arch/x86/pci/common.c

   1 /*
   2  *      Low-Level PCI Support for PC
   3  *
   4  *      (c) 1999--2000 Martin Mares <mj@ucw.cz>
   5  */
   6
   7 #include <linux/sched.h>
   8 #include <linux/pci.h>
   9 #include <linux/ioport.h>
  10 #include <linux/init.h>
  11 #include <linux/dmi.h>
  12
  13 #include <asm/acpi.h>
  14 #include <asm/segment.h>
  15 #include <asm/io.h>
  16 #include <asm/smp.h>
  17 #include <asm/pci_x86.h>
  18
  19 unsigned int pci_probe = PCI_PROBE_BIOS | PCI_PROBE_CONF1 | PCI_PROBE_CONF2 |
  20                                 PCI_PROBE_MMCONF;
  21
  22 unsigned int pci_early_dump_regs;
  23 static int pci_bf_sort;
  24 int pci_routeirq;
  25 int noioapicquirk;
  26 #ifdef CONFIG_X86_REROUTE_FOR_BROKEN_BOOT_IRQS
  27 int noioapicreroute = 0;
  28 #else
  29 int noioapicreroute = 1;
  30 #endif
  31 int pcibios_last_bus = -1;
  32 unsigned long pirq_table_addr;
  33 struct pci_bus *pci_root_bus;
  34 struct pci_raw_ops *raw_pci_ops;
  35 struct pci_raw_ops *raw_pci_ext_ops;
  36
  37 int raw_pci_read(unsigned int domain, unsigned int bus, unsigned int devfn,
  38                                                 int reg, int len, u32 *val)
  39 {
  40         if (domain == 0 && reg < 256 && raw_pci_ops)
  41                 return raw_pci_ops->read(domain, bus, devfn, reg, len, val);
  42         if (raw_pci_ext_ops)
  43                 return raw_pci_ext_ops->read(domain, bus, devfn, reg, len, val);
  44         return -EINVAL;
  45 }
  46
  47 int raw_pci_write(unsigned int domain, unsigned int bus, unsigned int devfn,
  48                                                 int reg, int len, u32 val)
  49 {
  50         if (domain == 0 && reg < 256 && raw_pci_ops)
  51                 return raw_pci_ops->write(domain, bus, devfn, reg, len, val);
  52         if (raw_pci_ext_ops)
  53                 return raw_pci_ext_ops->write(domain, bus, devfn, reg, len, val);
  54         return -EINVAL;
  55 }
  56
  57 static int pci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *value)
  58 {
  59         return raw_pci_read(pci_domain_nr(bus), bus->number,
  60                                  devfn, where, size, value);
  61 }
  62
  63 static int pci_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 value)
  64 {
  65         return raw_pci_write(pci_domain_nr(bus), bus->number,
  66                                   devfn, where, size, value);
  67 }
  68
  69 struct pci_ops pci_root_ops = {
  70         .read = pci_read,
  71         .write = pci_write,
  72 };
  73
  74 /*
  75  * legacy, numa, and acpi all want to call pcibios_scan_root
  76  * from their initcalls. This flag prevents that.
  77  */
  78 int pcibios_scanned;
  79
  80 /*
  81  * This interrupt-safe spinlock protects all accesses to PCI
  82  * configuration space.
  83  */
  84 DEFINE_SPINLOCK(pci_config_lock);
  85
  86 static int __devinit can_skip_ioresource_align(const struct dmi_system_id *d)
  87 {
  88         pci_probe |= PCI_CAN_SKIP_ISA_ALIGN;
  89         printk(KERN_INFO "PCI: %s detected, can skip ISA alignment\n", d->ident);
  90         return 0;
  91 }
  92
  93 static const struct dmi_system_id can_skip_pciprobe_dmi_table[] __devinitconst = {
  94 /*
  95  * Systems where PCI IO resource ISA alignment can be skipped
  96  * when the ISA enable bit in the bridge control is not set
  97  */
  98         {
  99                 .callback = can_skip_ioresource_align,
 100                 .ident = "IBM System x3800",
 101                 .matches = {
 102                         DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
 103                         DMI_MATCH(DMI_PRODUCT_NAME, "x3800"),
 104                 },
 105         },
 106         {
 107                 .callback = can_skip_ioresource_align,
 108                 .ident = "IBM System x3850",
 109                 .matches = {
 110                         DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
 111                         DMI_MATCH(DMI_PRODUCT_NAME, "x3850"),
 112                 },
 113         },
 114         {
 115                 .callback = can_skip_ioresource_align,
 116                 .ident = "IBM System x3950",
 117                 .matches = {
 118                         DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
 119                         DMI_MATCH(DMI_PRODUCT_NAME, "x3950"),
 120                 },
 121         },
 122         {}
 123 };
 124
 125 void __init dmi_check_skip_isa_align(void)
 126 {
 127         dmi_check_system(can_skip_pciprobe_dmi_table);
 128 }
 129
 130 static void __devinit pcibios_fixup_device_resources(struct pci_dev *dev)
 131 {
 132         struct resource *rom_r = &dev->resource[PCI_ROM_RESOURCE];
 133
 134         if (pci_probe & PCI_NOASSIGN_ROMS) {
 135                 if (rom_r->parent)
 136                         return;
 137                 if (rom_r->start) {
 138                         /* we deal with BIOS assigned ROM later */
 139                         return;
 140                 }
 141                 rom_r->start = rom_r->end = rom_r->flags = 0;
 142         }
 143 }
 144
 145 /*
 146  *  Called after each bus is probed, but before its children
 147  *  are examined.
 148  */
 149
 150 void __devinit pcibios_fixup_bus(struct pci_bus *b)
 151 {
 152         struct pci_dev *dev;
 153
 154         /* root bus? */
 155         if (!b->parent)
 156                 x86_pci_root_bus_res_quirks(b);
 157         pci_read_bridge_bases(b);
 158         list_for_each_entry(dev, &b->devices, bus_list)
 159                 pcibios_fixup_device_resources(dev);
 160 }
 161
 162 /*
 163  * Only use DMI information to set this if nothing was passed
 164  * on the kernel command line (which was parsed earlier).
 165  */
 166
 167 static int __devinit set_bf_sort(const struct dmi_system_id *d)
 168 {
 169         if (pci_bf_sort == pci_bf_sort_default) {
 170                 pci_bf_sort = pci_dmi_bf;
 171                 printk(KERN_INFO "PCI: %s detected, enabling pci=bfsort.\n", d->ident);
 172         }
 173         return 0;
 174 }
 175
 176 /*
 177  * Enable renumbering of PCI bus# ranges to reach all PCI busses (Cardbus)
 178  */
 179 #ifdef __i386__
 180 static int __devinit assign_all_busses(const struct dmi_system_id *d)
 181 {
 182         pci_probe |= PCI_ASSIGN_ALL_BUSSES;
 183         printk(KERN_INFO "%s detected: enabling PCI bus# renumbering"
 184                         " (pci=assign-busses)\n", d->ident);
 185         return 0;
 186 }
 187 #endif
 188
 189 static const struct dmi_system_id __devinitconst pciprobe_dmi_table[] = {
 190 #ifdef __i386__
 191 /*
 192  * Laptops which need pci=assign-busses to see Cardbus cards
 193  */
 194         {
 195                 .callback = assign_all_busses,
 196                 .ident = "Samsung X20 Laptop",
 197                 .matches = {
 198                         DMI_MATCH(DMI_SYS_VENDOR, "Samsung Electronics"),
 199                         DMI_MATCH(DMI_PRODUCT_NAME, "SX20S"),
 200                 },
 201         },
 202 #endif          /* __i386__ */
 203         {
 204                 .callback = set_bf_sort,
 205                 .ident = "Dell PowerEdge 1950",
 206                 .matches = {
 207                         DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
 208                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1950"),
 209                 },
 210         },
 211         {
 212                 .callback = set_bf_sort,
 213                 .ident = "Dell PowerEdge 1955",
 214                 .matches = {
 215                         DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
 216                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1955"),
 217                 },
 218         },
 219         {
 220                 .callback = set_bf_sort,
 221                 .ident = "Dell PowerEdge 2900",
 222                 .matches = {
 223                         DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
 224                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2900"),
 225                 },
 226         },
 227         {
 228                 .callback = set_bf_sort,
 229                 .ident = "Dell PowerEdge 2950",
 230                 .matches = {
 231                         DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
 232                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2950"),
 233                 },
 234         },
 235         {
 236                 .callback = set_bf_sort,
 237                 .ident = "Dell PowerEdge R900",
 238                 .matches = {
 239                         DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
 240                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge R900"),
 241                 },
 242         },
 243         {
 244                 .callback = set_bf_sort,
 245                 .ident = "HP ProLiant BL20p G3",
 246                 .matches = {
 247                         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
 248                         DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL20p G3"),
 249                 },
 250         },
 251         {
 252                 .callback = set_bf_sort,
 253                 .ident = "HP ProLiant BL20p G4",
 254                 .matches = {
 255                         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
 256                         DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL20p G4"),
 257                 },
 258         },
 259         {
 260                 .callback = set_bf_sort,
 261                 .ident = "HP ProLiant BL30p G1",
 262                 .matches = {
 263                         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
 264                         DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL30p G1"),
 265                 },
 266         },
 267         {
 268                 .callback = set_bf_sort,
 269                 .ident = "HP ProLiant BL25p G1",
 270                 .matches = {
 271                         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
 272                         DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL25p G1"),
 273                 },
 274         },
 275         {
 276                 .callback = set_bf_sort,
 277                 .ident = "HP ProLiant BL35p G1",
 278                 .matches = {
 279                         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
 280                         DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL35p G1"),
 281                 },
 282         },
 283         {
 284                 .callback = set_bf_sort,
 285                 .ident = "HP ProLiant BL45p G1",
 286                 .matches = {
 287                         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
 288                         DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL45p G1"),
 289                 },
 290         },
 291         {
 292                 .callback = set_bf_sort,
 293                 .ident = "HP ProLiant BL45p G2",
 294                 .matches = {
 295                         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
 296                         DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL45p G2"),
 297                 },
 298         },
 299         {
 300                 .callback = set_bf_sort,
 301                 .ident = "HP ProLiant BL460c G1",
 302                 .matches = {
 303                         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
 304                         DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL460c G1"),
 305                 },
 306         },
 307         {
 308                 .callback = set_bf_sort,
 309                 .ident = "HP ProLiant BL465c G1",
 310                 .matches = {
 311                         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
 312                         DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL465c G1"),
 313                 },
 314         },
 315         {
 316                 .callback = set_bf_sort,
 317                 .ident = "HP ProLiant BL480c G1",
 318                 .matches = {
 319                         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
 320                         DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL480c G1"),
 321                 },
 322         },
 323         {
 324                 .callback = set_bf_sort,
 325                 .ident = "HP ProLiant BL685c G1",
 326                 .matches = {
 327                         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
 328                         DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL685c G1"),
 329                 },
 330         },
 331         {
 332                 .callback = set_bf_sort,
 333                 .ident = "HP ProLiant DL360",
 334                 .matches = {
 335                         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
 336                         DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant DL360"),
 337                 },
 338         },
 339         {
 340                 .callback = set_bf_sort,
 341                 .ident = "HP ProLiant DL380",
 342                 .matches = {
 343                         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
 344                         DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant DL380"),
 345                 },
 346         },
 347 #ifdef __i386__
 348         {
 349                 .callback = assign_all_busses,
 350                 .ident = "Compaq EVO N800c",
 351                 .matches = {
 352                         DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
 353                         DMI_MATCH(DMI_PRODUCT_NAME, "EVO N800c"),
 354                 },
 355         },
 356 #endif
 357         {
 358                 .callback = set_bf_sort,
 359                 .ident = "HP ProLiant DL385 G2",
 360                 .matches = {
 361                         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
 362                         DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant DL385 G2"),
 363                 },
 364         },
 365         {
 366                 .callback = set_bf_sort,
 367                 .ident = "HP ProLiant DL585 G2",
 368                 .matches = {
 369                         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
 370                         DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant DL585 G2"),
 371                 },
 372         },
 373         {}
 374 };
 375
 376 void __init dmi_check_pciprobe(void)
 377 {
 378         dmi_check_system(pciprobe_dmi_table);
 379 }
 380
 381 struct pci_bus * __devinit pcibios_scan_root(int busnum)
 382 {
 383         struct pci_bus *bus = NULL;
 384         struct pci_sysdata *sd;
 385
 386         while ((bus = pci_find_next_bus(bus)) != NULL) {
 387                 if (bus->number == busnum) {
 388                         /* Already scanned */
 389                         return bus;
 390                 }
 391         }
 392
 393         /* Allocate per-root-bus (not per bus) arch-specific data.
 394          * TODO: leak; this memory is never freed.
 395          * It's arguable whether it's worth the trouble to care.
 396          */
 397         sd = kzalloc(sizeof(*sd), GFP_KERNEL);
 398         if (!sd) {
 399                 printk(KERN_ERR "PCI: OOM, not probing PCI bus %02x\n", busnum);
 400                 return NULL;
 401         }
 402
 403         sd->node = get_mp_bus_to_node(busnum);
 404
 405         printk(KERN_DEBUG "PCI: Probing PCI hardware (bus %02x)\n", busnum);
 406         bus = pci_scan_bus_parented(NULL, busnum, &pci_root_ops, sd);
 407         if (!bus)
 408                 kfree(sd);
 409
 410         return bus;
 411 }
 412
 413 extern u8 pci_cache_line_size;
 414
 415 int __init pcibios_init(void)
 416 {
 417         struct cpuinfo_x86 *c = &boot_cpu_data;
 418
 419         if (!raw_pci_ops) {
 420                 printk(KERN_WARNING "PCI: System does not support PCI\n");
 421                 return 0;
 422         }
 423
 424         /*
 425          * Assume PCI cacheline size of 32 bytes for all x86s except K7/K8
 426          * and P4. It's also good for 386/486s (which actually have 16)
 427          * as quite a few PCI devices do not support smaller values.
 428          */
 429         pci_cache_line_size = 32 >> 2;
 430         if (c->x86 >= 6 && c->x86_vendor == X86_VENDOR_AMD)
 431                 pci_cache_line_size = 64 >> 2;  /* K7 & K8 */
 432         else if (c->x86 > 6 && c->x86_vendor == X86_VENDOR_INTEL)
 433                 pci_cache_line_size = 128 >> 2; /* P4 */
 434
 435         pcibios_resource_survey();
 436
 437         if (pci_bf_sort >= pci_force_bf)
 438                 pci_sort_breadthfirst();
 439         return 0;
 440 }
 441
 442 char * __devinit  pcibios_setup(char *str)
 443 {
 444         if (!strcmp(str, "off")) {
 445                 pci_probe = 0;
 446                 return NULL;
 447         } else if (!strcmp(str, "bfsort")) {
 448                 pci_bf_sort = pci_force_bf;
 449                 return NULL;
 450         } else if (!strcmp(str, "nobfsort")) {
 451                 pci_bf_sort = pci_force_nobf;
 452                 return NULL;
 453         }
 454 #ifdef CONFIG_PCI_BIOS
 455         else if (!strcmp(str, "bios")) {
 456                 pci_probe = PCI_PROBE_BIOS;
 457                 return NULL;
 458         } else if (!strcmp(str, "nobios")) {
 459                 pci_probe &= ~PCI_PROBE_BIOS;
 460                 return NULL;
 461         } else if (!strcmp(str, "biosirq")) {
 462                 pci_probe |= PCI_BIOS_IRQ_SCAN;
 463                 return NULL;
 464         } else if (!strncmp(str, "pirqaddr=", 9)) {
 465                 pirq_table_addr = simple_strtoul(str+9, NULL, 0);
 466                 return NULL;
 467         }
 468 #endif
 469 #ifdef CONFIG_PCI_DIRECT
 470         else if (!strcmp(str, "conf1")) {
 471                 pci_probe = PCI_PROBE_CONF1 | PCI_NO_CHECKS;
 472                 return NULL;
 473         }
 474         else if (!strcmp(str, "conf2")) {
 475                 pci_probe = PCI_PROBE_CONF2 | PCI_NO_CHECKS;
 476                 return NULL;
 477         }
 478 #endif
 479 #ifdef CONFIG_PCI_MMCONFIG
 480         else if (!strcmp(str, "nommconf")) {
 481                 pci_probe &= ~PCI_PROBE_MMCONF;
 482                 return NULL;
 483         }
 484         else if (!strcmp(str, "check_enable_amd_mmconf")) {
 485                 pci_probe |= PCI_CHECK_ENABLE_AMD_MMCONF;
 486                 return NULL;
 487         }
 488 #endif
 489         else if (!strcmp(str, "noacpi")) {
 490                 acpi_noirq_set();
 491                 return NULL;
 492         }
 493         else if (!strcmp(str, "noearly")) {
 494                 pci_probe |= PCI_PROBE_NOEARLY;
 495                 return NULL;
 496         }
 497 #ifndef CONFIG_X86_VISWS
 498         else if (!strcmp(str, "usepirqmask")) {
 499                 pci_probe |= PCI_USE_PIRQ_MASK;
 500                 return NULL;
 501         } else if (!strncmp(str, "irqmask=", 8)) {
 502                 pcibios_irq_mask = simple_strtol(str+8, NULL, 0);
 503                 return NULL;
 504         } else if (!strncmp(str, "lastbus=", 8)) {
 505                 pcibios_last_bus = simple_strtol(str+8, NULL, 0);
 506                 return NULL;
 507         }
 508 #endif
 509         else if (!strcmp(str, "rom")) {
 510                 pci_probe |= PCI_ASSIGN_ROMS;
 511                 return NULL;
 512         } else if (!strcmp(str, "norom")) {
 513                 pci_probe |= PCI_NOASSIGN_ROMS;
 514                 return NULL;
 515         } else if (!strcmp(str, "assign-busses")) {
 516                 pci_probe |= PCI_ASSIGN_ALL_BUSSES;
 517                 return NULL;
 518         } else if (!strcmp(str, "use_crs")) {
 519                 pci_probe |= PCI_USE__CRS;
 520                 return NULL;
 521         } else if (!strcmp(str, "earlydump")) {
 522                 pci_early_dump_regs = 1;
 523                 return NULL;
 524         } else if (!strcmp(str, "routeirq")) {
 525                 pci_routeirq = 1;
 526                 return NULL;
 527         } else if (!strcmp(str, "skip_isa_align")) {
 528                 pci_probe |= PCI_CAN_SKIP_ISA_ALIGN;
 529                 return NULL;
 530         } else if (!strcmp(str, "noioapicquirk")) {
 531                 noioapicquirk = 1;
 532                 return NULL;
 533         } else if (!strcmp(str, "ioapicreroute")) {
 534                 if (noioapicreroute != -1)
 535                         noioapicreroute = 0;
 536                 return NULL;
 537         } else if (!strcmp(str, "noioapicreroute")) {
 538                 if (noioapicreroute != -1)
 539                         noioapicreroute = 1;
 540                 return NULL;
 541         }
 542         return str;
 543 }
 544
 545 unsigned int pcibios_assign_all_busses(void)
 546 {
 547         return (pci_probe & PCI_ASSIGN_ALL_BUSSES) ? 1 : 0;
 548 }
 549
 550 int pcibios_enable_device(struct pci_dev *dev, int mask)
 551 {
 552         int err;
 553
 554         if ((err = pci_enable_resources(dev, mask)) < 0)
 555                 return err;
 556
 557         if (!pci_dev_msi_enabled(dev))
 558                 return pcibios_enable_irq(dev);
 559         return 0;
 560 }
 561
 562 void pcibios_disable_device (struct pci_dev *dev)
 563 {
 564         if (!pci_dev_msi_enabled(dev) && pcibios_disable_irq)
 565                 pcibios_disable_irq(dev);
 566 }
 567
 568 int pci_ext_cfg_avail(struct pci_dev *dev)
 569 {
 570         if (raw_pci_ext_ops)
 571                 return 1;
 572         else
 573                 return 0;
 574 }
 575
 576 struct pci_bus * __devinit pci_scan_bus_on_node(int busno, struct pci_ops *ops, int node)
 577 {
 578         struct pci_bus *bus = NULL;
 579         struct pci_sysdata *sd;
 580
 581         /*
 582          * Allocate per-root-bus (not per bus) arch-specific data.
