[dpdk-dev] [PATCH v2 4/6] net/sfc: use Tx queue max fill level calculated on init

[Andrew Rybchenko]

Prepare to support more options for number of Tx descriptors.

libefx-based datapath is updated just for completeness to
make code more readable and less error-prone.

Signed-off-by: Andrew Rybchenko <arybchenko at solarflare.com>
Reviewed-by: Andy Moreton <amoreton at solarflare.com>
---
 drivers/net/sfc/sfc_dp_tx.h   |  2 ++
 drivers/net/sfc/sfc_ef10_tx.c | 20 ++++++++------------
 drivers/net/sfc/sfc_tx.c      |  6 ++++--
 drivers/net/sfc/sfc_tx.h      |  1 +
 4 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/drivers/net/sfc/sfc_dp_tx.h b/drivers/net/sfc/sfc_dp_tx.h
index 32d7681..4485b2f 100644
--- a/drivers/net/sfc/sfc_dp_tx.h
+++ b/drivers/net/sfc/sfc_dp_tx.h
@@ -57,6 +57,8 @@ struct sfc_dp_txq {
  * readable.
  */
 struct sfc_dp_tx_qcreate_info {
+	/** Maximum number of pushed Tx descriptors */
+	unsigned int		max_fill_level;
 	/** Minimum number of unused Tx descriptors to do reap */
 	unsigned int		free_thresh;
 	/** Transmit queue configuration flags */
diff --git a/drivers/net/sfc/sfc_ef10_tx.c b/drivers/net/sfc/sfc_ef10_tx.c
index ab3334a..99fe87e 100644
--- a/drivers/net/sfc/sfc_ef10_tx.c
+++ b/drivers/net/sfc/sfc_ef10_tx.c
@@ -77,6 +77,7 @@ struct sfc_ef10_txq {
 	unsigned int			ptr_mask;
 	unsigned int			added;
 	unsigned int			completed;
+	unsigned int			max_fill_level;
 	unsigned int			free_thresh;
 	unsigned int			evq_read_ptr;
 	struct sfc_ef10_tx_sw_desc	*sw_ring;
@@ -288,7 +289,6 @@ static uint16_t
 sfc_ef10_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 {
 	struct sfc_ef10_txq * const txq = sfc_ef10_txq_by_dp_txq(tx_queue);
-	unsigned int ptr_mask;
 	unsigned int added;
 	unsigned int dma_desc_space;
 	bool reap_done;
@@ -299,16 +299,13 @@ sfc_ef10_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 		     (SFC_EF10_TXQ_NOT_RUNNING | SFC_EF10_TXQ_EXCEPTION)))
 		return 0;
 
-	ptr_mask = txq->ptr_mask;
 	added = txq->added;
-	dma_desc_space = SFC_EF10_TXQ_LIMIT(ptr_mask + 1) -
-			 (added - txq->completed);
+	dma_desc_space = txq->max_fill_level - (added - txq->completed);
 
 	reap_done = (dma_desc_space < txq->free_thresh);
 	if (reap_done) {
 		sfc_ef10_tx_reap(txq);
-		dma_desc_space = SFC_EF10_TXQ_LIMIT(ptr_mask + 1) -
-				 (added - txq->completed);
+		dma_desc_space = txq->max_fill_level - (added - txq->completed);
 	}
 
 	for (pktp = &tx_pkts[0], pktp_end = &tx_pkts[nb_pkts];
@@ -333,7 +330,7 @@ sfc_ef10_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 
 			sfc_ef10_tx_reap(txq);
 			reap_done = true;
-			dma_desc_space = SFC_EF10_TXQ_LIMIT(ptr_mask + 1) -
+			dma_desc_space = txq->max_fill_level -
 				(added - txq->completed);
 			if (sfc_ef10_tx_pkt_descs_max(m_seg) > dma_desc_space)
 				break;
@@ -343,7 +340,7 @@ sfc_ef10_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 		do {
 			rte_iova_t seg_addr = rte_mbuf_data_iova(m_seg);
 			unsigned int seg_len = rte_pktmbuf_data_len(m_seg);
-			unsigned int id = added & ptr_mask;
+			unsigned int id = added & txq->ptr_mask;
 
 			SFC_ASSERT(seg_len <= SFC_EF10_TX_DMA_DESC_LEN_MAX);
 
@@ -446,14 +443,12 @@ sfc_ef10_simple_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
 
 	ptr_mask = txq->ptr_mask;
 	added = txq->added;
-	dma_desc_space = SFC_EF10_TXQ_LIMIT(ptr_mask + 1) -
-			 (added - txq->completed);
+	dma_desc_space = txq->max_fill_level - (added - txq->completed);
 
 	reap_done = (dma_desc_space < RTE_MAX(txq->free_thresh, nb_pkts));
 	if (reap_done) {
 		sfc_ef10_simple_tx_reap(txq);
-		dma_desc_space = SFC_EF10_TXQ_LIMIT(ptr_mask + 1) -
-				 (added - txq->completed);
+		dma_desc_space = txq->max_fill_level - (added - txq->completed);
 	}
 
 	pktp_end = &tx_pkts[MIN(nb_pkts, dma_desc_space)];
@@ -532,6 +527,7 @@ sfc_ef10_tx_qcreate(uint16_t port_id, uint16_t queue_id,
 
 	txq->flags = SFC_EF10_TXQ_NOT_RUNNING;
 	txq->ptr_mask = info->txq_entries - 1;
+	txq->max_fill_level = info->max_fill_level;
 	txq->free_thresh = info->free_thresh;
 	txq->txq_hw_ring = info->txq_hw_ring;
 	txq->doorbell = (volatile uint8_t *)info->mem_bar +
diff --git a/drivers/net/sfc/sfc_tx.c b/drivers/net/sfc/sfc_tx.c
index 4d2882f..8f932b0 100644
--- a/drivers/net/sfc/sfc_tx.c
+++ b/drivers/net/sfc/sfc_tx.c
@@ -196,6 +196,7 @@ sfc_tx_qinit(struct sfc_adapter *sa, unsigned int sw_index,
 		goto fail_dma_alloc;
 
 	memset(&info, 0, sizeof(info));
+	info.max_fill_level = txq_max_fill_level;
 	info.free_thresh = txq->free_thresh;
 	info.flags = tx_conf->txq_flags;
 	info.txq_entries = txq_info->entries;
@@ -695,7 +696,7 @@ sfc_efx_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 	unsigned int pushed = added;
 	unsigned int pkts_sent = 0;
 	efx_desc_t *pend = &txq->pend_desc[0];
-	const unsigned int hard_max_fill = EFX_TXQ_LIMIT(txq->ptr_mask + 1);
+	const unsigned int hard_max_fill = txq->max_fill_level;
 	const unsigned int soft_max_fill = hard_max_fill - txq->free_thresh;
 	unsigned int fill_level = added - txq->completed;
 	boolean_t reap_done;
@@ -941,6 +942,7 @@ sfc_efx_tx_qcreate(uint16_t port_id, uint16_t queue_id,
 
 	txq->evq = ctrl_txq->evq;
 	txq->ptr_mask = info->txq_entries - 1;
+	txq->max_fill_level = info->max_fill_level;
 	txq->free_thresh = info->free_thresh;
 	txq->dma_desc_size_max = info->dma_desc_size_max;
 
@@ -1030,7 +1032,7 @@ sfc_efx_tx_qdesc_status(struct sfc_dp_txq *dp_txq, uint16_t offset)
 	if (unlikely(offset > txq->ptr_mask))
 		return -EINVAL;
 
-	if (unlikely(offset >= EFX_TXQ_LIMIT(txq->ptr_mask + 1)))
+	if (unlikely(offset >= txq->max_fill_level))
 		return RTE_ETH_TX_DESC_UNAVAIL;
 
 	/*
diff --git a/drivers/net/sfc/sfc_tx.h b/drivers/net/sfc/sfc_tx.h
index 0c1c708..2318f31 100644
--- a/drivers/net/sfc/sfc_tx.h
+++ b/drivers/net/sfc/sfc_tx.h
@@ -110,6 +110,7 @@ struct sfc_efx_txq {
 	unsigned int			added;
 	unsigned int			pending;
 	unsigned int			completed;
+	unsigned int			max_fill_level;
 	unsigned int			free_thresh;
 	uint16_t			hw_vlan_tci;
 	uint16_t			dma_desc_size_max;
-- 
2.7.4