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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 90B50CAC586 for ; Mon, 8 Sep 2025 12:45:38 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D92148E0003; Mon, 8 Sep 2025 08:45:37 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D69E16B00A5; Mon, 8 Sep 2025 08:45:37 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C584A8E0003; Mon, 8 Sep 2025 08:45:37 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id B058A6B00A4 for ; Mon, 8 Sep 2025 08:45:37 -0400 (EDT) Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 607AD83BA8 for ; Mon, 8 Sep 2025 12:45:37 +0000 (UTC) X-FDA: 83866054314.26.DEEC194 Received: from NAM12-BN8-obe.outbound.protection.outlook.com (mail-bn8nam12on2079.outbound.protection.outlook.com [40.107.237.79]) by imf30.hostedemail.com (Postfix) with ESMTP id 9D9DB80004 for ; Mon, 8 Sep 2025 12:45:34 +0000 (UTC) Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=TTXRCLKb; dmarc=pass (policy=reject) header.from=nvidia.com; spf=pass (imf30.hostedemail.com: domain of jgg@nvidia.com designates 40.107.237.79 as permitted sender) smtp.mailfrom=jgg@nvidia.com; arc=pass ("microsoft.com:s=arcselector10001:i=1") ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1757335534; a=rsa-sha256; cv=pass; b=hspGzmh7KqpBl3sJ9MpKn0mWaF71FLtMrVEng0Ie7iwvXwaBQSWObDpfbYRwG90ARF/CVZ fys2SZlI8Ugir0+xPsnfGcx6NLvvaVrNMjgzXM2+Fr5xdZLwr/6vA6Y4QOvA5wzZFxMOwE chKerr3kM7tkcJddPXi+Zilty1skSLY= ARC-Authentication-Results: i=2; imf30.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=TTXRCLKb; dmarc=pass (policy=reject) header.from=nvidia.com; spf=pass (imf30.hostedemail.com: domain of jgg@nvidia.com designates 40.107.237.79 as permitted sender) smtp.mailfrom=jgg@nvidia.com; arc=pass ("microsoft.com:s=arcselector10001:i=1") ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1757335534; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=kVtJy3VxH0BzMR5kUXXhlP/z9wRsHc79lEhpuG67Dec=; b=Aq9RHRuUScBY6zwqShJqFeaC/Re9k1vyf/1ZjY886NhntKOAtcP5pxxZkqoCRomo2vTDuq FzHmO41Hl66ivY8Dx7/KgwxJKbcE2W774XZZ2MxrPkStcsPIMSIH5K7SzOFklGzmwQ+HI7 g6KBbhtwRlQtlOD1saeghmzR/wHwGCM= ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=RdxQVyLbcPIzsM6sX7q8x7QmTn6cnd1lfXvY+FyzL1eEYsJhq9FOb6iapvK1Vz5owlYgWdY9IcbGDYG8U3EX3/aLA0nDcCYTJC7wHenAsnAO4Czyl77gaCg7SpKYxFc8vCEpuna490IbfIxsgf/ViI+4fzVEemqsS3aVW9Y2MZhLbVZX/uF/wNgSpbNCUvPBsT3kU7vL621wcjdrvJSbzaGGNtfbB6NLqSbDi0YipLdWfMOWLkamlIDFiHR9w25kDbwO3pu7Wt69fsWct0/Y9gw6jnJwFKcl+JSZ7v3pWCEiKmz6+YXiu/WBXR8/4CyQC2eB+n0kBVADV5jrPd0Tzg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; 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=kVtJy3VxH0BzMR5kUXXhlP/z9wRsHc79lEhpuG67Dec=; b=o3stciIRY0cSJ/aOoKNOmkPUysvopr5Wx/viD+gEzJmMnFkak7IdVhQbwrw7tsvA6T0FYwu2yQ5Nwoyj9qlnzkWKTaMRsALckATri7XTNhou0MLIyx2PuHCYXgCae/ZCpiwvzum50SCvDdvYJ4RAuY+eym69GzWs317bloT3QfKrPljCpgtlwN9FbC+UElJQ9nliFQDE2C/dHiswGGaVahPyeZI/oP7dvf56EbFJdVUZTHCqKDWGl3FY8GPa0201Ebw/riZkCBLrxZ0fJZQfdLnHV7BMPixp9lP7coa48gsTnOOWWAkA9bdBVWwItKKN47qeov3W/7ZsaJHd45YQhQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=kVtJy3VxH0BzMR5kUXXhlP/z9wRsHc79lEhpuG67Dec=; b=TTXRCLKbvDNzd5KMxBGwU4icKF5zN/F9rZAVOPQTpmAe2H1urLUqSZ2vgAtmyfMBWf2HsCCEc4/WtbChsSNi/3Pv1Zjk4Hw/+mt+mAwb/ciAqfptFuWataPLXR/6jj9igzgfifaMhvXm2ezJ1OpLfQ6e2qbAr7QTqZ77/fkcJxFV/bBTDr1R6ILLENwXsFGUIay1tWYhYlgNNt9JznW+pdjZ1NeaJ4gwuVbS8dzJhOiLGhFS/5QRDDAetxRUDr7ApoBQvjvcnk/iLP4GU5Wki5LlxIOK4JHlJVE6cLyfmXQCp9wzQYACVXV12CbG7qHf++PrC5Zn1ciQzJNCTG1moA== Received: from PH7PR12MB5757.namprd12.prod.outlook.com (2603:10b6:510:1d0::13) by BN7PPF915F74166.namprd12.prod.outlook.com (2603:10b6:40f:fc02::6d9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9094.22; Mon, 8 Sep 2025 12:45:29 +0000 Received: from PH7PR12MB5757.namprd12.prod.outlook.com ([fe80::f012:300c:6bf4:7632]) by PH7PR12MB5757.namprd12.prod.outlook.com ([fe80::f012:300c:6bf4:7632%2]) with mapi id 15.20.9094.017; Mon, 8 Sep 2025 12:45:29 +0000 Date: Mon, 8 Sep 2025 09:45:26 -0300 From: Jason Gunthorpe To: Marek Szyprowski , Abdiel Janulgue , Alexander Potapenko , Alex Gaynor , Andrew Morton , Christoph Hellwig , Danilo Krummrich , iommu@lists.linux.dev, Jason Wang , Jens Axboe , Joerg Roedel , Jonathan Corbet , Juergen Gross , kasan-dev@googlegroups.com, Keith Busch , linux-block@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-nvme@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-trace-kernel@vger.kernel.org, Madhavan Srinivasan , Masami Hiramatsu , Michael Ellerman , "Michael S. Tsirkin" , Miguel Ojeda , Robin Murphy , rust-for-linux@vger.kernel.org, Sagi Grimberg , Stefano Stabellini , Steven Rostedt , virtualization@lists.linux.dev, Will Deacon , xen-devel@lists.xenproject.org Subject: Re: [PATCH v4 00/16] dma-mapping: migrate to physical address-based API Message-ID: <20250908124526.GW616306@nvidia.com> References: <20250905174324.GI616306@nvidia.com> <20250907142509.GA507575@workstation.local> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250907142509.GA507575@workstation.local> X-ClientProxiedBy: YT4PR01CA0305.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:b01:10e::13) To PH7PR12MB5757.namprd12.prod.outlook.com (2603:10b6:510:1d0::13) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PH7PR12MB5757:EE_|BN7PPF915F74166:EE_ X-MS-Office365-Filtering-Correlation-Id: a297ed27-88a7-4d5b-a32b-08ddeed59743 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|1800799024|366016|921020; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?+6uZKrS/rFG7MRbc+Kg/J4Ot96foh2BlZEiEN1Gc4OuIi39qI6yHkY4PEkfG?= =?us-ascii?Q?jA/PRoUyT1q+EIGXzX7t0ApHKIxeYDeEAl20/rgmrNPntcmc8Iivg+AMC3Lw?= =?us-ascii?Q?WOAXYZ1L6evCFL9T/bmJmFODQWdI2MH4oHxaX1HopkzRh91IxyGj+9peL8RV?= =?us-ascii?Q?9fSFLbno4AmTJ1fSiEIyyohEE064gEroDSm8XNq/MB8OEEMKSIj0TriT3Ssw?= =?us-ascii?Q?VortqCOKPGT2hv8cT1JPF44pejI0n1LsWAyFLR1gutdbrehx8vokd3u6KVqI?= =?us-ascii?Q?GgPqNSiI3YrCnTVCk+Tz3GPC0uJ5ZIw2yNL/us3HAvbtqxm100PlHVaPKdYe?= =?us-ascii?Q?2V7O9MKWWOQeDozXhmfBSqmAUYFqt1oH5vl0hq4APA24BfIXU+HWhyrEsuz+?= =?us-ascii?Q?wq0KXWfVrz0k82RLqVQZ/J4eKXhnTPDrOA7AaaickgYp0gQu1EwhU7ifJqHV?= =?us-ascii?Q?rqQ23Oqz9AD/ntgir855KqvA3s5THBgyckszj+V270BVldG2vBOQkZhkBQia?= =?us-ascii?Q?e/Tr7EoOPpmzkqHbtsiw0H68hrG0eqMTcuE6RCl6X8SmIa+hl/4V2lg41ndB?= =?us-ascii?Q?EuqxZyKqlPaSw2MjBw8QvvlvhUWWiUpC97XjmiGOrmU5+WoChm8Zts5NOuVt?= =?us-ascii?Q?A8Ki/8+2p7ahT+pimvRT2prrUpAQcHs5cA/Fx4PDgspNgL/FwIU7g7Hccb+H?= =?us-ascii?Q?aqiEjctDv2j+q294LXOSulq2fbOjnK1RZtOSSVSPy1WhZZ1Alz3sTuPF99tO?= =?us-ascii?Q?udZXTc4yis+0F+KaFGNDjVCDRJc+lOAocmfLdbmKFPwbbIjX3mPFE7zajQd5?= =?us-ascii?Q?qfo7G1Gfvl2ydc15Lpk0AS5qoTk9zwU54HbX9pg74pg8KTlE5hRf+Pa5ocmO?= =?us-ascii?Q?cHlGOnwIcdwg2nys8IcpbhTR9gkPhnBbid/BFf6fcWoN3cpUWYOylZPFUk03?= =?us-ascii?Q?HywyUTCqV/tnz1EUkeEfa291hPquovP6yvS2pL9GrerxVbQaXpVgzcTJLbIg?= =?us-ascii?Q?+8EYx0FmnXIPtYM4tFEY3dbme+u69ebfrxAQIKIQVCNwN+nDWv0FHN5t7hbf?= =?us-ascii?Q?RzY9nK7LKxC9CAhWPmtD/3kHWAlIPWMC61O7+alpounDIUmQRJl3h+RGct+y?= =?us-ascii?Q?6eCVWNGJZe+TjhGMDjxpT33n6ZSxSyUd84vSC8czzPWG4JS/IhDOzsvQ7yDq?= =?us-ascii?Q?56yBS+5JjbfIywsP/qiEAV728XS198lNNAFaAmKvHE9QknNxJQTLoX29Kgl8?= =?us-ascii?Q?5WqbAaDpYtAJhHDkND5bkNY455cdXsjt0XTjDWEbD9A1p/r6J4Yf7kIXShZF?= =?us-ascii?Q?/IouUBTbEb9MU4sDMEZz8eKXYjmBhmh/Da085uGm9qmpvGAmnhn/4G5G2r+R?= =?us-ascii?Q?jOMfKZc3Z1rR6MN+r7VxpOBLd+Th1pqOiT7cDdD8m9TfkRZoSjdxvivtFHft?= =?us-ascii?Q?YZW6miCbA+sYYRu1iRXK+Yn5tSAnkNiRV8QX/Ztjw3FUI5xRUysfEA=3D=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:PH7PR12MB5757.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(7416014)(1800799024)(366016)(921020);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?VaRDYGzlyPZ446X9cUFcoyBn4ZNwDpZl+Wn1SszX+e8axirqjy+8nBXqF20N?= =?us-ascii?Q?9aKtqeEbs0Jq8B7NCS/khSfonEox/eWnFHb6kOf966QYkVg/ET8FoUvKKqBs?= =?us-ascii?Q?V3SUQYRMwHo9y8uXX3e/RdmPF/pmvKhvdm0Spa61mTHuGNXRojfrkkKuaOSU?= =?us-ascii?Q?h8XBNpQ8CHYvnI0fJHnJc2RyhrnvyE/7KZ1ah9zOSyDw2D6SqGFiMN5S454N?= =?us-ascii?Q?9CUDie0XpqHCbhArrhnYqWk5yEPecvZDL/ADhpHbKH+XYubEnKJZraeW4uor?= =?us-ascii?Q?8lEdL7JGpHDvrxXJ2JFAXFwbTCLSVPFx+xVqa1N1ByLX1AIjkCTQXU9th90X?= =?us-ascii?Q?Z2YrgDTc9Lq2tLjCMN6A6a08AckBGfEaFnPnABhrWuGD6Dx/DUECxnxL4Smm?= =?us-ascii?Q?j180nsWWH0EKFvhP/fwJuixzWKoj1gQL4jWDtJBormM/nSEDvS2OKF+4SVZ9?= =?us-ascii?Q?zxK2/RCBGAAdzl8uV0xrBNNFkpkRAnlez7v2PCxpTEzfAuollRpheC1xqfht?= =?us-ascii?Q?3HjN8M0xDa4a0wr8CW65uMdG1gwwRt9qrU5jnaWgT2n5gicGXcRSAdrRhx2a?= =?us-ascii?Q?/XmGx/189f0TGjStS02vZHAtQ3L5vtToX4bGwAKFAUq479985fhUESmNttMA?= =?us-ascii?Q?6Q2vmD6vLFaWZGjjpAY3kTV5LVzOtcFf7w16oM+Hddu70x29LoG42kbaNSGm?= =?us-ascii?Q?1lJm3SXmb2ykDFOcSeYoT/GONUv2ewDZqf7gh4rs8oA1HHXhs5UqzY2r3QJQ?= =?us-ascii?Q?/VOjHqme64F4KM8eT/nGkZeryj3tBQZ00Om5sH++YOs4GxP4TthE7mjG9o1/?