Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754049AbdLIACb (ORCPT ); Fri, 8 Dec 2017 19:02:31 -0500 Received: from ale.deltatee.com ([207.54.116.67]:47412 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753453AbdLIACX (ORCPT ); Fri, 8 Dec 2017 19:02:23 -0500 From: Logan Gunthorpe To: linux-ntb@googlegroups.com, linux-kernel@vger.kernel.org Cc: Logan Gunthorpe , Jon Mason Date: Fri, 8 Dec 2017 17:02:17 -0700 Message-Id: <20171209000217.18366-2-logang@deltatee.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20171209000217.18366-1-logang@deltatee.com> References: <20171209000217.18366-1-logang@deltatee.com> X-SA-Exim-Connect-IP: 172.16.1.31 X-SA-Exim-Rcpt-To: linux-ntb@googlegroups.com, linux-kernel@vger.kernel.org, logang@deltatee.com, jdmason@kudzu.us X-SA-Exim-Mail-From: gunthorp@deltatee.com Subject: [PATCH 2/2] ntb_hw_switchtec: Check for alignment of the buffer in mw_set_trans() X-SA-Exim-Version: 4.2.1 (built Tue, 02 Aug 2016 21:08:31 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1552 Lines: 41 With Switchtec hardware, the buffer used for a memory window must be aligned to its size (the hardware only replaces the lower bits). In certain circumstances dma_alloc_coherent() will not provide a buffer that adheres to this requirement like when using the CMA and CONFIG_CMA_ALIGNMENT is set lower than the buffer size. When we get an unaligned buffer mw_set_trans() should return an error. We also log an error so we know the cause of the problem. Signed-off-by: Logan Gunthorpe Cc: Jon Mason --- drivers/ntb/hw/mscc/ntb_hw_switchtec.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c index 709f37fbe232..984b83bc7dd3 100644 --- a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c +++ b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c @@ -315,6 +315,19 @@ static int switchtec_ntb_mw_set_trans(struct ntb_dev *ntb, int pidx, int widx, if (xlate_pos < 12) return -EINVAL; + if (addr & ((1 << xlate_pos) - 1)) { + /* + * In certain circumstances we can get a buffer that is + * not aligned to its size. (Most of the time + * dma_alloc_coherent ensures this). This can happen when + * using large buffers allocated by the CMA + * (see CMA_CONFIG_ALIGNMENT) + */ + dev_err(&sndev->stdev->dev, + "ERROR: Memory window address is not aligned to it's size!\n"); + return -EINVAL; + } + rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_LOCK, NTB_CTRL_PART_STATUS_LOCKED); if (rc) -- 2.11.0