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