From patchwork Mon Nov 10 16:41:46 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenzo Pieralisi X-Patchwork-Id: 5267381 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 [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id EED8F9F3ED for ; Mon, 10 Nov 2014 16:41:59 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id EA982201C0 for ; Mon, 10 Nov 2014 16:41:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EE3B120172 for ; Mon, 10 Nov 2014 16:41:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753804AbaKJQlx (ORCPT ); Mon, 10 Nov 2014 11:41:53 -0500 Received: from foss-mx-na.foss.arm.com ([217.140.108.86]:55626 "EHLO foss-mx-na.foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753798AbaKJQlw (ORCPT ); Mon, 10 Nov 2014 11:41:52 -0500 Received: from foss-smtp-na-1.foss.arm.com (unknown [10.80.61.8]) by foss-mx-na.foss.arm.com (Postfix) with ESMTP id D8DFA66; Mon, 10 Nov 2014 10:41:48 -0600 (CST) Received: from collaborate-mta1.arm.com (highbank-bc01-b06.austin.arm.com [10.112.81.134]) by foss-smtp-na-1.foss.arm.com (Postfix) with ESMTP id 8788E5FAD7; Mon, 10 Nov 2014 10:41:46 -0600 (CST) Received: from red-moon.cambridge.arm.com (red-moon.cambridge.arm.com [10.1.203.137]) by collaborate-mta1.arm.com (Postfix) with ESMTP id 24A6213F6EE; Mon, 10 Nov 2014 10:41:45 -0600 (CST) From: Lorenzo Pieralisi To: linux-arm-kernel@lists.infradead.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org Cc: Lorenzo Pieralisi , Arnd Bergmann , Liviu Dudau , Bjorn Helgaas , Rob Herring , Catalin Marinas Subject: [RFC PATCH v2] drivers: pci: move PCI domain assignment to generic PCI code Date: Mon, 10 Nov 2014 16:41:46 +0000 Message-Id: <1415637706-2195-1-git-send-email-lorenzo.pieralisi@arm.com> X-Mailer: git-send-email 2.1.2 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Spam-Status: No, score=-6.1 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, TRACKER_ID, 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 current logic used for PCI domain assignment in arm64 pci_bus_assign_domain_nr() is flawed in that, depending on the host controllers configuration for a platform and the respective initialization sequence, core code may end up allocating PCI domain numbers from both DT and the core code generic domain counter, which would result in PCI domain allocation aliases/errors. This patch fixes the logic behind the PCI domain number assignment and moves the resulting code to generic PCI core code so that the same domain allocation logic is used on all platforms selecting CONFIG_PCI_DOMAINS_GENERIC instead of resorting to an arch specific implementation that might end up duplicating the PCI domain assignment logic wrongly. Cc: Arnd Bergmann Cc: Liviu Dudau Cc: Bjorn Helgaas Cc: Rob Herring Cc: Catalin Marinas Signed-off-by: Lorenzo Pieralisi Acked-by: Liviu Dudau Acked-by: Arnd Bergmann --- v1 => v2: - Moved generic pci_bus_assign_domain_nr() code to PCI core instead of adding an OF layer API - Updated commit log and code comments arch/arm64/kernel/pci.c | 22 ---------------------- drivers/pci/pci.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 50 insertions(+), 22 deletions(-) diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c index ce5836c..6f93c24 100644 --- a/arch/arm64/kernel/pci.c +++ b/arch/arm64/kernel/pci.c @@ -46,25 +46,3 @@ int pcibios_add_device(struct pci_dev *dev) return 0; } - - -#ifdef CONFIG_PCI_DOMAINS_GENERIC -static bool dt_domain_found = false; - -void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent) -{ - int domain = of_get_pci_domain_nr(parent->of_node); - - if (domain >= 0) { - dt_domain_found = true; - } else if (dt_domain_found == true) { - dev_err(parent, "Node %s is missing \"linux,pci-domain\" property in DT\n", - parent->of_node->full_name); - return; - } else { - domain = pci_get_new_domain_nr(); - } - - bus->domain_nr = domain; -} -#endif diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 625a4ac..2279414 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -10,6 +10,8 @@ #include #include #include +#include +#include #include #include #include @@ -4447,6 +4449,54 @@ int pci_get_new_domain_nr(void) { return atomic_inc_return(&__domain_nr); } + +#ifdef CONFIG_PCI_DOMAINS_GENERIC + +void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent) +{ + static int use_dt_domains = -1; + int domain = of_get_pci_domain_nr(parent->of_node); + + /* + * Check DT domain and use_dt_domains values. + * + * If DT domain property is valid (domain >= 0) and + * use_dt_domains != 0, the DT assignment is valid since this means + * we have not previously allocated a domain number by using + * pci_get_new_domain_nr(); we should also update use_dt_domains to + * 1, to indicate that we have just assigned a domain number from + * DT. + * + * If DT domain property value is not valid (ie domain < 0), and we + * have not previously assigned a domain number from DT + * (use_dt_domains != 1) we should assign a domain number by + * using the: + * + * pci_get_new_domain_nr() + * + * API and update the use_dt_domains value to keep track of method we + * are using to assign domain numbers (use_dt_domains = 0). + * + * All other combinations imply we have a platform that is trying + * to mix domain numbers obtained from DT and pci_get_new_domain_nr(), + * which is a recipe for domain mishandling and it is prevented by + * invalidating the domain value (domain = -1) and printing a + * corresponding error. + */ + if (domain >= 0 && use_dt_domains) { + use_dt_domains = 1; + } else if (domain < 0 && use_dt_domains != 1) { + use_dt_domains = 0; + domain = pci_get_new_domain_nr(); + } else { + dev_err(parent, "Node %s has inconsistent \"linux,pci-domain\" property in DT\n", + parent->of_node->full_name); + domain = -1; + } + + bus->domain_nr = domain; +} +#endif #endif /**