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IB/ipath: Fix RDMA reads
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The PSN used to generate the request following a RDMA read was
incorrect and some state booking wasn't maintained correctly.  This
patch fixes that.

Signed-off-by: Ralph Campbell <[email protected]>
Signed-off-by: Bryan O'Sullivan <[email protected]>
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Ralph Campbell authored and Roland Dreier committed Oct 2, 2006
1 parent 3f168d2 commit 13b18c8
Showing 1 changed file with 32 additions and 27 deletions.
59 changes: 32 additions & 27 deletions drivers/infiniband/hw/ipath/ipath_rc.c
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Original file line number Diff line number Diff line change
Expand Up @@ -241,10 +241,7 @@ int ipath_make_rc_req(struct ipath_qp *qp,
* original work request since we may need to resend
* it.
*/
qp->s_sge.sge = wqe->sg_list[0];
qp->s_sge.sg_list = wqe->sg_list + 1;
qp->s_sge.num_sge = wqe->wr.num_sge;
qp->s_len = len = wqe->length;
len = wqe->length;
ss = &qp->s_sge;
bth2 = 0;
switch (wqe->wr.opcode) {
Expand Down Expand Up @@ -368,14 +365,23 @@ int ipath_make_rc_req(struct ipath_qp *qp,
default:
goto done;
}
qp->s_sge.sge = wqe->sg_list[0];
qp->s_sge.sg_list = wqe->sg_list + 1;
qp->s_sge.num_sge = wqe->wr.num_sge;
qp->s_len = wqe->length;
if (newreq) {
qp->s_tail++;
if (qp->s_tail >= qp->s_size)
qp->s_tail = 0;
}
bth2 |= qp->s_psn++ & IPATH_PSN_MASK;
if ((int)(qp->s_psn - qp->s_next_psn) > 0)
qp->s_next_psn = qp->s_psn;
bth2 |= qp->s_psn & IPATH_PSN_MASK;
if (wqe->wr.opcode == IB_WR_RDMA_READ)
qp->s_psn = wqe->lpsn + 1;
else {
qp->s_psn++;
if ((int)(qp->s_psn - qp->s_next_psn) > 0)
qp->s_next_psn = qp->s_psn;
}
/*
* Put the QP on the pending list so lost ACKs will cause
* a retry. More than one request can be pending so the
Expand Down Expand Up @@ -690,13 +696,6 @@ void ipath_restart_rc(struct ipath_qp *qp, u32 psn, struct ib_wc *wc)
struct ipath_swqe *wqe = get_swqe_ptr(qp, qp->s_last);
struct ipath_ibdev *dev;

/*
* If there are no requests pending, we are done.
*/
if (ipath_cmp24(psn, qp->s_next_psn) >= 0 ||
qp->s_last == qp->s_tail)
goto done;

if (qp->s_retry == 0) {
wc->wr_id = wqe->wr.wr_id;
wc->status = IB_WC_RETRY_EXC_ERR;
Expand Down Expand Up @@ -731,8 +730,6 @@ void ipath_restart_rc(struct ipath_qp *qp, u32 psn, struct ib_wc *wc)
dev->n_rc_resends += (int)qp->s_psn - (int)psn;

reset_psn(qp, psn);

done:
tasklet_hi_schedule(&qp->s_task);

bail:
Expand Down Expand Up @@ -765,6 +762,7 @@ static int do_rc_ack(struct ipath_qp *qp, u32 aeth, u32 psn, int opcode)
struct ib_wc wc;
struct ipath_swqe *wqe;
int ret = 0;
u32 ack_psn;

/*
* Remove the QP from the timeout queue (or RNR timeout queue).
Expand All @@ -777,26 +775,26 @@ static int do_rc_ack(struct ipath_qp *qp, u32 aeth, u32 psn, int opcode)
list_del_init(&qp->timerwait);
spin_unlock(&dev->pending_lock);

/* Nothing is pending to ACK/NAK. */
if (unlikely(qp->s_last == qp->s_tail))
goto bail;

/*
* Note that NAKs implicitly ACK outstanding SEND and RDMA write
* requests and implicitly NAK RDMA read and atomic requests issued
* before the NAK'ed request. The MSN won't include the NAK'ed
* request but will include an ACK'ed request(s).
*/
ack_psn = psn;
if (aeth >> 29)
ack_psn--;
wqe = get_swqe_ptr(qp, qp->s_last);

/* Nothing is pending to ACK/NAK. */
if (qp->s_last == qp->s_tail)
goto bail;

/*
* The MSN might be for a later WQE than the PSN indicates so
* only complete WQEs that the PSN finishes.
*/
while (ipath_cmp24(psn, wqe->lpsn) >= 0) {
/* If we are ACKing a WQE, the MSN should be >= the SSN. */
if (ipath_cmp24(aeth, wqe->ssn) < 0)
break;
while (ipath_cmp24(ack_psn, wqe->lpsn) >= 0) {
/*
* If this request is a RDMA read or atomic, and the ACK is
* for a later operation, this ACK NAKs the RDMA read or
Expand All @@ -807,7 +805,8 @@ static int do_rc_ack(struct ipath_qp *qp, u32 aeth, u32 psn, int opcode)
* is sent but before the response is received.
*/
if ((wqe->wr.opcode == IB_WR_RDMA_READ &&
opcode != OP(RDMA_READ_RESPONSE_LAST)) ||
(opcode != OP(RDMA_READ_RESPONSE_LAST) ||
ipath_cmp24(ack_psn, wqe->lpsn) != 0)) ||
((wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) &&
(opcode != OP(ATOMIC_ACKNOWLEDGE) ||
Expand All @@ -825,6 +824,10 @@ static int do_rc_ack(struct ipath_qp *qp, u32 aeth, u32 psn, int opcode)
*/
goto bail;
}
if (wqe->wr.opcode == IB_WR_RDMA_READ ||
wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)
tasklet_hi_schedule(&qp->s_task);
/* Post a send completion queue entry if requested. */
if (!test_bit(IPATH_S_SIGNAL_REQ_WR, &qp->s_flags) ||
(wqe->wr.send_flags & IB_SEND_SIGNALED)) {
Expand Down Expand Up @@ -1055,7 +1058,8 @@ static inline void ipath_rc_rcv_resp(struct ipath_ibdev *dev,
/* no AETH, no ACK */
if (unlikely(ipath_cmp24(psn, qp->s_last_psn + 1))) {
dev->n_rdma_seq++;
ipath_restart_rc(qp, qp->s_last_psn + 1, &wc);
if (qp->s_last != qp->s_tail)
ipath_restart_rc(qp, qp->s_last_psn + 1, &wc);
goto ack_done;
}
rdma_read:
Expand Down Expand Up @@ -1091,7 +1095,8 @@ static inline void ipath_rc_rcv_resp(struct ipath_ibdev *dev,
/* ACKs READ req. */
if (unlikely(ipath_cmp24(psn, qp->s_last_psn + 1))) {
dev->n_rdma_seq++;
ipath_restart_rc(qp, qp->s_last_psn + 1, &wc);
if (qp->s_last != qp->s_tail)
ipath_restart_rc(qp, qp->s_last_psn + 1, &wc);
goto ack_done;
}
/* FALLTHROUGH */
Expand Down

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