net/sfc: support Tx descriptor status API

[dpdk.git] / drivers / net / sfc / sfc_tx.c

diff --git a/drivers/net/sfc/sfc_tx.c b/drivers/net/sfc/sfc_tx.c
index fc439cb..bf59601 100644 (file)
--- a/drivers/net/sfc/sfc_tx.c
+++ b/drivers/net/sfc/sfc_tx.c
@@ -977,6 +977,44 @@ sfc_efx_tx_qreap(struct sfc_dp_txq *dp_txq)
        txq->flags &= ~SFC_EFX_TXQ_FLAG_STARTED;
 }
 
+static sfc_dp_tx_qdesc_status_t sfc_efx_tx_qdesc_status;
+static int
+sfc_efx_tx_qdesc_status(struct sfc_dp_txq *dp_txq, uint16_t offset)
+{
+       struct sfc_efx_txq *txq = sfc_efx_txq_by_dp_txq(dp_txq);
+
+       if (unlikely(offset > txq->ptr_mask))
+               return -EINVAL;
+
+       if (unlikely(offset >= EFX_TXQ_LIMIT(txq->ptr_mask + 1)))
+               return RTE_ETH_TX_DESC_UNAVAIL;
+
+       /*
+        * Poll EvQ to derive up-to-date 'txq->pending' figure;
+        * it is required for the queue to be running, but the
+        * check is omitted because API design assumes that it
+        * is the duty of the caller to satisfy all conditions
+        */
+       SFC_ASSERT((txq->flags & SFC_EFX_TXQ_FLAG_RUNNING) ==
+                  SFC_EFX_TXQ_FLAG_RUNNING);
+       sfc_ev_qpoll(txq->evq);
+
+       /*
+        * Ring tail is 'txq->pending', and although descriptors
+        * between 'txq->completed' and 'txq->pending' are still
+        * in use by the driver, they should be reported as DONE
+        */
+       if (unlikely(offset < (txq->added - txq->pending)))
+               return RTE_ETH_TX_DESC_FULL;
+
+       /*
+        * There is no separate return value for unused descriptors;
+        * the latter will be reported as DONE because genuine DONE
+        * descriptors will be freed anyway in SW on the next burst
+        */
+       return RTE_ETH_TX_DESC_DONE;
+}
+
 struct sfc_dp_tx sfc_efx_tx = {
        .dp = {
                .name           = SFC_KVARG_DATAPATH_EFX,
@@ -991,5 +1029,6 @@ struct sfc_dp_tx sfc_efx_tx = {
        .qstart                 = sfc_efx_tx_qstart,
        .qstop                  = sfc_efx_tx_qstop,
        .qreap                  = sfc_efx_tx_qreap,
+       .qdesc_status           = sfc_efx_tx_qdesc_status,
        .pkt_burst              = sfc_efx_xmit_pkts,
 };