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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, 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 8D19BC4338F for ; Wed, 11 Aug 2021 15:53:36 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (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 202E060E97 for ; Wed, 11 Aug 2021 15:53:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 202E060E97 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id E231583AF8; Wed, 11 Aug 2021 15:53:35 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id iDFUdZmQfUiM; Wed, 11 Aug 2021 15:53:32 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp1.osuosl.org (Postfix) with ESMTPS id C0D0C83AF9; Wed, 11 Aug 2021 15:53:31 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id A0557C0010; Wed, 11 Aug 2021 15:53:31 +0000 (UTC) Received: from smtp4.osuosl.org (smtp4.osuosl.org [IPv6:2605:bc80:3010::137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 2308EC000E for ; Wed, 11 Aug 2021 15:53:30 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id 2081140570 for ; Wed, 11 Aug 2021 15:53:30 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id X92uWdvZh1-5 for ; Wed, 11 Aug 2021 15:53:29 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp4.osuosl.org (Postfix) with ESMTP id 6B1B940553 for ; Wed, 11 Aug 2021 15:53:29 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id CCA36106F; Wed, 11 Aug 2021 08:53:28 -0700 (PDT) Received: from [10.57.36.146] (unknown [10.57.36.146]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 00EEA3F718; Wed, 11 Aug 2021 08:53:26 -0700 (PDT) Subject: Re: [PATCHv4] iommu/arm-smmu: Optimize ->tlb_flush_walk() for qcom implementation To: Will Deacon , Sai Prakash Ranjan References: <20210811060725.25221-1-saiprakash.ranjan@codeaurora.org> <20210811103011.GD4426@willie-the-truck> From: Robin Murphy Message-ID: <7be65300-632a-8626-e5da-13bc9e276763@arm.com> Date: Wed, 11 Aug 2021 16:53:25 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: <20210811103011.GD4426@willie-the-truck> Content-Language: en-GB Cc: linux-arm-msm@vger.kernel.org, Doug Anderson , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Thierry Reding , 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-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On 2021-08-11 11:30, Will Deacon wrote: > On Wed, Aug 11, 2021 at 11:37:25AM +0530, Sai Prakash Ranjan wrote: >> diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c >> index f7da8953afbe..3904b598e0f9 100644 >> --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c >> +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c >> @@ -327,9 +327,16 @@ static void arm_smmu_tlb_inv_range_s2(unsigned long iova, size_t size, >> static void arm_smmu_tlb_inv_walk_s1(unsigned long iova, size_t size, >> size_t granule, void *cookie) >> { >> - arm_smmu_tlb_inv_range_s1(iova, size, granule, cookie, >> - ARM_SMMU_CB_S1_TLBIVA); >> - arm_smmu_tlb_sync_context(cookie); >> + struct arm_smmu_domain *smmu_domain = cookie; >> + struct arm_smmu_cfg *cfg = &smmu_domain->cfg; >> + >> + if (cfg->flush_walk_prefer_tlbiasid) { >> + arm_smmu_tlb_inv_context_s1(cookie); > > Hmm, this introduces an unconditional wmb() if tlbiasid is preferred. I > think that should be predicated on ARM_SMMU_FEAT_COHERENT_WALK like it is > for the by-VA ops. Worth doing as a separate patch. > >> + } else { >> + arm_smmu_tlb_inv_range_s1(iova, size, granule, cookie, >> + ARM_SMMU_CB_S1_TLBIVA); >> + arm_smmu_tlb_sync_context(cookie); >> + } >> } >> >> static void arm_smmu_tlb_add_page_s1(struct iommu_iotlb_gather *gather, >> @@ -765,8 +772,10 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain, >> .iommu_dev = smmu->dev, >> }; >> >> - if (!iommu_get_dma_strict(domain)) >> + if (!iommu_get_dma_strict(domain)) { >> pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_NON_STRICT; >> + cfg->flush_walk_prefer_tlbiasid = true; > > This is going to interact badly with Robin's series to allow dynamic > transition to non-strict mode, as we don't have a mechanism to switch > over to the by-ASID behaviour. Yes, it should _work_, but it's ugly having > different TLBI behaviour just because of the how the domain became > non-strict. > > Robin -- I think this originated from your idea at [1]. Any idea how to make > it work with your other series, or shall we drop this part for now and leave > the TLB invalidation behaviour the same for now? Yeah, I'd say drop it - I'm currently half an hour into a first attempt at removing io_pgtable_tlb_flush_walk() entirely, which would make it moot for non-strict anyway. Robin. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu