net/mlx5: implement descriptor status API

Since there is no "descriptor done" flag like on Intel drivers, the
approach is different on mlx5 driver.
- for Tx, we call txq_complete() to free descriptors processed by
  the hw, then we check if the descriptor is between tail and head
- for Rx, we need to browse the cqes, managing compressed ones,
  to get the number of used descriptors.

Signed-off-by: Olivier Matz <olivier.matz@6wind.com>

diff --git a/doc/guides/nics/features/mlx5.ini b/doc/guides/nics/features/mlx5.ini
index f20d214..450d38e 100644 (file)
--- a/doc/guides/nics/features/mlx5.ini
+++ b/doc/guides/nics/features/mlx5.ini
@@ -27,6 +27,8 @@ VLAN offload         = Y
 L3 checksum offload  = Y
 L4 checksum offload  = Y
 Packet type parsing  = Y
+Rx descriptor status = Y
+Tx descriptor status = Y
 Basic stats          = Y
 Stats per queue      = Y
 Multiprocess aware   = Y

diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c
index d4bd469..4a6450c 100644 (file)
--- a/drivers/net/mlx5/mlx5.c
+++ b/drivers/net/mlx5/mlx5.c
@@ -222,6 +222,8 @@ static const struct eth_dev_ops mlx5_dev_ops = {
        .rss_hash_update = mlx5_rss_hash_update,
        .rss_hash_conf_get = mlx5_rss_hash_conf_get,
        .filter_ctrl = mlx5_dev_filter_ctrl,
+       .rx_descriptor_status = mlx5_rx_descriptor_status,
+       .tx_descriptor_status = mlx5_tx_descriptor_status,
 };
 
 static struct {

diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
index 88b0354..b8d2bf6 100644 (file)
--- a/drivers/net/mlx5/mlx5_rxtx.c
+++ b/drivers/net/mlx5/mlx5_rxtx.c
@@ -344,6 +344,82 @@ mlx5_tx_dbrec(struct txq *txq, volatile struct mlx5_wqe *wqe)
        *dst = *src;
 }
 
+/**
+ * DPDK callback to check the status of a tx descriptor.
+ *
+ * @param tx_queue
+ *   The tx queue.
+ * @param[in] offset
+ *   The index of the descriptor in the ring.
+ *
+ * @return
+ *   The status of the tx descriptor.
+ */
+int
+mlx5_tx_descriptor_status(void *tx_queue, uint16_t offset)
+{
+       struct txq *txq = tx_queue;
+       const unsigned int elts_n = 1 << txq->elts_n;
+       const unsigned int elts_cnt = elts_n - 1;
+       unsigned int used;
+
+       txq_complete(txq);
+       used = (txq->elts_head - txq->elts_tail) & elts_cnt;
+       if (offset < used)
+               return RTE_ETH_TX_DESC_FULL;
+       return RTE_ETH_TX_DESC_DONE;
+}
+
+/**
+ * DPDK callback to check the status of a rx descriptor.
+ *
+ * @param rx_queue
+ *   The rx queue.
+ * @param[in] offset
+ *   The index of the descriptor in the ring.
+ *
+ * @return
+ *   The status of the tx descriptor.
+ */
+int
+mlx5_rx_descriptor_status(void *rx_queue, uint16_t offset)
+{
+       struct rxq *rxq = rx_queue;
+       struct rxq_zip *zip = &rxq->zip;
+       volatile struct mlx5_cqe *cqe;
+       const unsigned int cqe_n = (1 << rxq->cqe_n);
+       const unsigned int cqe_cnt = cqe_n - 1;
+       unsigned int cq_ci;
+       unsigned int used;
+
+       /* if we are processing a compressed cqe */
+       if (zip->ai) {
+               used = zip->cqe_cnt - zip->ca;
+               cq_ci = zip->cq_ci;
+       } else {
+               used = 0;
+               cq_ci = rxq->cq_ci;
+       }
+       cqe = &(*rxq->cqes)[cq_ci & cqe_cnt];
+       while (check_cqe(cqe, cqe_n, cq_ci) == 0) {
+               int8_t op_own;
+               unsigned int n;
+
+               op_own = cqe->op_own;
+               if (MLX5_CQE_FORMAT(op_own) == MLX5_COMPRESSED)
+                       n = ntohl(cqe->byte_cnt);
+               else
+                       n = 1;
+               cq_ci += n;
+               used += n;
+               cqe = &(*rxq->cqes)[cq_ci & cqe_cnt];
+       }
+       used = RTE_MIN(used, (1U << rxq->elts_n) - 1);
+       if (offset < used)
+               return RTE_ETH_RX_DESC_DONE;
+       return RTE_ETH_RX_DESC_AVAIL;
+}
+
 /**
  * DPDK callback for TX.
  *

diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h
index 41a34d7..012207e 100644 (file)
--- a/drivers/net/mlx5/mlx5_rxtx.h
+++ b/drivers/net/mlx5/mlx5_rxtx.h
@@ -323,6 +323,8 @@ uint16_t mlx5_tx_burst_mpw_inline(void *, struct rte_mbuf **, uint16_t);
 uint16_t mlx5_rx_burst(void *, struct rte_mbuf **, uint16_t);
 uint16_t removed_tx_burst(void *, struct rte_mbuf **, uint16_t);
 uint16_t removed_rx_burst(void *, struct rte_mbuf **, uint16_t);
+int mlx5_rx_descriptor_status(void *, uint16_t);
+int mlx5_tx_descriptor_status(void *, uint16_t);
 
 /* mlx5_mr.c */