Commit 9d5e6a70 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'bnxt-tx-napi-disabling-resiliency-improvements' 

Jakub Kicinski says:

====================
bnxt: Tx NAPI disabling resiliency improvements

A lockdep warning was triggered by netpoll because napi poll
was taking the xmit lock. Fix that and a couple more issues
noticed while reading the code.
====================

Link: https://lore.kernel.org/r/20210812214242.578039-1-kuba@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents f8e6dfc6 fb9f7190

drivers/net/ethernet/broadcom/bnxt/bnxt.c

+61 −37
Original line number Diff line number Diff line
@@ -72,7 +72,8 @@ 
#include "bnxt_debugfs.h"



#define BNXT_TX_TIMEOUT		(5 * HZ)

#define BNXT_DEF_MSG_ENABLE	(NETIF_MSG_DRV | NETIF_MSG_HW)

#define BNXT_DEF_MSG_ENABLE	(NETIF_MSG_DRV | NETIF_MSG_HW | \

				 NETIF_MSG_TX_ERR)



MODULE_LICENSE("GPL");

MODULE_DESCRIPTION("Broadcom BCM573xx network driver");
@@ -365,6 +366,33 @@ static u16 bnxt_xmit_get_cfa_action(struct sk_buff *skb) 
	return md_dst->u.port_info.port_id;

}



static void bnxt_txr_db_kick(struct bnxt *bp, struct bnxt_tx_ring_info *txr,

			     u16 prod)

{

	bnxt_db_write(bp, &txr->tx_db, prod);

	txr->kick_pending = 0;

}



static bool bnxt_txr_netif_try_stop_queue(struct bnxt *bp,

					  struct bnxt_tx_ring_info *txr,

					  struct netdev_queue *txq)

{

	netif_tx_stop_queue(txq);



	/* netif_tx_stop_queue() must be done before checking

	 * tx index in bnxt_tx_avail() below, because in

	 * bnxt_tx_int(), we update tx index before checking for

	 * netif_tx_queue_stopped().

	 */

	smp_mb();

	if (bnxt_tx_avail(bp, txr) > bp->tx_wake_thresh) {

		netif_tx_wake_queue(txq);

		return false;

	}



	return true;

}



static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev)

{

	struct bnxt *bp = netdev_priv(dev);
@@ -384,6 +412,7 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev) 
	i = skb_get_queue_mapping(skb);

	if (unlikely(i >= bp->tx_nr_rings)) {

		dev_kfree_skb_any(skb);

		atomic_long_inc(&dev->tx_dropped);

		return NETDEV_TX_OK;

	}
@@ -393,7 +422,11 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev) 


	free_size = bnxt_tx_avail(bp, txr);

	if (unlikely(free_size < skb_shinfo(skb)->nr_frags + 2)) {

		netif_tx_stop_queue(txq);

		/* We must have raced with NAPI cleanup */

		if (net_ratelimit() && txr->kick_pending)

			netif_warn(bp, tx_err, dev,

				   "bnxt: ring busy w/ flush pending!\n");

		if (bnxt_txr_netif_try_stop_queue(bp, txr, txq))

			return NETDEV_TX_BUSY;

	}
@@ -517,21 +550,16 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev) 
normal_tx:

	if (length < BNXT_MIN_PKT_SIZE) {

		pad = BNXT_MIN_PKT_SIZE - length;

		if (skb_pad(skb, pad)) {

		if (skb_pad(skb, pad))

			/* SKB already freed. */

			tx_buf->skb = NULL;

			return NETDEV_TX_OK;

		}

			goto tx_kick_pending;

		length = BNXT_MIN_PKT_SIZE;

	}



	mapping = dma_map_single(&pdev->dev, skb->data, len, DMA_TO_DEVICE);



	if (unlikely(dma_mapping_error(&pdev->dev, mapping))) {

		dev_kfree_skb_any(skb);

		tx_buf->skb = NULL;

		return NETDEV_TX_OK;

	}

	if (unlikely(dma_mapping_error(&pdev->dev, mapping)))

		goto tx_free;



	dma_unmap_addr_set(tx_buf, mapping, mapping);

	flags = (len << TX_BD_LEN_SHIFT) | TX_BD_TYPE_LONG_TX_BD |
@@ -618,24 +646,17 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev) 
	txr->tx_prod = prod;



	if (!netdev_xmit_more() || netif_xmit_stopped(txq))

		bnxt_db_write(bp, &txr->tx_db, prod);

		bnxt_txr_db_kick(bp, txr, prod);

	else

		txr->kick_pending = 1;



tx_done:



	if (unlikely(bnxt_tx_avail(bp, txr) <= MAX_SKB_FRAGS + 1)) {

		if (netdev_xmit_more() && !tx_buf->is_push)

			bnxt_db_write(bp, &txr->tx_db, prod);



		netif_tx_stop_queue(txq);

			bnxt_txr_db_kick(bp, txr, prod);



		/* netif_tx_stop_queue() must be done before checking

		 * tx index in bnxt_tx_avail() below, because in

		 * bnxt_tx_int(), we update tx index before checking for

		 * netif_tx_queue_stopped().

		 */

		smp_mb();

		if (bnxt_tx_avail(bp, txr) > bp->tx_wake_thresh)

			netif_tx_wake_queue(txq);

		bnxt_txr_netif_try_stop_queue(bp, txr, txq);

	}

	return NETDEV_TX_OK;
@@ -648,7 +669,6 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev) 
	/* start back at beginning and unmap skb */

	prod = txr->tx_prod;

	tx_buf = &txr->tx_buf_ring[prod];

	tx_buf->skb = NULL;

	dma_unmap_single(&pdev->dev, dma_unmap_addr(tx_buf, mapping),

			 skb_headlen(skb), PCI_DMA_TODEVICE);

	prod = NEXT_TX(prod);
@@ -662,7 +682,13 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev) 
			       PCI_DMA_TODEVICE);

	}



tx_free:

	dev_kfree_skb_any(skb);

tx_kick_pending:

	if (txr->kick_pending)

		bnxt_txr_db_kick(bp, txr, txr->tx_prod);

	txr->tx_buf_ring[txr->tx_prod].skb = NULL;

	atomic_long_inc(&dev->tx_dropped);

	return NETDEV_TX_OK;

}
@@ -732,14 +758,9 @@ static void bnxt_tx_int(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts) 
	smp_mb();



	if (unlikely(netif_tx_queue_stopped(txq)) &&

	    (bnxt_tx_avail(bp, txr) > bp->tx_wake_thresh)) {

		__netif_tx_lock(txq, smp_processor_id());

		if (netif_tx_queue_stopped(txq) &&

	    bnxt_tx_avail(bp, txr) > bp->tx_wake_thresh &&

		    txr->dev_state != BNXT_DEV_STATE_CLOSING)

	    READ_ONCE(txr->dev_state) != BNXT_DEV_STATE_CLOSING)

		netif_tx_wake_queue(txq);

		__netif_tx_unlock(txq);

	}

}



static struct page *__bnxt_alloc_rx_page(struct bnxt *bp, dma_addr_t *mapping,
@@ -9128,10 +9149,9 @@ static void bnxt_disable_napi(struct bnxt *bp) 
	for (i = 0; i < bp->cp_nr_rings; i++) {

		struct bnxt_cp_ring_info *cpr = &bp->bnapi[i]->cp_ring;



		napi_disable(&bp->bnapi[i]->napi);

		if (bp->bnapi[i]->rx_ring)

			cancel_work_sync(&cpr->dim.work);



		napi_disable(&bp->bnapi[i]->napi);

	}

}
@@ -9165,9 +9185,11 @@ void bnxt_tx_disable(struct bnxt *bp) 
	if (bp->tx_ring) {

		for (i = 0; i < bp->tx_nr_rings; i++) {

			txr = &bp->tx_ring[i];

			txr->dev_state = BNXT_DEV_STATE_CLOSING;

			WRITE_ONCE(txr->dev_state, BNXT_DEV_STATE_CLOSING);

		}

	}

	/* Make sure napi polls see @dev_state change */

	synchronize_net();

	/* Drop carrier first to prevent TX timeout */

	netif_carrier_off(bp->dev);

	/* Stop all TX queues */
@@ -9181,8 +9203,10 @@ void bnxt_tx_enable(struct bnxt *bp) 


	for (i = 0; i < bp->tx_nr_rings; i++) {

		txr = &bp->tx_ring[i];

		txr->dev_state = 0;

		WRITE_ONCE(txr->dev_state, 0);

	}

	/* Make sure napi polls see @dev_state change */

	synchronize_net();

	netif_tx_wake_all_queues(bp->dev);

	if (bp->link_info.link_up)

		netif_carrier_on(bp->dev);

drivers/net/ethernet/broadcom/bnxt/bnxt.h

+1 −0
Original line number Diff line number Diff line
@@ -786,6 +786,7 @@ struct bnxt_tx_ring_info { 
	u16			tx_prod;

	u16			tx_cons;

	u16			txq_index;

	u8			kick_pending;

	struct bnxt_db_info	tx_db;



	struct tx_bd		*tx_desc_ring[MAX_TX_PAGES];