Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757727Ab3JJPuw (ORCPT ); Thu, 10 Oct 2013 11:50:52 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:53092 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757590Ab3JJPus (ORCPT ); Thu, 10 Oct 2013 11:50:48 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Ben Hutchings , Kamal Mostafa Subject: [PATCH 029/104] sfc: Fix efx_rx_buf_offset() for recycled pages Date: Thu, 10 Oct 2013 08:41:17 -0700 Message-Id: <1381419752-29733-30-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1381419752-29733-1-git-send-email-kamal@canonical.com> References: <1381419752-29733-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2121 Lines: 52 3.8.13.11 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Ben Hutchings 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 Signed-off-by: Kamal Mostafa --- drivers/net/ethernet/sfc/rx.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/sfc/rx.c b/drivers/net/ethernet/sfc/rx.c index bb579a6..688d42e 100644 --- a/drivers/net/ethernet/sfc/rx.c +++ b/drivers/net/ethernet/sfc/rx.c @@ -302,8 +302,9 @@ 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; -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/