[RFC PATCH 19/29] net/qdma: add callback function for Tx desc status

[Aman Kumar <aman.kumar@vvdntech.in>]

This patch implements dev->tx_descriptor_status
function for net_qdma PMD.

Signed-off-by: Aman Kumar <aman.kumar@vvdntech.in>
---
 drivers/net/qdma/qdma_devops.c |  1 +
 drivers/net/qdma/qdma_rxtx.c   | 47 ++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+)

diff --git a/drivers/net/qdma/qdma_devops.c b/drivers/net/qdma/qdma_devops.c
index 12391790f0..dfa41a9aa7 100644
--- a/drivers/net/qdma/qdma_devops.c
+++ b/drivers/net/qdma/qdma_devops.c
@@ -1759,4 +1759,5 @@ void qdma_dev_ops_init(struct rte_eth_dev *dev)
 	dev->tx_pkt_burst = &qdma_xmit_pkts;
 	dev->rx_queue_count = &qdma_dev_rx_queue_count;
 	dev->rx_descriptor_status = &qdma_dev_rx_descriptor_status;
+	dev->tx_descriptor_status = &qdma_dev_tx_descriptor_status;
 }
diff --git a/drivers/net/qdma/qdma_rxtx.c b/drivers/net/qdma/qdma_rxtx.c
index 6842203ada..3abc72717f 100644
--- a/drivers/net/qdma/qdma_rxtx.c
+++ b/drivers/net/qdma/qdma_rxtx.c
@@ -559,6 +559,53 @@ qdma_dev_tx_done_cleanup(void *tx_queue, uint32_t free_cnt)
 	return reclaim_tx_mbuf(txq, txq->wb_status->cidx, free_cnt);
 }
 
+/**
+ * DPDK callback to check the status of a Tx descriptor in the queue.
+ *
+ * @param tx_queue
+ *   Pointer to Tx queue specific data structure.
+ * @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.
+ */
+int
+qdma_dev_tx_descriptor_status(void *tx_queue, uint16_t offset)
+{
+	struct qdma_tx_queue *txq = tx_queue;
+	uint16_t id;
+	int avail, in_use;
+	uint16_t cidx = 0;
+
+	if (unlikely(offset >= (txq->nb_tx_desc - 1)))
+		return -EINVAL;
+
+	/* One descriptor is reserved so that pidx is not same as old pidx */
+	if (offset == (txq->nb_tx_desc - 2))
+		return RTE_ETH_TX_DESC_UNAVAIL;
+
+	id = txq->q_pidx_info.pidx;
+	cidx = txq->wb_status->cidx;
+
+	in_use = (int)id - cidx;
+	if (in_use < 0)
+		in_use += (txq->nb_tx_desc - 1);
+	avail = txq->nb_tx_desc - 2 - in_use;
+
+	if (offset < avail)
+		return RTE_ETH_TX_DESC_DONE;
+
+	return RTE_ETH_TX_DESC_FULL;
+}
+
 /* Transmit API for Streaming mode */
 uint16_t qdma_xmit_pkts_st(struct qdma_tx_queue *txq, struct rte_mbuf **tx_pkts,
 			uint16_t nb_pkts)
-- 
2.36.1