netdev - [PATCH net-next] net: ethernet: ti: netcp: Use u64_stats_t with u64_stats

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Message-ID: <20260123164841.2890054-1-mmyangfl@gmail.com>
Date: Sat, 24 Jan 2026 00:48:36 +0800
From: David Yang <mmyangfl@...il.com>
To: netdev@...r.kernel.org
Cc: David Yang <mmyangfl@...il.com>,
	Andrew Lunn <andrew+netdev@...n.ch>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>,
	Paolo Abeni <pabeni@...hat.com>,
	Vadim Fedorenko <vadim.fedorenko@...ux.dev>,
	Kory Maincent <kory.maincent@...tlin.com>,
	Jacob Keller <jacob.e.keller@...el.com>,
	Nishanth Menon <nm@...com>,
	linux-kernel@...r.kernel.org
Subject: [PATCH net-next] net: ethernet: ti: netcp: Use u64_stats_t with u64_stats_sync properly

On 64bit arches, struct u64_stats_sync is empty and provides no help
against load/store tearing. Convert to u64_stats_t to ensure atomic
operations.

Note that does not mean the code is now tear-free: there're u32 counters
unprotected by u64_stats or anything else.

Signed-off-by: David Yang <mmyangfl@...il.com>
---
 drivers/net/ethernet/ti/netcp.h      |  8 ++++----
 drivers/net/ethernet/ti/netcp_core.c | 16 ++++++++--------
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/ti/netcp.h b/drivers/net/ethernet/ti/netcp.h
index b9cbd3b4a8a2..9cfddaa807e2 100644
--- a/drivers/net/ethernet/ti/netcp.h
+++ b/drivers/net/ethernet/ti/netcp.h
@@ -65,14 +65,14 @@ struct netcp_addr {
 
 struct netcp_stats {
 	struct u64_stats_sync   syncp_rx ____cacheline_aligned_in_smp;
-	u64                     rx_packets;
-	u64                     rx_bytes;
+	u64_stats_t             rx_packets;
+	u64_stats_t             rx_bytes;
 	u32                     rx_errors;
 	u32                     rx_dropped;
 
 	struct u64_stats_sync   syncp_tx ____cacheline_aligned_in_smp;
-	u64                     tx_packets;
-	u64                     tx_bytes;
+	u64_stats_t             tx_packets;
+	u64_stats_t             tx_bytes;
 	u32                     tx_errors;
 	u32                     tx_dropped;
 };
diff --git a/drivers/net/ethernet/ti/netcp_core.c b/drivers/net/ethernet/ti/netcp_core.c
index 5ed1c46bbcb1..eb8fc2ed05f4 100644
--- a/drivers/net/ethernet/ti/netcp_core.c
+++ b/drivers/net/ethernet/ti/netcp_core.c
@@ -759,8 +759,8 @@ static int netcp_process_one_rx_packet(struct netcp_intf *netcp)
 	knav_pool_desc_put(netcp->rx_pool, desc);
 
 	u64_stats_update_begin(&rx_stats->syncp_rx);
-	rx_stats->rx_packets++;
-	rx_stats->rx_bytes += skb->len;
+	u64_stats_inc(&rx_stats->rx_packets);
+	u64_stats_add(&rx_stats->rx_bytes, skb->len);
 	u64_stats_update_end(&rx_stats->syncp_rx);
 
 	/* push skb up the stack */
@@ -1045,8 +1045,8 @@ static int netcp_process_tx_compl_packets(struct netcp_intf *netcp,
 		}
 
 		u64_stats_update_begin(&tx_stats->syncp_tx);
-		tx_stats->tx_packets++;
-		tx_stats->tx_bytes += skb->len;
+		u64_stats_inc(&tx_stats->tx_packets);
+		u64_stats_add(&tx_stats->tx_bytes, skb->len);
 		u64_stats_update_end(&tx_stats->syncp_tx);
 		dev_kfree_skb(skb);
 		pkts++;
@@ -1973,14 +1973,14 @@ netcp_get_stats(struct net_device *ndev, struct rtnl_link_stats64 *stats)
 
 	do {
 		start = u64_stats_fetch_begin(&p->syncp_rx);
-		rxpackets       = p->rx_packets;
-		rxbytes         = p->rx_bytes;
+		rxpackets       = u64_stats_read(&p->rx_packets);
+		rxbytes         = u64_stats_read(&p->rx_bytes);
 	} while (u64_stats_fetch_retry(&p->syncp_rx, start));
 
 	do {
 		start = u64_stats_fetch_begin(&p->syncp_tx);
-		txpackets       = p->tx_packets;
-		txbytes         = p->tx_bytes;
+		txpackets       = u64_stats_read(&p->tx_packets);
+		txbytes         = u64_stats_read(&p->tx_bytes);
 	} while (u64_stats_fetch_retry(&p->syncp_tx, start));
 
 	stats->rx_packets = rxpackets;
-- 
2.51.0