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=2.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,UNWANTED_LANGUAGE_BODY,URIBL_BLOCKED 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 DFA22C28CF6 for ; Tue, 24 Jul 2018 22:25:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6E14D20874 for ; Tue, 24 Jul 2018 22:25:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6E14D20874 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388851AbeGXXdt (ORCPT ); Tue, 24 Jul 2018 19:33:49 -0400 Received: from foss.arm.com ([217.140.101.70]:58470 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388659AbeGXXdt (ORCPT ); Tue, 24 Jul 2018 19:33:49 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 069CE15A2; Tue, 24 Jul 2018 15:25:13 -0700 (PDT) Received: from [192.168.1.123] (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1C1953F5B3; Tue, 24 Jul 2018 15:25:10 -0700 (PDT) Subject: Re: [PATCH v3 4/6] iommu/io-pgtable-arm: add support for non-strict mode To: Zhen Lei , Jean-Philippe Brucker , Will Deacon , Joerg Roedel , linux-arm-kernel , iommu , linux-kernel References: <1531376312-2192-1-git-send-email-thunder.leizhen@huawei.com> <1531376312-2192-5-git-send-email-thunder.leizhen@huawei.com> From: Robin Murphy Message-ID: <89cc2201-99ab-3f3b-a2d1-1766515d4375@arm.com> Date: Tue, 24 Jul 2018 23:25:14 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <1531376312-2192-5-git-send-email-thunder.leizhen@huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018-07-12 7:18 AM, Zhen Lei wrote: > To support the non-strict mode, now we only tlbi and sync for the strict > mode. But for the non-leaf case, always follow strict mode. > > Use the lowest bit of the iova parameter to pass the strict mode: > 0, IOMMU_STRICT; > 1, IOMMU_NON_STRICT; > Treat 0 as IOMMU_STRICT, so that the unmap operation can compatible with > other IOMMUs which still use strict mode. > > Signed-off-by: Zhen Lei > --- > drivers/iommu/io-pgtable-arm.c | 23 ++++++++++++++--------- > 1 file changed, 14 insertions(+), 9 deletions(-) > > diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c > index 010a254..9234db3 100644 > --- a/drivers/iommu/io-pgtable-arm.c > +++ b/drivers/iommu/io-pgtable-arm.c > @@ -292,7 +292,7 @@ static void __arm_lpae_set_pte(arm_lpae_iopte *ptep, arm_lpae_iopte pte, > > static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable *data, > unsigned long iova, size_t size, int lvl, > - arm_lpae_iopte *ptep); > + arm_lpae_iopte *ptep, int strict); > > static void __arm_lpae_init_pte(struct arm_lpae_io_pgtable *data, > phys_addr_t paddr, arm_lpae_iopte prot, > @@ -334,7 +334,7 @@ static int arm_lpae_init_pte(struct arm_lpae_io_pgtable *data, > size_t sz = ARM_LPAE_BLOCK_SIZE(lvl, data); > > tblp = ptep - ARM_LPAE_LVL_IDX(iova, lvl, data); > - if (WARN_ON(__arm_lpae_unmap(data, iova, sz, lvl, tblp) != sz)) > + if (WARN_ON(__arm_lpae_unmap(data, iova, sz, lvl, tblp, IOMMU_STRICT) != sz)) > return -EINVAL; > } > > @@ -531,7 +531,7 @@ static void arm_lpae_free_pgtable(struct io_pgtable *iop) > static size_t arm_lpae_split_blk_unmap(struct arm_lpae_io_pgtable *data, > unsigned long iova, size_t size, > arm_lpae_iopte blk_pte, int lvl, > - arm_lpae_iopte *ptep) > + arm_lpae_iopte *ptep, int strict) DMA code should never ever be splitting blocks anyway, and frankly the TLB maintenance here is dodgy enough (since we can't reasonably do break-before make as VMSA says we should) that I *really* don't want to introduce any possibility of making it more asynchronous. I'd much rather just hard-code the expectation of strict == true for this. Robin. > { > struct io_pgtable_cfg *cfg = &data->iop.cfg; > arm_lpae_iopte pte, *tablep; > @@ -576,15 +576,18 @@ static size_t arm_lpae_split_blk_unmap(struct arm_lpae_io_pgtable *data, > } > > if (unmap_idx < 0) > - return __arm_lpae_unmap(data, iova, size, lvl, tablep); > + return __arm_lpae_unmap(data, iova, size, lvl, tablep, strict); > > io_pgtable_tlb_add_flush(&data->iop, iova, size, size, true); > + if (!strict) > + io_pgtable_tlb_sync(&data->iop); > + > return size; > } > > static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable *data, > unsigned long iova, size_t size, int lvl, > - arm_lpae_iopte *ptep) > + arm_lpae_iopte *ptep, int strict) > { > arm_lpae_iopte pte; > struct io_pgtable *iop = &data->iop; > @@ -609,7 +612,7 @@ static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable *data, > io_pgtable_tlb_sync(iop); > ptep = iopte_deref(pte, data); > __arm_lpae_free_pgtable(data, lvl + 1, ptep); > - } else { > + } else if (strict) { > io_pgtable_tlb_add_flush(iop, iova, size, size, true); > } > > @@ -620,25 +623,27 @@ static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable *data, > * minus the part we want to unmap > */ > return arm_lpae_split_blk_unmap(data, iova, size, pte, > - lvl + 1, ptep); > + lvl + 1, ptep, strict); > } > > /* Keep on walkin' */ > ptep = iopte_deref(pte, data); > - return __arm_lpae_unmap(data, iova, size, lvl + 1, ptep); > + return __arm_lpae_unmap(data, iova, size, lvl + 1, ptep, strict); > } > > static size_t arm_lpae_unmap(struct io_pgtable_ops *ops, unsigned long iova, > size_t size) > { > + int strict = ((iova & IOMMU_STRICT_MODE_MASK) == IOMMU_STRICT); > struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops); > arm_lpae_iopte *ptep = data->pgd; > int lvl = ARM_LPAE_START_LVL(data); > > + iova &= ~IOMMU_STRICT_MODE_MASK; > if (WARN_ON(iova >= (1ULL << data->iop.cfg.ias))) > return 0; > > - return __arm_lpae_unmap(data, iova, size, lvl, ptep); > + return __arm_lpae_unmap(data, iova, size, lvl, ptep, strict); > } > > static phys_addr_t arm_lpae_iova_to_phys(struct io_pgtable_ops *ops, >