[PATCH net-next 11/14] net: bcmgenet: support reclaiming unsent Tx packets

From: Doug Berger
Date: Thu Mar 06 2025 - 14:30:51 EST


When disabling the transmitter any outstanding packets can now
be reclaimed by bcmgenet_tx_reclaim_all() rather than by the
bcmgenet_fini_dma() function.

Signed-off-by: Doug Berger <opendmb@xxxxxxxxx>
---
.../net/ethernet/broadcom/genet/bcmgenet.c | 37 +++++++++++++++----
1 file changed, 30 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index 38943bbc35b1..0706c9635689 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -1903,12 +1903,39 @@ static unsigned int __bcmgenet_tx_reclaim(struct net_device *dev,
}

static unsigned int bcmgenet_tx_reclaim(struct net_device *dev,
- struct bcmgenet_tx_ring *ring)
+ struct bcmgenet_tx_ring *ring,
+ bool all)
{
- unsigned int released;
+ struct bcmgenet_priv *priv = netdev_priv(dev);
+ struct device *kdev = &priv->pdev->dev;
+ unsigned int released, drop, wr_ptr;
+ struct enet_cb *cb_ptr;
+ struct sk_buff *skb;

spin_lock_bh(&ring->lock);
released = __bcmgenet_tx_reclaim(dev, ring);
+ if (all) {
+ skb = NULL;
+ drop = (ring->prod_index - ring->c_index) & DMA_C_INDEX_MASK;
+ released += drop;
+ ring->prod_index = ring->c_index & DMA_C_INDEX_MASK;
+ while (drop--) {
+ cb_ptr = bcmgenet_put_txcb(priv, ring);
+ skb = cb_ptr->skb;
+ bcmgenet_free_tx_cb(kdev, cb_ptr);
+ if (skb && cb_ptr == GENET_CB(skb)->first_cb) {
+ dev_consume_skb_any(skb);
+ skb = NULL;
+ }
+ }
+ if (skb)
+ dev_consume_skb_any(skb);
+ bcmgenet_tdma_ring_writel(priv, ring->index,
+ ring->prod_index, TDMA_PROD_INDEX);
+ wr_ptr = ring->write_ptr * WORDS_PER_BD(priv);
+ bcmgenet_tdma_ring_writel(priv, ring->index, wr_ptr,
+ TDMA_WRITE_PTR);
+ }
spin_unlock_bh(&ring->lock);

return released;
@@ -1945,7 +1972,7 @@ static void bcmgenet_tx_reclaim_all(struct net_device *dev)
int i = 0;

do {
- bcmgenet_tx_reclaim(dev, &priv->tx_rings[i++]);
+ bcmgenet_tx_reclaim(dev, &priv->tx_rings[i++], true);
} while (i <= priv->hw_params->tx_queues && netif_is_multiqueue(dev));
}

@@ -2921,10 +2948,6 @@ static void bcmgenet_fini_dma(struct bcmgenet_priv *priv)
bcmgenet_fini_rx_napi(priv);
bcmgenet_fini_tx_napi(priv);

- for (i = 0; i < priv->num_tx_bds; i++)
- dev_kfree_skb(bcmgenet_free_tx_cb(&priv->pdev->dev,
- priv->tx_cbs + i));
-
for (i = 0; i <= priv->hw_params->tx_queues; i++) {
txq = netdev_get_tx_queue(priv->dev, i);
netdev_tx_reset_queue(txq);
--
2.34.1