/**
 * ipath_ruc_loopback - handle UC and RC lookback requests
 * @sqp: the sending QP
 *
 * 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
 * receive interrupts since this is a connected protocol and all packets
 * will pass through here.
 */
static void ipath_ruc_loopback(struct ipath_qp *sqp)
{
	struct ipath_ibdev *dev = to_idev(sqp->ibqp.device);
	struct ipath_qp *qp;
	struct ipath_swqe *wqe;
	struct ipath_sge *sge;
	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);

	spin_lock_irqsave(&sqp->s_lock, flags);

	/* 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;

	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.
	 */
	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);

	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;
	sqp->s_sge.num_sge = wqe->wr.num_sge;
	sqp->s_len = wqe->length;
	switch (wqe->wr.opcode) {
	case IB_WR_SEND_WITH_IMM:
		wc.wc_flags = IB_WC_WITH_IMM;
		wc.imm_data = wqe->wr.ex.imm_data;
		/* FALLTHROUGH */
	case IB_WR_SEND:
		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.ex.imm_data;
		if (!ipath_get_rwqe(qp, 1))
			goto rnr_nak;
		/* 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(qp, &qp->r_sge, wqe->length,
					    wqe->wr.wr.rdma.remote_addr,
					    wqe->wr.wr.rdma.rkey,
					    IB_ACCESS_REMOTE_WRITE)))
			goto acc_err;
		break;

	case IB_WR_RDMA_READ:
		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;
		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;
		break;

	case IB_WR_ATOMIC_CMP_AND_SWP:
	case IB_WR_ATOMIC_FETCH_AND_ADD:
		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. */
		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:
		send_status = IB_WC_LOC_QP_OP_ERR;
		goto serr;
	}

	sge = &sqp->s_sge.sge;
	while (sqp->s_len) {
		u32 len = sqp->s_len;

		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;
		sge->length -= len;
		sge->sge_length -= len;
		if (sge->sge_length == 0) {
			if (--sqp->s_sge.num_sge)
				*sge = *sqp->s_sge.sg_list++;
		} else if (sge->length == 0 && sge->mr != NULL) {
			if (++sge->n >= IPATH_SEGSZ) {
				if (++sge->m >= sge->mr->mapsz)
					break;
				sge->n = 0;
			}
			sge->vaddr =
				sge->mr->map[sge->m]->segs[sge->n].vaddr;
			sge->length =
				sge->mr->map[sge->m]->segs[sge->n].length;
		}
		sqp->s_len -= len;
	}

	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)
		wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
	else
		wc.opcode = IB_WC_RECV;
	wc.wr_id = qp->r_wr_id;
	wc.status = IB_WC_SUCCESS;
	wc.byte_len = wqe->length;
	wc.qp = &qp->ibqp;
	wc.src_qp = qp->remote_qpn;
	wc.slid = qp->remote_ah_attr.dlid;
	wc.sl = qp->remote_ah_attr.sl;
	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;

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;
	}
	if (sqp->s_rnr_retry_cnt < 7)
		sqp->s_rnr_retry--;
	spin_lock_irqsave(&sqp->s_lock, flags);
	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 (qp && atomic_dec_and_test(&qp->refcount))
		wake_up(&qp->wait);
}
Beispiel #2
0
static void ipath_ruc_loopback(struct ipath_qp *sqp)
{
	struct ipath_ibdev *dev = to_idev(sqp->ibqp.device);
	struct ipath_qp *qp;
	struct ipath_swqe *wqe;
	struct ipath_sge *sge;
	unsigned long flags;
	struct ib_wc wc;
	u64 sdata;
	atomic64_t *maddr;
	enum ib_wc_status send_status;

	
	qp = ipath_lookup_qpn(&dev->qp_table, sqp->remote_qpn);

	spin_lock_irqsave(&sqp->s_lock, flags);

	
	if ((sqp->s_flags & (IPATH_S_BUSY | IPATH_S_ANY_WAIT)) ||
	    !(ib_ipath_state_ops[sqp->state] & IPATH_PROCESS_OR_FLUSH_SEND))
		goto unlock;

	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);

	
	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;
		
		send_status = IB_WC_WR_FLUSH_ERR;
		goto flush_send;
	}

	
	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);

	if (!qp || !(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK)) {
		dev->n_pkt_drops++;
		
		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;
	sqp->s_sge.num_sge = wqe->wr.num_sge;
	sqp->s_len = wqe->length;
	switch (wqe->wr.opcode) {
	case IB_WR_SEND_WITH_IMM:
		wc.wc_flags = IB_WC_WITH_IMM;
		wc.ex.imm_data = wqe->wr.ex.imm_data;
		
	case IB_WR_SEND:
		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.ex.imm_data = wqe->wr.ex.imm_data;
		if (!ipath_get_rwqe(qp, 1))
			goto rnr_nak;
		
	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(qp, &qp->r_sge, wqe->length,
					    wqe->wr.wr.rdma.remote_addr,
					    wqe->wr.wr.rdma.rkey,
					    IB_ACCESS_REMOTE_WRITE)))
			goto acc_err;
		break;

	case IB_WR_RDMA_READ:
		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;
		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;
		break;

	case IB_WR_ATOMIC_CMP_AND_SWP:
	case IB_WR_ATOMIC_FETCH_AND_ADD:
		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;
		
		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:
		send_status = IB_WC_LOC_QP_OP_ERR;
		goto serr;
	}

	sge = &sqp->s_sge.sge;
	while (sqp->s_len) {
		u32 len = sqp->s_len;

		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;
		sge->length -= len;
		sge->sge_length -= len;
		if (sge->sge_length == 0) {
			if (--sqp->s_sge.num_sge)
				*sge = *sqp->s_sge.sg_list++;
		} else if (sge->length == 0 && sge->mr != NULL) {
			if (++sge->n >= IPATH_SEGSZ) {
				if (++sge->m >= sge->mr->mapsz)
					break;
				sge->n = 0;
			}
			sge->vaddr =
				sge->mr->map[sge->m]->segs[sge->n].vaddr;
			sge->length =
				sge->mr->map[sge->m]->segs[sge->n].length;
		}
		sqp->s_len -= len;
	}

	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)
		wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
	else
		wc.opcode = IB_WC_RECV;
	wc.wr_id = qp->r_wr_id;
	wc.status = IB_WC_SUCCESS;
	wc.byte_len = wqe->length;
	wc.qp = &qp->ibqp;
	wc.src_qp = qp->remote_qpn;
	wc.slid = qp->remote_ah_attr.dlid;
	wc.sl = qp->remote_ah_attr.sl;
	wc.port_num = 1;
	
	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;

rnr_nak:
	
	if (qp->ibqp.qp_type == IB_QPT_UC)
		goto send_comp;
	
	if (sqp->s_rnr_retry == 0) {
		send_status = IB_WC_RNR_RETRY_EXC_ERR;
		goto serr;
	}
	if (sqp->s_rnr_retry_cnt < 7)
		sqp->s_rnr_retry--;
	spin_lock_irqsave(&sqp->s_lock, flags);
	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:
	
	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 (qp && atomic_dec_and_test(&qp->refcount))
		wake_up(&qp->wait);
}