+ * A valid Rx queue identifier on this port.
+ * @param offset
+ * The offset of the descriptor starting from tail (0 is the next
+ * packet to be received by the driver).
+ *
+ * @return
+ * - (RTE_ETH_RX_DESC_AVAIL): Descriptor is available for the hardware to
+ * receive a packet.
+ * - (RTE_ETH_RX_DESC_DONE): Descriptor is done, it is filled by hw, but
+ * not yet processed by the driver (i.e. in the receive queue).
+ * - (RTE_ETH_RX_DESC_UNAVAIL): Descriptor is unavailable, either hold by
+ * the driver and not yet returned to hw, or reserved by the hw.
+ * - (-EINVAL) bad descriptor offset.
+ * - (-ENOTSUP) if the device does not support this function.
+ * - (-ENODEV) bad port or queue (only if compiled with debug).
+ */
+static inline int
+rte_eth_rx_descriptor_status(uint8_t port_id, uint16_t queue_id,
+ uint16_t offset)
+{
+ struct rte_eth_dev *dev;
+ void *rxq;
+
+#ifdef RTE_LIBRTE_ETHDEV_DEBUG
+ RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
+#endif
+ dev = &rte_eth_devices[port_id];
+#ifdef RTE_LIBRTE_ETHDEV_DEBUG
+ if (queue_id >= dev->data->nb_rx_queues)
+ return -ENODEV;
+#endif
+ RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->rx_descriptor_status, -ENOTSUP);
+ rxq = dev->data->rx_queues[queue_id];
+
+ return (*dev->dev_ops->rx_descriptor_status)(rxq, offset);
+}
+
+#define RTE_ETH_TX_DESC_FULL 0 /**< Desc filled for hw, waiting xmit. */
+#define RTE_ETH_TX_DESC_DONE 1 /**< Desc done, packet is transmitted. */
+#define RTE_ETH_TX_DESC_UNAVAIL 2 /**< Desc used by driver or hw. */
+
+/**
+ * Check the status of a Tx descriptor in the queue.
+ *
+ * It should be called in a similar context than the Tx function:
+ * - on a dataplane core
+ * - not concurrently on the same queue
+ *
+ * Since it's a dataplane function, no check is performed on port_id and
+ * queue_id. The caller must therefore ensure that the port is enabled
+ * and the queue is configured and running.
+ *
+ * Note: accessing to a random descriptor in the ring may trigger cache
+ * misses and have a performance impact.
+ *
+ * @param port_id
+ * A valid port identifier of the Ethernet device which.
+ * @param queue_id
+ * A valid Tx queue identifier on this port.
+ * @param offset
+ * The offset of the descriptor starting from tail (0 is the place where
+ * the next packet will be send).
+ *
+ * @return
+ * - (RTE_ETH_TX_DESC_FULL) Descriptor is being processed by the hw, i.e.
+ * in the transmit queue.
+ * - (RTE_ETH_TX_DESC_DONE) Hardware is done with this descriptor, it can
+ * be reused by the driver.
+ * - (RTE_ETH_TX_DESC_UNAVAIL): Descriptor is unavailable, reserved by the
+ * driver or the hardware.
+ * - (-EINVAL) bad descriptor offset.
+ * - (-ENOTSUP) if the device does not support this function.
+ * - (-ENODEV) bad port or queue (only if compiled with debug).
+ */
+static inline int rte_eth_tx_descriptor_status(uint8_t port_id,
+ uint16_t queue_id, uint16_t offset)
+{
+ struct rte_eth_dev *dev;
+ void *txq;
+
+#ifdef RTE_LIBRTE_ETHDEV_DEBUG
+ RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
+#endif
+ dev = &rte_eth_devices[port_id];
+#ifdef RTE_LIBRTE_ETHDEV_DEBUG
+ if (queue_id >= dev->data->nb_tx_queues)
+ return -ENODEV;
+#endif
+ RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->tx_descriptor_status, -ENOTSUP);
+ txq = dev->data->tx_queues[queue_id];
+
+ return (*dev->dev_ops->tx_descriptor_status)(txq, offset);
+}
+
+/**
+ * Send a burst of output packets on a transmit queue of an Ethernet device.
+ *
+ * The rte_eth_tx_burst() function is invoked to transmit output packets
+ * on the output queue *queue_id* of the Ethernet device designated by its
+ * *port_id*.
+ * The *nb_pkts* parameter is the number of packets to send which are
+ * supplied in the *tx_pkts* array of *rte_mbuf* structures, each of them
+ * allocated from a pool created with rte_pktmbuf_pool_create().
+ * The rte_eth_tx_burst() function loops, sending *nb_pkts* packets,
+ * up to the number of transmit descriptors available in the TX ring of the
+ * transmit queue.
+ * For each packet to send, the rte_eth_tx_burst() function performs
+ * the following operations:
+ *
+ * - Pick up the next available descriptor in the transmit ring.
+ *
+ * - Free the network buffer previously sent with that descriptor, if any.
+ *
+ * - Initialize the transmit descriptor with the information provided
+ * in the *rte_mbuf data structure.
+ *
+ * In the case of a segmented packet composed of a list of *rte_mbuf* buffers,
+ * the rte_eth_tx_burst() function uses several transmit descriptors
+ * of the ring.
+ *
+ * The rte_eth_tx_burst() function returns the number of packets it
+ * actually sent. A return value equal to *nb_pkts* means that all packets
+ * have been sent, and this is likely to signify that other output packets
+ * could be immediately transmitted again. Applications that implement a
+ * "send as many packets to transmit as possible" policy can check this
+ * specific case and keep invoking the rte_eth_tx_burst() function until
+ * a value less than *nb_pkts* is returned.
+ *
+ * It is the responsibility of the rte_eth_tx_burst() function to
+ * transparently free the memory buffers of packets previously sent.
+ * This feature is driven by the *tx_free_thresh* value supplied to the
+ * rte_eth_dev_configure() function at device configuration time.
+ * When the number of free TX descriptors drops below this threshold, the
+ * rte_eth_tx_burst() function must [attempt to] free the *rte_mbuf* buffers
+ * of those packets whose transmission was effectively completed.
+ *
+ * @param port_id
+ * The port identifier of the Ethernet device.
+ * @param queue_id
+ * The index of the transmit queue through which output packets must be
+ * sent.
+ * The value must be in the range [0, nb_tx_queue - 1] previously supplied