net: enetc: count the tc-taprio window drops

The enetc scheduler for IEEE 802.1Qbv has 2 options (depending on
PTGCR[TG_DROP_DISABLE]) when we attempt to send an oversized packet
which will never fit in its allotted time slot for its traffic class:
either block the entire port due to head-of-line blocking, or drop the
packet and set a bit in the writeback format of the transmit buffer
descriptor, allowing other packets to be sent.

We obviously choose the second option in the driver, but we do not
detect the drop condition, so from the perspective of the network stack,
the packet is sent and no error counter is incremented.

This change checks the writeback of the TX BD when tc-taprio is enabled,
and increments a specific ethtool statistics counter and a generic
"tx_dropped" counter in ndo_get_stats64.

Signed-off-by: Po Liu <Po.Liu@nxp.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index d6930a797c6c323f0f5038b005edcf669ba52894..4470a4a3e4c3ead28f46d769436bba29e181db83 100644 (file)
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -172,7 +172,8 @@ static int enetc_map_tx_buffs(struct enetc_bdr *tx_ring, struct sk_buff *skb)
        }
 
        tx_swbd->do_twostep_tstamp = do_twostep_tstamp;
-       tx_swbd->check_wb = tx_swbd->do_twostep_tstamp;
+       tx_swbd->qbv_en = !!(priv->active_offloads & ENETC_F_QBV);
+       tx_swbd->check_wb = tx_swbd->do_twostep_tstamp || tx_swbd->qbv_en;
 
        if (do_vlan || do_onestep_tstamp || do_twostep_tstamp)
                flags |= ENETC_TXBD_FLAGS_EX;
@@ -792,9 +793,9 @@ static void enetc_recycle_xdp_tx_buff(struct enetc_bdr *tx_ring,
 
 static bool enetc_clean_tx_ring(struct enetc_bdr *tx_ring, int napi_budget)
 {
+       int tx_frm_cnt = 0, tx_byte_cnt = 0, tx_win_drop = 0;
        struct net_device *ndev = tx_ring->ndev;
        struct enetc_ndev_priv *priv = netdev_priv(ndev);
-       int tx_frm_cnt = 0, tx_byte_cnt = 0;
        struct enetc_tx_swbd *tx_swbd;
        int i, bds_to_clean;
        bool do_twostep_tstamp;
@@ -821,6 +822,10 @@ static bool enetc_clean_tx_ring(struct enetc_bdr *tx_ring, int napi_budget)
                                                    &tstamp);
                                do_twostep_tstamp = true;
                        }
+
+                       if (tx_swbd->qbv_en &&
+                           txbd->wb.status & ENETC_TXBD_STATS_WIN)
+                               tx_win_drop++;
                }
 
                if (tx_swbd->is_xdp_tx)
@@ -873,6 +878,7 @@ static bool enetc_clean_tx_ring(struct enetc_bdr *tx_ring, int napi_budget)
        tx_ring->next_to_clean = i;
        tx_ring->stats.packets += tx_frm_cnt;
        tx_ring->stats.bytes += tx_byte_cnt;
+       tx_ring->stats.win_drop += tx_win_drop;
 
        if (unlikely(tx_frm_cnt && netif_carrier_ok(ndev) &&
                     __netif_subqueue_stopped(ndev, tx_ring->index) &&
@@ -2552,6 +2558,7 @@ struct net_device_stats *enetc_get_stats(struct net_device *ndev)
        struct enetc_ndev_priv *priv = netdev_priv(ndev);
        struct net_device_stats *stats = &ndev->stats;
        unsigned long packets = 0, bytes = 0;
+       unsigned long tx_dropped = 0;
        int i;
 
        for (i = 0; i < priv->num_rx_rings; i++) {
@@ -2567,10 +2574,12 @@ struct net_device_stats *enetc_get_stats(struct net_device *ndev)
        for (i = 0; i < priv->num_tx_rings; i++) {
                packets += priv->tx_ring[i]->stats.packets;
                bytes   += priv->tx_ring[i]->stats.bytes;
+               tx_dropped += priv->tx_ring[i]->stats.win_drop;
        }
 
        stats->tx_packets = packets;
        stats->tx_bytes = bytes;
+       stats->tx_dropped = tx_dropped;
 
        return stats;
 }

diff --git a/drivers/net/ethernet/freescale/enetc/enetc.h b/drivers/net/ethernet/freescale/enetc/enetc.h
index 68d806dc3701da5c9cf930d4c17e0f00357a32f2..29922c20531f0a43ed1e480dc769b3efb46f71ac 100644 (file)
--- a/drivers/net/ethernet/freescale/enetc/enetc.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc.h
@@ -36,6 +36,7 @@ struct enetc_tx_swbd {
        u8 is_eof:1;
        u8 is_xdp_tx:1;
        u8 is_xdp_redirect:1;
+       u8 qbv_en:1;
 };
 
 #define ENETC_RX_MAXFRM_SIZE   ENETC_MAC_MAXFRM_SIZE
@@ -72,6 +73,7 @@ struct enetc_ring_stats {
        unsigned int xdp_redirect_sg;
        unsigned int recycles;
        unsigned int recycle_failures;
+       unsigned int win_drop;
 };
 
 struct enetc_xdp_data {

diff --git a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
index 60ec64bfb3f0b52b77187bd52fe1efdd3c63e96d..ff872e40ce85d7617f21f1587ffe4bd4bf58f441 100644 (file)
--- a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
@@ -204,6 +204,7 @@ static const char tx_ring_stats[][ETH_GSTRING_LEN] = {
        "Tx ring %2d frames",
        "Tx ring %2d XDP frames",
        "Tx ring %2d XDP drops",
+       "Tx window drop %2d frames",
 };
 
 static int enetc_get_sset_count(struct net_device *ndev, int sset)
@@ -279,6 +280,7 @@ static void enetc_get_ethtool_stats(struct net_device *ndev,
                data[o++] = priv->tx_ring[i]->stats.packets;
                data[o++] = priv->tx_ring[i]->stats.xdp_tx;
                data[o++] = priv->tx_ring[i]->stats.xdp_tx_drops;
+               data[o++] = priv->tx_ring[i]->stats.win_drop;
        }
 
        for (i = 0; i < priv->num_rx_rings; i++) {

diff --git a/drivers/net/ethernet/freescale/enetc/enetc_hw.h b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
index ce5b677e8c2fcfa6caceca470a77ce6b567f4c9e..647c87f73bf75791b8d8553a0c9f47149aa4111b 100644 (file)
--- a/drivers/net/ethernet/freescale/enetc/enetc_hw.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
@@ -543,6 +543,7 @@ enum enetc_txbd_flags {
        ENETC_TXBD_FLAGS_EX = BIT(6),
        ENETC_TXBD_FLAGS_F = BIT(7)
 };
+#define ENETC_TXBD_STATS_WIN   BIT(7)
 #define ENETC_TXBD_TXSTART_MASK GENMASK(24, 0)
 #define ENETC_TXBD_FLAGS_OFFSET 24