1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * PCI detection and setup code 4 */ 5 6 #include <linux/kernel.h> 7 #include <linux/delay.h> 8 #include <linux/init.h> 9 #include <linux/pci.h> 10 #include <linux/msi.h> 11 #include <linux/of_device.h> 12 #include <linux/of_pci.h> 13 #include <linux/pci_hotplug.h> 14 #include <linux/slab.h> 15 #include <linux/module.h> 16 #include <linux/cpumask.h> 17 #include <linux/aer.h> 18 #include <linux/acpi.h> 19 #include <linux/hypervisor.h> 20 #include <linux/irqdomain.h> 21 #include <linux/pm_runtime.h> 22 #include "pci.h" 23 24 #define CARDBUS_LATENCY_TIMER 176 /* secondary latency timer */ 25 #define CARDBUS_RESERVE_BUSNR 3 26 27 static struct resource busn_resource = { 28 .name = "PCI busn", 29 .start = 0, 30 .end = 255, 31 .flags = IORESOURCE_BUS, 32 }; 33 34 /* Ugh. Need to stop exporting this to modules. */ 35 LIST_HEAD(pci_root_buses); 36 EXPORT_SYMBOL(pci_root_buses); 37 38 static LIST_HEAD(pci_domain_busn_res_list); 39 40 struct pci_domain_busn_res { 41 struct list_head list; 42 struct resource res; 43 int domain_nr; 44 }; 45 46 static struct resource *get_pci_domain_busn_res(int domain_nr) 47 { 48 struct pci_domain_busn_res *r; 49 50 list_for_each_entry(r, &pci_domain_busn_res_list, list) 51 if (r->domain_nr == domain_nr) 52 return &r->res; 53 54 r = kzalloc(sizeof(*r), GFP_KERNEL); 55 if (!r) 56 return NULL; 57 58 r->domain_nr = domain_nr; 59 r->res.start = 0; 60 r->res.end = 0xff; 61 r->res.flags = IORESOURCE_BUS | IORESOURCE_PCI_FIXED; 62 63 list_add_tail(&r->list, &pci_domain_busn_res_list); 64 65 return &r->res; 66 } 67 68 /* 69 * Some device drivers need know if PCI is initiated. 70 * Basically, we think PCI is not initiated when there 71 * is no device to be found on the pci_bus_type. 72 */ 73 int no_pci_devices(void) 74 { 75 struct device *dev; 76 int no_devices; 77 78 dev = bus_find_next_device(&pci_bus_type, NULL); 79 no_devices = (dev == NULL); 80 put_device(dev); 81 return no_devices; 82 } 83 EXPORT_SYMBOL(no_pci_devices); 84 85 /* 86 * PCI Bus Class 87 */ 88 static void release_pcibus_dev(struct device *dev) 89 { 90 struct pci_bus *pci_bus = to_pci_bus(dev); 91 92 put_device(pci_bus->bridge); 93 pci_bus_remove_resources(pci_bus); 94 pci_release_bus_of_node(pci_bus); 95 kfree(pci_bus); 96 } 97 98 static struct class pcibus_class = { 99 .name = "pci_bus", 100 .dev_release = &release_pcibus_dev, 101 .dev_groups = pcibus_groups, 102 }; 103 104 static int __init pcibus_class_init(void) 105 { 106 return class_register(&pcibus_class); 107 } 108 postcore_initcall(pcibus_class_init); 109 110 static u64 pci_size(u64 base, u64 maxbase, u64 mask) 111 { 112 u64 size = mask & maxbase; /* Find the significant bits */ 113 if (!size) 114 return 0; 115 116 /* 117 * Get the lowest of them to find the decode size, and from that 118 * the extent. 119 */ 120 size = size & ~(size-1); 121 122 /* 123 * base == maxbase can be valid only if the BAR has already been 124 * programmed with all 1s. 125 */ 126 if (base == maxbase && ((base | (size - 1)) & mask) != mask) 127 return 0; 128 129 return size; 130 } 131 132 static inline unsigned long decode_bar(struct pci_dev *dev, u32 bar) 133 { 134 u32 mem_type; 135 unsigned long flags; 136 137 if ((bar & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) { 138 flags = bar & ~PCI_BASE_ADDRESS_IO_MASK; 139 flags |= IORESOURCE_IO; 140 return flags; 141 } 142 143 flags = bar & ~PCI_BASE_ADDRESS_MEM_MASK; 144 flags |= IORESOURCE_MEM; 145 if (flags & PCI_BASE_ADDRESS_MEM_PREFETCH) 146 flags |= IORESOURCE_PREFETCH; 147 148 mem_type = bar & PCI_BASE_ADDRESS_MEM_TYPE_MASK; 149 switch (mem_type) { 150 case PCI_BASE_ADDRESS_MEM_TYPE_32: 151 break; 152 case PCI_BASE_ADDRESS_MEM_TYPE_1M: 153 /* 1M mem BAR treated as 32-bit BAR */ 154 break; 155 case PCI_BASE_ADDRESS_MEM_TYPE_64: 156 flags |= IORESOURCE_MEM_64; 157 break; 158 default: 159 /* mem unknown type treated as 32-bit BAR */ 160 break; 161 } 162 return flags; 163 } 164 165 #define PCI_COMMAND_DECODE_ENABLE (PCI_COMMAND_MEMORY | PCI_COMMAND_IO) 166 167 /** 168 * __pci_read_base - Read a PCI BAR 169 * @dev: the PCI device 170 * @type: type of the BAR 171 * @res: resource buffer to be filled in 172 * @pos: BAR position in the config space 173 * 174 * Returns 1 if the BAR is 64-bit, or 0 if 32-bit. 175 */ 176 int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, 177 struct resource *res, unsigned int pos) 178 { 179 u32 l = 0, sz = 0, mask; 180 u64 l64, sz64, mask64; 181 u16 orig_cmd; 182 struct pci_bus_region region, inverted_region; 183 184 mask = type ? PCI_ROM_ADDRESS_MASK : ~0; 185 186 /* No printks while decoding is disabled! */ 187 if (!dev->mmio_always_on) { 188 pci_read_config_word(dev, PCI_COMMAND, &orig_cmd); 189 if (orig_cmd & PCI_COMMAND_DECODE_ENABLE) { 190 pci_write_config_word(dev, PCI_COMMAND, 191 orig_cmd & ~PCI_COMMAND_DECODE_ENABLE); 192 } 193 } 194 195 res->name = pci_name(dev); 196 197 pci_read_config_dword(dev, pos, &l); 198 pci_write_config_dword(dev, pos, l | mask); 199 pci_read_config_dword(dev, pos, &sz); 200 pci_write_config_dword(dev, pos, l); 201 202 /* 203 * All bits set in sz means the device isn't working properly. 204 * If the BAR isn't implemented, all bits must be 0. If it's a 205 * memory BAR or a ROM, bit 0 must be clear; if it's an io BAR, bit 206 * 1 must be clear. 207 */ 208 if (sz == 0xffffffff) 209 sz = 0; 210 211 /* 212 * I don't know how l can have all bits set. Copied from old code. 213 * Maybe it fixes a bug on some ancient platform. 214 */ 215 if (l == 0xffffffff) 216 l = 0; 217 218 if (type == pci_bar_unknown) { 219 res->flags = decode_bar(dev, l); 220 res->flags |= IORESOURCE_SIZEALIGN; 221 if (res->flags & IORESOURCE_IO) { 222 l64 = l & PCI_BASE_ADDRESS_IO_MASK; 223 sz64 = sz & PCI_BASE_ADDRESS_IO_MASK; 224 mask64 = PCI_BASE_ADDRESS_IO_MASK & (u32)IO_SPACE_LIMIT; 225 } else { 226 l64 = l & PCI_BASE_ADDRESS_MEM_MASK; 227 sz64 = sz & PCI_BASE_ADDRESS_MEM_MASK; 228 mask64 = (u32)PCI_BASE_ADDRESS_MEM_MASK; 229 } 230 } else { 231 if (l & PCI_ROM_ADDRESS_ENABLE) 232 res->flags |= IORESOURCE_ROM_ENABLE; 233 l64 = l & PCI_ROM_ADDRESS_MASK; 234 sz64 = sz & PCI_ROM_ADDRESS_MASK; 235 mask64 = PCI_ROM_ADDRESS_MASK; 236 } 237 238 if (res->flags & IORESOURCE_MEM_64) { 239 pci_read_config_dword(dev, pos + 4, &l); 240 pci_write_config_dword(dev, pos + 4, ~0); 241 pci_read_config_dword(dev, pos + 4, &sz); 242 pci_write_config_dword(dev, pos + 4, l); 243 244 l64 |= ((u64)l << 32); 245 sz64 |= ((u64)sz << 32); 246 mask64 |= ((u64)~0 << 32); 247 } 248 249 if (!dev->mmio_always_on && (orig_cmd & PCI_COMMAND_DECODE_ENABLE)) 250 pci_write_config_word(dev, PCI_COMMAND, orig_cmd); 251 252 if (!sz64) 253 goto fail; 254 255 sz64 = pci_size(l64, sz64, mask64); 256 if (!sz64) { 257 pci_info(dev, FW_BUG "reg 0x%x: invalid BAR (can't size)\n", 258 pos); 259 goto fail; 260 } 261 262 if (res->flags & IORESOURCE_MEM_64) { 263 if ((sizeof(pci_bus_addr_t) < 8 || sizeof(resource_size_t) < 8) 264 && sz64 > 0x100000000ULL) { 265 res->flags |= IORESOURCE_UNSET | IORESOURCE_DISABLED; 266 res->start = 0; 267 res->end = 0; 268 pci_err(dev, "reg 0x%x: can't handle BAR larger than 4GB (size %#010llx)\n", 269 pos, (unsigned long long)sz64); 270 goto out; 271 } 272 273 if ((sizeof(pci_bus_addr_t) < 8) && l) { 274 /* Above 32-bit boundary; try to reallocate */ 275 res->flags |= IORESOURCE_UNSET; 276 res->start = 0; 277 res->end = sz64 - 1; 278 pci_info(dev, "reg 0x%x: can't handle BAR above 4GB (bus address %#010llx)\n", 279 pos, (unsigned long long)l64); 280 goto out; 281 } 282 } 283 284 region.start = l64; 285 region.end = l64 + sz64 - 1; 286 287 pcibios_bus_to_resource(dev->bus, res, ®ion); 288 pcibios_resource_to_bus(dev->bus, &inverted_region, res); 289 290 /* 291 * If "A" is a BAR value (a bus address), "bus_to_resource(A)" is 292 * the corresponding resource address (the physical address used by 293 * the CPU. Converting that resource address back to a bus address 294 * should yield the original BAR value: 295 * 296 * resource_to_bus(bus_to_resource(A)) == A 297 * 298 * If it doesn't, CPU accesses to "bus_to_resource(A)" will not 299 * be claimed by the device. 300 */ 301 if (inverted_region.start != region.start) { 302 res->flags |= IORESOURCE_UNSET; 303 res->start = 0; 304 res->end = region.end - region.start; 305 pci_info(dev, "reg 0x%x: initial BAR value %#010llx invalid\n", 306 pos, (unsigned long long)region.start); 307 } 308 309 goto out; 310 311 312 fail: 313 res->flags = 0; 314 out: 315 if (res->flags) 316 pci_info(dev, "reg 0x%x: %pR\n", pos, res); 317 318 return (res->flags & IORESOURCE_MEM_64) ? 1 : 0; 319 } 320 321 static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom) 322 { 323 unsigned int pos, reg; 324 325 if (dev->non_compliant_bars) 326 return; 327 328 /* Per PCIe r4.0, sec 9.3.4.1.11, the VF BARs are all RO Zero */ 329 if (dev->is_virtfn) 330 return; 331 332 for (pos = 0; pos < howmany; pos++) { 333 struct resource *res = &dev->resource[pos]; 334 reg = PCI_BASE_ADDRESS_0 + (pos << 2); 335 pos += __pci_read_base(dev, pci_bar_unknown, res, reg); 336 } 337 338 if (rom) { 339 struct resource *res = &dev->resource[PCI_ROM_RESOURCE]; 340 dev->rom_base_reg = rom; 341 res->flags = IORESOURCE_MEM | IORESOURCE_PREFETCH | 342 IORESOURCE_READONLY | IORESOURCE_SIZEALIGN; 343 __pci_read_base(dev, pci_bar_mem32, res, rom); 344 } 345 } 346 347 static void pci_read_bridge_windows(struct pci_dev *bridge) 348 { 349 u16 io; 350 u32 pmem, tmp; 351 352 pci_read_config_word(bridge, PCI_IO_BASE, &io); 353 if (!io) { 354 pci_write_config_word(bridge, PCI_IO_BASE, 0xe0f0); 355 pci_read_config_word(bridge, PCI_IO_BASE, &io); 356 pci_write_config_word(bridge, PCI_IO_BASE, 0x0); 357 } 358 if (io) 359 bridge->io_window = 1; 360 361 /* 362 * DECchip 21050 pass 2 errata: the bridge may miss an address 363 * disconnect boundary by one PCI data phase. Workaround: do not 364 * use prefetching on this device. 365 */ 366 if (bridge->vendor == PCI_VENDOR_ID_DEC && bridge->device == 0x0001) 367 return; 368 369 pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem); 370 if (!pmem) { 371 pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, 372 0xffe0fff0); 373 pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem); 374 pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, 0x0); 375 } 376 if (!pmem) 377 return; 378 379 bridge->pref_window = 1; 380 381 if ((pmem & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64) { 382 383 /* 384 * Bridge claims to have a 64-bit prefetchable memory 385 * window; verify that the upper bits are actually 386 * writable. 387 */ 388 pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &pmem); 389 pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, 390 0xffffffff); 391 pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &tmp); 392 pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, pmem); 393 if (tmp) 394 bridge->pref_64_window = 1; 395 } 396 } 397 398 static void pci_read_bridge_io(struct pci_bus *child) 399 { 400 struct pci_dev *dev = child->self; 401 u8 io_base_lo, io_limit_lo; 402 unsigned long io_mask, io_granularity, base, limit; 403 struct pci_bus_region region; 404 struct resource *res; 405 406 io_mask = PCI_IO_RANGE_MASK; 407 io_granularity = 0x1000; 408 if (dev->io_window_1k) { 409 /* Support 1K I/O space granularity */ 410 io_mask = PCI_IO_1K_RANGE_MASK; 411 io_granularity = 0x400; 412 } 413 414 res = child->resource[0]; 415 pci_read_config_byte(dev, PCI_IO_BASE, &io_base_lo); 416 pci_read_config_byte(dev, PCI_IO_LIMIT, &io_limit_lo); 417 base = (io_base_lo & io_mask) << 8; 418 limit = (io_limit_lo & io_mask) << 8; 419 420 if ((io_base_lo & PCI_IO_RANGE_TYPE_MASK) == PCI_IO_RANGE_TYPE_32) { 421 u16 io_base_hi, io_limit_hi; 422 423 pci_read_config_word(dev, PCI_IO_BASE_UPPER16, &io_base_hi); 424 pci_read_config_word(dev, PCI_IO_LIMIT_UPPER16, &io_limit_hi); 425 base |= ((unsigned long) io_base_hi << 16); 426 limit |= ((unsigned long) io_limit_hi << 16); 427 } 428 429 if (base <= limit) { 430 res->flags = (io_base_lo & PCI_IO_RANGE_TYPE_MASK) | IORESOURCE_IO; 431 region.start = base; 432 region.end = limit + io_granularity - 1; 433 pcibios_bus_to_resource(dev->bus, res, ®ion); 434 pci_info(dev, " bridge window %pR\n", res); 435 } 436 } 437 438 static void pci_read_bridge_mmio(struct pci_bus *child) 439 { 440 struct pci_dev *dev = child->self; 441 u16 mem_base_lo, mem_limit_lo; 442 unsigned long base, limit; 443 struct pci_bus_region region; 444 struct resource *res; 445 446 res = child->resource[1]; 447 pci_read_config_word(dev, PCI_MEMORY_BASE, &mem_base_lo); 448 pci_read_config_word(dev, PCI_MEMORY_LIMIT, &mem_limit_lo); 449 base = ((unsigned long) mem_base_lo & PCI_MEMORY_RANGE_MASK) << 16; 450 limit = ((unsigned long) mem_limit_lo & PCI_MEMORY_RANGE_MASK) << 16; 451 if (base <= limit) { 452 res->flags = (mem_base_lo & PCI_MEMORY_RANGE_TYPE_MASK) | IORESOURCE_MEM; 453 region.start = base; 454 region.end = limit + 0xfffff; 455 pcibios_bus_to_resource(dev->bus, res, ®ion); 456 pci_info(dev, " bridge window %pR\n", res); 457 } 458 } 459 460 static void pci_read_bridge_mmio_pref(struct pci_bus *child) 461 { 462 struct pci_dev *dev = child->self; 463 u16 mem_base_lo, mem_limit_lo; 464 u64 base64, limit64; 465 pci_bus_addr_t base, limit; 466 struct pci_bus_region region; 467 struct resource *res; 468 469 res = child->resource[2]; 470 pci_read_config_word(dev, PCI_PREF_MEMORY_BASE, &mem_base_lo); 471 pci_read_config_word(dev, PCI_PREF_MEMORY_LIMIT, &mem_limit_lo); 472 base64 = (mem_base_lo & PCI_PREF_RANGE_MASK) << 16; 473 limit64 = (mem_limit_lo & PCI_PREF_RANGE_MASK) << 16; 474 475 if ((mem_base_lo & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64) { 476 u32 mem_base_hi, mem_limit_hi; 477 478 pci_read_config_dword(dev, PCI_PREF_BASE_UPPER32, &mem_base_hi); 479 pci_read_config_dword(dev, PCI_PREF_LIMIT_UPPER32, &mem_limit_hi); 480 481 /* 482 * Some bridges set the base > limit by default, and some 483 * (broken) BIOSes do not initialize them. If we find 484 * this, just assume they are not being used. 485 */ 486 if (mem_base_hi <= mem_limit_hi) { 487 base64 |= (u64) mem_base_hi << 32; 488 limit64 |= (u64) mem_limit_hi << 32; 489 } 490 } 491 492 base = (pci_bus_addr_t) base64; 493 limit = (pci_bus_addr_t) limit64; 494 495 if (base != base64) { 496 pci_err(dev, "can't handle bridge window above 4GB (bus address %#010llx)\n", 497 (unsigned long long) base64); 498 return; 499 } 500 501 if (base <= limit) { 502 res->flags = (mem_base_lo & PCI_PREF_RANGE_TYPE_MASK) | 503 IORESOURCE_MEM | IORESOURCE_PREFETCH; 504 if (res->flags & PCI_PREF_RANGE_TYPE_64) 505 res->flags |= IORESOURCE_MEM_64; 506 region.start = base; 507 region.end = limit + 0xfffff; 508 pcibios_bus_to_resource(dev->bus, res, ®ion); 509 pci_info(dev, " bridge window %pR\n", res); 510 } 511 } 512 513 void pci_read_bridge_bases(struct pci_bus *child) 514 { 515 struct pci_dev *dev = child->self; 516 struct resource *res; 517 int i; 518 519 if (pci_is_root_bus(child)) /* It's a host bus, nothing to read */ 520 return; 521 522 pci_info(dev, "PCI bridge to %pR%s\n", 523 &child->busn_res, 524 dev->transparent ? " (subtractive decode)" : ""); 525 526 pci_bus_remove_resources(child); 527 for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++) 528 child->resource[i] = &dev->resource[PCI_BRIDGE_RESOURCES+i]; 529 530 pci_read_bridge_io(child); 531 pci_read_bridge_mmio(child); 532 pci_read_bridge_mmio_pref(child); 533 534 if (dev->transparent) { 535 pci_bus_for_each_resource(child->parent, res, i) { 536 if (res && res->flags) { 537 pci_bus_add_resource(child, res, 538 PCI_SUBTRACTIVE_DECODE); 539 pci_info(dev, " bridge window %pR (subtractive decode)\n", 540 res); 541 } 542 } 543 } 544 } 545 546 static struct pci_bus *pci_alloc_bus(struct pci_bus *parent) 547 { 548 struct pci_bus *b; 549 550 b = kzalloc(sizeof(*b), GFP_KERNEL); 551 if (!b) 552 return NULL; 553 554 INIT_LIST_HEAD(&b->node); 555 INIT_LIST_HEAD(&b->children); 556 INIT_LIST_HEAD(&b->devices); 557 INIT_LIST_HEAD(&b->slots); 558 INIT_LIST_HEAD(&b->resources); 559 b->max_bus_speed = PCI_SPEED_UNKNOWN; 560 b->cur_bus_speed = PCI_SPEED_UNKNOWN; 561 #ifdef CONFIG_PCI_DOMAINS_GENERIC 562 if (parent) 563 b->domain_nr = parent->domain_nr; 564 #endif 565 return b; 566 } 567 568 static void pci_release_host_bridge_dev(struct device *dev) 569 { 570 struct pci_host_bridge *bridge = to_pci_host_bridge(dev); 571 572 if (bridge->release_fn) 573 bridge->release_fn(bridge); 574 575 pci_free_resource_list(&bridge->windows); 576 pci_free_resource_list(&bridge->dma_ranges); 577 kfree(bridge); 578 } 579 580 static void pci_init_host_bridge(struct pci_host_bridge *bridge) 581 { 582 INIT_LIST_HEAD(&bridge->windows); 583 INIT_LIST_HEAD(&bridge->dma_ranges); 584 585 /* 586 * We assume we can manage these PCIe features. Some systems may 587 * reserve these for use by the platform itself, e.g., an ACPI BIOS 588 * may implement its own AER handling and use _OSC to prevent the 589 * OS from interfering. 590 */ 591 bridge->native_aer = 1; 592 bridge->native_pcie_hotplug = 1; 593 bridge->native_shpc_hotplug = 1; 594 bridge->native_pme = 1; 595 bridge->native_ltr = 1; 596 bridge->native_dpc = 1; 597 598 device_initialize(&bridge->dev); 599 } 600 601 struct pci_host_bridge *pci_alloc_host_bridge(size_t priv) 602 { 603 struct pci_host_bridge *bridge; 604 605 bridge = kzalloc(sizeof(*bridge) + priv, GFP_KERNEL); 606 if (!bridge) 607 return NULL; 608 609 pci_init_host_bridge(bridge); 610 bridge->dev.release = pci_release_host_bridge_dev; 611 612 return bridge; 613 } 614 EXPORT_SYMBOL(pci_alloc_host_bridge); 615 616 static void devm_pci_alloc_host_bridge_release(void *data) 617 { 618 pci_free_host_bridge(data); 619 } 620 621 struct pci_host_bridge *devm_pci_alloc_host_bridge(struct device *dev, 622 size_t priv) 623 { 624 int ret; 625 struct pci_host_bridge *bridge; 626 627 bridge = pci_alloc_host_bridge(priv); 628 if (!bridge) 629 return NULL; 630 631 bridge->dev.parent = dev; 632 633 ret = devm_add_action_or_reset(dev, devm_pci_alloc_host_bridge_release, 634 bridge); 635 if (ret) 636 return NULL; 637 638 ret = devm_of_pci_bridge_init(dev, bridge); 639 if (ret) 640 return NULL; 641 642 return bridge; 643 } 644 EXPORT_SYMBOL(devm_pci_alloc_host_bridge); 645 646 void pci_free_host_bridge(struct pci_host_bridge *bridge) 647 { 648 put_device(&bridge->dev); 649 } 650 EXPORT_SYMBOL(pci_free_host_bridge); 651 652 /* Indexed by PCI_X_SSTATUS_FREQ (secondary bus mode and frequency) */ 653 static const unsigned char pcix_bus_speed[] = { 654 PCI_SPEED_UNKNOWN, /* 0 */ 655 PCI_SPEED_66MHz_PCIX, /* 1 */ 656 PCI_SPEED_100MHz_PCIX, /* 2 */ 657 PCI_SPEED_133MHz_PCIX, /* 3 */ 658 PCI_SPEED_UNKNOWN, /* 4 */ 659 PCI_SPEED_66MHz_PCIX_ECC, /* 5 */ 660 PCI_SPEED_100MHz_PCIX_ECC, /* 6 */ 661 PCI_SPEED_133MHz_PCIX_ECC, /* 7 */ 662 PCI_SPEED_UNKNOWN, /* 8 */ 663 PCI_SPEED_66MHz_PCIX_266, /* 9 */ 664 PCI_SPEED_100MHz_PCIX_266, /* A */ 665 PCI_SPEED_133MHz_PCIX_266, /* B */ 666 PCI_SPEED_UNKNOWN, /* C */ 667 PCI_SPEED_66MHz_PCIX_533, /* D */ 668 PCI_SPEED_100MHz_PCIX_533, /* E */ 669 PCI_SPEED_133MHz_PCIX_533 /* F */ 670 }; 671 672 /* Indexed by PCI_EXP_LNKCAP_SLS, PCI_EXP_LNKSTA_CLS */ 673 const unsigned char pcie_link_speed[] = { 674 PCI_SPEED_UNKNOWN, /* 0 */ 675 PCIE_SPEED_2_5GT, /* 1 */ 676 PCIE_SPEED_5_0GT, /* 2 */ 677 PCIE_SPEED_8_0GT, /* 3 */ 678 PCIE_SPEED_16_0GT, /* 4 */ 679 PCIE_SPEED_32_0GT, /* 5 */ 680 PCIE_SPEED_64_0GT, /* 6 */ 681 PCI_SPEED_UNKNOWN, /* 7 */ 682 PCI_SPEED_UNKNOWN, /* 8 */ 683 PCI_SPEED_UNKNOWN, /* 9 */ 684 PCI_SPEED_UNKNOWN, /* A */ 685 PCI_SPEED_UNKNOWN, /* B */ 686 PCI_SPEED_UNKNOWN, /* C */ 687 PCI_SPEED_UNKNOWN, /* D */ 688 PCI_SPEED_UNKNOWN, /* E */ 689 PCI_SPEED_UNKNOWN /* F */ 690 }; 691 EXPORT_SYMBOL_GPL(pcie_link_speed); 692 693 const char *pci_speed_string(enum pci_bus_speed speed) 694 { 695 /* Indexed by the pci_bus_speed enum */ 696 static const char *speed_strings[] = { 697 "33 MHz PCI", /* 0x00 */ 698 "66 MHz PCI", /* 0x01 */ 699 "66 MHz PCI-X", /* 0x02 */ 700 "100 MHz PCI-X", /* 0x03 */ 701 "133 MHz PCI-X", /* 0x04 */ 702 NULL, /* 0x05 */ 703 NULL, /* 0x06 */ 704 NULL, /* 0x07 */ 705 NULL, /* 0x08 */ 706 "66 MHz PCI-X 266", /* 0x09 */ 707 "100 MHz PCI-X 266", /* 0x0a */ 708 "133 MHz PCI-X 266", /* 0x0b */ 709 "Unknown AGP", /* 0x0c */ 710 "1x AGP", /* 0x0d */ 711 "2x AGP", /* 0x0e */ 712 "4x AGP", /* 0x0f */ 713 "8x AGP", /* 0x10 */ 714 "66 MHz PCI-X 533", /* 0x11 */ 715 "100 MHz PCI-X 533", /* 0x12 */ 716 "133 MHz PCI-X 533", /* 0x13 */ 717 "2.5 GT/s PCIe", /* 0x14 */ 718 "5.0 GT/s PCIe", /* 0x15 */ 719 "8.0 GT/s PCIe", /* 0x16 */ 720 "16.0 GT/s PCIe", /* 0x17 */ 721 "32.0 GT/s PCIe", /* 0x18 */ 722 "64.0 GT/s PCIe", /* 0x19 */ 723 }; 724 725 if (speed < ARRAY_SIZE(speed_strings)) 726 return speed_strings[speed]; 727 return "Unknown"; 728 } 729 EXPORT_SYMBOL_GPL(pci_speed_string); 730 731 void pcie_update_link_speed(struct pci_bus *bus, u16 linksta) 732 { 733 bus->cur_bus_speed = pcie_link_speed[linksta & PCI_EXP_LNKSTA_CLS]; 734 } 735 EXPORT_SYMBOL_GPL(pcie_update_link_speed); 736 737 static unsigned char agp_speeds[] = { 738 AGP_UNKNOWN, 739 AGP_1X, 740 AGP_2X, 741 AGP_4X, 742 AGP_8X 743 }; 744 745 static enum pci_bus_speed agp_speed(int agp3, int agpstat) 746 { 747 int index = 0; 748 749 if (agpstat & 4) 750 index = 3; 751 else if (agpstat & 2) 752 index = 2; 753 else if (agpstat & 1) 754 index = 1; 755 else 756 goto out; 757 758 if (agp3) { 759 index += 2; 760 if (index == 5) 761 index = 0; 762 } 763 764 out: 765 return agp_speeds[index]; 766 } 767 768 static void pci_set_bus_speed(struct pci_bus *bus) 769 { 770 struct pci_dev *bridge = bus->self; 771 int pos; 772 773 pos = pci_find_capability(bridge, PCI_CAP_ID_AGP); 774 if (!pos) 775 pos = pci_find_capability(bridge, PCI_CAP_ID_AGP3); 776 if (pos) { 777 u32 agpstat, agpcmd; 778 779 pci_read_config_dword(bridge, pos + PCI_AGP_STATUS, &agpstat); 780 bus->max_bus_speed = agp_speed(agpstat & 8, agpstat & 7); 781 782 pci_read_config_dword(bridge, pos + PCI_AGP_COMMAND, &agpcmd); 783 bus->cur_bus_speed = agp_speed(agpstat & 8, agpcmd & 7); 784 } 785 786 pos = pci_find_capability(bridge, PCI_CAP_ID_PCIX); 787 if (pos) { 788 u16 status; 789 enum pci_bus_speed max; 790 791 pci_read_config_word(bridge, pos + PCI_X_BRIDGE_SSTATUS, 792 &status); 793 794 if (status & PCI_X_SSTATUS_533MHZ) { 795 max = PCI_SPEED_133MHz_PCIX_533; 796 } else if (status & PCI_X_SSTATUS_266MHZ) { 797 max = PCI_SPEED_133MHz_PCIX_266; 798 } else if (status & PCI_X_SSTATUS_133MHZ) { 799 if ((status & PCI_X_SSTATUS_VERS) == PCI_X_SSTATUS_V2) 800 max = PCI_SPEED_133MHz_PCIX_ECC; 801 else 802 max = PCI_SPEED_133MHz_PCIX; 803 } else { 804 max = PCI_SPEED_66MHz_PCIX; 805 } 806 807 bus->max_bus_speed = max; 808 bus->cur_bus_speed = pcix_bus_speed[ 809 (status & PCI_X_SSTATUS_FREQ) >> 6]; 810 811 return; 812 } 813 814 if (pci_is_pcie(bridge)) { 815 u32 linkcap; 816 u16 linksta; 817 818 pcie_capability_read_dword(bridge, PCI_EXP_LNKCAP, &linkcap); 819 bus->max_bus_speed = pcie_link_speed[linkcap & PCI_EXP_LNKCAP_SLS]; 820 bridge->link_active_reporting = !!(linkcap & PCI_EXP_LNKCAP_DLLLARC); 821 822 pcie_capability_read_word(bridge, PCI_EXP_LNKSTA, &linksta); 823 pcie_update_link_speed(bus, linksta); 824 } 825 } 826 827 static struct irq_domain *pci_host_bridge_msi_domain(struct pci_bus *bus) 828 { 829 struct irq_domain *d; 830 831 /* 832 * Any firmware interface that can resolve the msi_domain 833 * should be called from here. 834 */ 835 d = pci_host_bridge_of_msi_domain(bus); 836 if (!d) 837 d = pci_host_bridge_acpi_msi_domain(bus); 838 839 #ifdef CONFIG_PCI_MSI_IRQ_DOMAIN 840 /* 841 * If no IRQ domain was found via the OF tree, try looking it up 842 * directly through the fwnode_handle. 843 */ 844 if (!d) { 845 struct fwnode_handle *fwnode = pci_root_bus_fwnode(bus); 846 847 if (fwnode) 848 d = irq_find_matching_fwnode(fwnode, 849 DOMAIN_BUS_PCI_MSI); 850 } 851 #endif 852 853 return d; 854 } 855 856 static void pci_set_bus_msi_domain(struct pci_bus *bus) 857 { 858 struct irq_domain *d; 859 struct pci_bus *b; 860 861 /* 862 * The bus can be a root bus, a subordinate bus, or a virtual bus 863 * created by an SR-IOV device. Walk up to the first bridge device 864 * found or derive the domain from the host bridge. 865 */ 866 for (b = bus, d = NULL; !d && !pci_is_root_bus(b); b = b->parent) { 867 if (b->self) 868 d = dev_get_msi_domain(&b->self->dev); 869 } 870 871 if (!d) 872 d = pci_host_bridge_msi_domain(b); 873 874 dev_set_msi_domain(&bus->dev, d); 875 } 876 877 static int pci_register_host_bridge(struct pci_host_bridge *bridge) 878 { 879 struct device *parent = bridge->dev.parent; 880 struct resource_entry *window, *n; 881 struct pci_bus *bus, *b; 882 resource_size_t offset; 883 LIST_HEAD(resources); 884 struct resource *res; 885 char addr[64], *fmt; 886 const char *name; 887 int err; 888 889 bus = pci_alloc_bus(NULL); 890 if (!bus) 891 return -ENOMEM; 892 893 bridge->bus = bus; 894 895 /* Temporarily move resources off the list */ 896 list_splice_init(&bridge->windows, &resources); 897 bus->sysdata = bridge->sysdata; 898 bus->ops = bridge->ops; 899 bus->number = bus->busn_res.start = bridge->busnr; 900 #ifdef CONFIG_PCI_DOMAINS_GENERIC 901 bus->domain_nr = pci_bus_find_domain_nr(bus, parent); 902 #endif 903 904 b = pci_find_bus(pci_domain_nr(bus), bridge->busnr); 905 if (b) { 906 /* Ignore it if we already got here via a different bridge */ 907 dev_dbg(&b->dev, "bus already known\n"); 908 err = -EEXIST; 909 goto free; 910 } 911 912 dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(bus), 913 bridge->busnr); 914 915 err = pcibios_root_bridge_prepare(bridge); 916 if (err) 917 goto free; 918 919 err = device_add(&bridge->dev); 920 if (err) { 921 put_device(&bridge->dev); 922 goto free; 923 } 924 bus->bridge = get_device(&bridge->dev); 925 device_enable_async_suspend(bus->bridge); 926 pci_set_bus_of_node(bus); 927 pci_set_bus_msi_domain(bus); 928 if (bridge->msi_domain && !dev_get_msi_domain(&bus->dev) && 929 !pci_host_of_has_msi_map(parent)) 930 bus->bus_flags |= PCI_BUS_FLAGS_NO_MSI; 931 932 if (!parent) 933 set_dev_node(bus->bridge, pcibus_to_node(bus)); 934 935 bus->dev.class = &pcibus_class; 936 bus->dev.parent = bus->bridge; 937 938 dev_set_name(&bus->dev, "%04x:%02x", pci_domain_nr(bus), bus->number); 939 name = dev_name(&bus->dev); 940 941 err = device_register(&bus->dev); 942 if (err) 943 goto unregister; 944 945 pcibios_add_bus(bus); 946 947 if (bus->ops->add_bus) { 948 err = bus->ops->add_bus(bus); 949 if (WARN_ON(err < 0)) 950 dev_err(&bus->dev, "failed to add bus: %d\n", err); 951 } 952 953 /* Create legacy_io and legacy_mem files for this bus */ 954 pci_create_legacy_files(bus); 955 956 if (parent) 957 dev_info(parent, "PCI host bridge to bus %s\n", name); 958 else 959 pr_info("PCI host bridge to bus %s\n", name); 960 961 if (nr_node_ids > 1 && pcibus_to_node(bus) == NUMA_NO_NODE) 962 dev_warn(&bus->dev, "Unknown NUMA node; performance will be reduced\n"); 963 964 /* Add initial resources to the bus */ 965 resource_list_for_each_entry_safe(window, n, &resources) { 966 list_move_tail(&window->node, &bridge->windows); 967 offset = window->offset; 968 res = window->res; 969 970 if (res->flags & IORESOURCE_BUS) 971 pci_bus_insert_busn_res(bus, bus->number, res->end); 972 else 973 pci_bus_add_resource(bus, res, 0); 974 975 if (offset) { 976 if (resource_type(res) == IORESOURCE_IO) 977 fmt = " (bus address [%#06llx-%#06llx])"; 978 else 979 fmt = " (bus address [%#010llx-%#010llx])"; 980 981 snprintf(addr, sizeof(addr), fmt, 982 (unsigned long long)(res->start - offset), 983 (unsigned long long)(res->end - offset)); 984 } else 985 addr[0] = '\0'; 986 987 dev_info(&bus->dev, "root bus resource %pR%s\n", res, addr); 988 } 989 990 down_write(&pci_bus_sem); 991 list_add_tail(&bus->node, &pci_root_buses); 992 up_write(&pci_bus_sem); 993 994 return 0; 995 996 unregister: 997 put_device(&bridge->dev); 998 device_del(&bridge->dev); 999 1000 free: 1001 kfree(bus); 1002 return err; 1003 } 1004 1005 static bool pci_bridge_child_ext_cfg_accessible(struct pci_dev *bridge) 1006 { 1007 int pos; 1008 u32 status; 1009 1010 /* 1011 * If extended config space isn't accessible on a bridge's primary 1012 * bus, we certainly can't access it on the secondary bus. 1013 */ 1014 if (bridge->bus->bus_flags & PCI_BUS_FLAGS_NO_EXTCFG) 1015 return false; 1016 1017 /* 1018 * PCIe Root Ports and switch ports are PCIe on both sides, so if 1019 * extended config space is accessible on the primary, it's also 1020 * accessible on the secondary. 1021 */ 1022 if (pci_is_pcie(bridge) && 1023 (pci_pcie_type(bridge) == PCI_EXP_TYPE_ROOT_PORT || 1024 pci_pcie_type(bridge) == PCI_EXP_TYPE_UPSTREAM || 1025 pci_pcie_type(bridge) == PCI_EXP_TYPE_DOWNSTREAM)) 1026 return true; 1027 1028 /* 1029 * For the other bridge types: 1030 * - PCI-to-PCI bridges 1031 * - PCIe-to-PCI/PCI-X forward bridges 1032 * - PCI/PCI-X-to-PCIe reverse bridges 1033 * extended config space on the secondary side is only accessible 1034 * if the bridge supports PCI-X Mode 2. 1035 */ 1036 pos = pci_find_capability(bridge, PCI_CAP_ID_PCIX); 1037 if (!pos) 1038 return false; 1039 1040 pci_read_config_dword(bridge, pos + PCI_X_STATUS, &status); 1041 return status & (PCI_X_STATUS_266MHZ | PCI_X_STATUS_533MHZ); 1042 } 1043 1044 static struct pci_bus *pci_alloc_child_bus(struct pci_bus *parent, 1045 struct pci_dev *bridge, int busnr) 1046 { 1047 struct pci_bus *child; 1048 struct pci_host_bridge *host; 1049 int i; 1050 int ret; 1051 1052 /* Allocate a new bus and inherit stuff from the parent */ 1053 child = pci_alloc_bus(parent); 1054 if (!child) 1055 return NULL; 1056 1057 child->parent = parent; 1058 child->sysdata = parent->sysdata; 1059 child->bus_flags = parent->bus_flags; 1060 1061 host = pci_find_host_bridge(parent); 1062 if (host->child_ops) 1063 child->ops = host->child_ops; 1064 else 1065 child->ops = parent->ops; 1066 1067 /* 1068 * Initialize some portions of the bus device, but don't register 1069 * it now as the parent is not properly set up yet. 1070 */ 1071 child->dev.class = &pcibus_class; 1072 dev_set_name(&child->dev, "%04x:%02x", pci_domain_nr(child), busnr); 1073 1074 /* Set up the primary, secondary and subordinate bus numbers */ 1075 child->number = child->busn_res.start = busnr; 1076 child->primary = parent->busn_res.start; 1077 child->busn_res.end = 0xff; 1078 1079 if (!bridge) { 1080 child->dev.parent = parent->bridge; 1081 goto add_dev; 1082 } 1083 1084 child->self = bridge; 1085 child->bridge = get_device(&bridge->dev); 1086 child->dev.parent = child->bridge; 1087 pci_set_bus_of_node(child); 1088 pci_set_bus_speed(child); 1089 1090 /* 1091 * Check whether extended config space is accessible on the child 1092 * bus. Note that we currently assume it is always accessible on 1093 * the root bus. 1094 */ 1095 if (!pci_bridge_child_ext_cfg_accessible(bridge)) { 1096 child->bus_flags |= PCI_BUS_FLAGS_NO_EXTCFG; 1097 pci_info(child, "extended config space not accessible\n"); 1098 } 1099 1100 /* Set up default resource pointers and names */ 1101 for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++) { 1102 child->resource[i] = &bridge->resource[PCI_BRIDGE_RESOURCES+i]; 1103 child->resource[i]->name = child->name; 1104 } 1105 bridge->subordinate = child; 1106 1107 add_dev: 1108 pci_set_bus_msi_domain(child); 1109 ret = device_register(&child->dev); 1110 WARN_ON(ret < 0); 1111 1112 pcibios_add_bus(child); 1113 1114 if (child->ops->add_bus) { 1115 ret = child->ops->add_bus(child); 1116 if (WARN_ON(ret < 0)) 1117 dev_err(&child->dev, "failed to add bus: %d\n", ret); 1118 } 1119 1120 /* Create legacy_io and legacy_mem files for this bus */ 1121 pci_create_legacy_files(child); 1122 1123 return child; 1124 } 1125 1126 struct pci_bus *pci_add_new_bus(struct pci_bus *parent, struct pci_dev *dev, 1127 int busnr) 1128 { 1129 struct pci_bus *child; 1130 1131 child = pci_alloc_child_bus(parent, dev, busnr); 1132 if (child) { 1133 down_write(&pci_bus_sem); 1134 list_add_tail(&child->node, &parent->children); 1135 up_write(&pci_bus_sem); 1136 } 1137 return child; 1138 } 1139 EXPORT_SYMBOL(pci_add_new_bus); 1140 1141 static void pci_enable_crs(struct pci_dev *pdev) 1142 { 1143 u16 root_cap = 0; 1144 1145 /* Enable CRS Software Visibility if supported */ 1146 pcie_capability_read_word(pdev, PCI_EXP_RTCAP, &root_cap); 1147 if (root_cap & PCI_EXP_RTCAP_CRSVIS) 1148 pcie_capability_set_word(pdev, PCI_EXP_RTCTL, 1149 PCI_EXP_RTCTL_CRSSVE); 1150 } 1151 1152 static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus, 1153 unsigned int available_buses); 1154 /** 1155 * pci_ea_fixed_busnrs() - Read fixed Secondary and Subordinate bus 1156 * numbers from EA capability. 1157 * @dev: Bridge 1158 * @sec: updated with secondary bus number from EA 1159 * @sub: updated with subordinate bus number from EA 1160 * 1161 * If @dev is a bridge with EA capability that specifies valid secondary 1162 * and subordinate bus numbers, return true with the bus numbers in @sec 1163 * and @sub. Otherwise return false. 1164 */ 1165 static bool pci_ea_fixed_busnrs(struct pci_dev *dev, u8 *sec, u8 *sub) 1166 { 1167 int ea, offset; 1168 u32 dw; 1169 u8 ea_sec, ea_sub; 1170 1171 if (dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) 1172 return false; 1173 1174 /* find PCI EA capability in list */ 1175 ea = pci_find_capability(dev, PCI_CAP_ID_EA); 1176 if (!ea) 1177 return false; 1178 1179 offset = ea + PCI_EA_FIRST_ENT; 1180 pci_read_config_dword(dev, offset, &dw); 1181 ea_sec = dw & PCI_EA_SEC_BUS_MASK; 1182 ea_sub = (dw & PCI_EA_SUB_BUS_MASK) >> PCI_EA_SUB_BUS_SHIFT; 1183 if (ea_sec == 0 || ea_sub < ea_sec) 1184 return false; 1185 1186 *sec = ea_sec; 1187 *sub = ea_sub; 1188 return true; 1189 } 1190 1191 /* 1192 * pci_scan_bridge_extend() - Scan buses behind a bridge 1193 * @bus: Parent bus the bridge is on 1194 * @dev: Bridge itself 1195 * @max: Starting subordinate number of buses behind this bridge 1196 * @available_buses: Total number of buses available for this bridge and 1197 * the devices below. After the minimal bus space has 1198 * been allocated the remaining buses will be 1199 * distributed equally between hotplug-capable bridges. 1200 * @pass: Either %0 (scan already configured bridges) or %1 (scan bridges 1201 * that need to be reconfigured. 1202 * 1203 * If it's a bridge, configure it and scan the bus behind it. 1204 * For CardBus bridges, we don't scan behind as the devices will 1205 * be handled by the bridge driver itself. 1206 * 1207 * We need to process bridges in two passes -- first we scan those 1208 * already configured by the BIOS and after we are done with all of 1209 * them, we proceed to assigning numbers to the remaining buses in 1210 * order to avoid overlaps between old and new bus numbers. 1211 * 1212 * Return: New subordinate number covering all buses behind this bridge. 1213 */ 1214 static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev, 1215 int max, unsigned int available_buses, 1216 int pass) 1217 { 1218 struct pci_bus *child; 1219 int is_cardbus = (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS); 1220 u32 buses, i, j = 0; 1221 u16 bctl; 1222 u8 primary, secondary, subordinate; 1223 int broken = 0; 1224 bool fixed_buses; 1225 u8 fixed_sec, fixed_sub; 1226 int next_busnr; 1227 1228 /* 1229 * Make sure the bridge is powered on to be able to access config 1230 * space of devices below it. 1231 */ 1232 pm_runtime_get_sync(&dev->dev); 1233 1234 pci_read_config_dword(dev, PCI_PRIMARY_BUS, &buses); 1235 primary = buses & 0xFF; 1236 secondary = (buses >> 8) & 0xFF; 1237 subordinate = (buses >> 16) & 0xFF; 1238 1239 pci_dbg(dev, "scanning [bus %02x-%02x] behind bridge, pass %d\n", 1240 secondary, subordinate, pass); 1241 1242 if (!primary && (primary != bus->number) && secondary && subordinate) { 1243 pci_warn(dev, "Primary bus is hard wired to 0\n"); 1244 primary = bus->number; 1245 } 1246 1247 /* Check if setup is sensible at all */ 1248 if (!pass && 1249 (primary != bus->number || secondary <= bus->number || 1250 secondary > subordinate)) { 1251 pci_info(dev, "bridge configuration invalid ([bus %02x-%02x]), reconfiguring\n", 1252 secondary, subordinate); 1253 broken = 1; 1254 } 1255 1256 /* 1257 * Disable Master-Abort Mode during probing to avoid reporting of 1258 * bus errors in some architectures. 1259 */ 1260 pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &bctl); 1261 pci_write_config_word(dev, PCI_BRIDGE_CONTROL, 1262 bctl & ~PCI_BRIDGE_CTL_MASTER_ABORT); 1263 1264 pci_enable_crs(dev); 1265 1266 if ((secondary || subordinate) && !pcibios_assign_all_busses() && 1267 !is_cardbus && !broken) { 1268 unsigned int cmax; 1269 1270 /* 1271 * Bus already configured by firmware, process it in the 1272 * first pass and just note the configuration. 1273 */ 1274 if (pass) 1275 goto out; 1276 1277 /* 1278 * The bus might already exist for two reasons: Either we 1279 * are rescanning the bus or the bus is reachable through 1280 * more than one bridge. The second case can happen with 1281 * the i450NX chipset. 1282 */ 1283 child = pci_find_bus(pci_domain_nr(bus), secondary); 1284 if (!child) { 1285 child = pci_add_new_bus(bus, dev, secondary); 1286 if (!child) 1287 goto out; 1288 child->primary = primary; 1289 pci_bus_insert_busn_res(child, secondary, subordinate); 1290 child->bridge_ctl = bctl; 1291 } 1292 1293 cmax = pci_scan_child_bus(child); 1294 if (cmax > subordinate) 1295 pci_warn(dev, "bridge has subordinate %02x but max busn %02x\n", 1296 subordinate, cmax); 1297 1298 /* Subordinate should equal child->busn_res.end */ 1299 if (subordinate > max) 1300 max = subordinate; 1301 } else { 1302 1303 /* 1304 * We need to assign a number to this bus which we always 1305 * do in the second pass. 1306 */ 1307 if (!pass) { 1308 if (pcibios_assign_all_busses() || broken || is_cardbus) 1309 1310 /* 1311 * Temporarily disable forwarding of the 1312 * configuration cycles on all bridges in 1313 * this bus segment to avoid possible 1314 * conflicts in the second pass between two 1315 * bridges programmed with overlapping bus 1316 * ranges. 1317 */ 1318 pci_write_config_dword(dev, PCI_PRIMARY_BUS, 1319 buses & ~0xffffff); 1320 goto out; 1321 } 1322 1323 /* Clear errors */ 1324 pci_write_config_word(dev, PCI_STATUS, 0xffff); 1325 1326 /* Read bus numbers from EA Capability (if present) */ 1327 fixed_buses = pci_ea_fixed_busnrs(dev, &fixed_sec, &fixed_sub); 1328 if (fixed_buses) 1329 next_busnr = fixed_sec; 1330 else 1331 next_busnr = max + 1; 1332 1333 /* 1334 * Prevent assigning a bus number that already exists. 1335 * This can happen when a bridge is hot-plugged, so in this 1336 * case we only re-scan this bus. 1337 */ 1338 child = pci_find_bus(pci_domain_nr(bus), next_busnr); 1339 if (!child) { 1340 child = pci_add_new_bus(bus, dev, next_busnr); 1341 if (!child) 1342 goto out; 1343 pci_bus_insert_busn_res(child, next_busnr, 1344 bus->busn_res.end); 1345 } 1346 max++; 1347 if (available_buses) 1348 available_buses--; 1349 1350 buses = (buses & 0xff000000) 1351 | ((unsigned int)(child->primary) << 0) 1352 | ((unsigned int)(child->busn_res.start) << 8) 1353 | ((unsigned int)(child->busn_res.end) << 16); 1354 1355 /* 1356 * yenta.c forces a secondary latency timer of 176. 1357 * Copy that behaviour here. 1358 */ 1359 if (is_cardbus) { 1360 buses &= ~0xff000000; 1361 buses |= CARDBUS_LATENCY_TIMER << 24; 1362 } 1363 1364 /* We need to blast all three values with a single write */ 1365 pci_write_config_dword(dev, PCI_PRIMARY_BUS, buses); 1366 1367 if (!is_cardbus) { 1368 child->bridge_ctl = bctl; 1369 max = pci_scan_child_bus_extend(child, available_buses); 1370 } else { 1371 1372 /* 1373 * For CardBus bridges, we leave 4 bus numbers as 1374 * cards with a PCI-to-PCI bridge can be inserted 1375 * later. 1376 */ 1377 for (i = 0; i < CARDBUS_RESERVE_BUSNR; i++) { 1378 struct pci_bus *parent = bus; 1379 if (pci_find_bus(pci_domain_nr(bus), 1380 max+i+1)) 1381 break; 1382 while (parent->parent) { 1383 if ((!pcibios_assign_all_busses()) && 1384 (parent->busn_res.end > max) && 1385 (parent->busn_res.end <= max+i)) { 1386 j = 1; 1387 } 1388 parent = parent->parent; 1389 } 1390 if (j) { 1391 1392 /* 1393 * Often, there are two CardBus 1394 * bridges -- try to leave one 1395 * valid bus number for each one. 1396 */ 1397 i /= 2; 1398 break; 1399 } 1400 } 1401 max += i; 1402 } 1403 1404 /* 1405 * Set subordinate bus number to its real value. 1406 * If fixed subordinate bus number exists from EA 1407 * capability then use it. 1408 */ 1409 if (fixed_buses) 1410 max = fixed_sub; 1411 pci_bus_update_busn_res_end(child, max); 1412 pci_write_config_byte(dev, PCI_SUBORDINATE_BUS, max); 1413 } 1414 1415 sprintf(child->name, 1416 (is_cardbus ? "PCI CardBus %04x:%02x" : "PCI Bus %04x:%02x"), 1417 pci_domain_nr(bus), child->number); 1418 1419 /* Check that all devices are accessible */ 1420 while (bus->parent) { 1421 if ((child->busn_res.end > bus->busn_res.end) || 1422 (child->number > bus->busn_res.end) || 1423 (child->number < bus->number) || 1424 (child->busn_res.end < bus->number)) { 1425 dev_info(&dev->dev, "devices behind bridge are unusable because %pR cannot be assigned for them\n", 1426 &child->busn_res); 1427 break; 1428 } 1429 bus = bus->parent; 1430 } 1431 1432 out: 1433 pci_write_config_word(dev, PCI_BRIDGE_CONTROL, bctl); 1434 1435 pm_runtime_put(&dev->dev); 1436 1437 return max; 1438 } 1439 1440 /* 1441 * pci_scan_bridge() - Scan buses behind a bridge 1442 * @bus: Parent bus the bridge is on 1443 * @dev: Bridge itself 1444 * @max: Starting subordinate number of buses behind this bridge 1445 * @pass: Either %0 (scan already configured bridges) or %1 (scan bridges 1446 * that need to be reconfigured. 1447 * 1448 * If it's a bridge, configure it and scan the bus behind it. 1449 * For CardBus bridges, we don't scan behind as the devices will 1450 * be handled by the bridge driver itself. 1451 * 1452 * We need to process bridges in two passes -- first we scan those 1453 * already configured by the BIOS and after we are done with all of 1454 * them, we proceed to assigning numbers to the remaining buses in 1455 * order to avoid overlaps between old and new bus numbers. 1456 * 1457 * Return: New subordinate number covering all buses behind this bridge. 1458 */ 1459 int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass) 1460 { 1461 return pci_scan_bridge_extend(bus, dev, max, 0, pass); 1462 } 1463 EXPORT_SYMBOL(pci_scan_bridge); 1464 1465 /* 1466 * Read interrupt line and base address registers. 1467 * The architecture-dependent code can tweak these, of course. 1468 */ 1469 static void pci_read_irq(struct pci_dev *dev) 1470 { 1471 unsigned char irq; 1472 1473 /* VFs are not allowed to use INTx, so skip the config reads */ 1474 if (dev->is_virtfn) { 1475 dev->pin = 0; 1476 dev->irq = 0; 1477 return; 1478 } 1479 1480 pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &irq); 1481 dev->pin = irq; 1482 if (irq) 1483 pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &irq); 1484 dev->irq = irq; 1485 } 1486 1487 void set_pcie_port_type(struct pci_dev *pdev) 1488 { 1489 int pos; 1490 u16 reg16; 1491 int type; 1492 struct pci_dev *parent; 1493 1494 pos = pci_find_capability(pdev, PCI_CAP_ID_EXP); 1495 if (!pos) 1496 return; 1497 1498 pdev->pcie_cap = pos; 1499 pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, ®16); 1500 pdev->pcie_flags_reg = reg16; 1501 pci_read_config_word(pdev, pos + PCI_EXP_DEVCAP, ®16); 1502 pdev->pcie_mpss = reg16 & PCI_EXP_DEVCAP_PAYLOAD; 1503 1504 parent = pci_upstream_bridge(pdev); 1505 if (!parent) 1506 return; 1507 1508 /* 1509 * Some systems do not identify their upstream/downstream ports 1510 * correctly so detect impossible configurations here and correct 1511 * the port type accordingly. 1512 */ 1513 type = pci_pcie_type(pdev); 1514 if (type == PCI_EXP_TYPE_DOWNSTREAM) { 1515 /* 1516 * If pdev claims to be downstream port but the parent 1517 * device is also downstream port assume pdev is actually 1518 * upstream port. 1519 */ 1520 if (pcie_downstream_port(parent)) { 1521 pci_info(pdev, "claims to be downstream port but is acting as upstream port, correcting type\n"); 1522 pdev->pcie_flags_reg &= ~PCI_EXP_FLAGS_TYPE; 1523 pdev->pcie_flags_reg |= PCI_EXP_TYPE_UPSTREAM; 1524 } 1525 } else if (type == PCI_EXP_TYPE_UPSTREAM) { 1526 /* 1527 * If pdev claims to be upstream port but the parent 1528 * device is also upstream port assume pdev is actually 1529 * downstream port. 1530 */ 1531 if (pci_pcie_type(parent) == PCI_EXP_TYPE_UPSTREAM) { 1532 pci_info(pdev, "claims to be upstream port but is acting as downstream port, correcting type\n"); 1533 pdev->pcie_flags_reg &= ~PCI_EXP_FLAGS_TYPE; 1534 pdev->pcie_flags_reg |= PCI_EXP_TYPE_DOWNSTREAM; 1535 } 1536 } 1537 } 1538 1539 void set_pcie_hotplug_bridge(struct pci_dev *pdev) 1540 { 1541 u32 reg32; 1542 1543 pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, ®32); 1544 if (reg32 & PCI_EXP_SLTCAP_HPC) 1545 pdev->is_hotplug_bridge = 1; 1546 } 1547 1548 static void set_pcie_thunderbolt(struct pci_dev *dev) 1549 { 1550 int vsec = 0; 1551 u32 header; 1552 1553 while ((vsec = pci_find_next_ext_capability(dev, vsec, 1554 PCI_EXT_CAP_ID_VNDR))) { 1555 pci_read_config_dword(dev, vsec + PCI_VNDR_HEADER, &header); 1556 1557 /* Is the device part of a Thunderbolt controller? */ 1558 if (dev->vendor == PCI_VENDOR_ID_INTEL && 1559 PCI_VNDR_HEADER_ID(header) == PCI_VSEC_ID_INTEL_TBT) { 1560 dev->is_thunderbolt = 1; 1561 return; 1562 } 1563 } 1564 } 1565 1566 static void set_pcie_untrusted(struct pci_dev *dev) 1567 { 1568 struct pci_dev *parent; 1569 1570 /* 1571 * If the upstream bridge is untrusted we treat this device 1572 * untrusted as well. 1573 */ 1574 parent = pci_upstream_bridge(dev); 1575 if (parent && (parent->untrusted || parent->external_facing)) 1576 dev->untrusted = true; 1577 } 1578 1579 /** 1580 * pci_ext_cfg_is_aliased - Is ext config space just an alias of std config? 1581 * @dev: PCI device 1582 * 1583 * PCI Express to PCI/PCI-X Bridge Specification, rev 1.0, 4.1.4 says that 1584 * when forwarding a type1 configuration request the bridge must check that 1585 * the extended register address field is zero. The bridge is not permitted 1586 * to forward the transactions and must handle it as an Unsupported Request. 1587 * Some bridges do not follow this rule and simply drop the extended register 1588 * bits, resulting in the standard config space being aliased, every 256 1589 * bytes across the entire configuration space. Test for this condition by 1590 * comparing the first dword of each potential alias to the vendor/device ID. 1591 * Known offenders: 1592 * ASM1083/1085 PCIe-to-PCI Reversible Bridge (1b21:1080, rev 01 & 03) 1593 * AMD/ATI SBx00 PCI to PCI Bridge (1002:4384, rev 40) 1594 */ 1595 static bool pci_ext_cfg_is_aliased(struct pci_dev *dev) 1596 { 1597 #ifdef CONFIG_PCI_QUIRKS 1598 int pos; 1599 u32 header, tmp; 1600 1601 pci_read_config_dword(dev, PCI_VENDOR_ID, &header); 1602 1603 for (pos = PCI_CFG_SPACE_SIZE; 1604 pos < PCI_CFG_SPACE_EXP_SIZE; pos += PCI_CFG_SPACE_SIZE) { 1605 if (pci_read_config_dword(dev, pos, &tmp) != PCIBIOS_SUCCESSFUL 1606 || header != tmp) 1607 return false; 1608 } 1609 1610 return true; 1611 #else 1612 return false; 1613 #endif 1614 } 1615 1616 /** 1617 * pci_cfg_space_size_ext - Get the configuration space size of the PCI device 1618 * @dev: PCI device 1619 * 1620 * Regular PCI devices have 256 bytes, but PCI-X 2 and PCI Express devices 1621 * have 4096 bytes. Even if the device is capable, that doesn't mean we can 1622 * access it. Maybe we don't have a way to generate extended config space 1623 * accesses, or the device is behind a reverse Express bridge. So we try 1624 * reading the dword at 0x100 which must either be 0 or a valid extended 1625 * capability header. 1626 */ 1627 static int pci_cfg_space_size_ext(struct pci_dev *dev) 1628 { 1629 u32 status; 1630 int pos = PCI_CFG_SPACE_SIZE; 1631 1632 if (pci_read_config_dword(dev, pos, &status) != PCIBIOS_SUCCESSFUL) 1633 return PCI_CFG_SPACE_SIZE; 1634 if (status == 0xffffffff || pci_ext_cfg_is_aliased(dev)) 1635 return PCI_CFG_SPACE_SIZE; 1636 1637 return PCI_CFG_SPACE_EXP_SIZE; 1638 } 1639 1640 int pci_cfg_space_size(struct pci_dev *dev) 1641 { 1642 int pos; 1643 u32 status; 1644 u16 class; 1645 1646 #ifdef CONFIG_PCI_IOV 1647 /* 1648 * Per the SR-IOV specification (rev 1.1, sec 3.5), VFs are required to 1649 * implement a PCIe capability and therefore must implement extended 1650 * config space. We can skip the NO_EXTCFG test below and the 1651 * reachability/aliasing test in pci_cfg_space_size_ext() by virtue of 1652 * the fact that the SR-IOV capability on the PF resides in extended 1653 * config space and must be accessible and non-aliased to have enabled 1654 * support for this VF. This is a micro performance optimization for 1655 * systems supporting many VFs. 1656 */ 1657 if (dev->is_virtfn) 1658 return PCI_CFG_SPACE_EXP_SIZE; 1659 #endif 1660 1661 if (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_EXTCFG) 1662 return PCI_CFG_SPACE_SIZE; 1663 1664 class = dev->class >> 8; 1665 if (class == PCI_CLASS_BRIDGE_HOST) 1666 return pci_cfg_space_size_ext(dev); 1667 1668 if (pci_is_pcie(dev)) 1669 return pci_cfg_space_size_ext(dev); 1670 1671 pos = pci_find_capability(dev, PCI_CAP_ID_PCIX); 1672 if (!pos) 1673 return PCI_CFG_SPACE_SIZE; 1674 1675 pci_read_config_dword(dev, pos + PCI_X_STATUS, &status); 1676 if (status & (PCI_X_STATUS_266MHZ | PCI_X_STATUS_533MHZ)) 1677 return pci_cfg_space_size_ext(dev); 1678 1679 return PCI_CFG_SPACE_SIZE; 1680 } 1681 1682 static u32 pci_class(struct pci_dev *dev) 1683 { 1684 u32 class; 1685 1686 #ifdef CONFIG_PCI_IOV 1687 if (dev->is_virtfn) 1688 return dev->physfn->sriov->class; 1689 #endif 1690 pci_read_config_dword(dev, PCI_CLASS_REVISION, &class); 1691 return class; 1692 } 1693 1694 static void pci_subsystem_ids(struct pci_dev *dev, u16 *vendor, u16 *device) 1695 { 1696 #ifdef CONFIG_PCI_IOV 1697 if (dev->is_virtfn) { 1698 *vendor = dev->physfn->sriov->subsystem_vendor; 1699 *device = dev->physfn->sriov->subsystem_device; 1700 return; 1701 } 1702 #endif 1703 pci_read_config_word(dev, PCI_SUBSYSTEM_VENDOR_ID, vendor); 1704 pci_read_config_word(dev, PCI_SUBSYSTEM_ID, device); 1705 } 1706 1707 static u8 pci_hdr_type(struct pci_dev *dev) 1708 { 1709 u8 hdr_type; 1710 1711 #ifdef CONFIG_PCI_IOV 1712 if (dev->is_virtfn) 1713 return dev->physfn->sriov->hdr_type; 1714 #endif 1715 pci_read_config_byte(dev, PCI_HEADER_TYPE, &hdr_type); 1716 return hdr_type; 1717 } 1718 1719 #define LEGACY_IO_RESOURCE (IORESOURCE_IO | IORESOURCE_PCI_FIXED) 1720 1721 /** 1722 * pci_intx_mask_broken - Test PCI_COMMAND_INTX_DISABLE writability 1723 * @dev: PCI device 1724 * 1725 * Test whether PCI_COMMAND_INTX_DISABLE is writable for @dev. Check this 1726 * at enumeration-time to avoid modifying PCI_COMMAND at run-time. 1727 */ 1728 static int pci_intx_mask_broken(struct pci_dev *dev) 1729 { 1730 u16 orig, toggle, new; 1731 1732 pci_read_config_word(dev, PCI_COMMAND, &orig); 1733 toggle = orig ^ PCI_COMMAND_INTX_DISABLE; 1734 pci_write_config_word(dev, PCI_COMMAND, toggle); 1735 pci_read_config_word(dev, PCI_COMMAND, &new); 1736 1737 pci_write_config_word(dev, PCI_COMMAND, orig); 1738 1739 /* 1740 * PCI_COMMAND_INTX_DISABLE was reserved and read-only prior to PCI 1741 * r2.3, so strictly speaking, a device is not *broken* if it's not 1742 * writable. But we'll live with the misnomer for now. 1743 */ 1744 if (new != toggle) 1745 return 1; 1746 return 0; 1747 } 1748 1749 static void early_dump_pci_device(struct pci_dev *pdev) 1750 { 1751 u32 value[256 / 4]; 1752 int i; 1753 1754 pci_info(pdev, "config space:\n"); 1755 1756 for (i = 0; i < 256; i += 4) 1757 pci_read_config_dword(pdev, i, &value[i / 4]); 1758 1759 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET, 16, 1, 1760 value, 256, false); 1761 } 1762 1763 /** 1764 * pci_setup_device - Fill in class and map information of a device 1765 * @dev: the device structure to fill 1766 * 1767 * Initialize the device structure with information about the device's 1768 * vendor,class,memory and IO-space addresses, IRQ lines etc. 1769 * Called at initialisation of the PCI subsystem and by CardBus services. 1770 * Returns 0 on success and negative if unknown type of device (not normal, 1771 * bridge or CardBus). 1772 */ 1773 int pci_setup_device(struct pci_dev *dev) 1774 { 1775 u32 class; 1776 u16 cmd; 1777 u8 hdr_type; 1778 int pos = 0; 1779 struct pci_bus_region region; 1780 struct resource *res; 1781 1782 hdr_type = pci_hdr_type(dev); 1783 1784 dev->sysdata = dev->bus->sysdata; 1785 dev->dev.parent = dev->bus->bridge; 1786 dev->dev.bus = &pci_bus_type; 1787 dev->hdr_type = hdr_type & 0x7f; 1788 dev->multifunction = !!(hdr_type & 0x80); 1789 dev->error_state = pci_channel_io_normal; 1790 set_pcie_port_type(dev); 1791 1792 pci_dev_assign_slot(dev); 1793 1794 /* 1795 * Assume 32-bit PCI; let 64-bit PCI cards (which are far rarer) 1796 * set this higher, assuming the system even supports it. 1797 */ 1798 dev->dma_mask = 0xffffffff; 1799 1800 dev_set_name(&dev->dev, "%04x:%02x:%02x.%d", pci_domain_nr(dev->bus), 1801 dev->bus->number, PCI_SLOT(dev->devfn), 1802 PCI_FUNC(dev->devfn)); 1803 1804 class = pci_class(dev); 1805 1806 dev->revision = class & 0xff; 1807 dev->class = class >> 8; /* upper 3 bytes */ 1808 1809 if (pci_early_dump) 1810 early_dump_pci_device(dev); 1811 1812 /* Need to have dev->class ready */ 1813 dev->cfg_size = pci_cfg_space_size(dev); 1814 1815 /* Need to have dev->cfg_size ready */ 1816 set_pcie_thunderbolt(dev); 1817 1818 set_pcie_untrusted(dev); 1819 1820 /* "Unknown power state" */ 1821 dev->current_state = PCI_UNKNOWN; 1822 1823 /* Early fixups, before probing the BARs */ 1824 pci_fixup_device(pci_fixup_early, dev); 1825 1826 pci_info(dev, "[%04x:%04x] type %02x class %#08x\n", 1827 dev->vendor, dev->device, dev->hdr_type, dev->class); 1828 1829 /* Device class may be changed after fixup */ 1830 class = dev->class >> 8; 1831 1832 if (dev->non_compliant_bars && !dev->mmio_always_on) { 1833 pci_read_config_word(dev, PCI_COMMAND, &cmd); 1834 if (cmd & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) { 1835 pci_info(dev, "device has non-compliant BARs; disabling IO/MEM decoding\n"); 1836 cmd &= ~PCI_COMMAND_IO; 1837 cmd &= ~PCI_COMMAND_MEMORY; 1838 pci_write_config_word(dev, PCI_COMMAND, cmd); 1839 } 1840 } 1841 1842 dev->broken_intx_masking = pci_intx_mask_broken(dev); 1843 1844 switch (dev->hdr_type) { /* header type */ 1845 case PCI_HEADER_TYPE_NORMAL: /* standard header */ 1846 if (class == PCI_CLASS_BRIDGE_PCI) 1847 goto bad; 1848 pci_read_irq(dev); 1849 pci_read_bases(dev, 6, PCI_ROM_ADDRESS); 1850 1851 pci_subsystem_ids(dev, &dev->subsystem_vendor, &dev->subsystem_device); 1852 1853 /* 1854 * Do the ugly legacy mode stuff here rather than broken chip 1855 * quirk code. Legacy mode ATA controllers have fixed 1856 * addresses. These are not always echoed in BAR0-3, and 1857 * BAR0-3 in a few cases contain junk! 1858 */ 1859 if (class == PCI_CLASS_STORAGE_IDE) { 1860 u8 progif; 1861 pci_read_config_byte(dev, PCI_CLASS_PROG, &progif); 1862 if ((progif & 1) == 0) { 1863 region.start = 0x1F0; 1864 region.end = 0x1F7; 1865 res = &dev->resource[0]; 1866 res->flags = LEGACY_IO_RESOURCE; 1867 pcibios_bus_to_resource(dev->bus, res, ®ion); 1868 pci_info(dev, "legacy IDE quirk: reg 0x10: %pR\n", 1869 res); 1870 region.start = 0x3F6; 1871 region.end = 0x3F6; 1872 res = &dev->resource[1]; 1873 res->flags = LEGACY_IO_RESOURCE; 1874 pcibios_bus_to_resource(dev->bus, res, ®ion); 1875 pci_info(dev, "legacy IDE quirk: reg 0x14: %pR\n", 1876 res); 1877 } 1878 if ((progif & 4) == 0) { 1879 region.start = 0x170; 1880 region.end = 0x177; 1881 res = &dev->resource[2]; 1882 res->flags = LEGACY_IO_RESOURCE; 1883 pcibios_bus_to_resource(dev->bus, res, ®ion); 1884 pci_info(dev, "legacy IDE quirk: reg 0x18: %pR\n", 1885 res); 1886 region.start = 0x376; 1887 region.end = 0x376; 1888 res = &dev->resource[3]; 1889 res->flags = LEGACY_IO_RESOURCE; 1890 pcibios_bus_to_resource(dev->bus, res, ®ion); 1891 pci_info(dev, "legacy IDE quirk: reg 0x1c: %pR\n", 1892 res); 1893 } 1894 } 1895 break; 1896 1897 case PCI_HEADER_TYPE_BRIDGE: /* bridge header */ 1898 /* 1899 * The PCI-to-PCI bridge spec requires that subtractive 1900 * decoding (i.e. transparent) bridge must have programming 1901 * interface code of 0x01. 1902 */ 1903 pci_read_irq(dev); 1904 dev->transparent = ((dev->class & 0xff) == 1); 1905 pci_read_bases(dev, 2, PCI_ROM_ADDRESS1); 1906 pci_read_bridge_windows(dev); 1907 set_pcie_hotplug_bridge(dev); 1908 pos = pci_find_capability(dev, PCI_CAP_ID_SSVID); 1909 if (pos) { 1910 pci_read_config_word(dev, pos + PCI_SSVID_VENDOR_ID, &dev->subsystem_vendor); 1911 pci_read_config_word(dev, pos + PCI_SSVID_DEVICE_ID, &dev->subsystem_device); 1912 } 1913 break; 1914 1915 case PCI_HEADER_TYPE_CARDBUS: /* CardBus bridge header */ 1916 if (class != PCI_CLASS_BRIDGE_CARDBUS) 1917 goto bad; 1918 pci_read_irq(dev); 1919 pci_read_bases(dev, 1, 0); 1920 pci_read_config_word(dev, PCI_CB_SUBSYSTEM_VENDOR_ID, &dev->subsystem_vendor); 1921 pci_read_config_word(dev, PCI_CB_SUBSYSTEM_ID, &dev->subsystem_device); 1922 break; 1923 1924 default: /* unknown header */ 1925 pci_err(dev, "unknown header type %02x, ignoring device\n", 1926 dev->hdr_type); 1927 return -EIO; 1928 1929 bad: 1930 pci_err(dev, "ignoring class %#08x (doesn't match header type %02x)\n", 1931 dev->class, dev->hdr_type); 1932 dev->class = PCI_CLASS_NOT_DEFINED << 8; 1933 } 1934 1935 /* We found a fine healthy device, go go go... */ 1936 return 0; 1937 } 1938 1939 static void pci_configure_mps(struct pci_dev *dev) 1940 { 1941 struct pci_dev *bridge = pci_upstream_bridge(dev); 1942 int mps, mpss, p_mps, rc; 1943 1944 if (!pci_is_pcie(dev)) 1945 return; 1946 1947 /* MPS and MRRS fields are of type 'RsvdP' for VFs, short-circuit out */ 1948 if (dev->is_virtfn) 1949 return; 1950 1951 /* 1952 * For Root Complex Integrated Endpoints, program the maximum 1953 * supported value unless limited by the PCIE_BUS_PEER2PEER case. 1954 */ 1955 if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) { 1956 if (pcie_bus_config == PCIE_BUS_PEER2PEER) 1957 mps = 128; 1958 else 1959 mps = 128 << dev->pcie_mpss; 1960 rc = pcie_set_mps(dev, mps); 1961 if (rc) { 1962 pci_warn(dev, "can't set Max Payload Size to %d; if necessary, use \"pci=pcie_bus_safe\" and report a bug\n", 1963 mps); 1964 } 1965 return; 1966 } 1967 1968 if (!bridge || !pci_is_pcie(bridge)) 1969 return; 1970 1971 mps = pcie_get_mps(dev); 1972 p_mps = pcie_get_mps(bridge); 1973 1974 if (mps == p_mps) 1975 return; 1976 1977 if (pcie_bus_config == PCIE_BUS_TUNE_OFF) { 1978 pci_warn(dev, "Max Payload Size %d, but upstream %s set to %d; if necessary, use \"pci=pcie_bus_safe\" and report a bug\n", 1979 mps, pci_name(bridge), p_mps); 1980 return; 1981 } 1982 1983 /* 1984 * Fancier MPS configuration is done later by 1985 * pcie_bus_configure_settings() 1986 */ 1987 if (pcie_bus_config != PCIE_BUS_DEFAULT) 1988 return; 1989 1990 mpss = 128 << dev->pcie_mpss; 1991 if (mpss < p_mps && pci_pcie_type(bridge) == PCI_EXP_TYPE_ROOT_PORT) { 1992 pcie_set_mps(bridge, mpss); 1993 pci_info(dev, "Upstream bridge's Max Payload Size set to %d (was %d, max %d)\n", 1994 mpss, p_mps, 128 << bridge->pcie_mpss); 1995 p_mps = pcie_get_mps(bridge); 1996 } 1997 1998 rc = pcie_set_mps(dev, p_mps); 1999 if (rc) { 2000 pci_warn(dev, "can't set Max Payload Size to %d; if necessary, use \"pci=pcie_bus_safe\" and report a bug\n", 2001 p_mps); 2002 return; 2003 } 2004 2005 pci_info(dev, "Max Payload Size set to %d (was %d, max %d)\n", 2006 p_mps, mps, mpss); 2007 } 2008 2009 int pci_configure_extended_tags(struct pci_dev *dev, void *ign) 2010 { 2011 struct pci_host_bridge *host; 2012 u32 cap; 2013 u16 ctl; 2014 int ret; 2015 2016 if (!pci_is_pcie(dev)) 2017 return 0; 2018 2019 ret = pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap); 2020 if (ret) 2021 return 0; 2022 2023 if (!(cap & PCI_EXP_DEVCAP_EXT_TAG)) 2024 return 0; 2025 2026 ret = pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl); 2027 if (ret) 2028 return 0; 2029 2030 host = pci_find_host_bridge(dev->bus); 2031 if (!host) 2032 return 0; 2033 2034 /* 2035 * If some device in the hierarchy doesn't handle Extended Tags 2036 * correctly, make sure they're disabled. 2037 */ 2038 if (host->no_ext_tags) { 2039 if (ctl & PCI_EXP_DEVCTL_EXT_TAG) { 2040 pci_info(dev, "disabling Extended Tags\n"); 2041 pcie_capability_clear_word(dev, PCI_EXP_DEVCTL, 2042 PCI_EXP_DEVCTL_EXT_TAG); 2043 } 2044 return 0; 2045 } 2046 2047 if (!(ctl & PCI_EXP_DEVCTL_EXT_TAG)) { 2048 pci_info(dev, "enabling Extended Tags\n"); 2049 pcie_capability_set_word(dev, PCI_EXP_DEVCTL, 2050 PCI_EXP_DEVCTL_EXT_TAG); 2051 } 2052 return 0; 2053 } 2054 2055 /** 2056 * pcie_relaxed_ordering_enabled - Probe for PCIe relaxed ordering enable 2057 * @dev: PCI device to query 2058 * 2059 * Returns true if the device has enabled relaxed ordering attribute. 2060 */ 2061 bool pcie_relaxed_ordering_enabled(struct pci_dev *dev) 2062 { 2063 u16 v; 2064 2065 pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &v); 2066 2067 return !!(v & PCI_EXP_DEVCTL_RELAX_EN); 2068 } 2069 EXPORT_SYMBOL(pcie_relaxed_ordering_enabled); 2070 2071 static void pci_configure_relaxed_ordering(struct pci_dev *dev) 2072 { 2073 struct pci_dev *root; 2074 2075 /* PCI_EXP_DEVICE_RELAX_EN is RsvdP in VFs */ 2076 if (dev->is_virtfn) 2077 return; 2078 2079 if (!pcie_relaxed_ordering_enabled(dev)) 2080 return; 2081 2082 /* 2083 * For now, we only deal with Relaxed Ordering issues with Root 2084 * Ports. Peer-to-Peer DMA is another can of worms. 2085 */ 2086 root = pcie_find_root_port(dev); 2087 if (!root) 2088 return; 2089 2090 if (root->dev_flags & PCI_DEV_FLAGS_NO_RELAXED_ORDERING) { 2091 pcie_capability_clear_word(dev, PCI_EXP_DEVCTL, 2092 PCI_EXP_DEVCTL_RELAX_EN); 2093 pci_info(dev, "Relaxed Ordering disabled because the Root Port didn't support it\n"); 2094 } 2095 } 2096 2097 static void pci_configure_ltr(struct pci_dev *dev) 2098 { 2099 #ifdef CONFIG_PCIEASPM 2100 struct pci_host_bridge *host = pci_find_host_bridge(dev->bus); 2101 struct pci_dev *bridge; 2102 u32 cap, ctl; 2103 2104 if (!pci_is_pcie(dev)) 2105 return; 2106 2107 /* Read L1 PM substate capabilities */ 2108 dev->l1ss = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_L1SS); 2109 2110 pcie_capability_read_dword(dev, PCI_EXP_DEVCAP2, &cap); 2111 if (!(cap & PCI_EXP_DEVCAP2_LTR)) 2112 return; 2113 2114 pcie_capability_read_dword(dev, PCI_EXP_DEVCTL2, &ctl); 2115 if (ctl & PCI_EXP_DEVCTL2_LTR_EN) { 2116 if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) { 2117 dev->ltr_path = 1; 2118 return; 2119 } 2120 2121 bridge = pci_upstream_bridge(dev); 2122 if (bridge && bridge->ltr_path) 2123 dev->ltr_path = 1; 2124 2125 return; 2126 } 2127 2128 if (!host->native_ltr) 2129 return; 2130 2131 /* 2132 * Software must not enable LTR in an Endpoint unless the Root 2133 * Complex and all intermediate Switches indicate support for LTR. 2134 * PCIe r4.0, sec 6.18. 2135 */ 2136 if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT || 2137 ((bridge = pci_upstream_bridge(dev)) && 2138 bridge->ltr_path)) { 2139 pcie_capability_set_word(dev, PCI_EXP_DEVCTL2, 2140 PCI_EXP_DEVCTL2_LTR_EN); 2141 dev->ltr_path = 1; 2142 } 2143 #endif 2144 } 2145 2146 static void pci_configure_eetlp_prefix(struct pci_dev *dev) 2147 { 2148 #ifdef CONFIG_PCI_PASID 2149 struct pci_dev *bridge; 2150 int pcie_type; 2151 u32 cap; 2152 2153 if (!pci_is_pcie(dev)) 2154 return; 2155 2156 pcie_capability_read_dword(dev, PCI_EXP_DEVCAP2, &cap); 2157 if (!(cap & PCI_EXP_DEVCAP2_EE_PREFIX)) 2158 return; 2159 2160 pcie_type = pci_pcie_type(dev); 2161 if (pcie_type == PCI_EXP_TYPE_ROOT_PORT || 2162 pcie_type == PCI_EXP_TYPE_RC_END) 2163 dev->eetlp_prefix_path = 1; 2164 else { 2165 bridge = pci_upstream_bridge(dev); 2166 if (bridge && bridge->eetlp_prefix_path) 2167 dev->eetlp_prefix_path = 1; 2168 } 2169 #endif 2170 } 2171 2172 static void pci_configure_serr(struct pci_dev *dev) 2173 { 2174 u16 control; 2175 2176 if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { 2177 2178 /* 2179 * A bridge will not forward ERR_ messages coming from an 2180 * endpoint unless SERR# forwarding is enabled. 2181 */ 2182 pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &control); 2183 if (!(control & PCI_BRIDGE_CTL_SERR)) { 2184 control |= PCI_BRIDGE_CTL_SERR; 2185 pci_write_config_word(dev, PCI_BRIDGE_CONTROL, control); 2186 } 2187 } 2188 } 2189 2190 static void pci_configure_device(struct pci_dev *dev) 2191 { 2192 pci_configure_mps(dev); 2193 pci_configure_extended_tags(dev, NULL); 2194 pci_configure_relaxed_ordering(dev); 2195 pci_configure_ltr(dev); 2196 pci_configure_eetlp_prefix(dev); 2197 pci_configure_serr(dev); 2198 2199 pci_acpi_program_hp_params(dev); 2200 } 2201 2202 static void pci_release_capabilities(struct pci_dev *dev) 2203 { 2204 pci_aer_exit(dev); 2205 pci_rcec_exit(dev); 2206 pci_vpd_release(dev); 2207 pci_iov_release(dev); 2208 pci_free_cap_save_buffers(dev); 2209 } 2210 2211 /** 2212 * pci_release_dev - Free a PCI device structure when all users of it are 2213 * finished 2214 * @dev: device that's been disconnected 2215 * 2216 * Will be called only by the device core when all users of this PCI device are 2217 * done. 2218 */ 2219 static void pci_release_dev(struct device *dev) 2220 { 2221 struct pci_dev *pci_dev; 2222 2223 pci_dev = to_pci_dev(dev); 2224 pci_release_capabilities(pci_dev); 2225 pci_release_of_node(pci_dev); 2226 pcibios_release_device(pci_dev); 2227 pci_bus_put(pci_dev->bus); 2228 kfree(pci_dev->driver_override); 2229 bitmap_free(pci_dev->dma_alias_mask); 2230 kfree(pci_dev); 2231 } 2232 2233 struct pci_dev *pci_alloc_dev(struct pci_bus *bus) 2234 { 2235 struct pci_dev *dev; 2236 2237 dev = kzalloc(sizeof(struct pci_dev), GFP_KERNEL); 2238 if (!dev) 2239 return NULL; 2240 2241 INIT_LIST_HEAD(&dev->bus_list); 2242 dev->dev.type = &pci_dev_type; 2243 dev->bus = pci_bus_get(bus); 2244 2245 return dev; 2246 } 2247 EXPORT_SYMBOL(pci_alloc_dev); 2248 2249 static bool pci_bus_crs_vendor_id(u32 l) 2250 { 2251 return (l & 0xffff) == 0x0001; 2252 } 2253 2254 static bool pci_bus_wait_crs(struct pci_bus *bus, int devfn, u32 *l, 2255 int timeout) 2256 { 2257 int delay = 1; 2258 2259 if (!pci_bus_crs_vendor_id(*l)) 2260 return true; /* not a CRS completion */ 2261 2262 if (!timeout) 2263 return false; /* CRS, but caller doesn't want to wait */ 2264 2265 /* 2266 * We got the reserved Vendor ID that indicates a completion with 2267 * Configuration Request Retry Status (CRS). Retry until we get a 2268 * valid Vendor ID or we time out. 2269 */ 2270 while (pci_bus_crs_vendor_id(*l)) { 2271 if (delay > timeout) { 2272 pr_warn("pci %04x:%02x:%02x.%d: not ready after %dms; giving up\n", 2273 pci_domain_nr(bus), bus->number, 2274 PCI_SLOT(devfn), PCI_FUNC(devfn), delay - 1); 2275 2276 return false; 2277 } 2278 if (delay >= 1000) 2279 pr_info("pci %04x:%02x:%02x.%d: not ready after %dms; waiting\n", 2280 pci_domain_nr(bus), bus->number, 2281 PCI_SLOT(devfn), PCI_FUNC(devfn), delay - 1); 2282 2283 msleep(delay); 2284 delay *= 2; 2285 2286 if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, l)) 2287 return false; 2288 } 2289 2290 if (delay >= 1000) 2291 pr_info("pci %04x:%02x:%02x.%d: ready after %dms\n", 2292 pci_domain_nr(bus), bus->number, 2293 PCI_SLOT(devfn), PCI_FUNC(devfn), delay - 1); 2294 2295 return true; 2296 } 2297 2298 bool pci_bus_generic_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l, 2299 int timeout) 2300 { 2301 if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, l)) 2302 return false; 2303 2304 /* Some broken boards return 0 or ~0 if a slot is empty: */ 2305 if (*l == 0xffffffff || *l == 0x00000000 || 2306 *l == 0x0000ffff || *l == 0xffff0000) 2307 return false; 2308 2309 if (pci_bus_crs_vendor_id(*l)) 2310 return pci_bus_wait_crs(bus, devfn, l, timeout); 2311 2312 return true; 2313 } 2314 2315 bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l, 2316 int timeout) 2317 { 2318 #ifdef CONFIG_PCI_QUIRKS 2319 struct pci_dev *bridge = bus->self; 2320 2321 /* 2322 * Certain IDT switches have an issue where they improperly trigger 2323 * ACS Source Validation errors on completions for config reads. 2324 */ 2325 if (bridge && bridge->vendor == PCI_VENDOR_ID_IDT && 2326 bridge->device == 0x80b5) 2327 return pci_idt_bus_quirk(bus, devfn, l, timeout); 2328 #endif 2329 2330 return pci_bus_generic_read_dev_vendor_id(bus, devfn, l, timeout); 2331 } 2332 EXPORT_SYMBOL(pci_bus_read_dev_vendor_id); 2333 2334 /* 2335 * Read the config data for a PCI device, sanity-check it, 2336 * and fill in the dev structure. 2337 */ 2338 static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn) 2339 { 2340 struct pci_dev *dev; 2341 u32 l; 2342 2343 if (!pci_bus_read_dev_vendor_id(bus, devfn, &l, 60*1000)) 2344 return NULL; 2345 2346 dev = pci_alloc_dev(bus); 2347 if (!dev) 2348 return NULL; 2349 2350 dev->devfn = devfn; 2351 dev->vendor = l & 0xffff; 2352 dev->device = (l >> 16) & 0xffff; 2353 2354 pci_set_of_node(dev); 2355 2356 if (pci_setup_device(dev)) { 2357 pci_release_of_node(dev); 2358 pci_bus_put(dev->bus); 2359 kfree(dev); 2360 return NULL; 2361 } 2362 2363 return dev; 2364 } 2365 2366 void pcie_report_downtraining(struct pci_dev *dev) 2367 { 2368 if (!pci_is_pcie(dev)) 2369 return; 2370 2371 /* Look from the device up to avoid downstream ports with no devices */ 2372 if ((pci_pcie_type(dev) != PCI_EXP_TYPE_ENDPOINT) && 2373 (pci_pcie_type(dev) != PCI_EXP_TYPE_LEG_END) && 2374 (pci_pcie_type(dev) != PCI_EXP_TYPE_UPSTREAM)) 2375 return; 2376 2377 /* Multi-function PCIe devices share the same link/status */ 2378 if (PCI_FUNC(dev->devfn) != 0 || dev->is_virtfn) 2379 return; 2380 2381 /* Print link status only if the device is constrained by the fabric */ 2382 __pcie_print_link_status(dev, false); 2383 } 2384 2385 static void pci_init_capabilities(struct pci_dev *dev) 2386 { 2387 pci_ea_init(dev); /* Enhanced Allocation */ 2388 pci_msi_init(dev); /* Disable MSI */ 2389 pci_msix_init(dev); /* Disable MSI-X */ 2390 2391 /* Buffers for saving PCIe and PCI-X capabilities */ 2392 pci_allocate_cap_save_buffers(dev); 2393 2394 pci_pm_init(dev); /* Power Management */ 2395 pci_vpd_init(dev); /* Vital Product Data */ 2396 pci_configure_ari(dev); /* Alternative Routing-ID Forwarding */ 2397 pci_iov_init(dev); /* Single Root I/O Virtualization */ 2398 pci_ats_init(dev); /* Address Translation Services */ 2399 pci_pri_init(dev); /* Page Request Interface */ 2400 pci_pasid_init(dev); /* Process Address Space ID */ 2401 pci_acs_init(dev); /* Access Control Services */ 2402 pci_ptm_init(dev); /* Precision Time Measurement */ 2403 pci_aer_init(dev); /* Advanced Error Reporting */ 2404 pci_dpc_init(dev); /* Downstream Port Containment */ 2405 pci_rcec_init(dev); /* Root Complex Event Collector */ 2406 2407 pcie_report_downtraining(dev); 2408 2409 if (pci_probe_reset_function(dev) == 0) 2410 dev->reset_fn = 1; 2411 } 2412 2413 /* 2414 * This is the equivalent of pci_host_bridge_msi_domain() that acts on 2415 * devices. Firmware interfaces that can select the MSI domain on a 2416 * per-device basis should be called from here. 2417 */ 2418 static struct irq_domain *pci_dev_msi_domain(struct pci_dev *dev) 2419 { 2420 struct irq_domain *d; 2421 2422 /* 2423 * If a domain has been set through the pcibios_add_device() 2424 * callback, then this is the one (platform code knows best). 2425 */ 2426 d = dev_get_msi_domain(&dev->dev); 2427 if (d) 2428 return d; 2429 2430 /* 2431 * Let's see if we have a firmware interface able to provide 2432 * the domain. 2433 */ 2434 d = pci_msi_get_device_domain(dev); 2435 if (d) 2436 return d; 2437 2438 return NULL; 2439 } 2440 2441 static void pci_set_msi_domain(struct pci_dev *dev) 2442 { 2443 struct irq_domain *d; 2444 2445 /* 2446 * If the platform or firmware interfaces cannot supply a 2447 * device-specific MSI domain, then inherit the default domain 2448 * from the host bridge itself. 2449 */ 2450 d = pci_dev_msi_domain(dev); 2451 if (!d) 2452 d = dev_get_msi_domain(&dev->bus->dev); 2453 2454 dev_set_msi_domain(&dev->dev, d); 2455 } 2456 2457 void pci_device_add(struct pci_dev *dev, struct pci_bus *bus) 2458 { 2459 int ret; 2460 2461 pci_configure_device(dev); 2462 2463 device_initialize(&dev->dev); 2464 dev->dev.release = pci_release_dev; 2465 2466 set_dev_node(&dev->dev, pcibus_to_node(bus)); 2467 dev->dev.dma_mask = &dev->dma_mask; 2468 dev->dev.dma_parms = &dev->dma_parms; 2469 dev->dev.coherent_dma_mask = 0xffffffffull; 2470 2471 dma_set_max_seg_size(&dev->dev, 65536); 2472 dma_set_seg_boundary(&dev->dev, 0xffffffff); 2473 2474 /* Fix up broken headers */ 2475 pci_fixup_device(pci_fixup_header, dev); 2476 2477 pci_reassigndev_resource_alignment(dev); 2478 2479 dev->state_saved = false; 2480 2481 pci_init_capabilities(dev); 2482 2483 /* 2484 * Add the device to our list of discovered devices 2485 * and the bus list for fixup functions, etc. 2486 */ 2487 down_write(&pci_bus_sem); 2488 list_add_tail(&dev->bus_list, &bus->devices); 2489 up_write(&pci_bus_sem); 2490 2491 ret = pcibios_add_device(dev); 2492 WARN_ON(ret < 0); 2493 2494 /* Set up MSI IRQ domain */ 2495 pci_set_msi_domain(dev); 2496 2497 /* Notifier could use PCI capabilities */ 2498 dev->match_driver = false; 2499 ret = device_add(&dev->dev); 2500 WARN_ON(ret < 0); 2501 } 2502 2503 struct pci_dev *pci_scan_single_device(struct pci_bus *bus, int devfn) 2504 { 2505 struct pci_dev *dev; 2506 2507 dev = pci_get_slot(bus, devfn); 2508 if (dev) { 2509 pci_dev_put(dev); 2510 return dev; 2511 } 2512 2513 dev = pci_scan_device(bus, devfn); 2514 if (!dev) 2515 return NULL; 2516 2517 pci_device_add(dev, bus); 2518 2519 return dev; 2520 } 2521 EXPORT_SYMBOL(pci_scan_single_device); 2522 2523 static unsigned next_fn(struct pci_bus *bus, struct pci_dev *dev, unsigned fn) 2524 { 2525 int pos; 2526 u16 cap = 0; 2527 unsigned next_fn; 2528 2529 if (pci_ari_enabled(bus)) { 2530 if (!dev) 2531 return 0; 2532 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI); 2533 if (!pos) 2534 return 0; 2535 2536 pci_read_config_word(dev, pos + PCI_ARI_CAP, &cap); 2537 next_fn = PCI_ARI_CAP_NFN(cap); 2538 if (next_fn <= fn) 2539 return 0; /* protect against malformed list */ 2540 2541 return next_fn; 2542 } 2543 2544 /* dev may be NULL for non-contiguous multifunction devices */ 2545 if (!dev || dev->multifunction) 2546 return (fn + 1) % 8; 2547 2548 return 0; 2549 } 2550 2551 static int only_one_child(struct pci_bus *bus) 2552 { 2553 struct pci_dev *bridge = bus->self; 2554 2555 /* 2556 * Systems with unusual topologies set PCI_SCAN_ALL_PCIE_DEVS so 2557 * we scan for all possible devices, not just Device 0. 2558 */ 2559 if (pci_has_flag(PCI_SCAN_ALL_PCIE_DEVS)) 2560 return 0; 2561 2562 /* 2563 * A PCIe Downstream Port normally leads to a Link with only Device 2564 * 0 on it (PCIe spec r3.1, sec 7.3.1). As an optimization, scan 2565 * only for Device 0 in that situation. 2566 */ 2567 if (bridge && pci_is_pcie(bridge) && pcie_downstream_port(bridge)) 2568 return 1; 2569 2570 return 0; 2571 } 2572 2573 /** 2574 * pci_scan_slot - Scan a PCI slot on a bus for devices 2575 * @bus: PCI bus to scan 2576 * @devfn: slot number to scan (must have zero function) 2577 * 2578 * Scan a PCI slot on the specified PCI bus for devices, adding 2579 * discovered devices to the @bus->devices list. New devices 2580 * will not have is_added set. 2581 * 2582 * Returns the number of new devices found. 2583 */ 2584 int pci_scan_slot(struct pci_bus *bus, int devfn) 2585 { 2586 unsigned fn, nr = 0; 2587 struct pci_dev *dev; 2588 2589 if (only_one_child(bus) && (devfn > 0)) 2590 return 0; /* Already scanned the entire slot */ 2591 2592 dev = pci_scan_single_device(bus, devfn); 2593 if (!dev) 2594 return 0; 2595 if (!pci_dev_is_added(dev)) 2596 nr++; 2597 2598 for (fn = next_fn(bus, dev, 0); fn > 0; fn = next_fn(bus, dev, fn)) { 2599 dev = pci_scan_single_device(bus, devfn + fn); 2600 if (dev) { 2601 if (!pci_dev_is_added(dev)) 2602 nr++; 2603 dev->multifunction = 1; 2604 } 2605 } 2606 2607 /* Only one slot has PCIe device */ 2608 if (bus->self && nr) 2609 pcie_aspm_init_link_state(bus->self); 2610 2611 return nr; 2612 } 2613 EXPORT_SYMBOL(pci_scan_slot); 2614 2615 static int pcie_find_smpss(struct pci_dev *dev, void *data) 2616 { 2617 u8 *smpss = data; 2618 2619 if (!pci_is_pcie(dev)) 2620 return 0; 2621 2622 /* 2623 * We don't have a way to change MPS settings on devices that have 2624 * drivers attached. A hot-added device might support only the minimum 2625 * MPS setting (MPS=128). Therefore, if the fabric contains a bridge 2626 * where devices may be hot-added, we limit the fabric MPS to 128 so 2627 * hot-added devices will work correctly. 2628 * 2629 * However, if we hot-add a device to a slot directly below a Root 2630 * Port, it's impossible for there to be other existing devices below 2631 * the port. We don't limit the MPS in this case because we can 2632 * reconfigure MPS on both the Root Port and the hot-added device, 2633 * and there are no other devices involved. 2634 * 2635 * Note that this PCIE_BUS_SAFE path assumes no peer-to-peer DMA. 2636 */ 2637 if (dev->is_hotplug_bridge && 2638 pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT) 2639 *smpss = 0; 2640 2641 if (*smpss > dev->pcie_mpss) 2642 *smpss = dev->pcie_mpss; 2643 2644 return 0; 2645 } 2646 2647 static void pcie_write_mps(struct pci_dev *dev, int mps) 2648 { 2649 int rc; 2650 2651 if (pcie_bus_config == PCIE_BUS_PERFORMANCE) { 2652 mps = 128 << dev->pcie_mpss; 2653 2654 if (pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT && 2655 dev->bus->self) 2656 2657 /* 2658 * For "Performance", the assumption is made that 2659 * downstream communication will never be larger than 2660 * the MRRS. So, the MPS only needs to be configured 2661 * for the upstream communication. This being the case, 2662 * walk from the top down and set the MPS of the child 2663 * to that of the parent bus. 2664 * 2665 * Configure the device MPS with the smaller of the 2666 * device MPSS or the bridge MPS (which is assumed to be 2667 * properly configured at this point to the largest 2668 * allowable MPS based on its parent bus). 2669 */ 2670 mps = min(mps, pcie_get_mps(dev->bus->self)); 2671 } 2672 2673 rc = pcie_set_mps(dev, mps); 2674 if (rc) 2675 pci_err(dev, "Failed attempting to set the MPS\n"); 2676 } 2677 2678 static void pcie_write_mrrs(struct pci_dev *dev) 2679 { 2680 int rc, mrrs; 2681 2682 /* 2683 * In the "safe" case, do not configure the MRRS. There appear to be 2684 * issues with setting MRRS to 0 on a number of devices. 2685 */ 2686 if (pcie_bus_config != PCIE_BUS_PERFORMANCE) 2687 return; 2688 2689 /* 2690 * For max performance, the MRRS must be set to the largest supported 2691 * value. However, it cannot be configured larger than the MPS the 2692 * device or the bus can support. This should already be properly 2693 * configured by a prior call to pcie_write_mps(). 2694 */ 2695 mrrs = pcie_get_mps(dev); 2696 2697 /* 2698 * MRRS is a R/W register. Invalid values can be written, but a 2699 * subsequent read will verify if the value is acceptable or not. 2700 * If the MRRS value provided is not acceptable (e.g., too large), 2701 * shrink the value until it is acceptable to the HW. 2702 */ 2703 while (mrrs != pcie_get_readrq(dev) && mrrs >= 128) { 2704 rc = pcie_set_readrq(dev, mrrs); 2705 if (!rc) 2706 break; 2707 2708 pci_warn(dev, "Failed attempting to set the MRRS\n"); 2709 mrrs /= 2; 2710 } 2711 2712 if (mrrs < 128) 2713 pci_err(dev, "MRRS was unable to be configured with a safe value. If problems are experienced, try running with pci=pcie_bus_safe\n"); 2714 } 2715 2716 static int pcie_bus_configure_set(struct pci_dev *dev, void *data) 2717 { 2718 int mps, orig_mps; 2719 2720 if (!pci_is_pcie(dev)) 2721 return 0; 2722 2723 if (pcie_bus_config == PCIE_BUS_TUNE_OFF || 2724 pcie_bus_config == PCIE_BUS_DEFAULT) 2725 return 0; 2726 2727 mps = 128 << *(u8 *)data; 2728 orig_mps = pcie_get_mps(dev); 2729 2730 pcie_write_mps(dev, mps); 2731 pcie_write_mrrs(dev); 2732 2733 pci_info(dev, "Max Payload Size set to %4d/%4d (was %4d), Max Read Rq %4d\n", 2734 pcie_get_mps(dev), 128 << dev->pcie_mpss, 2735 orig_mps, pcie_get_readrq(dev)); 2736 2737 return 0; 2738 } 2739 2740 /* 2741 * pcie_bus_configure_settings() requires that pci_walk_bus work in a top-down, 2742 * parents then children fashion. If this changes, then this code will not 2743 * work as designed. 2744 */ 2745 void pcie_bus_configure_settings(struct pci_bus *bus) 2746 { 2747 u8 smpss = 0; 2748 2749 if (!bus->self) 2750 return; 2751 2752 if (!pci_is_pcie(bus->self)) 2753 return; 2754 2755 /* 2756 * FIXME - Peer to peer DMA is possible, though the endpoint would need 2757 * to be aware of the MPS of the destination. To work around this, 2758 * simply force the MPS of the entire system to the smallest possible. 2759 */ 2760 if (pcie_bus_config == PCIE_BUS_PEER2PEER) 2761 smpss = 0; 2762 2763 if (pcie_bus_config == PCIE_BUS_SAFE) { 2764 smpss = bus->self->pcie_mpss; 2765 2766 pcie_find_smpss(bus->self, &smpss); 2767 pci_walk_bus(bus, pcie_find_smpss, &smpss); 2768 } 2769 2770 pcie_bus_configure_set(bus->self, &smpss); 2771 pci_walk_bus(bus, pcie_bus_configure_set, &smpss); 2772 } 2773 EXPORT_SYMBOL_GPL(pcie_bus_configure_settings); 2774 2775 /* 2776 * Called after each bus is probed, but before its children are examined. This 2777 * is marked as __weak because multiple architectures define it. 2778 */ 2779 void __weak pcibios_fixup_bus(struct pci_bus *bus) 2780 { 2781 /* nothing to do, expected to be removed in the future */ 2782 } 2783 2784 /** 2785 * pci_scan_child_bus_extend() - Scan devices below a bus 2786 * @bus: Bus to scan for devices 2787 * @available_buses: Total number of buses available (%0 does not try to 2788 * extend beyond the minimal) 2789 * 2790 * Scans devices below @bus including subordinate buses. Returns new 2791 * subordinate number including all the found devices. Passing 2792 * @available_buses causes the remaining bus space to be distributed 2793 * equally between hotplug-capable bridges to allow future extension of the 2794 * hierarchy. 2795 */ 2796 static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus, 2797 unsigned int available_buses) 2798 { 2799 unsigned int used_buses, normal_bridges = 0, hotplug_bridges = 0; 2800 unsigned int start = bus->busn_res.start; 2801 unsigned int devfn, fn, cmax, max = start; 2802 struct pci_dev *dev; 2803 int nr_devs; 2804 2805 dev_dbg(&bus->dev, "scanning bus\n"); 2806 2807 /* Go find them, Rover! */ 2808 for (devfn = 0; devfn < 256; devfn += 8) { 2809 nr_devs = pci_scan_slot(bus, devfn); 2810 2811 /* 2812 * The Jailhouse hypervisor may pass individual functions of a 2813 * multi-function device to a guest without passing function 0. 2814 * Look for them as well. 2815 */ 2816 if (jailhouse_paravirt() && nr_devs == 0) { 2817 for (fn = 1; fn < 8; fn++) { 2818 dev = pci_scan_single_device(bus, devfn + fn); 2819 if (dev) 2820 dev->multifunction = 1; 2821 } 2822 } 2823 } 2824 2825 /* Reserve buses for SR-IOV capability */ 2826 used_buses = pci_iov_bus_range(bus); 2827 max += used_buses; 2828 2829 /* 2830 * After performing arch-dependent fixup of the bus, look behind 2831 * all PCI-to-PCI bridges on this bus. 2832 */ 2833 if (!bus->is_added) { 2834 dev_dbg(&bus->dev, "fixups for bus\n"); 2835 pcibios_fixup_bus(bus); 2836 bus->is_added = 1; 2837 } 2838 2839 /* 2840 * Calculate how many hotplug bridges and normal bridges there 2841 * are on this bus. We will distribute the additional available 2842 * buses between hotplug bridges. 2843 */ 2844 for_each_pci_bridge(dev, bus) { 2845 if (dev->is_hotplug_bridge) 2846 hotplug_bridges++; 2847 else 2848 normal_bridges++; 2849 } 2850 2851 /* 2852 * Scan bridges that are already configured. We don't touch them 2853 * unless they are misconfigured (which will be done in the second 2854 * scan below). 2855 */ 2856 for_each_pci_bridge(dev, bus) { 2857 cmax = max; 2858 max = pci_scan_bridge_extend(bus, dev, max, 0, 0); 2859 2860 /* 2861 * Reserve one bus for each bridge now to avoid extending 2862 * hotplug bridges too much during the second scan below. 2863 */ 2864 used_buses++; 2865 if (cmax - max > 1) 2866 used_buses += cmax - max - 1; 2867 } 2868 2869 /* Scan bridges that need to be reconfigured */ 2870 for_each_pci_bridge(dev, bus) { 2871 unsigned int buses = 0; 2872 2873 if (!hotplug_bridges && normal_bridges == 1) { 2874 2875 /* 2876 * There is only one bridge on the bus (upstream 2877 * port) so it gets all available buses which it 2878 * can then distribute to the possible hotplug 2879 * bridges below. 2880 */ 2881 buses = available_buses; 2882 } else if (dev->is_hotplug_bridge) { 2883 2884 /* 2885 * Distribute the extra buses between hotplug 2886 * bridges if any. 2887 */ 2888 buses = available_buses / hotplug_bridges; 2889 buses = min(buses, available_buses - used_buses + 1); 2890 } 2891 2892 cmax = max; 2893 max = pci_scan_bridge_extend(bus, dev, cmax, buses, 1); 2894 /* One bus is already accounted so don't add it again */ 2895 if (max - cmax > 1) 2896 used_buses += max - cmax - 1; 2897 } 2898 2899 /* 2900 * Make sure a hotplug bridge has at least the minimum requested 2901 * number of buses but allow it to grow up to the maximum available 2902 * bus number of there is room. 2903 */ 2904 if (bus->self && bus->self->is_hotplug_bridge) { 2905 used_buses = max_t(unsigned int, available_buses, 2906 pci_hotplug_bus_size - 1); 2907 if (max - start < used_buses) { 2908 max = start + used_buses; 2909 2910 /* Do not allocate more buses than we have room left */ 2911 if (max > bus->busn_res.end) 2912 max = bus->busn_res.end; 2913 2914 dev_dbg(&bus->dev, "%pR extended by %#02x\n", 2915 &bus->busn_res, max - start); 2916 } 2917 } 2918 2919 /* 2920 * We've scanned the bus and so we know all about what's on 2921 * the other side of any bridges that may be on this bus plus 2922 * any devices. 2923 * 2924 * Return how far we've got finding sub-buses. 2925 */ 2926 dev_dbg(&bus->dev, "bus scan returning with max=%02x\n", max); 2927 return max; 2928 } 2929 2930 /** 2931 * pci_scan_child_bus() - Scan devices below a bus 2932 * @bus: Bus to scan for devices 2933 * 2934 * Scans devices below @bus including subordinate buses. Returns new 2935 * subordinate number including all the found devices. 2936 */ 2937 unsigned int pci_scan_child_bus(struct pci_bus *bus) 2938 { 2939 return pci_scan_child_bus_extend(bus, 0); 2940 } 2941 EXPORT_SYMBOL_GPL(pci_scan_child_bus); 2942 2943 /** 2944 * pcibios_root_bridge_prepare - Platform-specific host bridge setup 2945 * @bridge: Host bridge to set up 2946 * 2947 * Default empty implementation. Replace with an architecture-specific setup 2948 * routine, if necessary. 2949 */ 2950 int __weak pcibios_root_bridge_prepare(struct pci_host_bridge *bridge) 2951 { 2952 return 0; 2953 } 2954 2955 void __weak pcibios_add_bus(struct pci_bus *bus) 2956 { 2957 } 2958 2959 void __weak pcibios_remove_bus(struct pci_bus *bus) 2960 { 2961 } 2962 2963 struct pci_bus *pci_create_root_bus(struct device *parent, int bus, 2964 struct pci_ops *ops, void *sysdata, struct list_head *resources) 2965 { 2966 int error; 2967 struct pci_host_bridge *bridge; 2968 2969 bridge = pci_alloc_host_bridge(0); 2970 if (!bridge) 2971 return NULL; 2972 2973 bridge->dev.parent = parent; 2974 2975 list_splice_init(resources, &bridge->windows); 2976 bridge->sysdata = sysdata; 2977 bridge->busnr = bus; 2978 bridge->ops = ops; 2979 2980 error = pci_register_host_bridge(bridge); 2981 if (error < 0) 2982 goto err_out; 2983 2984 return bridge->bus; 2985 2986 err_out: 2987 put_device(&bridge->dev); 2988 return NULL; 2989 } 2990 EXPORT_SYMBOL_GPL(pci_create_root_bus); 2991 2992 int pci_host_probe(struct pci_host_bridge *bridge) 2993 { 2994 struct pci_bus *bus, *child; 2995 int ret; 2996 2997 ret = pci_scan_root_bus_bridge(bridge); 2998 if (ret < 0) { 2999 dev_err(bridge->dev.parent, "Scanning root bridge failed"); 3000 return ret; 3001 } 3002 3003 bus = bridge->bus; 3004 3005 /* 3006 * We insert PCI resources into the iomem_resource and 3007 * ioport_resource trees in either pci_bus_claim_resources() 3008 * or pci_bus_assign_resources(). 3009 */ 3010 if (pci_has_flag(PCI_PROBE_ONLY)) { 3011 pci_bus_claim_resources(bus); 3012 } else { 3013 pci_bus_size_bridges(bus); 3014 pci_bus_assign_resources(bus); 3015 3016 list_for_each_entry(child, &bus->children, node) 3017 pcie_bus_configure_settings(child); 3018 } 3019 3020 pci_bus_add_devices(bus); 3021 return 0; 3022 } 3023 EXPORT_SYMBOL_GPL(pci_host_probe); 3024 3025 int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int bus_max) 3026 { 3027 struct resource *res = &b->busn_res; 3028 struct resource *parent_res, *conflict; 3029 3030 res->start = bus; 3031 res->end = bus_max; 3032 res->flags = IORESOURCE_BUS; 3033 3034 if (!pci_is_root_bus(b)) 3035 parent_res = &b->parent->busn_res; 3036 else { 3037 parent_res = get_pci_domain_busn_res(pci_domain_nr(b)); 3038 res->flags |= IORESOURCE_PCI_FIXED; 3039 } 3040 3041 conflict = request_resource_conflict(parent_res, res); 3042 3043 if (conflict) 3044 dev_info(&b->dev, 3045 "busn_res: can not insert %pR under %s%pR (conflicts with %s %pR)\n", 3046 res, pci_is_root_bus(b) ? "domain " : "", 3047 parent_res, conflict->name, conflict); 3048 3049 return conflict == NULL; 3050 } 3051 3052 int pci_bus_update_busn_res_end(struct pci_bus *b, int bus_max) 3053 { 3054 struct resource *res = &b->busn_res; 3055 struct resource old_res = *res; 3056 resource_size_t size; 3057 int ret; 3058 3059 if (res->start > bus_max) 3060 return -EINVAL; 3061 3062 size = bus_max - res->start + 1; 3063 ret = adjust_resource(res, res->start, size); 3064 dev_info(&b->dev, "busn_res: %pR end %s updated to %02x\n", 3065 &old_res, ret ? "can not be" : "is", bus_max); 3066 3067 if (!ret && !res->parent) 3068 pci_bus_insert_busn_res(b, res->start, res->end); 3069 3070 return ret; 3071 } 3072 3073 void pci_bus_release_busn_res(struct pci_bus *b) 3074 { 3075 struct resource *res = &b->busn_res; 3076 int ret; 3077 3078 if (!res->flags || !res->parent) 3079 return; 3080 3081 ret = release_resource(res); 3082 dev_info(&b->dev, "busn_res: %pR %s released\n", 3083 res, ret ? "can not be" : "is"); 3084 } 3085 3086 int pci_scan_root_bus_bridge(struct pci_host_bridge *bridge) 3087 { 3088 struct resource_entry *window; 3089 bool found = false; 3090 struct pci_bus *b; 3091 int max, bus, ret; 3092 3093 if (!bridge) 3094 return -EINVAL; 3095 3096 resource_list_for_each_entry(window, &bridge->windows) 3097 if (window->res->flags & IORESOURCE_BUS) { 3098 bridge->busnr = window->res->start; 3099 found = true; 3100 break; 3101 } 3102 3103 ret = pci_register_host_bridge(bridge); 3104 if (ret < 0) 3105 return ret; 3106 3107 b = bridge->bus; 3108 bus = bridge->busnr; 3109 3110 if (!found) { 3111 dev_info(&b->dev, 3112 "No busn resource found for root bus, will use [bus %02x-ff]\n", 3113 bus); 3114 pci_bus_insert_busn_res(b, bus, 255); 3115 } 3116 3117 max = pci_scan_child_bus(b); 3118 3119 if (!found) 3120 pci_bus_update_busn_res_end(b, max); 3121 3122 return 0; 3123 } 3124 EXPORT_SYMBOL(pci_scan_root_bus_bridge); 3125 3126 struct pci_bus *pci_scan_root_bus(struct device *parent, int bus, 3127 struct pci_ops *ops, void *sysdata, struct list_head *resources) 3128 { 3129 struct resource_entry *window; 3130 bool found = false; 3131 struct pci_bus *b; 3132 int max; 3133 3134 resource_list_for_each_entry(window, resources) 3135 if (window->res->flags & IORESOURCE_BUS) { 3136 found = true; 3137 break; 3138 } 3139 3140 b = pci_create_root_bus(parent, bus, ops, sysdata, resources); 3141 if (!b) 3142 return NULL; 3143 3144 if (!found) { 3145 dev_info(&b->dev, 3146 "No busn resource found for root bus, will use [bus %02x-ff]\n", 3147 bus); 3148 pci_bus_insert_busn_res(b, bus, 255); 3149 } 3150 3151 max = pci_scan_child_bus(b); 3152 3153 if (!found) 3154 pci_bus_update_busn_res_end(b, max); 3155 3156 return b; 3157 } 3158 EXPORT_SYMBOL(pci_scan_root_bus); 3159 3160 struct pci_bus *pci_scan_bus(int bus, struct pci_ops *ops, 3161 void *sysdata) 3162 { 3163 LIST_HEAD(resources); 3164 struct pci_bus *b; 3165 3166 pci_add_resource(&resources, &ioport_resource); 3167 pci_add_resource(&resources, &iomem_resource); 3168 pci_add_resource(&resources, &busn_resource); 3169 b = pci_create_root_bus(NULL, bus, ops, sysdata, &resources); 3170 if (b) { 3171 pci_scan_child_bus(b); 3172 } else { 3173 pci_free_resource_list(&resources); 3174 } 3175 return b; 3176 } 3177 EXPORT_SYMBOL(pci_scan_bus); 3178 3179 /** 3180 * pci_rescan_bus_bridge_resize - Scan a PCI bus for devices 3181 * @bridge: PCI bridge for the bus to scan 3182 * 3183 * Scan a PCI bus and child buses for new devices, add them, 3184 * and enable them, resizing bridge mmio/io resource if necessary 3185 * and possible. The caller must ensure the child devices are already 3186 * removed for resizing to occur. 3187 * 3188 * Returns the max number of subordinate bus discovered. 3189 */ 3190 unsigned int pci_rescan_bus_bridge_resize(struct pci_dev *bridge) 3191 { 3192 unsigned int max; 3193 struct pci_bus *bus = bridge->subordinate; 3194 3195 max = pci_scan_child_bus(bus); 3196 3197 pci_assign_unassigned_bridge_resources(bridge); 3198 3199 pci_bus_add_devices(bus); 3200 3201 return max; 3202 } 3203 3204 /** 3205 * pci_rescan_bus - Scan a PCI bus for devices 3206 * @bus: PCI bus to scan 3207 * 3208 * Scan a PCI bus and child buses for new devices, add them, 3209 * and enable them. 3210 * 3211 * Returns the max number of subordinate bus discovered. 3212 */ 3213 unsigned int pci_rescan_bus(struct pci_bus *bus) 3214 { 3215 unsigned int max; 3216 3217 max = pci_scan_child_bus(bus); 3218 pci_assign_unassigned_bus_resources(bus); 3219 pci_bus_add_devices(bus); 3220 3221 return max; 3222 } 3223 EXPORT_SYMBOL_GPL(pci_rescan_bus); 3224 3225 /* 3226 * pci_rescan_bus(), pci_rescan_bus_bridge_resize() and PCI device removal 3227 * routines should always be executed under this mutex. 3228 */ 3229 static DEFINE_MUTEX(pci_rescan_remove_lock); 3230 3231 void pci_lock_rescan_remove(void) 3232 { 3233 mutex_lock(&pci_rescan_remove_lock); 3234 } 3235 EXPORT_SYMBOL_GPL(pci_lock_rescan_remove); 3236 3237 void pci_unlock_rescan_remove(void) 3238 { 3239 mutex_unlock(&pci_rescan_remove_lock); 3240 } 3241 EXPORT_SYMBOL_GPL(pci_unlock_rescan_remove); 3242 3243 static int __init pci_sort_bf_cmp(const struct device *d_a, 3244 const struct device *d_b) 3245 { 3246 const struct pci_dev *a = to_pci_dev(d_a); 3247 const struct pci_dev *b = to_pci_dev(d_b); 3248 3249 if (pci_domain_nr(a->bus) < pci_domain_nr(b->bus)) return -1; 3250 else if (pci_domain_nr(a->bus) > pci_domain_nr(b->bus)) return 1; 3251 3252 if (a->bus->number < b->bus->number) return -1; 3253 else if (a->bus->number > b->bus->number) return 1; 3254 3255 if (a->devfn < b->devfn) return -1; 3256 else if (a->devfn > b->devfn) return 1; 3257 3258 return 0; 3259 } 3260 3261 void __init pci_sort_breadthfirst(void) 3262 { 3263 bus_sort_breadthfirst(&pci_bus_type, &pci_sort_bf_cmp); 3264 } 3265 3266 int pci_hp_add_bridge(struct pci_dev *dev) 3267 { 3268 struct pci_bus *parent = dev->bus; 3269 int busnr, start = parent->busn_res.start; 3270 unsigned int available_buses = 0; 3271 int end = parent->busn_res.end; 3272 3273 for (busnr = start; busnr <= end; busnr++) { 3274 if (!pci_find_bus(pci_domain_nr(parent), busnr)) 3275 break; 3276 } 3277 if (busnr-- > end) { 3278 pci_err(dev, "No bus number available for hot-added bridge\n"); 3279 return -1; 3280 } 3281 3282 /* Scan bridges that are already configured */ 3283 busnr = pci_scan_bridge(parent, dev, busnr, 0); 3284 3285 /* 3286 * Distribute the available bus numbers between hotplug-capable 3287 * bridges to make extending the chain later possible. 3288 */ 3289 available_buses = end - busnr; 3290 3291 /* Scan bridges that need to be reconfigured */ 3292 pci_scan_bridge_extend(parent, dev, busnr, available_buses, 1); 3293 3294 if (!dev->subordinate) 3295 return -1; 3296 3297 return 0; 3298 } 3299 EXPORT_SYMBOL_GPL(pci_hp_add_bridge); 3300