[PATCH 3/7] net/cnxk: devarg to set force tail drop

[Rahul Bhansali]

A new devarg is added to configure force tail drop.
Also, CQ descriptors are doubled under this option.

To enable this devarg, it needs to be pass as
force_tail_drop=1 for nix device.
e.g.: 0002:02:00.0,force_tail_drop=1

Signed-off-by: Rahul Bhansali <rbhansali at marvell.com>
---
 drivers/net/cnxk/cnxk_ethdev.c         | 4 ++++
 drivers/net/cnxk/cnxk_ethdev_devargs.c | 7 ++++++-
 drivers/net/cnxk/cnxk_ethdev_ops.c     | 2 ++
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/net/cnxk/cnxk_ethdev.c b/drivers/net/cnxk/cnxk_ethdev.c
index b9a0b37425..1ba09c068b 100644
--- a/drivers/net/cnxk/cnxk_ethdev.c
+++ b/drivers/net/cnxk/cnxk_ethdev.c
@@ -708,6 +708,10 @@ cnxk_nix_rx_queue_setup(struct rte_eth_dev *eth_dev, uint16_t qid,
 	if (dev->rx_offloads & RTE_ETH_RX_OFFLOAD_SECURITY)
 		nb_desc = nix_inl_cq_sz_clamp_up(nix, lpb_pool, nb_desc);
 
+	/* Double the CQ descriptors */
+	if (nix->force_tail_drop)
+		nb_desc = 2 * RTE_MAX(nb_desc, (uint32_t)4096);
+
 	/* Setup ROC CQ */
 	cq = &dev->cqs[qid];
 	cq->qid = qid;
diff --git a/drivers/net/cnxk/cnxk_ethdev_devargs.c b/drivers/net/cnxk/cnxk_ethdev_devargs.c
index aa2fe7dfe1..7013849ad3 100644
--- a/drivers/net/cnxk/cnxk_ethdev_devargs.c
+++ b/drivers/net/cnxk/cnxk_ethdev_devargs.c
@@ -281,6 +281,7 @@ parse_val_u16(const char *key, const char *value, void *extra_args)
 #define CNXK_NIX_RX_INJ_ENABLE	"rx_inj_ena"
 #define CNXK_CUSTOM_META_AURA_DIS "custom_meta_aura_dis"
 #define CNXK_CUSTOM_INB_SA	  "custom_inb_sa"
+#define CNXK_FORCE_TAIL_DROP	  "force_tail_drop"
 
 int
 cnxk_ethdev_parse_devargs(struct rte_devargs *devargs, struct cnxk_eth_dev *dev)
@@ -301,6 +302,7 @@ cnxk_ethdev_parse_devargs(struct rte_devargs *devargs, struct cnxk_eth_dev *dev)
 	uint16_t outb_nb_desc = 8200;
 	struct sdp_channel sdp_chan;
 	uint16_t rss_tag_as_xor = 0;
+	uint8_t force_tail_drop = 0;
 	uint16_t scalar_enable = 0;
 	uint16_t tx_compl_ena = 0;
 	uint16_t custom_sa_act = 0;
@@ -364,6 +366,7 @@ cnxk_ethdev_parse_devargs(struct rte_devargs *devargs, struct cnxk_eth_dev *dev)
 	rte_kvargs_process(kvlist, CNXK_CUSTOM_META_AURA_DIS, &parse_flag,
 			   &custom_meta_aura_dis);
 	rte_kvargs_process(kvlist, CNXK_CUSTOM_INB_SA, &parse_flag, &custom_inb_sa);
+	rte_kvargs_process(kvlist, CNXK_FORCE_TAIL_DROP, &parse_flag, &force_tail_drop);
 	rte_kvargs_free(kvlist);
 
 null_devargs:
@@ -405,6 +408,7 @@ cnxk_ethdev_parse_devargs(struct rte_devargs *devargs, struct cnxk_eth_dev *dev)
 	dev->npc.flow_age.aging_poll_freq = aging_thread_poll_freq;
 	if (roc_feature_nix_has_rx_inject())
 		dev->nix.rx_inj_ena = rx_inj_ena;
+	dev->nix.force_tail_drop = force_tail_drop;
 	return 0;
 exit:
 	return -EINVAL;
@@ -429,4 +433,5 @@ RTE_PMD_REGISTER_PARAM_STRING(net_cnxk,
 			      CNXK_SQB_SLACK "=<12-512>"
 			      CNXK_FLOW_AGING_POLL_FREQ "=<10-65535>"
 			      CNXK_NIX_RX_INJ_ENABLE "=1"
-			      CNXK_CUSTOM_META_AURA_DIS "=1");
+			      CNXK_CUSTOM_META_AURA_DIS "=1"
+			      CNXK_FORCE_TAIL_DROP "=1");
diff --git a/drivers/net/cnxk/cnxk_ethdev_ops.c b/drivers/net/cnxk/cnxk_ethdev_ops.c
index 9970c5ff5c..7c8a4d8416 100644
--- a/drivers/net/cnxk/cnxk_ethdev_ops.c
+++ b/drivers/net/cnxk/cnxk_ethdev_ops.c
@@ -313,6 +313,7 @@ cnxk_nix_flow_ctrl_set(struct rte_eth_dev *eth_dev,
 		fc_cfg.rq_cfg.pool = rq->aura_handle;
 		fc_cfg.rq_cfg.spb_pool = rq->spb_aura_handle;
 		fc_cfg.rq_cfg.cq_drop = cq->drop_thresh;
+		fc_cfg.rq_cfg.cq_bp = cq->bp_thresh;
 		fc_cfg.rq_cfg.pool_drop_pct = ROC_NIX_AURA_THRESH;
 
 		rc = roc_nix_fc_config_set(nix, &fc_cfg);
@@ -1239,6 +1240,7 @@ nix_priority_flow_ctrl_rq_conf(struct rte_eth_dev *eth_dev, uint16_t qid,
 	fc_cfg.rq_cfg.pool = rxq->qconf.mp->pool_id;
 	fc_cfg.rq_cfg.spb_pool = rq->spb_aura_handle;
 	fc_cfg.rq_cfg.cq_drop = cq->drop_thresh;
+	fc_cfg.rq_cfg.cq_bp = cq->bp_thresh;
 	fc_cfg.rq_cfg.pool_drop_pct = ROC_NIX_AURA_THRESH;
 	rc = roc_nix_fc_config_set(nix, &fc_cfg);
 	if (rc)
-- 
2.25.1