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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MSGID_FROM_MTA_HEADER,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 882C2C433B4 for ; Tue, 6 Apr 2021 15:10:51 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DA7DA61362 for ; Tue, 6 Apr 2021 15:10:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DA7DA61362 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:In-Reply-To:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ewzDX2rWMgJRFzcZRRAOqDAaOGRjUyXhknr9vaKP31s=; b=ixfh3w9MZdLAhQhToBrKDaE3z I2oiFOS282swAW5QMytjk0oqZK3Xij+JMJVP2JIZ1HVPzVvoDXpDpVSjs77qO/6y9vPun2uc/BZFY aM/OQIktNoWf1vZou/pmu64bxWR8eUS6BokrIvnXumDN5aWr2F4BN1B+nteMLZ8itcSXBvdISYVhD fGKQWXrs57LRvVB+ZSBTSnMkC4HgsRlSb2X7liJEBKRY9BmrT3g+42ywHWfpWNB0oSg1B55NbB69G k9DvyHu6z1udFYOfgAUma6RHl4sYz7Q6rLgntsQYPjMX4mF6RDmbeRw4WoaPGZbi/dCujTpiY5S1i 4zzXH5sBA==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lTnK1-002toR-NC; Tue, 06 Apr 2021 15:08:54 +0000 Received: from mail-eopbgr10067.outbound.protection.outlook.com ([40.107.1.67] helo=EUR02-HE1-obe.outbound.protection.outlook.com) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lTnJv-002tnj-EW for linux-arm-kernel@lists.infradead.org; Tue, 06 Apr 2021 15:08:49 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=armh.onmicrosoft.com; s=selector2-armh-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=R+Qyyq/wqN+J3QEIfQgoafbfE52NTE/nkWJszsx1uMs=; b=w6STXdhQk9Eh9f10wsR+ZFdjtsVmph9t1sf20dm9NufITOml0g6OLrptEa9JweJUT4+Ll97V0y6Ah7TlBF6iarX0sgw8pdDK+0BM7JGMY7Rw4wHDP6JixcnbqsOSNfCd3xoheYHw3fx4VzdPAfXfVCejjUsro0W1QYt8FtJbaRY= Received: from AS8PR05CA0020.eurprd05.prod.outlook.com (2603:10a6:20b:311::25) by DB9PR08MB6443.eurprd08.prod.outlook.com (2603:10a6:10:261::23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3955.18; Tue, 6 Apr 2021 15:08:39 +0000 Received: from AM5EUR03FT018.eop-EUR03.prod.protection.outlook.com (2603:10a6:20b:311:cafe::4c) by AS8PR05CA0020.outlook.office365.com (2603:10a6:20b:311::25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3999.32 via Frontend Transport; Tue, 6 Apr 2021 15:08:39 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 63.35.35.123) smtp.mailfrom=arm.com; lists.infradead.org; dkim=pass (signature was verified) header.d=armh.onmicrosoft.com;lists.infradead.org; dmarc=pass action=none header.from=arm.com; Received-SPF: Pass (protection.outlook.com: domain of arm.com designates 63.35.35.123 as permitted sender) receiver=protection.outlook.com; client-ip=63.35.35.123; helo=64aa7808-outbound-1.mta.getcheckrecipient.com; Received: from 64aa7808-outbound-1.mta.getcheckrecipient.com (63.35.35.123) by AM5EUR03FT018.mail.protection.outlook.com (10.152.16.114) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3999.29 via Frontend Transport; Tue, 6 Apr 2021 15:08:39 +0000 Received: ("Tessian outbound 9bcb3c8d6cb1:v90"); Tue, 06 Apr 2021 15:08:37 +0000 X-CheckRecipientChecked: true X-CR-MTA-CID: a6e311aa3bed019b X-CR-MTA-TID: 64aa7808 Received: from b8c24f98c827.1 by 64aa7808-outbound-1.mta.getcheckrecipient.com id 7E69CB3F-7BF3-4692-89B7-2906E058A0F5.1; Tue, 06 Apr 2021 15:08:30 +0000 Received: from EUR04-DB3-obe.outbound.protection.outlook.com by 64aa7808-outbound-1.mta.getcheckrecipient.com with ESMTPS id b8c24f98c827.1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384); Tue, 06 Apr 2021 15:08:30 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=Pujb2saTORzGaA2CEx8U1eXq9qAokBMgKWuiJ22GJcRMUENipk1tCPz//mgwT/KHK2Dh0bUZeKTMYk4GIPnuBzd+Ltpdgv/Qg7EHMpUTD4zZYs9Kvj9Dr/9K+6lPGhQdU8dEHfI9CpWJ8sZ7P/kQTRw/vDXsmnL5jTKaklNuM0iJX8b7so402dZNMLm3+YnVDa3DySZq76T8dI0/Awyg5nA7MkUuEo/utLBSbA90snQ9KvYryU0OcNCMpg7a86HvMCKGc0G655fk9sca8LmjszZxTGteAV41tEJC+xoZKxD22dvvsHhVU9nl38Q0KVQ/sq+nnaFMh1dNXHQXFudqCg== 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-SenderADCheck; bh=R+Qyyq/wqN+J3QEIfQgoafbfE52NTE/nkWJszsx1uMs=; b=oYF3EOyVEFSJ8Ze02WublIKBY2lud10YbE8ohd/b102fiZ1Om+SPn2MPBKAFChIZiQk8LVvnz9Lf026pK0pg7EQNc8WwG6dDg7RUETYAi8QbnXTs9koDRjddrg+IEH2/shubV+jGDSrQtOvDrYZtykKFcCHFfeNPc00SdrlEpVKv/ohVHo59yRxNEfI3ixs/8Yv5hAGzT1THxxLZfgI73wWlDYn8tLhyVA9W+bnRzUcVSfmErAcMIqhfCjsqq8f2NT2fEureTDb0v5XnjLtbE0h23z8IQ5Rmay2zRy5gOloBYwZCPXs+jTCq3bw/Oz0IWLr6P4hvIJJiXiwZPGnBDg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=arm.com; dmarc=pass action=none header.from=arm.com; dkim=pass header.d=arm.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=armh.onmicrosoft.com; s=selector2-armh-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=R+Qyyq/wqN+J3QEIfQgoafbfE52NTE/nkWJszsx1uMs=; b=w6STXdhQk9Eh9f10wsR+ZFdjtsVmph9t1sf20dm9NufITOml0g6OLrptEa9JweJUT4+Ll97V0y6Ah7TlBF6iarX0sgw8pdDK+0BM7JGMY7Rw4wHDP6JixcnbqsOSNfCd3xoheYHw3fx4VzdPAfXfVCejjUsro0W1QYt8FtJbaRY= Authentication-Results-Original: kernel.org; dkim=none (message not signed) header.d=none;kernel.org; dmarc=none action=none header.from=arm.com; Received: from AS8PR08MB6822.eurprd08.prod.outlook.com (2603:10a6:20b:39c::20) by AS8PR08MB6024.eurprd08.prod.outlook.com (2603:10a6:20b:23d::15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3999.28; Tue, 6 Apr 2021 15:08:29 +0000 Received: from AS8PR08MB6822.eurprd08.prod.outlook.com ([fe80::d1cd:4615:3552:8cf0]) by AS8PR08MB6822.eurprd08.prod.outlook.com ([fe80::d1cd:4615:3552:8cf0%3]) with mapi id 15.20.3999.032; Tue, 6 Apr 2021 15:08:29 +0000 Date: Tue, 6 Apr 2021 16:08:21 +0100 From: Achin Gupta To: Rob Herring Cc: Sumit Garg , Sudeep Holla , linux-arm-kernel , Devicetree List , Trilok Soni , arve@android.com, Andrew Walbran , David Hartley , Jens Wiklander , Arunachalam Ganapathy , Marc Bonnici , nd@arm.com Subject: Re: [PATCH v5 1/7] dt-bindings: Arm: Add Firmware Framework for Armv8-A (FF-A) binding Message-ID: References: <20210325143255.1532452-1-sudeep.holla@arm.com> <20210325143255.1532452-2-sudeep.holla@arm.com> <20210326105545.44rdcbrumg3q6i7y@bogus> <20210330150312.GA284502@robh.at.kernel.org> Content-Disposition: inline In-Reply-To: <20210330150312.GA284502@robh.at.kernel.org> X-Originating-IP: [90.247.115.55] X-ClientProxiedBy: LO2P265CA0028.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:61::16) To AS8PR08MB6822.eurprd08.prod.outlook.com (2603:10a6:20b:39c::20) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from C02ZJ1BRLVDN (90.247.115.55) by LO2P265CA0028.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:61::16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3999.27 via Frontend Transport; Tue, 6 Apr 2021 15:08:28 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: a6e0a508-64cd-4cc1-3e7e-08d8f90ddc02 X-MS-TrafficTypeDiagnostic: AS8PR08MB6024:|DB9PR08MB6443: X-MS-Exchange-Transport-Forked: True X-Microsoft-Antispam-PRVS: x-checkrecipientrouted: true NoDisclaimer: true X-MS-Oob-TLC-OOBClassifiers: OLM:10000;OLM:10000; X-MS-Exchange-SenderADCheck: 1 X-Microsoft-Antispam-Untrusted: BCL:0; X-Microsoft-Antispam-Message-Info-Original: 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 X-Forefront-Antispam-Report-Untrusted: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:AS8PR08MB6822.eurprd08.prod.outlook.com; PTR:; CAT:NONE; SFS:(4636009)(39860400002)(366004)(136003)(346002)(396003)(376002)(83380400001)(44832011)(33716001)(38100700001)(66946007)(66556008)(9686003)(54906003)(66476007)(2906002)(6916009)(8936002)(6666004)(55016002)(26005)(478600001)(956004)(16526019)(5660300002)(52116002)(86362001)(186003)(6496006)(316002)(4326008)(8676002)(38350700001); DIR:OUT; SFP:1101; X-MS-Exchange-AntiSpam-MessageData: =?us-ascii?Q?G6mPJazbcaiPuqOidkvJE+jvRNyMmoz5DLtmqf7W4mtN5QbxT0BqdbIFsdg4?= =?us-ascii?Q?q2hhaL4dJzG6nLEO41n2jL3MFE1F6D8A2cgoQTTPxRqt5iQz/NwMoDMOV/Zq?= =?us-ascii?Q?W3gLbNryPwGh9a+BeyvhJIJDsg/nj7gnTIgkkbAGRbK86XgEj4o+FKX3QG80?= =?us-ascii?Q?raaxZQsNIKZG8Q1i5Mz5gV5nQrWInvJHfeViFfVj8Q/cgN4FPUjUqtBAFnaL?= =?us-ascii?Q?i7l1rb4Sp9tRyeVDPOuCr6KDN6ZAWapz8jAqAZLv8x4Qm4mi7ahUQG/Wn4Tu?= =?us-ascii?Q?1qts5HSCRvwziYO6g/gdYEscWSei1A3HAYnYpQW2Yj94ftDkXWvcBLUWLgo5?= =?us-ascii?Q?c870DdIcwmISNQXokGuIosQH9W4EaU6PBowIJZUXONz8K/3g8+eKIx/5CYkd?= =?us-ascii?Q?E8bwGCtXQrMh+MEDL7ZehVWVQCDSJvy0qbZ95zUxjVbH4InvHE2VhMcw58Gu?= =?us-ascii?Q?WztJUR2bwdX+XOzkEqJRf8KNw88MpFXR62XAQFZ9z79tnHwCEJr2jVwD2oQk?= =?us-ascii?Q?kH2dIdRWi2AJCC0Hgk8BYw7qD6Qz2tw0ntYYna4WSGDjQLuASWAo6oE4YhzT?= =?us-ascii?Q?mAP0Pz1ftIZ2+I75v2CRfoe7L0xHqQWlPRRtTJ5ZqAZkcDJCia7AG43mwEM2?= =?us-ascii?Q?wTouWaRuOta8aW0OOLYY/J44MJR4bfBT5+2cmPoAVqRdFS43S7p+RdedcRGT?= =?us-ascii?Q?jkr//di9DRqFVTMhzptbfJecGrnnACf04RHa+4dn1X5QduyZi1lt6dvWOQQd?= =?us-ascii?Q?aLcu+ZTPyNZzoWvfXtvloZtmVDptIGdZjlFpJmAcOTR1Q1XquDdRbVhj0hBt?= =?us-ascii?Q?8ppRSk++Du2TCSk6F/e7gmvhQUF69FosyKEuQybEiiZSQJkNByDDZagGuJaB?= =?us-ascii?Q?nf+ny/CeVNl0WdNspUWAZwhjv25J1UEXx+7zgLDSGpwA7tkob31pQFvInwaM?= =?us-ascii?Q?93CrfZwwUhdX7QkumFQ0amoT81hBDmfmjA/S3N59UUseDo+ydA4CEppkK4N7?= =?us-ascii?Q?GSE6h8+1QoHcErUK36+9LERNGDLCyewOp1/2hBi0oxaK6iPcTodgWTd9Tn6r?= =?us-ascii?Q?5F9Kj6ATC1sK4yh+w2A1ceGKGjIcFFk1NIA5a1c3wkKCnwwX6HsoqSQwuyLy?= =?us-ascii?Q?AE8oU6RQ8k0ejlF5hqdcqbqVBknTTKEV6GNU/wfeWAe7fKOnrDEU8/m7TAge?= =?us-ascii?Q?BLGMtWKxOpmsroolZK4uXBVoyfWI/LqyI/ldEi/yuLeOqJbi0XSYWl5xJFSR?= =?us-ascii?Q?dvleH5A8FX3NPLgcR1OYx8OOMW2p95Fc0txalKaHVHUsdbP6hG8VIYNOURY7?= =?us-ascii?Q?gOCCiOYe4pyvJs1e116Z/mrG?= X-MS-Exchange-Transport-CrossTenantHeadersStamped: AS8PR08MB6024 Original-Authentication-Results: kernel.org; dkim=none (message not signed) header.d=none;kernel.org; dmarc=none action=none header.from=arm.com; X-EOPAttributedMessage: 0 X-MS-Exchange-Transport-CrossTenantHeadersStripped: AM5EUR03FT018.eop-EUR03.prod.protection.outlook.com X-MS-Office365-Filtering-Correlation-Id-Prvs: b504b4e7-35f9-4eaf-9b2d-08d8f90dd5d9 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:63.35.35.123; CTRY:IE; LANG:en; SCL:1; SRV:; IPV:CAL; SFV:NSPM; H:64aa7808-outbound-1.mta.getcheckrecipient.com; PTR:ec2-63-35-35-123.eu-west-1.compute.amazonaws.com; CAT:NONE; SFS:(4636009)(136003)(346002)(396003)(376002)(39860400002)(36840700001)(46966006)(8936002)(8676002)(6666004)(9686003)(478600001)(86362001)(55016002)(26005)(316002)(54906003)(36860700001)(33716001)(82740400003)(44832011)(356005)(70586007)(5660300002)(6862004)(336012)(2906002)(956004)(81166007)(186003)(16526019)(82310400003)(6496006)(47076005)(83380400001)(70206006)(4326008); DIR:OUT; SFP:1101; X-OriginatorOrg: arm.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Apr 2021 15:08:39.3181 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: a6e0a508-64cd-4cc1-3e7e-08d8f90ddc02 X-MS-Exchange-CrossTenant-Id: f34e5979-57d9-4aaa-ad4d-b122a662184d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=f34e5979-57d9-4aaa-ad4d-b122a662184d; Ip=[63.35.35.123]; Helo=[64aa7808-outbound-1.mta.getcheckrecipient.com] X-MS-Exchange-CrossTenant-AuthSource: AM5EUR03FT018.eop-EUR03.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DB9PR08MB6443 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210406_160847_661226_8D1F4883 X-CRM114-Status: GOOD ( 36.15 ) 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-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Rob, On Tue, Mar 30, 2021 at 10:03:12AM -0500, Rob Herring wrote: > On Fri, Mar 26, 2021 at 05:26:52PM +0530, Sumit Garg wrote: > > On Fri, 26 Mar 2021 at 16:25, Sudeep Holla wrote: > > > > > > On Fri, Mar 26, 2021 at 10:35:23AM +0530, Sumit Garg wrote: > > > > Hi Sudeep, > > > > > > > > Apologies for catching up late on this patch-set. > > > > > > > > On Thu, 25 Mar 2021 at 20:05, Sudeep Holla wrote: > > > > > > > > > > Since the FF-A v1.0 specification doesn't list the UUID of all the > > > > > partitions in the discovery API, we need to specify the UUID of the > > > > > partitions that need to be accessed by drivers within the kernel. > > > > > > > > > > > > > Wouldn't we be able to implement auto-discovery of ffa partitions? I > > > > think enumeration of ffa partitions on FFA bus should be quite similar > > > > to enumeration of TAs on TEE bus (see [1]). Otherwise we need to put > > > > these redundant DT entries for every ffa partition which IMHO would > > > > bloat up device trees for every platform. > > > > > > > > > > Any suggestions on how to ? Clearly spec doesn't have that provision, I > > > had raised this point in the past. Jens has similar concern and he did > > > ask the same[1]. As I replied to him in that thread[2]. > > > > > > I am open to suggestion on how to auto-discover, currently as I see spec > > > doesn't support it. > > > > > > > Thanks for sharing links to prior discussions and I can see that > > currently spec doesn't support it. But from an implementation > > perspective, I can't find any reason that we can't support > > auto-discover. Have a look at below proposed simple FFA ABI: > > > > FFA_LIST_PARTITIONS > > > > - No input params. > > - Returns an array of secure partition UUIDs to which this non-secure > > virtual/physical FF-A instance is allowed to communicate with. > > > > I think with auto-discovery, one of the major benefits is that if the > > OEM is using a common platform to cater to multiple use-cases which > > rely on different secure partitions then OEM doesn't have to bother > > about shipping separate DTs. > > +1 > > DT should not be the dumping ground for everything forgotten to be made > discoverable. There's not much we can do about h/w, but firmware is > different and can be changed. In other threads (e.g. PCI config space > SMC calls), fixing in firmware is the proposed answer. So let's do that > here. > > Maybe if there are implementations shipping and changing is too late > (yet not too late to use a new binding), then I'd feel differently. But > being in a spec or not alone is not enough reason alone to accept this. > It's obvious the spec did not have wide enough review. The v1.0 specification (released almost one year back) was reviewed by a few Trusted OS vendors amongst other partners. Nobody provided feedback that a FFA_LIST_PARTITIONS like discovery mechanism is a gating factor. Hindsight is a wonderful thing! The ability of discover UUIDs of partitions would indeed be a very useful thing and this will be added to the next version of the specification. I think it is worth providing some background in any case. The usage model envisioned was that a partition would export services that would be identified by a UUID. An FF-A client that wants to use these services would query their presence by specifying this UUID. The FF-A discovery ABI returns a 16-bit ID of the partition that implements the services. This ID is more user-friendly and space efficient than a 16 byte UUID for register and shared memory based IPC between the client and the server. For example, OP-TEE would have a UUID to represent the TEE service. The OP-TEE driver would ask the FF-A driver if there is a partition with a UUID that provides OP-TEE's TEE service. The assumption was that a client must identify the service(s) it wants to access to be able to use FF-A ABIs to talk to the partition that implements them. This was more important than a discovery mechanism where the client says: I don't know what I want but please list all the UUIDs of all partitions in the system. I will then see if I can find anything that I like. In this model, it was not envisioned that the FF-A driver would carry the UUIDs of services that its clients could want to access. The client would know the UUID and the FF-A driver would return the properties of the partition and its ID to enable further communication. We did envision the need for the FF-A driver to know the IDs of all the partitions in the system and their properties e.g. number of vCPUs etc. The FFA_PARTITION_INFO_GET ABI when invoked with a NULL UUID returns this information. It is a bit like "grep *.*". The implementation choice to have an FF-A bus with partitions as devices on it was made after the specification was released. This was not obvious at all at the time of writing the specification. Clearly, in this model the FF-A driver needs to the know the UUIDs. But this does not change the fact that the clients of the FF-A driver still need to know the UUID of the services they are interested in. For v1.0 we are left with no choice but to carry them in the DT. This will be addressed in v1.1. I see this as a case where implementation choices drive the evolution of a specification. I hope you can understand that it was a bit difficult to foresee this usage model for v1.0 when specification and implementation are temporally separated. I also think that this issue is different from the cluster **** the PCIe ECAM SMC discussion is. I do hope this helps clarify the situation to some extent. Please let me know if you need any more info or if I have missed anything. Also, apologies for not getting back sooner as I was on holiday. cheers, Achin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel