drivers/pci/setup-bus.c

   1 /*
   2  *      drivers/pci/setup-bus.c
   3  *
   4  * Extruded from code written by
   5  *      Dave Rusling (david.rusling@reo.mts.dec.com)
   6  *      David Mosberger (davidm@cs.arizona.edu)
   7  *      David Miller (davem@redhat.com)
   8  *
   9  * Support routines for initializing a PCI subsystem.
  10  */
  11
  12 /*
  13  * Nov 2000, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
  14  *           PCI-PCI bridges cleanup, sorted resource allocation.
  15  * Feb 2002, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
  16  *           Converted to allocation in 3 passes, which gives
  17  *           tighter packing. Prefetchable range support.
  18  */
  19
  20 #include <linux/init.h>
  21 #include <linux/kernel.h>
  22 #include <linux/module.h>
  23 #include <linux/pci.h>
  24 #include <linux/errno.h>
  25 #include <linux/ioport.h>
  26 #include <linux/cache.h>
  27 #include <linux/slab.h>
  28
  29
  30 static void pbus_assign_resources_sorted(struct pci_bus *bus)
  31 {
  32         struct pci_dev *dev;
  33         struct resource *res;
  34         struct resource_list head, *list, *tmp;
  35         int idx;
  36
  37         head.next = NULL;
  38         list_for_each_entry(dev, &bus->devices, bus_list) {
  39                 u16 class = dev->class >> 8;
  40
  41                 /* Don't touch classless devices or host bridges or ioapics.  */
  42                 if (class == PCI_CLASS_NOT_DEFINED ||
  43                     class == PCI_CLASS_BRIDGE_HOST)
  44                         continue;
  45
  46                 /* Don't touch ioapic devices already enabled by firmware */
  47                 if (class == PCI_CLASS_SYSTEM_PIC) {
  48                         u16 command;
  49                         pci_read_config_word(dev, PCI_COMMAND, &command);
  50                         if (command & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY))
  51                                 continue;
  52                 }
  53
  54                 pdev_sort_resources(dev, &head);
  55         }
  56
  57         for (list = head.next; list;) {
  58                 res = list->res;
  59                 idx = res - &list->dev->resource[0];
  60                 if (pci_assign_resource(list->dev, idx)) {
  61                         /* FIXME: get rid of this */
  62                         res->start = 0;
  63                         res->end = 0;
  64                         res->flags = 0;
  65                 }
  66                 tmp = list;
  67                 list = list->next;
  68                 kfree(tmp);
  69         }
  70 }
  71
  72 void pci_setup_cardbus(struct pci_bus *bus)
  73 {
  74         struct pci_dev *bridge = bus->self;
  75         struct pci_bus_region region;
  76
  77         dev_info(&bridge->dev, "CardBus bridge, secondary bus %04x:%02x\n",
  78                  pci_domain_nr(bus), bus->number);
  79
  80         pcibios_resource_to_bus(bridge, &region, bus->resource[0]);
  81         if (bus->resource[0]->flags & IORESOURCE_IO) {
  82                 /*
  83                  * The IO resource is allocated a range twice as large as it
  84                  * would normally need.  This allows us to set both IO regs.
  85                  */
  86                 dev_info(&bridge->dev, "  IO window: %#08lx-%#08lx\n",
  87                        (unsigned long)region.start,
  88                        (unsigned long)region.end);
  89                 pci_write_config_dword(bridge, PCI_CB_IO_BASE_0,
  90                                         region.start);
  91                 pci_write_config_dword(bridge, PCI_CB_IO_LIMIT_0,
  92                                         region.end);
  93         }
  94
  95         pcibios_resource_to_bus(bridge, &region, bus->resource[1]);
  96         if (bus->resource[1]->flags & IORESOURCE_IO) {
  97                 dev_info(&bridge->dev, "  IO window: %#08lx-%#08lx\n",
  98                        (unsigned long)region.start,
  99                        (unsigned long)region.end);
 100                 pci_write_config_dword(bridge, PCI_CB_IO_BASE_1,
 101                                         region.start);
 102                 pci_write_config_dword(bridge, PCI_CB_IO_LIMIT_1,
 103                                         region.end);
 104         }
 105
 106         pcibios_resource_to_bus(bridge, &region, bus->resource[2]);
 107         if (bus->resource[2]->flags & IORESOURCE_MEM) {
 108                 dev_info(&bridge->dev, "  PREFETCH window: %#08lx-%#08lx\n",
 109                        (unsigned long)region.start,
 110                        (unsigned long)region.end);
 111                 pci_write_config_dword(bridge, PCI_CB_MEMORY_BASE_0,
 112                                         region.start);
 113                 pci_write_config_dword(bridge, PCI_CB_MEMORY_LIMIT_0,
 114                                         region.end);
 115         }
 116
 117         pcibios_resource_to_bus(bridge, &region, bus->resource[3]);
 118         if (bus->resource[3]->flags & IORESOURCE_MEM) {
 119                 dev_info(&bridge->dev, "  MEM window: %#08lx-%#08lx\n",
 120                        (unsigned long)region.start,
 121                        (unsigned long)region.end);
 122                 pci_write_config_dword(bridge, PCI_CB_MEMORY_BASE_1,
 123                                         region.start);
 124                 pci_write_config_dword(bridge, PCI_CB_MEMORY_LIMIT_1,
 125                                         region.end);
 126         }
 127 }
 128 EXPORT_SYMBOL(pci_setup_cardbus);
 129
 130 /* Initialize bridges with base/limit values we have collected.
 131    PCI-to-PCI Bridge Architecture Specification rev. 1.1 (1998)
 132    requires that if there is no I/O ports or memory behind the
 133    bridge, corresponding range must be turned off by writing base
 134    value greater than limit to the bridge's base/limit registers.
 135
 136    Note: care must be taken when updating I/O base/limit registers
 137    of bridges which support 32-bit I/O. This update requires two
 138    config space writes, so it's quite possible that an I/O window of
 139    the bridge will have some undesirable address (e.g. 0) after the
 140    first write. Ditto 64-bit prefetchable MMIO.  */
 141 static void pci_setup_bridge(struct pci_bus *bus)
 142 {
 143         struct pci_dev *bridge = bus->self;
 144         struct pci_bus_region region;
 145         u32 l, bu, lu, io_upper16;
 146
 147         dev_info(&bridge->dev, "PCI bridge, secondary bus %04x:%02x\n",
 148                  pci_domain_nr(bus), bus->number);
 149
 150         /* Set up the top and bottom of the PCI I/O segment for this bus. */
 151         pcibios_resource_to_bus(bridge, &region, bus->resource[0]);
 152         if (bus->resource[0]->flags & IORESOURCE_IO) {
 153                 pci_read_config_dword(bridge, PCI_IO_BASE, &l);
 154                 l &= 0xffff0000;
 155                 l |= (region.start >> 8) & 0x00f0;
 156                 l |= region.end & 0xf000;
 157                 /* Set up upper 16 bits of I/O base/limit. */
 158                 io_upper16 = (region.end & 0xffff0000) | (region.start >> 16);
 159                 dev_info(&bridge->dev, "  IO window: %#04lx-%#04lx\n",
 160                     (unsigned long)region.start,
 161                     (unsigned long)region.end);
 162         }
 163         else {
 164                 /* Clear upper 16 bits of I/O base/limit. */
 165                 io_upper16 = 0;
 166                 l = 0x00f0;
 167                 dev_info(&bridge->dev, "  IO window: disabled\n");
 168         }
 169         /* Temporarily disable the I/O range before updating PCI_IO_BASE. */
 170         pci_write_config_dword(bridge, PCI_IO_BASE_UPPER16, 0x0000ffff);
 171         /* Update lower 16 bits of I/O base/limit. */
 172         pci_write_config_dword(bridge, PCI_IO_BASE, l);
 173         /* Update upper 16 bits of I/O base/limit. */
 174         pci_write_config_dword(bridge, PCI_IO_BASE_UPPER16, io_upper16);
 175
 176         /* Set up the top and bottom of the PCI Memory segment
 177            for this bus. */
 178         pcibios_resource_to_bus(bridge, &region, bus->resource[1]);
 179         if (bus->resource[1]->flags & IORESOURCE_MEM) {
 180                 l = (region.start >> 16) & 0xfff0;
 181                 l |= region.end & 0xfff00000;
 182                 dev_info(&bridge->dev, "  MEM window: %#08lx-%#08lx\n",
 183                     (unsigned long)region.start,
 184                     (unsigned long)region.end);
 185         }
 186         else {
 187                 l = 0x0000fff0;
 188                 dev_info(&bridge->dev, "  MEM window: disabled\n");
 189         }
 190         pci_write_config_dword(bridge, PCI_MEMORY_BASE, l);
 191
 192         /* Clear out the upper 32 bits of PREF limit.
 193            If PCI_PREF_BASE_UPPER32 was non-zero, this temporarily
 194            disables PREF range, which is ok. */
 195         pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, 0);
 196
 197         /* Set up PREF base/limit. */
 198         bu = lu = 0;
 199         pcibios_resource_to_bus(bridge, &region, bus->resource[2]);
 200         if (bus->resource[2]->flags & IORESOURCE_PREFETCH) {
 201                 l = (region.start >> 16) & 0xfff0;
 202                 l |= region.end & 0xfff00000;
 203                 bu = upper_32_bits(region.start);
 204                 lu = upper_32_bits(region.end);
 205                 dev_info(&bridge->dev, "  PREFETCH window: %#016llx-%#016llx\n",
 206                     (unsigned long long)region.start,
 207                     (unsigned long long)region.end);
 208         }
 209         else {
 210                 l = 0x0000fff0;
 211                 dev_info(&bridge->dev, "  PREFETCH window: disabled\n");
 212         }
 213         pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, l);
 214
 215         /* Set the upper 32 bits of PREF base & limit. */
 216         pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, bu);
 217         pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, lu);
 218
 219         pci_write_config_word(bridge, PCI_BRIDGE_CONTROL, bus->bridge_ctl);
 220 }
 221
 222 /* Check whether the bridge supports optional I/O and
 223    prefetchable memory ranges. If not, the respective
 224    base/limit registers must be read-only and read as 0. */
 225 static void pci_bridge_check_ranges(struct pci_bus *bus)
 226 {
 227         u16 io;
 228         u32 pmem;
 229         struct pci_dev *bridge = bus->self;
 230         struct resource *b_res;
 231
 232         b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
 233         b_res[1].flags |= IORESOURCE_MEM;
 234
 235         pci_read_config_word(bridge, PCI_IO_BASE, &io);
 236         if (!io) {
 237                 pci_write_config_word(bridge, PCI_IO_BASE, 0xf0f0);
 238                 pci_read_config_word(bridge, PCI_IO_BASE, &io);
 239                 pci_write_config_word(bridge, PCI_IO_BASE, 0x0);
 240         }
 241         if (io)
 242                 b_res[0].flags |= IORESOURCE_IO;
 243         /*  DECchip 21050 pass 2 errata: the bridge may miss an address
 244             disconnect boundary by one PCI data phase.
 245             Workaround: do not use prefetching on this device. */
 246         if (bridge->vendor == PCI_VENDOR_ID_DEC && bridge->device == 0x0001)
 247                 return;
 248         pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
 249         if (!pmem) {
 250                 pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE,
 251                                                0xfff0fff0);
 252                 pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
 253                 pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, 0x0);
 254         }
 255         if (pmem)
 256                 b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
 257 }
 258
 259 /* Helper function for sizing routines: find first available
 260    bus resource of a given type. Note: we intentionally skip
 261    the bus resources which have already been assigned (that is,
 262    have non-NULL parent resource). */
 263 static struct resource *find_free_bus_resource(struct pci_bus *bus, unsigned long type)
 264 {
 265         int i;
 266         struct resource *r;
 267         unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
 268                                   IORESOURCE_PREFETCH;
 269
 270         for (i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
 271                 r = bus->resource[i];
 272                 if (r == &ioport_resource || r == &iomem_resource)
 273                         continue;
 274                 if (r && (r->flags & type_mask) == type && !r->parent)
 275                         return r;
 276         }
 277         return NULL;
 278 }
 279
 280 /* Sizing the IO windows of the PCI-PCI bridge is trivial,
 281    since these windows have 4K granularity and the IO ranges
 282    of non-bridge PCI devices are limited to 256 bytes.
 283    We must be careful with the ISA aliasing though. */
 284 static void pbus_size_io(struct pci_bus *bus)
 285 {
 286         struct pci_dev *dev;
 287         struct resource *b_res = find_free_bus_resource(bus, IORESOURCE_IO);
 288         unsigned long size = 0, size1 = 0;
 289
 290         if (!b_res)
 291                 return;
 292
 293         list_for_each_entry(dev, &bus->devices, bus_list) {
 294                 int i;
 295
 296                 for (i = 0; i < PCI_NUM_RESOURCES; i++) {
 297                         struct resource *r = &dev->resource[i];
 298                         unsigned long r_size;
 299
 300                         if (r->parent || !(r->flags & IORESOURCE_IO))
 301                                 continue;
 302                         r_size = r->end - r->start + 1;
 303
 304                         if (r_size < 0x400)
 305                                 /* Might be re-aligned for ISA */
 306                                 size += r_size;
 307                         else
 308                                 size1 += r_size;
 309                 }
 310         }
 311 /* To be fixed in 2.5: we should have sort of HAVE_ISA
 312    flag in the struct pci_bus. */
 313 #if defined(CONFIG_ISA) || defined(CONFIG_EISA)
 314         size = (size & 0xff) + ((size & ~0xffUL) << 2);
 315 #endif
 316         size = ALIGN(size + size1, 4096);
 317         if (!size) {
 318                 b_res->flags = 0;
 319                 return;
 320         }
 321         /* Alignment of the IO window is always 4K */
 322         b_res->start = 4096;
 323         b_res->end = b_res->start + size - 1;
 324         b_res->flags |= IORESOURCE_STARTALIGN;
 325 }
 326
 327 /* Calculate the size of the bus and minimal alignment which
 328    guarantees that all child resources fit in this size. */
 329 static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, unsigned long type)
 330 {
 331         struct pci_dev *dev;
 332         resource_size_t min_align, align, size;
 333         resource_size_t aligns[12];     /* Alignments from 1Mb to 2Gb */
 334         int order, max_order;
 335         struct resource *b_res = find_free_bus_resource(bus, type);
 336
 337         if (!b_res)
 338                 return 0;
 339
 340         memset(aligns, 0, sizeof(aligns));
 341         max_order = 0;
 342         size = 0;
 343
 344         list_for_each_entry(dev, &bus->devices, bus_list) {
 345                 int i;
 346
 347                 for (i = 0; i < PCI_NUM_RESOURCES; i++) {
 348                         struct resource *r = &dev->resource[i];
 349                         resource_size_t r_size;
 350
 351                         if (r->parent || (r->flags & mask) != type)
 352                                 continue;
 353                         r_size = r->end - r->start + 1;
 354                         /* For bridges size != alignment */
 355                         align = (i < PCI_BRIDGE_RESOURCES) ? r_size : r->start;
 356                         order = __ffs(align) - 20;
 357                         if (order > 11) {
 358                                 dev_warn(&dev->dev, "BAR %d too large: "
 359                                        "%#016llx-%#016llx\n", i,
 360                                        (unsigned long long)r->start,
 361                                        (unsigned long long)r->end);
 362                                 r->flags = 0;
 363                                 continue;
 364                         }
 365                         size += r_size;
 366                         if (order < 0)
 367                                 order = 0;
 368                         /* Exclude ranges with size > align from
 369                            calculation of the alignment. */
 370                         if (r_size == align)
 371                                 aligns[order] += align;
 372                         if (order > max_order)
 373                                 max_order = order;
 374                 }
 375         }
 376
 377         align = 0;
 378         min_align = 0;
 379         for (order = 0; order <= max_order; order++) {
 380 #ifdef CONFIG_RESOURCES_64BIT
 381                 resource_size_t align1 = 1ULL << (order + 20);
 382 #else
 383                 resource_size_t align1 = 1U << (order + 20);
 384 #endif
 385                 if (!align)
 386                         min_align = align1;
 387                 else if (ALIGN(align + min_align, min_align) < align1)
 388                         min_align = align1 >> 1;
 389                 align += aligns[order];
 390         }
 391         size = ALIGN(size, min_align);
 392         if (!size) {
 393                 b_res->flags = 0;
 394                 return 1;
 395         }
 396         b_res->start = min_align;
 397         b_res->end = size + min_align - 1;
 398         b_res->flags |= IORESOURCE_STARTALIGN;
 399         return 1;
 400 }
 401
 402 static void pci_bus_size_cardbus(struct pci_bus *bus)
 403 {
 404         struct pci_dev *bridge = bus->self;
 405         struct resource *b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
 406         u16 ctrl;
 407
 408         /*
 409          * Reserve some resources for CardBus.  We reserve
 410          * a fixed amount of bus space for CardBus bridges.
 411          */
 412         b_res[0].start = 0;
 413         b_res[0].end = pci_cardbus_io_size - 1;
 414         b_res[0].flags |= IORESOURCE_IO | IORESOURCE_SIZEALIGN;
 415
 416         b_res[1].start = 0;
 417         b_res[1].end = pci_cardbus_io_size - 1;
 418         b_res[1].flags |= IORESOURCE_IO | IORESOURCE_SIZEALIGN;
 419
 420         /*
 421          * Check whether prefetchable memory is supported
 422          * by this bridge.
 423          */
 424         pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
 425         if (!(ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0)) {
 426                 ctrl |= PCI_CB_BRIDGE_CTL_PREFETCH_MEM0;
 427                 pci_write_config_word(bridge, PCI_CB_BRIDGE_CONTROL, ctrl);
 428                 pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
 429         }
 430
 431         /*
 432          * If we have prefetchable memory support, allocate
 433          * two regions.  Otherwise, allocate one region of
 434          * twice the size.
 435          */
 436         if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0) {
 437                 b_res[2].start = 0;
 438                 b_res[2].end = pci_cardbus_mem_size - 1;
 439                 b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH | IORESOURCE_SIZEALIGN;
 440
 441                 b_res[3].start = 0;
 442                 b_res[3].end = pci_cardbus_mem_size - 1;
 443                 b_res[3].flags |= IORESOURCE_MEM | IORESOURCE_SIZEALIGN;
 444         } else {
 445                 b_res[3].start = 0;
 446                 b_res[3].end = pci_cardbus_mem_size * 2 - 1;
 447                 b_res[3].flags |= IORESOURCE_MEM | IORESOURCE_SIZEALIGN;
 448         }
 449 }
 450
 451 void __ref pci_bus_size_bridges(struct pci_bus *bus)
 452 {
 453         struct pci_dev *dev;
 454         unsigned long mask, prefmask;
 455
 456         list_for_each_entry(dev, &bus->devices, bus_list) {
 457                 struct pci_bus *b = dev->subordinate;
 458                 if (!b)
 459                         continue;
 460
 461                 switch (dev->class >> 8) {
 462                 case PCI_CLASS_BRIDGE_CARDBUS:
 463                         pci_bus_size_cardbus(b);
 464                         break;
 465
 466                 case PCI_CLASS_BRIDGE_PCI:
 467                 default:
 468                         pci_bus_size_bridges(b);
 469                         break;
 470                 }
 471         }
 472
 473         /* The root bus? */
 474         if (!bus->self)
 475                 return;
 476
 477         switch (bus->self->class >> 8) {
 478         case PCI_CLASS_BRIDGE_CARDBUS:
 479                 /* don't size cardbuses yet. */
 480                 break;
 481
 482         case PCI_CLASS_BRIDGE_PCI:
 483                 pci_bridge_check_ranges(bus);
 484         default:
 485                 pbus_size_io(bus);
 486                 /* If the bridge supports prefetchable range, size it
 487                    separately. If it doesn't, or its prefetchable window
 488                    has already been allocated by arch code, try
 489                    non-prefetchable range for both types of PCI memory
 490                    resources. */
 491                 mask = IORESOURCE_MEM;
 492                 prefmask = IORESOURCE_MEM | IORESOURCE_PREFETCH;
 493                 if (pbus_size_mem(bus, prefmask, prefmask))
 494                         mask = prefmask; /* Success, size non-prefetch only. */
 495                 pbus_size_mem(bus, mask, IORESOURCE_MEM);
 496                 break;
 497         }
 498 }
 499 EXPORT_SYMBOL(pci_bus_size_bridges);
 500
 501 void __ref pci_bus_assign_resources(struct pci_bus *bus)
 502 {
 503         struct pci_bus *b;
 504         struct pci_dev *dev;
 505
 506         pbus_assign_resources_sorted(bus);
 507
 508         list_for_each_entry(dev, &bus->devices, bus_list) {
 509                 b = dev->subordinate;
 510                 if (!b)
 511                         continue;
 512
 513                 pci_bus_assign_resources(b);
 514
 515                 switch (dev->class >> 8) {
 516                 case PCI_CLASS_BRIDGE_PCI:
 517                         pci_setup_bridge(b);
 518                         break;
 519
 520                 case PCI_CLASS_BRIDGE_CARDBUS:
 521                         pci_setup_cardbus(b);
 522                         break;
 523
 524                 default:
 525                         dev_info(&dev->dev, "not setting up bridge for bus "
 526                                  "%04x:%02x\n", pci_domain_nr(b), b->number);
 527                         break;
 528                 }
 529         }
 530 }
 531 EXPORT_SYMBOL(pci_bus_assign_resources);
 532
 533 void __init
 534 pci_assign_unassigned_resources(void)
 535 {
 536         struct pci_bus *bus;
 537
 538         /* Depth first, calculate sizes and alignments of all
 539            subordinate buses. */
 540         list_for_each_entry(bus, &pci_root_buses, node) {
 541                 pci_bus_size_bridges(bus);
 542         }
 543         /* Depth last, allocate resources and update the hardware. */
 544         list_for_each_entry(bus, &pci_root_buses, node) {
 545                 pci_bus_assign_resources(bus);
 546                 pci_enable_bridges(bus);
 547         }
 548 }