[dpdk-dev] [PATCH 05/12] net/bnxt: improve support for small ring sizes

[Lance Richardson]

Improve support for small ring sizes:
   - Ensure that transmit free threshold is no more than 1/4 ring size.
   - Ensure that receive free threshold is no more than 1/4 ring size.
   - Validate requested ring sizes against minimum supported size.
   - Use rxq receive free threshold instead of fixed maximum burst
     size to trigger bulk receive buffer allocation.

Reviewed-by: Ajit Kumar Khaparde <ajit.khaparde at broadcom.com>
Signed-off-by: Lance Richardson <lance.richardson at broadcom.com>
---
 drivers/net/bnxt/bnxt_rxq.c             |  6 +++--
 drivers/net/bnxt/bnxt_rxtx_vec_common.h | 10 +++++----
 drivers/net/bnxt/bnxt_rxtx_vec_neon.c   | 29 +++++++++++++------------
 drivers/net/bnxt/bnxt_rxtx_vec_sse.c    | 29 +++++++++++++------------
 drivers/net/bnxt/bnxt_txq.c             |  7 ++++--
 5 files changed, 45 insertions(+), 36 deletions(-)

diff --git a/drivers/net/bnxt/bnxt_rxq.c b/drivers/net/bnxt/bnxt_rxq.c
index db9aa1f3ed..4ef3b5cb5c 100644
--- a/drivers/net/bnxt/bnxt_rxq.c
+++ b/drivers/net/bnxt/bnxt_rxq.c
@@ -14,6 +14,7 @@
 #include "bnxt_rxq.h"
 #include "bnxt_rxr.h"
 #include "bnxt_vnic.h"
+#include "bnxt_rxtx_vec_common.h"
 #include "hsi_struct_def_dpdk.h"
 
 /*
@@ -305,7 +306,7 @@ int bnxt_rx_queue_setup_op(struct rte_eth_dev *eth_dev,
 		return -EINVAL;
 	}
 
-	if (!nb_desc || nb_desc > MAX_RX_DESC_CNT) {
+	if (nb_desc < BNXT_MIN_RING_DESC || nb_desc > MAX_RX_DESC_CNT) {
 		PMD_DRV_LOG(ERR, "nb_desc %d is invalid\n", nb_desc);
 		rc = -EINVAL;
 		goto out;
@@ -326,7 +327,8 @@ int bnxt_rx_queue_setup_op(struct rte_eth_dev *eth_dev,
 	rxq->bp = bp;
 	rxq->mb_pool = mp;
 	rxq->nb_rx_desc = nb_desc;
-	rxq->rx_free_thresh = rx_conf->rx_free_thresh;
+	rxq->rx_free_thresh =
+		RTE_MIN(rte_align32pow2(nb_desc) / 4, RTE_BNXT_MAX_RX_BURST);
 
 	PMD_DRV_LOG(DEBUG, "RX Buf MTU %d\n", eth_dev->data->mtu);
 
diff --git a/drivers/net/bnxt/bnxt_rxtx_vec_common.h b/drivers/net/bnxt/bnxt_rxtx_vec_common.h
index 3da3c48f4e..2f28759d06 100644
--- a/drivers/net/bnxt/bnxt_rxtx_vec_common.h
+++ b/drivers/net/bnxt/bnxt_rxtx_vec_common.h
@@ -5,11 +5,13 @@
 
 #ifndef _BNXT_RXTX_VEC_COMMON_H_
 #define _BNXT_RXTX_VEC_COMMON_H_
+#include "hsi_struct_def_dpdk.h"
+#include "bnxt_rxq.h"
+#include "bnxt_rxr.h"
 
-#define RTE_BNXT_MAX_RX_BURST		32
-#define RTE_BNXT_MAX_TX_BURST		32
-#define RTE_BNXT_RXQ_REARM_THRESH	32
-#define RTE_BNXT_DESCS_PER_LOOP		4
+#define RTE_BNXT_MAX_RX_BURST		32U
+#define RTE_BNXT_MAX_TX_BURST		32U
+#define RTE_BNXT_DESCS_PER_LOOP		4U
 
 #define TX_BD_FLAGS_CMPL ((1 << TX_BD_LONG_FLAGS_BD_CNT_SFT) | \
 			  TX_BD_SHORT_FLAGS_COAL_NOW | \
diff --git a/drivers/net/bnxt/bnxt_rxtx_vec_neon.c b/drivers/net/bnxt/bnxt_rxtx_vec_neon.c
index a212d46cbe..7f3eabcda1 100644
--- a/drivers/net/bnxt/bnxt_rxtx_vec_neon.c
+++ b/drivers/net/bnxt/bnxt_rxtx_vec_neon.c
@@ -13,9 +13,6 @@
 #include "bnxt.h"
 #include "bnxt_cpr.h"
 #include "bnxt_ring.h"
-#include "bnxt_rxr.h"
-#include "bnxt_rxq.h"
-#include "hsi_struct_def_dpdk.h"
 #include "bnxt_rxtx_vec_common.h"
 
 #include "bnxt_txq.h"
@@ -31,23 +28,27 @@ bnxt_rxq_rearm(struct bnxt_rx_queue *rxq, struct bnxt_rx_ring_info *rxr)
 	struct rx_prod_pkt_bd *rxbds = &rxr->rx_desc_ring[rxq->rxrearm_start];
 	struct rte_mbuf **rx_bufs = &rxr->rx_buf_ring[rxq->rxrearm_start];
 	struct rte_mbuf *mb0, *mb1;
-	int i;
+	int nb, i;
 
 	const uint64x2_t hdr_room = {0, RTE_PKTMBUF_HEADROOM};
 	const uint64x2_t addrmask = {0, UINT64_MAX};
 
-	/* Pull RTE_BNXT_RXQ_REARM_THRESH more mbufs into the software ring */
-	if (rte_mempool_get_bulk(rxq->mb_pool,
-				 (void *)rx_bufs,
-				 RTE_BNXT_RXQ_REARM_THRESH) < 0) {
-		rte_eth_devices[rxq->port_id].data->rx_mbuf_alloc_failed +=
-			RTE_BNXT_RXQ_REARM_THRESH;
+	/*
+	 * Number of mbufs to allocate must be a multiple of two. The
+	 * allocation must not go past the end of the ring.
+	 */
+	nb = RTE_MIN(rxq->rxrearm_nb & ~0x1,
+		     rxq->nb_rx_desc - rxq->rxrearm_start);
+
+	/* Allocate new mbufs into the software ring */
+	if (rte_mempool_get_bulk(rxq->mb_pool, (void *)rx_bufs, nb) < 0) {
+		rte_eth_devices[rxq->port_id].data->rx_mbuf_alloc_failed += nb;
 
 		return;
 	}
 
 	/* Initialize the mbufs in vector, process 2 mbufs in one loop */
-	for (i = 0; i < RTE_BNXT_RXQ_REARM_THRESH; i += 2, rx_bufs += 2) {
+	for (i = 0; i < nb; i += 2, rx_bufs += 2) {
 		uint64x2_t buf_addr0, buf_addr1;
 		uint64x2_t rxbd0, rxbd1;
 
@@ -83,12 +84,12 @@ bnxt_rxq_rearm(struct bnxt_rx_queue *rxq, struct bnxt_rx_ring_info *rxr)
 		vst1q_u64((uint64_t *)(rxbds++), rxbd1);
 	}
 
-	rxq->rxrearm_start += RTE_BNXT_RXQ_REARM_THRESH;
+	rxq->rxrearm_start += nb;
 	bnxt_db_write(&rxr->rx_db, rxq->rxrearm_start - 1);
 	if (rxq->rxrearm_start >= rxq->nb_rx_desc)
 		rxq->rxrearm_start = 0;
 
-	rxq->rxrearm_nb -= RTE_BNXT_RXQ_REARM_THRESH;
+	rxq->rxrearm_nb -= nb;
 }
 
 static uint32_t
@@ -220,7 +221,7 @@ bnxt_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
 	if (unlikely(!rxq->rx_started))
 		return 0;
 
-	if (rxq->rxrearm_nb >= RTE_BNXT_RXQ_REARM_THRESH)
+	if (rxq->rxrearm_nb >= rxq->rx_free_thresh)
 		bnxt_rxq_rearm(rxq, rxr);
 
 	/* Return no more than RTE_BNXT_MAX_RX_BURST per call. */
diff --git a/drivers/net/bnxt/bnxt_rxtx_vec_sse.c b/drivers/net/bnxt/bnxt_rxtx_vec_sse.c
index c00d7f6807..eced74e4e3 100644
--- a/drivers/net/bnxt/bnxt_rxtx_vec_sse.c
+++ b/drivers/net/bnxt/bnxt_rxtx_vec_sse.c
@@ -17,9 +17,6 @@
 #include "bnxt.h"
 #include "bnxt_cpr.h"
 #include "bnxt_ring.h"
-#include "bnxt_rxr.h"
-#include "bnxt_rxq.h"
-#include "hsi_struct_def_dpdk.h"
 #include "bnxt_rxtx_vec_common.h"
 
 #include "bnxt_txq.h"
@@ -35,23 +32,27 @@ bnxt_rxq_rearm(struct bnxt_rx_queue *rxq, struct bnxt_rx_ring_info *rxr)
 	struct rx_prod_pkt_bd *rxbds = &rxr->rx_desc_ring[rxq->rxrearm_start];
 	struct rte_mbuf **rx_bufs = &rxr->rx_buf_ring[rxq->rxrearm_start];
 	struct rte_mbuf *mb0, *mb1;
-	int i;
+	int nb, i;
 
 	const __m128i hdr_room = _mm_set_epi64x(RTE_PKTMBUF_HEADROOM, 0);
 	const __m128i addrmask = _mm_set_epi64x(UINT64_MAX, 0);
 
