[PATCH v9 09/12] OF: Introduce helper function for getting PCI domain_nr
From: Liviu Dudau <Liviu.Dudau@arm.com>
Date: 2014-08-12 16:26:56
Also in:
linux-arch, linux-arm-kernel, linux-pci, lkml
Subsystem:
open firmware and flattened device tree, pci subsystem, the rest · Maintainers:
Rob Herring, Saravana Kannan, Bjorn Helgaas, Linus Torvalds
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 <bhelgaas@google.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Grant Likely <redacted> Cc: Rob Herring <robh+dt@kernel.org> Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com> --- drivers/of/of_pci.c | 34 ++++++++++++++++++++++++++++++++++ include/linux/of_pci.h | 7 +++++++ 2 files changed, 41 insertions(+)
diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
index 8481996..a107edb 100644
--- a/drivers/of/of_pci.c
+++ b/drivers/of/of_pci.c@@ -89,6 +89,40 @@ 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); + +/** + * 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 = of_alias_get_id(node, "pci-domain"); + if (domain == -ENODEV) { + if (allocate_if_missing) + domain = atomic_inc_return(&of_domain_nr); + else + domain = atomic_read(&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)
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2.0.4