net: ifb: support ethtools stats

With this feature, we can use the ethtools to get tx/rx
queues stats. This patch, introduce the ifb_update_q_stats
helper to update the queues stats, and ifb_q_stats to simplify
the codes.

Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Link: https://lore.kernel.org/r/20211128014631.43627-1-xiangxia.m.yue@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ifb.c b/drivers/net/ifb.c
index 31f522b..1c64d53 100644 (file)
--- a/drivers/net/ifb.c
+++ b/drivers/net/ifb.c
@@ -27,6 +27,7 @@
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/netdevice.h>
+#include <linux/ethtool.h>
 #include <linux/etherdevice.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
@@ -36,30 +37,55 @@
 #include <net/net_namespace.h>
 
 #define TX_Q_LIMIT    32
+
+struct ifb_q_stats {
+       u64 packets;
+       u64 bytes;
+       struct u64_stats_sync   sync;
+};
+
 struct ifb_q_private {
        struct net_device       *dev;
        struct tasklet_struct   ifb_tasklet;
        int                     tasklet_pending;
        int                     txqnum;
        struct sk_buff_head     rq;
-       u64                     rx_packets;
-       u64                     rx_bytes;
-       struct u64_stats_sync   rsync;
-
-       struct u64_stats_sync   tsync;
-       u64                     tx_packets;
-       u64                     tx_bytes;
        struct sk_buff_head     tq;
+       struct ifb_q_stats      rx_stats;
+       struct ifb_q_stats      tx_stats;
 } ____cacheline_aligned_in_smp;
 
 struct ifb_dev_private {
        struct ifb_q_private *tx_private;
 };
 
+/* For ethtools stats. */
+struct ifb_q_stats_desc {
+       char    desc[ETH_GSTRING_LEN];
+       size_t  offset;
+};
+
+#define IFB_Q_STAT(m)  offsetof(struct ifb_q_stats, m)
+
+static const struct ifb_q_stats_desc ifb_q_stats_desc[] = {
+       { "packets",    IFB_Q_STAT(packets) },
+       { "bytes",      IFB_Q_STAT(bytes) },
+};
+
+#define IFB_Q_STATS_LEN        ARRAY_SIZE(ifb_q_stats_desc)
+
 static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev);
 static int ifb_open(struct net_device *dev);
 static int ifb_close(struct net_device *dev);
 
+static void ifb_update_q_stats(struct ifb_q_stats *stats, int len)
+{
+       u64_stats_update_begin(&stats->sync);
+       stats->packets++;
+       stats->bytes += len;
+       u64_stats_update_end(&stats->sync);
+}
+
 static void ifb_ri_tasklet(struct tasklet_struct *t)
 {
        struct ifb_q_private *txp = from_tasklet(txp, t, ifb_tasklet);
@@ -83,10 +109,7 @@ static void ifb_ri_tasklet(struct tasklet_struct *t)
 #endif
                nf_skip_egress(skb, true);
 
-               u64_stats_update_begin(&txp->tsync);
-               txp->tx_packets++;
-               txp->tx_bytes += skb->len;
-               u64_stats_update_end(&txp->tsync);
+               ifb_update_q_stats(&txp->tx_stats, skb->len);
 
                rcu_read_lock();
                skb->dev = dev_get_by_index_rcu(dev_net(txp->dev), skb->skb_iif);
@@ -139,18 +162,18 @@ static void ifb_stats64(struct net_device *dev,
 
        for (i = 0; i < dev->num_tx_queues; i++,txp++) {
                do {
-                       start = u64_stats_fetch_begin_irq(&txp->rsync);
-                       packets = txp->rx_packets;
-                       bytes = txp->rx_bytes;
-               } while (u64_stats_fetch_retry_irq(&txp->rsync, start));
+                       start = u64_stats_fetch_begin_irq(&txp->rx_stats.sync);
+                       packets = txp->rx_stats.packets;
+                       bytes = txp->rx_stats.bytes;
+               } while (u64_stats_fetch_retry_irq(&txp->rx_stats.sync, start));
                stats->rx_packets += packets;
                stats->rx_bytes += bytes;
 
                do {
-                       start = u64_stats_fetch_begin_irq(&txp->tsync);
-                       packets = txp->tx_packets;
-                       bytes = txp->tx_bytes;
-               } while (u64_stats_fetch_retry_irq(&txp->tsync, start));
+                       start = u64_stats_fetch_begin_irq(&txp->tx_stats.sync);
+                       packets = txp->tx_stats.packets;
+                       bytes = txp->tx_stats.bytes;
+               } while (u64_stats_fetch_retry_irq(&txp->tx_stats.sync, start));
                stats->tx_packets += packets;
                stats->tx_bytes += bytes;
        }
@@ -173,14 +196,83 @@ static int ifb_dev_init(struct net_device *dev)
                txp->dev = dev;
                __skb_queue_head_init(&txp->rq);
                __skb_queue_head_init(&txp->tq);
-               u64_stats_init(&txp->rsync);
-               u64_stats_init(&txp->tsync);
+               u64_stats_init(&txp->rx_stats.sync);
+               u64_stats_init(&txp->tx_stats.sync);
                tasklet_setup(&txp->ifb_tasklet, ifb_ri_tasklet);
                netif_tx_start_queue(netdev_get_tx_queue(dev, i));
        }
        return 0;
 }
 
+static void ifb_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
+{
+       u8 *p = buf;
+       int i, j;
+
+       switch (stringset) {
+       case ETH_SS_STATS:
+               for (i = 0; i < dev->real_num_rx_queues; i++)
+                       for (j = 0; j < IFB_Q_STATS_LEN; j++)
+                               ethtool_sprintf(&p, "rx_queue_%u_%.18s",
+                                               i, ifb_q_stats_desc[j].desc);
+
+               for (i = 0; i < dev->real_num_tx_queues; i++)
+                       for (j = 0; j < IFB_Q_STATS_LEN; j++)
+                               ethtool_sprintf(&p, "tx_queue_%u_%.18s",
+                                               i, ifb_q_stats_desc[j].desc);
+
+               break;
+       }
+}
+
+static int ifb_get_sset_count(struct net_device *dev, int sset)
+{
+       switch (sset) {
+       case ETH_SS_STATS:
+               return IFB_Q_STATS_LEN * (dev->real_num_rx_queues +
+                                         dev->real_num_tx_queues);
+       default:
+               return -EOPNOTSUPP;
+       }
+}
+
+static void ifb_fill_stats_data(u64 **data,
+                               struct ifb_q_stats *q_stats)
+{
+       void *stats_base = (void *)q_stats;
+       unsigned int start;
+       size_t offset;
+       int j;
+
+       do {
+               start = u64_stats_fetch_begin_irq(&q_stats->sync);
+               for (j = 0; j < IFB_Q_STATS_LEN; j++) {
+                       offset = ifb_q_stats_desc[j].offset;
+                       (*data)[j] = *(u64 *)(stats_base + offset);
+               }
+       } while (u64_stats_fetch_retry_irq(&q_stats->sync, start));
+
+       *data += IFB_Q_STATS_LEN;
+}
+
+static void ifb_get_ethtool_stats(struct net_device *dev,
+                                 struct ethtool_stats *stats, u64 *data)
+{
+       struct ifb_dev_private *dp = netdev_priv(dev);
+       struct ifb_q_private *txp;
+       int i;
+
+       for (i = 0; i < dev->real_num_rx_queues; i++) {
+               txp = dp->tx_private + i;
+               ifb_fill_stats_data(&data, &txp->rx_stats);
+       }
+
+       for (i = 0; i < dev->real_num_tx_queues; i++) {
+               txp = dp->tx_private + i;
+               ifb_fill_stats_data(&data, &txp->tx_stats);
+       }
+}
+
 static const struct net_device_ops ifb_netdev_ops = {
        .ndo_open       = ifb_open,
        .ndo_stop       = ifb_close,
@@ -190,6 +282,12 @@ static const struct net_device_ops ifb_netdev_ops = {
        .ndo_init       = ifb_dev_init,
 };
 
+static const struct ethtool_ops ifb_ethtool_ops = {
+       .get_strings            = ifb_get_strings,
+       .get_sset_count         = ifb_get_sset_count,
+       .get_ethtool_stats      = ifb_get_ethtool_stats,
+};
+
 #define IFB_FEATURES (NETIF_F_HW_CSUM | NETIF_F_SG  | NETIF_F_FRAGLIST | \
                      NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL      | \
                      NETIF_F_HIGHDMA | NETIF_F_HW_VLAN_CTAG_TX         | \
@@ -213,6 +311,7 @@ static void ifb_setup(struct net_device *dev)
 {
        /* Initialize the device structure. */
        dev->netdev_ops = &ifb_netdev_ops;
+       dev->ethtool_ops = &ifb_ethtool_ops;
 
        /* Fill in device structure with ethernet-generic values. */
        ether_setup(dev);
@@ -241,10 +340,7 @@ static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev)
        struct ifb_dev_private *dp = netdev_priv(dev);
        struct ifb_q_private *txp = dp->tx_private + skb_get_queue_mapping(skb);
 
-       u64_stats_update_begin(&txp->rsync);
-       txp->rx_packets++;
-       txp->rx_bytes += skb->len;
-       u64_stats_update_end(&txp->rsync);
+       ifb_update_q_stats(&txp->rx_stats, skb->len);
 
        if (!skb->redirected || !skb->skb_iif) {
                dev_kfree_skb(skb);