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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 949D8C433B4 for ; Fri, 14 May 2021 13:57:21 +0000 (UTC) Received: from smtp4.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2098F6145D for ; Fri, 14 May 2021 13:57:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2098F6145D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id C3906404E2; Fri, 14 May 2021 13:57:20 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id UFpOqJM2EUwd; Fri, 14 May 2021 13:57:19 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp4.osuosl.org (Postfix) with ESMTP id 79A2F4049D; Fri, 14 May 2021 13:57:19 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 5B548C000D; Fri, 14 May 2021 13:57:19 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [IPv6:2605:bc80:3010::138]) by lists.linuxfoundation.org (Postfix) with ESMTP id DEE5AC0001 for ; Fri, 14 May 2021 13:57:17 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id C6F6A83C82 for ; Fri, 14 May 2021 13:57:17 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 3GlHQWGiM5YO for ; Fri, 14 May 2021 13:57:17 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by smtp1.osuosl.org (Postfix) with ESMTPS id 36CD383C7B for ; Fri, 14 May 2021 13:57:17 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 176846736F; Fri, 14 May 2021 15:57:13 +0200 (CEST) Date: Fri, 14 May 2021 15:57:12 +0200 From: Christoph Hellwig To: Logan Gunthorpe Subject: Re: [PATCH v2 15/22] dma-direct: Support PCI P2PDMA pages in dma-direct map_sg Message-ID: <20210514135712.GD4715@lst.de> References: <20210513223203.5542-1-logang@deltatee.com> <20210513223203.5542-16-logang@deltatee.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210513223203.5542-16-logang@deltatee.com> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: linux-pci@vger.kernel.org, Dave Hansen , linux-nvme@lists.infradead.org, Stephen Bates , linux-mm@kvack.org, Jason Ekstrand , Ira Weiny , Christoph Hellwig , Minturn Dave B , Matthew Wilcox , Jason Gunthorpe , Bjorn Helgaas , Daniel Vetter , John Hubbard , linux-block@vger.kernel.org, Dan Williams , Jakowski Andrzej , Xiong Jianxin , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Robin Murphy , Christian =?iso-8859-1?Q?K=F6nig?= X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" > + for_each_sg(sgl, sg, nents, i) { > + if (sg_is_dma_pci_p2pdma(sg)) { > + sg_dma_unmark_pci_p2pdma(sg); > + } else { Double space here. We also don't really need the curly braces to start with. > + struct pci_p2pdma_map_state p2pdma_state = {}; > + enum pci_p2pdma_map_type map; > struct scatterlist *sg; > + int i, ret; > > for_each_sg(sgl, sg, nents, i) { > + if (is_pci_p2pdma_page(sg_page(sg))) { > + map = pci_p2pdma_map_segment(&p2pdma_state, dev, sg); > + switch (map) { Why not just: switch (pci_p2pdma_map_segment(&p2pdma_state, dev, sg)) { (even better with a shorter name for p2pdma_state so that it all fits on a single line)? > + case PCI_P2PDMA_MAP_BUS_ADDR: > + continue; > + case PCI_P2PDMA_MAP_THRU_HOST_BRIDGE: > + /* > + * Mapping through host bridge should be > + * mapped normally, thus we do nothing > + * and continue below. > + */ I have a bit of a hard time parsing this comment. > + if (sg->dma_address == DMA_MAPPING_ERROR) { > + ret = -EINVAL; > goto out_unmap; > + } > sg_dma_len(sg) = sg->length; > } > > @@ -411,7 +443,7 @@ int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents, > > out_unmap: > dma_direct_unmap_sg(dev, sgl, i, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC); > - return -EINVAL; > + return ret; Maybe just initialize ret to -EINVAL at declaration time to simplify this a bit? _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu