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