ixgbe: retrieve RX available descriptors

[dpdk.git] / lib / librte_pmd_ixgbe / ixgbe_rxtx.c

diff --git a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
index 922525c..9b7ba2c 100644 (file)
--- a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
+++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
@@ -127,6 +127,7 @@ struct igb_rx_queue {
        volatile union ixgbe_adv_rx_desc *rx_ring; /**< RX ring virtual address. */
        uint64_t            rx_ring_phys_addr; /**< RX ring DMA address. */
        volatile uint32_t   *rdt_reg_addr; /**< RDT register address. */
+       volatile uint32_t   *rdh_reg_addr; /**< RDH register address. */
        struct igb_rx_entry *sw_ring; /**< address of RX software ring. */
        struct rte_mbuf *pkt_first_seg; /**< First segment of current packet. */
        struct rte_mbuf *pkt_last_seg; /**< Last segment of current packet. */
@@ -2256,6 +2257,31 @@ ixgbe_dev_rx_queue_setup(struct rte_eth_dev *dev,
        return 0;
 }
 
+uint32_t ixgbe_dev_rx_queue_count(struct rte_eth_dev *dev,
+                                       uint16_t rx_queue_id)
+{
+       struct igb_rx_queue *rxq;
+       uint32_t nb_pkts_available;
+       uint32_t rx_rdh;
+       uint32_t rx_id;
+
+       if (rx_queue_id >= dev->data->nb_rx_queues) {
+           PMD_RX_LOG(DEBUG,"Invalid RX queue_id=%d\n", rx_queue_id);
+           return 0;
+       }
+
+       rxq = dev->data->rx_queues[rx_queue_id];
+       rx_id = (uint16_t)((rxq->rx_tail == 0) ?
+               (rxq->nb_rx_desc - 1) : (rxq->rx_tail - 1));
+       rx_rdh = IXGBE_PCI_REG(rxq->rdh_reg_addr);
+       if (rx_rdh > rx_id) 
+           nb_pkts_available = rx_rdh - rx_id;
+       else 
+           nb_pkts_available = rx_rdh - rx_id + rxq->nb_rx_desc;
+ 
+       return (nb_pkts_available);
+}
+
 void
 ixgbe_dev_clear_queues(struct rte_eth_dev *dev)
 {