[dpdk-stable] patch 'net/bnxt: fix Rx completion ring size calculation' has been queued to stable release 20.11.1

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 20.11.1

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 02/11/21. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/bluca/dpdk-stable

This queued commit can be viewed at:
https://github.com/bluca/dpdk-stable/commit/42f7f70176ac78335f522fcdd7b15e613bfbddd9

Thanks.

Luca Boccassi

---
>From 42f7f70176ac78335f522fcdd7b15e613bfbddd9 Mon Sep 17 00:00:00 2001
From: Lance Richardson <lance.richardson at broadcom.com>
Date: Fri, 29 Jan 2021 13:07:09 -0500
Subject: [PATCH] net/bnxt: fix Rx completion ring size calculation

[ upstream commit 8e18a019c1fc942321e5fe4529edfc793a4f0d2a ]

The size of the receive completion ring should be recalculated
when MTU is increased to a size that requires scattered receive
or when LRO is enabled. Move logic for this calculation from
the ring configuration path to the device start path.
   - Made size calculation dependent only on scattered_rx
     status.
   - Moved calculation of scattered_rx up in the initialization
     sequence.
   - Made LRO offload status part of scattered_rx calculation.

When the completion ring size is too small, completion overflows
can occur causing the ring to be disabled in hardware.

Fixes: 04067844a3e9 ("net/bnxt: reduce CQ queue size without aggregation ring")

Signed-off-by: Lance Richardson <lance.richardson at broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde at broadcom.com>
---
 drivers/net/bnxt/bnxt_ethdev.c | 12 ++++++++----
 drivers/net/bnxt/bnxt_ring.c   | 22 ++++++++++++++++++++++
 drivers/net/bnxt/bnxt_rxr.c    | 15 +--------------
 3 files changed, 31 insertions(+), 18 deletions(-)

diff --git a/drivers/net/bnxt/bnxt_ethdev.c b/drivers/net/bnxt/bnxt_ethdev.c
index a4a31f224f..3aa346d45c 100644
--- a/drivers/net/bnxt/bnxt_ethdev.c
+++ b/drivers/net/bnxt/bnxt_ethdev.c
@@ -1147,6 +1147,9 @@ static int bnxt_scattered_rx(struct rte_eth_dev *eth_dev)
 	if (eth_dev->data->dev_conf.rxmode.offloads & DEV_RX_OFFLOAD_SCATTER)
 		return 1;
 
+	if (eth_dev->data->dev_conf.rxmode.offloads & DEV_RX_OFFLOAD_TCP_LRO)
+		return 1;
+
 	for (i = 0; i < eth_dev->data->nb_rx_queues; i++) {
 		struct bnxt_rx_queue *rxq = eth_dev->data->rx_queues[i];
 
@@ -1395,11 +1398,12 @@ static int bnxt_dev_start_op(struct rte_eth_dev *eth_dev)
 
 	bnxt_enable_int(bp);
 
-	rc = bnxt_start_nic(bp);
-	if (rc)
-		goto error;
-
 	eth_dev->data->scattered_rx = bnxt_scattered_rx(eth_dev);
+
+	rc = bnxt_start_nic(bp);
+	if (rc)
+		goto error;
+
 	eth_dev->data->dev_started = 1;
 
 	bnxt_link_update_op(eth_dev, 1);
diff --git a/drivers/net/bnxt/bnxt_ring.c b/drivers/net/bnxt/bnxt_ring.c
index aeb6cb6150..94cf7d3de2 100644
--- a/drivers/net/bnxt/bnxt_ring.c
+++ b/drivers/net/bnxt/bnxt_ring.c
@@ -568,6 +568,17 @@ int bnxt_alloc_hwrm_rx_ring(struct bnxt *bp, int queue_index)
 	struct bnxt_rx_ring_info *rxr = rxq->rx_ring;
 	int rc;
 
+	/*
+	 * Storage for the cp ring is allocated based on worst-case
+	 * usage, the actual size to be used by hw is computed here.
+	 */
+	cp_ring->ring_size = rxr->rx_ring_struct->ring_size * 2;
+
+	if (bp->eth_dev->data->scattered_rx)
+		cp_ring->ring_size *= AGG_RING_SIZE_FACTOR;
+
+	cp_ring->ring_mask = cp_ring->ring_size - 1;
+
 	rc = bnxt_alloc_cmpl_ring(bp, queue_index, cpr);
 	if (rc)
 		goto err_out;
@@ -679,6 +690,17 @@ int bnxt_alloc_hwrm_rings(struct bnxt *bp)
 		struct bnxt_ring *cp_ring = cpr->cp_ring_struct;
 		struct bnxt_rx_ring_info *rxr = rxq->rx_ring;
 
+		/*
+		 * Storage for the cp ring is allocated based on worst-case
+		 * usage, the actual size to be used by hw is computed here.
+		 */
+		cp_ring->ring_size = rxr->rx_ring_struct->ring_size * 2;
+
+		if (bp->eth_dev->data->scattered_rx)
+			cp_ring->ring_size *= AGG_RING_SIZE_FACTOR;
+
+		cp_ring->ring_mask = cp_ring->ring_size - 1;
+
 		if (bnxt_alloc_cmpl_ring(bp, i, cpr))
 			goto err_out;
 
diff --git a/drivers/net/bnxt/bnxt_rxr.c b/drivers/net/bnxt/bnxt_rxr.c
index ddb1021251..b28b7fb561 100644
--- a/drivers/net/bnxt/bnxt_rxr.c
+++ b/drivers/net/bnxt/bnxt_rxr.c
@@ -1040,12 +1040,9 @@ void bnxt_free_rx_rings(struct bnxt *bp)
 
 int bnxt_init_rx_ring_struct(struct bnxt_rx_queue *rxq, unsigned int socket_id)
 {
-	struct rte_eth_dev *eth_dev = rxq->bp->eth_dev;
-	struct rte_eth_rxmode *rxmode;
 	struct bnxt_cp_ring_info *cpr;
 	struct bnxt_rx_ring_info *rxr;
 	struct bnxt_ring *ring;
-	bool use_agg_ring;
 
 	rxq->rx_buf_size = BNXT_MAX_PKT_LEN + sizeof(struct rte_mbuf);
 
@@ -1088,19 +1085,9 @@ int bnxt_init_rx_ring_struct(struct bnxt_rx_queue *rxq, unsigned int socket_id)
 		return -ENOMEM;
 	cpr->cp_ring_struct = ring;
 
-	rxmode = &eth_dev->data->dev_conf.rxmode;
-	use_agg_ring = (rxmode->offloads & DEV_RX_OFFLOAD_SCATTER) ||
-		       (rxmode->offloads & DEV_RX_OFFLOAD_TCP_LRO) ||
-		       (rxmode->max_rx_pkt_len >
-			 (uint32_t)(rte_pktmbuf_data_room_size(rxq->mb_pool) -
-				    RTE_PKTMBUF_HEADROOM));
-
 	/* Allocate two completion slots per entry in desc ring. */
 	ring->ring_size = rxr->rx_ring_struct->ring_size * 2;
-
-	/* Allocate additional slots if aggregation ring is in use. */
-	if (use_agg_ring)
-		ring->ring_size *= AGG_RING_SIZE_FACTOR;
+	ring->ring_size *= AGG_RING_SIZE_FACTOR;
 
 	ring->ring_size = rte_align32pow2(ring->ring_size);
 	ring->ring_mask = ring->ring_size - 1;
-- 
2.29.2

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2021-02-09 10:34:57.978611773 +0000
+++ 0001-net-bnxt-fix-Rx-completion-ring-size-calculation.patch	2021-02-09 10:34:57.818582221 +0000
@@ -1 +1 @@
-From 8e18a019c1fc942321e5fe4529edfc793a4f0d2a Mon Sep 17 00:00:00 2001
+From 42f7f70176ac78335f522fcdd7b15e613bfbddd9 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 8e18a019c1fc942321e5fe4529edfc793a4f0d2a ]
+
@@ -20 +21,0 @@
-Cc: stable at dpdk.org
@@ -31 +32 @@
-index 4b76cd5591..22c880c5c3 100644
+index a4a31f224f..3aa346d45c 100644
@@ -34 +35 @@
-@@ -1143,6 +1143,9 @@ static int bnxt_scattered_rx(struct rte_eth_dev *eth_dev)
+@@ -1147,6 +1147,9 @@ static int bnxt_scattered_rx(struct rte_eth_dev *eth_dev)
@@ -44 +45 @@
-@@ -1418,11 +1421,12 @@ static int bnxt_dev_start_op(struct rte_eth_dev *eth_dev)
+@@ -1395,11 +1398,12 @@ static int bnxt_dev_start_op(struct rte_eth_dev *eth_dev)
@@ -62 +63 @@
-index 4e513244a6..ba23c1fa03 100644
+index aeb6cb6150..94cf7d3de2 100644
@@ -65 +66 @@
-@@ -583,6 +583,17 @@ int bnxt_alloc_hwrm_rx_ring(struct bnxt *bp, int queue_index)
+@@ -568,6 +568,17 @@ int bnxt_alloc_hwrm_rx_ring(struct bnxt *bp, int queue_index)
@@ -83 +84 @@
-@@ -693,6 +704,17 @@ int bnxt_alloc_hwrm_rings(struct bnxt *bp)
+@@ -679,6 +690,17 @@ int bnxt_alloc_hwrm_rings(struct bnxt *bp)
@@ -102 +103 @@
-index 8c2781c968..4674f7cea2 100644
+index ddb1021251..b28b7fb561 100644
@@ -105 +106 @@
-@@ -1116,12 +1116,9 @@ void bnxt_free_rx_rings(struct bnxt *bp)
+@@ -1040,12 +1040,9 @@ void bnxt_free_rx_rings(struct bnxt *bp)
@@ -118 +119 @@
-@@ -1164,19 +1161,9 @@ int bnxt_init_rx_ring_struct(struct bnxt_rx_queue *rxq, unsigned int socket_id)
+@@ -1088,19 +1085,9 @@ int bnxt_init_rx_ring_struct(struct bnxt_rx_queue *rxq, unsigned int socket_id)