Track transmit counters per TX queue to avoid cache line contention in
the xmit hot path and expose per-queue visibility via ethtool -S and
ndo_get_stats64() aggregation.

Global tx_large_packets and tx_send_failed continue to be aggregated on
the ethtool read path for backward compatibility with existing tools.

Signed-off-by: Mingming Cao <[email protected]>
Reviewed-by: Dave Marquardt <[email protected]>
---
 drivers/net/ethernet/ibm/ibmveth.c | 129 +++++++++++++++++++++++++----
 drivers/net/ethernet/ibm/ibmveth.h |  13 +++
 2 files changed, 124 insertions(+), 18 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmveth.c 
b/drivers/net/ethernet/ibm/ibmveth.c
index 1c08082ffbd6..4e3f49b6346f 100644
--- a/drivers/net/ethernet/ibm/ibmveth.c
+++ b/drivers/net/ethernet/ibm/ibmveth.c
@@ -252,6 +252,33 @@ static void ibmveth_free_rx_qstats(struct ibmveth_adapter 
*adapter)
        adapter->rx_qstats = NULL;
 }
 
+/**
+ * ibmveth_alloc_tx_qstats - Allocate per-queue TX statistics
+ * @adapter: ibmveth adapter structure
+ *
+ * Return: 0 on success, -ENOMEM on failure
+ */
+static int ibmveth_alloc_tx_qstats(struct ibmveth_adapter *adapter)
+{
+       adapter->tx_qstats = kcalloc(IBMVETH_MAX_QUEUES,
+                                    sizeof(struct ibmveth_tx_queue_stats),
+                                    GFP_KERNEL);
+       if (!adapter->tx_qstats)
+               return -ENOMEM;
+
+       return 0;
+}
+
+/**
+ * ibmveth_free_tx_qstats - Free per-queue TX statistics
+ * @adapter: ibmveth adapter structure
+ */
+static void ibmveth_free_tx_qstats(struct ibmveth_adapter *adapter)
+{
+       kfree(adapter->tx_qstats);
+       adapter->tx_qstats = NULL;
+}
+
 /**
  * ibmveth_alloc_rx_queues - Allocate per-queue RX resources
  * @adapter: ibmveth adapter structure
@@ -1628,6 +1655,10 @@ static int ibmveth_open(struct net_device *netdev)
        if (rc)
                goto out_cleanup_rx_interrupts;
 
+       rc = ibmveth_alloc_tx_qstats(adapter);
+       if (rc)
+               goto out_free_tx_resources;
+
        netif_tx_start_all_queues(netdev);
 
        netdev_dbg(netdev, "open complete\n");
@@ -1668,6 +1699,7 @@ static int ibmveth_close(struct net_device *netdev)
                }
        }
 
+       ibmveth_free_tx_qstats(adapter);
        ibmveth_free_tx_resources(adapter);
        ibmveth_cleanup_rx_interrupts(adapter);
        ibmveth_update_rx_no_buffer(adapter);
@@ -1960,6 +1992,32 @@ static void ibmveth_aggregate_rx_qstats(struct 
ibmveth_adapter *adapter)
        adapter->rx_large_packets = total_large;
 }
 
+/**
+ * ibmveth_aggregate_tx_qstats - Sum per-queue TX stats into globals
+ * @adapter: ibmveth adapter
+ *
+ * Cold path only (ethtool). Keeps legacy global counters meaningful for
+ * tools that read the adapter-level fields in ibmveth_stats[].
+ */
+static void ibmveth_aggregate_tx_qstats(struct ibmveth_adapter *adapter)
+{
+       struct net_device *netdev = adapter->netdev;
+       u64 total_large = 0;
+       u64 total_send_failed = 0;
+       int i;
+
+       if (!adapter->tx_qstats)
+               return;
+
+       for (i = 0; i < netdev->real_num_tx_queues; i++) {
+               total_large += adapter->tx_qstats[i].large_packets;
+               total_send_failed += adapter->tx_qstats[i].send_failures;
+       }
+
+       adapter->tx_large_packets = total_large;
+       adapter->tx_send_failed = total_send_failed;
+}
+
 static void ibmveth_get_strings(struct net_device *dev, u32 stringset, u8 
*data)
 {
        struct ibmveth_adapter *adapter = netdev_priv(dev);
@@ -1984,6 +2042,15 @@ static void ibmveth_get_strings(struct net_device *dev, 
u32 stringset, u8 *data)
                ethtool_sprintf(&p, "rx%d_no_buffer_drops", i);
        }
 
+       for (i = 0; i < dev->real_num_tx_queues; i++) {
+               ethtool_sprintf(&p, "tx%d_packets", i);
+               ethtool_sprintf(&p, "tx%d_bytes", i);
+               ethtool_sprintf(&p, "tx%d_large_packets", i);
+               ethtool_sprintf(&p, "tx%d_dropped_packets", i);
+               ethtool_sprintf(&p, "tx%d_send_failures", i);
+               ethtool_sprintf(&p, "tx%d_checksum_offload", i);
+       }
+
        for (i = 0; i < IBMVETH_NUM_BUFF_POOLS; i++) {
                ethtool_sprintf(&p, "pool%d_size", i);
                ethtool_sprintf(&p, "pool%d_active", i);
@@ -1999,6 +2066,7 @@ static int ibmveth_get_sset_count(struct net_device *dev, 
int sset)
        case ETH_SS_STATS:
                return ARRAY_SIZE(ibmveth_stats) +
                       adapter->num_rx_queues * IBMVETH_NUM_RX_QSTATS +
+                      dev->real_num_tx_queues * IBMVETH_NUM_TX_QSTATS +
                       IBMVETH_NUM_BUFF_POOLS * 3;
        default:
                return -EOPNOTSUPP;
@@ -2012,6 +2080,7 @@ static void ibmveth_get_ethtool_stats(struct net_device 
*dev,
        int i, j;
 
        ibmveth_aggregate_rx_qstats(adapter);
+       ibmveth_aggregate_tx_qstats(adapter);
 
        for (i = 0; i < ARRAY_SIZE(ibmveth_stats); i++)
                data[i] = IBMVETH_GET_STAT(adapter, ibmveth_stats[i].offset);
@@ -2030,6 +2099,19 @@ static void ibmveth_get_ethtool_stats(struct net_device 
*dev,
                }
        }
 
+       for (j = 0; j < dev->real_num_tx_queues; j++) {
+               if (adapter->tx_qstats) {
+                       data[i++] = adapter->tx_qstats[j].packets;
+                       data[i++] = adapter->tx_qstats[j].bytes;
+                       data[i++] = adapter->tx_qstats[j].large_packets;
+                       data[i++] = adapter->tx_qstats[j].dropped_packets;
+                       data[i++] = adapter->tx_qstats[j].send_failures;
+                       data[i++] = adapter->tx_qstats[j].checksum_offload;
+               } else {
+                       i += IBMVETH_NUM_TX_QSTATS;
+               }
+       }
+
        for (j = 0; j < IBMVETH_NUM_BUFF_POOLS; j++) {
                data[i++] = adapter->rx_buff_pool[0][j].size;
                data[i++] = adapter->rx_buff_pool[0][j].active;
@@ -2152,8 +2234,10 @@ static int ibmveth_send(struct ibmveth_adapter *adapter,
 }
 
 static int ibmveth_is_packet_unsupported(struct sk_buff *skb,
-                                        struct net_device *netdev)
+                                        struct ibmveth_adapter *adapter,
+                                        int queue_num)
 {
+       struct net_device *netdev = adapter->netdev;
        struct ethhdr *ether_header;
        int ret = 0;
 
@@ -2161,7 +2245,8 @@ static int ibmveth_is_packet_unsupported(struct sk_buff 
*skb,
 
        if (ether_addr_equal(ether_header->h_dest, netdev->dev_addr)) {
                netdev_dbg(netdev, "veth doesn't support loopback packets, 
dropping packet.\n");
-               netdev->stats.tx_dropped++;
+               if (adapter->tx_qstats)
+                       adapter->tx_qstats[queue_num].dropped_packets++;
                ret = -EOPNOTSUPP;
        }
 
@@ -2177,7 +2262,7 @@ static netdev_tx_t ibmveth_start_xmit(struct sk_buff *skb,
        int i, queue_num = skb_get_queue_mapping(skb);
        unsigned long mss = 0;
 
-       if (ibmveth_is_packet_unsupported(skb, netdev))
+       if (ibmveth_is_packet_unsupported(skb, adapter, queue_num))
                goto out;
        /* veth can't checksum offload UDP */
        if (skb->ip_summed == CHECKSUM_PARTIAL &&
@@ -2188,7 +2273,7 @@ static netdev_tx_t ibmveth_start_xmit(struct sk_buff *skb,
            skb_checksum_help(skb)) {
 
                netdev_err(netdev, "tx: failed to checksum packet\n");
-               netdev->stats.tx_dropped++;
+               adapter->tx_qstats[queue_num].dropped_packets++;
                goto out;
        }
 
@@ -2200,6 +2285,8 @@ static netdev_tx_t ibmveth_start_xmit(struct sk_buff *skb,
 
                desc_flags |= (IBMVETH_BUF_NO_CSUM | IBMVETH_BUF_CSUM_GOOD);
 
+               adapter->tx_qstats[queue_num].checksum_offload++;
+
                /* Need to zero out the checksum */
                buf[0] = 0;
                buf[1] = 0;
@@ -2211,7 +2298,7 @@ static netdev_tx_t ibmveth_start_xmit(struct sk_buff *skb,
        if (skb->ip_summed == CHECKSUM_PARTIAL && skb_is_gso(skb)) {
                if (adapter->fw_large_send_support) {
                        mss = (unsigned long)skb_shinfo(skb)->gso_size;
-                       adapter->tx_large_packets++;
+                       adapter->tx_qstats[queue_num].large_packets++;
                } else if (!skb_is_gso_v6(skb)) {
                        /* Put -1 in the IP checksum to tell phyp it
                         * is a largesend packet. Put the mss in
@@ -2220,7 +2307,7 @@ static netdev_tx_t ibmveth_start_xmit(struct sk_buff *skb,
                        ip_hdr(skb)->check = 0xffff;
                        tcp_hdr(skb)->check =
                                cpu_to_be16(skb_shinfo(skb)->gso_size);
-                       adapter->tx_large_packets++;
+                       adapter->tx_qstats[queue_num].large_packets++;
                }
        }
 
@@ -2228,7 +2315,7 @@ static netdev_tx_t ibmveth_start_xmit(struct sk_buff *skb,
        if (unlikely(skb->len > adapter->tx_ltb_size)) {
                netdev_err(adapter->netdev, "tx: packet size (%u) exceeds ltb 
(%u)\n",
                           skb->len, adapter->tx_ltb_size);
-               netdev->stats.tx_dropped++;
+               adapter->tx_qstats[queue_num].dropped_packets++;
                goto out;
        }
        memcpy(adapter->tx_ltb_ptr[queue_num], skb->data, skb_headlen(skb));
@@ -2245,7 +2332,7 @@ static netdev_tx_t ibmveth_start_xmit(struct sk_buff *skb,
        if (unlikely(total_bytes != skb->len)) {
                netdev_err(adapter->netdev, "tx: incorrect packet len copied 
into ltb (%u != %u)\n",
                           skb->len, total_bytes);
-               netdev->stats.tx_dropped++;
+               adapter->tx_qstats[queue_num].dropped_packets++;
                goto out;
        }
        desc.fields.flags_len = desc_flags | skb->len;
@@ -2254,11 +2341,11 @@ static netdev_tx_t ibmveth_start_xmit(struct sk_buff 
*skb,
        dma_wmb();
 
