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/random.h>
  36 #include <linux/rwsem.h>
  37 #include <linux/slab.h>
  38 #include <linux/spinlock.h>
  39 #include <linux/string.h>
  40 #include <linux/workqueue.h>
  41
  42 #include <linux/atomic.h>
  43 #include <asm/byteorder.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 just after the entry with the
 117  * @key. The string is zero-terminated. An overlong string is silently truncated such that it
 118  * and the zero byte fit into @size.
 119  *
 120  * Returns strlen(buf) or a negative error code.
 121  */
 122 int fw_csr_string(const u32 *directory, int key, char *buf, size_t size)
 123 {
 124         const u32 *leaf = search_leaf(directory, key);
 125         if (!leaf)
 126                 return -ENOENT;
 127
 128         return textual_leaf_to_string(leaf, buf, size);
 129 }
 130 EXPORT_SYMBOL(fw_csr_string);
 131
 132 static void get_ids(const u32 *directory, int *id)
 133 {
 134         struct fw_csr_iterator ci;
 135         int key, value;
 136
 137         fw_csr_iterator_init(&ci, directory);
 138         while (fw_csr_iterator_next(&ci, &key, &value)) {
 139                 switch (key) {
 140                 case CSR_VENDOR:        id[0] = value; break;
 141                 case CSR_MODEL:         id[1] = value; break;
 142                 case CSR_SPECIFIER_ID:  id[2] = value; break;
 143                 case CSR_VERSION:       id[3] = value; break;
 144                 }
 145         }
 146 }
 147
 148 static void get_modalias_ids(struct fw_unit *unit, int *id)
 149 {
 150         get_ids(&fw_parent_device(unit)->config_rom[5], id);
 151         get_ids(unit->directory, id);
 152 }
 153
 154 static bool match_ids(const struct ieee1394_device_id *id_table, int *id)
 155 {
 156         int match = 0;
 157
 158         if (id[0] == id_table->vendor_id)
 159                 match |= IEEE1394_MATCH_VENDOR_ID;
 160         if (id[1] == id_table->model_id)
 161                 match |= IEEE1394_MATCH_MODEL_ID;
 162         if (id[2] == id_table->specifier_id)
 163                 match |= IEEE1394_MATCH_SPECIFIER_ID;
 164         if (id[3] == id_table->version)
 165                 match |= IEEE1394_MATCH_VERSION;
 166
 167         return (match & id_table->match_flags) == id_table->match_flags;
 168 }
 169
 170 static const struct ieee1394_device_id *unit_match(struct device *dev,
 171                                                    struct device_driver *drv)
 172 {
 173         const struct ieee1394_device_id *id_table =
 174                         container_of(drv, struct fw_driver, driver)->id_table;
 175         int id[] = {0, 0, 0, 0};
 176
 177         get_modalias_ids(fw_unit(dev), id);
 178
 179         for (; id_table->match_flags != 0; id_table++)
 180                 if (match_ids(id_table, id))
 181                         return id_table;
 182
 183         return NULL;
 184 }
 185
 186 static bool is_fw_unit(struct device *dev);
 187
 188 static int fw_unit_match(struct device *dev, struct device_driver *drv)
 189 {
 190         /* We only allow binding to fw_units. */
 191         return is_fw_unit(dev) && unit_match(dev, drv) != NULL;
 192 }
 193
 194 static int fw_unit_probe(struct device *dev)
 195 {
 196         struct fw_driver *driver =
 197                         container_of(dev->driver, struct fw_driver, driver);
 198
 199         return driver->probe(fw_unit(dev), unit_match(dev, dev->driver));
 200 }
 201
 202 static int fw_unit_remove(struct device *dev)
 203 {
 204         struct fw_driver *driver =
 205                         container_of(dev->driver, struct fw_driver, driver);
 206
 207         return driver->remove(fw_unit(dev)), 0;
 208 }
 209
 210 static int get_modalias(struct fw_unit *unit, char *buffer, size_t buffer_size)
 211 {
 212         int id[] = {0, 0, 0, 0};
 213
 214         get_modalias_ids(unit, id);
 215
 216         return snprintf(buffer, buffer_size,
 217                         "ieee1394:ven%08Xmo%08Xsp%08Xver%08X",
 218                         id[0], id[1], id[2], id[3]);
 219 }
 220
 221 static int fw_unit_uevent(struct device *dev, struct kobj_uevent_env *env)
 222 {
 223         struct fw_unit *unit = fw_unit(dev);
 224         char modalias[64];
 225
 226         get_modalias(unit, modalias, sizeof(modalias));
 227
 228         if (add_uevent_var(env, "MODALIAS=%s", modalias))
 229                 return -ENOMEM;
 230
 231         return 0;
 232 }
 233
 234 struct bus_type fw_bus_type = {
 235         .name = "firewire",
 236         .match = fw_unit_match,
 237         .probe = fw_unit_probe,
 238         .remove = fw_unit_remove,
 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 ssize_t is_local_show(struct device *dev,
 426                              struct device_attribute *attr, char *buf)
 427 {
 428         struct fw_device *device = fw_device(dev);
 429
 430         return sprintf(buf, "%u\n", device->is_local);
 431 }
 432
 433 static int units_sprintf(char *buf, const u32 *directory)
 434 {
 435         struct fw_csr_iterator ci;
 436         int key, value;
 437         int specifier_id = 0;
 438         int version = 0;
 439
 440         fw_csr_iterator_init(&ci, directory);
 441         while (fw_csr_iterator_next(&ci, &key, &value)) {
 442                 switch (key) {
 443                 case CSR_SPECIFIER_ID:
 444                         specifier_id = value;
 445                         break;
 446                 case CSR_VERSION:
 447                         version = value;
 448                         break;
 449                 }
 450         }
 451
 452         return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version);
 453 }
 454
 455 static ssize_t units_show(struct device *dev,
 456                           struct device_attribute *attr, char *buf)
 457 {
 458         struct fw_device *device = fw_device(dev);
 459         struct fw_csr_iterator ci;
 460         int key, value, i = 0;
 461
 462         down_read(&fw_device_rwsem);
 463         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 464         while (fw_csr_iterator_next(&ci, &key, &value)) {
 465                 if (key != (CSR_UNIT | CSR_DIRECTORY))
 466                         continue;
 467                 i += units_sprintf(&buf[i], ci.p + value - 1);
 468                 if (i >= PAGE_SIZE - (8 + 1 + 8 + 1))
 469                         break;
 470         }
 471         up_read(&fw_device_rwsem);
 472
 473         if (i)
 474                 buf[i - 1] = '\n';
 475
 476         return i;
 477 }
 478
 479 static struct device_attribute fw_device_attributes[] = {
 480         __ATTR_RO(config_rom),
 481         __ATTR_RO(guid),
 482         __ATTR_RO(is_local),
 483         __ATTR_RO(units),
 484         __ATTR_NULL,
 485 };
 486
 487 static int read_rom(struct fw_device *device,
 488                     int generation, int index, u32 *data)
 489 {
 490         u64 offset = (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4;
 491         int i, rcode;
 492
 493         /* device->node_id, accessed below, must not be older than generation */
 494         smp_rmb();
 495
 496         for (i = 10; i < 100; i += 10) {
 497                 rcode = fw_run_transaction(device->card,
 498                                 TCODE_READ_QUADLET_REQUEST, device->node_id,
 499                                 generation, device->max_speed, offset, data, 4);
 500                 if (rcode != RCODE_BUSY)
 501                         break;
 502                 msleep(i);
 503         }
 504         be32_to_cpus(data);
 505
 506         return rcode;
 507 }
 508
 509 #define MAX_CONFIG_ROM_SIZE 256
 510
 511 /*
 512  * Read the bus info block, perform a speed probe, and read all of the rest of
 513  * the config ROM.  We do all this with a cached bus generation.  If the bus
 514  * generation changes under us, read_config_rom will fail and get retried.
 515  * It's better to start all over in this case because the node from which we
 516  * are reading the ROM may have changed the ROM during the reset.
 517  * Returns either a result code or a negative error code.
 518  */
 519 static int read_config_rom(struct fw_device *device, int generation)
 520 {
 521         struct fw_card *card = device->card;
 522         const u32 *old_rom, *new_rom;
 523         u32 *rom, *stack;
 524         u32 sp, key;
 525         int i, end, length, ret;
 526
 527         rom = kmalloc(sizeof(*rom) * MAX_CONFIG_ROM_SIZE +
 528                       sizeof(*stack) * MAX_CONFIG_ROM_SIZE, GFP_KERNEL);
 529         if (rom == NULL)
 530                 return -ENOMEM;
 531
 532         stack = &rom[MAX_CONFIG_ROM_SIZE];
 533         memset(rom, 0, sizeof(*rom) * MAX_CONFIG_ROM_SIZE);
 534
 535         device->max_speed = SCODE_100;
 536
 537         /* First read the bus info block. */
 538         for (i = 0; i < 5; i++) {
 539                 ret = read_rom(device, generation, i, &rom[i]);
 540                 if (ret != RCODE_COMPLETE)
 541                         goto out;
 542                 /*
 543                  * As per IEEE1212 7.2, during initialization, devices can
 544                  * reply with a 0 for the first quadlet of the config
 545                  * rom to indicate that they are booting (for example,
 546                  * if the firmware is on the disk of a external
 547                  * harddisk).  In that case we just fail, and the
 548                  * retry mechanism will try again later.
 549                  */
 550                 if (i == 0 && rom[i] == 0) {
 551                         ret = RCODE_BUSY;
 552                         goto out;
 553                 }
 554         }
 555
 556         device->max_speed = device->node->max_speed;
 557
 558         /*
 559          * Determine the speed of
 560          *   - devices with link speed less than PHY speed,
 561          *   - devices with 1394b PHY (unless only connected to 1394a PHYs),
 562          *   - all devices if there are 1394b repeaters.
 563          * Note, we cannot use the bus info block's link_spd as starting point
 564          * because some buggy firmwares set it lower than necessary and because
 565          * 1394-1995 nodes do not have the field.
 566          */
 567         if ((rom[2] & 0x7) < device->max_speed ||
 568             device->max_speed == SCODE_BETA ||
 569             card->beta_repeaters_present) {
 570                 u32 dummy;
 571
 572                 /* for S1600 and S3200 */
 573                 if (device->max_speed == SCODE_BETA)
 574                         device->max_speed = card->link_speed;
 575
 576                 while (device->max_speed > SCODE_100) {
 577                         if (read_rom(device, generation, 0, &dummy) ==
 578                             RCODE_COMPLETE)
 579                                 break;
 580                         device->max_speed--;
 581                 }
 582         }
 583
 584         /*
 585          * Now parse the config rom.  The config rom is a recursive
 586          * directory structure so we parse it using a stack of
 587          * references to the blocks that make up the structure.  We
 588          * push a reference to the root directory on the stack to
 589          * start things off.
 590          */
 591         length = i;
 592         sp = 0;
 593         stack[sp++] = 0xc0000005;
 594         while (sp > 0) {
 595                 /*
 596                  * Pop the next block reference of the stack.  The
 597                  * lower 24 bits is the offset into the config rom,
 598                  * the upper 8 bits are the type of the reference the
 599                  * block.
 600                  */
 601                 key = stack[--sp];
 602                 i = key & 0xffffff;
 603                 if (WARN_ON(i >= MAX_CONFIG_ROM_SIZE)) {
 604                         ret = -ENXIO;
 605                         goto out;
 606                 }
 607
 608                 /* Read header quadlet for the block to get the length. */
 609                 ret = read_rom(device, generation, i, &rom[i]);
 610                 if (ret != RCODE_COMPLETE)
 611                         goto out;
 612                 end = i + (rom[i] >> 16) + 1;
 613                 if (end > MAX_CONFIG_ROM_SIZE) {
 614                         /*
 615                          * This block extends outside the config ROM which is
 616                          * a firmware bug.  Ignore this whole block, i.e.
 617                          * simply set a fake block length of 0.
 618                          */
 619                         fw_err(card, "skipped invalid ROM block %x at %llx\n",
 620                                rom[i],
 621                                i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 622                         rom[i] = 0;
 623                         end = i;
 624                 }
 625                 i++;
 626
 627                 /*
 628                  * Now read in the block.  If this is a directory
 629                  * block, check the entries as we read them to see if
 630                  * it references another block, and push it in that case.
 631                  */
 632                 for (; i < end; i++) {
 633                         ret = read_rom(device, generation, i, &rom[i]);
 634                         if (ret != RCODE_COMPLETE)
 635                                 goto out;
 636
 637                         if ((key >> 30) != 3 || (rom[i] >> 30) < 2)
 638                                 continue;
 639                         /*
 640                          * Offset points outside the ROM.  May be a firmware
 641                          * bug or an Extended ROM entry (IEEE 1212-2001 clause
 642                          * 7.7.18).  Simply overwrite this pointer here by a
 643                          * fake immediate entry so that later iterators over
 644                          * the ROM don't have to check offsets all the time.
 645                          */
 646                         if (i + (rom[i] & 0xffffff) >= MAX_CONFIG_ROM_SIZE) {
 647                                 fw_err(card,
 648                                        "skipped unsupported ROM entry %x at %llx\n",
 649                                        rom[i],
 650                                        i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 651                                 rom[i] = 0;
 652                                 continue;
 653                         }
 654                         stack[sp++] = i + rom[i];
 655                 }
 656                 if (length < i)
 657                         length = i;
 658         }
 659
 660         old_rom = device->config_rom;
 661         new_rom = kmemdup(rom, length * 4, GFP_KERNEL);
 662         if (new_rom == NULL) {
 663                 ret = -ENOMEM;
 664                 goto out;
 665         }
 666
 667         down_write(&fw_device_rwsem);
 668         device->config_rom = new_rom;
 669         device->config_rom_length = length;
 670         up_write(&fw_device_rwsem);
 671
 672         kfree(old_rom);
 673         ret = RCODE_COMPLETE;
 674         device->max_rec = rom[2] >> 12 & 0xf;
 675         device->cmc     = rom[2] >> 30 & 1;
 676         device->irmc    = rom[2] >> 31 & 1;
 677  out:
 678         kfree(rom);
 679
 680         return ret;
 681 }
 682
 683 static void fw_unit_release(struct device *dev)
 684 {
 685         struct fw_unit *unit = fw_unit(dev);
 686
 687         fw_device_put(fw_parent_device(unit));
 688         kfree(unit);
 689 }
 690
 691 static struct device_type fw_unit_type = {
 692         .uevent         = fw_unit_uevent,
 693         .release        = fw_unit_release,
 694 };
 695
 696 static bool is_fw_unit(struct device *dev)
 697 {
 698         return dev->type == &fw_unit_type;
 699 }
 700
 701 static void create_units(struct fw_device *device)
 702 {
 703         struct fw_csr_iterator ci;
 704         struct fw_unit *unit;
 705         int key, value, i;
 706
 707         i = 0;
 708         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 709         while (fw_csr_iterator_next(&ci, &key, &value)) {
 710                 if (key != (CSR_UNIT | CSR_DIRECTORY))
 711                         continue;
 712
 713                 /*
 714                  * Get the address of the unit directory and try to
 715                  * match the drivers id_tables against it.
 716                  */
 717                 unit = kzalloc(sizeof(*unit), GFP_KERNEL);
 718                 if (unit == NULL)
 719                         continue;
 720
 721                 unit->directory = ci.p + value - 1;
 722                 unit->device.bus = &fw_bus_type;
 723                 unit->device.type = &fw_unit_type;
 724                 unit->device.parent = &device->device;
 725                 dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++);
 726
 727                 BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) <
 728                                 ARRAY_SIZE(fw_unit_attributes) +
 729                                 ARRAY_SIZE(config_rom_attributes));
 730                 init_fw_attribute_group(&unit->device,
 731                                         fw_unit_attributes,
 732                                         &unit->attribute_group);
 733
 734                 fw_device_get(device);
 735                 if (device_register(&unit->device) < 0) {
 736                         put_device(&unit->device);
 737                         continue;
 738                 }
 739         }
 740 }
 741
 742 static int shutdown_unit(struct device *device, void *data)
 743 {
 744         device_unregister(device);
 745
 746         return 0;
 747 }
 748
 749 /*
 750  * fw_device_rwsem acts as dual purpose mutex:
 751  *   - serializes accesses to fw_device_idr,
 752  *   - serializes accesses to fw_device.config_rom/.config_rom_length and
 753  *     fw_unit.directory, unless those accesses happen at safe occasions
 754  */
 755 DECLARE_RWSEM(fw_device_rwsem);
 756
 757 DEFINE_IDR(fw_device_idr);
 758 int fw_cdev_major;
 759
 760 struct fw_device *fw_device_get_by_devt(dev_t devt)
 761 {
 762         struct fw_device *device;
 763
 764         down_read(&fw_device_rwsem);
 765         device = idr_find(&fw_device_idr, MINOR(devt));
 766         if (device)
 767                 fw_device_get(device);
 768         up_read(&fw_device_rwsem);
 769
 770         return device;
 771 }
 772
 773 struct workqueue_struct *fw_workqueue;
 774 EXPORT_SYMBOL(fw_workqueue);
 775
 776 static void fw_schedule_device_work(struct fw_device *device,
 777                                     unsigned long delay)
 778 {
 779         queue_delayed_work(fw_workqueue, &device->work, delay);
 780 }
 781
 782 /*
 783  * These defines control the retry behavior for reading the config
 784  * rom.  It shouldn't be necessary to tweak these; if the device
 785  * doesn't respond to a config rom read within 10 seconds, it's not
 786  * going to respond at all.  As for the initial delay, a lot of
 787  * devices will be able to respond within half a second after bus
 788  * reset.  On the other hand, it's not really worth being more
 789  * aggressive than that, since it scales pretty well; if 10 devices
 790  * are plugged in, they're all getting read within one second.
 791  */
 792
 793 #define MAX_RETRIES     10
 794 #define RETRY_DELAY     (3 * HZ)
 795 #define INITIAL_DELAY   (HZ / 2)
 796 #define SHUTDOWN_DELAY  (2 * HZ)
 797
 798 static void fw_device_shutdown(struct work_struct *work)
 799 {
 800         struct fw_device *device =
 801                 container_of(work, struct fw_device, work.work);
 802         int minor = MINOR(device->device.devt);
 803
 804         if (time_before64(get_jiffies_64(),
 805                           device->card->reset_jiffies + SHUTDOWN_DELAY)
 806             && !list_empty(&device->card->link)) {
 807                 fw_schedule_device_work(device, SHUTDOWN_DELAY);
 808                 return;
 809         }
 810
 811         if (atomic_cmpxchg(&device->state,
 812                            FW_DEVICE_GONE,
 813                            FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE)
 814                 return;
 815
 816         fw_device_cdev_remove(device);
 817         device_for_each_child(&device->device, NULL, shutdown_unit);
 818         device_unregister(&device->device);
 819
 820         down_write(&fw_device_rwsem);
 821         idr_remove(&fw_device_idr, minor);
 822         up_write(&fw_device_rwsem);
 823
 824         fw_device_put(device);
 825 }
 826
 827 static void fw_device_release(struct device *dev)
 828 {
 829         struct fw_device *device = fw_device(dev);
 830         struct fw_card *card = device->card;
 831         unsigned long flags;
 832
 833         /*
 834          * Take the card lock so we don't set this to NULL while a
 835          * FW_NODE_UPDATED callback is being handled or while the
 836          * bus manager work looks at this node.
 837          */
 838         spin_lock_irqsave(&card->lock, flags);
 839         device->node->data = NULL;
 840         spin_unlock_irqrestore(&card->lock, flags);
 841
 842         fw_node_put(device->node);
 843         kfree(device->config_rom);
 844         kfree(device);
 845         fw_card_put(card);
 846 }
 847
 848 static struct device_type fw_device_type = {
 849         .release = fw_device_release,
 850 };
 851
 852 static bool is_fw_device(struct device *dev)
 853 {
 854         return dev->type == &fw_device_type;
 855 }
 856
 857 static int update_unit(struct device *dev, void *data)
 858 {
 859         struct fw_unit *unit = fw_unit(dev);
 860         struct fw_driver *driver = (struct fw_driver *)dev->driver;
 861
 862         if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) {
 863                 device_lock(dev);
 864                 driver->update(unit);
 865                 device_unlock(dev);
 866         }
 867
 868         return 0;
 869 }
 870
 871 static void fw_device_update(struct work_struct *work)
 872 {
 873         struct fw_device *device =
 874                 container_of(work, struct fw_device, work.work);
 875
 876         fw_device_cdev_update(device);
 877         device_for_each_child(&device->device, NULL, update_unit);
 878 }
 879
 880 /*
 881  * If a device was pending for deletion because its node went away but its
 882  * bus info block and root directory header matches that of a newly discovered
 883  * device, revive the existing fw_device.
 884  * The newly allocated fw_device becomes obsolete instead.
 885  */
 886 static int lookup_existing_device(struct device *dev, void *data)
 887 {
 888         struct fw_device *old = fw_device(dev);
 889         struct fw_device *new = data;
 890         struct fw_card *card = new->card;
 891         int match = 0;
 892
 893         if (!is_fw_device(dev))
 894                 return 0;
 895
 896         down_read(&fw_device_rwsem); /* serialize config_rom access */
 897         spin_lock_irq(&card->lock);  /* serialize node access */
 898
 899         if (memcmp(old->config_rom, new->config_rom, 6 * 4) == 0 &&
 900             atomic_cmpxchg(&old->state,
 901                            FW_DEVICE_GONE,
 902                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
 903                 struct fw_node *current_node = new->node;
 904                 struct fw_node *obsolete_node = old->node;
 905
 906                 new->node = obsolete_node;
 907                 new->node->data = new;
 908                 old->node = current_node;
 909                 old->node->data = old;
 910
 911                 old->max_speed = new->max_speed;
 912                 old->node_id = current_node->node_id;
 913                 smp_wmb();  /* update node_id before generation */
 914                 old->generation = card->generation;
 915                 old->config_rom_retries = 0;
 916                 fw_notice(card, "rediscovered device %s\n", dev_name(dev));
 917
 918                 old->workfn = fw_device_update;
 919                 fw_schedule_device_work(old, 0);
 920
 921                 if (current_node == card->root_node)
 922                         fw_schedule_bm_work(card, 0);
 923
 924                 match = 1;
 925         }
 926
 927         spin_unlock_irq(&card->lock);
 928         up_read(&fw_device_rwsem);
 929
 930         return match;
 931 }
 932
 933 enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, };
 934
 935 static void set_broadcast_channel(struct fw_device *device, int generation)
 936 {
 937         struct fw_card *card = device->card;
 938         __be32 data;
 939         int rcode;
 940
 941         if (!card->broadcast_channel_allocated)
 942                 return;
 943
 944         /*
 945          * The Broadcast_Channel Valid bit is required by nodes which want to
 946          * transmit on this channel.  Such transmissions are practically
 947          * exclusive to IP over 1394 (RFC 2734).  IP capable nodes are required
 948          * to be IRM capable and have a max_rec of 8 or more.  We use this fact
 949          * to narrow down to which nodes we send Broadcast_Channel updates.
 950          */
 951         if (!device->irmc || device->max_rec < 8)
 952                 return;
 953
 954         /*
 955          * Some 1394-1995 nodes crash if this 1394a-2000 register is written.
 956          * Perform a read test first.
 957          */
 958         if (device->bc_implemented == BC_UNKNOWN) {
 959                 rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST,
 960                                 device->node_id, generation, device->max_speed,
 961                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 962                                 &data, 4);
 963                 switch (rcode) {
 964                 case RCODE_COMPLETE:
 965                         if (data & cpu_to_be32(1 << 31)) {
 966                                 device->bc_implemented = BC_IMPLEMENTED;
 967                                 break;
 968                         }
 969                         /* else fall through to case address error */
 970                 case RCODE_ADDRESS_ERROR:
 971                         device->bc_implemented = BC_UNIMPLEMENTED;
 972                 }
 973         }
 974
 975         if (device->bc_implemented == BC_IMPLEMENTED) {
 976                 data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL |
 977                                    BROADCAST_CHANNEL_VALID);
 978                 fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
 979                                 device->node_id, generation, device->max_speed,
 980                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 981                                 &data, 4);
 982         }
 983 }
 984
 985 int fw_device_set_broadcast_channel(struct device *dev, void *gen)
 986 {
 987         if (is_fw_device(dev))
 988                 set_broadcast_channel(fw_device(dev), (long)gen);
 989
 990         return 0;
 991 }
 992
 993 static void fw_device_init(struct work_struct *work)
 994 {
 995         struct fw_device *device =
 996                 container_of(work, struct fw_device, work.work);
 997         struct fw_card *card = device->card;
 998         struct device *revived_dev;
 999         int minor, ret;
1000
1001         /*
1002          * All failure paths here set node->data to NULL, so that we
1003          * don't try to do device_for_each_child() on a kfree()'d
1004          * device.
1005          */
1006
1007         ret = read_config_rom(device, device->generation);
1008         if (ret != RCODE_COMPLETE) {
1009                 if (device->config_rom_retries < MAX_RETRIES &&
1010                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1011                         device->config_rom_retries++;
1012                         fw_schedule_device_work(device, RETRY_DELAY);
1013                 } else {
1014                         if (device->node->link_on)
1015                                 fw_notice(card, "giving up on node %x: reading config rom failed: %s\n",
1016                                           device->node_id,
1017                                           fw_rcode_string(ret));
1018                         if (device->node == card->root_node)
1019                                 fw_schedule_bm_work(card, 0);
1020                         fw_device_release(&device->device);
1021                 }
1022                 return;
1023         }
1024
1025         revived_dev = device_find_child(card->device,
1026                                         device, lookup_existing_device);
1027         if (revived_dev) {
1028                 put_device(revived_dev);
1029                 fw_device_release(&device->device);
1030
1031                 return;
1032         }
1033
1034         device_initialize(&device->device);
1035
1036         fw_device_get(device);
1037         down_write(&fw_device_rwsem);
1038         minor = idr_alloc(&fw_device_idr, device, 0, 1 << MINORBITS,
1039                         GFP_KERNEL);
1040         up_write(&fw_device_rwsem);
1041
1042         if (minor < 0)
1043                 goto error;
1044
1045         device->device.bus = &fw_bus_type;
1046         device->device.type = &fw_device_type;
1047         device->device.parent = card->device;
1048         device->device.devt = MKDEV(fw_cdev_major, minor);
1049         dev_set_name(&device->device, "fw%d", minor);
1050
1051         BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) <
1052                         ARRAY_SIZE(fw_device_attributes) +
1053                         ARRAY_SIZE(config_rom_attributes));
1054         init_fw_attribute_group(&device->device,
1055                                 fw_device_attributes,
1056                                 &device->attribute_group);
1057
1058         if (device_add(&device->device)) {
1059                 fw_err(card, "failed to add device\n");
1060                 goto error_with_cdev;
1061         }
1062
1063         create_units(device);
1064
1065         /*
1066          * Transition the device to running state.  If it got pulled
1067          * out from under us while we did the initialization work, we
1068          * have to shut down the device again here.  Normally, though,
1069          * fw_node_event will be responsible for shutting it down when
1070          * necessary.  We have to use the atomic cmpxchg here to avoid
1071          * racing with the FW_NODE_DESTROYED case in
1072          * fw_node_event().
1073          */
1074         if (atomic_cmpxchg(&device->state,
1075                            FW_DEVICE_INITIALIZING,
1076                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
1077                 device->workfn = fw_device_shutdown;
1078                 fw_schedule_device_work(device, SHUTDOWN_DELAY);
1079         } else {
1080                 fw_notice(card, "created device %s: GUID %08x%08x, S%d00\n",
1081                           dev_name(&device->device),
1082                           device->config_rom[3], device->config_rom[4],
1083                           1 << device->max_speed);
1084                 device->config_rom_retries = 0;
1085
1086                 set_broadcast_channel(device, device->generation);
1087
1088                 add_device_randomness(&device->config_rom[3], 8);
1089         }
1090
1091         /*
1092          * Reschedule the IRM work if we just finished reading the
1093          * root node config rom.  If this races with a bus reset we
1094          * just end up running the IRM work a couple of extra times -
1095          * pretty harmless.
1096          */
1097         if (device->node == card->root_node)
1098                 fw_schedule_bm_work(card, 0);
1099
1100         return;
1101
1102  error_with_cdev:
1103         down_write(&fw_device_rwsem);
1104         idr_remove(&fw_device_idr, minor);
1105         up_write(&fw_device_rwsem);
1106  error:
1107         fw_device_put(device);          /* fw_device_idr's reference */
1108
1109         put_device(&device->device);    /* our reference */
1110 }
1111
1112 /* Reread and compare bus info block and header of root directory */
1113 static int reread_config_rom(struct fw_device *device, int generation,
1114                              bool *changed)
1115 {
1116         u32 q;
1117         int i, rcode;
1118
1119         for (i = 0; i < 6; i++) {
1120                 rcode = read_rom(device, generation, i, &q);
1121                 if (rcode != RCODE_COMPLETE)
1122                         return rcode;
1123
1124                 if (i == 0 && q == 0)
1125                         /* inaccessible (see read_config_rom); retry later */
1126                         return RCODE_BUSY;
1127
1128                 if (q != device->config_rom[i]) {
1129                         *changed = true;
1130                         return RCODE_COMPLETE;
1131                 }
1132         }
1133
1134         *changed = false;
1135         return RCODE_COMPLETE;
1136 }
1137
1138 static void fw_device_refresh(struct work_struct *work)
1139 {
1140         struct fw_device *device =
1141                 container_of(work, struct fw_device, work.work);
1142         struct fw_card *card = device->card;
1143         int ret, node_id = device->node_id;
1144         bool changed;
1145
1146         ret = reread_config_rom(device, device->generation, &changed);
1147         if (ret != RCODE_COMPLETE)
1148                 goto failed_config_rom;
1149
1150         if (!changed) {
1151                 if (atomic_cmpxchg(&device->state,
1152                                    FW_DEVICE_INITIALIZING,
1153                                    FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1154                         goto gone;
1155
1156                 fw_device_update(work);
1157                 device->config_rom_retries = 0;
1158                 goto out;
1159         }
1160
1161         /*
1162          * Something changed.  We keep things simple and don't investigate
1163          * further.  We just destroy all previous units and create new ones.
1164          */
1165         device_for_each_child(&device->device, NULL, shutdown_unit);
1166
1167         ret = read_config_rom(device, device->generation);
1168         if (ret != RCODE_COMPLETE)
1169                 goto failed_config_rom;
1170
1171         fw_device_cdev_update(device);
1172         create_units(device);
1173
1174         /* Userspace may want to re-read attributes. */
1175         kobject_uevent(&device->device.kobj, KOBJ_CHANGE);
1176
1177         if (atomic_cmpxchg(&device->state,
1178                            FW_DEVICE_INITIALIZING,
1179                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1180                 goto gone;
1181
1182         fw_notice(card, "refreshed device %s\n", dev_name(&device->device));
1183         device->config_rom_retries = 0;
1184         goto out;
1185
1186  failed_config_rom:
1187         if (device->config_rom_retries < MAX_RETRIES &&
1188             atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1189                 device->config_rom_retries++;
1190                 fw_schedule_device_work(device, RETRY_DELAY);
1191                 return;
1192         }
1193
1194         fw_notice(card, "giving up on refresh of device %s: %s\n",
1195                   dev_name(&device->device), fw_rcode_string(ret));
1196  gone:
1197         atomic_set(&device->state, FW_DEVICE_GONE);
1198         device->workfn = fw_device_shutdown;
1199         fw_schedule_device_work(device, SHUTDOWN_DELAY);
1200  out:
1201         if (node_id == card->root_node->node_id)
1202                 fw_schedule_bm_work(card, 0);
1203 }
1204
1205 static void fw_device_workfn(struct work_struct *work)
1206 {
1207         struct fw_device *device = container_of(to_delayed_work(work),
1208                                                 struct fw_device, work);
1209         device->workfn(work);
1210 }
1211
1212 void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
1213 {
1214         struct fw_device *device;
1215
1216         switch (event) {
1217         case FW_NODE_CREATED:
1218                 /*
1219                  * Attempt to scan the node, regardless whether its self ID has
1220                  * the L (link active) flag set or not.  Some broken devices
1221                  * send L=0 but have an up-and-running link; others send L=1
1222                  * without actually having a link.
1223                  */
1224  create:
1225                 device = kzalloc(sizeof(*device), GFP_ATOMIC);
1226                 if (device == NULL)
1227                         break;
1228
1229                 /*
1230                  * Do minimal initialization of the device here, the
1231                  * rest will happen in fw_device_init().
1232                  *
1233                  * Attention:  A lot of things, even fw_device_get(),
1234                  * cannot be done before fw_device_init() finished!
1235                  * You can basically just check device->state and
1236                  * schedule work until then, but only while holding
1237                  * card->lock.
1238                  */
1239                 atomic_set(&device->state, FW_DEVICE_INITIALIZING);
1240                 device->card = fw_card_get(card);
1241                 device->node = fw_node_get(node);
1242                 device->node_id = node->node_id;
1243                 device->generation = card->generation;
1244                 device->is_local = node == card->local_node;
1245                 mutex_init(&device->client_list_mutex);
1246                 INIT_LIST_HEAD(&device->client_list);
1247
1248                 /*
1249                  * Set the node data to point back to this device so
1250                  * FW_NODE_UPDATED callbacks can update the node_id
1251                  * and generation for the device.
1252                  */
1253                 node->data = device;
1254
1255                 /*
1256                  * Many devices are slow to respond after bus resets,
1257                  * especially if they are bus powered and go through
1258                  * power-up after getting plugged in.  We schedule the
1259                  * first config rom scan half a second after bus reset.
1260                  */
1261                 device->workfn = fw_device_init;
1262                 INIT_DELAYED_WORK(&device->work, fw_device_workfn);
1263                 fw_schedule_device_work(device, INITIAL_DELAY);
1264                 break;
1265
1266         case FW_NODE_INITIATED_RESET:
1267         case FW_NODE_LINK_ON:
1268                 device = node->data;
1269                 if (device == NULL)
1270                         goto create;
1271
1272                 device->node_id = node->node_id;
1273                 smp_wmb();  /* update node_id before generation */
1274                 device->generation = card->generation;
1275                 if (atomic_cmpxchg(&device->state,
1276                             FW_DEVICE_RUNNING,
1277                             FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) {
1278                         device->workfn = fw_device_refresh;
1279                         fw_schedule_device_work(device,
1280                                 device->is_local ? 0 : INITIAL_DELAY);
1281                 }
1282                 break;
1283
1284         case FW_NODE_UPDATED:
1285                 device = node->data;
1286                 if (device == NULL)
1287                         break;
1288
1289                 device->node_id = node->node_id;
1290                 smp_wmb();  /* update node_id before generation */
1291                 device->generation = card->generation;
1292                 if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
1293                         device->workfn = fw_device_update;
1294                         fw_schedule_device_work(device, 0);
1295                 }
1296                 break;
1297
1298         case FW_NODE_DESTROYED:
1299         case FW_NODE_LINK_OFF:
1300                 if (!node->data)
1301                         break;
1302
1303                 /*
1304                  * Destroy the device associated with the node.  There
1305                  * are two cases here: either the device is fully
1306                  * initialized (FW_DEVICE_RUNNING) or we're in the
1307                  * process of reading its config rom
1308                  * (FW_DEVICE_INITIALIZING).  If it is fully
1309                  * initialized we can reuse device->work to schedule a
1310                  * full fw_device_shutdown().  If not, there's work
1311                  * scheduled to read it's config rom, and we just put
1312                  * the device in shutdown state to have that code fail
1313                  * to create the device.
1314                  */
1315                 device = node->data;
1316                 if (atomic_xchg(&device->state,
1317                                 FW_DEVICE_GONE) == FW_DEVICE_RUNNING) {
1318                         device->workfn = fw_device_shutdown;
1319                         fw_schedule_device_work(device,
1320                                 list_empty(&card->link) ? 0 : SHUTDOWN_DELAY);
1321                 }
1322                 break;
1323         }
1324 }