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,USER_AGENT_SANE_1 autolearn=unavailable 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 3A667C4708A for ; Thu, 27 May 2021 13:25:16 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 9AE7E613EB for ; Thu, 27 May 2021 13:25:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9AE7E613EB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4FrT8B3Hpsz3068 for ; Thu, 27 May 2021 23:25:14 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lst.de (client-ip=213.95.11.211; helo=verein.lst.de; envelope-from=hch@lst.de; receiver=) Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4FrT7k3JP8z2xZS for ; Thu, 27 May 2021 23:24:50 +1000 (AEST) Received: by verein.lst.de (Postfix, from userid 2407) id A8FB568AFE; Thu, 27 May 2021 15:24:42 +0200 (CEST) Date: Thu, 27 May 2021 15:24:42 +0200 From: Christoph Hellwig To: Claire Chang Subject: Re: [PATCH v7 02/15] swiotlb: Refactor swiotlb_create_debugfs Message-ID: <20210527132442.GA26160@lst.de> References: <20210518064215.2856977-1-tientzu@chromium.org> <20210518064215.2856977-3-tientzu@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210518064215.2856977-3-tientzu@chromium.org> User-Agent: Mutt/1.5.17 (2007-11-01) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: heikki.krogerus@linux.intel.com, thomas.hellstrom@linux.intel.com, peterz@infradead.org, joonas.lahtinen@linux.intel.com, dri-devel@lists.freedesktop.org, chris@chris-wilson.co.uk, grant.likely@arm.com, paulus@samba.org, Frank Rowand , mingo@kernel.org, Marek Szyprowski , sstabellini@kernel.org, Saravana Kannan , Joerg Roedel , "Rafael J . Wysocki" , Christoph Hellwig , Bartosz Golaszewski , bskeggs@redhat.com, linux-pci@vger.kernel.org, xen-devel@lists.xenproject.org, Thierry Reding , intel-gfx@lists.freedesktop.org, matthew.auld@intel.com, linux-devicetree , jxgao@google.com, daniel@ffwll.ch, Will Deacon , Konrad Rzeszutek Wilk , maarten.lankhorst@linux.intel.com, airlied@linux.ie, Dan Williams , linuxppc-dev@lists.ozlabs.org, jani.nikula@linux.intel.com, Rob Herring , rodrigo.vivi@intel.com, bhelgaas@google.com, boris.ostrovsky@oracle.com, Andy Shevchenko , jgross@suse.com, Nicolas Boichat , Greg KH , Randy Dunlap , lkml , tfiga@chromium.org, "list@263.net:IOMMU DRIVERS" , Jim Quinlan , xypron.glpk@gmx.de, Robin Murphy , bauerman@linux.ibm.com Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Tue, May 18, 2021 at 02:42:02PM +0800, Claire Chang wrote: > struct io_tlb_mem *io_tlb_default_mem; > +static struct dentry *debugfs_dir; > > /* > * Max segment that we can provide which (if pages are contingous) will > @@ -662,18 +663,30 @@ EXPORT_SYMBOL_GPL(is_swiotlb_active); > > #ifdef CONFIG_DEBUG_FS > > +static void swiotlb_create_debugfs(struct io_tlb_mem *mem, const char *name) > { > if (!mem) > + return; I don't think this check makes much sense here. > +} > + > +static int __init swiotlb_create_default_debugfs(void) > +{ > + struct io_tlb_mem *mem = io_tlb_default_mem; > + > + if (mem) { > + swiotlb_create_debugfs(mem, "swiotlb"); > + debugfs_dir = mem->debugfs; > + } else { > + debugfs_dir = debugfs_create_dir("swiotlb", NULL); > + } This also looks rather strange. I'd much rather create move the directory creation of out swiotlb_create_debugfs. E.g. something like: static void swiotlb_create_debugfs_file(struct io_tlb_mem *mem) { debugfs_create_ulong("io_tlb_nslabs", 0400, mem->debugfs, &mem->nslabs); debugfs_create_ulong("io_tlb_used", 0400, mem->debugfs, &mem->used); } static int __init swiotlb_init_debugfs(void) { debugfs_dir = debugfs_create_dir("swiotlb", NULL); if (io_tlb_default_mem) { io_tlb_default_mem->debugfs = debugfs_dir; swiotlb_create_debugfs_files(io_tlb_default_mem); } return 0; } late_initcall(swiotlb_init_debugfs); ... static int rmem_swiotlb_device_init(struct reserved_mem *rmem, struct device *dev) { ... mem->debugfs = debugfs_create_dir(rmem->name, debugfs_dir); swiotlb_create_debugfs_files(mem->debugfs); }