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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 6927EC4CECE for ; Tue, 17 Sep 2019 17:20:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 423BB214AF for ; Tue, 17 Sep 2019 17:20:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568740830; bh=LwKNamw9E4oxB1xQosrZOWdgQe92VETqR14nO7/u3js=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=DtHpvtIFIJtmwYXvNHfHLRWjfKqYfIjEPP0ToOIwsz5dfst7bac5tWLaXAAe/Z9/q MwiZp1xmXMRUhJkisVZdwdEtYGbwzALh7lNCUGq5ELiKb4wLShNeRk42LQLMLLeqYF d+gbtYCDC9v9KzZ4uK4MNdrKkIq1xDWWzqeCqvnM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730906AbfIQRU0 (ORCPT ); Tue, 17 Sep 2019 13:20:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:35634 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726744AbfIQRU0 (ORCPT ); Tue, 17 Sep 2019 13:20:26 -0400 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 C131A2053B; Tue, 17 Sep 2019 17:20:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568740825; bh=LwKNamw9E4oxB1xQosrZOWdgQe92VETqR14nO7/u3js=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=rJlZcMxRdss/C5nXphHfwkC11ZGWaIGXj83MelUvHMUq8I5gSd3pOW0iqwlgLnYdo Pgfz4aYr9Vr2E/C3Kyr89FbWapiRPt+LjPYLADOrXfUF9UNAeOhYsNWikqPBTHHu5L OYwtmN9LUz73DR3FfZJOVIZucfs12gYrcDTf4euM= Date: Tue, 17 Sep 2019 18:20:20 +0100 From: Will Deacon To: Jordan Crouse Cc: freedreno@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Robin Murphy , Joerg Roedel , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 5/7] iommu/arm-smmu: Support DOMAIN_ATTR_SPLIT_TABLES Message-ID: <20190917172020.hpv5qqdpihvqkehp@willie-the-truck> References: <1566327992-362-1-git-send-email-jcrouse@codeaurora.org> <1566327992-362-6-git-send-email-jcrouse@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1566327992-362-6-git-send-email-jcrouse@codeaurora.org> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On Tue, Aug 20, 2019 at 01:06:30PM -0600, Jordan Crouse wrote: > Support the DOMAIN_ATTR_SPLIT_TABLES attribute to let the leaf driver > know if split pagetables are enabled for the domain. > > Signed-off-by: Jordan Crouse > --- > > drivers/iommu/arm-smmu.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c > index 3f41cf7..6a512ff 100644 > --- a/drivers/iommu/arm-smmu.c > +++ b/drivers/iommu/arm-smmu.c > @@ -1442,6 +1442,9 @@ static int arm_smmu_domain_get_attr(struct iommu_domain *domain, > case DOMAIN_ATTR_NESTING: > *(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED); > return 0; > + case DOMAIN_ATTR_SPLIT_TABLES: > + *(int *)data = !!(smmu_domain->split_pagetables); > + return 0; Hmm. Could you move the setting of this attribute into arm_smmu_domain_set_attr() and reject it if the ias != 48 in there? That way the user of the domain can request this feature, rather than us enforcing it based on the compatible string. I'd also prefer to call it DOMAIN_ATTR_USE_TTBR1 instead, since it's pretty ARM specific at this point. Will