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 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 void get_ids(const u32 *directory, int *id)
 131 {
 132         struct fw_csr_iterator ci;
 133         int key, value;
 134
 135         fw_csr_iterator_init(&ci, directory);
 136         while (fw_csr_iterator_next(&ci, &key, &value)) {
 137                 switch (key) {
 138                 case CSR_VENDOR:        id[0] = value; break;
 139                 case CSR_MODEL:         id[1] = value; break;
 140                 case CSR_SPECIFIER_ID:  id[2] = value; break;
 141                 case CSR_VERSION:       id[3] = value; break;
 142                 }
 143         }
 144 }
 145
 146 static void get_modalias_ids(struct fw_unit *unit, int *id)
 147 {
 148         get_ids(&fw_parent_device(unit)->config_rom[5], id);
 149         get_ids(unit->directory, id);
 150 }
 151
 152 static bool match_ids(const struct ieee1394_device_id *id_table, int *id)
 153 {
 154         int match = 0;
 155
 156         if (id[0] == id_table->vendor_id)
 157                 match |= IEEE1394_MATCH_VENDOR_ID;
 158         if (id[1] == id_table->model_id)
 159                 match |= IEEE1394_MATCH_MODEL_ID;
 160         if (id[2] == id_table->specifier_id)
 161                 match |= IEEE1394_MATCH_SPECIFIER_ID;
 162         if (id[3] == id_table->version)
 163                 match |= IEEE1394_MATCH_VERSION;
 164
 165         return (match & id_table->match_flags) == id_table->match_flags;
 166 }
 167
 168 static bool is_fw_unit(struct device *dev);
 169
 170 static int fw_unit_match(struct device *dev, struct device_driver *drv)
 171 {
 172         const struct ieee1394_device_id *id_table =
 173                         container_of(drv, struct fw_driver, driver)->id_table;
 174         int id[] = {0, 0, 0, 0};
 175
 176         /* We only allow binding to fw_units. */
 177         if (!is_fw_unit(dev))
 178                 return 0;
 179
 180         get_modalias_ids(fw_unit(dev), id);
 181
 182         for (; id_table->match_flags != 0; id_table++)
 183                 if (match_ids(id_table, id))
 184                         return 1;
 185
 186         return 0;
 187 }
 188
 189 static int get_modalias(struct fw_unit *unit, char *buffer, size_t buffer_size)
 190 {
 191         int id[] = {0, 0, 0, 0};
 192
 193         get_modalias_ids(unit, id);
 194
 195         return snprintf(buffer, buffer_size,
 196                         "ieee1394:ven%08Xmo%08Xsp%08Xver%08X",
 197                         id[0], id[1], id[2], id[3]);
 198 }
 199
 200 static int fw_unit_uevent(struct device *dev, struct kobj_uevent_env *env)
 201 {
 202         struct fw_unit *unit = fw_unit(dev);
 203         char modalias[64];
 204
 205         get_modalias(unit, modalias, sizeof(modalias));
 206
 207         if (add_uevent_var(env, "MODALIAS=%s", modalias))
 208                 return -ENOMEM;
 209
 210         return 0;
 211 }
 212
 213 struct bus_type fw_bus_type = {
 214         .name = "firewire",
 215         .match = fw_unit_match,
 216 };
 217 EXPORT_SYMBOL(fw_bus_type);
 218
 219 int fw_device_enable_phys_dma(struct fw_device *device)
 220 {
 221         int generation = device->generation;
 222
 223         /* device->node_id, accessed below, must not be older than generation */
 224         smp_rmb();
 225
 226         return device->card->driver->enable_phys_dma(device->card,
 227                                                      device->node_id,
 228                                                      generation);
 229 }
 230 EXPORT_SYMBOL(fw_device_enable_phys_dma);
 231
 232 struct config_rom_attribute {
 233         struct device_attribute attr;
 234         u32 key;
 235 };
 236
 237 static ssize_t show_immediate(struct device *dev,
 238                               struct device_attribute *dattr, char *buf)
 239 {
 240         struct config_rom_attribute *attr =
 241                 container_of(dattr, struct config_rom_attribute, attr);
 242         struct fw_csr_iterator ci;
 243         const u32 *dir;
 244         int key, value, ret = -ENOENT;
 245
 246         down_read(&fw_device_rwsem);
 247
 248         if (is_fw_unit(dev))
 249                 dir = fw_unit(dev)->directory;
 250         else
 251                 dir = fw_device(dev)->config_rom + 5;
 252
 253         fw_csr_iterator_init(&ci, dir);
 254         while (fw_csr_iterator_next(&ci, &key, &value))
 255                 if (attr->key == key) {
 256                         ret = snprintf(buf, buf ? PAGE_SIZE : 0,
 257                                        "0x%06x\n", value);
 258                         break;
 259                 }
 260
 261         up_read(&fw_device_rwsem);
 262
 263         return ret;
 264 }
 265
 266 #define IMMEDIATE_ATTR(name, key)                               \
 267         { __ATTR(name, S_IRUGO, show_immediate, NULL), key }
 268
 269 static ssize_t show_text_leaf(struct device *dev,
 270                               struct device_attribute *dattr, char *buf)
 271 {
 272         struct config_rom_attribute *attr =
 273                 container_of(dattr, struct config_rom_attribute, attr);
 274         const u32 *dir;
 275         size_t bufsize;
 276         char dummy_buf[2];
 277         int ret;
 278
 279         down_read(&fw_device_rwsem);
 280
 281         if (is_fw_unit(dev))
 282                 dir = fw_unit(dev)->directory;
 283         else
 284                 dir = fw_device(dev)->config_rom + 5;
 285
 286         if (buf) {
 287                 bufsize = PAGE_SIZE - 1;
 288         } else {
 289                 buf = dummy_buf;
 290                 bufsize = 1;
 291         }
 292
 293         ret = fw_csr_string(dir, attr->key, buf, bufsize);
 294
 295         if (ret >= 0) {
 296                 /* Strip trailing whitespace and add newline. */
 297                 while (ret > 0 && isspace(buf[ret - 1]))
 298                         ret--;
 299                 strcpy(buf + ret, "\n");
 300                 ret++;
 301         }
 302
 303         up_read(&fw_device_rwsem);
 304
 305         return ret;
 306 }
 307
 308 #define TEXT_LEAF_ATTR(name, key)                               \
 309         { __ATTR(name, S_IRUGO, show_text_leaf, NULL), key }
 310
 311 static struct config_rom_attribute config_rom_attributes[] = {
 312         IMMEDIATE_ATTR(vendor, CSR_VENDOR),
 313         IMMEDIATE_ATTR(hardware_version, CSR_HARDWARE_VERSION),
 314         IMMEDIATE_ATTR(specifier_id, CSR_SPECIFIER_ID),
 315         IMMEDIATE_ATTR(version, CSR_VERSION),
 316         IMMEDIATE_ATTR(model, CSR_MODEL),
 317         TEXT_LEAF_ATTR(vendor_name, CSR_VENDOR),
 318         TEXT_LEAF_ATTR(model_name, CSR_MODEL),
 319         TEXT_LEAF_ATTR(hardware_version_name, CSR_HARDWARE_VERSION),
 320 };
 321
 322 static void init_fw_attribute_group(struct device *dev,
 323                                     struct device_attribute *attrs,
 324                                     struct fw_attribute_group *group)
 325 {
 326         struct device_attribute *attr;
 327         int i, j;
 328
 329         for (j = 0; attrs[j].attr.name != NULL; j++)
 330                 group->attrs[j] = &attrs[j].attr;
 331
 332         for (i = 0; i < ARRAY_SIZE(config_rom_attributes); i++) {
 333                 attr = &config_rom_attributes[i].attr;
 334                 if (attr->show(dev, attr, NULL) < 0)
 335                         continue;
 336                 group->attrs[j++] = &attr->attr;
 337         }
 338
 339         group->attrs[j] = NULL;
 340         group->groups[0] = &group->group;
 341         group->groups[1] = NULL;
 342         group->group.attrs = group->attrs;
 343         dev->groups = (const struct attribute_group **) group->groups;
 344 }
 345
 346 static ssize_t modalias_show(struct device *dev,
 347                              struct device_attribute *attr, char *buf)
 348 {
 349         struct fw_unit *unit = fw_unit(dev);
 350         int length;
 351
 352         length = get_modalias(unit, buf, PAGE_SIZE);
 353         strcpy(buf + length, "\n");
 354
 355         return length + 1;
 356 }
 357
 358 static ssize_t rom_index_show(struct device *dev,
 359                               struct device_attribute *attr, char *buf)
 360 {
 361         struct fw_device *device = fw_device(dev->parent);
 362         struct fw_unit *unit = fw_unit(dev);
 363
 364         return snprintf(buf, PAGE_SIZE, "%d\n",
 365                         (int)(unit->directory - device->config_rom));
 366 }
 367
 368 static struct device_attribute fw_unit_attributes[] = {
 369         __ATTR_RO(modalias),
 370         __ATTR_RO(rom_index),
 371         __ATTR_NULL,
 372 };
 373
 374 static ssize_t config_rom_show(struct device *dev,
 375                                struct device_attribute *attr, char *buf)
 376 {
 377         struct fw_device *device = fw_device(dev);
 378         size_t length;
 379
 380         down_read(&fw_device_rwsem);
 381         length = device->config_rom_length * 4;
 382         memcpy(buf, device->config_rom, length);
 383         up_read(&fw_device_rwsem);
 384
 385         return length;
 386 }
 387
 388 static ssize_t guid_show(struct device *dev,
 389                          struct device_attribute *attr, char *buf)
 390 {
 391         struct fw_device *device = fw_device(dev);
 392         int ret;
 393
 394         down_read(&fw_device_rwsem);
 395         ret = snprintf(buf, PAGE_SIZE, "0x%08x%08x\n",
 396                        device->config_rom[3], device->config_rom[4]);
 397         up_read(&fw_device_rwsem);
 398
 399         return ret;
 400 }
 401
 402 static ssize_t is_local_show(struct device *dev,
 403                              struct device_attribute *attr, char *buf)
 404 {
 405         struct fw_device *device = fw_device(dev);
 406
 407         return sprintf(buf, "%u\n", device->is_local);
 408 }
 409
 410 static int units_sprintf(char *buf, const u32 *directory)
 411 {
 412         struct fw_csr_iterator ci;
 413         int key, value;
 414         int specifier_id = 0;
 415         int version = 0;
 416
 417         fw_csr_iterator_init(&ci, directory);
 418         while (fw_csr_iterator_next(&ci, &key, &value)) {
 419                 switch (key) {
 420                 case CSR_SPECIFIER_ID:
 421                         specifier_id = value;
 422                         break;
 423                 case CSR_VERSION:
 424                         version = value;
 425                         break;
 426                 }
 427         }
 428
 429         return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version);
 430 }
 431
 432 static ssize_t units_show(struct device *dev,
 433                           struct device_attribute *attr, char *buf)
 434 {
 435         struct fw_device *device = fw_device(dev);
 436         struct fw_csr_iterator ci;
 437         int key, value, i = 0;
 438
 439         down_read(&fw_device_rwsem);
 440         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 441         while (fw_csr_iterator_next(&ci, &key, &value)) {
 442                 if (key != (CSR_UNIT | CSR_DIRECTORY))
 443                         continue;
 444                 i += units_sprintf(&buf[i], ci.p + value - 1);
 445                 if (i >= PAGE_SIZE - (8 + 1 + 8 + 1))
 446                         break;
 447         }
 448         up_read(&fw_device_rwsem);
 449
 450         if (i)
 451                 buf[i - 1] = '\n';
 452
 453         return i;
 454 }
 455
 456 static struct device_attribute fw_device_attributes[] = {
 457         __ATTR_RO(config_rom),
 458         __ATTR_RO(guid),
 459         __ATTR_RO(is_local),
 460         __ATTR_RO(units),
 461         __ATTR_NULL,
 462 };
 463
 464 static int read_rom(struct fw_device *device,
 465                     int generation, int index, u32 *data)
 466 {
 467         u64 offset = (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4;
 468         int i, rcode;
 469
 470         /* device->node_id, accessed below, must not be older than generation */
 471         smp_rmb();
 472
 473         for (i = 10; i < 100; i += 10) {
 474                 rcode = fw_run_transaction(device->card,
 475                                 TCODE_READ_QUADLET_REQUEST, device->node_id,
 476                                 generation, device->max_speed, offset, data, 4);
 477                 if (rcode != RCODE_BUSY)
 478                         break;
 479                 msleep(i);
 480         }
 481         be32_to_cpus(data);
 482
 483         return rcode;
 484 }
 485
 486 #define MAX_CONFIG_ROM_SIZE 256
 487
 488 /*
 489  * Read the bus info block, perform a speed probe, and read all of the rest of
 490  * the config ROM.  We do all this with a cached bus generation.  If the bus
 491  * generation changes under us, read_config_rom will fail and get retried.
 492  * It's better to start all over in this case because the node from which we
 493  * are reading the ROM may have changed the ROM during the reset.
 494  * Returns either a result code or a negative error code.
 495  */
 496 static int read_config_rom(struct fw_device *device, int generation)
 497 {
 498         struct fw_card *card = device->card;
 499         const u32 *old_rom, *new_rom;
 500         u32 *rom, *stack;
 501         u32 sp, key;
 502         int i, end, length, ret;
 503
 504         rom = kmalloc(sizeof(*rom) * MAX_CONFIG_ROM_SIZE +
 505                       sizeof(*stack) * MAX_CONFIG_ROM_SIZE, GFP_KERNEL);
 506         if (rom == NULL)
 507                 return -ENOMEM;
 508
 509         stack = &rom[MAX_CONFIG_ROM_SIZE];
 510         memset(rom, 0, sizeof(*rom) * MAX_CONFIG_ROM_SIZE);
 511
 512         device->max_speed = SCODE_100;
 513
 514         /* First read the bus info block. */
 515         for (i = 0; i < 5; i++) {
 516                 ret = read_rom(device, generation, i, &rom[i]);
 517                 if (ret != RCODE_COMPLETE)
 518                         goto out;
 519                 /*
 520                  * As per IEEE1212 7.2, during initialization, devices can
 521                  * reply with a 0 for the first quadlet of the config
 522                  * rom to indicate that they are booting (for example,
 523                  * if the firmware is on the disk of a external
 524                  * harddisk).  In that case we just fail, and the
 525                  * retry mechanism will try again later.
 526                  */
 527                 if (i == 0 && rom[i] == 0) {
 528                         ret = RCODE_BUSY;
 529                         goto out;
 530                 }
 531         }
 532
 533         device->max_speed = device->node->max_speed;
 534
 535         /*
 536          * Determine the speed of
 537          *   - devices with link speed less than PHY speed,
 538          *   - devices with 1394b PHY (unless only connected to 1394a PHYs),
 539          *   - all devices if there are 1394b repeaters.
 540          * Note, we cannot use the bus info block's link_spd as starting point
 541          * because some buggy firmwares set it lower than necessary and because
 542          * 1394-1995 nodes do not have the field.
 543          */
 544         if ((rom[2] & 0x7) < device->max_speed ||
 545             device->max_speed == SCODE_BETA ||
 546             card->beta_repeaters_present) {
 547                 u32 dummy;
 548
 549                 /* for S1600 and S3200 */
 550                 if (device->max_speed == SCODE_BETA)
 551                         device->max_speed = card->link_speed;
 552
 553                 while (device->max_speed > SCODE_100) {
 554                         if (read_rom(device, generation, 0, &dummy) ==
 555                             RCODE_COMPLETE)
 556                                 break;
 557                         device->max_speed--;
 558                 }
 559         }
 560
 561         /*
 562          * Now parse the config rom.  The config rom is a recursive
 563          * directory structure so we parse it using a stack of
 564          * references to the blocks that make up the structure.  We
 565          * push a reference to the root directory on the stack to
 566          * start things off.
 567          */
 568         length = i;
 569         sp = 0;
 570         stack[sp++] = 0xc0000005;
 571         while (sp > 0) {
 572                 /*
 573                  * Pop the next block reference of the stack.  The
 574                  * lower 24 bits is the offset into the config rom,
 575                  * the upper 8 bits are the type of the reference the
 576                  * block.
 577                  */
 578                 key = stack[--sp];
 579                 i = key & 0xffffff;
 580                 if (WARN_ON(i >= MAX_CONFIG_ROM_SIZE)) {
 581                         ret = -ENXIO;
 582                         goto out;
 583                 }
 584
 585                 /* Read header quadlet for the block to get the length. */
 586                 ret = read_rom(device, generation, i, &rom[i]);
 587                 if (ret != RCODE_COMPLETE)
 588                         goto out;
 589                 end = i + (rom[i] >> 16) + 1;
 590                 if (end > MAX_CONFIG_ROM_SIZE) {
 591                         /*
 592                          * This block extends outside the config ROM which is
 593                          * a firmware bug.  Ignore this whole block, i.e.
 594                          * simply set a fake block length of 0.
 595                          */
 596                         fw_err(card, "skipped invalid ROM block %x at %llx\n",
 597                                rom[i],
 598                                i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 599                         rom[i] = 0;
 600                         end = i;
 601                 }
 602                 i++;
 603
 604                 /*
 605                  * Now read in the block.  If this is a directory
 606                  * block, check the entries as we read them to see if
 607                  * it references another block, and push it in that case.
 608                  */
 609                 for (; i < end; i++) {
 610                         ret = read_rom(device, generation, i, &rom[i]);
 611                         if (ret != RCODE_COMPLETE)
 612                                 goto out;
 613
 614                         if ((key >> 30) != 3 || (rom[i] >> 30) < 2)
 615                                 continue;
 616                         /*
 617                          * Offset points outside the ROM.  May be a firmware
 618                          * bug or an Extended ROM entry (IEEE 1212-2001 clause
 619                          * 7.7.18).  Simply overwrite this pointer here by a
 620                          * fake immediate entry so that later iterators over
 621                          * the ROM don't have to check offsets all the time.
 622                          */
 623                         if (i + (rom[i] & 0xffffff) >= MAX_CONFIG_ROM_SIZE) {
 624                                 fw_err(card,
 625                                        "skipped unsupported ROM entry %x at %llx\n",
 626                                        rom[i],
 627                                        i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 628                                 rom[i] = 0;
 629                                 continue;
 630                         }
 631                         stack[sp++] = i + rom[i];
 632                 }
 633                 if (length < i)
 634                         length = i;
 635         }
 636
 637         old_rom = device->config_rom;
 638         new_rom = kmemdup(rom, length * 4, GFP_KERNEL);
 639         if (new_rom == NULL) {
 640                 ret = -ENOMEM;
 641                 goto out;
 642         }
 643
 644         down_write(&fw_device_rwsem);
 645         device->config_rom = new_rom;
 646         device->config_rom_length = length;
 647         up_write(&fw_device_rwsem);
 648
 649         kfree(old_rom);
 650         ret = RCODE_COMPLETE;
 651         device->max_rec = rom[2] >> 12 & 0xf;
 652         device->cmc     = rom[2] >> 30 & 1;
 653         device->irmc    = rom[2] >> 31 & 1;
 654  out:
 655         kfree(rom);
 656
 657         return ret;
 658 }
 659
 660 static void fw_unit_release(struct device *dev)
 661 {
 662         struct fw_unit *unit = fw_unit(dev);
 663
 664         fw_device_put(fw_parent_device(unit));
 665         kfree(unit);
 666 }
 667
 668 static struct device_type fw_unit_type = {
 669         .uevent         = fw_unit_uevent,
 670         .release        = fw_unit_release,
 671 };
 672
 673 static bool is_fw_unit(struct device *dev)
 674 {
 675         return dev->type == &fw_unit_type;
 676 }
 677
 678 static void create_units(struct fw_device *device)
 679 {
 680         struct fw_csr_iterator ci;
 681         struct fw_unit *unit;
 682         int key, value, i;
 683
 684         i = 0;
 685         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 686         while (fw_csr_iterator_next(&ci, &key, &value)) {
 687                 if (key != (CSR_UNIT | CSR_DIRECTORY))
 688                         continue;
 689
 690                 /*
 691                  * Get the address of the unit directory and try to
 692                  * match the drivers id_tables against it.
 693                  */
 694                 unit = kzalloc(sizeof(*unit), GFP_KERNEL);
 695                 if (unit == NULL) {
 696                         fw_err(device->card, "out of memory for unit\n");
 697                         continue;
 698                 }
 699
 700                 unit->directory = ci.p + value - 1;
 701                 unit->device.bus = &fw_bus_type;
 702                 unit->device.type = &fw_unit_type;
 703                 unit->device.parent = &device->device;
 704                 dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++);
 705
 706                 BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) <
 707                                 ARRAY_SIZE(fw_unit_attributes) +
 708                                 ARRAY_SIZE(config_rom_attributes));
 709                 init_fw_attribute_group(&unit->device,
 710                                         fw_unit_attributes,
 711                                         &unit->attribute_group);
 712
 713                 if (device_register(&unit->device) < 0)
 714                         goto skip_unit;
 715
 716                 fw_device_get(device);
 717                 continue;
 718
 719         skip_unit:
 720                 kfree(unit);
 721         }
 722 }
 723
 724 static int shutdown_unit(struct device *device, void *data)
 725 {
 726         device_unregister(device);
 727
 728         return 0;
 729 }
 730
 731 /*
 732  * fw_device_rwsem acts as dual purpose mutex:
 733  *   - serializes accesses to fw_device_idr,
 734  *   - serializes accesses to fw_device.config_rom/.config_rom_length and
 735  *     fw_unit.directory, unless those accesses happen at safe occasions
 736  */
 737 DECLARE_RWSEM(fw_device_rwsem);
 738
 739 DEFINE_IDR(fw_device_idr);
 740 int fw_cdev_major;
 741
 742 struct fw_device *fw_device_get_by_devt(dev_t devt)
 743 {
 744         struct fw_device *device;
 745
 746         down_read(&fw_device_rwsem);
 747         device = idr_find(&fw_device_idr, MINOR(devt));
 748         if (device)
 749                 fw_device_get(device);
 750         up_read(&fw_device_rwsem);
 751
 752         return device;
 753 }
 754
 755 struct workqueue_struct *fw_workqueue;
 756 EXPORT_SYMBOL(fw_workqueue);
 757
 758 static void fw_schedule_device_work(struct fw_device *device,
 759                                     unsigned long delay)
 760 {
 761         queue_delayed_work(fw_workqueue, &device->work, delay);
 762 }
 763
 764 /*
 765  * These defines control the retry behavior for reading the config
 766  * rom.  It shouldn't be necessary to tweak these; if the device
 767  * doesn't respond to a config rom read within 10 seconds, it's not
 768  * going to respond at all.  As for the initial delay, a lot of
 769  * devices will be able to respond within half a second after bus
 770  * reset.  On the other hand, it's not really worth being more
 771  * aggressive than that, since it scales pretty well; if 10 devices
 772  * are plugged in, they're all getting read within one second.
 773  */
 774
 775 #define MAX_RETRIES     10
 776 #define RETRY_DELAY     (3 * HZ)
 777 #define INITIAL_DELAY   (HZ / 2)
 778 #define SHUTDOWN_DELAY  (2 * HZ)
 779
 780 static void fw_device_shutdown(struct work_struct *work)
 781 {
 782         struct fw_device *device =
 783                 container_of(work, struct fw_device, work.work);
 784         int minor = MINOR(device->device.devt);
 785
 786         if (time_before64(get_jiffies_64(),
 787                           device->card->reset_jiffies + SHUTDOWN_DELAY)
 788             && !list_empty(&device->card->link)) {
 789                 fw_schedule_device_work(device, SHUTDOWN_DELAY);
 790                 return;
 791         }
 792
 793         if (atomic_cmpxchg(&device->state,
 794                            FW_DEVICE_GONE,
 795                            FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE)
 796                 return;
 797
 798         fw_device_cdev_remove(device);
 799         device_for_each_child(&device->device, NULL, shutdown_unit);
 800         device_unregister(&device->device);
 801
 802         down_write(&fw_device_rwsem);
 803         idr_remove(&fw_device_idr, minor);
 804         up_write(&fw_device_rwsem);
 805
 806         fw_device_put(device);
 807 }
 808
 809 static void fw_device_release(struct device *dev)
 810 {
 811         struct fw_device *device = fw_device(dev);
 812         struct fw_card *card = device->card;
 813         unsigned long flags;
 814
 815         /*
 816          * Take the card lock so we don't set this to NULL while a
 817          * FW_NODE_UPDATED callback is being handled or while the
 818          * bus manager work looks at this node.
 819          */
 820         spin_lock_irqsave(&card->lock, flags);
 821         device->node->data = NULL;
 822         spin_unlock_irqrestore(&card->lock, flags);
 823
 824         fw_node_put(device->node);
 825         kfree(device->config_rom);
 826         kfree(device);
 827         fw_card_put(card);
 828 }
 829
 830 static struct device_type fw_device_type = {
 831         .release = fw_device_release,
 832 };
 833
 834 static bool is_fw_device(struct device *dev)
 835 {
 836         return dev->type == &fw_device_type;
 837 }
 838
 839 static int update_unit(struct device *dev, void *data)
 840 {
 841         struct fw_unit *unit = fw_unit(dev);
 842         struct fw_driver *driver = (struct fw_driver *)dev->driver;
 843
 844         if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) {
 845                 device_lock(dev);
 846                 driver->update(unit);
 847                 device_unlock(dev);
 848         }
 849
 850         return 0;
 851 }
 852
 853 static void fw_device_update(struct work_struct *work)
 854 {
 855         struct fw_device *device =
 856                 container_of(work, struct fw_device, work.work);
 857
 858         fw_device_cdev_update(device);
 859         device_for_each_child(&device->device, NULL, update_unit);
 860 }
 861
 862 /*
 863  * If a device was pending for deletion because its node went away but its
 864  * bus info block and root directory header matches that of a newly discovered
 865  * device, revive the existing fw_device.
 866  * The newly allocated fw_device becomes obsolete instead.
 867  */
 868 static int lookup_existing_device(struct device *dev, void *data)
 869 {
 870         struct fw_device *old = fw_device(dev);
 871         struct fw_device *new = data;
 872         struct fw_card *card = new->card;
 873         int match = 0;
 874
 875         if (!is_fw_device(dev))
 876                 return 0;
 877
 878         down_read(&fw_device_rwsem); /* serialize config_rom access */
 879         spin_lock_irq(&card->lock);  /* serialize node access */
 880
 881         if (memcmp(old->config_rom, new->config_rom, 6 * 4) == 0 &&
 882             atomic_cmpxchg(&old->state,
 883                            FW_DEVICE_GONE,
 884                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
 885                 struct fw_node *current_node = new->node;
 886                 struct fw_node *obsolete_node = old->node;
 887
 888                 new->node = obsolete_node;
 889                 new->node->data = new;
 890                 old->node = current_node;
 891                 old->node->data = old;
 892
 893                 old->max_speed = new->max_speed;
 894                 old->node_id = current_node->node_id;
 895                 smp_wmb();  /* update node_id before generation */
 896                 old->generation = card->generation;
 897                 old->config_rom_retries = 0;
 898                 fw_notice(card, "rediscovered device %s\n", dev_name(dev));
 899
 900                 PREPARE_DELAYED_WORK(&old->work, fw_device_update);
 901                 fw_schedule_device_work(old, 0);
 902
 903                 if (current_node == card->root_node)
 904                         fw_schedule_bm_work(card, 0);
 905
 906                 match = 1;
 907         }
 908
 909         spin_unlock_irq(&card->lock);
 910         up_read(&fw_device_rwsem);
 911
 912         return match;
 913 }
 914
 915 enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, };
 916
 917 static void set_broadcast_channel(struct fw_device *device, int generation)
 918 {
 919         struct fw_card *card = device->card;
 920         __be32 data;
 921         int rcode;
 922
 923         if (!card->broadcast_channel_allocated)
 924                 return;
 925
 926         /*
 927          * The Broadcast_Channel Valid bit is required by nodes which want to
 928          * transmit on this channel.  Such transmissions are practically
 929          * exclusive to IP over 1394 (RFC 2734).  IP capable nodes are required
 930          * to be IRM capable and have a max_rec of 8 or more.  We use this fact
 931          * to narrow down to which nodes we send Broadcast_Channel updates.
 932          */
 933         if (!device->irmc || device->max_rec < 8)
 934                 return;
 935
 936         /*
 937          * Some 1394-1995 nodes crash if this 1394a-2000 register is written.
 938          * Perform a read test first.
 939          */
 940         if (device->bc_implemented == BC_UNKNOWN) {
 941                 rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST,
 942                                 device->node_id, generation, device->max_speed,
 943                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 944                                 &data, 4);
 945                 switch (rcode) {
 946                 case RCODE_COMPLETE:
 947                         if (data & cpu_to_be32(1 << 31)) {
 948                                 device->bc_implemented = BC_IMPLEMENTED;
 949                                 break;
 950                         }
 951                         /* else fall through to case address error */
 952                 case RCODE_ADDRESS_ERROR:
 953                         device->bc_implemented = BC_UNIMPLEMENTED;
 954                 }
 955         }
 956
 957         if (device->bc_implemented == BC_IMPLEMENTED) {
 958                 data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL |
 959                                    BROADCAST_CHANNEL_VALID);
 960                 fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
 961                                 device->node_id, generation, device->max_speed,
 962                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 963                                 &data, 4);
 964         }
 965 }
 966
 967 int fw_device_set_broadcast_channel(struct device *dev, void *gen)
 968 {
 969         if (is_fw_device(dev))
 970                 set_broadcast_channel(fw_device(dev), (long)gen);
 971
 972         return 0;
 973 }
 974
 975 static void fw_device_init(struct work_struct *work)
 976 {
 977         struct fw_device *device =
 978                 container_of(work, struct fw_device, work.work);
 979         struct fw_card *card = device->card;
 980         struct device *revived_dev;
 981         int minor, ret;
 982
 983         /*
 984          * All failure paths here set node->data to NULL, so that we
 985          * don't try to do device_for_each_child() on a kfree()'d
 986          * device.
 987          */
 988
 989         ret = read_config_rom(device, device->generation);
 990         if (ret != RCODE_COMPLETE) {
 991                 if (device->config_rom_retries < MAX_RETRIES &&
 992                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
 993                         device->config_rom_retries++;
 994                         fw_schedule_device_work(device, RETRY_DELAY);
 995                 } else {
 996                         if (device->node->link_on)
 997                                 fw_notice(card, "giving up on node %x: reading config rom failed: %s\n",
 998                                           device->node_id,
 999                                           fw_rcode_string(ret));
1000                         if (device->node == card->root_node)
1001                                 fw_schedule_bm_work(card, 0);
1002                         fw_device_release(&device->device);
1003                 }
1004                 return;
1005         }
1006
1007         revived_dev = device_find_child(card->device,
1008                                         device, lookup_existing_device);
1009         if (revived_dev) {
1010                 put_device(revived_dev);
1011                 fw_device_release(&device->device);
1012
1013                 return;
1014         }
1015
1016         device_initialize(&device->device);
1017
1018         fw_device_get(device);
1019         down_write(&fw_device_rwsem);
1020         ret = idr_pre_get(&fw_device_idr, GFP_KERNEL) ?
1021               idr_get_new(&fw_device_idr, device, &minor) :
1022               -ENOMEM;
1023         up_write(&fw_device_rwsem);
1024
1025         if (ret < 0)
1026                 goto error;
1027
1028         device->device.bus = &fw_bus_type;
1029         device->device.type = &fw_device_type;
1030         device->device.parent = card->device;
1031         device->device.devt = MKDEV(fw_cdev_major, minor);
1032         dev_set_name(&device->device, "fw%d", minor);
1033
1034         BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) <
1035                         ARRAY_SIZE(fw_device_attributes) +
1036                         ARRAY_SIZE(config_rom_attributes));
1037         init_fw_attribute_group(&device->device,
1038                                 fw_device_attributes,
1039                                 &device->attribute_group);
1040
1041         if (device_add(&device->device)) {
1042                 fw_err(card, "failed to add device\n");
1043                 goto error_with_cdev;
1044         }
1045
1046         create_units(device);
1047
1048         /*
1049          * Transition the device to running state.  If it got pulled
1050          * out from under us while we did the intialization work, we
1051          * have to shut down the device again here.  Normally, though,
1052          * fw_node_event will be responsible for shutting it down when
1053          * necessary.  We have to use the atomic cmpxchg here to avoid
1054          * racing with the FW_NODE_DESTROYED case in
1055          * fw_node_event().
1056          */
1057         if (atomic_cmpxchg(&device->state,
1058                            FW_DEVICE_INITIALIZING,
1059                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
1060                 PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1061                 fw_schedule_device_work(device, SHUTDOWN_DELAY);
1062         } else {
1063                 fw_notice(card, "created device %s: GUID %08x%08x, S%d00\n",
1064                           dev_name(&device->device),
1065                           device->config_rom[3], device->config_rom[4],
1066                           1 << device->max_speed);
1067                 device->config_rom_retries = 0;
1068
1069                 set_broadcast_channel(device, device->generation);
1070
1071                 add_device_randomness(&device->config_rom[3], 8);
1072         }
1073
1074         /*
1075          * Reschedule the IRM work if we just finished reading the
1076          * root node config rom.  If this races with a bus reset we
1077          * just end up running the IRM work a couple of extra times -
1078          * pretty harmless.
1079          */
1080         if (device->node == card->root_node)
1081                 fw_schedule_bm_work(card, 0);
1082
1083         return;
1084
1085  error_with_cdev:
1086         down_write(&fw_device_rwsem);
1087         idr_remove(&fw_device_idr, minor);
1088         up_write(&fw_device_rwsem);
1089  error:
1090         fw_device_put(device);          /* fw_device_idr's reference */
1091
1092         put_device(&device->device);    /* our reference */
1093 }
1094
1095 /* Reread and compare bus info block and header of root directory */
1096 static int reread_config_rom(struct fw_device *device, int generation,
1097                              bool *changed)
1098 {
1099         u32 q;
1100         int i, rcode;
1101
1102         for (i = 0; i < 6; i++) {
1103                 rcode = read_rom(device, generation, i, &q);
1104                 if (rcode != RCODE_COMPLETE)
1105                         return rcode;
1106
1107                 if (i == 0 && q == 0)
1108                         /* inaccessible (see read_config_rom); retry later */
1109                         return RCODE_BUSY;
1110
1111                 if (q != device->config_rom[i]) {
1112                         *changed = true;
1113                         return RCODE_COMPLETE;
1114                 }
1115         }
1116
1117         *changed = false;
1118         return RCODE_COMPLETE;
1119 }
1120
1121 static void fw_device_refresh(struct work_struct *work)
1122 {
1123         struct fw_device *device =
1124                 container_of(work, struct fw_device, work.work);
1125         struct fw_card *card = device->card;
1126         int ret, node_id = device->node_id;
1127         bool changed;
1128
1129         ret = reread_config_rom(device, device->generation, &changed);
1130         if (ret != RCODE_COMPLETE)
1131                 goto failed_config_rom;
1132
1133         if (!changed) {
1134                 if (atomic_cmpxchg(&device->state,
1135                                    FW_DEVICE_INITIALIZING,
1136                                    FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1137                         goto gone;
1138
1139                 fw_device_update(work);
1140                 device->config_rom_retries = 0;
1141                 goto out;
1142         }
1143
1144         /*
1145          * Something changed.  We keep things simple and don't investigate
1146          * further.  We just destroy all previous units and create new ones.
1147          */
1148         device_for_each_child(&device->device, NULL, shutdown_unit);
1149
1150         ret = read_config_rom(device, device->generation);
1151         if (ret != RCODE_COMPLETE)
1152                 goto failed_config_rom;
1153
1154         fw_device_cdev_update(device);
1155         create_units(device);
1156
1157         /* Userspace may want to re-read attributes. */
1158         kobject_uevent(&device->device.kobj, KOBJ_CHANGE);
1159
1160         if (atomic_cmpxchg(&device->state,
1161                            FW_DEVICE_INITIALIZING,
1162                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1163                 goto gone;
1164
1165         fw_notice(card, "refreshed device %s\n", dev_name(&device->device));
1166         device->config_rom_retries = 0;
1167         goto out;
1168
1169  failed_config_rom:
1170         if (device->config_rom_retries < MAX_RETRIES &&
1171             atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1172                 device->config_rom_retries++;
1173                 fw_schedule_device_work(device, RETRY_DELAY);
1174                 return;
1175         }
1176
1177         fw_notice(card, "giving up on refresh of device %s: %s\n",
1178                   dev_name(&device->device), fw_rcode_string(ret));
1179  gone:
1180         atomic_set(&device->state, FW_DEVICE_GONE);
1181         PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1182         fw_schedule_device_work(device, 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                 /*
1195                  * Attempt to scan the node, regardless whether its self ID has
1196                  * the L (link active) flag set or not.  Some broken devices
1197                  * send L=0 but have an up-and-running link; others send L=1
1198                  * without actually having a link.
1199                  */
1200  create:
1201                 device = kzalloc(sizeof(*device), GFP_ATOMIC);
1202                 if (device == NULL)
1203                         break;
1204
1205                 /*
1206                  * Do minimal intialization of the device here, the
1207                  * rest will happen in fw_device_init().
1208                  *
1209                  * Attention:  A lot of things, even fw_device_get(),
1210                  * cannot be done before fw_device_init() finished!
1211                  * You can basically just check device->state and
1212                  * schedule work until then, but only while holding
1213                  * card->lock.
1214                  */
1215                 atomic_set(&device->state, FW_DEVICE_INITIALIZING);
1216                 device->card = fw_card_get(card);
1217                 device->node = fw_node_get(node);
1218                 device->node_id = node->node_id;
1219                 device->generation = card->generation;
1220                 device->is_local = node == card->local_node;
1221                 mutex_init(&device->client_list_mutex);
1222                 INIT_LIST_HEAD(&device->client_list);
1223
1224                 /*
1225                  * Set the node data to point back to this device so
1226                  * FW_NODE_UPDATED callbacks can update the node_id
1227                  * and generation for the device.
1228                  */
1229                 node->data = device;
1230
1231                 /*
1232                  * Many devices are slow to respond after bus resets,
1233                  * especially if they are bus powered and go through
1234                  * power-up after getting plugged in.  We schedule the
1235                  * first config rom scan half a second after bus reset.
1236                  */
1237                 INIT_DELAYED_WORK(&device->work, fw_device_init);
1238                 fw_schedule_device_work(device, INITIAL_DELAY);
1239                 break;
1240
1241         case FW_NODE_INITIATED_RESET:
1242         case FW_NODE_LINK_ON:
1243                 device = node->data;
1244                 if (device == NULL)
1245                         goto create;
1246
1247                 device->node_id = node->node_id;
1248                 smp_wmb();  /* update node_id before generation */
1249                 device->generation = card->generation;
1250                 if (atomic_cmpxchg(&device->state,
1251                             FW_DEVICE_RUNNING,
1252                             FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) {
1253                         PREPARE_DELAYED_WORK(&device->work, fw_device_refresh);
1254                         fw_schedule_device_work(device,
1255                                 device->is_local ? 0 : INITIAL_DELAY);
1256                 }
1257                 break;
1258
1259         case FW_NODE_UPDATED:
1260                 device = node->data;
1261                 if (device == NULL)
1262                         break;
1263
1264                 device->node_id = node->node_id;
1265                 smp_wmb();  /* update node_id before generation */
1266                 device->generation = card->generation;
1267                 if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
1268                         PREPARE_DELAYED_WORK(&device->work, fw_device_update);
1269                         fw_schedule_device_work(device, 0);
1270                 }
1271                 break;
1272
1273         case FW_NODE_DESTROYED:
1274         case FW_NODE_LINK_OFF:
1275                 if (!node->data)
1276                         break;
1277
1278                 /*
1279                  * Destroy the device associated with the node.  There
1280                  * are two cases here: either the device is fully
1281                  * initialized (FW_DEVICE_RUNNING) or we're in the
1282                  * process of reading its config rom
1283                  * (FW_DEVICE_INITIALIZING).  If it is fully
1284                  * initialized we can reuse device->work to schedule a
1285                  * full fw_device_shutdown().  If not, there's work
1286                  * scheduled to read it's config rom, and we just put
1287                  * the device in shutdown state to have that code fail
1288                  * to create the device.
1289                  */
1290                 device = node->data;
1291                 if (atomic_xchg(&device->state,
1292                                 FW_DEVICE_GONE) == FW_DEVICE_RUNNING) {
1293                         PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1294                         fw_schedule_device_work(device,
1295                                 list_empty(&card->link) ? 0 : SHUTDOWN_DELAY);
1296                 }
1297                 break;
1298         }
1299 }