1 /* 2 * Device probing and sysfs code. 3 * 4 * Copyright (C) 2005-2006 Kristian Hoegsberg <krh@bitplanet.net> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software Foundation, 18 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 19 */ 20 21 #include <linux/bug.h> 22 #include <linux/ctype.h> 23 #include <linux/delay.h> 24 #include <linux/device.h> 25 #include <linux/errno.h> 26 #include <linux/firewire.h> 27 #include <linux/firewire-constants.h> 28 #include <linux/idr.h> 29 #include <linux/jiffies.h> 30 #include <linux/kobject.h> 31 #include <linux/list.h> 32 #include <linux/mod_devicetable.h> 33 #include <linux/module.h> 34 #include <linux/mutex.h> 35 #include <linux/random.h> 36 #include <linux/rwsem.h> 37 #include <linux/slab.h> 38 #include <linux/spinlock.h> 39 #include <linux/string.h> 40 #include <linux/workqueue.h> 41 42 #include <linux/atomic.h> 43 #include <asm/byteorder.h> 44 45 #include "core.h" 46 47 void fw_csr_iterator_init(struct fw_csr_iterator *ci, const u32 *p) 48 { 49 ci->p = p + 1; 50 ci->end = ci->p + (p[0] >> 16); 51 } 52 EXPORT_SYMBOL(fw_csr_iterator_init); 53 54 int fw_csr_iterator_next(struct fw_csr_iterator *ci, int *key, int *value) 55 { 56 *key = *ci->p >> 24; 57 *value = *ci->p & 0xffffff; 58 59 return ci->p++ < ci->end; 60 } 61 EXPORT_SYMBOL(fw_csr_iterator_next); 62 63 static const u32 *search_leaf(const u32 *directory, int search_key) 64 { 65 struct fw_csr_iterator ci; 66 int last_key = 0, key, value; 67 68 fw_csr_iterator_init(&ci, directory); 69 while (fw_csr_iterator_next(&ci, &key, &value)) { 70 if (last_key == search_key && 71 key == (CSR_DESCRIPTOR | CSR_LEAF)) 72 return ci.p - 1 + value; 73 74 last_key = key; 75 } 76 77 return NULL; 78 } 79 80 static int textual_leaf_to_string(const u32 *block, char *buf, size_t size) 81 { 82 unsigned int quadlets, i; 83 char c; 84 85 if (!size || !buf) 86 return -EINVAL; 87 88 quadlets = min(block[0] >> 16, 256U); 89 if (quadlets < 2) 90 return -ENODATA; 91 92 if (block[1] != 0 || block[2] != 0) 93 /* unknown language/character set */ 94 return -ENODATA; 95 96 block += 3; 97 quadlets -= 2; 98 for (i = 0; i < quadlets * 4 && i < size - 1; i++) { 99 c = block[i / 4] >> (24 - 8 * (i % 4)); 100 if (c == '\0') 101 break; 102 buf[i] = c; 103 } 104 buf[i] = '\0'; 105 106 return i; 107 } 108 109 /** 110 * fw_csr_string() - reads a string from the configuration ROM 111 * @directory: e.g. root directory or unit directory 112 * @key: the key of the preceding directory entry 113 * @buf: where to put the string 114 * @size: size of @buf, in bytes 115 * 116 * The string is taken from a minimal ASCII text descriptor leaf after 117 * the immediate entry with @key. The string is zero-terminated. 118 * An overlong string is silently truncated such that it and the 119 * zero byte fit into @size. 120 * 121 * Returns strlen(buf) or a negative error code. 122 */ 123 int fw_csr_string(const u32 *directory, int key, char *buf, size_t size) 124 { 125 const u32 *leaf = search_leaf(directory, key); 126 if (!leaf) 127 return -ENOENT; 128 129 return textual_leaf_to_string(leaf, buf, size); 130 } 131 EXPORT_SYMBOL(fw_csr_string); 132 133 static void get_ids(const u32 *directory, int *id) 134 { 135 struct fw_csr_iterator ci; 136 int key, value; 137 138 fw_csr_iterator_init(&ci, directory); 139 while (fw_csr_iterator_next(&ci, &key, &value)) { 140 switch (key) { 141 case CSR_VENDOR: id[0] = value; break; 142 case CSR_MODEL: id[1] = value; break; 143 case CSR_SPECIFIER_ID: id[2] = value; break; 144 case CSR_VERSION: id[3] = value; break; 145 } 146 } 147 } 148 149 static void get_modalias_ids(struct fw_unit *unit, int *id) 150 { 151 get_ids(&fw_parent_device(unit)->config_rom[5], id); 152 get_ids(unit->directory, id); 153 } 154 155 static bool match_ids(const struct ieee1394_device_id *id_table, int *id) 156 { 157 int match = 0; 158 159 if (id[0] == id_table->vendor_id) 160 match |= IEEE1394_MATCH_VENDOR_ID; 161 if (id[1] == id_table->model_id) 162 match |= IEEE1394_MATCH_MODEL_ID; 163 if (id[2] == id_table->specifier_id) 164 match |= IEEE1394_MATCH_SPECIFIER_ID; 165 if (id[3] == id_table->version) 166 match |= IEEE1394_MATCH_VERSION; 167 168 return (match & id_table->match_flags) == id_table->match_flags; 169 } 170 171 static const struct ieee1394_device_id *unit_match(struct device *dev, 172 struct device_driver *drv) 173 { 174 const struct ieee1394_device_id *id_table = 175 container_of(drv, struct fw_driver, driver)->id_table; 176 int id[] = {0, 0, 0, 0}; 177 178 get_modalias_ids(fw_unit(dev), id); 179 180 for (; id_table->match_flags != 0; id_table++) 181 if (match_ids(id_table, id)) 182 return id_table; 183 184 return NULL; 185 } 186 187 static bool is_fw_unit(struct device *dev); 188 189 static int fw_unit_match(struct device *dev, struct device_driver *drv) 190 { 191 /* We only allow binding to fw_units. */ 192 return is_fw_unit(dev) && unit_match(dev, drv) != NULL; 193 } 194 195 static int fw_unit_probe(struct device *dev) 196 { 197 struct fw_driver *driver = 198 container_of(dev->driver, struct fw_driver, driver); 199 200 return driver->probe(fw_unit(dev), unit_match(dev, dev->driver)); 201 } 202 203 static int fw_unit_remove(struct device *dev) 204 { 205 struct fw_driver *driver = 206 container_of(dev->driver, struct fw_driver, driver); 207 208 return driver->remove(fw_unit(dev)), 0; 209 } 210 211 static int get_modalias(struct fw_unit *unit, char *buffer, size_t buffer_size) 212 { 213 int id[] = {0, 0, 0, 0}; 214 215 get_modalias_ids(unit, id); 216 217 return snprintf(buffer, buffer_size, 218 "ieee1394:ven%08Xmo%08Xsp%08Xver%08X", 219 id[0], id[1], id[2], id[3]); 220 } 221 222 static int fw_unit_uevent(struct device *dev, struct kobj_uevent_env *env) 223 { 224 struct fw_unit *unit = fw_unit(dev); 225 char modalias[64]; 226 227 get_modalias(unit, modalias, sizeof(modalias)); 228 229 if (add_uevent_var(env, "MODALIAS=%s", modalias)) 230 return -ENOMEM; 231 232 return 0; 233 } 234 235 struct bus_type fw_bus_type = { 236 .name = "firewire", 237 .match = fw_unit_match, 238 .probe = fw_unit_probe, 239 .remove = fw_unit_remove, 240 }; 241 EXPORT_SYMBOL(fw_bus_type); 242 243 int fw_device_enable_phys_dma(struct fw_device *device) 244 { 245 int generation = device->generation; 246 247 /* device->node_id, accessed below, must not be older than generation */ 248 smp_rmb(); 249 250 return device->card->driver->enable_phys_dma(device->card, 251 device->node_id, 252 generation); 253 } 254 EXPORT_SYMBOL(fw_device_enable_phys_dma); 255 256 struct config_rom_attribute { 257 struct device_attribute attr; 258 u32 key; 259 }; 260 261 static ssize_t show_immediate(struct device *dev, 262 struct device_attribute *dattr, char *buf) 263 { 264 struct config_rom_attribute *attr = 265 container_of(dattr, struct config_rom_attribute, attr); 266 struct fw_csr_iterator ci; 267 const u32 *dir; 268 int key, value, ret = -ENOENT; 269 270 down_read(&fw_device_rwsem); 271 272 if (is_fw_unit(dev)) 273 dir = fw_unit(dev)->directory; 274 else 275 dir = fw_device(dev)->config_rom + 5; 276 277 fw_csr_iterator_init(&ci, dir); 278 while (fw_csr_iterator_next(&ci, &key, &value)) 279 if (attr->key == key) { 280 ret = snprintf(buf, buf ? PAGE_SIZE : 0, 281 "0x%06x\n", value); 282 break; 283 } 284 285 up_read(&fw_device_rwsem); 286 287 return ret; 288 } 289 290 #define IMMEDIATE_ATTR(name, key) \ 291 { __ATTR(name, S_IRUGO, show_immediate, NULL), key } 292 293 static ssize_t show_text_leaf(struct device *dev, 294 struct device_attribute *dattr, char *buf) 295 { 296 struct config_rom_attribute *attr = 297 container_of(dattr, struct config_rom_attribute, attr); 298 const u32 *dir; 299 size_t bufsize; 300 char dummy_buf[2]; 301 int ret; 302 303 down_read(&fw_device_rwsem); 304 305 if (is_fw_unit(dev)) 306 dir = fw_unit(dev)->directory; 307 else 308 dir = fw_device(dev)->config_rom + 5; 309 310 if (buf) { 311 bufsize = PAGE_SIZE - 1; 312 } else { 313 buf = dummy_buf; 314 bufsize = 1; 315 } 316 317 ret = fw_csr_string(dir, attr->key, buf, bufsize); 318 319 if (ret >= 0) { 320 /* Strip trailing whitespace and add newline. */ 321 while (ret > 0 && isspace(buf[ret - 1])) 322 ret--; 323 strcpy(buf + ret, "\n"); 324 ret++; 325 } 326 327 up_read(&fw_device_rwsem); 328 329 return ret; 330 } 331 332 #define TEXT_LEAF_ATTR(name, key) \ 333 { __ATTR(name, S_IRUGO, show_text_leaf, NULL), key } 334 335 static struct config_rom_attribute config_rom_attributes[] = { 336 IMMEDIATE_ATTR(vendor, CSR_VENDOR), 337 IMMEDIATE_ATTR(hardware_version, CSR_HARDWARE_VERSION), 338 IMMEDIATE_ATTR(specifier_id, CSR_SPECIFIER_ID), 339 IMMEDIATE_ATTR(version, CSR_VERSION), 340 IMMEDIATE_ATTR(model, CSR_MODEL), 341 TEXT_LEAF_ATTR(vendor_name, CSR_VENDOR), 342 TEXT_LEAF_ATTR(model_name, CSR_MODEL), 343 TEXT_LEAF_ATTR(hardware_version_name, CSR_HARDWARE_VERSION), 344 }; 345 346 static void init_fw_attribute_group(struct device *dev, 347 struct device_attribute *attrs, 348 struct fw_attribute_group *group) 349 { 350 struct device_attribute *attr; 351 int i, j; 352 353 for (j = 0; attrs[j].attr.name != NULL; j++) 354 group->attrs[j] = &attrs[j].attr; 355 356 for (i = 0; i < ARRAY_SIZE(config_rom_attributes); i++) { 357 attr = &config_rom_attributes[i].attr; 358 if (attr->show(dev, attr, NULL) < 0) 359 continue; 360 group->attrs[j++] = &attr->attr; 361 } 362 363 group->attrs[j] = NULL; 364 group->groups[0] = &group->group; 365 group->groups[1] = NULL; 366 group->group.attrs = group->attrs; 367 dev->groups = (const struct attribute_group **) group->groups; 368 } 369 370 static ssize_t modalias_show(struct device *dev, 371 struct device_attribute *attr, char *buf) 372 { 373 struct fw_unit *unit = fw_unit(dev); 374 int length; 375 376 length = get_modalias(unit, buf, PAGE_SIZE); 377 strcpy(buf + length, "\n"); 378 379 return length + 1; 380 } 381 382 static ssize_t rom_index_show(struct device *dev, 383 struct device_attribute *attr, char *buf) 384 { 385 struct fw_device *device = fw_device(dev->parent); 386 struct fw_unit *unit = fw_unit(dev); 387 388 return snprintf(buf, PAGE_SIZE, "%d\n", 389 (int)(unit->directory - device->config_rom)); 390 } 391 392 static struct device_attribute fw_unit_attributes[] = { 393 __ATTR_RO(modalias), 394 __ATTR_RO(rom_index), 395 __ATTR_NULL, 396 }; 397 398 static ssize_t config_rom_show(struct device *dev, 399 struct device_attribute *attr, char *buf) 400 { 401 struct fw_device *device = fw_device(dev); 402 size_t length; 403 404 down_read(&fw_device_rwsem); 405 length = device->config_rom_length * 4; 406 memcpy(buf, device->config_rom, length); 407 up_read(&fw_device_rwsem); 408 409 return length; 410 } 411 412 static ssize_t guid_show(struct device *dev, 413 struct device_attribute *attr, char *buf) 414 { 415 struct fw_device *device = fw_device(dev); 416 int ret; 417 418 down_read(&fw_device_rwsem); 419 ret = snprintf(buf, PAGE_SIZE, "0x%08x%08x\n", 420 device->config_rom[3], device->config_rom[4]); 421 up_read(&fw_device_rwsem); 422 423 return ret; 424 } 425 426 static ssize_t is_local_show(struct device *dev, 427 struct device_attribute *attr, char *buf) 428 { 429 struct fw_device *device = fw_device(dev); 430 431 return sprintf(buf, "%u\n", device->is_local); 432 } 433 434 static int units_sprintf(char *buf, const u32 *directory) 435 { 436 struct fw_csr_iterator ci; 437 int key, value; 438 int specifier_id = 0; 439 int version = 0; 440 441 fw_csr_iterator_init(&ci, directory); 442 while (fw_csr_iterator_next(&ci, &key, &value)) { 443 switch (key) { 444 case CSR_SPECIFIER_ID: 445 specifier_id = value; 446 break; 447 case CSR_VERSION: 448 version = value; 449 break; 450 } 451 } 452 453 return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version); 454 } 455 456 static ssize_t units_show(struct device *dev, 457 struct device_attribute *attr, char *buf) 458 { 459 struct fw_device *device = fw_device(dev); 460 struct fw_csr_iterator ci; 461 int key, value, i = 0; 462 463 down_read(&fw_device_rwsem); 464 fw_csr_iterator_init(&ci, &device->config_rom[5]); 465 while (fw_csr_iterator_next(&ci, &key, &value)) { 466 if (key != (CSR_UNIT | CSR_DIRECTORY)) 467 continue; 468 i += units_sprintf(&buf[i], ci.p + value - 1); 469 if (i >= PAGE_SIZE - (8 + 1 + 8 + 1)) 470 break; 471 } 472 up_read(&fw_device_rwsem); 473 474 if (i) 475 buf[i - 1] = '\n'; 476 477 return i; 478 } 479 480 static struct device_attribute fw_device_attributes[] = { 481 __ATTR_RO(config_rom), 482 __ATTR_RO(guid), 483 __ATTR_RO(is_local), 484 __ATTR_RO(units), 485 __ATTR_NULL, 486 }; 487 488 static int read_rom(struct fw_device *device, 489 int generation, int index, u32 *data) 490 { 491 u64 offset = (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4; 492 int i, rcode; 493 494 /* device->node_id, accessed below, must not be older than generation */ 495 smp_rmb(); 496 497 for (i = 10; i < 100; i += 10) { 498 rcode = fw_run_transaction(device->card, 499 TCODE_READ_QUADLET_REQUEST, device->node_id, 500 generation, device->max_speed, offset, data, 4); 501 if (rcode != RCODE_BUSY) 502 break; 503 msleep(i); 504 } 505 be32_to_cpus(data); 506 507 return rcode; 508 } 509 510 #define MAX_CONFIG_ROM_SIZE 256 511 512 /* 513 * Read the bus info block, perform a speed probe, and read all of the rest of 514 * the config ROM. We do all this with a cached bus generation. If the bus 515 * generation changes under us, read_config_rom will fail and get retried. 516 * It's better to start all over in this case because the node from which we 517 * are reading the ROM may have changed the ROM during the reset. 518 * Returns either a result code or a negative error code. 519 */ 520 static int read_config_rom(struct fw_device *device, int generation) 521 { 522 struct fw_card *card = device->card; 523 const u32 *old_rom, *new_rom; 524 u32 *rom, *stack; 525 u32 sp, key; 526 int i, end, length, ret; 527 528 rom = kmalloc(sizeof(*rom) * MAX_CONFIG_ROM_SIZE + 529 sizeof(*stack) * MAX_CONFIG_ROM_SIZE, GFP_KERNEL); 530 if (rom == NULL) 531 return -ENOMEM; 532 533 stack = &rom[MAX_CONFIG_ROM_SIZE]; 534 memset(rom, 0, sizeof(*rom) * MAX_CONFIG_ROM_SIZE); 535 536 device->max_speed = SCODE_100; 537 538 /* First read the bus info block. */ 539 for (i = 0; i < 5; i++) { 540 ret = read_rom(device, generation, i, &rom[i]); 541 if (ret != RCODE_COMPLETE) 542 goto out; 543 /* 544 * As per IEEE1212 7.2, during initialization, devices can 545 * reply with a 0 for the first quadlet of the config 546 * rom to indicate that they are booting (for example, 547 * if the firmware is on the disk of a external 548 * harddisk). In that case we just fail, and the 549 * retry mechanism will try again later. 550 */ 551 if (i == 0 && rom[i] == 0) { 552 ret = RCODE_BUSY; 553 goto out; 554 } 555 } 556 557 device->max_speed = device->node->max_speed; 558 559 /* 560 * Determine the speed of 561 * - devices with link speed less than PHY speed, 562 * - devices with 1394b PHY (unless only connected to 1394a PHYs), 563 * - all devices if there are 1394b repeaters. 564 * Note, we cannot use the bus info block's link_spd as starting point 565 * because some buggy firmwares set it lower than necessary and because 566 * 1394-1995 nodes do not have the field. 567 */ 568 if ((rom[2] & 0x7) < device->max_speed || 569 device->max_speed == SCODE_BETA || 570 card->beta_repeaters_present) { 571 u32 dummy; 572 573 /* for S1600 and S3200 */ 574 if (device->max_speed == SCODE_BETA) 575 device->max_speed = card->link_speed; 576 577 while (device->max_speed > SCODE_100) { 578 if (read_rom(device, generation, 0, &dummy) == 579 RCODE_COMPLETE) 580 break; 581 device->max_speed--; 582 } 583 } 584 585 /* 586 * Now parse the config rom. The config rom is a recursive 587 * directory structure so we parse it using a stack of 588 * references to the blocks that make up the structure. We 589 * push a reference to the root directory on the stack to 590 * start things off. 591 */ 592 length = i; 593 sp = 0; 594 stack[sp++] = 0xc0000005; 595 while (sp > 0) { 596 /* 597 * Pop the next block reference of the stack. The 598 * lower 24 bits is the offset into the config rom, 599 * the upper 8 bits are the type of the reference the 600 * block. 601 */ 602 key = stack[--sp]; 603 i = key & 0xffffff; 604 if (WARN_ON(i >= MAX_CONFIG_ROM_SIZE)) { 605 ret = -ENXIO; 606 goto out; 607 } 608 609 /* Read header quadlet for the block to get the length. */ 610 ret = read_rom(device, generation, i, &rom[i]); 611 if (ret != RCODE_COMPLETE) 612 goto out; 613 end = i + (rom[i] >> 16) + 1; 614 if (end > MAX_CONFIG_ROM_SIZE) { 615 /* 616 * This block extends outside the config ROM which is 617 * a firmware bug. Ignore this whole block, i.e. 618 * simply set a fake block length of 0. 