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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7F7CAC4321E for ; Wed, 30 Nov 2022 09:02:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229580AbiK3JCy (ORCPT ); Wed, 30 Nov 2022 04:02:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36898 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229515AbiK3JCv (ORCPT ); Wed, 30 Nov 2022 04:02:51 -0500 Received: from mail-ej1-x62a.google.com (mail-ej1-x62a.google.com [IPv6:2a00:1450:4864:20::62a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A7C2315838 for ; Wed, 30 Nov 2022 01:02:50 -0800 (PST) Received: by mail-ej1-x62a.google.com with SMTP id vp12so38441823ejc.8 for ; Wed, 30 Nov 2022 01:02:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=bvCkSPWWXEisBKO+mE/xfJ0iMceCkypfEF6PFvX87bk=; b=LjLp7O13cRq+xDrs1MAO2ZcpkbECDNbMAGdmn1nST/EMEngSM+h+F7Iae4N0CyzhT3 asYogNfUqIBeeN8Bxf7Fb9LYfuHCYzJMQA09Ydkei5tkdlJsKYWvPz9zcyr+Fe0Y6Jtn IGNVsq7PheOygDpPiAPN3kT/GVTyJ+Lvy1znjQP81zgEve2NFF8J16qwk1HKWU2m+BjW ZXmR7rZQUrFFk4ybAylMqu4qumJ1bqog4E7SLmHvDSTRMCw8DRC/8u3GKRvcJWsvgtXa zMFhcu6DVwm9JwN9SaZqEMMkiNsGeXea9pVSbqVeNaZpcu1xzniXMJq6RDcaiILC/3wh EPZQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=bvCkSPWWXEisBKO+mE/xfJ0iMceCkypfEF6PFvX87bk=; b=rgUAGo0uO/86EOuweUst70SIprPaKvAYWqmNk3NtlWUXIw+mB2BL526qb2JPZL0dnw G5glHoEmDf6UirLecqCqQnFeIJ348IGFDtiu1Eg6qiueZnLWeSw6g7lCU5mbQEYa36YX GJeDamGyK57rNbwnVVJhCBtow8SoYNcc9VSYHAG/dE5gf5/E91RGk9pSMzx9aPHQ7vLo DRLcffqKQyvXpULt2eGYUgcgqKuZxv1KmhqGWxs8H5dZI2OO2zxwmqOLxlbP60GQqVwN hFeCj2pPVakGBGGTpur0JPRyJjPX5aT/gztpRXDar6wWA5/leEHaGaggSPgDsQWOAoEU tM4w== X-Gm-Message-State: ANoB5pl03h5u4TnZ60dnqZQ2K/x2aM3TKNrCCvE8kVzc0eOF3AwB/Yd3 kRHkw142XVp+oFkwFtkWWTFPe5mFnrc+hOzqrTM= X-Google-Smtp-Source: AA0mqf4/GBvpR8BDs7aXcNHCJIURnlX8+Q4URsljIZcfS/jf5Ko1DXgZkiwT07uqHCIh2Z7p4zHN0wKVOWUvDZPbXKA= X-Received: by 2002:a17:906:9c8a:b0:7bf:6698:d444 with SMTP id fj10-20020a1709069c8a00b007bf6698d444mr12679921ejc.548.1669798968899; Wed, 30 Nov 2022 01:02:48 -0800 (PST) MIME-Version: 1.0 References: <20221128064648.1934720-1-baolu.lu@linux.intel.com> <20221128064648.1934720-9-baolu.lu@linux.intel.com> In-Reply-To: From: Chunyan Zhang Date: Wed, 30 Nov 2022 17:02:11 +0800 Message-ID: Subject: Re: [PATCH v3 08/20] iommu/sprd: Remove detach_dev callback To: "Tian, Kevin" Cc: Lu Baolu , Joerg Roedel , Jason Gunthorpe , Christoph Hellwig , Will Deacon , Robin Murphy , Jean-Philippe Brucker , Suravee Suthikulpanit , Hector Martin , Sven Peter , Rob Clark , Marek Szyprowski , Krzysztof Kozlowski , Andy Gross , Bjorn Andersson , Yong Wu , Matthias Brugger , Heiko Stuebner , Matthew Rosato , Orson Zhai , Baolin Wang , Chen-Yu Tsai , Thierry Reding , "iommu@lists.linux.dev" , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 29 Nov 2022 at 11:35, Tian, Kevin wrote: > > > From: Lu Baolu > > Sent: Monday, November 28, 2022 2:47 PM > > > > The IOMMU driver supports default domain, so the detach_dev op will never > > be called. Remove it to avoid dead code. > > > > Signed-off-by: Lu Baolu > > --- > > drivers/iommu/sprd-iommu.c | 16 ---------------- > > 1 file changed, 16 deletions(-) > > > > diff --git a/drivers/iommu/sprd-iommu.c b/drivers/iommu/sprd-iommu.c > > index 219bfa11f7f4..ae94d74b73f4 100644 > > --- a/drivers/iommu/sprd-iommu.c > > +++ b/drivers/iommu/sprd-iommu.c > > @@ -255,21 +255,6 @@ static int sprd_iommu_attach_device(struct > > iommu_domain *domain, > > return 0; > > } > > > > -static void sprd_iommu_detach_device(struct iommu_domain *domain, > > - struct device *dev) > > -{ > > - struct sprd_iommu_domain *dom = to_sprd_domain(domain); > > - struct sprd_iommu_device *sdev = dom->sdev; > > - size_t pgt_size = sprd_iommu_pgt_size(domain); > > - > > - if (!sdev) > > - return; > > - > > - dma_free_coherent(sdev->dev, pgt_size, dom->pgt_va, dom- > > >pgt_pa); > > - sprd_iommu_hw_en(sdev, false); > > - dom->sdev = NULL; > > -} > > - > > Looks this reveals a bug in this driver (not caused by this removal). > > sprd_iommu_attach_device() doesn't check whether the device has > been already attached to a domain and do auto detach. > > It's written in a way that .detach_dev() must be called to free the > dma buffer but ignores the fact that it's not called when default > domain support is claimed. > > Then the dma buffer allocated for the previous domain was left > unhandled, causing memory leak. I'll look into the issue, thanks for pointing this out. Chunyan