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_pci.h> 12#include <linux/pci_hotplug.h> 13#include <linux/slab.h> 14#include <linux/module.h> 15#include <linux/cpumask.h> 16#include <linux/aer.h> 17#include <linux/acpi.h> 18#include <linux/hypervisor.h> 19#include <linux/irqdomain.h> 20#include <linux/pm_runtime.h> 21#include <linux/bitfield.h> 22#include "pci.h" 23 24#define CARDBUS_LATENCY_TIMER 176 /* secondary latency timer */ 25#define CARDBUS_RESERVE_BUSNR 3 26 27static 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. */ 35LIST_HEAD(pci_root_buses); 36EXPORT_SYMBOL(pci_root_buses); 37 38static LIST_HEAD(pci_domain_busn_res_list); 39 40struct pci_domain_busn_res { 41 struct list_head list; 42 struct resource res; 43 int domain_nr; 44}; 45 46static 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 */ 73int 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} 83EXPORT_SYMBOL(no_pci_devices); 84 85/* 86 * PCI Bus Class 87 */ 88static 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 98static struct class pcibus_class = { 99 .name = "pci_bus", 100 .dev_release = &release_pcibus_dev, 101 .dev_groups = pcibus_groups, 102}; 103 104static int __init pcibus_class_init(void) 105{ 106 return class_register(&pcibus_class); 107} 108postcore_initcall(pcibus_class_init); 109 110static 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 132static 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 */ 176int __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 const char *res_name = pci_resource_name(dev, res - dev->resource); 184 185 mask = type ? PCI_ROM_ADDRESS_MASK : ~0; 186 187 /* No printks while decoding is disabled! */ 188 if (!dev->mmio_always_on) { 189 pci_read_config_word(dev, PCI_COMMAND, &orig_cmd); 190 if (orig_cmd & PCI_COMMAND_DECODE_ENABLE) { 191 pci_write_config_word(dev, PCI_COMMAND, 192 orig_cmd & ~PCI_COMMAND_DECODE_ENABLE); 193 } 194 } 195 196 res->name = pci_name(dev); 197 198 pci_read_config_dword(dev, pos, &l); 199 pci_write_config_dword(dev, pos, l | mask); 200 pci_read_config_dword(dev, pos, &sz); 201 pci_write_config_dword(dev, pos, l); 202 203 /* 204 * All bits set in sz means the device isn't working properly. 205 * If the BAR isn't implemented, all bits must be 0. If it's a 206 * memory BAR or a ROM, bit 0 must be clear; if it's an io BAR, bit 207 * 1 must be clear. 208 */ 209 if (PCI_POSSIBLE_ERROR(sz)) 210 sz = 0; 211 212 /* 213 * I don't know how l can have all bits set. Copied from old code. 214 * Maybe it fixes a bug on some ancient platform. 215 */ 216 if (PCI_POSSIBLE_ERROR(l)) 217 l = 0; 218 219 if (type == pci_bar_unknown) { 220 res->flags = decode_bar(dev, l); 221 res->flags |= IORESOURCE_SIZEALIGN; 222 if (res->flags & IORESOURCE_IO) { 223 l64 = l & PCI_BASE_ADDRESS_IO_MASK; 224 sz64 = sz & PCI_BASE_ADDRESS_IO_MASK; 225 mask64 = PCI_BASE_ADDRESS_IO_MASK & (u32)IO_SPACE_LIMIT; 226 } else { 227 l64 = l & PCI_BASE_ADDRESS_MEM_MASK; 228 sz64 = sz & PCI_BASE_ADDRESS_MEM_MASK; 229 mask64 = (u32)PCI_BASE_ADDRESS_MEM_MASK; 230 } 231 } else { 232 if (l & PCI_ROM_ADDRESS_ENABLE) 233 res->flags |= IORESOURCE_ROM_ENABLE; 234 l64 = l & PCI_ROM_ADDRESS_MASK; 235 sz64 = sz & PCI_ROM_ADDRESS_MASK; 236 mask64 = PCI_ROM_ADDRESS_MASK; 237 } 238 239 if (res->flags & IORESOURCE_MEM_64) { 240 pci_read_config_dword(dev, pos + 4, &l); 241 pci_write_config_dword(dev, pos + 4, ~0); 242 pci_read_config_dword(dev, pos + 4, &sz); 243 pci_write_config_dword(dev, pos + 4, l); 244 245 l64 |= ((u64)l << 32); 246 sz64 |= ((u64)sz << 32); 247 mask64 |= ((u64)~0 << 32); 248 } 249 250 if (!dev->mmio_always_on && (orig_cmd & PCI_COMMAND_DECODE_ENABLE)) 251 pci_write_config_word(dev, PCI_COMMAND, orig_cmd); 252 253 if (!sz64) 254 goto fail; 255 256 sz64 = pci_size(l64, sz64, mask64); 257 if (!sz64) { 258 pci_info(dev, FW_BUG "%s: invalid; can't size\n", res_name); 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, "%s: can't handle BAR larger than 4GB (size %#010llx)\n", 269 res_name, (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, "%s: can't handle BAR above 4GB (bus address %#010llx)\n", 279 res_name, (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, "%s: initial BAR value %#010llx invalid\n", 306 res_name, (unsigned long long)region.start); 307 } 308 309 goto out; 310 311 312fail: 313 res->flags = 0; 314out: 315 if (res->flags) 316 pci_info(dev, "%s %pR\n", res_name, res); 317 318 return (res->flags & IORESOURCE_MEM_64) ? 1 : 0; 319} 320 321static 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 347static void pci_read_bridge_io(struct pci_dev *dev, struct resource *res, 348 bool log) 349{ 350 u8 io_base_lo, io_limit_lo; 351 unsigned long io_mask, io_granularity, base, limit; 352 struct pci_bus_region region; 353 354 io_mask = PCI_IO_RANGE_MASK; 355 io_granularity = 0x1000; 356 if (dev->io_window_1k) { 357 /* Support 1K I/O space granularity */ 358 io_mask = PCI_IO_1K_RANGE_MASK; 359 io_granularity = 0x400; 360 } 361 362 pci_read_config_byte(dev, PCI_IO_BASE, &io_base_lo); 363 pci_read_config_byte(dev, PCI_IO_LIMIT, &io_limit_lo); 364 base = (io_base_lo & io_mask) << 8; 365 limit = (io_limit_lo & io_mask) << 8; 366 367 if ((io_base_lo & PCI_IO_RANGE_TYPE_MASK) == PCI_IO_RANGE_TYPE_32) { 368 u16 io_base_hi, io_limit_hi; 369 370 pci_read_config_word(dev, PCI_IO_BASE_UPPER16, &io_base_hi); 371 pci_read_config_word(dev, PCI_IO_LIMIT_UPPER16, &io_limit_hi); 372 base |= ((unsigned long) io_base_hi << 16); 373 limit |= ((unsigned long) io_limit_hi << 16); 374 } 375 376 if (base <= limit) { 377 res->flags = (io_base_lo & PCI_IO_RANGE_TYPE_MASK) | IORESOURCE_IO; 378 region.start = base; 379 region.end = limit + io_granularity - 1; 380 pcibios_bus_to_resource(dev->bus, res, ®ion); 381 if (log) 382 pci_info(dev, " bridge window %pR\n", res); 383 } 384} 385 386static void pci_read_bridge_mmio(struct pci_dev *dev, struct resource *res, 387 bool log) 388{ 389 u16 mem_base_lo, mem_limit_lo; 390 unsigned long base, limit; 391 struct pci_bus_region region; 392 393 pci_read_config_word(dev, PCI_MEMORY_BASE, &mem_base_lo); 394 pci_read_config_word(dev, PCI_MEMORY_LIMIT, &mem_limit_lo); 395 base = ((unsigned long) mem_base_lo & PCI_MEMORY_RANGE_MASK) << 16; 396 limit = ((unsigned long) mem_limit_lo & PCI_MEMORY_RANGE_MASK) << 16; 397 if (base <= limit) { 398 res->flags = (mem_base_lo & PCI_MEMORY_RANGE_TYPE_MASK) | IORESOURCE_MEM; 399 region.start = base; 400 region.end = limit + 0xfffff; 401 pcibios_bus_to_resource(dev->bus, res, ®ion); 402 if (log) 403 pci_info(dev, " bridge window %pR\n", res); 404 } 405} 406 407static void pci_read_bridge_mmio_pref(struct pci_dev *dev, struct resource *res, 408 bool log) 409{ 410 u16 mem_base_lo, mem_limit_lo; 411 u64 base64, limit64; 412 pci_bus_addr_t base, limit; 413 struct pci_bus_region region; 414 415 pci_read_config_word(dev, PCI_PREF_MEMORY_BASE, &mem_base_lo); 416 pci_read_config_word(dev, PCI_PREF_MEMORY_LIMIT, &mem_limit_lo); 417 base64 = (mem_base_lo & PCI_PREF_RANGE_MASK) << 16; 418 limit64 = (mem_limit_lo & PCI_PREF_RANGE_MASK) << 16; 419 420 if ((mem_base_lo & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64) { 421 u32 mem_base_hi, mem_limit_hi; 422 423 pci_read_config_dword(dev, PCI_PREF_BASE_UPPER32, &mem_base_hi); 424 pci_read_config_dword(dev, PCI_PREF_LIMIT_UPPER32, &mem_limit_hi); 425 426 /* 427 * Some bridges set the base > limit by default, and some 428 * (broken) BIOSes do not initialize them. If we find 429 * this, just assume they are not being used. 430 */ 431 if (mem_base_hi <= mem_limit_hi) { 432 base64 |= (u64) mem_base_hi << 32; 433 limit64 |= (u64) mem_limit_hi << 32; 434 } 435 } 436 437 base = (pci_bus_addr_t) base64; 438 limit = (pci_bus_addr_t) limit64; 439 440 if (base != base64) { 441 pci_err(dev, "can't handle bridge window above 4GB (bus address %#010llx)\n", 442 (unsigned long long) base64); 443 return; 444 } 445 446 if (base <= limit) { 447 res->flags = (mem_base_lo & PCI_PREF_RANGE_TYPE_MASK) | 448 IORESOURCE_MEM | IORESOURCE_PREFETCH; 449 if (res->flags & PCI_PREF_RANGE_TYPE_64) 450 res->flags |= IORESOURCE_MEM_64; 451 region.start = base; 452 region.end = limit + 0xfffff; 453 pcibios_bus_to_resource(dev->bus, res, ®ion); 454 if (log) 455 pci_info(dev, " bridge window %pR\n", res); 456 } 457} 458 459static void pci_read_bridge_windows(struct pci_dev *bridge) 460{ 461 u32 buses; 462 u16 io; 463 u32 pmem, tmp; 464 struct resource res; 465 466 pci_read_config_dword(bridge, PCI_PRIMARY_BUS, &buses); 467 res.flags = IORESOURCE_BUS; 468 res.start = (buses >> 8) & 0xff; 469 res.end = (buses >> 16) & 0xff; 470 pci_info(bridge, "PCI bridge to %pR%s\n", &res, 471 bridge->transparent ? " (subtractive decode)" : ""); 472 473 pci_read_config_word(bridge, PCI_IO_BASE, &io); 474 if (!io) { 475 pci_write_config_word(bridge, PCI_IO_BASE, 0xe0f0); 476 pci_read_config_word(bridge, PCI_IO_BASE, &io); 477 pci_write_config_word(bridge, PCI_IO_BASE, 0x0); 478 } 479 if (io) { 480 bridge->io_window = 1; 481 pci_read_bridge_io(bridge, &res, true); 482 } 483 484 pci_read_bridge_mmio(bridge, &res, true); 485 486 /* 487 * DECchip 21050 pass 2 errata: the bridge may miss an address 488 * disconnect boundary by one PCI data phase. Workaround: do not 489 * use prefetching on this device. 490 */ 491 if (bridge->vendor == PCI_VENDOR_ID_DEC && bridge->device == 0x0001) 492 return; 493 494 pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem); 495 if (!pmem) { 496 pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, 497 0xffe0fff0); 498 pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem); 499 pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, 0x0); 500 } 501 if (!pmem) 502 return; 503 504 bridge->pref_window = 1; 505 506 if ((pmem & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64) { 507 508 /* 509 * Bridge claims to have a 64-bit prefetchable memory 510 * window; verify that the upper bits are actually 511 * writable. 512 */ 513 pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &pmem); 514 pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, 515 0xffffffff); 516 pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &tmp); 517 pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, pmem); 518 if (tmp) 519 bridge->pref_64_window = 1; 520 } 521 522 pci_read_bridge_mmio_pref(bridge, &res, true); 523} 524 525void pci_read_bridge_bases(struct pci_bus *child) 526{ 527 struct pci_dev *dev = child->self; 528 struct resource *res; 529 int i; 530 531 if (pci_is_root_bus(child)) /* It's a host bus, nothing to read */ 532 return; 533 534 pci_info(dev, "PCI bridge to %pR%s\n", 535 &child->busn_res, 536 dev->transparent ? " (subtractive decode)" : ""); 537 538 pci_bus_remove_resources(child); 539 for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++) 540 child->resource[i] = &dev->resource[PCI_BRIDGE_RESOURCES+i]; 541 542 pci_read_bridge_io(child->self, child->resource[0], false); 543 pci_read_bridge_mmio(child->self, child->resource[1], false); 544 pci_read_bridge_mmio_pref(child->self, child->resource[2], false); 545 546 if (dev->transparent) { 547 pci_bus_for_each_resource(child->parent, res) { 548 if (res && res->flags) { 549 pci_bus_add_resource(child, res, 550 PCI_SUBTRACTIVE_DECODE); 551 pci_info(dev, " bridge window %pR (subtractive decode)\n", 552 res); 553 } 554 } 555 } 556} 557 558static struct pci_bus *pci_alloc_bus(struct pci_bus *parent) 559{ 560 struct pci_bus *b; 561 562 b = kzalloc(sizeof(*b), GFP_KERNEL); 563 if (!b) 564 return NULL; 565 566 INIT_LIST_HEAD(&b->node); 567 INIT_LIST_HEAD(&b->children); 568 INIT_LIST_HEAD(&b->devices); 569 INIT_LIST_HEAD(&b->slots); 570 INIT_LIST_HEAD(&b->resources); 571 b->max_bus_speed = PCI_SPEED_UNKNOWN; 572 b->cur_bus_speed = PCI_SPEED_UNKNOWN; 573#ifdef CONFIG_PCI_DOMAINS_GENERIC 574 if (parent) 575 b->domain_nr = parent->domain_nr; 576#endif 577 return b; 578} 579 580static void pci_release_host_bridge_dev(struct device *dev) 581{ 582 struct pci_host_bridge *bridge = to_pci_host_bridge(dev); 583 584 if (bridge->release_fn) 585 bridge->release_fn(bridge); 586 587 pci_free_resource_list(&bridge->windows); 588 pci_free_resource_list(&bridge->dma_ranges); 589 kfree(bridge); 590} 591 592static void pci_init_host_bridge(struct pci_host_bridge *bridge) 593{ 594 INIT_LIST_HEAD(&bridge->windows); 595 INIT_LIST_HEAD(&bridge->dma_ranges); 596 597 /* 598 * We assume we can manage these PCIe features. Some systems may 599 * reserve these for use by the platform itself, e.g., an ACPI BIOS 600 * may implement its own AER handling and use _OSC to prevent the 601 * OS from interfering. 602 */ 603 bridge->native_aer = 1; 604 bridge->native_pcie_hotplug = 1; 605 bridge->native_shpc_hotplug = 1; 606 bridge->native_pme = 1; 607 bridge->native_ltr = 1; 608 bridge->native_dpc = 1; 609 bridge->domain_nr = PCI_DOMAIN_NR_NOT_SET; 610 bridge->native_cxl_error = 1; 611 612 device_initialize(&bridge->dev); 613} 614 615struct pci_host_bridge *pci_alloc_host_bridge(size_t priv) 616{ 617 struct pci_host_bridge *bridge; 618 619 bridge = kzalloc(sizeof(*bridge) + priv, GFP_KERNEL); 620 if (!bridge) 621 return NULL; 622 623 pci_init_host_bridge(bridge); 624 bridge->dev.release = pci_release_host_bridge_dev; 625 626 return bridge; 627} 628EXPORT_SYMBOL(pci_alloc_host_bridge); 629 630static void devm_pci_alloc_host_bridge_release(void *data) 631{ 632 pci_free_host_bridge(data); 633} 634 635struct pci_host_bridge *devm_pci_alloc_host_bridge(struct device *dev, 636 size_t priv) 637{ 638 int ret; 639 struct pci_host_bridge *bridge; 640 641 bridge = pci_alloc_host_bridge(priv); 642 if (!bridge) 643 return NULL; 644 645 bridge->dev.parent = dev; 646 647 ret = devm_add_action_or_reset(dev, devm_pci_alloc_host_bridge_release, 648 bridge); 649 if (ret) 650 return NULL; 651 652 ret = devm_of_pci_bridge_init(dev, bridge); 653 if (ret) 654 return NULL; 655 656 return bridge; 657} 658EXPORT_SYMBOL(devm_pci_alloc_host_bridge); 659 660void pci_free_host_bridge(struct pci_host_bridge *bridge) 661{ 662 put_device(&bridge->dev); 663} 664EXPORT_SYMBOL(pci_free_host_bridge); 665 666/* Indexed by PCI_X_SSTATUS_FREQ (secondary bus mode and frequency) */ 667static const unsigned char pcix_bus_speed[] = { 668 PCI_SPEED_UNKNOWN, /* 0 */ 669 PCI_SPEED_66MHz_PCIX, /* 1 */ 670 PCI_SPEED_100MHz_PCIX, /* 2 */ 671 PCI_SPEED_133MHz_PCIX, /* 3 */ 672 PCI_SPEED_UNKNOWN, /* 4 */ 673 PCI_SPEED_66MHz_PCIX_ECC, /* 5 */ 674 PCI_SPEED_100MHz_PCIX_ECC, /* 6 */ 675 PCI_SPEED_133MHz_PCIX_ECC, /* 7 */ 676 PCI_SPEED_UNKNOWN, /* 8 */ 677 PCI_SPEED_66MHz_PCIX_266, /* 9 */ 678 PCI_SPEED_100MHz_PCIX_266, /* A */ 679 PCI_SPEED_133MHz_PCIX_266, /* B */ 680 PCI_SPEED_UNKNOWN, /* C */ 681 PCI_SPEED_66MHz_PCIX_533, /* D */ 682 PCI_SPEED_100MHz_PCIX_533, /* E */ 683 PCI_SPEED_133MHz_PCIX_533 /* F */ 684}; 685 686/* Indexed by PCI_EXP_LNKCAP_SLS, PCI_EXP_LNKSTA_CLS */ 687const unsigned char pcie_link_speed[] = { 688 PCI_SPEED_UNKNOWN, /* 0 */ 689 PCIE_SPEED_2_5GT, /* 1 */ 690 PCIE_SPEED_5_0GT, /* 2 */ 691 PCIE_SPEED_8_0GT, /* 3 */ 692 PCIE_SPEED_16_0GT, /* 4 */ 693 PCIE_SPEED_32_0GT, /* 5 */ 694 PCIE_SPEED_64_0GT, /* 6 */ 695 PCI_SPEED_UNKNOWN, /* 7 */ 696 PCI_SPEED_UNKNOWN, /* 8 */ 697 PCI_SPEED_UNKNOWN, /* 9 */ 698 PCI_SPEED_UNKNOWN, /* A */ 699 PCI_SPEED_UNKNOWN, /* B */ 700 PCI_SPEED_UNKNOWN, /* C */ 701 PCI_SPEED_UNKNOWN, /* D */ 702 PCI_SPEED_UNKNOWN, /* E */ 703 PCI_SPEED_UNKNOWN /* F */ 704}; 705EXPORT_SYMBOL_GPL(pcie_link_speed); 706 707const char *pci_speed_string(enum pci_bus_speed speed) 708{ 709 /* Indexed by the pci_bus_speed enum */ 710 static const char *speed_strings[] = { 711 "33 MHz PCI", /* 0x00 */ 712 "66 MHz PCI", /* 0x01 */ 713 "66 MHz PCI-X", /* 0x02 */ 714 "100 MHz PCI-X", /* 0x03 */ 715 "133 MHz PCI-X", /* 0x04 */ 716 NULL, /* 0x05 */ 717 NULL, /* 0x06 */ 718 NULL, /* 0x07 */ 719 NULL, /* 0x08 */ 720 "66 MHz PCI-X 266", /* 0x09 */ 721 "100 MHz PCI-X 266", /* 0x0a */ 722 "133 MHz PCI-X 266", /* 0x0b */ 723 "Unknown AGP", /* 0x0c */ 724 "1x AGP", /* 0x0d */ 725 "2x AGP", /* 0x0e */ 726 "4x AGP", /* 0x0f */ 727 "8x AGP", /* 0x10 */ 728 "66 MHz PCI-X 533", /* 0x11 */ 729 "100 MHz PCI-X 533", /* 0x12 */ 730 "133 MHz PCI-X 533", /* 0x13 */ 731 "2.5 GT/s PCIe", /* 0x14 */ 732 "5.0 GT/s PCIe", /* 0x15 */ 733 "8.0 GT/s PCIe", /* 0x16 */ 734 "16.0 GT/s PCIe", /* 0x17 */ 735 "32.0 GT/s PCIe", /* 0x18 */ 736 "64.0 GT/s PCIe", /* 0x19 */ 737 }; 738 739 if (speed < ARRAY_SIZE(speed_strings)) 740 return speed_strings[speed]; 741 return "Unknown"; 742} 743EXPORT_SYMBOL_GPL(pci_speed_string); 744 745void pcie_update_link_speed(struct pci_bus *bus, u16 linksta) 746{ 747 bus->cur_bus_speed = pcie_link_speed[linksta & PCI_EXP_LNKSTA_CLS]; 748} 749EXPORT_SYMBOL_GPL(pcie_update_link_speed); 750 751static unsigned char agp_speeds[] = { 752 AGP_UNKNOWN, 753 AGP_1X, 754 AGP_2X, 755 AGP_4X, 756 AGP_8X 757}; 758 759static enum pci_bus_speed agp_speed(int agp3, int agpstat) 760{ 761 int index = 0; 762 763 if (agpstat & 4) 764 index = 3; 765 else if (agpstat & 2) 766 index = 2; 767 else if (agpstat & 1) 768 index = 1; 769 else 770 goto out; 771 772 if (agp3) { 773 index += 2; 774 if (index == 5) 775 index = 0; 776 } 777 778 out: 779 return agp_speeds[index]; 780} 781 782static void pci_set_bus_speed(struct pci_bus *bus) 783{ 784 struct pci_dev *bridge = bus->self; 785 int pos; 786 787 pos = pci_find_capability(bridge, PCI_CAP_ID_AGP); 788 if (!pos) 789 pos = pci_find_capability(bridge, PCI_CAP_ID_AGP3); 790 if (pos) { 791 u32 agpstat, agpcmd; 792 793 pci_read_config_dword(bridge, pos + PCI_AGP_STATUS, &agpstat); 794 bus->max_bus_speed = agp_speed(agpstat & 8, agpstat & 7); 795 796 pci_read_config_dword(bridge, pos + PCI_AGP_COMMAND, &agpcmd); 797 bus->cur_bus_speed = agp_speed(agpstat & 8, agpcmd & 7); 798 } 799 800 pos = pci_find_capability(bridge, PCI_CAP_ID_PCIX); 801 if (pos) { 802 u16 status; 803 enum pci_bus_speed max; 804 805 pci_read_config_word(bridge, pos + PCI_X_BRIDGE_SSTATUS, 806 &status); 807 808 if (status & PCI_X_SSTATUS_533MHZ) { 809 max = PCI_SPEED_133MHz_PCIX_533; 810 } else if (status & PCI_X_SSTATUS_266MHZ) { 811 max = PCI_SPEED_133MHz_PCIX_266; 812 } else if (status & PCI_X_SSTATUS_133MHZ) { 813 if ((status & PCI_X_SSTATUS_VERS) == PCI_X_SSTATUS_V2) 814 max = PCI_SPEED_133MHz_PCIX_ECC; 815 else 816 max = PCI_SPEED_133MHz_PCIX; 817 } else { 818 max = PCI_SPEED_66MHz_PCIX; 819 } 820 821 bus->max_bus_speed = max; 822 bus->cur_bus_speed = 823 pcix_bus_speed[FIELD_GET(PCI_X_SSTATUS_FREQ, status)]; 824 825 return; 826 } 827 828 if (pci_is_pcie(bridge)) { 829 u32 linkcap; 830 u16 linksta; 831 832 pcie_capability_read_dword(bridge, PCI_EXP_LNKCAP, &linkcap); 833 bus->max_bus_speed = pcie_link_speed[linkcap & PCI_EXP_LNKCAP_SLS]; 834 835 pcie_capability_read_word(bridge, PCI_EXP_LNKSTA, &linksta); 836 pcie_update_link_speed(bus, linksta); 837 } 838} 839 840static struct irq_domain *pci_host_bridge_msi_domain(struct pci_bus *bus) 841{ 842 struct irq_domain *d; 843 844 /* If the host bridge driver sets a MSI domain of the bridge, use it */ 845 d = dev_get_msi_domain(bus->bridge); 846 847 /* 848 * Any firmware interface that can resolve the msi_domain 849 * should be called from here. 850 */ 851 if (!d) 852 d = pci_host_bridge_of_msi_domain(bus); 853 if (!d) 854 d = pci_host_bridge_acpi_msi_domain(bus); 855 856 /* 857 * If no IRQ domain was found via the OF tree, try looking it up 858 * directly through the fwnode_handle. 859 */ 860 if (!d) { 861 struct fwnode_handle *fwnode = pci_root_bus_fwnode(bus); 862 863 if (fwnode) 864 d = irq_find_matching_fwnode(fwnode, 865 DOMAIN_BUS_PCI_MSI); 866 } 867 868 return d; 869} 870 871static void pci_set_bus_msi_domain(struct pci_bus *bus) 872{ 873 struct irq_domain *d; 874 struct pci_bus *b; 875 876 /* 877 * The bus can be a root bus, a subordinate bus, or a virtual bus 878 * created by an SR-IOV device. Walk up to the first bridge device 879 * found or derive the domain from the host bridge. 880 */ 881 for (b = bus, d = NULL; !d && !pci_is_root_bus(b); b = b->parent) { 882 if (b->self) 883 d = dev_get_msi_domain(&b->self->dev); 884 } 885 886 if (!d) 887 d = pci_host_bridge_msi_domain(b); 888 889 dev_set_msi_domain(&bus->dev, d); 890} 891 892static int pci_register_host_bridge(struct pci_host_bridge *bridge) 893{ 894 struct device *parent = bridge->dev.parent; 895 struct resource_entry *window, *next, *n; 896 struct pci_bus *bus, *b; 897 resource_size_t offset, next_offset; 898 LIST_HEAD(resources); 899 struct resource *res, *next_res; 900 char addr[64], *fmt; 901 const char *name; 902 int err; 903 904 bus = pci_alloc_bus(NULL); 905 if (!bus) 906 return -ENOMEM; 907 908 bridge->bus = bus; 909 910 bus->sysdata = bridge->sysdata; 911 bus->ops = bridge->ops; 912 bus->number = bus->busn_res.start = bridge->busnr; 913#ifdef CONFIG_PCI_DOMAINS_GENERIC 914 if (bridge->domain_nr == PCI_DOMAIN_NR_NOT_SET) 915 bus->domain_nr = pci_bus_find_domain_nr(bus, parent); 916 else 917 bus->domain_nr = bridge->domain_nr; 918 if (bus->domain_nr < 0) { 919 err = bus->domain_nr; 920 goto free; 921 } 922#endif 923 924 b = pci_find_bus(pci_domain_nr(bus), bridge->busnr); 925 if (b) { 926 /* Ignore it if we already got here via a different bridge */ 927 dev_dbg(&b->dev, "bus already known\n"); 928 err = -EEXIST; 929 goto free; 930 } 931 932 dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(bus), 933 bridge->busnr); 934 935 err = pcibios_root_bridge_prepare(bridge); 936 if (err) 937 goto free; 938 939 /* Temporarily move resources off the list */ 940 list_splice_init(&bridge->windows, &resources); 941 err = device_add(&bridge->dev); 942 if (err) { 943 put_device(&bridge->dev); 944 goto free; 945 } 946 bus->bridge = get_device(&bridge->dev); 947 device_enable_async_suspend(bus->bridge); 948 pci_set_bus_of_node(bus); 949 pci_set_bus_msi_domain(bus); 950 if (bridge->msi_domain && !dev_get_msi_domain(&bus->dev) && 951 !pci_host_of_has_msi_map(parent)) 952 bus->bus_flags |= PCI_BUS_FLAGS_NO_MSI; 953 954 if (!parent) 955 set_dev_node(bus->bridge, pcibus_to_node(bus)); 956 957 bus->dev.class = &pcibus_class; 958 bus->dev.parent = bus->bridge; 959 960 dev_set_name(&bus->dev, "%04x:%02x", pci_domain_nr(bus), bus->number); 961 name = dev_name(&bus->dev); 962 963 err = device_register(&bus->dev); 964 if (err) 965 goto unregister; 966 967 pcibios_add_bus(bus); 968 969 if (bus->ops->add_bus) { 970 err = bus->ops->add_bus(bus); 971 if (WARN_ON(err < 0)) 972 dev_err(&bus->dev, "failed to add bus: %d\n", err); 973 } 974 975 /* Create legacy_io and legacy_mem files for this bus */ 976 pci_create_legacy_files(bus); 977 978 if (parent) 979 dev_info(parent, "PCI host bridge to bus %s\n", name); 980 else 981 pr_info("PCI host bridge to bus %s\n", name); 982 983 if (nr_node_ids > 1 && pcibus_to_node(bus) == NUMA_NO_NODE) 984 dev_warn(&bus->dev, "Unknown NUMA node; performance will be reduced\n"); 985 986 /* Coalesce contiguous windows */ 987 resource_list_for_each_entry_safe(window, n, &resources) { 988 if (list_is_last(&window->node, &resources)) 989 break; 990 991 next = list_next_entry(window, node); 992 offset = window->offset; 993 res = window->res; 994 next_offset = next->offset; 995 next_res = next->res; 996 997 if (res->flags != next_res->flags || offset != next_offset) 998 continue; 999 1000 if (res->end + 1 == next_res->start) { 1001 next_res->start = res->start; 1002 res->flags = res->start = res->end = 0; 1003 } 1004 } 1005 1006 /* Add initial resources to the bus */ 1007 resource_list_for_each_entry_safe(window, n, &resources) { 1008 offset = window->offset; 1009 res = window->res; 1010 if (!res->flags && !res->start && !res->end) { 1011 release_resource(res); 1012 resource_list_destroy_entry(window); 1013 continue; 1014 } 1015 1016 list_move_tail(&window->node, &bridge->windows); 1017 1018 if (res->flags & IORESOURCE_BUS) 1019 pci_bus_insert_busn_res(bus, bus->number, res->end); 1020 else 1021 pci_bus_add_resource(bus, res, 0); 1022 1023 if (offset) { 1024 if (resource_type(res) == IORESOURCE_IO) 1025 fmt = " (bus address [%#06llx-%#06llx])"; 1026 else 1027 fmt = " (bus address [%#010llx-%#010llx])"; 1028 1029 snprintf(addr, sizeof(addr), fmt, 1030 (unsigned long long)(res->start - offset), 1031 (unsigned long long)(res->end - offset)); 1032 } else 1033 addr[0] = '\0'; 1034 1035 dev_info(&bus->dev, "root bus resource %pR%s\n", res, addr); 1036 } 1037 1038 down_write(&pci_bus_sem); 1039 list_add_tail(&bus->node, &pci_root_buses); 1040 up_write(&pci_bus_sem); 1041 1042 return 0; 1043 1044unregister: 1045 put_device(&bridge->dev); 1046 device_del(&bridge->dev); 1047 1048free: 1049#ifdef CONFIG_PCI_DOMAINS_GENERIC 1050 pci_bus_release_domain_nr(bus, parent); 1051#endif 1052 kfree(bus); 1053 return err; 1054} 1055 1056static bool pci_bridge_child_ext_cfg_accessible(struct pci_dev *bridge) 1057{ 1058 int pos; 1059 u32 status; 1060 1061 /* 1062 * If extended config space isn't accessible on a bridge's primary 1063 * bus, we certainly can't access it on the secondary bus. 1064 */ 1065 if (bridge->bus->bus_flags & PCI_BUS_FLAGS_NO_EXTCFG) 1066 return false; 1067 1068 /* 1069 * PCIe Root Ports and switch ports are PCIe on both sides, so if 1070 * extended config space is accessible on the primary, it's also 1071 * accessible on the secondary. 1072 */ 1073 if (pci_is_pcie(bridge) && 1074 (pci_pcie_type(bridge) == PCI_EXP_TYPE_ROOT_PORT || 1075 pci_pcie_type(bridge) == PCI_EXP_TYPE_UPSTREAM || 1076 pci_pcie_type(bridge) == PCI_EXP_TYPE_DOWNSTREAM)) 1077 return true; 1078 1079 /* 1080 * For the other bridge types: 1081 * - PCI-to-PCI bridges 1082 * - PCIe-to-PCI/PCI-X forward bridges 1083 * - PCI/PCI-X-to-PCIe reverse bridges 1084 * extended config space on the secondary side is only accessible 1085 * if the bridge supports PCI-X Mode 2. 1086 */ 1087 pos = pci_find_capability(bridge, PCI_CAP_ID_PCIX); 1088 if (!pos) 1089 return false; 1090 1091 pci_read_config_dword(bridge, pos + PCI_X_STATUS, &status); 1092 return status & (PCI_X_STATUS_266MHZ | PCI_X_STATUS_533MHZ); 1093} 1094 1095static struct pci_bus *pci_alloc_child_bus(struct pci_bus *parent, 1096 struct pci_dev *bridge, int busnr) 1097{ 1098 struct pci_bus *child; 1099 struct pci_host_bridge *host; 1100 int i; 1101 int ret; 1102 1103 /* Allocate a new bus and inherit stuff from the parent */ 1104 child = pci_alloc_bus(parent); 1105 if (!child) 1106 return NULL; 1107 1108 child->parent = parent; 1109 child->sysdata = parent->sysdata; 1110 child->bus_flags = parent->bus_flags; 1111 1112 host = pci_find_host_bridge(parent); 1113 if (host->child_ops) 1114 child->ops = host->child_ops; 1115 else 1116 child->ops = parent->ops; 1117 1118 /* 1119 * Initialize some portions of the bus device, but don't register 1120 * it now as the parent is not properly set up yet. 1121 */ 1122 child->dev.class = &pcibus_class; 1123 dev_set_name(&child->dev, "%04x:%02x", pci_domain_nr(child), busnr); 1124 1125 /* Set up the primary, secondary and subordinate bus numbers */ 1126 child->number = child->busn_res.start = busnr; 1127 child->primary = parent->busn_res.start; 1128 child->busn_res.end = 0xff; 1129 1130 if (!bridge) { 1131 child->dev.parent = parent->bridge; 1132 goto add_dev; 1133 } 1134 1135 child->self = bridge; 1136 child->bridge = get_device(&bridge->dev); 1137 child->dev.parent = child->bridge; 1138 pci_set_bus_of_node(child); 1139 pci_set_bus_speed(child); 1140 1141 /* 1142 * Check whether extended config space is accessible on the child 1143 * bus. Note that we currently assume it is always accessible on 1144 * the root bus. 1145 */ 1146 if (!pci_bridge_child_ext_cfg_accessible(bridge)) { 1147 child->bus_flags |= PCI_BUS_FLAGS_NO_EXTCFG; 1148 pci_info(child, "extended config space not accessible\n"); 1149 } 1150 1151 /* Set up default resource pointers and names */ 1152 for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++) { 1153 child->resource[i] = &bridge->resource[PCI_BRIDGE_RESOURCES+i]; 1154 child->resource[i]->name = child->name; 1155 } 1156 bridge->subordinate = child; 1157 1158add_dev: 1159 pci_set_bus_msi_domain(child); 1160 ret = device_register(&child->dev); 1161 WARN_ON(ret < 0); 1162 1163 pcibios_add_bus(child); 1164 1165 if (child->ops->add_bus) { 1166 ret = child->ops->add_bus(child); 1167 if (WARN_ON(ret < 0)) 1168 dev_err(&child->dev, "failed to add bus: %d\n", ret); 1169 } 1170 1171 /* Create legacy_io and legacy_mem files for this bus */ 1172 pci_create_legacy_files(child); 1173 1174 return child; 1175} 1176 1177struct pci_bus *pci_add_new_bus(struct pci_bus *parent, struct pci_dev *dev, 1178 int busnr) 1179{ 1180 struct pci_bus *child; 1181 1182 child = pci_alloc_child_bus(parent, dev, busnr); 1183 if (child) { 1184 down_write(&pci_bus_sem); 1185 list_add_tail(&child->node, &parent->children); 1186 up_write(&pci_bus_sem); 1187 } 1188 return child; 1189} 1190EXPORT_SYMBOL(pci_add_new_bus); 1191 1192static void pci_enable_crs(struct pci_dev *pdev) 1193{ 1194 u16 root_cap = 0; 1195 1196 /* Enable CRS Software Visibility if supported */ 1197 pcie_capability_read_word(pdev, PCI_EXP_RTCAP, &root_cap); 1198 if (root_cap & PCI_EXP_RTCAP_CRSVIS) 1199 pcie_capability_set_word(pdev, PCI_EXP_RTCTL, 1200 PCI_EXP_RTCTL_CRSSVE); 1201} 1202 1203static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus, 1204 unsigned int available_buses); 1205/** 1206 * pci_ea_fixed_busnrs() - Read fixed Secondary and Subordinate bus 1207 * numbers from EA capability. 1208 * @dev: Bridge 1209 * @sec: updated with secondary bus number from EA 1210 * @sub: updated with subordinate bus number from EA 1211 * 1212 * If @dev is a bridge with EA capability that specifies valid secondary 1213 * and subordinate bus numbers, return true with the bus numbers in @sec 1214 * and @sub. Otherwise return false. 1215 */ 1216static bool pci_ea_fixed_busnrs(struct pci_dev *dev, u8 *sec, u8 *sub) 1217{ 1218 int ea, offset; 1219 u32 dw; 1220 u8 ea_sec, ea_sub; 1221 1222 if (dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) 1223 return false; 1224 1225 /* find PCI EA capability in list */ 1226 ea = pci_find_capability(dev, PCI_CAP_ID_EA); 1227 if (!ea) 1228 return false; 1229 1230 offset = ea + PCI_EA_FIRST_ENT; 1231 pci_read_config_dword(dev, offset, &dw); 1232 ea_sec = FIELD_GET(PCI_EA_SEC_BUS_MASK, dw); 1233 ea_sub = FIELD_GET(PCI_EA_SUB_BUS_MASK, dw); 1234 if (ea_sec == 0 || ea_sub < ea_sec) 1235 return false; 1236 1237 *sec = ea_sec; 1238 *sub = ea_sub; 1239 return true; 1240} 1241 1242/* 1243 * pci_scan_bridge_extend() - Scan buses behind a bridge 1244 * @bus: Parent bus the bridge is on 1245 * @dev: Bridge itself 1246 * @max: Starting subordinate number of buses behind this bridge 1247 * @available_buses: Total number of buses available for this bridge and 1248 * the devices below. After the minimal bus space has 1249 * been allocated the remaining buses will be 1250 * distributed equally between hotplug-capable bridges. 1251 * @pass: Either %0 (scan already configured bridges) or %1 (scan bridges 1252 * that need to be reconfigured. 1253 * 1254 * If it's a bridge, configure it and scan the bus behind it. 1255 * For CardBus bridges, we don't scan behind as the devices will 1256 * be handled by the bridge driver itself. 1257 * 1258 * We need to process bridges in two passes -- first we scan those 1259 * already configured by the BIOS and after we are done with all of 1260 * them, we proceed to assigning numbers to the remaining buses in 1261 * order to avoid overlaps between old and new bus numbers. 1262 * 1263 * Return: New subordinate number covering all buses behind this bridge. 1264 */ 1265static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev, 1266 int max, unsigned int available_buses, 1267 int pass) 1268{ 1269 struct pci_bus *child; 1270 int is_cardbus = (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS); 1271 u32 buses, i, j = 0; 1272 u16 bctl; 1273 u8 primary, secondary, subordinate; 1274 int broken = 0; 1275 bool fixed_buses; 1276 u8 fixed_sec, fixed_sub; 1277 int next_busnr; 1278 1279 /* 1280 * Make sure the bridge is powered on to be able to access config 1281 * space of devices below it. 1282 */ 1283 pm_runtime_get_sync(&dev->dev); 1284 1285 pci_read_config_dword(dev, PCI_PRIMARY_BUS, &buses); 1286 primary = buses & 0xFF; 1287 secondary = (buses >> 8) & 0xFF; 1288 subordinate = (buses >> 16) & 0xFF; 1289 1290 pci_dbg(dev, "scanning [bus %02x-%02x] behind bridge, pass %d\n", 1291 secondary, subordinate, pass); 1292 1293 if (!primary && (primary != bus->number) && secondary && subordinate) { 1294 pci_warn(dev, "Primary bus is hard wired to 0\n"); 1295 primary = bus->number; 1296 } 1297 1298 /* Check if setup is sensible at all */ 1299 if (!pass && 1300 (primary != bus->number || secondary <= bus->number || 1301 secondary > subordinate)) { 1302 pci_info(dev, "bridge configuration invalid ([bus %02x-%02x]), reconfiguring\n", 1303 secondary, subordinate); 1304 broken = 1; 1305 } 1306 1307 /* 1308 * Disable Master-Abort Mode during probing to avoid reporting of 1309 * bus errors in some architectures. 1310 */ 1311 pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &bctl); 1312 pci_write_config_word(dev, PCI_BRIDGE_CONTROL, 1313 bctl & ~PCI_BRIDGE_CTL_MASTER_ABORT); 1314 1315 pci_enable_crs(dev); 1316 1317 if ((secondary || subordinate) && !pcibios_assign_all_busses() && 1318 !is_cardbus && !broken) { 1319 unsigned int cmax, buses; 1320 1321 /* 1322 * Bus already configured by firmware, process it in the 1323 * first pass and just note the configuration. 1324 */ 1325 if (pass) 1326 goto out; 1327 1328 /* 1329 * The bus might already exist for two reasons: Either we 1330 * are rescanning the bus or the bus is reachable through 1331 * more than one bridge. The second case can happen with 1332 * the i450NX chipset. 1333 */ 1334 child = pci_find_bus(pci_domain_nr(bus), secondary); 1335 if (!child) { 1336 child = pci_add_new_bus(bus, dev, secondary); 1337 if (!child) 1338 goto out; 1339 child->primary = primary; 1340 pci_bus_insert_busn_res(child, secondary, subordinate); 1341 child->bridge_ctl = bctl; 1342 } 1343 1344 buses = subordinate - secondary; 1345 cmax = pci_scan_child_bus_extend(child, buses); 1346 if (cmax > subordinate) 1347 pci_warn(dev, "bridge has subordinate %02x but max busn %02x\n", 1348 subordinate, cmax); 1349 1350 /* Subordinate should equal child->busn_res.end */ 1351 if (subordinate > max) 1352 max = subordinate; 1353 } else { 1354 1355 /* 1356 * We need to assign a number to this bus which we always 1357 * do in the second pass. 1358 */ 1359 if (!pass) { 1360 if (pcibios_assign_all_busses() || broken || is_cardbus) 1361 1362 /* 1363 * Temporarily disable forwarding of the 1364 * configuration cycles on all bridges in 1365 * this bus segment to avoid possible 1366 * conflicts in the second pass between two 1367 * bridges programmed with overlapping bus 1368 * ranges. 1369 */ 1370 pci_write_config_dword(dev, PCI_PRIMARY_BUS, 1371 buses & ~0xffffff); 1372 goto out; 1373 } 1374 1375 /* Clear errors */ 1376 pci_write_config_word(dev, PCI_STATUS, 0xffff); 1377 1378 /* Read bus numbers from EA Capability (if present) */ 1379 fixed_buses = pci_ea_fixed_busnrs(dev, &fixed_sec, &fixed_sub); 1380 if (fixed_buses) 1381 next_busnr = fixed_sec; 1382 else 1383 next_busnr = max + 1; 1384 1385 /* 1386 * Prevent assigning a bus number that already exists. 1387 * This can happen when a bridge is hot-plugged, so in this 1388 * case we only re-scan this bus. 1389 */ 1390 child = pci_find_bus(pci_domain_nr(bus), next_busnr); 1391 if (!child) { 1392 child = pci_add_new_bus(bus, dev, next_busnr); 1393 if (!child) 1394 goto out; 1395 pci_bus_insert_busn_res(child, next_busnr, 1396 bus->busn_res.end); 1397 } 1398 max++; 1399 if (available_buses) 1400 available_buses--; 1401 1402 buses = (buses & 0xff000000) 1403 | ((unsigned int)(child->primary) << 0) 1404 | ((unsigned int)(child->busn_res.start) << 8) 1405 | ((unsigned int)(child->busn_res.end) << 16); 1406 1407 /* 1408 * yenta.c forces a secondary latency timer of 176. 1409 * Copy that behaviour here. 1410 */ 1411 if (is_cardbus) { 1412 buses &= ~0xff000000; 1413 buses |= CARDBUS_LATENCY_TIMER << 24; 1414 } 1415 1416 /* We need to blast all three values with a single write */ 1417 pci_write_config_dword(dev, PCI_PRIMARY_BUS, buses); 1418 1419 if (!is_cardbus) { 1420 child->bridge_ctl = bctl; 1421 max = pci_scan_child_bus_extend(child, available_buses); 1422 } else { 1423 1424 /* 1425 * For CardBus bridges, we leave 4 bus numbers as 1426 * cards with a PCI-to-PCI bridge can be inserted 1427 * later. 1428 */ 1429 for (i = 0; i < CARDBUS_RESERVE_BUSNR; i++) { 1430 struct pci_bus *parent = bus; 1431 if (pci_find_bus(pci_domain_nr(bus), 1432 max+i+1)) 1433 break; 1434 while (parent->parent) { 1435 if ((!pcibios_assign_all_busses()) && 1436 (parent->busn_res.end > max) && 1437 (parent->busn_res.end <= max+i)) { 1438 j = 1; 1439 } 1440 parent = parent->parent; 1441 } 1442 if (j) { 1443 1444 /* 1445 * Often, there are two CardBus 1446 * bridges -- try to leave one 1447 * valid bus number for each one. 1448 */ 1449 i /= 2; 1450 break; 1451 } 1452 } 1453 max += i; 1454 } 1455 1456 /* 1457 * Set subordinate bus number to its real value. 1458 * If fixed subordinate bus number exists from EA 1459 * capability then use it. 1460 */ 1461 if (fixed_buses) 1462 max = fixed_sub; 1463 pci_bus_update_busn_res_end(child, max); 1464 pci_write_config_byte(dev, PCI_SUBORDINATE_BUS, max); 1465 } 1466 1467 sprintf(child->name, 1468 (is_cardbus ? "PCI CardBus %04x:%02x" : "PCI Bus %04x:%02x"), 1469 pci_domain_nr(bus), child->number); 1470 1471 /* Check that all devices are accessible */ 1472 while (bus->parent) { 1473 if ((child->busn_res.end > bus->busn_res.end) || 1474 (child->number > bus->busn_res.end) || 1475 (child->number < bus->number) || 1476 (child->busn_res.end < bus->number)) { 1477 dev_info(&dev->dev, "devices behind bridge are unusable because %pR cannot be assigned for them\n", 1478 &child->busn_res); 1479 break; 1480 } 1481 bus = bus->parent; 1482 } 1483 1484out: 1485 pci_write_config_word(dev, PCI_BRIDGE_CONTROL, bctl); 1486 1487 pm_runtime_put(&dev->dev); 1488 1489 return max; 1490} 1491 1492/* 1493 * pci_scan_bridge() - Scan buses behind a bridge 1494 * @bus: Parent bus the bridge is on 1495 * @dev: Bridge itself 1496 * @max: Starting subordinate number of buses behind this bridge 1497 * @pass: Either %0 (scan already configured bridges) or %1 (scan bridges 1498 * that need to be reconfigured. 1499 * 1500 * If it's a bridge, configure it and scan the bus behind it. 1501 * For CardBus bridges, we don't scan behind as the devices will 1502 * be handled by the bridge driver itself. 1503 * 1504 * We need to process bridges in two passes -- first we scan those 1505 * already configured by the BIOS and after we are done with all of 1506 * them, we proceed to assigning numbers to the remaining buses in 1507 * order to avoid overlaps between old and new bus numbers. 1508 * 1509 * Return: New subordinate number covering all buses behind this bridge. 1510 */ 1511int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass) 1512{ 1513 return pci_scan_bridge_extend(bus, dev, max, 0, pass); 1514} 1515EXPORT_SYMBOL(pci_scan_bridge); 1516 1517/* 1518 * Read interrupt line and base address registers. 1519 * The architecture-dependent code can tweak these, of course. 1520 */ 1521static void pci_read_irq(struct pci_dev *dev) 1522{ 1523 unsigned char irq; 1524 1525 /* VFs are not allowed to use INTx, so skip the config reads */ 1526 if (dev->is_virtfn) { 1527 dev->pin = 0; 1528 dev->irq = 0; 1529 return; 1530 } 1531 1532 pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &irq); 1533 dev->pin = irq; 1534 if (irq) 1535 pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &irq); 1536 dev->irq = irq; 1537} 1538 1539void set_pcie_port_type(struct pci_dev *pdev) 1540{ 1541 int pos; 1542 u16 reg16; 1543 u32 reg32; 1544 int type; 1545 struct pci_dev *parent; 1546 1547 pos = pci_find_capability(pdev, PCI_CAP_ID_EXP); 1548 if (!pos) 1549 return; 1550 1551 pdev->pcie_cap = pos; 1552 pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, ®16); 1553 pdev->pcie_flags_reg = reg16; 1554 pci_read_config_dword(pdev, pos + PCI_EXP_DEVCAP, &pdev->devcap); 1555 pdev->pcie_mpss = FIELD_GET(PCI_EXP_DEVCAP_PAYLOAD, pdev->devcap); 1556 1557 pcie_capability_read_dword(pdev, PCI_EXP_LNKCAP, ®32); 1558 if (reg32 & PCI_EXP_LNKCAP_DLLLARC) 1559 pdev->link_active_reporting = 1; 1560 1561 parent = pci_upstream_bridge(pdev); 1562 if (!parent) 1563 return; 1564 1565 /* 1566 * Some systems do not identify their upstream/downstream ports 1567 * correctly so detect impossible configurations here and correct 1568 * the port type accordingly. 1569 */ 1570 type = pci_pcie_type(pdev); 1571 if (type == PCI_EXP_TYPE_DOWNSTREAM) { 1572 /* 1573 * If pdev claims to be downstream port but the parent 1574 * device is also downstream port assume pdev is actually 1575 * upstream port. 1576 */ 1577 if (pcie_downstream_port(parent)) { 1578 pci_info(pdev, "claims to be downstream port but is acting as upstream port, correcting type\n"); 1579 pdev->pcie_flags_reg &= ~PCI_EXP_FLAGS_TYPE; 1580 pdev->pcie_flags_reg |= PCI_EXP_TYPE_UPSTREAM; 1581 } 1582 } else if (type == PCI_EXP_TYPE_UPSTREAM) { 1583 /* 1584 * If pdev claims to be upstream port but the parent 1585 * device is also upstream port assume pdev is actually 1586 * downstream port. 1587 */ 1588 if (pci_pcie_type(parent) == PCI_EXP_TYPE_UPSTREAM) { 1589 pci_info(pdev, "claims to be upstream port but is acting as downstream port, correcting type\n"); 1590 pdev->pcie_flags_reg &= ~PCI_EXP_FLAGS_TYPE; 1591 pdev->pcie_flags_reg |= PCI_EXP_TYPE_DOWNSTREAM; 1592 } 1593 } 1594} 1595 1596void set_pcie_hotplug_bridge(struct pci_dev *pdev) 1597{ 1598 u32 reg32; 1599 1600 pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, ®32); 1601 if (reg32 & PCI_EXP_SLTCAP_HPC) 1602 pdev->is_hotplug_bridge = 1; 1603} 1604 1605static void set_pcie_thunderbolt(struct pci_dev *dev) 1606{ 1607 u16 vsec; 1608 1609 /* Is the device part of a Thunderbolt controller? */ 1610 vsec = pci_find_vsec_capability(dev, PCI_VENDOR_ID_INTEL, PCI_VSEC_ID_INTEL_TBT); 1611 if (vsec) 1612 dev->is_thunderbolt = 1; 1613} 1614 1615static void set_pcie_untrusted(struct pci_dev *dev) 1616{ 1617 struct pci_dev *parent; 1618 1619 /* 1620 * If the upstream bridge is untrusted we treat this device 1621 * untrusted as well. 1622 */ 1623 parent = pci_upstream_bridge(dev); 1624 if (parent && (parent->untrusted || parent->external_facing)) 1625 dev->untrusted = true; 1626} 1627 1628static void pci_set_removable(struct pci_dev *dev) 1629{ 1630 struct pci_dev *parent = pci_upstream_bridge(dev); 1631 1632 /* 1633 * We (only) consider everything downstream from an external_facing 1634 * device to be removable by the user. We're mainly concerned with 1635 * consumer platforms with user accessible thunderbolt ports that are 1636 * vulnerable to DMA attacks, and we expect those ports to be marked by 1637 * the firmware as external_facing. Devices in traditional hotplug 1638 * slots can technically be removed, but the expectation is that unless 1639 * the port is marked with external_facing, such devices are less 1640 * accessible to user / may not be removed by end user, and thus not 1641 * exposed as "removable" to userspace. 1642 */ 1643 if (parent && 1644 (parent->external_facing || dev_is_removable(&parent->dev))) 1645 dev_set_removable(&dev->dev, DEVICE_REMOVABLE); 1646} 1647 1648/** 1649 * pci_ext_cfg_is_aliased - Is ext config space just an alias of std config? 1650 * @dev: PCI device 1651 * 1652 * PCI Express to PCI/PCI-X Bridge Specification, rev 1.0, 4.1.4 says that 1653 * when forwarding a type1 configuration request the bridge must check that 1654 * the extended register address field is zero. The bridge is not permitted 1655 * to forward the transactions and must handle it as an Unsupported Request. 1656 * Some bridges do not follow this rule and simply drop the extended register 1657 * bits, resulting in the standard config space being aliased, every 256 1658 * bytes across the entire configuration space. Test for this condition by 1659 * comparing the first dword of each potential alias to the vendor/device ID. 1660 * Known offenders: 1661 * ASM1083/1085 PCIe-to-PCI Reversible Bridge (1b21:1080, rev 01 & 03) 1662 * AMD/ATI SBx00 PCI to PCI Bridge (1002:4384, rev 40) 1663 */ 1664static bool pci_ext_cfg_is_aliased(struct pci_dev *dev) 1665{ 1666#ifdef CONFIG_PCI_QUIRKS 1667 int pos, ret; 1668 u32 header, tmp; 1669 1670 pci_read_config_dword(dev, PCI_VENDOR_ID, &header); 1671 1672 for (pos = PCI_CFG_SPACE_SIZE; 1673 pos < PCI_CFG_SPACE_EXP_SIZE; pos += PCI_CFG_SPACE_SIZE) { 1674 ret = pci_read_config_dword(dev, pos, &tmp); 1675 if ((ret != PCIBIOS_SUCCESSFUL) || (header != tmp)) 1676 return false; 1677 } 1678 1679 return true; 1680#else 1681 return false; 1682#endif 1683} 1684 1685/** 1686 * pci_cfg_space_size_ext - Get the configuration space size of the PCI device 1687 * @dev: PCI device 1688 * 1689 * Regular PCI devices have 256 bytes, but PCI-X 2 and PCI Express devices 1690 * have 4096 bytes. Even if the device is capable, that doesn't mean we can 1691 * access it. Maybe we don't have a way to generate extended config space 1692 * accesses, or the device is behind a reverse Express bridge. So we try 1693 * reading the dword at 0x100 which must either be 0 or a valid extended 1694 * capability header. 1695 */ 1696static int pci_cfg_space_size_ext(struct pci_dev *dev) 1697{ 1698 u32 status; 1699 int pos = PCI_CFG_SPACE_SIZE; 1700 1701 if (pci_read_config_dword(dev, pos, &status) != PCIBIOS_SUCCESSFUL) 1702 return PCI_CFG_SPACE_SIZE; 1703 if (PCI_POSSIBLE_ERROR(status) || pci_ext_cfg_is_aliased(dev)) 1704 return PCI_CFG_SPACE_SIZE; 1705 1706 return PCI_CFG_SPACE_EXP_SIZE; 1707} 1708 1709int pci_cfg_space_size(struct pci_dev *dev) 1710{ 1711 int pos; 1712 u32 status; 1713 u16 class; 1714 1715#ifdef CONFIG_PCI_IOV 1716 /* 1717 * Per the SR-IOV specification (rev 1.1, sec 3.5), VFs are required to 1718 * implement a PCIe capability and therefore must implement extended 1719 * config space. We can skip the NO_EXTCFG test below and the 1720 * reachability/aliasing test in pci_cfg_space_size_ext() by virtue of 1721 * the fact that the SR-IOV capability on the PF resides in extended 1722 * config space and must be accessible and non-aliased to have enabled 1723 * support for this VF. This is a micro performance optimization for 1724 * systems supporting many VFs. 1725 */ 1726 if (dev->is_virtfn) 1727 return PCI_CFG_SPACE_EXP_SIZE; 1728#endif 1729 1730 if (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_EXTCFG) 1731 return PCI_CFG_SPACE_SIZE; 1732 1733 class = dev->class >> 8; 1734 if (class == PCI_CLASS_BRIDGE_HOST) 1735 return pci_cfg_space_size_ext(dev); 1736 1737 if (pci_is_pcie(dev)) 1738 return pci_cfg_space_size_ext(dev); 1739 1740 pos = pci_find_capability(dev, PCI_CAP_ID_PCIX); 1741 if (!pos) 1742 return PCI_CFG_SPACE_SIZE; 1743 1744 pci_read_config_dword(dev, pos + PCI_X_STATUS, &status); 1745 if (status & (PCI_X_STATUS_266MHZ | PCI_X_STATUS_533MHZ)) 1746 return pci_cfg_space_size_ext(dev); 1747 1748 return PCI_CFG_SPACE_SIZE; 1749} 1750 1751static u32 pci_class(struct pci_dev *dev) 1752{ 1753 u32 class; 1754 1755#ifdef CONFIG_PCI_IOV 1756 if (dev->is_virtfn) 1757 return dev->physfn->sriov->class; 1758#endif 1759 pci_read_config_dword(dev, PCI_CLASS_REVISION, &class); 1760 return class; 1761} 1762 1763static void pci_subsystem_ids(struct pci_dev *dev, u16 *vendor, u16 *device) 1764{ 1765#ifdef CONFIG_PCI_IOV 1766 if (dev->is_virtfn) { 1767 *vendor = dev->physfn->sriov->subsystem_vendor; 1768 *device = dev->physfn->sriov->subsystem_device; 1769 return; 1770 } 1771#endif 1772 pci_read_config_word(dev, PCI_SUBSYSTEM_VENDOR_ID, vendor); 1773 pci_read_config_word(dev, PCI_SUBSYSTEM_ID, device); 1774} 1775 1776static u8 pci_hdr_type(struct pci_dev *dev) 1777{ 1778 u8 hdr_type; 1779 1780#ifdef CONFIG_PCI_IOV 1781 if (dev->is_virtfn) 1782 return dev->physfn->sriov->hdr_type; 1783#endif 1784 pci_read_config_byte(dev, PCI_HEADER_TYPE, &hdr_type); 1785 return hdr_type; 1786} 1787 1788#define LEGACY_IO_RESOURCE (IORESOURCE_IO | IORESOURCE_PCI_FIXED) 1789 1790/** 1791 * pci_intx_mask_broken - Test PCI_COMMAND_INTX_DISABLE writability 1792 * @dev: PCI device 1793 * 1794 * Test whether PCI_COMMAND_INTX_DISABLE is writable for @dev. Check this 1795 * at enumeration-time to avoid modifying PCI_COMMAND at run-time. 1796 */ 1797static int pci_intx_mask_broken(struct pci_dev *dev) 1798{ 1799 u16 orig, toggle, new; 1800 1801 pci_read_config_word(dev, PCI_COMMAND, &orig); 1802 toggle = orig ^ PCI_COMMAND_INTX_DISABLE; 1803 pci_write_config_word(dev, PCI_COMMAND, toggle); 1804 pci_read_config_word(dev, PCI_COMMAND, &new); 1805 1806 pci_write_config_word(dev, PCI_COMMAND, orig); 1807 1808 /* 1809 * PCI_COMMAND_INTX_DISABLE was reserved and read-only prior to PCI 1810 * r2.3, so strictly speaking, a device is not *broken* if it's not 1811 * writable. But we'll live with the misnomer for now. 1812 */ 1813 if (new != toggle) 1814 return 1; 1815 return 0; 1816} 1817 1818static void early_dump_pci_device(struct pci_dev *pdev) 1819{ 1820 u32 value[256 / 4]; 1821 int i; 1822 1823 pci_info(pdev, "config space:\n"); 1824 1825 for (i = 0; i < 256; i += 4) 1826 pci_read_config_dword(pdev, i, &value[i / 4]); 1827 1828 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET, 16, 1, 1829 value, 256, false); 1830} 1831 1832static const char *pci_type_str(struct pci_dev *dev) 1833{ 1834 static const char * const str[] = { 1835 "PCIe Endpoint", 1836 "PCIe Legacy Endpoint", 1837 "PCIe unknown", 1838 "PCIe unknown", 1839 "PCIe Root Port", 1840 "PCIe Switch Upstream Port", 1841 "PCIe Switch Downstream Port", 1842 "PCIe to PCI/PCI-X bridge", 1843 "PCI/PCI-X to PCIe bridge", 1844 "PCIe Root Complex Integrated Endpoint", 1845 "PCIe Root Complex Event Collector", 1846 }; 1847 int type; 1848 1849 if (pci_is_pcie(dev)) { 1850 type = pci_pcie_type(dev); 1851 if (type < ARRAY_SIZE(str)) 1852 return str[type]; 1853 1854 return "PCIe unknown"; 1855 } 1856 1857 switch (dev->hdr_type) { 1858 case PCI_HEADER_TYPE_NORMAL: 1859 return "conventional PCI endpoint"; 1860 case PCI_HEADER_TYPE_BRIDGE: 1861 return "conventional PCI bridge"; 1862 case PCI_HEADER_TYPE_CARDBUS: 1863 return "CardBus bridge"; 1864 default: 1865 return "conventional PCI"; 1866 } 1867} 1868 1869/** 1870 * pci_setup_device - Fill in class and map information of a device 1871 * @dev: the device structure to fill 1872 * 1873 * Initialize the device structure with information about the device's 1874 * vendor,class,memory and IO-space addresses, IRQ lines etc. 1875 * Called at initialisation of the PCI subsystem and by CardBus services. 1876 * Returns 0 on success and negative if unknown type of device (not normal, 1877 * bridge or CardBus). 1878 */ 1879int pci_setup_device(struct pci_dev *dev) 1880{ 1881 u32 class; 1882 u16 cmd; 1883 u8 hdr_type; 1884 int err, pos = 0; 1885 struct pci_bus_region region; 1886 struct resource *res; 1887 1888 hdr_type = pci_hdr_type(dev); 1889 1890 dev->sysdata = dev->bus->sysdata; 1891 dev->dev.parent = dev->bus->bridge; 1892 dev->dev.bus = &pci_bus_type; 1893 dev->hdr_type = hdr_type & 0x7f; 1894 dev->multifunction = !!(hdr_type & 0x80); 1895 dev->error_state = pci_channel_io_normal; 1896 set_pcie_port_type(dev); 1897 1898 err = pci_set_of_node(dev); 1899 if (err) 1900 return err; 1901 pci_set_acpi_fwnode(dev); 1902 1903 pci_dev_assign_slot(dev); 1904 1905 /* 1906 * Assume 32-bit PCI; let 64-bit PCI cards (which are far rarer) 1907 * set this higher, assuming the system even supports it. 1908 */ 1909 dev->dma_mask = 0xffffffff; 1910 1911 dev_set_name(&dev->dev, "%04x:%02x:%02x.%d", pci_domain_nr(dev->bus), 1912 dev->bus->number, PCI_SLOT(dev->devfn), 1913 PCI_FUNC(dev->devfn)); 1914 1915 class = pci_class(dev); 1916 1917 dev->revision = class & 0xff; 1918 dev->class = class >> 8; /* upper 3 bytes */ 1919 1920 if (pci_early_dump) 1921 early_dump_pci_device(dev); 1922 1923 /* Need to have dev->class ready */ 1924 dev->cfg_size = pci_cfg_space_size(dev); 1925 1926 /* Need to have dev->cfg_size ready */ 1927 set_pcie_thunderbolt(dev); 1928 1929 set_pcie_untrusted(dev); 1930 1931 /* "Unknown power state" */ 1932 dev->current_state = PCI_UNKNOWN; 1933 1934 /* Early fixups, before probing the BARs */ 1935 pci_fixup_device(pci_fixup_early, dev); 1936 1937 pci_set_removable(dev); 1938 1939 pci_info(dev, "[%04x:%04x] type %02x class %#08x %s\n", 1940 dev->vendor, dev->device, dev->hdr_type, dev->class, 1941 pci_type_str(dev)); 1942 1943 /* Device class may be changed after fixup */ 1944 class = dev->class >> 8; 1945 1946 if (dev->non_compliant_bars && !dev->mmio_always_on) { 1947 pci_read_config_word(dev, PCI_COMMAND, &cmd); 1948 if (cmd & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) { 1949 pci_info(dev, "device has non-compliant BARs; disabling IO/MEM decoding\n"); 1950 cmd &= ~PCI_COMMAND_IO; 1951 cmd &= ~PCI_COMMAND_MEMORY; 1952 pci_write_config_word(dev, PCI_COMMAND, cmd); 1953 } 1954 } 1955 1956 dev->broken_intx_masking = pci_intx_mask_broken(dev); 1957 1958 switch (dev->hdr_type) { /* header type */ 1959 case PCI_HEADER_TYPE_NORMAL: /* standard header */ 1960 if (class == PCI_CLASS_BRIDGE_PCI) 1961 goto bad; 1962 pci_read_irq(dev); 1963 pci_read_bases(dev, 6, PCI_ROM_ADDRESS); 1964 1965 pci_subsystem_ids(dev, &dev->subsystem_vendor, &dev->subsystem_device); 1966 1967 /* 1968 * Do the ugly legacy mode stuff here rather than broken chip 1969 * quirk code. Legacy mode ATA controllers have fixed 1970 * addresses. These are not always echoed in BAR0-3, and 1971 * BAR0-3 in a few cases contain junk! 1972 */ 1973 if (class == PCI_CLASS_STORAGE_IDE) { 1974 u8 progif; 1975 pci_read_config_byte(dev, PCI_CLASS_PROG, &progif); 1976 if ((progif & 1) == 0) { 1977 region.start = 0x1F0; 1978 region.end = 0x1F7; 1979 res = &dev->resource[0]; 1980 res->flags = LEGACY_IO_RESOURCE; 1981 pcibios_bus_to_resource(dev->bus, res, ®ion); 1982 pci_info(dev, "BAR 0 %pR: legacy IDE quirk\n", 1983 res); 1984 region.start = 0x3F6; 1985 region.end = 0x3F6; 1986 res = &dev->resource[1]; 1987 res->flags = LEGACY_IO_RESOURCE; 1988 pcibios_bus_to_resource(dev->bus, res, ®ion); 1989 pci_info(dev, "BAR 1 %pR: legacy IDE quirk\n", 1990 res); 1991 } 1992 if ((progif & 4) == 0) { 1993 region.start = 0x170; 1994 region.end = 0x177; 1995 res = &dev->resource[2]; 1996 res->flags = LEGACY_IO_RESOURCE; 1997 pcibios_bus_to_resource(dev->bus, res, ®ion); 1998 pci_info(dev, "BAR 2 %pR: legacy IDE quirk\n", 1999 res); 2000 region.start = 0x376; 2001 region.end = 0x376; 2002 res = &dev->resource[3]; 2003 res->flags = LEGACY_IO_RESOURCE; 2004 pcibios_bus_to_resource(dev->bus, res, ®ion); 2005 pci_info(dev, "BAR 3 %pR: legacy IDE quirk\n", 2006 res); 2007 } 2008 } 2009 break; 2010 2011 case PCI_HEADER_TYPE_BRIDGE: /* bridge header */ 2012 /* 2013 * The PCI-to-PCI bridge spec requires that subtractive 2014 * decoding (i.e. transparent) bridge must have programming 2015 * interface code of 0x01. 2016 */ 2017 pci_read_irq(dev); 2018 dev->transparent = ((dev->class & 0xff) == 1); 2019 pci_read_bases(dev, 2, PCI_ROM_ADDRESS1); 2020 pci_read_bridge_windows(dev); 2021 set_pcie_hotplug_bridge(dev); 2022 pos = pci_find_capability(dev, PCI_CAP_ID_SSVID); 2023 if (pos) { 2024 pci_read_config_word(dev, pos + PCI_SSVID_VENDOR_ID, &dev->subsystem_vendor); 2025 pci_read_config_word(dev, pos + PCI_SSVID_DEVICE_ID, &dev->subsystem_device); 2026 } 2027 break; 2028 2029 case PCI_HEADER_TYPE_CARDBUS: /* CardBus bridge header */ 2030 if (class != PCI_CLASS_BRIDGE_CARDBUS) 2031 goto bad; 2032 pci_read_irq(dev); 2033 pci_read_bases(dev, 1, 0); 2034 pci_read_config_word(dev, PCI_CB_SUBSYSTEM_VENDOR_ID, &dev->subsystem_vendor); 2035 pci_read_config_word(dev, PCI_CB_SUBSYSTEM_ID, &dev->subsystem_device); 2036 break; 2037 2038 default: /* unknown header */ 2039 pci_err(dev, "unknown header type %02x, ignoring device\n", 2040 dev->hdr_type); 2041 pci_release_of_node(dev); 2042 return -EIO; 2043 2044 bad: 2045 pci_err(dev, "ignoring class %#08x (doesn't match header type %02x)\n", 2046 dev->class, dev->hdr_type); 2047 dev->class = PCI_CLASS_NOT_DEFINED << 8; 2048 } 2049 2050 /* We found a fine healthy device, go go go... */ 2051 return 0; 2052} 2053 2054static void pci_configure_mps(struct pci_dev *dev) 2055{ 2056 struct pci_dev *bridge = pci_upstream_bridge(dev); 2057 int mps, mpss, p_mps, rc; 2058 2059 if (!pci_is_pcie(dev)) 2060 return; 2061 2062 /* MPS and MRRS fields are of type 'RsvdP' for VFs, short-circuit out */ 2063 if (dev->is_virtfn) 2064 return; 2065 2066 /* 2067 * For Root Complex Integrated Endpoints, program the maximum 2068 * supported value unless limited by the PCIE_BUS_PEER2PEER case. 2069 */ 2070 if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) { 2071 if (pcie_bus_config == PCIE_BUS_PEER2PEER) 2072 mps = 128; 2073 else 2074 mps = 128 << dev->pcie_mpss; 2075 rc = pcie_set_mps(dev, mps); 2076 if (rc) { 2077 pci_warn(dev, "can't set Max Payload Size to %d; if necessary, use \"pci=pcie_bus_safe\" and report a bug\n", 2078 mps); 2079 } 2080 return; 2081 } 2082 2083 if (!bridge || !pci_is_pcie(bridge)) 2084 return; 2085 2086 mps = pcie_get_mps(dev); 2087 p_mps = pcie_get_mps(bridge); 2088 2089 if (mps == p_mps) 2090 return; 2091 2092 if (pcie_bus_config == PCIE_BUS_TUNE_OFF) { 2093 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", 2094 mps, pci_name(bridge), p_mps); 2095 return; 2096 } 2097 2098 /* 2099 * Fancier MPS configuration is done later by 2100 * pcie_bus_configure_settings() 2101 */ 2102 if (pcie_bus_config != PCIE_BUS_DEFAULT) 2103 return; 2104 2105 mpss = 128 << dev->pcie_mpss; 2106 if (mpss < p_mps && pci_pcie_type(bridge) == PCI_EXP_TYPE_ROOT_PORT) { 2107 pcie_set_mps(bridge, mpss); 2108 pci_info(dev, "Upstream bridge's Max Payload Size set to %d (was %d, max %d)\n", 2109 mpss, p_mps, 128 << bridge->pcie_mpss); 2110 p_mps = pcie_get_mps(bridge); 2111 } 2112 2113 rc = pcie_set_mps(dev, p_mps); 2114 if (rc) { 2115 pci_warn(dev, "can't set Max Payload Size to %d; if necessary, use \"pci=pcie_bus_safe\" and report a bug\n", 2116 p_mps); 2117 return; 2118 } 2119 2120 pci_info(dev, "Max Payload Size set to %d (was %d, max %d)\n", 2121 p_mps, mps, mpss); 2122} 2123 2124int pci_configure_extended_tags(struct pci_dev *dev, void *ign) 2125{ 2126 struct pci_host_bridge *host; 2127 u32 cap; 2128 u16 ctl; 2129 int ret; 2130 2131 if (!pci_is_pcie(dev)) 2132 return 0; 2133 2134 ret = pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap); 2135 if (ret) 2136 return 0; 2137 2138 if (!(cap & PCI_EXP_DEVCAP_EXT_TAG)) 2139 return 0; 2140 2141 ret = pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl); 2142 if (ret) 2143 return 0; 2144 2145 host = pci_find_host_bridge(dev->bus); 2146 if (!host) 2147 return 0; 2148 2149 /* 2150 * If some device in the hierarchy doesn't handle Extended Tags 2151 * correctly, make sure they're disabled. 2152 */ 2153 if (host->no_ext_tags) { 2154 if (ctl & PCI_EXP_DEVCTL_EXT_TAG) { 2155 pci_info(dev, "disabling Extended Tags\n"); 2156 pcie_capability_clear_word(dev, PCI_EXP_DEVCTL, 2157 PCI_EXP_DEVCTL_EXT_TAG); 2158 } 2159 return 0; 2160 } 2161 2162 if (!(ctl & PCI_EXP_DEVCTL_EXT_TAG)) { 2163 pci_info(dev, "enabling Extended Tags\n"); 2164 pcie_capability_set_word(dev, PCI_EXP_DEVCTL, 2165 PCI_EXP_DEVCTL_EXT_TAG); 2166 } 2167 return 0; 2168} 2169 2170/** 2171 * pcie_relaxed_ordering_enabled - Probe for PCIe relaxed ordering enable 2172 * @dev: PCI device to query 2173 * 2174 * Returns true if the device has enabled relaxed ordering attribute. 2175 */ 2176bool pcie_relaxed_ordering_enabled(struct pci_dev *dev) 2177{ 2178 u16 v; 2179 2180 pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &v); 2181 2182 return !!(v & PCI_EXP_DEVCTL_RELAX_EN); 2183} 2184EXPORT_SYMBOL(pcie_relaxed_ordering_enabled); 2185 2186static void pci_configure_relaxed_ordering(struct pci_dev *dev) 2187{ 2188 struct pci_dev *root; 2189 2190 /* PCI_EXP_DEVCTL_RELAX_EN is RsvdP in VFs */ 2191 if (dev->is_virtfn) 2192 return; 2193 2194 if (!pcie_relaxed_ordering_enabled(dev)) 2195 return; 2196 2197 /* 2198 * For now, we only deal with Relaxed Ordering issues with Root 2199 * Ports. Peer-to-Peer DMA is another can of worms. 2200 */ 2201 root = pcie_find_root_port(dev); 2202 if (!root) 2203 return; 2204 2205 if (root->dev_flags & PCI_DEV_FLAGS_NO_RELAXED_ORDERING) { 2206 pcie_capability_clear_word(dev, PCI_EXP_DEVCTL, 2207 PCI_EXP_DEVCTL_RELAX_EN); 2208 pci_info(dev, "Relaxed Ordering disabled because the Root Port didn't support it\n"); 2209 } 2210} 2211 2212static void pci_configure_eetlp_prefix(struct pci_dev *dev) 2213{ 2214#ifdef CONFIG_PCI_PASID 2215 struct pci_dev *bridge; 2216 int pcie_type; 2217 u32 cap; 2218 2219 if (!pci_is_pcie(dev)) 2220 return; 2221 2222 pcie_capability_read_dword(dev, PCI_EXP_DEVCAP2, &cap); 2223 if (!(cap & PCI_EXP_DEVCAP2_EE_PREFIX)) 2224 return; 2225 2226 pcie_type = pci_pcie_type(dev); 2227 if (pcie_type == PCI_EXP_TYPE_ROOT_PORT || 2228 pcie_type == PCI_EXP_TYPE_RC_END) 2229 dev->eetlp_prefix_path = 1; 2230 else { 2231 bridge = pci_upstream_bridge(dev); 2232 if (bridge && bridge->eetlp_prefix_path) 2233 dev->eetlp_prefix_path = 1; 2234 } 2235#endif 2236} 2237 2238static void pci_configure_serr(struct pci_dev *dev) 2239{ 2240 u16 control; 2241 2242 if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { 2243 2244 /* 2245 * A bridge will not forward ERR_ messages coming from an 2246 * endpoint unless SERR# forwarding is enabled. 2247 */ 2248 pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &control); 2249 if (!(control & PCI_BRIDGE_CTL_SERR)) { 2250 control |= PCI_BRIDGE_CTL_SERR; 2251 pci_write_config_word(dev, PCI_BRIDGE_CONTROL, control); 2252 } 2253 } 2254} 2255 2256static void pci_configure_device(struct pci_dev *dev) 2257{ 2258 pci_configure_mps(dev); 2259 pci_configure_extended_tags(dev, NULL); 2260 pci_configure_relaxed_ordering(dev); 2261 pci_configure_ltr(dev); 2262 pci_configure_aspm_l1ss(dev); 2263 pci_configure_eetlp_prefix(dev); 2264 pci_configure_serr(dev); 2265 2266 pci_acpi_program_hp_params(dev); 2267} 2268 2269static void pci_release_capabilities(struct pci_dev *dev) 2270{ 2271 pci_aer_exit(dev); 2272 pci_rcec_exit(dev); 2273 pci_iov_release(dev); 2274 pci_free_cap_save_buffers(dev); 2275} 2276 2277/** 2278 * pci_release_dev - Free a PCI device structure when all users of it are 2279 * finished 2280 * @dev: device that's been disconnected 2281 * 2282 * Will be called only by the device core when all users of this PCI device are 2283 * done. 2284 */ 2285static void pci_release_dev(struct device *dev) 2286{ 2287 struct pci_dev *pci_dev; 2288 2289 pci_dev = to_pci_dev(dev); 2290 pci_release_capabilities(pci_dev); 2291 pci_release_of_node(pci_dev); 2292 pcibios_release_device(pci_dev); 2293 pci_bus_put(pci_dev->bus); 2294 kfree(pci_dev->driver_override); 2295 bitmap_free(pci_dev->dma_alias_mask); 2296 dev_dbg(dev, "device released\n"); 2297 kfree(pci_dev); 2298} 2299 2300static const struct device_type pci_dev_type = { 2301 .groups = pci_dev_attr_groups, 2302}; 2303 2304struct pci_dev *pci_alloc_dev(struct pci_bus *bus) 2305{ 2306 struct pci_dev *dev; 2307 2308 dev = kzalloc(sizeof(struct pci_dev), GFP_KERNEL); 2309 if (!dev) 2310 return NULL; 2311 2312 INIT_LIST_HEAD(&dev->bus_list); 2313 dev->dev.type = &pci_dev_type; 2314 dev->bus = pci_bus_get(bus); 2315 dev->driver_exclusive_resource = (struct resource) { 2316 .name = "PCI Exclusive", 2317 .start = 0, 2318 .end = -1, 2319 }; 2320 2321 spin_lock_init(&dev->pcie_cap_lock); 2322#ifdef CONFIG_PCI_MSI 2323 raw_spin_lock_init(&dev->msi_lock); 2324#endif 2325 return dev; 2326} 2327EXPORT_SYMBOL(pci_alloc_dev); 2328 2329static bool pci_bus_crs_vendor_id(u32 l) 2330{ 2331 return (l & 0xffff) == PCI_VENDOR_ID_PCI_SIG; 2332} 2333 2334static bool pci_bus_wait_crs(struct pci_bus *bus, int devfn, u32 *l, 2335 int timeout) 2336{ 2337 int delay = 1; 2338 2339 if (!pci_bus_crs_vendor_id(*l)) 2340 return true; /* not a CRS completion */ 2341 2342 if (!timeout) 2343 return false; /* CRS, but caller doesn't want to wait */ 2344 2345 /* 2346 * We got the reserved Vendor ID that indicates a completion with 2347 * Configuration Request Retry Status (CRS). Retry until we get a 2348 * valid Vendor ID or we time out. 2349 */ 2350 while (pci_bus_crs_vendor_id(*l)) { 2351 if (delay > timeout) { 2352 pr_warn("pci %04x:%02x:%02x.%d: not ready after %dms; giving up\n", 2353 pci_domain_nr(bus), bus->number, 2354 PCI_SLOT(devfn), PCI_FUNC(devfn), delay - 1); 2355 2356 return false; 2357 } 2358 if (delay >= 1000) 2359 pr_info("pci %04x:%02x:%02x.%d: not ready after %dms; waiting\n", 2360 pci_domain_nr(bus), bus->number, 2361 PCI_SLOT(devfn), PCI_FUNC(devfn), delay - 1); 2362 2363 msleep(delay); 2364 delay *= 2; 2365 2366 if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, l)) 2367 return false; 2368 } 2369 2370 if (delay >= 1000) 2371 pr_info("pci %04x:%02x:%02x.%d: ready after %dms\n", 2372 pci_domain_nr(bus), bus->number, 2373 PCI_SLOT(devfn), PCI_FUNC(devfn), delay - 1); 2374 2375 return true; 2376} 2377 2378bool pci_bus_generic_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l, 2379 int timeout) 2380{ 2381 if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, l)) 2382 return false; 2383 2384 /* Some broken boards return 0 or ~0 (PCI_ERROR_RESPONSE) if a slot is empty: */ 2385 if (PCI_POSSIBLE_ERROR(*l) || *l == 0x00000000 || 2386 *l == 0x0000ffff || *l == 0xffff0000) 2387 return false; 2388 2389 if (pci_bus_crs_vendor_id(*l)) 2390 return pci_bus_wait_crs(bus, devfn, l, timeout); 2391 2392 return true; 2393} 2394 2395bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l, 2396 int timeout) 2397{ 2398#ifdef CONFIG_PCI_QUIRKS 2399 struct pci_dev *bridge = bus->self; 2400 2401 /* 2402 * Certain IDT switches have an issue where they improperly trigger 2403 * ACS Source Validation errors on completions for config reads. 2404 */ 2405 if (bridge && bridge->vendor == PCI_VENDOR_ID_IDT && 2406 bridge->device == 0x80b5) 2407 return pci_idt_bus_quirk(bus, devfn, l, timeout); 2408#endif 2409 2410 return pci_bus_generic_read_dev_vendor_id(bus, devfn, l, timeout); 2411} 2412EXPORT_SYMBOL(pci_bus_read_dev_vendor_id); 2413 2414/* 2415 * Read the config data for a PCI device, sanity-check it, 2416 * and fill in the dev structure. 2417 */ 2418static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn) 2419{ 2420 struct pci_dev *dev; 2421 u32 l; 2422 2423 if (!pci_bus_read_dev_vendor_id(bus, devfn, &l, 60*1000)) 2424 return NULL; 2425 2426 dev = pci_alloc_dev(bus); 2427 if (!dev) 2428 return NULL; 2429 2430 dev->devfn = devfn; 2431 dev->vendor = l & 0xffff; 2432 dev->device = (l >> 16) & 0xffff; 2433 2434 if (pci_setup_device(dev)) { 2435 pci_bus_put(dev->bus); 2436 kfree(dev); 2437 return NULL; 2438 } 2439 2440 return dev; 2441} 2442 2443void pcie_report_downtraining(struct pci_dev *dev) 2444{ 2445 if (!pci_is_pcie(dev)) 2446 return; 2447 2448 /* Look from the device up to avoid downstream ports with no devices */ 2449 if ((pci_pcie_type(dev) != PCI_EXP_TYPE_ENDPOINT) && 2450 (pci_pcie_type(dev) != PCI_EXP_TYPE_LEG_END) && 2451 (pci_pcie_type(dev) != PCI_EXP_TYPE_UPSTREAM)) 2452 return; 2453 2454 /* Multi-function PCIe devices share the same link/status */ 2455 if (PCI_FUNC(dev->devfn) != 0 || dev->is_virtfn) 2456 return; 2457 2458 /* Print link status only if the device is constrained by the fabric */ 2459 __pcie_print_link_status(dev, false); 2460} 2461 2462static void pci_init_capabilities(struct pci_dev *dev) 2463{ 2464 pci_ea_init(dev); /* Enhanced Allocation */ 2465 pci_msi_init(dev); /* Disable MSI */ 2466 pci_msix_init(dev); /* Disable MSI-X */ 2467 2468 /* Buffers for saving PCIe and PCI-X capabilities */ 2469 pci_allocate_cap_save_buffers(dev); 2470 2471 pci_pm_init(dev); /* Power Management */ 2472 pci_vpd_init(dev); /* Vital Product Data */ 2473 pci_configure_ari(dev); /* Alternative Routing-ID Forwarding */ 2474 pci_iov_init(dev); /* Single Root I/O Virtualization */ 2475 pci_ats_init(dev); /* Address Translation Services */ 2476 pci_pri_init(dev); /* Page Request Interface */ 2477 pci_pasid_init(dev); /* Process Address Space ID */ 2478 pci_acs_init(dev); /* Access Control Services */ 2479 pci_ptm_init(dev); /* Precision Time Measurement */ 2480 pci_aer_init(dev); /* Advanced Error Reporting */ 2481 pci_dpc_init(dev); /* Downstream Port Containment */ 2482 pci_rcec_init(dev); /* Root Complex Event Collector */ 2483 pci_doe_init(dev); /* Data Object Exchange */ 2484 2485 pcie_report_downtraining(dev); 2486 pci_init_reset_methods(dev); 2487} 2488 2489/* 2490 * This is the equivalent of pci_host_bridge_msi_domain() that acts on 2491 * devices. Firmware interfaces that can select the MSI domain on a 2492 * per-device basis should be called from here. 2493 */ 2494static struct irq_domain *pci_dev_msi_domain(struct pci_dev *dev) 2495{ 2496 struct irq_domain *d; 2497 2498 /* 2499 * If a domain has been set through the pcibios_device_add() 2500 * callback, then this is the one (platform code knows best). 2501 */ 2502 d = dev_get_msi_domain(&dev->dev); 2503 if (d) 2504 return d; 2505 2506 /* 2507 * Let's see if we have a firmware interface able to provide 2508 * the domain. 2509 */ 2510 d = pci_msi_get_device_domain(dev); 2511 if (d) 2512 return d; 2513 2514 return NULL; 2515} 2516 2517static void pci_set_msi_domain(struct pci_dev *dev) 2518{ 2519 struct irq_domain *d; 2520 2521 /* 2522 * If the platform or firmware interfaces cannot supply a 2523 * device-specific MSI domain, then inherit the default domain 2524 * from the host bridge itself. 2525 */ 2526 d = pci_dev_msi_domain(dev); 2527 if (!d) 2528 d = dev_get_msi_domain(&dev->bus->dev); 2529 2530 dev_set_msi_domain(&dev->dev, d); 2531} 2532 2533void pci_device_add(struct pci_dev *dev, struct pci_bus *bus) 2534{ 2535 int ret; 2536 2537 pci_configure_device(dev); 2538 2539 device_initialize(&dev->dev); 2540 dev->dev.release = pci_release_dev; 2541 2542 set_dev_node(&dev->dev, pcibus_to_node(bus)); 2543 dev->dev.dma_mask = &dev->dma_mask; 2544 dev->dev.dma_parms = &dev->dma_parms; 2545 dev->dev.coherent_dma_mask = 0xffffffffull; 2546 2547 dma_set_max_seg_size(&dev->dev, 65536); 2548 dma_set_seg_boundary(&dev->dev, 0xffffffff); 2549 2550 pcie_failed_link_retrain(dev); 2551 2552 /* Fix up broken headers */ 2553 pci_fixup_device(pci_fixup_header, dev); 2554 2555 pci_reassigndev_resource_alignment(dev); 2556 2557 dev->state_saved = false; 2558 2559 pci_init_capabilities(dev); 2560 2561 /* 2562 * Add the device to our list of discovered devices 2563 * and the bus list for fixup functions, etc. 2564 */ 2565 down_write(&pci_bus_sem); 2566 list_add_tail(&dev->bus_list, &bus->devices); 2567 up_write(&pci_bus_sem); 2568 2569 ret = pcibios_device_add(dev); 2570 WARN_ON(ret < 0); 2571 2572 /* Set up MSI IRQ domain */ 2573 pci_set_msi_domain(dev); 2574 2575 /* Notifier could use PCI capabilities */ 2576 dev->match_driver = false; 2577 ret = device_add(&dev->dev); 2578 WARN_ON(ret < 0); 2579} 2580 2581struct pci_dev *pci_scan_single_device(struct pci_bus *bus, int devfn) 2582{ 2583 struct pci_dev *dev; 2584 2585 dev = pci_get_slot(bus, devfn); 2586 if (dev) { 2587 pci_dev_put(dev); 2588 return dev; 2589 } 2590 2591 dev = pci_scan_device(bus, devfn); 2592 if (!dev) 2593 return NULL; 2594 2595 pci_device_add(dev, bus); 2596 2597 return dev; 2598} 2599EXPORT_SYMBOL(pci_scan_single_device); 2600 2601static int next_ari_fn(struct pci_bus *bus, struct pci_dev *dev, int fn) 2602{ 2603 int pos; 2604 u16 cap = 0; 2605 unsigned int next_fn; 2606 2607 if (!dev) 2608 return -ENODEV; 2609 2610 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI); 2611 if (!pos) 2612 return -ENODEV; 2613 2614 pci_read_config_word(dev, pos + PCI_ARI_CAP, &cap); 2615 next_fn = PCI_ARI_CAP_NFN(cap); 2616 if (next_fn <= fn) 2617 return -ENODEV; /* protect against malformed list */ 2618 2619 return next_fn; 2620} 2621 2622static int next_fn(struct pci_bus *bus, struct pci_dev *dev, int fn) 2623{ 2624 if (pci_ari_enabled(bus)) 2625 return next_ari_fn(bus, dev, fn); 2626 2627 if (fn >= 7) 2628 return -ENODEV; 2629 /* only multifunction devices may have more functions */ 2630 if (dev && !dev->multifunction) 2631 return -ENODEV; 2632 2633 return fn + 1; 2634} 2635 2636static int only_one_child(struct pci_bus *bus) 2637{ 2638 struct pci_dev *bridge = bus->self; 2639 2640 /* 2641 * Systems with unusual topologies set PCI_SCAN_ALL_PCIE_DEVS so 2642 * we scan for all possible devices, not just Device 0. 2643 */ 2644 if (pci_has_flag(PCI_SCAN_ALL_PCIE_DEVS)) 2645 return 0; 2646 2647 /* 2648 * A PCIe Downstream Port normally leads to a Link with only Device 2649 * 0 on it (PCIe spec r3.1, sec 7.3.1). As an optimization, scan 2650 * only for Device 0 in that situation. 2651 */ 2652 if (bridge && pci_is_pcie(bridge) && pcie_downstream_port(bridge)) 2653 return 1; 2654 2655 return 0; 2656} 2657 2658/** 2659 * pci_scan_slot - Scan a PCI slot on a bus for devices 2660 * @bus: PCI bus to scan 2661 * @devfn: slot number to scan (must have zero function) 2662 * 2663 * Scan a PCI slot on the specified PCI bus for devices, adding 2664 * discovered devices to the @bus->devices list. New devices 2665 * will not have is_added set. 2666 * 2667 * Returns the number of new devices found. 2668 */ 2669int pci_scan_slot(struct pci_bus *bus, int devfn) 2670{ 2671 struct pci_dev *dev; 2672 int fn = 0, nr = 0; 2673 2674 if (only_one_child(bus) && (devfn > 0)) 2675 return 0; /* Already scanned the entire slot */ 2676 2677 do { 2678 dev = pci_scan_single_device(bus, devfn + fn); 2679 if (dev) { 2680 if (!pci_dev_is_added(dev)) 2681 nr++; 2682 if (fn > 0) 2683 dev->multifunction = 1; 2684 } else if (fn == 0) { 2685 /* 2686 * Function 0 is required unless we are running on 2687 * a hypervisor that passes through individual PCI 2688 * functions. 2689 */ 2690 if (!hypervisor_isolated_pci_functions()) 2691 break; 2692 } 2693 fn = next_fn(bus, dev, fn); 2694 } while (fn >= 0); 2695 2696 /* Only one slot has PCIe device */ 2697 if (bus->self && nr) 2698 pcie_aspm_init_link_state(bus->self); 2699 2700 return nr; 2701} 2702EXPORT_SYMBOL(pci_scan_slot); 2703 2704static int pcie_find_smpss(struct pci_dev *dev, void *data) 2705{ 2706 u8 *smpss = data; 2707 2708 if (!pci_is_pcie(dev)) 2709 return 0; 2710 2711 /* 2712 * We don't have a way to change MPS settings on devices that have 2713 * drivers attached. A hot-added device might support only the minimum 2714 * MPS setting (MPS=128). Therefore, if the fabric contains a bridge 2715 * where devices may be hot-added, we limit the fabric MPS to 128 so 2716 * hot-added devices will work correctly. 2717 * 2718 * However, if we hot-add a device to a slot directly below a Root 2719 * Port, it's impossible for there to be other existing devices below 2720 * the port. We don't limit the MPS in this case because we can 2721 * reconfigure MPS on both the Root Port and the hot-added device, 2722 * and there are no other devices involved. 2723 * 2724 * Note that this PCIE_BUS_SAFE path assumes no peer-to-peer DMA. 2725 */ 2726 if (dev->is_hotplug_bridge && 2727 pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT) 2728 *smpss = 0; 2729 2730 if (*smpss > dev->pcie_mpss) 2731 *smpss = dev->pcie_mpss; 2732 2733 return 0; 2734} 2735 2736static void pcie_write_mps(struct pci_dev *dev, int mps) 2737{ 2738 int rc; 2739 2740 if (pcie_bus_config == PCIE_BUS_PERFORMANCE) { 2741 mps = 128 << dev->pcie_mpss; 2742 2743 if (pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT && 2744 dev->bus->self) 2745 2746 /* 2747 * For "Performance", the assumption is made that 2748 * downstream communication will never be larger than 2749 * the MRRS. So, the MPS only needs to be configured 2750 * for the upstream communication. This being the case, 2751 * walk from the top down and set the MPS of the child 2752 * to that of the parent bus. 2753 * 2754 * Configure the device MPS with the smaller of the 2755 * device MPSS or the bridge MPS (which is assumed to be 2756 * properly configured at this point to the largest 2757 * allowable MPS based on its parent bus). 2758 */ 2759 mps = min(mps, pcie_get_mps(dev->bus->self)); 2760 } 2761 2762 rc = pcie_set_mps(dev, mps); 2763 if (rc) 2764 pci_err(dev, "Failed attempting to set the MPS\n"); 2765} 2766 2767static void pcie_write_mrrs(struct pci_dev *dev) 2768{ 2769 int rc, mrrs; 2770 2771 /* 2772 * In the "safe" case, do not configure the MRRS. There appear to be 2773 * issues with setting MRRS to 0 on a number of devices. 2774 */ 2775 if (pcie_bus_config != PCIE_BUS_PERFORMANCE) 2776 return; 2777 2778 /* 2779 * For max performance, the MRRS must be set to the largest supported 2780 * value. However, it cannot be configured larger than the MPS the 2781 * device or the bus can support. This should already be properly 2782 * configured by a prior call to pcie_write_mps(). 2783 */ 2784 mrrs = pcie_get_mps(dev); 2785 2786 /* 2787 * MRRS is a R/W register. Invalid values can be written, but a 2788 * subsequent read will verify if the value is acceptable or not. 2789 * If the MRRS value provided is not acceptable (e.g., too large), 2790 * shrink the value until it is acceptable to the HW. 2791 */ 2792 while (mrrs != pcie_get_readrq(dev) && mrrs >= 128) { 2793 rc = pcie_set_readrq(dev, mrrs); 2794 if (!rc) 2795 break; 2796 2797 pci_warn(dev, "Failed attempting to set the MRRS\n"); 2798 mrrs /= 2; 2799 } 2800 2801 if (mrrs < 128) 2802 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"); 2803} 2804 2805static int pcie_bus_configure_set(struct pci_dev *dev, void *data) 2806{ 2807 int mps, orig_mps; 2808 2809 if (!pci_is_pcie(dev)) 2810 return 0; 2811 2812 if (pcie_bus_config == PCIE_BUS_TUNE_OFF || 2813 pcie_bus_config == PCIE_BUS_DEFAULT) 2814 return 0; 2815 2816 mps = 128 << *(u8 *)data; 2817 orig_mps = pcie_get_mps(dev); 2818 2819 pcie_write_mps(dev, mps); 2820 pcie_write_mrrs(dev); 2821 2822 pci_info(dev, "Max Payload Size set to %4d/%4d (was %4d), Max Read Rq %4d\n", 2823 pcie_get_mps(dev), 128 << dev->pcie_mpss, 2824 orig_mps, pcie_get_readrq(dev)); 2825 2826 return 0; 2827} 2828 2829/* 2830 * pcie_bus_configure_settings() requires that pci_walk_bus work in a top-down, 2831 * parents then children fashion. If this changes, then this code will not 2832 * work as designed. 2833 */ 2834void pcie_bus_configure_settings(struct pci_bus *bus) 2835{ 2836 u8 smpss = 0; 2837 2838 if (!bus->self) 2839 return; 2840 2841 if (!pci_is_pcie(bus->self)) 2842 return; 2843 2844 /* 2845 * FIXME - Peer to peer DMA is possible, though the endpoint would need 2846 * to be aware of the MPS of the destination. To work around this, 2847 * simply force the MPS of the entire system to the smallest possible. 2848 */ 2849 if (pcie_bus_config == PCIE_BUS_PEER2PEER) 2850 smpss = 0; 2851 2852 if (pcie_bus_config == PCIE_BUS_SAFE) { 2853 smpss = bus->self->pcie_mpss; 2854 2855 pcie_find_smpss(bus->self, &smpss); 2856 pci_walk_bus(bus, pcie_find_smpss, &smpss); 2857 } 2858 2859 pcie_bus_configure_set(bus->self, &smpss); 2860 pci_walk_bus(bus, pcie_bus_configure_set, &smpss); 2861} 2862EXPORT_SYMBOL_GPL(pcie_bus_configure_settings); 2863 2864/* 2865 * Called after each bus is probed, but before its children are examined. This 2866 * is marked as __weak because multiple architectures define it. 2867 */ 2868void __weak pcibios_fixup_bus(struct pci_bus *bus) 2869{ 2870 /* nothing to do, expected to be removed in the future */ 2871} 2872 2873/** 2874 * pci_scan_child_bus_extend() - Scan devices below a bus 2875 * @bus: Bus to scan for devices 2876 * @available_buses: Total number of buses available (%0 does not try to 2877 * extend beyond the minimal) 2878 * 2879 * Scans devices below @bus including subordinate buses. Returns new 2880 * subordinate number including all the found devices. Passing 2881 * @available_buses causes the remaining bus space to be distributed 2882 * equally between hotplug-capable bridges to allow future extension of the 2883 * hierarchy. 2884 */ 2885static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus, 2886 unsigned int available_buses) 2887{ 2888 unsigned int used_buses, normal_bridges = 0, hotplug_bridges = 0; 2889 unsigned int start = bus->busn_res.start; 2890 unsigned int devfn, cmax, max = start; 2891 struct pci_dev *dev; 2892 2893 dev_dbg(&bus->dev, "scanning bus\n"); 2894 2895 /* Go find them, Rover! */ 2896 for (devfn = 0; devfn < 256; devfn += 8) 2897 pci_scan_slot(bus, devfn); 2898 2899 /* Reserve buses for SR-IOV capability */ 2900 used_buses = pci_iov_bus_range(bus); 2901 max += used_buses; 2902 2903 /* 2904 * After performing arch-dependent fixup of the bus, look behind 2905 * all PCI-to-PCI bridges on this bus. 2906 */ 2907 if (!bus->is_added) { 2908 dev_dbg(&bus->dev, "fixups for bus\n"); 2909 pcibios_fixup_bus(bus); 2910 bus->is_added = 1; 2911 } 2912 2913 /* 2914 * Calculate how many hotplug bridges and normal bridges there 2915 * are on this bus. We will distribute the additional available 2916 * buses between hotplug bridges. 2917 */ 2918 for_each_pci_bridge(dev, bus) { 2919 if (dev->is_hotplug_bridge) 2920 hotplug_bridges++; 2921 else 2922 normal_bridges++; 2923 } 2924 2925 /* 2926 * Scan bridges that are already configured. We don't touch them 2927 * unless they are misconfigured (which will be done in the second 2928 * scan below). 2929 */ 2930 for_each_pci_bridge(dev, bus) { 2931 cmax = max; 2932 max = pci_scan_bridge_extend(bus, dev, max, 0, 0); 2933 2934 /* 2935 * Reserve one bus for each bridge now to avoid extending 2936 * hotplug bridges too much during the second scan below. 2937 */ 2938 used_buses++; 2939 if (max - cmax > 1) 2940 used_buses += max - cmax - 1; 2941 } 2942 2943 /* Scan bridges that need to be reconfigured */ 2944 for_each_pci_bridge(dev, bus) { 2945 unsigned int buses = 0; 2946 2947 if (!hotplug_bridges && normal_bridges == 1) { 2948 /* 2949 * There is only one bridge on the bus (upstream 2950 * port) so it gets all available buses which it 2951 * can then distribute to the possible hotplug 2952 * bridges below. 2953 */ 2954 buses = available_buses; 2955 } else if (dev->is_hotplug_bridge) { 2956 /* 2957 * Distribute the extra buses between hotplug 2958 * bridges if any. 2959 */ 2960 buses = available_buses / hotplug_bridges; 2961 buses = min(buses, available_buses - used_buses + 1); 2962 } 2963 2964 cmax = max; 2965 max = pci_scan_bridge_extend(bus, dev, cmax, buses, 1); 2966 /* One bus is already accounted so don't add it again */ 2967 if (max - cmax > 1) 2968 used_buses += max - cmax - 1; 2969 } 2970 2971 /* 2972 * Make sure a hotplug bridge has at least the minimum requested 2973 * number of buses but allow it to grow up to the maximum available 2974 * bus number if there is room. 2975 */ 2976 if (bus->self && bus->self->is_hotplug_bridge) { 2977 used_buses = max_t(unsigned int, available_buses, 2978 pci_hotplug_bus_size - 1); 2979 if (max - start < used_buses) { 2980 max = start + used_buses; 2981 2982 /* Do not allocate more buses than we have room left */ 2983 if (max > bus->busn_res.end) 2984 max = bus->busn_res.end; 2985 2986 dev_dbg(&bus->dev, "%pR extended by %#02x\n", 2987 &bus->busn_res, max - start); 2988 } 2989 } 2990 2991 /* 2992 * We've scanned the bus and so we know all about what's on 2993 * the other side of any bridges that may be on this bus plus 2994 * any devices. 2995 * 2996 * Return how far we've got finding sub-buses. 2997 */ 2998 dev_dbg(&bus->dev, "bus scan returning with max=%02x\n", max); 2999 return max; 3000} 3001 3002/** 3003 * pci_scan_child_bus() - Scan devices below a bus 3004 * @bus: Bus to scan for devices 3005 * 3006 * Scans devices below @bus including subordinate buses. Returns new 3007 * subordinate number including all the found devices. 3008 */ 3009unsigned int pci_scan_child_bus(struct pci_bus *bus) 3010{ 3011 return pci_scan_child_bus_extend(bus, 0); 3012} 3013EXPORT_SYMBOL_GPL(pci_scan_child_bus); 3014 3015/** 3016 * pcibios_root_bridge_prepare - Platform-specific host bridge setup 3017 * @bridge: Host bridge to set up 3018 * 3019 * Default empty implementation. Replace with an architecture-specific setup 3020 * routine, if necessary. 3021 */ 3022int __weak pcibios_root_bridge_prepare(struct pci_host_bridge *bridge) 3023{ 3024 return 0; 3025} 3026 3027void __weak pcibios_add_bus(struct pci_bus *bus) 3028{ 3029} 3030 3031void __weak pcibios_remove_bus(struct pci_bus *bus) 3032{ 3033} 3034 3035struct pci_bus *pci_create_root_bus(struct device *parent, int bus, 3036 struct pci_ops *ops, void *sysdata, struct list_head *resources) 3037{ 3038 int error; 3039 struct pci_host_bridge *bridge; 3040 3041 bridge = pci_alloc_host_bridge(0); 3042 if (!bridge) 3043 return NULL; 3044 3045 bridge->dev.parent = parent; 3046 3047 list_splice_init(resources, &bridge->windows); 3048 bridge->sysdata = sysdata; 3049 bridge->busnr = bus; 3050 bridge->ops = ops; 3051 3052 error = pci_register_host_bridge(bridge); 3053 if (error < 0) 3054 goto err_out; 3055 3056 return bridge->bus; 3057 3058err_out: 3059 put_device(&bridge->dev); 3060 return NULL; 3061} 3062EXPORT_SYMBOL_GPL(pci_create_root_bus); 3063 3064int pci_host_probe(struct pci_host_bridge *bridge) 3065{ 3066 struct pci_bus *bus, *child; 3067 int ret; 3068 3069 ret = pci_scan_root_bus_bridge(bridge); 3070 if (ret < 0) { 3071 dev_err(bridge->dev.parent, "Scanning root bridge failed"); 3072 return ret; 3073 } 3074 3075 bus = bridge->bus; 3076 3077 /* 3078 * We insert PCI resources into the iomem_resource and 3079 * ioport_resource trees in either pci_bus_claim_resources() 3080 * or pci_bus_assign_resources(). 3081 */ 3082 if (pci_has_flag(PCI_PROBE_ONLY)) { 3083 pci_bus_claim_resources(bus); 3084 } else { 3085 pci_bus_size_bridges(bus); 3086 pci_bus_assign_resources(bus); 3087 3088 list_for_each_entry(child, &bus->children, node) 3089 pcie_bus_configure_settings(child); 3090 } 3091 3092 pci_bus_add_devices(bus); 3093 return 0; 3094} 3095EXPORT_SYMBOL_GPL(pci_host_probe); 3096 3097int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int bus_max) 3098{ 3099 struct resource *res = &b->busn_res; 3100 struct resource *parent_res, *conflict; 3101 3102 res->start = bus; 3103 res->end = bus_max; 3104 res->flags = IORESOURCE_BUS; 3105 3106 if (!pci_is_root_bus(b)) 3107 parent_res = &b->parent->busn_res; 3108 else { 3109 parent_res = get_pci_domain_busn_res(pci_domain_nr(b)); 3110 res->flags |= IORESOURCE_PCI_FIXED; 3111 } 3112 3113 conflict = request_resource_conflict(parent_res, res); 3114 3115 if (conflict) 3116 dev_info(&b->dev, 3117 "busn_res: can not insert %pR under %s%pR (conflicts with %s %pR)\n", 3118 res, pci_is_root_bus(b) ? "domain " : "", 3119 parent_res, conflict->name, conflict); 3120 3121 return conflict == NULL; 3122} 3123 3124int pci_bus_update_busn_res_end(struct pci_bus *b, int bus_max) 3125{ 3126 struct resource *res = &b->busn_res; 3127 struct resource old_res = *res; 3128 resource_size_t size; 3129 int ret; 3130 3131 if (res->start > bus_max) 3132 return -EINVAL; 3133 3134 size = bus_max - res->start + 1; 3135 ret = adjust_resource(res, res->start, size); 3136 dev_info(&b->dev, "busn_res: %pR end %s updated to %02x\n", 3137 &old_res, ret ? "can not be" : "is", bus_max); 3138 3139 if (!ret && !res->parent) 3140 pci_bus_insert_busn_res(b, res->start, res->end); 3141 3142 return ret; 3143} 3144 3145void pci_bus_release_busn_res(struct pci_bus *b) 3146{ 3147 struct resource *res = &b->busn_res; 3148 int ret; 3149 3150 if (!res->flags || !res->parent) 3151 return; 3152 3153 ret = release_resource(res); 3154 dev_info(&b->dev, "busn_res: %pR %s released\n", 3155 res, ret ? "can not be" : "is"); 3156} 3157 3158int pci_scan_root_bus_bridge(struct pci_host_bridge *bridge) 3159{ 3160 struct resource_entry *window; 3161 bool found = false; 3162 struct pci_bus *b; 3163 int max, bus, ret; 3164 3165 if (!bridge) 3166 return -EINVAL; 3167 3168 resource_list_for_each_entry(window, &bridge->windows) 3169 if (window->res->flags & IORESOURCE_BUS) { 3170 bridge->busnr = window->res->start; 3171 found = true; 3172 break; 3173 } 3174 3175 ret = pci_register_host_bridge(bridge); 3176 if (ret < 0) 3177 return ret; 3178 3179 b = bridge->bus; 3180 bus = bridge->busnr; 3181 3182 if (!found) { 3183 dev_info(&b->dev, 3184 "No busn resource found for root bus, will use [bus %02x-ff]\n", 3185 bus); 3186 pci_bus_insert_busn_res(b, bus, 255); 3187 } 3188 3189 max = pci_scan_child_bus(b); 3190 3191 if (!found) 3192 pci_bus_update_busn_res_end(b, max); 3193 3194 return 0; 3195} 3196EXPORT_SYMBOL(pci_scan_root_bus_bridge); 3197 3198struct pci_bus *pci_scan_root_bus(struct device *parent, int bus, 3199 struct pci_ops *ops, void *sysdata, struct list_head *resources) 3200{ 3201 struct resource_entry *window; 3202 bool found = false; 3203 struct pci_bus *b; 3204 int max; 3205 3206 resource_list_for_each_entry(window, resources) 3207 if (window->res->flags & IORESOURCE_BUS) { 3208 found = true; 3209 break; 3210 } 3211 3212 b = pci_create_root_bus(parent, bus, ops, sysdata, resources); 3213 if (!b) 3214 return NULL; 3215 3216 if (!found) { 3217 dev_info(&b->dev, 3218 "No busn resource found for root bus, will use [bus %02x-ff]\n", 3219 bus); 3220 pci_bus_insert_busn_res(b, bus, 255); 3221 } 3222 3223 max = pci_scan_child_bus(b); 3224 3225 if (!found) 3226 pci_bus_update_busn_res_end(b, max); 3227 3228 return b; 3229} 3230EXPORT_SYMBOL(pci_scan_root_bus); 3231 3232struct pci_bus *pci_scan_bus(int bus, struct pci_ops *ops, 3233 void *sysdata) 3234{ 3235 LIST_HEAD(resources); 3236 struct pci_bus *b; 3237 3238 pci_add_resource(&resources, &ioport_resource); 3239 pci_add_resource(&resources, &iomem_resource); 3240 pci_add_resource(&resources, &busn_resource); 3241 b = pci_create_root_bus(NULL, bus, ops, sysdata, &resources); 3242 if (b) { 3243 pci_scan_child_bus(b); 3244 } else { 3245 pci_free_resource_list(&resources); 3246 } 3247 return b; 3248} 3249EXPORT_SYMBOL(pci_scan_bus); 3250 3251/** 3252 * pci_rescan_bus_bridge_resize - Scan a PCI bus for devices 3253 * @bridge: PCI bridge for the bus to scan 3254 * 3255 * Scan a PCI bus and child buses for new devices, add them, 3256 * and enable them, resizing bridge mmio/io resource if necessary 3257 * and possible. The caller must ensure the child devices are already 3258 * removed for resizing to occur. 3259 * 3260 * Returns the max number of subordinate bus discovered. 3261 */ 3262unsigned int pci_rescan_bus_bridge_resize(struct pci_dev *bridge) 3263{ 3264 unsigned int max; 3265 struct pci_bus *bus = bridge->subordinate; 3266 3267 max = pci_scan_child_bus(bus); 3268 3269 pci_assign_unassigned_bridge_resources(bridge); 3270 3271 pci_bus_add_devices(bus); 3272 3273 return max; 3274} 3275 3276/** 3277 * pci_rescan_bus - Scan a PCI bus for devices 3278 * @bus: PCI bus to scan 3279 * 3280 * Scan a PCI bus and child buses for new devices, add them, 3281 * and enable them. 3282 * 3283 * Returns the max number of subordinate bus discovered. 3284 */ 3285unsigned int pci_rescan_bus(struct pci_bus *bus) 3286{ 3287 unsigned int max; 3288 3289 max = pci_scan_child_bus(bus); 3290 pci_assign_unassigned_bus_resources(bus); 3291 pci_bus_add_devices(bus); 3292 3293 return max; 3294} 3295EXPORT_SYMBOL_GPL(pci_rescan_bus); 3296 3297/* 3298 * pci_rescan_bus(), pci_rescan_bus_bridge_resize() and PCI device removal 3299 * routines should always be executed under this mutex. 3300 */ 3301static DEFINE_MUTEX(pci_rescan_remove_lock); 3302 3303void pci_lock_rescan_remove(void) 3304{ 3305 mutex_lock(&pci_rescan_remove_lock); 3306} 3307EXPORT_SYMBOL_GPL(pci_lock_rescan_remove); 3308 3309void pci_unlock_rescan_remove(void) 3310{ 3311 mutex_unlock(&pci_rescan_remove_lock); 3312} 3313EXPORT_SYMBOL_GPL(pci_unlock_rescan_remove); 3314 3315static int __init pci_sort_bf_cmp(const struct device *d_a, 3316 const struct device *d_b) 3317{ 3318 const struct pci_dev *a = to_pci_dev(d_a); 3319 const struct pci_dev *b = to_pci_dev(d_b); 3320 3321 if (pci_domain_nr(a->bus) < pci_domain_nr(b->bus)) return -1; 3322 else if (pci_domain_nr(a->bus) > pci_domain_nr(b->bus)) return 1; 3323 3324 if (a->bus->number < b->bus->number) return -1; 3325 else if (a->bus->number > b->bus->number) return 1; 3326 3327 if (a->devfn < b->devfn) return -1; 3328 else if (a->devfn > b->devfn) return 1; 3329 3330 return 0; 3331} 3332 3333void __init pci_sort_breadthfirst(void) 3334{ 3335 bus_sort_breadthfirst(&pci_bus_type, &pci_sort_bf_cmp); 3336} 3337 3338int pci_hp_add_bridge(struct pci_dev *dev) 3339{ 3340 struct pci_bus *parent = dev->bus; 3341 int busnr, start = parent->busn_res.start; 3342 unsigned int available_buses = 0; 3343 int end = parent->busn_res.end; 3344 3345 for (busnr = start; busnr <= end; busnr++) { 3346 if (!pci_find_bus(pci_domain_nr(parent), busnr)) 3347 break; 3348 } 3349 if (busnr-- > end) { 3350 pci_err(dev, "No bus number available for hot-added bridge\n"); 3351 return -1; 3352 } 3353 3354 /* Scan bridges that are already configured */ 3355 busnr = pci_scan_bridge(parent, dev, busnr, 0); 3356 3357 /* 3358 * Distribute the available bus numbers between hotplug-capable 3359 * bridges to make extending the chain later possible. 3360 */ 3361 available_buses = end - busnr; 3362 3363 /* Scan bridges that need to be reconfigured */ 3364 pci_scan_bridge_extend(parent, dev, busnr, available_buses, 1); 3365 3366 if (!dev->subordinate) 3367 return -1; 3368 3369 return 0; 3370} 3371EXPORT_SYMBOL_GPL(pci_hp_add_bridge); 3372