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