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 #include "pci.h" 29 30 static void pbus_assign_resources_sorted(const 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 res->start = 0; 62 res->end = 0; 63 res->flags = 0; 64 } 65 tmp = list; 66 list = list->next; 67 kfree(tmp); 68 } 69 } 70 71 void pci_setup_cardbus(struct pci_bus *bus) 72 { 73 struct pci_dev *bridge = bus->self; 74 struct pci_bus_region region; 75 76 dev_info(&bridge->dev, "CardBus bridge, secondary bus %04x:%02x\n", 77 pci_domain_nr(bus), bus->number); 78 79 pcibios_resource_to_bus(bridge, ®ion, bus->resource[0]); 80 if (bus->resource[0]->flags & IORESOURCE_IO) { 81 /* 82 * The IO resource is allocated a range twice as large as it 83 * would normally need. This allows us to set both IO regs. 84 */ 85 dev_info(&bridge->dev, " IO window: %#08lx-%#08lx\n", 86 (unsigned long)region.start, 87 (unsigned long)region.end); 88 pci_write_config_dword(bridge, PCI_CB_IO_BASE_0, 89 region.start); 90 pci_write_config_dword(bridge, PCI_CB_IO_LIMIT_0, 91 region.end); 92 } 93 94 pcibios_resource_to_bus(bridge, ®ion, bus->resource[1]); 95 if (bus->resource[1]->flags & IORESOURCE_IO) { 96 dev_info(&bridge->dev, " IO window: %#08lx-%#08lx\n", 97 (unsigned long)region.start, 98 (unsigned long)region.end); 99 pci_write_config_dword(bridge, PCI_CB_IO_BASE_1, 100 region.start); 101 pci_write_config_dword(bridge, PCI_CB_IO_LIMIT_1, 102 region.end); 103 } 104 105 pcibios_resource_to_bus(bridge, ®ion, bus->resource[2]); 106 if (bus->resource[2]->flags & IORESOURCE_MEM) { 107 dev_info(&bridge->dev, " PREFETCH window: %#08lx-%#08lx\n", 108 (unsigned long)region.start, 109 (unsigned long)region.end); 110 pci_write_config_dword(bridge, PCI_CB_MEMORY_BASE_0, 111 region.start); 112 pci_write_config_dword(bridge, PCI_CB_MEMORY_LIMIT_0, 113 region.end); 114 } 115 116 pcibios_resource_to_bus(bridge, ®ion, bus->resource[3]); 117 if (bus->resource[3]->flags & IORESOURCE_MEM) { 118 dev_info(&bridge->dev, " MEM window: %#08lx-%#08lx\n", 119 (unsigned long)region.start, 120 (unsigned long)region.end); 121 pci_write_config_dword(bridge, PCI_CB_MEMORY_BASE_1, 122 region.start); 123 pci_write_config_dword(bridge, PCI_CB_MEMORY_LIMIT_1, 124 region.end); 125 } 126 } 127 EXPORT_SYMBOL(pci_setup_cardbus); 128 129 /* Initialize bridges with base/limit values we have collected. 130 PCI-to-PCI Bridge Architecture Specification rev. 1.1 (1998) 131 requires that if there is no I/O ports or memory behind the 132 bridge, corresponding range must be turned off by writing base 133 value greater than limit to the bridge's base/limit registers. 134 135 Note: care must be taken when updating I/O base/limit registers 136 of bridges which support 32-bit I/O. This update requires two 137 config space writes, so it's quite possible that an I/O window of 138 the bridge will have some undesirable address (e.g. 0) after the 139 first write. Ditto 64-bit prefetchable MMIO. */ 140 static void pci_setup_bridge(struct pci_bus *bus) 141 { 142 struct pci_dev *bridge = bus->self; 143 struct pci_bus_region region; 144 u32 l, bu, lu, io_upper16; 145 int pref_mem64; 146 147 if (pci_is_enabled(bridge)) 148 return; 149 150 dev_info(&bridge->dev, "PCI bridge, secondary bus %04x:%02x\n", 151 pci_domain_nr(bus), bus->number); 152 153 /* Set up the top and bottom of the PCI I/O segment for this bus. */ 154 pcibios_resource_to_bus(bridge, ®ion, bus->resource[0]); 155 if (bus->resource[0]->flags & IORESOURCE_IO) { 156 pci_read_config_dword(bridge, PCI_IO_BASE, &l); 157 l &= 0xffff0000; 158 l |= (region.start >> 8) & 0x00f0; 159 l |= region.end & 0xf000; 160 /* Set up upper 16 bits of I/O base/limit. */ 161 io_upper16 = (region.end & 0xffff0000) | (region.start >> 16); 162 dev_info(&bridge->dev, " IO window: %#04lx-%#04lx\n", 163 (unsigned long)region.start, 164 (unsigned long)region.end); 165 } 166 else { 167 /* Clear upper 16 bits of I/O base/limit. */ 168 io_upper16 = 0; 169 l = 0x00f0; 170 dev_info(&bridge->dev, " IO window: disabled\n"); 171 } 172 /* Temporarily disable the I/O range before updating PCI_IO_BASE. */ 173 pci_write_config_dword(bridge, PCI_IO_BASE_UPPER16, 0x0000ffff); 174 /* Update lower 16 bits of I/O base/limit. */ 175 pci_write_config_dword(bridge, PCI_IO_BASE, l); 176 /* Update upper 16 bits of I/O base/limit. */ 177 pci_write_config_dword(bridge, PCI_IO_BASE_UPPER16, io_upper16); 178 179 /* Set up the top and bottom of the PCI Memory segment 180 for this bus. */ 181 pcibios_resource_to_bus(bridge, ®ion, bus->resource[1]); 182 if (bus->resource[1]->flags & IORESOURCE_MEM) { 183 l = (region.start >> 16) & 0xfff0; 184 l |= region.end & 0xfff00000; 185 dev_info(&bridge->dev, " MEM window: %#08lx-%#08lx\n", 186 (unsigned long)region.start, 187 (unsigned long)region.end); 188 } 189 else { 190 l = 0x0000fff0; 191 dev_info(&bridge->dev, " MEM window: disabled\n"); 192 } 193 pci_write_config_dword(bridge, PCI_MEMORY_BASE, l); 194 195 /* Clear out the upper 32 bits of PREF limit. 196 If PCI_PREF_BASE_UPPER32 was non-zero, this temporarily 197 disables PREF range, which is ok. */ 198 pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, 0); 199 200 /* Set up PREF base/limit. */ 201 pref_mem64 = 0; 202 bu = lu = 0; 203 pcibios_resource_to_bus(bridge, ®ion, bus->resource[2]); 204 if (bus->resource[2]->flags & IORESOURCE_PREFETCH) { 205 int width = 8; 206 l = (region.start >> 16) & 0xfff0; 207 l |= region.end & 0xfff00000; 208 if (bus->resource[2]->flags & IORESOURCE_MEM_64) { 209 pref_mem64 = 1; 210 bu = upper_32_bits(region.start); 211 lu = upper_32_bits(region.end); 212 width = 16; 213 } 214 dev_info(&bridge->dev, " PREFETCH window: %#0*llx-%#0*llx\n", 215 width, (unsigned long long)region.start, 216 width, (unsigned long long)region.end); 217 } 218 else { 219 l = 0x0000fff0; 220 dev_info(&bridge->dev, " PREFETCH window: disabled\n"); 221 } 222 pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, l); 223 224 if (pref_mem64) { 225 /* Set the upper 32 bits of PREF base & limit. */ 226 pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, bu); 227 pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, lu); 228 } 229 230 pci_write_config_word(bridge, PCI_BRIDGE_CONTROL, bus->bridge_ctl); 231 } 232 233 /* Check whether the bridge supports optional I/O and 234 prefetchable memory ranges. If not, the respective 235 base/limit registers must be read-only and read as 0. */ 236 static void pci_bridge_check_ranges(struct pci_bus *bus) 237 { 238 u16 io; 239 u32 pmem; 240 struct pci_dev *bridge = bus->self; 241 struct resource *b_res; 242 243 b_res = &bridge->resource[PCI_BRIDGE_RESOURCES]; 244 b_res[1].flags |= IORESOURCE_MEM; 245 246 pci_read_config_word(bridge, PCI_IO_BASE, &io); 247 if (!io) { 248 pci_write_config_word(bridge, PCI_IO_BASE, 0xf0f0); 249 pci_read_config_word(bridge, PCI_IO_BASE, &io); 250 pci_write_config_word(bridge, PCI_IO_BASE, 0x0); 251 } 252 if (io) 253 b_res[0].flags |= IORESOURCE_IO; 254 /* DECchip 21050 pass 2 errata: the bridge may miss an address 255 disconnect boundary by one PCI data phase. 256 Workaround: do not use prefetching on this device. */ 257 if (bridge->vendor == PCI_VENDOR_ID_DEC && bridge->device == 0x0001) 258 return; 259 pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem); 260 if (!pmem) { 261 pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, 262 0xfff0fff0); 263 pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem); 264 pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, 0x0); 265 } 266 if (pmem) { 267 b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH; 268 if ((pmem & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64) 269 b_res[2].flags |= IORESOURCE_MEM_64; 270 } 271 272 /* double check if bridge does support 64 bit pref */ 273 if (b_res[2].flags & IORESOURCE_MEM_64) { 274 u32 mem_base_hi, tmp; 275 pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, 276 &mem_base_hi); 277 pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, 278 0xffffffff); 279 pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &tmp); 280 if (!tmp) 281 b_res[2].flags &= ~IORESOURCE_MEM_64; 282 pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, 283 mem_base_hi); 284 } 285 } 286 287 /* Helper function for sizing routines: find first available 288 bus resource of a given type. Note: we intentionally skip 289 the bus resources which have already been assigned (that is, 290 have non-NULL parent resource). */ 291 static struct resource *find_free_bus_resource(struct pci_bus *bus, unsigned long type) 292 { 293 int i; 294 struct resource *r; 295 unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM | 296 IORESOURCE_PREFETCH; 297 298 for (i = 0; i < PCI_BUS_NUM_RESOURCES; i++) { 299 r = bus->resource[i]; 300 if (r == &ioport_resource || r == &iomem_resource) 301 continue; 302 if (r && (r->flags & type_mask) == type) { 303 if (!r->parent) 304 return r; 305 /* 306 * if there is no child under that, we should release 307 * and use it. don't need to reset it, pbus_size_* will 308 * set it again 309 */ 310 if (!r->child && !release_resource(r)) 311 return r; 312 } 313 } 314 return NULL; 315 } 316 317 /* Sizing the IO windows of the PCI-PCI bridge is trivial, 318 since these windows have 4K granularity and the IO ranges 319 of non-bridge PCI devices are limited to 256 bytes. 320 We must be careful with the ISA aliasing though. */ 321 static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size) 322 { 323 struct pci_dev *dev; 324 struct resource *b_res = find_free_bus_resource(bus, IORESOURCE_IO); 325 unsigned long size = 0, size1 = 0; 326 327 if (!b_res) 328 return; 329 330 list_for_each_entry(dev, &bus->devices, bus_list) { 331 int i; 332 333 for (i = 0; i < PCI_NUM_RESOURCES; i++) { 334 struct resource *r = &dev->resource[i]; 335 unsigned long r_size; 336 337 if (r->parent || !(r->flags & IORESOURCE_IO)) 338 continue; 339 r_size = resource_size(r); 340 341 if (r_size < 0x400) 342 /* Might be re-aligned for ISA */ 343 size += r_size; 344 else 345 size1 += r_size; 346 } 347 } 348 if (size < min_size) 349 size = min_size; 350 /* To be fixed in 2.5: we should have sort of HAVE_ISA 351 flag in the struct pci_bus. */ 352 #if defined(CONFIG_ISA) || defined(CONFIG_EISA) 353 size = (size & 0xff) + ((size & ~0xffUL) << 2); 354 #endif 355 size = ALIGN(size + size1, 4096); 356 if (!size) { 357 b_res->flags = 0; 358 return; 359 } 360 /* Alignment of the IO window is always 4K */ 361 b_res->start = 4096; 362 b_res->end = b_res->start + size - 1; 363 b_res->flags |= IORESOURCE_STARTALIGN; 364 } 365 366 /* Calculate the size of the bus and minimal alignment which 367 guarantees that all child resources fit in this size. */ 368 static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, 369 unsigned long type, resource_size_t