From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e28smtp01.in.ibm.com (e28smtp01.in.ibm.com [125.16.236.1]) (using TLSv1.2 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3qzhgm65f3zDqBW for ; Tue, 3 May 2016 23:23:16 +1000 (AEST) Received: from localhost by e28smtp01.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 3 May 2016 18:53:14 +0530 Received: from d28relay08.in.ibm.com (d28relay08.in.ibm.com [9.184.220.159]) by d28dlp03.in.ibm.com (Postfix) with ESMTP id 89359125805C for ; Tue, 3 May 2016 18:55:15 +0530 (IST) Received: from d28av08.in.ibm.com (d28av08.in.ibm.com [9.184.220.148]) by d28relay08.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u43DNCVq24313886 for ; Tue, 3 May 2016 18:53:12 +0530 Received: from d28av08.in.ibm.com (localhost [127.0.0.1]) by d28av08.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u43DNDAF031665 for ; Tue, 3 May 2016 18:53:16 +0530 From: Gavin Shan To: linuxppc-dev@lists.ozlabs.org Cc: linux-pci@vger.kernel.org, devicetree@vger.kernel.org, benh@kernel.crashing.org, mpe@ellerman.id.au, aik@ozlabs.ru, bhelgaas@google.com, robherring2@gmail.com, dja@axtens.net, alistair@popple.id.au, Gavin Shan Subject: [PATCH v9 08/22] powerpc/powernv: Extend PCI bridge resources Date: Tue, 3 May 2016 23:22:39 +1000 Message-Id: <1462281773-26438-9-git-send-email-gwshan@linux.vnet.ibm.com> In-Reply-To: <1462281773-26438-1-git-send-email-gwshan@linux.vnet.ibm.com> References: <1462281773-26438-1-git-send-email-gwshan@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 de3f292..b518364 100644 --- a/arch/powerpc/platforms/powernv/pci-ioda.c +++ b/arch/powerpc/platforms/powernv/pci-ioda.c @@ -3146,6 +3146,49 @@ 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); @@ -3154,6 +3197,9 @@ 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); -- 2.1.0