From patchwork Wed Aug 6 07:10:16 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gavin Shan X-Patchwork-Id: 376922 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [103.22.144.68]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id F07071400AF for ; Wed, 6 Aug 2014 17:11:02 +1000 (EST) Received: from ozlabs.org (ozlabs.org [103.22.144.67]) by lists.ozlabs.org (Postfix) with ESMTP id DB6341A08B4 for ; Wed, 6 Aug 2014 17:11:02 +1000 (EST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Received: from e23smtp03.au.ibm.com (e23smtp03.au.ibm.com [202.81.31.145]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id BD5BB1A0372 for ; Wed, 6 Aug 2014 17:10:25 +1000 (EST) Received: from /spool/local by e23smtp03.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Wed, 6 Aug 2014 17:10:21 +1000 Received: from d23relay06.au.ibm.com (d23relay06.au.ibm.com [9.185.63.219]) by d23dlp02.au.ibm.com (Postfix) with ESMTP id A898C2BB002D for ; Wed, 6 Aug 2014 17:10:21 +1000 (EST) Received: from d23av03.au.ibm.com (d23av03.au.ibm.com [9.190.234.97]) by d23relay06.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s767AueF12910732 for ; Wed, 6 Aug 2014 17:10:56 +1000 Received: from d23av03.au.ibm.com (localhost [127.0.0.1]) by d23av03.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s767AKsV013276 for ; Wed, 6 Aug 2014 17:10:21 +1000 Received: from shangw (shangw.cn.ibm.com [9.125.213.210]) by d23av03.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with SMTP id s767AI0m013248; Wed, 6 Aug 2014 17:10:19 +1000 Received: by shangw (Postfix, from userid 1000) id 15E373E1F2C; Wed, 6 Aug 2014 17:10:19 +1000 (EST) From: Gavin Shan To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH 1/2 v2] powerpc/powernv: Fix IOMMU group lost Date: Wed, 6 Aug 2014 17:10:16 +1000 Message-Id: <1407309017-13870-1-git-send-email-gwshan@linux.vnet.ibm.com> X-Mailer: git-send-email 1.8.3.2 X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14080607-5028-0000-0000-0000001E5978 Cc: Gavin Shan , stable@vger.kernel.org X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" When we take full hotplug to recover from EEH errors, PCI buses could be involved. For the case, the child devices of involved PCI buses can't be attached to IOMMU group properly, which is caused by commit 3f28c5a ("powerpc/powernv: Reduce multi-hit of iommu_add_device()"). When adding the PCI devices of the newly created PCI buses to the system, the IOMMU group is expected to be added in (C). (A) fails to bind the IOMMU group because bus->is_added is false. (B) fails because the device doesn't have binding IOMMU table yet. bus->is_added is set to true at end of (C) and pdev->is_added is set to true at (D). pcibios_add_pci_devices() pci_scan_bridge() pci_scan_child_bus() pci_scan_slot() pci_scan_single_device() pci_scan_device() pci_device_add() pcibios_add_device() A: Ignore device_add() B: Ignore pcibios_fixup_bus() pcibios_setup_bus_devices() pcibios_setup_device() C: Hit pcibios_finish_adding_to_bus() pci_bus_add_devices() pci_bus_add_device() D: Add device If the parent PCI bus isn't involved in hotplug, the IOMMU group is expected to be bound in (B). (A) should fail as the sysfs entries aren't populated. The patch fixes the issue by reverting commit 3f28c5a and remove WARN_ON() in iommu_add_device() to allow calling the function even the specified device already has associated IOMMU group. Cc: # 3.16+ Reported-by: Thadeu Lima de Souza Cascardo Signed-off-by: Gavin Shan Acked-by: Wei Yang --- v2: Bail if sysfs entries aren't populated in iommu_add_device() --- arch/powerpc/kernel/iommu.c | 38 +++++++++++++++++-------------- arch/powerpc/platforms/powernv/pci-ioda.c | 2 +- 2 files changed, 22 insertions(+), 18 deletions(-) diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index 88e3ec6..48fb2c1 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -1120,37 +1120,41 @@ EXPORT_SYMBOL_GPL(iommu_release_ownership); int iommu_add_device(struct device *dev) { struct iommu_table *tbl; - int ret = 0; - if (WARN_ON(dev->iommu_group)) { - pr_warn("iommu_tce: device %s is already in iommu group %d, skipping\n", - dev_name(dev), - iommu_group_id(dev->iommu_group)); + /* + * The sysfs entries should be populated before + * binding IOMMU group. If sysfs entries isn't + * ready, we simply bail. + */ + if (!device_is_registered(dev)) + return -ENOENT; + + if (dev->iommu_group) { + pr_debug("%s: Skipping device %s with iommu group %d\n", + __func__, dev_name(dev), + iommu_group_id(dev->iommu_group)); return -EBUSY; } tbl = get_iommu_table_base(dev); if (!tbl || !tbl->it_group) { - pr_debug("iommu_tce: skipping device %s with no tbl\n", - dev_name(dev)); + pr_debug("%s: Skipping device %s with no tbl\n", + __func__, dev_name(dev)); return 0; } - pr_debug("iommu_tce: adding %s to iommu group %d\n", - dev_name(dev), iommu_group_id(tbl->it_group)); + pr_debug("%s: Adding %s to iommu group %d\n", + __func__, dev_name(dev), + iommu_group_id(tbl->it_group)); if (PAGE_SIZE < IOMMU_PAGE_SIZE(tbl)) { - pr_err("iommu_tce: unsupported iommu page size."); - pr_err("%s has not been added\n", dev_name(dev)); + pr_err("%s: Invalid IOMMU page size %lx (%lx) on %s\n", + __func__, IOMMU_PAGE_SIZE(tbl), + PAGE_SIZE, dev_name(dev)); return -EINVAL; } - ret = iommu_group_add_device(tbl->it_group, dev); - if (ret < 0) - pr_err("iommu_tce: %s has not been added, ret=%d\n", - dev_name(dev), ret); - - return ret; + return iommu_group_add_device(tbl->it_group, dev); } EXPORT_SYMBOL_GPL(iommu_add_device); diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c index de19ede..86290eb 100644 --- a/arch/powerpc/platforms/powernv/pci-ioda.c +++ b/arch/powerpc/platforms/powernv/pci-ioda.c @@ -462,7 +462,7 @@ static void pnv_pci_ioda_dma_dev_setup(struct pnv_phb *phb, struct pci_dev *pdev pe = &phb->ioda.pe_array[pdn->pe_number]; WARN_ON(get_dma_ops(&pdev->dev) != &dma_iommu_ops); - set_iommu_table_base(&pdev->dev, &pe->tce32_table); + set_iommu_table_base_and_group(&pdev->dev, &pe->tce32_table); } static int pnv_pci_ioda_dma_set_mask(struct pnv_phb *phb,