From nobody Thu Sep 11 18:24:15 2025 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 717A4C05027 for ; Fri, 17 Feb 2023 09:56:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230289AbjBQJ4l (ORCPT ); Fri, 17 Feb 2023 04:56:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49200 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230254AbjBQJ43 (ORCPT ); Fri, 17 Feb 2023 04:56:29 -0500 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3565D6243C for ; Fri, 17 Feb 2023 01:56:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1676627783; x=1708163783; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=L0BLlBlx7/lIGCWsyetXVIlqgQEx+QKVJ6i4zLx6NnI=; b=Md1qDKVQACDyefwtH6zjbVYoiUT4gHvZhbYcHlc4NCwi01V93GWgjr2G oJZJi3rINceIgOnHddEgC1NrTPo8aoGFBaU4bTnOdQI4XoaHblcAJtoUn I/KTKMpBNmh4OkaI6mlyHdS14hEaNVFQk61zN4hkUbg1Pdz7snqzuLq1D NfD9MDvMTJ+2lJUuqk55/KyPZz1Grxl8RupLloSQVQx66jYvJRMS/elBj xHUd9uk0Vqx0rfJPeU3rRsCylbBqfL6Ns7SqRs7XK6cLO6O6fEDrwHrAb prvGCkbQZhTd9WGRoHtSgLya89HDOWimaXmyVkHZuunHiGTBNTwUelRKN A==; X-IronPort-AV: E=McAfee;i="6500,9779,10623"; a="331955298" X-IronPort-AV: E=Sophos;i="5.97,304,1669104000"; d="scan'208";a="331955298" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Feb 2023 01:56:21 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10623"; a="999391241" X-IronPort-AV: E=Sophos;i="5.97,304,1669104000"; d="scan'208";a="999391241" Received: from allen-box.sh.intel.com ([10.239.159.48]) by fmsmga005.fm.intel.com with ESMTP; 17 Feb 2023 01:56:19 -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 v2 6/6] iommu: Cleanup iommu_change_dev_def_domain() Date: Fri, 17 Feb 2023 17:47:36 +0800 Message-Id: <20230217094736.159005-7-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230217094736.159005-1-baolu.lu@linux.intel.com> References: <20230217094736.159005-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" As the singleton group limitation has been removed, cleanup the code in iommu_change_dev_def_domain() accordingly. Documentation is also updated. Signed-off-by: Lu Baolu --- drivers/iommu/iommu.c | 81 +++++-------------- .../ABI/testing/sysfs-kernel-iommu_groups | 1 - 2 files changed, 21 insertions(+), 61 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 18dac155a178..c06757224bec 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2871,11 +2871,10 @@ int iommu_dev_disable_feature(struct device *dev, e= num iommu_dev_features feat) EXPORT_SYMBOL_GPL(iommu_dev_disable_feature); =20 /* - * Changes the default domain of an iommu group that has *only* one device + * Changes the default domain of an iommu group * * @group: The group for which the default domain should be changed - * @prev_dev: The device in the group (this is used to make sure that the = device - * hasn't changed after the caller has called this function) + * @dev: The first device in the group * @type: The type of the new default domain that gets associated with the= group * * Returns 0 on success and error code on failure @@ -2886,101 +2885,63 @@ EXPORT_SYMBOL_GPL(iommu_dev_disable_feature); * Please take a closer look if intended to use for other purposes. */ static int iommu_change_dev_def_domain(struct iommu_group *group, - struct device *prev_dev, int type) + struct device *dev, int type) { + struct __group_domain_type gtype =3D {NULL, 0}; struct iommu_domain *prev_dom; - int ret, dev_def_dom; - struct device *dev; + int ret; =20 lockdep_assert_held(&group->mutex); =20 - if (group->default_domain !=3D group->domain) { - dev_err_ratelimited(prev_dev, "Group not assigned to default domain\n"); - ret =3D -EBUSY; - goto out; - } - - /* - * iommu group wasn't locked while acquiring device lock in - * iommu_group_store_type(). So, make sure that the device count hasn't - * changed while acquiring device lock. - * - * Changing default domain of an iommu group with two or more devices - * isn't supported because there could be a potential deadlock. Consider - * the following scenario. T1 is trying to acquire device locks of all - * the devices in the group and before it could acquire all of them, - * there could be another thread T2 (from different sub-system and use - * case) that has already acquired some of the device locks and might be - * waiting for T1 to release other device locks. - */ - if (iommu_group_device_count(group) !=3D 1) { - dev_err_ratelimited(prev_dev, "Cannot change default domain: Group has m= ore than one device\n"); - ret =3D -EINVAL; - goto out; - } - - /* Since group has only one device */ - dev =3D iommu_group_first_dev(group); - - if (prev_dev !=3D dev) { - dev_err_ratelimited(prev_dev, "Cannot change default domain: Device has = been changed\n"); - ret =3D -EBUSY; - goto out; - } - prev_dom =3D group->default_domain; - if (!prev_dom) { - ret =3D -EINVAL; - goto out; - } - - dev_def_dom =3D iommu_get_def_domain_type(dev); + __iommu_group_for_each_dev(group, >ype, + probe_get_default_domain_type); if (!type) { /* * If the user hasn't requested any specific type of domain and * if the device supports both the domains, then default to the * domain the device was booted with */ - type =3D dev_def_dom ? : iommu_def_domain_type; - } else if (dev_def_dom && type !=3D dev_def_dom) { - dev_err_ratelimited(prev_dev, "Device cannot be in %s domain\n", + type =3D gtype.type ? : iommu_def_domain_type; + } else if (gtype.type && type !=3D gtype.type) { + dev_err_ratelimited(dev, "Device cannot be in %s domain\n", iommu_domain_type_str(type)); - ret =3D -EINVAL; - goto out; + return -EINVAL; } =20 /* * Switch to a new domain only if the requested domain type is different * from the existing default domain type */ - if (prev_dom->type =3D=3D type) { - ret =3D 0; - goto out; - } + if (prev_dom->type =3D=3D type) + return 0; + + group->default_domain =3D NULL; + group->domain =3D NULL; =20 /* Sets group->default_domain to the newly allocated domain */ ret =3D iommu_group_alloc_default_domain(group, dev, type); if (ret) - goto out; + goto restore_old_domain; =20 - ret =3D iommu_create_device_direct_mappings(group, dev); + ret =3D iommu_group_create_direct_mappings(group); if (ret) goto free_new_domain; =20 - ret =3D __iommu_attach_device(group->default_domain, dev); + ret =3D __iommu_attach_group(group->default_domain, group); if (ret) goto free_new_domain; =20 - group->domain =3D group->default_domain; iommu_domain_free(prev_dom); =20 return 0; =20 free_new_domain: iommu_domain_free(group->default_domain); +restore_old_domain: group->default_domain =3D prev_dom; group->domain =3D prev_dom; -out: + return ret; } =20 diff --git a/Documentation/ABI/testing/sysfs-kernel-iommu_groups b/Document= ation/ABI/testing/sysfs-kernel-iommu_groups index b15af6a5bc08..a42d4383d999 100644 --- a/Documentation/ABI/testing/sysfs-kernel-iommu_groups +++ b/Documentation/ABI/testing/sysfs-kernel-iommu_groups @@ -53,7 +53,6 @@ Description: /sys/kernel/iommu_groups//type shows= the type of default =20 The default domain type of a group may be modified only when =20 - - The group has only one device. - The device in the group is not bound to any device driver. So, the users must unbind the appropriate driver before changing the default domain type. --=20 2.34.1