Re: [dpdk-dev] [RFC] ethdev: remove all offload API

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 6/9/2018 9:04 AM, Andrew Rybchenko wrote:
> On 06/09/2018 01:41 AM, Ferruh Yigit wrote:
>> Cc: Shahaf Shuler <shahafs@mellanox.com>
>>
>> Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
>> ---
> 
> <...>
> 
>> diff --git a/app/test-eventdev/test_perf_common.c b/app/test-eventdev/test_perf_common.c
>> index d00f91802..9fe042ffe 100644
>> --- a/app/test-eventdev/test_perf_common.c
>> +++ b/app/test-eventdev/test_perf_common.c
>> @@ -680,13 +680,7 @@ perf_ethdev_setup(struct evt_test *test, struct evt_options *opt)
>>  			.mq_mode = ETH_MQ_RX_RSS,
>>  			.max_rx_pkt_len = ETHER_MAX_LEN,
>>  			.split_hdr_size = 0,
>> -			.header_split   = 0,
>> -			.hw_ip_checksum = 0,
>> -			.hw_vlan_filter = 0,
>> -			.hw_vlan_strip  = 0,
>> -			.hw_vlan_extend = 0,
>>  			.jumbo_frame    = 0,
>> -			.hw_strip_crc   = 1,
> 

Hi Andrew,

> I have 2 questions here:
>  1. Why is jumbo_frame kept? There is DEV_RX_OFFLOAD_JUMBO_FRAME.

Because there are still some usage of this flag in PMDs, they need to be
clarified before removing the flag. I am for removing the flag in final version,
but for this RFC I am not able to find enough time to work on PMDs for it.

>  2. Why is hw_strip_crc=1 discarded? Yes, I remember plans to make it
>      default behaviour and introduce flag to keep CRC, but right now the
>      patch looks like mixture of two changes which is not good.

Yes it is wrong, app should replace "".hw_strip_crc=1 with KEEP_CRC offload.
Since both are RFC, kind of hard to maintain, but I think good to create a
dependency from this patch to KEEP_CRC one.

> 
> There are more cases in the patch where hw_strip_crc=1 is simply discarded.
> 
> <...>
> 
>> diff --git a/drivers/net/sfc/sfc_ethdev.c b/drivers/net/sfc/sfc_ethdev.c
>> index 1b6499f85..ee8ae5b9f 100644
>> --- a/drivers/net/sfc/sfc_ethdev.c
>> +++ b/drivers/net/sfc/sfc_ethdev.c
>> @@ -1089,7 +1089,6 @@ sfc_tx_queue_info_get(struct rte_eth_dev *dev, uint16_t tx_queue_id,
>>  
>>  	memset(qinfo, 0, sizeof(*qinfo));
>>  
>> -	qinfo->conf.txq_flags = txq_info->txq->flags;
>>  	qinfo->conf.offloads = txq_info->txq->offloads;
>>  	qinfo->conf.tx_free_thresh = txq_info->txq->free_thresh;
>>  	qinfo->conf.tx_deferred_start = txq_info->deferred_start;
>> diff --git a/drivers/net/sfc/sfc_rx.c b/drivers/net/sfc/sfc_rx.c
>> index cc76a5b15..58a0df583 100644
>> --- a/drivers/net/sfc/sfc_rx.c
>> +++ b/drivers/net/sfc/sfc_rx.c
>> @@ -1446,7 +1446,6 @@ sfc_rx_check_mode(struct sfc_adapter *sa, struct rte_eth_rxmode *rxmode)
>>  	if (~rxmode->offloads & DEV_RX_OFFLOAD_CRC_STRIP) {
>>  		sfc_warn(sa, "FCS stripping cannot be disabled - always on");
>>  		rxmode->offloads |= DEV_RX_OFFLOAD_CRC_STRIP;
>> -		rxmode->hw_strip_crc = 1;
>>  	}
>>  
>>  	return rc;
>> diff --git a/drivers/net/sfc/sfc_tx.c b/drivers/net/sfc/sfc_tx.c
>> index 1bcc2c697..6d42a1a65 100644
>> --- a/drivers/net/sfc/sfc_tx.c
>> +++ b/drivers/net/sfc/sfc_tx.c
>> @@ -171,7 +171,6 @@ sfc_tx_qinit(struct sfc_adapter *sa, unsigned int sw_index,
>>  	txq->free_thresh =
>>  		(tx_conf->tx_free_thresh) ? tx_conf->tx_free_thresh :
>>  		SFC_TX_DEFAULT_FREE_THRESH;
>> -	txq->flags = tx_conf->txq_flags;
>>  	txq->offloads = offloads;
>>  
>>  	rc = sfc_dma_alloc(sa, "txq", sw_index, EFX_TXQ_SIZE(txq_info->entries),
>> @@ -182,7 +181,6 @@ sfc_tx_qinit(struct sfc_adapter *sa, unsigned int sw_index,
>>  	memset(&info, 0, sizeof(info));
>>  	info.max_fill_level = txq_max_fill_level;
>>  	info.free_thresh = txq->free_thresh;
>> -	info.flags = tx_conf->txq_flags;
>>  	info.offloads = offloads;
>>  	info.txq_entries = txq_info->entries;
>>  	info.dma_desc_size_max = encp->enc_tx_dma_desc_size_max;
>> @@ -431,18 +429,10 @@ sfc_tx_qstart(struct sfc_adapter *sa, unsigned int sw_index)
>>  	if (rc != 0)
>>  		goto fail_ev_qstart;
>>  
>> -	/*
>> -	 * The absence of ETH_TXQ_FLAGS_IGNORE is associated with a legacy
>> -	 * application which expects that IPv4 checksum offload is enabled
>> -	 * all the time as there is no legacy flag to turn off the offload.
>> -	 */
>> -	if ((txq->offloads & DEV_TX_OFFLOAD_IPV4_CKSUM) ||
>> -	    (~txq->flags & ETH_TXQ_FLAGS_IGNORE))
>> +	if (txq->offloads & DEV_TX_OFFLOAD_IPV4_CKSUM)
>>  		flags |= EFX_TXQ_CKSUM_IPV4;
>>  
>> -	if ((txq->offloads & DEV_TX_OFFLOAD_OUTER_IPV4_CKSUM) ||
>> -	    ((~txq->flags & ETH_TXQ_FLAGS_IGNORE) &&
>> -	     (offloads_supported & DEV_TX_OFFLOAD_OUTER_IPV4_CKSUM)))
>> +	if (txq->offloads & DEV_TX_OFFLOAD_OUTER_IPV4_CKSUM)
>>  		flags |= EFX_TXQ_CKSUM_INNER_IPV4;
>>  
>>  	if ((txq->offloads & DEV_TX_OFFLOAD_TCP_CKSUM) ||
>> @@ -453,16 +443,7 @@ sfc_tx_qstart(struct sfc_adapter *sa, unsigned int sw_index)
>>  			flags |= EFX_TXQ_CKSUM_INNER_TCPUDP;
>>  	}
>>  
>> -	/*
>> -	 * The absence of ETH_TXQ_FLAGS_IGNORE is associated with a legacy
>> -	 * application. In turn, the absence of ETH_TXQ_FLAGS_NOXSUMTCP is
>> -	 * associated specifically with a legacy application which expects
>> -	 * both TCP checksum offload and TSO to be enabled because the legacy
>> -	 * API does not provide a dedicated mechanism to control TSO.
>> -	 */
>> -	if ((txq->offloads & DEV_TX_OFFLOAD_TCP_TSO) ||
>> -	    ((~txq->flags & ETH_TXQ_FLAGS_IGNORE) &&
>> -	     (~txq->flags & ETH_TXQ_FLAGS_NOXSUMTCP)))
>> +	if (txq->offloads & DEV_TX_OFFLOAD_TCP_TSO)
>>  		flags |= EFX_TXQ_FATSOV2;
>>  
>>  	rc = efx_tx_qcreate(sa->nic, sw_index, 0, &txq->mem,
> 
> net/sfc changes looks good.
> Plus 'struct sfc_txq -> flags' (drivers/net/sfc/sfc_tx.h) and
> 'struct sfc_dp_tx_qcreate_info -> flags' (drivers/net/sfc/sfc_dp_tx.h) should be
> removed since there are not used now.
> 
> If finally rxmode.jumbo_frame is removed, it should removed from
> net/sfc as well (but compiler will help to find it in any case).
> 
> After applying the patch:
> $ git grep ETH_TXQ_FLAGS
> drivers/net/fm10k/fm10k.h:#define FM10K_SIMPLE_TX_FLAG
> ((uint32_t)ETH_TXQ_FLAGS_NOMULTSEGS | \
> drivers/net/fm10k/fm10k.h:                              ETH_TXQ_FLAGS_NOOFFLOADS)

Thanks, will remove this too.

> 
> In general I think that we should do it ASAP. Also it will guarantee
> that new PMDs do not use corresponding structure members etc.

+1, +1