        if (ibmveth_send(adapter, desc.desc, mss)) {
-               adapter->tx_send_failed++;
-               netdev->stats.tx_dropped++;
+               adapter->tx_qstats[queue_num].send_failures++;
+               adapter->tx_qstats[queue_num].dropped_packets++;
        } else {
-               netdev->stats.tx_packets++;
-               netdev->stats.tx_bytes += skb->len;
+               adapter->tx_qstats[queue_num].packets++;
+               adapter->tx_qstats[queue_num].bytes += skb->len;
        }
 
 out:
@@ -2759,12 +2846,13 @@ static netdev_features_t ibmveth_features_check(struct 
sk_buff *skb,
 }
 
 /**
- * ibmveth_get_stats64 - Return aggregated per-queue RX statistics
+ * ibmveth_get_stats64 - Return aggregated per-queue statistics
  * @dev: network device
  * @stats: rtnl link statistics storage
  *
- * Sums per-queue rx_qstats into rx_packets/rx_bytes for multi-queue mode.
- * TX counters continue to come from netdev->stats (updated in start_xmit).
+ * Sums per-queue rx_qstats and tx_qstats into the rtnl counters.
+ * Callers use ndo_get_stats64(); avoid updating netdev->stats on the
+ * xmit/poll paths to keep per-queue counters off the hot cache line.
  */
 static void ibmveth_get_stats64(struct net_device *dev,
                                struct rtnl_link_stats64 *stats)
@@ -2779,9 +2867,14 @@ static void ibmveth_get_stats64(struct net_device *dev,
                }
        }
 
-       stats->tx_packets = dev->stats.tx_packets;
-       stats->tx_bytes = dev->stats.tx_bytes;
-       stats->tx_dropped = dev->stats.tx_dropped;
+       if (adapter->tx_qstats) {
+               for (i = 0; i < dev->real_num_tx_queues; i++) {
+                       stats->tx_packets += adapter->tx_qstats[i].packets;
+                       stats->tx_bytes += adapter->tx_qstats[i].bytes;
+                       stats->tx_dropped += 
adapter->tx_qstats[i].dropped_packets;
+               }
+       }
+
        stats->tx_errors = dev->stats.tx_errors;
 }
 
diff --git a/drivers/net/ethernet/ibm/ibmveth.h 
b/drivers/net/ethernet/ibm/ibmveth.h
index f7b20fd01acb..390c660af979 100644
--- a/drivers/net/ethernet/ibm/ibmveth.h
+++ b/drivers/net/ethernet/ibm/ibmveth.h
@@ -316,9 +316,21 @@ struct ibmveth_rx_queue_stats {
        u64 no_buffer_drops;
 };
 
+struct ibmveth_tx_queue_stats {
+       u64 packets;
+       u64 bytes;
+       u64 large_packets;
+       u64 dropped_packets;
+       u64 send_failures;
+       u64 checksum_offload;
+};
+
 #define IBMVETH_NUM_RX_QSTATS \
        (sizeof(struct ibmveth_rx_queue_stats) / sizeof(u64))
 
+#define IBMVETH_NUM_TX_QSTATS \
+       (sizeof(struct ibmveth_tx_queue_stats) / sizeof(u64))
+
 struct ibmveth_buff_pool {
     u32 size;
     u32 index;
@@ -386,6 +398,7 @@ struct ibmveth_adapter {
        /* Multi-queue statistics */
        struct ibmveth_hcall_stats hcall_stats;
        struct ibmveth_rx_queue_stats *rx_qstats;
+       struct ibmveth_tx_queue_stats *tx_qstats;
 
        /* Ethtool settings */
        u8 duplex;
-- 
2.39.3 (Apple Git-146)


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