From patchwork Tue Jun 6 00:59:42 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Gunthorpe X-Patchwork-Id: 13268128 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 EF460C7EE24 for ; Tue, 6 Jun 2023 01:00:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233223AbjFFBAZ (ORCPT ); Mon, 5 Jun 2023 21:00:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47126 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232455AbjFFBAC (ORCPT ); Mon, 5 Jun 2023 21:00:02 -0400 Received: from NAM04-BN8-obe.outbound.protection.outlook.com (mail-bn8nam04on2049.outbound.protection.outlook.com [40.107.100.49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 60F49106 for ; Mon, 5 Jun 2023 18:00:00 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=L5hkTxuUIOLyeJvLtdM+RmeqBAXb3JeuP4Ejn7vVs+aXUObX/sbfCX1Hwb91/e4z0VXPAPv+xyFRTtYAVhf6JnDx1Okgjy0Tdpxf4OOXnBFmhRJAcGsDEog0x5Juo0phEIVJcpfTnfgJitRMDY9yUuoPVa1kEgKw+CyYK7OUQ8apzUhNcdaD2ap0Lhrrnpjk4P9WowAF8MleVPJKdmISrX4eCOdrjaQjr9E3gm4Hi2xQob2ZX0dw+RznZtSgPFoYRoB86zgUA3xJwu56iLUPnfyM9M2v+/Sa/UGBpblN3YmPm9xCA3MKpdDg8xW8NAlR0Dy89wdwbx9Wn1r9v+LLdA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=mWztvG5qzwtJvxZjAKbwxApkK7ultrIqaGPBbkHXrp4=; b=SxDvLSeBjsGRFoXuk7TZGfd0Ehts5ovc9rsZKQrilY0tTtTZ3g/NUifbXOAnIoRTOGMOKn9uG4Ap/WRosFuHFn0jTSHuY5WXKhBaCJ4kslLh8a/pZXEnJl0EQTCfhTmtb4YDShZwpESUvPhLeovxri7UaBz2P4Q19n+0/92L45KqZDp0z1y8iWLEL4BIsZ0gLjc/IJURurWven0xETg5fS67pejOmHri8YG1wGyuNgC2Y1JJEYZgfTBlern/NDXJCI3EAPU0If7Vt+rctVwdgstZ22i44bCg2/mvgdmwYYNk9My0PlKIUJnoxyXQ/NX7cx2s2AyCMt/4u0UBSczU7g== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=mWztvG5qzwtJvxZjAKbwxApkK7ultrIqaGPBbkHXrp4=; b=tVb3sItgpxL+4xI1KcilkuZVFLAetSDb8H+wK8HEgDrp/CKhqs/L/cdoji4jVFw+cx66zjujll2lmBDMU7gbV9gL9kCO+C39BTCDwoFNJNYSbFgB4SRCz6bSJBlqhGp2eDXHfHDKKj7mG9dvRlSmZQNCx9nGGWV7M4WvAE6xVfwNx5Q8MkpIG2PVITIkjqZQ7g7cXy0VN4w+6TIZeuTqrylOV/EFNrETY5pT8UDQShTz0Hfc3iCF2uqFpP16mHxt6Y2O2qZLIl9ujTfwePiegIHLG3nGAzp4y1Bnv+34t+OlKLDigs05+DSFiLPCUEYzC3mCYABCiOcgsviRU2daNA== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from LV2PR12MB5869.namprd12.prod.outlook.com (2603:10b6:408:176::16) by CH2PR12MB4085.namprd12.prod.outlook.com (2603:10b6:610:79::9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6455.33; Tue, 6 Jun 2023 00:59:54 +0000 Received: from LV2PR12MB5869.namprd12.prod.outlook.com ([fe80::f7a7:a561:87e9:5fab]) by LV2PR12MB5869.namprd12.prod.outlook.com ([fe80::f7a7:a561:87e9:5fab%6]) with mapi id 15.20.6455.028; Tue, 6 Jun 2023 00:59:54 +0000 From: Jason Gunthorpe To: David Woodhouse , iommu@lists.linux.dev, Joerg Roedel , Len Brown , linux-acpi@vger.kernel.org, "Rafael J. Wysocki" , Robin Murphy , Will Deacon Cc: Lu Baolu , Kevin Tian , Nicolin Chen , "Rafael J. Wysocki" Subject: [PATCH v3 04/10] iommu: Simplify the __iommu_group_remove_device() flow Date: Mon, 5 Jun 2023 21:59:42 -0300 Message-Id: <4-v3-328044aa278c+45e49-iommu_probe_jgg@nvidia.com> In-Reply-To: <0-v3-328044aa278c+45e49-iommu_probe_jgg@nvidia.com> References: X-ClientProxiedBy: BY3PR10CA0011.namprd10.prod.outlook.com (2603:10b6:a03:255::16) To LV2PR12MB5869.namprd12.prod.outlook.com (2603:10b6:408:176::16) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: LV2PR12MB5869:EE_|CH2PR12MB4085:EE_ X-MS-Office365-Filtering-Correlation-Id: caf3bffb-f4e5-420e-ae6c-08db66295547 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:LV2PR12MB5869.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230028)(4636009)(376002)(346002)(396003)(366004)(136003)(39860400002)(451199021)(36756003)(110136005)(54906003)(2906002)(478600001)(86362001)(38100700002)(7416002)(41300700001)(8936002)(8676002)(5660300002)(316002)(4326008)(66556008)(66946007)(66476007)(83380400001)(6506007)(2616005)(6512007)(26005)(186003)(6486002)(6666004)(4216001);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: 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 X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: caf3bffb-f4e5-420e-ae6c-08db66295547 X-MS-Exchange-CrossTenant-AuthSource: LV2PR12MB5869.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Jun 2023 00:59:51.4765 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: +STJ60y6Ltv9Q88w21xtBh8OlGSwMf2+SHrS4JMtXWTiQLvHKd55ex9MXWZb+Vam X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH2PR12MB4085 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org Instead of returning the struct group_device and then later freeing it, do the entire free under the group->mutex and defer only putting the iommu_group. It is safe to remove the sysfs_links and free memory while holding that mutex. Move the sanity assert of the group status into __iommu_group_free_device(). The next patch will improve upon this and consolidate the group put and the mutex into __iommu_group_remove_device(). __iommu_group_free_device() is close to being the paired undo of iommu_group_add_device(), following patches will improve on that. Reviewed-by: Kevin Tian Reviewed-by: Lu Baolu Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommu.c | 83 ++++++++++++++++++++----------------------- 1 file changed, 39 insertions(+), 44 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 480a3640d94c3d..456c2d2934896c 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -470,32 +470,8 @@ int iommu_probe_device(struct device *dev) } -/* - * Remove a device from a group's device list and return the group device - * if successful. - */ -static struct group_device * -__iommu_group_remove_device(struct iommu_group *group, struct device *dev) -{ - struct group_device *device; - - lockdep_assert_held(&group->mutex); - for_each_group_device(group, device) { - if (device->dev == dev) { - list_del(&device->list); - return device; - } - } - - return NULL; -} - -/* - * Release a device from its group and decrements the iommu group reference - * count. - */ -static void __iommu_group_release_device(struct iommu_group *group, - struct group_device *grp_dev) +static void __iommu_group_free_device(struct iommu_group *group, + struct group_device *grp_dev) { struct device *dev = grp_dev->dev; @@ -504,16 +480,45 @@ static void __iommu_group_release_device(struct iommu_group *group, trace_remove_device_from_group(group->id, dev); + /* + * If the group has become empty then ownership must have been + * released, and the current domain must be set back to NULL or + * the default domain. + */ + if (list_empty(&group->devices)) + WARN_ON(group->owner_cnt || + group->domain != group->default_domain); + kfree(grp_dev->name); kfree(grp_dev); dev->iommu_group = NULL; - iommu_group_put(group); +} + +/* + * Remove the iommu_group from the struct device. The attached group must be put + * by the caller after releaseing the group->mutex. + */ +static void __iommu_group_remove_device(struct device *dev) +{ + struct iommu_group *group = dev->iommu_group; + struct group_device *device; + + lockdep_assert_held(&group->mutex); + for_each_group_device(group, device) { + if (device->dev != dev) + continue; + + list_del(&device->list); + __iommu_group_free_device(group, device); + /* Caller must put iommu_group */ + return; + } + WARN(true, "Corrupted iommu_group device_list"); } static void iommu_release_device(struct device *dev) { struct iommu_group *group = dev->iommu_group; - struct group_device *device; const struct iommu_ops *ops; if (!dev->iommu || !group) @@ -522,16 +527,7 @@ static void iommu_release_device(struct device *dev) iommu_device_unlink(dev->iommu->iommu_dev, dev); mutex_lock(&group->mutex); - device = __iommu_group_remove_device(group, dev); - - /* - * If the group has become empty then ownership must have been released, - * and the current domain must be set back to NULL or the default - * domain. - */ - if (list_empty(&group->devices)) - WARN_ON(group->owner_cnt || - group->domain != group->default_domain); + __iommu_group_remove_device(dev); /* * release_device() must stop using any attached domain on the device. @@ -547,8 +543,8 @@ static void iommu_release_device(struct device *dev) ops->release_device(dev); mutex_unlock(&group->mutex); - if (device) - __iommu_group_release_device(group, device); + /* Pairs with the get in iommu_group_add_device() */ + iommu_group_put(group); module_put(ops->owner); dev_iommu_free(dev); @@ -1107,7 +1103,6 @@ EXPORT_SYMBOL_GPL(iommu_group_add_device); void iommu_group_remove_device(struct device *dev) { struct iommu_group *group = dev->iommu_group; - struct group_device *device; if (!group) return; @@ -1115,11 +1110,11 @@ void iommu_group_remove_device(struct device *dev) dev_info(dev, "Removing from iommu group %d\n", group->id); mutex_lock(&group->mutex); - device = __iommu_group_remove_device(group, dev); + __iommu_group_remove_device(dev); mutex_unlock(&group->mutex); - if (device) - __iommu_group_release_device(group, device); + /* Pairs with the get in iommu_group_add_device() */ + iommu_group_put(group); } EXPORT_SYMBOL_GPL(iommu_group_remove_device);