1 // SPDX-License-Identifier: GPL-2.0+
3 * PCI <-> OF mapping helpers
5 * Copyright 2011 IBM Corp.
7 #define pr_fmt(fmt) "PCI: OF: " fmt
9 #include <linux/irqdomain.h>
10 #include <linux/kernel.h>
11 #include <linux/pci.h>
13 #include <linux/of_irq.h>
14 #include <linux/of_address.h>
15 #include <linux/of_pci.h>
19 void pci_set_of_node(struct pci_dev *dev)
21 if (!dev->bus->dev.of_node)
23 dev->dev.of_node = of_pci_find_child_device(dev->bus->dev.of_node,
27 void pci_release_of_node(struct pci_dev *dev)
29 of_node_put(dev->dev.of_node);
30 dev->dev.of_node = NULL;
33 void pci_set_bus_of_node(struct pci_bus *bus)
35 struct device_node *node;
37 if (bus->self == NULL) {
38 node = pcibios_get_phb_of_node(bus);
40 node = of_node_get(bus->self->dev.of_node);
41 if (node && of_property_read_bool(node, "external-facing"))
42 bus->self->untrusted = true;
44 bus->dev.of_node = node;
47 void pci_release_bus_of_node(struct pci_bus *bus)
49 of_node_put(bus->dev.of_node);
50 bus->dev.of_node = NULL;
53 struct device_node * __weak pcibios_get_phb_of_node(struct pci_bus *bus)
55 /* This should only be called for PHBs */
56 if (WARN_ON(bus->self || bus->parent))
60 * Look for a node pointer in either the intermediary device we
61 * create above the root bus or its own parent. Normally only
62 * the later is populated.
64 if (bus->bridge->of_node)
65 return of_node_get(bus->bridge->of_node);
66 if (bus->bridge->parent && bus->bridge->parent->of_node)
67 return of_node_get(bus->bridge->parent->of_node);
71 struct irq_domain *pci_host_bridge_of_msi_domain(struct pci_bus *bus)
73 #ifdef CONFIG_IRQ_DOMAIN
76 if (!bus->dev.of_node)
79 /* Start looking for a phandle to an MSI controller. */
80 d = of_msi_get_domain(&bus->dev, bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
85 * If we don't have an msi-parent property, look for a domain
86 * directly attached to the host bridge.
88 d = irq_find_matching_host(bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
92 return irq_find_host(bus->dev.of_node);
98 static inline int __of_pci_pci_compare(struct device_node *node,
103 devfn = of_pci_get_devfn(node);
107 return devfn == data;
110 struct device_node *of_pci_find_child_device(struct device_node *parent,
113 struct device_node *node, *node2;
115 for_each_child_of_node(parent, node) {
116 if (__of_pci_pci_compare(node, devfn))
119 * Some OFs create a parent node "multifunc-device" as
120 * a fake root for all functions of a multi-function
121 * device we go down them as well.
123 if (of_node_name_eq(node, "multifunc-device")) {
124 for_each_child_of_node(node, node2) {
125 if (__of_pci_pci_compare(node2, devfn)) {
134 EXPORT_SYMBOL_GPL(of_pci_find_child_device);
137 * of_pci_get_devfn() - Get device and function numbers for a device node
140 * Parses a standard 5-cell PCI resource and returns an 8-bit value that can
141 * be passed to the PCI_SLOT() and PCI_FUNC() macros to extract the device
142 * and function numbers respectively. On error a negative error code is
145 int of_pci_get_devfn(struct device_node *np)
150 error = of_property_read_u32_array(np, "reg", reg, ARRAY_SIZE(reg));
154 return (reg[0] >> 8) & 0xff;
156 EXPORT_SYMBOL_GPL(of_pci_get_devfn);
159 * of_pci_parse_bus_range() - parse the bus-range property of a PCI device
161 * @res: address to a struct resource to return the bus-range
163 * Returns 0 on success or a negative error-code on failure.
165 int of_pci_parse_bus_range(struct device_node *node, struct resource *res)
170 error = of_property_read_u32_array(node, "bus-range", bus_range,
171 ARRAY_SIZE(bus_range));
175 res->name = node->name;
176 res->start = bus_range[0];
177 res->end = bus_range[1];
178 res->flags = IORESOURCE_BUS;
182 EXPORT_SYMBOL_GPL(of_pci_parse_bus_range);
185 * This function will try to obtain the host bridge domain number by
186 * finding a property called "linux,pci-domain" of the given device node.
188 * @node: device tree node with the domain information
190 * Returns the associated domain number from DT in the range [0-0xffff], or
191 * a negative value if the required property is not found.
193 int of_get_pci_domain_nr(struct device_node *node)
198 error = of_property_read_u32(node, "linux,pci-domain", &domain);
204 EXPORT_SYMBOL_GPL(of_get_pci_domain_nr);
207 * of_pci_check_probe_only - Setup probe only mode if linux,pci-probe-only
208 * is present and valid
210 void of_pci_check_probe_only(void)
215 ret = of_property_read_u32(of_chosen, "linux,pci-probe-only", &val);
217 if (ret == -ENODATA || ret == -EOVERFLOW)
218 pr_warn("linux,pci-probe-only without valid value, ignoring\n");
223 pci_add_flags(PCI_PROBE_ONLY);
225 pci_clear_flags(PCI_PROBE_ONLY);
227 pr_info("PROBE_ONLY %sabled\n", val ? "en" : "dis");
229 EXPORT_SYMBOL_GPL(of_pci_check_probe_only);
231 #if defined(CONFIG_OF_ADDRESS)
233 * devm_of_pci_get_host_bridge_resources() - Resource-managed parsing of PCI
234 * host bridge resources from DT
235 * @dev: host bridge device
236 * @busno: bus number associated with the bridge root bus
237 * @bus_max: maximum number of buses for this bridge
238 * @resources: list where the range of resources will be added after DT parsing
239 * @io_base: pointer to a variable that will contain on return the physical
240 * address for the start of the I/O range. Can be NULL if the caller doesn't
241 * expect I/O ranges to be present in the device tree.
243 * This function will parse the "ranges" property of a PCI host bridge device
244 * node and setup the resource mapping based on its content. It is expected
245 * that the property conforms with the Power ePAPR document.
247 * It returns zero if the range parsing has been successful or a standard error
248 * value if it failed.
250 int devm_of_pci_get_host_bridge_resources(struct device *dev,
251 unsigned char busno, unsigned char bus_max,
252 struct list_head *resources, resource_size_t *io_base)
254 struct device_node *dev_node = dev->of_node;
255 struct resource *res, tmp_res;
256 struct resource *bus_range;
257 struct of_pci_range range;
258 struct of_pci_range_parser parser;
263 *io_base = (resource_size_t)OF_BAD_ADDR;
265 bus_range = devm_kzalloc(dev, sizeof(*bus_range), GFP_KERNEL);
269 dev_info(dev, "host bridge %pOF ranges:\n", dev_node);
271 err = of_pci_parse_bus_range(dev_node, bus_range);
273 bus_range->start = busno;
274 bus_range->end = bus_max;
275 bus_range->flags = IORESOURCE_BUS;
276 dev_info(dev, " No bus range found for %pOF, using %pR\n",
277 dev_node, bus_range);
279 if (bus_range->end > bus_range->start + bus_max)
280 bus_range->end = bus_range->start + bus_max;
282 pci_add_resource(resources, bus_range);
284 /* Check for ranges property */
285 err = of_pci_range_parser_init(&parser, dev_node);
289 dev_dbg(dev, "Parsing ranges property...\n");
290 for_each_of_pci_range(&parser, &range) {
291 /* Read next ranges element */
292 if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO)
293 snprintf(range_type, 4, " IO");
294 else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM)
295 snprintf(range_type, 4, "MEM");
297 snprintf(range_type, 4, "err");
298 dev_info(dev, " %s %#010llx..%#010llx -> %#010llx\n",
299 range_type, range.cpu_addr,
300 range.cpu_addr + range.size - 1, range.pci_addr);
303 * If we failed translation or got a zero-sized region
304 * then skip this range
306 if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
309 err = of_pci_range_to_resource(&range, dev_node, &tmp_res);
313 res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL);
319 if (resource_type(res) == IORESOURCE_IO) {
321 dev_err(dev, "I/O range found for %pOF. Please provide an io_base pointer to save CPU base address\n",
326 if (*io_base != (resource_size_t)OF_BAD_ADDR)
327 dev_warn(dev, "More than one I/O resource converted for %pOF. CPU base address for old range lost!\n",
329 *io_base = range.cpu_addr;
332 pci_add_resource_offset(resources, res, res->start - range.pci_addr);
338 pci_free_resource_list(resources);
341 EXPORT_SYMBOL_GPL(devm_of_pci_get_host_bridge_resources);
342 #endif /* CONFIG_OF_ADDRESS */
344 #if IS_ENABLED(CONFIG_OF_IRQ)
346 * of_irq_parse_pci - Resolve the interrupt for a PCI device
347 * @pdev: the device whose interrupt is to be resolved
348 * @out_irq: structure of_irq filled by this function
350 * This function resolves the PCI interrupt for a given PCI device. If a
351 * device-node exists for a given pci_dev, it will use normal OF tree
352 * walking. If not, it will implement standard swizzling and walk up the
353 * PCI tree until an device-node is found, at which point it will finish
354 * resolving using the OF tree walking.
356 static int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq)
358 struct device_node *dn, *ppnode;
359 struct pci_dev *ppdev;
365 * Check if we have a device node, if yes, fallback to standard
366 * device tree parsing
368 dn = pci_device_to_OF_node(pdev);
370 rc = of_irq_parse_one(dn, 0, out_irq);
376 * Ok, we don't, time to have fun. Let's start by building up an
377 * interrupt spec. we assume #interrupt-cells is 1, which is standard
378 * for PCI. If you do different, then don't use that routine.
380 rc = pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin);
383 /* No pin, exit with no error message. */
387 /* Now we walk up the PCI tree */
389 /* Get the pci_dev of our parent */
390 ppdev = pdev->bus->self;
392 /* Ouch, it's a host bridge... */
394 ppnode = pci_bus_to_OF_node(pdev->bus);
396 /* No node for host bridge ? give up */
397 if (ppnode == NULL) {
402 /* We found a P2P bridge, check if it has a node */
403 ppnode = pci_device_to_OF_node(ppdev);
407 * Ok, we have found a parent with a device-node, hand over to
408 * the OF parsing code.
409 * We build a unit address from the linux device to be used for
410 * resolution. Note that we use the linux bus number which may
411 * not match your firmware bus numbering.
412 * Fortunately, in most cases, interrupt-map-mask doesn't
413 * include the bus number as part of the matching.
414 * You should still be careful about that though if you intend
415 * to rely on this function (you ship a firmware that doesn't
416 * create device nodes for all PCI devices).
422 * We can only get here if we hit a P2P bridge with no node;
423 * let's do standard swizzling and try again
425 pin = pci_swizzle_interrupt_pin(pdev, pin);
429 out_irq->np = ppnode;
430 out_irq->args_count = 1;
431 out_irq->args[0] = pin;
432 laddr[0] = cpu_to_be32((pdev->bus->number << 16) | (pdev->devfn << 8));
433 laddr[1] = laddr[2] = cpu_to_be32(0);
434 rc = of_irq_parse_raw(laddr, out_irq);
441 "%s: no interrupt-map found, INTx interrupts not available\n",
443 pr_warn_once("%s: possibly some PCI slots don't have level triggered interrupts capability\n",
446 dev_err(&pdev->dev, "%s: failed with rc=%d\n", __func__, rc);
452 * of_irq_parse_and_map_pci() - Decode a PCI IRQ from the device tree and map to a VIRQ
453 * @dev: The PCI device needing an IRQ
454 * @slot: PCI slot number; passed when used as map_irq callback. Unused
455 * @pin: PCI IRQ pin number; passed when used as map_irq callback. Unused
457 * @slot and @pin are unused, but included in the function so that this
458 * function can be used directly as the map_irq callback to
459 * pci_assign_irq() and struct pci_host_bridge.map_irq pointer
461 int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin)
463 struct of_phandle_args oirq;
466 ret = of_irq_parse_pci(dev, &oirq);
468 return 0; /* Proper return code 0 == NO_IRQ */
470 return irq_create_of_mapping(&oirq);
472 EXPORT_SYMBOL_GPL(of_irq_parse_and_map_pci);
473 #endif /* CONFIG_OF_IRQ */
475 int pci_parse_request_of_pci_ranges(struct device *dev,
476 struct list_head *resources,
477 struct resource **bus_range)
479 int err, res_valid = 0;
480 resource_size_t iobase;
481 struct resource_entry *win, *tmp;
483 INIT_LIST_HEAD(resources);
484 err = devm_of_pci_get_host_bridge_resources(dev, 0, 0xff, resources,
489 err = devm_request_pci_bus_resources(dev, resources);
491 goto out_release_res;
493 resource_list_for_each_entry_safe(win, tmp, resources) {
494 struct resource *res = win->res;
496 switch (resource_type(res)) {
498 err = devm_pci_remap_iospace(dev, res, iobase);
500 dev_warn(dev, "error %d: failed to map resource %pR\n",
502 resource_list_destroy_entry(win);
506 res_valid |= !(res->flags & IORESOURCE_PREFETCH);
518 dev_err(dev, "non-prefetchable memory resource required\n");
522 pci_free_resource_list(resources);
526 #endif /* CONFIG_PCI */
529 * This function will try to find the limitation of link speed by finding
530 * a property called "max-link-speed" of the given device node.
532 * @node: device tree node with the max link speed information
534 * Returns the associated max link speed from DT, or a negative value if the
535 * required property is not found or is invalid.
537 int of_pci_get_max_link_speed(struct device_node *node)
541 if (of_property_read_u32(node, "max-link-speed", &max_link_speed) ||
545 return max_link_speed;
547 EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed);