diff --git a/drivers/net/mlx4/mlx4.h b/drivers/net/mlx4/mlx4.h
index e0a9853..70cf453 100644
--- a/drivers/net/mlx4/mlx4.h
+++ b/drivers/net/mlx4/mlx4.h
@@ -160,5 +160,7 @@ int mlx4_flow_ctrl_set(struct rte_eth_dev *dev,
 /* mlx4_mr.c */
 
 struct ibv_mr *mlx4_mp2mr(struct ibv_pd *pd, struct rte_mempool *mp);
+uint32_t mlx4_txq_add_mr(struct txq *txq, struct rte_mempool *mp,
+			 uint32_t i);
 
 #endif /* RTE_PMD_MLX4_H_ */
diff --git a/drivers/net/mlx4/mlx4_mr.c b/drivers/net/mlx4/mlx4_mr.c
index 9700884..ebf6547 100644
--- a/drivers/net/mlx4/mlx4_mr.c
+++ b/drivers/net/mlx4/mlx4_mr.c
@@ -56,6 +56,7 @@
 #include <rte_mempool.h>
 
 #include "mlx4_utils.h"
+#include "mlx4_rxtx.h"
 
 struct mlx4_check_mempool_data {
 	int ret;
@@ -181,3 +182,48 @@ struct ibv_mr *
 		rte_errno = errno ? errno : EINVAL;
 	return mr;
 }
+
+/**
+ * Add memory region (MR) <-> memory pool (MP) association to txq->mp2mr[].
+ * If mp2mr[] is full, remove an entry first.
+ *
+ * @param txq
+ *   Pointer to Tx queue structure.
+ * @param[in] mp
+ *   Memory pool for which a memory region lkey must be added
+ * @param[in] i
+ *   Index in memory pool (MP) where to add memory region (MR)
+ *
+ * @return
+ *   Added mr->lkey on success, (uint32_t)-1 on failure.
+ */
+uint32_t mlx4_txq_add_mr(struct txq *txq, struct rte_mempool *mp, uint32_t i)
+{
+	struct ibv_mr *mr;
+
+	/* Add a new entry, register MR first. */
+	DEBUG("%p: discovered new memory pool \"%s\" (%p)",
+	      (void *)txq, mp->name, (void *)mp);
+	mr = mlx4_mp2mr(txq->priv->pd, mp);
+	if (unlikely(mr == NULL)) {
+		DEBUG("%p: unable to configure MR, ibv_reg_mr() failed.",
+		      (void *)txq);
+		return (uint32_t)-1;
+	}
+	if (unlikely(i == RTE_DIM(txq->mp2mr))) {
+		/* Table is full, remove oldest entry. */
+		DEBUG("%p: MR <-> MP table full, dropping oldest entry.",
+		      (void *)txq);
+		--i;
+		claim_zero(ibv_dereg_mr(txq->mp2mr[0].mr));
+		memmove(&txq->mp2mr[0], &txq->mp2mr[1],
+			(sizeof(txq->mp2mr) - sizeof(txq->mp2mr[0])));
+	}
+	/* Store the new entry. */
+	txq->mp2mr[i].mp = mp;
+	txq->mp2mr[i].mr = mr;
+	txq->mp2mr[i].lkey = mr->lkey;
+	DEBUG("%p: new MR lkey for MP \"%s\" (%p): 0x%08" PRIU32,
+	      (void *)txq, mp->name, (void *)mp, txq->mp2mr[i].lkey);
+	return txq->mp2mr[i].lkey;
+}
diff --git a/drivers/net/mlx4/mlx4_rxtx.c b/drivers/net/mlx4/mlx4_rxtx.c
index 4f899ff..f89df46 100644
--- a/drivers/net/mlx4/mlx4_rxtx.c
+++ b/drivers/net/mlx4/mlx4_rxtx.c
@@ -239,63 +239,6 @@ struct pv {
 }
 
 /**
- * Get memory region (MR) <-> memory pool (MP) association from txq->mp2mr[].
- * Add MP to txq->mp2mr[] if it's not registered yet. If mp2mr[] is full,
- * remove an entry first.
- *
- * @param txq
- *   Pointer to Tx queue structure.
- * @param[in] mp
- *   Memory pool for which a memory region lkey must be returned.
- *
- * @return
- *   mr->lkey on success, (uint32_t)-1 on failure.
- */
-uint32_t
-mlx4_txq_mp2mr(struct txq *txq, struct rte_mempool *mp)
-{
-	unsigned int i;
-	struct ibv_mr *mr;
-
-	for (i = 0; (i != RTE_DIM(txq->mp2mr)); ++i) {
-		if (unlikely(txq->mp2mr[i].mp == NULL)) {
-			/* Unknown MP, add a new MR for it. */
-			break;
-		}
-		if (txq->mp2mr[i].mp == mp) {
-			assert(txq->mp2mr[i].lkey != (uint32_t)-1);
-			assert(txq->mp2mr[i].mr->lkey == txq->mp2mr[i].lkey);
-			return txq->mp2mr[i].lkey;
-		}
-	}
-	/* Add a new entry, register MR first. */
-	DEBUG("%p: discovered new memory pool \"%s\" (%p)",
-	      (void *)txq, mp->name, (void *)mp);
-	mr = mlx4_mp2mr(txq->priv->pd, mp);
-	if (unlikely(mr == NULL)) {
-		DEBUG("%p: unable to configure MR, ibv_reg_mr() failed.",
-		      (void *)txq);
-		return (uint32_t)-1;
-	}
-	if (unlikely(i == RTE_DIM(txq->mp2mr))) {
-		/* Table is full, remove oldest entry. */
-		DEBUG("%p: MR <-> MP table full, dropping oldest entry.",
-		      (void *)txq);
-		--i;
-		claim_zero(ibv_dereg_mr(txq->mp2mr[0].mr));
-		memmove(&txq->mp2mr[0], &txq->mp2mr[1],
-			(sizeof(txq->mp2mr) - sizeof(txq->mp2mr[0])));
-	}
-	/* Store the new entry. */
-	txq->mp2mr[i].mp = mp;
-	txq->mp2mr[i].mr = mr;
-	txq->mp2mr[i].lkey = mr->lkey;
-	DEBUG("%p: new MR lkey for MP \"%s\" (%p): 0x%08" PRIu32,
-	      (void *)txq, mp->name, (void *)mp, txq->mp2mr[i].lkey);
-	return txq->mp2mr[i].lkey;
-}
-
-/**
  * Posts a single work request to a send queue.
  *
  * @param txq
diff --git a/drivers/net/mlx4/mlx4_rxtx.h b/drivers/net/mlx4/mlx4_rxtx.h
index 7d67748..b32fcc9 100644
--- a/drivers/net/mlx4/mlx4_rxtx.h
+++ b/drivers/net/mlx4/mlx4_rxtx.h
@@ -36,6 +36,7 @@
 
 #include <stdint.h>
 #include <sys/queue.h>
+#include <assert.h>
 
 /* Verbs headers do not support -pedantic. */
 #ifdef PEDANTIC
@@ -165,7 +166,6 @@ int mlx4_rx_queue_setup(struct rte_eth_dev *dev, uint16_t idx,
 
 /* mlx4_rxtx.c */
 
-uint32_t mlx4_txq_mp2mr(struct txq *txq, struct rte_mempool *mp);
 uint16_t mlx4_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts,
 		       uint16_t pkts_n);
 uint16_t mlx4_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts,
@@ -182,4 +182,35 @@ int mlx4_tx_queue_setup(struct rte_eth_dev *dev, uint16_t idx,
 			const struct rte_eth_txconf *conf);
 void mlx4_tx_queue_release(void *dpdk_txq);
 
+
+/**
+ * Get memory region (MR) <-> memory pool (MP) association from txq->mp2mr[].
+ * Call mlx4_txq_add_mr() if MP is not registered yet.
+ *
+ * @param txq
+ *   Pointer to Tx queue structure.
+ * @param[in] mp
+ *   Memory pool for which a memory region lkey must be returned.
+ *
+ * @return
+ *   mr->lkey on success, (uint32_t)-1 on failure.
+ */
+static inline uint32_t
+mlx4_txq_mp2mr(struct txq *txq, struct rte_mempool *mp)
+{
+	unsigned int i;
+
+	for (i = 0; (i != RTE_DIM(txq->mp2mr)); ++i) {
+		if (unlikely(txq->mp2mr[i].mp == NULL)) {
+			/* Unknown MP, add a new MR for it. */
+			break;
+		}
+		if (txq->mp2mr[i].mp == mp) {
+			assert(txq->mp2mr[i].lkey != (uint32_t)-1);
+			assert(txq->mp2mr[i].mr->lkey == txq->mp2mr[i].lkey);
+			return txq->mp2mr[i].lkey;
+		}
+	}
+	return mlx4_txq_add_mr(txq, mp, i);
+}
 #endif /* MLX4_RXTX_H_ */
