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 if (bus->self == NULL)
36 bus->dev.of_node = pcibios_get_phb_of_node(bus);
38 bus->dev.of_node = of_node_get(bus->self->dev.of_node);
41 void pci_release_bus_of_node(struct pci_bus *bus)
43 of_node_put(bus->dev.of_node);
44 bus->dev.of_node = NULL;
47 struct device_node * __weak pcibios_get_phb_of_node(struct pci_bus *bus)
49 /* This should only be called for PHBs */
50 if (WARN_ON(bus->self || bus->parent))
54 * Look for a node pointer in either the intermediary device we
55 * create above the root bus or its own parent. Normally only
56 * the later is populated.
58 if (bus->bridge->of_node)
59 return of_node_get(bus->bridge->of_node);
60 if (bus->bridge->parent && bus->bridge->parent->of_node)
61 return of_node_get(bus->bridge->parent->of_node);
65 struct irq_domain *pci_host_bridge_of_msi_domain(struct pci_bus *bus)
67 #ifdef CONFIG_IRQ_DOMAIN
70 if (!bus->dev.of_node)
73 /* Start looking for a phandle to an MSI controller. */
74 d = of_msi_get_domain(&bus->dev, bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
79 * If we don't have an msi-parent property, look for a domain
80 * directly attached to the host bridge.
82 d = irq_find_matching_host(bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
86 return irq_find_host(bus->dev.of_node);
92 static inline int __of_pci_pci_compare(struct device_node *node,
97 devfn = of_pci_get_devfn(node);
101 return devfn == data;
104 struct device_node *of_pci_find_child_device(struct device_node *parent,
107 struct device_node *node, *node2;
109 for_each_child_of_node(parent, node) {
110 if (__of_pci_pci_compare(node, devfn))
113 * Some OFs create a parent node "multifunc-device" as
114 * a fake root for all functions of a multi-function
115 * device we go down them as well.
117 if (of_node_name_eq(node, "multifunc-device")) {
118 for_each_child_of_node(node, node2) {
119 if (__of_pci_pci_compare(node2, devfn)) {
128 EXPORT_SYMBOL_GPL(of_pci_find_child_device);
131 * of_pci_get_devfn() - Get device and function numbers for a device node
134 * Parses a standard 5-cell PCI resource and returns an 8-bit value that can
135 * be passed to the PCI_SLOT() and PCI_FUNC() macros to extract the device
136 * and function numbers respectively. On error a negative error code is
139 int of_pci_get_devfn(struct device_node *np)
144 error = of_property_read_u32_array(np, "reg", reg, ARRAY_SIZE(reg));
148 return (reg[0] >> 8) & 0xff;
150 EXPORT_SYMBOL_GPL(of_pci_get_devfn);
153 * of_pci_parse_bus_range() - parse the bus-range property of a PCI device
155 * @res: address to a struct resource to return the bus-range
157 * Returns 0 on success or a negative error-code on failure.
159 int of_pci_parse_bus_range(struct device_node *node, struct resource *res)
164 error = of_property_read_u32_array(node, "bus-range", bus_range,
165 ARRAY_SIZE(bus_range));
169 res->name = node->name;
170 res->start = bus_range[0];
171 res->end = bus_range[1];
172 res->flags = IORESOURCE_BUS;
176 EXPORT_SYMBOL_GPL(of_pci_parse_bus_range);
179 * This function will try to obtain the host bridge domain number by
180 * finding a property called "linux,pci-domain" of the given device node.
182 * @node: device tree node with the domain information
184 * Returns the associated domain number from DT in the range [0-0xffff], or
185 * a negative value if the required property is not found.
187 int of_get_pci_domain_nr(struct device_node *node)
192 error = of_property_read_u32(node, "linux,pci-domain", &domain);
198 EXPORT_SYMBOL_GPL(of_get_pci_domain_nr);
201 * of_pci_check_probe_only - Setup probe only mode if linux,pci-probe-only
202 * is present and valid
204 void of_pci_check_probe_only(void)
209 ret = of_property_read_u32(of_chosen, "linux,pci-probe-only", &val);
211 if (ret == -ENODATA || ret == -EOVERFLOW)
212 pr_warn("linux,pci-probe-only without valid value, ignoring\n");
217 pci_add_flags(PCI_PROBE_ONLY);
219 pci_clear_flags(PCI_PROBE_ONLY);
221 pr_info("PROBE_ONLY %sabled\n", val ? "en" : "dis");
223 EXPORT_SYMBOL_GPL(of_pci_check_probe_only);
225 #if defined(CONFIG_OF_ADDRESS)
227 * devm_of_pci_get_host_bridge_resources() - Resource-managed parsing of PCI
228 * host bridge resources from DT
229 * @dev: host bridge device
230 * @busno: bus number associated with the bridge root bus
231 * @bus_max: maximum number of buses for this bridge
232 * @resources: list where the range of resources will be added after DT parsing
233 * @io_base: pointer to a variable that will contain on return the physical
234 * address for the start of the I/O range. Can be NULL if the caller doesn't
235 * expect I/O ranges to be present in the device tree.
237 * This function will parse the "ranges" property of a PCI host bridge device
238 * node and setup the resource mapping based on its content. It is expected
239 * that the property conforms with the Power ePAPR document.
241 * It returns zero if the range parsing has been successful or a standard error
242 * value if it failed.
244 int devm_of_pci_get_host_bridge_resources(struct device *dev,
245 unsigned char busno, unsigned char bus_max,
246 struct list_head *resources, resource_size_t *io_base)
248 struct device_node *dev_node = dev->of_node;
249 struct resource *res, tmp_res;
250 struct resource *bus_range;
251 struct of_pci_range range;
252 struct of_pci_range_parser parser;
257 *io_base = (resource_size_t)OF_BAD_ADDR;
259 bus_range = devm_kzalloc(dev, sizeof(*bus_range), GFP_KERNEL);
263 dev_info(dev, "host bridge %pOF ranges:\n", dev_node);
265 err = of_pci_parse_bus_range(dev_node, bus_range);
267 bus_range->start = busno;
268 bus_range->end = bus_max;
269 bus_range->flags = IORESOURCE_BUS;
270 dev_info(dev, " No bus range found for %pOF, using %pR\n",
271 dev_node, bus_range);
273 if (bus_range->end > bus_range->start + bus_max)
274 bus_range->end = bus_range->start + bus_max;
276 pci_add_resource(resources, bus_range);
278 /* Check for ranges property */
279 err = of_pci_range_parser_init(&parser, dev_node);
283 dev_dbg(dev, "Parsing ranges property...\n");
284 for_each_of_pci_range(&parser, &range) {
285 /* Read next ranges element */
286 if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO)
287 snprintf(range_type, 4, " IO");
288 else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM)
289 snprintf(range_type, 4, "MEM");
291 snprintf(range_type, 4, "err");
292 dev_info(dev, " %s %#010llx..%#010llx -> %#010llx\n",
293 range_type, range.cpu_addr,
294 range.cpu_addr + range.size - 1, range.pci_addr);
297 * If we failed translation or got a zero-sized region
298 * then skip this range
300 if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
303 err = of_pci_range_to_resource(&range, dev_node, &tmp_res);
307 res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL);
313 if (resource_type(res) == IORESOURCE_IO) {
315 dev_err(dev, "I/O range found for %pOF. Please provide an io_base pointer to save CPU base address\n",
320 if (*io_base != (resource_size_t)OF_BAD_ADDR)
321 dev_warn(dev, "More than one I/O resource converted for %pOF. CPU base address for old range lost!\n",
323 *io_base = range.cpu_addr;
326 pci_add_resource_offset(resources, res, res->start - range.pci_addr);
332 pci_free_resource_list(resources);
335 EXPORT_SYMBOL_GPL(devm_of_pci_get_host_bridge_resources);
336 #endif /* CONFIG_OF_ADDRESS */
338 #if IS_ENABLED(CONFIG_OF_IRQ)
340 * of_irq_parse_pci - Resolve the interrupt for a PCI device
341 * @pdev: the device whose interrupt is to be resolved
342 * @out_irq: structure of_irq filled by this function
344 * This function resolves the PCI interrupt for a given PCI device. If a
345 * device-node exists for a given pci_dev, it will use normal OF tree
346 * walking. If not, it will implement standard swizzling and walk up the
347 * PCI tree until an device-node is found, at which point it will finish
348 * resolving using the OF tree walking.
350 static int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq)
352 struct device_node *dn, *ppnode;
353 struct pci_dev *ppdev;
359 * Check if we have a device node, if yes, fallback to standard
360 * device tree parsing
362 dn = pci_device_to_OF_node(pdev);
364 rc = of_irq_parse_one(dn, 0, out_irq);
370 * Ok, we don't, time to have fun. Let's start by building up an
371 * interrupt spec. we assume #interrupt-cells is 1, which is standard
372 * for PCI. If you do different, then don't use that routine.
374 rc = pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin);
377 /* No pin, exit with no error message. */
381 /* Now we walk up the PCI tree */
383 /* Get the pci_dev of our parent */
384 ppdev = pdev->bus->self;
386 /* Ouch, it's a host bridge... */
388 ppnode = pci_bus_to_OF_node(pdev->bus);
390 /* No node for host bridge ? give up */
391 if (ppnode == NULL) {
396 /* We found a P2P bridge, check if it has a node */
397 ppnode = pci_device_to_OF_node(ppdev);
401 * Ok, we have found a parent with a device-node, hand over to
402 * the OF parsing code.
403 * We build a unit address from the linux device to be used for
404 * resolution. Note that we use the linux bus number which may
405 * not match your firmware bus numbering.
406 * Fortunately, in most cases, interrupt-map-mask doesn't
407 * include the bus number as part of the matching.
408 * You should still be careful about that though if you intend
409 * to rely on this function (you ship a firmware that doesn't
410 * create device nodes for all PCI devices).
416 * We can only get here if we hit a P2P bridge with no node;
417 * let's do standard swizzling and try again
419 pin = pci_swizzle_interrupt_pin(pdev, pin);
423 out_irq->np = ppnode;
424 out_irq->args_count = 1;
425 out_irq->args[0] = pin;
426 laddr[0] = cpu_to_be32((pdev->bus->number << 16) | (pdev->devfn << 8));
427 laddr[1] = laddr[2] = cpu_to_be32(0);
428 rc = of_irq_parse_raw(laddr, out_irq);
435 "%s: no interrupt-map found, INTx interrupts not available\n",
437 pr_warn_once("%s: possibly some PCI slots don't have level triggered interrupts capability\n",
440 dev_err(&pdev->dev, "%s: failed with rc=%d\n", __func__, rc);
446 * of_irq_parse_and_map_pci() - Decode a PCI IRQ from the device tree and map to a VIRQ
447 * @dev: The PCI device needing an IRQ
448 * @slot: PCI slot number; passed when used as map_irq callback. Unused
449 * @pin: PCI IRQ pin number; passed when used as map_irq callback. Unused
451 * @slot and @pin are unused, but included in the function so that this
452 * function can be used directly as the map_irq callback to
453 * pci_assign_irq() and struct pci_host_bridge.map_irq pointer
455 int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin)
457 struct of_phandle_args oirq;
460 ret = of_irq_parse_pci(dev, &oirq);
462 return 0; /* Proper return code 0 == NO_IRQ */
464 return irq_create_of_mapping(&oirq);
466 EXPORT_SYMBOL_GPL(of_irq_parse_and_map_pci);
467 #endif /* CONFIG_OF_IRQ */
469 int pci_parse_request_of_pci_ranges(struct device *dev,
470 struct list_head *resources,
471 struct resource **bus_range)
473 int err, res_valid = 0;
474 resource_size_t iobase;
475 struct resource_entry *win, *tmp;
477 INIT_LIST_HEAD(resources);
478 err = devm_of_pci_get_host_bridge_resources(dev, 0, 0xff, resources,
483 err = devm_request_pci_bus_resources(dev, resources);
485 goto out_release_res;
487 resource_list_for_each_entry_safe(win, tmp, resources) {
488 struct resource *res = win->res;
490 switch (resource_type(res)) {
492 err = devm_pci_remap_iospace(dev, res, iobase);
494 dev_warn(dev, "error %d: failed to map resource %pR\n",
496 resource_list_destroy_entry(win);
500 res_valid |= !(res->flags & IORESOURCE_PREFETCH);
512 dev_err(dev, "non-prefetchable memory resource required\n");
516 pci_free_resource_list(resources);
520 #endif /* CONFIG_PCI */
523 * This function will try to find the limitation of link speed by finding
524 * a property called "max-link-speed" of the given device node.
526 * @node: device tree node with the max link speed information
528 * Returns the associated max link speed from DT, or a negative value if the
529 * required property is not found or is invalid.
531 int of_pci_get_max_link_speed(struct device_node *node)
535 if (of_property_read_u32(node, "max-link-speed", &max_link_speed) ||
539 return max_link_speed;
541 EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed);