RDMA/rxe: Extend response packets for frags

Extend prepare_ack_packet(), read_reply() and send_common_ack() in
rxe_resp.c to support fragmented skbs.  Adjust calls to these routines
for the changed API.

This is in preparation for using fragmented skbs.

Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>

drivers/infiniband/sw/rxe/rxe_resp.c

@@ -660,10 +660,8 @@ static enum resp_states atomic_reply(struct rxe_qp *qp,
 
 static struct sk_buff *prepare_ack_packet(struct rxe_qp *qp,
 					  struct rxe_pkt_info *ack,
-					  int opcode,
-					  int payload,
-					  u32 psn,
-					  u8 syndrome)
+					  int opcode, int payload, u32 psn,
+					  u8 syndrome, bool *fragp)
 {
 	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
 	struct sk_buff *skb;
@@ -682,7 +680,7 @@ static struct sk_buff *prepare_ack_packet(struct rxe_qp *qp,
 	ack->psn = psn;
 	ack->port_num = 1;
 
-	skb = rxe_init_packet(qp, &qp->pri_av, ack, NULL);
+	skb = rxe_init_packet(qp, &qp->pri_av, ack, fragp);
 	if (!skb)
 		return NULL;
 
@@ -698,12 +696,14 @@ static struct sk_buff *prepare_ack_packet(struct rxe_qp *qp,
 		atmack_set_orig(ack, qp->resp.res->atomic.orig_val);
 
 	err = rxe_prepare(&qp->pri_av, ack, skb);
-	if (err) {
-		kfree_skb(skb);
-		return NULL;
-	}
+	if (err)
+		goto err_free_skb;
 
 	return skb;
+
+err_free_skb:
+	kfree_skb(skb);
+	return NULL;
 }
 
 /**
@@ -775,6 +775,8 @@ static enum resp_states read_reply(struct rxe_qp *qp,
 	struct resp_res *res = qp->resp.res;
 	struct rxe_mr *mr;
 	int skb_offset = 0;
+	bool frag;
+	enum rxe_mr_copy_op op;
 
 	if (!res) {
 		res = rxe_prepare_res(qp, req_pkt, RXE_READ_MASK);
@@ -787,8 +789,10 @@ static enum resp_states read_reply(struct rxe_qp *qp,
 			qp->resp.mr = NULL;
 		} else {
 			mr = rxe_recheck_mr(qp, res->read.rkey);
-			if (!mr)
-				return RESPST_ERR_RKEY_VIOLATION;
+			if (!mr) {
+				state = RESPST_ERR_RKEY_VIOLATION;
+				goto err_out;
+			}
 		}
 
 		if (res->read.resid <= mtu)
@@ -797,44 +801,44 @@ static enum resp_states read_reply(struct rxe_qp *qp,
 			opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST;
 	} else {
 		mr = rxe_recheck_mr(qp, res->read.rkey);
-		if (!mr)
-			return RESPST_ERR_RKEY_VIOLATION;
+		if (!mr) {
+			state = RESPST_ERR_RKEY_VIOLATION;
+			goto err_out;
+		}
 
 		if (res->read.resid > mtu)
 			opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE;
 		else
 			opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST;
 	}
 
-	res->state = rdatm_res_state_next;
-
 	payload = min_t(int, res->read.resid, mtu);
 
 	skb = prepare_ack_packet(qp, &ack_pkt, opcode, payload,
-				 res->cur_psn, AETH_ACK_UNLIMITED);
-	if (!skb)
-		return RESPST_ERR_RNR;
+				 res->cur_psn, AETH_ACK_UNLIMITED, &frag);
+	if (!skb) {
+		state = RESPST_ERR_RNR;
+		goto err_put_mr;
+	}
 
+	op = frag ? RXE_FRAG_FROM_MR : RXE_COPY_FROM_MR;
 	err = rxe_copy_mr_data(skb, mr, res->read.va, payload_addr(&ack_pkt),
-			       skb_offset, payload, RXE_COPY_FROM_MR);
+			       skb_offset, payload, op);
 	if (err) {
-		kfree_skb(skb);
-		rxe_put(mr);
-		return RESPST_ERR_RKEY_VIOLATION;
+		state = RESPST_ERR_RKEY_VIOLATION;
+		goto err_free_skb;
 	}
 
-	if (mr)
-		rxe_put(mr);
-
-	if (bth_pad(&ack_pkt)) {
-		u8 *pad = payload_addr(&ack_pkt) + payload;
-
-		memset(pad, 0, bth_pad(&ack_pkt));
-	}
+	err = rxe_prepare_pad_icrc(&ack_pkt, skb, payload, frag);
+	if (err)
+		goto err_free_skb;
 
 	err = rxe_xmit_packet(qp, &ack_pkt, skb);
-	if (err)
-		return RESPST_ERR_RNR;
+	if (err) {
+		/* rxe_xmit_packet will consume the packet */
+		state = RESPST_ERR_RNR;
+		goto err_put_mr;
+	}
 
 	res->read.va += payload;
 	res->read.resid -= payload;
@@ -851,6 +855,16 @@ static enum resp_states read_reply(struct rxe_qp *qp,
 		state = RESPST_CLEANUP;
 	}
 
+	/* keep these after all error exits */
+	res->state = rdatm_res_state_next;
+	rxe_put(mr);
+	return state;
+
+err_free_skb:
+	kfree_skb(skb);
+err_put_mr:
+	rxe_put(mr);
+err_out:
 	return state;
 }
 
@@ -1041,14 +1055,19 @@ static int send_common_ack(struct rxe_qp *qp, u8 syndrome, u32 psn,
 				  int opcode, const char *msg)
 {
 	int err;
-	struct rxe_pkt_info ack_pkt;
+	struct rxe_pkt_info ack;
 	struct sk_buff *skb;
+	int payload = 0;
 
-	skb = prepare_ack_packet(qp, &ack_pkt, opcode, 0, psn, syndrome);
+	skb = prepare_ack_packet(qp, &ack, opcode, payload,
+				 psn, syndrome, NULL);
 	if (!skb)
 		return -ENOMEM;
 
-	err = rxe_xmit_packet(qp, &ack_pkt, skb);
+	/* doesn't fail if frag == false */
+	(void)rxe_prepare_pad_icrc(&ack, skb, payload, false);
+
+	err = rxe_xmit_packet(qp, &ack, skb);
 	if (err)
 		pr_err_ratelimited("Failed sending %s\n", msg);