 583          * TODO: leak; this memory is never freed.
 584          * It's arguable whether it's worth the trouble to care.
 585          */
 586         sd = kzalloc(sizeof(*sd), GFP_KERNEL);
 587         if (!sd) {
 588                 printk(KERN_ERR "PCI: OOM, skipping PCI bus %02x\n", busno);
 589                 return NULL;
 590         }
 591         sd->node = node;
 592         bus = pci_scan_bus(busno, ops, sd);
 593         if (!bus)
 594                 kfree(sd);
 595
 596         return bus;
 597 }
 598
 599 struct pci_bus * __devinit pci_scan_bus_with_sysdata(int busno)
 600 {
 601         return pci_scan_bus_on_node(busno, &pci_root_ops, -1);
 602 }
 603
 604 /*
 605  * NUMA info for PCI busses
 606  *
 607  * Early arch code is responsible for filling in reasonable values here.
 608  * A node id of "-1" means "use current node".  In other words, if a bus
 609  * has a -1 node id, it's not tightly coupled to any particular chunk
 610  * of memory (as is the case on some Nehalem systems).
 611  */
 612 #ifdef CONFIG_NUMA
 613
 614 #define BUS_NR 256
 615
 616 #ifdef CONFIG_X86_64
 617
 618 static int mp_bus_to_node[BUS_NR] = {
 619         [0 ... BUS_NR - 1] = -1
 620 };
 621
 622 void set_mp_bus_to_node(int busnum, int node)
 623 {
 624         if (busnum >= 0 &&  busnum < BUS_NR)
 625                 mp_bus_to_node[busnum] = node;
 626 }
 627
 628 int get_mp_bus_to_node(int busnum)
 629 {
 630         int node = -1;
 631
 632         if (busnum < 0 || busnum > (BUS_NR - 1))
 633                 return node;
 634
 635         node = mp_bus_to_node[busnum];
 636
 637         /*
 638          * let numa_node_id to decide it later in dma_alloc_pages
 639          * if there is no ram on that node
 640          */
 641         if (node != -1 && !node_online(node))
 642                 node = -1;
 643
 644         return node;
 645 }
 646
 647 #else /* CONFIG_X86_32 */
 648
 649 static unsigned char mp_bus_to_node[BUS_NR] = {
 650         [0 ... BUS_NR - 1] = -1
 651 };
 652
 653 void set_mp_bus_to_node(int busnum, int node)
 654 {
 655         if (busnum >= 0 &&  busnum < BUS_NR)
 656         mp_bus_to_node[busnum] = (unsigned char) node;
 657 }
 658
 659 int get_mp_bus_to_node(int busnum)
 660 {
 661         int node;
 662
 663         if (busnum < 0 || busnum > (BUS_NR - 1))
 664                 return 0;
 665         node = mp_bus_to_node[busnum];
 666         return node;
 667 }
 668
 669 #endif /* CONFIG_X86_32 */
 670
 671 #endif /* CONFIG_NUMA */