net: airoha: Implement BQL support

Introduce BQL support in the airoha_eth driver reporting to the kernel
info about tx hw DMA queues in order to avoid bufferbloat and keep the
latency small.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20241012-en7581-bql-v2-1-4deb4efdb60b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/mediatek/airoha_eth.c b/drivers/net/ethernet/mediatek/airoha_eth.c
index e037f725f6d3505a8b91815ae26322f5d1b8590c..836a957aad77bec972c536567a4ee7d304ac7b52 100644 (file)
--- a/drivers/net/ethernet/mediatek/airoha_eth.c
+++ b/drivers/net/ethernet/mediatek/airoha_eth.c
@@ -1709,9 +1709,11 @@ static int airoha_qdma_tx_napi_poll(struct napi_struct *napi, int budget)
                        WRITE_ONCE(desc->msg1, 0);
 
                        if (skb) {
+                               u16 queue = skb_get_queue_mapping(skb);
                                struct netdev_queue *txq;
 
-                               txq = netdev_get_tx_queue(skb->dev, qid);
+                               txq = netdev_get_tx_queue(skb->dev, queue);
+                               netdev_tx_completed_queue(txq, 1, skb->len);
                                if (netif_tx_queue_stopped(txq) &&
                                    q->ndesc - q->queued >= q->free_thr)
                                        netif_tx_wake_queue(txq);
@@ -2487,7 +2489,9 @@ static netdev_tx_t airoha_dev_xmit(struct sk_buff *skb,
        q->queued += i;
 
        skb_tx_timestamp(skb);
-       if (!netdev_xmit_more())
+       netdev_tx_sent_queue(txq, skb->len);
+
+       if (netif_xmit_stopped(txq) || !netdev_xmit_more())
                airoha_qdma_rmw(qdma, REG_TX_CPU_IDX(qid),
                                TX_RING_CPU_IDX_MASK,
                                FIELD_PREP(TX_RING_CPU_IDX_MASK, q->head));