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 X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4E46AC4724C for ; Mon, 4 May 2020 16:36:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2AB5D2073E for ; Mon, 4 May 2020 16:36:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="ie+B2GQn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729702AbgEDQgG (ORCPT ); Mon, 4 May 2020 12:36:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43664 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728655AbgEDQgG (ORCPT ); Mon, 4 May 2020 12:36:06 -0400 Received: from mail-wr1-x441.google.com (mail-wr1-x441.google.com [IPv6:2a00:1450:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BFA51C061A0E for ; Mon, 4 May 2020 09:36:05 -0700 (PDT) Received: by mail-wr1-x441.google.com with SMTP id k1so21768422wrx.4 for ; Mon, 04 May 2020 09:36:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=Kl5xt2RTiHls+O1+Q0mo8BGBZHrI/nlz87XckVdCL1g=; b=ie+B2GQn0xE9JMPS6WF8xSO2Nb3Bq/Z6k2tntw6DutFeL6B9N4DPWVklfbNH4FnjaN t/FdSJpizjKhO8r7qWYTVIfj5tsh0Pyre46+FgQl/czQpS77eCKBAx7l0fXzqe5oMoJN srD+3dXDSZ1b8gDIeuMqWa8VuGSbuKmcgrBbHkW2D7hnwsTKJTes6Tw8OLdAyIdx9DsB hoEzpcXksJ2R6iwRnxlq1Hy4FZn4zTesCpGIx+6colQIPrKfNOCzGL8j1llscgSmy5B/ 5cauF3xMhaLP0b+LA+EjuCFSF43vHxSqLu21aoJ22r7LNEmYy0ZayKBxq3kGlHDl94a6 bpsg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=Kl5xt2RTiHls+O1+Q0mo8BGBZHrI/nlz87XckVdCL1g=; b=Dyanh3Ovwtyl+b5rLzAeG+BsPsRsD36eRAPVaOgCPmdnNZ9AeGHGpclqcf+ZQT+7kt umbnMPyJXFXaUuMyWiKzdE9eIEhyurFJ+dvLMKZ14gAx2+A1DGjh7rZvz7rvbNHL90oF atFXfvBQivAkNZO4L2msIPx479fDW2e/PZTi3FMekp+l7RBRxzyKB8X4+zhK0Oi5ZKfz 36KHwLqddI3dKk/UuZ579LVMlaV6aH8q/3XTZlZbCkPYlvB0PTGj0wZ8ZuRi3cSowtZt 8Z82ktCJaIuIfDoEs08AXqW1qMyMEEhRRTQ89hYLwrxLgmW0E+TVeThVmtNDjvMFwou3 20Tw== X-Gm-Message-State: AGi0PuaKT2mFRUt30rb7xBePQK6+py/L96UYJ7ow2ggreShyyKWT5k0k B45MdbgfNFkuMtRdHGxslGjpaA== X-Google-Smtp-Source: APiQypLd6vuo0MczRTSEBPfkSN84zUGhA14hWPmpa6tAN+ckf2g+Pmwwtmh//IwEutIpZVdWAHOW4g== X-Received: by 2002:a05:6000:10c4:: with SMTP id b4mr20516301wrx.203.1588610164479; Mon, 04 May 2020 09:36:04 -0700 (PDT) Received: from myrica ([2001:171b:226e:c200:c43b:ef78:d083:b355]) by smtp.gmail.com with ESMTPSA id z1sm13717417wmf.15.2020.05.04.09.36.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 04 May 2020 09:36:03 -0700 (PDT) Date: Mon, 4 May 2020 18:35:53 +0200 From: Jean-Philippe Brucker To: Prabhakar Kushwaha Cc: iommu@lists.linux-foundation.org, devicetree@vger.kernel.org, linux-arm-kernel , linux-pci@vger.kernel.org, linux-mm@kvack.org, joro@8bytes.org, Catalin Marinas , Will Deacon , Robin Murphy , kevin.tian@intel.com, baolu.lu@linux.intel.com, Jonathan.Cameron@huawei.com, jacob.jun.pan@linux.intel.com, christian.koenig@amd.com, felix.kuehling@amd.com, zhangfei.gao@linaro.org, jgg@ziepe.ca, xuzaibo@huawei.com, fenghua.yu@intel.com, hch@infradead.org, Ganapatrao Prabhakerrao Kulkarni , tanmay@marvell.com Subject: Re: [PATCH v6 19/25] iommu/arm-smmu-v3: Add support for Hardware Translation Table Update Message-ID: <20200504163553.GI170104@myrica> References: <20200430143424.2787566-1-jean-philippe@linaro.org> <20200430143424.2787566-20-jean-philippe@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Hi, On Mon, May 04, 2020 at 07:54:03PM +0530, Prabhakar Kushwaha wrote: > Dear Jean, > > On Thu, Apr 30, 2020 at 8:11 PM Jean-Philippe Brucker > wrote: > > > > If the SMMU supports it and the kernel was built with HTTU support, enable > > is there any framework/config for HTTU which must be enabled to use this patch? > > > > We can enable HTTU even if CPUs don't support it, because the kernel > > always checks for HW dirty bit and updates the PTE flags atomically. > > > I believe, this statement is valid in context of this patch-set only. > > One cannot use code snipped to test HTTU because exiting > io-pgtable-arm.c driver doesn't have framework to leverage HTTU > benfits. It by-default sets AF=1 and does not set DBM. Right, this patch only sets the hardware access and dirty flags for SVA (page tables shared with the CPU through iommu_bind*()), it doesn't enable anything for iommu_map/unmap(). Although I remember discussing it for VM migration, I don't know of any effort to use hardware access/dirty bits outside of SVA. Thanks, Jean