From nobody Thu Sep 11 18:16:33 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 668CFC6FD1F for ; Wed, 22 Mar 2023 06:50:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229717AbjCVGu2 (ORCPT ); Wed, 22 Mar 2023 02:50:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59572 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230105AbjCVGuJ (ORCPT ); Wed, 22 Mar 2023 02:50:09 -0400 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C1DC32B9EA for ; Tue, 21 Mar 2023 23:49:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1679467792; x=1711003792; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=5/QtRJNGbVy0gqEC5sJtBu3RE6LTB+TTy8zzoXdzsNA=; b=YtPG9MeTu8t46wv4wJrQqSXA6SDKhO9V9yjOsVm/ILmBHgM1I2hYNOlu ulHfTmfjJ3gFDKxWVLxVxEFDO/6bZV4Y7MPPaSf707mZX83cOQpNUzupo Yz9775Ir1NNjpb0owfDawmPqe+VVNbhvEHKW83XkrnBvARbaEX4IG2Bnt lMBftsHtquAaoqhMerBPRcQ+9V874O6QM0dowY2WdmIsDK9tGV+WQa68J 2PS/Rn9PQZoOu5ZfQMuDA5/pdyjpnQGyemzOdxLe0/msqr3PqhUvDsVAR BuyzGrxp+F1s1MTD2qA1JPyax6nQcADzNONFV48Tzr/eBMJTwD/KyjWZV A==; X-IronPort-AV: E=McAfee;i="6600,9927,10656"; a="337866787" X-IronPort-AV: E=Sophos;i="5.98,281,1673942400"; d="scan'208";a="337866787" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Mar 2023 23:49:52 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10656"; a="659080461" X-IronPort-AV: E=Sophos;i="5.98,281,1673942400"; d="scan'208";a="659080461" Received: from allen-box.sh.intel.com ([10.239.159.48]) by orsmga006.jf.intel.com with ESMTP; 21 Mar 2023 23:49:49 -0700 From: Lu Baolu To: Joerg Roedel Cc: Jason Gunthorpe , Robin Murphy , Christoph Hellwig , Kevin Tian , Will Deacon , iommu@lists.linux.dev, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH v4 6/6] iommu: Cleanup iommu_change_dev_def_domain() Date: Wed, 22 Mar 2023 14:49:56 +0800 Message-Id: <20230322064956.263419-7-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230322064956.263419-1-baolu.lu@linux.intel.com> References: <20230322064956.263419-1-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 Reviewed-by: Jason Gunthorpe --- drivers/iommu/iommu.c | 83 +++++-------------- .../ABI/testing/sysfs-kernel-iommu_groups | 1 - 2 files changed, 21 insertions(+), 63 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index b780cdddf415..a38b9f279c5d 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2867,11 +2867,10 @@ 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 @@ -2882,103 +2881,63 @@ 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; - struct group_device *grp_dev; - 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 */ - grp_dev =3D list_first_entry(&group->devices, struct group_device, list); - dev =3D grp_dev->dev; - - 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(dev->bus, group, 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