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,
26 dev->dev.fwnode = &dev->dev.of_node->fwnode;
29 void pci_release_of_node(struct pci_dev *dev)
31 of_node_put(dev->dev.of_node);
32 dev->dev.of_node = NULL;
33 dev->dev.fwnode = NULL;
36 void pci_set_bus_of_node(struct pci_bus *bus)
38 struct device_node *node;
40 if (bus->self == NULL) {
41 node = pcibios_get_phb_of_node(bus);
43 node = of_node_get(bus->self->dev.of_node);
44 if (node && of_property_read_bool(node, "external-facing"))
45 bus->self->external_facing = true;
48 bus->dev.of_node = node;
51 bus->dev.fwnode = &bus->dev.of_node->fwnode;
54 void pci_release_bus_of_node(struct pci_bus *bus)
56 of_node_put(bus->dev.of_node);
57 bus->dev.of_node = NULL;
58 bus->dev.fwnode = NULL;
61 struct device_node * __weak pcibios_get_phb_of_node(struct pci_bus *bus)
63 /* This should only be called for PHBs */
64 if (WARN_ON(bus->self || bus->parent))
68 * Look for a node pointer in either the intermediary device we
69 * create above the root bus or its own parent. Normally only
70 * the later is populated.
72 if (bus->bridge->of_node)
73 return of_node_get(bus->bridge->of_node);
74 if (bus->bridge->parent && bus->bridge->parent->of_node)
75 return of_node_get(bus->bridge->parent->of_node);
79 struct irq_domain *pci_host_bridge_of_msi_domain(struct pci_bus *bus)
81 #ifdef CONFIG_IRQ_DOMAIN
84 if (!bus->dev.of_node)
87 /* Start looking for a phandle to an MSI controller. */
88 d = of_msi_get_domain(&bus->dev, bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
93 * If we don't have an msi-parent property, look for a domain
94 * directly attached to the host bridge.
96 d = irq_find_matching_host(bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
100 return irq_find_host(bus->dev.of_node);
106 static inline int __of_pci_pci_compare(struct device_node *node,
111 devfn = of_pci_get_devfn(node);
115 return devfn == data;
118 struct device_node *of_pci_find_child_device(struct device_node *parent,
121 struct device_node *node, *node2;
123 for_each_child_of_node(parent, node) {
124 if (__of_pci_pci_compare(node, devfn))
127 * Some OFs create a parent node "multifunc-device" as
128 * a fake root for all functions of a multi-function
129 * device we go down them as well.
131 if (of_node_name_eq(node, "multifunc-device")) {
132 for_each_child_of_node(node, node2) {
133 if (__of_pci_pci_compare(node2, devfn)) {
142 EXPORT_SYMBOL_GPL(of_pci_find_child_device);
145 * of_pci_get_devfn() - Get device and function numbers for a device node
148 * Parses a standard 5-cell PCI resource and returns an 8-bit value that can
149 * be passed to the PCI_SLOT() and PCI_FUNC() macros to extract the device
150 * and function numbers respectively. On error a negative error code is
153 int of_pci_get_devfn(struct device_node *np)
158 error = of_property_read_u32_array(np, "reg", reg, ARRAY_SIZE(reg));
162 return (reg[0] >> 8) & 0xff;
164 EXPORT_SYMBOL_GPL(of_pci_get_devfn);
167 * of_pci_parse_bus_range() - parse the bus-range property of a PCI device
169 * @res: address to a struct resource to return the bus-range
171 * Returns 0 on success or a negative error-code on failure.
173 int of_pci_parse_bus_range(struct device_node *node, struct resource *res)
178 error = of_property_read_u32_array(node, "bus-range", bus_range,
179 ARRAY_SIZE(bus_range));
183 res->name = node->name;
184 res->start = bus_range[0];
185 res->end = bus_range[1];
186 res->flags = IORESOURCE_BUS;
190 EXPORT_SYMBOL_GPL(of_pci_parse_bus_range);
193 * of_get_pci_domain_nr - Find the host bridge domain number
194 * of the given device node.
195 * @node: Device tree node with the domain information.
197 * This function will try to obtain the host bridge domain number by finding
198 * a property called "linux,pci-domain" of the given device node.
201 * * > 0 - On success, an associated domain number.
202 * * -EINVAL - The property "linux,pci-domain" does not exist.
203 * * -ENODATA - The linux,pci-domain" property does not have value.
204 * * -EOVERFLOW - Invalid "linux,pci-domain" property value.
206 * Returns the associated domain number from DT in the range [0-0xffff], or
207 * a negative value if the required property is not found.
209 int of_get_pci_domain_nr(struct device_node *node)
214 error = of_property_read_u32(node, "linux,pci-domain", &domain);
220 EXPORT_SYMBOL_GPL(of_get_pci_domain_nr);
223 * of_pci_check_probe_only - Setup probe only mode if linux,pci-probe-only
224 * is present and valid
226 void of_pci_check_probe_only(void)
231 ret = of_property_read_u32(of_chosen, "linux,pci-probe-only", &val);
233 if (ret == -ENODATA || ret == -EOVERFLOW)
234 pr_warn("linux,pci-probe-only without valid value, ignoring\n");
239 pci_add_flags(PCI_PROBE_ONLY);
241 pci_clear_flags(PCI_PROBE_ONLY);
243 pr_info("PROBE_ONLY %sabled\n", val ? "en" : "dis");
245 EXPORT_SYMBOL_GPL(of_pci_check_probe_only);
248 * devm_of_pci_get_host_bridge_resources() - Resource-managed parsing of PCI
249 * host bridge resources from DT
250 * @dev: host bridge device
251 * @busno: bus number associated with the bridge root bus
252 * @bus_max: maximum number of buses for this bridge
253 * @resources: list where the range of resources will be added after DT parsing
254 * @ib_resources: list where the range of inbound resources (with addresses
255 * from 'dma-ranges') will be added after DT parsing
256 * @io_base: pointer to a variable that will contain on return the physical
257 * address for the start of the I/O range. Can be NULL if the caller doesn't
258 * expect I/O ranges to be present in the device tree.
260 * This function will parse the "ranges" property of a PCI host bridge device
261 * node and setup the resource mapping based on its content. It is expected
262 * that the property conforms with the Power ePAPR document.
264 * It returns zero if the range parsing has been successful or a standard error
265 * value if it failed.
267 static int devm_of_pci_get_host_bridge_resources(struct device *dev,
268 unsigned char busno, unsigned char bus_max,
269 struct list_head *resources,
270 struct list_head *ib_resources,
271 resource_size_t *io_base)
273 struct device_node *dev_node = dev->of_node;
274 struct resource *res, tmp_res;
275 struct resource *bus_range;
276 struct of_pci_range range;
277 struct of_pci_range_parser parser;
278 const char *range_type;
282 *io_base = (resource_size_t)OF_BAD_ADDR;
284 bus_range = devm_kzalloc(dev, sizeof(*bus_range), GFP_KERNEL);
288 dev_info(dev, "host bridge %pOF ranges:\n", dev_node);
290 err = of_pci_parse_bus_range(dev_node, bus_range);
292 bus_range->start = busno;
293 bus_range->end = bus_max;
294 bus_range->flags = IORESOURCE_BUS;
295 dev_info(dev, " No bus range found for %pOF, using %pR\n",
296 dev_node, bus_range);
298 if (bus_range->end > bus_range->start + bus_max)
299 bus_range->end = bus_range->start + bus_max;
301 pci_add_resource(resources, bus_range);
303 /* Check for ranges property */
304 err = of_pci_range_parser_init(&parser, dev_node);
308 dev_dbg(dev, "Parsing ranges property...\n");
309 for_each_of_pci_range(&parser, &range) {
310 /* Read next ranges element */
311 if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO)
313 else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM)
317 dev_info(dev, " %6s %#012llx..%#012llx -> %#012llx\n",
318 range_type, range.cpu_addr,
319 range.cpu_addr + range.size - 1, range.pci_addr);
322 * If we failed translation or got a zero-sized region
323 * then skip this range
325 if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
328 err = of_pci_range_to_resource(&range, dev_node, &tmp_res);
332 res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL);
338 if (resource_type(res) == IORESOURCE_IO) {
340 dev_err(dev, "I/O range found for %pOF. Please provide an io_base pointer to save CPU base address\n",
345 if (*io_base != (resource_size_t)OF_BAD_ADDR)
346 dev_warn(dev, "More than one I/O resource converted for %pOF. CPU base address for old range lost!\n",
348 *io_base = range.cpu_addr;
351 pci_add_resource_offset(resources, res, res->start - range.pci_addr);
354 /* Check for dma-ranges property */
357 err = of_pci_dma_range_parser_init(&parser, dev_node);
361 dev_dbg(dev, "Parsing dma-ranges property...\n");
362 for_each_of_pci_range(&parser, &range) {
363 struct resource_entry *entry;
365 * If we failed translation or got a zero-sized region
366 * then skip this range
368 if (((range.flags & IORESOURCE_TYPE_BITS) != IORESOURCE_MEM) ||
369 range.cpu_addr == OF_BAD_ADDR || range.size == 0)
372 dev_info(dev, " %6s %#012llx..%#012llx -> %#012llx\n",
373 "IB MEM", range.cpu_addr,
374 range.cpu_addr + range.size - 1, range.pci_addr);
377 err = of_pci_range_to_resource(&range, dev_node, &tmp_res);
381 res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL);
387 /* Keep the resource list sorted */
388 resource_list_for_each_entry(entry, ib_resources)
389 if (entry->res->start > res->start)
392 pci_add_resource_offset(&entry->node, res,
393 res->start - range.pci_addr);
399 pci_free_resource_list(resources);
403 #if IS_ENABLED(CONFIG_OF_IRQ)
405 * of_irq_parse_pci - Resolve the interrupt for a PCI device
406 * @pdev: the device whose interrupt is to be resolved
407 * @out_irq: structure of_phandle_args filled by this function
409 * This function resolves the PCI interrupt for a given PCI device. If a
410 * device-node exists for a given pci_dev, it will use normal OF tree
411 * walking. If not, it will implement standard swizzling and walk up the
412 * PCI tree until an device-node is found, at which point it will finish
413 * resolving using the OF tree walking.
415 static int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq)
417 struct device_node *dn, *ppnode;
418 struct pci_dev *ppdev;
424 * Check if we have a device node, if yes, fallback to standard
425 * device tree parsing
427 dn = pci_device_to_OF_node(pdev);
429 rc = of_irq_parse_one(dn, 0, out_irq);
435 * Ok, we don't, time to have fun. Let's start by building up an
436 * interrupt spec. we assume #interrupt-cells is 1, which is standard
437 * for PCI. If you do different, then don't use that routine.
439 rc = pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin);
442 /* No pin, exit with no error message. */
446 /* Now we walk up the PCI tree */
448 /* Get the pci_dev of our parent */
449 ppdev = pdev->bus->self;
451 /* Ouch, it's a host bridge... */
453 ppnode = pci_bus_to_OF_node(pdev->bus);
455 /* No node for host bridge ? give up */
456 if (ppnode == NULL) {
461 /* We found a P2P bridge, check if it has a node */
462 ppnode = pci_device_to_OF_node(ppdev);
466 * Ok, we have found a parent with a device-node, hand over to
467 * the OF parsing code.
468 * We build a unit address from the linux device to be used for
469 * resolution. Note that we use the linux bus number which may
470 * not match your firmware bus numbering.
471 * Fortunately, in most cases, interrupt-map-mask doesn't
472 * include the bus number as part of the matching.
473 * You should still be careful about that though if you intend
474 * to rely on this function (you ship a firmware that doesn't
475 * create device nodes for all PCI devices).
481 * We can only get here if we hit a P2P bridge with no node;
482 * let's do standard swizzling and try again
484 pin = pci_swizzle_interrupt_pin(pdev, pin);
488 out_irq->np = ppnode;
489 out_irq->args_count = 1;
490 out_irq->args[0] = pin;
491 laddr[0] = cpu_to_be32((pdev->bus->number << 16) | (pdev->devfn << 8));
492 laddr[1] = laddr[2] = cpu_to_be32(0);
493 rc = of_irq_parse_raw(laddr, out_irq);
500 "%s: no interrupt-map found, INTx interrupts not available\n",
502 pr_warn_once("%s: possibly some PCI slots don't have level triggered interrupts capability\n",
505 dev_err(&pdev->dev, "%s: failed with rc=%d\n", __func__, rc);
511 * of_irq_parse_and_map_pci() - Decode a PCI IRQ from the device tree and map to a VIRQ
512 * @dev: The PCI device needing an IRQ
513 * @slot: PCI slot number; passed when used as map_irq callback. Unused
514 * @pin: PCI IRQ pin number; passed when used as map_irq callback. Unused
516 * @slot and @pin are unused, but included in the function so that this
517 * function can be used directly as the map_irq callback to
518 * pci_assign_irq() and struct pci_host_bridge.map_irq pointer
520 int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin)
522 struct of_phandle_args oirq;
525 ret = of_irq_parse_pci(dev, &oirq);
527 return 0; /* Proper return code 0 == NO_IRQ */
529 return irq_create_of_mapping(&oirq);
531 EXPORT_SYMBOL_GPL(of_irq_parse_and_map_pci);
532 #endif /* CONFIG_OF_IRQ */
534 static int pci_parse_request_of_pci_ranges(struct device *dev,
535 struct pci_host_bridge *bridge)
537 int err, res_valid = 0;
538 resource_size_t iobase;
539 struct resource_entry *win, *tmp;
541 INIT_LIST_HEAD(&bridge->windows);
542 INIT_LIST_HEAD(&bridge->dma_ranges);
544 err = devm_of_pci_get_host_bridge_resources(dev, 0, 0xff, &bridge->windows,
545 &bridge->dma_ranges, &iobase);
549 err = devm_request_pci_bus_resources(dev, &bridge->windows);
553 resource_list_for_each_entry_safe(win, tmp, &bridge->windows) {
554 struct resource *res = win->res;
556 switch (resource_type(res)) {
558 err = devm_pci_remap_iospace(dev, res, iobase);
560 dev_warn(dev, "error %d: failed to map resource %pR\n",
562 resource_list_destroy_entry(win);
566 res_valid |= !(res->flags & IORESOURCE_PREFETCH);
568 if (!(res->flags & IORESOURCE_PREFETCH))
569 if (upper_32_bits(resource_size(res)))
570 dev_warn(dev, "Memory resource size exceeds max for 32 bits\n");
577 dev_warn(dev, "non-prefetchable memory resource required\n");
582 int devm_of_pci_bridge_init(struct device *dev, struct pci_host_bridge *bridge)
587 bridge->swizzle_irq = pci_common_swizzle;
588 bridge->map_irq = of_irq_parse_and_map_pci;
590 return pci_parse_request_of_pci_ranges(dev, bridge);
593 #endif /* CONFIG_PCI */
596 * of_pci_get_max_link_speed - Find the maximum link speed of the given device node.
597 * @node: Device tree node with the maximum link speed information.
599 * This function will try to find the limitation of link speed by finding
600 * a property called "max-link-speed" of the given device node.
603 * * > 0 - On success, a maximum link speed.
604 * * -EINVAL - Invalid "max-link-speed" property value, or failure to access
605 * the property of the device tree node.
607 * Returns the associated max link speed from DT, or a negative value if the
608 * required property is not found or is invalid.
610 int of_pci_get_max_link_speed(struct device_node *node)
614 if (of_property_read_u32(node, "max-link-speed", &max_link_speed) ||
615 max_link_speed == 0 || max_link_speed > 4)
618 return max_link_speed;
620 EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed);