From patchwork Thu Sep 18 01:30:22 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Liviu Dudau X-Patchwork-Id: 390611 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id EDA5F14009C for ; Thu, 18 Sep 2014 11:35:57 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757320AbaIRBcZ (ORCPT ); Wed, 17 Sep 2014 21:32:25 -0400 Received: from fw-tnat.cambridge.arm.com ([217.140.96.21]:54528 "EHLO cam-smtp0.cambridge.arm.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1757220AbaIRBcH (ORCPT ); Wed, 17 Sep 2014 21:32:07 -0400 Received: from e106497-lin.cambridge.arm.com (e106497-lin.cambridge.arm.com [10.1.195.53]) by cam-smtp0.cambridge.arm.com (8.13.8/8.13.8) with ESMTP id s8I1UPlB003595; Thu, 18 Sep 2014 02:30:30 +0100 From: Liviu Dudau To: Bjorn Helgaas , Arnd Bergmann , Rob Herring , Jason Gunthorpe , Benjamin Herrenschmidt , Catalin Marinas , Will Deacon , Russell King , linux-pci , Linus Walleij Cc: Tanmay Inamdar , Grant Likely , Sinan Kaya , Jingoo Han , Kukjin Kim , Suravee Suthikulanit , linux-arch , LKML , Device Tree ML , LAKML , Grant Likely Subject: [PATCH v11 07/10] OF: Introduce helper function for getting PCI domain_nr Date: Thu, 18 Sep 2014 02:30:22 +0100 Message-Id: <1411003825-21521-8-git-send-email-Liviu.Dudau@arm.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1411003825-21521-1-git-send-email-Liviu.Dudau@arm.com> References: <1411003825-21521-1-git-send-email-Liviu.Dudau@arm.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Add of_pci_get_domain_nr() to retrieve the PCI domain number of a given device from DT. If the information is not present, the function can be requested to allocate a new domain number. Cc: Bjorn Helgaas Cc: Arnd Bergmann Cc: Grant Likely Cc: Rob Herring Reviewed-by: Catalin Marinas Signed-off-by: Liviu Dudau Acked-by: Arnd Bergmann --- drivers/of/of_pci.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/of_pci.h | 7 ++++++ 2 files changed, 69 insertions(+) diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c index 8481996..7eaeac2 100644 --- a/drivers/of/of_pci.c +++ b/drivers/of/of_pci.c @@ -3,6 +3,8 @@ #include #include +#include "of_private.h" + static inline int __of_pci_pci_compare(struct device_node *node, unsigned int data) { @@ -89,6 +91,66 @@ int of_pci_parse_bus_range(struct device_node *node, struct resource *res) } EXPORT_SYMBOL_GPL(of_pci_parse_bus_range); +static atomic_t of_domain_nr = ATOMIC_INIT(-1); + +/* + * Get the maximum value for a domain number from the device tree + */ +static int of_get_max_pci_domain_nr(void) +{ + struct alias_prop *app; + int max_domain = -1; + + mutex_lock(&of_mutex); + list_for_each_entry(app, &aliases_lookup, link) { + if (strncmp(app->stem, "pci-domain", 10) != 0) + continue; + + max_domain = max(max_domain, app->id); + } + mutex_unlock(&of_mutex); + + return max_domain; +} + +/** + * This function will try to obtain the host bridge domain number by + * using of_alias_get_id() call with "pci-domain" as a stem. If that + * fails, a local allocator will be used. The local allocator can + * be requested to return a new domain_nr if the information is missing + * from the device tree. + * + * @node: device tree node with the domain information + * @allocate_if_missing: if DT lacks information about the domain nr, + * allocate a new number. + * + * Returns the associated domain number from DT, or a new domain number + * if DT information is missing and @allocate_if_missing is true. If + * @allocate_if_missing is false then the last allocated domain number + * will be returned. + */ +int of_pci_get_domain_nr(struct device_node *node, bool allocate_if_missing) +{ + int domain; + + domain = atomic_read(&of_domain_nr); + if (domain == -1) { + /* first run, get max defined domain nr in device tree */ + domain = of_get_max_pci_domain_nr(); + /* then set the start value for allocator to be max + 1 */ + atomic_set(&of_domain_nr, domain + 1); + } + domain = of_alias_get_id(node, "pci-domain"); + if (domain == -ENODEV) { + domain = atomic_read(&of_domain_nr); + if (allocate_if_missing) + atomic_inc(&of_domain_nr); + } + + return domain; +} +EXPORT_SYMBOL_GPL(of_pci_get_domain_nr); + #ifdef CONFIG_PCI_MSI static LIST_HEAD(of_pci_msi_chip_list); diff --git a/include/linux/of_pci.h b/include/linux/of_pci.h index dde3a4a..3a3824c 100644 --- a/include/linux/of_pci.h +++ b/include/linux/of_pci.h @@ -15,6 +15,7 @@ struct device_node *of_pci_find_child_device(struct device_node *parent, int of_pci_get_devfn(struct device_node *np); int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin); int of_pci_parse_bus_range(struct device_node *node, struct resource *res); +int of_pci_get_domain_nr(struct device_node *node, bool allocate_if_missing); #else static inline int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq) { @@ -43,6 +44,12 @@ of_pci_parse_bus_range(struct device_node *node, struct resource *res) { return -EINVAL; } + +static inline int +of_pci_get_domain_nr(struct device_node *node, bool allocate_if_missing) +{ + return -1; +} #endif #if defined(CONFIG_OF) && defined(CONFIG_PCI_MSI)