diff options
Diffstat (limited to 'drivers/of/of_pci.c')
| -rw-r--r-- | drivers/of/of_pci.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c index 848199633798..8882b467be95 100644 --- a/drivers/of/of_pci.c +++ b/drivers/of/of_pci.c @@ -1,7 +1,9 @@ #include <linux/kernel.h> #include <linux/export.h> #include <linux/of.h> +#include <linux/of_address.h> #include <linux/of_pci.h> +#include <linux/slab.h> static inline int __of_pci_pci_compare(struct device_node *node, unsigned int data) @@ -89,6 +91,146 @@ 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); + +#if defined(CONFIG_OF_ADDRESS) +/** + * of_pci_get_host_bridge_resources - Parse PCI host bridge resources from DT + * @dev: device node of the host bridge having the range property + * @busno: bus number associated with the bridge root bus + * @bus_max: maximum number of buses for this bridge + * @resources: list where the range of resources will be added after DT parsing + * @io_base: pointer to a variable that will contain on return the physical + * address for the start of the I/O range. Can be NULL if the caller doesn't + * expect IO ranges to be present in the device tree. + * + * It is the caller's job to free the @resources list. + * + * This function will parse the "ranges" property of a PCI host bridge device + * node and setup the resource mapping based on its content. It is expected + * that the property conforms with the Power ePAPR document. + * + * It returns zero if the range parsing has been successful or a standard error + * value if it failed. + */ +int of_pci_get_host_bridge_resources(struct device_node *dev, + unsigned char busno, unsigned char bus_max, + struct list_head *resources, resource_size_t *io_base) +{ + struct resource *res; + struct resource *bus_range; + struct of_pci_range range; + struct of_pci_range_parser parser; + char range_type[4]; + int err; + + if (io_base) + *io_base = (resource_size_t)OF_BAD_ADDR; + + bus_range = kzalloc(sizeof(*bus_range), GFP_KERNEL); + if (!bus_range) + return -ENOMEM; + + pr_info("PCI host bridge %s ranges:\n", dev->full_name); + + err = of_pci_parse_bus_range(dev, bus_range); + if (err) { + bus_range->start = busno; + bus_range->end = bus_max; + bus_range->flags = IORESOURCE_BUS; + pr_info(" No bus range found for %s, using %pR\n", + dev->full_name, bus_range); + } else { + if (bus_range->end > bus_range->start + bus_max) + bus_range->end = bus_range->start + bus_max; + } + pci_add_resource(resources, bus_range); + + /* Check for ranges property */ + err = of_pci_range_parser_init(&parser, dev); + if (err) + goto parse_failed; + + pr_debug("Parsing ranges property...\n"); + for_each_of_pci_range(&parser, &range) { + /* Read next ranges element */ + if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO) + snprintf(range_type, 4, " IO"); + else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM) + snprintf(range_type, 4, "MEM"); + else + snprintf(range_type, 4, "err"); + pr_info(" %s %#010llx..%#010llx -> %#010llx\n", range_type, + range.cpu_addr, range.cpu_addr + range.size - 1, + range.pci_addr); + + /* + * If we failed translation or got a zero-sized region + * then skip this range + */ + if (range.cpu_addr == OF_BAD_ADDR || range.size == 0) + continue; + + res = kzalloc(sizeof(struct resource), GFP_KERNEL); + if (!res) { + err = -ENOMEM; + goto parse_failed; + } + + err = of_pci_range_to_resource(&range, dev, res); + if (err) + goto conversion_failed; + + if (resource_type(res) == IORESOURCE_IO) { + if (!io_base) { + pr_err("I/O range found for %s. Please provide an io_base pointer to save CPU base address\n", + dev->full_name); + err = -EINVAL; + goto conversion_failed; + } + if (*io_base != (resource_size_t)OF_BAD_ADDR) + pr_warn("More than one I/O resource converted for %s. CPU base address for old range lost!\n", + dev->full_name); + *io_base = range.cpu_addr; + } + + pci_add_resource_offset(resources, res, res->start - range.pci_addr); + } + + return 0; + +conversion_failed: + kfree(res); +parse_failed: + pci_free_resource_list(resources); + return err; +} +EXPORT_SYMBOL_GPL(of_pci_get_host_bridge_resources); +#endif /* CONFIG_OF_ADDRESS */ + #ifdef CONFIG_PCI_MSI static LIST_HEAD(of_pci_msi_chip_list); |