From a22bd22b706316b4a55439952e6a83df45f5a8a5 Mon Sep 17 00:00:00 2001
From: Michal Krawczyk <mk@semihalf.com>
Date: Wed, 8 Apr 2020 10:29:12 +0200
Subject: [PATCH 105/177] net/ena: add Tx drops statistic

ENA device can report in the AENQ handler amount of Tx packets that were
dropped and not sent.

This statistic is showing global value for the device and because
rte_eth_stats is missing field that could indicate this value (it
isn't the Tx error), it is being presented as a extended statistic.

As the current design of extended statistics prevents tx_drops from
being an atomic variable and both tx_drops and rx_drops are only updated
from the AENQ handler, both were set as non-atomic for the alignment.

Signed-off-by: Michal Krawczyk <mk@semihalf.com>
Reviewed-by: Igor Chauskin <igorch@amazon.com>
Reviewed-by: Guy Tzalik <gtzalik@amazon.com>
---
 doc/guides/rel_notes/release_16_11.rst |  1 +
 drivers/net/ena/ena_ethdev.c           | 11 ++++++++---
 drivers/net/ena/ena_ethdev.h           |  8 +++++++-
 3 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/doc/guides/rel_notes/release_16_11.rst b/doc/guides/rel_notes/release_16_11.rst
index 39e4b812ea..d9d415190d 100644
--- a/doc/guides/rel_notes/release_16_11.rst
+++ b/doc/guides/rel_notes/release_16_11.rst
@@ -187,6 +187,7 @@ New Features
     bursts of packets.
   * Added per queue statistics.
   * Added extended statistics using xstats DPDK API.
+  * Added Tx drops as new extended driver statistic.
   * The reset routine was aligned with the DPDK API, so now it can be
     handled as in other PMDs.
   * Fixed out of order (OOO) completion.
diff --git a/drivers/net/ena/ena_ethdev.c b/drivers/net/ena/ena_ethdev.c
index 338dfeb25a..0b1675e0e1 100644
--- a/drivers/net/ena/ena_ethdev.c
+++ b/drivers/net/ena/ena_ethdev.c
@@ -95,6 +95,7 @@ static const struct ena_stats ena_stats_global_strings[] = {
 	ENA_STAT_GLOBAL_ENTRY(wd_expired),
 	ENA_STAT_GLOBAL_ENTRY(dev_start),
 	ENA_STAT_GLOBAL_ENTRY(dev_stop),
+	ENA_STAT_GLOBAL_ENTRY(tx_drops),
 };
 
 static const struct ena_stats ena_stats_tx_strings[] = {
@@ -881,7 +882,7 @@ static void ena_stats_restart(struct rte_eth_dev *dev)
 	rte_atomic64_init(&adapter->drv_stats->ierrors);
 	rte_atomic64_init(&adapter->drv_stats->oerrors);
 	rte_atomic64_init(&adapter->drv_stats->rx_nombuf);
-	rte_atomic64_init(&adapter->drv_stats->rx_drops);
+	adapter->drv_stats->rx_drops = 0;
 }
 
 static void ena_stats_get(struct rte_eth_dev *dev,
@@ -915,7 +916,7 @@ static void ena_stats_get(struct rte_eth_dev *dev,
 					ena_stats.tx_bytes_low);
 
 	/* Driver related stats */
-	stats->imissed = rte_atomic64_read(&adapter->drv_stats->rx_drops);
+	stats->imissed = adapter->drv_stats->rx_drops;
 	stats->ierrors = rte_atomic64_read(&adapter->drv_stats->ierrors);
 	stats->oerrors = rte_atomic64_read(&adapter->drv_stats->oerrors);
 	stats->rx_nombuf = rte_atomic64_read(&adapter->drv_stats->rx_nombuf);
@@ -2532,12 +2533,16 @@ static void ena_keep_alive(void *adapter_data,
 	struct ena_adapter *adapter = adapter_data;
 	struct ena_admin_aenq_keep_alive_desc *desc;
 	uint64_t rx_drops;
+	uint64_t tx_drops;
 
 	adapter->timestamp_wd = rte_get_timer_cycles();
 
 	desc = (struct ena_admin_aenq_keep_alive_desc *)aenq_e;
 	rx_drops = ((uint64_t)desc->rx_drops_high << 32) | desc->rx_drops_low;
-	rte_atomic64_set(&adapter->drv_stats->rx_drops, rx_drops);
+	tx_drops = ((uint64_t)desc->tx_drops_high << 32) | desc->tx_drops_low;
+
+	adapter->drv_stats->rx_drops = rx_drops;
+	adapter->dev_stats.tx_drops = tx_drops;
 }
 
 /**
diff --git a/drivers/net/ena/ena_ethdev.h b/drivers/net/ena/ena_ethdev.h
index 963f027abe..0c705ea008 100644
--- a/drivers/net/ena/ena_ethdev.h
+++ b/drivers/net/ena/ena_ethdev.h
@@ -132,13 +132,19 @@ struct ena_driver_stats {
 	rte_atomic64_t ierrors;
 	rte_atomic64_t oerrors;
 	rte_atomic64_t rx_nombuf;
-	rte_atomic64_t rx_drops;
+	u64 rx_drops;
 };
 
 struct ena_stats_dev {
 	u64 wd_expired;
 	u64 dev_start;
 	u64 dev_stop;
+	/*
+	 * Tx drops cannot be reported as the driver statistic, because DPDK
+	 * rte_eth_stats structure isn't providing appropriate field for that.
+	 * As a workaround it is being published as an extended statistic.
+	 */
+	u64 tx_drops;
 };
 
 /* board specific private data structure */
-- 
2.25.1

