[RFC v1 1/7] net/mlx5: add LWM support for Rxq

[Spike Du <spiked@nvidia.com>]

Add lwm(Limit WaterMark) field to Rxq object which indicates the percentage
of RX queue size used by HW to raise LWM event to the user.
Allow LWM setting in modify_rq command.
Allow the LWM configuration dynamically by adding RDY2RDY state change.

Signed-off-by: Spike Du <spiked@nvidia.com>
---
 drivers/net/mlx5/mlx5.h      |  1 +
 drivers/net/mlx5/mlx5_devx.c | 13 ++++++++++++-
 drivers/net/mlx5/mlx5_devx.h |  1 +
 drivers/net/mlx5/mlx5_rx.h   |  1 +
 4 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/net/mlx5/mlx5.h b/drivers/net/mlx5/mlx5.h
index 23a28f6..f3e6682 100644
--- a/drivers/net/mlx5/mlx5.h
+++ b/drivers/net/mlx5/mlx5.h
@@ -1391,6 +1391,7 @@ enum mlx5_rxq_modify_type {
 	MLX5_RXQ_MOD_RST2RDY, /* modify state from reset to ready. */
 	MLX5_RXQ_MOD_RDY2ERR, /* modify state from ready to error. */
 	MLX5_RXQ_MOD_RDY2RST, /* modify state from ready to reset. */
+	MLX5_RXQ_MOD_RDY2RDY, /* modify state from ready to ready. */
 };
 
 enum mlx5_txq_modify_type {
diff --git a/drivers/net/mlx5/mlx5_devx.c b/drivers/net/mlx5/mlx5_devx.c
index 03c0fac..4fbfcaa 100644
--- a/drivers/net/mlx5/mlx5_devx.c
+++ b/drivers/net/mlx5/mlx5_devx.c
@@ -62,7 +62,7 @@
  * @return
  *   0 on success, a negative errno value otherwise and rte_errno is set.
  */
-static int
+int
 mlx5_devx_modify_rq(struct mlx5_rxq_priv *rxq, uint8_t type)
 {
 	struct mlx5_devx_modify_rq_attr rq_attr;
@@ -76,6 +76,11 @@
 	case MLX5_RXQ_MOD_RST2RDY:
 		rq_attr.rq_state = MLX5_RQC_STATE_RST;
 		rq_attr.state = MLX5_RQC_STATE_RDY;
+		if (rxq->lwm) {
+			rq_attr.modify_bitmask |=
+				MLX5_MODIFY_RQ_IN_MODIFY_BITMASK_WQ_LWM;
+			rq_attr.lwm = rxq->lwm;
+		}
 		break;
 	case MLX5_RXQ_MOD_RDY2ERR:
 		rq_attr.rq_state = MLX5_RQC_STATE_RDY;
@@ -85,6 +90,12 @@
 		rq_attr.rq_state = MLX5_RQC_STATE_RDY;
 		rq_attr.state = MLX5_RQC_STATE_RST;
 		break;
+	case MLX5_RXQ_MOD_RDY2RDY:
+		rq_attr.rq_state = MLX5_RQC_STATE_RDY;
+		rq_attr.state = MLX5_RQC_STATE_RDY;
+		rq_attr.modify_bitmask |= MLX5_MODIFY_RQ_IN_MODIFY_BITMASK_WQ_LWM;
+		rq_attr.lwm = rxq->lwm;
+		break;
 	default:
 		break;
 	}
diff --git a/drivers/net/mlx5/mlx5_devx.h b/drivers/net/mlx5/mlx5_devx.h
index a95207a..ebd1da4 100644
--- a/drivers/net/mlx5/mlx5_devx.h
+++ b/drivers/net/mlx5/mlx5_devx.h
@@ -11,6 +11,7 @@
 int mlx5_txq_devx_modify(struct mlx5_txq_obj *obj,
 			 enum mlx5_txq_modify_type type, uint8_t dev_port);
 void mlx5_txq_devx_obj_release(struct mlx5_txq_obj *txq_obj);
+int mlx5_devx_modify_rq(struct mlx5_rxq_priv *rxq, uint8_t type);
 
 extern struct mlx5_obj_ops devx_obj_ops;
 
diff --git a/drivers/net/mlx5/mlx5_rx.h b/drivers/net/mlx5/mlx5_rx.h
index e715ed6..25a5f2c 100644
--- a/drivers/net/mlx5/mlx5_rx.h
+++ b/drivers/net/mlx5/mlx5_rx.h
@@ -175,6 +175,7 @@ struct mlx5_rxq_priv {
 	struct mlx5_devx_rq devx_rq;
 	struct rte_eth_hairpin_conf hairpin_conf; /* Hairpin configuration. */
 	uint32_t hairpin_status; /* Hairpin binding status. */
+	uint32_t lwm:16;
 };
 
 /* External RX queue descriptor. */
-- 
1.8.3.1