Re: [PATCH net-next v3] net/mlx5e: link NAPI instances to queues and IRQs

[Tariq Toukan <ttoukan.linux@gmail.com>]

On 08/02/2024 5:07, Joe Damato wrote:
> Make mlx5 compatible with the newly added netlink queue GET APIs.
> 
> Signed-off-by: Joe Damato <jdamato@fastly.com>
> ---
> v2 -> v3:
>    - Fix commit message subject
>    - call netif_queue_set_napi in mlx5e_ptp_activate_channel and
>      mlx5e_ptp_deactivate_channel to enable/disable NETDEV_QUEUE_TYPE_RX for
>      the PTP channel.
>    - Modify mlx5e_activate_txqsq and mlx5e_deactivate_txqsq to set
>      NETDEV_QUEUE_TYPE_TX which should take care of all TX queues including
>      QoS/HTB and PTP.
>    - Rearrange mlx5e_activate_channel and mlx5e_deactivate_channel for
>      better ordering when setting and unsetting NETDEV_QUEUE_TYPE_RX NAPI
>      structs
> 
> v1 -> v2:
>    - Move netlink NULL code to mlx5e_deactivate_channel
>    - Move netif_napi_set_irq to mlx5e_open_channel and avoid storing the
>      irq, after netif_napi_add which itself sets the IRQ to -1
> 
>   drivers/net/ethernet/mellanox/mlx5/core/en/ptp.c  | 3 +++
>   drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 7 +++++++
>   2 files changed, 10 insertions(+)
> 
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/ptp.c b/drivers/net/ethernet/mellanox/mlx5/core/en/ptp.c
> index 078f56a3cbb2..fbbc287d924d 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/en/ptp.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/ptp.c
> @@ -927,6 +927,8 @@ void mlx5e_ptp_activate_channel(struct mlx5e_ptp *c)
>   	int tc;
>   
>   	napi_enable(&c->napi);
> +	netif_queue_set_napi(c->netdev, c->rq.ix, NETDEV_QUEUE_TYPE_RX,
> +			     &c->napi);
>   
>   	if (test_bit(MLX5E_PTP_STATE_TX, c->state)) {
>   		for (tc = 0; tc < c->num_tc; tc++)
> @@ -951,6 +953,7 @@ void mlx5e_ptp_deactivate_channel(struct mlx5e_ptp *c)
>   			mlx5e_deactivate_txqsq(&c->ptpsq[tc].txqsq);
>   	}
>   
> +	netif_queue_set_napi(c->netdev, c->rq.ix, NETDEV_QUEUE_TYPE_RX, NULL);
>   	napi_disable(&c->napi);
>   }
>   
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
> index c8e8f512803e..2f1792854dd5 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
> @@ -1806,6 +1806,7 @@ void mlx5e_activate_txqsq(struct mlx5e_txqsq *sq)
>   	set_bit(MLX5E_SQ_STATE_ENABLED, &sq->state);
>   	netdev_tx_reset_queue(sq->txq);
>   	netif_tx_start_queue(sq->txq);
> +	netif_queue_set_napi(sq->channel->netdev, sq->txq_ix, NETDEV_QUEUE_TYPE_TX, &sq->channel->napi);

Might be called with channel==NULL.
For example for PTP.

Prefer sq->netdev and sq->cq.napi.

>   }
>   
>   void mlx5e_tx_disable_queue(struct netdev_queue *txq)
> @@ -1819,6 +1820,7 @@ void mlx5e_deactivate_txqsq(struct mlx5e_txqsq *sq)
>   {
>   	struct mlx5_wq_cyc *wq = &sq->wq;
>   
> +	netif_queue_set_napi(sq->channel->netdev, sq->txq_ix, NETDEV_QUEUE_TYPE_TX, NULL);

Same here.

>   	clear_bit(MLX5E_SQ_STATE_ENABLED, &sq->state);
>   	synchronize_net(); /* Sync with NAPI to prevent netif_tx_wake_queue. */
>   
> @@ -2560,6 +2562,7 @@ static int mlx5e_open_channel(struct mlx5e_priv *priv, int ix,
>   	c->lag_port = mlx5e_enumerate_lag_port(priv->mdev, ix);
>   
>   	netif_napi_add(netdev, &c->napi, mlx5e_napi_poll);
> +	netif_napi_set_irq(&c->napi, irq);
>   
>   	err = mlx5e_open_queues(c, params, cparam);
>   	if (unlikely(err))
> @@ -2602,12 +2605,16 @@ static void mlx5e_activate_channel(struct mlx5e_channel *c)
>   		mlx5e_activate_xsk(c);
>   	else
>   		mlx5e_activate_rq(&c->rq);
> +
> +	netif_queue_set_napi(c->netdev, c->ix, NETDEV_QUEUE_TYPE_RX, &c->napi);
>   }
>   
>   static void mlx5e_deactivate_channel(struct mlx5e_channel *c)
>   {
>   	int tc;
>   
> +	netif_queue_set_napi(c->netdev, c->ix, NETDEV_QUEUE_TYPE_RX, NULL);
> +
>   	if (test_bit(MLX5E_CHANNEL_STATE_XSK, c->state))
>   		mlx5e_deactivate_xsk(c);
>   	else