From patchwork Fri Jul 18 23:50:19 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Pinchart X-Patchwork-Id: 4588201 X-Patchwork-Delegate: vinod.koul@intel.com Return-Path: X-Original-To: patchwork-dmaengine@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 3E5489F1D6 for ; Fri, 18 Jul 2014 23:50:29 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 4AF3520125 for ; Fri, 18 Jul 2014 23:50:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 55CB020120 for ; Fri, 18 Jul 2014 23:50:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755183AbaGRXuY (ORCPT ); Fri, 18 Jul 2014 19:50:24 -0400 Received: from perceval.ideasonboard.com ([95.142.166.194]:46509 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752140AbaGRXuX (ORCPT ); Fri, 18 Jul 2014 19:50:23 -0400 Received: from avalon.ideasonboard.com (131.239-240-81.adsl-dyn.isp.belgacom.be [81.240.239.131]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id D36AF359FC; Sat, 19 Jul 2014 01:49:14 +0200 (CEST) From: Laurent Pinchart To: linux-sh@vger.kernel.org Cc: dmaengine@vger.kernel.org, Kuninori Morimoto Subject: [PATCH v2 2/8] dmaengine: shdma: Make channel filter ignore unrelated devices Date: Sat, 19 Jul 2014 01:50:19 +0200 Message-Id: <1405727425-6237-3-git-send-email-laurent.pinchart+renesas@ideasonboard.com> X-Mailer: git-send-email 1.8.5.5 In-Reply-To: <1405727425-6237-1-git-send-email-laurent.pinchart+renesas@ideasonboard.com> References: <1405727425-6237-1-git-send-email-laurent.pinchart+renesas@ideasonboard.com> Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The shdma_chan_filter() function relies on the DMA channel being embedded in an shdma_chan structure. If this assumption isn't true, for instance when the system contains DMA channels supported by an unrelated driver, the function will crash. Avoid this by returning false directly when the channel belongs to an unrelated device. Signed-off-by: Laurent Pinchart --- drivers/dma/sh/shdma-base.c | 84 ++++++++++++++++++++++++--------------------- 1 file changed, 45 insertions(+), 39 deletions(-) diff --git a/drivers/dma/sh/shdma-base.c b/drivers/dma/sh/shdma-base.c index b35007e..94b6bde 100644 --- a/drivers/dma/sh/shdma-base.c +++ b/drivers/dma/sh/shdma-base.c @@ -206,45 +206,6 @@ static int shdma_setup_slave(struct shdma_chan *schan, int slave_id, return 0; } -/* - * This is the standard shdma filter function to be used as a replacement to the - * "old" method, using the .private pointer. If for some reason you allocate a - * channel without slave data, use something like ERR_PTR(-EINVAL) as a filter - * parameter. If this filter is used, the slave driver, after calling - * dma_request_channel(), will also have to call dmaengine_slave_config() with - * .slave_id, .direction, and either .src_addr or .dst_addr set. - * NOTE: this filter doesn't support multiple DMAC drivers with the DMA_SLAVE - * capability! If this becomes a requirement, hardware glue drivers, using this - * services would have to provide their own filters, which first would check - * the device driver, similar to how other DMAC drivers, e.g., sa11x0-dma.c, do - * this, and only then, in case of a match, call this common filter. - * NOTE 2: This filter function is also used in the DT case by shdma_of_xlate(). - * In that case the MID-RID value is used for slave channel filtering and is - * passed to this function in the "arg" parameter. - */ -bool shdma_chan_filter(struct dma_chan *chan, void *arg) -{ - struct shdma_chan *schan = to_shdma_chan(chan); - struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device); - const struct shdma_ops *ops = sdev->ops; - int match = (long)arg; - int ret; - - if (match < 0) - /* No slave requested - arbitrary channel */ - return true; - - if (!schan->dev->of_node && match >= slave_num) - return false; - - ret = ops->set_slave(schan, match, 0, true); - if (ret < 0) - return false; - - return true; -} -EXPORT_SYMBOL(shdma_chan_filter); - static int shdma_alloc_chan_resources(struct dma_chan *chan) { struct shdma_chan *schan = to_shdma_chan(chan); @@ -295,6 +256,51 @@ esetslave: return ret; } +/* + * This is the standard shdma filter function to be used as a replacement to the + * "old" method, using the .private pointer. If for some reason you allocate a + * channel without slave data, use something like ERR_PTR(-EINVAL) as a filter + * parameter. If this filter is used, the slave driver, after calling + * dma_request_channel(), will also have to call dmaengine_slave_config() with + * .slave_id, .direction, and either .src_addr or .dst_addr set. + * NOTE: this filter doesn't support multiple DMAC drivers with the DMA_SLAVE + * capability! If this becomes a requirement, hardware glue drivers, using this + * services would have to provide their own filters, which first would check + * the device driver, similar to how other DMAC drivers, e.g., sa11x0-dma.c, do + * this, and only then, in case of a match, call this common filter. + * NOTE 2: This filter function is also used in the DT case by shdma_of_xlate(). + * In that case the MID-RID value is used for slave channel filtering and is + * passed to this function in the "arg" parameter. + */ +bool shdma_chan_filter(struct dma_chan *chan, void *arg) +{ + struct shdma_chan *schan; + struct shdma_dev *sdev; + int match = (long)arg; + int ret; + + /* Only support channels handled by this driver. */ + if (chan->device->device_alloc_chan_resources != + shdma_alloc_chan_resources) + return false; + + if (match < 0) + /* No slave requested - arbitrary channel */ + return true; + + schan = to_shdma_chan(chan); + if (!schan->dev->of_node && match >= slave_num) + return false; + + sdev = to_shdma_dev(schan->dma_chan.device); + ret = sdev->ops->set_slave(schan, match, 0, true); + if (ret < 0) + return false; + + return true; +} +EXPORT_SYMBOL(shdma_chan_filter); + static dma_async_tx_callback __ld_cleanup(struct shdma_chan *schan, bool all) { struct shdma_desc *desc, *_desc;