Re: [dpdk-dev] [PATCH V14 1/3] ethdev: introduce FEC API

[Andrew Rybchenko <arybchenko@solarflare.com>]

On 9/28/20 2:08 PM, Min Hu (Connor) wrote:
> This patch adds Forward error correction(FEC) support for ethdev.
> Introduce APIs which support query and config FEC information in
> hardware.
> 
> Signed-off-by: Min Hu (Connor) <humin29@huawei.com>
> Reviewed-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>
> Reviewed-by: Chengwen Feng <fengchengwen@huawei.com>
> Reviewed-by: Chengchang Tang <tangchengchang@huawei.com>
> Acked-by: Andrew Rybchenko <arybchenko@solarflare.com>

[snip]

> diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
> index dfe5c1b..996d230 100644
> --- a/lib/librte_ethdev/rte_ethdev.c
> +++ b/lib/librte_ethdev/rte_ethdev.c
> @@ -3679,6 +3679,50 @@ rte_eth_led_off(uint16_t port_id)
>  	return eth_err(port_id, (*dev->dev_ops->dev_led_off)(dev));
>  }
>  
> +int
> +rte_eth_fec_get_capability(uint16_t port_id,
> +			   struct rte_eth_fec_capa *speed_fec_capa,
> +			   unsigned int num)
> +{
> +	struct rte_eth_dev *dev;
> +	int ret;
> +
> +	if (speed_fec_capa == NULL && num > 0)
> +		return -EINVAL;
> +
> +	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
> +	dev = &rte_eth_devices[port_id];
> +	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->fec_get_capability, -ENOTSUP);
> +	ret = (*dev->dev_ops->fec_get_capability)(dev, speed_fec_capa, num);
> +
> +	return ret;
> +}
> +
> +int
> +rte_eth_fec_get(uint16_t port_id, uint32_t *fec_capa)
> +{
> +	struct rte_eth_dev *dev;
> +
> +	if (fec_capa == NULL)
> +		return -EINVAL;
> +
> +	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
> +	dev = &rte_eth_devices[port_id];
> +	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->fec_get, -ENOTSUP);
> +	return eth_err(port_id, (*dev->dev_ops->fec_get)(dev, fec_capa));
> +}
> +
> +int
> +rte_eth_fec_set(uint16_t port_id, uint32_t mode)

mode -> fec_capa, since it is not a single mode

> +{
> +	struct rte_eth_dev *dev;
> +
> +	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
> +	dev = &rte_eth_devices[port_id];
> +	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->fec_set, -ENOTSUP);
> +	return eth_err(port_id, (*dev->dev_ops->fec_set)(dev, mode));
> +}
> +
>  /*
>   * Returns index into MAC address array of addr. Use 00:00:00:00:00:00 to find
>   * an empty spot.
> diff --git a/lib/librte_ethdev/rte_ethdev.h b/lib/librte_ethdev/rte_ethdev.h
> index 645a186..50c5280 100644
> --- a/lib/librte_ethdev/rte_ethdev.h
> +++ b/lib/librte_ethdev/rte_ethdev.h

[snip]

> @@ -3397,6 +3420,85 @@ int  rte_eth_led_on(uint16_t port_id);
>  int  rte_eth_led_off(uint16_t port_id);
>  
>  /**
> + * @warning
> + * @b EXPERIMENTAL: this API may change, or be removed, without prior notice
> + *
> + * Get Forward Error Correction(FEC) capability.
> + *
> + * @param port_id
> + *   The port identifier of the Ethernet device.
> + * @param speed_fec_capa
> + *   speed_fec_capa is out only with per-speed capabilities.
> + *   If set to NULL, the function returns the required number
> + *   of required array entries.
> + * @param num
> + *   a number of elements in an speed_fec_capa array.
> + *
> + * @return
> + *   - A positive value lower or equal to num: success. The return value

positive -> non-negative
since 0 is OK if FEC is not applicable/supported

> + *     is the number of entries filled in the fec capa array.
> + *   - A positive value higher than num: error, the given fec capa array

same, positive -> non-negative

> + *     is too small. The return value corresponds to the num that should
> + *     be given to succeed. The entries in fec capa array are not valid and
> + *     shall not be used by the caller.

OK for me, possible option is to fill in just provided entries
(up to num)

> + *   - (-ENOTSUP) if underlying hardware OR driver doesn't support.
> + *     that operation.
> + *   - (-EIO) if device is removed.
> + *   - (-ENODEV)  if *port_id* invalid.
> + *   - (-EINVAL)  if *num* or *speed_fec_capa* invalid
> + */
> +__rte_experimental
> +int rte_eth_fec_get_capability(uint16_t port_id,
> +			       struct rte_eth_fec_capa *speed_fec_capa,
> +			       unsigned int num);
> +
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this API may change, or be removed, without prior notice
> + *
> + * Get current Forward Error Correction(FEC) mode.
> + * If link is down and AUTO is enabled, AUTO is returned, otherwise,
> + * configured FEC mode is returned.
> + * If link is up, current FEC mode is returned.
> + *
> + * @param port_id
> + *   The port identifier of the Ethernet device.
> + * @param fec_capa
> + *   A bitmask of enabled FEC modes. If AUTO bit is set, other
> + *   bits specify FEC modes which may be negotiated. If AUTO
> + *   bit is clear, specify FEC modes to be used (only one valid
> + *   mode per speed may be set).
> + * @return
> + *   - (0) if successful.
> + *   - (-ENOTSUP) if underlying hardware OR driver doesn't support.
> + *     that operation.
> + *   - (-EIO) if device is removed.
> + *   - (-ENODEV)  if *port_id* invalid.
> + */
> +__rte_experimental
> +int rte_eth_fec_get(uint16_t port_id, uint32_t *fec_capa);
> +
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this API may change, or be removed, without prior notice
> + *
> + * Set Forward Error Correction(FEC) mode.
> + *
> + * @param port_id
> + *   The port identifier of the Ethernet device.
> + * @param mode
> + *   The FEC mode.

mode -> fec_capa
with description from callback below

> + * @return
> + *   - (0) if successful.
> + *   - (-EINVAL) if the FEC mode is not valid.
> + *   - (-ENOTSUP) if underlying hardware OR driver doesn't support.
> + *   - (-EIO) if device is removed.
> + *   - (-ENODEV)  if *port_id* invalid.
> + */
> +__rte_experimental
> +int rte_eth_fec_set(uint16_t port_id, uint32_t mode);
> +
> +/**
>   * Get current status of the Ethernet link flow control for Ethernet device
>   *
>   * @param port_id
> diff --git a/lib/librte_ethdev/rte_ethdev_driver.h b/lib/librte_ethdev/rte_ethdev_driver.h
> index 23cc1e0..a1f10d6 100644
> --- a/lib/librte_ethdev/rte_ethdev_driver.h
> +++ b/lib/librte_ethdev/rte_ethdev_driver.h
> @@ -575,6 +575,87 @@ typedef int (*eth_tx_hairpin_queue_setup_t)
>  	 const struct rte_eth_hairpin_conf *hairpin_conf);
>  
>  /**
> + * @internal
> + * Get Forward Error Correction(FEC) capability.
> + *
> + * @param dev
> + *   ethdev handle of port.
> + * @param speed_fec_capa
> + *   speed_fec_capa is out only with per-speed capabilities.
> + * @param num
> + *   a number of elements in an speed_fec_capa array.
> + *
> + * @return
> + *   Negative errno value on error, positive value on success.
> + *
> + * @retval positive value
> + *   A positive value lower or equal to num: success. The return value

same as above

> + *   is the number of entries filled in the fec capa array.
> + *   A positive value higher than num: error, the given fec capa array

same as above

> + *   is too small. The return value corresponds to the num that should
> + *   be given to succeed. The entries in the fec capa array are not valid
> + *   and shall not be used by the caller.
> + * @retval -ENOTSUP
> + *   Operation is not supported.
> + * @retval -EIO
> + *   Device is removed.
> + * @retval -EINVAL
> + *   *num* or *speed_fec_capa* invalid.
> + */
> +typedef int (*eth_fec_get_capability_t)(struct rte_eth_dev *dev,
> +		struct rte_eth_fec_capa *speed_fec_capa, unsigned int num);
> +
> +/**
> + * @internal
> + * Get Forward Error Correction(FEC) mode.
> + *
> + * @param dev
> + *   ethdev handle of port.
> + * @param fec_capa
> + *   a bitmask of enabled FEC modes. If AUTO bit is set, other
> + *   bits specify FEC modes which may be negotiated. If AUTO
> + *   bit is clear, specify FEC modes to be used (only one valid
> + *   mode per speed may be set).
> + *
> + * @return
> + *   Negative errno value on error, 0 on success.
> + *
> + * @retval 0
> + *   Success, get FEC success.
> + * @retval -ENOTSUP
> + *   Operation is not supported.
> + * @retval -EIO
> + *   Device is removed.
> + */
> +typedef int (*eth_fec_get_t)(struct rte_eth_dev *dev,
> +			     uint32_t *fec_capa);
> +
> +/**
> + * @internal
> + * Set Forward Error Correction(FEC) mode.
> + *
> + * @param dev
> + *   ethdev handle of port.
> + * @param mode

mode -> fec_capa

> + *   bitmask of allowed FEC modes. It must be only one
> + *   if AUTO is disabled. If AUTO is enabled, other
> + *   bits specify FEC modes which may be negotiated.
> + *
> + * @return
> + *   Negative errno value on error, 0 on success.
> + *
> + * @retval 0
> + *   Success, set FEC success.
> + * @retval -ENOTSUP
> + *   Operation is not supported.
> + * @retval -EINVAL
> + *   Unsupported FEC mode requested.
> + * @retval -EIO
> + *   Device is removed.
> + */
> +typedef int (*eth_fec_set_t)(struct rte_eth_dev *dev, uint32_t mode);
> +
> +/**
>   * @internal A structure containing the functions exported by an Ethernet driver.
>   */
>  struct eth_dev_ops {
> @@ -713,6 +794,13 @@ struct eth_dev_ops {
>  	/**< Set up device RX hairpin queue. */
>  	eth_tx_hairpin_queue_setup_t tx_hairpin_queue_setup;
>  	/**< Set up device TX hairpin queue. */
> +
> +	eth_fec_get_capability_t fec_get_capability;
> +	/**< Get Forward Error Correction(FEC) capability. */
> +	eth_fec_get_t fec_get;
> +	/**< Get Forward Error Correction(FEC) mode. */
> +	eth_fec_set_t fec_set;
> +	/**< Set Forward Error Correction(FEC) mode. */
>  };
>  
>  /**
> diff --git a/lib/librte_ethdev/rte_ethdev_version.map b/lib/librte_ethdev/rte_ethdev_version.map
> index c95ef51..b9ace3a 100644
> --- a/lib/librte_ethdev/rte_ethdev_version.map
> +++ b/lib/librte_ethdev/rte_ethdev_version.map
> @@ -229,6 +229,9 @@ EXPERIMENTAL {
>  	# added in 20.11
>  	rte_eth_link_speed_to_str;
>  	rte_eth_link_to_str;
> +	rte_eth_fec_get_capability;
> +	rte_eth_fec_get;
> +	rte_eth_fec_set;
>  };
>  
>  INTERNAL {
>