[PATCH] net/mlx5: fix external Rx and Tx queues access

[Gregory Etelson <getelson@nvidia.com>]

mlx5_ext_rxq_get() and mlx5_ext_txq_get() functions did not return
NULL value if query index was not referencing external queue.

As a result, calling functions did not expect the NULL on return.

External Rx queue:

- In mlx5_ext_rxq_get() remove assert and return NULL if a queue index
  does not point to a valid external queue.

- In mlx5_ext_rxq_verify() validate that probed queue index references
  a valid extern queue.

External Tx queue:

-  In mlx5_ext_txq_get() remove assert and return NULL if a queue index
   does not point to a valid external queue.

- In mlx5_ext_txq_verify() validate that probed queue index references
  a valid extern queue.

Fixes: 311b17e669ab ("net/mlx5: support queue/RSS actions for external Rx queue")

Signed-off-by: Gregory Etelson <getelson@nvidia.com>
Acked-by: Dariusz Sosnowski <dsosnowski@nvidia.com>
---
 drivers/net/mlx5/mlx5_rxq.c | 10 +++++-----
 drivers/net/mlx5/mlx5_txq.c | 10 +++++-----
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_rxq.c b/drivers/net/mlx5/mlx5_rxq.c
index 77c5848c37..c615a5c64b 100644
--- a/drivers/net/mlx5/mlx5_rxq.c
+++ b/drivers/net/mlx5/mlx5_rxq.c
@@ -2250,8 +2250,8 @@ mlx5_ext_rxq_get(struct rte_eth_dev *dev, uint16_t idx)
 {
 	struct mlx5_priv *priv = dev->data->dev_private;
 
-	MLX5_ASSERT(mlx5_is_external_rxq(dev, idx));
-	return &priv->ext_rxqs[idx - RTE_PMD_MLX5_EXTERNAL_RX_QUEUE_ID_MIN];
+	return mlx5_is_external_rxq(dev, idx) ?
+		&priv->ext_rxqs[idx -  RTE_PMD_MLX5_EXTERNAL_RX_QUEUE_ID_MIN] : NULL;
 }
 
 /**
@@ -2413,7 +2413,6 @@ int
 mlx5_ext_rxq_verify(struct rte_eth_dev *dev)
 {
 	struct mlx5_priv *priv = dev->data->dev_private;
-	struct mlx5_external_q *rxq;
 	uint32_t i;
 	int ret = 0;
 
@@ -2421,8 +2420,9 @@ mlx5_ext_rxq_verify(struct rte_eth_dev *dev)
 		return 0;
 
 	for (i = RTE_PMD_MLX5_EXTERNAL_RX_QUEUE_ID_MIN; i <= UINT16_MAX ; ++i) {
-		rxq = mlx5_ext_rxq_get(dev, i);
-		if (rxq->refcnt < 2)
+		struct mlx5_external_q *rxq = mlx5_ext_rxq_get(dev, i);
+
+		if (rxq == NULL || rxq->refcnt < 2)
 			continue;
 		DRV_LOG(DEBUG, "Port %u external RxQ %u still referenced.",
 			dev->data->port_id, i);
diff --git a/drivers/net/mlx5/mlx5_txq.c b/drivers/net/mlx5/mlx5_txq.c
index b090d8274d..2aa2475a8a 100644
--- a/drivers/net/mlx5/mlx5_txq.c
+++ b/drivers/net/mlx5/mlx5_txq.c
@@ -1281,8 +1281,8 @@ mlx5_ext_txq_get(struct rte_eth_dev *dev, uint16_t idx)
 {
 	struct mlx5_priv *priv = dev->data->dev_private;
 
-	MLX5_ASSERT(mlx5_is_external_txq(dev, idx));
-	return &priv->ext_txqs[idx - MLX5_EXTERNAL_TX_QUEUE_ID_MIN];
+	return mlx5_is_external_txq(dev, idx) ?
+		&priv->ext_txqs[idx - MLX5_EXTERNAL_TX_QUEUE_ID_MIN] : NULL;
 }
 
 /**
@@ -1298,7 +1298,6 @@ int
 mlx5_ext_txq_verify(struct rte_eth_dev *dev)
 {
 	struct mlx5_priv *priv = dev->data->dev_private;
-	struct mlx5_external_q *txq;
 	uint32_t i;
 	int ret = 0;
 
@@ -1306,8 +1305,9 @@ mlx5_ext_txq_verify(struct rte_eth_dev *dev)
 		return 0;
 
 	for (i = MLX5_EXTERNAL_TX_QUEUE_ID_MIN; i <= UINT16_MAX ; ++i) {
-		txq = mlx5_ext_txq_get(dev, i);
-		if (txq->refcnt < 2)
+		struct mlx5_external_q *txq = mlx5_ext_txq_get(dev, i);
+
+		if (txq == NULL || txq->refcnt < 2)
 			continue;
 		DRV_LOG(DEBUG, "Port %u external TxQ %u still referenced.",
 			dev->data->port_id, i);
-- 
2.48.1