diff options
| author | Ben Hutchings <bhutchings@solarflare.com> | 2013-09-06 22:39:20 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-10-01 08:55:48 -0700 |
| commit | f77b78d931314d3e066266c23b44f90807ee5774 (patch) | |
| tree | b89c4db702d41d2a43a1d50296a6996a0ed5b15d /drivers | |
| parent | fe826cd4ead9e72cdb0815660a306e267eab34d1 (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>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/sfc/rx.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/net/sfc/rx.c b/drivers/net/sfc/rx.c index d429f0aadb0..26e4cca1a87 100644 --- a/drivers/net/sfc/rx.c +++ b/drivers/net/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->is_page = true; ++rx_queue->added_count; |