// SPDX-License-Identifier: GPL-2.0+ /* * PCI <-> OF mapping helpers * * Copyright 2011 IBM Corp. */ #define pr_fmt(fmt) "PCI: OF: " fmt #include #include #include #include #include #include #include #include "pci.h" #ifdef CONFIG_PCI void pci_set_of_node(struct pci_dev *dev) { if (!dev->bus->dev.of_node) return; dev->dev.of_node = of_pci_find_child_device(dev->bus->dev.of_node, dev->devfn); if (dev->dev.of_node) dev->dev.fwnode = &dev->dev.of_node->fwnode; } void pci_release_of_node(struct pci_dev *dev) { of_node_put(dev->dev.of_node); dev->dev.of_node = NULL; dev->dev.fwnode = NULL; } void pci_set_bus_of_node(struct pci_bus *bus) { struct device_node *node; if (bus->self == NULL) { node = pcibios_get_phb_of_node(bus); } else { node = of_node_get(bus->self->dev.of_node); if (node && of_property_read_bool(node, "external-facing")) bus->self->untrusted = true; } bus->dev.of_node = node; if (bus->dev.of_node) bus->dev.fwnode = &bus->dev.of_node->fwnode; } void pci_release_bus_of_node(struct pci_bus *bus) { of_node_put(bus->dev.of_node); bus->dev.of_node = NULL; bus->dev.fwnode = NULL; } struct device_node * __weak pcibios_get_phb_of_node(struct pci_bus *bus) { /* This should only be called for PHBs */ if (WARN_ON(bus->self || bus->parent)) return NULL; /* * Look for a node pointer in either the intermediary device we * create above the root bus or its own parent. Normally only * the later is populated. */ if (bus->bridge->of_node) return of_node_get(bus->bridge->of_node); if (bus->bridge->parent && bus->bridge->parent->of_node) return of_node_get(bus->bridge->parent->of_node); return NULL; } struct irq_domain *pci_host_bridge_of_msi_domain(struct pci_bus *bus) { #ifdef CONFIG_IRQ_DOMAIN struct irq_domain *d; if (!bus->dev.of_node) return NULL; /* Start looking for a phandle to an MSI controller. */ d = of_msi_get_domain(&bus->dev, bus->dev.of_node, DOMAIN_BUS_PCI_MSI); if (d) return d; /* * If we don't have an msi-parent property, look for a domain * directly attached to the host bridge. */ d = irq_find_matching_host(bus->dev.of_node, DOMAIN_BUS_PCI_MSI); if (d) return d; return irq_find_host(bus->dev.of_node); #else return NULL; #endif } static inline int __of_pci_pci_compare(struct device_node *node, unsigned int data) { int devfn; devfn = of_pci_get_devfn(node); if (devfn < 0) return 0; return devfn == data; } struct device_node *of_pci_find_child_device(struct device_node *parent, unsigned int devfn) { struct device_node *node, *node2; for_each_child_of_node(parent, node) { if (__of_pci_pci_compare(node, devfn)) return node; /* * Some OFs create a parent node "multifunc-device" as * a fake root for all functions of a multi-function * device we go down them as well. */ if (of_node_name_eq(node, "multifunc-device")) { for_each_child_of_node(node, node2) { if (__of_pci_pci_compare(node2, devfn)) { of_node_put(node); return node2; } } } } return NULL; } EXPORT_SYMBOL_GPL(of_pci_find_child_device); /** * of_pci_get_devfn() - Get device and function numbers for a device node * @np: device node * * Parses a standard 5-cell PCI resource and returns an 8-bit value that can * be passed to the PCI_SLOT() and PCI_FUNC() macros to extract the device * and function numbers respectively. On error a negative error code is * returned. */ int of_pci_get_devfn(struct device_node *np) { u32 reg[5]; int error; error = of_property_read_u32_array(np, "reg", reg, ARRAY_SIZE(reg)); if (error) return error; return (reg[0] >> 8) & 0xff; } EXPORT_SYMBOL_GPL(of_pci_get_devfn); /** * of_pci_parse_bus_range() - parse the bus-range property of a PCI device * @node: device node * @res: address to a struct resource to return the bus-range * * Returns 0 on success or a negative error-code on failure. */ int of_pci_parse_bus_range(struct device_node *node, struct resource *res) { u32 bus_range[2]; int error; error = of_property_read_u32_array(node, "bus-range", bus_range, ARRAY_SIZE(bus_range)); if (error) return error; res->name = node->name; res->start = bus_range[0]; res->end = bus_range[1]; res->flags = IORESOURCE_BUS; return 0; } 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) { u32 domain; int error; error = of_property_read_u32(node, "linux,pci-domain", &domain); if (error) return error; return (u16)domain; } EXPORT_SYMBOL_GPL(of_get_pci_domain_nr); /** * of_pci_check_probe_only - Setup probe only mode if linux,pci-probe-only * is present and valid */ void of_pci_check_probe_only(void) { u32 val; int ret; ret = of_property_read_u32(of_chosen, "linux,pci-probe-only", &val); if (ret) { if (ret == -ENODATA || ret == -EOVERFLOW) pr_warn("linux,pci-probe-only without valid value, ignoring\n"); return; } if (val) pci_add_flags(PCI_PROBE_ONLY); else pci_clear_flags(PCI_PROBE_ONLY); pr_info("PROBE_ONLY %sabled\n", val ? "en" : "dis"); } EXPORT_SYMBOL_GPL(of_pci_check_probe_only); #if defined(CONFIG_OF_ADDRESS) /** * devm_of_pci_get_host_bridge_resources() - Resource-managed parsing of PCI * host bridge resources from DT * @dev: host bridge device * @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 I/O ranges to be present in the device tree. * * 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 devm_of_pci_get_host_bridge_resources(struct device *dev, unsigned char busno, unsigned char bus_max, struct list_head *resources, resource_size_t *io_base) { struct device_node *dev_node = dev->of_node; struct resource *res, tmp_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 = devm_kzalloc(dev, sizeof(*bus_range), GFP_KERNEL); if (!bus_range) return -ENOMEM; dev_info(dev, "host bridge %pOF ranges:\n", dev_node); err = of_pci_parse_bus_range(dev_node, bus_range); if (err) { bus_range->start = busno; bus_range->end = bus_max; bus_range->flags = IORESOURCE_BUS; dev_info(dev, " No bus range found for %pOF, using %pR\n", dev_node, 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_node); if (err) goto failed; dev_dbg(dev, "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"); dev_info(dev, " %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; err = of_pci_range_to_resource(&range, dev_node, &tmp_res); if (err) continue; res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL); if (!res) { err = -ENOMEM; goto failed; } if (resource_type(res) == IORESOURCE_IO) { if (!io_base) { dev_err(dev, "I/O range found for %pOF. Please provide an io_base pointer to save CPU base address\n", dev_node); err = -EINVAL; goto failed; } if (*io_base != (resource_size_t)OF_BAD_ADDR) dev_warn(dev, "More than one I/O resource converted for %pOF. CPU base address for old range lost!\n", dev_node); *io_base = range.cpu_addr; } pci_add_resource_offset(resources, res, res->start - range.pci_addr); } return 0; failed: pci_free_resource_list(resources); return err; } EXPORT_SYMBOL_GPL(devm_of_pci_get_host_bridge_resources); #endif /* CONFIG_OF_ADDRESS */ #if IS_ENABLED(CONFIG_OF_IRQ) /** * of_irq_parse_pci - Resolve the interrupt for a PCI device * @pdev: the device whose interrupt is to be resolved * @out_irq: structure of_phandle_args filled by this function * * This function resolves the PCI interrupt for a given PCI device. If a * device-node exists for a given pci_dev, it will use normal OF tree * walking. If not, it will implement standard swizzling and walk up the * PCI tree until an device-node is found, at which point it will finish * resolving using the OF tree walking. */ static int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq) { struct device_node *dn, *ppnode; struct pci_dev *ppdev; __be32 laddr[3]; u8 pin; int rc; /* * Check if we have a device node, if yes, fallback to standard * device tree parsing */ dn = pci_device_to_OF_node(pdev); if (dn) { rc = of_irq_parse_one(dn, 0, out_irq); if (!rc) return rc; } /* * Ok, we don't, time to have fun. Let's start by building up an * interrupt spec. we assume #interrupt-cells is 1, which is standard * for PCI. If you do different, then don't use that routine. */ rc = pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin); if (rc != 0) goto err; /* No pin, exit with no error message. */ if (pin == 0) return -ENODEV; /* Now we walk up the PCI tree */ for (;;) { /* Get the pci_dev of