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authorBen Hutchings <bhutchings@solarflare.com>2013-09-06 22:39:20 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-10-01 09:10:52 -0700
commit43cbf1f46f0cdc56db7a424c6dda57bd9288376e (patch)
tree5fd8fad6fabf7dd61bdc68c4c8c3fd57acf3b156
parent4d75da4294e10475b3b255e34f446999832f4d17 (diff)
downloadlinux-linaro-stable-43cbf1f46f0cdc56db7a424c6dda57bd9288376e.tar.gz
sfc: Fix efx_rx_buf_offset() for recycled pages
This bug fix is only for stable branches older than 3.10. The bug was fixed upstream by commit 2768935a4660 ('sfc: reuse pages to avoid DMA mapping/unmapping costs'), but that change is totally unsuitable for stable. Commit b590ace09d51 ('sfc: Fix efx_rx_buf_offset() in the presence of swiotlb') added an explicit page_offset member to struct efx_rx_buffer, which must be set consistently with the u.page and dma_addr fields. However, it failed to add the necessary assignment in efx_resurrect_rx_buffer(). It also did not correct the calculation of efx_rx_buffer::dma_addr in efx_resurrect_rx_buffer(), which assumes that DMA-mapping a page will result in a page-aligned DMA address (exactly what swiotlb violates). Add the assignment of efx_rx_buffer::page_offset and change the calculation of dma_addr to make use of it. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Acked-by: David Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/net/ethernet/sfc/rx.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/net/ethernet/sfc/rx.c b/drivers/net/ethernet/sfc/rx.c
index 7b3c068..62311ad 100644
--- a/drivers/net/ethernet/sfc/rx.c
+++ b/drivers/net/ethernet/sfc/rx.c
@@ -311,8 +311,9 @@ static void efx_resurrect_rx_buffer(struct efx_rx_queue *rx_queue,
index = rx_queue->added_count & rx_queue->ptr_mask;
new_buf = efx_rx_buffer(rx_queue, index);
- new_buf->dma_addr = rx_buf->dma_addr ^ (PAGE_SIZE >> 1);
new_buf->u.page = rx_buf->u.page;
+ new_buf->page_offset = rx_buf->page_offset ^ (PAGE_SIZE >> 1);
+ new_buf->dma_addr = state->dma_addr + new_buf->page_offset;
new_buf->len = rx_buf->len;
new_buf->flags = EFX_RX_BUF_PAGE;
++rx_queue->added_count;