net: xilinx: axienet: Implement BQL

Implement byte queue limits to allow queueing disciplines to account for
packets enqueued in the ring buffers but not yet transmitted.

Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Link: https://patch.msgid.link/20250214211252.2615573-1-sean.anderson@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/xilinx/xilinx_axienet_main.c

@@ -1002,6 +1002,7 @@ static int axienet_tx_poll(struct napi_struct *napi, int budget)
 					&size, budget);
 
 	if (packets) {
+		netdev_completed_queue(ndev, packets, size);
 		u64_stats_update_begin(&lp->tx_stat_sync);
 		u64_stats_add(&lp->tx_packets, packets);
 		u64_stats_add(&lp->tx_bytes, size);
@@ -1125,6 +1126,7 @@ axienet_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 	if (++new_tail_ptr >= lp->tx_bd_num)
 		new_tail_ptr = 0;
 	WRITE_ONCE(lp->tx_bd_tail, new_tail_ptr);
+	netdev_sent_queue(ndev, skb->len);
 
 	/* Start the transfer */
 	axienet_dma_out_addr(lp, XAXIDMA_TX_TDESC_OFFSET, tail_p);
@@ -1751,6 +1753,7 @@ static int axienet_stop(struct net_device *ndev)
 		dma_release_channel(lp->tx_chan);
 	}
 
+	netdev_reset_queue(ndev);
 	axienet_iow(lp, XAE_IE_OFFSET, 0);
 
 	if (lp->eth_irq > 0)
@@ -2676,6 +2679,7 @@ static void axienet_dma_err_handler(struct work_struct *work)
 			   ~(XAE_OPTION_TXEN | XAE_OPTION_RXEN));
 
 	axienet_dma_stop(lp);
+	netdev_reset_queue(ndev);
 
 	for (i = 0; i < lp->tx_bd_num; i++) {
 		cur_p = &lp->tx_bd_v[i];