[dpdk-dev] [PATCH v3 3/4] net/mlx5: add free on completion queue

[Viacheslav Ovsiienko <viacheslavo@mellanox.com>]

The new software manged entity is introduced in Tx datapath
- free on completion queue. This queue keeps the information
how many buffers stored in elts array must freed on send
comletion. Each element of the queue contains transmitting
descriptor index to be in synch with completion entries (in
debug build only) and the index in elts array to free buffers.

Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
Acked-by: Matan Azrad <matan@mellanox.com>
---
 drivers/net/mlx5/mlx5_rxtx.h |  5 +++++
 drivers/net/mlx5/mlx5_txq.c  | 15 +++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h
index 8a2185a..7d1b2fa 100644
--- a/drivers/net/mlx5/mlx5_rxtx.h
+++ b/drivers/net/mlx5/mlx5_rxtx.h
@@ -297,6 +297,11 @@ struct mlx5_txq_data {
 	struct mlx5_mr_ctrl mr_ctrl; /* MR control descriptor. */
 	struct mlx5_wqe *wqes; /* Work queue. */
 	struct mlx5_wqe *wqes_end; /* Work queue array limit. */
+#ifdef NDEBUG
+	uint16_t *fcqs; /* Free completion queue. */
+#else
+	uint32_t *fcqs; /* Free completion queue (debug extended). */
+#endif
 	volatile struct mlx5_cqe *cqes; /* Completion queue. */
 	volatile uint32_t *qp_db; /* Work queue doorbell. */
 	volatile uint32_t *cq_db; /* Completion queue doorbell. */
diff --git a/drivers/net/mlx5/mlx5_txq.c b/drivers/net/mlx5/mlx5_txq.c
index abe0947..aee0970 100644
--- a/drivers/net/mlx5/mlx5_txq.c
+++ b/drivers/net/mlx5/mlx5_txq.c
@@ -724,6 +724,17 @@ struct mlx5_txq_obj *
 	txq_data->wqe_pi = 0;
 	txq_data->wqe_comp = 0;
 	txq_data->wqe_thres = txq_data->wqe_s / MLX5_TX_COMP_THRESH_INLINE_DIV;
+	txq_data->fcqs = rte_calloc_socket(__func__,
+					   txq_data->cqe_s,
+					   sizeof(*txq_data->fcqs),
+					   RTE_CACHE_LINE_SIZE,
+					   txq_ctrl->socket);
+	if (!txq_data->fcqs) {
+		DRV_LOG(ERR, "port %u Tx queue %u cannot allocate memory (FCQ)",
+			dev->data->port_id, idx);
+		rte_errno = ENOMEM;
+		goto error;
+	}
 #ifdef HAVE_IBV_FLOW_DV_SUPPORT
 	/*
 	 * If using DevX need to query and store TIS transport domain value.
@@ -772,6 +783,8 @@ struct mlx5_txq_obj *
 		claim_zero(mlx5_glue->destroy_cq(tmpl.cq));
 	if (tmpl.qp)
 		claim_zero(mlx5_glue->destroy_qp(tmpl.qp));
+	if (txq_data && txq_data->fcqs)
+		rte_free(txq_data->fcqs);
 	if (txq_obj)
 		rte_free(txq_obj);
 	priv->verbs_alloc_ctx.type = MLX5_VERBS_ALLOC_TYPE_NONE;
@@ -826,6 +839,8 @@ struct mlx5_txq_obj *
 		} else {
 			claim_zero(mlx5_glue->destroy_qp(txq_obj->qp));
 			claim_zero(mlx5_glue->destroy_cq(txq_obj->cq));
+				if (txq_obj->txq_ctrl->txq.fcqs)
+					rte_free(txq_obj->txq_ctrl->txq.fcqs);
 		}
 		LIST_REMOVE(txq_obj, next);
 		rte_free(txq_obj);
-- 
1.8.3.1