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 9682BC61DA4 for ; Mon, 6 Mar 2023 02:59:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229700AbjCFC7e (ORCPT ); Sun, 5 Mar 2023 21:59:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49282 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229676AbjCFC71 (ORCPT ); Sun, 5 Mar 2023 21:59:27 -0500 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4548A11668 for ; Sun, 5 Mar 2023 18:59:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1678071565; x=1709607565; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=MdWuluD3W8nfCHmXoPEsni78ipVq2xDF2ne8PYskGyM=; b=JFVSLHH5v9MCBzXy40dN2rMYzu/Po924qnmOkJOUJmXpGxL/K/3otyVN EIM7f3bMDZzicpjwbAtb1VJaS8NhA+Op6ZAP5lEh5/TVQuCv/HJRFScYv IM6NK+SYMk9uujPtksR652+MSMZbI/AnaNHELWqAodHE5eeLhD8bD3gha KBqHxtgrtyXhv+OPO6OlA45aqyfE+HBL9M+2Dma9JdzUE845toBd1sp33 23b0VGQ2U+ku+w7nEfIv3+hxWNLJw778Pm0YPHqRh92MZBw8BCI86Xvfj 9uXixdOK3ba0pcnUBBgSu2iToKgtVpZzIOYH18w6L0FEpNKX/7hj6pDaB Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10640"; a="363071524" X-IronPort-AV: E=Sophos;i="5.98,236,1673942400"; d="scan'208";a="363071524" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Mar 2023 18:59:25 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10640"; a="765072484" X-IronPort-AV: E=Sophos;i="5.98,236,1673942400"; d="scan'208";a="765072484" Received: from allen-box.sh.intel.com ([10.239.159.48]) by FMSMGA003.fm.intel.com with ESMTP; 05 Mar 2023 18:59:22 -0800 From: Lu Baolu To: iommu@lists.linux.dev Cc: Joerg Roedel , Jason Gunthorpe , Christoph Hellwig , Kevin Tian , Will Deacon , Robin Murphy , linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH v3 4/6] iommu: Move lock from iommu_change_dev_def_domain() to its caller Date: Mon, 6 Mar 2023 10:58:02 +0800 Message-Id: <20230306025804.13912-5-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230306025804.13912-1-baolu.lu@linux.intel.com> References: <20230306025804.13912-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The intention is to make it possible to put group ownership check and default domain change in a same critical region protected by the group's mutex lock. No intentional functional change. Signed-off-by: Lu Baolu --- drivers/iommu/iommu.c | 29 ++++++++++++++--------------- 1 file changed, 14 insertions(+), 15 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 0bcd9625090d..f8f400548a10 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2945,7 +2945,7 @@ static int iommu_change_dev_def_domain(struct iommu_group *group, int ret, dev_def_dom; struct device *dev; - mutex_lock(&group->mutex); + lockdep_assert_held(&group->mutex); if (group->default_domain != group->domain) { dev_err_ratelimited(prev_dev, "Group not assigned to default domain\n"); @@ -3033,28 +3033,15 @@ static int iommu_change_dev_def_domain(struct iommu_group *group, goto free_new_domain; group->domain = group->default_domain; - - /* - * Release the mutex here because ops->probe_finalize() call-back of - * some vendor IOMMU drivers calls arm_iommu_attach_device() which - * in-turn might call back into IOMMU core code, where it tries to take - * group->mutex, resulting in a deadlock. - */ - mutex_unlock(&group->mutex); - - /* Make sure dma_ops is appropriatley set */ - iommu_group_do_probe_finalize(dev, group->default_domain); iommu_domain_free(prev_dom); + return 0; free_new_domain: iommu_domain_free(group->default_domain); group->default_domain = prev_dom; group->domain = prev_dom; - out: - mutex_unlock(&group->mutex); - return ret; } @@ -3142,7 +3129,19 @@ static ssize_t iommu_group_store_type(struct iommu_group *group, goto out; } + mutex_lock(&group->mutex); ret = iommu_change_dev_def_domain(group, dev, req_type); + /* + * Release the mutex here because ops->probe_finalize() call-back of + * some vendor IOMMU drivers calls arm_iommu_attach_device() which + * in-turn might call back into IOMMU core code, where it tries to take + * group->mutex, resulting in a deadlock. + */ + mutex_unlock(&group->mutex); + + /* Make sure dma_ops is appropriatley set */ + if (!ret) + iommu_group_do_probe_finalize(dev, group->default_domain); ret = ret ?: count; out: -- 2.34.1