[dpdk-dev] [PATCH 5/6] net/sfc: support more options for a number of Rx descriptors

[Andrew Rybchenko <arybchenko@solarflare.com>]

The number of Rx descriptors is not used as HW Rx ring size any more.
It simply defines maximum fill level.

Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
Reviewed-by: Andy Moreton <amoreton@solarflare.com>
---
 drivers/net/sfc/sfc_dp_rx.h   |  8 ++++++++
 drivers/net/sfc/sfc_ef10_rx.c | 30 +++++++++++++++++++++++++++---
 drivers/net/sfc/sfc_ethdev.c  |  4 ++++
 drivers/net/sfc/sfc_rx.c      |  4 ++++
 4 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/drivers/net/sfc/sfc_dp_rx.h b/drivers/net/sfc/sfc_dp_rx.h
index f62d79a..367477a 100644
--- a/drivers/net/sfc/sfc_dp_rx.h
+++ b/drivers/net/sfc/sfc_dp_rx.h
@@ -103,6 +103,13 @@ struct sfc_dp_rx_qcreate_info {
 };
 
 /**
+ * Get Rx datapath specific device info.
+ *
+ * @param dev_info		Device info to be adjusted
+ */
+typedef void (sfc_dp_rx_get_dev_info_t)(struct rte_eth_dev_info *dev_info);
+
+/**
  * Get size of receive and event queue rings by the number of Rx
  * descriptors.
  *
@@ -184,6 +191,7 @@ struct sfc_dp_rx {
 	unsigned int				features;
 #define SFC_DP_RX_FEAT_SCATTER			0x1
 #define SFC_DP_RX_FEAT_MULTI_PROCESS		0x2
+	sfc_dp_rx_get_dev_info_t		*get_dev_info;
 	sfc_dp_rx_qsize_up_rings_t		*qsize_up_rings;
 	sfc_dp_rx_qcreate_t			*qcreate;
 	sfc_dp_rx_qdestroy_t			*qdestroy;
diff --git a/drivers/net/sfc/sfc_ef10_rx.c b/drivers/net/sfc/sfc_ef10_rx.c
index fc89078..8516e25 100644
--- a/drivers/net/sfc/sfc_ef10_rx.c
+++ b/drivers/net/sfc/sfc_ef10_rx.c
@@ -553,6 +553,19 @@ sfc_ef10_rx_qdesc_status(__rte_unused struct sfc_dp_rxq *dp_rxq,
 }
 
 
+static sfc_dp_rx_get_dev_info_t sfc_ef10_rx_get_dev_info;
+static void
+sfc_ef10_rx_get_dev_info(struct rte_eth_dev_info *dev_info)
+{
+	/*
+	 * Number of descriptors just defines maximum number of pushed
+	 * descriptors (fill level).
+	 */
+	dev_info->rx_desc_lim.nb_min = SFC_RX_REFILL_BULK;
+	dev_info->rx_desc_lim.nb_align = SFC_RX_REFILL_BULK;
+}
+
+
 static sfc_dp_rx_qsize_up_rings_t sfc_ef10_rx_qsize_up_rings;
 static int
 sfc_ef10_rx_qsize_up_rings(uint16_t nb_rx_desc,
@@ -560,9 +573,19 @@ sfc_ef10_rx_qsize_up_rings(uint16_t nb_rx_desc,
 			   unsigned int *evq_entries,
 			   unsigned int *rxq_max_fill_level)
 {
-	*rxq_entries = nb_rx_desc;
-	*evq_entries = nb_rx_desc;
-	*rxq_max_fill_level = SFC_EF10_RXQ_LIMIT(*rxq_entries);
+	/*
+	 * rte_ethdev API guarantees that the number meets min, max and
+	 * alignment requirements.
+	 */
+	if (nb_rx_desc <= EFX_RXQ_MINNDESCS)
+		*rxq_entries = EFX_RXQ_MINNDESCS;
+	else
+		*rxq_entries = rte_align32pow2(nb_rx_desc);
+
+	*evq_entries = *rxq_entries;
+
+	*rxq_max_fill_level = RTE_MIN(nb_rx_desc,
+				      SFC_EF10_RXQ_LIMIT(*evq_entries));
 	return 0;
 }
 
@@ -723,6 +746,7 @@ struct sfc_dp_rx sfc_ef10_rx = {
 		.hw_fw_caps	= SFC_DP_HW_FW_CAP_EF10,
 	},
 	.features		= SFC_DP_RX_FEAT_MULTI_PROCESS,
+	.get_dev_info		= sfc_ef10_rx_get_dev_info,
 	.qsize_up_rings		= sfc_ef10_rx_qsize_up_rings,
 	.qcreate		= sfc_ef10_rx_qcreate,
 	.qdestroy		= sfc_ef10_rx_qdestroy,
diff --git a/drivers/net/sfc/sfc_ethdev.c b/drivers/net/sfc/sfc_ethdev.c
index fabcc32..6ff4595 100644
--- a/drivers/net/sfc/sfc_ethdev.c
+++ b/drivers/net/sfc/sfc_ethdev.c
@@ -163,6 +163,7 @@ sfc_dev_infos_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *dev_info)
 	if (sa->tso)
 		dev_info->tx_offload_capa |= DEV_TX_OFFLOAD_TCP_TSO;
 
+	/* Initialize to hardware limits */
 	dev_info->rx_desc_lim.nb_max = EFX_RXQ_MAXNDESCS;
 	dev_info->rx_desc_lim.nb_min = EFX_RXQ_MINNDESCS;
 	/* The RXQ hardware requires that the descriptor count is a power
@@ -177,6 +178,9 @@ sfc_dev_infos_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *dev_info)
 	 * of 2, but tx_desc_lim cannot properly describe that constraint
 	 */
 	dev_info->tx_desc_lim.nb_align = EFX_TXQ_MINNDESCS;
+
+	if (sa->dp_rx->get_dev_info != NULL)
+		sa->dp_rx->get_dev_info(dev_info);
 }
 
 static const uint32_t *
diff --git a/drivers/net/sfc/sfc_rx.c b/drivers/net/sfc/sfc_rx.c
index ecf8e99..6b31e56 100644
--- a/drivers/net/sfc/sfc_rx.c
+++ b/drivers/net/sfc/sfc_rx.c
@@ -933,6 +933,10 @@ sfc_rx_qinit(struct sfc_adapter *sa, unsigned int sw_index,
 				       &rxq_max_fill_level);
 	if (rc != 0)
 		goto fail_size_up_rings;
+	SFC_ASSERT(rxq_entries >= EFX_RXQ_MINNDESCS);
+	SFC_ASSERT(rxq_entries <= EFX_RXQ_MAXNDESCS);
+	SFC_ASSERT(rxq_entries >= nb_rx_desc);
+	SFC_ASSERT(rxq_max_fill_level <= nb_rx_desc);
 
 	rc = sfc_rx_qcheck_conf(sa, rxq_max_fill_level, rx_conf);
 	if (rc != 0)
-- 
2.7.4