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Commit 432aa7ed authored by Matt Carlson's avatar Matt Carlson Committed by David S. Miller
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tg3: Cleanup transmit error path 



This patch consolidates the skb cleanup code into a function named
tg3_skb_error_unmap().  The modification addresses a long-standing bug
where pci_unmap_single() was incorrectly being called instead of
pci_unmap_page() in tigon3_dma_hwbug_workaround().

Signed-off-by: default avatarMatt Carlson <mcarlson@broadcom.com>
Reviewed-by: default avatarMichael Chan <mchan@broadcom.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2ffcc981

drivers/net/tg3.c

+38 −60
Original line number Diff line number Diff line
@@ -5758,16 +5758,39 @@ static void tg3_set_txd(struct tg3_napi *tnapi, int entry, 
	txd->vlan_tag = vlan_tag << TXD_VLAN_TAG_SHIFT;

}



static void tg3_skb_error_unmap(struct tg3_napi *tnapi,

				struct sk_buff *skb, int last)

{

	int i;

	u32 entry = tnapi->tx_prod;

	struct ring_info *txb = &tnapi->tx_buffers[entry];



	pci_unmap_single(tnapi->tp->pdev,

			 dma_unmap_addr(txb, mapping),

			 skb_headlen(skb),

			 PCI_DMA_TODEVICE);

	for (i = 0; i <= last; i++) {

		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];



		entry = NEXT_TX(entry);

		txb = &tnapi->tx_buffers[entry];



		pci_unmap_page(tnapi->tp->pdev,

			       dma_unmap_addr(txb, mapping),

			       frag->size, PCI_DMA_TODEVICE);

	}

}



/* Workaround 4GB and 40-bit hardware DMA bugs. */

static int tigon3_dma_hwbug_workaround(struct tg3_napi *tnapi,

				       struct sk_buff *skb, u32 last_plus_one,

				       u32 *start, u32 base_flags, u32 mss)

				       struct sk_buff *skb,

				       u32 base_flags, u32 mss)

{

	struct tg3 *tp = tnapi->tp;

	struct sk_buff *new_skb;

	dma_addr_t new_addr = 0;

	u32 entry = *start;

	int i, ret = 0;

	u32 entry = tnapi->tx_prod;

	int ret = 0;



	if (GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5701)

		new_skb = skb_copy(skb, GFP_ATOMIC);
@@ -5783,14 +5806,12 @@ static int tigon3_dma_hwbug_workaround(struct tg3_napi *tnapi, 
		ret = -1;

	} else {

		/* New SKB is guaranteed to be linear. */

		entry = *start;

		new_addr = pci_map_single(tp->pdev, new_skb->data, new_skb->len,

					  PCI_DMA_TODEVICE);

		/* Make sure the mapping succeeded */

		if (pci_dma_mapping_error(tp->pdev, new_addr)) {

			ret = -1;

			dev_kfree_skb(new_skb);

			new_skb = NULL;



		/* Make sure new skb does not cross any 4G boundaries.

		 * Drop the packet if it does.
@@ -5801,39 +5822,16 @@ static int tigon3_dma_hwbug_workaround(struct tg3_napi *tnapi, 
					 PCI_DMA_TODEVICE);

			ret = -1;

			dev_kfree_skb(new_skb);

			new_skb = NULL;

		} else {

			tnapi->tx_buffers[entry].skb = new_skb;

			dma_unmap_addr_set(&tnapi->tx_buffers[entry],

					   mapping, new_addr);



			tg3_set_txd(tnapi, entry, new_addr, new_skb->len,

				    base_flags, 1 | (mss << 1));

			*start = NEXT_TX(entry);

		}

	}



	/* Now clean up the sw ring entries. */

	i = 0;

	while (entry != last_plus_one) {

		int len;



		if (i == 0)

			len = skb_headlen(skb);

		else

			len = skb_shinfo(skb)->frags[i-1].size;



		pci_unmap_single(tp->pdev,

				 dma_unmap_addr(&tnapi->tx_buffers[entry],

						mapping),

				 len, PCI_DMA_TODEVICE);

		if (i == 0) {

			tnapi->tx_buffers[entry].skb = new_skb;

			dma_unmap_addr_set(&tnapi->tx_buffers[entry], mapping,

					   new_addr);

		} else {

			tnapi->tx_buffers[entry].skb = NULL;

		}

		entry = NEXT_TX(entry);

		i++;

	}



	dev_kfree_skb(skb);



	return ret;
@@ -5889,11 +5887,11 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb, struct net_device *dev) 
{

	struct tg3 *tp = netdev_priv(dev);

	u32 len, entry, base_flags, mss;

	int would_hit_hwbug;

	int i = -1, would_hit_hwbug;

	dma_addr_t mapping;

	struct tg3_napi *tnapi;

	struct netdev_queue *txq;

	unsigned int i, last;

	unsigned int last;



	txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));

	tnapi = &tp->napi[skb_get_queue_mapping(skb)];
@@ -6074,20 +6072,15 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb, struct net_device *dev) 
	}



	if (would_hit_hwbug) {

		u32 last_plus_one = entry;

		u32 start;



		start = entry - 1 - skb_shinfo(skb)->nr_frags;

		start &= (TG3_TX_RING_SIZE - 1);

		tg3_skb_error_unmap(tnapi, skb, i);



		/* If the workaround fails due to memory/mapping

		 * failure, silently drop this packet.

		 */

		if (tigon3_dma_hwbug_workaround(tnapi, skb, last_plus_one,

						&start, base_flags, mss))

		if (tigon3_dma_hwbug_workaround(tnapi, skb, base_flags, mss))

			goto out_unlock;



		entry = start;

		entry = NEXT_TX(tnapi->tx_prod);

	}



	/* Packets are ready, update Tx producer idx local and on card. */
@@ -6113,24 +6106,9 @@ out_unlock: 
	return NETDEV_TX_OK;



dma_error:

	last = i;

	entry = tnapi->tx_prod;

	tnapi->tx_buffers[entry].skb = NULL;

	pci_unmap_single(tp->pdev,

			 dma_unmap_addr(&tnapi->tx_buffers[entry], mapping),

			 skb_headlen(skb),

			 PCI_DMA_TODEVICE);

	for (i = 0; i <= last; i++) {

		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];

		entry = NEXT_TX(entry);



		pci_unmap_page(tp->pdev,

			       dma_unmap_addr(&tnapi->tx_buffers[entry],

					      mapping),

			       frag->size, PCI_DMA_TODEVICE);

	}



	tg3_skb_error_unmap(tnapi, skb, i);

	dev_kfree_skb(skb);

	tnapi->tx_buffers[tnapi->tx_prod].skb = NULL;

	return NETDEV_TX_OK;

}