+/**
+ * Bottom-half of LKey search on Tx. If it can't be searched in the memseg
+ * list, register the mempool of the mbuf as externally allocated memory.
+ *
+ * @param txq
+ * Pointer to Tx queue structure.
+ * @param mb
+ * Pointer to mbuf.
+ *
+ * @return
+ * Searched LKey on success, UINT32_MAX on no match.
+ */
+uint32_t
+mlx4_tx_mb2mr_bh(struct txq *txq, struct rte_mbuf *mb)
+{
+ uintptr_t addr = (uintptr_t)mb->buf_addr;
+ uint32_t lkey;
+
+ lkey = mlx4_tx_addr2mr_bh(txq, addr);
+ if (lkey == UINT32_MAX && rte_errno == ENXIO) {
+ /* Mempool may have externally allocated memory. */
+ return mlx4_tx_update_ext_mp(txq, addr, mlx4_mb2mp(mb));
+ }
+ return lkey;
+}
+