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=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 2EFABC10DCE for ; Fri, 6 Mar 2020 11:04:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0904B20866 for ; Fri, 6 Mar 2020 11:04:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726240AbgCFLEb (ORCPT ); Fri, 6 Mar 2020 06:04:31 -0500 Received: from szxga05-in.huawei.com ([45.249.212.191]:11192 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726025AbgCFLEb (ORCPT ); Fri, 6 Mar 2020 06:04:31 -0500 Received: from DGGEMS409-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 6BC413F04F0A13261840; Fri, 6 Mar 2020 19:04:28 +0800 (CST) Received: from [127.0.0.1] (10.177.223.23) by DGGEMS409-HUB.china.huawei.com (10.3.19.209) with Microsoft SMTP Server id 14.3.439.0; Fri, 6 Mar 2020 19:04:17 +0800 Subject: Re: [PATCH 00/14] iommu: Move iommu_fwspec out of 'struct device' To: Jean-Philippe Brucker CC: Joerg Roedel , , , , , , Lorenzo Pieralisi , Sudeep Holla , Rob Clark , Sean Paul , Will Deacon , Robin Murphy , Matthias Brugger , Thierry Reding , "Andy Gross" , Bjorn Andersson , Linuxarm References: <20200228150820.15340-1-joro@8bytes.org> <20200306100955.GB50020@myrica> From: Hanjun Guo Message-ID: Date: Fri, 6 Mar 2020 19:04:07 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: <20200306100955.GB50020@myrica> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.223.23] X-CFilter-Loop: Reflected Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On 2020/3/6 18:09, Jean-Philippe Brucker wrote: > On Fri, Mar 06, 2020 at 04:39:37PM +0800, Hanjun Guo wrote: >> Hi Joerg, >> >> On 2020/2/28 23:08, Joerg Roedel wrote: >>> Hi, >>> >>> here is a patch-set to rename iommu_param to dev_iommu and >>> establish it as a struct for generic per-device iommu-data. >>> Also move the iommu_fwspec pointer from struct device into >>> dev_iommu to have less iommu-related pointers in struct >>> device. >>> >>> The bigger part of this patch-set moves the iommu_priv >>> pointer from struct iommu_fwspec to dev_iommu, making is >>> usable for iommu-drivers which do not use fwspecs. >>> >>> The changes for that were mostly straightforward, except for >>> the arm-smmu (_not_ arm-smmu-v3) and the qcom iommu driver. >>> Unfortunatly I don't have the hardware for those, so any >>> testing of these drivers is greatly appreciated. >> >> I tested this patch set on Kunpeng 920 ARM64 server which >> using smmu-v3 with ACPI booting, but triggered a NULL >> pointer dereference and panic at boot: > > I think that's because patch 01/14 move the fwspec access too early. In > > err = pci_for_each_dma_alias(to_pci_dev(dev), > iort_pci_iommu_init, &info); > > if (!err && iort_pci_rc_supports_ats(node)) > dev->iommu_fwspec->flags |= IOMMU_FWSPEC_PCI_RC_ATS; > > the iommu_fwspec is only valid if iort_pci_iommu_init() initialized it > successfully, if err == 0. The following might fix it: Good catch :) > > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c > index 0e981d7f3c7d..7d04424189df 100644 > --- a/drivers/acpi/arm64/iort.c > +++ b/drivers/acpi/arm64/iort.c > @@ -1015,7 +1015,7 @@ const struct iommu_ops *iort_iommu_configure(struct device *dev) > return ops; > > if (dev_is_pci(dev)) { > - struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); > + struct iommu_fwspec *fwspec; > struct pci_bus *bus = to_pci_dev(dev)->bus; > struct iort_pci_alias_info info = { .dev = dev }; > > @@ -1028,7 +1028,8 @@ const struct iommu_ops *iort_iommu_configure(struct device *dev) > err = pci_for_each_dma_alias(to_pci_dev(dev), > iort_pci_iommu_init, &info); > > - if (!err && iort_pci_rc_supports_ats(node)) > + fwspec = dev_iommu_fwspec_get(dev); > + if (fwspec && iort_pci_rc_supports_ats(node)) > fwspec->flags |= IOMMU_FWSPEC_PCI_RC_ATS; > } else { > int i = 0; And the panic disappeared. Joerg, please feel free to add my Tested-by for smmu-v3 and IORT ACPI patches with above changes. > > > Note that this use of iommu_fwspec will be removed by the ATS cleanup > series [1], but this change should work as a temporary fix. Yes, as your patch set will set the ats_supported flag in the host bridge level, not per device, nice cleanup. Thanks Hanjun