From patchwork Tue Sep 23 19:01:10 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Liviu Dudau X-Patchwork-Id: 4959811 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 420AF9F3DF for ; Tue, 23 Sep 2014 20:13:18 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 50B152026C for ; Tue, 23 Sep 2014 20:13:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 371892010B for ; Tue, 23 Sep 2014 20:13:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756050AbaIWUM4 (ORCPT ); Tue, 23 Sep 2014 16:12:56 -0400 Received: from fw-tnat.cambridge.arm.com ([217.140.96.21]:51829 "EHLO cam-smtp0.cambridge.arm.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753090AbaIWUMz (ORCPT ); Tue, 23 Sep 2014 16:12:55 -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 s8NJ1Eh5027659; Tue, 23 Sep 2014 20:01:23 +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 v12 08/12] PCI: OF: Introduce helper function for retrieving PCI domain numbers Date: Tue, 23 Sep 2014 20:01:10 +0100 Message-Id: <1411498874-9864-9-git-send-email-Liviu.Dudau@arm.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1411498874-9864-1-git-send-email-Liviu.Dudau@arm.com> References: <1411498874-9864-1-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 X-Spam-Status: No, score=-7.6 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 Add pci_get_new_domain_nr() to allocate a new domain number and of_get_pci_domain_nr() to retrieve the PCI domain number of a given device from DT. Host bridge drivers or architecture specific code can choose to implement their PCI domain number policy using these two functions. Using of_get_pci_domain_nr() guarantees a stable PCI domain number on every boot provided that all host bridge controllers are assigned a number in the device tree using "linux,pci-domain" property. Mix use of pci_get_new_domain_nr() and of_get_pci_domain_nr() is not recommended as it can lead to potentially conflicting domain numbers being assigned to root busses behind different host bridges. Cc: Bjorn Helgaas Cc: Arnd Bergmann Cc: Grant Likely Cc: Rob Herring Cc: Catalin Marinas Signed-off-by: Liviu Dudau --- drivers/of/of_pci.c | 25 +++++++++++++++++++++++++ drivers/pci/pci.c | 9 +++++++++ include/linux/of_pci.h | 7 +++++++ include/linux/pci.h | 3 +++ 4 files changed, 44 insertions(+) diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c index 8481996..82d172f 100644 --- a/drivers/of/of_pci.c +++ b/drivers/of/of_pci.c @@ -89,6 +89,31 @@ int of_pci_parse_bus_range(struct device_node *node, struct resource *res) } EXPORT_SYMBOL_GPL(of_pci_parse_bus_range); +/** + * This function will try to obtain the host bridge domain number by + * finding a property called "linux,pci-domain" of the given device node. + * + * @node: device tree node with the domain information + * + * Returns the associated domain number from DT in the range [0-0xffff], or + * a negative value if the required property is not found. + */ +int of_get_pci_domain_nr(struct device_node *node) +{ + const __be32 *value; + int len; + u16 domain; + + value = of_get_property(node, "linux,pci-domain", &len); + if (!value || len < sizeof(*value)) + return -EINVAL; + + domain = (u16)be32_to_cpup(value); + + return domain; +} +EXPORT_SYMBOL_GPL(of_get_pci_domain_nr); + #ifdef CONFIG_PCI_MSI static LIST_HEAD(of_pci_msi_chip_list); diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 2c9ac70..d36f35f 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4406,6 +4406,15 @@ static void pci_no_domains(void) #endif } +#ifdef CONFIG_PCI_DOMAINS +static atomic_t __domain_nr = ATOMIC_INIT(-1); + +int pci_get_new_domain_nr(void) +{ + return atomic_inc_return(&__domain_nr); +} +#endif + /** * pci_ext_cfg_avail - can we access extended PCI config space? * diff --git a/include/linux/of_pci.h b/include/linux/of_pci.h index dde3a4a..71062e9 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_get_pci_domain_nr(struct device_node *node); #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_get_pci_domain_nr(struct device_node *node) +{ + return -1; +} #endif #if defined(CONFIG_OF) && defined(CONFIG_PCI_MSI) diff --git a/include/linux/pci.h b/include/linux/pci.h index a494e5d..150da2d 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1285,10 +1285,12 @@ void pci_cfg_access_unlock(struct pci_dev *dev); */ #ifdef CONFIG_PCI_DOMAINS extern int pci_domains_supported; +int pci_get_new_domain_nr(void); #else enum { pci_domains_supported = 0 }; static inline int pci_domain_nr(struct pci_bus *bus) { return 0; } static inline int pci_proc_domain(struct pci_bus *bus) { return 0; } +static inline int pci_get_new_domain_nr(void) { return -ENOSYS; } #endif /* CONFIG_PCI_DOMAINS */ /* @@ -1417,6 +1419,7 @@ static inline struct pci_dev *pci_get_bus_and_slot(unsigned int bus, static inline int pci_domain_nr(struct pci_bus *bus) { return 0; } static inline struct pci_dev *pci_dev_get(struct pci_dev *dev) { return NULL; } +static inline int pci_get_new_domain_nr(void) { return -ENOSYS; } #define dev_is_pci(d) (false) #define dev_is_pf(d) (false)