From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751943AbeERVC4 (ORCPT ); Fri, 18 May 2018 17:02:56 -0400 Received: from mail-dm3nam03on0058.outbound.protection.outlook.com ([104.47.41.58]:40576 "EHLO NAM03-DM3-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751298AbeERVCy (ORCPT ); Fri, 18 May 2018 17:02:54 -0400 Authentication-Results: spf=none (sender IP is ) smtp.mailfrom=Gary.Hook@amd.com; Subject: Re: [PATCH v7 2/2] iommu/amd: Add basic debugfs infrastructure for AMD IOMMU To: Randy Dunlap , Joerg Roedel Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org References: <152631818082.18929.13970142119193316487.stgit@sosxen2.amd.com> <152631842907.18929.8819955271544326298.stgit@sosxen2.amd.com> <5e45f38e-cb45-d4a1-f351-30543f787290@amd.com> <20180515134603.GD18595@8bytes.org> <4041cb33-19a2-5542-4211-1dce51de5e40@amd.com> <89a0e3af-8970-cd80-418d-630841795807@infradead.org> From: Gary R Hook Message-ID: <3eefbef8-142e-0a29-3e97-536717f63a98@amd.com> Date: Fri, 18 May 2018 16:02:46 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <89a0e3af-8970-cd80-418d-630841795807@infradead.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [165.204.78.1] X-ClientProxiedBy: SN2PR01CA0065.prod.exchangelabs.com (2603:10b6:800::33) To MWHPR12MB1453.namprd12.prod.outlook.com (2603:10b6:301:e::22) X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-HT: Tenant X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:(7020095)(4652020)(5600026)(48565401081)(4534165)(4627221)(201703031133081)(201702281549075)(2017052603328)(7153060)(7193020);SRVR:MWHPR12MB1453; X-Microsoft-Exchange-Diagnostics: 1;MWHPR12MB1453;3:rWV5Spl2h4ky0/KVTy/caTPPi9kzIiACm5K5lWJNaVM6F61dVDy7Df22yEU684geNt5s5K6DVPZ+UYaQ8obo8cwaTND4vmacFpTKJEkStZZx+wW/N/xu31ExXtyESmtUSuL6YgqfMKc70MGBj6/LwG7joO5NV3mfR0lJm7U0cRdlsLumKyjnk6dz+VttXLl0XcNSJW+F23As5sRpDjxxKG/d2miF9XNk06geMOlIbQGy3o4XMXXza/d4GJKwmKPH;25:/rMXkWmoHVg8LEtOFlLFd4ll/lGXNNCSnDPmJV6wSK5MBB8qO1ZYpunj/fkKfZFBkXyKxBn6nd0plPf84IvDrVO2QAkCMaxgPEm/0UrKGuPAdckFuqSfxYJHpuFAjwOOVcPJexmsKoEUe+iegF9k3yKHRqH9o5i50YmLH6Gr5qY4ER9UmsVDRI6/wRwZnOallXUx8Xz5w8fv7tOWyBQm4iC0/DYGt4JgjBobSGAtIVuSsscrkaZPeWiuMXaPhwNY/9y5aKz5ZQ7APzov9xn6h4BM8LIGvLQzcO5B/MpgRPV45sfy3W+WMcnRd+qhqy0GwkZPbRuRYJDCuH7aIevIww==;31:A1mgaXLFT69vyBwkz7JpnoA9ODXyiNlcdi2f8gcoIMON87upx+m7Sq+cZsCgXmVv8FkL6vZLqDexVAV+OI97v1gxmn1IPVvTvRJO2YTbUpTqvOZYV1VkrxwjV21YUDGdUEZln96Q3euZc2rbBHnTK6F5HxMvVoJk//+GXeCE66ReEm1+LFsAFmFkdFo6MfcC46sC2LYxx8XG7jVaQM8b2+bfvt/NIWiZOOpWJrhLV24= X-MS-TrafficTypeDiagnostic: MWHPR12MB1453: X-Microsoft-Exchange-Diagnostics: 1;MWHPR12MB1453;20: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;4:qwVCrUxfOPqEBOupP8gc89kzmd2WaTFxnI4B+x1dLkH6lwm6Pdb2EvQoVuIo5BinD6IvKqiuDA/jAUBzCA3dO//HG+05qAa6uUVUijqty+xFKYeOpLyZ2RzZ1f+WcxhSzOw5/Zr30J6xZ3QS6dLcFP0Er2EaOU6kSdub47oJ68PJUiN+mW8birBrWtA9k9IUPZYRJImZPhjdHctz84jkgiF7SFE8cWs1E3QC9bKDWIgfUO3U4ou4U2T4G8wRVRs1q5LjjYGDPFzViEDBQj5L5A== X-Microsoft-Antispam-PRVS: X-Exchange-Antispam-Report-Test: UriScan:; X-MS-Exchange-SenderADCheck: 1 X-Exchange-Antispam-Report-CFA-Test: BCL:0;PCL:0;RULEID:(8211001083)(6040522)(2401047)(8121501046)(5005006)(93006095)(93001095)(3231254)(944501410)(52105095)(10201501046)(3002001)(6055026)(149027)(150027)(6041310)(20161123562045)(20161123560045)(201703131423095)(201702281528075)(20161123555045)(201703061421075)(201703061406153)(20161123558120)(20161123564045)(6072148)(201708071742011)(7699016);SRVR:MWHPR12MB1453;BCL:0;PCL:0;RULEID:;SRVR:MWHPR12MB1453; X-Forefront-PRVS: 0676F530A9 X-Forefront-Antispam-Report: SFV:NSPM;SFS:(10009020)(6049001)(39860400002)(376002)(366004)(346002)(396003)(39380400002)(199004)(189003)(31686004)(3846002)(11346002)(486006)(23676004)(97736004)(52146003)(386003)(7736002)(76176011)(2906002)(2486003)(2616005)(305945005)(956004)(476003)(6246003)(5660300001)(8676002)(52116002)(81156014)(81166006)(8936002)(53546011)(4326008)(186003)(86362001)(229853002)(77096007)(446003)(6116002)(26005)(47776003)(66066001)(65806001)(65956001)(31696002)(16526019)(65826007)(230700001)(93886005)(25786009)(68736007)(50466002)(110136005)(58126008)(316002)(53936002)(16576012)(6486002)(67846002)(106356001)(105586002)(36756003)(478600001)(64126003)(72206003)(6666003);DIR:OUT;SFP:1101;SCL:1;SRVR:MWHPR12MB1453;H:[10.236.109.62];FPR:;SPF:None;LANG:en;PTR:InfoNoRecords;A:1;MX:1; X-Microsoft-Exchange-Diagnostics: =?utf-8?B?MTtNV0hQUjEyTUIxNDUzOzIzOmV6RjlVQk9nS1RieFFJU1QwN1RVWEVISU9t?= =?utf-8?B?MXBGSzAwQVVoazFvR3hxeVRydWRtYWhFU0MvYVVvb3habHRXQm90aHIxOUNH?= =?utf-8?B?Q1hXS2lJZ1dWSGVDMG9hUHc3aTdlUVFQSWlOWmVhamhFNFNPcUg4UUhENGZ3?= =?utf-8?B?VWUrd0gwRjU3T2dHYVQ2Vk9PSHdzUzBjSnFQbCthR0k0b3dzdjhyQmhDQTFQ?= =?utf-8?B?d3piYnkvODdSc1RhdWtFcmdtcktzbHQvNlAybmU4MGVuVHIxL3lyOEx1bWQ4?= =?utf-8?B?WXQ3eXVzOU5uMUEwV1NEa3E2cnNNZlZpZFdlYU1SR21YL3Nxa3JXWU50Njkz?= =?utf-8?B?MFNuTVZTQVFSdVRqNEFNRWxRaUozcHFjNXZpRkM3TG40a25QTVhxa0NwTDg1?= =?utf-8?B?dlR5K01sQ01MQys2akZYTzg5TXRNVkxhRm8vNWl5ako1bFkzejl3Rk1QVHcx?= =?utf-8?B?bGZtVG9SeFl2WnJpcWJOSXpkeXQwMlRFWC9pNXBsb2ttNjZWb2N6czRzV2JW?= =?utf-8?B?NFo2UTNVYVovV3VFckgySTk2ekk4SDRDSWRxdVVYTlBKUHplZVV0Q3BoQnVF?= =?utf-8?B?MkpBZzZvTkRPSEtKWEc2M0p6b3g2UjJCUDc2MUo3T0hQSVNjaTEwZUVKcThX?= =?utf-8?B?TXJ6WUxCYzJqV01LNm9ndFdxRDNPaThjcDZ3VkIxSjhhb1hST1dJMXB5M1Rv?= =?utf-8?B?RXNpZnpva1ZKNVJVQnBlb3krYnhoOHJIRStpdEhQckJEQzFGQ3YrK1liVHBU?= =?utf-8?B?V0xOTkRwYXlQRVZ2d3d2MklUOWFiSFdQS2h0bW5vSllaY3VlTnN3am5IZkFB?= =?utf-8?B?d3Fxc0UzZS9ONDRjdGxvb1M0akVpUEx5QlkrUDY4cEpKMXpmbmZSUUY0bW14?= =?utf-8?B?RTVmUkZCem5MM09rR0EydDgxbmdJNkZrK0EyM2Zmc0FLamcxa1JkT3o3WHpB?= =?utf-8?B?WnBCZlpMTDlWbEczRlZwR2dmWkdFYXFjU0lYTkVSVGRmbFhydFVoMWNWM1U3?= =?utf-8?B?UktRU3B5OG9Ua0NqeDJhdG1hOWxWVmo1Z2Ivdy93U3UrcFBNMmZkTmYyRmU2?= =?utf-8?B?dUVYL0h3bHFGbXBSYUFObE5SS0E3ek4yZVE4NExZQ25kK2VzOVZVczc4WDY3?= =?utf-8?B?dTJGN05EZ1F5NlpSREtyZ1hPL1VCN20ya09NQVRrNnNHLzBrUzV5TWd2bnVr?= =?utf-8?B?SXJ1cS81bENFQmpnbEdFSUJZWkMzL05iYWw1d09kN0k4Yk1PQ3M0ZTZlaWtn?= =?utf-8?B?SGcveTVrdm9NbG5hMGFJOTc4bitnSkl0MVp2SENBSEZYOVMxaHZ6c3pCcGU0?= =?utf-8?B?NnllbEl1enViL0FsZTEvZ2VudW1rNlcxTHhlUG93RDNnNzk2a3Y5S3VXd0gx?= =?utf-8?B?VUNMWXd1K0Fyd0c0NTRNUnQxT0hGNCtZNlVITWNCOVlUaFBROWpUMFp5QmNM?= =?utf-8?B?Z3dQU0xoZk5Lck00bCtOTTNJcGZ2ZGxaRDBVZ0RSaHJ6NFNCU0ZjQ1FFd24w?= =?utf-8?B?NHZwci9TMll5MG00emVhdjZ3c1MvU29xQk42S0dpZlU0K2VtdWJCWm1pb0FS?= =?utf-8?B?MU5XZ3ZqVU9wN1FXcEU2eUNjZnZCdHFYdGFESHdwU0dHWGxmTUF5WDN2TUFx?= =?utf-8?B?MzEvN293eUxFRGlxelNhMUgvZENQU05WbnRDTFZWN0JkU2pTQWFTUHAraUJO?= =?utf-8?B?aVdVWk9KUVEzeWplNC9QTVhVeVNqdGhqMDlOc3Bwd1d6djZNTFQvazB3RGVU?= =?utf-8?B?OUMwd3h1MGR6QTI2SXI4Yk0wWXQ1WDkvSnUwMjRybkk2dmhjRjhVMjNEelMy?= =?utf-8?B?TXlmQXRIaEE3dFBhRVdoNHd6ajhKUGFiYUhjZXdOajVETUdGaGZreXVTTTE4?= =?utf-8?B?ZFArTkNzdm5CNjJobnBDSEd2bFlxT1B4UGQrNklsNGhPRGRZYTJDSSt6YXFP?= =?utf-8?B?K1pvNjhwVElKZndNWkovdUJ0KzMxUHJqSGtWNU9lbXAyNFJ2bEhaT0tIMlZX?= =?utf-8?B?VDNGNkVZUTdCZDdoRnIyK0kvSWN0RXNGcW5mdz09?= X-Microsoft-Antispam-Message-Info: 8DQAnWs3Vgsuzy8LoDFrge1iBptL5Vw1i1B0BAYQseIbedR3TTDuFkxH4vYviOCojChsXs992H5qBmyKT0+Ofh4cWGUzWstXh2AaLfZ+f6BhkOf+0ruF9bU6xc3/+1YKfWzxn4ZlGnbI9OIOTl9MKIFcYujFvxvsRryL1Qgl/K9+4kpMBKrY1faVCLtCK+Vw X-Microsoft-Exchange-Diagnostics: 1;MWHPR12MB1453;6:pMMU+AaGrdUmLqX6qn6QpncnVouC2S+t1Js3VfQXj1Hu59yu8fI9ZeKst2Lealet/rMstKtkJ9f1xcTuKvwdia03858R1FeC34oHRX8AZzvus0jbngcVXxQJYHm0AOiGHzky2h0KoqVXIMdL8qF0idgrFkeTvnOhe56/AUIeA/2g5lSNtHnVmx4Mj50S1yGzP+n5d7jHdtwi9sX6Bvszy+003HH6F+w0MsDOT22iNG33UGjG3hg9b7tbjQubAwL+5/CECP37qFxdVVKuHbyQ+lHFu7gsrLr5/PczcJ2cJY+QIKIOITo/iav7TdIihn8cXmABn4/V8MIF7T6hsPr2M0qNKKjafe74S/0ZdolpFDMEKHvmJt/qHLNaLnk9DC+LM3rVX+9OUd8+UDadzhPYeh/SEyTNEQFWkPtipM4P1MIhSpYnFeQ3CN7ItCW9xGBeBfYr1yH+ZOy89Fqj0wwyfQ==;5:Dba+GufqkKHhppzBilpbBDRpTWtZZjc8/y1TDovT/qu3DtKUTCNCHsRC/yfi2RBcuh9DPt+bSI1LW4bzKEGoLi8jncjVzY617wOboPlDYgux04Ix8inbd2ydvlCJjj7iRKwnFlEMwst4z8yyx6/F19mZQhmtVNPqAC1XGZ2jugQ=;24:9G0b2EqPtLPTOkV1QR23GmSI88CFFoAoGZTF+K0hfvW8rq0F7iTEsIFCn1Sm/WrHoQT3O7LRrPd2CZJZlG8y0jCJXb6tBOz8w5UcpRFPYsQ= SpamDiagnosticOutput: 1:99 SpamDiagnosticMetadata: NSPM X-Microsoft-Exchange-Diagnostics: 1;MWHPR12MB1453;7:FKw2gyqMC/2IrrO4jTDNjNHrqqMCqfGg03PVAly7RWkQtGa1OCHCRyP5t03D4O6P/ZsGi/gs6Cl3clw9+7BHh7yY3Ee1VfqwREReIhnWV/x0KW1UhMr6UrwKsxocNeuK/DpDN7+o1T27P4CejfHMohXuZBe2KVlK6XpeBkPF+pG1U2BFNQfira28WWoVajdWUbq8KmyO6lYLUjF3IaJ3XotZ2JN6rrShumf7Hj4Dff6sf6w0f4zvkYryuJrw8uRE;20:UOIZc8kiBdyOBL6XEjUfB3Mxt/5tENcgb+fY0tvhZUO+svMOW0HNjFZ0Nu7bAK/SPyWLw/zacmU4Dx8FZU9JDripCUg9b+VcShh77hKx/7mSsW2z2ITxf2WKamMnR+LQQcO1Te4ZcFMSW31k7yxTHQ04E3v+d/S+9B8E3D9FyQAbUmZ2gBG9pQMsi4LlsoO+hcCr+FPqpyEHlblZuypolneH6ztICysO7iK0UKGmgZ2F+fMle4Lr0Ak8e6GRWa/t X-MS-Office365-Filtering-Correlation-Id: a9ceaf2c-efb3-45b1-4c1b-08d5bd02b83d X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 18 May 2018 21:02:51.7496 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: a9ceaf2c-efb3-45b1-4c1b-08d5bd02b83d X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-Transport-CrossTenantHeadersStamped: MWHPR12MB1453 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/18/2018 11:49 AM, Randy Dunlap wrote: > On 05/18/2018 08:20 AM, Gary R Hook wrote: >> On 05/15/2018 08:46 AM, Joerg Roedel wrote: >>> On Mon, May 14, 2018 at 03:00:50PM -0500, Gary R Hook wrote: >>>> This was brought up a few weeks ago in, I believe, version 3 of this patch. >>>> That question was discussed (because that's what I did the first time out), >>>> and _someone_ _else_ asked about why I didn't just do it the way I've done >>>> it here. >>> >>> You don't have this problem if you put the code in amd_iommu.c in an >>> IOMMU_DEBUGFS ifdef. >> >> Of course. My preference, however, is a separate file to avoid size creep. That's why I've done it this way. >> >> To whit: there have been threads discussing the advisability/acceptability of using #ifdefs for debug code. My take-away was to avoid them. Perhaps I misunderstood. >> >> So: I don't understand your comment. Is this an observation, or is it an imperative statement? I'd like for a maintainer to clearly indicate what is acceptable, and I'll do it. >> >> > > Hi, > I looked back at Robin Murphy's comments on April 17: > > > Well, you could do a makefile-level dependency i.e.: > > ifeq ($(CONFIG_IOMMU_DEBUG), y) > obj-$(CONFIG_AMD_IOMMU) += amd_iommu_debugfs.o > obj-$(CONFIG_BLAH_IOMMU) += blah_iommu_debugfs.o > ... > endif > > Or alternatively have an intermediate silent Kconfig option: > > config AMD_IOMMU_DEBUG > def_bool y > depends on AMD_IOMMU && IOMMU_DEBUG > > The makefile option is arguably ugly, but does at least scale better ;) > > > > I think the Kconfig option would have been the correct choice. "Preferred", perhaps. Neither is incorrect. And really, the Makefile/Kconfig choice is somewhat separate from the organization issue. So I've made the changes for this. Now I'm waiting on Joerg to make a decision on the code/file organization. I still prefer a separate file for the debug fs code.