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/jiffies.h> 16 #include <linux/kobject.h> 17 #include <linux/list.h> 18 #include <linux/mod_devicetable.h> 19 #include <linux/module.h> 20 #include <linux/mutex.h> 21 #include <linux/random.h> 22 #include <linux/rwsem.h> 23 #include <linux/slab.h> 24 #include <linux/spinlock.h> 25 #include <linux/string.h> 26 #include <linux/workqueue.h> 27 28 #include <linux/atomic.h> 29 #include <asm/byteorder.h> 30 31 #include "core.h" 32 33 #define ROOT_DIR_OFFSET 5 34 35 void fw_csr_iterator_init(struct fw_csr_iterator *ci, const u32 *p) 36 { 37 ci->p = p + 1; 38 ci->end = ci->p + (p[0] >> 16); 39 } 40 EXPORT_SYMBOL(fw_csr_iterator_init); 41 42 int fw_csr_iterator_next(struct fw_csr_iterator *ci, int *key, int *value) 43 { 44 *key = *ci->p >> 24; 45 *value = *ci->p & 0xffffff; 46 47 return ci->p++ < ci->end; 48 } 49 EXPORT_SYMBOL(fw_csr_iterator_next); 50 51 static const u32 *search_directory(const u32 *directory, int search_key) 52 { 53 struct fw_csr_iterator ci; 54 int key, value; 55 56 search_key |= CSR_DIRECTORY; 57 58 fw_csr_iterator_init(&ci, directory); 59 while (fw_csr_iterator_next(&ci, &key, &value)) { 60 if (key == search_key) 61 return ci.p - 1 + value; 62 } 63 64 return NULL; 65 } 66 67 static const u32 *search_leaf(const u32 *directory, int search_key) 68 { 69 struct fw_csr_iterator ci; 70 int last_key = 0, key, value; 71 72 fw_csr_iterator_init(&ci, directory); 73 while (fw_csr_iterator_next(&ci, &key, &value)) { 74 if (last_key == search_key && 75 key == (CSR_DESCRIPTOR | CSR_LEAF)) 76 return ci.p - 1 + value; 77 78 last_key = key; 79 } 80 81 return NULL; 82 } 83 84 static int textual_leaf_to_string(const u32 *block, char *buf, size_t size) 85 { 86 unsigned int quadlets, i; 87 char c; 88 89 if (!size || !buf) 90 return -EINVAL; 91 92 quadlets = min(block[0] >> 16, 256U); 93 if (quadlets < 2) 94 return -ENODATA; 95 96 if (block[1] != 0 || block[2] != 0) 97 /* unknown language/character set */ 98 return -ENODATA; 99 100 block += 3; 101 quadlets -= 2; 102 for (i = 0; i < quadlets * 4 && i < size - 1; i++) { 103 c = block[i / 4] >> (24 - 8 * (i % 4)); 104 if (c == '\0') 105 break; 106 buf[i] = c; 107 } 108 buf[i] = '\0'; 109 110 return i; 111 } 112 113 /** 114 * fw_csr_string() - reads a string from the configuration ROM 115 * @directory: e.g. root directory or unit directory 116 * @key: the key of the preceding directory entry 117 * @buf: where to put the string 118 * @size: size of @buf, in bytes 119 * 120 * The string is taken from a minimal ASCII text descriptor leaf just after the entry with the 121 * @key. The string is zero-terminated. An overlong string is silently truncated such that it 122 * and the zero byte fit into @size. 123 * 124 * Returns strlen(buf) or a negative error code. 125 */ 126 int fw_csr_string(const u32 *directory, int key, char *buf, size_t size) 127 { 128 const u32 *leaf = search_leaf(directory, key); 129 if (!leaf) 130 return -ENOENT; 131 132 return textual_leaf_to_string(leaf, buf, size); 133 } 134 EXPORT_SYMBOL(fw_csr_string); 135 136 static void get_ids(const u32 *directory, int *id) 137 { 138 struct fw_csr_iterator ci; 139 int key, value; 140 141 fw_csr_iterator_init(&ci, directory); 142 while (fw_csr_iterator_next(&ci, &key, &value)) { 143 switch (key) { 144 case CSR_VENDOR: id[0] = value; break; 145 case CSR_MODEL: id[1] = value; break; 146 case CSR_SPECIFIER_ID: id[2] = value; break; 147 case CSR_VERSION: id[3] = value; break; 148 } 149 } 150 } 151 152 static void get_modalias_ids(const struct fw_unit *unit, int *id) 153 { 154 const u32 *root_directory = &fw_parent_device(unit)->config_rom[ROOT_DIR_OFFSET]; 155 const u32 *directories[] = {NULL, NULL, NULL}; 156 const u32 *vendor_directory; 157 int i; 158 159 directories[0] = root_directory; 160 161 // Legacy layout of configuration ROM described in Annex 1 of 'Configuration ROM for AV/C 162 // Devices 1.0 (December 12, 2000, 1394 Trading Association, TA Document 1999027)'. 163 vendor_directory = search_directory(root_directory, CSR_VENDOR); 164 if (!vendor_directory) { 165 directories[1] = unit->directory; 166 } else { 167 directories[1] = vendor_directory; 168 directories[2] = unit->directory; 169 } 170 171 for (i = 0; i < ARRAY_SIZE(directories) && !!directories[i]; ++i) 172 get_ids(directories[i], id); 173 } 174 175 static bool match_ids(const struct ieee1394_device_id *id_table, int *id) 176 { 177 int match = 0; 178 179 if (id[0] == id_table->vendor_id) 180 match |= IEEE1394_MATCH_VENDOR_ID; 181 if (id[1] == id_table->model_id) 182 match |= IEEE1394_MATCH_MODEL_ID; 183 if (id[2] == id_table->specifier_id) 184 match |= IEEE1394_MATCH_SPECIFIER_ID; 185 if (id[3] == id_table->version) 186 match |= IEEE1394_MATCH_VERSION; 187 188 return (match & id_table->match_flags) == id_table->match_flags; 189 } 190 191 static const struct ieee1394_device_id *unit_match(struct device *dev, 192 const struct device_driver *drv) 193 { 194 const struct ieee1394_device_id *id_table = 195 container_of_const(drv, struct fw_driver, driver)->id_table; 196 int id[] = {0, 0, 0, 0}; 197 198 get_modalias_ids(fw_unit(dev), id); 199 200 for (; id_table->match_flags != 0; id_table++) 201 if (match_ids(id_table, id)) 202 return id_table; 203 204 return NULL; 205 } 206 207 static bool is_fw_unit(const struct device *dev); 208 209 static int fw_unit_match(struct device *dev, const struct device_driver *drv) 210 { 211 /* We only allow binding to fw_units. */ 212 return is_fw_unit(dev) && unit_match(dev, drv) != NULL; 213 } 214 215 static int fw_unit_probe(struct device *dev) 216 { 217 struct fw_driver *driver = 218 container_of(dev->driver, struct fw_driver, driver); 219 220 return driver->probe(fw_unit(dev), unit_match(dev, dev->driver)); 221 } 222 223 static void fw_unit_remove(struct device *dev) 224 { 225 struct fw_driver *driver = 226 container_of(dev->driver, struct fw_driver, driver); 227 228 driver->remove(fw_unit(dev)); 229 } 230 231 static int get_modalias(const struct fw_unit *unit, char *buffer, size_t buffer_size) 232 { 233 int id[] = {0, 0, 0, 0}; 234 235 get_modalias_ids(unit, id); 236 237 return snprintf(buffer, buffer_size, 238 "ieee1394:ven%08Xmo%08Xsp%08Xver%08X", 239 id[0], id[1], id[2], id[3]); 240 } 241 242 static int fw_unit_uevent(const struct device *dev, struct kobj_uevent_env *env) 243 { 244 const struct fw_unit *unit = fw_unit(dev); 245 char modalias[64]; 246 247 get_modalias(unit, modalias, sizeof(modalias)); 248 249 if (add_uevent_var(env, "MODALIAS=%s", modalias)) 250 return -ENOMEM; 251 252 return 0; 253 } 254 255 const struct bus_type fw_bus_type = { 256 .name = "firewire", 257 .match = fw_unit_match, 258 .probe = fw_unit_probe, 259 .remove = fw_unit_remove, 260 }; 261 EXPORT_SYMBOL(fw_bus_type); 262 263 int fw_device_enable_phys_dma(struct fw_device *device) 264 { 265 int generation = device->generation; 266 267 /* device->node_id, accessed below, must not be older than generation */ 268 smp_rmb(); 269 270 return device->card->driver->enable_phys_dma(device->card, 271 device->node_id, 272 generation); 273 } 274 EXPORT_SYMBOL(fw_device_enable_phys_dma); 275 276 struct config_rom_attribute { 277 struct device_attribute attr; 278 u32 key; 279 }; 280 281 static ssize_t show_immediate(struct device *dev, 282 struct device_attribute *dattr, char *buf) 283 { 284 struct config_rom_attribute *attr = 285 container_of(dattr, struct config_rom_attribute, attr); 286 struct fw_csr_iterator ci; 287 const u32 *directories[] = {NULL, NULL}; 288 int i, value = -1; 289 290 guard(rwsem_read)(&fw_device_rwsem); 291 292 if (is_fw_unit(dev)) { 293 directories[0] = fw_unit(dev)->directory; 294 } else { 295 const u32 *root_directory = fw_device(dev)->config_rom + ROOT_DIR_OFFSET; 296 const u32 *vendor_directory = search_directory(root_directory, CSR_VENDOR); 297 298 if (!vendor_directory) { 299 directories[0] = root_directory; 300 } else { 301 // Legacy layout of configuration ROM described in Annex 1 of 302 // 'Configuration ROM for AV/C Devices 1.0 (December 12, 2000, 1394 Trading 303 // Association, TA Document 1999027)'. 304 directories[0] = vendor_directory; 305 directories[1] = root_directory; 306 } 307 } 308 309 for (i = 0; i < ARRAY_SIZE(directories) && !!directories[i]; ++i) { 310 int key, val; 311 312 fw_csr_iterator_init(&ci, directories[i]); 313 while (fw_csr_iterator_next(&ci, &key, &val)) { 314 if (attr->key == key) 315 value = val; 316 } 317 } 318 319 if (value < 0) 320 return -ENOENT; 321 322 // Note that this function is also called by init_fw_attribute_group() with NULL pointer. 323 return buf ? sysfs_emit(buf, "0x%06x\n", value) : 0; 324 } 325 326 #define IMMEDIATE_ATTR(name, key) \ 327 { __ATTR(name, S_IRUGO, show_immediate, NULL), key } 328 329 static ssize_t show_text_leaf(struct device *dev, 330 struct device_attribute *dattr, char *buf) 331 { 332 struct config_rom_attribute *attr = 333 container_of(dattr, struct config_rom_attribute, attr); 334 const u32 *directories[] = {NULL, NULL}; 335 size_t bufsize; 336 char dummy_buf[2]; 337 int i, ret = -ENOENT; 338 339 guard(rwsem_read)(&fw_device_rwsem); 340 341 if (is_fw_unit(dev)) { 342 directories[0] = fw_unit(dev)->directory; 343 } else { 344 const u32 *root_directory = fw_device(dev)->config_rom + ROOT_DIR_OFFSET; 345 const u32 *vendor_directory = search_directory(root_directory, CSR_VENDOR); 346 347 if (!vendor_directory) { 348 directories[0] = root_directory; 349 } else { 350 // Legacy layout of configuration ROM described in Annex 1 of 351 // 'Configuration ROM for AV/C Devices 1.0 (December 12, 2000, 1394 352 // Trading Association, TA Document 1999027)'. 353 directories[0] = root_directory; 354 directories[1] = vendor_directory; 355 } 356 } 357 358 // Note that this function is also called by init_fw_attribute_group() with NULL pointer. 359 if (buf) { 360 bufsize = PAGE_SIZE - 1; 361 } else { 362 buf = dummy_buf; 363 bufsize = 1; 364 } 365 366 for (i = 0; i < ARRAY_SIZE(directories) && !!directories[i]; ++i) { 367 int result = fw_csr_string(directories[i], attr->key, buf, bufsize); 368 // Detected. 369 if (result >= 0) { 370 ret = result; 371 } else if (i == 0 && attr->key == CSR_VENDOR) { 372 // Sony DVMC-DA1 has configuration ROM such that the descriptor leaf entry 373 // in the root directory follows to the directory entry for vendor ID 374 // instead of the immediate value for vendor ID. 375 result = fw_csr_string(directories[i], CSR_DIRECTORY | attr->key, buf, 376 bufsize); 377 if (result >= 0) 378 ret = result; 379 } 380 } 381 382 if (ret < 0) 383 return ret; 384 385 // Strip trailing whitespace and add newline. 386 while (ret > 0 && isspace(buf[ret - 1])) 387 ret--; 388 strcpy(buf + ret, "\n"); 389 ret++; 390 391 return ret; 392 } 393 394 #define TEXT_LEAF_ATTR(name, key) \ 395 { __ATTR(name, S_IRUGO, show_text_leaf, NULL), key } 396 397 static struct config_rom_attribute config_rom_attributes[] = { 398 IMMEDIATE_ATTR(vendor, CSR_VENDOR), 399 IMMEDIATE_ATTR(hardware_version, CSR_HARDWARE_VERSION), 400 IMMEDIATE_ATTR(specifier_id, CSR_SPECIFIER_ID), 401 IMMEDIATE_ATTR(version, CSR_VERSION), 402 IMMEDIATE_ATTR(model, CSR_MODEL), 403 TEXT_LEAF_ATTR(vendor_name, CSR_VENDOR), 404 TEXT_LEAF_ATTR(model_name, CSR_MODEL), 405 TEXT_LEAF_ATTR(hardware_version_name, CSR_HARDWARE_VERSION), 406 }; 407 408 static void init_fw_attribute_group(struct device *dev, 409 struct device_attribute *attrs, 410 struct fw_attribute_group *group) 411 { 412 struct device_attribute *attr; 413 int i, j; 414 415 for (j = 0; attrs[j].attr.name != NULL; j++) 416 group->attrs[j] = &attrs[j].attr; 417 418 for (i = 0; i < ARRAY_SIZE(config_rom_attributes); i++) { 419 attr = &config_rom_attributes[i].attr; 420 if (attr->show(dev, attr, NULL) < 0) 421 continue; 422 group->attrs[j++] = &attr->attr; 423 } 424 425 group->attrs[j] = NULL; 426 group->groups[0] = &group->group; 427 group->groups[1] = NULL; 428 group->group.attrs = group->attrs; 429 dev->groups = (const struct attribute_group **) group->groups; 430 } 431 432 static ssize_t modalias_show(struct device *dev, 433 struct device_attribute *attr, char *buf) 434 { 435 struct fw_unit *unit = fw_unit(dev); 436 int length; 437 438 length = get_modalias(unit, buf, PAGE_SIZE); 439 strcpy(buf + length, "\n"); 440 441 return length + 1; 442 } 443 444 static ssize_t rom_index_show(struct device *dev, 445 struct device_attribute *attr, char *buf) 446 { 447 struct fw_device *device = fw_device(dev->parent); 448 struct fw_unit *unit = fw_unit(dev); 449 450 return sysfs_emit(buf, "%td\n", unit->directory - device->config_rom); 451 } 452 453 static struct device_attribute fw_unit_attributes[] = { 454 __ATTR_RO(modalias), 455 __ATTR_RO(rom_index), 456 __ATTR_NULL, 457 }; 458 459 static ssize_t config_rom_show(struct device *dev, 460 struct device_attribute *attr, char *buf) 461 { 462 struct fw_device *device = fw_device(dev); 463 size_t length; 464 465 guard(rwsem_read)(&fw_device_rwsem); 466 467 length = device->config_rom_length * 4; 468 memcpy(buf, device->config_rom, length); 469 470 return length; 471 } 472 473 static ssize_t guid_show(struct device *dev, 474 struct device_attribute *attr, char *buf) 475 { 476 struct fw_device *device = fw_device(dev); 477 478 guard(rwsem_read)(&fw_device_rwsem); 479 480 return sysfs_emit(buf, "0x%08x%08x\n", device->config_rom[3], device->config_rom[4]); 481 } 482 483 static ssize_t is_local_show(struct device *dev, 484 struct device_attribute *attr, char *buf) 485 { 486 struct fw_device *device = fw_device(dev); 487 488 return sysfs_emit(buf, "%u\n", device->is_local); 489 } 490 491 static int units_sprintf(char *buf, const u32 *directory) 492 { 493 struct fw_csr_iterator ci; 494 int key, value; 495 int specifier_id = 0; 496 int version = 0; 497 498 fw_csr_iterator_init(&ci, directory); 499 while (fw_csr_iterator_next(&ci, &key, &value)) { 500 switch (key) { 501 case CSR_SPECIFIER_ID: 502 specifier_id = value; 503 break; 504 case CSR_VERSION: 505 version = value; 506 break; 507 } 508 } 509 510 return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version); 511 } 512 513 static ssize_t units_show(struct device *dev, 514 struct device_attribute *attr, char *buf) 515 { 516 struct fw_device *device = fw_device(dev); 517 struct fw_csr_iterator ci; 518 int key, value, i = 0; 519 520 guard(rwsem_read)(&fw_device_rwsem); 521 522 fw_csr_iterator_init(&ci, &device->config_rom[ROOT_DIR_OFFSET]); 523 while (fw_csr_iterator_next(&ci, &key, &value)) { 524 if (key != (CSR_UNIT | CSR_DIRECTORY)) 525 continue; 526 i += units_sprintf(&buf[i], ci.p + value - 1); 527 if (i >= PAGE_SIZE - (8 + 1 + 8 + 1)) 528 break; 529 } 530 531 if (i) 532 buf[i - 1] = '\n'; 533 534 return i; 535 } 536 537 static struct device_attribute fw_device_attributes[] = { 538 __ATTR_RO(config_rom), 539 __ATTR_RO(guid), 540 __ATTR_RO(is_local), 541 __ATTR_RO(units), 542 __ATTR_NULL, 543 }; 544 545 static int read_rom(struct fw_device *device, 546 int generation, int index, u32 *data) 547 { 548 u64 offset = (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4; 549 int i, rcode; 550 551 /* device->node_id, accessed below, must not be older than generation */ 552 smp_rmb(); 553 554 for (i = 10; i < 100; i += 10) { 555 rcode = fw_run_transaction(device->card, 556 TCODE_READ_QUADLET_REQUEST, device->node_id, 557 generation, device->max_speed, offset, data, 4); 558 if (rcode != RCODE_BUSY) 559 break; 560 msleep(i); 561 } 562 be32_to_cpus(data); 563 564 return rcode; 565 } 566 567 // By quadlet unit. 568 #define MAX_CONFIG_ROM_SIZE ((CSR_CONFIG_ROM_END - CSR_CONFIG_ROM) / sizeof(u32)) 569 570 /* 571 * Read the bus info block, perform a speed probe, and read all of the rest of 572 * the config ROM. We do all this with a cached bus generation. If the bus 573 * generation changes under us, read_config_rom will fail and get retried. 574 * It's better to start all over in this case because the node from which we 575 * are reading the ROM may have changed the ROM during the reset. 576 * Returns either a result code or a negative error code. 577 */ 578 static int read_config_rom(struct fw_device *device, int generation) 579 { 580 struct fw_card *card = device->card; 581 const u32 *old_rom, *new_rom; 582 u32 *rom, *stack; 583 u32 sp, key; 584 int i, end, length, ret; 585 586 rom = kmalloc(sizeof(*rom) * MAX_CONFIG_ROM_SIZE + 587 sizeof(*stack) * MAX_CONFIG_ROM_SIZE, GFP_KERNEL); 588 if (rom == NULL) 589 return -ENOMEM; 590 591 stack = &rom[MAX_CONFIG_ROM_SIZE]; 592 memset(rom, 0, sizeof(*rom) * MAX_CONFIG_ROM_SIZE); 593 594 device->max_speed = SCODE_100; 595 596 /* First read the bus info block. */ 597 for (i = 0; i < 5; i++) { 598 ret = read_rom(device, generation, i, &rom[i]); 599 if (ret != RCODE_COMPLETE) 600 goto out; 601 /* 602 * As per IEEE1212 7.2, during initialization, devices can 603 * reply with a 0 for the first quadlet of the config 604 * rom to indicate that they are booting (for example, 605 * if the firmware is on the disk of a external 606 * harddisk). In that case we just fail, and the 607 * retry mechanism will try again later. 608 */ 609 if (i == 0 && rom[i] == 0) { 610 ret = RCODE_BUSY; 611 goto out; 612 } 613 } 614 615 device->max_speed = device->node->max_speed; 616 617 /* 618 * Determine the speed of 619 * - devices with link speed less than PHY speed, 620 * - devices with 1394b PHY (unless only connected to 1394a PHYs), 621 * - all devices if there are 1394b repeaters. 622 * Note, we cannot use the bus info block's link_spd as starting point 623 * because some buggy firmwares set it lower than necessary and because 624 * 1394-1995 nodes do not have the field. 625 */ 626 if ((rom[2] & 0x7) < device->max_speed || 627 device->max_speed == SCODE_BETA || 628 card->beta_repeaters_present) { 629 u32 dummy; 630 631 /* for S1600 and S3200 */ 632 if (device->max_speed == SCODE_BETA) 633 device->max_speed = card->link_speed; 634 635 while (device->max_speed > SCODE_100) { 636 if (read_rom(device, generation, 0, &dummy) == 637 RCODE_COMPLETE) 638 break; 639 device->max_speed--; 640 } 641 } 642 643 /* 644 * Now parse the config rom. The config rom is a recursive 645 * directory structure so we parse it using a stack of 646 * references to the blocks that make up the structure. We 647 * push a reference to the root directory on the stack to 648 * start things off. 649 */ 650 length = i; 651 sp = 0; 652 stack[sp++] = 0xc0000005; 653 while (sp > 0) { 654 /* 655 * Pop the next block reference of the stack. The 656 * lower 24 bits is the offset into the config rom, 657 * the upper 8 bits are the type of the reference the 658 * block. 659 */ 660 key = stack[--sp]; 661 i = key & 0xffffff; 662 if (WARN_ON(i >= MAX_CONFIG_ROM_SIZE)) { 663 ret = -ENXIO; 664 goto out; 665 } 666 667 /* Read header quadlet for the block to get the length. */ 668 ret = read_rom(device, generation, i, &rom[i]); 669 if (ret != RCODE_COMPLETE) 670 goto out; 671 end = i + (rom[i] >> 16) + 1; 672 if (end > MAX_CONFIG_ROM_SIZE) { 673 /* 674 * This block extends outside the config ROM which is 675 * a firmware bug. Ignore this whole block, i.e. 676 * simply set a fake block length of 0. 677 */ 678 fw_err(card, "skipped invalid ROM block %x at %llx\n", 679 rom[i], 680 i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM); 681 rom[i] = 0; 682 end = i; 683 } 684 i++; 685 686 /* 687 * Now read in the block. If this is a directory 688 * block, check the entries as we read them to see if 689 * it references another block, and push it in that case. 690 */ 691 for (; i < end; i++) { 692 ret = read_rom(device, generation, i, &rom[i]); 693 if (ret != RCODE_COMPLETE) 694 goto out; 695 696 if ((key >> 30) != 3 || (rom[i] >> 30) < 2) 697 continue; 698 /* 699 * Offset points outside the ROM. May be a firmware 700 * bug or an Extended ROM entry (IEEE 1212-2001 clause 701 * 7.7.18). Simply overwrite this pointer here by a 702 * fake immediate entry so that later iterators over 703 * the ROM don't have to check offsets all the time. 704 */ 705 if (i + (rom[i] & 0xffffff) >= MAX_CONFIG_ROM_SIZE) { 706 fw_err(card, 707 "skipped unsupported ROM entry %x at %llx\n", 708 rom[i], 709 i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM); 710 rom[i] = 0; 711 continue; 712 } 713 stack[sp++] = i + rom[i]; 714 } 715 if (length < i) 716 length = i; 717 } 718 719 old_rom = device->config_rom; 720 new_rom = kmemdup(rom, length * 4, GFP_KERNEL); 721 if (new_rom == NULL) { 722 ret = -ENOMEM; 723 goto out; 724 } 725 726 scoped_guard(rwsem_write, &fw_device_rwsem) { 727 device->config_rom = new_rom; 728 device->config_rom_length = length; 729 } 730 731 kfree(old_rom); 732 ret = RCODE_COMPLETE; 733 device->max_rec = rom[2] >> 12 & 0xf; 734 device->cmc = rom[2] >> 30 & 1; 735 device->irmc = rom[2] >> 31 & 1; 736 out: 737 kfree(rom); 738 739 return ret; 740 } 741 742 static void fw_unit_release(struct device *dev) 743 { 744 struct fw_unit *unit = fw_unit(dev); 745 746 fw_device_put(fw_parent_device(unit)); 747 kfree(unit); 748 } 749 750 static struct device_type fw_unit_type = { 751 .uevent = fw_unit_uevent, 752 .release = fw_unit_release, 753 }; 754 755 static bool is_fw_unit(const struct device *dev) 756 { 757 return dev->type == &fw_unit_type; 758 } 759 760 static void create_units(struct fw_device *device) 761 { 762 struct fw_csr_iterator ci; 763 struct fw_unit *unit; 764 int key, value, i; 765 766 i = 0; 767 fw_csr_iterator_init(&ci, &device->config_rom[ROOT_DIR_OFFSET]); 768 while (fw_csr_iterator_next(&ci, &key, &value)) { 769 if (key != (CSR_UNIT | CSR_DIRECTORY)) 770 continue; 771 772 /* 773 * Get the address of the unit directory and try to 774 * match the drivers id_tables against it. 775 */ 776 unit = kzalloc(sizeof(*unit), GFP_KERNEL); 777 if (unit == NULL) 778 continue; 779 780 unit->directory = ci.p + value - 1; 781 unit->device.bus = &fw_bus_type; 782 unit->device.type = &fw_unit_type; 783 unit->device.parent = &device->device; 784 dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++); 785 786 BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) < 787 ARRAY_SIZE(fw_unit_attributes) + 788 ARRAY_SIZE(config_rom_attributes)); 789 init_fw_attribute_group(&unit->device, 790 fw_unit_attributes, 791 &unit->attribute_group); 792 793 fw_device_get(device); 794 if (device_register(&unit->device) < 0) { 795 put_device(&unit->device); 796 continue; 797 } 798 } 799 } 800 801 static int shutdown_unit(struct device *device, void *data) 802 { 803 device_unregister(device); 804 805 return 0; 806 } 807 808 /* 809 * fw_device_rwsem acts as dual purpose mutex: 810 * - serializes accesses to fw_device.config_rom/.config_rom_length and 811 * fw_unit.directory, unless those accesses happen at safe occasions 812 */ 813 DECLARE_RWSEM(fw_device_rwsem); 814 815 DEFINE_XARRAY_ALLOC(fw_device_xa); 816 int fw_cdev_major; 817 818 struct fw_device *fw_device_get_by_devt(dev_t devt) 819 { 820 struct fw_device *device; 821 822 device = xa_load(&fw_device_xa, MINOR(devt)); 823 if (device) 824 fw_device_get(device); 825 826 return device; 827 } 828 829 struct workqueue_struct *fw_workqueue; 830 EXPORT_SYMBOL(fw_workqueue); 831 832 static void fw_schedule_device_work(struct fw_device *device, 833 unsigned long delay) 834 { 835 queue_delayed_work(fw_workqueue, &device->work, delay); 836 } 837 838 /* 839 * These defines control the retry behavior for reading the config 840 * rom. It shouldn't be necessary to tweak these; if the device 841 * doesn't respond to a config rom read within 10 seconds, it's not 842 * going to respond at all. As for the initial delay, a lot of 843 * devices will be able to respond within half a second after bus 844 * reset. On the other hand, it's not really worth being more 845 * aggressive than that, since it scales pretty well; if 10 devices 846 * are plugged in, they're all getting read within one second. 847 */ 848 849 #define MAX_RETRIES 10 850 #define RETRY_DELAY (3 * HZ) 851 #define INITIAL_DELAY (HZ / 2) 852 #define SHUTDOWN_DELAY (2 * HZ) 853 854 static void fw_device_shutdown(struct work_struct *work) 855 { 856 struct fw_device *device = 857 container_of(work, struct fw_device, work.work); 858 859 if (time_before64(get_jiffies_64(), 860 device->card->reset_jiffies + SHUTDOWN_DELAY) 861 && !list_empty(&device->card->link)) { 862 fw_schedule_device_work(device, SHUTDOWN_DELAY); 863 return; 864 } 865 866 if (atomic_cmpxchg(&device->state, 867 FW_DEVICE_GONE, 868 FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE) 869 return; 870 871 fw_device_cdev_remove(device); 872 device_for_each_child(&device->device, NULL, shutdown_unit); 873 device_unregister(&device->device); 874 875 xa_erase(&fw_device_xa, MINOR(device->device.devt)); 876 877 fw_device_put(device); 878 } 879 880 static void fw_device_release(struct device *dev) 881 { 882 struct fw_device *device = fw_device(dev); 883 struct fw_card *card = device->card; 884 885 /* 886 * Take the card lock so we don't set this to NULL while a 887 * FW_NODE_UPDATED callback is being handled or while the 888 * bus manager work looks at this node. 889 */ 890 scoped_guard(spinlock_irqsave, &card->lock) 891 device->node->data = NULL; 892 893 fw_node_put(device->node); 894 kfree(device->config_rom); 895 kfree(device); 896 fw_card_put(card); 897 } 898 899 static struct device_type fw_device_type = { 900 .release = fw_device_release, 901 }; 902 903 static bool is_fw_device(const struct device *dev) 904 { 905 return dev->type == &fw_device_type; 906 } 907 908 static int update_unit(struct device *dev, void *data) 909 { 910 struct fw_unit *unit = fw_unit(dev); 911 struct fw_driver *driver = (struct fw_driver *)dev->driver; 912 913 if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) { 914 device_lock(dev); 915 driver->update(unit); 916 device_unlock(dev); 917 } 918 919 return 0; 920 } 921 922 static void fw_device_update(struct work_struct *work) 923 { 924 struct fw_device *device = 925 container_of(work, struct fw_device, work.work); 926 927 fw_device_cdev_update(device); 928 device_for_each_child(&device->device, NULL, update_unit); 929 } 930 931 enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, }; 932 933 static void set_broadcast_channel(struct fw_device *device, int generation) 934 { 935 struct fw_card *card = device->card; 936 __be32 data; 937 int rcode; 938 939 if (!card->broadcast_channel_allocated) 940 return; 941 942 /* 943 * The Broadcast_Channel Valid bit is required by nodes which want to 944 * transmit on this channel. Such transmissions are practically 945 * exclusive to IP over 1394 (RFC 2734). IP capable nodes are required 946 * to be IRM capable and have a max_rec of 8 or more. We use this fact 947 * to narrow down to which nodes we send Broadcast_Channel updates. 948 */ 949 if (!device->irmc || device->max_rec < 8) 950 return; 951 952 /* 953 * Some 1394-1995 nodes crash if this 1394a-2000 register is written. 954 * Perform a read test first. 955 */ 956 if (device->bc_implemented == BC_UNKNOWN) { 957 rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST, 958 device->node_id, generation, device->max_speed, 959 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL, 960 &data, 4); 961 switch (rcode) { 962 case RCODE_COMPLETE: 963 if (data & cpu_to_be32(1 << 31)) { 964 device->bc_implemented = BC_IMPLEMENTED; 965 break; 966 } 967 fallthrough; /* to case address error */ 968 case RCODE_ADDRESS_ERROR: 969 device->bc_implemented = BC_UNIMPLEMENTED; 970 } 971 } 972 973 if (device->bc_implemented == BC_IMPLEMENTED) { 974 data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL | 975 BROADCAST_CHANNEL_VALID); 976 fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST, 977 device->node_id, generation, device->max_speed, 978 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL, 979 &data, 4); 980 } 981 } 982 983 int fw_device_set_broadcast_channel(struct device *dev, void *gen) 984 { 985 if (is_fw_device(dev)) 986 set_broadcast_channel(fw_device(dev), (long)gen); 987 988 return 0; 989 } 990 991 static int compare_configuration_rom(struct device *dev, void *data) 992 { 993 const struct fw_device *old = fw_device(dev); 994 const u32 *config_rom = data; 995 996 if (!is_fw_device(dev)) 997 return 0; 998 999 // Compare the bus information block and root_length/root_crc. 1000 return !memcmp(old->config_rom, config_rom, 6 * 4); 1001 } 1002 1003 static void fw_device_init(struct work_struct *work) 1004 { 1005 struct fw_device *device = 1006 container_of(work, struct fw_device, work.work); 1007 struct fw_card *card = device->card; 1008 struct device *found; 1009 u32 minor; 1010 int ret; 1011 1012 /* 1013 * All failure paths here set node->data to NULL, so that we 1014 * don't try to do device_for_each_child() on a kfree()'d 1015 * device. 1016 */ 1017 1018 ret = read_config_rom(device, device->generation); 1019 if (ret != RCODE_COMPLETE) { 1020 if (device->config_rom_retries < MAX_RETRIES && 1021 atomic_read(&device->state) == FW_DEVICE_INITIALIZING) { 1022 device->config_rom_retries++; 1023 fw_schedule_device_work(device, RETRY_DELAY); 1024 } else { 1025 if (device->node->link_on) 1026 fw_notice(card, "giving up on node %x: reading config rom failed: %s\n", 1027 device->node_id, 1028 fw_rcode_string(ret)); 1029 if (device->node == card->root_node) 1030 fw_schedule_bm_work(card, 0); 1031 fw_device_release(&device->device); 1032 } 1033 return; 1034 } 1035 1036 // If a device was pending for deletion because its node went away but its bus info block 1037 // and root directory header matches that of a newly discovered device, revive the 1038 // existing fw_device. The newly allocated fw_device becomes obsolete instead. 1039 // 1040 // serialize config_rom access. 1041 scoped_guard(rwsem_read, &fw_device_rwsem) { 1042 found = device_find_child(card->device, (void *)device->config_rom, 1043 compare_configuration_rom); 1044 } 1045 if (found) { 1046 struct fw_device *reused = fw_device(found); 1047 1048 if (atomic_cmpxchg(&reused->state, 1049 FW_DEVICE_GONE, 1050 FW_DEVICE_RUNNING) == FW_DEVICE_GONE) { 1051 // serialize node access 1052 scoped_guard(spinlock_irq, &card->lock) { 1053 struct fw_node *current_node = device->node; 1054 struct fw_node *obsolete_node = reused->node; 1055 1056 device->node = obsolete_node; 1057 device->node->data = device; 1058 reused->node = current_node; 1059 reused->node->data = reused; 1060 1061 reused->max_speed = device->max_speed; 1062 reused->node_id = current_node->node_id; 1063 smp_wmb(); /* update node_id before generation */ 1064 reused->generation = card->generation; 1065 reused->config_rom_retries = 0; 1066 fw_notice(card, "rediscovered device %s\n", 1067 dev_name(found)); 1068 1069 reused->workfn = fw_device_update; 1070 fw_schedule_device_work(reused, 0); 1071 1072 if (current_node == card->root_node) 1073 fw_schedule_bm_work(card, 0); 1074 } 1075 1076 put_device(found); 1077 fw_device_release(&device->device); 1078 1079 return; 1080 } 1081 1082 put_device(found); 1083 } 1084 1085 device_initialize(&device->device); 1086 1087 fw_device_get(device); 1088 1089 // The index of allocated entry is used for minor identifier of device node. 1090 ret = xa_alloc(&fw_device_xa, &minor, device, XA_LIMIT(0, MINORMASK), GFP_KERNEL); 1091 if (ret < 0) 1092 goto error; 1093 1094 device->device.bus = &fw_bus_type; 1095 device->device.type = &fw_device_type; 1096 device->device.parent = card->device; 1097 device->device.devt = MKDEV(fw_cdev_major, minor); 1098 dev_set_name(&device->device, "fw%d", minor); 1099 1100 BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) < 1101 ARRAY_SIZE(fw_device_attributes) + 1102 ARRAY_SIZE(config_rom_attributes)); 1103 init_fw_attribute_group(&device->device, 1104 fw_device_attributes, 1105 &device->attribute_group); 1106 1107 if (device_add(&device->device)) { 1108 fw_err(card, "failed to add device\n"); 1109 goto error_with_cdev; 1110 } 1111 1112 create_units(device); 1113 1114 /* 1115 * Transition the device to running state. If it got pulled 1116 * out from under us while we did the initialization work, we 1117 * have to shut down the device again here. Normally, though, 1118 * fw_node_event will be responsible for shutting it down when 1119 * necessary. We have to use the atomic cmpxchg here to avoid 1120 * racing with the FW_NODE_DESTROYED case in 1121 * fw_node_event(). 1122 */ 1123 if (atomic_cmpxchg(&device->state, 1124 FW_DEVICE_INITIALIZING, 1125 FW_DEVICE_RUNNING) == FW_DEVICE_GONE) { 1126 device->workfn = fw_device_shutdown; 1127 fw_schedule_device_work(device, SHUTDOWN_DELAY); 1128 } else { 1129 fw_notice(card, "created device %s: GUID %08x%08x, S%d00\n", 1130 dev_name(&device->device), 1131 device->config_rom[3], device->config_rom[4], 1132 1 << device->max_speed); 1133 device->config_rom_retries = 0; 1134 1135 set_broadcast_channel(device, device->generation); 1136 1137 add_device_randomness(&device->config_rom[3], 8); 1138 } 1139 1140 /* 1141 * Reschedule the IRM work if we just finished reading the 1142 * root node config rom. If this races with a bus reset we 1143 * just end up running the IRM work a couple of extra times - 1144 * pretty harmless. 1145 */ 1146 if (device->node == card->root_node) 1147 fw_schedule_bm_work(card, 0); 1148 1149 return; 1150 1151 error_with_cdev: 1152 xa_erase(&fw_device_xa, minor); 1153 error: 1154 fw_device_put(device); // fw_device_xa's reference. 1155 1156 put_device(&device->device); /* our reference */ 1157 } 1158 1159 /* Reread and compare bus info block and header of root directory */ 1160 static int reread_config_rom(struct fw_device *device, int generation, 1161 bool *changed) 1162 { 1163 u32 q; 1164 int i, rcode; 1165 1166 for (i = 0; i < 6; i++) { 1167 rcode = read_rom(device, generation, i, &q); 1168 if (rcode != RCODE_COMPLETE) 1169 return rcode; 1170 1171 if (i == 0 && q == 0) 1172 /* inaccessible (see read_config_rom); retry later */ 1173 return RCODE_BUSY; 1174 1175 if (q != device->config_rom[i]) { 1176 *changed = true; 1177 return RCODE_COMPLETE; 1178 } 1179 } 1180 1181 *changed = false; 1182 return RCODE_COMPLETE; 1183 } 1184 1185 static void fw_device_refresh(struct work_struct *work) 1186 { 1187 struct fw_device *device = 1188 container_of(work, struct fw_device, work.work); 1189 struct fw_card *card = device->card; 1190 int ret, node_id = device->node_id; 1191 bool changed; 1192 1193 ret = reread_config_rom(device, device->generation, &changed); 1194 if (ret != RCODE_COMPLETE) 1195 goto failed_config_rom; 1196 1197 if (!changed) { 1198 if (atomic_cmpxchg(&device->state, 1199 FW_DEVICE_INITIALIZING, 1200 FW_DEVICE_RUNNING) == FW_DEVICE_GONE) 1201 goto gone; 1202 1203 fw_device_update(work); 1204 device->config_rom_retries = 0; 1205 goto out; 1206 } 1207 1208 /* 1209 * Something changed. We keep things simple and don't investigate 1210 * further. We just destroy all previous units and create new ones. 1211 */ 1212 device_for_each_child(&device->device, NULL, shutdown_unit); 1213 1214 ret = read_config_rom(device, device->generation); 1215 if (ret != RCODE_COMPLETE) 1216 goto failed_config_rom; 1217 1218 fw_device_cdev_update(device); 1219 create_units(device); 1220 1221 /* Userspace may want to re-read attributes. */ 1222 kobject_uevent(&device->device.kobj, KOBJ_CHANGE); 1223 1224 if (atomic_cmpxchg(&device->state, 1225 FW_DEVICE_INITIALIZING, 1226 FW_DEVICE_RUNNING) == FW_DEVICE_GONE) 1227 goto gone; 1228 1229 fw_notice(card, "refreshed device %s\n", dev_name(&device->device)); 1230 device->config_rom_retries = 0; 1231 goto out; 1232 1233 failed_config_rom: 1234 if (device->config_rom_retries < MAX_RETRIES && 1235 atomic_read(&device->state) == FW_DEVICE_INITIALIZING) { 1236 device->config_rom_retries++; 1237 fw_schedule_device_work(device, RETRY_DELAY); 1238 return; 1239 } 1240 1241 fw_notice(card, "giving up on refresh of device %s: %s\n", 1242 dev_name(&device->device), fw_rcode_string(ret)); 1243 gone: 1244 atomic_set(&device->state, FW_DEVICE_GONE); 1245 device->workfn = fw_device_shutdown; 1246 fw_schedule_device_work(device, SHUTDOWN_DELAY); 1247 out: 1248 if (node_id == card->root_node->node_id) 1249 fw_schedule_bm_work(card, 0); 1250 } 1251 1252 static void fw_device_workfn(struct work_struct *work) 1253 { 1254 struct fw_device *device = container_of(to_delayed_work(work), 1255 struct fw_device, work); 1256 device->workfn(work); 1257 } 1258 1259 void fw_node_event(struct fw_card *card, struct fw_node *node, int event) 1260 { 1261 struct fw_device *device; 1262 1263 switch (event) { 1264 case FW_NODE_CREATED: 1265 /* 1266 * Attempt to scan the node, regardless whether its self ID has 1267 * the L (link active) flag set or not. Some broken devices 1268 * send L=0 but have an up-and-running link; others send L=1 1269 * without actually having a link. 1270 */ 1271 create: 1272 device = kzalloc(sizeof(*device), GFP_ATOMIC); 1273 if (device == NULL) 1274 break; 1275 1276 /* 1277 * Do minimal initialization of the device here, the 1278 * rest will happen in fw_device_init(). 1279 * 1280 * Attention: A lot of things, even fw_device_get(), 1281 * cannot be done before fw_device_init() finished! 1282 * You can basically just check device->state and 1283 * schedule work until then, but only while holding 1284 * card->lock. 1285 */ 1286 atomic_set(&device->state, FW_DEVICE_INITIALIZING); 1287 device->card = fw_card_get(card); 1288 device->node = fw_node_get(node); 1289 device->node_id = node->node_id; 1290 device->generation = card->generation; 1291 device->is_local = node == card->local_node; 1292 mutex_init(&device->client_list_mutex); 1293 INIT_LIST_HEAD(&device->client_list); 1294 1295 /* 1296 * Set the node data to point back to this device so 1297 * FW_NODE_UPDATED callbacks can update the node_id 1298 * and generation for the device. 1299 */ 1300 node->data = device; 1301 1302 /* 1303 * Many devices are slow to respond after bus resets, 1304 * especially if they are bus powered and go through 1305 * power-up after getting plugged in. We schedule the 1306 * first config rom scan half a second after bus reset. 1307 */ 1308 device->workfn = fw_device_init; 1309 INIT_DELAYED_WORK(&device->work, fw_device_workfn); 1310 fw_schedule_device_work(device, INITIAL_DELAY); 1311 break; 1312 1313 case FW_NODE_INITIATED_RESET: 1314 case FW_NODE_LINK_ON: 1315 device = node->data; 1316 if (device == NULL) 1317 goto create; 1318 1319 device->node_id = node->node_id; 1320 smp_wmb(); /* update node_id before generation */ 1321 device->generation = card->generation; 1322 if (atomic_cmpxchg(&device->state, 1323 FW_DEVICE_RUNNING, 1324 FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) { 1325 device->workfn = fw_device_refresh; 1326 fw_schedule_device_work(device, 1327 device->is_local ? 0 : INITIAL_DELAY); 1328 } 1329 break; 1330 1331 case FW_NODE_UPDATED: 1332 device = node->data; 1333 if (device == NULL) 1334 break; 1335 1336 device->node_id = node->node_id; 1337 smp_wmb(); /* update node_id before generation */ 1338 device->generation = card->generation; 1339 if (atomic_read(&device->state) == FW_DEVICE_RUNNING) { 1340 device->workfn = fw_device_update; 1341 fw_schedule_device_work(device, 0); 1342 } 1343 break; 1344 1345 case FW_NODE_DESTROYED: 1346 case FW_NODE_LINK_OFF: 1347 if (!node->data) 1348 break; 1349 1350 /* 1351 * Destroy the device associated with the node. There 1352 * are two cases here: either the device is fully 1353 * initialized (FW_DEVICE_RUNNING) or we're in the 1354 * process of reading its config rom 1355 * (FW_DEVICE_INITIALIZING). If it is fully 1356 * initialized we can reuse device->work to schedule a 1357 * full fw_device_shutdown(). If not, there's work 1358 * scheduled to read it's config rom, and we just put 1359 * the device in shutdown state to have that code fail 1360 * to create the device. 1361 */ 1362 device = node->data; 1363 if (atomic_xchg(&device->state, 1364 FW_DEVICE_GONE) == FW_DEVICE_RUNNING) { 1365 device->workfn = fw_device_shutdown; 1366 fw_schedule_device_work(device, 1367 list_empty(&card->link) ? 0 : SHUTDOWN_DELAY); 1368 } 1369 break; 1370 } 1371 } 1372 1373 #ifdef CONFIG_FIREWIRE_KUNIT_DEVICE_ATTRIBUTE_TEST 1374 #include "device-attribute-test.c" 1375 #endif 1376