From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Sasha Levin To: "stable@vger.kernel.org" , "linux-kernel@vger.kernel.org" CC: Logan Gunthorpe , Jon Mason , Sasha Levin Subject: [PATCH AUTOSEL for 4.15 106/189] ntb_hw_switchtec: Check for alignment of the buffer in mw_set_trans() Date: Mon, 9 Apr 2018 00:18:09 +0000 Message-ID: <20180409001637.162453-106-alexander.levin@microsoft.com> References: <20180409001637.162453-1-alexander.levin@microsoft.com> In-Reply-To: <20180409001637.162453-1-alexander.levin@microsoft.com> Content-Language: en-US Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: From: Logan Gunthorpe [ Upstream commit 1e2fd202f8593985cdadca32e0c322f98e7fe7cb ] 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 Signed-off-by: Jon Mason Signed-off-by: Sasha Levin --- 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/n= tb_hw_switchtec.c index ca0334a6b759..fc9ce0a31c04 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; =20 + if (!IS_ALIGNED(addr, BIT_ULL(xlate_pos))) { + /* + * 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 =3D switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_LOCK, NTB_CTRL_PART_STATUS_LOCKED); if (rc) --=20 2.15.1