Commit 3eef6c06 authored by David Yang's avatar David Yang Committed by Jakub Kicinski
Browse files

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: default avatarDavid Yang <mmyangfl@gmail.com>
Link: https://patch.msgid.link/20260123164841.2890054-1-mmyangfl@gmail.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 5c05b3db

drivers/net/ethernet/ti/netcp.h

+4 −4
Original line number Diff line number Diff line
@@ -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;

};

drivers/net/ethernet/ti/netcp_core.c

+8 −8
Original line number Diff line number Diff line
@@ -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;