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 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 * @ib_resources: list where the range of inbound resources (with addresses 247 * from 'dma-ranges') will be added after DT parsing 248 * @io_base: pointer to a variable that will contain on return the physical 249 * address for the start of the I/O range. Can be NULL if the caller doesn't 250 * expect I/O ranges to be present in the device tree. 251 * 252 * This function will parse the "ranges" property of a PCI host bridge device 253 * node and setup the resource mapping based on its content. It is expected 254 * that the property conforms with the Power ePAPR document. 255 * 256 * It returns zero if the range parsing has been successful or a standard error 257 * value if it failed. 258 */ 259 static int devm_of_pci_get_host_bridge_resources(struct device *dev, 260 unsigned char busno, unsigned char bus_max, 261 struct list_head *resources, 262 struct list_head *ib_resources, 263 resource_size_t *io_base) 264 { 265 struct device_node *dev_node = dev->of_node; 266 struct resource *res, tmp_res; 267 struct resource *bus_range; 268 struct of_pci_range range; 269 struct of_pci_range_parser parser; 270 const char *range_type; 271 int err; 272 273 if (io_base) 274 *io_base = (resource_size_t)OF_BAD_ADDR; 275 276 bus_range = devm_kzalloc(dev, sizeof(*bus_range), GFP_KERNEL); 277 if (!bus_range) 278 return -ENOMEM; 279 280 dev_info(dev, "host bridge %pOF ranges:\n", dev_node); 281 282 err = of_pci_parse_bus_range(dev_node, bus_range); 283 if (err) { 284 bus_range->start = busno; 285 bus_range->end = bus_max; 286 bus_range->flags = IORESOURCE_BUS; 287 dev_info(dev, " No bus range found for %pOF, using %pR\n", 288 dev_node, bus_range); 289 } else { 290 if (bus_range->end > bus_range->start + bus_max) 291 bus_range->end = bus_range->start + bus_max; 292 } 293 pci_add_resource(resources, bus_range); 294 295 /* Check for ranges property */ 296 err = of_pci_range_parser_init(&parser, dev_node); 297 if (err) 298 goto failed; 299 300 dev_dbg(dev, "Parsing ranges property...\n"); 301 for_each_of_pci_range(&parser, &range) { 302 /* Read next ranges element */ 303 if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO) 304 range_type = "IO"; 305 else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM) 306 range_type = "MEM"; 307 else 308 range_type = "err"; 309 dev_info(dev, " %6s %#012llx..%#012llx -> %#012llx\n", 310 range_type, range.cpu_addr, 311 range.cpu_addr + range.size - 1, range.pci_addr); 312 313 /* 314 * If we failed translation or got a zero-sized region 315 * then skip this range 316 */ 317 if (range.cpu_addr == OF_BAD_ADDR || range.size == 0) 318 continue; 319 320 err = of_pci_range_to_resource(&range, dev_node, &tmp_res); 321 if (err) 322 continue; 323 324 res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL); 325 if (!res) { 326 err = -ENOMEM; 327 goto failed; 328 } 329 330 if (resource_type(res) == IORESOURCE_IO) { 331 if (!io_base) { 332 dev_err(dev, "I/O range found for %pOF. Please provide an io_base pointer to save CPU base address\n", 333 dev_node); 334 err = -EINVAL; 335 goto failed; 336 } 337 if (*io_base != (resource_size_t)OF_BAD_ADDR) 338 dev_warn(dev, "More than one I/O resource converted for %pOF. CPU base address for old range lost!\n", 339 dev_node); 340 *io_base = range.cpu_addr; 341 } 342 343 pci_add_resource_offset(resources, res, res->start - range.pci_addr); 344 } 345 346 /* Check for dma-ranges property */ 347 if (!ib_resources) 348 return 0; 349 err = of_pci_dma_range_parser_init(&parser, dev_node); 350 if (err) 351 return 0; 352 353 dev_dbg(dev, "Parsing dma-ranges property...\n"); 354 for_each_of_pci_range(&parser, &range) { 355 struct resource_entry *entry; 356 /* 357 * If we failed translation or got a zero-sized region 358 * then skip this range 359 */ 360 if (((range.flags & IORESOURCE_TYPE_BITS) != IORESOURCE_MEM) || 361 range.cpu_addr == OF_BAD_ADDR || range.size == 0) 362 continue; 363 364 dev_info(dev, " %6s %#012llx..%#012llx -> %#012llx\n", 365 "IB MEM", range.cpu_addr, 366 range.cpu_addr + range.size - 1, range.pci_addr); 367 368 369 err = of_pci_range_to_resource(&range, dev_node, &tmp_res); 370 if (err) 371 continue; 372 373 res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL); 374 if (!res) { 375 err = -ENOMEM; 376 goto failed; 377 } 378 379 /* Keep the resource list sorted */ 380 resource_list_for_each_entry(entry, ib_resources) 381 if (entry->res->start > res->start) 382 break; 383 384 pci_add_resource_offset(&entry->node, res, 385 res->start - range.pci_addr); 386 } 387 388 return 0; 389 390 failed: 391 pci_free_resource_list(resources); 392 return err; 393 } 394 395 #if IS_ENABLED(CONFIG_OF_IRQ) 396 /** 397 * of_irq_parse_pci - Resolve the interrupt for a PCI device 398 * @pdev: the device whose interrupt is to be resolved 399 * @out_irq: structure of_phandle_args filled by this function 400 * 401 * This function resolves the PCI interrupt for a given PCI device. If a 402 * device-node exists for a given pci_dev, it will use normal OF tree 403 * walking. If not, it will implement standard swizzling and walk up the 404 * PCI tree until an device-node is found, at which point it will finish 405 * resolving using the OF tree walking. 406 */ 407 static int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq) 408 { 409 struct device_node *dn, *ppnode; 410 struct pci_dev *ppdev; 411 __be32 laddr[3]; 412 u8 pin; 413 int rc; 414 415 /* 416 * Check if we have a device node, if yes, fallback to standard 417 * device tree parsing 418 */ 419 dn = pci_device_to_OF_node(pdev); 420 if (dn) { 421 rc = of_irq_parse_one(dn, 0, out_irq); 422 if (!rc) 423 return rc; 424 } 425 426 /* 427 * Ok, we don't, time to have fun. Let's start by building up an 428 * interrupt spec. we assume #interrupt-cells is 1, which is standard 429 * for PCI. If you do different, then don't use that routine. 430 */ 431 rc = pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin); 432 if (rc != 0) 433 goto err; 434 /* No pin, exit with no error message. */ 435 if (pin == 0) 436 return -ENODEV; 437 438 /* Now we walk up the PCI tree */ 439 for (;;) { 440 /* Get the pci_dev of our parent */ 441 ppdev = pdev->bus->self; 442 443 /* Ouch, it's a host bridge... */ 444 if (ppdev == NULL) { 445 ppnode = pci_bus_to_OF_node(pdev->bus); 446 447 /* No node for host bridge ? give up */ 448 if (ppnode == NULL) { 449 rc = -EINVAL; 450 goto err; 451 } 452 } else { 453 /* We found a P2P bridge, check if it has a node */ 454 ppnode = pci_device_to_OF_node(ppdev); 455 } 456 457 /* 458 * Ok, we have found a parent with a device-node, hand over to 459 * the OF parsing code. 460 * We build a unit address from the linux device to be used for 461 * resolution. Note that we use the linux bus number which may 462 * not match your firmware bus numbering. 463 * Fortunately, in most cases, interrupt-map-mask doesn't 464 * include the bus number as part of the matching. 465 * You should still be careful about that though if you intend 466 * to rely on this function (you ship a firmware that doesn't 467 * create device nodes for all PCI devices). 468 */ 469 if (ppnode) 470 break; 471 472 /* 473 * We can only get here if we hit a P2P bridge with no node; 474 * let's do standard swizzling and try again 475 */ 476 pin = pci_swizzle_interrupt_pin(pdev, pin); 477 pdev = ppdev; 478 } 479 480 out_irq->np = ppnode; 481 out_irq->args_count = 1; 482 out_irq->args[0] = pin; 483 laddr[0] = cpu_to_be32((pdev->bus->number << 16) | (pdev->devfn << 8)); 484 laddr[1] = laddr[2] = cpu_to_be32(0); 485 rc = of_irq_parse_raw(laddr, out_irq); 486 if (rc) 487 goto err; 488 return 0; 489 err: 490 if (rc == -ENOENT) { 491 dev_warn(&pdev->dev, 492 "%s: no interrupt-map found, INTx interrupts not available\n", 493 __func__); 494 pr_warn_once("%s: possibly some PCI slots don't have level triggered interrupts capability\n", 495 __func__); 496 } else { 497 dev_err(&pdev->dev, "%s: failed with rc=%d\n", __func__, rc); 498 } 499 return rc; 500 } 501 502 /** 503 * of_irq_parse_and_map_pci() - Decode a PCI IRQ from the device tree and map to a VIRQ 504 * @dev: The PCI device needing an IRQ 505 * @slot: PCI slot number; passed when used as map_irq callback. Unused 506 * @pin: PCI IRQ pin number; passed when used as map_irq callback. Unused 507 * 508 * @slot and @pin are unused, but included in the function so that this 509 * function can be used directly as the map_irq callback to 510 * pci_assign_irq() and struct pci_host_bridge.map_irq pointer 511 */ 512 int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin) 513 { 514 struct of_phandle_args oirq; 515 int ret; 516 517 ret = of_irq_parse_pci(dev, &oirq); 518 if (ret) 519 return 0; /* Proper return code 0 == NO_IRQ */ 520 521 return irq_create_of_mapping(&oirq); 522 } 523 EXPORT_SYMBOL_GPL(of_irq_parse_and_map_pci); 524 #endif /* CONFIG_OF_IRQ */ 525 526 static int pci_parse_request_of_pci_ranges(struct device *dev, 527 struct pci_host_bridge *bridge) 528 { 529 int err, res_valid = 0; 530 resource_size_t iobase; 531 struct resource_entry *win, *tmp; 532 533 INIT_LIST_HEAD(&bridge->windows); 534 INIT_LIST_HEAD(&bridge->dma_ranges); 535 536 err = devm_of_pci_get_host_bridge_resources(dev, 0, 0xff, &bridge->windows, 537 &bridge->dma_ranges, &iobase); 538 if (err) 539 return err; 540 541 err = devm_request_pci_bus_resources(dev, &bridge->windows); 542 if (err) 543 return err; 544 545 resource_list_for_each_entry_safe(win, tmp, &bridge->windows) { 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); 559 560 if (!(res->flags & IORESOURCE_PREFETCH)) 561 if (upper_32_bits(resource_size(res))) 562 dev_warn(dev, "Memory resource size exceeds max for 32 bits\n"); 563 564 break; 565 } 566 } 567 568 if (!res_valid) 569 dev_warn(dev, "non-prefetchable memory resource required\n"); 570 571 return 0; 572 } 573 574 int devm_of_pci_bridge_init(struct device *dev, struct pci_host_bridge *bridge) 575 { 576 if (!dev->of_node) 577 return 0; 578 579 bridge->swizzle_irq = pci_common_swizzle; 580 bridge->map_irq = of_irq_parse_and_map_pci; 581 582 return pci_parse_request_of_pci_ranges(dev, bridge); 583 } 584 585 #endif /* CONFIG_PCI */ 586 587 /** 588 * This function will try to find the limitation of link speed by finding 589 * a property called "max-link-speed" of the given device node. 590 * 591 * @node: device tree node with the max link speed information 592 * 593 * Returns the associated max link speed from DT, or a negative value if the 594 * required property is not found or is invalid. 595 */ 596 int of_pci_get_max_link_speed(struct device_node *node) 597 { 598 u32 max_link_speed; 599 600 if (of_property_read_u32(node, "max-link-speed", &max_link_speed) || 601 max_link_speed == 0 || max_link_speed > 4) 602 return -EINVAL; 603 604 return max_link_speed; 605 } 606 EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed); 607