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>

drivers/infiniband/hw/hfi1/tid_rdma.c

@@ -1797,3 +1797,332 @@ u32 hfi1_build_tid_rdma_read_req(struct rvt_qp *qp, struct rvt_swqe *wqe,
 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);
+}

drivers/infiniband/hw/hfi1/tid_rdma.h

@@ -73,9 +73,14 @@ struct tid_rdma_request {
 	u16 flow_idx;		/* flow index most recently set up */
 
 	u32 seg_len;
+	u32 total_len;
+	u32 r_flow_psn;         /* IB PSN of next segment start */
 	u32 s_next_psn;		/* IB PSN of next segment start for read */
 
+	u32 total_segs;		/* segments required to complete a request */
 	u32 cur_seg;		/* index of current segment */
+	u32 comp_seg;           /* index of last completed segment */
+	u32 ack_seg;            /* index of last ack'ed segment */
 	u32 isge;		/* index of "current" sge */
 	u32 ack_pending;        /* num acks pending for this request */
 
@@ -131,6 +136,8 @@ struct tid_rdma_flow {
 	 */
 	struct flow_state flow_state;
 	struct tid_rdma_request *req;
+	u32 tid_qpn;
+	u32 tid_offset;
 	u32 length;
 	u32 sent;
 	u8 tnode_cnt;
@@ -190,5 +197,6 @@ u32 hfi1_build_tid_rdma_read_packet(struct rvt_swqe *wqe,
 u32 hfi1_build_tid_rdma_read_req(struct rvt_qp *qp, struct rvt_swqe *wqe,
 				 struct ib_other_headers *ohdr, u32 *bth1,
 				 u32 *bth2, u32 *len);
+void hfi1_rc_rcv_tid_rdma_read_req(struct hfi1_packet *packet);
 
 #endif /* HFI1_TID_RDMA_H */

drivers/infiniband/hw/hfi1/verbs.h

@@ -340,6 +340,11 @@ static inline struct tid_rdma_request *wqe_to_tid_req(struct rvt_swqe *wqe)
 	return &((struct hfi1_swqe_priv *)wqe->priv)->tid_req;
 }
 
+static inline struct tid_rdma_request *ack_to_tid_req(struct rvt_ack_entry *e)
+{
+	return &((struct hfi1_ack_priv *)e->priv)->tid_req;
+}
+
 /*
  * Look through all the active flows for a TID RDMA request and find
  * the one (if it exists) that contains the specified PSN.