[dpdk-dev] [PATCH 20/31] net/sfc: support deferred start of receive queues

[Andrew Rybchenko <arybchenko@solarflare.com>]

Reviewed-by: Andrew Lee <alee@solarflare.com>
Reviewed-by: Robert Stonehouse <rstonehouse@solarflare.com>
Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
---
 doc/guides/nics/features/sfc_efx.ini |  1 +
 doc/guides/nics/sfc_efx.rst          |  2 ++
 drivers/net/sfc/sfc_ethdev.c         | 51 ++++++++++++++++++++++++++++++++++++
 drivers/net/sfc/sfc_rx.c             | 18 +++++++------
 drivers/net/sfc/sfc_rx.h             |  2 ++
 5 files changed, 66 insertions(+), 8 deletions(-)

diff --git a/doc/guides/nics/features/sfc_efx.ini b/doc/guides/nics/features/sfc_efx.ini
index 74cc942..4a887f0 100644
--- a/doc/guides/nics/features/sfc_efx.ini
+++ b/doc/guides/nics/features/sfc_efx.ini
@@ -7,6 +7,7 @@
 Speed capabilities   = Y
 Link status          = Y
 Link status event    = Y
+Queue start/stop     = P
 MTU update           = Y
 Jumbo frame          = Y
 Scattered Rx         = Y
diff --git a/doc/guides/nics/sfc_efx.rst b/doc/guides/nics/sfc_efx.rst
index a0f25d3..3d705bc 100644
--- a/doc/guides/nics/sfc_efx.rst
+++ b/doc/guides/nics/sfc_efx.rst
@@ -68,6 +68,8 @@ SFC EFX PMD has support for:
 
 - Scattered Rx DMA for packet that are larger that a single Rx descriptor
 
+- Deferred receive queue start
+
 
 Non-supported Features
 ----------------------
diff --git a/drivers/net/sfc/sfc_ethdev.c b/drivers/net/sfc/sfc_ethdev.c
index f1b655b..c531fdb 100644
--- a/drivers/net/sfc/sfc_ethdev.c
+++ b/drivers/net/sfc/sfc_ethdev.c
@@ -840,6 +840,7 @@ sfc_rx_queue_info_get(struct rte_eth_dev *dev, uint16_t rx_queue_id,
 	qinfo->mp = rxq->refill_mb_pool;
 	qinfo->conf.rx_free_thresh = rxq->refill_threshold;
 	qinfo->conf.rx_drop_en = 1;
+	qinfo->conf.rx_deferred_start = rxq_info->deferred_start;
 	qinfo->scattered_rx = (rxq_info->type == EFX_RXQ_TYPE_SCATTER);
 	qinfo->nb_desc = rxq_info->entries;
 
@@ -864,6 +865,54 @@ sfc_rx_descriptor_done(void *queue, uint16_t offset)
 	return sfc_rx_qdesc_done(rxq, offset);
 }
 
+static int
+sfc_rx_queue_start(struct rte_eth_dev *dev, uint16_t rx_queue_id)
+{
+	struct sfc_adapter *sa = dev->data->dev_private;
+	int rc;
+
+	sfc_log_init(sa, "RxQ=%u", rx_queue_id);
+
+	sfc_adapter_lock(sa);
+
+	rc = EINVAL;
+	if (sa->state != SFC_ADAPTER_STARTED)
+		goto fail_not_started;
+
+	rc = sfc_rx_qstart(sa, rx_queue_id);
+	if (rc != 0)
+		goto fail_rx_qstart;
+
+	sa->rxq_info[rx_queue_id].deferred_started = B_TRUE;
+
+	sfc_adapter_unlock(sa);
+
+	return 0;
+
+fail_rx_qstart:
+fail_not_started:
+	sfc_adapter_unlock(sa);
+	SFC_ASSERT(rc > 0);
+	return -rc;
+}
+
+static int
+sfc_rx_queue_stop(struct rte_eth_dev *dev, uint16_t rx_queue_id)
+{
+	struct sfc_adapter *sa = dev->data->dev_private;
+
+	sfc_log_init(sa, "RxQ=%u", rx_queue_id);
+
+	sfc_adapter_lock(sa);
+	sfc_rx_qstop(sa, rx_queue_id);
+
+	sa->rxq_info[rx_queue_id].deferred_started = B_FALSE;
+
+	sfc_adapter_unlock(sa);
+
+	return 0;
+}
+
 static const struct eth_dev_ops sfc_eth_dev_ops = {
 	.dev_configure			= sfc_dev_configure,
 	.dev_start			= sfc_dev_start,
@@ -882,6 +931,8 @@ static const struct eth_dev_ops sfc_eth_dev_ops = {
 	.dev_infos_get			= sfc_dev_infos_get,
 	.dev_supported_ptypes_get	= sfc_dev_supported_ptypes_get,
 	.mtu_set			= sfc_dev_set_mtu,
+	.rx_queue_start			= sfc_rx_queue_start,
+	.rx_queue_stop			= sfc_rx_queue_stop,
 	.rx_queue_setup			= sfc_rx_queue_setup,
 	.rx_queue_release		= sfc_rx_queue_release,
 	.rx_queue_count			= sfc_rx_queue_count,
diff --git a/drivers/net/sfc/sfc_rx.c b/drivers/net/sfc/sfc_rx.c
index 2909ec0..3bfce1c 100644
--- a/drivers/net/sfc/sfc_rx.c
+++ b/drivers/net/sfc/sfc_rx.c
@@ -444,6 +444,9 @@ sfc_rx_qstop(struct sfc_adapter *sa, unsigned int sw_index)
 
 	rxq_info = &sa->rxq_info[sw_index];
 	rxq = rxq_info->rxq;
+
+	if (rxq->state == SFC_RXQ_INITIALIZED)
+		return;
 	SFC_ASSERT(rxq->state & SFC_RXQ_STARTED);
 
 	/* It seems to be used by DPDK for debug purposes only ('rte_ether') */
@@ -491,11 +494,6 @@ sfc_rx_qcheck_conf(struct sfc_adapter *sa, uint16_t nb_rx_desc,
 		rc = EINVAL;
 	}
 
-	if (rx_conf->rx_deferred_start != 0) {
-		sfc_err(sa, "RxQ deferred start is not supported");
-		rc = EINVAL;
-	}
-
 	return rc;
 }
 
@@ -688,6 +686,7 @@ sfc_rx_qinit(struct sfc_adapter *sa, unsigned int sw_index,
 	rxq->state = SFC_RXQ_INITIALIZED;
 
 	rxq_info->rxq = rxq;
+	rxq_info->deferred_start = (rx_conf->rx_deferred_start != 0);
 
 	return 0;
 
@@ -742,9 +741,12 @@ sfc_rx_start(struct sfc_adapter *sa)
 		goto fail_rx_init;
 
 	for (sw_index = 0; sw_index < sa->rxq_count; ++sw_index) {
-		rc = sfc_rx_qstart(sa, sw_index);
-		if (rc != 0)
-			goto fail_rx_qstart;
+		if ((!sa->rxq_info[sw_index].deferred_start ||
+		     sa->rxq_info[sw_index].deferred_started)) {
+			rc = sfc_rx_qstart(sa, sw_index);
+			if (rc != 0)
+				goto fail_rx_qstart;
+		}
 	}
 
 	return 0;
diff --git a/drivers/net/sfc/sfc_rx.h b/drivers/net/sfc/sfc_rx.h
index 8d8e709..4aa6aea 100644
--- a/drivers/net/sfc/sfc_rx.h
+++ b/drivers/net/sfc/sfc_rx.h
@@ -119,6 +119,8 @@ struct sfc_rxq_info {
 	unsigned int		entries;
 	efx_rxq_type_t		type;
 	struct sfc_rxq		*rxq;
+	boolean_t		deferred_start;
+	boolean_t		deferred_started;
 };
 
 int sfc_rx_init(struct sfc_adapter *sa);
-- 
2.5.5