[PATCH 5.10 215/545] net: hinic: fix bug that ethtool get wrong stats

From: Greg Kroah-Hartman
Date: Fri Aug 19 2022 - 12:12:48 EST

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From: Qiao Ma <mqaio@xxxxxxxxxxxxxxxxx>

[ Upstream commit 67dffd3db98570af8ff54c934f7d14664c0d182a ]

Function hinic_get_stats64() will do two operations:
1. reads stats from every hinic_rxq/txq and accumulates them
2. calls hinic_rxq/txq_clean_stats() to clean every rxq/txq's stats

For hinic_get_stats64(), it could get right data, because it sums all
data to nic_dev->rx_stats/tx_stats.
But it is wrong for get_drv_queue_stats(), this function will read
hinic_rxq's stats, which have been cleared to zero by hinic_get_stats64().

I have observed hinic's cleanup operation by using such command:
> watch -n 1 "cat ethtool -S eth4 | tail -40"

Result before:
...
rxq7_pkts: 1
rxq7_bytes: 90
rxq7_errors: 0
rxq7_csum_errors: 0
rxq7_other_errors: 0
...
rxq9_pkts: 11
rxq9_bytes: 726
rxq9_errors: 0
rxq9_csum_errors: 0
rxq9_other_errors: 0
...
rxq11_pkts: 0
rxq11_bytes: 0
rxq11_errors: 0
rxq11_csum_errors: 0
rxq11_other_errors: 0

Result after a few seconds:
...
rxq7_pkts: 0
rxq7_bytes: 0
rxq7_errors: 0
rxq7_csum_errors: 0
rxq7_other_errors: 0
...
rxq9_pkts: 2
rxq9_bytes: 132
rxq9_errors: 0
rxq9_csum_errors: 0
rxq9_other_errors: 0
...
rxq11_pkts: 1
rxq11_bytes: 170
rxq11_errors: 0
rxq11_csum_errors: 0
rxq11_other_errors: 0

To solve this problem, we just keep every queue's total stats in their own
queue (aka hinic_{rxq|txq}), and simply sum all per-queue stats every time
calling hinic_get_stats64().
With that solution, there is no need to clean per-queue stats now,
and there is no need to maintain global hinic_dev.{tx|rx}_stats, too.

Fixes: edd384f682cc ("net-next/hinic: Add ethtool and stats")
Signed-off-by: Qiao Ma <mqaio@xxxxxxxxxxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/huawei/hinic/hinic_dev.h | 3 -
.../net/ethernet/huawei/hinic/hinic_main.c | 57 ++++++-------------
drivers/net/ethernet/huawei/hinic/hinic_rx.c | 2 -
drivers/net/ethernet/huawei/hinic/hinic_tx.c | 2 -
4 files changed, 16 insertions(+), 48 deletions(-)

diff --git a/drivers/net/ethernet/huawei/hinic/hinic_dev.h b/drivers/net/ethernet/huawei/hinic/hinic_dev.h
index fb3e89141a0d..a4fbf44f944c 100644
--- a/drivers/net/ethernet/huawei/hinic/hinic_dev.h
+++ b/drivers/net/ethernet/huawei/hinic/hinic_dev.h
@@ -95,9 +95,6 @@ struct hinic_dev {
u16 sq_depth;
u16 rq_depth;

- struct hinic_txq_stats tx_stats;
- struct hinic_rxq_stats rx_stats;
-
u8 rss_tmpl_idx;
u8 rss_hash_engine;
u16 num_rss;
diff --git a/drivers/net/ethernet/huawei/hinic/hinic_main.c b/drivers/net/ethernet/huawei/hinic/hinic_main.c
index 2376edf6c263..5edc96b7cc8a 100644
--- a/drivers/net/ethernet/huawei/hinic/hinic_main.c
+++ b/drivers/net/ethernet/huawei/hinic/hinic_main.c
@@ -80,56 +80,44 @@ static int set_features(struct hinic_dev *nic_dev,
netdev_features_t pre_features,
netdev_features_t features, bool force_change);

-static void update_rx_stats(struct hinic_dev *nic_dev, struct hinic_rxq *rxq)
+static void gather_rx_stats(struct hinic_rxq_stats *nic_rx_stats, struct hinic_rxq *rxq)
{
- struct hinic_rxq_stats *nic_rx_stats = &nic_dev->rx_stats;
struct hinic_rxq_stats rx_stats;

- u64_stats_init(&rx_stats.syncp);
-
hinic_rxq_get_stats(rxq, &rx_stats);

- u64_stats_update_begin(&nic_rx_stats->syncp);
nic_rx_stats->bytes += rx_stats.bytes;
nic_rx_stats->pkts += rx_stats.pkts;
nic_rx_stats->errors += rx_stats.errors;
nic_rx_stats->csum_errors += rx_stats.csum_errors;
nic_rx_stats->other_errors += rx_stats.other_errors;
- u64_stats_update_end(&nic_rx_stats->syncp);
-
- hinic_rxq_clean_stats(rxq);
}

-static void update_tx_stats(struct hinic_dev *nic_dev, struct hinic_txq *txq)
+static void gather_tx_stats(struct hinic_txq_stats *nic_tx_stats, struct hinic_txq *txq)
{
- struct hinic_txq_stats *nic_tx_stats = &nic_dev->tx_stats;
struct hinic_txq_stats tx_stats;

- u64_stats_init(&tx_stats.syncp);
-
hinic_txq_get_stats(txq, &tx_stats);

- u64_stats_update_begin(&nic_tx_stats->syncp);
nic_tx_stats->bytes += tx_stats.bytes;
nic_tx_stats->pkts += tx_stats.pkts;
nic_tx_stats->tx_busy += tx_stats.tx_busy;
nic_tx_stats->tx_wake += tx_stats.tx_wake;
nic_tx_stats->tx_dropped += tx_stats.tx_dropped;
nic_tx_stats->big_frags_pkts += tx_stats.big_frags_pkts;
- u64_stats_update_end(&nic_tx_stats->syncp);
-
- hinic_txq_clean_stats(txq);
}

-static void update_nic_stats(struct hinic_dev *nic_dev)
+static void gather_nic_stats(struct hinic_dev *nic_dev,
+ struct hinic_rxq_stats *nic_rx_stats,
+ struct hinic_txq_stats *nic_tx_stats)
{
int i, num_qps = hinic_hwdev_num_qps(nic_dev->hwdev);

for (i = 0; i < num_qps; i++)
- update_rx_stats(nic_dev, &nic_dev->rxqs[i]);
+ gather_rx_stats(nic_rx_stats, &nic_dev->rxqs[i]);

for (i = 0; i < num_qps; i++)
- update_tx_stats(nic_dev, &nic_dev->txqs[i]);
+ gather_tx_stats(nic_tx_stats, &nic_dev->txqs[i]);
}

/**
@@ -565,8 +553,6 @@ int hinic_close(struct net_device *netdev)
netif_carrier_off(netdev);
netif_tx_disable(netdev);

- update_nic_stats(nic_dev);
-
up(&nic_dev->mgmt_lock);

if (!HINIC_IS_VF(nic_dev->hwdev->hwif))
@@ -860,26 +846,23 @@ static void hinic_get_stats64(struct net_device *netdev,
struct rtnl_link_stats64 *stats)
{
struct hinic_dev *nic_dev = netdev_priv(netdev);
- struct hinic_rxq_stats *nic_rx_stats;
- struct hinic_txq_stats *nic_tx_stats;
-
- nic_rx_stats = &nic_dev->rx_stats;
- nic_tx_stats = &nic_dev->tx_stats;
+ struct hinic_rxq_stats nic_rx_stats = {};
+ struct hinic_txq_stats nic_tx_stats = {};

down(&nic_dev->mgmt_lock);

if (nic_dev->flags & HINIC_INTF_UP)
- update_nic_stats(nic_dev);
+ gather_nic_stats(nic_dev, &nic_rx_stats, &nic_tx_stats);

up(&nic_dev->mgmt_lock);

- stats->rx_bytes = nic_rx_stats->bytes;
- stats->rx_packets = nic_rx_stats->pkts;
- stats->rx_errors = nic_rx_stats->errors;
+ stats->rx_bytes = nic_rx_stats.bytes;
+ stats->rx_packets = nic_rx_stats.pkts;
+ stats->rx_errors = nic_rx_stats.errors;