our parent */ ppdev = pdev->bus->self; /* Ouch, it's a host bridge... */ if (ppdev == NULL) { ppnode = pci_bus_to_OF_node(pdev->bus); /* No node for host bridge ? give up */ if (ppnode == NULL) { rc = -EINVAL; goto err; } } else { /* We found a P2P bridge, check if it has a node */ ppnode = pci_device_to_OF_node(ppdev); } /* * Ok, we have found a parent with a device-node, hand over to * the OF parsing code. * We build a unit address from the linux device to be used for * resolution. Note that we use the linux bus number which may * not match your firmware bus numbering. * Fortunately, in most cases, interrupt-map-mask doesn't * include the bus number as part of the matching. * You should still be careful about that though if you intend * to rely on this function (you ship a firmware that doesn't * create device nodes for all PCI devices). */ if (ppnode) break; /* * We can only get here if we hit a P2P bridge with no node; * let's do standard swizzling and try again */ pin = pci_swizzle_interrupt_pin(pdev, pin); pdev = ppdev; } out_irq->np = ppnode; out_irq->args_count = 1; out_irq->args[0] = pin; laddr[0] = cpu_to_be32((pdev->bus->number << 16) | (pdev->devfn << 8)); laddr[1] = laddr[2] = cpu_to_be32(0); rc = of_irq_parse_raw(laddr, out_irq); if (rc) goto err; return 0; err: if (rc == -ENOENT) { dev_warn(&pdev->dev, "%s: no interrupt-map found, INTx interrupts not available\n", __func__); pr_warn_once("%s: possibly some PCI slots don't have level triggered interrupts capability\n", __func__); } else { dev_err(&pdev->dev, "%s: failed with rc=%d\n", __func__, rc); } return rc; } /** * of_irq_parse_and_map_pci() - Decode a PCI IRQ from the device tree and map to a VIRQ * @dev: The PCI device needing an IRQ * @slot: PCI slot number; passed when used as map_irq callback. Unused * @pin: PCI IRQ pin number; passed when used as map_irq callback. Unused * * @slot and @pin are unused, but included in the function so that this * function can be used directly as the map_irq callback to * pci_assign_irq() and struct pci_host_bridge.map_irq pointer */ int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin) { struct of_phandle_args oirq; int ret; ret = of_irq_parse_pci(dev, &oirq); if (ret) return 0; /* Proper return code 0 == NO_IRQ */ return irq_create_of_mapping(&oirq); } EXPORT_SYMBOL_GPL(of_irq_parse_and_map_pci); #endif /* CONFIG_OF_IRQ */ int pci_parse_request_of_pci_ranges(struct device *dev, struct list_head *resources, struct resource **bus_range) { int err, res_valid = 0; resource_size_t iobase; struct resource_entry *win, *tmp; INIT_LIST_HEAD(resources); err = devm_of_pci_get_host_bridge_resources(dev, 0, 0xff, resources, &iobase); if (err) return err; err = devm_request_pci_bus_resources(dev, resources); if (err) goto out_release_res; resource_list_for_each_entry_safe(win, tmp, resources) { struct resource *res = win->res; switch (resource_type(res)) { case IORESOURCE_IO: err = devm_pci_remap_iospace(dev, res, iobase); if (err) { dev_warn(dev, "error %d: failed to map resource %pR\n", err, res); resource_list_destroy_entry(win); } break; case IORESOURCE_MEM: res_valid |= !(res->flags & IORESOURCE_PREFETCH); break; case IORESOURCE_BUS: if (bus_range) *bus_range = res; break; } } if (res_valid) return 0; dev_err(dev, "non-prefetchable memory resource required\n"); err = -EINVAL; out_release_res: pci_free_resource_list(resources); return err; } EXPORT_SYMBOL_GPL(pci_parse_request_of_pci_ranges); #endif /* CONFIG_PCI */ /** * This function will try to find the limitation of link speed by finding * a property called "max-link-speed" of the given device node. * * @node: device tree node with the max link speed information * * Returns the associated max link speed from DT, or a negative value if the * required property is not found or is invalid. */ int of_pci_get_max_link_speed(struct device_node *node) { u32 max_link_speed; if (of_property_read_u32(node, "max-link-speed", &max_link_speed) || max_link_speed > 4) return -EINVAL; return max_link_speed; } EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed);