[PATCH v5 01/40] ethdev: overwrite some comment related to RSS

[Ferruh Yigit]

On 10/11/2023 10:27 AM, Jie Hai wrote:
> 1. overwrite the comments of fields of 'rte_eth_rss_conf'.
> 2. Add comments for RTE_ETH_HASH_FUNCTION_DEFAULT.
> 
> Signed-off-by: Jie Hai <haijie1 at huawei.com>
> ---
>  lib/ethdev/rte_ethdev.h | 29 ++++++++++++++---------------
>  lib/ethdev/rte_flow.h   |  3 +++
>  2 files changed, 17 insertions(+), 15 deletions(-)
> 
> diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
> index 8542257721c9..b9e4e21189d2 100644
> --- a/lib/ethdev/rte_ethdev.h
> +++ b/lib/ethdev/rte_ethdev.h
> @@ -448,24 +448,23 @@ struct rte_vlan_filter_conf {
>  /**
>   * A structure used to configure the Receive Side Scaling (RSS) feature
>   * of an Ethernet port.
> - * If not NULL, the *rss_key* pointer of the *rss_conf* structure points
> - * to an array holding the RSS key to use for hashing specific header
> - * fields of received packets. The length of this array should be indicated
> - * by *rss_key_len* below. Otherwise, a default random hash key is used by
> - * the device driver.
> - *
> - * The *rss_key_len* field of the *rss_conf* structure indicates the length
> - * in bytes of the array pointed by *rss_key*. To be compatible, this length
> - * will be checked in i40e only. Others assume 40 bytes to be used as before.
> - *
> - * The *rss_hf* field of the *rss_conf* structure indicates the different
> - * types of IPv4/IPv6 packets to which the RSS hashing must be applied.
> - * Supplying an *rss_hf* equal to zero disables the RSS feature.
>   */
>  struct rte_eth_rss_conf {
> -	uint8_t *rss_key;    /**< If not NULL, 40-byte hash key. */
> +	/**
> +	 * If used to query, the'rss_key_len' indicates the size of rss key of
> +	 * the hardware. And only when rss_key_len is not zero, the 'rss_key'
> +	 * is valid.
> +	 * If used to configure, rss_key_len indicates the length of the
> +	 * 'rss_key' if 'rss_key' is not empty.
>

Ahh, different APIs have different expectations :(
Can you please explicitly name the APIs, instead of "to query", "to
configure"?

And there is a note in original comment that *rss_key_len* is only
checked by i40e, rest assume this value as 40 bytes. New comment doesn't
have it.


> +	 */
> +	uint8_t *rss_key;
>  	uint8_t rss_key_len; /**< hash key length in bytes. */
> -	uint64_t rss_hf;     /**< Hash functions to apply - see below. */
> +	/**
> +	 * Indicating which type of packets and which part of the packets
> +	 * to apply for RSS hash, (see RTE_ETH_RSS_*).
>

There is something doesn't sound right from language perspective,
perhaps someone whose native language is English can help, what about:

"Indicates the type of packets or the specific part of packets to which
RSS hashing is to be applied."


> +	 * Setting *rss_hf* to zero disables the RSS feature.
> +	 */
> +	uint64_t rss_hf;
>  };
>  
>  /*
> diff --git a/lib/ethdev/rte_flow.h b/lib/ethdev/rte_flow.h
> index b385741fba6d..5d9e3c68af7b 100644
> --- a/lib/ethdev/rte_flow.h
> +++ b/lib/ethdev/rte_flow.h
> @@ -3227,6 +3227,9 @@ struct rte_flow_query_count {
>   * Hash function types.
>   */
>  enum rte_eth_hash_function {
> +	/**
> +	 * DEFAULT means driver decides which hash algorithm to pick.
> +	 */
>  	RTE_ETH_HASH_FUNCTION_DEFAULT = 0,
>  	RTE_ETH_HASH_FUNCTION_TOEPLITZ, /**< Toeplitz */
>  	RTE_ETH_HASH_FUNCTION_SIMPLE_XOR, /**< Simple XOR */