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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1F879C433EF for ; Wed, 6 Jul 2022 02:37:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:To:Subject:Cc: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=dzOfS4QTgqbfmfrBx7MEwiyGHms+bsunh7F36uqz8sU=; b=wA75O/VQxi5qyL 0VgPOgKmHZeMmSRMsA9Y6K2zESzZ1imHJ8X4rz7P5K/BoJFHuVYKZx8yw99JD1U2xoNKcEKzfpCan L2XjS1ZJDOWOU88ORbvB0p/+dhX0uRl7ZvNOCvrYloZkULdbNiFuHM8jV0XHUB6v2WgFQAchxrvUB dVucdh72Lt+q7Oe1c3sFTzx8J29UF5Lj8TLSrNsqorktjDmHcw/dcwonQhFf2k0ZlI72WDk+GsA9C nJ0YPYdUbHvf0cxJ+k/nqSCdZJny5Vs6uhw2ol+a0v+SyMWiiyBRff48h3KXocevW2sYORVHq5guN mL9QJDMzLBbSZ+Ks+0IA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o8ut8-005MvX-BH; Wed, 06 Jul 2022 02:35:38 +0000 Received: from mga12.intel.com ([192.55.52.136]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1o8ut4-005Mtw-GR for linux-arm-kernel@lists.infradead.org; Wed, 06 Jul 2022 02:35:35 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1657074934; x=1688610934; h=message-id:date:mime-version:cc:subject:to:references: from:in-reply-to:content-transfer-encoding; bh=/qKfGncLBodraY8iG9SYn0Nbai2B5nyW3PrxStAGttw=; b=nBESqoj7hjMhFo/VNZVgYvWgvguZd3BiHYb0EMv37beULBWIVed3FYp8 SV56ll5YXkdk/kpUbTmDvZj/dd2+0HnwGj2tjgFtG4hMpPb++cIbmBf4S /cBoA4RN4/zhylM0MXM+uRQlLDI0f0rPutzCK1yJSn5sP5Zy0pCSBuxmF t6LR3v95i6E/nOODwgFtRw2mPtGOqpR6X2P0I1BcNmci32iVw3nKqaGbO G+XpsRm+bqSHDJodH1jDK3uVkBq1drJdT+CVqIA1BCLqo5C8eU+M1bUPU r0TZUSQAAZQ8RTCR+Uz9W2//ctW52AACnjIqHvHUbLbXf8qFLEGIAZmIx Q==; X-IronPort-AV: E=McAfee;i="6400,9594,10399"; a="263409639" X-IronPort-AV: E=Sophos;i="5.92,248,1650956400"; d="scan'208";a="263409639" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga106.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> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220705_193534_609531_EC729A5A X-CRM114-Status: UNSURE ( 9.60 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.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 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel