| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.11 20/66] net/mlx4_en: Fix pages never dma unmapped on rx | Date | Fri, 1 Nov 2013 15:06:56 -0700 |
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3.11-stable review patch. If anyone has any objections, please let me know.
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From: Amir Vadai <amirv@mellanox.com>
[ Upstream commit 021f1107ffdae7a82af6c53f4c52654062e365c6 ]
This patch fixes a bug introduced by commit 51151a16 (mlx4: allow order-0 memory allocations in RX path).
dma_unmap_page never reached because condition to detect last fragment in page is wrong. offset+frag_stride can't be greater than size, need to make sure no additional frag will fit in page => compare offset + frag_stride + next_frag_size instead. next_frag_size is the same as the current one, since page is shared only with frags of the same size.
CC: Eric Dumazet <edumazet@google.com> Signed-off-by: Amir Vadai <amirv@mellanox.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/net/ethernet/mellanox/mlx4/en_rx.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c @@ -135,9 +135,10 @@ static void mlx4_en_free_frag(struct mlx int i) { const struct mlx4_en_frag_info *frag_info = &priv->frag_info[i]; + u32 next_frag_end = frags[i].page_offset + 2 * frag_info->frag_stride; - if (frags[i].page_offset + frag_info->frag_stride > - frags[i].page_size) + + if (next_frag_end > frags[i].page_size) dma_unmap_page(priv->ddev, frags[i].dma, frags[i].page_size, PCI_DMA_FROMDEVICE);
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