[dpdk-stable] [PATCH 1/2] net/octeontx2: avoid per packet barrier with multi segment

[dpdk-stable] [PATCH 1/2] net/octeontx2: avoid per packet barrier with multi segment

[Murphy Yang]

From: Nithin Dabilpuram <ndabilpuram@marvell.com>

Avoid per-pkt barrier with multi-seg with fast free
and remove mbuf update to NULL.

Fixes: ce8628c66a22 ("net/octeontx2: fix jumbo frame crash")
Cc: stable@dpdk.org

Signed-off-by: Nithin Dabilpuram <ndabilpuram@marvell.com>
Signed-off-by: Jerin Jacob <jerinj@marvell.com>
---
 drivers/event/octeontx2/otx2_worker.h | 22 ++++++++--------------
 drivers/net/octeontx2/otx2_tx.c       |  8 ++++++--
 drivers/net/octeontx2/otx2_tx.h       | 12 ++++++++----
 3 files changed, 22 insertions(+), 20 deletions(-)

diff --git a/drivers/event/octeontx2/otx2_worker.h b/drivers/event/octeontx2/otx2_worker.h
index 4501f4e0e7..3efd3ba97f 100644
--- a/drivers/event/octeontx2/otx2_worker.h
+++ b/drivers/event/octeontx2/otx2_worker.h
@@ -288,18 +288,12 @@ otx2_ssogws_event_tx(struct otx2_ssogws *ws, struct rte_event ev[],
 
 	/* Perform header writes before barrier for TSO */
 	otx2_nix_xmit_prepare_tso(m, flags);
-	/* Lets commit any changes in the packet here in case of single seg as
-	 * no further changes to mbuf will be done.
-	 * While for multi seg all mbufs used are set to NULL in
-	 * otx2_nix_prepare_mseg() after preparing the sg list and these changes
-	 * should be committed before LMTST.
-	 * Also in no fast free case some mbuf fields are updated in
-	 * otx2_nix_prefree_seg
-	 * Hence otx2_nix_xmit_submit_lmt_release/otx2_nix_xmit_mseg_one_release
-	 * has store barrier for multiseg.
+	/* Lets commit any changes in the packet here in case when
+	 * fast free is set as no further changes will be made to mbuf.
+	 * In case of fast free is not set, both otx2_nix_prepare_mseg()
+	 * and otx2_nix_xmit_prepare() has a barrier after refcnt update.
 	 */
-	if (!(flags & NIX_TX_MULTI_SEG_F) &&
-	    !(flags & NIX_TX_OFFLOAD_MBUF_NOFF_F))
+	if (!(flags & NIX_TX_OFFLOAD_MBUF_NOFF_F))
 		rte_io_wmb();
 	txq = otx2_ssogws_xtract_meta(m, txq_data);
 	otx2_ssogws_prepare_pkt(txq, m, cmd, flags);
@@ -311,12 +305,12 @@ otx2_ssogws_event_tx(struct otx2_ssogws *ws, struct rte_event ev[],
 		if (!ev->sched_type) {
 			otx2_nix_xmit_mseg_prep_lmt(cmd, txq->lmt_addr, segdw);
 			otx2_ssogws_head_wait(ws);
-			if (otx2_nix_xmit_submit_lmt_release(txq->io_addr) == 0)
+			if (otx2_nix_xmit_submit_lmt(txq->io_addr) == 0)
 				otx2_nix_xmit_mseg_one(cmd, txq->lmt_addr,
 						       txq->io_addr, segdw);
 		} else {
-			otx2_nix_xmit_mseg_one_release(cmd, txq->lmt_addr,
-						       txq->io_addr, segdw);
+			otx2_nix_xmit_mseg_one(cmd, txq->lmt_addr,
+					       txq->io_addr, segdw);
 		}
 	} else {
 		/* Passing no of segdw as 4: HDR + EXT + SG + SMEM */
diff --git a/drivers/net/octeontx2/otx2_tx.c b/drivers/net/octeontx2/otx2_tx.c
index 4458d8bca7..439c46f61c 100644
--- a/drivers/net/octeontx2/otx2_tx.c
+++ b/drivers/net/octeontx2/otx2_tx.c
@@ -77,11 +77,15 @@ nix_xmit_pkts_mseg(void *tx_queue, struct rte_mbuf **tx_pkts,
 			otx2_nix_xmit_prepare_tso(tx_pkts[i], flags);
 	}
 
+	/* Lets commit any changes in the packet here as no further changes
+	 * to the packet will be done unless no fast free is enabled.
+	 */
+	if (!(flags & NIX_TX_OFFLOAD_MBUF_NOFF_F))
+		rte_io_wmb();
+
 	for (i = 0; i < pkts; i++) {
 		otx2_nix_xmit_prepare(tx_pkts[i], cmd, flags);
 		segdw = otx2_nix_prepare_mseg(tx_pkts[i], cmd, flags);
-		/* Lets commit any changes in the packet */
-		rte_io_wmb();
 		otx2_nix_xmit_prepare_tstamp(cmd, &txq->cmd[0],
 					     tx_pkts[i]->ol_flags, segdw,
 					     flags);
diff --git a/drivers/net/octeontx2/otx2_tx.h b/drivers/net/octeontx2/otx2_tx.h
index d6ea3b4874..a97b160677 100644
--- a/drivers/net/octeontx2/otx2_tx.h
+++ b/drivers/net/octeontx2/otx2_tx.h
@@ -440,13 +440,17 @@ otx2_nix_prepare_mseg(struct rte_mbuf *m, uint64_t *cmd, const uint16_t flags)
 		sg_u = sg_u | ((uint64_t)m->data_len << (i << 4));
 		*slist = rte_mbuf_data_iova(m);
 		/* Set invert df if buffer is not to be freed by H/W */
-		if (flags & NIX_TX_OFFLOAD_MBUF_NOFF_F)
+		if (flags & NIX_TX_OFFLOAD_MBUF_NOFF_F) {
 			sg_u |=	(otx2_nix_prefree_seg(m) << (i + 55));
+			/* Commit changes to mbuf */
+			rte_io_wmb();
+		}
 		/* Mark mempool object as "put" since it is freed by NIX */
-		if (!(sg_u & (1ULL << (i + 55)))) {
-			m->next = NULL;
+#ifdef RTE_LIBRTE_MEMPOOL_DEBUG
+		if (!(sg_u & (1ULL << (i + 55))))
 			__mempool_check_cookies(m->pool, (void **)&m, 1, 0);
-		}
+		rte_io_wmb();
+#endif
 		slist++;
 		i++;
 		nb_segs--;
-- 
2.17.1