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=-11.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,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 C4DBDC4338F for ; Wed, 11 Aug 2021 15:55:23 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 6F87F60F46 for ; Wed, 11 Aug 2021 15:55:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 6F87F60F46 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=74f68/3FMcnlSrnELsszLr4K6POnKz0OGwRv2XqmcY4=; b=ES1Z66hvHhkOinA117YrC2q1xE eP8cJz3gx+ARm0mpu8aTg0ru4OwJCiSkK0AsKPifh6e3AKzE+0OPvv2Oo2iT63wlDkPQHJ+mH2SRJ Epe+g1fdjH7gGyoM+x8otRFMmwlrpZ+x3JYt6Yz8ERUfYlE2+ntLBlpSOcBfv5zsS8seBPIMKY5t9 XmWiAUmFH2m4GB8m/9kArkKK1aKBgVy60P6uV0d+XMP+KmAw94zxS4LemZs67EgRQ3PGGSc4J58sn POUqDKgKgiup2WIHgm7ZBix43fNwzyMxuUadBp8S3yAwMWS/F2IDetEccjjCUx45I3w1bvenYJxoh 0iJ8ArIA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mDqXu-007cRy-QC; Wed, 11 Aug 2021 15:53:34 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mDqXq-007cR9-MH for linux-arm-kernel@lists.infradead.org; Wed, 11 Aug 2021 15:53:32 +0000 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210811_085330_832260_462F1416 X-CRM114-Status: GOOD ( 22.80 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Bjorn Andersson , Tomasz Figa , linux-arm-msm@vger.kernel.org, Joerg Roedel , Doug Anderson , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Thierry Reding , linux-arm-kernel@lists.infradead.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel