drivers/firewire/core-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/bug.h>
  22 #include <linux/ctype.h>
  23 #include <linux/delay.h>
  24 #include <linux/device.h>
  25 #include <linux/errno.h>
  26 #include <linux/firewire.h>
  27 #include <linux/firewire-constants.h>
  28 #include <linux/idr.h>
  29 #include <linux/jiffies.h>
  30 #include <linux/kobject.h>
  31 #include <linux/list.h>
  32 #include <linux/mod_devicetable.h>
  33 #include <linux/module.h>
  34 #include <linux/mutex.h>
  35 #include <linux/rwsem.h>
  36 #include <linux/semaphore.h>
  37 #include <linux/spinlock.h>
  38 #include <linux/string.h>
  39 #include <linux/workqueue.h>
  40
  41 #include <asm/atomic.h>
  42 #include <asm/byteorder.h>
  43 #include <asm/system.h>
  44
  45 #include "core.h"
  46
  47 void fw_csr_iterator_init(struct fw_csr_iterator *ci, const u32 *p)
  48 {
  49         ci->p = p + 1;
  50         ci->end = ci->p + (p[0] >> 16);
  51 }
  52 EXPORT_SYMBOL(fw_csr_iterator_init);
  53
  54 int fw_csr_iterator_next(struct fw_csr_iterator *ci, int *key, int *value)
  55 {
  56         *key = *ci->p >> 24;
  57         *value = *ci->p & 0xffffff;
  58
  59         return ci->p++ < ci->end;
  60 }
  61 EXPORT_SYMBOL(fw_csr_iterator_next);
  62
  63 static const u32 *search_leaf(const u32 *directory, int search_key)
  64 {
  65         struct fw_csr_iterator ci;
  66         int last_key = 0, key, value;
  67
  68         fw_csr_iterator_init(&ci, directory);
  69         while (fw_csr_iterator_next(&ci, &key, &value)) {
  70                 if (last_key == search_key &&
  71                     key == (CSR_DESCRIPTOR | CSR_LEAF))
  72                         return ci.p - 1 + value;
  73
  74                 last_key = key;
  75         }
  76
  77         return NULL;
  78 }
  79
  80 static int textual_leaf_to_string(const u32 *block, char *buf, size_t size)
  81 {
  82         unsigned int quadlets, i;
  83         char c;
  84
  85         if (!size || !buf)
  86                 return -EINVAL;
  87
  88         quadlets = min(block[0] >> 16, 256U);
  89         if (quadlets < 2)
  90                 return -ENODATA;
  91
  92         if (block[1] != 0 || block[2] != 0)
  93                 /* unknown language/character set */
  94                 return -ENODATA;
  95
  96         block += 3;
  97         quadlets -= 2;
  98         for (i = 0; i < quadlets * 4 && i < size - 1; i++) {
  99                 c = block[i / 4] >> (24 - 8 * (i % 4));
 100                 if (c == '\0')
 101                         break;
 102                 buf[i] = c;
 103         }
 104         buf[i] = '\0';
 105
 106         return i;
 107 }
 108
 109 /**
 110  * fw_csr_string - reads a string from the configuration ROM
 111  * @directory: e.g. root directory or unit directory
 112  * @key: the key of the preceding directory entry
 113  * @buf: where to put the string
 114  * @size: size of @buf, in bytes
 115  *
 116  * The string is taken from a minimal ASCII text descriptor leaf after
 117  * the immediate entry with @key.  The string is zero-terminated.
 118  * Returns strlen(buf) or a negative error code.
 119  */
 120 int fw_csr_string(const u32 *directory, int key, char *buf, size_t size)
 121 {
 122         const u32 *leaf = search_leaf(directory, key);
 123         if (!leaf)
 124                 return -ENOENT;
 125
 126         return textual_leaf_to_string(leaf, buf, size);
 127 }
 128 EXPORT_SYMBOL(fw_csr_string);
 129
 130 static bool is_fw_unit(struct device *dev);
 131
 132 static int match_unit_directory(const u32 *directory, u32 match_flags,
 133                                 const struct ieee1394_device_id *id)
 134 {
 135         struct fw_csr_iterator ci;
 136         int key, value, match;
 137
 138         match = 0;
 139         fw_csr_iterator_init(&ci, directory);
 140         while (fw_csr_iterator_next(&ci, &key, &value)) {
 141                 if (key == CSR_VENDOR && value == id->vendor_id)
 142                         match |= IEEE1394_MATCH_VENDOR_ID;
 143                 if (key == CSR_MODEL && value == id->model_id)
 144                         match |= IEEE1394_MATCH_MODEL_ID;
 145                 if (key == CSR_SPECIFIER_ID && value == id->specifier_id)
 146                         match |= IEEE1394_MATCH_SPECIFIER_ID;
 147                 if (key == CSR_VERSION && value == id->version)
 148                         match |= IEEE1394_MATCH_VERSION;
 149         }
 150
 151         return (match & match_flags) == match_flags;
 152 }
 153
 154 static int fw_unit_match(struct device *dev, struct device_driver *drv)
 155 {
 156         struct fw_unit *unit = fw_unit(dev);
 157         struct fw_device *device;
 158         const struct ieee1394_device_id *id;
 159
 160         /* We only allow binding to fw_units. */
 161         if (!is_fw_unit(dev))
 162                 return 0;
 163
 164         device = fw_parent_device(unit);
 165         id = container_of(drv, struct fw_driver, driver)->id_table;
 166
 167         for (; id->match_flags != 0; id++) {
 168                 if (match_unit_directory(unit->directory, id->match_flags, id))
 169                         return 1;
 170
 171                 /* Also check vendor ID in the root directory. */
 172                 if ((id->match_flags & IEEE1394_MATCH_VENDOR_ID) &&
 173                     match_unit_directory(&device->config_rom[5],
 174                                 IEEE1394_MATCH_VENDOR_ID, id) &&
 175                     match_unit_directory(unit->directory, id->match_flags
 176                                 & ~IEEE1394_MATCH_VENDOR_ID, id))
 177                         return 1;
 178         }
 179
 180         return 0;
 181 }
 182
 183 static int get_modalias(struct fw_unit *unit, char *buffer, size_t buffer_size)
 184 {
 185         struct fw_device *device = fw_parent_device(unit);
 186         struct fw_csr_iterator ci;
 187
 188         int key, value;
 189         int vendor = 0;
 190         int model = 0;
 191         int specifier_id = 0;
 192         int version = 0;
 193
 194         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 195         while (fw_csr_iterator_next(&ci, &key, &value)) {
 196                 switch (key) {
 197                 case CSR_VENDOR:
 198                         vendor = value;
 199                         break;
 200                 case CSR_MODEL:
 201                         model = value;
 202                         break;
 203                 }
 204         }
 205
 206         fw_csr_iterator_init(&ci, unit->directory);
 207         while (fw_csr_iterator_next(&ci, &key, &value)) {
 208                 switch (key) {
 209                 case CSR_SPECIFIER_ID:
 210                         specifier_id = value;
 211                         break;
 212                 case CSR_VERSION:
 213                         version = value;
 214                         break;
 215                 }
 216         }
 217
 218         return snprintf(buffer, buffer_size,
 219                         "ieee1394:ven%08Xmo%08Xsp%08Xver%08X",
 220                         vendor, model, specifier_id, version);
 221 }
 222
 223 static int fw_unit_uevent(struct device *dev, struct kobj_uevent_env *env)
 224 {
 225         struct fw_unit *unit = fw_unit(dev);
 226         char modalias[64];
 227
 228         get_modalias(unit, modalias, sizeof(modalias));
 229
 230         if (add_uevent_var(env, "MODALIAS=%s", modalias))
 231                 return -ENOMEM;
 232
 233         return 0;
 234 }
 235
 236 struct bus_type fw_bus_type = {
 237         .name = "firewire",
 238         .match = fw_unit_match,
 239 };
 240 EXPORT_SYMBOL(fw_bus_type);
 241
 242 int fw_device_enable_phys_dma(struct fw_device *device)
 243 {
 244         int generation = device->generation;
 245
 246         /* device->node_id, accessed below, must not be older than generation */
 247         smp_rmb();
 248
 249         return device->card->driver->enable_phys_dma(device->card,
 250                                                      device->node_id,
 251                                                      generation);
 252 }
 253 EXPORT_SYMBOL(fw_device_enable_phys_dma);
 254
 255 struct config_rom_attribute {
 256         struct device_attribute attr;
 257         u32 key;
 258 };
 259
 260 static ssize_t show_immediate(struct device *dev,
 261                               struct device_attribute *dattr, char *buf)
 262 {
 263         struct config_rom_attribute *attr =
 264                 container_of(dattr, struct config_rom_attribute, attr);
 265         struct fw_csr_iterator ci;
 266         const u32 *dir;
 267         int key, value, ret = -ENOENT;
 268
 269         down_read(&fw_device_rwsem);
 270
 271         if (is_fw_unit(dev))
 272                 dir = fw_unit(dev)->directory;
 273         else
 274                 dir = fw_device(dev)->config_rom + 5;
 275
 276         fw_csr_iterator_init(&ci, dir);
 277         while (fw_csr_iterator_next(&ci, &key, &value))
 278                 if (attr->key == key) {
 279                         ret = snprintf(buf, buf ? PAGE_SIZE : 0,
 280                                        "0x%06x\n", value);
 281                         break;
 282                 }
 283
 284         up_read(&fw_device_rwsem);
 285
 286         return ret;
 287 }
 288
 289 #define IMMEDIATE_ATTR(name, key)                               \
 290         { __ATTR(name, S_IRUGO, show_immediate, NULL), key }
 291
 292 static ssize_t show_text_leaf(struct device *dev,
 293                               struct device_attribute *dattr, char *buf)
 294 {
 295         struct config_rom_attribute *attr =
 296                 container_of(dattr, struct config_rom_attribute, attr);
 297         const u32 *dir;
 298         size_t bufsize;
 299         char dummy_buf[2];
 300         int ret;
 301
 302         down_read(&fw_device_rwsem);
 303
 304         if (is_fw_unit(dev))
 305                 dir = fw_unit(dev)->directory;
 306         else
 307                 dir = fw_device(dev)->config_rom + 5;
 308
 309         if (buf) {
 310                 bufsize = PAGE_SIZE - 1;
 311         } else {
 312                 buf = dummy_buf;
 313                 bufsize = 1;
 314         }
 315
 316         ret = fw_csr_string(dir, attr->key, buf, bufsize);
 317
 318         if (ret >= 0) {
 319                 /* Strip trailing whitespace and add newline. */
 320                 while (ret > 0 && isspace(buf[ret - 1]))
 321                         ret--;
 322                 strcpy(buf + ret, "\n");
 323                 ret++;
 324         }
 325
 326         up_read(&fw_device_rwsem);
 327
 328         return ret;
 329 }
 330
 331 #define TEXT_LEAF_ATTR(name, key)                               \
 332         { __ATTR(name, S_IRUGO, show_text_leaf, NULL), key }
 333
 334 static struct config_rom_attribute config_rom_attributes[] = {
 335         IMMEDIATE_ATTR(vendor, CSR_VENDOR),
 336         IMMEDIATE_ATTR(hardware_version, CSR_HARDWARE_VERSION),
 337         IMMEDIATE_ATTR(specifier_id, CSR_SPECIFIER_ID),
 338         IMMEDIATE_ATTR(version, CSR_VERSION),
 339         IMMEDIATE_ATTR(model, CSR_MODEL),
 340         TEXT_LEAF_ATTR(vendor_name, CSR_VENDOR),
 341         TEXT_LEAF_ATTR(model_name, CSR_MODEL),
 342         TEXT_LEAF_ATTR(hardware_version_name, CSR_HARDWARE_VERSION),
 343 };
 344
 345 static void init_fw_attribute_group(struct device *dev,
 346                                     struct device_attribute *attrs,
 347                                     struct fw_attribute_group *group)
 348 {
 349         struct device_attribute *attr;
 350         int i, j;
 351
 352         for (j = 0; attrs[j].attr.name != NULL; j++)
 353                 group->attrs[j] = &attrs[j].attr;
 354
 355         for (i = 0; i < ARRAY_SIZE(config_rom_attributes); i++) {
 356                 attr = &config_rom_attributes[i].attr;
 357                 if (attr->show(dev, attr, NULL) < 0)
 358                         continue;
 359                 group->attrs[j++] = &attr->attr;
 360         }
 361
 362         group->attrs[j] = NULL;
 363         group->groups[0] = &group->group;
 364         group->groups[1] = NULL;
 365         group->group.attrs = group->attrs;
 366         dev->groups = (const struct attribute_group **) group->groups;
 367 }
 368
 369 static ssize_t modalias_show(struct device *dev,
 370                              struct device_attribute *attr, char *buf)
 371 {
 372         struct fw_unit *unit = fw_unit(dev);
 373         int length;
 374
 375         length = get_modalias(unit, buf, PAGE_SIZE);
 376         strcpy(buf + length, "\n");
 377
 378         return length + 1;
 379 }
 380
 381 static ssize_t rom_index_show(struct device *dev,
 382                               struct device_attribute *attr, char *buf)
 383 {
 384         struct fw_device *device = fw_device(dev->parent);
 385         struct fw_unit *unit = fw_unit(dev);
 386
 387         return snprintf(buf, PAGE_SIZE, "%d\n",
 388                         (int)(unit->directory - device->config_rom));
 389 }
 390
 391 static struct device_attribute fw_unit_attributes[] = {
 392         __ATTR_RO(modalias),
 393         __ATTR_RO(rom_index),
 394         __ATTR_NULL,
 395 };
 396
 397 static ssize_t config_rom_show(struct device *dev,
 398                                struct device_attribute *attr, char *buf)
 399 {
 400         struct fw_device *device = fw_device(dev);
 401         size_t length;
 402
 403         down_read(&fw_device_rwsem);
 404         length = device->config_rom_length * 4;
 405         memcpy(buf, device->config_rom, length);
 406         up_read(&fw_device_rwsem);
 407
 408         return length;
 409 }
 410
 411 static ssize_t guid_show(struct device *dev,
 412                          struct device_attribute *attr, char *buf)
 413 {
 414         struct fw_device *device = fw_device(dev);
 415         int ret;
 416
 417         down_read(&fw_device_rwsem);
 418         ret = snprintf(buf, PAGE_SIZE, "0x%08x%08x\n",
 419                        device->config_rom[3], device->config_rom[4]);
 420         up_read(&fw_device_rwsem);
 421
 422         return ret;
 423 }
 424
 425 static int units_sprintf(char *buf, const u32 *directory)
 426 {
 427         struct fw_csr_iterator ci;
 428         int key, value;
 429         int specifier_id = 0;
 430         int version = 0;
 431
 432         fw_csr_iterator_init(&ci, directory);
 433         while (fw_csr_iterator_next(&ci, &key, &value)) {
 434                 switch (key) {
 435                 case CSR_SPECIFIER_ID:
 436                         specifier_id = value;
 437                         break;
 438                 case CSR_VERSION:
 439                         version = value;
 440                         break;
 441                 }
 442         }
 443
 444         return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version);
 445 }
 446
 447 static ssize_t units_show(struct device *dev,
 448                           struct device_attribute *attr, char *buf)
 449 {
 450         struct fw_device *device = fw_device(dev);
 451         struct fw_csr_iterator ci;
 452         int key, value, i = 0;
 453
 454         down_read(&fw_device_rwsem);
 455         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 456         while (fw_csr_iterator_next(&ci, &key, &value)) {
 457                 if (key != (CSR_UNIT | CSR_DIRECTORY))
 458                         continue;
 459                 i += units_sprintf(&buf[i], ci.p + value - 1);
 460                 if (i >= PAGE_SIZE - (8 + 1 + 8 + 1))
 461                         break;
 462         }
 463         up_read(&fw_device_rwsem);
 464
 465         if (i)
 466                 buf[i - 1] = '\n';
 467
 468         return i;
 469 }
 470
 471 static struct device_attribute fw_device_attributes[] = {
 472         __ATTR_RO(config_rom),
 473         __ATTR_RO(guid),
 474         __ATTR_RO(units),
 475         __ATTR_NULL,
 476 };
 477
 478 static int read_rom(struct fw_device *device,
 479                     int generation, int index, u32 *data)
 480 {
 481         int rcode;
 482
 483         /* device->node_id, accessed below, must not be older than generation */
 484         smp_rmb();
 485
 486         rcode = fw_run_transaction(device->card, TCODE_READ_QUADLET_REQUEST,
 487                         device->node_id, generation, device->max_speed,
 488                         (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4,
 489                         data, 4);
 490         be32_to_cpus(data);
 491
 492         return rcode;
 493 }
 494
 495 #define READ_BIB_ROM_SIZE       256
 496 #define READ_BIB_STACK_SIZE     16
 497
 498 /*
 499  * Read the bus info block, perform a speed probe, and read all of the rest of
 500  * the config ROM.  We do all this with a cached bus generation.  If the bus
 501  * generation changes under us, read_bus_info_block will fail and get retried.
 502  * It's better to start all over in this case because the node from which we
 503  * are reading the ROM may have changed the ROM during the reset.
 504  */
 505 static int read_bus_info_block(struct fw_device *device, int generation)
 506 {
 507         const u32 *old_rom, *new_rom;
 508         u32 *rom, *stack;
 509         u32 sp, key;
 510         int i, end, length, ret = -1;
 511
 512         rom = kmalloc(sizeof(*rom) * READ_BIB_ROM_SIZE +
 513                       sizeof(*stack) * READ_BIB_STACK_SIZE, GFP_KERNEL);
 514         if (rom == NULL)
 515                 return -ENOMEM;
 516
 517         stack = &rom[READ_BIB_ROM_SIZE];
 518
 519         device->max_speed = SCODE_100;
 520
 521         /* First read the bus info block. */
 522         for (i = 0; i < 5; i++) {
 523                 if (read_rom(device, generation, i, &rom[i]) != RCODE_COMPLETE)
 524                         goto out;
 525                 /*
 526                  * As per IEEE1212 7.2, during power-up, devices can
 527                  * reply with a 0 for the first quadlet of the config
 528                  * rom to indicate that they are booting (for example,
 529                  * if the firmware is on the disk of a external
 530                  * harddisk).  In that case we just fail, and the
 531                  * retry mechanism will try again later.
 532                  */
 533                 if (i == 0 && rom[i] == 0)
 534                         goto out;
 535         }
 536
 537         device->max_speed = device->node->max_speed;
 538
 539         /*
 540          * Determine the speed of
 541          *   - devices with link speed less than PHY speed,
 542          *   - devices with 1394b PHY (unless only connected to 1394a PHYs),
 543          *   - all devices if there are 1394b repeaters.
 544          * Note, we cannot use the bus info block's link_spd as starting point
 545          * because some buggy firmwares set it lower than necessary and because
 546          * 1394-1995 nodes do not have the field.
 547          */
 548         if ((rom[2] & 0x7) < device->max_speed ||
 549             device->max_speed == SCODE_BETA ||
 550             device->card->beta_repeaters_present) {
 551                 u32 dummy;
 552
 553                 /* for S1600 and S3200 */
 554                 if (device->max_speed == SCODE_BETA)
 555                         device->max_speed = device->card->link_speed;
 556
 557                 while (device->max_speed > SCODE_100) {
 558                         if (read_rom(device, generation, 0, &dummy) ==
 559                             RCODE_COMPLETE)
 560                                 break;
 561                         device->max_speed--;
 562                 }
 563         }
 564
 565         /*
 566          * Now parse the config rom.  The config rom is a recursive
 567          * directory structure so we parse it using a stack of
 568          * references to the blocks that make up the structure.  We
 569          * push a reference to the root directory on the stack to
 570          * start things off.
 571          */
 572         length = i;
 573         sp = 0;
 574         stack[sp++] = 0xc0000005;
 575         while (sp > 0) {
 576                 /*
 577                  * Pop the next block reference of the stack.  The
 578                  * lower 24 bits is the offset into the config rom,
 579                  * the upper 8 bits are the type of the reference the
 580                  * block.
 581                  */
 582                 key = stack[--sp];
 583                 i = key & 0xffffff;
 584                 if (WARN_ON(i >= READ_BIB_ROM_SIZE))
 585                         goto out;
 586
 587                 /* Read header quadlet for the block to get the length. */
 588                 if (read_rom(device, generation, i, &rom[i]) != RCODE_COMPLETE)
 589                         goto out;
 590                 end = i + (rom[i] >> 16) + 1;
 591                 if (end > READ_BIB_ROM_SIZE) {
 592                         /*
 593                          * This block extends outside the config ROM which is
 594                          * a firmware bug.  Ignore this whole block, i.e.
 595                          * simply set a fake block length of 0.
 596                          */
 597                         fw_error("skipped invalid ROM block %x at %llx\n",
 598                                  rom[i],
 599                                  i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 600                         rom[i] = 0;
 601                         end = i;
 602                 }
 603                 i++;
 604
 605                 /*
 606                  * Now read in the block.  If this is a directory
 607                  * block, check the entries as we read them to see if
 608                  * it references another block, and push it in that case.
 609                  */
 610                 for (; i < end; i++) {
 611                         if (read_rom(device, generation, i, &rom[i]) !=
 612                             RCODE_COMPLETE)
 613                                 goto out;
 614
 615                         if ((key >> 30) != 3 || (rom[i] >> 30) < 2 ||
 616                             sp >= READ_BIB_STACK_SIZE)
 617                                 continue;
 618                         /*
 619                          * Offset points outside the ROM.  May be a firmware
 620                          * bug or an Extended ROM entry (IEEE 1212-2001 clause
 621                          * 7.7.18).  Simply overwrite this pointer here by a
 622                          * fake immediate entry so that later iterators over
 623                          * the ROM don't have to check offsets all the time.
 624                          */
 625                         if (i + (rom[i] & 0xffffff) >= READ_BIB_ROM_SIZE) {
 626                                 fw_error("skipped unsupported ROM entry %x at %llx\n",
 627                                          rom[i],
 628                                          i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 629                                 rom[i] = 0;
 630                                 continue;
 631                         }
 632                         stack[sp++] = i + rom[i];
 633                 }
 634                 if (length < i)
 635                         length = i;
 636         }
 637
 638         old_rom = device->config_rom;
 639         new_rom = kmemdup(rom, length * 4, GFP_KERNEL);
 640         if (new_rom == NULL)
 641                 goto out;
 642
 643         down_write(&fw_device_rwsem);
 644         device->config_rom = new_rom;
 645         device->config_rom_length = length;
 646         up_write(&fw_device_rwsem);
 647
 648         kfree(old_rom);
 649         ret = 0;
 650         device->max_rec = rom[2] >> 12 & 0xf;
 651         device->cmc     = rom[2] >> 30 & 1;
 652         device->irmc    = rom[2] >> 31 & 1;
 653  out:
 654         kfree(rom);
 655
 656         return ret;
 657 }
 658
 659 static void fw_unit_release(struct device *dev)
 660 {
 661         struct fw_unit *unit = fw_unit(dev);
 662
 663         kfree(unit);
 664 }
 665
 666 static struct device_type fw_unit_type = {
 667         .uevent         = fw_unit_uevent,
 668         .release        = fw_unit_release,
 669 };
 670
 671 static bool is_fw_unit(struct device *dev)
 672 {
 673         return dev->type == &fw_unit_type;
 674 }
 675
 676 static void create_units(struct fw_device *device)
 677 {
 678         struct fw_csr_iterator ci;
 679         struct fw_unit *unit;
 680         int key, value, i;
 681
 682         i = 0;
 683         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 684         while (fw_csr_iterator_next(&ci, &key, &value)) {
 685                 if (key != (CSR_UNIT | CSR_DIRECTORY))
 686                         continue;
 687
 688                 /*
 689                  * Get the address of the unit directory and try to
 690                  * match the drivers id_tables against it.
 691                  */
 692                 unit = kzalloc(sizeof(*unit), GFP_KERNEL);
 693                 if (unit == NULL) {
 694                         fw_error("failed to allocate memory for unit\n");
 695                         continue;
 696                 }
 697
 698                 unit->directory = ci.p + value - 1;
 699                 unit->device.bus = &fw_bus_type;
 700                 unit->device.type = &fw_unit_type;
 701                 unit->device.parent = &device->device;
 702                 dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++);
 703
 704                 BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) <
 705                                 ARRAY_SIZE(fw_unit_attributes) +
 706                                 ARRAY_SIZE(config_rom_attributes));
 707                 init_fw_attribute_group(&unit->device,
 708                                         fw_unit_attributes,
 709                                         &unit->attribute_group);
 710
 711                 if (device_register(&unit->device) < 0)
 712                         goto skip_unit;
 713
 714                 continue;
 715
 716         skip_unit:
 717                 kfree(unit);
 718         }
 719 }
 720
 721 static int shutdown_unit(struct device *device, void *data)
 722 {
 723         device_unregister(device);
 724
 725         return 0;
 726 }
 727
 728 /*
 729  * fw_device_rwsem acts as dual purpose mutex:
 730  *   - serializes accesses to fw_device_idr,
 731  *   - serializes accesses to fw_device.config_rom/.config_rom_length and
 732  *     fw_unit.directory, unless those accesses happen at safe occasions
 733  */
 734 DECLARE_RWSEM(fw_device_rwsem);
 735
 736 DEFINE_IDR(fw_device_idr);
 737 int fw_cdev_major;
 738
 739 struct fw_device *fw_device_get_by_devt(dev_t devt)
 740 {
 741         struct fw_device *device;
 742
 743         down_read(&fw_device_rwsem);
 744         device = idr_find(&fw_device_idr, MINOR(devt));
 745         if (device)
 746                 fw_device_get(device);
 747         up_read(&fw_device_rwsem);
 748
 749         return device;
 750 }
 751
 752 /*
 753  * These defines control the retry behavior for reading the config
 754  * rom.  It shouldn't be necessary to tweak these; if the device
 755  * doesn't respond to a config rom read within 10 seconds, it's not
 756  * going to respond at all.  As for the initial delay, a lot of
 757  * devices will be able to respond within half a second after bus
 758  * reset.  On the other hand, it's not really worth being more
 759  * aggressive than that, since it scales pretty well; if 10 devices
 760  * are plugged in, they're all getting read within one second.
 761  */
 762
 763 #define MAX_RETRIES     10
 764 #define RETRY_DELAY     (3 * HZ)
 765 #define INITIAL_DELAY   (HZ / 2)
 766 #define SHUTDOWN_DELAY  (2 * HZ)
 767
 768 static void fw_device_shutdown(struct work_struct *work)
 769 {
 770         struct fw_device *device =
 771                 container_of(work, struct fw_device, work.work);
 772         int minor = MINOR(device->device.devt);
 773
 774         if (time_is_after_jiffies(device->card->reset_jiffies + SHUTDOWN_DELAY)
 775             && !list_empty(&device->card->link)) {
 776                 schedule_delayed_work(&device->work, SHUTDOWN_DELAY);
 777                 return;
 778         }
 779
 780         if (atomic_cmpxchg(&device->state,
 781                            FW_DEVICE_GONE,
 782                            FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE)
 783                 return;
 784
 785         fw_device_cdev_remove(device);
 786         device_for_each_child(&device->device, NULL, shutdown_unit);
 787         device_unregister(&device->device);
 788
 789         down_write(&fw_device_rwsem);
 790         idr_remove(&fw_device_idr, minor);
 791         up_write(&fw_device_rwsem);
 792
 793         fw_device_put(device);
 794 }
 795
 796 static void fw_device_release(struct device *dev)
 797 {
 798         struct fw_device *device = fw_device(dev);
 799         struct fw_card *card = device->card;
 800         unsigned long flags;
 801
 802         /*
 803          * Take the card lock so we don't set this to NULL while a
 804          * FW_NODE_UPDATED callback is being handled or while the
 805          * bus manager work looks at this node.
 806          */
 807         spin_lock_irqsave(&card->lock, flags);
 808         device->node->data = NULL;
 809         spin_unlock_irqrestore(&card->lock, flags);
 810
 811         fw_node_put(device->node);
 812         kfree(device->config_rom);
 813         kfree(device);
 814         fw_card_put(card);
 815 }
 816
 817 static struct device_type fw_device_type = {
 818         .release = fw_device_release,
 819 };
 820
 821 static bool is_fw_device(struct device *dev)
 822 {
 823         return dev->type == &fw_device_type;
 824 }
 825
 826 static int update_unit(struct device *dev, void *data)
 827 {
 828         struct fw_unit *unit = fw_unit(dev);
 829         struct fw_driver *driver = (struct fw_driver *)dev->driver;
 830
 831         if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) {
 832                 down(&dev->sem);
 833                 driver->update(unit);
 834                 up(&dev->sem);
 835         }
 836
 837         return 0;
 838 }
 839
 840 static void fw_device_update(struct work_struct *work)
 841 {
 842         struct fw_device *device =
 843                 container_of(work, struct fw_device, work.work);
 844
 845         fw_device_cdev_update(device);
 846         device_for_each_child(&device->device, NULL, update_unit);
 847 }
 848
 849 /*
 850  * If a device was pending for deletion because its node went away but its
 851  * bus info block and root directory header matches that of a newly discovered
 852  * device, revive the existing fw_device.
 853  * The newly allocated fw_device becomes obsolete instead.
 854  */
 855 static int lookup_existing_device(struct device *dev, void *data)
 856 {
 857         struct fw_device *old = fw_device(dev);
 858         struct fw_device *new = data;
 859         struct fw_card *card = new->card;
 860         int match = 0;
 861
 862         if (!is_fw_device(dev))
 863                 return 0;
 864
 865         down_read(&fw_device_rwsem); /* serialize config_rom access */
 866         spin_lock_irq(&card->lock);  /* serialize node access */
 867
 868         if (memcmp(old->config_rom, new->config_rom, 6 * 4) == 0 &&
 869             atomic_cmpxchg(&old->state,
 870                            FW_DEVICE_GONE,
 871                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
 872                 struct fw_node *current_node = new->node;
 873                 struct fw_node *obsolete_node = old->node;
 874
 875                 new->node = obsolete_node;
 876                 new->node->data = new;
 877                 old->node = current_node;
 878                 old->node->data = old;
 879
 880                 old->max_speed = new->max_speed;
 881                 old->node_id = current_node->node_id;
 882                 smp_wmb();  /* update node_id before generation */
 883                 old->generation = card->generation;
 884                 old->config_rom_retries = 0;
 885                 fw_notify("rediscovered device %s\n", dev_name(dev));
 886
 887                 PREPARE_DELAYED_WORK(&old->work, fw_device_update);
 888                 schedule_delayed_work(&old->work, 0);
 889
 890                 if (current_node == card->root_node)
 891                         fw_schedule_bm_work(card, 0);
 892
 893                 match = 1;
 894         }
 895
 896         spin_unlock_irq(&card->lock);
 897         up_read(&fw_device_rwsem);
 898
 899         return match;
 900 }
 901
 902 enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, };
 903
 904 static void set_broadcast_channel(struct fw_device *device, int generation)
 905 {
 906         struct fw_card *card = device->card;
 907         __be32 data;
 908         int rcode;
 909
 910         if (!card->broadcast_channel_allocated)
 911                 return;
 912
 913         /*
 914          * The Broadcast_Channel Valid bit is required by nodes which want to
 915          * transmit on this channel.  Such transmissions are practically
 916          * exclusive to IP over 1394 (RFC 2734).  IP capable nodes are required
 917          * to be IRM capable and have a max_rec of 8 or more.  We use this fact
 918          * to narrow down to which nodes we send Broadcast_Channel updates.
 919          */
 920         if (!device->irmc || device->max_rec < 8)
 921                 return;
 922
 923         /*
 924          * Some 1394-1995 nodes crash if this 1394a-2000 register is written.
 925          * Perform a read test first.
 926          */
 927         if (device->bc_implemented == BC_UNKNOWN) {
 928                 rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST,
 929                                 device->node_id, generation, device->max_speed,
 930                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 931                                 &data, 4);
 932                 switch (rcode) {
 933                 case RCODE_COMPLETE:
 934                         if (data & cpu_to_be32(1 << 31)) {
 935                                 device->bc_implemented = BC_IMPLEMENTED;
 936                                 break;
 937                         }
 938                         /* else fall through to case address error */
 939                 case RCODE_ADDRESS_ERROR:
 940                         device->bc_implemented = BC_UNIMPLEMENTED;
 941                 }
 942         }
 943
 944         if (device->bc_implemented == BC_IMPLEMENTED) {
 945                 data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL |
 946                                    BROADCAST_CHANNEL_VALID);
 947                 fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
 948                                 device->node_id, generation, device->max_speed,
 949                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 950                                 &data, 4);
 951         }
 952 }
 953
 954 int fw_device_set_broadcast_channel(struct device *dev, void *gen)
 955 {
 956         if (is_fw_device(dev))
 957                 set_broadcast_channel(fw_device(dev), (long)gen);
 958
 959         return 0;
 960 }
 961
 962 static void fw_device_init(struct work_struct *work)
 963 {
 964         struct fw_device *device =
 965                 container_of(work, struct fw_device, work.work);
 966         struct device *revived_dev;
 967         int minor, ret;
 968
 969         /*
 970          * All failure paths here set node->data to NULL, so that we
 971          * don't try to do device_for_each_child() on a kfree()'d
 972          * device.
 973          */
 974
 975         if (read_bus_info_block(device, device->generation) < 0) {
 976                 if (device->config_rom_retries < MAX_RETRIES &&
 977                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
 978                         device->config_rom_retries++;
 979                         schedule_delayed_work(&device->work, RETRY_DELAY);
 980                 } else {
 981                         fw_notify("giving up on config rom for node id %x\n",
 982                                   device->node_id);
 983                         if (device->node == device->card->root_node)
 984                                 fw_schedule_bm_work(device->card, 0);
 985                         fw_device_release(&device->device);
 986                 }
 987                 return;
 988         }
 989
 990         revived_dev = device_find_child(device->card->device,
 991                                         device, lookup_existing_device);
 992         if (revived_dev) {
 993                 put_device(revived_dev);
 994                 fw_device_release(&device->device);
 995
 996                 return;
 997         }
 998
 999         device_initialize(&device->device);
1000
1001         fw_device_get(device);
1002         down_write(&fw_device_rwsem);
1003         ret = idr_pre_get(&fw_device_idr, GFP_KERNEL) ?
1004               idr_get_new(&fw_device_idr, device, &minor) :
1005               -ENOMEM;
1006         up_write(&fw_device_rwsem);
1007
1008         if (ret < 0)
1009                 goto error;
1010
1011         device->device.bus = &fw_bus_type;
1012         device->device.type = &fw_device_type;
1013         device->device.parent = device->card->device;
1014         device->device.devt = MKDEV(fw_cdev_major, minor);
1015         dev_set_name(&device->device, "fw%d", minor);
1016
1017         BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) <
1018                         ARRAY_SIZE(fw_device_attributes) +
1019                         ARRAY_SIZE(config_rom_attributes));
1020         init_fw_attribute_group(&device->device,
1021                                 fw_device_attributes,
1022                                 &device->attribute_group);
1023
1024         if (device_add(&device->device)) {
1025                 fw_error("Failed to add device.\n");
1026                 goto error_with_cdev;
1027         }
1028
1029         create_units(device);
1030
1031         /*
1032          * Transition the device to running state.  If it got pulled
1033          * out from under us while we did the intialization work, we
1034          * have to shut down the device again here.  Normally, though,
1035          * fw_node_event will be responsible for shutting it down when
1036          * necessary.  We have to use the atomic cmpxchg here to avoid
1037          * racing with the FW_NODE_DESTROYED case in
1038          * fw_node_event().
1039          */
1040         if (atomic_cmpxchg(&device->state,
1041                            FW_DEVICE_INITIALIZING,
1042                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
1043                 PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1044                 schedule_delayed_work(&device->work, SHUTDOWN_DELAY);
1045         } else {
1046                 if (device->config_rom_retries)
1047                         fw_notify("created device %s: GUID %08x%08x, S%d00, "
1048                                   "%d config ROM retries\n",
1049                                   dev_name(&device->device),
1050                                   device->config_rom[3], device->config_rom[4],
1051                                   1 << device->max_speed,
1052                                   device->config_rom_retries);
1053                 else
1054                         fw_notify("created device %s: GUID %08x%08x, S%d00\n",
1055                                   dev_name(&device->device),
1056                                   device->config_rom[3], device->config_rom[4],
1057                                   1 << device->max_speed);
1058                 device->config_rom_retries = 0;
1059
1060                 set_broadcast_channel(device, device->generation);
1061         }
1062
1063         /*
1064          * Reschedule the IRM work if we just finished reading the
1065          * root node config rom.  If this races with a bus reset we
1066          * just end up running the IRM work a couple of extra times -
1067          * pretty harmless.
1068          */
1069         if (device->node == device->card->root_node)
1070                 fw_schedule_bm_work(device->card, 0);
1071
1072         return;
1073
1074  error_with_cdev:
1075         down_write(&fw_device_rwsem);
1076         idr_remove(&fw_device_idr, minor);
1077         up_write(&fw_device_rwsem);
1078  error:
1079         fw_device_put(device);          /* fw_device_idr's reference */
1080
1081         put_device(&device->device);    /* our reference */
1082 }
1083
1084 enum {
1085         REREAD_BIB_ERROR,
1086         REREAD_BIB_GONE,
1087         REREAD_BIB_UNCHANGED,
1088         REREAD_BIB_CHANGED,
1089 };
1090
1091 /* Reread and compare bus info block and header of root directory */
1092 static int reread_bus_info_block(struct fw_device *device, int generation)
1093 {
1094         u32 q;
1095         int i;
1096
1097         for (i = 0; i < 6; i++) {
1098                 if (read_rom(device, generation, i, &q) != RCODE_COMPLETE)
1099                         return REREAD_BIB_ERROR;
1100
1101                 if (i == 0 && q == 0)
1102                         return REREAD_BIB_GONE;
1103
1104                 if (q != device->config_rom[i])
1105                         return REREAD_BIB_CHANGED;
1106         }
1107
1108         return REREAD_BIB_UNCHANGED;
1109 }
1110
1111 static void fw_device_refresh(struct work_struct *work)
1112 {
1113         struct fw_device *device =
1114                 container_of(work, struct fw_device, work.work);
1115         struct fw_card *card = device->card;
1116         int node_id = device->node_id;
1117
1118         switch (reread_bus_info_block(device, device->generation)) {
1119         case REREAD_BIB_ERROR:
1120                 if (device->config_rom_retries < MAX_RETRIES / 2 &&
1121                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1122                         device->config_rom_retries++;
1123                         schedule_delayed_work(&device->work, RETRY_DELAY / 2);
1124
1125                         return;
1126                 }
1127                 goto give_up;
1128
1129         case REREAD_BIB_GONE:
1130                 goto gone;
1131
1132         case REREAD_BIB_UNCHANGED:
1133                 if (atomic_cmpxchg(&device->state,
1134                                    FW_DEVICE_INITIALIZING,
1135                                    FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1136                         goto gone;
1137
1138                 fw_device_update(work);
1139                 device->config_rom_retries = 0;
1140                 goto out;
1141
1142         case REREAD_BIB_CHANGED:
1143                 break;
1144         }
1145
1146         /*
1147          * Something changed.  We keep things simple and don't investigate
1148          * further.  We just destroy all previous units and create new ones.
1149          */
1150         device_for_each_child(&device->device, NULL, shutdown_unit);
1151
1152         if (read_bus_info_block(device, device->generation) < 0) {
1153                 if (device->config_rom_retries < MAX_RETRIES &&
1154                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1155                         device->config_rom_retries++;
1156                         schedule_delayed_work(&device->work, RETRY_DELAY);
1157
1158                         return;
1159                 }
1160                 goto give_up;
1161         }
1162
1163         create_units(device);
1164
1165         /* Userspace may want to re-read attributes. */
1166         kobject_uevent(&device->device.kobj, KOBJ_CHANGE);
1167
1168         if (atomic_cmpxchg(&device->state,
1169                            FW_DEVICE_INITIALIZING,
1170                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1171                 goto gone;
1172
1173         fw_notify("refreshed device %s\n", dev_name(&device->device));
1174         device->config_rom_retries = 0;
1175         goto out;
1176
1177  give_up:
1178         fw_notify("giving up on refresh of device %s\n", dev_name(&device->device));
1179  gone:
1180         atomic_set(&device->state, FW_DEVICE_GONE);
1181         PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1182         schedule_delayed_work(&device->work, SHUTDOWN_DELAY);
1183  out:
1184         if (node_id == card->root_node->node_id)
1185                 fw_schedule_bm_work(card, 0);
1186 }
1187
1188 void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
1189 {
1190         struct fw_device *device;
1191
1192         switch (event) {
1193         case FW_NODE_CREATED:
1194         case FW_NODE_LINK_ON:
1195                 if (!node->link_on)
1196                         break;
1197  create:
1198                 device = kzalloc(sizeof(*device), GFP_ATOMIC);
1199                 if (device == NULL)
1200                         break;
1201
1202                 /*
1203                  * Do minimal intialization of the device here, the
1204                  * rest will happen in fw_device_init().
1205                  *
1206                  * Attention:  A lot of things, even fw_device_get(),
1207                  * cannot be done before fw_device_init() finished!
1208                  * You can basically just check device->state and
1209                  * schedule work until then, but only while holding
1210                  * card->lock.
1211                  */
1212                 atomic_set(&device->state, FW_DEVICE_INITIALIZING);
1213                 device->card = fw_card_get(card);
1214                 device->node = fw_node_get(node);
1215                 device->node_id = node->node_id;
1216                 device->generation = card->generation;
1217                 device->is_local = node == card->local_node;
1218                 mutex_init(&device->client_list_mutex);
1219                 INIT_LIST_HEAD(&device->client_list);
1220
1221                 /*
1222                  * Set the node data to point back to this device so
1223                  * FW_NODE_UPDATED callbacks can update the node_id
1224                  * and generation for the device.
1225                  */
1226                 node->data = device;
1227
1228                 /*
1229                  * Many devices are slow to respond after bus resets,
1230                  * especially if they are bus powered and go through
1231                  * power-up after getting plugged in.  We schedule the
1232                  * first config rom scan half a second after bus reset.
1233                  */
1234                 INIT_DELAYED_WORK(&device->work, fw_device_init);
1235                 schedule_delayed_work(&device->work, INITIAL_DELAY);
1236                 break;
1237
1238         case FW_NODE_INITIATED_RESET:
1239                 device = node->data;
1240                 if (device == NULL)
1241                         goto create;
1242
1243                 device->node_id = node->node_id;
1244                 smp_wmb();  /* update node_id before generation */
1245                 device->generation = card->generation;
1246                 if (atomic_cmpxchg(&device->state,
1247                             FW_DEVICE_RUNNING,
1248                             FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) {
1249                         PREPARE_DELAYED_WORK(&device->work, fw_device_refresh);
1250                         schedule_delayed_work(&device->work,
1251                                 device->is_local ? 0 : INITIAL_DELAY);
1252                 }
1253                 break;
1254
1255         case FW_NODE_UPDATED:
1256                 if (!node->link_on || node->data == NULL)
1257                         break;
1258
1259                 device = node->data;
1260                 device->node_id = node->node_id;
1261                 smp_wmb();  /* update node_id before generation */
1262                 device->generation = card->generation;
1263                 if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
1264                         PREPARE_DELAYED_WORK(&device->work, fw_device_update);
1265                         schedule_delayed_work(&device->work, 0);
1266                 }
1267                 break;
1268
1269         case FW_NODE_DESTROYED:
1270         case FW_NODE_LINK_OFF:
1271                 if (!node->data)
1272                         break;
1273
1274                 /*
1275                  * Destroy the device associated with the node.  There
1276                  * are two cases here: either the device is fully
1277                  * initialized (FW_DEVICE_RUNNING) or we're in the
1278                  * process of reading its config rom
1279                  * (FW_DEVICE_INITIALIZING).  If it is fully
1280                  * initialized we can reuse device->work to schedule a
1281                  * full fw_device_shutdown().  If not, there's work
1282                  * scheduled to read it's config rom, and we just put
1283                  * the device in shutdown state to have that code fail
1284                  * to create the device.
1285                  */
1286                 device = node->data;
1287                 if (atomic_xchg(&device->state,
1288                                 FW_DEVICE_GONE) == FW_DEVICE_RUNNING) {
1289                         PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1290                         schedule_delayed_work(&device->work,
1291                                 list_empty(&card->link) ? 0 : SHUTDOWN_DELAY);
1292                 }
1293                 break;
1294         }
1295 }