[dpdk-dev] [PATCH v8 09/15] net/sfc: use new rte_eth_linkstatus functions

[Andrew Rybchenko]

On 01/26/2018 05:01 AM, Stephen Hemminger wrote:
> Use the new API rte_eth_linkstatus_set to handle link status update.
>
> Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
> ---
>   drivers/net/sfc/sfc_ethdev.c | 24 +++++-------------------
>   drivers/net/sfc/sfc_ev.c     | 20 ++------------------
>   2 files changed, 7 insertions(+), 37 deletions(-)
>
> diff --git a/drivers/net/sfc/sfc_ethdev.c b/drivers/net/sfc/sfc_ethdev.c
> index 89a452907621..7d51db979a03 100644
> --- a/drivers/net/sfc/sfc_ethdev.c
> +++ b/drivers/net/sfc/sfc_ethdev.c
> @@ -236,22 +236,13 @@ static int
>   sfc_dev_link_update(struct rte_eth_dev *dev, int wait_to_complete)
>   {
>   	struct sfc_adapter *sa = dev->data->dev_private;
> -	struct rte_eth_link *dev_link = &dev->data->dev_link;
> -	struct rte_eth_link old_link;
>   	struct rte_eth_link current_link;
> +	int ret;
>   
>   	sfc_log_init(sa, "entry");
>   
> -retry:
> -	EFX_STATIC_ASSERT(sizeof(*dev_link) == sizeof(rte_atomic64_t));
> -	*(int64_t *)&old_link = rte_atomic64_read((rte_atomic64_t *)dev_link);
> -
>   	if (sa->state != SFC_ADAPTER_STARTED) {
>   		sfc_port_link_mode_to_info(EFX_LINK_UNKNOWN, &current_link);
> -		if (!rte_atomic64_cmpset((volatile uint64_t *)dev_link,
> -					 *(uint64_t *)&old_link,
> -					 *(uint64_t *)&current_link))
> -			goto retry;
>   	} else if (wait_to_complete) {
>   		efx_link_mode_t link_mode;
>   
> @@ -259,21 +250,16 @@ sfc_dev_link_update(struct rte_eth_dev *dev, int wait_to_complete)
>   			link_mode = EFX_LINK_UNKNOWN;
>   		sfc_port_link_mode_to_info(link_mode, &current_link);
>   
> -		if (!rte_atomic64_cmpset((volatile uint64_t *)dev_link,
> -					 *(uint64_t *)&old_link,
> -					 *(uint64_t *)&current_link))
> -			goto retry;
>   	} else {
>   		sfc_ev_mgmt_qpoll(sa);
> -		*(int64_t *)&current_link =
> -			rte_atomic64_read((rte_atomic64_t *)dev_link);
> +		rte_eth_linkstatus_get(dev, &current_link);
>   	}
>   
> -	if (old_link.link_status != current_link.link_status)
> +	ret = rte_eth_linkstatus_set(dev, &current_link);
> +	if (ret == 0)
>   		sfc_info(sa, "Link status is %s",
>   			 current_link.link_status ? "UP" : "DOWN");
> -
> -	return old_link.link_status == current_link.link_status ? 0 : -1;
> +	return ret;
>   }
>   
>   static void

These changes are OK.

> diff --git a/drivers/net/sfc/sfc_ev.c b/drivers/net/sfc/sfc_ev.c
> index 7abe61ae5ff1..273a92ccb222 100644
> --- a/drivers/net/sfc/sfc_ev.c
> +++ b/drivers/net/sfc/sfc_ev.c
> @@ -382,27 +382,11 @@ sfc_ev_link_change(void *arg, efx_link_mode_t link_mode)
>   {
>   	struct sfc_evq *evq = arg;
>   	struct sfc_adapter *sa = evq->sa;
> -	struct rte_eth_link *dev_link = &sa->eth_dev->data->dev_link;
>   	struct rte_eth_link new_link;
> -	uint64_t new_link_u64;
> -	uint64_t old_link_u64;
> -
> -	EFX_STATIC_ASSERT(sizeof(*dev_link) == sizeof(rte_atomic64_t));
>   
>   	sfc_port_link_mode_to_info(link_mode, &new_link);
> -
> -	new_link_u64 = *(uint64_t *)&new_link;
> -	do {
> -		old_link_u64 = rte_atomic64_read((rte_atomic64_t *)dev_link);
> -		if (old_link_u64 == new_link_u64)
> -			break;
> -
> -		if (rte_atomic64_cmpset((volatile uint64_t *)dev_link,
> -					old_link_u64, new_link_u64)) {
> -			evq->sa->port.lsc_seq++;
> -			break;
> -		}
> -	} while (B_TRUE);
> +	if (rte_eth_linkstatus_set(sa->eth_dev, &new_link))
> +		evq->sa->port.lsc_seq++;
>   
>   	return B_FALSE;
>   }

Let me repeat part of my review notes for v4:
 >>
lsc_seq should be incremented in the case of any changes in link,
not up/down changes only and it should be preserved.
<<
and I'd like to keep it here. Thanks to rte_atomic64_exchange()
the function can be simplified to:
  - convert link mode to link info (as now)
  - do exchange
  - compare old and new value as uint64_t and increment lsc_seq
    if different

Thanks.