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From: Anton Blanchard <anton@samba.org>
Newsgroups: gmane.linux.network
Subject: [PATCH 2/4] ibmveth: Fix issue with DMA mapping failure
Date: Thu, 08 Sep 2011 10:41:04 +1000
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To: Santiago Leon <santil@linux.vnet.ibm.com>,
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descs[].fields.address is 32bit which truncates any dma mapping
errors so dma_mapping_error() fails to catch it.
Use a dma_addr_t to do the comparison. With this patch I was able
to transfer many gigabytes of data with IOMMU fault injection set
at 10% probability.
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: <stable@kernel.org> # v2.6.37+
---
Index: linux-build/drivers/net/ibmveth.c
===================================================================
--- linux-build.orig/drivers/net/ibmveth.c 2011-09-01 15:01:18.066844039 +1000
+++ linux-build/drivers/net/ibmveth.c 2011-09-01 15:03:34.299079796 +1000
@@ -930,6 +930,7 @@ static netdev_tx_t ibmveth_start_xmit(st
union ibmveth_buf_desc descs[6];
int last, i;
int force_bounce = 0;
+ dma_addr_t dma_addr;
/*
* veth handles a maximum of 6 segments including the header, so
@@ -994,17 +995,16 @@ retry_bounce:
}
/* Map the header */
- descs[0].fields.address = dma_map_single(&adapter->vdev->dev, skb->data,
- skb_headlen(skb),
- DMA_TO_DEVICE);
- if (dma_mapping_error(&adapter->vdev->dev, descs[0].fields.address))
+ dma_addr = dma_map_single(&adapter->vdev->dev, skb->data,
+ skb_headlen(skb), DMA_TO_DEVICE);
+ if (dma_mapping_error(&adapter->vdev->dev, dma_addr))
goto map_failed;
descs[0].fields.flags_len = desc_flags | skb_headlen(skb);
+ descs[0].fields.address = dma_addr;
/* Map the frags */
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
- unsigned long dma_addr;
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
dma_addr = dma_map_page(&adapter->vdev->dev, frag->page,