min_size) 370 { 371 struct pci_dev *dev; 372 resource_size_t min_align, align, size; 373 resource_size_t aligns[12]; /* Alignments from 1Mb to 2Gb */ 374 int order, max_order; 375 struct resource *b_res = find_free_bus_resource(bus, type); 376 unsigned int mem64_mask = 0; 377 378 if (!b_res) 379 return 0; 380 381 memset(aligns, 0, sizeof(aligns)); 382 max_order = 0; 383 size = 0; 384 385 mem64_mask = b_res->flags & IORESOURCE_MEM_64; 386 b_res->flags &= ~IORESOURCE_MEM_64; 387 388 list_for_each_entry(dev, &bus->devices, bus_list) { 389 int i; 390 391 for (i = 0; i < PCI_NUM_RESOURCES; i++) { 392 struct resource *r = &dev->resource[i]; 393 resource_size_t r_size; 394 395 if (r->parent || (r->flags & mask) != type) 396 continue; 397 r_size = resource_size(r); 398 /* For bridges size != alignment */ 399 align = pci_resource_alignment(dev, r); 400 order = __ffs(align) - 20; 401 if (order > 11) { 402 dev_warn(&dev->dev, "BAR %d bad alignment %llx: " 403 "%pR\n", i, (unsigned long long)align, r); 404 r->flags = 0; 405 continue; 406 } 407 size += r_size; 408 if (order < 0) 409 order = 0; 410 /* Exclude ranges with size > align from 411 calculation of the alignment. */ 412 if (r_size == align) 413 aligns[order] += align; 414 if (order > max_order) 415 max_order = order; 416 mem64_mask &= r->flags & IORESOURCE_MEM_64; 417 } 418 } 419 if (size < min_size) 420 size = min_size; 421 422 align = 0; 423 min_align = 0; 424 for (order = 0; order <= max_order; order++) { 425 resource_size_t align1 = 1; 426 427 align1 <<= (order + 20); 428 429 if (!align) 430 min_align = align1; 431 else if (ALIGN(align + min_align, min_align) < align1) 432 min_align = align1 >> 1; 433 align += aligns[order]; 434 } 435 size = ALIGN(size, min_align); 436 if (!size) { 437 b_res->flags = 0; 438 return 1; 439 } 440 b_res->start = min_align; 441 b_res->end = size + min_align - 1; 442 b_res->flags |= IORESOURCE_STARTALIGN; 443 b_res->flags |= mem64_mask; 444 return 1; 445 } 446 447 static void pci_bus_size_cardbus(struct pci_bus *bus) 448 { 449 struct pci_dev *bridge = bus->self; 450 struct resource *b_res = &bridge->resource[PCI_BRIDGE_RESOURCES]; 451 u16 ctrl; 452 453 /* 454 * Reserve some resources for CardBus. We reserve 455 * a fixed amount of bus space for CardBus bridges. 456 */ 457 b_res[0].start = 0; 458 b_res[0].end = pci_cardbus_io_size - 1; 459 b_res[0].flags |= IORESOURCE_IO | IORESOURCE_SIZEALIGN; 460 461 b_res[1].start = 0; 462 b_res[1].end = pci_cardbus_io_size - 1; 463 b_res[1].flags |= IORESOURCE_IO | IORESOURCE_SIZEALIGN; 464 465 /* 466 * Check whether prefetchable memory is supported 467 * by this bridge. 468 */ 469 pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl); 470 if (!(ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0)) { 471 ctrl |= PCI_CB_BRIDGE_CTL_PREFETCH_MEM0; 472 pci_write_config_word(bridge, PCI_CB_BRIDGE_CONTROL, ctrl); 473 pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl); 474 } 475 476 /* 477 * If we have prefetchable memory support, allocate 478 * two regions. Otherwise, allocate one region of 479 * twice the size. 480 */ 481 if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0) { 482 b_res[2].start = 0; 483 b_res[2].end = pci_cardbus_mem_size - 1; 484 b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH | IORESOURCE_SIZEALIGN; 485 486 b_res[3].start = 0; 487 b_res[3].end = pci_cardbus_mem_size - 1; 488 b_res[3].flags |= IORESOURCE_MEM | IORESOURCE_SIZEALIGN; 489 } else { 490 b_res[3].start = 0; 491 b_res[3].end = pci_cardbus_mem_size * 2 - 1; 492 b_res[3].flags |= IORESOURCE_MEM | IORESOURCE_SIZEALIGN; 493 } 494 } 495 496 void __ref pci_bus_size_bridges(struct pci_bus *bus) 497 { 498 struct pci_dev *dev; 499 unsigned long mask, prefmask; 500 resource_size_t min_mem_size = 0, min_io_size = 0; 501 502 list_for_each_entry(dev, &bus->devices, bus_list) { 503 struct pci_bus *b = dev->subordinate; 504 if (!b) 505 continue; 506 507 switch (dev->class >> 8) { 508 case PCI_CLASS_BRIDGE_CARDBUS: 509 pci_bus_size_cardbus(b); 510 break; 511 512 case PCI_CLASS_BRIDGE_PCI: 513 default: 514 pci_bus_size_bridges(b); 515 break; 516 } 517 } 518 519 /* The root bus? */ 520 if (!bus->self) 521 return; 522 523 switch (bus->self->class >> 8) { 524 case PCI_CLASS_BRIDGE_CARDBUS: 525 /* don't size cardbuses yet. */ 526 break; 527 528 case PCI_CLASS_BRIDGE_PCI: 529 pci_bridge_check_ranges(bus); 530 if (bus->self->is_hotplug_bridge) { 531 min_io_size = pci_hotplug_io_size; 532 min_mem_size = pci_hotplug_mem_size; 533 } 534 default: 535 pbus_size_io(bus, min_io_size); 536 /* If the bridge supports prefetchable range, size it 537 separately. If it doesn't, or its prefetchable window 538 has already been allocated by arch code, try 539 non-prefetchable range for both types of PCI memory 540 resources. */ 541 mask = IORESOURCE_MEM; 542 prefmask = IORESOURCE_MEM | IORESOURCE_PREFETCH; 543 if (pbus_size_mem(bus, prefmask, prefmask, min_mem_size)) 544 mask = prefmask; /* Success, size non-prefetch only. */ 545 else 546 min_mem_size += min_mem_size; 547 pbus_size_mem(bus, mask, IORESOURCE_MEM, min_mem_size); 548 break; 549 } 550 } 551 EXPORT_SYMBOL(pci_bus_size_bridges); 552 553 void __ref pci_bus_assign_resources(const struct pci_bus *bus) 554 { 555 struct pci_bus *b; 556 struct pci_dev *dev; 557 558 pbus_assign_resources_sorted(bus); 559 560 list_for_each_entry(dev, &bus->devices, bus_list) { 561 b = dev->subordinate; 562 if (!b) 563 continue; 564 565 pci_bus_assign_resources(b); 566 567 switch (dev->class >> 8) { 568 case PCI_CLASS_BRIDGE_PCI: 569 pci_setup_bridge(b); 570 break; 571 572 case PCI_CLASS_BRIDGE_CARDBUS: 573 pci_setup_cardbus(b); 574 break; 575 576 default: 577 dev_info(&dev->dev, "not setting up bridge for bus " 578 "%04x:%02x\n", pci_domain_nr(b), b->number); 579 break; 580 } 581 } 582 } 583 EXPORT_SYMBOL(pci_bus_assign_resources); 584 585 static void pci_bus_dump_res(struct pci_bus *bus) 586 { 587 int i; 588 589 for (i = 0; i < PCI_BUS_NUM_RESOURCES; i++) { 590 struct resource *res = bus->resource[i]; 591 if (!res || !res->end) 592 continue; 593 594 dev_printk(KERN_DEBUG, &bus->dev, "resource %d %s %pR\n", i, 595 (res->flags & IORESOURCE_IO) ? "io: " : 596 ((res->flags & IORESOURCE_PREFETCH)? "pref mem":"mem:"), 597 res); 598 } 599 } 600 601 static void pci_bus_dump_resources(struct pci_bus *bus) 602 { 603 struct pci_bus *b; 604 struct pci_dev *dev; 605 606 607 pci_bus_dump_res(bus); 608 609 list_for_each_entry(dev, &bus->devices, bus_list) { 610 b = dev->subordinate; 611 if (!b) 612 continue; 613 614 pci_bus_dump_resources(b); 615 } 616 } 617 618 void __init 619 pci_assign_unassigned_resources(void) 620 { 621 struct pci_bus *bus; 622 623 /* Depth first, calculate sizes and alignments of all 624 subordinate buses. */ 625 list_for_each_entry(bus, &pci_root_buses, node) { 626 pci_bus_size_bridges(bus); 627 } 628 /* Depth last, allocate resources and update the hardware. */ 629 list_for_each_entry(bus, &pci_root_buses, node) { 630 pci_bus_assign_resources(bus); 631 pci_enable_bridges(bus); 632 } 633 634 /* dump the resource on buses */ 635 list_for_each_entry(bus, &pci_root_buses, node) { 636 pci_bus_dump_resources(bus); 637 } 638 } 639