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path: root/drivers/infiniband/hw/qib/qib_ruc.c
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Diffstat (limited to 'drivers/infiniband/hw/qib/qib_ruc.c')
-rw-r--r--drivers/infiniband/hw/qib/qib_ruc.c191
1 files changed, 107 insertions, 84 deletions
diff --git a/drivers/infiniband/hw/qib/qib_ruc.c b/drivers/infiniband/hw/qib/qib_ruc.c
index b1aa21bdd484..a5f07a64b228 100644
--- a/drivers/infiniband/hw/qib/qib_ruc.c
+++ b/drivers/infiniband/hw/qib/qib_ruc.c
@@ -79,16 +79,16 @@ const u32 ib_qib_rnr_table[32] = {
* Validate a RWQE and fill in the SGE state.
* Return 1 if OK.
*/
-static int qib_init_sge(struct qib_qp *qp, struct qib_rwqe *wqe)
+static int qib_init_sge(struct rvt_qp *qp, struct rvt_rwqe *wqe)
{
int i, j, ret;
struct ib_wc wc;
- struct qib_lkey_table *rkt;
- struct qib_pd *pd;
- struct qib_sge_state *ss;
+ struct rvt_lkey_table *rkt;
+ struct rvt_pd *pd;
+ struct rvt_sge_state *ss;
- rkt = &to_idev(qp->ibqp.device)->lk_table;
- pd = to_ipd(qp->ibqp.srq ? qp->ibqp.srq->pd : qp->ibqp.pd);
+ rkt = &to_idev(qp->ibqp.device)->rdi.lkey_table;
+ pd = ibpd_to_rvtpd(qp->ibqp.srq ? qp->ibqp.srq->pd : qp->ibqp.pd);
ss = &qp->r_sge;
ss->sg_list = qp->r_sg_list;
qp->r_len = 0;
@@ -96,7 +96,7 @@ static int qib_init_sge(struct qib_qp *qp, struct qib_rwqe *wqe)
if (wqe->sg_list[i].length == 0)
continue;
/* Check LKEY */
- if (!qib_lkey_ok(rkt, pd, j ? &ss->sg_list[j - 1] : &ss->sge,
+ if (!rvt_lkey_ok(rkt, pd, j ? &ss->sg_list[j - 1] : &ss->sge,
&wqe->sg_list[i], IB_ACCESS_LOCAL_WRITE))
goto bad_lkey;
qp->r_len += wqe->sg_list[i].length;
@@ -109,9 +109,9 @@ static int qib_init_sge(struct qib_qp *qp, struct qib_rwqe *wqe)
bad_lkey:
while (j) {
- struct qib_sge *sge = --j ? &ss->sg_list[j - 1] : &ss->sge;
+ struct rvt_sge *sge = --j ? &ss->sg_list[j - 1] : &ss->sge;
- qib_put_mr(sge->mr);
+ rvt_put_mr(sge->mr);
}
ss->num_sge = 0;
memset(&wc, 0, sizeof(wc));
@@ -120,7 +120,7 @@ bad_lkey:
wc.opcode = IB_WC_RECV;
wc.qp = &qp->ibqp;
/* Signal solicited completion event. */
- qib_cq_enter(to_icq(qp->ibqp.recv_cq), &wc, 1);
+ rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.recv_cq), &wc, 1);
ret = 0;
bail:
return ret;
@@ -136,19 +136,19 @@ bail:
*
* Can be called from interrupt level.
*/
-int qib_get_rwqe(struct qib_qp *qp, int wr_id_only)
+int qib_get_rwqe(struct rvt_qp *qp, int wr_id_only)
{
unsigned long flags;
- struct qib_rq *rq;
- struct qib_rwq *wq;
- struct qib_srq *srq;
- struct qib_rwqe *wqe;
+ struct rvt_rq *rq;
+ struct rvt_rwq *wq;
+ struct rvt_srq *srq;
+ struct rvt_rwqe *wqe;
void (*handler)(struct ib_event *, void *);
u32 tail;
int ret;
if (qp->ibqp.srq) {
- srq = to_isrq(qp->ibqp.srq);
+ srq = ibsrq_to_rvtsrq(qp->ibqp.srq);
handler = srq->ibsrq.event_handler;
rq = &srq->rq;
} else {
@@ -158,7 +158,7 @@ int qib_get_rwqe(struct qib_qp *qp, int wr_id_only)
}
spin_lock_irqsave(&rq->lock, flags);
- if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK)) {
+ if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK)) {
ret = 0;
goto unlock;
}
@@ -174,7 +174,7 @@ int qib_get_rwqe(struct qib_qp *qp, int wr_id_only)
}
/* Make sure entry is read after head index is read. */
smp_rmb();
- wqe = get_rwqe_ptr(rq, tail);
+ wqe = rvt_get_rwqe_ptr(rq, tail);
/*
* Even though we update the tail index in memory, the verbs
* consumer is not supposed to post more entries until a
@@ -190,7 +190,7 @@ int qib_get_rwqe(struct qib_qp *qp, int wr_id_only)
qp->r_wr_id = wqe->wr_id;
ret = 1;
- set_bit(QIB_R_WRID_VALID, &qp->r_aflags);
+ set_bit(RVT_R_WRID_VALID, &qp->r_aflags);
if (handler) {
u32 n;
@@ -227,7 +227,7 @@ bail:
* Switch to alternate path.
* The QP s_lock should be held and interrupts disabled.
*/
-void qib_migrate_qp(struct qib_qp *qp)
+void qib_migrate_qp(struct rvt_qp *qp)
{
struct ib_event ev;
@@ -266,7 +266,7 @@ static int gid_ok(union ib_gid *gid, __be64 gid_prefix, __be64 id)
* The s_lock will be acquired around the qib_migrate_qp() call.
*/
int qib_ruc_check_hdr(struct qib_ibport *ibp, struct qib_ib_header *hdr,
- int has_grh, struct qib_qp *qp, u32 bth0)
+ int has_grh, struct rvt_qp *qp, u32 bth0)
{
__be64 guid;
unsigned long flags;
@@ -279,7 +279,8 @@ int qib_ruc_check_hdr(struct qib_ibport *ibp, struct qib_ib_header *hdr,
if (!(qp->alt_ah_attr.ah_flags & IB_AH_GRH))
goto err;
guid = get_sguid(ibp, qp->alt_ah_attr.grh.sgid_index);
- if (!gid_ok(&hdr->u.l.grh.dgid, ibp->gid_prefix, guid))
+ if (!gid_ok(&hdr->u.l.grh.dgid,
+ ibp->rvp.gid_prefix, guid))
goto err;
if (!gid_ok(&hdr->u.l.grh.sgid,
qp->alt_ah_attr.grh.dgid.global.subnet_prefix,
@@ -311,7 +312,8 @@ int qib_ruc_check_hdr(struct qib_ibport *ibp, struct qib_ib_header *hdr,
goto err;
guid = get_sguid(ibp,
qp->remote_ah_attr.grh.sgid_index);
- if (!gid_ok(&hdr->u.l.grh.dgid, ibp->gid_prefix, guid))
+ if (!gid_ok(&hdr->u.l.grh.dgid,
+ ibp->rvp.gid_prefix, guid))
goto err;
if (!gid_ok(&hdr->u.l.grh.sgid,
qp->remote_ah_attr.grh.dgid.global.subnet_prefix,
@@ -353,12 +355,15 @@ err:
* receive interrupts since this is a connected protocol and all packets
* will pass through here.
*/
-static void qib_ruc_loopback(struct qib_qp *sqp)
+static void qib_ruc_loopback(struct rvt_qp *sqp)
{
struct qib_ibport *ibp = to_iport(sqp->ibqp.device, sqp->port_num);
- struct qib_qp *qp;
- struct qib_swqe *wqe;
- struct qib_sge *sge;
+ struct qib_pportdata *ppd = ppd_from_ibp(ibp);
+ struct qib_devdata *dd = ppd->dd;
+ struct rvt_dev_info *rdi = &dd->verbs_dev.rdi;
+ struct rvt_qp *qp;
+ struct rvt_swqe *wqe;
+ struct rvt_sge *sge;
unsigned long flags;
struct ib_wc wc;
u64 sdata;
@@ -367,29 +372,33 @@ static void qib_ruc_loopback(struct qib_qp *sqp)
int release;
int ret;
+ rcu_read_lock();
/*
* Note that we check the responder QP state after
* checking the requester's state.
*/
- qp = qib_lookup_qpn(ibp, sqp->remote_qpn);
+ qp = rvt_lookup_qpn(rdi, &ibp->rvp, sqp->remote_qpn);
+ if (!qp)
+ goto done;
spin_lock_irqsave(&sqp->s_lock, flags);
/* Return if we are already busy processing a work request. */
- if ((sqp->s_flags & (QIB_S_BUSY | QIB_S_ANY_WAIT)) ||
- !(ib_qib_state_ops[sqp->state] & QIB_PROCESS_OR_FLUSH_SEND))
+ if ((sqp->s_flags & (RVT_S_BUSY | RVT_S_ANY_WAIT)) ||
+ !(ib_rvt_state_ops[sqp->state] & RVT_PROCESS_OR_FLUSH_SEND))
goto unlock;
- sqp->s_flags |= QIB_S_BUSY;
+ sqp->s_flags |= RVT_S_BUSY;
again:
- if (sqp->s_last == sqp->s_head)
+ smp_read_barrier_depends(); /* see post_one_send() */
+ if (sqp->s_last == ACCESS_ONCE(sqp->s_head))
goto clr_busy;
- wqe = get_swqe_ptr(sqp, sqp->s_last);
+ wqe = rvt_get_swqe_ptr(sqp, sqp->s_last);
/* Return if it is not OK to start a new work reqeust. */
- if (!(ib_qib_state_ops[sqp->state] & QIB_PROCESS_NEXT_SEND_OK)) {
- if (!(ib_qib_state_ops[sqp->state] & QIB_FLUSH_SEND))
+ if (!(ib_rvt_state_ops[sqp->state] & RVT_PROCESS_NEXT_SEND_OK)) {
+ if (!(ib_rvt_state_ops[sqp->state] & RVT_FLUSH_SEND))
goto clr_busy;
/* We are in the error state, flush the work request. */
send_status = IB_WC_WR_FLUSH_ERR;
@@ -407,9 +416,9 @@ again:
}
spin_unlock_irqrestore(&sqp->s_lock, flags);
- if (!qp || !(ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK) ||
+ if (!qp || !(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK) ||
qp->ibqp.qp_type != sqp->ibqp.qp_type) {
- ibp->n_pkt_drops++;
+ ibp->rvp.n_pkt_drops++;
/*
* For RC, the requester would timeout and retry so
* shortcut the timeouts and just signal too many retries.
@@ -458,7 +467,7 @@ again:
goto inv_err;
if (wqe->length == 0)
break;
- if (unlikely(!qib_rkey_ok(qp, &qp->r_sge.sge, wqe->length,
+ if (unlikely(!rvt_rkey_ok(qp, &qp->r_sge.sge, wqe->length,
wqe->rdma_wr.remote_addr,
wqe->rdma_wr.rkey,
IB_ACCESS_REMOTE_WRITE)))
@@ -471,7 +480,7 @@ again:
case IB_WR_RDMA_READ:
if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_READ)))
goto inv_err;
- if (unlikely(!qib_rkey_ok(qp, &sqp->s_sge.sge, wqe->length,
+ if (unlikely(!rvt_rkey_ok(qp, &sqp->s_sge.sge, wqe->length,
wqe->rdma_wr.remote_addr,
wqe->rdma_wr.rkey,
IB_ACCESS_REMOTE_READ)))
@@ -489,7 +498,7 @@ again:
case IB_WR_ATOMIC_FETCH_AND_ADD:
if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_ATOMIC)))
goto inv_err;
- if (unlikely(!qib_rkey_ok(qp, &qp->r_sge.sge, sizeof(u64),
+ if (unlikely(!rvt_rkey_ok(qp, &qp->r_sge.sge, sizeof(u64),
wqe->atomic_wr.remote_addr,
wqe->atomic_wr.rkey,
IB_ACCESS_REMOTE_ATOMIC)))
@@ -502,7 +511,7 @@ again:
(u64) atomic64_add_return(sdata, maddr) - sdata :
(u64) cmpxchg((u64 *) qp->r_sge.sge.vaddr,
sdata, wqe->atomic_wr.swap);
- qib_put_mr(qp->r_sge.sge.mr);
+ rvt_put_mr(qp->r_sge.sge.mr);
qp->r_sge.num_sge = 0;
goto send_comp;
@@ -526,11 +535,11 @@ again:
sge->sge_length -= len;
if (sge->sge_length == 0) {
if (!release)
- qib_put_mr(sge->mr);
+ rvt_put_mr(sge->mr);
if (--sqp->s_sge.num_sge)
*sge = *sqp->s_sge.sg_list++;
} else if (sge->length == 0 && sge->mr->lkey) {
- if (++sge->n >= QIB_SEGSZ) {
+ if (++sge->n >= RVT_SEGSZ) {
if (++sge->m >= sge->mr->mapsz)
break;
sge->n = 0;
@@ -543,9 +552,9 @@ again:
sqp->s_len -= len;
}
if (release)
- qib_put_ss(&qp->r_sge);
+ rvt_put_ss(&qp->r_sge);
- if (!test_and_clear_bit(QIB_R_WRID_VALID, &qp->r_aflags))
+ if (!test_and_clear_bit(RVT_R_WRID_VALID, &qp->r_aflags))
goto send_comp;
if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM)
@@ -561,12 +570,12 @@ again:
wc.sl = qp->remote_ah_attr.sl;
wc.port_num = 1;
/* Signal completion event if the solicited bit is set. */
- qib_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
- wqe->wr.send_flags & IB_SEND_SOLICITED);
+ rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.recv_cq), &wc,
+ wqe->wr.send_flags & IB_SEND_SOLICITED);
send_comp:
spin_lock_irqsave(&sqp->s_lock, flags);
- ibp->n_loop_pkts++;
+ ibp->rvp.n_loop_pkts++;
flush_send:
sqp->s_rnr_retry = sqp->s_rnr_retry_cnt;
qib_send_complete(sqp, wqe, send_status);
@@ -576,7 +585,7 @@ rnr_nak:
/* Handle RNR NAK */
if (qp->ibqp.qp_type == IB_QPT_UC)
goto send_comp;
- ibp->n_rnr_naks++;
+ ibp->rvp.n_rnr_naks++;
/*
* Note: we don't need the s_lock held since the BUSY flag
* makes this single threaded.
@@ -588,9 +597,9 @@ rnr_nak:
if (sqp->s_rnr_retry_cnt < 7)
sqp->s_rnr_retry--;
spin_lock_irqsave(&sqp->s_lock, flags);
- if (!(ib_qib_state_ops[sqp->state] & QIB_PROCESS_RECV_OK))
+ if (!(ib_rvt_state_ops[sqp->state] & RVT_PROCESS_RECV_OK))
goto clr_busy;
- sqp->s_flags |= QIB_S_WAIT_RNR;
+ sqp->s_flags |= RVT_S_WAIT_RNR;
sqp->s_timer.function = qib_rc_rnr_retry;
sqp->s_timer.expires = jiffies +
usecs_to_jiffies(ib_qib_rnr_table[qp->r_min_rnr_timer]);
@@ -618,9 +627,9 @@ serr:
spin_lock_irqsave(&sqp->s_lock, flags);
qib_send_complete(sqp, wqe, send_status);
if (sqp->ibqp.qp_type == IB_QPT_RC) {
- int lastwqe = qib_error_qp(sqp, IB_WC_WR_FLUSH_ERR);
+ int lastwqe = rvt_error_qp(sqp, IB_WC_WR_FLUSH_ERR);
- sqp->s_flags &= ~QIB_S_BUSY;
+ sqp->s_flags &= ~RVT_S_BUSY;
spin_unlock_irqrestore(&sqp->s_lock, flags);
if (lastwqe) {
struct ib_event ev;
@@ -633,12 +642,11 @@ serr:
goto done;
}
clr_busy:
- sqp->s_flags &= ~QIB_S_BUSY;
+ sqp->s_flags &= ~RVT_S_BUSY;
unlock:
spin_unlock_irqrestore(&sqp->s_lock, flags);
done:
- if (qp && atomic_dec_and_test(&qp->refcount))
- wake_up(&qp->wait);
+ rcu_read_unlock();
}
/**
@@ -663,7 +671,7 @@ u32 qib_make_grh(struct qib_ibport *ibp, struct ib_grh *hdr,
hdr->next_hdr = IB_GRH_NEXT_HDR;
hdr->hop_limit = grh->hop_limit;
/* The SGID is 32-bit aligned. */
- hdr->sgid.global.subnet_prefix = ibp->gid_prefix;
+ hdr->sgid.global.subnet_prefix = ibp->rvp.gid_prefix;
hdr->sgid.global.interface_id = grh->sgid_index ?
ibp->guids[grh->sgid_index - 1] : ppd_from_ibp(ibp)->guid;
hdr->dgid = grh->dgid;
@@ -672,9 +680,10 @@ u32 qib_make_grh(struct qib_ibport *ibp, struct ib_grh *hdr,
return sizeof(struct ib_grh) / sizeof(u32);
}
-void qib_make_ruc_header(struct qib_qp *qp, struct qib_other_headers *ohdr,
+void qib_make_ruc_header(struct rvt_qp *qp, struct qib_other_headers *ohdr,
u32 bth0, u32 bth2)
{
+ struct qib_qp_priv *priv = qp->priv;
struct qib_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
u16 lrh0;
u32 nwords;
@@ -685,17 +694,18 @@ void qib_make_ruc_header(struct qib_qp *qp, struct qib_other_headers *ohdr,
nwords = (qp->s_cur_size + extra_bytes) >> 2;
lrh0 = QIB_LRH_BTH;
if (unlikely(qp->remote_ah_attr.ah_flags & IB_AH_GRH)) {
- qp->s_hdrwords += qib_make_grh(ibp, &qp->s_hdr->u.l.grh,
+ qp->s_hdrwords += qib_make_grh(ibp, &priv->s_hdr->u.l.grh,
&qp->remote_ah_attr.grh,
qp->s_hdrwords, nwords);
lrh0 = QIB_LRH_GRH;
}
lrh0 |= ibp->sl_to_vl[qp->remote_ah_attr.sl] << 12 |
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(ppd_from_ibp(ibp)->lid |
+ priv->s_hdr->lrh[0] = cpu_to_be16(lrh0);
+ priv->s_hdr->lrh[1] = cpu_to_be16(qp->remote_ah_attr.dlid);
+ priv->s_hdr->lrh[2] =
+ cpu_to_be16(qp->s_hdrwords + nwords + SIZE_OF_CRC);
+ priv->s_hdr->lrh[3] = cpu_to_be16(ppd_from_ibp(ibp)->lid |
qp->remote_ah_attr.src_path_bits);
bth0 |= qib_get_pkey(ibp, qp->s_pkey_index);
bth0 |= extra_bytes << 20;
@@ -707,20 +717,29 @@ void qib_make_ruc_header(struct qib_qp *qp, struct qib_other_headers *ohdr,
this_cpu_inc(ibp->pmastats->n_unicast_xmit);
}
+void _qib_do_send(struct work_struct *work)
+{
+ struct qib_qp_priv *priv = container_of(work, struct qib_qp_priv,
+ s_work);
+ struct rvt_qp *qp = priv->owner;
+
+ qib_do_send(qp);
+}
+
/**
* qib_do_send - perform a send on a QP
- * @work: contains a pointer to the QP
+ * @qp: 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, two threads could send packets out of order.
