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=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLACK,USER_AGENT_GIT 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 8E5C1C2BA83 for ; Fri, 14 Feb 2020 18:20:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5948C2168B for ; Fri, 14 Feb 2020 18:20:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581704448; bh=aaj207FIdZCp8J89QIqEslcb0Ntch/67YAl/hSeNfyc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=OKwam1e4TaXDZW/MxYaVnzJhoPGv05CbaFEJeTw6y0ZPPBJ7A29CsGp3Bzk+6cyuI veDa3bWis0U5e2sWEnM+msxm9RDBzfmuS6rq7LqcTF2vXqnfzG4m/QYeWxSV7pGpCS KHdgQXK+wvYU/VCldFvZ8ybZa6Se82TyFjlzESSA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730274AbgBNPt6 (ORCPT ); Fri, 14 Feb 2020 10:49:58 -0500 Received: from mail.kernel.org ([198.145.29.99]:53492 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730298AbgBNPt6 (ORCPT ); Fri, 14 Feb 2020 10:49:58 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4B7AE24684; Fri, 14 Feb 2020 15:49:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581695397; bh=aaj207FIdZCp8J89QIqEslcb0Ntch/67YAl/hSeNfyc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GL+L2HHXiK9XH2Asc4qLT4FLUlpKW6pzVX01DSRoWMkPC2d2G6/WLjt0KAvm2tY94 2g0xW6zEmj/IG2TjDkgiKuJh/zEXCJji0mkr+hYyS3hr3TzBSgPFcAYt/MpO8HnTsc 3UkCuwvOoeO43qKSIx+2BxVmfASFVb9S9mCm+FUI= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Oliver O'Halloran , Alexey Kardashevskiy , Michael Ellerman , Sasha Levin , linuxppc-dev@lists.ozlabs.org Subject: [PATCH AUTOSEL 5.5 048/542] powerpc/powernv/iov: Ensure the pdn for VFs always contains a valid PE number Date: Fri, 14 Feb 2020 10:40:40 -0500 Message-Id: <20200214154854.6746-48-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200214154854.6746-1-sashal@kernel.org> References: <20200214154854.6746-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Oliver O'Halloran [ Upstream commit 3b5b9997b331e77ce967eba2c4bc80dc3134a7fe ] On pseries there is a bug with adding hotplugged devices to an IOMMU group. For a number of dumb reasons fixing that bug first requires re-working how VFs are configured on PowerNV. For background, on PowerNV we use the pcibios_sriov_enable() hook to do two things: 1. Create a pci_dn structure for each of the VFs, and 2. Configure the PHB's internal BARs so the MMIO range for each VF maps to a unique PE. Roughly speaking a PE is the hardware counterpart to a Linux IOMMU group since all the devices in a PE share the same IOMMU table. A PE also defines the set of devices that should be isolated in response to a PCI error (i.e. bad DMA, UR/CA, AER events, etc). When isolated all MMIO and DMA traffic to and from devicein the PE is blocked by the root complex until the PE is recovered by the OS. The requirement to block MMIO causes a giant headache because the P8 PHB generally uses a fixed mapping between MMIO addresses and PEs. As a result we need to delay configuring the IOMMU groups for device until after MMIO resources are assigned. For physical devices (i.e. non-VFs) the PE assignment is done in pcibios_setup_bridge() which is called immediately after the MMIO resources for downstream devices (and the bridge's windows) are assigned. For VFs the setup is more complicated because: a) pcibios_setup_bridge() is not called again when VFs are activated, and b) The pci_dev for VFs are created by generic code which runs after pcibios_sriov_enable() is called. The work around for this is a two step process: 1. A fixup in pcibios_add_device() is used to initialised the cached pe_number in pci_dn, then 2. A bus notifier then adds the device to the IOMMU group for the PE specified in pci_dn->pe_number. A side effect fixing the pseries bug mentioned in the first paragraph is moving the fixup out of pcibios_add_device() and into pcibios_bus_add_device(), which is called much later. This results in step 2. failing because pci_dn->pe_number won't be initialised when the bus notifier is run. We can fix this by removing the need for the fixup. The PE for a VF is known before the VF is even scanned so we can initialise pci_dn->pe_number pcibios_sriov_enable() instead. Unfortunately, moving the initialisation causes two problems: 1. We trip the WARN_ON() in the current fixup code, and 2. The EEH core clears pdn->pe_number when recovering a VF and relies on the fixup to correctly re-set it. The only justification for either of these is a comment in eeh_rmv_device() suggesting that pdn->pe_number *must* be set to IODA_INVALID_PE in order for the VF to be scanned. However, this comment appears to have no basis in reality. Both bugs can be fixed by just deleting the code. Tested-by: Alexey Kardashevskiy Reviewed-by: Alexey Kardashevskiy Signed-off-by: Oliver O'Halloran Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20191028085424.12006-1-oohall@gmail.com Signed-off-by: Sasha Levin --- arch/powerpc/kernel/eeh_driver.c | 6 ------ arch/powerpc/platforms/powernv/pci-ioda.c | 19 +++++++++++++++---- arch/powerpc/platforms/powernv/pci.c | 4 ---- 3 files changed, 15 insertions(+), 14 deletions(-) diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c index 3dd1a422fc29d..a1eaffe868de4 100644 --- a/arch/powerpc/kernel/eeh_driver.c +++ b/arch/powerpc/kernel/eeh_driver.c @@ -525,12 +525,6 @@ static void eeh_rmv_device(struct eeh_dev *edev, void *userdata) pci_iov_remove_virtfn(edev->physfn, pdn->vf_index); edev->pdev = NULL; - - /* - * We have to set the VF PE number to invalid one, which is - * required to plug the VF successfully. - */ - pdn->pe_number = IODA_INVALID_PE; #endif if (rmv_data) list_add(&edev->rmv_entry, &rmv_data->removed_vf_list); diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c index da1068a9c2637..4374836b033b4 100644 --- a/arch/powerpc/platforms/powernv/pci-ioda.c +++ b/arch/powerpc/platforms/powernv/pci-ioda.c @@ -1558,6 +1558,10 @@ static void pnv_ioda_setup_vf_PE(struct pci_dev *pdev, u16 num_vfs) /* Reserve PE for each VF */ for (vf_index = 0; vf_index < num_vfs; vf_index++) { + int vf_devfn = pci_iov_virtfn_devfn(pdev, vf_index); + int vf_bus = pci_iov_virtfn_bus(pdev, vf_index); + struct pci_dn *vf_pdn; + if (pdn->m64_single_mode) pe_num = pdn->pe_num_map[vf_index]; else @@ -1570,13 +1574,11 @@ static void pnv_ioda_setup_vf_PE(struct pci_dev *pdev, u16 num_vfs) pe->pbus = NULL; pe->parent_dev = pdev; pe->mve_number = -1; - pe->rid = (pci_iov_virtfn_bus(pdev, vf_index) << 8) | - pci_iov_virtfn_devfn(pdev, vf_index); + pe->rid = (vf_bus << 8) | vf_devfn; pe_info(pe, "VF %04d:%02d:%02d.%d associated with PE#%x\n", hose->global_number, pdev->bus->number, - PCI_SLOT(pci_iov_virtfn_devfn(pdev, vf_index)), - PCI_FUNC(pci_iov_virtfn_devfn(pdev, vf_index)), pe_num); + PCI_SLOT(vf_devfn), PCI_FUNC(vf_devfn), pe_num); if (pnv_ioda_configure_pe(phb, pe)) { /* XXX What do we do here ? */ @@ -1590,6 +1592,15 @@ static void pnv_ioda_setup_vf_PE(struct pci_dev *pdev, u16 num_vfs) list_add_tail(&pe->list, &phb->ioda.pe_list); mutex_unlock(&phb->ioda.pe_list_mutex); + /* associate this pe to it's pdn */ + list_for_each_entry(vf_pdn, &pdn->parent->child_list, list) { + if (vf_pdn->busno == vf_bus && + vf_pdn->devfn == vf_devfn) { + vf_pdn->pe_number = pe_num; + break; + } + } + pnv_pci_ioda2_setup_dma_pe(phb, pe); #ifdef CONFIG_IOMMU_API iommu_register_group(&pe->table_group, diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c index c0bea75ac27bf..e8e58a2cccddf 100644 --- a/arch/powerpc/platforms/powernv/pci.c +++ b/arch/powerpc/platforms/powernv/pci.c @@ -816,16 +816,12 @@ void pnv_pci_dma_dev_setup(struct pci_dev *pdev) struct pnv_phb *phb = hose->private_data; #ifdef CONFIG_PCI_IOV struct pnv_ioda_pe *pe; - struct pci_dn *pdn; /* Fix the VF pdn PE number */ if (pdev->is_virtfn) { - pdn = pci_get_pdn(pdev); - WARN_ON(pdn->pe_number != IODA_INVALID_PE); list_for_each_entry(pe, &phb->ioda.pe_list, list) { if (pe->rid == ((pdev->bus->number << 8) | (pdev->devfn & 0xff))) { - pdn->pe_number = pe->pe_number; pe->pdev = pdev; break; } -- 2.20.1