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 <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index 14545a8797a8a2c9b61abc96cbdb1a3542481745..92336ac4c5e68f63b814d6a70e7361b8954a91cf 100644 (file)
--- 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;

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 1f140a6b66dfbd1dd86d2d6b0e0adb812de4b243..75561992c31f7c32f5a50e3879bafb5a54bc5fa3 100644 (file)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2401,6 +2401,8 @@ struct pcpu_lstats {
        struct u64_stats_sync syncp;
 } __aligned(2 * sizeof(u64));
 
+void dev_lstats_read(struct net_device *dev, u64 *packets, u64 *bytes);
+
 #define __netdev_alloc_pcpu_stats(type, gfp)                           \
 ({                                                                     \
        typeof(type) __percpu *pcpu_stats = alloc_percpu_gfp(type, gfp);\