arch/ppc/syslib/pci_auto.c

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