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

[Shahaf Shuler <shahafs@mellanox.com>]

Hi Ferruh,

Thanks for this patch. 

Monday, June 11, 2018 12:10 PM, Ferruh Yigit:
> Subject: Re: [RFC] ethdev: remove all offload API
> 
> 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.

Can you elaborate?
Is this something more than just a replace of the jumbo_frame bit with its corresponding flag? 

> 
> >  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