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=-3.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 4B684C433DF for ; Fri, 21 Aug 2020 08:35:39 +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 1F436207DA for ; Fri, 21 Aug 2020 08:35:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1F436207DA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com 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 C0D0A22D0D; Fri, 21 Aug 2020 08:35:38 +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 gxEfukVcDADZ; Fri, 21 Aug 2020 08:35:32 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by silver.osuosl.org (Postfix) with ESMTP id 4D94320448; Fri, 21 Aug 2020 08:35:32 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 3E3BFC07FF; Fri, 21 Aug 2020 08:35:32 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id 516AFC0051 for ; Fri, 21 Aug 2020 08:35:31 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id 35D338853D for ; Fri, 21 Aug 2020 08:35:31 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id rFm9IBAjj8cg for ; Fri, 21 Aug 2020 08:35:30 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by whitealder.osuosl.org (Postfix) with ESMTPS id 684BC8065F for ; Fri, 21 Aug 2020 08:35:30 +0000 (UTC) IronPort-SDR: sT/em1bXOvVsb+sTJ8B4JQGQdf1oVP/Rxj5xtB1VlfweU9hXCLl/euE0Ow/9XmUEuQyJ0IJrVu W3ZFfyPxZmJw== X-IronPort-AV: E=McAfee;i="6000,8403,9719"; a="240310875" X-IronPort-AV: E=Sophos;i="5.76,335,1592895600"; d="scan'208";a="240310875" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Aug 2020 01:35:29 -0700 IronPort-SDR: sFEKwv6y/kLUfJd0c/oiHtZBJBdoOxUSjHH+8M4J6WHXjAjmPnpfKPCWAHeow4nT3yt/VMUMRr IMpAxfbWC23A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.76,335,1592895600"; d="scan'208";a="327705580" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by orsmga008.jf.intel.com with ESMTP; 21 Aug 2020 01:35:17 -0700 Received: from andy by smile with local (Exim 4.94) (envelope-from ) id 1k920K-00AHyO-Ln; Fri, 21 Aug 2020 11:02:28 +0300 Date: Fri, 21 Aug 2020 11:02:28 +0300 From: Andy Shevchenko To: Jim Quinlan Subject: Re: [PATCH RESEND v10 07/11] device-mapping: Introduce DMA range map, supplanting dma_pfn_offset Message-ID: <20200821080228.GF1891694@smile.fi.intel.com> References: <20200817215326.30912-1-james.quinlan@broadcom.com> <20200817215326.30912-8-james.quinlan@broadcom.com> <20200818081225.GA1891694@smile.fi.intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Cc: Rich Felker , "open list:SUPERH" , David Airlie , "open list:PCI NATIVE HOST BRIDGE AND ENDPOINT DRIVERS" , Hanjun Guo , "open list:REMOTE PROCESSOR \(REMOTEPROC\) SUBSYSTEM" , "open list:DRM DRIVERS FOR ALLWINNER A10" , Julien Grall , Heikki Krogerus , "H. Peter Anvin" , Will Deacon , Christoph Hellwig , "open list:STAGING SUBSYSTEM" , Jean-Philippe Brucker , Yoshinori Sato , Frank Rowand , "maintainer:X86 ARCHITECTURE \(32-BIT AND 64-BIT\)" , Russell King , "open list:ACPI FOR ARM64 \(ACPI/arm64\)" , Chen-Yu Tsai , Ingo Molnar , "maintainer:BROADCOM BCM7XXX ARM ARCHITECTURE" , Alan Stern , Len Brown , Ohad Ben-Cohen , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE" , Arnd Bergmann , Maxime Ripard , Rob Herring , Borislav Petkov , Yong Deng , Santosh Shilimkar , Bjorn Helgaas , Thomas Gleixner , Mauro Carvalho Chehab , "moderated list:ARM PORT" , Saravana Kannan , Greg Kroah-Hartman , "open list:USB SUBSYSTEM" , "Rafael J. Wysocki" , open list , Paul Kocialkowski , "open list:IOMMU DRIVERS" , Stefano Stabellini , Daniel Vetter , Sudeep Holla , "open list:ALLWINNER A10 CSI DRIVER" , Robin Murphy 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 Thu, Aug 20, 2020 at 09:37:12AM -0400, Jim Quinlan wrote: > On Tue, Aug 18, 2020 at 4:14 AM Andy Shevchenko > wrote: > > On Mon, Aug 17, 2020 at 05:53:09PM -0400, Jim Quinlan wrote: ... > > > +static inline u64 dma_offset_from_dma_addr(struct device *dev, dma_addr_t dma_addr) > > > +{ > > > + const struct bus_dma_region *m = dev->dma_range_map; > > > + > > > + if (!m) > > > + return 0; > > > + for (; m->size; m++) > > > + if (dma_addr >= m->dma_start && dma_addr - m->dma_start < m->size) > > > + return m->offset; > > > + return 0; > > > +} > > > + > > > +static inline u64 dma_offset_from_phys_addr(struct device *dev, phys_addr_t paddr) > > > +{ > > > + const struct bus_dma_region *m = dev->dma_range_map; > > > + > > > + if (!m) > > > + return 0; > > > + for (; m->size; m++) > > > + if (paddr >= m->cpu_start && paddr - m->cpu_start < m->size) > > > + return m->offset; > > > + return 0; > > > +} > > > > Perhaps for these the form with one return 0 is easier to read > > > > if (m) { > > for (; m->size; m++) > > if (paddr >= m->cpu_start && paddr - m->cpu_start < m->size) > > return m->offset; > > } > > return 0; > > > > ? > I see what you are saying but I don't think there is enough difference > between the two to justify changing it. The difference is that you have return 0 / non-0 cases one each. I think it's slightly easier to read and understand, but it's up to you. -- With Best Regards, Andy Shevchenko _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu