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=-5.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham 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 9E0D6C433E1 for ; Thu, 21 May 2020 11:12:42 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 62B48207D3 for ; Thu, 21 May 2020 11:12:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="LbQZQM+G" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 62B48207D3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 2EC988933A; Thu, 21 May 2020 11:12:42 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id RJpPcG2Trd07; Thu, 21 May 2020 11:12:41 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by hemlock.osuosl.org (Postfix) with ESMTP id 1BA03892B1; Thu, 21 May 2020 11:12:41 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id F2F08C088A; Thu, 21 May 2020 11:12:40 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists.linuxfoundation.org (Postfix) with ESMTP id 51493C0176 for ; Thu, 21 May 2020 11:12:39 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id 2E69E24F92 for ; Thu, 21 May 2020 11:12:39 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 5mD2UuncFfwO for ; Thu, 21 May 2020 11:12:38 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by silver.osuosl.org (Postfix) with ESMTPS id 65A8E204A9 for ; Thu, 21 May 2020 11:12:38 +0000 (UTC) Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 155D420721; Thu, 21 May 2020 11:12:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590059558; bh=iYAjQM9yDvPql0mmE1wLbplsG3C1/FtvidpyoFZTNcE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=LbQZQM+GNTzrdOvhJbIb17KBDxPUiI5biwavwK0ds9PBU1FY7uibn+697skdDAIVQ yFXwMF5VvH/1rukebrLHWPGWqFtQ3+3TV0Kj0D1fp7w/HPbsd6cZlPIsSXZgvG/azC D0cHphBjPJAlwYQJ5TJAw32lHV/7I7vDY2pYw23U= Date: Thu, 21 May 2020 12:12:31 +0100 From: Will Deacon To: Jean-Philippe Brucker Subject: Re: [PATCH v7 18/24] iommu/arm-smmu-v3: Add support for Hardware Translation Table Update Message-ID: <20200521111231.GA5949@willie-the-truck> References: <20200519175502.2504091-1-jean-philippe@linaro.org> <20200519175502.2504091-19-jean-philippe@linaro.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200519175502.2504091-19-jean-philippe@linaro.org> User-Agent: Mutt/1.10.1 (2018-07-13) Cc: devicetree@vger.kernel.org, kevin.tian@intel.com, jgg@ziepe.ca, linux-pci@vger.kernel.org, fenghua.yu@intel.com, hch@infradead.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, zhangfei.gao@linaro.org, catalin.marinas@arm.com, felix.kuehling@amd.com, robin.murphy@arm.com, christian.koenig@amd.com, linux-arm-kernel@lists.infradead.org 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-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Tue, May 19, 2020 at 07:54:56PM +0200, Jean-Philippe Brucker wrote: > If the SMMU supports it and the kernel was built with HTTU support, > enable hardware update of access and dirty flags. This is essential for > shared page tables, to reduce the number of access faults on the fault > queue. Normal DMA with io-pgtables doesn't currently use the access or > dirty flags. > > 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. > > Signed-off-by: Jean-Philippe Brucker > --- > drivers/iommu/arm-smmu-v3.c | 24 +++++++++++++++++++++++- > 1 file changed, 23 insertions(+), 1 deletion(-) How does this work if the SMMU isn't cache coherent? I'm guessing we don't want to enable any SVA stuff in that case, but I couldn't spot where that was being enforced. Did I just miss it? Will _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu