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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,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 6BB28C3A589 for ; Tue, 20 Aug 2019 16:50:11 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (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 3A35A2054F for ; Tue, 20 Aug 2019 16:50:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3A35A2054F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 05BA1CD5; Tue, 20 Aug 2019 16:50:11 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id CB369CB5 for ; Tue, 20 Aug 2019 16:50:09 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 536D812E for ; Tue, 20 Aug 2019 16:50:09 +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 DFC7928; Tue, 20 Aug 2019 09:50:08 -0700 (PDT) Received: from [10.1.197.57] (e110467-lin.cambridge.arm.com [10.1.197.57]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 359AD3F718; Tue, 20 Aug 2019 09:50:08 -0700 (PDT) Subject: Re: [PATCH 3/4] iommu/arm-smmu-v3: Fix ATC invalidation ordering wrt main TLBs To: Will Deacon , iommu@lists.linux-foundation.org References: <20190820154549.17018-1-will@kernel.org> <20190820154549.17018-4-will@kernel.org> From: Robin Murphy Message-ID: <983be1bc-1b51-77e7-5aee-8395a4f3724e@arm.com> Date: Tue, 20 Aug 2019 17:50:06 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190820154549.17018-4-will@kernel.org> Content-Language: en-GB Cc: Jean-Philippe Brucker X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 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" Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org Archived-At: List-Archive: On 20/08/2019 16:45, Will Deacon wrote: > When invalidating the ATC for an PCIe endpoint using ATS, we must take > care to complete invalidation of the main SMMU TLBs beforehand, otherwise > the device could immediately repopulate its ATC with stale translations. > > Hooking the ATC invalidation into ->unmap() as we currently do does the > exact opposite: it ensures that the ATC is invalidated *before* the > main TLBs, which is bogus. > > Move ATC invalidation into the actual (leaf) invalidation routines so > that it is always called after completing main TLB invalidation. > > Signed-off-by: Will Deacon > --- > drivers/iommu/arm-smmu-v3.c | 12 +++++------- > 1 file changed, 5 insertions(+), 7 deletions(-) > > diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c > index 9096eca0c480..183a1c121179 100644 > --- a/drivers/iommu/arm-smmu-v3.c > +++ b/drivers/iommu/arm-smmu-v3.c > @@ -1961,6 +1961,7 @@ static void arm_smmu_tlb_inv_context(void *cookie) > */ > arm_smmu_cmdq_issue_cmd(smmu, &cmd); > arm_smmu_cmdq_issue_sync(smmu); > + arm_smmu_atc_inv_domain(smmu_domain, 0, 0, 0); > } > > static void arm_smmu_tlb_inv_range(unsigned long iova, size_t size, > @@ -1969,7 +1970,7 @@ static void arm_smmu_tlb_inv_range(unsigned long iova, size_t size, > { > u64 cmds[CMDQ_BATCH_ENTRIES * CMDQ_ENT_DWORDS]; > struct arm_smmu_device *smmu = smmu_domain->smmu; > - unsigned long end = iova + size; > + unsigned long start = iova, end = iova + size; > int i = 0; > struct arm_smmu_cmdq_ent cmd = { > .tlbi = { > @@ -1998,6 +1999,8 @@ static void arm_smmu_tlb_inv_range(unsigned long iova, size_t size, > } > > arm_smmu_cmdq_issue_cmdlist(smmu, cmds, i, true); > + if (leaf) > + arm_smmu_atc_inv_domain(smmu_domain, 0, start, size); I still need to get up to speed on your cmdlist and unmap changes, but in isolation this "if (leaf)" guard looks a bit dodgy - in the case where io-pgtable goes to unmap a 2MB block, finds it's mapped as a table, and blows it away in one go, we'll only see a non-leaf TLBI call for that range, no? Tangentially, does arm_smmu_atc_inv_domain() really need to sync once for each individual master, or could that do better as well? Not something we should worry about right now, but now that I'm looking I may as well note it for the record. Robin. > } > > static void arm_smmu_tlb_inv_page_nosync(struct iommu_iotlb_gather *gather, > @@ -2416,18 +2419,13 @@ static int arm_smmu_map(struct iommu_domain *domain, unsigned long iova, > static size_t arm_smmu_unmap(struct iommu_domain *domain, unsigned long iova, > size_t size, struct iommu_iotlb_gather *gather) > { > - int ret; > struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain); > struct io_pgtable_ops *ops = smmu_domain->pgtbl_ops; > > if (!ops) > return 0; > > - ret = ops->unmap(ops, iova, size, gather); > - if (ret && arm_smmu_atc_inv_domain(smmu_domain, 0, iova, size)) > - return 0; > - > - return ret; > + return ops->unmap(ops, iova, size, gather); > } > > static void arm_smmu_flush_iotlb_all(struct iommu_domain *domain) > _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu