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Commit 237a3a3b authored by Amir Vadai's avatar Amir Vadai Committed by David S. Miller
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net/mlx4_en: Fix handling of dma_map failure 



Result of skb_frag_dma_map() and dma_map_single() wasn't checked.
Added a check and proper handling in case of failure.
Moved the mapping to the beginning of mlx4_en_xmit(), before updating
the ring data structure to make error handling easier.

Signed-off-by: default avatarAmir Vadai <amirv@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent bd2f631d

drivers/net/ethernet/mellanox/mlx4/en_tx.c

+62 −35
Original line number Diff line number Diff line
@@ -588,6 +588,7 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) 
{

	struct mlx4_en_priv *priv = netdev_priv(dev);

	struct mlx4_en_dev *mdev = priv->mdev;

	struct device *ddev = priv->ddev;

	struct mlx4_en_tx_ring *ring;

	struct mlx4_en_tx_desc *tx_desc;

	struct mlx4_wqe_data_seg *data;
@@ -674,6 +675,56 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) 
	tx_info->skb = skb;

	tx_info->nr_txbb = nr_txbb;



	if (lso_header_size)

		data = ((void *)&tx_desc->lso + ALIGN(lso_header_size + 4,

						      DS_SIZE));

	else

		data = &tx_desc->data;



	/* valid only for none inline segments */

	tx_info->data_offset = (void *)data - (void *)tx_desc;



	tx_info->linear = (lso_header_size < skb_headlen(skb) &&

			   !is_inline(skb, NULL)) ? 1 : 0;



	data += skb_shinfo(skb)->nr_frags + tx_info->linear - 1;



	if (is_inline(skb, &fragptr)) {

		tx_info->inl = 1;

	} else {

		/* Map fragments */

		for (i = skb_shinfo(skb)->nr_frags - 1; i >= 0; i--) {

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

			dma = skb_frag_dma_map(ddev, frag,

					       0, skb_frag_size(frag),

					       DMA_TO_DEVICE);

			if (dma_mapping_error(ddev, dma))

				goto tx_drop_unmap;



			data->addr = cpu_to_be64(dma);

			data->lkey = cpu_to_be32(mdev->mr.key);

			wmb();

			data->byte_count = cpu_to_be32(skb_frag_size(frag));

			--data;

		}



		/* Map linear part */

		if (tx_info->linear) {

			u32 byte_count = skb_headlen(skb) - lso_header_size;

			dma = dma_map_single(ddev, skb->data +

					     lso_header_size, byte_count,

					     PCI_DMA_TODEVICE);

			if (dma_mapping_error(ddev, dma))

				goto tx_drop_unmap;



			data->addr = cpu_to_be64(dma);

			data->lkey = cpu_to_be32(mdev->mr.key);

			wmb();

			data->byte_count = cpu_to_be32(byte_count);

		}

		tx_info->inl = 0;

	}



	/*

	 * For timestamping add flag to skb_shinfo and

	 * set flag for further reference
@@ -720,8 +771,6 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) 
		/* Copy headers;

		 * note that we already verified that it is linear */

		memcpy(tx_desc->lso.header, skb->data, lso_header_size);

		data = ((void *) &tx_desc->lso +

			ALIGN(lso_header_size + 4, DS_SIZE));



		priv->port_stats.tso_packets++;

		i = ((skb->len - lso_header_size) / skb_shinfo(skb)->gso_size) +
@@ -733,7 +782,6 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) 
		op_own = cpu_to_be32(MLX4_OPCODE_SEND) |

			((ring->prod & ring->size) ?

			 cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);

		data = &tx_desc->data;

		tx_info->nr_bytes = max_t(unsigned int, skb->len, ETH_ZLEN);

		ring->packets++;
@@ -742,38 +790,7 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) 
	netdev_tx_sent_queue(ring->tx_queue, tx_info->nr_bytes);

	AVG_PERF_COUNTER(priv->pstats.tx_pktsz_avg, skb->len);





	/* valid only for none inline segments */

	tx_info->data_offset = (void *) data - (void *) tx_desc;



	tx_info->linear = (lso_header_size < skb_headlen(skb) && !is_inline(skb, NULL)) ? 1 : 0;

	data += skb_shinfo(skb)->nr_frags + tx_info->linear - 1;



	if (!is_inline(skb, &fragptr)) {

		/* Map fragments */

		for (i = skb_shinfo(skb)->nr_frags - 1; i >= 0; i--) {

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

			dma = skb_frag_dma_map(priv->ddev, frag,

					       0, skb_frag_size(frag),

					       DMA_TO_DEVICE);

			data->addr = cpu_to_be64(dma);

			data->lkey = cpu_to_be32(mdev->mr.key);

			wmb();

			data->byte_count = cpu_to_be32(skb_frag_size(frag));

			--data;

		}



		/* Map linear part */

		if (tx_info->linear) {

			dma = dma_map_single(priv->ddev, skb->data + lso_header_size,

					     skb_headlen(skb) - lso_header_size, PCI_DMA_TODEVICE);

			data->addr = cpu_to_be64(dma);

			data->lkey = cpu_to_be32(mdev->mr.key);

			wmb();

			data->byte_count = cpu_to_be32(skb_headlen(skb) - lso_header_size);

		}

		tx_info->inl = 0;

	} else {

	if (tx_info->inl) {

		build_inline_wqe(tx_desc, skb, real_size, &vlan_tag, tx_ind, fragptr);

		tx_info->inl = 1;

	}
@@ -813,6 +830,16 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) 


	return NETDEV_TX_OK;



tx_drop_unmap:

	en_err(priv, "DMA mapping error\n");



	for (i++; i < skb_shinfo(skb)->nr_frags; i++) {

		data++;

		dma_unmap_page(ddev, (dma_addr_t) be64_to_cpu(data->addr),

			       be32_to_cpu(data->byte_count),

			       PCI_DMA_TODEVICE);

	}



tx_drop:

	dev_kfree_skb_any(skb);

	priv->stats.tx_dropped++;