ethdev: add API to retrieve queue information

Add the ability for the upper layer to query RX/TX queue information.
Add into rte_eth_dev_info new fields to represent information about
RX/TX descriptors min/max/alig nnumbers per queue for the device.

Add new structures:
struct rte_eth_rxq_info
struct rte_eth_txq_info

new functions:
rte_eth_rx_queue_info_get
rte_eth_tx_queue_info_get

into rte_etdev API.

Left extra free space in the queue info structures,
so extra fields could be added later without ABI breakage.

Add new fields:
rx_desc_lim
tx_desc_lim
into rte_eth_dev_info.

Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Acked-by: Remy Horton <remy.horton@intel.com>

doc/guides/rel_notes/release_2_2.rst

@@ -4,6 +4,12 @@ DPDK Release 2.2
 New Features
 ------------
 
+* **Added API in ethdev to retrieve RX/TX queue information.**
+
+  *  Add the ability for the upper layer to query RX/TX queue information.
+  *  Add into rte_eth_dev_info new fields to represent information about
+     RX/TX descriptors min/max/align numbers per queue for the device.
+
 * **Added RSS dynamic configuration to bonding.**
 
 * **Added e1000 Rx interrupt support.**
@@ -158,6 +164,9 @@ ABI Changes
 * The ethdev flow director entries for SCTP were changed.
   It was already done in 2.1 for CONFIG_RTE_NEXT_ABI.
 
+* The new fields rx_desc_lim and tx_desc_lim are added into rte_eth_dev_info
+  structure.
+
 * The mbuf structure was changed to support unified packet type.
   It was already done in 2.1 for CONFIG_RTE_NEXT_ABI.
 

lib/librte_ether/rte_ethdev.c

@@ -1248,6 +1248,19 @@ rte_eth_rx_queue_setup(uint8_t port_id, uint16_t rx_queue_id,
 		return -EINVAL;
 	}
 
+	if (nb_rx_desc > dev_info.rx_desc_lim.nb_max ||
+			nb_rx_desc < dev_info.rx_desc_lim.nb_min ||
+			nb_rx_desc % dev_info.rx_desc_lim.nb_align != 0) {
+
+		PMD_DEBUG_TRACE("Invalid value for nb_rx_desc(=%hu), "
+			"should be: <= %hu, = %hu, and a product of %hu\n",
+			nb_rx_desc,
+			dev_info.rx_desc_lim.nb_max,
+			dev_info.rx_desc_lim.nb_min,
+			dev_info.rx_desc_lim.nb_align);
+		return -EINVAL;
+	}
+
 	if (rx_conf == NULL)
 		rx_conf = &dev_info.default_rxconf;
 
@@ -1587,11 +1600,18 @@ void
 rte_eth_dev_info_get(uint8_t port_id, struct rte_eth_dev_info *dev_info)
 {
 	struct rte_eth_dev *dev;
+	const struct rte_eth_desc_lim lim = {
+		.nb_max = UINT16_MAX,
+		.nb_min = 0,
+		.nb_align = 1,
+	};
 
 	VALID_PORTID_OR_RET(port_id);
 	dev = &rte_eth_devices[port_id];
 
 	memset(dev_info, 0, sizeof(struct rte_eth_dev_info));
+	dev_info->rx_desc_lim = lim;
+	dev_info->tx_desc_lim = lim;
 
 	FUNC_PTR_OR_RET(*dev->dev_ops->dev_infos_get);
 	(*dev->dev_ops->dev_infos_get)(dev, dev_info);
@@ -3021,6 +3041,54 @@ rte_eth_remove_tx_callback(uint8_t port_id, uint16_t queue_id,
 	return -EINVAL;
 }
 
+int
+rte_eth_rx_queue_info_get(uint8_t port_id, uint16_t queue_id,
+	struct rte_eth_rxq_info *qinfo)
+{
+	struct rte_eth_dev *dev;
+
+	VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
+
+	if (qinfo == NULL)
+		return -EINVAL;
+
+	dev = &rte_eth_devices[port_id];
+	if (queue_id >= dev->data->nb_rx_queues) {
+		PMD_DEBUG_TRACE("Invalid RX queue_id=%d\n", queue_id);
+		return -EINVAL;
+	}
+
+	FUNC_PTR_OR_ERR_RET(*dev->dev_ops->rxq_info_get, -ENOTSUP);
+
+	memset(qinfo, 0, sizeof(*qinfo));
+	dev->dev_ops->rxq_info_get(dev, queue_id, qinfo);
+	return 0;
+}
+
+int
+rte_eth_tx_queue_info_get(uint8_t port_id, uint16_t queue_id,
+	struct rte_eth_txq_info *qinfo)
+{
+	struct rte_eth_dev *dev;
+
+	VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
+
+	if (qinfo == NULL)
+		return -EINVAL;
+
+	dev = &rte_eth_devices[port_id];
+	if (queue_id >= dev->data->nb_tx_queues) {
+		PMD_DEBUG_TRACE("Invalid TX queue_id=%d\n", queue_id);
+		return -EINVAL;
+	}
+
+	FUNC_PTR_OR_ERR_RET(*dev->dev_ops->txq_info_get, -ENOTSUP);
+
+	memset(qinfo, 0, sizeof(*qinfo));
+	dev->dev_ops->txq_info_get(dev, queue_id, qinfo);
+	return 0;
+}
+
 int
 rte_eth_dev_set_mc_addr_list(uint8_t port_id,
 			     struct ether_addr *mc_addr_set,

lib/librte_ether/rte_ethdev.h

@@ -652,6 +652,15 @@ struct rte_eth_txconf {
 	uint8_t tx_deferred_start; /**< Do not start queue with rte_eth_dev_start(). */
 };
 
+/**
+ * A structure contains information about HW descriptor ring limitations.
+ */
+struct rte_eth_desc_lim {
+	uint16_t nb_max;   /**< Max allowed number of descriptors. */
+	uint16_t nb_min;   /**< Min allowed number of descriptors. */
+	uint16_t nb_align; /**< Number of descriptors should be aligned to. */
+};
+
 /**
  * This enum indicates the flow control mode
  */
@@ -837,8 +846,30 @@ struct rte_eth_dev_info {
 	uint16_t vmdq_queue_base; /**< First queue ID for VMDQ pools. */
 	uint16_t vmdq_queue_num;  /**< Queue number for VMDQ pools. */
 	uint16_t vmdq_pool_base;  /**< First ID of VMDQ pools. */
+	struct rte_eth_desc_lim rx_desc_lim;  /**< RX descriptors limits */
+	struct rte_eth_desc_lim tx_desc_lim;  /**< TX descriptors limits */
 };
 
+/**
+ * Ethernet device RX queue information structure.
+ * Used to retieve information about configured queue.
+ */
+struct rte_eth_rxq_info {
+	struct rte_mempool *mp;     /**< mempool used by that queue. */
+	struct rte_eth_rxconf conf; /**< queue config parameters. */
+	uint8_t scattered_rx;       /**< scattered packets RX supported. */
+	uint16_t nb_desc;           /**< configured number of RXDs. */
+} __rte_cache_aligned;
+
+/**
+ * Ethernet device TX queue information structure.
+ * Used to retieve information about configured queue.
+ */
+struct rte_eth_txq_info {
+	struct rte_eth_txconf conf; /**< queue config parameters. */
+	uint16_t nb_desc;           /**< configured number of TXDs. */
+} __rte_cache_aligned;
+
 /** Maximum name length for extended statistics counters */
 #define RTE_ETH_XSTATS_NAME_SIZE 64
 
@@ -997,6 +1028,12 @@ typedef uint32_t (*eth_rx_queue_count_t)(struct rte_eth_dev *dev,
 typedef int (*eth_rx_descriptor_done_t)(void *rxq, uint16_t offset);
 /**< @internal Check DD bit of specific RX descriptor */
 
+typedef void (*eth_rxq_info_get_t)(struct rte_eth_dev *dev,
+	uint16_t rx_queue_id, struct rte_eth_rxq_info *qinfo);
+
+typedef void (*eth_txq_info_get_t)(struct rte_eth_dev *dev,
+	uint16_t tx_queue_id, struct rte_eth_txq_info *qinfo);
+
 typedef int (*mtu_set_t)(struct rte_eth_dev *dev, uint16_t mtu);
 /**< @internal Set MTU. */
 
@@ -1337,9 +1374,13 @@ struct eth_dev_ops {
 	rss_hash_update_t rss_hash_update;
 	/** Get current RSS hash configuration. */
 	rss_hash_conf_get_t rss_hash_conf_get;
-	eth_filter_ctrl_t              filter_ctrl;          /**< common filter control*/
+	eth_filter_ctrl_t              filter_ctrl;
+	/**< common filter control. */
 	eth_set_mc_addr_list_t set_mc_addr_list; /**< set list of mcast addrs */
-
+	eth_rxq_info_get_t rxq_info_get;
+	/**< retrieve RX queue information. */
+	eth_txq_info_get_t txq_info_get;
+	/**< retrieve TX queue information. */
 	/** Turn IEEE1588/802.1AS timestamping on. */
 	eth_timesync_enable_t timesync_enable;
 	/** Turn IEEE1588/802.1AS timestamping off. */
@@ -3495,6 +3536,46 @@ int rte_eth_remove_tx_callback(uint8_t port_id, uint16_t queue_id,
 		struct rte_eth_rxtx_callback *user_cb);
 
 /**
+ * Retrieve information about given port's RX queue.
+ *
+ * @param port_id
+ *   The port identifier of the Ethernet device.
+ * @param queue_id
+ *   The RX queue on the Ethernet device for which information
+ *   will be retrieved.
+ * @param qinfo
+ *   A pointer to a structure of type *rte_eth_rxq_info_info* to be filled with
+ *   the information of the Ethernet device.
+ *
+ * @return
+ *   - 0: Success
+ *   - -ENOTSUP: routine is not supported by the device PMD.
+ *   - -EINVAL:  The port_id or the queue_id is out of range.
+ */
+int rte_eth_rx_queue_info_get(uint8_t port_id, uint16_t queue_id,
+	struct rte_eth_rxq_info *qinfo);
+
+/**
+ * Retrieve information about given port's TX queue.
+ *
+ * @param port_id
+ *   The port identifier of the Ethernet device.
+ * @param queue_id
+ *   The TX queue on the Ethernet device for which information
+ *   will be retrieved.
+ * @param qinfo
+ *   A pointer to a structure of type *rte_eth_txq_info_info* to be filled with
+ *   the information of the Ethernet device.
+ *
+ * @return
+ *   - 0: Success
+ *   - -ENOTSUP: routine is not supported by the device PMD.
+ *   - -EINVAL:  The port_id or the queue_id is out of range.
+ */
+int rte_eth_tx_queue_info_get(uint8_t port_id, uint16_t queue_id,
+	struct rte_eth_txq_info *qinfo);
+
+/*
  * Retrieve number of available registers for access
  *
  * @param port_id

lib/librte_ether/rte_ether_version.map

@@ -132,5 +132,7 @@ DPDK_2.2 {
 	global:
 
 	rte_eth_dev_get_dcb_info;
+	rte_eth_rx_queue_info_get;
+	rte_eth_tx_queue_info_get;
 
 } DPDK_2.1;