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]) by smtp.lore.kernel.org (Postfix) with ESMTP id DF932C433FE for ; Thu, 21 Apr 2022 07:37:05 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 696996B0073; Thu, 21 Apr 2022 03:37:05 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 66B516B0074; Thu, 21 Apr 2022 03:37:05 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 50C746B0075; Thu, 21 Apr 2022 03:37:05 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.28]) by kanga.kvack.org (Postfix) with ESMTP id 4007F6B0073 for ; Thu, 21 Apr 2022 03:37:05 -0400 (EDT) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay11.hostedemail.com (Postfix) with ESMTP id 0F6C982C3E for ; Thu, 21 Apr 2022 07:37:05 +0000 (UTC) X-FDA: 79380080010.03.4DE34A9 Received: from mout.kundenserver.de (mout.kundenserver.de [212.227.126.131]) by imf19.hostedemail.com (Postfix) with ESMTP id 7AFFF1A0018 for ; Thu, 21 Apr 2022 07:37:02 +0000 (UTC) Received: from mail-wm1-f48.google.com ([209.85.128.48]) by mrelayeu.kundenserver.de (mreue009 [213.165.67.97]) with ESMTPSA (Nemesis) id 1M4s91-1niowr3vDL-0020V7 for ; Thu, 21 Apr 2022 09:37:02 +0200 Received: by mail-wm1-f48.google.com with SMTP id ay11-20020a05600c1e0b00b0038eb92fa965so5254150wmb.4 for ; Thu, 21 Apr 2022 00:37:02 -0700 (PDT) X-Gm-Message-State: AOAM5335wLgG2mYEwHkAlqmsGIHGMWCPsmKZlCLrzqsUq2lGuOT27DLG k4J34mMhZMBTGMoCQMbSkJCtr4UUNiZXMuzudDY= X-Google-Smtp-Source: ABdhPJwHFANIhlSxRKH9yHfX8gB2Ane77t+Nbt2ag7w+sIPoSWj1s9wj3aJHPT4PYoCntWM2lk8INTR7f05YbnZQfyw= X-Received: by 2002:a05:600c:4e4a:b0:392:88e1:74a7 with SMTP id e10-20020a05600c4e4a00b0039288e174a7mr7297619wmq.174.1650526622334; Thu, 21 Apr 2022 00:37:02 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Arnd Bergmann Date: Thu, 21 Apr 2022 09:36:46 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 07/10] crypto: Use ARCH_DMA_MINALIGN instead of ARCH_KMALLOC_MINALIGN To: Christoph Hellwig Cc: Arnd Bergmann , Ard Biesheuvel , Catalin Marinas , Herbert Xu , Will Deacon , Marc Zyngier , Greg Kroah-Hartman , Andrew Morton , Linus Torvalds , Linux Memory Management List , Linux ARM , Linux Kernel Mailing List , "David S. Miller" Content-Type: text/plain; charset="UTF-8" X-Provags-ID: V03:K1:NwwBMquakbbiStaIceMcZrxZkUwiVjPkExZ+s6vTvATT4R2Trq/ hC27gj+k7o7SgYHbCHZcTAKEUhv00y+zdHhSC05Fef1QrvxjZWLdVFV0oSiTI7Otxde+1B+ X1kEG6N1LkzaCorz6vwvAjz9bIv4FfvIgsaHXA1DbenLYvgsgiA63Nif5D1RDLEL5uTKOwT DBYvhhseDN9XGh0d1OX1Q== X-UI-Out-Filterresults: notjunk:1;V03:K0:wPsTZGKdr7I=:3msqdEKAFkdnDZBfo32bl4 CVt0rX6cjrN0WDVyhXkdesLrIYO9BbSGT7wkHzAfwnCwNoUrYoMaZZJeLJ98a8ny/wMO98aJ/ kn1U7JyLtOdgJbafiDiQ4fI1kQV3RMGmEs5QoAtRUXMavd6oRo5g0oXGdeREP5MDHz2wYC1YC GbVxVQwljo3y18B9lgDwq1GUavBevaVJafIrtUnVaSMtaVbLOAvmwZGeolvluwqo7Jl0EmqHf 0nEubNmVBXGF9mko6n4wPB09uYZ8CBqdiX9hQjbVJiWJbyFZTtBB2tBdm+qY7jA2nykavPm1z D/gBr45o247sgTxtCQNnzejxFG1x+Ikh1lt8xDB4eGNMDvyPmZDfO769fR2Kr2jdlnC3X/2yK /fgRdD30cqa8DU+69xQZ2tFttQRnhR73nsOEnURAfI3mVf91n33ZsL7f96dhBuijMQpoeCq6w mimMoiCnF1rL/aFLm/j//cOe4Lfzf3hV0lOxWptuF0Bg9JIYdag4umKi0Ddnxr6wHF2qkxMW2 fNhptLvHnoaMJ+6XX7Ov+z/aF4rDkwuBEKNqQBMOocNZlilgcM4OMo/wHG/iJIfuNKBifC5lT ypU4q8eeSUnZX3FpDhPZ+bxpltCA/XyXkRN1ajOnGP4G0wORqe2wj+Q1yC1ZASbMkMrUmzoSX 53YmGRT3nlKNvYGBdLgiSEalekVR13Fn0SPZZBfMhrnpD7B1xKKS4ou39Vi4CDKlWMB7TklEJ mSch9zg6IHfc4baYYdGPqd6KBNUsStpFT02c9JSI5rF4YTWuvucwP7iEluXbgiDTb3Fq7ixyW Vy+KxkM2K+N/SfETEqyY/8501fzQDm2j0jHp9djfLUlCXhdgVg= X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 7AFFF1A0018 X-Rspam-User: Authentication-Results: imf19.hostedemail.com; dkim=none; dmarc=none; spf=none (imf19.hostedemail.com: domain of arnd@arndb.de has no SPF policy when checking 212.227.126.131) smtp.mailfrom=arnd@arndb.de X-Stat-Signature: ed1oefd9n47p1r9u7qe7656rmgpwqsoj X-HE-Tag: 1650526622-367781 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: On Thu, Apr 21, 2022 at 9:20 AM Christoph Hellwig wrote: > > Btw, there is another option: Most real systems already require having > swiotlb to bounce buffer in some cases. We could simply force bounce > buffering in the dma mapping code for too small or not properly aligned > transfers and just decrease the dma alignment. I like the idea because these days we already rely on bounce buffering for sub-page buffers in many iommu based cases for strict isolation purposes, as well as most 64-bit machines that lack an iommu. Does this work on all 32-bit architectures as well? I see that you added swiotlb for ARM LPASE systems in 2019, but I don't know if that has any additional requirements for the other 32-bit architectures that don't select SWIOTLB today. Arnd