[dpdk-dev] i40e: configure MTU

  This patch enables configuring MTU for i40e.
Since changing MTU needs to reconfigure queue, stop port first
before configuring MTU.

Signed-off-by: Beilei Xing <beilei.xing@intel.com>
---
 drivers/net/i40e/i40e_ethdev.c | 49 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)
  

On 4/23/2016 7:26 PM, Xing, Beilei wrote:
> This patch enables configuring MTU for i40e.
> Since changing MTU needs to reconfigure queue, stop port first
> before configuring MTU.
>
> Signed-off-by: Beilei Xing <beilei.xing@intel.com>
> ---
>   drivers/net/i40e/i40e_ethdev.c | 49 ++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 49 insertions(+)
>
> diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
> index bc28d3c..29259b9 100644
> --- a/drivers/net/i40e/i40e_ethdev.c
> +++ b/drivers/net/i40e/i40e_ethdev.c
> @@ -447,6 +447,8 @@ static int i40e_get_eeprom(struct rte_eth_dev *dev,
>   static void i40e_set_default_mac_addr(struct rte_eth_dev *dev,
>   				      struct ether_addr *mac_addr);
>   
> +static int i40e_dev_mtu_set(struct rte_eth_dev *dev, uint16_t mtu);
> +
>   static const struct rte_pci_id pci_id_i40e_map[] = {
>   #define RTE_PCI_DEV_ID_DECL_I40E(vend, dev) {RTE_PCI_DEVICE(vend, dev)},
>   #include "rte_pci_dev_ids.h"
> @@ -520,6 +522,7 @@ static const struct eth_dev_ops i40e_eth_dev_ops = {
>   	.get_eeprom_length            = i40e_get_eeprom_length,
>   	.get_eeprom                   = i40e_get_eeprom,
>   	.mac_addr_set                 = i40e_set_default_mac_addr,
> +	.mtu_set                      = i40e_dev_mtu_set,
>   };
>   
>   /* store statistics names and its offset in stats structure */
> @@ -9104,3 +9107,49 @@ static void i40e_set_default_mac_addr(struct rte_eth_dev *dev,
>   	/* Flags: 0x3 updates port address */
>   	i40e_aq_mac_address_write(hw, 0x3, mac_addr->addr_bytes, NULL);
>   }
> +
> +static int i40e_dev_mtu_set(struct rte_eth_dev *dev, uint16_t mtu)
According to the coding style, at function definition, "The function 
type should be on a line by itself preceding the function."
> +{
> +	struct i40e_pf *pf = I40E_DEV_PRIVATE_TO_PF(dev->data->dev_private);
> +	struct i40e_hw *hw = I40E_DEV_PRIVATE_TO_HW(dev->data->dev_private);
> +	struct rte_eth_dev_data *dev_data = pf->dev_data;
> +	struct rte_eth_dev_info dev_info;
> +	struct i40e_rx_queue *rxq;
> +	int i;
> +	uint16_t len;
> +	uint32_t frame_size = mtu + ETHER_HDR_LEN + ETHER_CRC_LEN;
> +	int ret = 0;
> +
> +	i40e_dev_info_get(dev, &dev_info);
> +
> +	/* check if mtu is within the allowed range */
> +	if ((mtu < ETHER_MIN_MTU) || (frame_size > dev_info.max_rx_pktlen))
> +		return -EINVAL;
> +
The dev_info.max_rx_pktlen queried by i40e_dev_info_get is 
"I40E_FRAME_SIZE_MAX".
No need to call the API to get dev info in driver.
  

Hello,

On 04/23/2016 01:26 PM, Beilei Xing wrote:
[...]
> +	/* mtu setting is forbidden if port is start */
> +	if (dev_data->dev_started) {
> +		PMD_DRV_LOG(ERR,
> +			    "port %d must be stopped before configuration\n",
> +			    dev_data->port_id);
> +		return -EBUSY;
> +	}

According to rte_ethdev.h, only 4 return codes are supported for
rte_eth_dev_set_mtu:

* - (0) if successful.
* - (-ENOTSUP) if operation is not supported.
* - (-ENODEV) if *port_id* invalid.
* - (-EINVAL) if *mtu* invalid.

EBUSY should not be returned.

> +	for (i = 0; i < dev_data->nb_rx_queues; i++) {
> +		rxq = dev_data->rx_queues[i];
> +		if (!rxq || !rxq->q_set)
> +			continue;
> +
> +		dev_data->dev_conf.rxmode.max_rx_pkt_len = frame_size;
> +		len = hw->func_caps.rx_buf_chain_len * rxq->rx_buf_len;
> +		rxq->max_pkt_len = RTE_MIN(len, frame_size);
> +	}
> +
> +	ret = i40e_dev_rx_init(pf);
> +
> +	return ret;
> +}
> 

Why do want to reconfigure rxq here ? All these operations are already
done when you call i40e_dev_rx_init.
i40e_dev_rx_init => i40e_rx_queue_init (for each queue) =>
i40e_rx_queue_config => redefine rxq->max_pkt_len

Moreover, you should move dev_data->dev_conf.rxmode.max_rx_pkt_len out
of the loop. frame_size is the same for all rx_queues.
  

> -----Original Message-----
> From: Julien Meunier [mailto:julien.meunier@6wind.com]
> Sent: Wednesday, April 27, 2016 7:44 PM
> To: Xing, Beilei <beilei.xing@intel.com>; Wu, Jingjing <jingjing.wu@intel.com>
> Cc: dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH] i40e: configure MTU
> 
> Hello,
> 
> On 04/23/2016 01:26 PM, Beilei Xing wrote:
> [...]
> > +	/* mtu setting is forbidden if port is start */
> > +	if (dev_data->dev_started) {
> > +		PMD_DRV_LOG(ERR,
> > +			    "port %d must be stopped before configuration\n",
> > +			    dev_data->port_id);
> > +		return -EBUSY;
> > +	}
> 
> According to rte_ethdev.h, only 4 return codes are supported for
> rte_eth_dev_set_mtu:
> 
> * - (0) if successful.
> * - (-ENOTSUP) if operation is not supported.
> * - (-ENODEV) if *port_id* invalid.
> * - (-EINVAL) if *mtu* invalid.
> 
> EBUSY should not be returned.

Hi Meunier,
Thanks for your comments, it shouldn't be EBUSY here.

> 
> > +	for (i = 0; i < dev_data->nb_rx_queues; i++) {
> > +		rxq = dev_data->rx_queues[i];
> > +		if (!rxq || !rxq->q_set)
> > +			continue;
> > +
> > +		dev_data->dev_conf.rxmode.max_rx_pkt_len = frame_size;
> > +		len = hw->func_caps.rx_buf_chain_len * rxq->rx_buf_len;
> > +		rxq->max_pkt_len = RTE_MIN(len, frame_size);
> > +	}
> > +
> > +	ret = i40e_dev_rx_init(pf);
> > +
> > +	return ret;
> > +}
> >
> 
> Why do want to reconfigure rxq here ? All these operations are already done
> when you call i40e_dev_rx_init.
> i40e_dev_rx_init => i40e_rx_queue_init (for each queue) =>
> i40e_rx_queue_config => redefine rxq->max_pkt_len
> 
> Moreover, you should move dev_data->dev_conf.rxmode.max_rx_pkt_len out
> of the loop. frame_size is the same for all rx_queues.

Yes, you're right, needn't reconfigure rxq->max_pkt_len here, I just need reconfigure dev_data->dev_conf.rxmode.max_rx_pkt_len cause i40e_dev_rx_init will cover all. 
Thanks very much.
Beilei

> 
> --
> Julien MEUNIER
> 6WIND