From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Schmitz Subject: Re: [PATCH v2 3/3] arch/*/: remove CONFIG_VIRT_TO_BUS Date: Fri, 1 Jul 2022 07:21:53 +1200 Message-ID: References: <20220617125750.728590-1-arnd@kernel.org> <20220617125750.728590-4-arnd@kernel.org> <6ba86afe-bf9f-1aca-7af1-d0d348d75ffc@gmail.com> <9289fd82-285c-035f-5355-4d70ce4f87b0@gmail.com> <9f812d3d-0fcd-46e6-6d7e-6d4bf66f24ab@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=l005vzshb3NCX9X2VM+PRHsKSH+cwoE8+hpxYOqA4As=; b=Ryekk371jQ1QiVX/pYGZ1Fxnqlqp0Twrw4fdw7rwXdWNZd8linJuCpYUZVY+Q0iPyf MQtHmLDECOfQliv0UkVXxBpP1oEkjtqBA+m+vXUw7eTKeZQm+pLSA86FeQvRbD+P0G11 vgeXEKD6isj/F1Ee/eKIdEVU/vkXQM/wI5kbLINfslHCrrzOI44xnSHDUGCbhqvwVddM j34tTrE1+UG2QZsXwyPCsEBPg2rxRpPI3L1pBalHzCrfK7rgExkmBMwK3cN5a26ttPxc nujxQaN3aRGOZJRNQAC0dUIV+4oE8cjHO5gI3kzVIoJ4RZMsmRwklddwhggK/OvBOGty iS1w== Content-Language: en-US In-Reply-To: List-ID: Content-Type: text/plain; charset="utf-8"; format="flowed" To: Christoph Hellwig Cc: Arnd Bergmann , Geert Uytterhoeven , scsi , Linux Kernel Mailing List , Arnd Bergmann , Jakub Kicinski , Marek Szyprowski , Robin Murphy , Linux IOMMU , Khalid Aziz , "Maciej W . Rozycki" , Matt Wang , Miquel van Smoorenburg , Mark Salyzyn , linuxppc-dev , Linux-Arch , alpha , linux-m68k , Parisc List Hi Christoph, On 29/06/22 18:21, Christoph Hellwig wrote: > On Wed, Jun 29, 2022 at 11:09:00AM +1200, Michael Schmitz wrote: >> And all SCSI buffers are allocated using kmalloc? No way at all for user >> space to pass unaligned data? > Most that you will see actually comes from the page allocator. But > the block layer has a dma_alignment limit, and when userspace sends > I/O that is not properly aligned it will be bounce buffered before > it it sent to the driver. That limit is set to L1_CACHE_BYTES on m68k so we're good here. Thanks,     Michael 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5EF6CCCA47B for ; Thu, 30 Jun 2022 19:22:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236635AbiF3TWH (ORCPT ); Thu, 30 Jun 2022 15:22:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55482 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235833AbiF3TWG (ORCPT ); Thu, 30 Jun 2022 15:22:06 -0400 Received: from mail-pg1-x529.google.com (mail-pg1-x529.google.com [IPv6:2607:f8b0:4864:20::529]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 917CF42EDA; Thu, 30 Jun 2022 12:22:05 -0700 (PDT) Received: by mail-pg1-x529.google.com with SMTP id r66so272772pgr.2; Thu, 30 Jun 2022 12:22:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=l005vzshb3NCX9X2VM+PRHsKSH+cwoE8+hpxYOqA4As=; b=Ryekk371jQ1QiVX/pYGZ1Fxnqlqp0Twrw4fdw7rwXdWNZd8linJuCpYUZVY+Q0iPyf MQtHmLDECOfQliv0UkVXxBpP1oEkjtqBA+m+vXUw7eTKeZQm+pLSA86FeQvRbD+P0G11 vgeXEKD6isj/F1Ee/eKIdEVU/vkXQM/wI5kbLINfslHCrrzOI44xnSHDUGCbhqvwVddM j34tTrE1+UG2QZsXwyPCsEBPg2rxRpPI3L1pBalHzCrfK7rgExkmBMwK3cN5a26ttPxc nujxQaN3aRGOZJRNQAC0dUIV+4oE8cjHO5gI3kzVIoJ4RZMsmRwklddwhggK/OvBOGty iS1w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=l005vzshb3NCX9X2VM+PRHsKSH+cwoE8+hpxYOqA4As=; b=OZ1vQKOIwXQzF+ihG5piJ2OLW8zgQeKk23bWieZNXHK+d5dt/GTKu2oIWFPKf1rIUx o/O185/IDs3/lFjXVK59ptN4UNI3KqRm2TOQK4vBAPokDi2L6d3JtaPrEyecW9Q5x7Um +PFkEGfnErMdVrSVBivJynFd1VPL7Cl3K3pnNwgivCTZmR/Um+BFK2/BLDUAd5LolYj2 h2DOOp9FmD8IOpW33ME78lqFnCef4o+8CeirCCmEuQWRqWhE1aSjhs83AYn7X7kOf4kp Q7XXXxzYtBJnhFqIJfw17rct71JBpd/PrtxN2UqaKlEak1/VPmC2Czx9MtqJWtHXCPZq cOXg== X-Gm-Message-State: AJIora9K4nozs8s+qe8k7LWArsdT1riIp9llWiSy+Nrr0LGYf6UkHf44 ZYPSEhOYB/yAM0jKaVHigJA= X-Google-Smtp-Source: AGRyM1slOrPQAMr1SPYrSza35gnZ53yO5OmKuyILVUgGuCU6HEAC2pr8Byjfbqxc2GodF/4gt0QEFw== X-Received: by 2002:a05:6a00:21c8:b0:4fd:f89f:ec0e with SMTP id t8-20020a056a0021c800b004fdf89fec0emr17286632pfj.83.1656616925098; Thu, 30 Jun 2022 12:22:05 -0700 (PDT) Received: from ?IPV6:2001:df0:0:200c:b411:35d2:9458:bbe5? ([2001:df0:0:200c:b411:35d2:9458:bbe5]) by smtp.gmail.com with ESMTPSA id q13-20020a170902a3cd00b0016403cae7desm13907355plb.276.2022.06.30.12.21.56 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 30 Jun 2022 12:22:03 -0700 (PDT) Message-ID: Date: Fri, 1 Jul 2022 07:21:53 +1200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Subject: Re: [PATCH v2 3/3] arch/*/: remove CONFIG_VIRT_TO_BUS Content-Language: en-US To: Christoph Hellwig Cc: Arnd Bergmann , Geert Uytterhoeven , scsi , Linux Kernel Mailing List , Arnd Bergmann , Jakub Kicinski , Marek Szyprowski , Robin Murphy , Linux IOMMU , Khalid Aziz , "Maciej W . Rozycki" , Matt Wang , Miquel van Smoorenburg , Mark Salyzyn , linuxppc-dev , Linux-Arch , alpha , linux-m68k , Parisc List , Denis Efremov , Michael Ellerman , John Paul Adrian Glaubitz References: <20220617125750.728590-1-arnd@kernel.org> <20220617125750.728590-4-arnd@kernel.org> <6ba86afe-bf9f-1aca-7af1-d0d348d75ffc@gmail.com> <9289fd82-285c-035f-5355-4d70ce4f87b0@gmail.com> <9f812d3d-0fcd-46e6-6d7e-6d4bf66f24ab@gmail.com> From: Michael Schmitz In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org Hi Christoph, On 29/06/22 18:21, Christoph Hellwig wrote: > On Wed, Jun 29, 2022 at 11:09:00AM +1200, Michael Schmitz wrote: >> And all SCSI buffers are allocated using kmalloc? No way at all for user >> space to pass unaligned data? > Most that you will see actually comes from the page allocator. But > the block layer has a dma_alignment limit, and when userspace sends > I/O that is not properly aligned it will be bounce buffered before > it it sent to the driver. That limit is set to L1_CACHE_BYTES on m68k so we're good here. 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([2001:df0:0:200c:b411:35d2:9458:bbe5]) by smtp.gmail.com with ESMTPSA id q13-20020a170902a3cd00b0016403cae7desm13907355plb.276.2022.06.30.12.21.56 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 30 Jun 2022 12:22:03 -0700 (PDT) Message-ID: Date: Fri, 1 Jul 2022 07:21:53 +1200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Subject: Re: [PATCH v2 3/3] arch/*/: remove CONFIG_VIRT_TO_BUS Content-Language: en-US To: Christoph Hellwig References: <20220617125750.728590-1-arnd@kernel.org> <20220617125750.728590-4-arnd@kernel.org> <6ba86afe-bf9f-1aca-7af1-d0d348d75ffc@gmail.com> <9289fd82-285c-035f-5355-4d70ce4f87b0@gmail.com> <9f812d3d-0fcd-46e6-6d7e-6d4bf66f24ab@gmail.com> From: Michael Schmitz In-Reply-To: Cc: Linux-Arch , scsi , Michael Ellerman , Geert Uytterhoeven , Jakub Kicinski , Arnd Bergmann , Miquel van Smoorenburg , Denis Efremov , linux-m68k , John Paul Adrian Glaubitz , Khalid Aziz , Arnd Bergmann , Parisc List , Robin Murphy , Matt Wang , Linux Kernel Mailing List , Mark Salyzyn , Linux IOMMU , alpha , linuxppc-dev , "Maciej W . Rozycki" X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: base64 Content-Type: text/plain; charset="utf-8"; Format="flowed" Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" SGkgQ2hyaXN0b3BoLAoKT24gMjkvMDYvMjIgMTg6MjEsIENocmlzdG9waCBIZWxsd2lnIHdyb3Rl Ogo+IE9uIFdlZCwgSnVuIDI5LCAyMDIyIGF0IDExOjA5OjAwQU0gKzEyMDAsIE1pY2hhZWwgU2No bWl0eiB3cm90ZToKPj4gQW5kIGFsbCBTQ1NJIGJ1ZmZlcnMgYXJlIGFsbG9jYXRlZCB1c2luZyBr bWFsbG9jPyBObyB3YXkgYXQgYWxsIGZvciB1c2VyCj4+IHNwYWNlIHRvIHBhc3MgdW5hbGlnbmVk IGRhdGE/Cj4gTW9zdCB0aGF0IHlvdSB3aWxsIHNlZSBhY3R1YWxseSBjb21lcyBmcm9tIHRoZSBw YWdlIGFsbG9jYXRvci4gIEJ1dAo+IHRoZSBibG9jayBsYXllciBoYXMgYSBkbWFfYWxpZ25tZW50 IGxpbWl0LCBhbmQgd2hlbiB1c2Vyc3BhY2Ugc2VuZHMKPiBJL08gdGhhdCBpcyBub3QgcHJvcGVy bHkgYWxpZ25lZCBpdCB3aWxsIGJlIGJvdW5jZSBidWZmZXJlZCBiZWZvcmUKPiBpdCBpdCBzZW50 IHRvIHRoZSBkcml2ZXIuCgpUaGF0IGxpbWl0IGlzIHNldCB0byBMMV9DQUNIRV9CWVRFUyBvbiBt NjhrIHNvIHdlJ3JlIGdvb2QgaGVyZS4KClRoYW5rcywKCiDCoMKgwqAgTWljaGFlbAoKCl9fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCmlvbW11IG1haWxpbmcg bGlzdAppb21tdUBsaXN0cy5saW51eC1mb3VuZGF0aW9uLm9yZwpodHRwczovL2xpc3RzLmxpbnV4 Zm91bmRhdGlvbi5vcmcvbWFpbG1hbi9saXN0aW5mby9pb21tdQ== 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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AB7C8C433EF for ; Thu, 30 Jun 2022 19:22:51 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4LYpBd5t09z3dqF for ; Fri, 1 Jul 2022 05:22:49 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20210112 header.b=Ryekk371; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gmail.com (client-ip=2607:f8b0:4864:20::52d; helo=mail-pg1-x52d.google.com; envelope-from=schmitzmic@gmail.com; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20210112 header.b=Ryekk371; dkim-atps=neutral Received: from mail-pg1-x52d.google.com (mail-pg1-x52d.google.com [IPv6:2607:f8b0:4864:20::52d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4LYp9s1Cr7z3bkV for ; Fri, 1 Jul 2022 05:22:08 +1000 (AEST) Received: by mail-pg1-x52d.google.com with SMTP id g4so276529pgc.1 for ; Thu, 30 Jun 2022 12:22:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=l005vzshb3NCX9X2VM+PRHsKSH+cwoE8+hpxYOqA4As=; b=Ryekk371jQ1QiVX/pYGZ1Fxnqlqp0Twrw4fdw7rwXdWNZd8linJuCpYUZVY+Q0iPyf MQtHmLDECOfQliv0UkVXxBpP1oEkjtqBA+m+vXUw7eTKeZQm+pLSA86FeQvRbD+P0G11 vgeXEKD6isj/F1Ee/eKIdEVU/vkXQM/wI5kbLINfslHCrrzOI44xnSHDUGCbhqvwVddM j34tTrE1+UG2QZsXwyPCsEBPg2rxRpPI3L1pBalHzCrfK7rgExkmBMwK3cN5a26ttPxc nujxQaN3aRGOZJRNQAC0dUIV+4oE8cjHO5gI3kzVIoJ4RZMsmRwklddwhggK/OvBOGty iS1w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=l005vzshb3NCX9X2VM+PRHsKSH+cwoE8+hpxYOqA4As=; b=5JMkbT+tbVIx8xvtxLIy8wMoNcsvFklK2uAYceo00BDjLat4o2v0w1bFfND0GLKwdF 2NcnTYoUANhj7Gnc6O6JsXuSTHXFixyAqWEIck1U66Ctz2lMvS9J0UwiP7JH6gvXxKug Tq3b9PkeanBFokbQgAsRPiLpJx37R9VT4hg5vTRUM8DDtepMZv4xCC5WSRfGDqPhnxqH ovQ9tk5c4MWYew4r2+3kHDxAW0SMsD9dIBB64bIln5NeyBVlL8nhC3wVeXRiXohIng/z exFwqZ0dtj0hHv0RVcraZAAF7pKfnRqJsqdo1YevVlgXVMzhgNJDJU33v4hVlhDBGc8W woYQ== X-Gm-Message-State: AJIora/hiGwrHe07vgCuZc1dhJmkMZBAxTaQYLkdMRFH1/sxdkWhFHEV 21glCO1T/sYs7qsDOcIxZrc= X-Google-Smtp-Source: AGRyM1slOrPQAMr1SPYrSza35gnZ53yO5OmKuyILVUgGuCU6HEAC2pr8Byjfbqxc2GodF/4gt0QEFw== X-Received: by 2002:a05:6a00:21c8:b0:4fd:f89f:ec0e with SMTP id t8-20020a056a0021c800b004fdf89fec0emr17286632pfj.83.1656616925098; Thu, 30 Jun 2022 12:22:05 -0700 (PDT) Received: from ?IPV6:2001:df0:0:200c:b411:35d2:9458:bbe5? ([2001:df0:0:200c:b411:35d2:9458:bbe5]) by smtp.gmail.com with ESMTPSA id q13-20020a170902a3cd00b0016403cae7desm13907355plb.276.2022.06.30.12.21.56 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 30 Jun 2022 12:22:03 -0700 (PDT) Message-ID: Date: Fri, 1 Jul 2022 07:21:53 +1200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Subject: Re: [PATCH v2 3/3] arch/*/: remove CONFIG_VIRT_TO_BUS Content-Language: en-US To: Christoph Hellwig References: <20220617125750.728590-1-arnd@kernel.org> <20220617125750.728590-4-arnd@kernel.org> <6ba86afe-bf9f-1aca-7af1-d0d348d75ffc@gmail.com> <9289fd82-285c-035f-5355-4d70ce4f87b0@gmail.com> <9f812d3d-0fcd-46e6-6d7e-6d4bf66f24ab@gmail.com> From: Michael Schmitz In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Marek Szyprowski , Linux-Arch , scsi , Geert Uytterhoeven , Jakub Kicinski , Arnd Bergmann , Miquel van Smoorenburg , Denis Efremov , linux-m68k , John Paul Adrian Glaubitz , Khalid Aziz , Arnd Bergmann , Parisc List , Robin Murphy , Matt Wang , Linux Kernel Mailing List , Mark Salyzyn , Linux IOMMU , alpha , linuxppc-dev , "Maciej W . Rozycki" Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Hi Christoph, On 29/06/22 18:21, Christoph Hellwig wrote: > On Wed, Jun 29, 2022 at 11:09:00AM +1200, Michael Schmitz wrote: >> And all SCSI buffers are allocated using kmalloc? No way at all for user >> space to pass unaligned data? > Most that you will see actually comes from the page allocator. But > the block layer has a dma_alignment limit, and when userspace sends > I/O that is not properly aligned it will be bounce buffered before > it it sent to the driver. That limit is set to L1_CACHE_BYTES on m68k so we're good here. Thanks,     Michael