s_hdr.lrh[1] = cpu_to_be16(qp->remote_ah_attr.dlid);
-       qp->s_hdr.lrh[2] = cpu_to_be16(qp->s_hdrwords + nwords +
-                                      SIZE_OF_CRC);
-       qp->s_hdr.lrh[3] = cpu_to_be16(ipath_layer_get_lid(dev->dd));
-       bth0 |= ipath_layer_get_pkey(dev->dd, qp->s_pkey_index);
-       bth0 |= extra_bytes << 20;
-       ohdr->bth[0] = cpu_to_be32(bth0);
-       ohdr->bth[1] = cpu_to_be32(qp->remote_qpn);
-       ohdr->bth[2] = cpu_to_be32(bth2);
+       if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_OR_FLUSH_SEND))
+               return;
 
-       /* Check for more work to do. */
-       goto again;
+       /* See ch. 11.2.4.1 and 10.7.3.1 */
+       if (!(qp->s_flags & IPATH_S_SIGNAL_REQ_WR) ||
+           (wqe->wr.send_flags & IB_SEND_SIGNALED) ||
+           status != IB_WC_SUCCESS) {
+               struct ib_wc wc;
 
-clear:
-       clear_bit(IPATH_S_BUSY, &qp->s_flags);
-bail:
-       return;
+               memset(&wc, 0, sizeof wc);
+               wc.wr_id = wqe->wr.wr_id;
+               wc.status = status;
+               wc.opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
+               wc.qp = &qp->ibqp;
+               if (status == IB_WC_SUCCESS)
+                       wc.byte_len = wqe->length;
+               ipath_cq_enter(to_icq(qp->ibqp.send_cq), &wc,
+                              status != IB_WC_SUCCESS);
+       }
+
+       old_last = last = qp->s_last;
+       if (++last >= qp->s_size)
+               last = 0;
+       qp->s_last = last;
+       if (qp->s_cur == old_last)
+               qp->s_cur = last;
+       if (qp->s_tail == old_last)
+               qp->s_tail = last;
+       if (qp->state == IB_QPS_SQD && last == qp->s_cur)
+               qp->s_draining = 0;
 }