[dpdk-stable] patch 'net/sfc: fix Rx packets counter' has been queued to LTS release 17.11.6

[Yongseok Koh <yskoh@mellanox.com>]

Hi,

FYI, your patch has been queued to LTS release 17.11.6

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objection by 03/13/19. So please
shout if anyone has objection.

Also note that after the patch there's a diff of the upstream commit vs the patch applied
to the branch. If the code is different (ie: not only metadata diffs), due for example to
a change in context or macro names, please double check it.

Thanks.

Yongseok

---
>From 10498b42efd1f989bbf211dab69de474d4f68169 Mon Sep 17 00:00:00 2001
From: Andrew Rybchenko <arybchenko@solarflare.com>
Date: Thu, 17 Jan 2019 06:17:32 +0000
Subject: [PATCH] net/sfc: fix Rx packets counter

[ upstream commit ab77a0013a811aacdde49e903786eff7abb308ec ]

Errors, missed and pauses should not be included in delivered
good Rx packets reported by ipackets.

Fixes: 1caab2f1e684 ("net/sfc: add basic statistics")

Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
---
 drivers/net/sfc/sfc.h        |  2 ++
 drivers/net/sfc/sfc_ethdev.c | 31 ++++++++++++++++++++++++++++++-
 drivers/net/sfc/sfc_port.c   | 14 ++++++++++++++
 3 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/drivers/net/sfc/sfc.h b/drivers/net/sfc/sfc.h
index 7bc7a077c..b62306512 100644
--- a/drivers/net/sfc/sfc.h
+++ b/drivers/net/sfc/sfc.h
@@ -175,6 +175,8 @@ struct sfc_port {
 	uint64_t			mac_stats_last_request_timestamp;
 
 	uint32_t		mac_stats_mask[EFX_MAC_STATS_MASK_NPAGES];
+
+	uint64_t			ipackets;
 };
 
 /* Adapter private data */
diff --git a/drivers/net/sfc/sfc_ethdev.c b/drivers/net/sfc/sfc_ethdev.c
index 5854fd76a..09ab4ec8a 100644
--- a/drivers/net/sfc/sfc_ethdev.c
+++ b/drivers/net/sfc/sfc_ethdev.c
@@ -518,6 +518,29 @@ sfc_tx_queue_release(void *queue)
 	sfc_adapter_unlock(sa);
 }
 
+/*
+ * Some statistics are computed as A - B where A and B each increase
+ * monotonically with some hardware counter(s) and the counters are read
+ * asynchronously.
+ *
+ * If packet X is counted in A, but not counted in B yet, computed value is
+ * greater than real.
+ *
+ * If packet X is not counted in A at the moment of reading the counter,
+ * but counted in B at the moment of reading the counter, computed value
+ * is less than real.
+ *
+ * However, counter which grows backward is worse evil than slightly wrong
+ * value. So, let's try to guarantee that it never happens except may be
+ * the case when the MAC stats are zeroed as a result of a NIC reset.
+ */
+static void
+sfc_update_diff_stat(uint64_t *stat, uint64_t newval)
+{
+	if ((int64_t)(newval - *stat) > 0 || newval == 0)
+		*stat = newval;
+}
+
 static int
 sfc_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *stats)
 {
@@ -555,7 +578,6 @@ sfc_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *stats)
 		stats->imissed = mac_stats[EFX_MAC_VADAPTER_RX_BAD_PACKETS];
 		stats->oerrors = mac_stats[EFX_MAC_VADAPTER_TX_BAD_PACKETS];
 	} else {
-		stats->ipackets = mac_stats[EFX_MAC_RX_PKTS];
 		stats->opackets = mac_stats[EFX_MAC_TX_PKTS];
 		stats->ibytes = mac_stats[EFX_MAC_RX_OCTETS];
 		stats->obytes = mac_stats[EFX_MAC_TX_OCTETS];
@@ -581,6 +603,13 @@ sfc_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *stats)
 			mac_stats[EFX_MAC_RX_ALIGN_ERRORS] +
 			mac_stats[EFX_MAC_RX_JABBER_PKTS];
 		/* no oerrors counters supported on EF10 */
+
+		/* Exclude missed, errors and pauses from Rx packets */
+		sfc_update_diff_stat(&port->ipackets,
+			mac_stats[EFX_MAC_RX_PKTS] -
+			mac_stats[EFX_MAC_RX_PAUSE_PKTS] -
+			stats->imissed - stats->ierrors);
+		stats->ipackets = port->ipackets;
 	}
 
 unlock:
diff --git a/drivers/net/sfc/sfc_port.c b/drivers/net/sfc/sfc_port.c
index 5254394c9..109981f13 100644
--- a/drivers/net/sfc/sfc_port.c
+++ b/drivers/net/sfc/sfc_port.c
@@ -109,6 +109,18 @@ sfc_port_update_mac_stats(struct sfc_adapter *sa)
 	return 0;
 }
 
+static void
+sfc_port_reset_sw_stats(struct sfc_adapter *sa)
+{
+	struct sfc_port *port = &sa->port;
+
+	/*
+	 * Reset diff stats explicitly since check which does not allow
+	 * the statistics to grow backward could deny it.
+	 */
+	port->ipackets = 0;
+}
+
 int
 sfc_port_reset_mac_stats(struct sfc_adapter *sa)
 {
@@ -117,6 +129,8 @@ sfc_port_reset_mac_stats(struct sfc_adapter *sa)
 
 	rte_spinlock_lock(&port->mac_stats_lock);
 	rc = efx_mac_stats_clear(sa->nic);
+	if (rc == 0)
+		sfc_port_reset_sw_stats(sa);
 	rte_spinlock_unlock(&port->mac_stats_lock);
 
 	return rc;
-- 
2.11.0

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2019-03-08 09:46:42.973675250 -0800
+++ 0056-net-sfc-fix-Rx-packets-counter.patch	2019-03-08 09:46:40.295402000 -0800
@@ -1,13 +1,14 @@
-From ab77a0013a811aacdde49e903786eff7abb308ec Mon Sep 17 00:00:00 2001
+From 10498b42efd1f989bbf211dab69de474d4f68169 Mon Sep 17 00:00:00 2001
 From: Andrew Rybchenko <arybchenko@solarflare.com>
 Date: Thu, 17 Jan 2019 06:17:32 +0000
 Subject: [PATCH] net/sfc: fix Rx packets counter
 
+[ upstream commit ab77a0013a811aacdde49e903786eff7abb308ec ]
+
 Errors, missed and pauses should not be included in delivered
 good Rx packets reported by ipackets.
 
 Fixes: 1caab2f1e684 ("net/sfc: add basic statistics")
-Cc: stable@dpdk.org
 
 Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
 ---
@@ -17,10 +18,10 @@
  3 files changed, 46 insertions(+), 1 deletion(-)
 
 diff --git a/drivers/net/sfc/sfc.h b/drivers/net/sfc/sfc.h
-index 0b852340f..a94ca8e75 100644
+index 7bc7a077c..b62306512 100644
 --- a/drivers/net/sfc/sfc.h
 +++ b/drivers/net/sfc/sfc.h
-@@ -149,6 +149,8 @@ struct sfc_port {
+@@ -175,6 +175,8 @@ struct sfc_port {
  	uint64_t			mac_stats_last_request_timestamp;
  
  	uint32_t		mac_stats_mask[EFX_MAC_STATS_MASK_NPAGES];
@@ -28,12 +29,12 @@
 +	uint64_t			ipackets;
  };
  
- struct sfc_rss_hf_rte_to_efx {
+ /* Adapter private data */
 diff --git a/drivers/net/sfc/sfc_ethdev.c b/drivers/net/sfc/sfc_ethdev.c
-index 08d3271cb..a7322a1eb 100644
+index 5854fd76a..09ab4ec8a 100644
 --- a/drivers/net/sfc/sfc_ethdev.c
 +++ b/drivers/net/sfc/sfc_ethdev.c
-@@ -503,6 +503,29 @@ sfc_tx_queue_release(void *queue)
+@@ -518,6 +518,29 @@ sfc_tx_queue_release(void *queue)
  	sfc_adapter_unlock(sa);
  }
  
@@ -63,7 +64,7 @@
  static int
  sfc_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *stats)
  {
-@@ -540,7 +563,6 @@ sfc_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *stats)
+@@ -555,7 +578,6 @@ sfc_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *stats)
  		stats->imissed = mac_stats[EFX_MAC_VADAPTER_RX_BAD_PACKETS];
  		stats->oerrors = mac_stats[EFX_MAC_VADAPTER_TX_BAD_PACKETS];
  	} else {
@@ -71,7 +72,7 @@
  		stats->opackets = mac_stats[EFX_MAC_TX_PKTS];
  		stats->ibytes = mac_stats[EFX_MAC_RX_OCTETS];
  		stats->obytes = mac_stats[EFX_MAC_TX_OCTETS];
-@@ -566,6 +588,13 @@ sfc_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *stats)
+@@ -581,6 +603,13 @@ sfc_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *stats)
  			mac_stats[EFX_MAC_RX_ALIGN_ERRORS] +
  			mac_stats[EFX_MAC_RX_JABBER_PKTS];
  		/* no oerrors counters supported on EF10 */
@@ -86,10 +87,10 @@
  
  unlock:
 diff --git a/drivers/net/sfc/sfc_port.c b/drivers/net/sfc/sfc_port.c
-index 5384dbbdb..5eb4b3aca 100644
+index 5254394c9..109981f13 100644
 --- a/drivers/net/sfc/sfc_port.c
 +++ b/drivers/net/sfc/sfc_port.c
-@@ -87,6 +87,18 @@ sfc_port_update_mac_stats(struct sfc_adapter *sa)
+@@ -109,6 +109,18 @@ sfc_port_update_mac_stats(struct sfc_adapter *sa)
  	return 0;
  }
  
@@ -108,7 +109,7 @@
  int
  sfc_port_reset_mac_stats(struct sfc_adapter *sa)
  {
-@@ -95,6 +107,8 @@ sfc_port_reset_mac_stats(struct sfc_adapter *sa)
+@@ -117,6 +129,8 @@ sfc_port_reset_mac_stats(struct sfc_adapter *sa)
  
  	rte_spinlock_lock(&port->mac_stats_lock);
  	rc = efx_mac_stats_clear(sa->nic);