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 080CBE66882 for ; Fri, 19 Dec 2025 17:32:32 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5F25D6B00A9; Fri, 19 Dec 2025 12:32:32 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 575FB6B00AA; Fri, 19 Dec 2025 12:32:32 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 457806B00AC; Fri, 19 Dec 2025 12:32:32 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 345116B00A9 for ; Fri, 19 Dec 2025 12:32:32 -0500 (EST) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id E54ECC02D9 for ; Fri, 19 Dec 2025 17:32:31 +0000 (UTC) X-FDA: 84236914902.23.60BE452 Received: from mail-qv1-f49.google.com (mail-qv1-f49.google.com [209.85.219.49]) by imf20.hostedemail.com (Postfix) with ESMTP id B3B671C0025 for ; Fri, 19 Dec 2025 17:32:29 +0000 (UTC) Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=ziepe.ca header.s=google header.b="iNgE/d6c"; dmarc=none; spf=pass (imf20.hostedemail.com: domain of jgg@ziepe.ca designates 209.85.219.49 as permitted sender) smtp.mailfrom=jgg@ziepe.ca ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1766165549; a=rsa-sha256; cv=none; b=F1ehNZkbqjkLE33+BBMLmzO24IrhlVCWepPs7l64hGrh3qa2v4eqZgM8Ny62mNqO8Cu4yL XD5O3o5NQYogmLxusVCMd2N0zu/tSfPLGFdTo24eNwrfN4b6SBfOPJIDBxhJL96+ObPD87 ekmqm5qvMz0LERRK2NmzHAsKUAiK8jY= ARC-Authentication-Results: i=1; imf20.hostedemail.com; dkim=pass header.d=ziepe.ca header.s=google header.b="iNgE/d6c"; dmarc=none; spf=pass (imf20.hostedemail.com: domain of jgg@ziepe.ca designates 209.85.219.49 as permitted sender) smtp.mailfrom=jgg@ziepe.ca ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1766165549; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=1hC/VXab9lpTCQATnomkfbW2pa0Vc9kadnS6vaPWuw8=; b=eWfPnNCHTDS00fhrTMmwuhIgFXG+zWnXT+O12ahCOXlOUNnDc1Yveqru0hJWlhFXhOinqP uiom3JB1fPNcvj9MWJVUpd+V6IE7C67A0Ca49Z566JwRqjwiNxutIElZRiLVaZ//cHPANq ElOO6JguzueY7u+/2ANR3dyou9YwTps= Received: by mail-qv1-f49.google.com with SMTP id 6a1803df08f44-888310b91c5so26425726d6.1 for ; Fri, 19 Dec 2025 09:32:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; t=1766165549; x=1766770349; darn=kvack.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=1hC/VXab9lpTCQATnomkfbW2pa0Vc9kadnS6vaPWuw8=; b=iNgE/d6cYZxZGokALCoYysZO9uPVjQNg+5G28S/CZMfLoAL6zHdStXFFuV7vm89cr/ hNPeHDqkn7elkz1MYzh/fAvc5mbljgx7O5wmtnwsG3zL5JsdEZkIcD2y1cfYvJqsRUwo nmd1ymD0+fgPaoW+5CKXIowkZxEy2VYwGcLAXjya7B4RKQioU5S3wrdO30kxKoAX9x0T VYZOlxzxFCYH/Kv6rKNjsmC4wDRfLL6FYTzptzkPRRrwwesojxe9SUZIrBZ/Cd+njBLq WNVKT3APZjF5fH0Nr+3PJ6WJMpUZ7Omr8XikVwjBuZu2YW2PFJ1ucp0AaD3b4+s8P6wm x9qA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1766165549; x=1766770349; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=1hC/VXab9lpTCQATnomkfbW2pa0Vc9kadnS6vaPWuw8=; b=H8mzqS4FR58llOc5ZTqSF5AxAiQy9uxdxBKu6PH26ujA56Czk2Od6eTk8ZXt6yK4B6 tpoPgaafJ/6zw4EoE4DXIj+gKrBvujYzZcvLdXgg4bFjBL1d+p7mJCF52q6FhOos8i22 QYNLw6PuaXNK8NrlDebMnSH0vFIaaejD1vS/jUegL6iRL0FgWGCEa11vfafnKRhdMmQ1 jZDsidKr7TxVUiv5wJF+hmDJkKzuJvNd7qz/1PZ/t3/Q7xV8hmrwsTuSytHsUJzHfMr6 m9lcYbLFviRi0NFuwC6d3xv+9xPesttjomye8H4sF60XvUp7YQAmKzESHN3lirLYWGcb E3YA== X-Forwarded-Encrypted: i=1; AJvYcCV8MW9kctBGYARtu6sYso+U0F8H53dg8vwsTfwTKPE8VarRcLqIwg5u6YCdFyGhGs6a1i8lF6V9KQ==@kvack.org X-Gm-Message-State: AOJu0YzQVjtXXvvyazG2Gqqra6AiZMNmdhumrP41PMYSZfpj6yEL1czO tmMU1gHQu1ed4cH3cBT7PmYhsSiliBesHY76Y/Dv/tTKDPGPQzsm6f3D3VUTu9EGzAE= X-Gm-Gg: AY/fxX7KFmmkMJ5hqPvtXzx3YnknnPPftCv9gKu1DykINnNAG0glplTxhOHWFfL+SGt c8Auv4G5EHOfcTjWg16glT+vDI2RnnKGxoCXrpq2vr/aLH4rz2rz2XuSqxyXdOYRg6l6pL/0dlS gr6Ackt9PN83okaaDCae6iIZo5RAJCkNibfZXrx1m34mPOLU5F4QdonPQlCNs29ItP+xeymGQlG udSiV5Bf/CM8FwTxaExO7K2GptbScqNLFsx3hlDWwGA5kiqLVMmbe31NBf5jNRfOd3aMhm3zjA7 v8KM34NFkO0hW3RoGUmon+klIccm8LpIOehROAX0LZy+AOrP3S2GMhrrvQwOT7a7miybioT/5Wu ivTvy/RmEElrlxrrlekqfQAi08TMvrbAzHWJvwsaSyOODPKgB5h8EYSYSWJraKAV71UR7u43WB0 sZTSy4SFU3Howj7oyBY9+HbWht5j4lyyJBv8dQ+7wAyFfhj64ksii2JoFmA5T7YYRT+oA= X-Google-Smtp-Source: AGHT+IGYAWh2sxLwizpTExt2w6pCX2ECxkldvqQUVe1MFbSK91RMxz7SwBO+heTsOJkJoalFRECn7g== X-Received: by 2002:a05:620a:c50:b0:8b2:3484:8e22 with SMTP id af79cd13be357-8bee5dcdd8cmr986687885a.0.1766165548739; Fri, 19 Dec 2025 09:32:28 -0800 (PST) Received: from ziepe.ca (hlfxns017vw-47-55-120-4.dhcp-dynamic.fibreop.ns.bellaliant.net. [47.55.120.4]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-88d925f935asm23424216d6.0.2025.12.19.09.32.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Dec 2025 09:32:27 -0800 (PST) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1vWeL5-00000001b6X-0xBQ; Fri, 19 Dec 2025 13:32:27 -0400 Date: Fri, 19 Dec 2025 13:32:27 -0400 From: Jason Gunthorpe To: Boris Brezillon Cc: Alice Ryhl , Miguel Ojeda , Will Deacon , Daniel Almeida , Robin Murphy , Boqun Feng , Gary Guo , =?utf-8?B?QmrDtnJu?= Roy Baron , Benno Lossin , Andreas Hindborg , Trevor Gross , Danilo Krummrich , Joerg Roedel , Lorenzo Stoakes , "Liam R. Howlett" , Asahi Lina , linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, iommu@lists.linux.dev, linux-mm@kvack.org Subject: Re: [PATCH v4] io: add io_pgtable abstraction Message-ID: <20251219173227.GJ31492@ziepe.ca> References: <20251219-io-pgtable-v4-1-68aaa7a40380@google.com> <20251219140557.GH31492@ziepe.ca> <20251219161153.420d1c46@fedora> <20251219151434.GI31492@ziepe.ca> <20251219162734.46f3aa9d@fedora> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251219162734.46f3aa9d@fedora> X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: B3B671C0025 X-Stat-Signature: tbjhc8stmzhm8uydkkmya4orwfr38xbs X-Rspam-User: X-HE-Tag: 1766165549-669024 X-HE-Meta: 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 azcxHE0D cTjpatsBFgcDwgVqi7YBtbd7cd1B/fIcvxjLuDIAbVAgaiCfPylKZ+JjADrrnPpdEu0tDywq0oEXS2rtUwIfo7smNnSWDR9qAAf3Nb4C7/WIsy+BGIMAx/D9qV8DW1UlEeXHQuIwsThcFaznlbL8j31LCTf6lNsfcySwInEa8ehKOhf6fHRwMnPOPSgWDqxlw8v2LhdTI2I0yk8w3lK6dDFgTGEzxnmdUF2LOotVgyBTl+U1X48bHADWNumMqns4sagssochjuPjSnyxsRaQtYSlGUJqN/Z1JeN56A8J4XN6yAOntnkJDheaEBXphEfqtT5bA3IC9Q45F3jslDOibbdXPzEdcTKkGeCTbdqj6QdDUoreIxbx5Lb7nfClAJkhVv39KIo20vD79NLVDEBjbf4LUmCp0T0qSCmo8Ye7YxT1JX7mERVfG7FbF3uMSPGCbOPQQiqlqZSq067KA7lMBRn0/6g== 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 Fri, Dec 19, 2025 at 04:27:34PM +0100, Boris Brezillon wrote: > On Fri, 19 Dec 2025 11:14:34 -0400 > Jason Gunthorpe wrote: > > > On Fri, Dec 19, 2025 at 04:11:53PM +0100, Boris Brezillon wrote: > > > > > There's actually a confusion between TLB invalidation and L1/L2 cache > > > flush/invalidation. The things we can decide to flush/invalidate around > > > map/unmap ops are L1/L2 caches. The TLB invalidate, we don't have > > > direct control on: it happens as part of the LOCK+UNLOCK sequence, and > > > no matter what you execute (map or unmap), you have to surround it with > > > a LOCK/UNLOCK to provide support for atomic updates (GPU is blocked if > > > anything accesses the locked range while an update is on-going). > > > > That makes more sense, so these GPU drivers just flush the entire TLB > > every time they change it - built into the UNLOCK operation? > > I don't have implementation details, so I can't really tell what > happens internally. What's sure is that LOCK takes a range, so they > might be optimizing the TLB flush to only evict entries covered by this > range, dunno. So, I'd probably just simplify that comment: For the initial users of these rust bindings the GPU FW is managing the IOTLB and performs all required invalidations using a range. There is no need for it get ARM style invalidation instructions from the page table code. Jason