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 B56AEC433F5 for ; Fri, 28 Jan 2022 22:32:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351700AbiA1Wcf (ORCPT ); Fri, 28 Jan 2022 17:32:35 -0500 Received: from mail-eopbgr30134.outbound.protection.outlook.com ([40.107.3.134]:55513 "EHLO EUR03-AM5-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1351661AbiA1Wce (ORCPT ); Fri, 28 Jan 2022 17:32:34 -0500 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=EEXS1UYxpDKtZbsBRh51M4BMbxQk932sVPllnUT8EqEdXw8u7EvtCnRdrYtSY+8+Uxg0ONG/E9F+M1yw41Kd/8Ef75LZc7bo8c+P+GupLwDUnH58IOS/+oQz3eAS8IVNQ5v6tT09wW/pp8ej+2JP6BepMjRvyswuUQrNTQ617R1wVnVTiN/YV9igJ5dh9/qrK6NwbJtyPKvffGnLzDmJoOeod9rQO5PsGRktNaYWoXaObxXVa+F+Ys+rCWLf07A/Rj6TsBJLHSSCdI6rFlX7LPHQaRHtJpfNCjY1vwyeyZrX8QEfOG77CVv6ueAChGdzeljPmnTMOUYy+QO8qRpPzA== 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=XcRQX9PrxnpT96skImbpQu6ioMUrZfMqxEZ72+gjvck=; b=ae1Xx34hnwGPX6ce/bFi4W6FUcQ0O6qC6pNz2g/BQrIKqFDE/sw8seI/UyRfOHBis+nBQm1iOGsff8vDk+YNQEsxHjqFzqRip0LfUrBdZEUd15egpG8d7Ka+0XiF8fROo1ophrR9BDPixWdILUBKW4mk+VCrSmFhfVAdPcqRdUIAWZCWkZqC4LQ5+B5UXmuAxgg/hYO8jb9NjUmoHzeETwNOniVg+zY+1t8yHs6hsetGDjMsbq23+ihK9tYSYvYMNG8BvWT50XspUk1cqTapxwuU3+u63qY8YnlumSF/rUgY+e2zhWsmavrHNcWPBLDomfMkeo22mRk3TN72uOUJsQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=none; dmarc=none; dkim=none; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nokia.onmicrosoft.com; s=selector1-nokia-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=XcRQX9PrxnpT96skImbpQu6ioMUrZfMqxEZ72+gjvck=; b=NlBVPEKNcKp5AH7INLawXkHnDyfdXOQI6cHdm6TaJSyROSP8waxNy/YUymyRtMsBeDU6boTuEAugdjtNwluSRAGHtS5x0r5FKt3qQyl1EseNAEnfvlnwCjF1pFCD+wRcp0aP5kkDhGphOI6YvOqt0K6F52lQC0Ap4XdkvfrYBxY= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nokia.com; Received: from DU2PR07MB8110.eurprd07.prod.outlook.com (2603:10a6:10:239::15) by DB6PR0701MB2215.eurprd07.prod.outlook.com (2603:10a6:4:51::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4951.6; Fri, 28 Jan 2022 22:32:30 +0000 Received: from DU2PR07MB8110.eurprd07.prod.outlook.com ([fe80::adfc:7f91:31e5:f103]) by DU2PR07MB8110.eurprd07.prod.outlook.com ([fe80::adfc:7f91:31e5:f103%6]) with mapi id 15.20.4951.006; Fri, 28 Jan 2022 22:32:30 +0000 Date: Fri, 28 Jan 2022 23:32:19 +0100 From: Krzysztof Adamski To: Wolfram Sang , Catalin Marinas , Will Deacon , Mark Rutland , Peter Collingbourne , Guenter Roeck , Alexander Sverdlin , Matija Glavinic-Pecotic , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] arm64: move efi_reboot to restart handler Message-ID: References: Content-Type: text/plain; charset=utf-8; format=flowed Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-ClientProxiedBy: CH0PR03CA0421.namprd03.prod.outlook.com (2603:10b6:610:10e::26) To DU2PR07MB8110.eurprd07.prod.outlook.com (2603:10a6:10:239::15) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 61ad7cfb-a61d-494b-dbf8-08d9e2ae1176 X-MS-TrafficTypeDiagnostic: DB6PR0701MB2215:EE_ X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:10000; X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: GEow5RhHqd6ffsD7TlGVVKHQ0LXdRrMh+3m2ZrKbtyx6CkvLHVko5BTNOPK7wQxOQv81BTt3fKhmkhXlAR2hgoNAr1OypJceMUkLgY8tmk+wpZWusSbLo0J8L7V7G2dgJ0l5jqalEZrJYA6YOrYetFi2YxrKdaFzmPqaAI1pyYhXsjWapYN9dRpdgQGqm45398+c4wjoQlune/8VDrT5wnRXq9PAEiu1xvwG/VB4fen/yUx551+b6zECrdzN7C8bj8a93tmb9+tgitZzlo1xUO8/1sttjUMGi1OGfdw24EiYrBSLF8J3cvhQ11v5KtrjiKr7qw9p0E+9jAHoH0wCLUV48I82lSiV39aIHpHFAO43dxyiC6Z8oQet81Feb/b+gPutD+ogtvtTdBVK0kq1nJe4id0iKC46tkoeK2xcKneOxYwqprG+iNFu/GECHMVMgxC2SBBsVoHcnBvHN15xAvgazBWVZgPu+qeHtBeCyyiQv4lxzqJv/Ul3iig6kJPqBfG8c1LnJLLwXg517f6gTLyt0scH46x+X7HI9DHoWt85tE5DVRfqyq6UlG+H+2IT3czGcXumqmO7Q5b9aCKXwNO+jahtjYbZgtlNHUatf1sc0NJxkZmBKJpegRiaDW24O3qZfS8e9bnG0FSqOgW7I9L124WCJKnattUFPSJrCtVAY4V9AqF5Omm8sCsFGnNTfSeHutSaSzyEwIhCFe8iJAG6rjonWL8U3DEYnphs+Vo= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DU2PR07MB8110.eurprd07.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230001)(4636009)(366004)(44832011)(186003)(8936002)(6486002)(26005)(66476007)(66946007)(5660300002)(66556008)(86362001)(8676002)(9686003)(82960400001)(316002)(52116002)(6506007)(6512007)(6666004)(110136005)(2906002)(38350700002)(921005)(508600001)(38100700002)(20210929001);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?SDIrSkZWRTQ3Y1JyRVU1bjVQeVg4OFgxM1BqeWxOdW12ZThWM25CNzZjWFpC?= =?utf-8?B?RmdzL29LQ0FJUUM0M215VkVxK2M3b1RSSDhTdnhxTC9XSnYrRFJ1SjduWWxG?= =?utf-8?B?ZnNGN1IzU3o0MmxuWms2SktDWHZ3ZFlUWEtZZzhxU2FOZmJwai9WdmhUbUQv?= =?utf-8?B?V3QwcmRha21EUzFEOHE0K2E1SXF5VzRRTmlLZTRMbEhRUmkwV0w0SFQvUEMw?= =?utf-8?B?S1B5ZnBGZFl1U2xua0hPUjYzWXNqaGExWlZHbmVZaEFrTnY5TnhKWEdmalhW?= =?utf-8?B?TGQzVG5LaklsQ0MyaHczbW5KMXlvR2VDMWRpcXl5anhpWGxqMFBwditJWkh6?= =?utf-8?B?c2hUdG9JajBwaFcrY01rYWprWUp5cHNwdlBEZ2thQXdDZDNzZEM5UnlHM3dX?= =?utf-8?B?YmhkOFphTk1kTzd3NVdHa2t0d0Q0SUxVcXU3cFRtTVJTdlFxZzh2VGNtMzJG?= =?utf-8?B?ejBqUldHK3Jhcnl3bWVxTjZGeWMvTGprLzVUNU0vWTIzS2JmV3hyS1dmS21I?= =?utf-8?B?SWtIZWROYUE2Zkd0dnA5VDcwZlZsNU5kL1lhUi9ZZC9sVUFnTE43ZDdnTmQ1?= =?utf-8?B?b3RCVUp3N1h2NlU3SlFORDlDMGo4eE5EQjNpTTM5Z1NkdGlDeXQwSjlZMGhK?= =?utf-8?B?Zmk2SS9Dc3JFTXhGNVNXeEtNRjdHTXV5NGZ5bTBvZFlsMG5iVCtDcW85MUFk?= =?utf-8?B?MCtZYytVaDgxbjBzT0RHVzBGbndYOFRPV0p2NWFWQ0k3bnducG13Yi9IcXFK?= =?utf-8?B?WVkrQTBpVktDblAvTXVObEIvM0pETEc3eURPTHZncjd3eDhiVCttTjZkVHFN?= =?utf-8?B?Q2MwYXp6ZU5jWlZSYisrKzNNaiswUmtkQjM0ZFlWSkgwU1oxL2VvRnNpSHVh?= =?utf-8?B?U24zR2tpcjFqK2FYNFlRN3J2M0NDVHIxSjdBeTF0L1BPSWJ2a2p1aTYzU1lO?= =?utf-8?B?dUxGY1l6cVl4bVBUVFFWd2RTRTVLbklWNWlHcmp5RTNJUHNBQUZkdSt1WFZ5?= =?utf-8?B?eWtWOEJDalJmYVMrcGcrMmpOWUMxOUlQaGdYMC80QzJBVWx3YVdFakxQNEov?= =?utf-8?B?V3pLSDZZN1VpTGg5d2VTQVh3MEJXMTVvdHlnNjFBNzcvUC9hZ1dFbWNPNVFG?= =?utf-8?B?MGsvak02SDdmMEc2MFhESnpNemJOUTFSOGFzTEVLa04yVTRXN29yTzJjWlRu?= =?utf-8?B?aE5DUnp5Rlh5RHNRTHYvOXVtcC8vUmQ1cFZ0Vk5qL1BjdDBjN1QxclFsTVdx?= =?utf-8?B?NVY1eE5KekNUQXFMa29yVDJFbXJvRFB3TkRTNlBudTVIT1dNTzFENGEwb2dw?= =?utf-8?B?Y1NQZzhVa2VkMTRZZXFFZ1Jxcm5ZR1pYcGhRU2psQU9Ta2JxSzNIbG55YXdB?= =?utf-8?B?dVZrY2NkRlhGSXlFZmpIeFY0cUovcldkWUdUMVpCSFZHSWR5UVBNK1QvbTZD?= =?utf-8?B?ZzM1RFRpd0JEUXVpUHNqYzBrakdyU3VyOVBuTWxvMmlqcHhqanNmUi9mWHpi?= =?utf-8?B?ZGZncFUwSXkrVHVUdUhoOG5XQ3ZqTXMyRk10MzZ2Z3NWdHg2R3VVaXM3TERj?= =?utf-8?B?elJ2cURhRUxIUHQwbE12RDc1aVpSMDJpZ29iSUNoZGZyY0h1VnNSeG9aUG5P?= =?utf-8?B?ZUNnWlZKOGtrQVZWem1ONzJya0lSZ1RyVDJsWWFNeDRCYUxIRU5XNnNIcFRD?= =?utf-8?B?WWRJa3JBSkRlaXJ5N3lpam5NNnZHVXVwZjY5dHNlakpSV3RQcUM3THhhTnA5?= =?utf-8?B?b3IyaENJQjJIRmZmWThvdUlic3h2elRibjZKT2IvR3ppWDNHNUNMQUEyNElR?= =?utf-8?B?aG44cENhTHBZWGJFbFhxZlNPZ3RsbTFZVGN1R2pYbXcvMld6TEJGWHJ4b1ps?= =?utf-8?B?bTgzY3IzS2FDeUFTM0RCV0k3QVRxQVM1RlhCQURKSWp2d1pwZGhYYTgxNGJX?= =?utf-8?B?RUVtS0NYZzlJYjZObk9UL1plbHU3L3NDZTBkSmV0WHJZV0VWR2UvRnFrVW9G?= =?utf-8?B?Q0xGdHRlcXBWUlA4VjVuZVJ5UzRybmlaa2VJNmU0Ylo3MWhzSmVyWnh2UU80?= =?utf-8?B?VTZCOXZIMFM1M0RCaVRlQk5wTnViVk1oOVYyK0ZXaVh6N2EwaGpXQ05BN202?= =?utf-8?B?MXVhcWZmY0hNbjREN29Wa2xmVmQzRy9HSXp2SmxaVFBwY3hXcDV4RFgrdTFM?= =?utf-8?B?MVBSODVpOGpnVXZBQjFidy9NV1ppL1FKMWNrVXBpN2VPbTdTOThpNkkxUThz?= =?utf-8?B?dEdCWVlLVGpOdTNIbm5zeHdHZWtRPT0=?= X-OriginatorOrg: nokia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 61ad7cfb-a61d-494b-dbf8-08d9e2ae1176 X-MS-Exchange-CrossTenant-AuthSource: DU2PR07MB8110.eurprd07.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 28 Jan 2022 22:32:30.2804 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 5d471751-9675-428d-917b-70f44f9630b0 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: em/GzGqGrD21u3ONiQ7vkwITz4nb89ZsbRBsyaILyit79gLnKjnvCAHt0lURbHrkh3xkOEULl2gkdR+jxF1PciOfbHKNwkClrbewn/iGw7c= X-MS-Exchange-Transport-CrossTenantHeadersStamped: DB6PR0701MB2215 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Dnia Fri, Jan 28, 2022 at 08:29:06PM +0100, Wolfram Sang napisał(a): > >> + /* We want this to take priority over PSCI which has priority of 129. */ >> + .priority = 130, > >Is it an idea to add a #define for the PSCI priority somewhere and use >here the define + 1? Hardcoded priorities look a bit fragile to me. > You are right. Our priority policy for restart handlers isn't really good and it is hard to choose right priority just about every time a handler is added. That being said, after reading Mark's argumentation, I now thing that just being before PSCI is not enough. I think that a much higher priority should be used as it is not normal situation that you would like to run something before efi_reboot(). I would really still like to move the efi_reboot() to the restart_handler even if you consider running some code before efi_reboot() crazy. Since 255 is max priorty but using it basically does not make sense (as this would let to the exact same situation we have now). I would use something like 250, or even 254, just to indicate that we know that most certainly nothing should be run before efi_reboot(), but still allow those silly people like me, to do what they want in their system, without the need to run the custom kernel. I think we could even add a proper comment, so it woudld become something like: /** * If you are running UEFI based system, you most certainly should let * efi_reboot() do a reset for you. If you think you know better, we * leave you a window of opportunity here by not using maximal priorty * here. */ .priority = 250, What is the downside of doing that? That we will run through atomic notfier chain instead of calling efi_reboot directly? Sure this is slightly more complicated but it works on all our platforms and is battle proven and we don't worry about that there. And the upside is that we give people possibility to use their beloved mechanism if they really like to. Because flexibility is a good thing. What do you think? Krzysztof