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=-11.6 required=3.0 tests=BAYES_00,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 382C3C2D0A3 for ; Thu, 12 Nov 2020 09:44:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D18C621D40 for ; Thu, 12 Nov 2020 09:44:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="NJxlZKiQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727838AbgKLJoD (ORCPT ); Thu, 12 Nov 2020 04:44:03 -0500 Received: from mail.kernel.org ([198.145.29.99]:40100 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727560AbgKLJoA (ORCPT ); Thu, 12 Nov 2020 04:44:00 -0500 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 131DA221FC; Thu, 12 Nov 2020 09:43:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605174239; bh=PX0Rx6DcDiPgOuXIk7NQwtEU8lgYXlKPndWTh8AkZDM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=NJxlZKiQ5RXRwLtdPQ973uyiOTFXEykVI1DX9HmOJRvYKPh3u0K8Cszg6f/NljKSF diotEEHr2Um5xjKVUnh/nL6p3VIaEvbDAD+193gZDC62PiTc8QjnvFILYIx2E6JRCJ 4k4dUTiNPZZmeB5XqjVkNNvPYbl6OpWNP6NBWtzY= Date: Thu, 12 Nov 2020 09:43:53 +0000 From: Will Deacon To: Sai Prakash Ranjan Cc: Robin Murphy , Joerg Roedel , Jordan Crouse , Rob Clark , iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, Akhil P Oommen , freedreno@lists.freedesktop.org, "Kristian H . Kristensen" , dri-devel@lists.freedesktop.org Subject: Re: [PATCHv7 1/7] iommu/io-pgtable-arm: Add support to use system cache Message-ID: <20201112094353.GB19049@willie-the-truck> References: <1d4979c0dcf649c5717605c598067b4b225ab9de.1604048969.git.saiprakash.ranjan@codeaurora.org> <20201110121855.GD16239@willie-the-truck> <329542c0c09054a46fa8d6d8f92ad739@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <329542c0c09054a46fa8d6d8f92ad739@codeaurora.org> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 11, 2020 at 11:32:42AM +0530, Sai Prakash Ranjan wrote: > On 2020-11-10 17:48, Will Deacon wrote: > > On Fri, Oct 30, 2020 at 02:53:08PM +0530, Sai Prakash Ranjan wrote: > > > Add a quirk IO_PGTABLE_QUIRK_SYS_CACHE to override the > > > attributes set in TCR for the page table walker when > > > using system cache. > > > > > > Signed-off-by: Sai Prakash Ranjan > > > --- > > > drivers/iommu/io-pgtable-arm.c | 7 ++++++- > > > include/linux/io-pgtable.h | 4 ++++ > > > 2 files changed, 10 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/iommu/io-pgtable-arm.c > > > b/drivers/iommu/io-pgtable-arm.c > > > index a7a9bc08dcd1..a356caf1683a 100644 > > > --- a/drivers/iommu/io-pgtable-arm.c > > > +++ b/drivers/iommu/io-pgtable-arm.c > > > @@ -761,7 +761,8 @@ arm_64_lpae_alloc_pgtable_s1(struct > > > io_pgtable_cfg *cfg, void *cookie) > > > > > > if (cfg->quirks & ~(IO_PGTABLE_QUIRK_ARM_NS | > > > IO_PGTABLE_QUIRK_NON_STRICT | > > > - IO_PGTABLE_QUIRK_ARM_TTBR1)) > > > + IO_PGTABLE_QUIRK_ARM_TTBR1 | > > > + IO_PGTABLE_QUIRK_SYS_CACHE)) > > > return NULL; > > > > > > data = arm_lpae_alloc_pgtable(cfg); > > > @@ -773,6 +774,10 @@ arm_64_lpae_alloc_pgtable_s1(struct > > > io_pgtable_cfg *cfg, void *cookie) > > > tcr->sh = ARM_LPAE_TCR_SH_IS; > > > tcr->irgn = ARM_LPAE_TCR_RGN_WBWA; > > > tcr->orgn = ARM_LPAE_TCR_RGN_WBWA; > > > + } else if (cfg->quirks & IO_PGTABLE_QUIRK_SYS_CACHE) { > > > + tcr->sh = ARM_LPAE_TCR_SH_OS; > > > + tcr->irgn = ARM_LPAE_TCR_RGN_NC; > > > + tcr->orgn = ARM_LPAE_TCR_RGN_WBWA; > > > > Given that this only applies in the case where then page-table walker is > > non-coherent, I think we'd be better off renaming the quirk to something > > like IO_PGTABLE_QUIRK_ARM_OUTER_WBWA and then rejecting it in the > > non-coherent case. > > > > Do you mean like below? > > diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c > index a7a9bc08dcd1..94de1f71db42 100644 > --- a/drivers/iommu/io-pgtable-arm.c > +++ b/drivers/iommu/io-pgtable-arm.c > @@ -776,7 +776,10 @@ arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg > *cfg, void *cookie) > } else { > tcr->sh = ARM_LPAE_TCR_SH_OS; > tcr->irgn = ARM_LPAE_TCR_RGN_NC; > - tcr->orgn = ARM_LPAE_TCR_RGN_NC; > + if (!(cfg->quirks & IO_PGTABLE_QUIRK_ARM_OUTER_WBWA)) > + tcr->orgn = ARM_LPAE_TCR_RGN_NC; > + else > + tcr->orgn = ARM_LPAE_TCR_RGN_WBWA; Yes, but rejecting the quirk if the walker is coherent (I accidentally said "non-coherent" earlier on). Will