[PATCH v10 2/4] net/i40e: implement mbufs recycle mode

[Feifei Wang <feifei.wang2@arm.com>]

Define specific function implementation for i40e driver.
Currently, mbufs recycle mode can support 128bit
vector path and avx2 path. And can be enabled both in
fast free and no fast free mode.

Suggested-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
---
 drivers/net/i40e/i40e_ethdev.c                |   1 +
 drivers/net/i40e/i40e_ethdev.h                |   2 +
 .../net/i40e/i40e_recycle_mbufs_vec_common.c  | 147 ++++++++++++++++++
 drivers/net/i40e/i40e_rxtx.c                  |  32 ++++
 drivers/net/i40e/i40e_rxtx.h                  |   4 +
 drivers/net/i40e/meson.build                  |   1 +
 6 files changed, 187 insertions(+)
 create mode 100644 drivers/net/i40e/i40e_recycle_mbufs_vec_common.c

diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
index 8271bbb394..50ba9aac94 100644
--- a/drivers/net/i40e/i40e_ethdev.c
+++ b/drivers/net/i40e/i40e_ethdev.c
@@ -496,6 +496,7 @@ static const struct eth_dev_ops i40e_eth_dev_ops = {
 	.flow_ops_get                 = i40e_dev_flow_ops_get,
 	.rxq_info_get                 = i40e_rxq_info_get,
 	.txq_info_get                 = i40e_txq_info_get,
+	.recycle_rxq_info_get         = i40e_recycle_rxq_info_get,
 	.rx_burst_mode_get            = i40e_rx_burst_mode_get,
 	.tx_burst_mode_get            = i40e_tx_burst_mode_get,
 	.timesync_enable              = i40e_timesync_enable,
diff --git a/drivers/net/i40e/i40e_ethdev.h b/drivers/net/i40e/i40e_ethdev.h
index 6f65d5e0ac..af758798e1 100644
--- a/drivers/net/i40e/i40e_ethdev.h
+++ b/drivers/net/i40e/i40e_ethdev.h
@@ -1355,6 +1355,8 @@ void i40e_rxq_info_get(struct rte_eth_dev *dev, uint16_t queue_id,
 	struct rte_eth_rxq_info *qinfo);
 void i40e_txq_info_get(struct rte_eth_dev *dev, uint16_t queue_id,
 	struct rte_eth_txq_info *qinfo);
+void i40e_recycle_rxq_info_get(struct rte_eth_dev *dev, uint16_t queue_id,
+	struct rte_eth_recycle_rxq_info *recycle_rxq_info);
 int i40e_rx_burst_mode_get(struct rte_eth_dev *dev, uint16_t queue_id,
 			   struct rte_eth_burst_mode *mode);
 int i40e_tx_burst_mode_get(struct rte_eth_dev *dev, uint16_t queue_id,
diff --git a/drivers/net/i40e/i40e_recycle_mbufs_vec_common.c b/drivers/net/i40e/i40e_recycle_mbufs_vec_common.c
new file mode 100644
index 0000000000..5663ecccde
--- /dev/null
+++ b/drivers/net/i40e/i40e_recycle_mbufs_vec_common.c
@@ -0,0 +1,147 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright (c) 2023 Arm Limited.
+ */
+
+#include <stdint.h>
+#include <ethdev_driver.h>
+
+#include "base/i40e_prototype.h"
+#include "base/i40e_type.h"
+#include "i40e_ethdev.h"
+#include "i40e_rxtx.h"
+
+#pragma GCC diagnostic ignored "-Wcast-qual"
+
+void
+i40e_recycle_rx_descriptors_refill_vec(void *rx_queue, uint16_t nb_mbufs)
+{
+	struct i40e_rx_queue *rxq = rx_queue;
+	struct i40e_rx_entry *rxep;
+	volatile union i40e_rx_desc *rxdp;
+	uint16_t rx_id;
+	uint64_t paddr;
+	uint64_t dma_addr;
+	uint16_t i;
+
+	rxdp = rxq->rx_ring + rxq->rxrearm_start;
+	rxep = &rxq->sw_ring[rxq->rxrearm_start];
+
+	for (i = 0; i < nb_mbufs; i++) {
+		/* Initialize rxdp descs. */
+		paddr = (rxep[i].mbuf)->buf_iova + RTE_PKTMBUF_HEADROOM;
+		dma_addr = rte_cpu_to_le_64(paddr);
+		/* flush desc with pa dma_addr */
+		rxdp[i].read.hdr_addr = 0;
+		rxdp[i].read.pkt_addr = dma_addr;
+	}
+
+	/* Update the descriptor initializer index */
+	rxq->rxrearm_start += nb_mbufs;
+	rx_id = rxq->rxrearm_start - 1;
+
+	if (unlikely(rxq->rxrearm_start >= rxq->nb_rx_desc)) {
+		rxq->rxrearm_start = 0;
+		rx_id = rxq->nb_rx_desc - 1;
+	}
+
+	rxq->rxrearm_nb -= nb_mbufs;
+
+	rte_io_wmb();
+	/* Update the tail pointer on the NIC */
+	I40E_PCI_REG_WRITE_RELAXED(rxq->qrx_tail, rx_id);
+}
+
+uint16_t
+i40e_recycle_tx_mbufs_reuse_vec(void *tx_queue,
+	struct rte_eth_recycle_rxq_info *recycle_rxq_info)
+{
+	struct i40e_tx_queue *txq = tx_queue;
+	struct i40e_tx_entry *txep;
+	struct rte_mbuf **rxep;
+	int i, n;
+	uint16_t nb_recycle_mbufs;
+	uint16_t avail = 0;
+	uint16_t mbuf_ring_size = recycle_rxq_info->mbuf_ring_size;
+	uint16_t mask = recycle_rxq_info->mbuf_ring_size - 1;
+	uint16_t refill_requirement = recycle_rxq_info->refill_requirement;
+	uint16_t refill_head = *recycle_rxq_info->refill_head;
+	uint16_t receive_tail = *recycle_rxq_info->receive_tail;
+
+	/* Get available recycling Rx buffers. */
+	avail = (mbuf_ring_size - (refill_head - receive_tail)) & mask;
+
+	/* Check Tx free thresh and Rx available space. */
+	if (txq->nb_tx_free > txq->tx_free_thresh || avail <= txq->tx_rs_thresh)
+		return 0;
+
+	/* check DD bits on threshold descriptor */
+	if ((txq->tx_ring[txq->tx_next_dd].cmd_type_offset_bsz &
+				rte_cpu_to_le_64(I40E_TXD_QW1_DTYPE_MASK)) !=
+			rte_cpu_to_le_64(I40E_TX_DESC_DTYPE_DESC_DONE))
+		return 0;
+
+	n = txq->tx_rs_thresh;
+	nb_recycle_mbufs = n;
+
+	/* Mbufs recycle mode can only support no ring buffer wrapping around.
+	 * Two case for this:
+	 *
+	 * case 1: The refill head of Rx buffer ring needs to be aligned with
+	 * mbuf ring size. In this case, the number of Tx freeing buffers
+	 * should be equal to refill_requirement.
+	 *
+	 * case 2: The refill head of Rx ring buffer does not need to be aligned
+	 * with mbuf ring size. In this case, the update of refill head can not
+	 * exceed the Rx mbuf ring size.
+	 */
+	if (refill_requirement != n ||
+		(!refill_requirement && (refill_head + n > mbuf_ring_size)))
+		return 0;
+
+	/* First buffer to free from S/W ring is at index
+	 * tx_next_dd - (tx_rs_thresh-1).
+	 */
+	txep = &txq->sw_ring[txq->tx_next_dd - (n - 1)];
+	rxep = recycle_rxq_info->mbuf_ring;
+	rxep += refill_head;
+
+	if (txq->offloads & RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE) {
+		/* Avoid txq contains buffers from unexpected mempool. */
+		if (unlikely(recycle_rxq_info->mp
+					!= txep[0].mbuf->pool))
+			return 0;
+
+		/* Directly put mbufs from Tx to Rx. */
+		for (i = 0; i < n; i++)
+			rxep[i] = txep[i].mbuf;
+	} else {
+		for (i = 0; i < n; i++) {
+			rxep[i] = rte_pktmbuf_prefree_seg(txep[i].mbuf);
+
+			/* If Tx buffers are not the last reference or from
+			 * unexpected mempool, previous copied buffers are
+			 * considered as invalid.
+			 */
+			if (unlikely((rxep[i] == NULL && refill_requirement) ||
+					recycle_rxq_info->mp != txep[i].mbuf->pool))
+				nb_recycle_mbufs = 0;
+		}
+		/* If Tx buffers are not the last reference or
+		 * from unexpected mempool, all recycled buffers
+		 * are put into mempool.
+		 */
+		if (nb_recycle_mbufs == 0)
+			for (i = 0; i < n; i++) {
+				if (rxep[i] != NULL)
+					rte_mempool_put(rxep[i]->pool, rxep[i]);
+			}
+	}
+
+	/* Update counters for Tx. */
+	txq->nb_tx_free = (uint16_t)(txq->nb_tx_free + txq->tx_rs_thresh);
+	txq->tx_next_dd = (uint16_t)(txq->tx_next_dd + txq->tx_rs_thresh);
+	if (txq->tx_next_dd >= txq->nb_tx_desc)
+		txq->tx_next_dd = (uint16_t)(txq->tx_rs_thresh - 1);
+
+	return nb_recycle_mbufs;
+}
diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c
index b4f65b58fa..a9c9eb331c 100644
--- a/drivers/net/i40e/i40e_rxtx.c
+++ b/drivers/net/i40e/i40e_rxtx.c
@@ -3199,6 +3199,30 @@ i40e_txq_info_get(struct rte_eth_dev *dev, uint16_t queue_id,
 	qinfo->conf.offloads = txq->offloads;
 }
 
+void
+i40e_recycle_rxq_info_get(struct rte_eth_dev *dev, uint16_t queue_id,
+	struct rte_eth_recycle_rxq_info *recycle_rxq_info)
+{
+	struct i40e_rx_queue *rxq;
+	struct i40e_adapter *ad =
+		I40E_DEV_PRIVATE_TO_ADAPTER(dev->data->dev_private);
+
+	rxq = dev->data->rx_queues[queue_id];
+
+	recycle_rxq_info->mbuf_ring = (void *)rxq->sw_ring;
+	recycle_rxq_info->mp = rxq->mp;
+	recycle_rxq_info->mbuf_ring_size = rxq->nb_rx_desc;
+	recycle_rxq_info->receive_tail = &rxq->rx_tail;
+
+	if (ad->rx_vec_allowed) {
+		recycle_rxq_info->refill_requirement = RTE_I40E_RXQ_REARM_THRESH;
+		recycle_rxq_info->refill_head = &rxq->rxrearm_start;
+	} else {
+		recycle_rxq_info->refill_requirement = rxq->rx_free_thresh;
+		recycle_rxq_info->refill_head = &rxq->rx_free_trigger;
+	}
+}
+
 #ifdef RTE_ARCH_X86
 static inline bool
 get_avx_supported(bool request_avx512)
@@ -3293,6 +3317,8 @@ i40e_set_rx_function(struct rte_eth_dev *dev)
 				dev->rx_pkt_burst = ad->rx_use_avx2 ?
 					i40e_recv_scattered_pkts_vec_avx2 :
 					i40e_recv_scattered_pkts_vec;
+				dev->recycle_rx_descriptors_refill =
+					i40e_recycle_rx_descriptors_refill_vec;
 			}
 		} else {
 			if (ad->rx_use_avx512) {
@@ -3311,9 +3337,12 @@ i40e_set_rx_function(struct rte_eth_dev *dev)
 				dev->rx_pkt_burst = ad->rx_use_avx2 ?
 					i40e_recv_pkts_vec_avx2 :
 					i40e_recv_pkts_vec;
+				dev->recycle_rx_descriptors_refill =
+					i40e_recycle_rx_descriptors_refill_vec;
 			}
 		}
 #else /* RTE_ARCH_X86 */
+		dev->recycle_rx_descriptors_refill = i40e_recycle_rx_descriptors_refill_vec;
 		if (dev->data->scattered_rx) {
 			PMD_INIT_LOG(DEBUG,
 				     "Using Vector Scattered Rx (port %d).",
@@ -3481,15 +3510,18 @@ i40e_set_tx_function(struct rte_eth_dev *dev)
 				dev->tx_pkt_burst = ad->tx_use_avx2 ?
 						    i40e_xmit_pkts_vec_avx2 :
 						    i40e_xmit_pkts_vec;
+				dev->recycle_tx_mbufs_reuse = i40e_recycle_tx_mbufs_reuse_vec;
 			}
 #else /* RTE_ARCH_X86 */
 			PMD_INIT_LOG(DEBUG, "Using Vector Tx (port %d).",
 				     dev->data->port_id);
 			dev->tx_pkt_burst = i40e_xmit_pkts_vec;
+			dev->recycle_tx_mbufs_reuse = i40e_recycle_tx_mbufs_reuse_vec;
 #endif /* RTE_ARCH_X86 */
 		} else {
 			PMD_INIT_LOG(DEBUG, "Simple tx finally be used.");
 			dev->tx_pkt_burst = i40e_xmit_pkts_simple;
+			dev->recycle_tx_mbufs_reuse = i40e_recycle_tx_mbufs_reuse_vec;
 		}
 		dev->tx_pkt_prepare = i40e_simple_prep_pkts;
 	} else {
diff --git a/drivers/net/i40e/i40e_rxtx.h b/drivers/net/i40e/i40e_rxtx.h
index a8686224e5..b191f23e1f 100644
--- a/drivers/net/i40e/i40e_rxtx.h
+++ b/drivers/net/i40e/i40e_rxtx.h
@@ -236,6 +236,10 @@ uint32_t i40e_dev_rx_queue_count(void *rx_queue);
 int i40e_dev_rx_descriptor_status(void *rx_queue, uint16_t offset);
 int i40e_dev_tx_descriptor_status(void *tx_queue, uint16_t offset);
 
+uint16_t i40e_recycle_tx_mbufs_reuse_vec(void *tx_queue,
+		struct rte_eth_recycle_rxq_info *recycle_rxq_info);
+void i40e_recycle_rx_descriptors_refill_vec(void *rx_queue, uint16_t nb_mbufs);
+
 uint16_t i40e_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
 			    uint16_t nb_pkts);
 uint16_t i40e_recv_scattered_pkts_vec(void *rx_queue,
diff --git a/drivers/net/i40e/meson.build b/drivers/net/i40e/meson.build
index 8e53b87a65..3b1a233c84 100644
--- a/drivers/net/i40e/meson.build
+++ b/drivers/net/i40e/meson.build
@@ -34,6 +34,7 @@ sources = files(
         'i40e_tm.c',
         'i40e_hash.c',
         'i40e_vf_representor.c',
+	'i40e_recycle_mbufs_vec_common.c',
         'rte_pmd_i40e.c',
 )
 
-- 
2.25.1