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=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,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 8CB1EC433DB for ; Thu, 28 Jan 2021 21:11:34 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 2C9AC64DD9 for ; Thu, 28 Jan 2021 21:11:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2C9AC64DD9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Kw2XLbXzOs+Tc7EzndM/BMMwMPt+1gQ2m1rEMazq4t8=; b=phdsUYa0UhT+DdGOAaZpzATGU TOm4ahQQhFflVXSjr8xk6o4ZcgVijRTQVW026fzslzZmbh5dZl5sSXegpYlEsS7IhFSVS9GOh9au3 e0PUX6I1xd5FKpruuQYMr/QsXt8vyWgmVxvOorzNgcnZpD/HHPfrSbbQYkmS90818wu3mR4lPbvQe DgZIlWhk9xsOF+P8/AXfHX5QdTieZZ4hxE6UlNQU6O36CehLdBNtDFGYPOBIxx5nKoonH4fXJ5AnW pT1DVvPBi2hre7SbkiHJpwvCbbXAKU1rkvWItJzGPvJQTUriz8IgKIGg3rIstNO/GW5feumRv5v09 +0yx9wrqA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l5EYf-0007c0-H0; Thu, 28 Jan 2021 21:10:29 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l5EYd-0007b4-DI; Thu, 28 Jan 2021 21:10:28 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id E203464DDB; Thu, 28 Jan 2021 21:10:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1611868226; bh=Wa3oCHdbhNI1rC5aNsjPzPLiyWlgSVs5J8jobh+d16o=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=UDy8g1B6xXUCMyvUCEeP3sXc/2mWaH+aOzhkdIt9x4BNWlNenfnPapZYWW8Am2sA0 1P2Qr5F1Ssd+GPV0IbsWoNHLqxohnEy/M6feG0Sz6CS1rlYGIKNIUeE1xtVno9B/g4 9RAF0vPuqOR028QU/LMmX1/Vjw9AQxLEkAw1QMPyVsJza2HePfbkP6rApwZZBXlZZU ZWH/oMCV/7zu/gOVT5AD0j2RGsyQ5AILr6L2tyo9xIMQXyLXXXU+e6pEYRYNiq7Rqy GlqCM3FSWikkY89/Yil+uuctnscrmmcMqJV/IfckIyfCmg5bgG3FIyDm7NpmplejKK j+hxxClSbtcNA== Date: Thu, 28 Jan 2021 21:10:20 +0000 From: Will Deacon To: Yong Wu Subject: Re: [PATCH v6 07/33] iommu: Avoid reallocate default domain for a group Message-ID: <20210128211020.GA3531@willie-the-truck> References: <20210111111914.22211-1-yong.wu@mediatek.com> <20210111111914.22211-8-yong.wu@mediatek.com> <20210126222305.GB30460@willie-the-truck> <1611740356.5302.14.camel@mhfsdcap03> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1611740356.5302.14.camel@mhfsdcap03> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210128_161027_521189_7F3470F0 X-CRM114-Status: GOOD ( 25.53 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: youlin.pei@mediatek.com, devicetree@vger.kernel.org, Nicolas Boichat , srv_heupstream@mediatek.com, chao.hao@mediatek.com, Joerg Roedel , linux-kernel@vger.kernel.org, Evan Green , Tomasz Figa , iommu@lists.linux-foundation.org, Rob Herring , linux-mediatek@lists.infradead.org, Krzysztof Kozlowski , Matthias Brugger , anan.sun@mediatek.com, Robin Murphy , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Jan 27, 2021 at 05:39:16PM +0800, Yong Wu wrote: > On Tue, 2021-01-26 at 22:23 +0000, Will Deacon wrote: > > On Mon, Jan 11, 2021 at 07:18:48PM +0800, Yong Wu wrote: > > > If group->default_domain exists, avoid reallocate it. > > > > > > In some iommu drivers, there may be several devices share a group. Avoid > > > realloc the default domain for this case. > > > > > > Signed-off-by: Yong Wu > > > --- > > > drivers/iommu/iommu.c | 3 ++- > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > > > index 3d099a31ddca..f4b87e6abe80 100644 > > > --- a/drivers/iommu/iommu.c > > > +++ b/drivers/iommu/iommu.c > > > @@ -266,7 +266,8 @@ int iommu_probe_device(struct device *dev) > > > * support default domains, so the return value is not yet > > > * checked. > > > */ > > > - iommu_alloc_default_domain(group, dev); > > > + if (!group->default_domain) > > > + iommu_alloc_default_domain(group, dev); > > > > I don't really get what this achieves, since iommu_alloc_default_domain() > > looks like this: > > > > static int iommu_alloc_default_domain(struct iommu_group *group, > > struct device *dev) > > { > > unsigned int type; > > > > if (group->default_domain) > > return 0; > > > > ... > > > > in which case, it should be fine? > > oh. sorry, I overlooked this. the current code is enough. > I will remove this patch. and send the next version in this week. > Thanks very much. Actually, looking at this again, if we're dropping this patch and patch 6 just needs the kfree() moving about, then there's no need to repost. The issue that Robin and Paul are discussing can be handled separately. Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel