[PATCH AUTOSEL 5.15 05/10] net: ethernet: litex: add support for 64 bit stats

From: Sasha Levin
Date: Sun Jul 09 2023 - 11:28:50 EST


From: Jisheng Zhang <jszhang@xxxxxxxxxx>

[ Upstream commit 18da174d865a87d47d2f33f5b0a322efcf067728 ]

Implement 64 bit per cpu stats to fix the overflow of netdev->stats
on 32 bit platforms. To simplify the code, we use net core
pcpu_sw_netstats infrastructure. One small drawback is some memory
overhead because litex uses just one queue, but we allocate the
counters per cpu.

Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxx>
Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx>
Acked-by: Gabriel Somlo <gsomlo@xxxxxxxxx>
Link: https://lore.kernel.org/r/20230614162035.300-1-jszhang@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/litex/litex_liteeth.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/litex/litex_liteeth.c b/drivers/net/ethernet/litex/litex_liteeth.c
index 5bb1cc8a2ce13..7b39b910e4a14 100644
--- a/drivers/net/ethernet/litex/litex_liteeth.c
+++ b/drivers/net/ethernet/litex/litex_liteeth.c
@@ -78,8 +78,7 @@ static int liteeth_rx(struct net_device *netdev)
memcpy_fromio(data, priv->rx_base + rx_slot * priv->slot_size, len);
skb->protocol = eth_type_trans(skb, netdev);

- netdev->stats.rx_packets++;
- netdev->stats.rx_bytes += len;
+ dev_sw_netstats_rx_add(netdev, len);

return netif_rx(skb);

@@ -184,8 +183,7 @@ static int liteeth_start_xmit(struct sk_buff *skb, struct net_device *netdev)
litex_write16(priv->base + LITEETH_READER_LENGTH, skb->len);
litex_write8(priv->base + LITEETH_READER_START, 1);

- netdev->stats.tx_bytes += skb->len;
- netdev->stats.tx_packets++;
+ dev_sw_netstats_tx_add(netdev, 1, skb->len);

priv->tx_slot = (priv->tx_slot + 1) % priv->num_tx_slots;
dev_kfree_skb_any(skb);
@@ -193,9 +191,17 @@ static int liteeth_start_xmit(struct sk_buff *skb, struct net_device *netdev)
return NETDEV_TX_OK;
}

+static void
+liteeth_get_stats64(struct net_device *netdev, struct rtnl_link_stats64 *stats)
+{
+ netdev_stats_to_stats64(stats, &netdev->stats);
+ dev_fetch_sw_netstats(stats, netdev->tstats);
+}
+
static const struct net_device_ops liteeth_netdev_ops = {
.ndo_open = liteeth_open,
.ndo_stop = liteeth_stop,
+ .ndo_get_stats64 = liteeth_get_stats64,
.ndo_start_xmit = liteeth_start_xmit,
};

@@ -241,6 +247,11 @@ static int liteeth_probe(struct platform_device *pdev)
priv->netdev = netdev;
priv->dev = &pdev->dev;

+ netdev->tstats = devm_netdev_alloc_pcpu_stats(&pdev->dev,
+ struct pcpu_sw_netstats);
+ if (!netdev->tstats)
+ return -ENOMEM;
+
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "Failed to get IRQ %d\n", irq);
--
2.39.2