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 B377DC678DB for ; Mon, 6 Mar 2023 02:59:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229676AbjCFC7w (ORCPT ); Sun, 5 Mar 2023 21:59:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50002 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229709AbjCFC7j (ORCPT ); Sun, 5 Mar 2023 21:59:39 -0500 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3AEE912069 for ; Sun, 5 Mar 2023 18:59:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1678071570; x=1709607570; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Taiw2o2chkLGjTGNeAmtwqU/UhEE9L3oW9AzQ9w2d3I=; b=mAtgoytfVraoykZ6qVCf+TvF0IPuLGw/txjzRvN9GMVa0YVXwtQIM2AB X1XvLgvuS/oEwOgEMgOoruQeV+Duc7D34CTZWZHbPCPSH52d+Mndgt/vt jjcpLXFNK4I9Hf2JVqOpOLqJiJHdTlimGljngkM2EkpK/G8WUNE1u3zHW wbrTT8rRdDQR3NZNSog324A1qMp4j5LH+Q4XBzhEBVpxT+4u7xQcmjh6r qCcHsd5yJ/COq0y+dku6r3isu0SIym40aUAJcyqZnoBtukpDjmyUV/xjX G6vc0rutLwDFTF+RN44LRKWx/T6OpnLmnpHwkr1EL/JrbIjIH2DjaAwSr g==; X-IronPort-AV: E=McAfee;i="6500,9779,10640"; a="363071543" X-IronPort-AV: E=Sophos;i="5.98,236,1673942400"; d="scan'208";a="363071543" 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 18:59:29 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10640"; a="765072490" X-IronPort-AV: E=Sophos;i="5.98,236,1673942400"; d="scan'208";a="765072490" Received: from allen-box.sh.intel.com ([10.239.159.48]) by FMSMGA003.fm.intel.com with ESMTP; 05 Mar 2023 18:59:27 -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 6/6] iommu: Cleanup iommu_change_dev_def_domain() Date: Mon, 6 Mar 2023 10:58:04 +0800 Message-Id: <20230306025804.13912-7-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 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 9fe6d149f281..735554ccc04b 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2924,11 +2924,10 @@ int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat) EXPORT_SYMBOL_GPL(iommu_dev_disable_feature); /* - * 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 @@ -2939,101 +2938,63 @@ 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 = {NULL, 0}; struct iommu_domain *prev_dom; - int ret, dev_def_dom; - struct device *dev; + int ret; lockdep_assert_held(&group->mutex); - if (group->default_domain != group->domain) { - dev_err_ratelimited(prev_dev, "Group not assigned to default domain\n"); - ret = -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) != 1) { - dev_err_ratelimited(prev_dev, "Cannot change default domain: Group has more than one device\n"); - ret = -EINVAL; - goto out; - } - - /* Since group has only one device */ - dev = iommu_group_first_dev(group); - - if (prev_dev != dev) { - dev_err_ratelimited(prev_dev, "Cannot change default domain: Device has been changed\n"); - ret = -EBUSY; - goto out; - } - prev_dom = group->default_domain; - if (!prev_dom) { - ret = -EINVAL; - goto out; - } - - dev_def_dom = 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 = dev_def_dom ? : iommu_def_domain_type; - } else if (dev_def_dom && type != dev_def_dom) { - dev_err_ratelimited(prev_dev, "Device cannot be in %s domain\n", + type = gtype.type ? : iommu_def_domain_type; + } else if (gtype.type && type != gtype.type) { + dev_err_ratelimited(dev, "Device cannot be in %s domain\n", iommu_domain_type_str(type)); - ret = -EINVAL; - goto out; + return -EINVAL; } /* * Switch to a new domain only if the requested domain type is different * from the existing default domain type */ - if (prev_dom->type == type) { - ret = 0; - goto out; - } + if (prev_dom->type == type) + return 0; + + group->default_domain = NULL; + group->domain = NULL; /* Sets group->default_domain to the newly allocated domain */ ret = iommu_group_alloc_default_domain(group, dev, type); if (ret) - goto out; + goto restore_old_domain; - ret = iommu_create_device_direct_mappings(group, dev); + ret = iommu_group_create_direct_mappings(group); if (ret) goto free_new_domain; - ret = __iommu_attach_device(group->default_domain, dev); + ret = __iommu_attach_group(group->default_domain, group); if (ret) goto free_new_domain; - group->domain = group->default_domain; iommu_domain_free(prev_dom); return 0; free_new_domain: iommu_domain_free(group->default_domain); +restore_old_domain: group->default_domain = prev_dom; group->domain = prev_dom; -out: + return ret; } diff --git a/Documentation/ABI/testing/sysfs-kernel-iommu_groups b/Documentation/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 The default domain type of a group may be modified only when - - 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. -- 2.34.1