From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2B660C433E1 for ; Mon, 17 Aug 2020 17:37:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 03F9C20738 for ; Mon, 17 Aug 2020 17:37:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597685828; bh=70U/j3EOCkHqW9olwUsw787MZO+sPdWvgTDRm3H4ins=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=AhP+mGvRB5EiMcuCAJ4QkmSHIT2n14sQJq1QXiMjNWX3DtGbCJRiVR0KLA9CcW2rN 0LZ+Q8pDIJ+eOJoscAoLrJu65Wb7jpkph1YaOHETxvhi6E6HjBBQjj9mAyeLFxl+Cd EQPjZLF26iaWpf8ThIx8vr0Or4iPV8WGkhiodBO8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731178AbgHQRhB (ORCPT ); Mon, 17 Aug 2020 13:37:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:60868 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729988AbgHQQR3 (ORCPT ); Mon, 17 Aug 2020 12:17:29 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EB5A620657; Mon, 17 Aug 2020 16:17:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597681048; bh=70U/j3EOCkHqW9olwUsw787MZO+sPdWvgTDRm3H4ins=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=z7+LVXINcGqIsiJlSlNvF1yQDLolgmSX8FyhEt273CcGjh49VyHpvlDRCiUEZArPd 1fbm+En/Z2/k6JF9/aO9G43Rvrc0qSQAEJToZi4f4o4A5xfsy+0JsoQ5+D9Gn8vTgu 16VKeGQFxkv5vOG5csV3OqBhRoTMUeow0NmIyi60= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christian Eggers , Mark Brown Subject: [PATCH 4.19 160/168] spi: spidev: Align buffers for DMA Date: Mon, 17 Aug 2020 17:18:11 +0200 Message-Id: <20200817143741.663477319@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200817143733.692105228@linuxfoundation.org> References: <20200817143733.692105228@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Christian Eggers commit aa9e862d7d5bcecd4dca9f39e8b684b93dd84ee7 upstream. Simply copying all xfers from userspace into one bounce buffer causes alignment problems if the SPI controller uses DMA. Ensure that all transfer data blocks within the rx and tx bounce buffers are aligned for DMA (according to ARCH_KMALLOC_MINALIGN). Alignment may increase the usage of the bounce buffers. In some cases, the buffers may need to be increased using the "bufsiz" module parameter. Signed-off-by: Christian Eggers Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200728100832.24788-1-ceggers@arri.de Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- drivers/spi/spidev.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) --- a/drivers/spi/spidev.c +++ b/drivers/spi/spidev.c @@ -232,6 +232,11 @@ static int spidev_message(struct spidev_ for (n = n_xfers, k_tmp = k_xfers, u_tmp = u_xfers; n; n--, k_tmp++, u_tmp++) { + /* Ensure that also following allocations from rx_buf/tx_buf will meet + * DMA alignment requirements. + */ + unsigned int len_aligned = ALIGN(u_tmp->len, ARCH_KMALLOC_MINALIGN); + k_tmp->len = u_tmp->len; total += k_tmp->len; @@ -247,17 +252,17 @@ static int spidev_message(struct spidev_ if (u_tmp->rx_buf) { /* this transfer needs space in RX bounce buffer */ - rx_total += k_tmp->len; + rx_total += len_aligned; if (rx_total > bufsiz) { status = -EMSGSIZE; goto done; } k_tmp->rx_buf = rx_buf; - rx_buf += k_tmp->len; + rx_buf += len_aligned; } if (u_tmp->tx_buf) { /* this transfer needs space in TX bounce buffer */ - tx_total += k_tmp->len; + tx_total += len_aligned; if (tx_total > bufsiz) { status = -EMSGSIZE; goto done; @@ -267,7 +272,7 @@ static int spidev_message(struct spidev_ (uintptr_t) u_tmp->tx_buf, u_tmp->len)) goto done; - tx_buf += k_tmp->len; + tx_buf += len_aligned; } k_tmp->cs_change = !!u_tmp->cs_change; @@ -297,16 +302,16 @@ static int spidev_message(struct spidev_ goto done; /* copy any rx data out of bounce buffer */ - rx_buf = spidev->rx_buffer; - for (n = n_xfers, u_tmp = u_xfers; n; n--, u_tmp++) { + for (n = n_xfers, k_tmp = k_xfers, u_tmp = u_xfers; + n; + n--, k_tmp++, u_tmp++) { if (u_tmp->rx_buf) { if (copy_to_user((u8 __user *) - (uintptr_t) u_tmp->rx_buf, rx_buf, + (uintptr_t) u_tmp->rx_buf, k_tmp->rx_buf, u_tmp->len)) { status = -EFAULT; goto done; } - rx_buf += u_tmp->len; } } status = total;