IB/hfi1: Add functions to receive TID RDMA READ request

This patch adds the functions to receive TID RDMA READ request. The TID
resource information will be stored and tracked. Duplicate request
will also be handled properly.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 329 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/hfi1/tid_rdma.c b/drivers/infiniband/hw/hfi1/tid_rdma.c
index 56c8c10b5a85..d8a46b7ddca0 100644
--- a/drivers/infiniband/hw/hfi1/tid_rdma.c
+++ b/drivers/infiniband/hw/hfi1/tid_rdma.c
@@ -1797,3 +1797,332 @@ sync_check:
 done:
 	return hdwords;
 }
+
+/*
+ * Validate and accept the TID RDMA READ request parameters.
+ * Return 0 if the request is accepted successfully;
+ * Return 1 otherwise.
+ */
+static int tid_rdma_rcv_read_request(struct rvt_qp *qp,
+				     struct rvt_ack_entry *e,
+				     struct hfi1_packet *packet,
+				     struct ib_other_headers *ohdr,
+				     u32 bth0, u32 psn, u64 vaddr, u32 len)
+{
+	struct hfi1_qp_priv *qpriv = qp->priv;
+	struct tid_rdma_request *req;
+	struct tid_rdma_flow *flow;
+	u32 flow_psn, i, tidlen = 0, pktlen, tlen;
+
+	req = ack_to_tid_req(e);
+
+	/* Validate the payload first */
+	flow = &req->flows[req->setup_head];
+
+	/* payload length = packet length - (header length + ICRC length) */
+	pktlen = packet->tlen - (packet->hlen + 4);
+	if (pktlen > sizeof(flow->tid_entry))
+		return 1;
+	memcpy(flow->tid_entry, packet->ebuf, pktlen);
+	flow->tidcnt = pktlen / sizeof(*flow->tid_entry);
+
+	/*
+	 * Walk the TID_ENTRY list to make sure we have enough space for a
+	 * complete segment. Also calculate the number of required packets.
+	 */
+	flow->npkts = rvt_div_round_up_mtu(qp, len);
+	for (i = 0; i < flow->tidcnt; i++) {
+		tlen = EXP_TID_GET(flow->tid_entry[i], LEN);
+		if (!tlen)
+			return 1;
+
+		/*
+		 * For tid pair (tidctr == 3), the buffer size of the pair
+		 * should be the sum of the buffer size described by each
+		 * tid entry. However, only the first entry needs to be
+		 * specified in the request (see WFR HAS Section 8.5.7.1).
+		 */
+		tidlen += tlen;
+	}
+	if (tidlen * PAGE_SIZE < len)
+		return 1;
+
+	/* Empty the flow array */
+	req->clear_tail = req->setup_head;
+	flow->pkt = 0;
+	flow->tid_idx = 0;
+	flow->tid_offset = 0;
+	flow->sent = 0;
+	flow->tid_qpn = be32_to_cpu(ohdr->u.tid_rdma.r_req.tid_flow_qp);
+	flow->idx = (flow->tid_qpn >> TID_RDMA_DESTQP_FLOW_SHIFT) &
+		    TID_RDMA_DESTQP_FLOW_MASK;
+	flow_psn = mask_psn(be32_to_cpu(ohdr->u.tid_rdma.r_req.tid_flow_psn));
+	flow->flow_state.generation = flow_psn >> HFI1_KDETH_BTH_SEQ_SHIFT;
+	flow->flow_state.spsn = flow_psn & HFI1_KDETH_BTH_SEQ_MASK;
+	flow->length = len;
+
+	flow->flow_state.lpsn = flow->flow_state.spsn +
+		flow->npkts - 1;
+	flow->flow_state.ib_spsn = psn;
+	flow->flow_state.ib_lpsn = flow->flow_state.ib_spsn + flow->npkts - 1;
+
+	/* Set the initial flow index to the current flow. */
+	req->flow_idx = req->setup_head;
+
+	/* advance circular buffer head */
+	req->setup_head = (req->setup_head + 1) & (MAX_FLOWS - 1);
+
+	/*
+	 * Compute last PSN for request.
+	 */
+	e->opcode = (bth0 >> 24) & 0xff;
+	e->psn = psn;
+	e->lpsn = psn + flow->npkts - 1;
+	e->sent = 0;
+
+	req->n_flows = qpriv->tid_rdma.local.max_read;
+	req->state = TID_REQUEST_ACTIVE;
+	req->cur_seg = 0;
+	req->comp_seg = 0;
+	req->ack_seg = 0;
+	req->isge = 0;
+	req->seg_len = qpriv->tid_rdma.local.max_len;
+	req->total_len = len;
+	req->total_segs = 1;
+	req->r_flow_psn = e->psn;
+
+	return 0;
+}
+
+static int tid_rdma_rcv_error(struct hfi1_packet *packet,
+			      struct ib_other_headers *ohdr,
+			      struct rvt_qp *qp, u32 psn, int diff)
+{
+	struct hfi1_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
+	struct hfi1_ctxtdata *rcd = ((struct hfi1_qp_priv *)qp->priv)->rcd;
+	struct rvt_ack_entry *e;
+	struct tid_rdma_request *req;
+	unsigned long flags;
+	u8 prev;
+	bool old_req;
+
+	if (diff > 0) {
+		/* sequence error */
+		if (!qp->r_nak_state) {
+			ibp->rvp.n_rc_seqnak++;
+			qp->r_nak_state = IB_NAK_PSN_ERROR;
+			qp->r_ack_psn = qp->r_psn;
+			rc_defered_ack(rcd, qp);
+		}
+		goto done;
+	}
+
+	ibp->rvp.n_rc_dupreq++;
+
+	spin_lock_irqsave(&qp->s_lock, flags);
+	e = find_prev_entry(qp, psn, &prev, NULL, &old_req);
+	if (!e || e->opcode != TID_OP(READ_REQ))
+		goto unlock;
+
+	req = ack_to_tid_req(e);
+	req->r_flow_psn = psn;
+
+	if (e->opcode == TID_OP(READ_REQ)) {
+		struct ib_reth *reth;
+		u32 offset;
+		u32 len;
+		u32 rkey;
+		u64 vaddr;
+		int ok;
+		u32 bth0;
+
+		reth = &ohdr->u.tid_rdma.r_req.reth;
+		/*
+		 * The requester always restarts from the start of the original
+		 * request.
+		 */
+		offset = delta_psn(psn, e->psn) * qp->pmtu;
+		len = be32_to_cpu(reth->length);
+		if (psn != e->psn || len != req->total_len)
+			goto unlock;
+
+		if (e->rdma_sge.mr) {
+			rvt_put_mr(e->rdma_sge.mr);
+			e->rdma_sge.mr = NULL;
+		}
+
+		rkey = be32_to_cpu(reth->rkey);
+		vaddr = get_ib_reth_vaddr(reth);
+
+		qp->r_len = len;
+		ok = rvt_rkey_ok(qp, &e->rdma_sge, len, vaddr, rkey,
+				 IB_ACCESS_REMOTE_READ);
+		if (unlikely(!ok))
+			goto unlock;
+
+		/*
+		 * If all the response packets for the current request have
+		 * been sent out and this request is complete (old_request
+		 * == false) and the TID flow may be unusable (the
+		 * req->clear_tail is advanced). However, when an earlier
+		 * request is received, this request will not be complete any
+		 * more (qp->s_tail_ack_queue is moved back, see below).
+		 * Consequently, we need to update the TID flow info everytime
+		 * a duplicate request is received.
+		 */
+		bth0 = be32_to_cpu(ohdr->bth[0]);
+		if (tid_rdma_rcv_read_request(qp, e, packet, ohdr, bth0, psn,
+					      vaddr, len))
+			goto unlock;
+
+		/*
+		 * True if the request is already scheduled (between
+		 * qp->s_tail_ack_queue and qp->r_head_ack_queue);
+		 */
+		if (old_req)
+			goto unlock;
+	}
+	/* Re-process old requests.*/
+	qp->s_tail_ack_queue = prev;
+	/*
+	 * Since the qp->s_tail_ack_queue is modified, the
+	 * qp->s_ack_state must be changed to re-initialize
+	 * qp->s_ack_rdma_sge; Otherwise, we will end up in
+	 * wrong memory region.
+	 */
+	qp->s_ack_state = OP(ACKNOWLEDGE);
+	qp->r_state = e->opcode;
+	qp->r_nak_state = 0;
+	qp->s_flags |= RVT_S_RESP_PENDING;
+	hfi1_schedule_send(qp);
+unlock:
+	spin_unlock_irqrestore(&qp->s_lock, flags);
+done:
+	return 1;
+}
+
+void hfi1_rc_rcv_tid_rdma_read_req(struct hfi1_packet *packet)
+{
+	/* HANDLER FOR TID RDMA READ REQUEST packet (Responder side)*/
+
+	/*
+	 * 1. Verify TID RDMA READ REQ as per IB_OPCODE_RC_RDMA_READ
+	 *    (see hfi1_rc_rcv())
+	 * 2. Put TID RDMA READ REQ into the response queueu (s_ack_queue)
+	 *     - Setup struct tid_rdma_req with request info
+	 *     - Initialize struct tid_rdma_flow info;
+	 *     - Copy TID entries;
+	 * 3. Set the qp->s_ack_state.
+	 * 4. Set RVT_S_RESP_PENDING in s_flags.
+	 * 5. Kick the send engine (hfi1_schedule_send())
+	 */
+	struct hfi1_ctxtdata *rcd = packet->rcd;
+	struct rvt_qp *qp = packet->qp;
+	struct hfi1_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
+	struct ib_other_headers *ohdr = packet->ohdr;
+	struct rvt_ack_entry *e;
+	unsigned long flags;
+	struct ib_reth *reth;
+	struct hfi1_qp_priv *qpriv = qp->priv;
+	u32 bth0, psn, len, rkey;
+	bool is_fecn;
+	u8 next;
+	u64 vaddr;
+	int diff;
+	u8 nack_state = IB_NAK_INVALID_REQUEST;
+
+	bth0 = be32_to_cpu(ohdr->bth[0]);
+	if (hfi1_ruc_check_hdr(ibp, packet))
+		return;
+
+	is_fecn = process_ecn(qp, packet);
+	psn = mask_psn(be32_to_cpu(ohdr->bth[2]));
+
+	if (qp->state == IB_QPS_RTR && !(qp->r_flags & RVT_R_COMM_EST))
+		rvt_comm_est(qp);
+
+	if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_READ)))
+		goto nack_inv;
+
+	reth = &ohdr->u.tid_rdma.r_req.reth;
+	vaddr = be64_to_cpu(reth->vaddr);
+	len = be32_to_cpu(reth->length);
+	/* The length needs to be in multiples of PAGE_SIZE */
+	if (!len || len & ~PAGE_MASK || len > qpriv->tid_rdma.local.max_len)
+		goto nack_inv;
+
+	diff = delta_psn(psn, qp->r_psn);
+	if (unlikely(diff)) {
+		if (tid_rdma_rcv_error(packet, ohdr, qp, psn, diff))
+			return;
+		goto send_ack;
+	}
+
+	/* We've verified the request, insert it into the ack queue. */
+	next = qp->r_head_ack_queue + 1;
+	if (next > rvt_size_atomic(ib_to_rvt(qp->ibqp.device)))
+		next = 0;
+	spin_lock_irqsave(&qp->s_lock, flags);
+	if (unlikely(next == qp->s_tail_ack_queue)) {
+		if (!qp->s_ack_queue[next].sent) {
+			nack_state = IB_NAK_REMOTE_OPERATIONAL_ERROR;
+			goto nack_inv_unlock;
+		}
+		update_ack_queue(qp, next);
+	}
+	e = &qp->s_ack_queue[qp->r_head_ack_queue];
+	if (e->rdma_sge.mr) {
+		rvt_put_mr(e->rdma_sge.mr);
+		e->rdma_sge.mr = NULL;
+	}
+
+	rkey = be32_to_cpu(reth->rkey);
+	qp->r_len = len;
+
+	if (unlikely(!rvt_rkey_ok(qp, &e->rdma_sge, qp->r_len, vaddr,
+				  rkey, IB_ACCESS_REMOTE_READ)))
+		goto nack_acc;
+
+	/* Accept the request parameters */
+	if (tid_rdma_rcv_read_request(qp, e, packet, ohdr, bth0, psn, vaddr,
+				      len))
+		goto nack_inv_unlock;
+
+	qp->r_state = e->opcode;
+	qp->r_nak_state = 0;
+	/*
+	 * We need to increment the MSN here instead of when we
+	 * finish sending the result since a duplicate request would
+	 * increment it more than once.
+	 */
+	qp->r_msn++;
+	qp->r_psn += e->lpsn - e->psn + 1;
+
+	qp->r_head_ack_queue = next;
+
+	/* Schedule the send tasklet. */
+	qp->s_flags |= RVT_S_RESP_PENDING;
+	hfi1_schedule_send(qp);
+
+	spin_unlock_irqrestore(&qp->s_lock, flags);
+	if (is_fecn)
+		goto send_ack;
+	return;
+
+nack_inv_unlock:
+	spin_unlock_irqrestore(&qp->s_lock, flags);
+nack_inv:
+	rvt_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
+	qp->r_nak_state = nack_state;
+	qp->r_ack_psn = qp->r_psn;
+	/* Queue NAK for later */
+	rc_defered_ack(rcd, qp);
+	return;
+nack_acc:
+	spin_unlock_irqrestore(&qp->s_lock, flags);
+	rvt_rc_error(qp, IB_WC_LOC_PROT_ERR);
+	qp->r_nak_state = IB_NAK_REMOTE_ACCESS_ERROR;
+	qp->r_ack_psn = qp->r_psn;
+send_ack:
+	hfi1_send_rc_ack(packet, is_fecn);
+}