From patchwork Fri May 20 06:41:33 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gavin Shan X-Patchwork-Id: 9128653 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 7F39C60762 for ; Fri, 20 May 2016 06:43:16 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7206826E82 for ; Fri, 20 May 2016 06:43:16 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 66FA527672; Fri, 20 May 2016 06:43:16 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0A01226E82 for ; Fri, 20 May 2016 06:43:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754753AbcETGnO (ORCPT ); Fri, 20 May 2016 02:43:14 -0400 Received: from e23smtp05.au.ibm.com ([202.81.31.147]:39069 "EHLO e23smtp05.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754835AbcETGnN (ORCPT ); Fri, 20 May 2016 02:43:13 -0400 Received: from localhost by e23smtp05.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Fri, 20 May 2016 16:43:08 +1000 X-IBM-Helo: d23dlp02.au.ibm.com X-IBM-MailFrom: gwshan@linux.vnet.ibm.com X-IBM-RcptTo: linux-pci@vger.kernel.org Received: from d23relay06.au.ibm.com (d23relay06.au.ibm.com [9.185.63.219]) by d23dlp02.au.ibm.com (Postfix) with ESMTP id 042D92BB0057 for ; Fri, 20 May 2016 16:43:08 +1000 (EST) Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay06.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u4K6gxrc1311170 for ; Fri, 20 May 2016 16:43:07 +1000 Received: from d23av02.au.ibm.com (localhost [127.0.0.1]) by d23av02.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u4K6gYhG032197 for ; Fri, 20 May 2016 16:42:35 +1000 Received: from ozlabs.au.ibm.com (ozlabs.au.ibm.com [9.192.253.14]) by d23av02.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id u4K6gYEG031449; Fri, 20 May 2016 16:42:34 +1000 Received: from bran.ozlabs.ibm.com (haven.au.ibm.com [9.192.254.114]) by ozlabs.au.ibm.com (Postfix) with ESMTP id E8BAFA03B0; Fri, 20 May 2016 16:41:45 +1000 (AEST) Received: from gwshan (shangw.ozlabs.ibm.com [10.61.2.199]) by bran.ozlabs.ibm.com (Postfix) with ESMTP id EB75FE3A8C; Fri, 20 May 2016 16:41:45 +1000 (AEST) Received: by gwshan (Postfix, from userid 1000) id C6F99942543; Fri, 20 May 2016 16:41:45 +1000 (AEST) From: Gavin Shan To: linuxppc-dev@lists.ozlabs.org Cc: linux-pci@vger.kernel.org, benh@kernel.crashing.org, mpe@ellerman.id.au, alistair@popple.id.au, aik@ozlabs.ru, Gavin Shan Subject: [PATCH v10 09/18] powerpc/powernv: Extend PCI bridge resources Date: Fri, 20 May 2016 16:41:33 +1000 Message-Id: <1463726502-14679-10-git-send-email-gwshan@linux.vnet.ibm.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1463726502-14679-1-git-send-email-gwshan@linux.vnet.ibm.com> References: <1463726502-14679-1-git-send-email-gwshan@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16052006-0017-0000-0000-000004AA6C6A X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The PCI slots are associated with root port or downstream ports of the PCIe switch connected to root port. When adapter is hot added to the PCI slot, it usually requests more IO or memory resource from the directly connected parent bridge (port) and update the bridge's windows accordingly. The resource windows of upstream bridges can't be updated automatically. It possibly leads to unbalanced resource across the bridges: The window of downstream bridge is overruning that of upstream bridge. The IO or MMIO path won't work. This resolves the above issue by extending bridge windows of root port and upstream port of the PCIe switch connected to the root port to PHB's windows. Signed-off-by: Gavin Shan --- arch/powerpc/platforms/powernv/pci-ioda.c | 46 +++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c index 3186a29..e97a5fa 100644 --- a/arch/powerpc/platforms/powernv/pci-ioda.c +++ b/arch/powerpc/platforms/powernv/pci-ioda.c @@ -3221,6 +3221,49 @@ static resource_size_t pnv_pci_window_alignment(struct pci_bus *bus, return phb->ioda.io_segsize; } +/* + * We are updating root port or the upstream port of the + * bridge behind the root port with PHB's windows in order + * to accommodate the changes on required resources during + * PCI (slot) hotplug, which is connected to either root + * port or the downstream ports of PCIe switch behind the + * root port. + */ +static void pnv_pci_fixup_bridge_resources(struct pci_bus *bus, + unsigned long type) +{ + struct pci_controller *hose = pci_bus_to_host(bus); + struct pnv_phb *phb = hose->private_data; + struct pci_dev *bridge = bus->self; + struct resource *r, *w; + int i; + + /* Check if we need apply fixup to the bridge's windows */ + if (!pci_is_root_bus(bridge->bus) && + !pci_is_root_bus(bridge->bus->self->bus)) + return; + + /* Fixup the resources */ + for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++) { + r = &bridge->resource[PCI_BRIDGE_RESOURCES + i]; + if (!r->flags || !r->parent) + continue; + + w = NULL; + if (r->flags & type & IORESOURCE_IO) + w = &hose->io_resource; + else if (pnv_pci_is_mem_pref_64(r->flags) && + (type & IORESOURCE_PREFETCH) && + phb->ioda.m64_segsize) + w = &hose->mem_resources[1]; + else if (r->flags & type & IORESOURCE_MEM) + w = &hose->mem_resources[0]; + + r->start = w->start; + r->end = w->end; + } +} + static void pnv_pci_setup_bridge(struct pci_bus *bus, unsigned long type) { struct pci_controller *hose = pci_bus_to_host(bus); @@ -3229,6 +3272,9 @@ static void pnv_pci_setup_bridge(struct pci_bus *bus, unsigned long type) struct pnv_ioda_pe *pe; bool all = (pci_pcie_type(bridge) == PCI_EXP_TYPE_PCI_BRIDGE); + /* Extend bridge's windows if necessary */ + pnv_pci_fixup_bridge_resources(bus, type); + /* The PE for root bus should be realized before any one else */ if (!phb->ioda.root_pe_populated) { pe = pnv_ioda_setup_bus_PE(phb->hose->bus, false);