arch/x86/pci/mmconfig-shared.c

   1 /*
   2  * mmconfig-shared.c - Low-level direct PCI config space access via
   3  *                     MMCONFIG - common code between i386 and x86-64.
   4  *
   5  * This code does:
   6  * - known chipset handling
   7  * - ACPI decoding and validation
   8  *
   9  * Per-architecture code takes care of the mappings and accesses
  10  * themselves.
  11  */
  12
  13 #include <linux/pci.h>
  14 #include <linux/init.h>
  15 #include <linux/acpi.h>
  16 #include <linux/sfi_acpi.h>
  17 #include <linux/bitmap.h>
  18 #include <linux/dmi.h>
  19 #include <linux/slab.h>
  20 #include <asm/e820.h>
  21 #include <asm/pci_x86.h>
  22 #include <asm/acpi.h>
  23
  24 #define PREFIX "PCI: "
  25
  26 /* Indicate if the mmcfg resources have been placed into the resource table. */
  27 static int __initdata pci_mmcfg_resources_inserted;
  28
  29 LIST_HEAD(pci_mmcfg_list);
  30
  31 static __init void pci_mmconfig_remove(struct pci_mmcfg_region *cfg)
  32 {
  33         if (cfg->res.parent)
  34                 release_resource(&cfg->res);
  35         list_del(&cfg->list);
  36         kfree(cfg);
  37 }
  38
  39 static __init void free_all_mmcfg(void)
  40 {
  41         struct pci_mmcfg_region *cfg, *tmp;
  42
  43         pci_mmcfg_arch_free();
  44         list_for_each_entry_safe(cfg, tmp, &pci_mmcfg_list, list)
  45                 pci_mmconfig_remove(cfg);
  46 }
  47
  48 static __init void list_add_sorted(struct pci_mmcfg_region *new)
  49 {
  50         struct pci_mmcfg_region *cfg;
  51
  52         /* keep list sorted by segment and starting bus number */
  53         list_for_each_entry(cfg, &pci_mmcfg_list, list) {
  54                 if (cfg->segment > new->segment ||
  55                     (cfg->segment == new->segment &&
  56                      cfg->start_bus >= new->start_bus)) {
  57                         list_add_tail(&new->list, &cfg->list);
  58                         return;
  59                 }
  60         }
  61         list_add_tail(&new->list, &pci_mmcfg_list);
  62 }
  63
  64 static __init struct pci_mmcfg_region *pci_mmconfig_add(int segment, int start,
  65                                                         int end, u64 addr)
  66 {
  67         struct pci_mmcfg_region *new;
  68         struct resource *res;
  69
  70         if (addr == 0)
  71                 return NULL;
  72
  73         new = kzalloc(sizeof(*new), GFP_KERNEL);
  74         if (!new)
  75                 return NULL;
  76
  77         new->address = addr;
  78         new->segment = segment;
  79         new->start_bus = start;
  80         new->end_bus = end;
  81
  82         list_add_sorted(new);
  83
  84         res = &new->res;
  85         res->start = addr + PCI_MMCFG_BUS_OFFSET(start);
  86         res->end = addr + PCI_MMCFG_BUS_OFFSET(end + 1) - 1;
  87         res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
  88         snprintf(new->name, PCI_MMCFG_RESOURCE_NAME_LEN,
  89                  "PCI MMCONFIG %04x [bus %02x-%02x]", segment, start, end);
  90         res->name = new->name;
  91
  92         printk(KERN_INFO PREFIX "MMCONFIG for domain %04x [bus %02x-%02x] at "
  93                "%pR (base %#lx)\n", segment, start, end, &new->res,
  94                (unsigned long) addr);
  95
  96         return new;
  97 }
  98
  99 struct pci_mmcfg_region *pci_mmconfig_lookup(int segment, int bus)
 100 {
 101         struct pci_mmcfg_region *cfg;
 102
 103         list_for_each_entry(cfg, &pci_mmcfg_list, list)
 104                 if (cfg->segment == segment &&
 105                     cfg->start_bus <= bus && bus <= cfg->end_bus)
 106                         return cfg;
 107
 108         return NULL;
 109 }
 110
 111 static const char __init *pci_mmcfg_e7520(void)
 112 {
 113         u32 win;
 114         raw_pci_ops->read(0, 0, PCI_DEVFN(0, 0), 0xce, 2, &win);
 115
 116         win = win & 0xf000;
 117         if (win == 0x0000 || win == 0xf000)
 118                 return NULL;
 119
 120         if (pci_mmconfig_add(0, 0, 255, win << 16) == NULL)
 121                 return NULL;
 122
 123         return "Intel Corporation E7520 Memory Controller Hub";
 124 }
 125
 126 static const char __init *pci_mmcfg_intel_945(void)
 127 {
 128         u32 pciexbar, mask = 0, len = 0;
 129
 130         raw_pci_ops->read(0, 0, PCI_DEVFN(0, 0), 0x48, 4, &pciexbar);
 131
 132         /* Enable bit */
 133         if (!(pciexbar & 1))
 134                 return NULL;
 135
 136         /* Size bits */
 137         switch ((pciexbar >> 1) & 3) {
 138         case 0:
 139                 mask = 0xf0000000U;
 140                 len  = 0x10000000U;
 141                 break;
 142         case 1:
 143                 mask = 0xf8000000U;
 144                 len  = 0x08000000U;
 145                 break;
 146         case 2:
 147                 mask = 0xfc000000U;
 148                 len  = 0x04000000U;
 149                 break;
 150         default:
 151                 return NULL;
 152         }
 153
 154         /* Errata #2, things break when not aligned on a 256Mb boundary */
 155         /* Can only happen in 64M/128M mode */
 156
 157         if ((pciexbar & mask) & 0x0fffffffU)
 158                 return NULL;
 159
 160         /* Don't hit the APIC registers and their friends */
 161         if ((pciexbar & mask) >= 0xf0000000U)
 162                 return NULL;
 163
 164         if (pci_mmconfig_add(0, 0, (len >> 20) - 1, pciexbar & mask) == NULL)
 165                 return NULL;
 166
 167         return "Intel Corporation 945G/GZ/P/PL Express Memory Controller Hub";
 168 }
 169
 170 static const char __init *pci_mmcfg_amd_fam10h(void)
 171 {
 172         u32 low, high, address;
 173         u64 base, msr;
 174         int i;
 175         unsigned segnbits = 0, busnbits, end_bus;
 176
 177         if (!(pci_probe & PCI_CHECK_ENABLE_AMD_MMCONF))
 178                 return NULL;
 179
 180         address = MSR_FAM10H_MMIO_CONF_BASE;
 181         if (rdmsr_safe(address, &low, &high))
 182                 return NULL;
 183
 184         msr = high;
 185         msr <<= 32;
 186         msr |= low;
 187
 188         /* mmconfig is not enable */
 189         if (!(msr & FAM10H_MMIO_CONF_ENABLE))
 190                 return NULL;
 191
 192         base = msr & (FAM10H_MMIO_CONF_BASE_MASK<<FAM10H_MMIO_CONF_BASE_SHIFT);
 193
 194         busnbits = (msr >> FAM10H_MMIO_CONF_BUSRANGE_SHIFT) &
 195                          FAM10H_MMIO_CONF_BUSRANGE_MASK;
 196
 197         /*
 198          * only handle bus 0 ?
 199          * need to skip it
 200          */
 201         if (!busnbits)
 202                 return NULL;
 203
 204         if (busnbits > 8) {
 205                 segnbits = busnbits - 8;
 206                 busnbits = 8;
 207         }
 208
 209         end_bus = (1 << busnbits) - 1;
 210         for (i = 0; i < (1 << segnbits); i++)
 211                 if (pci_mmconfig_add(i, 0, end_bus,
 212                                      base + (1<<28) * i) == NULL) {
 213                         free_all_mmcfg();
 214                         return NULL;
 215                 }
 216
 217         return "AMD Family 10h NB";
 218 }
 219
 220 static bool __initdata mcp55_checked;
 221 static const char __init *pci_mmcfg_nvidia_mcp55(void)
 222 {
 223         int bus;
 224         int mcp55_mmconf_found = 0;
 225
 226         static const u32 extcfg_regnum          = 0x90;
 227         static const u32 extcfg_regsize         = 4;
 228         static const u32 extcfg_enable_mask     = 1<<31;
 229         static const u32 extcfg_start_mask      = 0xff<<16;
 230         static const int extcfg_start_shift     = 16;
 231         static const u32 extcfg_size_mask       = 0x3<<28;
 232         static const int extcfg_size_shift      = 28;
 233         static const int extcfg_sizebus[]       = {0x100, 0x80, 0x40, 0x20};
 234         static const u32 extcfg_base_mask[]     = {0x7ff8, 0x7ffc, 0x7ffe, 0x7fff};
 235         static const int extcfg_base_lshift     = 25;
 236
 237         /*
 238          * do check if amd fam10h already took over
 239          */
 240         if (!acpi_disabled || !list_empty(&pci_mmcfg_list) || mcp55_checked)
 241                 return NULL;
 242
 243         mcp55_checked = true;
 244         for (bus = 0; bus < 256; bus++) {
 245                 u64 base;
 246                 u32 l, extcfg;
 247                 u16 vendor, device;
 248                 int start, size_index, end;
 249
 250                 raw_pci_ops->read(0, bus, PCI_DEVFN(0, 0), 0, 4, &l);
 251                 vendor = l & 0xffff;
 252                 device = (l >> 16) & 0xffff;
 253
 254                 if (PCI_VENDOR_ID_NVIDIA != vendor || 0x0369 != device)
 255                         continue;
 256
 257                 raw_pci_ops->read(0, bus, PCI_DEVFN(0, 0), extcfg_regnum,
 258                                   extcfg_regsize, &extcfg);
 259
 260                 if (!(extcfg & extcfg_enable_mask))
 261                         continue;
 262
 263                 size_index = (extcfg & extcfg_size_mask) >> extcfg_size_shift;
 264                 base = extcfg & extcfg_base_mask[size_index];
 265                 /* base could > 4G */
 266                 base <<= extcfg_base_lshift;
 267                 start = (extcfg & extcfg_start_mask) >> extcfg_start_shift;
 268                 end = start + extcfg_sizebus[size_index] - 1;
 269                 if (pci_mmconfig_add(0, start, end, base) == NULL)
 270                         continue;
 271                 mcp55_mmconf_found++;
 272         }
 273
 274         if (!mcp55_mmconf_found)
 275                 return NULL;
 276
 277         return "nVidia MCP55";
 278 }
 279
 280 struct pci_mmcfg_hostbridge_probe {
 281         u32 bus;
 282         u32 devfn;
 283         u32 vendor;
 284         u32 device;
 285         const char *(*probe)(void);
 286 };
 287
 288 static struct pci_mmcfg_hostbridge_probe pci_mmcfg_probes[] __initdata = {
 289         { 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_INTEL,
 290           PCI_DEVICE_ID_INTEL_E7520_MCH, pci_mmcfg_e7520 },
 291         { 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_INTEL,
 292           PCI_DEVICE_ID_INTEL_82945G_HB, pci_mmcfg_intel_945 },
 293         { 0, PCI_DEVFN(0x18, 0), PCI_VENDOR_ID_AMD,
 294           0x1200, pci_mmcfg_amd_fam10h },
 295         { 0xff, PCI_DEVFN(0, 0), PCI_VENDOR_ID_AMD,
 296           0x1200, pci_mmcfg_amd_fam10h },
 297         { 0, PCI_DEVFN(0, 0), PCI_VENDOR_ID_NVIDIA,
 298           0x0369, pci_mmcfg_nvidia_mcp55 },
 299 };
 300
 301 static void __init pci_mmcfg_check_end_bus_number(void)
 302 {
 303         struct pci_mmcfg_region *cfg, *cfgx;
 304
 305         /* Fixup overlaps */
 306         list_for_each_entry(cfg, &pci_mmcfg_list, list) {
 307                 if (cfg->end_bus < cfg->start_bus)
 308                         cfg->end_bus = 255;
 309
 310                 /* Don't access the list head ! */
 311                 if (cfg->list.next == &pci_mmcfg_list)
 312                         break;
 313
 314                 cfgx = list_entry(cfg->list.next, typeof(*cfg), list);
 315                 if (cfg->end_bus >= cfgx->start_bus)
 316                         cfg->end_bus = cfgx->start_bus - 1;
 317         }
 318 }
 319
 320 static int __init pci_mmcfg_check_hostbridge(void)
 321 {
 322         u32 l;
 323         u32 bus, devfn;
 324         u16 vendor, device;
 325         int i;
 326         const char *name;
 327
 328         if (!raw_pci_ops)
 329                 return 0;
 330
 331         free_all_mmcfg();
 332
 333         for (i = 0; i < ARRAY_SIZE(pci_mmcfg_probes); i++) {
 334                 bus =  pci_mmcfg_probes[i].bus;
 335                 devfn = pci_mmcfg_probes[i].devfn;
 336                 raw_pci_ops->read(0, bus, devfn, 0, 4, &l);
 337                 vendor = l & 0xffff;
 338                 device = (l >> 16) & 0xffff;
 339
 340                 name = NULL;
 341                 if (pci_mmcfg_probes[i].vendor == vendor &&
 342                     pci_mmcfg_probes[i].device == device)
 343                         name = pci_mmcfg_probes[i].probe();
 344
 345                 if (name)
 346                         printk(KERN_INFO PREFIX "%s with MMCONFIG support\n",
 347                                name);
 348         }
 349
 350         /* some end_bus_number is crazy, fix it */
 351         pci_mmcfg_check_end_bus_number();
 352
 353         return !list_empty(&pci_mmcfg_list);
 354 }
 355
 356 static void __init pci_mmcfg_insert_resources(void)
 357 {
 358         struct pci_mmcfg_region *cfg;
 359
 360         list_for_each_entry(cfg, &pci_mmcfg_list, list)
 361                 insert_resource(&iomem_resource, &cfg->res);
 362
 363         /* Mark that the resources have been inserted. */
 364         pci_mmcfg_resources_inserted = 1;
 365 }
 366
 367 static acpi_status __init check_mcfg_resource(struct acpi_resource *res,
 368                                               void *data)
 369 {
 370         struct resource *mcfg_res = data;
 371         struct acpi_resource_address64 address;
 372         acpi_status status;
 373
 374         if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
 375                 struct acpi_resource_fixed_memory32 *fixmem32 =
 376                         &res->data.fixed_memory32;
 377                 if (!fixmem32)
 378                         return AE_OK;
 379                 if ((mcfg_res->start >= fixmem32->address) &&
 380                     (mcfg_res->end < (fixmem32->address +
 381                                       fixmem32->address_length))) {
 382                         mcfg_res->flags = 1;
 383                         return AE_CTRL_TERMINATE;
 384                 }
 385         }
 386         if ((res->type != ACPI_RESOURCE_TYPE_ADDRESS32) &&
 387             (res->type != ACPI_RESOURCE_TYPE_ADDRESS64))
 388                 return AE_OK;
 389
 390         status = acpi_resource_to_address64(res, &address);
 391         if (ACPI_FAILURE(status) ||
 392            (address.address_length <= 0) ||
 393            (address.resource_type != ACPI_MEMORY_RANGE))
 394                 return AE_OK;
 395
 396         if ((mcfg_res->start >= address.minimum) &&
 397             (mcfg_res->end < (address.minimum + address.address_length))) {
 398                 mcfg_res->flags = 1;
 399                 return AE_CTRL_TERMINATE;
 400         }
 401         return AE_OK;
 402 }
 403
 404 static acpi_status __init find_mboard_resource(acpi_handle handle, u32 lvl,
 405                 void *context, void **rv)
 406 {
 407         struct resource *mcfg_res = context;
 408
 409         acpi_walk_resources(handle, METHOD_NAME__CRS,
 410                             check_mcfg_resource, context);
 411
 412         if (mcfg_res->flags)
 413                 return AE_CTRL_TERMINATE;
 414
 415         return AE_OK;
 416 }
 417
 418 static int __init is_acpi_reserved(u64 start, u64 end, unsigned not_used)
 419 {
 420         struct resource mcfg_res;
 421
 422         mcfg_res.start = start;
 423         mcfg_res.end = end - 1;
 424         mcfg_res.flags = 0;
 425
 426         acpi_get_devices("PNP0C01", find_mboard_resource, &mcfg_res, NULL);
 427
 428         if (!mcfg_res.flags)
 429                 acpi_get_devices("PNP0C02", find_mboard_resource, &mcfg_res,
 430                                  NULL);
 431
 432         return mcfg_res.flags;
 433 }
 434
 435 typedef int (*check_reserved_t)(u64 start, u64 end, unsigned type);
 436
 437 static int __init is_mmconf_reserved(check_reserved_t is_reserved,
 438                                     struct pci_mmcfg_region *cfg, int with_e820)
 439 {
 440         u64 addr = cfg->res.start;
 441         u64 size = resource_size(&cfg->res);
 442         u64 old_size = size;
 443         int valid = 0, num_buses;
 444
 445         while (!is_reserved(addr, addr + size, E820_RESERVED)) {
 446                 size >>= 1;
 447                 if (size < (16UL<<20))
 448                         break;
 449         }
 450
 451         if (size >= (16UL<<20) || size == old_size) {
 452                 printk(KERN_INFO PREFIX "MMCONFIG at %pR reserved in %s\n",
 453                        &cfg->res,
 454                        with_e820 ? "E820" : "ACPI motherboard resources");
 455                 valid = 1;
 456
 457                 if (old_size != size) {
 458                         /* update end_bus */
 459                         cfg->end_bus = cfg->start_bus + ((size>>20) - 1);
 460                         num_buses = cfg->end_bus - cfg->start_bus + 1;
 461                         cfg->res.end = cfg->res.start +
 462                             PCI_MMCFG_BUS_OFFSET(num_buses) - 1;
 463                         snprintf(cfg->name, PCI_MMCFG_RESOURCE_NAME_LEN,
 464                                  "PCI MMCONFIG %04x [bus %02x-%02x]",
 465                                  cfg->segment, cfg->start_bus, cfg->end_bus);
 466                         printk(KERN_INFO PREFIX
 467                                "MMCONFIG for %04x [bus%02x-%02x] "
 468                                "at %pR (base %#lx) (size reduced!)\n",
 469                                cfg->segment, cfg->start_bus, cfg->end_bus,
 470                                &cfg->res, (unsigned long) cfg->address);
 471                 }
 472         }
 473
 474         return valid;
 475 }
 476
 477 static void __init pci_mmcfg_reject_broken(int early)
 478 {
 479         struct pci_mmcfg_region *cfg;
 480
 481         list_for_each_entry(cfg, &pci_mmcfg_list, list) {
 482                 int valid = 0;
 483
 484                 if (!early && !acpi_disabled) {
 485                         valid = is_mmconf_reserved(is_acpi_reserved, cfg, 0);
 486
 487                         if (valid)
 488                                 continue;
 489                         else
 490                                 printk(KERN_ERR FW_BUG PREFIX
 491                                        "MMCONFIG at %pR not reserved in "
 492                                        "ACPI motherboard resources\n",
 493                                        &cfg->res);
 494                 }
 495
 496                 /* Don't try to do this check unless configuration
 497                    type 1 is available. how about type 2 ?*/
 498                 if (raw_pci_ops)
 499                         valid = is_mmconf_reserved(e820_all_mapped, cfg, 1);
 500
 501                 if (!valid)
 502                         goto reject;
 503         }
 504
 505         return;
 506
 507 reject:
 508         printk(KERN_INFO PREFIX "not using MMCONFIG\n");
 509         free_all_mmcfg();
 510 }
 511
 512 static int __initdata known_bridge;
 513
 514 static int __init acpi_mcfg_check_entry(struct acpi_table_mcfg *mcfg,
 515                                         struct acpi_mcfg_allocation *cfg)
 516 {
 517         int year;
 518
 519         if (cfg->address < 0xFFFFFFFF)
 520                 return 0;
 521
 522         if (!strcmp(mcfg->header.oem_id, "SGI"))
 523                 return 0;
 524
 525         if (mcfg->header.revision >= 1) {
 526                 if (dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL) &&
 527                     year >= 2010)
 528                         return 0;
 529         }
 530
 531         printk(KERN_ERR PREFIX "MCFG region for %04x [bus %02x-%02x] at %#llx "
 532                "is above 4GB, ignored\n", cfg->pci_segment,
 533                cfg->start_bus_number, cfg->end_bus_number, cfg->address);
 534         return -EINVAL;
 535 }
 536
 537 static int __init pci_parse_mcfg(struct acpi_table_header *header)
 538 {
 539         struct acpi_table_mcfg *mcfg;
 540         struct acpi_mcfg_allocation *cfg_table, *cfg;
 541         unsigned long i;
 542         int entries;
 543
 544         if (!header)
 545                 return -EINVAL;
 546
 547         mcfg = (struct acpi_table_mcfg *)header;
 548
 549         /* how many config structures do we have */
 550         free_all_mmcfg();
 551         entries = 0;
 552         i = header->length - sizeof(struct acpi_table_mcfg);
 553         while (i >= sizeof(struct acpi_mcfg_allocation)) {
 554                 entries++;
 555                 i -= sizeof(struct acpi_mcfg_allocation);
 556         };
 557         if (entries == 0) {
 558                 printk(KERN_ERR PREFIX "MMCONFIG has no entries\n");
 559                 return -ENODEV;
 560         }
 561
 562         cfg_table = (struct acpi_mcfg_allocation *) &mcfg[1];
 563         for (i = 0; i < entries; i++) {
 564                 cfg = &cfg_table[i];
 565                 if (acpi_mcfg_check_entry(mcfg, cfg)) {
 566                         free_all_mmcfg();
 567                         return -ENODEV;
 568                 }
 569
 570                 if (pci_mmconfig_add(cfg->pci_segment, cfg->start_bus_number,
 571                                    cfg->end_bus_number, cfg->address) == NULL) {
 572                         printk(KERN_WARNING PREFIX
 573                                "no memory for MCFG entries\n");
 574                         free_all_mmcfg();
 575                         return -ENOMEM;
 576                 }
 577         }
 578
 579         return 0;
 580 }
 581
 582 static void __init __pci_mmcfg_init(int early)
 583 {
 584         /* MMCONFIG disabled */
 585         if ((pci_probe & PCI_PROBE_MMCONF) == 0)
 586                 return;
 587
 588         /* MMCONFIG already enabled */
 589         if (!early && !(pci_probe & PCI_PROBE_MASK & ~PCI_PROBE_MMCONF))
 590                 return;
 591
 592         /* for late to exit */
 593         if (known_bridge)
 594                 return;
 595
 596         if (early) {
 597                 if (pci_mmcfg_check_hostbridge())
 598                         known_bridge = 1;
 599         }
 600
 601         if (!known_bridge)
 602                 acpi_sfi_table_parse(ACPI_SIG_MCFG, pci_parse_mcfg);
 603
 604         pci_mmcfg_reject_broken(early);
 605
 606         if (list_empty(&pci_mmcfg_list))
 607                 return;
 608
 609         if (pcibios_last_bus < 0) {
 610                 const struct pci_mmcfg_region *cfg;
 611
 612                 list_for_each_entry(cfg, &pci_mmcfg_list, list) {
 613                         if (cfg->segment)
 614                                 break;
 615                         pcibios_last_bus = cfg->end_bus;
 616                 }
 617         }
 618
 619         if (pci_mmcfg_arch_init())
 620                 pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
 621         else {
 622                 /*
 623                  * Signal not to attempt to insert mmcfg resources because
 624                  * the architecture mmcfg setup could not initialize.
 625                  */
 626                 pci_mmcfg_resources_inserted = 1;
 627         }
 628 }
 629
 630 void __init pci_mmcfg_early_init(void)
 631 {
 632         __pci_mmcfg_init(1);
 633 }
 634
 635 void __init pci_mmcfg_late_init(void)
 636 {
 637         __pci_mmcfg_init(0);
 638 }
 639
 640 static int __init pci_mmcfg_late_insert_resources(void)
 641 {
 642         /*
 643          * If resources are already inserted or we are not using MMCONFIG,
 644          * don't insert the resources.
 645          */
 646         if ((pci_mmcfg_resources_inserted == 1) ||
 647             (pci_probe & PCI_PROBE_MMCONF) == 0 ||
 648             list_empty(&pci_mmcfg_list))
 649                 return 1;
 650
 651         /*
 652          * Attempt to insert the mmcfg resources but not with the busy flag
 653          * marked so it won't cause request errors when __request_region is
 654          * called.
 655          */
 656         pci_mmcfg_insert_resources();
 657
 658         return 0;
 659 }
 660
 661 /*
 662  * Perform MMCONFIG resource insertion after PCI initialization to allow for
 663  * misprogrammed MCFG tables that state larger sizes but actually conflict
 664  * with other system resources.
 665  */
 666 late_initcall(pci_mmcfg_late_insert_resources);