Attachment 609839 Details for Bug 852842 – Patch submitted to netdev

[patch] Patch submitted to netdev

ibmveth_rx_queue_align.patch (text/plain), 2.79 KB, created by Santiago Leon on 2012-09-05 02:38:45 UTC

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Creator: Santiago Leon

Created: 2012-09-05 02:38:45 UTC

Size: 2.79 KB

patch

obsolete

>This patch fixes a bug found by Nish Aravamudan 
>(https://lkml.org/lkml/2012/5/15/220) where the driver is not following
>the spec (it is not aligning the rx buffer on a 16-byte boundary) and the
>hypervisor aborts the registration, making the device unusable. 
>
>The fix follows BenH's recommendation (https://lkml.org/lkml/2012/7/20/461)
>to replace the kmalloc+map for a single call to dma_alloc_coherent()
>because that function always aligns to a 16-byte boundary.
>
>The stable trees will run into this bug whenever the rx buffer kmalloc call
>returns something not aligned on a 16-byte boundary.
>
>Cc: <stable@vger.kernel.org>
>Signed-off-by: Santiago Leon <santil@linux.vnet.ibm.com>
>---
> ibmveth.c |   26 +++++++++-----------------
> 1 file changed, 9 insertions(+), 17 deletions(-)
>
>--- a/drivers/net/ethernet/ibm/ibmveth.c	2012-07-09 16:00:53.000000000 -0400
>+++ b/drivers/net/ethernet/ibm/ibmveth.c	2012-08-17 19:51:02.840000188 -0400
>@@ -472,14 +472,9 @@ static void ibmveth_cleanup(struct ibmve
> 	}
> 
> 	if (adapter->rx_queue.queue_addr != NULL) {
>-		if (!dma_mapping_error(dev, adapter->rx_queue.queue_dma)) {
>-			dma_unmap_single(dev,
>-					adapter->rx_queue.queue_dma,
>-					adapter->rx_queue.queue_len,
>-					DMA_BIDIRECTIONAL);
>-			adapter->rx_queue.queue_dma = DMA_ERROR_CODE;
>-		}
>-		kfree(adapter->rx_queue.queue_addr);
>+		dma_free_coherent(dev, adapter->rx_queue.queue_len,
>+				  adapter->rx_queue.queue_addr,
>+				  adapter->rx_queue.queue_dma);
> 		adapter->rx_queue.queue_addr = NULL;
> 	}
> 
>@@ -556,10 +551,13 @@ static int ibmveth_open(struct net_devic
> 		goto err_out;
> 	}
> 
>+	dev = &adapter->vdev->dev;
>+
> 	adapter->rx_queue.queue_len = sizeof(struct ibmveth_rx_q_entry) *
> 						rxq_entries;
>-	adapter->rx_queue.queue_addr = kmalloc(adapter->rx_queue.queue_len,
>-						GFP_KERNEL);
>+	adapter->rx_queue.queue_addr =
>+	    dma_alloc_coherent(dev, adapter->rx_queue.queue_len,
>+			       &adapter->rx_queue.queue_dma, GFP_KERNEL);
> 
> 	if (!adapter->rx_queue.queue_addr) {
> 		netdev_err(netdev, "unable to allocate rx queue pages\n");
>@@ -567,19 +565,13 @@ static int ibmveth_open(struct net_devic
> 		goto err_out;
> 	}
> 
>-	dev = &adapter->vdev->dev;
>-
> 	adapter->buffer_list_dma = dma_map_single(dev,
> 			adapter->buffer_list_addr, 4096, DMA_BIDIRECTIONAL);
> 	adapter->filter_list_dma = dma_map_single(dev,
> 			adapter->filter_list_addr, 4096, DMA_BIDIRECTIONAL);
>-	adapter->rx_queue.queue_dma = dma_map_single(dev,
>-			adapter->rx_queue.queue_addr,
>-			adapter->rx_queue.queue_len, DMA_BIDIRECTIONAL);
> 
> 	if ((dma_mapping_error(dev, adapter->buffer_list_dma)) ||
>-	    (dma_mapping_error(dev, adapter->filter_list_dma)) ||
>-	    (dma_mapping_error(dev, adapter->rx_queue.queue_dma))) {
>+	    (dma_mapping_error(dev, adapter->filter_list_dma))) {
> 		netdev_err(netdev, "unable to map filter or buffer list "
> 			   "pages\n");
> 		rc = -ENOMEM;

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Attachments on bug 852842: 607974 | 609839