diff options
| author | Ben Hutchings <bhutchings@solarflare.com> | 2013-09-06 22:39:20 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2013-10-26 21:06:11 +0100 |
| commit | 5f7f65dae41a2f2ba134b880d2b9a8bc459ba01b (patch) | |
| tree | 4169f8fdfcb1e94741609f3eae276560161af7f5 | |
| parent | 068d848f7f3d3db8c68e517ba93cb170914a64d8 (diff) | |
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>
| -rw-r--r-- | drivers/net/ethernet/sfc/rx.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/net/ethernet/sfc/rx.c b/drivers/net/ethernet/sfc/rx.c index 9ce8665b53bf..c231b3f67b2b 100644 --- a/drivers/net/ethernet/sfc/rx.c +++ b/drivers/net/ethernet/sfc/rx.c @@ -312,8 +312,9 @@ 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->is_page = true; ++rx_queue->added_count; |