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Commit 6f5c4074 authored by Ralph Campbell's avatar Ralph Campbell Committed by Roland Dreier
Browse files

IB/ipath: Fix PSN update for RC retries 



This patch fixes a number of bugs with updating the PSN for retries of
RC requests.

Signed-off-by: default avatarBryan O'Sullivan <bryan.osullivan@qlogic.com>
Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
parent 0434d271

drivers/infiniband/hw/ipath/ipath_rc.c

+38 −27
Original line number Diff line number Diff line
@@ -444,7 +444,7 @@ int ipath_make_rc_req(struct ipath_qp *qp, 
			qp->s_psn = wqe->lpsn + 1;

		else {

			qp->s_psn++;

			if ((int)(qp->s_psn - qp->s_next_psn) > 0)

			if (ipath_cmp24(qp->s_psn, qp->s_next_psn) > 0)

				qp->s_next_psn = qp->s_psn;

		}

		/*
@@ -471,7 +471,7 @@ int ipath_make_rc_req(struct ipath_qp *qp, 
		/* FALLTHROUGH */

	case OP(SEND_MIDDLE):

		bth2 = qp->s_psn++ & IPATH_PSN_MASK;

		if ((int)(qp->s_psn - qp->s_next_psn) > 0)

		if (ipath_cmp24(qp->s_psn, qp->s_next_psn) > 0)

			qp->s_next_psn = qp->s_psn;

		ss = &qp->s_sge;

		len = qp->s_len;
@@ -507,7 +507,7 @@ int ipath_make_rc_req(struct ipath_qp *qp, 
		/* FALLTHROUGH */

	case OP(RDMA_WRITE_MIDDLE):

		bth2 = qp->s_psn++ & IPATH_PSN_MASK;

		if ((int)(qp->s_psn - qp->s_next_psn) > 0)

		if (ipath_cmp24(qp->s_psn, qp->s_next_psn) > 0)

			qp->s_next_psn = qp->s_psn;

		ss = &qp->s_sge;

		len = qp->s_len;
@@ -546,7 +546,7 @@ int ipath_make_rc_req(struct ipath_qp *qp, 
		qp->s_state = OP(RDMA_READ_REQUEST);

		hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);

		bth2 = qp->s_psn++ & IPATH_PSN_MASK;

		if ((int)(qp->s_psn - qp->s_next_psn) > 0)

		if (ipath_cmp24(qp->s_psn, qp->s_next_psn) > 0)

			qp->s_next_psn = qp->s_psn;

		ss = NULL;

		len = 0;
@@ -779,7 +779,7 @@ void ipath_restart_rc(struct ipath_qp *qp, u32 psn, struct ib_wc *wc) 
	if (wqe->wr.opcode == IB_WR_RDMA_READ)

		dev->n_rc_resends++;

	else

		dev->n_rc_resends += (int)qp->s_psn - (int)psn;

		dev->n_rc_resends += (qp->s_psn - psn) & IPATH_PSN_MASK;



	reset_psn(qp, psn);

	tasklet_hi_schedule(&qp->s_task);
@@ -915,15 +915,19 @@ static int do_rc_ack(struct ipath_qp *qp, u32 aeth, u32 psn, int opcode) 
		if (qp->s_last == qp->s_cur) {

			if (++qp->s_cur >= qp->s_size)

				qp->s_cur = 0;

			qp->s_last = qp->s_cur;

			if (qp->s_last == qp->s_tail)

				break;

			wqe = get_swqe_ptr(qp, qp->s_cur);

			qp->s_state = OP(SEND_LAST);

			qp->s_psn = wqe->psn;

		}

		} else {

			if (++qp->s_last >= qp->s_size)

				qp->s_last = 0;

		wqe = get_swqe_ptr(qp, qp->s_last);

			if (qp->s_last == qp->s_tail)

				break;

			wqe = get_swqe_ptr(qp, qp->s_last);

		}

	}



	switch (aeth >> 29) {
@@ -935,6 +939,18 @@ static int do_rc_ack(struct ipath_qp *qp, u32 aeth, u32 psn, int opcode) 
			list_add_tail(&qp->timerwait,

				      &dev->pending[dev->pending_index]);

			spin_unlock(&dev->pending_lock);

			/*

			 * If we get a partial ACK for a resent operation,

			 * we can stop resending the earlier packets and

			 * continue with the next packet the receiver wants.

			 */

			if (ipath_cmp24(qp->s_psn, psn) <= 0) {

				reset_psn(qp, psn + 1);

				tasklet_hi_schedule(&qp->s_task);

			}

		} else if (ipath_cmp24(qp->s_psn, psn) <= 0) {

			qp->s_state = OP(SEND_LAST);

			qp->s_psn = psn + 1;

		}

		ipath_get_credit(qp, aeth);

		qp->s_rnr_retry = qp->s_rnr_retry_cnt;
@@ -945,22 +961,23 @@ static int do_rc_ack(struct ipath_qp *qp, u32 aeth, u32 psn, int opcode) 


	case 1:		/* RNR NAK */

		dev->n_rnr_naks++;

		if (qp->s_rnr_retry == 0) {

		if (qp->s_last == qp->s_tail)

			goto bail;



		if (qp->s_rnr_retry == 0) {

			wc.status = IB_WC_RNR_RETRY_EXC_ERR;

			goto class_b;

		}

		if (qp->s_rnr_retry_cnt < 7)

			qp->s_rnr_retry--;

		if (qp->s_last == qp->s_tail)

			goto bail;



		/* The last valid PSN is the previous PSN. */

		update_last_psn(qp, psn - 1);



		dev->n_rc_resends += (int)qp->s_psn - (int)psn;

		if (wqe->wr.opcode == IB_WR_RDMA_READ)

			dev->n_rc_resends++;

		else

			dev->n_rc_resends +=

				(qp->s_psn - psn) & IPATH_PSN_MASK;



		reset_psn(qp, psn);
@@ -971,26 +988,20 @@ static int do_rc_ack(struct ipath_qp *qp, u32 aeth, u32 psn, int opcode) 
		goto bail;



	case 3:		/* NAK */

		/* The last valid PSN seen is the previous request's. */

		if (qp->s_last != qp->s_tail)

			update_last_psn(qp, wqe->psn - 1);

		if (qp->s_last == qp->s_tail)

			goto bail;

		/* The last valid PSN is the previous PSN. */

		update_last_psn(qp, psn - 1);

		switch ((aeth >> IPATH_AETH_CREDIT_SHIFT) &

			IPATH_AETH_CREDIT_MASK) {

		case 0:	/* PSN sequence error */

			dev->n_seq_naks++;

			/*

			 * Back up to the responder's expected PSN.  XXX

			 * Back up to the responder's expected PSN.

			 * Note that we might get a NAK in the middle of an

			 * RDMA READ response which terminates the RDMA

			 * READ.

			 */

			if (qp->s_last == qp->s_tail)

				break;



			if (ipath_cmp24(psn, wqe->psn) < 0)

				break;



			/* Retry the request. */

			ipath_restart_rc(qp, psn, &wc);

			break;