*/
-void qib_do_send(struct work_struct *work)
+void qib_do_send(struct rvt_qp *qp)
{
- struct qib_qp *qp = container_of(work, struct qib_qp, s_work);
+ struct qib_qp_priv *priv = qp->priv;
struct qib_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
struct qib_pportdata *ppd = ppd_from_ibp(ibp);
- int (*make_req)(struct qib_qp *qp);
+ int (*make_req)(struct rvt_qp *qp);
unsigned long flags;
if ((qp->ibqp.qp_type == IB_QPT_RC ||
@@ -745,50 +764,59 @@ void qib_do_send(struct work_struct *work)
return;
}
- qp->s_flags |= QIB_S_BUSY;
-
- spin_unlock_irqrestore(&qp->s_lock, flags);
+ qp->s_flags |= RVT_S_BUSY;
do {
/* Check for a constructed packet to be sent. */
if (qp->s_hdrwords != 0) {
+ spin_unlock_irqrestore(&qp->s_lock, flags);
/*
* If the packet cannot be sent now, return and
* the send tasklet will be woken up later.
*/
- if (qib_verbs_send(qp, qp->s_hdr, qp->s_hdrwords,
+ if (qib_verbs_send(qp, priv->s_hdr, qp->s_hdrwords,
qp->s_cur_sge, qp->s_cur_size))
- break;
+ return;
/* Record that s_hdr is empty. */
qp->s_hdrwords = 0;
+ spin_lock_irqsave(&qp->s_lock, flags);
}
} while (make_req(qp));
+
+ spin_unlock_irqrestore(&qp->s_lock, flags);
}
/*
* This should be called with s_lock held.
*/
-void qib_send_complete(struct qib_qp *qp, struct qib_swqe *wqe,
+void qib_send_complete(struct rvt_qp *qp, struct rvt_swqe *wqe,
enum ib_wc_status status)
{
u32 old_last, last;
unsigned i;
- if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_OR_FLUSH_SEND))
+ if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_OR_FLUSH_SEND))
return;
+ last = qp->s_last;
+ old_last = last;
+ if (++last >= qp->s_size)
+ last = 0;
+ qp->s_last = last;
+ /* See post_send() */
+ barrier();
for (i = 0; i < wqe->wr.num_sge; i++) {
- struct qib_sge *sge = &wqe->sg_list[i];
+ struct rvt_sge *sge = &wqe->sg_list[i];
- qib_put_mr(sge->mr);
+ rvt_put_mr(sge->mr);
}
if (qp->ibqp.qp_type == IB_QPT_UD ||
qp->ibqp.qp_type == IB_QPT_SMI ||
qp->ibqp.qp_type == IB_QPT_GSI)
- atomic_dec(&to_iah(wqe->ud_wr.ah)->refcount);
+ atomic_dec(&ibah_to_rvtah(wqe->ud_wr.ah)->refcount);
/* See ch. 11.2.4.1 and 10.7.3.1 */
- if (!(qp->s_flags & QIB_S_SIGNAL_REQ_WR) ||
+ if (!(qp->s_flags & RVT_S_SIGNAL_REQ_WR) ||
(wqe->wr.send_flags & IB_SEND_SIGNALED) ||
status != IB_WC_SUCCESS) {
struct ib_wc wc;
@@ -800,15 +828,10 @@ void qib_send_complete(struct qib_qp *qp, struct qib_swqe *wqe,
wc.qp = &qp->ibqp;
if (status == IB_WC_SUCCESS)
wc.byte_len = wqe->length;
- qib_cq_enter(to_icq(qp->ibqp.send_cq), &wc,
+ rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.send_cq), &wc,
status != IB_WC_SUCCESS);
}
- last = qp->s_last;
- old_last = last;
- if (++last >= qp->s_size)
- last = 0;
- qp->s_last = last;
if (qp->s_acked == old_last)
qp->s_acked = last;
if (qp->s_cur == old_last)