From de7d5084d82794a8e83afb994fcb07f82da3cd7b Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 7 Nov 2019 16:27:14 -0800 Subject: net: provide dev_lstats_read() helper Many network drivers use hand-coded implementation of the same thing, let's factorize things so that u64_stats_t adoption is done once. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- drivers/net/loopback.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) (limited to 'drivers/net/loopback.c') diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c index 14545a8797a8..92336ac4c5e6 100644 --- a/drivers/net/loopback.c +++ b/drivers/net/loopback.c @@ -99,13 +99,13 @@ static netdev_tx_t loopback_xmit(struct sk_buff *skb, return NETDEV_TX_OK; } -static void loopback_get_stats64(struct net_device *dev, - struct rtnl_link_stats64 *stats) +void dev_lstats_read(struct net_device *dev, u64 *packets, u64 *bytes) { - u64 bytes = 0; - u64 packets = 0; int i; + *packets = 0; + *bytes = 0; + for_each_possible_cpu(i) { const struct pcpu_lstats *lb_stats; u64 tbytes, tpackets; @@ -114,12 +114,22 @@ static void loopback_get_stats64(struct net_device *dev, lb_stats = per_cpu_ptr(dev->lstats, i); do { start = u64_stats_fetch_begin_irq(&lb_stats->syncp); - tbytes = lb_stats->bytes; tpackets = lb_stats->packets; + tbytes = lb_stats->bytes; } while (u64_stats_fetch_retry_irq(&lb_stats->syncp, start)); - bytes += tbytes; - packets += tpackets; + *bytes += tbytes; + *packets += tpackets; } +} +EXPORT_SYMBOL(dev_lstats_read); + +static void loopback_get_stats64(struct net_device *dev, + struct rtnl_link_stats64 *stats) +{ + u64 packets, bytes; + + dev_lstats_read(dev, &packets, &bytes); + stats->rx_packets = packets; stats->tx_packets = packets; stats->rx_bytes = bytes; -- cgit v1.2.3 From dd5382a08157756510aa8d7269c662eccde775cb Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 7 Nov 2019 16:27:15 -0800 Subject: net: provide dev_lstats_add() helper Many network drivers need it and hand-coded the same function. In order to ease u64_stats_t adoption, it is time to factorize. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- drivers/net/loopback.c | 12 ++---------- include/linux/netdevice.h | 10 ++++++++++ 2 files changed, 12 insertions(+), 10 deletions(-) (limited to 'drivers/net/loopback.c') diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c index 92336ac4c5e6..47ad2478b9f3 100644 --- a/drivers/net/loopback.c +++ b/drivers/net/loopback.c @@ -68,7 +68,6 @@ EXPORT_SYMBOL(blackhole_netdev); static netdev_tx_t loopback_xmit(struct sk_buff *skb, struct net_device *dev) { - struct pcpu_lstats *lb_stats; int len; skb_tx_timestamp(skb); @@ -85,16 +84,9 @@ static netdev_tx_t loopback_xmit(struct sk_buff *skb, skb->protocol = eth_type_trans(skb, dev); - /* it's OK to use per_cpu_ptr() because BHs are off */ - lb_stats = this_cpu_ptr(dev->lstats); - len = skb->len; - if (likely(netif_rx(skb) == NET_RX_SUCCESS)) { - u64_stats_update_begin(&lb_stats->syncp); - lb_stats->bytes += len; - lb_stats->packets++; - u64_stats_update_end(&lb_stats->syncp); - } + if (likely(netif_rx(skb) == NET_RX_SUCCESS)) + dev_lstats_add(dev, len); return NETDEV_TX_OK; } diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 75561992c31f..461a36220cf4 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2403,6 +2403,16 @@ struct pcpu_lstats { void dev_lstats_read(struct net_device *dev, u64 *packets, u64 *bytes); +static inline void dev_lstats_add(struct net_device *dev, unsigned int len) +{ + struct pcpu_lstats *lstats = this_cpu_ptr(dev->lstats); + + u64_stats_update_begin(&lstats->syncp); + lstats->bytes += len; + lstats->packets++; + u64_stats_update_end(&lstats->syncp); +} + #define __netdev_alloc_pcpu_stats(type, gfp) \ ({ \ typeof(type) __percpu *pcpu_stats = alloc_percpu_gfp(type, gfp);\ -- cgit v1.2.3 From fd2f4737870eb866537fbbffa2b59414b9b0c0a2 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 7 Nov 2019 16:27:22 -0800 Subject: net: use u64_stats_t in struct pcpu_lstats In order to fix the data-race found by KCSAN, we can use the new u64_stats_t type and its accessors instead of plain u64 fields. This will still generate optimal code for both 32 and 64 bit platforms. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- drivers/net/loopback.c | 4 ++-- include/linux/netdevice.h | 8 ++++---- 2 files changed, 6 insertions(+), 6 deletions(-) (limited to 'drivers/net/loopback.c') diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c index 47ad2478b9f3..a1c77cc00416 100644 --- a/drivers/net/loopback.c +++ b/drivers/net/loopback.c @@ -106,8 +106,8 @@ void dev_lstats_read(struct net_device *dev, u64 *packets, u64 *bytes) lb_stats = per_cpu_ptr(dev->lstats, i); do { start = u64_stats_fetch_begin_irq(&lb_stats->syncp); - tpackets = lb_stats->packets; - tbytes = lb_stats->bytes; + tpackets = u64_stats_read(&lb_stats->packets); + tbytes = u64_stats_read(&lb_stats->bytes); } while (u64_stats_fetch_retry_irq(&lb_stats->syncp, start)); *bytes += tbytes; *packets += tpackets; diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 461a36220cf4..f857f01234f7 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2396,8 +2396,8 @@ struct pcpu_sw_netstats { } __aligned(4 * sizeof(u64)); struct pcpu_lstats { - u64 packets; - u64 bytes; + u64_stats_t packets; + u64_stats_t bytes; struct u64_stats_sync syncp; } __aligned(2 * sizeof(u64)); @@ -2408,8 +2408,8 @@ static inline void dev_lstats_add(struct net_device *dev, unsigned int len) struct pcpu_lstats *lstats = this_cpu_ptr(dev->lstats); u64_stats_update_begin(&lstats->syncp); - lstats->bytes += len; - lstats->packets++; + u64_stats_add(&lstats->bytes, len); + u64_stats_inc(&lstats->packets); u64_stats_update_end(&lstats->syncp); } -- cgit v1.2.3