= =?us-ascii?Q?+NREwv4TdTRck4CFdchOtToNAVaFsdjRNTXm6iC4oYgvGhvrKLBErUBPlCJI?= =?us-ascii?Q?wM6BKktsOqabF1AcVFQDveUBB2ClsKavMm1QNxk7j1UDVX6t0mZUvW8c0AWL?= =?us-ascii?Q?WLBJfWnMeOHkFjgkxv8t8rAbh6zXRa4kufED8fRgRu6RJ8Q0rg4V81zwsWQT?= =?us-ascii?Q?MwbMgIvsOD+RH4YMG85gaI87L8e4duL2bwy3WNN0OLmdqp33FDZ/e4D97/GJ?= =?us-ascii?Q?0CXch8MTyrNJvUgn3Ngw98JmGAOCsAAcutZbuaLFNbdfEBQVicuoUpHDnIyg?= =?us-ascii?Q?QGZFX8AolMrtqoIKanyrjxkT9NbIT+G0mDhu5k2puPxH+HKCAAqSUi7cmpiC?= =?us-ascii?Q?0yMmruH1U6FSi9mmYUfHUd5wY9LGYJGPiGtc2LQZx6wYSmVeVdp8bWT04woR?= =?us-ascii?Q?Y2RtqT6jhSLWiIxIAfZJE+xzPzLHyCBCRVL1/0s1ZJyqd54qkpczi5Ee4MhE?= =?us-ascii?Q?EhR+5d9FZQG6oAWosn95jIuApoA/2+iVxkRbpYQMoQJDUzegBmVqovtmhCbS?= =?us-ascii?Q?G9bErnrTylhfFf0su/qLKauImRiYfpG2bv15tp1wxP6EIrokn7NqJBrpF2fV?= =?us-ascii?Q?dsytqeOyByJ1NKoQ3EBtGBe2ts4yIFdPjYbAd7U5CCARf9OsQF01liBQECFV?= =?us-ascii?Q?lmxnQJL/+8WPn4LrX61pDLzje5ZofXzt0MPyPqqFj6keh/m1o8Rf/X29YzX7?= =?us-ascii?Q?pyTTDKVvBwcaN+fjkt4=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: a297ed27-88a7-4d5b-a32b-08ddeed59743 X-MS-Exchange-CrossTenant-AuthSource: PH7PR12MB5757.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Sep 2025 12:45:29.4369 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: MpjeEYUBSzxhLqO+CFbT2nbSUFImadVFjjLPJK1baSpu1/pO2lfM5uOGwpCMQBKu X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN7PPF915F74166 X-Rspamd-Queue-Id: 9D9DB80004 X-Stat-Signature: r7nn41q59e5zu4i3g7r7e4y8apjhtcco X-Rspam-User: X-Rspamd-Server: rspam06 X-HE-Tag: 1757335534-732268 X-HE-Meta: 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 4GL3dVsH 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Sun, Sep 07, 2025 at 11:25:09PM +0900, Takashi Sakamoto wrote: > Hi, > > I'm a present maintainer of Linux FireWire subsystem, and recent years > have been working to modernize the subsystem. > > On Fri, Sep 05, 2025 at 14:43:24PM -0300, Jason Gunthorpe wrote: > > There is only one user I found of alloc_pages: > > > > drivers/firewire/ohci.c: ctx->pages[i] = dma_alloc_pages(dev, PAGE_SIZE, &dma_addr, > > > > And it deliberately uses page->private: > > > > set_page_private(ctx->pages[i], dma_addr); > > > > So it is correct to use the struct page API. > > I've already realized it, and it is in my TODO list to use modern > alternative APIs to replace it (but not yet). If you know some > candidates for this purpose, it is really helpful to accomplish it. I think for now it is probably OKish, but in the medium/longer term this probably wants to have its own memdesc like other cases. Ie instead of using page->private you'd have a struct ohci_desc { unsigned long __page_flags; dma_addr_t dma_addr; [..] }; And instead of using page->private you'd use ohci_desc::dma_addr. This would require changing dma_alloc_pages() to be able to allocate the frozen memdescs.. Which we are not quite there yet, but maybe come back to this in 2026? Jason