Re: [dpdk-dev] [PATCH 2/7] ethdev: move inline device operations

[Andrew Rybchenko <arybchenko@solarflare.com>]

On 8/24/20 12:40 PM, Ferruh Yigit wrote:
> This patch is a preparation to hide the 'struct eth_dev_ops' from
> applications by moving some device operations from 'struct eth_dev_ops'
> to 'struct rte_eth_dev'.
> 
> Mentioned ethdev APIs are in the data path and implemented as inline
> because of performance reasons.
> 
> Exposing 'struct eth_dev_ops' to applications is bad because it is a
> contract between ethdev and PMDs, not really needs to be known by
> applications, also changes in the struct causing ABI breakages which
> shouldn't.
> 
> To be able to both keep APIs inline and hide the 'struct eth_dev_ops',
> moving device operations used in ethdev inline APIs to 'struct
> rte_eth_dev' to the same level with Rx/Tx burst functions.
> 
> The list of dev_ops moved:
> eth_rx_queue_count_t       rx_queue_count;
> eth_rx_descriptor_status_t rx_descriptor_status;
> eth_tx_descriptor_status_t tx_descriptor_status;
> 
> Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>

Reviewed-by: Andrew Rybchenko <arybchenko@solarflare.com>

doc/guides/nics/features.rst should be updated since it says
that status callbacks live in eth_dev_ops.

plus an net/sfc-related nit below:

[snip]

> diff --git a/drivers/net/sfc/sfc_ethdev.c b/drivers/net/sfc/sfc_ethdev.c
> index 65e0ff7d48..0b06bf91a0 100644
> --- a/drivers/net/sfc/sfc_ethdev.c
> +++ b/drivers/net/sfc/sfc_ethdev.c

[snip]

> @@ -1962,6 +1959,9 @@ sfc_eth_dev_set_ops(struct rte_eth_dev *dev)
>  	dev->tx_pkt_burst = dp_tx->pkt_burst;
>  
>  	dev->dev_ops = &sfc_eth_dev_ops;
> +	dev->rx_queue_count = sfc_rx_queue_count;
> +	dev->rx_descriptor_status = sfc_rx_descriptor_status;
> +	dev->tx_descriptor_status = sfc_tx_descriptor_status;

May I ask to put it just after dev->tx_pkt_burst = ... line
since these callbacks go before dev_ops in the structure.

>  
>  	return 0;
>  
> @@ -2001,9 +2001,6 @@ sfc_eth_dev_clear_ops(struct rte_eth_dev *dev)
>  
>  static const struct eth_dev_ops sfc_eth_dev_secondary_ops = {
>  	.dev_supported_ptypes_get	= sfc_dev_supported_ptypes_get,
> -	.rx_queue_count			= sfc_rx_queue_count,
> -	.rx_descriptor_status		= sfc_rx_descriptor_status,
> -	.tx_descriptor_status		= sfc_tx_descriptor_status,
>  	.reta_query			= sfc_dev_rss_reta_query,
>  	.rss_hash_conf_get		= sfc_dev_rss_hash_conf_get,
>  	.rxq_info_get			= sfc_rx_queue_info_get,
> @@ -2069,6 +2066,9 @@ sfc_eth_dev_secondary_init(struct rte_eth_dev *dev, uint32_t logtype_main)
>  	dev->tx_pkt_prepare = dp_tx->pkt_prepare;
>  	dev->tx_pkt_burst = dp_tx->pkt_burst;
>  	dev->dev_ops = &sfc_eth_dev_secondary_ops;
> +	dev->rx_queue_count = sfc_rx_queue_count;
> +	dev->rx_descriptor_status = sfc_rx_descriptor_status;
> +	dev->tx_descriptor_status = sfc_tx_descriptor_status;

Same here.

[snip]