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 const struct ieee1394_device_id *unit_match(struct device *dev,
 169                                                    struct device_driver *drv)
 170 {
 171         const struct ieee1394_device_id *id_table =
 172                         container_of(drv, struct fw_driver, driver)->id_table;
 173         int id[] = {0, 0, 0, 0};
 174
 175         get_modalias_ids(fw_unit(dev), id);
 176
 177         for (; id_table->match_flags != 0; id_table++)
 178                 if (match_ids(id_table, id))
 179                         return id_table;
 180
 181         return NULL;
 182 }
 183
 184 static bool is_fw_unit(struct device *dev);
 185
 186 static int fw_unit_match(struct device *dev, struct device_driver *drv)
 187 {
 188         /* We only allow binding to fw_units. */
 189         return is_fw_unit(dev) && unit_match(dev, drv) != NULL;
 190 }
 191
 192 static int fw_unit_probe(struct device *dev)
 193 {
 194         struct fw_driver *driver =
 195                         container_of(dev->driver, struct fw_driver, driver);
 196
 197         return driver->probe(fw_unit(dev), unit_match(dev, dev->driver));
 198 }
 199
 200 static int fw_unit_remove(struct device *dev)
 201 {
 202         struct fw_driver *driver =
 203                         container_of(dev->driver, struct fw_driver, driver);
 204
 205         return driver->remove(fw_unit(dev)), 0;
 206 }
 207
 208 static int get_modalias(struct fw_unit *unit, char *buffer, size_t buffer_size)
 209 {
 210         int id[] = {0, 0, 0, 0};
 211
 212         get_modalias_ids(unit, id);
 213
 214         return snprintf(buffer, buffer_size,
 215                         "ieee1394:ven%08Xmo%08Xsp%08Xver%08X",
 216                         id[0], id[1], id[2], id[3]);
 217 }
 218
 219 static int fw_unit_uevent(struct device *dev, struct kobj_uevent_env *env)
 220 {
 221         struct fw_unit *unit = fw_unit(dev);
 222         char modalias[64];
 223
 224         get_modalias(unit, modalias, sizeof(modalias));
 225
 226         if (add_uevent_var(env, "MODALIAS=%s", modalias))
 227                 return -ENOMEM;
 228
 229         return 0;
 230 }
 231
 232 struct bus_type fw_bus_type = {
 233         .name = "firewire",
 234         .match = fw_unit_match,
 235         .probe = fw_unit_probe,
 236         .remove = fw_unit_remove,
 237 };
 238 EXPORT_SYMBOL(fw_bus_type);
 239
 240 int fw_device_enable_phys_dma(struct fw_device *device)
 241 {
 242         int generation = device->generation;
 243
 244         /* device->node_id, accessed below, must not be older than generation */
 245         smp_rmb();
 246
 247         return device->card->driver->enable_phys_dma(device->card,
 248                                                      device->node_id,
 249                                                      generation);
 250 }
 251 EXPORT_SYMBOL(fw_device_enable_phys_dma);
 252
 253 struct config_rom_attribute {
 254         struct device_attribute attr;
 255         u32 key;
 256 };
 257
 258 static ssize_t show_immediate(struct device *dev,
 259                               struct device_attribute *dattr, char *buf)
 260 {
 261         struct config_rom_attribute *attr =
 262                 container_of(dattr, struct config_rom_attribute, attr);
 263         struct fw_csr_iterator ci;
 264         const u32 *dir;
 265         int key, value, ret = -ENOENT;
 266
 267         down_read(&fw_device_rwsem);
 268
 269         if (is_fw_unit(dev))
 270                 dir = fw_unit(dev)->directory;
 271         else
 272                 dir = fw_device(dev)->config_rom + 5;
 273
 274         fw_csr_iterator_init(&ci, dir);
 275         while (fw_csr_iterator_next(&ci, &key, &value))
 276                 if (attr->key == key) {
 277                         ret = snprintf(buf, buf ? PAGE_SIZE : 0,
 278                                        "0x%06x\n", value);
 279                         break;
 280                 }
 281
 282         up_read(&fw_device_rwsem);
 283
 284         return ret;
 285 }
 286
 287 #define IMMEDIATE_ATTR(name, key)                               \
 288         { __ATTR(name, S_IRUGO, show_immediate, NULL), key }
 289
 290 static ssize_t show_text_leaf(struct device *dev,
 291                               struct device_attribute *dattr, char *buf)
 292 {
 293         struct config_rom_attribute *attr =
 294                 container_of(dattr, struct config_rom_attribute, attr);
 295         const u32 *dir;
 296         size_t bufsize;
 297         char dummy_buf[2];
 298         int ret;
 299
 300         down_read(&fw_device_rwsem);
 301
 302         if (is_fw_unit(dev))
 303                 dir = fw_unit(dev)->directory;
 304         else
 305                 dir = fw_device(dev)->config_rom + 5;
 306
 307         if (buf) {
 308                 bufsize = PAGE_SIZE - 1;
 309         } else {
 310                 buf = dummy_buf;
 311                 bufsize = 1;
 312         }
 313
 314         ret = fw_csr_string(dir, attr->key, buf, bufsize);
 315
 316         if (ret >= 0) {
 317                 /* Strip trailing whitespace and add newline. */
 318                 while (ret > 0 && isspace(buf[ret - 1]))
 319                         ret--;
 320                 strcpy(buf + ret, "\n");
 321                 ret++;
 322         }
 323
 324         up_read(&fw_device_rwsem);
 325
 326         return ret;
 327 }
 328
 329 #define TEXT_LEAF_ATTR(name, key)                               \
 330         { __ATTR(name, S_IRUGO, show_text_leaf, NULL), key }
 331
 332 static struct config_rom_attribute config_rom_attributes[] = {
 333         IMMEDIATE_ATTR(vendor, CSR_VENDOR),
 334         IMMEDIATE_ATTR(hardware_version, CSR_HARDWARE_VERSION),
 335         IMMEDIATE_ATTR(specifier_id, CSR_SPECIFIER_ID),
 336         IMMEDIATE_ATTR(version, CSR_VERSION),
 337         IMMEDIATE_ATTR(model, CSR_MODEL),
 338         TEXT_LEAF_ATTR(vendor_name, CSR_VENDOR),
 339         TEXT_LEAF_ATTR(model_name, CSR_MODEL),
 340         TEXT_LEAF_ATTR(hardware_version_name, CSR_HARDWARE_VERSION),
 341 };
 342
 343 static void init_fw_attribute_group(struct device *dev,
 344                                     struct device_attribute *attrs,
 345                                     struct fw_attribute_group *group)
 346 {
 347         struct device_attribute *attr;
 348         int i, j;
 349
 350         for (j = 0; attrs[j].attr.name != NULL; j++)
 351                 group->attrs[j] = &attrs[j].attr;
 352
 353         for (i = 0; i < ARRAY_SIZE(config_rom_attributes); i++) {
 354                 attr = &config_rom_attributes[i].attr;
 355                 if (attr->show(dev, attr, NULL) < 0)
 356                         continue;
 357                 group->attrs[j++] = &attr->attr;
 358         }
 359
 360         group->attrs[j] = NULL;
 361         group->groups[0] = &group->group;
 362         group->groups[1] = NULL;
 363         group->group.attrs = group->attrs;
 364         dev->groups = (const struct attribute_group **) group->groups;
 365 }
 366
 367 static ssize_t modalias_show(struct device *dev,
 368                              struct device_attribute *attr, char *buf)
 369 {
 370         struct fw_unit *unit = fw_unit(dev);
 371         int length;
 372
 373         length = get_modalias(unit, buf, PAGE_SIZE);
 374         strcpy(buf + length, "\n");
 375
 376         return length + 1;
 377 }
 378
 379 static ssize_t rom_index_show(struct device *dev,
 380                               struct device_attribute *attr, char *buf)
 381 {
 382         struct fw_device *device = fw_device(dev->parent);
 383         struct fw_unit *unit = fw_unit(dev);
 384
 385         return snprintf(buf, PAGE_SIZE, "%d\n",
 386                         (int)(unit->directory - device->config_rom));
 387 }
 388
 389 static struct device_attribute fw_unit_attributes[] = {
 390         __ATTR_RO(modalias),
 391         __ATTR_RO(rom_index),
 392         __ATTR_NULL,
 393 };
 394
 395 static ssize_t config_rom_show(struct device *dev,
 396                                struct device_attribute *attr, char *buf)
 397 {
 398         struct fw_device *device = fw_device(dev);
 399         size_t length;
 400
 401         down_read(&fw_device_rwsem);
 402         length = device->config_rom_length * 4;
 403         memcpy(buf, device->config_rom, length);
 404         up_read(&fw_device_rwsem);
 405
 406         return length;
 407 }
 408
 409 static ssize_t guid_show(struct device *dev,
 410                          struct device_attribute *attr, char *buf)
 411 {
 412         struct fw_device *device = fw_device(dev);
 413         int ret;
 414
 415         down_read(&fw_device_rwsem);
 416         ret = snprintf(buf, PAGE_SIZE, "0x%08x%08x\n",
 417                        device->config_rom[3], device->config_rom[4]);
 418         up_read(&fw_device_rwsem);
 419
 420         return ret;
 421 }
 422
 423 static ssize_t is_local_show(struct device *dev,
 424                              struct device_attribute *attr, char *buf)
 425 {
 426         struct fw_device *device = fw_device(dev);
 427
 428         return sprintf(buf, "%u\n", device->is_local);
 429 }
 430
 431 static int units_sprintf(char *buf, const u32 *directory)
 432 {
 433         struct fw_csr_iterator ci;
 434         int key, value;
 435         int specifier_id = 0;
 436         int version = 0;
 437
 438         fw_csr_iterator_init(&ci, directory);
 439         while (fw_csr_iterator_next(&ci, &key, &value)) {
 440                 switch (key) {
 441                 case CSR_SPECIFIER_ID:
 442                         specifier_id = value;
 443                         break;
 444                 case CSR_VERSION:
 445                         version = value;
 446                         break;
 447                 }
 448         }
 449
 450         return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version);
 451 }
 452
 453 static ssize_t units_show(struct device *dev,
 454                           struct device_attribute *attr, char *buf)
 455 {
 456         struct fw_device *device = fw_device(dev);
 457         struct fw_csr_iterator ci;
 458         int key, value, i = 0;
 459
 460         down_read(&fw_device_rwsem);
 461         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 462         while (fw_csr_iterator_next(&ci, &key, &value)) {
 463                 if (key != (CSR_UNIT | CSR_DIRECTORY))
 464                         continue;
 465                 i += units_sprintf(&buf[i], ci.p + value - 1);
 466                 if (i >= PAGE_SIZE - (8 + 1 + 8 + 1))
 467                         break;
 468         }
 469         up_read(&fw_device_rwsem);
 470
 471         if (i)
 472                 buf[i - 1] = '\n';
 473
 474         return i;
 475 }
 476
 477 static struct device_attribute fw_device_attributes[] = {
 478         __ATTR_RO(config_rom),
 479         __ATTR_RO(guid),
 480         __ATTR_RO(is_local),
 481         __ATTR_RO(units),
 482         __ATTR_NULL,
 483 };
 484
 485 static int read_rom(struct fw_device *device,
 486                     int generation, int index, u32 *data)
 487 {
 488         u64 offset = (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4;
 489         int i, rcode;
 490
 491         /* device->node_id, accessed below, must not be older than generation */
 492         smp_rmb();
 493
 494         for (i = 10; i < 100; i += 10) {
 495                 rcode = fw_run_transaction(device->card,
 496                                 TCODE_READ_QUADLET_REQUEST, device->node_id,
 497                                 generation, device->max_speed, offset, data, 4);
 498                 if (rcode != RCODE_BUSY)
 499                         break;
 500                 msleep(i);
 501         }
 502         be32_to_cpus(data);
 503
 504         return rcode;
 505 }
 506
 507 #define MAX_CONFIG_ROM_SIZE 256
 508
 509 /*
 510  * Read the bus info block, perform a speed probe, and read all of the rest of
 511  * the config ROM.  We do all this with a cached bus generation.  If the bus
 512  * generation changes under us, read_config_rom will fail and get retried.
 513  * It's better to start all over in this case because the node from which we
 514  * are reading the ROM may have changed the ROM during the reset.
 515  * Returns either a result code or a negative error code.
 516  */
 517 static int read_config_rom(struct fw_device *device, int generation)
 518 {
 519         struct fw_card *card = device->card;
 520         const u32 *old_rom, *new_rom;
 521         u32 *rom, *stack;
 522         u32 sp, key;
 523         int i, end, length, ret;
 524
 525         rom = kmalloc(sizeof(*rom) * MAX_CONFIG_ROM_SIZE +
 526                       sizeof(*stack) * MAX_CONFIG_ROM_SIZE, GFP_KERNEL);
 527         if (rom == NULL)
 528                 return -ENOMEM;
 529
 530         stack = &rom[MAX_CONFIG_ROM_SIZE];
 531         memset(rom, 0, sizeof(*rom) * MAX_CONFIG_ROM_SIZE);
 532
 533         device->max_speed = SCODE_100;
 534
 535         /* First read the bus info block. */
 536         for (i = 0; i < 5; i++) {
 537                 ret = read_rom(device, generation, i, &rom[i]);
 538                 if (ret != RCODE_COMPLETE)
 539                         goto out;
 540                 /*
 541                  * As per IEEE1212 7.2, during initialization, devices can
 542                  * reply with a 0 for the first quadlet of the config
 543                  * rom to indicate that they are booting (for example,
 544                  * if the firmware is on the disk of a external
 545                  * harddisk).  In that case we just fail, and the
 546                  * retry mechanism will try again later.
 547                  */
 548                 if (i == 0 && rom[i] == 0) {
 549                         ret = RCODE_BUSY;
 550                         goto out;
 551                 }
 552         }
 553
 554         device->max_speed = device->node->max_speed;
 555
 556         /*
 557          * Determine the speed of
 558          *   - devices with link speed less than PHY speed,
 559          *   - devices with 1394b PHY (unless only connected to 1394a PHYs),
 560          *   - all devices if there are 1394b repeaters.
 561          * Note, we cannot use the bus info block's link_spd as starting point
 562          * because some buggy firmwares set it lower than necessary and because
 563          * 1394-1995 nodes do not have the field.
 564          */
 565         if ((rom[2] & 0x7) < device->max_speed ||
 566             device->max_speed == SCODE_BETA ||
 567             card->beta_repeaters_present) {
 568                 u32 dummy;
 569
 570                 /* for S1600 and S3200 */
 571                 if (device->max_speed == SCODE_BETA)
 572                         device->max_speed = card->link_speed;
 573
 574                 while (device->max_speed > SCODE_100) {
 575                         if (read_rom(device, generation, 0, &dummy) ==
 576                             RCODE_COMPLETE)
 577                                 break;
 578                         device->max_speed--;
 579                 }
 580         }
 581
 582         /*
 583          * Now parse the config rom.  The config rom is a recursive
 584          * directory structure so we parse it using a stack of
 585          * references to the blocks that make up the structure.  We
 586          * push a reference to the root directory on the stack to
 587          * start things off.
 588          */
 589         length = i;
 590         sp = 0;
 591         stack[sp++] = 0xc0000005;
 592         while (sp > 0) {
 593                 /*
 594                  * Pop the next block reference of the stack.  The
 595                  * lower 24 bits is the offset into the config rom,
 596                  * the upper 8 bits are the type of the reference the
 597                  * block.
 598                  */
 599                 key = stack[--sp];
 600                 i = key & 0xffffff;
 601                 if (WARN_ON(i >= MAX_CONFIG_ROM_SIZE)) {
 602                         ret = -ENXIO;
 603                         goto out;
 604                 }
 605
 606                 /* Read header quadlet for the block to get the length. */
 607                 ret = read_rom(device, generation, i, &rom[i]);
 608                 if (ret != RCODE_COMPLETE)
 609                         goto out;
 610                 end = i + (rom[i] >> 16) + 1;
 611                 if (end > MAX_CONFIG_ROM_SIZE) {
 612                         /*
 613                          * This block extends outside the config ROM which is
 614                          * a firmware bug.  Ignore this whole block, i.e.
 615                          * simply set a fake block length of 0.
 616                          */
 617                         fw_err(card, "skipped invalid ROM block %x at %llx\n",
 618                                rom[i],
 619                                i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 620                         rom[i] = 0;
 621                         end = i;
 622                 }
 623                 i++;
 624
 625                 /*
 626                  * Now read in the block.  If this is a directory
 627                  * block, check the entries as we read them to see if
 628                  * it references another block, and push it in that case.
 629                  */
 630                 for (; i < end; i++) {
 631                         ret = read_rom(device, generation, i, &rom[i]);
 632                         if (ret != RCODE_COMPLETE)
 633                                 goto out;
 634
 635                         if ((key >> 30) != 3 || (rom[i] >> 30) < 2)
 636                                 continue;
 637                         /*
 638                          * Offset points outside the ROM.  May be a firmware
 639                          * bug or an Extended ROM entry (IEEE 1212-2001 clause
 640                          * 7.7.18).  Simply overwrite this pointer here by a
 641                          * fake immediate entry so that later iterators over
 642                          * the ROM don't have to check offsets all the time.
 643                          */
 644                         if (i + (rom[i] & 0xffffff) >= MAX_CONFIG_ROM_SIZE) {
 645                                 fw_err(card,
 646                                        "skipped unsupported ROM entry %x at %llx\n",
 647                                        rom[i],
 648                                        i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 649                                 rom[i] = 0;
 650                                 continue;
 651                         }
 652                         stack[sp++] = i + rom[i];
 653                 }
 654                 if (length < i)
 655                         length = i;
 656         }
 657
 658         old_rom = device->config_rom;
 659         new_rom = kmemdup(rom, length * 4, GFP_KERNEL);
 660         if (new_rom == NULL) {
 661                 ret = -ENOMEM;
 662                 goto out;
 663         }
 664
 665         down_write(&fw_device_rwsem);
 666         device->config_rom = new_rom;
 667         device->config_rom_length = length;
 668         up_write(&fw_device_rwsem);
 669
 670         kfree(old_rom);
 671         ret = RCODE_COMPLETE;
 672         device->max_rec = rom[2] >> 12 & 0xf;
 673         device->cmc     = rom[2] >> 30 & 1;
 674         device->irmc    = rom[2] >> 31 & 1;
 675  out:
 676         kfree(rom);
 677
 678         return ret;
 679 }
 680
 681 static void fw_unit_release(struct device *dev)
 682 {
 683         struct fw_unit *unit = fw_unit(dev);
 684
 685         fw_device_put(fw_parent_device(unit));
 686         kfree(unit);
 687 }
 688
 689 static struct device_type fw_unit_type = {
 690         .uevent         = fw_unit_uevent,
 691         .release        = fw_unit_release,
 692 };
 693
 694 static bool is_fw_unit(struct device *dev)
 695 {
 696         return dev->type == &fw_unit_type;
 697 }
 698
 699 static void create_units(struct fw_device *device)
 700 {
 701         struct fw_csr_iterator ci;
 702         struct fw_unit *unit;
 703         int key, value, i;
 704
 705         i = 0;
 706         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 707         while (fw_csr_iterator_next(&ci, &key, &value)) {
 708                 if (key != (CSR_UNIT | CSR_DIRECTORY))
 709                         continue;
 710
 711                 /*
 712                  * Get the address of the unit directory and try to
 713                  * match the drivers id_tables against it.
 714                  */
 715                 unit = kzalloc(sizeof(*unit), GFP_KERNEL);
 716                 if (unit == NULL)
 717                         continue;
 718
 719                 unit->directory = ci.p + value - 1;
 720                 unit->device.bus = &fw_bus_type;
 721                 unit->device.type = &fw_unit_type;
 722                 unit->device.parent = &device->device;
 723                 dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++);
 724
 725                 BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) <
 726                                 ARRAY_SIZE(fw_unit_attributes) +
 727                                 ARRAY_SIZE(config_rom_attributes));
 728                 init_fw_attribute_group(&unit->device,
 729                                         fw_unit_attributes,
 730                                         &unit->attribute_group);
 731
 732                 if (device_register(&unit->device) < 0)
 733                         goto skip_unit;
 734
 735                 fw_device_get(device);
 736                 continue;
 737
 738         skip_unit:
 739                 kfree(unit);
 740         }
 741 }
 742
 743 static int shutdown_unit(struct device *device, void *data)
 744 {
 745         device_unregister(device);
 746
 747         return 0;
 748 }
 749
 750 /*
 751  * fw_device_rwsem acts as dual purpose mutex:
 752  *   - serializes accesses to fw_device_idr,
 753  *   - serializes accesses to fw_device.config_rom/.config_rom_length and
 754  *     fw_unit.directory, unless those accesses happen at safe occasions
 755  */
 756 DECLARE_RWSEM(fw_device_rwsem);
 757
 758 DEFINE_IDR(fw_device_idr);
 759 int fw_cdev_major;
 760
 761 struct fw_device *fw_device_get_by_devt(dev_t devt)
 762 {
 763         struct fw_device *device;
 764
 765         down_read(&fw_device_rwsem);
 766         device = idr_find(&fw_device_idr, MINOR(devt));
 767         if (device)
 768                 fw_device_get(device);
 769         up_read(&fw_device_rwsem);
 770
 771         return device;
 772 }
 773
 774 struct workqueue_struct *fw_workqueue;
 775 EXPORT_SYMBOL(fw_workqueue);
 776
 777 static void fw_schedule_device_work(struct fw_device *device,
 778                                     unsigned long delay)
 779 {
 780         queue_delayed_work(fw_workqueue, &device->work, delay);
 781 }
 782
 783 /*
 784  * These defines control the retry behavior for reading the config
 785  * rom.  It shouldn't be necessary to tweak these; if the device
 786  * doesn't respond to a config rom read within 10 seconds, it's not
 787  * going to respond at all.  As for the initial delay, a lot of
 788  * devices will be able to respond within half a second after bus
 789  * reset.  On the other hand, it's not really worth being more
 790  * aggressive than that, since it scales pretty well; if 10 devices
 791  * are plugged in, they're all getting read within one second.
 792  */
 793
 794 #define MAX_RETRIES     10
 795 #define RETRY_DELAY     (3 * HZ)
 796 #define INITIAL_DELAY   (HZ / 2)
 797 #define SHUTDOWN_DELAY  (2 * HZ)
 798
 799 static void fw_device_shutdown(struct work_struct *work)
 800 {
 801         struct fw_device *device =
 802                 container_of(work, struct fw_device, work.work);
 803         int minor = MINOR(device->device.devt);
 804
 805         if (time_before64(get_jiffies_64(),
 806                           device->card->reset_jiffies + SHUTDOWN_DELAY)
 807             && !list_empty(&device->card->link)) {
 808                 fw_schedule_device_work(device, SHUTDOWN_DELAY);
 809                 return;
 810         }
 811
 812         if (atomic_cmpxchg(&device->state,
 813                            FW_DEVICE_GONE,
 814                            FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE)
 815                 return;
 816
 817         fw_device_cdev_remove(device);
 818         device_for_each_child(&device->device, NULL, shutdown_unit);
 819         device_unregister(&device->device);
 820
 821         down_write(&fw_device_rwsem);
 822         idr_remove(&fw_device_idr, minor);
 823         up_write(&fw_device_rwsem);
 824
 825         fw_device_put(device);
 826 }
 827
 828 static void fw_device_release(struct device *dev)
 829 {
 830         struct fw_device *device = fw_device(dev);
 831         struct fw_card *card = device->card;
 832         unsigned long flags;
 833
 834         /*
 835          * Take the card lock so we don't set this to NULL while a
 836          * FW_NODE_UPDATED callback is being handled or while the
 837          * bus manager work looks at this node.
 838          */
 839         spin_lock_irqsave(&card->lock, flags);
 840         device->node->data = NULL;
 841         spin_unlock_irqrestore(&card->lock, flags);
 842
 843         fw_node_put(device->node);
 844         kfree(device->config_rom);
 845         kfree(device);
 846         fw_card_put(card);
 847 }
 848
 849 static struct device_type fw_device_type = {
 850         .release = fw_device_release,
 851 };
 852
 853 static bool is_fw_device(struct device *dev)
 854 {
 855         return dev->type == &fw_device_type;
 856 }
 857
 858 static int update_unit(struct device *dev, void *data)
 859 {
 860         struct fw_unit *unit = fw_unit(dev);
 861         struct fw_driver *driver = (struct fw_driver *)dev->driver;
 862
 863         if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) {
 864                 device_lock(dev);
 865                 driver->update(unit);
 866                 device_unlock(dev);
 867         }
 868
 869         return 0;
 870 }
 871
 872 static void fw_device_update(struct work_struct *work)
 873 {
 874         struct fw_device *device =
 875                 container_of(work, struct fw_device, work.work);
 876
 877         fw_device_cdev_update(device);
 878         device_for_each_child(&device->device, NULL, update_unit);
 879 }
 880
 881 /*
 882  * If a device was pending for deletion because its node went away but its
 883  * bus info block and root directory header matches that of a newly discovered
 884  * device, revive the existing fw_device.
 885  * The newly allocated fw_device becomes obsolete instead.
 886  */
 887 static int lookup_existing_device(struct device *dev, void *data)
 888 {
 889         struct fw_device *old = fw_device(dev);
 890         struct fw_device *new = data;
 891         struct fw_card *card = new->card;
 892         int match = 0;
 893
 894         if (!is_fw_device(dev))
 895                 return 0;
 896
 897         down_read(&fw_device_rwsem); /* serialize config_rom access */
 898         spin_lock_irq(&card->lock);  /* serialize node access */
 899
 900         if (memcmp(old->config_rom, new->config_rom, 6 * 4) == 0 &&
 901             atomic_cmpxchg(&old->state,
 902                            FW_DEVICE_GONE,
 903                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
 904                 struct fw_node *current_node = new->node;
 905                 struct fw_node *obsolete_node = old->node;
 906
 907                 new->node = obsolete_node;
 908                 new->node->data = new;
 909                 old->node = current_node;
 910                 old->node->data = old;
 911
 912                 old->max_speed = new->max_speed;
 913                 old->node_id = current_node->node_id;
 914                 smp_wmb();  /* update node_id before generation */
 915                 old->generation = card->generation;
 916                 old->config_rom_retries = 0;
 917                 fw_notice(card, "rediscovered device %s\n", dev_name(dev));
 918
 919                 PREPARE_DELAYED_WORK(&old->work, fw_device_update);
 920                 fw_schedule_device_work(old, 0);
 921
 922                 if (current_node == card->root_node)
 923                         fw_schedule_bm_work(card, 0);
 924
 925                 match = 1;
 926         }
 927
 928         spin_unlock_irq(&card->lock);
 929         up_read(&fw_device_rwsem);
 930
 931         return match;
 932 }
 933
 934 enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, };
 935
 936 static void set_broadcast_channel(struct fw_device *device, int generation)
 937 {
 938         struct fw_card *card = device->card;
 939         __be32 data;
 940         int rcode;
 941
 942         if (!card->broadcast_channel_allocated)
 943                 return;
 944
 945         /*
 946          * The Broadcast_Channel Valid bit is required by nodes which want to
 947          * transmit on this channel.  Such transmissions are practically
 948          * exclusive to IP over 1394 (RFC 2734).  IP capable nodes are required
 949          * to be IRM capable and have a max_rec of 8 or more.  We use this fact
 950          * to narrow down to which nodes we send Broadcast_Channel updates.
 951          */
 952         if (!device->irmc || device->max_rec < 8)
 953                 return;
 954
 955         /*
 956          * Some 1394-1995 nodes crash if this 1394a-2000 register is written.
 957          * Perform a read test first.
 958          */
 959         if (device->bc_implemented == BC_UNKNOWN) {
 960                 rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST,
 961                                 device->node_id, generation, device->max_speed,
 962                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 963                                 &data, 4);
 964                 switch (rcode) {
 965                 case RCODE_COMPLETE:
 966                         if (data & cpu_to_be32(1 << 31)) {
 967                                 device->bc_implemented = BC_IMPLEMENTED;
 968                                 break;
 969                         }
 970                         /* else fall through to case address error */
 971                 case RCODE_ADDRESS_ERROR:
 972                         device->bc_implemented = BC_UNIMPLEMENTED;
 973                 }
 974         }
 975
 976         if (device->bc_implemented == BC_IMPLEMENTED) {
 977                 data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL |
 978                                    BROADCAST_CHANNEL_VALID);
 979                 fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
 980                                 device->node_id, generation, device->max_speed,
 981                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 982                                 &data, 4);
 983         }
 984 }
 985
 986 int fw_device_set_broadcast_channel(struct device *dev, void *gen)
 987 {
 988         if (is_fw_device(dev))
 989                 set_broadcast_channel(fw_device(dev), (long)gen);
 990
 991         return 0;
 992 }
 993
 994 static void fw_device_init(struct work_struct *work)
 995 {
 996         struct fw_device *device =
 997                 container_of(work, struct fw_device, work.work);
 998         struct fw_card *card = device->card;
 999         struct device *revived_dev;
1000         int minor, ret;
1001
1002         /*
1003          * All failure paths here set node->data to NULL, so that we
1004          * don't try to do device_for_each_child() on a kfree()'d
1005          * device.
1006          */
1007
1008         ret = read_config_rom(device, device->generation);
1009         if (ret != RCODE_COMPLETE) {
1010                 if (device->config_rom_retries < MAX_RETRIES &&
1011                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1012                         device->config_rom_retries++;
1013                         fw_schedule_device_work(device, RETRY_DELAY);
1014                 } else {
1015                         if (device->node->link_on)
1016                                 fw_notice(card, "giving up on node %x: reading config rom failed: %s\n",
1017                                           device->node_id,
1018                                           fw_rcode_string(ret));
1019                         if (device->node == card->root_node)
1020                                 fw_schedule_bm_work(card, 0);
1021                         fw_device_release(&device->device);
1022                 }
1023                 return;
1024         }
1025
1026         revived_dev = device_find_child(card->device,
1027                                         device, lookup_existing_device);
1028         if (revived_dev) {
1029                 put_device(revived_dev);
1030                 fw_device_release(&device->device);
1031
1032                 return;
1033         }
1034
1035         device_initialize(&device->device);
1036
1037         fw_device_get(device);
1038         down_write(&fw_device_rwsem);
1039         minor = idr_alloc(&fw_device_idr, device, 0, 1 << MINORBITS,
1040                         GFP_KERNEL);
1041         up_write(&fw_device_rwsem);
1042
1043         if (minor < 0)
1044                 goto error;
1045
1046         device->device.bus = &fw_bus_type;
1047         device->device.type = &fw_device_type;
1048         device->device.parent = card->device;
1049         device->device.devt = MKDEV(fw_cdev_major, minor);
1050         dev_set_name(&device->device, "fw%d", minor);
1051
1052         BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) <
1053                         ARRAY_SIZE(fw_device_attributes) +
1054                         ARRAY_SIZE(config_rom_attributes));
1055         init_fw_attribute_group(&device->device,
1056                                 fw_device_attributes,
1057                                 &device->attribute_group);
1058
1059         if (device_add(&device->device)) {
1060                 fw_err(card, "failed to add device\n");
1061                 goto error_with_cdev;
1062         }
1063
1064         create_units(device);
1065
1066         /*
1067          * Transition the device to running state.  If it got pulled
1068          * out from under us while we did the intialization work, we
1069          * have to shut down the device again here.  Normally, though,
1070          * fw_node_event will be responsible for shutting it down when
1071          * necessary.  We have to use the atomic cmpxchg here to avoid
1072          * racing with the FW_NODE_DESTROYED case in
1073          * fw_node_event().
1074          */
1075         if (atomic_cmpxchg(&device->state,
1076                            FW_DEVICE_INITIALIZING,
1077                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
1078                 PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1079                 fw_schedule_device_work(device, SHUTDOWN_DELAY);
1080         } else {
1081                 fw_notice(card, "created device %s: GUID %08x%08x, S%d00\n",
1082                           dev_name(&device->device),
1083                           device->config_rom[3], device->config_rom[4],
1084                           1 << device->max_speed);
1085                 device->config_rom_retries = 0;
1086
1087                 set_broadcast_channel(device, device->generation);
1088
1089                 add_device_randomness(&device->config_rom[3], 8);
1090         }
1091
1092         /*
1093          * Reschedule the IRM work if we just finished reading the
1094          * root node config rom.  If this races with a bus reset we
1095          * just end up running the IRM work a couple of extra times -
1096          * pretty harmless.
1097          */
1098         if (device->node == card->root_node)
1099                 fw_schedule_bm_work(card, 0);
1100
1101         return;
1102
1103  error_with_cdev:
1104         down_write(&fw_device_rwsem);
1105         idr_remove(&fw_device_idr, minor);
1106         up_write(&fw_device_rwsem);
1107  error:
1108         fw_device_put(device);          /* fw_device_idr's reference */
1109
1110         put_device(&device->device);    /* our reference */
1111 }
1112
1113 /* Reread and compare bus info block and header of root directory */
1114 static int reread_config_rom(struct fw_device *device, int generation,
1115                              bool *changed)
1116 {
1117         u32 q;
1118         int i, rcode;
1119
1120         for (i = 0; i < 6; i++) {
1121                 rcode = read_rom(device, generation, i, &q);
1122                 if (rcode != RCODE_COMPLETE)
1123                         return rcode;
1124
1125                 if (i == 0 && q == 0)
1126                         /* inaccessible (see read_config_rom); retry later */
1127                         return RCODE_BUSY;
1128
1129                 if (q != device->config_rom[i]) {
1130                         *changed = true;
1131                         return RCODE_COMPLETE;
1132                 }
1133         }
1134
1135         *changed = false;
1136         return RCODE_COMPLETE;
1137 }
1138
1139 static void fw_device_refresh(struct work_struct *work)
1140 {
1141         struct fw_device *device =
1142                 container_of(work, struct fw_device, work.work);
1143         struct fw_card *card = device->card;
1144         int ret, node_id = device->node_id;
1145         bool changed;
1146
1147         ret = reread_config_rom(device, device->generation, &changed);
1148         if (ret != RCODE_COMPLETE)
1149                 goto failed_config_rom;
1150
1151         if (!changed) {
1152                 if (atomic_cmpxchg(&device->state,
1153                                    FW_DEVICE_INITIALIZING,
1154                                    FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1155                         goto gone;
1156
1157                 fw_device_update(work);
1158                 device->config_rom_retries = 0;
1159                 goto out;
1160         }
1161
1162         /*
1163          * Something changed.  We keep things simple and don't investigate
1164          * further.  We just destroy all previous units and create new ones.
1165          */
1166         device_for_each_child(&device->device, NULL, shutdown_unit);
1167
1168         ret = read_config_rom(device, device->generation);
1169         if (ret != RCODE_COMPLETE)
1170                 goto failed_config_rom;
1171
1172         fw_device_cdev_update(device);
1173         create_units(device);
1174
1175         /* Userspace may want to re-read attributes. */
1176         kobject_uevent(&device->device.kobj, KOBJ_CHANGE);
1177
1178         if (atomic_cmpxchg(&device->state,
1179                            FW_DEVICE_INITIALIZING,
1180                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1181                 goto gone;
1182
1183         fw_notice(card, "refreshed device %s\n", dev_name(&device->device));
1184         device->config_rom_retries = 0;
1185         goto out;
1186
1187  failed_config_rom:
1188         if (device->config_rom_retries < MAX_RETRIES &&
1189             atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1190                 device->config_rom_retries++;
1191                 fw_schedule_device_work(device, RETRY_DELAY);
1192                 return;
1193         }
1194
1195         fw_notice(card, "giving up on refresh of device %s: %s\n",
1196                   dev_name(&device->device), fw_rcode_string(ret));
1197  gone:
1198         atomic_set(&device->state, FW_DEVICE_GONE);
1199         PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1200         fw_schedule_device_work(device, SHUTDOWN_DELAY);
1201  out:
1202         if (node_id == card->root_node->node_id)
1203                 fw_schedule_bm_work(card, 0);
1204 }
1205
1206 void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
1207 {
1208         struct fw_device *device;
1209
1210         switch (event) {
1211         case FW_NODE_CREATED:
1212                 /*
1213                  * Attempt to scan the node, regardless whether its self ID has
1214                  * the L (link active) flag set or not.  Some broken devices
1215                  * send L=0 but have an up-and-running link; others send L=1
1216                  * without actually having a link.
1217                  */
1218  create:
1219                 device = kzalloc(sizeof(*device), GFP_ATOMIC);
1220                 if (device == NULL)
1221                         break;
1222
1223                 /*
1224                  * Do minimal intialization of the device here, the
1225                  * rest will happen in fw_device_init().
1226                  *
1227                  * Attention:  A lot of things, even fw_device_get(),
1228                  * cannot be done before fw_device_init() finished!
1229                  * You can basically just check device->state and
1230                  * schedule work until then, but only while holding
1231                  * card->lock.
1232                  */
1233                 atomic_set(&device->state, FW_DEVICE_INITIALIZING);
1234                 device->card = fw_card_get(card);
1235                 device->node = fw_node_get(node);
1236                 device->node_id = node->node_id;
1237                 device->generation = card->generation;
1238                 device->is_local = node == card->local_node;
1239                 mutex_init(&device->client_list_mutex);
1240                 INIT_LIST_HEAD(&device->client_list);
1241
1242                 /*
1243                  * Set the node data to point back to this device so
1244                  * FW_NODE_UPDATED callbacks can update the node_id
1245                  * and generation for the device.
1246                  */
1247                 node->data = device;
1248
1249                 /*
1250                  * Many devices are slow to respond after bus resets,
1251                  * especially if they are bus powered and go through
1252                  * power-up after getting plugged in.  We schedule the
1253                  * first config rom scan half a second after bus reset.
1254                  */
1255                 INIT_DELAYED_WORK(&device->work, fw_device_init);
1256                 fw_schedule_device_work(device, INITIAL_DELAY);
1257                 break;
1258
1259         case FW_NODE_INITIATED_RESET:
1260         case FW_NODE_LINK_ON:
1261                 device = node->data;
1262                 if (device == NULL)
1263                         goto create;
1264
1265                 device->node_id = node->node_id;
1266                 smp_wmb();  /* update node_id before generation */
1267                 device->generation = card->generation;
1268                 if (atomic_cmpxchg(&device->state,
1269                             FW_DEVICE_RUNNING,
1270                             FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) {
1271                         PREPARE_DELAYED_WORK(&device->work, fw_device_refresh);
1272                         fw_schedule_device_work(device,
1273                                 device->is_local ? 0 : INITIAL_DELAY);
1274                 }
1275                 break;
1276
1277         case FW_NODE_UPDATED:
1278                 device = node->data;
1279                 if (device == NULL)
1280                         break;
1281
1282                 device->node_id = node->node_id;
1283                 smp_wmb();  /* update node_id before generation */
1284                 device->generation = card->generation;
1285                 if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
1286                         PREPARE_DELAYED_WORK(&device->work, fw_device_update);
1287                         fw_schedule_device_work(device, 0);
1288                 }
1289                 break;
1290
1291         case FW_NODE_DESTROYED:
1292         case FW_NODE_LINK_OFF:
1293                 if (!node->data)
1294                         break;
1295
1296                 /*
1297                  * Destroy the device associated with the node.  There
1298                  * are two cases here: either the device is fully
1299                  * initialized (FW_DEVICE_RUNNING) or we're in the
1300                  * process of reading its config rom
1301                  * (FW_DEVICE_INITIALIZING).  If it is fully
1302                  * initialized we can reuse device->work to schedule a
1303                  * full fw_device_shutdown().  If not, there's work
1304                  * scheduled to read it's config rom, and we just put
1305                  * the device in shutdown state to have that code fail
1306                  * to create the device.
1307                  */
1308                 device = node->data;
1309                 if (atomic_xchg(&device->state,
1310                                 FW_DEVICE_GONE) == FW_DEVICE_RUNNING) {
1311                         PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1312                         fw_schedule_device_work(device,
1313                                 list_empty(&card->link) ? 0 : SHUTDOWN_DELAY);
1314                 }
1315                 break;
1316         }
1317 }