1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * PCI <-> OF mapping helpers 4 * 5 * Copyright 2011 IBM Corp. 6 */ 7 #define pr_fmt(fmt) "PCI: OF: " fmt 8 9 #include <linux/irqdomain.h> 10 #include <linux/kernel.h> 11 #include <linux/pci.h> 12 #include <linux/of.h> 13 #include <linux/of_irq.h> 14 #include <linux/of_address.h> 15 #include <linux/of_pci.h> 16 #include "pci.h" 17 18 #ifdef CONFIG_PCI 19 void pci_set_of_node(struct pci_dev *dev) 20 { 21 if (!dev->bus->dev.of_node) 22 return; 23 dev->dev.of_node = of_pci_find_child_device(dev->bus->dev.of_node, 24 dev->devfn); 25 if (dev->dev.of_node) 26 dev->dev.fwnode = &dev->dev.of_node->fwnode; 27 } 28 29 void pci_release_of_node(struct pci_dev *dev) 30 { 31 of_node_put(dev->dev.of_node); 32 dev->dev.of_node = NULL; 33 dev->dev.fwnode = NULL; 34 } 35 36 void pci_set_bus_of_node(struct pci_bus *bus) 37 { 38 struct device_node *node; 39 40 if (bus->self == NULL) { 41 node = pcibios_get_phb_of_node(bus); 42 } else { 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; 46 } 47 48 bus->dev.of_node = node; 49 50 if (bus->dev.of_node) 51 bus->dev.fwnode = &bus->dev.of_node->fwnode; 52 } 53 54 void pci_release_bus_of_node(struct pci_bus *bus) 55 { 56 of_node_put(bus->dev.of_node); 57 bus->dev.of_node = NULL; 58 bus->dev.fwnode = NULL; 59 } 60 61 struct device_node * __weak pcibios_get_phb_of_node(struct pci_bus *bus) 62 { 63 /* This should only be called for PHBs */ 64 if (WARN_ON(bus->self || bus->parent)) 65 return NULL; 66 67 /* 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. 71 */ 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); 76 return NULL; 77 } 78 79 struct irq_domain *pci_host_bridge_of_msi_domain(struct pci_bus *bus) 80 { 81 #ifdef CONFIG_IRQ_DOMAIN 82 struct irq_domain *d; 83 84 if (!bus->dev.of_node) 85 return NULL; 86 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); 89 if (d) 90 return d; 91 92 /* 93 * If we don't have an msi-parent property, look for a domain 94 * directly attached to the host bridge. 95 */ 96 d = irq_find_matching_host(bus->dev.of_node, DOMAIN_BUS_PCI_MSI); 97 if (d) 98 return d; 99 100 return irq_find_host(bus->dev.of_node); 101 #else 102 return NULL; 103 #endif 104 } 105 106 bool pci_host_of_has_msi_map(struct device *dev) 107 { 108 if (dev && dev->of_node) 109 return of_get_property(dev->of_node, "msi-map", NULL); 110 return false; 111 } 112 113 static inline int __of_pci_pci_compare(struct device_node *node, 114 unsigned int data) 115 { 116 int devfn; 117 118 devfn = of_pci_get_devfn(node); 119 if (devfn < 0) 120 return 0; 121 122 return devfn == data; 123 } 124 125 struct device_node *of_pci_find_child_device(struct device_node *parent, 126 unsigned int devfn) 127 { 128 struct device_node *node, *node2; 129 130 for_each_child_of_node(parent, node) { 131 if (__of_pci_pci_compare(node, devfn)) 132 return node; 133 /* 134 * Some OFs create a parent node "multifunc-device" as 135 * a fake root for all functions of a multi-function 136 * device we go down them as well. 137 */ 138 if (of_node_name_eq(node, "multifunc-device")) { 139 for_each_child_of_node(node, node2) { 140 if (__of_pci_pci_compare(node2, devfn)) { 141 of_node_put(node); 142 return node2; 143 } 144 } 145 } 146 } 147 return NULL; 148 } 149 EXPORT_SYMBOL_GPL(of_pci_find_child_device); 150 151 /** 152 * of_pci_get_devfn() - Get device and function numbers for a device node 153 * @np: device node 154 * 155 * Parses a standard 5-cell PCI resource and returns an 8-bit value that can 156 * be passed to the PCI_SLOT() and PCI_FUNC() macros to extract the device 157 * and function numbers respectively. On error a negative error code is 158 * returned. 159 */ 160 int of_pci_get_devfn(struct device_node *np) 161 { 162 u32 reg[5]; 163 int error; 164 165 error = of_property_read_u32_array(np, "reg", reg, ARRAY_SIZE(reg)); 166 if (error) 167 return error; 168 169 return (reg[0] >> 8) & 0xff; 170 } 171 EXPORT_SYMBOL_GPL(of_pci_get_devfn); 172 173 /** 174 * of_pci_parse_bus_range() - parse the bus-range property of a PCI device 175 * @node: device node 176 * @res: address to a struct resource to return the bus-range 177 * 178 * Returns 0 on success or a negative error-code on failure. 179 */ 180 int of_pci_parse_bus_range(struct device_node *node, struct resource *res) 181 { 182 u32 bus_range[2]; 183 int error; 184 185 error = of_property_read_u32_array(node, "bus-range", bus_range, 186 ARRAY_SIZE(bus_range)); 187 if (error) 188 return error; 189 190 res->name = node->name; 191 res->start = bus_range[0]; 192 res->end = bus_range[1]; 193 res->flags = IORESOURCE_BUS; 194 195 return 0; 196 } 197 EXPORT_SYMBOL_GPL(of_pci_parse_bus_range); 198 199 /** 200 * of_get_pci_domain_nr - Find the host bridge domain number 201 * of the given device node. 202 * @node: Device tree node with the domain information. 203 * 204 * This function will try to obtain the host bridge domain number by finding 205 * a property called "linux,pci-domain" of the given device node. 206 * 207 * Return: 208 * * > 0 - On success, an associated domain number. 209 * * -EINVAL - The property "linux,pci-domain" does not exist. 210 * * -ENODATA - The linux,pci-domain" property does not have value. 211 * * -EOVERFLOW - Invalid "linux,pci-domain" property value. 212 * 213 * Returns the associated domain number from DT in the range [0-0xffff], or 214 * a negative value if the required property is not found. 215 */ 216 int of_get_pci_domain_nr(struct device_node *node) 217 { 218 u32 domain; 219 int error; 220 221 error = of_property_read_u32(node, "linux,pci-domain", &domain); 222 if (error) 223 return error; 224 225 return (u16)domain; 226 } 227 EXPORT_SYMBOL_GPL(of_get_pci_domain_nr); 228 229 /** 230 * of_pci_check_probe_only - Setup probe only mode if linux,pci-probe-only 231 * is present and valid 232 */ 233 void of_pci_check_probe_only(void) 234 { 235 u32 val; 236 int ret; 237 238 ret = of_property_read_u32(of_chosen, "linux,pci-probe-only", &val); 239 if (ret) { 240 if (ret == -ENODATA || ret == -EOVERFLOW) 241 pr_warn("linux,pci-probe-only without valid value, ignoring\n"); 242 return; 243 } 244 245 if (val) 246 pci_add_flags(PCI_PROBE_ONLY); 247 else 248 pci_clear_flags(PCI_PROBE_ONLY); 249 250 pr_info("PROBE_ONLY %sabled\n", val ? "en" : "dis"); 251 } 252 EXPORT_SYMBOL_GPL(of_pci_check_probe_only); 253 254 /** 255 * devm_of_pci_get_host_bridge_resources() - Resource-managed parsing of PCI 256 * host bridge resources from DT 257 * @dev: host bridge device 258 * @busno: bus number associated with the bridge root bus 259 * @bus_max: maximum number of buses for this bridge 260 * @resources: list where the range of resources will be added after DT parsing 261 * @ib_resources: list where the range of inbound resources (with addresses 262 * from 'dma-ranges') will be added after DT parsing 263 * @io_base: pointer to a variable that will contain on return the physical 264 * address for the start of the I/O range. Can be NULL if the caller doesn't 265 * expect I/O ranges to be present in the device tree. 266 * 267 * This function will parse the "ranges" property of a PCI host bridge device 268 * node and setup the resource mapping based on its content. It is expected 269 * that the property conforms with the Power ePAPR document. 270 * 271 * It returns zero if the range parsing has been successful or a standard error 272 * value if it failed. 273 */ 274 static int devm_of_pci_get_host_bridge_resources(struct device *dev, 275 unsigned char busno, unsigned char bus_max, 276 struct list_head *resources, 277 struct list_head *ib_resources, 278 resource_size_t *io_base) 279 { 280 struct device_node *dev_node = dev->of_node; 281 struct resource *res, tmp_res; 282 struct resource *bus_range; 283 struct of_pci_range range; 284 struct of_pci_range_parser parser; 285 const char *range_type; 286 int err; 287 288 if (io_base) 289 *io_base = (resource_size_t)OF_BAD_ADDR; 290 291 bus_range = devm_kzalloc(dev, sizeof(*bus_range), GFP_KERNEL); 292 if (!bus_range) 293 return -ENOMEM; 294 295 dev_info(dev, "host bridge %pOF ranges:\n", dev_node); 296 297 err = of_pci_parse_bus_range(dev_node, bus_range); 298 if (err) { 299 bus_range->start = busno; 300 bus_range->end = bus_max; 301 bus_range->flags = IORESOURCE_BUS; 302 dev_info(dev, " No bus range found for %pOF, using %pR\n", 303 dev_node, bus_range); 304 } else { 305 if (bus_range->end > bus_range->start + bus_max) 306 bus_range->end = bus_range->start + bus_max; 307 } 308 pci_add_resource(resources, bus_range); 309 310 /* Check for ranges property */ 311 err = of_pci_range_parser_init(&parser, dev_node); 312 if (err) 313 goto failed; 314 315 dev_dbg(dev, "Parsing ranges property...\n"); 316 for_each_of_pci_range(&parser, &range) { 317 /* Read next ranges element */ 318 if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO) 319 range_type = "IO"; 320 else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM) 321 range_type = "MEM"; 322 else 323 range_type = "err"; 324 dev_info(dev, " %6s %#012llx..%#012llx -> %#012llx\n", 325 range_type, range.cpu_addr, 326 range.cpu_addr + range.size - 1, range.pci_addr); 327 328 /* 329 * If we failed translation or got a zero-sized region 330 * then skip this range 331 */ 332 if (range.cpu_addr == OF_BAD_ADDR || range.size == 0) 333 continue; 334 335 err = of_pci_range_to_resource(&range, dev_node, &tmp_res); 336 if (err) 337 continue; 338 339 res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL); 340 if (!res) { 341 err = -ENOMEM; 342 goto failed; 343 } 344 345 if (resource_type(res) == IORESOURCE_IO) { 346 if (!io_base) { 347 dev_err(dev, "I/O range found for %pOF. Please provide an io_base pointer to save CPU base address\n", 348 dev_node); 349 err = -EINVAL; 350 goto failed; 351 } 352 if (*io_base != (resource_size_t)OF_BAD_ADDR) 353 dev_warn(dev, "More than one I/O resource converted for %pOF. CPU base address for old range lost!\n", 354 dev_node); 355 *io_base = range.cpu_addr; 356 } 357 358 pci_add_resource_offset(resources, res, res->start - range.pci_addr); 359 } 360 361 /* Check for dma-ranges property */ 362 if (!ib_resources) 363 return 0; 364 err = of_pci_dma_range_parser_init(&parser, dev_node); 365 if (err) 366 return 0; 367 368 dev_dbg(dev, "Parsing dma-ranges property...\n"); 369 for_each_of_pci_range(&parser, &range) { 370 struct resource_entry *entry; 371 /* 372 * If we failed translation or got a zero-sized region 373 * then skip this range 374 */ 375 if (((range.flags & IORESOURCE_TYPE_BITS) != IORESOURCE_MEM) || 376 range.cpu_addr == OF_BAD_ADDR || range.size == 0) 377 continue; 378 379 dev_info(dev, " %6s %#012llx..%#012llx -> %#012llx\n", 380 "IB MEM", range.cpu_addr, 381 range.cpu_addr + range.size - 1, range.pci_addr); 382 383 384 err = of_pci_range_to_resource(&range, dev_node, &tmp_res); 385 if (err) 386 continue; 387 388 res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL); 389 if (!res) { 390 err = -ENOMEM; 391 goto failed; 392 } 393 394 /* Keep the resource list sorted */ 395 resource_list_for_each_entry(entry, ib_resources) 396 if (entry->res->start > res->start) 397 break; 398 399 pci_add_resource_offset(&entry->node, res, 400 res->start - range.pci_addr); 401 } 402 403 return 0; 404 405 failed: 406 pci_free_resource_list(resources); 407 return err; 408 } 409 410 #if IS_ENABLED(CONFIG_OF_IRQ) 411 /** 412 * of_irq_parse_pci - Resolve the interrupt for a PCI device 413 * @pdev: the device whose interrupt is to be resolved 414 * @out_irq: structure of_phandle_args filled by this function 415 * 416 * This function resolves the PCI interrupt for a given PCI device. If a 417 * device-node exists for a given pci_dev, it will use normal OF tree 418 * walking. If not, it will implement standard swizzling and walk up the 419 * PCI tree until an device-node is found, at which point it will finish 420 * resolving using the OF tree walking. 421 */ 422 static int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq) 423 { 424 struct device_node *dn, *ppnode; 425 struct pci_dev *ppdev; 426 __be32 laddr[3]; 427 u8 pin; 428 int rc; 429 430 /* 431 * Check if we have a device node, if yes, fallback to standard 432 * device tree parsing 433 */ 434 dn = pci_device_to_OF_node(pdev); 435 if (dn) { 436 rc = of_irq_parse_one(dn, 0, out_irq); 437 if (!rc) 438 return rc; 439 } 440 441 /* 442 * Ok, we don't, time to have fun. Let's start by building up an 443 * interrupt spec. we assume #interrupt-cells is 1, which is standard 444 * for PCI. If you do different, then don't use that routine. 445 */ 446 rc = pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin); 447 if (rc != 0) 448 goto err; 449 /* No pin, exit with no error message. */ 450 if (pin == 0) 451 return -ENODEV; 452 453 /* Now we walk up the PCI tree */ 454 for (;;) { 455 /* Get the pci_dev of our parent */ 456 ppdev = pdev->bus->self; 457 458 /* Ouch, it's a host bridge... */ 459 if (ppdev == NULL) { 460 ppnode = pci_bus_to_OF_node(pdev->bus); 461 462 /* No node for host bridge ? give up */ 463 if (ppnode == NULL) { 464 rc = -EINVAL; 465 goto err; 466 } 467 } else { 468 /* We found a P2P bridge, check if it has a node */ 469 ppnode = pci_device_to_OF_node(ppdev); 470 } 471 472 /* 473 * Ok, we have found a parent with a device-node, hand over to 474 * the OF parsing code. 475 * We build a unit address from the linux device to be used for 476 * resolution. Note that we use the linux bus number which may 477 * not match your firmware bus numbering. 478 * Fortunately, in most cases, interrupt-map-mask doesn't 479 * include the bus number as part of the matching. 480 * You should still be careful about that though if you intend 481 * to rely on this function (you ship a firmware that doesn't 482 * create device nodes for all PCI devices). 483 */ 484 if (ppnode) 485 break; 486 487 /* 488 * We can only get here if we hit a P2P bridge with no node; 489 * let's do standard swizzling and try again 490 */ 491 pin = pci_swizzle_interrupt_pin(pdev, pin); 492 pdev = ppdev; 493 } 494 495 out_irq->np = ppnode; 496 out_irq->args_count = 1; 497 out_irq->args[0] = pin; 498 laddr[0] = cpu_to_be32((pdev->bus->number << 16) | (pdev->devfn << 8)); 499 laddr[1] = laddr[2] = cpu_to_be32(0); 500 rc = of_irq_parse_raw(laddr, out_irq); 501 if (rc) 502 goto err; 503 return 0; 504 err: 505 if (rc == -ENOENT) { 506 dev_warn(&pdev->dev, 507 "%s: no interrupt-map found, INTx interrupts not available\n", 508 __func__); 509 pr_warn_once("%s: possibly some PCI slots don't have level triggered interrupts capability\n", 510 __func__); 511 } else { 512 dev_err(&pdev->dev, "%s: failed with rc=%d\n", __func__, rc); 513 } 514 return rc; 515 } 516 517 /** 518 * of_irq_parse_and_map_pci() - Decode a PCI IRQ from the device tree and map to a VIRQ 519 * @dev: The PCI device needing an IRQ 520 * @slot: PCI slot number; passed when used as map_irq callback. Unused 521 * @pin: PCI IRQ pin number; passed when used as map_irq callback. Unused 522 * 523 * @slot and @pin are unused, but included in the function so that this 524 * function can be used directly as the map_irq callback to 525 * pci_assign_irq() and struct pci_host_bridge.map_irq pointer 526 */ 527 int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin) 528 { 529 struct of_phandle_args oirq; 530 int ret; 531 532 ret = of_irq_parse_pci(dev, &oirq); 533 if (ret) 534 return 0; /* Proper return code 0 == NO_IRQ */ 535 536 return irq_create_of_mapping(&oirq); 537 } 538 EXPORT_SYMBOL_GPL(of_irq_parse_and_map_pci); 539 #endif /* CONFIG_OF_IRQ */ 540 541 static int pci_parse_request_of_pci_ranges(struct device *dev, 542 struct pci_host_bridge *bridge) 543 { 544 int err, res_valid = 0; 545 resource_size_t iobase; 546 struct resource_entry *win, *tmp; 547 548 INIT_LIST_HEAD(&bridge->windows); 549 INIT_LIST_HEAD(&bridge->dma_ranges); 550 551 err = devm_of_pci_get_host_bridge_resources(dev, 0, 0xff, &bridge->windows, 552 &bridge->dma_ranges, &iobase); 553 if (err) 554 return err; 555 556 err = devm_request_pci_bus_resources(dev, &bridge->windows); 557 if (err) 558 return err; 559 560 resource_list_for_each_entry_safe(win, tmp, &bridge->windows) { 561 struct resource *res = win->res; 562 563 switch (resource_type(res)) { 564 case IORESOURCE_IO: 565 err = devm_pci_remap_iospace(dev, res, iobase); 566 if (err) { 567 dev_warn(dev, "error %d: failed to map resource %pR\n", 568 err, res); 569 resource_list_destroy_entry(win); 570 } 571 break; 572 case IORESOURCE_MEM: 573 res_valid |= !(res->flags & IORESOURCE_PREFETCH); 574 575 if (!(res->flags & IORESOURCE_PREFETCH)) 576 if (upper_32_bits(resource_size(res))) 577 dev_warn(dev, "Memory resource size exceeds max for 32 bits\n"); 578 579 break; 580 } 581 } 582 583 if (!res_valid) 584 dev_warn(dev, "non-prefetchable memory resource required\n"); 585 586 return 0; 587 } 588 589 int devm_of_pci_bridge_init(struct device *dev, struct pci_host_bridge *bridge) 590 { 591 if (!dev->of_node) 592 return 0; 593 594 bridge->swizzle_irq = pci_common_swizzle; 595 bridge->map_irq = of_irq_parse_and_map_pci; 596 597 return pci_parse_request_of_pci_ranges(dev, bridge); 598 } 599 600 #endif /* CONFIG_PCI */ 601 602 /** 603 * of_pci_get_max_link_speed - Find the maximum link speed of the given device node. 604 * @node: Device tree node with the maximum link speed information. 605 * 606 * This function will try to find the limitation of link speed by finding 607 * a property called "max-link-speed" of the given device node. 608 * 609 * Return: 610 * * > 0 - On success, a maximum link speed. 611 * * -EINVAL - Invalid "max-link-speed" property value, or failure to access 612 * the property of the device tree node. 613 * 614 * Returns the associated max link speed from DT, or a negative value if the 615 * required property is not found or is invalid. 616 */ 617 int of_pci_get_max_link_speed(struct device_node *node) 618 { 619 u32 max_link_speed; 620 621 if (of_property_read_u32(node, "max-link-speed", &max_link_speed) || 622 max_link_speed == 0 || max_link_speed > 4) 623 return -EINVAL; 624 625 return max_link_speed; 626 } 627 EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed); 628