Received: by 2002:a05:6a10:af89:0:0:0:0 with SMTP id iu9csp6182384pxb; Thu, 27 Jan 2022 08:10:08 -0800 (PST) X-Google-Smtp-Source: ABdhPJzBz+kbWLsIAe4pvy3Tpb/nWTe1G4OX6Aw8C4h/A9yfJ8H67NAVSr+Nhs2SYlNQQcUX7Qfk X-Received: by 2002:aa7:9989:: with SMTP id k9mr3545481pfh.23.1643299808684; Thu, 27 Jan 2022 08:10:08 -0800 (PST) ARC-Seal: i=2; a=rsa-sha256; t=1643299808; cv=pass; d=google.com; s=arc-20160816; b=vn5ep+z55iBXxM6Ipaut5xlO3atGMmc301jf5UpvlVYqFjp6KsLRK92JTEYPXnBT5/ bAiabP3IOuLzNVDRP2auosnB/+tTcWF4QM0GlJPX6Rk+WlnZo2cqQiATUZipJplIG1A1 edsdSJselMdNs6sp1P/MQIWMEEWNuLBUIyIU1REcwZXEkMJ9MhOi+nF/gsnExHiXiDTW 8fS1Ruk/d0xsjSye5D+JpjKC8kwMYKR2VL3i5tEhhVGfnbGmHNio7bL2KDGm4Rrliw1L KPmGnLVMJCBLflTLGTPShx9tGpA647UVsg+kglHr25ovM0iOEJPUSp3Fn7ssubvDQtLc KSTw== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:mime-version:content-transfer-encoding :in-reply-to:from:references:cc:to:content-language:subject :user-agent:date:message-id:dkim-signature; bh=8XAeANsy2vye/dYqaXLbEJeK6KI0DqVk+iuW449v0ug=; b=MR7+k3zBvJEvOg30zoUQQTOs3O6oIUxvX1p2Ji3YprjPK6D/dk4n0s+KxAmzVOY1zj m6KBEFZDETi1VLXnpop2d0pW7jmy1u29N4eECUOR/bPYws14an2OaWXVVjbHeSs0hFJT o5BsJ7LdxGSRVx6mG/xdbpopPU1dhBOjvTWi32jCgbjfzSPJm0jsOT83wBDmOp5O4V2U mS6D8TwU9nlFhDPTmRoRX/XHSO1f5pi7T6Xlnbfe6mhXeY4KVc95/NlvFoaIJGgR8Cja nB8KQHra9tR1fKVEDHfeP0m6u4BoArnAsWCeneQfsT6UDaoloBRqhtM2Bia7TJ+M/TJr ev2w== ARC-Authentication-Results: i=2; mx.google.com; dkim=pass header.i=@amd.com header.s=selector1 header.b=UQO94nd8; arc=pass (i=1); spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=amd.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id bc7si2330060plb.21.2022.01.27.08.09.55; Thu, 27 Jan 2022 08:10:08 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@amd.com header.s=selector1 header.b=UQO94nd8; arc=pass (i=1); spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=amd.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238487AbiA0JWF (ORCPT + 99 others); Thu, 27 Jan 2022 04:22:05 -0500 Received: from mail-mw2nam12on2044.outbound.protection.outlook.com ([40.107.244.44]:10145 "EHLO NAM12-MW2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S238477AbiA0JWD (ORCPT ); Thu, 27 Jan 2022 04:22:03 -0500 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=NHH4yiFAHMCoxQa8nvvcBVn+iUlZCBJ+sJNcOOLlgXmwLYrAo2Tk+PUpyr9uQmmgTgdHi5O3cZay/wcpJfbNR4CJLzTIGogAYUVOflQYnT02FRp8kbE/TVG+4Zyl1iA0ClY+okWH4i4nYlr9kVF5Tx/ANRijWGDtmYc1Ake6BwNd9Pz67Bw89HnuPfw9OILRqKCHq9t0BKxytyYVng1cOyH4l9HJZby6qMQRZQoUnB7xRMSozurvKplTTVbO8kdaoLLRARigseJJo4fi+X2LWgoQSMQi+w0Zg3jgqAhFWWAAPJGyUlrEmHTDoK4uiFa4jPG8HYFuh3TGB69c7FdjHA== 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=8XAeANsy2vye/dYqaXLbEJeK6KI0DqVk+iuW449v0ug=; b=b65S1O5dorABcUBQWe9EWcS6BJ/A7I59jgMcxSG9+GqBnA4rh2J7bCKrCBPEf4Fwwhh0Y70j+Hh8b+ueca6dgKGwxW0Oc2/q9mAT+mfRPoG87OOuDN5EvFEmUqfgZWeNtLK5QUYzvqxfyVEJjfFmacE+Q+M5Q7IRZRQnEAe6hOj72i6gGS3mWRTvjGcFQRCsCpHB2TYQPgpvrm5p11X8cRC9OAH1fi5tnZ7GQnFmBIHxyP9+T3k0/rSRQ6NC5SfFdOAHGDi77C5wlI/TQZN05LS2oFYVVZcj8XmjK91Z8u1LZR4K2m1y/NjeuxGwZrere7UAymCCGJeLZHM3xq6erQ== 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=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=8XAeANsy2vye/dYqaXLbEJeK6KI0DqVk+iuW449v0ug=; b=UQO94nd884qJD4sUqYhYgmEvRAHjmZB8QbcrLgAU8cggDO6ck5Q0nm3++9UyTQsugv3R13swizyhNd5ClbRvfBKVGaBsqfz2pc19UN3mMfQJzRQ2GfdWpr9HvbKVQGq7VGbTD+tqM8LAuCgqPs6UNFTFwXzcZ9hAt6+afWLExs0= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from BN8PR12MB3587.namprd12.prod.outlook.com (2603:10b6:408:43::13) by SN1PR12MB2366.namprd12.prod.outlook.com (2603:10b6:802:25::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4909.8; Thu, 27 Jan 2022 09:22:00 +0000 Received: from BN8PR12MB3587.namprd12.prod.outlook.com ([fe80::d8e7:e6b0:d63c:4a21]) by BN8PR12MB3587.namprd12.prod.outlook.com ([fe80::d8e7:e6b0:d63c:4a21%5]) with mapi id 15.20.4909.019; Thu, 27 Jan 2022 09:22:00 +0000 Message-ID: <69c260e4-f4b8-e51c-4930-e7aaf9bec2b9@amd.com> Date: Thu, 27 Jan 2022 10:21:53 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [Intel-gfx] [PATCH 02/19] dma-buf-map: Add helper to initialize second map Content-Language: en-US To: Lucas De Marchi Cc: linaro-mm-sig@lists.linaro.org, intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-media@vger.kernel.org, Thomas Zimmermann References: <20220126203702.1784589-1-lucas.demarchi@intel.com> <20220126203702.1784589-3-lucas.demarchi@intel.com> <20220127075728.ygwgorhnrwaocdqv@ldmartin-desk2> <3066c6a7-fc73-d34d-d209-a3ff6818dfb6@amd.com> <20220127081810.6zt6cyib4s7kpa6f@ldmartin-desk2> <3c6a9126-bf88-0f29-425f-36748271c179@amd.com> <20220127091247.3uqi5zhesqtecbsw@ldmartin-desk2> From: =?UTF-8?Q?Christian_K=c3=b6nig?= In-Reply-To: <20220127091247.3uqi5zhesqtecbsw@ldmartin-desk2> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: AM6PR08CA0027.eurprd08.prod.outlook.com (2603:10a6:20b:c0::15) To BN8PR12MB3587.namprd12.prod.outlook.com (2603:10b6:408:43::13) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: fbea7cc7-9770-4edb-63d8-08d9e17678c6 X-MS-TrafficTypeDiagnostic: SN1PR12MB2366:EE_ X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:4714; X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BN8PR12MB3587.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(4636009)(366004)(31696002)(31686004)(5660300002)(45080400002)(86362001)(508600001)(66556008)(2616005)(316002)(66476007)(4326008)(66574015)(6512007)(8936002)(36756003)(83380400001)(6666004)(2906002)(6916009)(26005)(6486002)(66946007)(6506007)(186003)(38100700002)(8676002)(966005)(45980500001)(43740500002);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?VVhEZ2VTWHZPTkFYNmE0VzhlTDM5ek5odnJzQ1lYNDBVUkZlTWI2Y29KYXBW?= =?utf-8?B?aHMrbnlOSkRvU1NmS2dhVG80Tkt6cnVEWTBSZHdNd2czOWdGdjl1RFZDSUI3?= =?utf-8?B?bjk0cW5acEZ0MkFqZGlUalBZOGc4bjd1M1dZV0YyWmxvQ05kWmtyVUR0ZTlL?= =?utf-8?B?YzVxM2ovMGN1TU42RW5hUkx0Yk11d2VMbXZmZW9HWTNrQmU2U3dibDAva0VN?= =?utf-8?B?U2R5cDVZUDNMeHNWcmwycU93NDBSU3I5U2x3YmtGRW1jeFloRWZxTldpcXhm?= =?utf-8?B?a0FjcVhqamdjcFJLRzhSeUx5MWpVcFVleVZYd2hBT1Y3MkJBd083Y1pSTFI2?= =?utf-8?B?aVdvSlBHVitSMTNwcEtKakRrbjNWZVFyV1NpTDA1SFJVc3RIc0hNSGNZcFJY?= =?utf-8?B?bTlLOG9pNm5KZ2gvaU1lVzJXc1JiUmlJRlUwTkMvSzEwcGVEMXhxR3RYK2pB?= =?utf-8?B?bEdWUUUzelRiRGUxTXUrdjdUZ2dQYlA0UU5NalJFOGUrZkUxN2xuZkpLdmlk?= =?utf-8?B?YVlPWU1uNllUZTcwZFlNdzJLMmtNbnoraW5tRFZCYWUrM01YRjVMM3ZhUzBN?= =?utf-8?B?UzlCaUQvK0JNeHpNMEtYcGwzTFFTeGF4dVMzUnpqOVZRVmJMT1p3T3M5eEFT?= =?utf-8?B?NFlWei9nTVZKK1ZhVU1oeFRKdEkwaGxhNVFPMFpaSnVWeFdENmpra2JlbmpY?= =?utf-8?B?V1JySTh2R0IrVFBQNy95enI3ZlZCRnpnWWdsTFZKcmxjSTU4eEp6bG5PMDJE?= =?utf-8?B?NFdzVm93YnVOYmFCYytac0FYWStERUY2UTdHdWNkbXBLWFpqMjRQYTJqbldK?= =?utf-8?B?M204RFBjaytVRkQwR3VFMThwb0V1ZTJUaDl3SGtwNTcxQUg5aHpzcW50WU95?= =?utf-8?B?UnJiUVFXWFJ6V0Q5ODExNndKRUpqMmR0aUtnVVFzQk1ZVkpFeWxGbFc3N2di?= =?utf-8?B?R0lHQUQ0TTNLRkIzdDQrNkZWQkVvdjNod2hLRmZVeDlMZlBmS3pwRlZnd2Ex?= =?utf-8?B?MWxzTGxYdkplWGRnV0VBb25IWDY3SlZFUVQ3cm5ldndlNm5kelNMR0U2Z3A4?= =?utf-8?B?MmFiNm9vZG9Ma0ZhK1FQdG5QSnRkM2hLbjhLa1RYd05MRWs0V1A0YmZYa1F6?= =?utf-8?B?QlNuK0wycDNFSFIycEZPR3pVNitIRk5NS0tJS055R0tvdFBJYXFJd0dYcDVy?= =?utf-8?B?b2NDM1YyeDFsdDJvTU1tclVUQlVzWlA4NDZGYlgxN0NpWEZNUmR4dDMrT0k2?= =?utf-8?B?NWcxdkFXcDROZnhBTVlvRHFWUTJXdnRzNFRpaC9OZW1oVmNOTEF2S053dEdu?= =?utf-8?B?RzlMTXlkaExwL0tEUVp5Q0lwQXJqUHYrV1o3NHRlYWtJUlV1WUVQNzhDY2hD?= =?utf-8?B?ajkvbUY4bUVrV21SWkZqYWxSa1cxTGhOODhscXQ1VzdCZ3d5RmxMdXVpRnNo?= =?utf-8?B?RDJLWmh1d3Q4bGp4b2wzaVFJVmZqZ0JTNnBWcHUvMFRLNnpib2lmUEw2ZGJq?= =?utf-8?B?cGp2T1FTMlVjYVJUSkh3bmpTYVhqSlpTMy9JM004MUlodzJwWVhnOVFyWk5I?= =?utf-8?B?THFLRlJ6YStVUlNuMm12RnIvMXJhdmxXQStiemJNWGFBeCtpS1FtY2hWSkhu?= =?utf-8?B?Z2hXVlYzRlVrOXpNNUdMVVpLTFRaUVA2dVI2cFhyb3BIMFIxc3BhSUdER3dz?= =?utf-8?B?UUtNeDVmaEFIVXZJL1haRFVUc0dUaVV0YXNIVUs3NEZOclNQYTBDYndSb25G?= =?utf-8?B?N2dobjVZWE1MSTV2Y1FoUmFPTDlCRWVzTDFNSDV5MDVpbitvbTB3OFpzeVJz?= =?utf-8?B?bWxvd2M5MmpCWXR3bCtDV1FXT3N0YVVDSjVTVVlReFhQRmhWQTMyamFJeWtX?= =?utf-8?B?Qys3SG84QjFrdEFjdmFoeG5ramN5QmphM1lMUVV2c3NMdThWdHpqWHR1WS9K?= =?utf-8?B?Mnh4ckdwQ3pNNUY5Q2RCVVBjdWYxQk9US0tTc01ENmJXRkNJREtybzVGYnc0?= =?utf-8?B?UGtNeitkV25NTXRxbytZTHI1N2hMdEN1cWpTYitncXEyank3c2xMck9DM1BE?= =?utf-8?B?R21yZkMySysyYjM0UDdTQXRGd1JJUUZZMFdRQnQxbUwvMXJUQk55RFBkUGJ1?= =?utf-8?Q?eoZw=3D?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: fbea7cc7-9770-4edb-63d8-08d9e17678c6 X-MS-Exchange-CrossTenant-AuthSource: BN8PR12MB3587.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 27 Jan 2022 09:22:00.1107 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: KHgUFnTKoTnyWRGq7+9xg/9BXvbTeuxG+1QM+X/yGAu48+rSzg359Z8CB0MrG1/9 X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN1PR12MB2366 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 27.01.22 um 10:12 schrieb Lucas De Marchi: > On Thu, Jan 27, 2022 at 09:55:05AM +0100, Christian König wrote: >> Am 27.01.22 um 09:18 schrieb Lucas De Marchi: >>> On Thu, Jan 27, 2022 at 09:02:54AM +0100, Christian König wrote: >>>> Am 27.01.22 um 08:57 schrieb Lucas De Marchi: >>>>> On Thu, Jan 27, 2022 at 08:27:11AM +0100, Christian König wrote: >>>>>> Am 26.01.22 um 21:36 schrieb Lucas De Marchi: >>>>>>> [SNIP] >>>>> humn... not sure if I was  clear. There is no importer and >>>>> exporter here. >>>> >>>> Yeah, and exactly that's what I'm pointing out as problem here. >>>> >>>> You are using the inter driver framework for something internal to >>>> the driver. That is an absolutely clear NAK! >>>> >>>> We could discuss that, but you guys are just sending around patches >>>> to do this without any consensus that this is a good idea. >>> >>> s/you guys/you/ if you have to blame anyone - I'm the only s-o-b in >>> these patches. I'm sending these to _build consensus_ on what may be >>> a good >>> use for it showing a real problem it's helping to fix. >> >> Well a cover letter would have been helpful, my impression was that >> you have a larger set and just want to upstream some minor DMA-buf >> changes necessary for it. > > I missed adding this sentence to the cover letter, as my impression > was that > dma-buf-map was already used outside inter-driver framework. But there > is actually a cover letter: > > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Fall%2F20220126203702.1784589-1-lucas.demarchi%40intel.com%2F&data=04%7C01%7Cchristian.koenig%40amd.com%7Cb36def4a6ebd4879731c08d9e1753ccd%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637788715933199161%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=gwW05OaUq%2FxlBWnY%2FPuPfl0YDdKp5VTbllaSmn45nE8%3D&reserved=0 > > > And looking at it now, it seems I missed adding Thomas Zimmermann to Cc. > >> >> Now I know why people are bugging me all the time to add cover >> letters to add more context to my sets. >> >>> >>> From its documentation: >>> >>>  * The type :c:type:`struct dma_buf_map ` and its >>> helpers are >>>  * actually independent from the dma-buf infrastructure. When >>> sharing buffers >>>  * among devices, drivers have to know the location of the memory to >>> access >>>  * the buffers in a safe way. :c:type:`struct dma_buf_map >>> ` >>>  * solves this problem for dma-buf and its users. If other drivers or >>>  * sub-systems require similar functionality, the type could be >>> generalized >>>  * and moved to a more prominent header file. >>> >>> if there is no consensus and a better alternative, I'm perfectly >>> fine in >>> throwing it out and using the better approach. >> >> When Thomas Zimmermann upstreamed the dma_buf_map work we had a >> discussion if that shouldn't be independent of the DMA-buf framework. >> >> The consensus was that as soon as we have more widely use for it this >> should be made independent. So basically that is what's happening now. >> >> I suggest the following approach: >> 1. Find a funky name for this, something like iomem_, kiomap_ or >> similar. > > iosys_map? Works for me. > >> 2. Separate this from all you driver dependent work and move the >> dma_buf_map structure out of DMA-buf into this new whatever_ prefix. > > should this be a follow up to the driver work or a prerequisite? Prerequisite. Structural changes like this always separate to the actually work switching over to them because the later needs a much fewer audience for review. Regards, Christian. > > thanks > Lucas De Marchi > >> 3. Ping Thomas, LKML, me and probably a couple of other core people >> if this is the right idea or not. >> 4. Work on dropping the map parameter from dma_buf_vunmap(). This is >> basically why we can't modify the pointers returned from >> dma_buf_vmap() and has already cause a few problems with >> dma_buf_map_incr(). >> >> Regards, >> Christian. >> >>> >>> Lucas De Marchi >>