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   1 /*
   2  * arch/ppc/syslib/pci_auto.c
   3  *
   4  * PCI autoconfiguration library
   5  *
   6  * Author: Matt Porter <mporter@mvista.com>
   7  *
   8  * 2001 (c) MontaVista, Software, Inc.  This file is licensed under
   9  * the terms of the GNU General Public License version 2.  This program
  10  * is licensed "as is" without any warranty of any kind, whether express
  11  * or implied.
  12  */
  13
  14 /*
  15  * The CardBus support is very preliminary.  Preallocating space is
  16  * the way to go but will require some change in card services to
  17  * make it useful.  Eventually this will ensure that we can put
  18  * multiple CB bridges behind multiple P2P bridges.  For now, at
  19  * least it ensures that we place the CB bridge BAR and assigned
  20  * initial bus numbers.  I definitely need to do something about
  21  * the lack of 16-bit I/O support. -MDP
  22  */
  23
  24 #include <linux/kernel.h>
  25 #include <linux/init.h>
  26 #include <linux/pci.h>
  27
  28 #include <asm/pci-bridge.h>
  29
  30 #define PCIAUTO_IDE_MODE_MASK           0x05
  31
  32 #undef DEBUG
  33
  34 #ifdef DEBUG
  35 #define DBG(x...) printk(x)
  36 #else
  37 #define DBG(x...)
  38 #endif /* DEBUG */
  39
  40 static int pciauto_upper_iospc;
  41 static int pciauto_upper_memspc;
  42
  43 void __init pciauto_setup_bars(struct pci_controller *hose,
  44                 int current_bus,
  45                 int pci_devfn,
  46                 int bar_limit)
  47 {
  48         int bar_response, bar_size, bar_value;
  49         int bar, addr_mask;
  50         int * upper_limit;
  51         int found_mem64 = 0;
  52
  53         DBG("PCI Autoconfig: Found Bus %d, Device %d, Function %d\n",
  54                 current_bus, PCI_SLOT(pci_devfn), PCI_FUNC(pci_devfn) );
  55
  56         for (bar = PCI_BASE_ADDRESS_0; bar <= bar_limit; bar+=4) {
  57                 /* Tickle the BAR and get the response */
  58                 early_write_config_dword(hose,
  59                                 current_bus,
  60                                 pci_devfn,
  61                                 bar,
  62                                 0xffffffff);
  63                 early_read_config_dword(hose,
  64                                 current_bus,
  65                                 pci_devfn,
  66                                 bar,
  67                                 &bar_response);
  68
  69                 /* If BAR is not implemented go to the next BAR */
  70                 if (!bar_response)
  71                         continue;
  72
  73                 /* Check the BAR type and set our address mask */
  74                 if (bar_response & PCI_BASE_ADDRESS_SPACE) {
  75                         addr_mask = PCI_BASE_ADDRESS_IO_MASK;
  76                         upper_limit = &pciauto_upper_iospc;
  77                         DBG("PCI Autoconfig: BAR 0x%x, I/O, ", bar);
  78                 } else {
  79                         if ( (bar_response & PCI_BASE_ADDRESS_MEM_TYPE_MASK) ==
  80                         PCI_BASE_ADDRESS_MEM_TYPE_64)
  81                                 found_mem64 = 1;
  82
  83                         addr_mask = PCI_BASE_ADDRESS_MEM_MASK;
  84                         upper_limit = &pciauto_upper_memspc;
  85                         DBG("PCI Autoconfig: BAR 0x%x, Mem ", bar);
  86                 }
  87
  88                 /* Calculate requested size */
  89                 bar_size = ~(bar_response & addr_mask) + 1;
  90
  91                 /* Allocate a base address */
  92                 bar_value = (*upper_limit - bar_size) & ~(bar_size - 1);
  93
  94                 /* Write it out and update our limit */
  95                 early_write_config_dword(hose,
  96                                 current_bus,
  97                                 pci_devfn,
  98                                 bar,
  99                                 bar_value);
 100
 101                 *upper_limit = bar_value;
 102
 103                 /*
 104                  * If we are a 64-bit decoder then increment to the
 105                  * upper 32 bits of the bar and force it to locate
 106                  * in the lower 4GB of memory.
 107                  */
 108                 if (found_mem64) {
 109                         bar += 4;
 110                         early_write_config_dword(hose,
 111                                         current_bus,
 112                                         pci_devfn,
 113                                         bar,
 114                                         0x00000000);
 115                         found_mem64 = 0;
 116                 }
 117
 118                 DBG("size=0x%x, address=0x%x\n",
 119                         bar_size, bar_value);
 120         }
 121
 122 }
 123
 124 void __init pciauto_prescan_setup_bridge(struct pci_controller *hose,
 125                 int current_bus,
 126                 int pci_devfn,
 127                 int sub_bus,
 128                 int *iosave,
 129                 int *memsave)
 130 {
 131         /* Configure bus number registers */
 132         early_write_config_byte(hose,
 133                         current_bus,
 134                         pci_devfn,
 135                         PCI_PRIMARY_BUS,
 136                         current_bus);
 137         early_write_config_byte(hose,
 138                         current_bus,
 139                         pci_devfn,
 140                         PCI_SECONDARY_BUS,
 141                         sub_bus + 1);
 142         early_write_config_byte(hose,
 143                         current_bus,
 144                         pci_devfn,
 145                         PCI_SUBORDINATE_BUS,
 146                         0xff);
 147
 148         /* Round memory allocator to 1MB boundary */
 149         pciauto_upper_memspc &= ~(0x100000 - 1);
 150         *memsave = pciauto_upper_memspc;
 151
 152         /* Round I/O allocator to 4KB boundary */
 153         pciauto_upper_iospc &= ~(0x1000 - 1);
 154         *iosave = pciauto_upper_iospc;
 155
 156         /* Set up memory and I/O filter limits, assume 32-bit I/O space */
 157         early_write_config_word(hose,
 158                         current_bus,
 159                         pci_devfn,
 160                         PCI_MEMORY_LIMIT,
 161                         ((pciauto_upper_memspc - 1) & 0xfff00000) >> 16);
 162         early_write_config_byte(hose,
 163                         current_bus,
 164                         pci_devfn,
 165                         PCI_IO_LIMIT,
 166                         ((pciauto_upper_iospc - 1) & 0x0000f000) >> 8);
 167         early_write_config_word(hose,
 168                         current_bus,
 169                         pci_devfn,
 170                         PCI_IO_LIMIT_UPPER16,
 171                         ((pciauto_upper_iospc - 1) & 0xffff0000) >> 16);
 172
 173         /* Zero upper 32 bits of prefetchable base/limit */
 174         early_write_config_dword(hose,
 175                         current_bus,
 176                         pci_devfn,
 177                         PCI_PREF_BASE_UPPER32,
 178                         0);
 179         early_write_config_dword(hose,
 180                         current_bus,
 181                         pci_devfn,
 182                         PCI_PREF_LIMIT_UPPER32,
 183                         0);
 184 }
 185
 186 void __init pciauto_postscan_setup_bridge(struct pci_controller *hose,
 187                 int current_bus,
 188                 int pci_devfn,
 189                 int sub_bus,
 190                 int *iosave,
 191                 int *memsave)
 192 {
 193         int cmdstat;
 194
 195         /* Configure bus number registers */
 196         early_write_config_byte(hose,
 197                         current_bus,
 198                         pci_devfn,
 199                         PCI_SUBORDINATE_BUS,
 200                         sub_bus);
 201
 202         /*
 203          * Round memory allocator to 1MB boundary.
 204          * If no space used, allocate minimum.
 205          */
 206         pciauto_upper_memspc &= ~(0x100000 - 1);
 207         if (*memsave == pciauto_upper_memspc)
 208                 pciauto_upper_memspc -= 0x00100000;
 209
 210         early_write_config_word(hose,
 211                         current_bus,
 212                         pci_devfn,
 213                         PCI_MEMORY_BASE,
 214                         pciauto_upper_memspc >> 16);
 215
 216         /* Allocate 1MB for pre-fretch */
 217         early_write_config_word(hose,
 218                         current_bus,
 219                         pci_devfn,
 220                         PCI_PREF_MEMORY_LIMIT,
 221                         ((pciauto_upper_memspc - 1) & 0xfff00000) >> 16);
 222
 223         pciauto_upper_memspc -= 0x100000;
 224
 225         early_write_config_word(hose,
 226                         current_bus,
 227                         pci_devfn,
 228                         PCI_PREF_MEMORY_BASE,
 229                         pciauto_upper_memspc >> 16);
 230
 231         /* Round I/O allocator to 4KB boundary */
 232         pciauto_upper_iospc &= ~(0x1000 - 1);
 233         if (*iosave == pciauto_upper_iospc)
 234                 pciauto_upper_iospc -= 0x1000;
 235
 236         early_write_config_byte(hose,
 237                         current_bus,
 238                         pci_devfn,
 239                         PCI_IO_BASE,
 240                         (pciauto_upper_iospc & 0x0000f000) >> 8);
 241         early_write_config_word(hose,
 242                         current_bus,
 243                         pci_devfn,
 244                         PCI_IO_BASE_UPPER16,
 245                         pciauto_upper_iospc >> 16);
 246
 247         /* Enable memory and I/O accesses, enable bus master */
 248         early_read_config_dword(hose,
 249                         current_bus,
 250                         pci_devfn,
 251                         PCI_COMMAND,
 252                         &cmdstat);
 253         early_write_config_dword(hose,
 254                         current_bus,
 255                         pci_devfn,
 256                         PCI_COMMAND,
 257                         cmdstat |
 258                         PCI_COMMAND_IO |
 259                         PCI_COMMAND_MEMORY |
 260                         PCI_COMMAND_MASTER);
 261 }
 262
 263 void __init pciauto_prescan_setup_cardbus_bridge(struct pci_controller *hose,
 264                 int current_bus,
 265                 int pci_devfn,
 266                 int sub_bus,
 267                 int *iosave,
 268                 int *memsave)
 269 {
 270         /* Configure bus number registers */
 271         early_write_config_byte(hose,
 272                         current_bus,
 273                         pci_devfn,
 274                         PCI_PRIMARY_BUS,
 275                         current_bus);
 276         early_write_config_byte(hose,
 277                         current_bus,
 278                         pci_devfn,
 279                         PCI_SECONDARY_BUS,
 280                         sub_bus + 1);
 281         early_write_config_byte(hose,
 282                         current_bus,
 283                         pci_devfn,
 284                         PCI_SUBORDINATE_BUS,
 285                         0xff);
 286
 287         /* Round memory allocator to 4KB boundary */
 288         pciauto_upper_memspc &= ~(0x1000 - 1);
 289         *memsave = pciauto_upper_memspc;
 290
 291         /* Round I/O allocator to 4 byte boundary */
 292         pciauto_upper_iospc &= ~(0x4 - 1);
 293         *iosave = pciauto_upper_iospc;
 294
 295         /* Set up memory and I/O filter limits, assume 32-bit I/O space */
 296         early_write_config_dword(hose,
 297                         current_bus,
 298                         pci_devfn,
 299                         0x20,
 300                         pciauto_upper_memspc - 1);
 301         early_write_config_dword(hose,
 302                         current_bus,
 303                         pci_devfn,
 304                         0x30,
 305                         pciauto_upper_iospc - 1);
 306 }
 307
 308 void __init pciauto_postscan_setup_cardbus_bridge(struct pci_controller *hose,
 309                 int current_bus,
 310                 int pci_devfn,
 311                 int sub_bus,
 312                 int *iosave,
 313                 int *memsave)
 314 {
 315         int cmdstat;
 316
 317         /*
 318          * Configure subordinate bus number.  The PCI subsystem
 319          * bus scan will renumber buses (reserving three additional
 320          * for this PCI<->CardBus bridge for the case where a CardBus
 321          * adapter contains a P2P or CB2CB bridge.
 322          */
 323         early_write_config_byte(hose,
 324                         current_bus,
 325                         pci_devfn,
 326                         PCI_SUBORDINATE_BUS,
 327                         sub_bus);
 328
 329         /*
 330          * Reserve an additional 4MB for mem space and 16KB for
 331          * I/O space.  This should cover any additional space
 332          * requirement of unusual CardBus devices with
 333          * additional bridges that can consume more address space.
 334          *
 335          * Although pcmcia-cs currently will reprogram bridge
 336          * windows, the goal is to add an option to leave them
 337          * alone and use the bridge window ranges as the regions
 338          * that are searched for free resources upon hot-insertion
 339          * of a device.  This will allow a PCI<->CardBus bridge
 340          * configured by this routine to happily live behind a
 341          * P2P bridge in a system.
 342          */
 343         pciauto_upper_memspc -= 0x00400000;
 344         pciauto_upper_iospc -= 0x00004000;
 345
 346         /* Round memory allocator to 4KB boundary */
 347         pciauto_upper_memspc &= ~(0x1000 - 1);
 348
 349         early_write_config_dword(hose,
 350                         current_bus,
 351                         pci_devfn,
 352                         0x1c,
 353                         pciauto_upper_memspc);
 354
 355         /* Round I/O allocator to 4 byte boundary */
 356         pciauto_upper_iospc &= ~(0x4 - 1);
 357         early_write_config_dword(hose,
 358                         current_bus,
 359                         pci_devfn,
 360                         0x2c,
 361                         pciauto_upper_iospc);
 362
 363         /* Enable memory and I/O accesses, enable bus master */
 364         early_read_config_dword(hose,
 365                         current_bus,
 366                         pci_devfn,
 367                         PCI_COMMAND,
 368                         &cmdstat);
 369         early_write_config_dword(hose,
 370                         current_bus,
 371                         pci_devfn,
 372                         PCI_COMMAND,
 373                         cmdstat |
 374                         PCI_COMMAND_IO |
 375                         PCI_COMMAND_MEMORY |
 376                         PCI_COMMAND_MASTER);
 377 }
 378
 379 int __init pciauto_bus_scan(struct pci_controller *hose, int current_bus)
 380 {
 381         int sub_bus, pci_devfn, pci_class, cmdstat, found_multi = 0;
 382         unsigned short vid;
 383         unsigned char header_type;
 384
 385         /*
 386          * Fetch our I/O and memory space upper boundaries used
 387          * to allocated base addresses on this hose.
 388          */
 389         if (current_bus == hose->first_busno) {
 390                 pciauto_upper_iospc = hose->io_space.end + 1;
 391                 pciauto_upper_memspc = hose->mem_space.end + 1;
 392         }
 393
 394         sub_bus = current_bus;
 395
 396         for (pci_devfn = 0; pci_devfn < 0xff; pci_devfn++) {
 397                 /* Skip our host bridge */
 398                 if ( (current_bus == hose->first_busno) && (pci_devfn == 0) )
 399                         continue;
 400
 401                 if (PCI_FUNC(pci_devfn) && !found_multi)
 402                         continue;
 403
 404                 /* If config space read fails from this device, move on */
 405                 if (early_read_config_byte(hose,
 406                                 current_bus,
 407                                 pci_devfn,
 408                                 PCI_HEADER_TYPE,
 409                                 &header_type))
 410                         continue;
 411
 412                 if (!PCI_FUNC(pci_devfn))
 413                         found_multi = header_type & 0x80;
 414
 415                 early_read_config_word(hose,
 416                                 current_bus,
 417                                 pci_devfn,
 418                                 PCI_VENDOR_ID,
 419                                 &vid);
 420
 421                 if (vid != 0xffff) {
 422                         early_read_config_dword(hose,
 423                                         current_bus,
 424                                         pci_devfn,
 425                                         PCI_CLASS_REVISION, &pci_class);
 426                         if ( (pci_class >> 16) == PCI_CLASS_BRIDGE_PCI ) {
 427                                 int iosave, memsave;
 428
 429                                 DBG("PCI Autoconfig: Found P2P bridge, device %d\n", PCI_SLOT(pci_devfn));
 430                                 /* Allocate PCI I/O and/or memory space */
 431                                 pciauto_setup_bars(hose,
 432                                                 current_bus,
 433                                                 pci_devfn,
 434                                                 PCI_BASE_ADDRESS_1);
 435
 436                                 pciauto_prescan_setup_bridge(hose,
 437                                                 current_bus,
 438                                                 pci_devfn,
 439                                                 sub_bus,
 440                                                 &iosave,
 441                                                 &memsave);
 442                                 sub_bus = pciauto_bus_scan(hose, sub_bus+1);
 443                                 pciauto_postscan_setup_bridge(hose,
 444                                                 current_bus,
 445                                                 pci_devfn,
 446                                                 sub_bus,
 447                                                 &iosave,
 448                                                 &memsave);
 449                         } else if ((pci_class >> 16) == PCI_CLASS_BRIDGE_CARDBUS) {
 450                                 int iosave, memsave;
 451
 452                                 DBG("PCI Autoconfig: Found CardBus bridge, device %d function %d\n", PCI_SLOT(pci_devfn), PCI_FUNC(pci_devfn));
 453                                 /* Place CardBus Socket/ExCA registers */
 454                                 pciauto_setup_bars(hose,
 455                                                 current_bus,
 456                                                 pci_devfn,
 457                                                 PCI_BASE_ADDRESS_0);
 458
 459                                 pciauto_prescan_setup_cardbus_bridge(hose,
 460                                                 current_bus,
 461                                                 pci_devfn,
 462                                                 sub_bus,
 463                                                 &iosave,
 464                                                 &memsave);
 465                                 sub_bus = pciauto_bus_scan(hose, sub_bus+1);
 466                                 pciauto_postscan_setup_cardbus_bridge(hose,
 467                                                 current_bus,
 468                                                 pci_devfn,
 469                                                 sub_bus,
 470                                                 &iosave,
 471                                                 &memsave);
 472                         } else {
 473                                 if ((pci_class >> 16) == PCI_CLASS_STORAGE_IDE) {
 474                                         unsigned char prg_iface;
 475
 476                                         early_read_config_byte(hose,
 477                                                         current_bus,
 478                                                         pci_devfn,
 479                                                         PCI_CLASS_PROG,
 480                                                         &prg_iface);
 481                                         if (!(prg_iface & PCIAUTO_IDE_MODE_MASK)) {
 482                                                 DBG("PCI Autoconfig: Skipping legacy mode IDE controller\n");
 483                                                 continue;
 484                                         }
 485                                 }
 486                                 /* Allocate PCI I/O and/or memory space */
 487                                 pciauto_setup_bars(hose,
 488                                                 current_bus,
 489                                                 pci_devfn,
 490                                                 PCI_BASE_ADDRESS_5);
 491
 492                                 /*
 493                                  * Enable some standard settings
 494                                  */
 495                                 early_read_config_dword(hose,
 496                                                 current_bus,
 497                                                 pci_devfn,
 498                                                 PCI_COMMAND,
 499                                                 &cmdstat);
 500                                 early_write_config_dword(hose,
 501                                                 current_bus,
 502                                                 pci_devfn,
 503                                                 PCI_COMMAND,
 504                                                 cmdstat |
 505                                                 PCI_COMMAND_IO |
 506                                                 PCI_COMMAND_MEMORY |
 507                                                 PCI_COMMAND_MASTER);
 508                                 early_write_config_byte(hose,
 509                                                 current_bus,
 510                                                 pci_devfn,
 511                                                 PCI_LATENCY_TIMER,
 512                                                 0x80);
 513                         }
 514                 }
 515         }
 516         return sub_bus;
 517 }