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Commit 6f2b6a30 authored by Neil Horman's avatar Neil Horman Committed by David S. Miller
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3c59x: Add dma error checking and recovery 



Noted that 3c59x has no checks on transmit for failed DMA mappings, and no
ability to unmap fragments when a single map fails in the middle of a transmit.
This patch provides error checking to ensure that dma mappings work properly,
and unrolls an skb mapping if a fragmented skb transmission has a mapping
failure to prevent leaks.

Signed-off-by: default avatarNeil Horman <nhorman@tuxdriver.com>
CC: Linux Kernel list <linux-kernel@vger.kernel.org>
CC: "David S. Miller" <davem@davemloft.net>
CC: Meelis Roos <mroos@linux.ee>
Tested-by: default avatarMeelis Roos <mroos@linux.ee>
parent f6f2332d

drivers/net/ethernet/3com/3c59x.c

+41 −9
Original line number Diff line number Diff line
@@ -2129,6 +2129,7 @@ boomerang_start_xmit(struct sk_buff *skb, struct net_device *dev) 
	int entry = vp->cur_tx % TX_RING_SIZE;

	struct boom_tx_desc *prev_entry = &vp->tx_ring[(vp->cur_tx-1) % TX_RING_SIZE];

	unsigned long flags;

	dma_addr_t dma_addr;



	if (vortex_debug > 6) {

		pr_debug("boomerang_start_xmit()\n");
@@ -2163,24 +2164,48 @@ boomerang_start_xmit(struct sk_buff *skb, struct net_device *dev) 
			vp->tx_ring[entry].status = cpu_to_le32(skb->len | TxIntrUploaded | AddTCPChksum | AddUDPChksum);



	if (!skb_shinfo(skb)->nr_frags) {

		vp->tx_ring[entry].frag[0].addr = cpu_to_le32(pci_map_single(VORTEX_PCI(vp), skb->data,

										skb->len, PCI_DMA_TODEVICE));

		dma_addr = pci_map_single(VORTEX_PCI(vp), skb->data, skb->len,

					  PCI_DMA_TODEVICE);

		if (dma_mapping_error(&VORTEX_PCI(vp)->dev, dma_addr))

			goto out_dma_err;



		vp->tx_ring[entry].frag[0].addr = cpu_to_le32(dma_addr);

		vp->tx_ring[entry].frag[0].length = cpu_to_le32(skb->len | LAST_FRAG);

	} else {

		int i;



		vp->tx_ring[entry].frag[0].addr = cpu_to_le32(pci_map_single(VORTEX_PCI(vp), skb->data,

										skb_headlen(skb), PCI_DMA_TODEVICE));

		dma_addr = pci_map_single(VORTEX_PCI(vp), skb->data,

					  skb_headlen(skb), PCI_DMA_TODEVICE);

		if (dma_mapping_error(&VORTEX_PCI(vp)->dev, dma_addr))

			goto out_dma_err;



		vp->tx_ring[entry].frag[0].addr = cpu_to_le32(dma_addr);

		vp->tx_ring[entry].frag[0].length = cpu_to_le32(skb_headlen(skb));



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

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



			dma_addr = skb_frag_dma_map(&VORTEX_PCI(vp)->dev, frag,

						    frag->page_offset,

						    frag->size,

						    DMA_TO_DEVICE);

			if (dma_mapping_error(&VORTEX_PCI(vp)->dev, dma_addr)) {

				for(i = i-1; i >= 0; i--)

					dma_unmap_page(&VORTEX_PCI(vp)->dev,

						       le32_to_cpu(vp->tx_ring[entry].frag[i+1].addr),

						       le32_to_cpu(vp->tx_ring[entry].frag[i+1].length),

						       DMA_TO_DEVICE);



				pci_unmap_single(VORTEX_PCI(vp),

						 le32_to_cpu(vp->tx_ring[entry].frag[0].addr),

						 le32_to_cpu(vp->tx_ring[entry].frag[0].length),

						 PCI_DMA_TODEVICE);



				goto out_dma_err;

			}



			vp->tx_ring[entry].frag[i+1].addr =

					cpu_to_le32(skb_frag_dma_map(

						&VORTEX_PCI(vp)->dev,

						frag,

						frag->page_offset, frag->size, DMA_TO_DEVICE));

						cpu_to_le32(dma_addr);



			if (i == skb_shinfo(skb)->nr_frags-1)

					vp->tx_ring[entry].frag[i+1].length = cpu_to_le32(skb_frag_size(frag)|LAST_FRAG);
@@ -2189,7 +2214,10 @@ boomerang_start_xmit(struct sk_buff *skb, struct net_device *dev) 
		}

	}

#else

	vp->tx_ring[entry].addr = cpu_to_le32(pci_map_single(VORTEX_PCI(vp), skb->data, skb->len, PCI_DMA_TODEVICE));

	dma_addr = cpu_to_le32(pci_map_single(VORTEX_PCI(vp), skb->data, skb->len, PCI_DMA_TODEVICE));

	if (dma_mapping_error(&VORTEX_PCI(vp)->dev, dma_addr))

		goto out_dma_err;

	vp->tx_ring[entry].addr = cpu_to_le32(dma_addr);

	vp->tx_ring[entry].length = cpu_to_le32(skb->len | LAST_FRAG);

	vp->tx_ring[entry].status = cpu_to_le32(skb->len | TxIntrUploaded);

#endif
@@ -2217,7 +2245,11 @@ boomerang_start_xmit(struct sk_buff *skb, struct net_device *dev) 
	skb_tx_timestamp(skb);

	iowrite16(DownUnstall, ioaddr + EL3_CMD);

	spin_unlock_irqrestore(&vp->lock, flags);

out:

	return NETDEV_TX_OK;

out_dma_err:

	dev_err(&VORTEX_PCI(vp)->dev, "Error mapping dma buffer\n");

	goto out;

}



/* The interrupt handler does all of the Rx thread work and cleans up