git.oblomov.eu Git - linux-2.6/blob - drivers/firewire/fw-device.c

   1 /*
   2  * Device probing and sysfs code.
   3  *
   4  * Copyright (C) 2005-2006  Kristian Hoegsberg <krh@bitplanet.net>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19  */
  20
  21 #include <linux/ctype.h>
  22 #include <linux/delay.h>
  23 #include <linux/device.h>
  24 #include <linux/errno.h>
  25 #include <linux/idr.h>
  26 #include <linux/jiffies.h>
  27 #include <linux/kobject.h>
  28 #include <linux/list.h>
  29 #include <linux/mod_devicetable.h>
  30 #include <linux/mutex.h>
  31 #include <linux/rwsem.h>
  32 #include <linux/semaphore.h>
  33 #include <linux/spinlock.h>
  34 #include <linux/string.h>
  35 #include <linux/workqueue.h>
  36
  37 #include <asm/system.h>
  38
  39 #include "fw-device.h"
  40 #include "fw-topology.h"
  41 #include "fw-transaction.h"
  42
  43 void fw_csr_iterator_init(struct fw_csr_iterator *ci, u32 * p)
  44 {
  45         ci->p = p + 1;
  46         ci->end = ci->p + (p[0] >> 16);
  47 }
  48 EXPORT_SYMBOL(fw_csr_iterator_init);
  49
  50 int fw_csr_iterator_next(struct fw_csr_iterator *ci, int *key, int *value)
  51 {
  52         *key = *ci->p >> 24;
  53         *value = *ci->p & 0xffffff;
  54
  55         return ci->p++ < ci->end;
  56 }
  57 EXPORT_SYMBOL(fw_csr_iterator_next);
  58
  59 static int is_fw_unit(struct device *dev);
  60
  61 static int match_unit_directory(u32 *directory,
  62                                 const struct ieee1394_device_id *id)
  63 {
  64         struct fw_csr_iterator ci;
  65         int key, value, match;
  66
  67         match = 0;
  68         fw_csr_iterator_init(&ci, directory);
  69         while (fw_csr_iterator_next(&ci, &key, &value)) {
  70                 if (key == CSR_VENDOR && value == id->vendor_id)
  71                         match |= IEEE1394_MATCH_VENDOR_ID;
  72                 if (key == CSR_MODEL && value == id->model_id)
  73                         match |= IEEE1394_MATCH_MODEL_ID;
  74                 if (key == CSR_SPECIFIER_ID && value == id->specifier_id)
  75                         match |= IEEE1394_MATCH_SPECIFIER_ID;
  76                 if (key == CSR_VERSION && value == id->version)
  77                         match |= IEEE1394_MATCH_VERSION;
  78         }
  79
  80         return (match & id->match_flags) == id->match_flags;
  81 }
  82
  83 static int fw_unit_match(struct device *dev, struct device_driver *drv)
  84 {
  85         struct fw_unit *unit = fw_unit(dev);
  86         struct fw_driver *driver = fw_driver(drv);
  87         int i;
  88
  89         /* We only allow binding to fw_units. */
  90         if (!is_fw_unit(dev))
  91                 return 0;
  92
  93         for (i = 0; driver->id_table[i].match_flags != 0; i++) {
  94                 if (match_unit_directory(unit->directory, &driver->id_table[i]))
  95                         return 1;
  96         }
  97
  98         return 0;
  99 }
 100
 101 static int get_modalias(struct fw_unit *unit, char *buffer, size_t buffer_size)
 102 {
 103         struct fw_device *device = fw_device(unit->device.parent);
 104         struct fw_csr_iterator ci;
 105
 106         int key, value;
 107         int vendor = 0;
 108         int model = 0;
 109         int specifier_id = 0;
 110         int version = 0;
 111
 112         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 113         while (fw_csr_iterator_next(&ci, &key, &value)) {
 114                 switch (key) {
 115                 case CSR_VENDOR:
 116                         vendor = value;
 117                         break;
 118                 case CSR_MODEL:
 119                         model = value;
 120                         break;
 121                 }
 122         }
 123
 124         fw_csr_iterator_init(&ci, unit->directory);
 125         while (fw_csr_iterator_next(&ci, &key, &value)) {
 126                 switch (key) {
 127                 case CSR_SPECIFIER_ID:
 128                         specifier_id = value;
 129                         break;
 130                 case CSR_VERSION:
 131                         version = value;
 132                         break;
 133                 }
 134         }
 135
 136         return snprintf(buffer, buffer_size,
 137                         "ieee1394:ven%08Xmo%08Xsp%08Xver%08X",
 138                         vendor, model, specifier_id, version);
 139 }
 140
 141 static int fw_unit_uevent(struct device *dev, struct kobj_uevent_env *env)
 142 {
 143         struct fw_unit *unit = fw_unit(dev);
 144         char modalias[64];
 145
 146         get_modalias(unit, modalias, sizeof(modalias));
 147
 148         if (add_uevent_var(env, "MODALIAS=%s", modalias))
 149                 return -ENOMEM;
 150
 151         return 0;
 152 }
 153
 154 struct bus_type fw_bus_type = {
 155         .name = "firewire",
 156         .match = fw_unit_match,
 157 };
 158 EXPORT_SYMBOL(fw_bus_type);
 159
 160 int fw_device_enable_phys_dma(struct fw_device *device)
 161 {
 162         int generation = device->generation;
 163
 164         /* device->node_id, accessed below, must not be older than generation */
 165         smp_rmb();
 166
 167         return device->card->driver->enable_phys_dma(device->card,
 168                                                      device->node_id,
 169                                                      generation);
 170 }
 171 EXPORT_SYMBOL(fw_device_enable_phys_dma);
 172
 173 struct config_rom_attribute {
 174         struct device_attribute attr;
 175         u32 key;
 176 };
 177
 178 static ssize_t show_immediate(struct device *dev,
 179                               struct device_attribute *dattr, char *buf)
 180 {
 181         struct config_rom_attribute *attr =
 182                 container_of(dattr, struct config_rom_attribute, attr);
 183         struct fw_csr_iterator ci;
 184         u32 *dir;
 185         int key, value, ret = -ENOENT;
 186
 187         down_read(&fw_device_rwsem);
 188
 189         if (is_fw_unit(dev))
 190                 dir = fw_unit(dev)->directory;
 191         else
 192                 dir = fw_device(dev)->config_rom + 5;
 193
 194         fw_csr_iterator_init(&ci, dir);
 195         while (fw_csr_iterator_next(&ci, &key, &value))
 196                 if (attr->key == key) {
 197                         ret = snprintf(buf, buf ? PAGE_SIZE : 0,
 198                                        "0x%06x\n", value);
 199                         break;
 200                 }
 201
 202         up_read(&fw_device_rwsem);
 203
 204         return ret;
 205 }
 206
 207 #define IMMEDIATE_ATTR(name, key)                               \
 208         { __ATTR(name, S_IRUGO, show_immediate, NULL), key }
 209
 210 static ssize_t show_text_leaf(struct device *dev,
 211                               struct device_attribute *dattr, char *buf)
 212 {
 213         struct config_rom_attribute *attr =
 214                 container_of(dattr, struct config_rom_attribute, attr);
 215         struct fw_csr_iterator ci;
 216         u32 *dir, *block = NULL, *p, *end;
 217         int length, key, value, last_key = 0, ret = -ENOENT;
 218         char *b;
 219
 220         down_read(&fw_device_rwsem);
 221
 222         if (is_fw_unit(dev))
 223                 dir = fw_unit(dev)->directory;
 224         else
 225                 dir = fw_device(dev)->config_rom + 5;
 226
 227         fw_csr_iterator_init(&ci, dir);
 228         while (fw_csr_iterator_next(&ci, &key, &value)) {
 229                 if (attr->key == last_key &&
 230                     key == (CSR_DESCRIPTOR | CSR_LEAF))
 231                         block = ci.p - 1 + value;
 232                 last_key = key;
 233         }
 234
 235         if (block == NULL)
 236                 goto out;
 237
 238         length = min(block[0] >> 16, 256U);
 239         if (length < 3)
 240                 goto out;
 241
 242         if (block[1] != 0 || block[2] != 0)
 243                 /* Unknown encoding. */
 244                 goto out;
 245
 246         if (buf == NULL) {
 247                 ret = length * 4;
 248                 goto out;
 249         }
 250
 251         b = buf;
 252         end = &block[length + 1];
 253         for (p = &block[3]; p < end; p++, b += 4)
 254                 * (u32 *) b = (__force u32) __cpu_to_be32(*p);
 255
 256         /* Strip trailing whitespace and add newline. */
 257         while (b--, (isspace(*b) || *b == '\0') && b > buf);
 258         strcpy(b + 1, "\n");
 259         ret = b + 2 - buf;
 260  out:
 261         up_read(&fw_device_rwsem);
 262
 263         return ret;
 264 }
 265
 266 #define TEXT_LEAF_ATTR(name, key)                               \
 267         { __ATTR(name, S_IRUGO, show_text_leaf, NULL), key }
 268
 269 static struct config_rom_attribute config_rom_attributes[] = {
 270         IMMEDIATE_ATTR(vendor, CSR_VENDOR),
 271         IMMEDIATE_ATTR(hardware_version, CSR_HARDWARE_VERSION),
 272         IMMEDIATE_ATTR(specifier_id, CSR_SPECIFIER_ID),
 273         IMMEDIATE_ATTR(version, CSR_VERSION),
 274         IMMEDIATE_ATTR(model, CSR_MODEL),
 275         TEXT_LEAF_ATTR(vendor_name, CSR_VENDOR),
 276         TEXT_LEAF_ATTR(model_name, CSR_MODEL),
 277         TEXT_LEAF_ATTR(hardware_version_name, CSR_HARDWARE_VERSION),
 278 };
 279
 280 static void init_fw_attribute_group(struct device *dev,
 281                                     struct device_attribute *attrs,
 282                                     struct fw_attribute_group *group)
 283 {
 284         struct device_attribute *attr;
 285         int i, j;
 286
 287         for (j = 0; attrs[j].attr.name != NULL; j++)
 288                 group->attrs[j] = &attrs[j].attr;
 289
 290         for (i = 0; i < ARRAY_SIZE(config_rom_attributes); i++) {
 291                 attr = &config_rom_attributes[i].attr;
 292                 if (attr->show(dev, attr, NULL) < 0)
 293                         continue;
 294                 group->attrs[j++] = &attr->attr;
 295         }
 296
 297         group->attrs[j] = NULL;
 298         group->groups[0] = &group->group;
 299         group->groups[1] = NULL;
 300         group->group.attrs = group->attrs;
 301         dev->groups = group->groups;
 302 }
 303
 304 static ssize_t modalias_show(struct device *dev,
 305                              struct device_attribute *attr, char *buf)
 306 {
 307         struct fw_unit *unit = fw_unit(dev);
 308         int length;
 309
 310         length = get_modalias(unit, buf, PAGE_SIZE);
 311         strcpy(buf + length, "\n");
 312
 313         return length + 1;
 314 }
 315
 316 static ssize_t rom_index_show(struct device *dev,
 317                               struct device_attribute *attr, char *buf)
 318 {
 319         struct fw_device *device = fw_device(dev->parent);
 320         struct fw_unit *unit = fw_unit(dev);
 321
 322         return snprintf(buf, PAGE_SIZE, "%d\n",
 323                         (int)(unit->directory - device->config_rom));
 324 }
 325
 326 static struct device_attribute fw_unit_attributes[] = {
 327         __ATTR_RO(modalias),
 328         __ATTR_RO(rom_index),
 329         __ATTR_NULL,
 330 };
 331
 332 static ssize_t config_rom_show(struct device *dev,
 333                                struct device_attribute *attr, char *buf)
 334 {
 335         struct fw_device *device = fw_device(dev);
 336         size_t length;
 337
 338         down_read(&fw_device_rwsem);
 339         length = device->config_rom_length * 4;
 340         memcpy(buf, device->config_rom, length);
 341         up_read(&fw_device_rwsem);
 342
 343         return length;
 344 }
 345
 346 static ssize_t guid_show(struct device *dev,
 347                          struct device_attribute *attr, char *buf)
 348 {
 349         struct fw_device *device = fw_device(dev);
 350         int ret;
 351
 352         down_read(&fw_device_rwsem);
 353         ret = snprintf(buf, PAGE_SIZE, "0x%08x%08x\n",
 354                        device->config_rom[3], device->config_rom[4]);
 355         up_read(&fw_device_rwsem);
 356
 357         return ret;
 358 }
 359
 360 static int units_sprintf(char *buf, u32 *directory)
 361 {
 362         struct fw_csr_iterator ci;
 363         int key, value;
 364         int specifier_id = 0;
 365         int version = 0;
 366
 367         fw_csr_iterator_init(&ci, directory);
 368         while (fw_csr_iterator_next(&ci, &key, &value)) {
 369                 switch (key) {
 370                 case CSR_SPECIFIER_ID:
 371                         specifier_id = value;
 372                         break;
 373                 case CSR_VERSION:
 374                         version = value;
 375                         break;
 376                 }
 377         }
 378
 379         return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version);
 380 }
 381
 382 static ssize_t units_show(struct device *dev,
 383                           struct device_attribute *attr, char *buf)
 384 {
 385         struct fw_device *device = fw_device(dev);
 386         struct fw_csr_iterator ci;
 387         int key, value, i = 0;
 388
 389         down_read(&fw_device_rwsem);
 390         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 391         while (fw_csr_iterator_next(&ci, &key, &value)) {
 392                 if (key != (CSR_UNIT | CSR_DIRECTORY))
 393                         continue;
 394                 i += units_sprintf(&buf[i], ci.p + value - 1);
 395                 if (i >= PAGE_SIZE - (8 + 1 + 8 + 1))
 396                         break;
 397         }
 398         up_read(&fw_device_rwsem);
 399
 400         if (i)
 401                 buf[i - 1] = '\n';
 402
 403         return i;
 404 }
 405
 406 static struct device_attribute fw_device_attributes[] = {
 407         __ATTR_RO(config_rom),
 408         __ATTR_RO(guid),
 409         __ATTR_RO(units),
 410         __ATTR_NULL,
 411 };
 412
 413 static int read_rom(struct fw_device *device,
 414                     int generation, int index, u32 *data)
 415 {
 416         int rcode;
 417
 418         /* device->node_id, accessed below, must not be older than generation */
 419         smp_rmb();
 420
 421         rcode = fw_run_transaction(device->card, TCODE_READ_QUADLET_REQUEST,
 422                         device->node_id, generation, device->max_speed,
 423                         (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4,
 424                         data, 4);
 425         be32_to_cpus(data);
 426
 427         return rcode;
 428 }
 429
 430 #define READ_BIB_ROM_SIZE       256
 431 #define READ_BIB_STACK_SIZE     16
 432
 433 /*
 434  * Read the bus info block, perform a speed probe, and read all of the rest of
 435  * the config ROM.  We do all this with a cached bus generation.  If the bus
 436  * generation changes under us, read_bus_info_block will fail and get retried.
 437  * It's better to start all over in this case because the node from which we
 438  * are reading the ROM may have changed the ROM during the reset.
 439  */
 440 static int read_bus_info_block(struct fw_device *device, int generation)
 441 {
 442         u32 *rom, *stack, *old_rom, *new_rom;
 443         u32 sp, key;
 444         int i, end, length, ret = -1;
 445
 446         rom = kmalloc(sizeof(*rom) * READ_BIB_ROM_SIZE +
 447                       sizeof(*stack) * READ_BIB_STACK_SIZE, GFP_KERNEL);
 448         if (rom == NULL)
 449                 return -ENOMEM;
 450
 451         stack = &rom[READ_BIB_ROM_SIZE];
 452
 453         device->max_speed = SCODE_100;
 454
 455         /* First read the bus info block. */
 456         for (i = 0; i < 5; i++) {
 457                 if (read_rom(device, generation, i, &rom[i]) != RCODE_COMPLETE)
 458                         goto out;
 459                 /*
 460                  * As per IEEE1212 7.2, during power-up, devices can
 461                  * reply with a 0 for the first quadlet of the config
 462                  * rom to indicate that they are booting (for example,
 463                  * if the firmware is on the disk of a external
 464                  * harddisk).  In that case we just fail, and the
 465                  * retry mechanism will try again later.
 466                  */
 467                 if (i == 0 && rom[i] == 0)
 468                         goto out;
 469         }
 470
 471         device->max_speed = device->node->max_speed;
 472
 473         /*
 474          * Determine the speed of
 475          *   - devices with link speed less than PHY speed,
 476          *   - devices with 1394b PHY (unless only connected to 1394a PHYs),
 477          *   - all devices if there are 1394b repeaters.
 478          * Note, we cannot use the bus info block's link_spd as starting point
 479          * because some buggy firmwares set it lower than necessary and because
 480          * 1394-1995 nodes do not have the field.
 481          */
 482         if ((rom[2] & 0x7) < device->max_speed ||
 483             device->max_speed == SCODE_BETA ||
 484             device->card->beta_repeaters_present) {
 485                 u32 dummy;
 486
 487                 /* for S1600 and S3200 */
 488                 if (device->max_speed == SCODE_BETA)
 489                         device->max_speed = device->card->link_speed;
 490
 491                 while (device->max_speed > SCODE_100) {
 492                         if (read_rom(device, generation, 0, &dummy) ==
 493                             RCODE_COMPLETE)
 494                                 break;
 495                         device->max_speed--;
 496                 }
 497         }
 498
 499         /*
 500          * Now parse the config rom.  The config rom is a recursive
 501          * directory structure so we parse it using a stack of
 502          * references to the blocks that make up the structure.  We
 503          * push a reference to the root directory on the stack to
 504          * start things off.
 505          */
 506         length = i;
 507         sp = 0;
 508         stack[sp++] = 0xc0000005;
 509         while (sp > 0) {
 510                 /*
 511                  * Pop the next block reference of the stack.  The
 512                  * lower 24 bits is the offset into the config rom,
 513                  * the upper 8 bits are the type of the reference the
 514                  * block.
 515                  */
 516                 key = stack[--sp];
 517                 i = key & 0xffffff;
 518                 if (i >= READ_BIB_ROM_SIZE)
 519                         /*
 520                          * The reference points outside the standard
 521                          * config rom area, something's fishy.
 522                          */
 523                         goto out;
 524
 525                 /* Read header quadlet for the block to get the length. */
 526                 if (read_rom(device, generation, i, &rom[i]) != RCODE_COMPLETE)
 527                         goto out;
 528                 end = i + (rom[i] >> 16) + 1;
 529                 i++;
 530                 if (end > READ_BIB_ROM_SIZE)
 531                         /*
 532                          * This block extends outside standard config
 533                          * area (and the array we're reading it
 534                          * into).  That's broken, so ignore this
 535                          * device.
 536                          */
 537                         goto out;
 538
 539                 /*
 540                  * Now read in the block.  If this is a directory
 541                  * block, check the entries as we read them to see if
 542                  * it references another block, and push it in that case.
 543                  */
 544                 while (i < end) {
 545                         if (read_rom(device, generation, i, &rom[i]) !=
 546                             RCODE_COMPLETE)
 547                                 goto out;
 548                         if ((key >> 30) == 3 && (rom[i] >> 30) > 1 &&
 549                             sp < READ_BIB_STACK_SIZE)
 550                                 stack[sp++] = i + rom[i];
 551                         i++;
 552                 }
 553                 if (length < i)
 554                         length = i;
 555         }
 556
 557         old_rom = device->config_rom;
 558         new_rom = kmemdup(rom, length * 4, GFP_KERNEL);
 559         if (new_rom == NULL)
 560                 goto out;
 561
 562         down_write(&fw_device_rwsem);
 563         device->config_rom = new_rom;
 564         device->config_rom_length = length;
 565         up_write(&fw_device_rwsem);
 566
 567         kfree(old_rom);
 568         ret = 0;
 569         device->cmc = rom[2] >> 30 & 1;
 570  out:
 571         kfree(rom);
 572
 573         return ret;
 574 }
 575
 576 static void fw_unit_release(struct device *dev)
 577 {
 578         struct fw_unit *unit = fw_unit(dev);
 579
 580         kfree(unit);
 581 }
 582
 583 static struct device_type fw_unit_type = {
 584         .uevent         = fw_unit_uevent,
 585         .release        = fw_unit_release,
 586 };
 587
 588 static int is_fw_unit(struct device *dev)
 589 {
 590         return dev->type == &fw_unit_type;
 591 }
 592
 593 static void create_units(struct fw_device *device)
 594 {
 595         struct fw_csr_iterator ci;
 596         struct fw_unit *unit;
 597         int key, value, i;
 598
 599         i = 0;
 600         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 601         while (fw_csr_iterator_next(&ci, &key, &value)) {
 602                 if (key != (CSR_UNIT | CSR_DIRECTORY))
 603                         continue;
 604
 605                 /*
 606                  * Get the address of the unit directory and try to
 607                  * match the drivers id_tables against it.
 608                  */
 609                 unit = kzalloc(sizeof(*unit), GFP_KERNEL);
 610                 if (unit == NULL) {
 611                         fw_error("failed to allocate memory for unit\n");
 612                         continue;
 613                 }
 614
 615                 unit->directory = ci.p + value - 1;
 616                 unit->device.bus = &fw_bus_type;
 617                 unit->device.type = &fw_unit_type;
 618                 unit->device.parent = &device->device;
 619                 dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++);
 620
 621                 BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) <
 622                                 ARRAY_SIZE(fw_unit_attributes) +
 623                                 ARRAY_SIZE(config_rom_attributes));
 624                 init_fw_attribute_group(&unit->device,
 625                                         fw_unit_attributes,
 626                                         &unit->attribute_group);
 627
 628                 if (device_register(&unit->device) < 0)
 629                         goto skip_unit;
 630
 631                 continue;
 632
 633         skip_unit:
 634                 kfree(unit);
 635         }
 636 }
 637
 638 static int shutdown_unit(struct device *device, void *data)
 639 {
 640         device_unregister(device);
 641
 642         return 0;
 643 }
 644
 645 /*
 646  * fw_device_rwsem acts as dual purpose mutex:
 647  *   - serializes accesses to fw_device_idr,
 648  *   - serializes accesses to fw_device.config_rom/.config_rom_length and
 649  *     fw_unit.directory, unless those accesses happen at safe occasions
 650  */
 651 DECLARE_RWSEM(fw_device_rwsem);
 652
 653 DEFINE_IDR(fw_device_idr);
 654 int fw_cdev_major;
 655
 656 struct fw_device *fw_device_get_by_devt(dev_t devt)
 657 {
 658         struct fw_device *device;
 659
 660         down_read(&fw_device_rwsem);
 661         device = idr_find(&fw_device_idr, MINOR(devt));
 662         if (device)
 663                 fw_device_get(device);
 664         up_read(&fw_device_rwsem);
 665
 666         return device;
 667 }
 668
 669 /*
 670  * These defines control the retry behavior for reading the config
 671  * rom.  It shouldn't be necessary to tweak these; if the device
 672  * doesn't respond to a config rom read within 10 seconds, it's not
 673  * going to respond at all.  As for the initial delay, a lot of
 674  * devices will be able to respond within half a second after bus
 675  * reset.  On the other hand, it's not really worth being more
 676  * aggressive than that, since it scales pretty well; if 10 devices
 677  * are plugged in, they're all getting read within one second.
 678  */
 679
 680 #define MAX_RETRIES     10
 681 #define RETRY_DELAY     (3 * HZ)
 682 #define INITIAL_DELAY   (HZ / 2)
 683 #define SHUTDOWN_DELAY  (2 * HZ)
 684
 685 static void fw_device_shutdown(struct work_struct *work)
 686 {
 687         struct fw_device *device =
 688                 container_of(work, struct fw_device, work.work);
 689         int minor = MINOR(device->device.devt);
 690
 691         if (time_is_after_jiffies(device->card->reset_jiffies + SHUTDOWN_DELAY)
 692             && !list_empty(&device->card->link)) {
 693                 schedule_delayed_work(&device->work, SHUTDOWN_DELAY);
 694                 return;
 695         }
 696
 697         if (atomic_cmpxchg(&device->state,
 698                            FW_DEVICE_GONE,
 699                            FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE)
 700                 return;
 701
 702         fw_device_cdev_remove(device);
 703         device_for_each_child(&device->device, NULL, shutdown_unit);
 704         device_unregister(&device->device);
 705
 706         down_write(&fw_device_rwsem);
 707         idr_remove(&fw_device_idr, minor);
 708         up_write(&fw_device_rwsem);
 709
 710         fw_device_put(device);
 711 }
 712
 713 static void fw_device_release(struct device *dev)
 714 {
 715         struct fw_device *device = fw_device(dev);
 716         struct fw_card *card = device->card;
 717         unsigned long flags;
 718
 719         /*
 720          * Take the card lock so we don't set this to NULL while a
 721          * FW_NODE_UPDATED callback is being handled or while the
 722          * bus manager work looks at this node.
 723          */
 724         spin_lock_irqsave(&card->lock, flags);
 725         device->node->data = NULL;
 726         spin_unlock_irqrestore(&card->lock, flags);
 727
 728         fw_node_put(device->node);
 729         kfree(device->config_rom);
 730         kfree(device);
 731         fw_card_put(card);
 732 }
 733
 734 static struct device_type fw_device_type = {
 735         .release = fw_device_release,
 736 };
 737
 738 static int update_unit(struct device *dev, void *data)
 739 {
 740         struct fw_unit *unit = fw_unit(dev);
 741         struct fw_driver *driver = (struct fw_driver *)dev->driver;
 742
 743         if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) {
 744                 down(&dev->sem);
 745                 driver->update(unit);
 746                 up(&dev->sem);
 747         }
 748
 749         return 0;
 750 }
 751
 752 static void fw_device_update(struct work_struct *work)
 753 {
 754         struct fw_device *device =
 755                 container_of(work, struct fw_device, work.work);
 756
 757         fw_device_cdev_update(device);
 758         device_for_each_child(&device->device, NULL, update_unit);
 759 }
 760
 761 /*
 762  * If a device was pending for deletion because its node went away but its
 763  * bus info block and root directory header matches that of a newly discovered
 764  * device, revive the existing fw_device.
 765  * The newly allocated fw_device becomes obsolete instead.
 766  */
 767 static int lookup_existing_device(struct device *dev, void *data)
 768 {
 769         struct fw_device *old = fw_device(dev);
 770         struct fw_device *new = data;
 771         struct fw_card *card = new->card;
 772         int match = 0;
 773
 774         down_read(&fw_device_rwsem); /* serialize config_rom access */
 775         spin_lock_irq(&card->lock);  /* serialize node access */
 776
 777         if (memcmp(old->config_rom, new->config_rom, 6 * 4) == 0 &&
 778             atomic_cmpxchg(&old->state,
 779                            FW_DEVICE_GONE,
 780                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
 781                 struct fw_node *current_node = new->node;
 782                 struct fw_node *obsolete_node = old->node;
 783
 784                 new->node = obsolete_node;
 785                 new->node->data = new;
 786                 old->node = current_node;
 787                 old->node->data = old;
 788
 789                 old->max_speed = new->max_speed;
 790                 old->node_id = current_node->node_id;
 791                 smp_wmb();  /* update node_id before generation */
 792                 old->generation = card->generation;
 793                 old->config_rom_retries = 0;
 794                 fw_notify("rediscovered device %s\n", dev_name(dev));
 795
 796                 PREPARE_DELAYED_WORK(&old->work, fw_device_update);
 797                 schedule_delayed_work(&old->work, 0);
 798
 799                 if (current_node == card->root_node)
 800                         fw_schedule_bm_work(card, 0);
 801
 802                 match = 1;
 803         }
 804
 805         spin_unlock_irq(&card->lock);
 806         up_read(&fw_device_rwsem);
 807
 808         return match;
 809 }
 810
 811 enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, };
 812
 813 void fw_device_set_broadcast_channel(struct fw_device *device, int generation)
 814 {
 815         struct fw_card *card = device->card;
 816         __be32 data;
 817         int rcode;
 818
 819         if (!card->broadcast_channel_allocated)
 820                 return;
 821
 822         if (device->bc_implemented == BC_UNKNOWN) {
 823                 rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST,
 824                                 device->node_id, generation, device->max_speed,
 825                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 826                                 &data, 4);
 827                 switch (rcode) {
 828                 case RCODE_COMPLETE:
 829                         if (data & cpu_to_be32(1 << 31)) {
 830                                 device->bc_implemented = BC_IMPLEMENTED;
 831                                 break;
 832                         }
 833                         /* else fall through to case address error */
 834                 case RCODE_ADDRESS_ERROR:
 835                         device->bc_implemented = BC_UNIMPLEMENTED;
 836                 }
 837         }
 838
 839         if (device->bc_implemented == BC_IMPLEMENTED) {
 840                 data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL |
 841                                    BROADCAST_CHANNEL_VALID);
 842                 fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
 843                                 device->node_id, generation, device->max_speed,
 844                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 845                                 &data, 4);
 846         }
 847 }
 848
 849 static void fw_device_init(struct work_struct *work)
 850 {
 851         struct fw_device *device =
 852                 container_of(work, struct fw_device, work.work);
 853         struct device *revived_dev;
 854         int minor, ret;
 855
 856         /*
 857          * All failure paths here set node->data to NULL, so that we
 858          * don't try to do device_for_each_child() on a kfree()'d
 859          * device.
 860          */
 861
 862         if (read_bus_info_block(device, device->generation) < 0) {
 863                 if (device->config_rom_retries < MAX_RETRIES &&
 864                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
 865                         device->config_rom_retries++;
 866                         schedule_delayed_work(&device->work, RETRY_DELAY);
 867                 } else {
 868                         fw_notify("giving up on config rom for node id %x\n",
 869                                   device->node_id);
 870                         if (device->node == device->card->root_node)
 871                                 fw_schedule_bm_work(device->card, 0);
 872                         fw_device_release(&device->device);
 873                 }
 874                 return;
 875         }
 876
 877         revived_dev = device_find_child(device->card->device,
 878                                         device, lookup_existing_device);
 879         if (revived_dev) {
 880                 put_device(revived_dev);
 881                 fw_device_release(&device->device);
 882
 883                 return;
 884         }
 885
 886         device_initialize(&device->device);
 887
 888         fw_device_get(device);
 889         down_write(&fw_device_rwsem);
 890         ret = idr_pre_get(&fw_device_idr, GFP_KERNEL) ?
 891               idr_get_new(&fw_device_idr, device, &minor) :
 892               -ENOMEM;
 893         up_write(&fw_device_rwsem);
 894
 895         if (ret < 0)
 896                 goto error;
 897
 898         device->device.bus = &fw_bus_type;
 899         device->device.type = &fw_device_type;
 900         device->device.parent = device->card->device;
 901         device->device.devt = MKDEV(fw_cdev_major, minor);
 902         dev_set_name(&device->device, "fw%d", minor);
 903
 904         BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) <
 905                         ARRAY_SIZE(fw_device_attributes) +
 906                         ARRAY_SIZE(config_rom_attributes));
 907         init_fw_attribute_group(&device->device,
 908                                 fw_device_attributes,
 909                                 &device->attribute_group);
 910
 911         if (device_add(&device->device)) {
 912                 fw_error("Failed to add device.\n");
 913                 goto error_with_cdev;
 914         }
 915
 916         create_units(device);
 917
 918         /*
 919          * Transition the device to running state.  If it got pulled
 920          * out from under us while we did the intialization work, we
 921          * have to shut down the device again here.  Normally, though,
 922          * fw_node_event will be responsible for shutting it down when
 923          * necessary.  We have to use the atomic cmpxchg here to avoid
 924          * racing with the FW_NODE_DESTROYED case in
 925          * fw_node_event().
 926          */
 927         if (atomic_cmpxchg(&device->state,
 928                            FW_DEVICE_INITIALIZING,
 929                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
 930                 PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
 931                 schedule_delayed_work(&device->work, SHUTDOWN_DELAY);
 932         } else {
 933                 if (device->config_rom_retries)
 934                         fw_notify("created device %s: GUID %08x%08x, S%d00, "
 935                                   "%d config ROM retries\n",
 936                                   dev_name(&device->device),
 937                                   device->config_rom[3], device->config_rom[4],
 938                                   1 << device->max_speed,
 939                                   device->config_rom_retries);
 940                 else
 941                         fw_notify("created device %s: GUID %08x%08x, S%d00\n",
 942                                   dev_name(&device->device),
 943                                   device->config_rom[3], device->config_rom[4],
 944                                   1 << device->max_speed);
 945                 device->config_rom_retries = 0;
 946
 947                 fw_device_set_broadcast_channel(device, device->generation);
 948         }
 949
 950         /*
 951          * Reschedule the IRM work if we just finished reading the
 952          * root node config rom.  If this races with a bus reset we
 953          * just end up running the IRM work a couple of extra times -
 954          * pretty harmless.
 955          */
 956         if (device->node == device->card->root_node)
 957                 fw_schedule_bm_work(device->card, 0);
 958
 959         return;
 960
 961  error_with_cdev:
 962         down_write(&fw_device_rwsem);
 963         idr_remove(&fw_device_idr, minor);
 964         up_write(&fw_device_rwsem);
 965  error:
 966         fw_device_put(device);          /* fw_device_idr's reference */
 967
 968         put_device(&device->device);    /* our reference */
 969 }
 970
 971 enum {
 972         REREAD_BIB_ERROR,
 973         REREAD_BIB_GONE,
 974         REREAD_BIB_UNCHANGED,
 975         REREAD_BIB_CHANGED,
 976 };
 977
 978 /* Reread and compare bus info block and header of root directory */
 979 static int reread_bus_info_block(struct fw_device *device, int generation)
 980 {
 981         u32 q;
 982         int i;
 983
 984         for (i = 0; i < 6; i++) {
 985                 if (read_rom(device, generation, i, &q) != RCODE_COMPLETE)
 986                         return REREAD_BIB_ERROR;
 987
 988                 if (i == 0 && q == 0)
 989                         return REREAD_BIB_GONE;
 990
 991                 if (q != device->config_rom[i])
 992                         return REREAD_BIB_CHANGED;
 993         }
 994
 995         return REREAD_BIB_UNCHANGED;
 996 }
 997
 998 static void fw_device_refresh(struct work_struct *work)
 999 {
1000         struct fw_device *device =
1001                 container_of(work, struct fw_device, work.work);
1002         struct fw_card *card = device->card;
1003         int node_id = device->node_id;
1004
1005         switch (reread_bus_info_block(device, device->generation)) {
1006         case REREAD_BIB_ERROR:
1007                 if (device->config_rom_retries < MAX_RETRIES / 2 &&
1008                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1009                         device->config_rom_retries++;
1010                         schedule_delayed_work(&device->work, RETRY_DELAY / 2);
1011
1012                         return;
1013                 }
1014                 goto give_up;
1015
1016         case REREAD_BIB_GONE:
1017                 goto gone;
1018
1019         case REREAD_BIB_UNCHANGED:
1020                 if (atomic_cmpxchg(&device->state,
1021                                    FW_DEVICE_INITIALIZING,
1022                                    FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1023                         goto gone;
1024
1025                 fw_device_update(work);
1026                 device->config_rom_retries = 0;
1027                 goto out;
1028
1029         case REREAD_BIB_CHANGED:
1030                 break;
1031         }
1032
1033         /*
1034          * Something changed.  We keep things simple and don't investigate
1035          * further.  We just destroy all previous units and create new ones.
1036          */
1037         device_for_each_child(&device->device, NULL, shutdown_unit);
1038
1039         if (read_bus_info_block(device, device->generation) < 0) {
1040                 if (device->config_rom_retries < MAX_RETRIES &&
1041                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1042                         device->config_rom_retries++;
1043                         schedule_delayed_work(&device->work, RETRY_DELAY);
1044
1045                         return;
1046                 }
1047                 goto give_up;
1048         }
1049
1050         create_units(device);
1051
1052         /* Userspace may want to re-read attributes. */
1053         kobject_uevent(&device->device.kobj, KOBJ_CHANGE);
1054
1055         if (atomic_cmpxchg(&device->state,
1056                            FW_DEVICE_INITIALIZING,
1057                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1058                 goto gone;
1059
1060         fw_notify("refreshed device %s\n", dev_name(&device->device));
1061         device->config_rom_retries = 0;
1062         goto out;
1063
1064  give_up:
1065         fw_notify("giving up on refresh of device %s\n", dev_name(&device->device));
1066  gone:
1067         atomic_set(&device->state, FW_DEVICE_GONE);
1068         PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1069         schedule_delayed_work(&device->work, SHUTDOWN_DELAY);
1070  out:
1071         if (node_id == card->root_node->node_id)
1072                 fw_schedule_bm_work(card, 0);
1073 }
1074
1075 void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
1076 {
1077         struct fw_device *device;
1078
1079         switch (event) {
1080         case FW_NODE_CREATED:
1081         case FW_NODE_LINK_ON:
1082                 if (!node->link_on)
1083                         break;
1084  create:
1085                 device = kzalloc(sizeof(*device), GFP_ATOMIC);
1086                 if (device == NULL)
1087                         break;
1088
1089                 /*
1090                  * Do minimal intialization of the device here, the
1091                  * rest will happen in fw_device_init().
1092                  *
1093                  * Attention:  A lot of things, even fw_device_get(),
1094                  * cannot be done before fw_device_init() finished!
1095                  * You can basically just check device->state and
1096                  * schedule work until then, but only while holding
1097                  * card->lock.
1098                  */
1099                 atomic_set(&device->state, FW_DEVICE_INITIALIZING);
1100                 device->card = fw_card_get(card);
1101                 device->node = fw_node_get(node);
1102                 device->node_id = node->node_id;
1103                 device->generation = card->generation;
1104                 device->is_local = node == card->local_node;
1105                 mutex_init(&device->client_list_mutex);
1106                 INIT_LIST_HEAD(&device->client_list);
1107
1108                 /*
1109                  * Set the node data to point back to this device so
1110                  * FW_NODE_UPDATED callbacks can update the node_id
1111                  * and generation for the device.
1112                  */
1113                 node->data = device;
1114
1115                 /*
1116                  * Many devices are slow to respond after bus resets,
1117                  * especially if they are bus powered and go through
1118                  * power-up after getting plugged in.  We schedule the
1119                  * first config rom scan half a second after bus reset.
1120                  */
1121                 INIT_DELAYED_WORK(&device->work, fw_device_init);
1122                 schedule_delayed_work(&device->work, INITIAL_DELAY);
1123                 break;
1124
1125         case FW_NODE_INITIATED_RESET:
1126                 device = node->data;
1127                 if (device == NULL)
1128                         goto create;
1129
1130                 device->node_id = node->node_id;
1131                 smp_wmb();  /* update node_id before generation */
1132                 device->generation = card->generation;
1133                 if (atomic_cmpxchg(&device->state,
1134                             FW_DEVICE_RUNNING,
1135                             FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) {
1136                         PREPARE_DELAYED_WORK(&device->work, fw_device_refresh);
1137                         schedule_delayed_work(&device->work,
1138                                 device->is_local ? 0 : INITIAL_DELAY);
1139                 }
1140                 break;
1141
1142         case FW_NODE_UPDATED:
1143                 if (!node->link_on || node->data == NULL)
1144                         break;
1145
1146                 device = node->data;
1147                 device->node_id = node->node_id;
1148                 smp_wmb();  /* update node_id before generation */
1149                 device->generation = card->generation;
1150                 if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
1151                         PREPARE_DELAYED_WORK(&device->work, fw_device_update);
1152                         schedule_delayed_work(&device->work, 0);
1153                 }
1154                 break;
1155
1156         case FW_NODE_DESTROYED:
1157         case FW_NODE_LINK_OFF:
1158                 if (!node->data)
1159                         break;
1160
1161                 /*
1162                  * Destroy the device associated with the node.  There
1163                  * are two cases here: either the device is fully
1164                  * initialized (FW_DEVICE_RUNNING) or we're in the
1165                  * process of reading its config rom
1166                  * (FW_DEVICE_INITIALIZING).  If it is fully
1167                  * initialized we can reuse device->work to schedule a
1168                  * full fw_device_shutdown().  If not, there's work
1169                  * scheduled to read it's config rom, and we just put
1170                  * the device in shutdown state to have that code fail
1171                  * to create the device.
1172                  */
1173                 device = node->data;
1174                 if (atomic_xchg(&device->state,
1175                                 FW_DEVICE_GONE) == FW_DEVICE_RUNNING) {
1176                         PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1177                         schedule_delayed_work(&device->work,
1178                                 list_empty(&card->link) ? 0 : SHUTDOWN_DELAY);
1179                 }
1180                 break;
1181         }
1182 }