- stats->tx_bytes = nic_tx_stats->bytes;
- stats->tx_packets = nic_tx_stats->pkts;
- stats->tx_errors = nic_tx_stats->tx_dropped;
+ stats->tx_bytes = nic_tx_stats.bytes;
+ stats->tx_packets = nic_tx_stats.pkts;
+ stats->tx_errors = nic_tx_stats.tx_dropped;
}

static int hinic_set_features(struct net_device *netdev,
@@ -1178,8 +1161,6 @@ static void hinic_free_intr_coalesce(struct hinic_dev *nic_dev)
static int nic_dev_init(struct pci_dev *pdev)
{
struct hinic_rx_mode_work *rx_mode_work;
- struct hinic_txq_stats *tx_stats;
- struct hinic_rxq_stats *rx_stats;
struct hinic_dev *nic_dev;
struct net_device *netdev;
struct hinic_hwdev *hwdev;
@@ -1240,12 +1221,6 @@ static int nic_dev_init(struct pci_dev *pdev)

sema_init(&nic_dev->mgmt_lock, 1);

- tx_stats = &nic_dev->tx_stats;
- rx_stats = &nic_dev->rx_stats;
-
- u64_stats_init(&tx_stats->syncp);
- u64_stats_init(&rx_stats->syncp);
-
nic_dev->vlan_bitmap = devm_bitmap_zalloc(&pdev->dev, VLAN_N_VID,
GFP_KERNEL);
if (!nic_dev->vlan_bitmap) {
diff --git a/drivers/net/ethernet/huawei/hinic/hinic_rx.c b/drivers/net/ethernet/huawei/hinic/hinic_rx.c
index 070a7cc6392e..04b19af63fd6 100644
--- a/drivers/net/ethernet/huawei/hinic/hinic_rx.c
+++ b/drivers/net/ethernet/huawei/hinic/hinic_rx.c
@@ -73,7 +73,6 @@ void hinic_rxq_get_stats(struct hinic_rxq *rxq, struct hinic_rxq_stats *stats)
struct hinic_rxq_stats *rxq_stats = &rxq->rxq_stats;
unsigned int start;

- u64_stats_update_begin(&stats->syncp);
do {
start = u64_stats_fetch_begin(&rxq_stats->syncp);
stats->pkts = rxq_stats->pkts;
@@ -83,7 +82,6 @@ void hinic_rxq_get_stats(struct hinic_rxq *rxq, struct hinic_rxq_stats *stats)
stats->csum_errors = rxq_stats->csum_errors;
stats->other_errors = rxq_stats->other_errors;
} while (u64_stats_fetch_retry(&rxq_stats->syncp, start));
- u64_stats_update_end(&stats->syncp);
}

/**
diff --git a/drivers/net/ethernet/huawei/hinic/hinic_tx.c b/drivers/net/ethernet/huawei/hinic/hinic_tx.c
index 3828b09bfea3..d13514a8160e 100644
--- a/drivers/net/ethernet/huawei/hinic/hinic_tx.c
+++ b/drivers/net/ethernet/huawei/hinic/hinic_tx.c
@@ -97,7 +97,6 @@ void hinic_txq_get_stats(struct hinic_txq *txq, struct hinic_txq_stats *stats)
struct hinic_txq_stats *txq_stats = &txq->txq_stats;
unsigned int start;

- u64_stats_update_begin(&stats->syncp);
do {
start = u64_stats_fetch_begin(&txq_stats->syncp);
stats->pkts = txq_stats->pkts;
@@ -107,7 +106,6 @@ void hinic_txq_get_stats(struct hinic_txq *txq, struct hinic_txq_stats *stats)
stats->tx_dropped = txq_stats->tx_dropped;
stats->big_frags_pkts = txq_stats->big_frags_pkts;
} while (u64_stats_fetch_retry(&txq_stats->syncp, start));
- u64_stats_update_end(&stats->syncp);
}

/**
--
2.35.1

Next message: Greg Kroah-Hartman: "[PATCH 5.10 233/545] wifi: p54: add missing parentheses in p54_flush()"
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