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=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 3BE05C433DB for ; Fri, 5 Feb 2021 09:45:23 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (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 9254064FB8 for ; Fri, 5 Feb 2021 09:45:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9254064FB8 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 whitealder.osuosl.org (Postfix) with ESMTP id 4428787116; Fri, 5 Feb 2021 09:45:22 +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 2Dtx-AOM4tPJ; Fri, 5 Feb 2021 09:45:21 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by whitealder.osuosl.org (Postfix) with ESMTP id 83FCB87112; Fri, 5 Feb 2021 09:45:21 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 7790DC08A1; Fri, 5 Feb 2021 09:45:21 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 3B8FEC1DA9 for ; Fri, 5 Feb 2021 09:45:19 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 37B2586044 for ; Fri, 5 Feb 2021 09:45:19 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id x2uX5GtD3F1i for ; Fri, 5 Feb 2021 09:45:18 +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 fraxinus.osuosl.org (Postfix) with ESMTPS id 231D185F56 for ; Fri, 5 Feb 2021 09:45:18 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 9B85068AFE; Fri, 5 Feb 2021 10:45:12 +0100 (CET) Date: Fri, 5 Feb 2021 10:45:11 +0100 From: Christoph Hellwig To: Robin Murphy Subject: Re: [PATCH 3/8] swiotlb: factor out a nr_slots helper Message-ID: <20210205094511.GA2801@lst.de> References: <20210204193035.2606838-1-hch@lst.de> <20210204193035.2606838-4-hch@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Cc: saravanak@google.com, konrad.wilk@oracle.com, marcorr@google.com, gregkh@linuxfoundation.org, linux-nvme@lists.infradead.org, kbusch@kernel.org, iommu@lists.linux-foundation.org, Christoph Hellwig , jxgao@google.com 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, Feb 04, 2021 at 10:09:02PM +0000, Robin Murphy wrote: >> diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c >> index 838dbad10ab916..0c0b81799edbdb 100644 >> --- a/kernel/dma/swiotlb.c >> +++ b/kernel/dma/swiotlb.c >> @@ -194,6 +194,11 @@ static inline unsigned long io_tlb_offset(unsigned long val) >> return val & (IO_TLB_SEGSIZE - 1); >> } >> +static unsigned long nr_slots(u64 val) >> +{ >> + return ALIGN(val, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT; > > Would DIV_ROUND_UP(val, 1 << IOTLB_SHIFT) be even clearer? Not sure it is all that much cleaner, but it does fit a common pattern, so I'll switch to that. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu