[PATCH v5 2/3] net/i40e: implement recycle buffer mode

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

Define specific function implementation for i40e driver.
Currently, recycle buffer 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 +
 drivers/net/i40e/i40e_rxtx.c   | 159 +++++++++++++++++++++++++++++++++
 drivers/net/i40e/i40e_rxtx.h   |   4 +
 4 files changed, 166 insertions(+)

diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
index cb0070f94b..456fb256f5 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,
+	.rxq_buf_recycle_info_get     = i40e_rxq_buf_recycle_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 9b806d130e..83c5ff5859 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_rxq_buf_recycle_info_get(struct rte_eth_dev *dev, uint16_t queue_id,
+	struct rte_eth_rxq_buf_recycle_info *rxq_buf_recycle_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_rxtx.c b/drivers/net/i40e/i40e_rxtx.c
index 788ffb51c2..55c788317f 100644
--- a/drivers/net/i40e/i40e_rxtx.c
+++ b/drivers/net/i40e/i40e_rxtx.c
@@ -1536,6 +1536,134 @@ i40e_xmit_pkts_vec(void *tx_queue, struct rte_mbuf **tx_pkts,
 	return nb_tx;
 }
 
+uint16_t
+i40e_tx_buf_stash_vec(void *tx_queue,
+	struct rte_eth_rxq_buf_recycle_info *rxq_buf_recycle_info)
+{
+	struct i40e_tx_queue *txq = tx_queue;
+	struct i40e_tx_entry *txep;
+	struct rte_mbuf **rxep;
+	struct rte_mbuf *m[RTE_I40E_TX_MAX_FREE_BUF_SZ];
+	int i, j, n;
+	uint16_t avail = 0;
+	uint16_t buf_ring_size = rxq_buf_recycle_info->buf_ring_size;
+	uint16_t mask = rxq_buf_recycle_info->buf_ring_size - 1;
+	uint16_t refill_request = rxq_buf_recycle_info->refill_request;
+	uint16_t refill_head = *rxq_buf_recycle_info->refill_head;
+	uint16_t receive_tail = *rxq_buf_recycle_info->receive_tail;
+
+	/* Get available recycling Rx buffers. */
+	avail = (buf_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;
+
+	/* Buffer recycle can only support no ring buffer wraparound.
+	 * Two case for this:
+	 *
+	 * case 1: The refill head of Rx buffer ring needs to be aligned with
+	 * buffer ring size. In this case, the number of Tx freeing buffers
+	 * should be equal to refill_request.
+	 *
+	 * case 2: The refill head of Rx ring buffer does not need to be aligned
+	 * with buffer ring size. In this case, the update of refill head can not
+	 * exceed the Rx buffer ring size.
+	 */
+	if (refill_request != n ||
+		(!refill_request && (refill_head + n > buf_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 = rxq_buf_recycle_info->buf_ring;
+	rxep += refill_head;
+
+	if (txq->offloads & RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE) {
+		/* Directly put mbufs from Tx to Rx. */
+		for (i = 0; i < n; i++, rxep++, txep++)
+			*rxep = txep[0].mbuf;
+	} else {
+		for (i = 0, j = 0; i < n; i++) {
+			/* Avoid txq contains buffers from expected mempoo. */
+			if (unlikely(rxq_buf_recycle_info->mp
+						!= txep[i].mbuf->pool))
+				return 0;
+
+			m[j] = rte_pktmbuf_prefree_seg(txep[i].mbuf);
+
+			/* In case 1, each of Tx buffers should be the
+			 * last reference.
+			 */
+			if (unlikely(m[j] == NULL && refill_request))
+				return 0;
+			/* In case 2, the number of valid Tx free
+			 * buffers should be recorded.
+			 */
+			j++;
+		}
+		rte_memcpy(rxep, m, sizeof(void *) * j);
+	}
+
+	/* 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 n;
+}
+
+uint16_t
+i40e_rx_descriptors_refill_vec(void *rx_queue, uint16_t nb)
+{
+	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; 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;
+	if (rxq->rxrearm_start >= rxq->nb_rx_desc)
+		rxq->rxrearm_start = 0;
+
+	rxq->rxrearm_nb -= nb;
+
+	rx_id = (uint16_t)((rxq->rxrearm_start == 0) ?
+			(rxq->nb_rx_desc - 1) : (rxq->rxrearm_start - 1));
+
+	rte_io_wmb();
+	/* Update the tail pointer on the NIC */
+	I40E_PCI_REG_WRITE_RELAXED(rxq->qrx_tail, rx_id);
+
+	return nb;
+}
+
 /*********************************************************************
  *
  *  TX simple prep functions
@@ -3197,6 +3325,30 @@ i40e_txq_info_get(struct rte_eth_dev *dev, uint16_t queue_id,
 	qinfo->conf.offloads = txq->offloads;
 }
 
+void
+i40e_rxq_buf_recycle_info_get(struct rte_eth_dev *dev, uint16_t queue_id,
+	struct rte_eth_rxq_buf_recycle_info *rxq_buf_recycle_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];
+
+	rxq_buf_recycle_info->buf_ring = (void *)rxq->sw_ring;
+	rxq_buf_recycle_info->mp = rxq->mp;
+	rxq_buf_recycle_info->buf_ring_size = rxq->nb_rx_desc;
+	rxq_buf_recycle_info->receive_tail = &rxq->rx_tail;
+
+	if (ad->rx_vec_allowed) {
+		rxq_buf_recycle_info->refill_request = RTE_I40E_RXQ_REARM_THRESH;
+		rxq_buf_recycle_info->refill_head = &rxq->rxrearm_start;
+	} else {
+		rxq_buf_recycle_info->refill_request = rxq->rx_free_thresh;
+		rxq_buf_recycle_info->refill_head = &rxq->rx_free_trigger;
+	}
+}
+
 #ifdef RTE_ARCH_X86
 static inline bool
 get_avx_supported(bool request_avx512)
@@ -3291,6 +3443,8 @@ 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->rx_descriptors_refill =
+					i40e_rx_descriptors_refill_vec;
 			}
 		} else {
 			if (ad->rx_use_avx512) {
@@ -3309,9 +3463,12 @@ 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->rx_descriptors_refill =
+					i40e_rx_descriptors_refill_vec;
 			}
 		}
 #else /* RTE_ARCH_X86 */
+		dev->rx_descriptors_refill = i40e_rx_descriptors_refill_vec;
 		if (dev->data->scattered_rx) {
 			PMD_INIT_LOG(DEBUG,
 				     "Using Vector Scattered Rx (port %d).",
@@ -3479,6 +3636,7 @@ 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->tx_buf_stash = i40e_tx_buf_stash_vec;
 			}
 #else /* RTE_ARCH_X86 */
 			PMD_INIT_LOG(DEBUG, "Using Vector Tx (port %d).",
@@ -3488,6 +3646,7 @@ i40e_set_tx_function(struct rte_eth_dev *dev)
 		} else {
 			PMD_INIT_LOG(DEBUG, "Simple tx finally be used.");
 			dev->tx_pkt_burst = i40e_xmit_pkts_simple;
+			dev->tx_buf_stash = i40e_tx_buf_stash_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 5e6eecc501..0ad8f530f9 100644
--- a/drivers/net/i40e/i40e_rxtx.h
+++ b/drivers/net/i40e/i40e_rxtx.h
@@ -233,6 +233,10 @@ 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_tx_buf_stash_vec(void *tx_queue,
+		struct rte_eth_rxq_buf_recycle_info *rxq_buf_recycle_info);
+uint16_t i40e_rx_descriptors_refill_vec(void *rx_queue, uint16_t nb);
+
 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,
-- 
2.25.1