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  * An overlong string is silently truncated such that it and the
 119  * zero byte fit into @size.
 120  *
 121  * Returns strlen(buf) or a negative error code.
 122  */
 123 int fw_csr_string(const u32 *directory, int key, char *buf, size_t size)
 124 {
 125         const u32 *leaf = search_leaf(directory, key);
 126         if (!leaf)
 127                 return -ENOENT;
 128
 129         return textual_leaf_to_string(leaf, buf, size);
 130 }
 131 EXPORT_SYMBOL(fw_csr_string);
 132
 133 static void get_ids(const u32 *directory, int *id)
 134 {
 135         struct fw_csr_iterator ci;
 136         int key, value;
 137
 138         fw_csr_iterator_init(&ci, directory);
 139         while (fw_csr_iterator_next(&ci, &key, &value)) {
 140                 switch (key) {
 141                 case CSR_VENDOR:        id[0] = value; break;
 142                 case CSR_MODEL:         id[1] = value; break;
 143                 case CSR_SPECIFIER_ID:  id[2] = value; break;
 144                 case CSR_VERSION:       id[3] = value; break;
 145                 }
 146         }
 147 }
 148
 149 static void get_modalias_ids(struct fw_unit *unit, int *id)
 150 {
 151         get_ids(&fw_parent_device(unit)->config_rom[5], id);
 152         get_ids(unit->directory, id);
 153 }
 154
 155 static bool match_ids(const struct ieee1394_device_id *id_table, int *id)
 156 {
 157         int match = 0;
 158
 159         if (id[0] == id_table->vendor_id)
 160                 match |= IEEE1394_MATCH_VENDOR_ID;
 161         if (id[1] == id_table->model_id)
 162                 match |= IEEE1394_MATCH_MODEL_ID;
 163         if (id[2] == id_table->specifier_id)
 164                 match |= IEEE1394_MATCH_SPECIFIER_ID;
 165         if (id[3] == id_table->version)
 166                 match |= IEEE1394_MATCH_VERSION;
 167
 168         return (match & id_table->match_flags) == id_table->match_flags;
 169 }
 170
 171 static const struct ieee1394_device_id *unit_match(struct device *dev,
 172                                                    struct device_driver *drv)
 173 {
 174         const struct ieee1394_device_id *id_table =
 175                         container_of(drv, struct fw_driver, driver)->id_table;
 176         int id[] = {0, 0, 0, 0};
 177
 178         get_modalias_ids(fw_unit(dev), id);
 179
 180         for (; id_table->match_flags != 0; id_table++)
 181                 if (match_ids(id_table, id))
 182                         return id_table;
 183
 184         return NULL;
 185 }
 186
 187 static bool is_fw_unit(struct device *dev);
 188
 189 static int fw_unit_match(struct device *dev, struct device_driver *drv)
 190 {
 191         /* We only allow binding to fw_units. */
 192         return is_fw_unit(dev) && unit_match(dev, drv) != NULL;
 193 }
 194
 195 static int fw_unit_probe(struct device *dev)
 196 {
 197         struct fw_driver *driver =
 198                         container_of(dev->driver, struct fw_driver, driver);
 199
 200         return driver->probe(fw_unit(dev), unit_match(dev, dev->driver));
 201 }
 202
 203 static int fw_unit_remove(struct device *dev)
 204 {
 205         struct fw_driver *driver =
 206                         container_of(dev->driver, struct fw_driver, driver);
 207
 208         return driver->remove(fw_unit(dev)), 0;
 209 }
 210
 211 static int get_modalias(struct fw_unit *unit, char *buffer, size_t buffer_size)
 212 {
 213         int id[] = {0, 0, 0, 0};
 214
 215         get_modalias_ids(unit, id);
 216
 217         return snprintf(buffer, buffer_size,
 218                         "ieee1394:ven%08Xmo%08Xsp%08Xver%08X",
 219                         id[0], id[1], id[2], id[3]);
 220 }
 221
 222 static int fw_unit_uevent(struct device *dev, struct kobj_uevent_env *env)
 223 {
 224         struct fw_unit *unit = fw_unit(dev);
 225         char modalias[64];
 226
 227         get_modalias(unit, modalias, sizeof(modalias));
 228
 229         if (add_uevent_var(env, "MODALIAS=%s", modalias))
 230                 return -ENOMEM;
 231
 232         return 0;
 233 }
 234
 235 struct bus_type fw_bus_type = {
 236         .name = "firewire",
 237         .match = fw_unit_match,
 238         .probe = fw_unit_probe,
 239         .remove = fw_unit_remove,
 240 };
 241 EXPORT_SYMBOL(fw_bus_type);
 242
 243 int fw_device_enable_phys_dma(struct fw_device *device)
 244 {
 245         int generation = device->generation;
 246
 247         /* device->node_id, accessed below, must not be older than generation */
 248         smp_rmb();
 249
 250         return device->card->driver->enable_phys_dma(device->card,
 251                                                      device->node_id,
 252                                                      generation);
 253 }
 254 EXPORT_SYMBOL(fw_device_enable_phys_dma);
 255
 256 struct config_rom_attribute {
 257         struct device_attribute attr;
 258         u32 key;
 259 };
 260
 261 static ssize_t show_immediate(struct device *dev,
 262                               struct device_attribute *dattr, char *buf)
 263 {
 264         struct config_rom_attribute *attr =
 265                 container_of(dattr, struct config_rom_attribute, attr);
 266         struct fw_csr_iterator ci;
 267         const u32 *dir;
 268         int key, value, ret = -ENOENT;
 269
 270         down_read(&fw_device_rwsem);
 271
 272         if (is_fw_unit(dev))
 273                 dir = fw_unit(dev)->directory;
 274         else
 275                 dir = fw_device(dev)->config_rom + 5;
 276
 277         fw_csr_iterator_init(&ci, dir);
 278         while (fw_csr_iterator_next(&ci, &key, &value))
 279                 if (attr->key == key) {
 280                         ret = snprintf(buf, buf ? PAGE_SIZE : 0,
 281                                        "0x%06x\n", value);
 282                         break;
 283                 }
 284
 285         up_read(&fw_device_rwsem);
 286
 287         return ret;
 288 }
 289
 290 #define IMMEDIATE_ATTR(name, key)                               \
 291         { __ATTR(name, S_IRUGO, show_immediate, NULL), key }
 292
 293 static ssize_t show_text_leaf(struct device *dev,
 294                               struct device_attribute *dattr, char *buf)
 295 {
 296         struct config_rom_attribute *attr =
 297                 container_of(dattr, struct config_rom_attribute, attr);
 298         const u32 *dir;
 299         size_t bufsize;
 300         char dummy_buf[2];
 301         int ret;
 302
 303         down_read(&fw_device_rwsem);
 304
 305         if (is_fw_unit(dev))
 306                 dir = fw_unit(dev)->directory;
 307         else
 308                 dir = fw_device(dev)->config_rom + 5;
 309
 310         if (buf) {
 311                 bufsize = PAGE_SIZE - 1;
 312         } else {
 313                 buf = dummy_buf;
 314                 bufsize = 1;
 315         }
 316
 317         ret = fw_csr_string(dir, attr->key, buf, bufsize);
 318
 319         if (ret >= 0) {
 320                 /* Strip trailing whitespace and add newline. */
 321                 while (ret > 0 && isspace(buf[ret - 1]))
 322                         ret--;
 323                 strcpy(buf + ret, "\n");
 324                 ret++;
 325         }
 326
 327         up_read(&fw_device_rwsem);
 328
 329         return ret;
 330 }
 331
 332 #define TEXT_LEAF_ATTR(name, key)                               \
 333         { __ATTR(name, S_IRUGO, show_text_leaf, NULL), key }
 334
 335 static struct config_rom_attribute config_rom_attributes[] = {
 336         IMMEDIATE_ATTR(vendor, CSR_VENDOR),
 337         IMMEDIATE_ATTR(hardware_version, CSR_HARDWARE_VERSION),
 338         IMMEDIATE_ATTR(specifier_id, CSR_SPECIFIER_ID),
 339         IMMEDIATE_ATTR(version, CSR_VERSION),
 340         IMMEDIATE_ATTR(model, CSR_MODEL),
 341         TEXT_LEAF_ATTR(vendor_name, CSR_VENDOR),
 342         TEXT_LEAF_ATTR(model_name, CSR_MODEL),
 343         TEXT_LEAF_ATTR(hardware_version_name, CSR_HARDWARE_VERSION),
 344 };
 345
 346 static void init_fw_attribute_group(struct device *dev,
 347                                     struct device_attribute *attrs,
 348                                     struct fw_attribute_group *group)
 349 {
 350         struct device_attribute *attr;
 351         int i, j;
 352
 353         for (j = 0; attrs[j].attr.name != NULL; j++)
 354                 group->attrs[j] = &attrs[j].attr;
 355
 356         for (i = 0; i < ARRAY_SIZE(config_rom_attributes); i++) {
 357                 attr = &config_rom_attributes[i].attr;
 358                 if (attr->show(dev, attr, NULL) < 0)
 359                         continue;
 360                 group->attrs[j++] = &attr->attr;
 361         }
 362
 363         group->attrs[j] = NULL;
 364         group->groups[0] = &group->group;
 365         group->groups[1] = NULL;
 366         group->group.attrs = group->attrs;
 367         dev->groups = (const struct attribute_group **) group->groups;
 368 }
 369
 370 static ssize_t modalias_show(struct device *dev,
 371                              struct device_attribute *attr, char *buf)
 372 {
 373         struct fw_unit *unit = fw_unit(dev);
 374         int length;
 375
 376         length = get_modalias(unit, buf, PAGE_SIZE);
 377         strcpy(buf + length, "\n");
 378
 379         return length + 1;
 380 }
 381
 382 static ssize_t rom_index_show(struct device *dev,
 383                               struct device_attribute *attr, char *buf)
 384 {
 385         struct fw_device *device = fw_device(dev->parent);
 386         struct fw_unit *unit = fw_unit(dev);
 387
 388         return snprintf(buf, PAGE_SIZE, "%d\n",
 389                         (int)(unit->directory - device->config_rom));
 390 }
 391
 392 static struct device_attribute fw_unit_attributes[] = {
 393         __ATTR_RO(modalias),
 394         __ATTR_RO(rom_index),
 395         __ATTR_NULL,
 396 };
 397
 398 static ssize_t config_rom_show(struct device *dev,
 399                                struct device_attribute *attr, char *buf)
 400 {
 401         struct fw_device *device = fw_device(dev);
 402         size_t length;
 403
 404         down_read(&fw_device_rwsem);
 405         length = device->config_rom_length * 4;
 406         memcpy(buf, device->config_rom, length);
 407         up_read(&fw_device_rwsem);
 408
 409         return length;
 410 }
 411
 412 static ssize_t guid_show(struct device *dev,
 413                          struct device_attribute *attr, char *buf)
 414 {
 415         struct fw_device *device = fw_device(dev);
 416         int ret;
 417
 418         down_read(&fw_device_rwsem);
 419         ret = snprintf(buf, PAGE_SIZE, "0x%08x%08x\n",
 420                        device->config_rom[3], device->config_rom[4]);
 421         up_read(&fw_device_rwsem);
 422
 423         return ret;
 424 }
 425
 426 static ssize_t is_local_show(struct device *dev,
 427                              struct device_attribute *attr, char *buf)
 428 {
 429         struct fw_device *device = fw_device(dev);
 430
 431         return sprintf(buf, "%u\n", device->is_local);
 432 }
 433
 434 static int units_sprintf(char *buf, const u32 *directory)
 435 {
 436         struct fw_csr_iterator ci;
 437         int key, value;
 438         int specifier_id = 0;
 439         int version = 0;
 440
 441         fw_csr_iterator_init(&ci, directory);
 442         while (fw_csr_iterator_next(&ci, &key, &value)) {
 443                 switch (key) {
 444                 case CSR_SPECIFIER_ID:
 445                         specifier_id = value;
 446                         break;
 447                 case CSR_VERSION:
 448                         version = value;
 449                         break;
 450                 }
 451         }
 452
 453         return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version);
 454 }
 455
 456 static ssize_t units_show(struct device *dev,
 457                           struct device_attribute *attr, char *buf)
 458 {
 459         struct fw_device *device = fw_device(dev);
 460         struct fw_csr_iterator ci;
 461         int key, value, i = 0;
 462
 463         down_read(&fw_device_rwsem);
 464         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 465         while (fw_csr_iterator_next(&ci, &key, &value)) {
 466                 if (key != (CSR_UNIT | CSR_DIRECTORY))
 467                         continue;
 468                 i += units_sprintf(&buf[i], ci.p + value - 1);
 469                 if (i >= PAGE_SIZE - (8 + 1 + 8 + 1))
 470                         break;
 471         }
 472         up_read(&fw_device_rwsem);
 473
 474         if (i)
 475                 buf[i - 1] = '\n';
 476
 477         return i;
 478 }
 479
 480 static struct device_attribute fw_device_attributes[] = {
 481         __ATTR_RO(config_rom),
 482         __ATTR_RO(guid),
 483         __ATTR_RO(is_local),
 484         __ATTR_RO(units),
 485         __ATTR_NULL,
 486 };
 487
 488 static int read_rom(struct fw_device *device,
 489                     int generation, int index, u32 *data)
 490 {
 491         u64 offset = (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4;
 492         int i, rcode;
 493
 494         /* device->node_id, accessed below, must not be older than generation */
 495         smp_rmb();
 496
 497         for (i = 10; i < 100; i += 10) {
 498                 rcode = fw_run_transaction(device->card,
 499                                 TCODE_READ_QUADLET_REQUEST, device->node_id,
 500                                 generation, device->max_speed, offset, data, 4);
 501                 if (rcode != RCODE_BUSY)
 502                         break;
 503                 msleep(i);
 504         }
 505         be32_to_cpus(data);
 506
 507         return rcode;
 508 }
 509
 510 #define MAX_CONFIG_ROM_SIZE 256
 511
 512 /*
 513  * Read the bus info block, perform a speed probe, and read all of the rest of
 514  * the config ROM.  We do all this with a cached bus generation.  If the bus
 515  * generation changes under us, read_config_rom will fail and get retried.
 516  * It's better to start all over in this case because the node from which we
 517  * are reading the ROM may have changed the ROM during the reset.
 518  * Returns either a result code or a negative error code.
 519  */
 520 static int read_config_rom(struct fw_device *device, int generation)
 521 {
 522         struct fw_card *card = device->card;
 523         const u32 *old_rom, *new_rom;
 524         u32 *rom, *stack;
 525         u32 sp, key;
 526         int i, end, length, ret;
 527
 528         rom = kmalloc(sizeof(*rom) * MAX_CONFIG_ROM_SIZE +
 529                       sizeof(*stack) * MAX_CONFIG_ROM_SIZE, GFP_KERNEL);
 530         if (rom == NULL)
 531                 return -ENOMEM;
 532
 533         stack = &rom[MAX_CONFIG_ROM_SIZE];
 534         memset(rom, 0, sizeof(*rom) * MAX_CONFIG_ROM_SIZE);
 535
 536         device->max_speed = SCODE_100;
 537
 538         /* First read the bus info block. */
 539         for (i = 0; i < 5; i++) {
 540                 ret = read_rom(device, generation, i, &rom[i]);
 541                 if (ret != RCODE_COMPLETE)
 542                         goto out;
 543                 /*
 544                  * As per IEEE1212 7.2, during initialization, devices can
 545                  * reply with a 0 for the first quadlet of the config
 546                  * rom to indicate that they are booting (for example,
 547                  * if the firmware is on the disk of a external
 548                  * harddisk).  In that case we just fail, and the
 549                  * retry mechanism will try again later.
 550                  */
 551                 if (i == 0 && rom[i] == 0) {
 552                         ret = RCODE_BUSY;
 553                         goto out;
 554                 }
 555         }
 556
 557         device->max_speed = device->node->max_speed;
 558
 559         /*
 560          * Determine the speed of
 561          *   - devices with link speed less than PHY speed,
 562          *   - devices with 1394b PHY (unless only connected to 1394a PHYs),
 563          *   - all devices if there are 1394b repeaters.
 564          * Note, we cannot use the bus info block's link_spd as starting point
 565          * because some buggy firmwares set it lower than necessary and because
 566          * 1394-1995 nodes do not have the field.
 567          */
 568         if ((rom[2] & 0x7) < device->max_speed ||
 569             device->max_speed == SCODE_BETA ||
 570             card->beta_repeaters_present) {
 571                 u32 dummy;
 572
 573                 /* for S1600 and S3200 */
 574                 if (device->max_speed == SCODE_BETA)
 575                         device->max_speed = card->link_speed;
 576
 577                 while (device->max_speed > SCODE_100) {
 578                         if (read_rom(device, generation, 0, &dummy) ==
 579                             RCODE_COMPLETE)
 580                                 break;
 581                         device->max_speed--;
 582                 }
 583         }
 584
 585         /*
 586          * Now parse the config rom.  The config rom is a recursive
 587          * directory structure so we parse it using a stack of
 588          * references to the blocks that make up the structure.  We
 589          * push a reference to the root directory on the stack to
 590          * start things off.
 591          */
 592         length = i;
 593         sp = 0;
 594         stack[sp++] = 0xc0000005;
 595         while (sp > 0) {
 596                 /*
 597                  * Pop the next block reference of the stack.  The
 598                  * lower 24 bits is the offset into the config rom,
 599                  * the upper 8 bits are the type of the reference the
 600                  * block.
 601                  */
 602                 key = stack[--sp];
 603                 i = key & 0xffffff;
 604                 if (WARN_ON(i >= MAX_CONFIG_ROM_SIZE)) {
 605                         ret = -ENXIO;
 606                         goto out;
 607                 }
 608
 609                 /* Read header quadlet for the block to get the length. */
 610                 ret = read_rom(device, generation, i, &rom[i]);
 611                 if (ret != RCODE_COMPLETE)
 612                         goto out;
 613                 end = i + (rom[i] >> 16) + 1;
 614                 if (end > MAX_CONFIG_ROM_SIZE) {
 615                         /*
 616                          * This block extends outside the config ROM which is
 617                          * a firmware bug.  Ignore this whole block, i.e.
 618                          * simply set a fake block length of 0.
 619                          */
 620                         fw_err(card, "skipped invalid ROM block %x at %llx\n",
 621                                rom[i],
 622                                i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 623                         rom[i] = 0;
 624                         end = i;
 625                 }
 626                 i++;
 627
 628                 /*
 629                  * Now read in the block.  If this is a directory
 630                  * block, check the entries as we read them to see if
 631                  * it references another block, and push it in that case.
 632                  */
 633                 for (; i < end; i++) {
 634                         ret = read_rom(device, generation, i, &rom[i]);
 635                         if (ret != RCODE_COMPLETE)
 636                                 goto out;
 637
 638                         if ((key >> 30) != 3 || (rom[i] >> 30) < 2)
 639                                 continue;
 640                         /*
 641                          * Offset points outside the ROM.  May be a firmware
 642                          * bug or an Extended ROM entry (IEEE 1212-2001 clause
 643                          * 7.7.18).  Simply overwrite this pointer here by a
 644                          * fake immediate entry so that later iterators over
 645                          * the ROM don't have to check offsets all the time.
 646                          */
 647                         if (i + (rom[i] & 0xffffff) >= MAX_CONFIG_ROM_SIZE) {
 648                                 fw_err(card,
 649                                        "skipped unsupported ROM entry %x at %llx\n",
 650                                        rom[i],
 651                                        i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 652                                 rom[i] = 0;
 653                                 continue;
 654                         }
 655                         stack[sp++] = i + rom[i];
 656                 }
 657                 if (length < i)
 658                         length = i;
 659         }
 660
 661         old_rom = device->config_rom;
 662         new_rom = kmemdup(rom, length * 4, GFP_KERNEL);
 663         if (new_rom == NULL) {
 664                 ret = -ENOMEM;
 665                 goto out;
 666         }
 667
 668         down_write(&fw_device_rwsem);
 669         device->config_rom = new_rom;
 670         device->config_rom_length = length;
 671         up_write(&fw_device_rwsem);
 672
 673         kfree(old_rom);
 674         ret = RCODE_COMPLETE;
 675         device->max_rec = rom[2] >> 12 & 0xf;
 676         device->cmc     = rom[2] >> 30 & 1;
 677         device->irmc    = rom[2] >> 31 & 1;
 678  out:
 679         kfree(rom);
 680
 681         return ret;
 682 }
 683
 684 static void fw_unit_release(struct device *dev)
 685 {
 686         struct fw_unit *unit = fw_unit(dev);
 687
 688         fw_device_put(fw_parent_device(unit));
 689         kfree(unit);
 690 }
 691
 692 static struct device_type fw_unit_type = {
 693         .uevent         = fw_unit_uevent,
 694         .release        = fw_unit_release,
 695 };
 696
 697 static bool is_fw_unit(struct device *dev)
 698 {
 699         return dev->type == &fw_unit_type;
 700 }
 701
 702 static void create_units(struct fw_device *device)
 703 {
 704         struct fw_csr_iterator ci;
 705         struct fw_unit *unit;
 706         int key, value, i;
 707
 708         i = 0;
 709         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 710         while (fw_csr_iterator_next(&ci, &key, &value)) {
 711                 if (key != (CSR_UNIT | CSR_DIRECTORY))
 712                         continue;
 713
 714                 /*
 715                  * Get the address of the unit directory and try to
 716                  * match the drivers id_tables against it.
 717                  */
 718                 unit = kzalloc(sizeof(*unit), GFP_KERNEL);
 719                 if (unit == NULL)
 720                         continue;
 721
 722                 unit->directory = ci.p + value - 1;
 723                 unit->device.bus = &fw_bus_type;
 724                 unit->device.type = &fw_unit_type;
 725                 unit->device.parent = &device->device;
 726                 dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++);
 727
 728                 BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) <
 729                                 ARRAY_SIZE(fw_unit_attributes) +
 730                                 ARRAY_SIZE(config_rom_attributes));
 731                 init_fw_attribute_group(&unit->device,
 732                                         fw_unit_attributes,
 733                                         &unit->attribute_group);
 734
 735                 if (device_register(&unit->device) < 0)
 736                         goto skip_unit;
 737
 738                 fw_device_get(device);
 739                 continue;
 740
 741         skip_unit:
 742                 kfree(unit);
 743         }
 744 }
 745
 746 static int shutdown_unit(struct device *device, void *data)
 747 {
 748         device_unregister(device);
 749
 750         return 0;
 751 }
 752
 753 /*
 754  * fw_device_rwsem acts as dual purpose mutex:
 755  *   - serializes accesses to fw_device_idr,
 756  *   - serializes accesses to fw_device.config_rom/.config_rom_length and
 757  *     fw_unit.directory, unless those accesses happen at safe occasions
 758  */
 759 DECLARE_RWSEM(fw_device_rwsem);
 760
 761 DEFINE_IDR(fw_device_idr);
 762 int fw_cdev_major;
 763
 764 struct fw_device *fw_device_get_by_devt(dev_t devt)
 765 {
 766         struct fw_device *device;
 767
 768         down_read(&fw_device_rwsem);
 769         device = idr_find(&fw_device_idr, MINOR(devt));
 770         if (device)
 771                 fw_device_get(device);
 772         up_read(&fw_device_rwsem);
 773
 774         return device;
 775 }
 776
 777 struct workqueue_struct *fw_workqueue;
 778 EXPORT_SYMBOL(fw_workqueue);
 779
 780 static void fw_schedule_device_work(struct fw_device *device,
 781                                     unsigned long delay)
 782 {
 783         queue_delayed_work(fw_workqueue, &device->work, delay);
 784 }
 785
 786 /*
 787  * These defines control the retry behavior for reading the config
 788  * rom.  It shouldn't be necessary to tweak these; if the device
 789  * doesn't respond to a config rom read within 10 seconds, it's not
 790  * going to respond at all.  As for the initial delay, a lot of
 791  * devices will be able to respond within half a second after bus
 792  * reset.  On the other hand, it's not really worth being more
 793  * aggressive than that, since it scales pretty well; if 10 devices
 794  * are plugged in, they're all getting read within one second.
 795  */
 796
 797 #define MAX_RETRIES     10
 798 #define RETRY_DELAY     (3 * HZ)
 799 #define INITIAL_DELAY   (HZ / 2)
 800 #define SHUTDOWN_DELAY  (2 * HZ)
 801
 802 static void fw_device_shutdown(struct work_struct *work)
 803 {
 804         struct fw_device *device =
 805                 container_of(work, struct fw_device, work.work);
 806         int minor = MINOR(device->device.devt);
 807
 808         if (time_before64(get_jiffies_64(),
 809                           device->card->reset_jiffies + SHUTDOWN_DELAY)
 810             && !list_empty(&device->card->link)) {
 811                 fw_schedule_device_work(device, SHUTDOWN_DELAY);
 812                 return;
 813         }
 814
 815         if (atomic_cmpxchg(&device->state,
 816                            FW_DEVICE_GONE,
 817                            FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE)
 818                 return;
 819
 820         fw_device_cdev_remove(device);
 821         device_for_each_child(&device->device, NULL, shutdown_unit);
 822         device_unregister(&device->device);
 823
 824         down_write(&fw_device_rwsem);
 825         idr_remove(&fw_device_idr, minor);
 826         up_write(&fw_device_rwsem);
 827
 828         fw_device_put(device);
 829 }
 830
 831 static void fw_device_release(struct device *dev)
 832 {
 833         struct fw_device *device = fw_device(dev);
 834         struct fw_card *card = device->card;
 835         unsigned long flags;
 836
 837         /*
 838          * Take the card lock so we don't set this to NULL while a
 839          * FW_NODE_UPDATED callback is being handled or while the
 840          * bus manager work looks at this node.
 841          */
 842         spin_lock_irqsave(&card->lock, flags);
 843         device->node->data = NULL;
 844         spin_unlock_irqrestore(&card->lock, flags);
 845
 846         fw_node_put(device->node);
 847         kfree(device->config_rom);
 848         kfree(device);
 849         fw_card_put(card);
 850 }
 851
 852 static struct device_type fw_device_type = {
 853         .release = fw_device_release,
 854 };
 855
 856 static bool is_fw_device(struct device *dev)
 857 {
 858         return dev->type == &fw_device_type;
 859 }
 860
 861 static int update_unit(struct device *dev, void *data)
 862 {
 863         struct fw_unit *unit = fw_unit(dev);
 864         struct fw_driver *driver = (struct fw_driver *)dev->driver;
 865
 866         if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) {
 867                 device_lock(dev);
 868                 driver->update(unit);
 869                 device_unlock(dev);
 870         }
 871
 872         return 0;
 873 }
 874
 875 static void fw_device_update(struct work_struct *work)
 876 {
 877         struct fw_device *device =
 878                 container_of(work, struct fw_device, work.work);
 879
 880         fw_device_cdev_update(device);
 881         device_for_each_child(&device->device, NULL, update_unit);
 882 }
 883
 884 /*
 885  * If a device was pending for deletion because its node went away but its
 886  * bus info block and root directory header matches that of a newly discovered
 887  * device, revive the existing fw_device.
 888  * The newly allocated fw_device becomes obsolete instead.
 889  */
 890 static int lookup_existing_device(struct device *dev, void *data)
 891 {
 892         struct fw_device *old = fw_device(dev);
 893         struct fw_device *new = data;
 894         struct fw_card *card = new->card;
 895         int match = 0;
 896
 897         if (!is_fw_device(dev))
 898                 return 0;
 899
 900         down_read(&fw_device_rwsem); /* serialize config_rom access */
 901         spin_lock_irq(&card->lock);  /* serialize node access */
 902
 903         if (memcmp(old->config_rom, new->config_rom, 6 * 4) == 0 &&
 904             atomic_cmpxchg(&old->state,
 905                            FW_DEVICE_GONE,
 906                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
 907                 struct fw_node *current_node = new->node;
 908                 struct fw_node *obsolete_node = old->node;
 909
 910                 new->node = obsolete_node;
 911                 new->node->data = new;
 912                 old->node = current_node;
 913                 old->node->data = old;
 914
 915                 old->max_speed = new->max_speed;
 916                 old->node_id = current_node->node_id;
 917                 smp_wmb();  /* update node_id before generation */
 918                 old->generation = card->generation;
 919                 old->config_rom_retries = 0;
 920                 fw_notice(card, "rediscovered device %s\n", dev_name(dev));
 921
 922                 old->workfn = fw_device_update;
 923                 fw_schedule_device_work(old, 0);
 924
 925                 if (current_node == card->root_node)
 926                         fw_schedule_bm_work(card, 0);
 927
 928                 match = 1;
 929         }
 930
 931         spin_unlock_irq(&card->lock);
 932         up_read(&fw_device_rwsem);
 933
 934         return match;
 935 }
 936
 937 enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, };
 938
 939 static void set_broadcast_channel(struct fw_device *device, int generation)
 940 {
 941         struct fw_card *card = device->card;
 942         __be32 data;
 943         int rcode;
 944
 945         if (!card->broadcast_channel_allocated)
 946                 return;
 947
 948         /*
 949          * The Broadcast_Channel Valid bit is required by nodes which want to
 950          * transmit on this channel.  Such transmissions are practically
 951          * exclusive to IP over 1394 (RFC 2734).  IP capable nodes are required
 952          * to be IRM capable and have a max_rec of 8 or more.  We use this fact
 953          * to narrow down to which nodes we send Broadcast_Channel updates.
 954          */
 955         if (!device->irmc || device->max_rec < 8)
 956                 return;
 957
 958         /*
 959          * Some 1394-1995 nodes crash if this 1394a-2000 register is written.
 960          * Perform a read test first.
 961          */
 962         if (device->bc_implemented == BC_UNKNOWN) {
 963                 rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST,
 964                                 device->node_id, generation, device->max_speed,
 965                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 966                                 &data, 4);
 967                 switch (rcode) {
 968                 case RCODE_COMPLETE:
 969                         if (data & cpu_to_be32(1 << 31)) {
 970                                 device->bc_implemented = BC_IMPLEMENTED;
 971                                 break;
 972                         }
 973                         /* else fall through to case address error */
 974                 case RCODE_ADDRESS_ERROR:
 975                         device->bc_implemented = BC_UNIMPLEMENTED;
 976                 }
 977         }
 978
 979         if (device->bc_implemented == BC_IMPLEMENTED) {
 980                 data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL |
 981                                    BROADCAST_CHANNEL_VALID);
 982                 fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
 983                                 device->node_id, generation, device->max_speed,
 984                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 985                                 &data, 4);
 986         }
 987 }
 988
 989 int fw_device_set_broadcast_channel(struct device *dev, void *gen)
 990 {
 991         if (is_fw_device(dev))
 992                 set_broadcast_channel(fw_device(dev), (long)gen);
 993
 994         return 0;
 995 }
 996
 997 static void fw_device_init(struct work_struct *work)
 998 {
 999         struct fw_device *device =
1000                 container_of(work, struct fw_device, work.work);
1001         struct fw_card *card = device->card;
1002         struct device *revived_dev;
1003         int minor, ret;
1004
1005         /*
1006          * All failure paths here set node->data to NULL, so that we
1007          * don't try to do device_for_each_child() on a kfree()'d
1008          * device.
1009          */
1010
1011         ret = read_config_rom(device, device->generation);
1012         if (ret != RCODE_COMPLETE) {
1013                 if (device->config_rom_retries < MAX_RETRIES &&
1014                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1015                         device->config_rom_retries++;
1016                         fw_schedule_device_work(device, RETRY_DELAY);
1017                 } else {
1018                         if (device->node->link_on)
1019                                 fw_notice(card, "giving up on node %x: reading config rom failed: %s\n",
1020                                           device->node_id,
1021                                           fw_rcode_string(ret));
1022                         if (device->node == card->root_node)
1023                                 fw_schedule_bm_work(card, 0);
1024                         fw_device_release(&device->device);
1025                 }
1026                 return;
1027         }
1028
1029         revived_dev = device_find_child(card->device,
1030                                         device, lookup_existing_device);
1031         if (revived_dev) {
1032                 put_device(revived_dev);
1033                 fw_device_release(&device->device);
1034
1035                 return;
1036         }
1037
1038         device_initialize(&device->device);
1039
1040         fw_device_get(device);
1041         down_write(&fw_device_rwsem);
1042         minor = idr_alloc(&fw_device_idr, device, 0, 1 << MINORBITS,
1043                         GFP_KERNEL);
1044         up_write(&fw_device_rwsem);
1045
1046         if (minor < 0)
1047                 goto error;
1048
1049         device->device.bus = &fw_bus_type;
1050         device->device.type = &fw_device_type;
1051         device->device.parent = card->device;
1052         device->device.devt = MKDEV(fw_cdev_major, minor);
1053         dev_set_name(&device->device, "fw%d", minor);
1054
1055         BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) <
1056                         ARRAY_SIZE(fw_device_attributes) +
1057                         ARRAY_SIZE(config_rom_attributes));
1058         init_fw_attribute_group(&device->device,
1059                                 fw_device_attributes,
1060                                 &device->attribute_group);
1061
1062         if (device_add(&device->device)) {
1063                 fw_err(card, "failed to add device\n");
1064                 goto error_with_cdev;
1065         }
1066
1067         create_units(device);
1068
1069         /*
1070          * Transition the device to running state.  If it got pulled
1071          * out from under us while we did the intialization work, we
1072          * have to shut down the device again here.  Normally, though,
1073          * fw_node_event will be responsible for shutting it down when
1074          * necessary.  We have to use the atomic cmpxchg here to avoid
1075          * racing with the FW_NODE_DESTROYED case in
1076          * fw_node_event().
1077          */
1078         if (atomic_cmpxchg(&device->state,
1079                            FW_DEVICE_INITIALIZING,
1080                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
1081                 device->workfn = fw_device_shutdown;
1082                 fw_schedule_device_work(device, SHUTDOWN_DELAY);
1083         } else {
1084                 fw_notice(card, "created device %s: GUID %08x%08x, S%d00\n",
1085                           dev_name(&device->device),
1086                           device->config_rom[3], device->config_rom[4],
1087                           1 << device->max_speed);
1088                 device->config_rom_retries = 0;
1089
1090                 set_broadcast_channel(device, device->generation);
1091
1092                 add_device_randomness(&device->config_rom[3], 8);
1093         }
1094
1095         /*
1096          * Reschedule the IRM work if we just finished reading the
1097          * root node config rom.  If this races with a bus reset we
1098          * just end up running the IRM work a couple of extra times -
1099          * pretty harmless.
1100          */
1101         if (device->node == card->root_node)
1102                 fw_schedule_bm_work(card, 0);
1103
1104         return;
1105
1106  error_with_cdev:
1107         down_write(&fw_device_rwsem);
1108         idr_remove(&fw_device_idr, minor);
1109         up_write(&fw_device_rwsem);
1110  error:
1111         fw_device_put(device);          /* fw_device_idr's reference */
1112
1113         put_device(&device->device);    /* our reference */
1114 }
1115
1116 /* Reread and compare bus info block and header of root directory */
1117 static int reread_config_rom(struct fw_device *device, int generation,
1118                              bool *changed)
1119 {
1120         u32 q;
1121         int i, rcode;
1122
1123         for (i = 0; i < 6; i++) {
1124                 rcode = read_rom(device, generation, i, &q);
1125                 if (rcode != RCODE_COMPLETE)
1126                         return rcode;
1127
1128                 if (i == 0 && q == 0)
1129                         /* inaccessible (see read_config_rom); retry later */
1130                         return RCODE_BUSY;
1131
1132                 if (q != device->config_rom[i]) {
1133                         *changed = true;
1134                         return RCODE_COMPLETE;
1135                 }
1136         }
1137
1138         *changed = false;
1139         return RCODE_COMPLETE;
1140 }
1141
1142 static void fw_device_refresh(struct work_struct *work)
1143 {
1144         struct fw_device *device =
1145                 container_of(work, struct fw_device, work.work);
1146         struct fw_card *card = device->card;
1147         int ret, node_id = device->node_id;
1148         bool changed;
1149
1150         ret = reread_config_rom(device, device->generation, &changed);
1151         if (ret != RCODE_COMPLETE)
1152                 goto failed_config_rom;
1153
1154         if (!changed) {
1155                 if (atomic_cmpxchg(&device->state,
1156                                    FW_DEVICE_INITIALIZING,
1157                                    FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1158                         goto gone;
1159
1160                 fw_device_update(work);
1161                 device->config_rom_retries = 0;
1162                 goto out;
1163         }
1164
1165         /*
1166          * Something changed.  We keep things simple and don't investigate
1167          * further.  We just destroy all previous units and create new ones.
1168          */
1169         device_for_each_child(&device->device, NULL, shutdown_unit);
1170
1171         ret = read_config_rom(device, device->generation);
1172         if (ret != RCODE_COMPLETE)
1173                 goto failed_config_rom;
1174
1175         fw_device_cdev_update(device);
1176         create_units(device);
1177
1178         /* Userspace may want to re-read attributes. */
1179         kobject_uevent(&device->device.kobj, KOBJ_CHANGE);
1180
1181         if (atomic_cmpxchg(&device->state,
1182                            FW_DEVICE_INITIALIZING,
1183                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1184                 goto gone;
1185
1186         fw_notice(card, "refreshed device %s\n", dev_name(&device->device));
1187         device->config_rom_retries = 0;
1188         goto out;
1189
1190  failed_config_rom:
1191         if (device->config_rom_retries < MAX_RETRIES &&
1192             atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1193                 device->config_rom_retries++;
1194                 fw_schedule_device_work(device, RETRY_DELAY);
1195                 return;
1196         }
1197
1198         fw_notice(card, "giving up on refresh of device %s: %s\n",
1199                   dev_name(&device->device), fw_rcode_string(ret));
1200  gone:
1201         atomic_set(&device->state, FW_DEVICE_GONE);
1202         device->workfn = fw_device_shutdown;
1203         fw_schedule_device_work(device, SHUTDOWN_DELAY);
1204  out:
1205         if (node_id == card->root_node->node_id)
1206                 fw_schedule_bm_work(card, 0);
1207 }
1208
1209 static void fw_device_workfn(struct work_struct *work)
1210 {
1211         struct fw_device *device = container_of(to_delayed_work(work),
1212                                                 struct fw_device, work);
1213         device->workfn(work);
1214 }
1215
1216 void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
1217 {
1218         struct fw_device *device;
1219
1220         switch (event) {
1221         case FW_NODE_CREATED:
1222                 /*
1223                  * Attempt to scan the node, regardless whether its self ID has
1224                  * the L (link active) flag set or not.  Some broken devices
1225                  * send L=0 but have an up-and-running link; others send L=1
1226                  * without actually having a link.
1227                  */
1228  create:
1229                 device = kzalloc(sizeof(*device), GFP_ATOMIC);
1230                 if (device == NULL)
1231                         break;
1232
1233                 /*
1234                  * Do minimal intialization of the device here, the
1235                  * rest will happen in fw_device_init().
1236                  *
1237                  * Attention:  A lot of things, even fw_device_get(),
1238                  * cannot be done before fw_device_init() finished!
1239                  * You can basically just check device->state and
1240                  * schedule work until then, but only while holding
1241                  * card->lock.
1242                  */
1243                 atomic_set(&device->state, FW_DEVICE_INITIALIZING);
1244                 device->card = fw_card_get(card);
1245                 device->node = fw_node_get(node);
1246                 device->node_id = node->node_id;
1247                 device->generation = card->generation;
1248                 device->is_local = node == card->local_node;
1249                 mutex_init(&device->client_list_mutex);
1250                 INIT_LIST_HEAD(&device->client_list);
1251
1252                 /*
1253                  * Set the node data to point back to this device so
1254                  * FW_NODE_UPDATED callbacks can update the node_id
1255                  * and generation for the device.
1256                  */
1257                 node->data = device;
1258
1259                 /*
1260                  * Many devices are slow to respond after bus resets,
1261                  * especially if they are bus powered and go through
1262                  * power-up after getting plugged in.  We schedule the
1263                  * first config rom scan half a second after bus reset.
1264                  */
1265                 device->workfn = fw_device_init;
1266                 INIT_DELAYED_WORK(&device->work, fw_device_workfn);
1267                 fw_schedule_device_work(device, INITIAL_DELAY);
1268                 break;
1269
1270         case FW_NODE_INITIATED_RESET:
1271         case FW_NODE_LINK_ON:
1272                 device = node->data;
1273                 if (device == NULL)
1274                         goto create;
1275
1276                 device->node_id = node->node_id;
1277                 smp_wmb();  /* update node_id before generation */
1278                 device->generation = card->generation;
1279                 if (atomic_cmpxchg(&device->state,
1280                             FW_DEVICE_RUNNING,
1281                             FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) {
1282                         device->workfn = fw_device_refresh;
1283                         fw_schedule_device_work(device,
1284                                 device->is_local ? 0 : INITIAL_DELAY);
1285                 }
1286                 break;
1287
1288         case FW_NODE_UPDATED:
1289                 device = node->data;
1290                 if (device == NULL)
1291                         break;
1292
1293                 device->node_id = node->node_id;
1294                 smp_wmb();  /* update node_id before generation */
1295                 device->generation = card->generation;
1296                 if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
1297                         device->workfn = fw_device_update;
1298                         fw_schedule_device_work(device, 0);
1299                 }
1300                 break;
1301
1302         case FW_NODE_DESTROYED:
1303         case FW_NODE_LINK_OFF:
1304                 if (!node->data)
1305                         break;
1306
1307                 /*
1308                  * Destroy the device associated with the node.  There
1309                  * are two cases here: either the device is fully
1310                  * initialized (FW_DEVICE_RUNNING) or we're in the
1311                  * process of reading its config rom
1312                  * (FW_DEVICE_INITIALIZING).  If it is fully
1313                  * initialized we can reuse device->work to schedule a
1314                  * full fw_device_shutdown().  If not, there's work
1315                  * scheduled to read it's config rom, and we just put
1316                  * the device in shutdown state to have that code fail
1317                  * to create the device.
1318                  */
1319                 device = node->data;
1320                 if (atomic_xchg(&device->state,
1321                                 FW_DEVICE_GONE) == FW_DEVICE_RUNNING) {
1322                         device->workfn = fw_device_shutdown;
1323                         fw_schedule_device_work(device,
1324                                 list_empty(&card->link) ? 0 : SHUTDOWN_DELAY);
1325                 }
1326                 break;
1327         }
1328 }