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 74650C433EF for ; Wed, 6 Jul 2022 02:35:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231304AbiGFCft (ORCPT ); Tue, 5 Jul 2022 22:35:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36592 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230387AbiGFCf3 (ORCPT ); Tue, 5 Jul 2022 22:35:29 -0400 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AB3CC1A056; Tue, 5 Jul 2022 19:35:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1657074927; x=1688610927; h=message-id:date:mime-version:cc:subject:to:references: from:in-reply-to:content-transfer-encoding; bh=/qKfGncLBodraY8iG9SYn0Nbai2B5nyW3PrxStAGttw=; b=IrVja+pQ+SYzyjNCom8dci9YVBvC5Oqh8IATeihSDOBajnpP51NBg58T ZEFg5thziC8bmw1a4E23VjjBkv1PCSBvYgXeJ3i7tGbDIxTDNMMBxbuKO 7cqBxgspkb9zrxvEB3B6BQGZqipMrucptT9dZhqjl8/8q54gpv3qRDynT a6Lj9rjqlH3tZ4bCfsNtJV/BiYA8L0aUcnj87hX0pdoVEdbthLe7ZPyTw +Bft9W8qW8qsV8Y9ny+I/CgcsVCbaitB4sXYZ8jMzBIF+5u6VbKsfPAfj PkYA3LGS1/rWiHsFGoa3k5YxXToRuxCXL6vK75tbv1x2hJsMIl+awNIxa Q==; X-IronPort-AV: E=McAfee;i="6400,9594,10399"; a="369941008" X-IronPort-AV: E=Sophos;i="5.92,248,1650956400"; d="scan'208";a="369941008" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Jul 2022 19:35:27 -0700 X-IronPort-AV: E=Sophos;i="5.92,248,1650956400"; d="scan'208";a="650447066" Received: from zhuoliu-mobl1.ccr.corp.intel.com (HELO [10.249.174.206]) ([10.249.174.206]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Jul 2022 19:35:24 -0700 Message-ID: Date: Wed, 6 Jul 2022 10:35:22 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Cc: baolu.lu@linux.intel.com, will@kernel.org, iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org, suravee.suthikulpanit@amd.com, vasant.hegde@amd.com, mjrosato@linux.ibm.com, gerald.schaefer@linux.ibm.com, schnelle@linux.ibm.com, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 04/15] iommu: Move bus setup to IOMMU device registration Content-Language: en-US To: Robin Murphy , joro@8bytes.org References: <5b9b608af21b3c4353af042355973bac55397962.1657034828.git.robin.murphy@arm.com> From: Baolu Lu In-Reply-To: <5b9b608af21b3c4353af042355973bac55397962.1657034828.git.robin.murphy@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/7/6 01:08, Robin Murphy wrote: > @@ -202,12 +210,32 @@ int iommu_device_register(struct iommu_device *iommu, > spin_lock(&iommu_device_lock); > list_add_tail(&iommu->list, &iommu_device_list); > spin_unlock(&iommu_device_lock); > + > + for (int i = 0; i < ARRAY_SIZE(iommu_buses); i++) { > + struct bus_type *bus = iommu_buses[i]; > + int err; > + > + if (bus->iommu_ops && bus->iommu_ops != ops) { > + err = -EBUSY; > + } else { > + bus->iommu_ops = ops; > + err = bus_iommu_probe(bus); > + } > + if (err) { > + iommu_device_unregister(iommu); > + return err; > + } > + } > + > return 0; > } > EXPORT_SYMBOL_GPL(iommu_device_register); With bus_set_iommu() retired, my understanding is that now we embrace the first-come-first-serve policy for bus->iommu_ops setting. This will lead to problem in different iommu_ops for different bus case. Did I overlook anything? Best regards, baolu