-	/* Pull RTE_BNXT_RXQ_REARM_THRESH more mbufs into the software ring */
-	if (rte_mempool_get_bulk(rxq->mb_pool,
-				 (void *)rx_bufs,
-				 RTE_BNXT_RXQ_REARM_THRESH) < 0) {
-		rte_eth_devices[rxq->port_id].data->rx_mbuf_alloc_failed +=
-			RTE_BNXT_RXQ_REARM_THRESH;
+	/*
+	 * Number of mbufs to allocate must be a multiple of two. The
+	 * allocation must not go past the end of the ring.
+	 */
+	nb = RTE_MIN(rxq->rxrearm_nb & ~0x1,
+		     rxq->nb_rx_desc - rxq->rxrearm_start);
+
+	/* Allocate new mbufs into the software ring */
+	if (rte_mempool_get_bulk(rxq->mb_pool, (void *)rx_bufs, nb) < 0) {
+		rte_eth_devices[rxq->port_id].data->rx_mbuf_alloc_failed += nb;
 
 		return;
 	}
 
 	/* Initialize the mbufs in vector, process 2 mbufs in one loop */
-	for (i = 0; i < RTE_BNXT_RXQ_REARM_THRESH; i += 2, rx_bufs += 2) {
+	for (i = 0; i < nb; i += 2, rx_bufs += 2) {
 		__m128i buf_addr0, buf_addr1;
 		__m128i rxbd0, rxbd1;
 
@@ -87,12 +88,12 @@ bnxt_rxq_rearm(struct bnxt_rx_queue *rxq, struct bnxt_rx_ring_info *rxr)
 		_mm_store_si128((__m128i *)(rxbds++), rxbd1);
 	}
 
-	rxq->rxrearm_start += RTE_BNXT_RXQ_REARM_THRESH;
+	rxq->rxrearm_start += nb;
 	bnxt_db_write(&rxr->rx_db, rxq->rxrearm_start - 1);
 	if (rxq->rxrearm_start >= rxq->nb_rx_desc)
 		rxq->rxrearm_start = 0;
 
-	rxq->rxrearm_nb -= RTE_BNXT_RXQ_REARM_THRESH;
+	rxq->rxrearm_nb -= nb;
 }
 
 static uint32_t
@@ -223,7 +224,7 @@ bnxt_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
 	if (unlikely(!rxq->rx_started))
 		return 0;
 
-	if (rxq->rxrearm_nb >= RTE_BNXT_RXQ_REARM_THRESH)
+	if (rxq->rxrearm_nb >= rxq->rx_free_thresh)
 		bnxt_rxq_rearm(rxq, rxr);
 
 	/* Return no more than RTE_BNXT_MAX_RX_BURST per call. */
diff --git a/drivers/net/bnxt/bnxt_txq.c b/drivers/net/bnxt/bnxt_txq.c
index 2d7645eeb0..42930abbf5 100644
--- a/drivers/net/bnxt/bnxt_txq.c
+++ b/drivers/net/bnxt/bnxt_txq.c
@@ -11,6 +11,7 @@
 #include "bnxt_ring.h"
 #include "bnxt_txq.h"
 #include "bnxt_txr.h"
+#include "bnxt_rxtx_vec_common.h"
 
 /*
  * TX Queues
@@ -97,7 +98,7 @@ int bnxt_tx_queue_setup_op(struct rte_eth_dev *eth_dev,
 		return -EINVAL;
 	}
 
-	if (!nb_desc || nb_desc > MAX_TX_DESC_CNT) {
+	if (nb_desc < BNXT_MIN_RING_DESC || nb_desc > MAX_TX_DESC_CNT) {
 		PMD_DRV_LOG(ERR, "nb_desc %d is invalid", nb_desc);
 		rc = -EINVAL;
 		goto out;
@@ -129,7 +130,9 @@ int bnxt_tx_queue_setup_op(struct rte_eth_dev *eth_dev,
 	}
 	txq->bp = bp;
 	txq->nb_tx_desc = nb_desc;
-	txq->tx_free_thresh = tx_conf->tx_free_thresh;
+	txq->tx_free_thresh =
+		RTE_MIN(rte_align32pow2(nb_desc) / 4, RTE_BNXT_MAX_TX_BURST);
+
 	txq->tx_deferred_start = tx_conf->tx_deferred_start;
 
 	rc = bnxt_init_tx_ring_struct(txq, socket_id);
-- 
2.25.1