From patchwork Thu Mar 17 20:03:46 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Guilherme G. Piccoli" X-Patchwork-Id: 8614041 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: patchwork-linux-pci@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 7EEAE9F54C for ; Thu, 17 Mar 2016 20:04:28 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 84A2D20304 for ; Thu, 17 Mar 2016 20:04:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6AE672020F for ; Thu, 17 Mar 2016 20:04:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933343AbcCQUEZ (ORCPT ); Thu, 17 Mar 2016 16:04:25 -0400 Received: from e24smtp03.br.ibm.com ([32.104.18.24]:60104 "EHLO e24smtp03.br.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932085AbcCQUEX (ORCPT ); Thu, 17 Mar 2016 16:04:23 -0400 Received: from localhost by e24smtp03.br.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Thu, 17 Mar 2016 17:04:19 -0300 X-IBM-Helo: d24dlp02.br.ibm.com X-IBM-MailFrom: gpiccoli@linux.vnet.ibm.com X-IBM-RcptTo: linux-pci@vger.kernel.org Received: from d24relay01.br.ibm.com (d24relay01.br.ibm.com [9.8.31.16]) by d24dlp02.br.ibm.com (Postfix) with ESMTP id B61AC1DC008C for ; Thu, 17 Mar 2016 16:04:10 -0400 (EDT) Received: from d24av04.br.ibm.com (d24av04.br.ibm.com [9.8.31.97]) by d24relay01.br.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u2HJ1wdg5230636 for ; Thu, 17 Mar 2016 16:01:58 -0300 Received: from d24av04.br.ibm.com (localhost [127.0.0.1]) by d24av04.br.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u2HK4Ele028400 for ; Thu, 17 Mar 2016 17:04:15 -0300 Received: from localhost (HarryBosch.br.ibm.com [9.18.235.82]) by d24av04.br.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id u2HK4EWr028394; Thu, 17 Mar 2016 17:04:14 -0300 From: "Guilherme G. Piccoli" To: linuxppc-dev@lists.ozlabs.org Cc: linux-pci@vger.kernel.org, mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org, imunsie@au1.ibm.com, mikey@neuling.org, andrew.donnellan@au1.ibm.com, gwshan@linux.vnet.ibm.com, bhelgaas@google.com, gpiccoli@linux.vnet.ibm.com Subject: [PATCH v3] powerpc/pci: Assign fixed PHB number based on device-tree properties Date: Thu, 17 Mar 2016 17:03:46 -0300 Message-Id: <1458245026-27635-1-git-send-email-gpiccoli@linux.vnet.ibm.com> X-Mailer: git-send-email 2.1.0 X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16031720-0025-0000-0000-000006A103B9 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The domain/PHB field of PCI addresses has its value obtained from a global variable, incremented each time a new domain (represented by struct pci_controller) is added on the system. The domain addition process happens during boot or due to PCI device hotplug. As recent kernels are using predictable naming for network interfaces, the network stack is more tied to PCI naming. This can be a problem in hotplug scenarios, because PCI addresses will change if devices are removed and then re-added. This situation seems unusual, but it can happen if a user wants to replace a NIC without rebooting the machine, for example. This patch changes the way PCI domain values are generated: now, we use device-tree properties to assign fixed PHB numbers to PCI addresses when available (meaning pSeries and PowerNV cases). We also use a bitmap to allow dynamic PHB numbering when device-tree properties are not used. This bitmap keeps track of used PHB numbers and if a PHB is released (by hotplug operations for example), it allows the reuse of this PHB number, avoiding PCI address to change in case of device remove and re-add soon after. No functional changes were introduced. Signed-off-by: Guilherme G. Piccoli Reviewed-by: Gavin Shan --- arch/powerpc/kernel/pci-common.c | 41 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 38 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c index 0f7a60f..8777614 100644 --- a/arch/powerpc/kernel/pci-common.c +++ b/arch/powerpc/kernel/pci-common.c @@ -44,8 +44,11 @@ static DEFINE_SPINLOCK(hose_spinlock); LIST_HEAD(hose_list); -/* XXX kill that some day ... */ -static int global_phb_number; /* Global phb counter */ +/* For dynamic PHB numbering on get_phb_number(): max number of PHBs. */ +#define MAX_PHBS 8192 + +/* For dynamic PHB numbering: used/free PHBs tracking bitmap. */ +static DECLARE_BITMAP(phb_bitmap, MAX_PHBS); /* ISA Memory physical address */ resource_size_t isa_mem_base; @@ -64,6 +67,33 @@ struct dma_map_ops *get_pci_dma_ops(void) } EXPORT_SYMBOL(get_pci_dma_ops); +static int get_phb_number(struct device_node *dn) +{ + const __be64 *prop64; + const __be32 *regs; + int phb_id = 0; + + /* try fixed PHB numbering first, by checking archs and reading + * the respective device-tree property. */ + if (machine_is(pseries)) { + regs = of_get_property(dn, "reg", NULL); + if (regs) + return (int)(be32_to_cpu(regs[1]) & 0xFFFF); + } else { + if (machine_is(powernv)) { + prop64 = of_get_property(dn, "ibm,opal-phbid", NULL); + if (prop64) + return (int)(be64_to_cpup(prop64) & 0xFFFF); + } + } + + /* if not pSeries nor PowerNV, fallback to dynamic PHB numbering */ + phb_id = find_first_zero_bit(phb_bitmap, MAX_PHBS); + BUG_ON(phb_id >= MAX_PHBS); /* reached maximum number of PHBs */ + set_bit(phb_id, phb_bitmap); + return phb_id; +} + struct pci_controller *pcibios_alloc_controller(struct device_node *dev) { struct pci_controller *phb; @@ -72,7 +102,7 @@ struct pci_controller *pcibios_alloc_controller(struct device_node *dev) if (phb == NULL) return NULL; spin_lock(&hose_spinlock); - phb->global_number = global_phb_number++; + phb->global_number = get_phb_number(dev); list_add_tail(&phb->list_node, &hose_list); spin_unlock(&hose_spinlock); phb->dn = dev; @@ -94,6 +124,11 @@ EXPORT_SYMBOL_GPL(pcibios_alloc_controller); void pcibios_free_controller(struct pci_controller *phb) { spin_lock(&hose_spinlock); + + /* clear bit of phb_bitmap to allow reuse of this phb number */ + if (phb->global_number < MAX_PHBS) + clear_bit(phb->global_number, phb_bitmap); + list_del(&phb->list_node); spin_unlock(&hose_spinlock);