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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 535F5C47247 for ; Tue, 5 May 2020 11:09:57 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (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 29867206B8 for ; Tue, 5 May 2020 11:09:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 29867206B8 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 silver.osuosl.org (Postfix) with ESMTP id CFE9A228DF; Tue, 5 May 2020 11:09:56 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 3UkzqTj9dOTZ; Tue, 5 May 2020 11:09:55 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by silver.osuosl.org (Postfix) with ESMTP id A838920418; Tue, 5 May 2020 11:09:55 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 9065CC088B; Tue, 5 May 2020 11:09:55 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists.linuxfoundation.org (Postfix) with ESMTP id 1AACAC0175 for ; Tue, 5 May 2020 11:09:55 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id 08A5820450 for ; Tue, 5 May 2020 11:09:55 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id cECcPpFP+QUW for ; Tue, 5 May 2020 11:09:54 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by silver.osuosl.org (Postfix) with ESMTPS id 41D1120418 for ; Tue, 5 May 2020 11:09:54 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 4A89768C4E; Tue, 5 May 2020 13:09:50 +0200 (CEST) Date: Tue, 5 May 2020 13:09:50 +0200 From: Christoph Hellwig To: Marek Szyprowski Subject: Re: [PATCH v3 02/25] drm: core: fix common struct sg_table related issues Message-ID: <20200505110950.GA19067@lst.de> References: <20200505083926.28503-1-m.szyprowski@samsung.com> <20200505084614.30424-1-m.szyprowski@samsung.com> <20200505084614.30424-2-m.szyprowski@samsung.com> <20200505101508.GA14860@lst.de> <5dd1cb55-accb-0dc6-4ca5-90c57cd19527@samsung.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <5dd1cb55-accb-0dc6-4ca5-90c57cd19527@samsung.com> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: Thomas Zimmermann , Bartlomiej Zolnierkiewicz , David Airlie , Maarten Lankhorst , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, iommu@lists.linux-foundation.org, Maxime Ripard , Daniel Vetter , Robin Murphy , Christoph Hellwig , linux-arm-kernel@lists.infradead.org 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" On Tue, May 05, 2020 at 12:51:58PM +0200, Marek Szyprowski wrote: > Hi Christoph, > > On 05.05.2020 12:15, Christoph Hellwig wrote: > >> - for_each_sg_page(st->sgl, &sg_iter, st->nents, 0) > >> + for_each_sg_page(st->sgl, &sg_iter, st->orig_nents, 0) > > Would it make sense to also add a for_each_sgtable_page helper that > > hides the use of orig_nents? To be used like: > > > > for_each_sgtable_page(st, &sg_iter, 0) { > > We would need two helpers: > > for_each_sgtable_cpu_page() and for_each_sgtable_dma_page(). > > I considered them, but then I found that there are already > for_each_sg_page(), for_each_sg_dma_page() and various special iterators > like sg_page_iter, sg_dma_page_iter and sg_mapping_iter. Too bad that > they are almost not used, at least in the DRM subsystem. I wonder if it > make sense to apply them or simply provide the two above mentioned > wrappers? None of the helpers helps with passing the right parameters from the sg_table. So in doube we'd need wrappers for all of the above, or none.. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu