drivers/firewire/core-device.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Device probing and sysfs code.
   4  *
   5  * Copyright (C) 2005-2006  Kristian Hoegsberg <krh@bitplanet.net>
   6  */
   7
   8 #include <linux/bug.h>
   9 #include <linux/ctype.h>
  10 #include <linux/delay.h>
  11 #include <linux/device.h>
  12 #include <linux/errno.h>
  13 #include <linux/firewire.h>
  14 #include <linux/firewire-constants.h>
  15 #include <linux/idr.h>
  16 #include <linux/jiffies.h>
  17 #include <linux/kobject.h>
  18 #include <linux/list.h>
  19 #include <linux/mod_devicetable.h>
  20 #include <linux/module.h>
  21 #include <linux/mutex.h>
  22 #include <linux/random.h>
  23 #include <linux/rwsem.h>
  24 #include <linux/slab.h>
  25 #include <linux/spinlock.h>
  26 #include <linux/string.h>
  27 #include <linux/workqueue.h>
  28
  29 #include <linux/atomic.h>
  30 #include <asm/byteorder.h>
  31
  32 #include "core.h"
  33
  34 void fw_csr_iterator_init(struct fw_csr_iterator *ci, const u32 *p)
  35 {
  36         ci->p = p + 1;
  37         ci->end = ci->p + (p[0] >> 16);
  38 }
  39 EXPORT_SYMBOL(fw_csr_iterator_init);
  40
  41 int fw_csr_iterator_next(struct fw_csr_iterator *ci, int *key, int *value)
  42 {
  43         *key = *ci->p >> 24;
  44         *value = *ci->p & 0xffffff;
  45
  46         return ci->p++ < ci->end;
  47 }
  48 EXPORT_SYMBOL(fw_csr_iterator_next);
  49
  50 static const u32 *search_leaf(const u32 *directory, int search_key)
  51 {
  52         struct fw_csr_iterator ci;
  53         int last_key = 0, key, value;
  54
  55         fw_csr_iterator_init(&ci, directory);
  56         while (fw_csr_iterator_next(&ci, &key, &value)) {
  57                 if (last_key == search_key &&
  58                     key == (CSR_DESCRIPTOR | CSR_LEAF))
  59                         return ci.p - 1 + value;
  60
  61                 last_key = key;
  62         }
  63
  64         return NULL;
  65 }
  66
  67 static int textual_leaf_to_string(const u32 *block, char *buf, size_t size)
  68 {
  69         unsigned int quadlets, i;
  70         char c;
  71
  72         if (!size || !buf)
  73                 return -EINVAL;
  74
  75         quadlets = min(block[0] >> 16, 256U);
  76         if (quadlets < 2)
  77                 return -ENODATA;
  78
  79         if (block[1] != 0 || block[2] != 0)
  80                 /* unknown language/character set */
  81                 return -ENODATA;
  82
  83         block += 3;
  84         quadlets -= 2;
  85         for (i = 0; i < quadlets * 4 && i < size - 1; i++) {
  86                 c = block[i / 4] >> (24 - 8 * (i % 4));
  87                 if (c == '\0')
  88                         break;
  89                 buf[i] = c;
  90         }
  91         buf[i] = '\0';
  92
  93         return i;
  94 }
  95
  96 /**
  97  * fw_csr_string() - reads a string from the configuration ROM
  98  * @directory:  e.g. root directory or unit directory
  99  * @key:        the key of the preceding directory entry
 100  * @buf:        where to put the string
 101  * @size:       size of @buf, in bytes
 102  *
 103  * The string is taken from a minimal ASCII text descriptor leaf after
 104  * the immediate entry with @key.  The string is zero-terminated.
 105  * An overlong string is silently truncated such that it and the
 106  * zero byte fit into @size.
 107  *
 108  * Returns strlen(buf) or a negative error code.
 109  */
 110 int fw_csr_string(const u32 *directory, int key, char *buf, size_t size)
 111 {
 112         const u32 *leaf = search_leaf(directory, key);
 113         if (!leaf)
 114                 return -ENOENT;
 115
 116         return textual_leaf_to_string(leaf, buf, size);
 117 }
 118 EXPORT_SYMBOL(fw_csr_string);
 119
 120 static void get_ids(const u32 *directory, int *id)
 121 {
 122         struct fw_csr_iterator ci;
 123         int key, value;
 124
 125         fw_csr_iterator_init(&ci, directory);
 126         while (fw_csr_iterator_next(&ci, &key, &value)) {
 127                 switch (key) {
 128                 case CSR_VENDOR:        id[0] = value; break;
 129                 case CSR_MODEL:         id[1] = value; break;
 130                 case CSR_SPECIFIER_ID:  id[2] = value; break;
 131                 case CSR_VERSION:       id[3] = value; break;
 132                 }
 133         }
 134 }
 135
 136 static void get_modalias_ids(const struct fw_unit *unit, int *id)
 137 {
 138         get_ids(&fw_parent_device(unit)->config_rom[5], id);
 139         get_ids(unit->directory, id);
 140 }
 141
 142 static bool match_ids(const struct ieee1394_device_id *id_table, int *id)
 143 {
 144         int match = 0;
 145
 146         if (id[0] == id_table->vendor_id)
 147                 match |= IEEE1394_MATCH_VENDOR_ID;
 148         if (id[1] == id_table->model_id)
 149                 match |= IEEE1394_MATCH_MODEL_ID;
 150         if (id[2] == id_table->specifier_id)
 151                 match |= IEEE1394_MATCH_SPECIFIER_ID;
 152         if (id[3] == id_table->version)
 153                 match |= IEEE1394_MATCH_VERSION;
 154
 155         return (match & id_table->match_flags) == id_table->match_flags;
 156 }
 157
 158 static const struct ieee1394_device_id *unit_match(struct device *dev,
 159                                                    struct device_driver *drv)
 160 {
 161         const struct ieee1394_device_id *id_table =
 162                         container_of(drv, struct fw_driver, driver)->id_table;
 163         int id[] = {0, 0, 0, 0};
 164
 165         get_modalias_ids(fw_unit(dev), id);
 166
 167         for (; id_table->match_flags != 0; id_table++)
 168                 if (match_ids(id_table, id))
 169                         return id_table;
 170
 171         return NULL;
 172 }
 173
 174 static bool is_fw_unit(struct device *dev);
 175
 176 static int fw_unit_match(struct device *dev, struct device_driver *drv)
 177 {
 178         /* We only allow binding to fw_units. */
 179         return is_fw_unit(dev) && unit_match(dev, drv) != NULL;
 180 }
 181
 182 static int fw_unit_probe(struct device *dev)
 183 {
 184         struct fw_driver *driver =
 185                         container_of(dev->driver, struct fw_driver, driver);
 186
 187         return driver->probe(fw_unit(dev), unit_match(dev, dev->driver));
 188 }
 189
 190 static void fw_unit_remove(struct device *dev)
 191 {
 192         struct fw_driver *driver =
 193                         container_of(dev->driver, struct fw_driver, driver);
 194
 195         driver->remove(fw_unit(dev));
 196 }
 197
 198 static int get_modalias(const struct fw_unit *unit, char *buffer, size_t buffer_size)
 199 {
 200         int id[] = {0, 0, 0, 0};
 201
 202         get_modalias_ids(unit, id);
 203
 204         return snprintf(buffer, buffer_size,
 205                         "ieee1394:ven%08Xmo%08Xsp%08Xver%08X",
 206                         id[0], id[1], id[2], id[3]);
 207 }
 208
 209 static int fw_unit_uevent(const struct device *dev, struct kobj_uevent_env *env)
 210 {
 211         const struct fw_unit *unit = fw_unit(dev);
 212         char modalias[64];
 213
 214         get_modalias(unit, modalias, sizeof(modalias));
 215
 216         if (add_uevent_var(env, "MODALIAS=%s", modalias))
 217                 return -ENOMEM;
 218
 219         return 0;
 220 }
 221
 222 struct bus_type fw_bus_type = {
 223         .name = "firewire",
 224         .match = fw_unit_match,
 225         .probe = fw_unit_probe,
 226         .remove = fw_unit_remove,
 227 };
 228 EXPORT_SYMBOL(fw_bus_type);
 229
 230 int fw_device_enable_phys_dma(struct fw_device *device)
 231 {
 232         int generation = device->generation;
 233
 234         /* device->node_id, accessed below, must not be older than generation */
 235         smp_rmb();
 236
 237         return device->card->driver->enable_phys_dma(device->card,
 238                                                      device->node_id,
 239                                                      generation);
 240 }
 241 EXPORT_SYMBOL(fw_device_enable_phys_dma);
 242
 243 struct config_rom_attribute {
 244         struct device_attribute attr;
 245         u32 key;
 246 };
 247
 248 static ssize_t show_immediate(struct device *dev,
 249                               struct device_attribute *dattr, char *buf)
 250 {
 251         struct config_rom_attribute *attr =
 252                 container_of(dattr, struct config_rom_attribute, attr);
 253         struct fw_csr_iterator ci;
 254         const u32 *dir;
 255         int key, value, ret = -ENOENT;
 256
 257         down_read(&fw_device_rwsem);
 258
 259         if (is_fw_unit(dev))
 260                 dir = fw_unit(dev)->directory;
 261         else
 262                 dir = fw_device(dev)->config_rom + 5;
 263
 264         fw_csr_iterator_init(&ci, dir);
 265         while (fw_csr_iterator_next(&ci, &key, &value))
 266                 if (attr->key == key) {
 267                         ret = snprintf(buf, buf ? PAGE_SIZE : 0,
 268                                        "0x%06x\n", value);
 269                         break;
 270                 }
 271
 272         up_read(&fw_device_rwsem);
 273
 274         return ret;
 275 }
 276
 277 #define IMMEDIATE_ATTR(name, key)                               \
 278         { __ATTR(name, S_IRUGO, show_immediate, NULL), key }
 279
 280 static ssize_t show_text_leaf(struct device *dev,
 281                               struct device_attribute *dattr, char *buf)
 282 {
 283         struct config_rom_attribute *attr =
 284                 container_of(dattr, struct config_rom_attribute, attr);
 285         const u32 *dir;
 286         size_t bufsize;
 287         char dummy_buf[2];
 288         int ret;
 289
 290         down_read(&fw_device_rwsem);
 291
 292         if (is_fw_unit(dev))
 293                 dir = fw_unit(dev)->directory;
 294         else
 295                 dir = fw_device(dev)->config_rom + 5;
 296
 297         if (buf) {
 298                 bufsize = PAGE_SIZE - 1;
 299         } else {
 300                 buf = dummy_buf;
 301                 bufsize = 1;
 302         }
 303
 304         ret = fw_csr_string(dir, attr->key, buf, bufsize);
 305
 306         if (ret >= 0) {
 307                 /* Strip trailing whitespace and add newline. */
 308                 while (ret > 0 && isspace(buf[ret - 1]))
 309                         ret--;
 310                 strcpy(buf + ret, "\n");
 311                 ret++;
 312         }
 313
 314         up_read(&fw_device_rwsem);
 315
 316         return ret;
 317 }
 318
 319 #define TEXT_LEAF_ATTR(name, key)                               \
 320         { __ATTR(name, S_IRUGO, show_text_leaf, NULL), key }
 321
 322 static struct config_rom_attribute config_rom_attributes[] = {
 323         IMMEDIATE_ATTR(vendor, CSR_VENDOR),
 324         IMMEDIATE_ATTR(hardware_version, CSR_HARDWARE_VERSION),
 325         IMMEDIATE_ATTR(specifier_id, CSR_SPECIFIER_ID),
 326         IMMEDIATE_ATTR(version, CSR_VERSION),
 327         IMMEDIATE_ATTR(model, CSR_MODEL),
 328         TEXT_LEAF_ATTR(vendor_name, CSR_VENDOR),
 329         TEXT_LEAF_ATTR(model_name, CSR_MODEL),
 330         TEXT_LEAF_ATTR(hardware_version_name, CSR_HARDWARE_VERSION),
 331 };
 332
 333 static void init_fw_attribute_group(struct device *dev,
 334                                     struct device_attribute *attrs,
 335                                     struct fw_attribute_group *group)
 336 {
 337         struct device_attribute *attr;
 338         int i, j;
 339
 340         for (j = 0; attrs[j].attr.name != NULL; j++)
 341                 group->attrs[j] = &attrs[j].attr;
 342
 343         for (i = 0; i < ARRAY_SIZE(config_rom_attributes); i++) {
 344                 attr = &config_rom_attributes[i].attr;
 345                 if (attr->show(dev, attr, NULL) < 0)
 346                         continue;
 347                 group->attrs[j++] = &attr->attr;
 348         }
 349
 350         group->attrs[j] = NULL;
 351         group->groups[0] = &group->group;
 352         group->groups[1] = NULL;
 353         group->group.attrs = group->attrs;
 354         dev->groups = (const struct attribute_group **) group->groups;
 355 }
 356
 357 static ssize_t modalias_show(struct device *dev,
 358                              struct device_attribute *attr, char *buf)
 359 {
 360         struct fw_unit *unit = fw_unit(dev);
 361         int length;
 362
 363         length = get_modalias(unit, buf, PAGE_SIZE);
 364         strcpy(buf + length, "\n");
 365
 366         return length + 1;
 367 }
 368
 369 static ssize_t rom_index_show(struct device *dev,
 370                               struct device_attribute *attr, char *buf)
 371 {
 372         struct fw_device *device = fw_device(dev->parent);
 373         struct fw_unit *unit = fw_unit(dev);
 374
 375         return sysfs_emit(buf, "%td\n", unit->directory - device->config_rom);
 376 }
 377
 378 static struct device_attribute fw_unit_attributes[] = {
 379         __ATTR_RO(modalias),
 380         __ATTR_RO(rom_index),
 381         __ATTR_NULL,
 382 };
 383
 384 static ssize_t config_rom_show(struct device *dev,
 385                                struct device_attribute *attr, char *buf)
 386 {
 387         struct fw_device *device = fw_device(dev);
 388         size_t length;
 389
 390         down_read(&fw_device_rwsem);
 391         length = device->config_rom_length * 4;
 392         memcpy(buf, device->config_rom, length);
 393         up_read(&fw_device_rwsem);
 394
 395         return length;
 396 }
 397
 398 static ssize_t guid_show(struct device *dev,
 399                          struct device_attribute *attr, char *buf)
 400 {
 401         struct fw_device *device = fw_device(dev);
 402         int ret;
 403
 404         down_read(&fw_device_rwsem);
 405         ret = sysfs_emit(buf, "0x%08x%08x\n", device->config_rom[3], device->config_rom[4]);
 406         up_read(&fw_device_rwsem);
 407
 408         return ret;
 409 }
 410
 411 static ssize_t is_local_show(struct device *dev,
 412                              struct device_attribute *attr, char *buf)
 413 {
 414         struct fw_device *device = fw_device(dev);
 415
 416         return sprintf(buf, "%u\n", device->is_local);
 417 }
 418
 419 static int units_sprintf(char *buf, const u32 *directory)
 420 {
 421         struct fw_csr_iterator ci;
 422         int key, value;
 423         int specifier_id = 0;
 424         int version = 0;
 425
 426         fw_csr_iterator_init(&ci, directory);
 427         while (fw_csr_iterator_next(&ci, &key, &value)) {
 428                 switch (key) {
 429                 case CSR_SPECIFIER_ID:
 430                         specifier_id = value;
 431                         break;
 432                 case CSR_VERSION:
 433                         version = value;
 434                         break;
 435                 }
 436         }
 437
 438         return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version);
 439 }
 440
 441 static ssize_t units_show(struct device *dev,
 442                           struct device_attribute *attr, char *buf)
 443 {
 444         struct fw_device *device = fw_device(dev);
 445         struct fw_csr_iterator ci;
 446         int key, value, i = 0;
 447
 448         down_read(&fw_device_rwsem);
 449         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 450         while (fw_csr_iterator_next(&ci, &key, &value)) {
 451                 if (key != (CSR_UNIT | CSR_DIRECTORY))
 452                         continue;
 453                 i += units_sprintf(&buf[i], ci.p + value - 1);
 454                 if (i >= PAGE_SIZE - (8 + 1 + 8 + 1))
 455                         break;
 456         }
 457         up_read(&fw_device_rwsem);
 458
 459         if (i)
 460                 buf[i - 1] = '\n';
 461
 462         return i;
 463 }
 464
 465 static struct device_attribute fw_device_attributes[] = {
 466         __ATTR_RO(config_rom),
 467         __ATTR_RO(guid),
 468         __ATTR_RO(is_local),
 469         __ATTR_RO(units),
 470         __ATTR_NULL,
 471 };
 472
 473 static int read_rom(struct fw_device *device,
 474                     int generation, int index, u32 *data)
 475 {
 476         u64 offset = (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4;
 477         int i, rcode;
 478
 479         /* device->node_id, accessed below, must not be older than generation */
 480         smp_rmb();
 481
 482         for (i = 10; i < 100; i += 10) {
 483                 rcode = fw_run_transaction(device->card,
 484                                 TCODE_READ_QUADLET_REQUEST, device->node_id,
 485                                 generation, device->max_speed, offset, data, 4);
 486                 if (rcode != RCODE_BUSY)
 487                         break;
 488                 msleep(i);
 489         }
 490         be32_to_cpus(data);
 491
 492         return rcode;
 493 }
 494
 495 #define MAX_CONFIG_ROM_SIZE 256
 496
 497 /*
 498  * Read the bus info block, perform a speed probe, and read all of the rest of
 499  * the config ROM.  We do all this with a cached bus generation.  If the bus
 500  * generation changes under us, read_config_rom will fail and get retried.
 501  * It's better to start all over in this case because the node from which we
 502  * are reading the ROM may have changed the ROM during the reset.
 503  * Returns either a result code or a negative error code.
 504  */
 505 static int read_config_rom(struct fw_device *device, int generation)
 506 {
 507         struct fw_card *card = device->card;
 508         const u32 *old_rom, *new_rom;
 509         u32 *rom, *stack;
 510         u32 sp, key;
 511         int i, end, length, ret;
 512
 513         rom = kmalloc(sizeof(*rom) * MAX_CONFIG_ROM_SIZE +
 514                       sizeof(*stack) * MAX_CONFIG_ROM_SIZE, GFP_KERNEL);
 515         if (rom == NULL)
 516                 return -ENOMEM;
 517
 518         stack = &rom[MAX_CONFIG_ROM_SIZE];
 519         memset(rom, 0, sizeof(*rom) * MAX_CONFIG_ROM_SIZE);
 520
 521         device->max_speed = SCODE_100;
 522
 523         /* First read the bus info block. */
 524         for (i = 0; i < 5; i++) {
 525                 ret = read_rom(device, generation, i, &rom[i]);
 526                 if (ret != RCODE_COMPLETE)
 527                         goto out;
 528                 /*
 529                  * As per IEEE1212 7.2, during initialization, devices can
 530                  * reply with a 0 for the first quadlet of the config
 531                  * rom to indicate that they are booting (for example,
 532                  * if the firmware is on the disk of a external
 533                  * harddisk).  In that case we just fail, and the
 534                  * retry mechanism will try again later.
 535                  */
 536                 if (i == 0 && rom[i] == 0) {
 537                         ret = RCODE_BUSY;
 538                         goto out;
 539                 }
 540         }
 541
 542         device->max_speed = device->node->max_speed;
 543
 544         /*
 545          * Determine the speed of
 546          *   - devices with link speed less than PHY speed,
 547          *   - devices with 1394b PHY (unless only connected to 1394a PHYs),
 548          *   - all devices if there are 1394b repeaters.
 549          * Note, we cannot use the bus info block's link_spd as starting point
 550          * because some buggy firmwares set it lower than necessary and because
 551          * 1394-1995 nodes do not have the field.
 552          */
 553         if ((rom[2] & 0x7) < device->max_speed ||
 554             device->max_speed == SCODE_BETA ||
 555             card->beta_repeaters_present) {
 556                 u32 dummy;
 557
 558                 /* for S1600 and S3200 */
 559                 if (device->max_speed == SCODE_BETA)
 560                         device->max_speed = card->link_speed;
 561
 562                 while (device->max_speed > SCODE_100) {
 563                         if (read_rom(device, generation, 0, &dummy) ==
 564                             RCODE_COMPLETE)
 565                                 break;
 566                         device->max_speed--;
 567                 }
 568         }
 569
 570         /*
 571          * Now parse the config rom.  The config rom is a recursive
 572          * directory structure so we parse it using a stack of
 573          * references to the blocks that make up the structure.  We
 574          * push a reference to the root directory on the stack to
 575          * start things off.
 576          */
 577         length = i;
 578         sp = 0;
 579         stack[sp++] = 0xc0000005;
 580         while (sp > 0) {
 581                 /*
 582                  * Pop the next block reference of the stack.  The
 583                  * lower 24 bits is the offset into the config rom,
 584                  * the upper 8 bits are the type of the reference the
 585                  * block.
 586                  */
 587                 key = stack[--sp];
 588                 i = key & 0xffffff;
 589                 if (WARN_ON(i >= MAX_CONFIG_ROM_SIZE)) {
 590                         ret = -ENXIO;
 591                         goto out;
 592                 }
 593
 594                 /* Read header quadlet for the block to get the length. */
 595                 ret = read_rom(device, generation, i, &rom[i]);
 596                 if (ret != RCODE_COMPLETE)
 597                         goto out;
 598                 end = i + (rom[i] >> 16) + 1;
 599                 if (end > MAX_CONFIG_ROM_SIZE) {
 600                         /*
 601                          * This block extends outside the config ROM which is
 602                          * a firmware bug.  Ignore this whole block, i.e.
 603                          * simply set a fake block length of 0.
 604                          */
 605                         fw_err(card, "skipped invalid ROM block %x at %llx\n",
 606                                rom[i],
 607                                i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 608                         rom[i] = 0;
 609                         end = i;
 610                 }
 611                 i++;
 612
 613                 /*
 614                  * Now read in the block.  If this is a directory
 615                  * block, check the entries as we read them to see if
 616                  * it references another block, and push it in that case.
 617                  */
 618                 for (; i < end; i++) {
 619                         ret = read_rom(device, generation, i, &rom[i]);
 620                         if (ret != RCODE_COMPLETE)
 621                                 goto out;
 622
 623                         if ((key >> 30) != 3 || (rom[i] >> 30) < 2)
 624                                 continue;
 625                         /*
 626                          * Offset points outside the ROM.  May be a firmware
 627                          * bug or an Extended ROM entry (IEEE 1212-2001 clause
 628                          * 7.7.18).  Simply overwrite this pointer here by a
 629                          * fake immediate entry so that later iterators over
 630                          * the ROM don't have to check offsets all the time.
 631                          */
 632                         if (i + (rom[i] & 0xffffff) >= MAX_CONFIG_ROM_SIZE) {
 633                                 fw_err(card,
 634                                        "skipped unsupported ROM entry %x at %llx\n",
 635                                        rom[i],
 636                                        i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 637                                 rom[i] = 0;
 638                                 continue;
 639                         }
 640                         stack[sp++] = i + rom[i];
 641                 }
 642                 if (length < i)
 643                         length = i;
 644         }
 645
 646         old_rom = device->config_rom;
 647         new_rom = kmemdup(rom, length * 4, GFP_KERNEL);
 648         if (new_rom == NULL) {
 649                 ret = -ENOMEM;
 650                 goto out;
 651         }
 652
 653         down_write(&fw_device_rwsem);
 654         device->config_rom = new_rom;
 655         device->config_rom_length = length;
 656         up_write(&fw_device_rwsem);
 657
 658         kfree(old_rom);
 659         ret = RCODE_COMPLETE;
 660         device->max_rec = rom[2] >> 12 & 0xf;
 661         device->cmc     = rom[2] >> 30 & 1;
 662         device->irmc    = rom[2] >> 31 & 1;
 663  out:
 664         kfree(rom);
 665
 666         return ret;
 667 }
 668
 669 static void fw_unit_release(struct device *dev)
 670 {
 671         struct fw_unit *unit = fw_unit(dev);
 672
 673         fw_device_put(fw_parent_device(unit));
 674         kfree(unit);
 675 }
 676
 677 static struct device_type fw_unit_type = {
 678         .uevent         = fw_unit_uevent,
 679         .release        = fw_unit_release,
 680 };
 681
 682 static bool is_fw_unit(struct device *dev)
 683 {
 684         return dev->type == &fw_unit_type;
 685 }
 686
 687 static void create_units(struct fw_device *device)
 688 {
 689         struct fw_csr_iterator ci;
 690         struct fw_unit *unit;
 691         int key, value, i;
 692
 693         i = 0;
 694         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 695         while (fw_csr_iterator_next(&ci, &key, &value)) {
 696                 if (key != (CSR_UNIT | CSR_DIRECTORY))
 697                         continue;
 698
 699                 /*
 700                  * Get the address of the unit directory and try to
 701                  * match the drivers id_tables against it.
 702                  */
 703                 unit = kzalloc(sizeof(*unit), GFP_KERNEL);
 704                 if (unit == NULL)
 705                         continue;
 706
 707                 unit->directory = ci.p + value - 1;
 708                 unit->device.bus = &fw_bus_type;
 709                 unit->device.type = &fw_unit_type;
 710                 unit->device.parent = &device->device;
 711                 dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++);
 712
 713                 BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) <
 714                                 ARRAY_SIZE(fw_unit_attributes) +
 715                                 ARRAY_SIZE(config_rom_attributes));
 716                 init_fw_attribute_group(&unit->device,
 717                                         fw_unit_attributes,
 718                                         &unit->attribute_group);
 719
 720                 fw_device_get(device);
 721                 if (device_register(&unit->device) < 0) {
 722                         put_device(&unit->device);
 723                         continue;
 724                 }
 725         }
 726 }
 727
 728 static int shutdown_unit(struct device *device, void *data)
 729 {
 730         device_unregister(device);
 731
 732         return 0;
 733 }
 734
 735 /*
 736  * fw_device_rwsem acts as dual purpose mutex:
 737  *   - serializes accesses to fw_device_idr,
 738  *   - serializes accesses to fw_device.config_rom/.config_rom_length and
 739  *     fw_unit.directory, unless those accesses happen at safe occasions
 740  */
 741 DECLARE_RWSEM(fw_device_rwsem);
 742
 743 DEFINE_IDR(fw_device_idr);
 744 int fw_cdev_major;
 745
 746 struct fw_device *fw_device_get_by_devt(dev_t devt)
 747 {
 748         struct fw_device *device;
 749
 750         down_read(&fw_device_rwsem);
 751         device = idr_find(&fw_device_idr, MINOR(devt));
 752         if (device)
 753                 fw_device_get(device);
 754         up_read(&fw_device_rwsem);
 755
 756         return device;
 757 }
 758
 759 struct workqueue_struct *fw_workqueue;
 760 EXPORT_SYMBOL(fw_workqueue);
 761
 762 static void fw_schedule_device_work(struct fw_device *device,
 763                                     unsigned long delay)
 764 {
 765         queue_delayed_work(fw_workqueue, &device->work, delay);
 766 }
 767
 768 /*
 769  * These defines control the retry behavior for reading the config
 770  * rom.  It shouldn't be necessary to tweak these; if the device
 771  * doesn't respond to a config rom read within 10 seconds, it's not
 772  * going to respond at all.  As for the initial delay, a lot of
 773  * devices will be able to respond within half a second after bus
 774  * reset.  On the other hand, it's not really worth being more
 775  * aggressive than that, since it scales pretty well; if 10 devices
 776  * are plugged in, they're all getting read within one second.
 777  */
 778
 779 #define MAX_RETRIES     10
 780 #define RETRY_DELAY     (3 * HZ)
 781 #define INITIAL_DELAY   (HZ / 2)
 782 #define SHUTDOWN_DELAY  (2 * HZ)
 783
 784 static void fw_device_shutdown(struct work_struct *work)
 785 {
 786         struct fw_device *device =
 787                 container_of(work, struct fw_device, work.work);
 788         int minor = MINOR(device->device.devt);
 789
 790         if (time_before64(get_jiffies_64(),
 791                           device->card->reset_jiffies + SHUTDOWN_DELAY)
 792             && !list_empty(&device->card->link)) {
 793                 fw_schedule_device_work(device, SHUTDOWN_DELAY);
 794                 return;
 795         }
 796
 797         if (atomic_cmpxchg(&device->state,
 798                            FW_DEVICE_GONE,
 799                            FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE)
 800                 return;
 801
 802         fw_device_cdev_remove(device);
 803         device_for_each_child(&device->device, NULL, shutdown_unit);
 804         device_unregister(&device->device);
 805
 806         down_write(&fw_device_rwsem);
 807         idr_remove(&fw_device_idr, minor);
 808         up_write(&fw_device_rwsem);
 809
 810         fw_device_put(device);
 811 }
 812
 813 static void fw_device_release(struct device *dev)
 814 {
 815         struct fw_device *device = fw_device(dev);
 816         struct fw_card *card = device->card;
 817         unsigned long flags;
 818
 819         /*
 820          * Take the card lock so we don't set this to NULL while a
 821          * FW_NODE_UPDATED callback is being handled or while the
 822          * bus manager work looks at this node.
 823          */
 824         spin_lock_irqsave(&card->lock, flags);
 825         device->node->data = NULL;
 826         spin_unlock_irqrestore(&card->lock, flags);
 827
 828         fw_node_put(device->node);
 829         kfree(device->config_rom);
 830         kfree(device);
 831         fw_card_put(card);
 832 }
 833
 834 static struct device_type fw_device_type = {
 835         .release = fw_device_release,
 836 };
 837
 838 static bool is_fw_device(struct device *dev)
 839 {
 840         return dev->type == &fw_device_type;
 841 }
 842
 843 static int update_unit(struct device *dev, void *data)
 844 {
 845         struct fw_unit *unit = fw_unit(dev);
 846         struct fw_driver *driver = (struct fw_driver *)dev->driver;
 847
 848         if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) {
 849                 device_lock(dev);
 850                 driver->update(unit);
 851                 device_unlock(dev);
 852         }
 853
 854         return 0;
 855 }
 856
 857 static void fw_device_update(struct work_struct *work)
 858 {
 859         struct fw_device *device =
 860                 container_of(work, struct fw_device, work.work);
 861
 862         fw_device_cdev_update(device);
 863         device_for_each_child(&device->device, NULL, update_unit);
 864 }
 865
 866 /*
 867  * If a device was pending for deletion because its node went away but its
 868  * bus info block and root directory header matches that of a newly discovered
 869  * device, revive the existing fw_device.
 870  * The newly allocated fw_device becomes obsolete instead.
 871  */
 872 static int lookup_existing_device(struct device *dev, void *data)
 873 {
 874         struct fw_device *old = fw_device(dev);
 875         struct fw_device *new = data;
 876         struct fw_card *card = new->card;
 877         int match = 0;
 878
 879         if (!is_fw_device(dev))
 880                 return 0;
 881
 882         down_read(&fw_device_rwsem); /* serialize config_rom access */
 883         spin_lock_irq(&card->lock);  /* serialize node access */
 884
 885         if (memcmp(old->config_rom, new->config_rom, 6 * 4) == 0 &&
 886             atomic_cmpxchg(&old->state,
 887                            FW_DEVICE_GONE,
 888                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
 889                 struct fw_node *current_node = new->node;
 890                 struct fw_node *obsolete_node = old->node;
 891
 892                 new->node = obsolete_node;
 893                 new->node->data = new;
 894                 old->node = current_node;
 895                 old->node->data = old;
 896
 897                 old->max_speed = new->max_speed;
 898                 old->node_id = current_node->node_id;
 899                 smp_wmb();  /* update node_id before generation */
 900                 old->generation = card->generation;
 901                 old->config_rom_retries = 0;
 902                 fw_notice(card, "rediscovered device %s\n", dev_name(dev));
 903
 904                 old->workfn = fw_device_update;
 905                 fw_schedule_device_work(old, 0);
 906
 907                 if (current_node == card->root_node)
 908                         fw_schedule_bm_work(card, 0);
 909
 910                 match = 1;
 911         }
 912
 913         spin_unlock_irq(&card->lock);
 914         up_read(&fw_device_rwsem);
 915
 916         return match;
 917 }
 918
 919 enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, };
 920
 921 static void set_broadcast_channel(struct fw_device *device, int generation)
 922 {
 923         struct fw_card *card = device->card;
 924         __be32 data;
 925         int rcode;
 926
 927         if (!card->broadcast_channel_allocated)
 928                 return;
 929
 930         /*
 931          * The Broadcast_Channel Valid bit is required by nodes which want to
 932          * transmit on this channel.  Such transmissions are practically
 933          * exclusive to IP over 1394 (RFC 2734).  IP capable nodes are required
 934          * to be IRM capable and have a max_rec of 8 or more.  We use this fact
 935          * to narrow down to which nodes we send Broadcast_Channel updates.
 936          */
 937         if (!device->irmc || device->max_rec < 8)
 938                 return;
 939
 940         /*
 941          * Some 1394-1995 nodes crash if this 1394a-2000 register is written.
 942          * Perform a read test first.
 943          */
 944         if (device->bc_implemented == BC_UNKNOWN) {
 945                 rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST,
 946                                 device->node_id, generation, device->max_speed,
 947                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 948                                 &data, 4);
 949                 switch (rcode) {
 950                 case RCODE_COMPLETE:
 951                         if (data & cpu_to_be32(1 << 31)) {
 952                                 device->bc_implemented = BC_IMPLEMENTED;
 953                                 break;
 954                         }
 955                         fallthrough;    /* to case address error */
 956                 case RCODE_ADDRESS_ERROR:
 957                         device->bc_implemented = BC_UNIMPLEMENTED;
 958                 }
 959         }
 960
 961         if (device->bc_implemented == BC_IMPLEMENTED) {
 962                 data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL |
 963                                    BROADCAST_CHANNEL_VALID);
 964                 fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
 965                                 device->node_id, generation, device->max_speed,
 966                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 967                                 &data, 4);
 968         }
 969 }
 970
 971 int fw_device_set_broadcast_channel(struct device *dev, void *gen)
 972 {
 973         if (is_fw_device(dev))
 974                 set_broadcast_channel(fw_device(dev), (long)gen);
 975
 976         return 0;
 977 }
 978
 979 static void fw_device_init(struct work_struct *work)
 980 {
 981         struct fw_device *device =
 982                 container_of(work, struct fw_device, work.work);
 983         struct fw_card *card = device->card;
 984         struct device *revived_dev;
 985         int minor, ret;
 986
 987         /*
 988          * All failure paths here set node->data to NULL, so that we
 989          * don't try to do device_for_each_child() on a kfree()'d
 990          * device.
 991          */
 992
 993         ret = read_config_rom(device, device->generation);
 994         if (ret != RCODE_COMPLETE) {
 995                 if (device->config_rom_retries < MAX_RETRIES &&
 996                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
 997                         device->config_rom_retries++;
 998                         fw_schedule_device_work(device, RETRY_DELAY);
 999                 } else {
1000                         if (device->node->link_on)
1001                                 fw_notice(card, "giving up on node %x: reading config rom failed: %s\n",
1002                                           device->node_id,
1003                                           fw_rcode_string(ret));
1004                         if (device->node == card->root_node)
1005                                 fw_schedule_bm_work(card, 0);
1006                         fw_device_release(&device->device);
1007                 }
1008                 return;
1009         }
1010
1011         revived_dev = device_find_child(card->device,
1012                                         device, lookup_existing_device);
1013         if (revived_dev) {
1014                 put_device(revived_dev);
1015                 fw_device_release(&device->device);
1016
1017                 return;
1018         }
1019
1020         device_initialize(&device->device);
1021
1022         fw_device_get(device);
1023         down_write(&fw_device_rwsem);
1024         minor = idr_alloc(&fw_device_idr, device, 0, 1 << MINORBITS,
1025                         GFP_KERNEL);
1026         up_write(&fw_device_rwsem);
1027
1028         if (minor < 0)
1029                 goto error;
1030
1031         device->device.bus = &fw_bus_type;
1032         device->device.type = &fw_device_type;
1033         device->device.parent = card->device;
1034         device->device.devt = MKDEV(fw_cdev_major, minor);
1035         dev_set_name(&device->device, "fw%d", minor);
1036
1037         BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) <
1038                         ARRAY_SIZE(fw_device_attributes) +
1039                         ARRAY_SIZE(config_rom_attributes));
1040         init_fw_attribute_group(&device->device,
1041                                 fw_device_attributes,
1042                                 &device->attribute_group);
1043
1044         if (device_add(&device->device)) {
1045                 fw_err(card, "failed to add device\n");
1046                 goto error_with_cdev;
1047         }
1048
1049         create_units(device);
1050
1051         /*
1052          * Transition the device to running state.  If it got pulled
1053          * out from under us while we did the initialization work, we
1054          * have to shut down the device again here.  Normally, though,
1055          * fw_node_event will be responsible for shutting it down when
1056          * necessary.  We have to use the atomic cmpxchg here to avoid
1057          * racing with the FW_NODE_DESTROYED case in
1058          * fw_node_event().
1059          */
1060         if (atomic_cmpxchg(&device->state,
1061                            FW_DEVICE_INITIALIZING,
1062                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
1063                 device->workfn = fw_device_shutdown;
1064                 fw_schedule_device_work(device, SHUTDOWN_DELAY);
1065         } else {
1066                 fw_notice(card, "created device %s: GUID %08x%08x, S%d00\n",
1067                           dev_name(&device->device),
1068                           device->config_rom[3], device->config_rom[4],
1069                           1 << device->max_speed);
1070                 device->config_rom_retries = 0;
1071
1072                 set_broadcast_channel(device, device->generation);
1073
1074                 add_device_randomness(&device->config_rom[3], 8);
1075         }
1076
1077         /*
1078          * Reschedule the IRM work if we just finished reading the
1079          * root node config rom.  If this races with a bus reset we
1080          * just end up running the IRM work a couple of extra times -
1081          * pretty harmless.
1082          */
1083         if (device->node == card->root_node)
1084                 fw_schedule_bm_work(card, 0);
1085
1086         return;
1087
1088  error_with_cdev:
1089         down_write(&fw_device_rwsem);
1090         idr_remove(&fw_device_idr, minor);
1091         up_write(&fw_device_rwsem);
1092  error:
1093         fw_device_put(device);          /* fw_device_idr's reference */
1094
1095         put_device(&device->device);    /* our reference */
1096 }
1097
1098 /* Reread and compare bus info block and header of root directory */
1099 static int reread_config_rom(struct fw_device *device, int generation,
1100                              bool *changed)
1101 {
1102         u32 q;
1103         int i, rcode;
1104
1105         for (i = 0; i < 6; i++) {
1106                 rcode = read_rom(device, generation, i, &q);
1107                 if (rcode != RCODE_COMPLETE)
1108                         return rcode;
1109
1110                 if (i == 0 && q == 0)
1111                         /* inaccessible (see read_config_rom); retry later */
1112                         return RCODE_BUSY;
1113
1114                 if (q != device->config_rom[i]) {
1115                         *changed = true;
1116                         return RCODE_COMPLETE;
1117                 }
1118         }
1119
1120         *changed = false;
1121         return RCODE_COMPLETE;
1122 }
1123
1124 static void fw_device_refresh(struct work_struct *work)
1125 {
1126         struct fw_device *device =
1127                 container_of(work, struct fw_device, work.work);
1128         struct fw_card *card = device->card;
1129         int ret, node_id = device->node_id;
1130         bool changed;
1131
1132         ret = reread_config_rom(device, device->generation, &changed);
1133         if (ret != RCODE_COMPLETE)
1134                 goto failed_config_rom;
1135
1136         if (!changed) {
1137                 if (atomic_cmpxchg(&device->state,
1138                                    FW_DEVICE_INITIALIZING,
1139                                    FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1140                         goto gone;
1141
1142                 fw_device_update(work);
1143                 device->config_rom_retries = 0;
1144                 goto out;
1145         }
1146
1147         /*
1148          * Something changed.  We keep things simple and don't investigate
1149          * further.  We just destroy all previous units and create new ones.
1150          */
1151         device_for_each_child(&device->device, NULL, shutdown_unit);
1152
1153         ret = read_config_rom(device, device->generation);
1154         if (ret != RCODE_COMPLETE)
1155                 goto failed_config_rom;
1156
1157         fw_device_cdev_update(device);
1158         create_units(device);
1159
1160         /* Userspace may want to re-read attributes. */
1161         kobject_uevent(&device->device.kobj, KOBJ_CHANGE);
1162
1163         if (atomic_cmpxchg(&device->state,
1164                            FW_DEVICE_INITIALIZING,
1165                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1166                 goto gone;
1167
1168         fw_notice(card, "refreshed device %s\n", dev_name(&device->device));
1169         device->config_rom_retries = 0;
1170         goto out;
1171
1172  failed_config_rom:
1173         if (device->config_rom_retries < MAX_RETRIES &&
1174             atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1175                 device->config_rom_retries++;
1176                 fw_schedule_device_work(device, RETRY_DELAY);
1177                 return;
1178         }
1179
1180         fw_notice(card, "giving up on refresh of device %s: %s\n",
1181                   dev_name(&device->device), fw_rcode_string(ret));
1182  gone:
1183         atomic_set(&device->state, FW_DEVICE_GONE);
1184         device->workfn = fw_device_shutdown;
1185         fw_schedule_device_work(device, SHUTDOWN_DELAY);
1186  out:
1187         if (node_id == card->root_node->node_id)
1188                 fw_schedule_bm_work(card, 0);
1189 }
1190
1191 static void fw_device_workfn(struct work_struct *work)
1192 {
1193         struct fw_device *device = container_of(to_delayed_work(work),
1194                                                 struct fw_device, work);
1195         device->workfn(work);
1196 }
1197
1198 void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
1199 {
1200         struct fw_device *device;
1201
1202         switch (event) {
1203         case FW_NODE_CREATED:
1204                 /*
1205                  * Attempt to scan the node, regardless whether its self ID has
1206                  * the L (link active) flag set or not.  Some broken devices
1207                  * send L=0 but have an up-and-running link; others send L=1
1208                  * without actually having a link.
1209                  */
1210  create:
1211                 device = kzalloc(sizeof(*device), GFP_ATOMIC);
1212                 if (device == NULL)
1213                         break;
1214
1215                 /*
1216                  * Do minimal initialization of the device here, the
1217                  * rest will happen in fw_device_init().
1218                  *
1219                  * Attention:  A lot of things, even fw_device_get(),
1220                  * cannot be done before fw_device_init() finished!
1221                  * You can basically just check device->state and
1222                  * schedule work until then, but only while holding
1223                  * card->lock.
1224                  */
1225                 atomic_set(&device->state, FW_DEVICE_INITIALIZING);
1226                 device->card = fw_card_get(card);
1227                 device->node = fw_node_get(node);
1228                 device->node_id = node->node_id;
1229                 device->generation = card->generation;
1230                 device->is_local = node == card->local_node;
1231                 mutex_init(&device->client_list_mutex);
1232                 INIT_LIST_HEAD(&device->client_list);
1233
1234                 /*
1235                  * Set the node data to point back to this device so
1236                  * FW_NODE_UPDATED callbacks can update the node_id
1237                  * and generation for the device.
1238                  */
1239                 node->data = device;
1240
1241                 /*
1242                  * Many devices are slow to respond after bus resets,
1243                  * especially if they are bus powered and go through
1244                  * power-up after getting plugged in.  We schedule the
1245                  * first config rom scan half a second after bus reset.
1246                  */
1247                 device->workfn = fw_device_init;
1248                 INIT_DELAYED_WORK(&device->work, fw_device_workfn);
1249                 fw_schedule_device_work(device, INITIAL_DELAY);
1250                 break;
1251
1252         case FW_NODE_INITIATED_RESET:
1253         case FW_NODE_LINK_ON:
1254                 device = node->data;
1255                 if (device == NULL)
1256                         goto create;
1257
1258                 device->node_id = node->node_id;
1259                 smp_wmb();  /* update node_id before generation */
1260                 device->generation = card->generation;
1261                 if (atomic_cmpxchg(&device->state,
1262                             FW_DEVICE_RUNNING,
1263                             FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) {
1264                         device->workfn = fw_device_refresh;
1265                         fw_schedule_device_work(device,
1266                                 device->is_local ? 0 : INITIAL_DELAY);
1267                 }
1268                 break;
1269
1270         case FW_NODE_UPDATED:
1271                 device = node->data;
1272                 if (device == NULL)
1273                         break;
1274
1275                 device->node_id = node->node_id;
1276                 smp_wmb();  /* update node_id before generation */
1277                 device->generation = card->generation;
1278                 if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
1279                         device->workfn = fw_device_update;
1280                         fw_schedule_device_work(device, 0);
1281                 }
1282                 break;
1283
1284         case FW_NODE_DESTROYED:
1285         case FW_NODE_LINK_OFF:
1286                 if (!node->data)
1287                         break;
1288
1289                 /*
1290                  * Destroy the device associated with the node.  There
1291                  * are two cases here: either the device is fully
1292                  * initialized (FW_DEVICE_RUNNING) or we're in the
1293                  * process of reading its config rom
1294                  * (FW_DEVICE_INITIALIZING).  If it is fully
1295                  * initialized we can reuse device->work to schedule a
1296                  * full fw_device_shutdown().  If not, there's work
1297                  * scheduled to read it's config rom, and we just put
1298                  * the device in shutdown state to have that code fail
1299                  * to create the device.
1300                  */
1301                 device = node->data;
1302                 if (atomic_xchg(&device->state,
1303                                 FW_DEVICE_GONE) == FW_DEVICE_RUNNING) {
1304                         device->workfn = fw_device_shutdown;
1305                         fw_schedule_device_work(device,
1306                                 list_empty(&card->link) ? 0 : SHUTDOWN_DELAY);
1307                 }
1308                 break;
1309         }
1310 }