[RFC PATCH 3/7] RDMA/rxe: Cleanup code for responder Atomic operations

[Daisuke Matsuda <matsuda-daisuke@xxxxxxxxxxx>]

Currently, rxe_responder() directly calls the function to execute Atomic
operations. This need to be modified to insert some conditional branches
for the new RDMA Write operation and the ODP feature.

Signed-off-by: Daisuke Matsuda <matsuda-daisuke@xxxxxxxxxxx>
---
 drivers/infiniband/sw/rxe/rxe_resp.c | 102 +++++++++++++++++----------
 1 file changed, 64 insertions(+), 38 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
index e97c55b292f0..cadc8fa64dd0 100644
--- a/drivers/infiniband/sw/rxe/rxe_resp.c
+++ b/drivers/infiniband/sw/rxe/rxe_resp.c
@@ -591,60 +591,86 @@ static struct resp_res *rxe_prepare_res(struct rxe_qp *qp,
 /* Guarantee atomicity of atomic operations at the machine level. */
 static DEFINE_SPINLOCK(atomic_ops_lock);
 
-static enum resp_states atomic_reply(struct rxe_qp *qp,
-					 struct rxe_pkt_info *pkt)
+enum resp_states rxe_process_atomic(struct rxe_qp *qp,
+				    struct rxe_pkt_info *pkt, u64 *vaddr)
 {
-	u64 *vaddr;
 	enum resp_states ret;
-	struct rxe_mr *mr = qp->resp.mr;
 	struct resp_res *res = qp->resp.res;
 	u64 value;
 
-	if (!res) {
-		res = rxe_prepare_res(qp, pkt, RXE_ATOMIC_MASK);
-		qp->resp.res = res;
+	/* check vaddr is 8 bytes aligned. */
+	if (!vaddr || (uintptr_t)vaddr & 7) {
+		ret = RESPST_ERR_MISALIGNED_ATOMIC;
+		goto out;
 	}
 
-	if (!res->replay) {
-		if (mr->state != RXE_MR_STATE_VALID) {
-			ret = RESPST_ERR_RKEY_VIOLATION;
-			goto out;
-		}
+	spin_lock(&atomic_ops_lock);
+	res->atomic.orig_val = value = *vaddr;
 
-		vaddr = iova_to_vaddr(mr, qp->resp.va + qp->resp.offset,
-					sizeof(u64));
+	if (pkt->opcode == IB_OPCODE_RC_COMPARE_SWAP) {
+		if (value == atmeth_comp(pkt))
+			value = atmeth_swap_add(pkt);
+	} else {
+		value += atmeth_swap_add(pkt);
+	}
 
-		/* check vaddr is 8 bytes aligned. */
-		if (!vaddr || (uintptr_t)vaddr & 7) {
-			ret = RESPST_ERR_MISALIGNED_ATOMIC;
-			goto out;
-		}
+	*vaddr = value;
+	spin_unlock(&atomic_ops_lock);
 
-		spin_lock_bh(&atomic_ops_lock);
-		res->atomic.orig_val = value = *vaddr;
+	qp->resp.msn++;
 
-		if (pkt->opcode == IB_OPCODE_RC_COMPARE_SWAP) {
-			if (value == atmeth_comp(pkt))
-				value = atmeth_swap_add(pkt);
-		} else {
-			value += atmeth_swap_add(pkt);
-		}
+	/* next expected psn, read handles this separately */
+	qp->resp.psn = (pkt->psn + 1) & BTH_PSN_MASK;
+	qp->resp.ack_psn = qp->resp.psn;
 
-		*vaddr = value;
-		spin_unlock_bh(&atomic_ops_lock);
+	qp->resp.opcode = pkt->opcode;
+	qp->resp.status = IB_WC_SUCCESS;
 
-		qp->resp.msn++;
+	ret = RESPST_ACKNOWLEDGE;
+out:
+	return ret;
+}
 
-		/* next expected psn, read handles this separately */
-		qp->resp.psn = (pkt->psn + 1) & BTH_PSN_MASK;
-		qp->resp.ack_psn = qp->resp.psn;
+static  enum resp_states rxe_atomic_ops(struct rxe_qp *qp,
+					struct rxe_pkt_info *pkt,
+					struct rxe_mr *mr)
+{
+	u64 *vaddr;
+	int ret;
 
-		qp->resp.opcode = pkt->opcode;
-		qp->resp.status = IB_WC_SUCCESS;
+	vaddr = iova_to_vaddr(mr, qp->resp.va + qp->resp.offset,
+			      sizeof(u64));
+
+	if (pkt->mask & RXE_ATOMIC_MASK) {
+		ret = rxe_process_atomic(qp, pkt, vaddr);
+	} else {
+		/*ATOMIC WRITE operation will come here. */
+		ret = RESPST_ERR_UNSUPPORTED_OPCODE;
 	}
 
-	ret = RESPST_ACKNOWLEDGE;
-out:
+	return ret;
+}
+
+static enum resp_states rxe_atomic_reply(struct rxe_qp *qp,
+					 struct rxe_pkt_info *pkt)
+{
+	struct rxe_mr *mr = qp->resp.mr;
+	struct resp_res *res = qp->resp.res;
+	int ret;
+
+	if (!res) {
+		res = rxe_prepare_res(qp, pkt, RXE_ATOMIC_MASK);
+		qp->resp.res = res;
+	}
+
+	if (!res->replay) {
+		if (mr->state != RXE_MR_STATE_VALID)
+			return RESPST_ERR_RKEY_VIOLATION;
+
+		ret = rxe_atomic_ops(qp, pkt, mr);
+	} else
+		ret = RESPST_ACKNOWLEDGE;
+
 	return ret;
 }
 
@@ -1327,7 +1353,7 @@ int rxe_responder(void *arg)
 			state = read_reply(qp, pkt);
 			break;
 		case RESPST_ATOMIC_REPLY:
-			state = atomic_reply(qp, pkt);
+			state = rxe_atomic_reply(qp, pkt);
 			break;
 		case RESPST_ACKNOWLEDGE:
 			state = acknowledge(qp, pkt);
-- 
2.31.1