Commit 71791dc8 authored by Andre Przywara's avatar Andre Przywara Committed by David S. Miller
Browse files

net: axienet: Check for DMA mapping errors 



Especially with the default 32-bit DMA mask, DMA buffers are a limited
resource, so their allocation can fail.
So as the DMA API documentation requires, add error checking code after
dma_map_single() calls to catch the case where we run out of "low" memory.

Signed-off-by: default avatarAndre Przywara <andre.przywara@arm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ab365c33

drivers/net/ethernet/xilinx/xilinx_axienet_main.c

+30 −1
Original line number Diff line number Diff line
@@ -248,6 +248,11 @@ static int axienet_dma_bd_init(struct net_device *ndev) 
						     skb->data,

						     lp->max_frm_size,

						     DMA_FROM_DEVICE);

		if (dma_mapping_error(ndev->dev.parent, lp->rx_bd_v[i].phys)) {

			netdev_err(ndev, "DMA mapping error\n");

			goto out;

		}



		lp->rx_bd_v[i].cntrl = lp->max_frm_size;

	}
@@ -679,6 +684,7 @@ axienet_start_xmit(struct sk_buff *skb, struct net_device *ndev) 
	dma_addr_t tail_p;

	struct axienet_local *lp = netdev_priv(ndev);

	struct axidma_bd *cur_p;

	u32 orig_tail_ptr = lp->tx_bd_tail;



	num_frag = skb_shinfo(skb)->nr_frags;

	cur_p = &lp->tx_bd_v[lp->tx_bd_tail];
@@ -714,9 +720,15 @@ axienet_start_xmit(struct sk_buff *skb, struct net_device *ndev) 
		cur_p->app0 |= 2; /* Tx Full Checksum Offload Enabled */

	}



	cur_p->cntrl = skb_headlen(skb) | XAXIDMA_BD_CTRL_TXSOF_MASK;

	cur_p->phys = dma_map_single(ndev->dev.parent, skb->data,

				     skb_headlen(skb), DMA_TO_DEVICE);

	if (unlikely(dma_mapping_error(ndev->dev.parent, cur_p->phys))) {

		if (net_ratelimit())

			netdev_err(ndev, "TX DMA mapping error\n");

		ndev->stats.tx_dropped++;

		return NETDEV_TX_OK;

	}

	cur_p->cntrl = skb_headlen(skb) | XAXIDMA_BD_CTRL_TXSOF_MASK;



	for (ii = 0; ii < num_frag; ii++) {

		if (++lp->tx_bd_tail >= lp->tx_bd_num)
@@ -727,6 +739,16 @@ axienet_start_xmit(struct sk_buff *skb, struct net_device *ndev) 
					     skb_frag_address(frag),

					     skb_frag_size(frag),

					     DMA_TO_DEVICE);

		if (unlikely(dma_mapping_error(ndev->dev.parent, cur_p->phys))) {

			if (net_ratelimit())

				netdev_err(ndev, "TX DMA mapping error\n");

			ndev->stats.tx_dropped++;

			axienet_free_tx_chain(ndev, orig_tail_ptr, ii + 1,

					      NULL);

			lp->tx_bd_tail = orig_tail_ptr;



			return NETDEV_TX_OK;

		}

		cur_p->cntrl = skb_frag_size(frag);

	}
@@ -807,6 +829,13 @@ static void axienet_recv(struct net_device *ndev) 
		cur_p->phys = dma_map_single(ndev->dev.parent, new_skb->data,

					     lp->max_frm_size,

					     DMA_FROM_DEVICE);

		if (unlikely(dma_mapping_error(ndev->dev.parent, cur_p->phys))) {

			if (net_ratelimit())

				netdev_err(ndev, "RX DMA mapping error\n");

			dev_kfree_skb(new_skb);

			return;

		}



		cur_p->cntrl = lp->max_frm_size;

		cur_p->status = 0;

		cur_p->skb = new_skb;

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