On 9/28/2021 1:05 PM, Andrew Rybchenko wrote:
> From: Ivan Ilchenko <ivan.ilche...@oktetlabs.ru>
>
> Update xstats by IDs callbacks documentation in accordance with
> ethdev usage of these callbacks. Document valid combinations of
> input arguments to make driver implementation simpler.
>
> Fixes: 79c913a42f0 ("ethdev: retrieve xstats by ID")
> Cc: sta...@dpdk.org
>
> Signed-off-by: Ivan Ilchenko <ivan.ilche...@oktetlabs.ru>
> Signed-off-by: Andrew Rybchenko <andrew.rybche...@oktetlabs.ru>
> Reviewed-by: Andy Moreton <amore...@xilinx.com>
> ---
> lib/ethdev/ethdev_driver.h | 42 ++++++++++++++++++++++++++++++++++++--
> 1 file changed, 40 insertions(+), 2 deletions(-)
>
> diff --git a/lib/ethdev/ethdev_driver.h b/lib/ethdev/ethdev_driver.h
> index 40e474aa7e..c89eefcc42 100644
> --- a/lib/ethdev/ethdev_driver.h
> +++ b/lib/ethdev/ethdev_driver.h
> @@ -187,11 +187,28 @@ typedef int (*eth_xstats_get_t)(struct rte_eth_dev *dev,
> struct rte_eth_xstat *stats, unsigned int n);
> /**< @internal Get extended stats of an Ethernet device. */
>
> +/**
> + * @internal
> + * Get extended stats of an Ethernet device.
> + *
> + * @param dev
> + * ethdev handle of port.
> + * @param ids
> + * IDs array to retrieve specific statistics. Must not be NULL.
> + * @param values
> + * A pointer to a table to be filled with device statistics values.
> + * Must not be NULL.
> + * @param n
> + * Element count in @p ids and @p values.
> + *
> + * @return
> + * - A number of filled in stats.
> + * - A negative value on error.
> + */
> typedef int (*eth_xstats_get_by_id_t)(struct rte_eth_dev *dev,
> const uint64_t *ids,
> uint64_t *values,
> unsigned int n);
> -/**< @internal Get extended stats of an Ethernet device. */
>
> /**
> * @internal
> @@ -218,10 +235,31 @@ typedef int (*eth_xstats_get_names_t)(struct
> rte_eth_dev *dev,
> struct rte_eth_xstat_name *xstats_names, unsigned int size);
> /**< @internal Get names of extended stats of an Ethernet device. */
>
> +/**
> + * @internal
> + * Get names of extended stats of an Ethernet device.
> + * For name count, set @p xstats_names and @p ids to NULL.
Why limiting this behavior to 'xstats_get_names_by_id'?
Internally 'xstats_get_names_by_id' is used to get the count, but I think this
is not intentionally selected, just one of the xstats_*_by_id dev_ops used.
I think it is confusing to have this support for one of the '_by_id' dev_ops but
not for other. Why not require both to support returning 'count'?
> + *
> + * @param dev
> + * ethdev handle of port.
> + * @param xstats_names
> + * An rte_eth_xstat_name array of at least *size* elements to
> + * be filled. Can be NULL together with @p ids to retrieve number of
> + * available statistics.
> + * @param ids
> + * IDs array to retrieve specific statistics. Can be NULL together
> + * with @p xstats_names to retrieve number of available statistics.
> + * @param size
> + * Element count in @p ids and @p xstats_names.
> + *
> + * @return
> + * - A number of filled in stats if both xstats_names and ids are not NULL.
> + * - A number of available stats if both xstats_names and ids are NULL.
> + * - A negative value on error.
> + */
> typedef int (*eth_xstats_get_names_by_id_t)(struct rte_eth_dev *dev,
> struct rte_eth_xstat_name *xstats_names, const uint64_t *ids,
> unsigned int size);
> -/**< @internal Get names of extended stats of an Ethernet device. */
>
> typedef int (*eth_queue_stats_mapping_set_t)(struct rte_eth_dev *dev,
> uint16_t queue_id,
>