619 */ 620 fw_err(card, "skipped invalid ROM block %x at %llx\n", 621 rom[i], 622 i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM); 623 rom[i] = 0; 624 end = i; 625 } 626 i++; 627 628 /* 629 * Now read in the block. If this is a directory 630 * block, check the entries as we read them to see if 631 * it references another block, and push it in that case. 632 */ 633 for (; i < end; i++) { 634 ret = read_rom(device, generation, i, &rom[i]); 635 if (ret != RCODE_COMPLETE) 636 goto out; 637 638 if ((key >> 30) != 3 || (rom[i] >> 30) < 2) 639 continue; 640 /* 641 * Offset points outside the ROM. May be a firmware 642 * bug or an Extended ROM entry (IEEE 1212-2001 clause 643 * 7.7.18). Simply overwrite this pointer here by a 644 * fake immediate entry so that later iterators over 645 * the ROM don't have to check offsets all the time. 646 */ 647 if (i + (rom[i] & 0xffffff) >= MAX_CONFIG_ROM_SIZE) { 648 fw_err(card, 649 "skipped unsupported ROM entry %x at %llx\n", 650 rom[i], 651 i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM); 652 rom[i] = 0; 653 continue; 654 } 655 stack[sp++] = i + rom[i]; 656 } 657 if (length < i) 658 length = i; 659 } 660 661 old_rom = device->config_rom; 662 new_rom = kmemdup(rom, length * 4, GFP_KERNEL); 663 if (new_rom == NULL) { 664 ret = -ENOMEM; 665 goto out; 666 } 667 668 down_write(&fw_device_rwsem); 669 device->config_rom = new_rom; 670 device->config_rom_length = length; 671 up_write(&fw_device_rwsem); 672 673 kfree(old_rom); 674 ret = RCODE_COMPLETE; 675 device->max_rec = rom[2] >> 12 & 0xf; 676 device->cmc = rom[2] >> 30 & 1; 677 device->irmc = rom[2] >> 31 & 1; 678 out: 679 kfree(rom); 680 681 return ret; 682 } 683 684 static void fw_unit_release(struct device *dev) 685 { 686 struct fw_unit *unit = fw_unit(dev); 687 688 fw_device_put(fw_parent_device(unit)); 689 kfree(unit); 690 } 691 692 static struct device_type fw_unit_type = { 693 .uevent = fw_unit_uevent, 694 .release = fw_unit_release, 695 }; 696 697 static bool is_fw_unit(struct device *dev) 698 { 699 return dev->type == &fw_unit_type; 700 } 701 702 static void create_units(struct fw_device *device) 703 { 704 struct fw_csr_iterator ci; 705 struct fw_unit *unit; 706 int key, value, i; 707 708 i = 0; 709 fw_csr_iterator_init(&ci, &device->config_rom[5]); 710 while (fw_csr_iterator_next(&ci, &key, &value)) { 711 if (key != (CSR_UNIT | CSR_DIRECTORY)) 712 continue; 713 714 /* 715 * Get the address of the unit directory and try to 716 * match the drivers id_tables against it. 717 */ 718 unit = kzalloc(sizeof(*unit), GFP_KERNEL); 719 if (unit == NULL) 720 continue; 721 722 unit->directory = ci.p + value - 1; 723 unit->device.bus = &fw_bus_type; 724 unit->device.type = &fw_unit_type; 725 unit->device.parent = &device->device; 726 dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++); 727 728 BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) < 729 ARRAY_SIZE(fw_unit_attributes) + 730 ARRAY_SIZE(config_rom_attributes)); 731 init_fw_attribute_group(&unit->device, 732 fw_unit_attributes, 733 &unit->attribute_group); 734 735 if (device_register(&unit->device) < 0) 736 goto skip_unit; 737 738 fw_device_get(device); 739 continue; 740 741 skip_unit: 742 kfree(unit); 743 } 744 } 745 746 static int shutdown_unit(struct device *device, void *data) 747 { 748 device_unregister(device); 749 750 return 0; 751 } 752 753 /* 754 * fw_device_rwsem acts as dual purpose mutex: 755 * - serializes accesses to fw_device_idr, 756 * - serializes accesses to fw_device.config_rom/.config_rom_length and 757 * fw_unit.directory, unless those accesses happen at safe occasions 758 */ 759 DECLARE_RWSEM(fw_device_rwsem); 760 761 DEFINE_IDR(fw_device_idr); 762 int fw_cdev_major; 763 764 struct fw_device *fw_device_get_by_devt(dev_t devt) 765 { 766 struct fw_device *device; 767 768 down_read(&fw_device_rwsem); 769 device = idr_find(&fw_device_idr, MINOR(devt)); 770 if (device) 771 fw_device_get(device); 772 up_read(&fw_device_rwsem); 773 774 return device; 775 } 776 777 struct workqueue_struct *fw_workqueue; 778 EXPORT_SYMBOL(fw_workqueue); 779 780 static void fw_schedule_device_work(struct fw_device *device, 781 unsigned long delay) 782 { 783 queue_delayed_work(fw_workqueue, &device->work, delay); 784 } 785 786 /* 787 * These defines control the retry behavior for reading the config 788 * rom. It shouldn't be necessary to tweak these; if the device 789 * doesn't respond to a config rom read within 10 seconds, it's not 790 * going to respond at all. As for the initial delay, a lot of 791 * devices will be able to respond within half a second after bus 792 * reset. On the other hand, it's not really worth being more 793 * aggressive than that, since it scales pretty well; if 10 devices 794 * are plugged in, they're all getting read within one second. 795 */ 796 797 #define MAX_RETRIES 10 798 #define RETRY_DELAY (3 * HZ) 799 #define INITIAL_DELAY (HZ / 2) 800 #define SHUTDOWN_DELAY (2 * HZ) 801 802 static void fw_device_shutdown(struct work_struct *work) 803 { 804 struct fw_device *device = 805 container_of(work, struct fw_device, work.work); 806 int minor = MINOR(device->device.devt); 807 808 if (time_before64(get_jiffies_64(), 809 device->card->reset_jiffies + SHUTDOWN_DELAY) 810 && !list_empty(&device->card->link)) { 811 fw_schedule_device_work(device, SHUTDOWN_DELAY); 812 return; 813 } 814 815 if (atomic_cmpxchg(&device->state, 816 FW_DEVICE_GONE, 817 FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE) 818 return; 819 820 fw_device_cdev_remove(device); 821 device_for_each_child(&device->device, NULL, shutdown_unit); 822 device_unregister(&device->device); 823 824 down_write(&fw_device_rwsem); 825 idr_remove(&fw_device_idr, minor); 826 up_write(&fw_device_rwsem); 827 828 fw_device_put(device); 829 } 830 831 static void fw_device_release(struct device *dev) 832 { 833 struct fw_device *device = fw_device(dev); 834 struct fw_card *card = device->card; 835 unsigned long flags; 836 837 /* 838 * Take the card lock so we don't set this to NULL while a 839 * FW_NODE_UPDATED callback is being handled or while the 840 * bus manager work looks at this node. 841 */ 842 spin_lock_irqsave(&card->lock, flags); 843 device->node->data = NULL; 844 spin_unlock_irqrestore(&card->lock, flags); 845 846 fw_node_put(device->node); 847 kfree(device->config_rom); 848 kfree(device); 849 fw_card_put(card); 850 } 851 852 static struct device_type fw_device_type = { 853 .release = fw_device_release, 854 }; 855 856 static bool is_fw_device(struct device *dev) 857 { 858 return dev->type == &fw_device_type; 859 } 860 861 static int update_unit(struct device *dev, void *data) 862 { 863 struct fw_unit *unit = fw_unit(dev); 864 struct fw_driver *driver = (struct fw_driver *)dev->driver; 865 866 if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) { 867 device_lock(dev); 868 driver->update(unit); 869 device_unlock(dev); 870 } 871 872 return 0; 873 } 874 875 static void fw_device_update(struct work_struct *work) 876 { 877 struct fw_device *device = 878 container_of(work, struct fw_device, work.work); 879 880 fw_device_cdev_update(device); 881 device_for_each_child(&device->device, NULL, update_unit); 882 } 883 884 /* 885 * If a device was pending for deletion because its node went away but its 886 * bus info block and root directory header matches that of a newly discovered 887 * device, revive the existing fw_device. 888 * The newly allocated fw_device becomes obsolete instead. 889 */ 890 static int lookup_existing_device(struct device *dev, void *data) 891 { 892 struct fw_device *old = fw_device(dev); 893 struct fw_device *new = data; 894 struct fw_card *card = new->card; 895 int match = 0; 896 897 if (!is_fw_device(dev)) 898 return 0; 899 900 down_read(&fw_device_rwsem); /* serialize config_rom access */ 901 spin_lock_irq(&card->lock); /* serialize node access */ 902 903 if (memcmp(old->config_rom, new->config_rom, 6 * 4) == 0 && 904 atomic_cmpxchg(&old->state, 905 FW_DEVICE_GONE, 906 FW_DEVICE_RUNNING) == FW_DEVICE_GONE) { 907 struct fw_node *current_node = new->node; 908 struct fw_node *obsolete_node = old->node; 909 910 new->node = obsolete_node; 911 new->node->data = new; 912 old->node = current_node; 913 old->node->data = old; 914 915 old->max_speed = new->max_speed; 916 old->node_id = current_node->node_id; 917 smp_wmb(); /* update node_id before generation */ 918 old->generation = card->generation; 919 old->config_rom_retries = 0; 920 fw_notice(card, "rediscovered device %s\n", dev_name(dev)); 921 922 old->workfn = fw_device_update; 923 fw_schedule_device_work(old, 0); 924 925 if (current_node == card->root_node) 926 fw_schedule_bm_work(card, 0); 927 928 match = 1; 929 } 930 931 spin_unlock_irq(&card->lock); 932 up_read(&fw_device_rwsem); 933 934 return match; 935 } 936 937 enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, }; 938 939 static void set_broadcast_channel(struct fw_device *device, int generation) 940 { 941 struct fw_card *card = device->card; 942 __be32 data; 943 int rcode; 944 945 if (!card->broadcast_channel_allocated) 946 return; 947 948 /* 949 * The Broadcast_Channel Valid bit is required by nodes which want to 950 * transmit on this channel. Such transmissions are practically 951 * exclusive to IP over 1394 (RFC 2734). IP capable nodes are required 952 * to be IRM capable and have a max_rec of 8 or more. We use this fact 953 * to narrow down to which nodes we send Broadcast_Channel updates. 954 */ 955 if (!device->irmc || device->max_rec < 8) 956 return; 957 958 /* 959 * Some 1394-1995 nodes crash if this 1394a-2000 register is written. 960 * Perform a read test first. 961 */ 962 if (device->bc_implemented == BC_UNKNOWN) { 963 rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST, 964 device->node_id, generation, device->max_speed, 965 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL, 966 &data, 4); 967 switch (rcode) { 968 case RCODE_COMPLETE: 969 if (data & cpu_to_be32(1 << 31)) { 970 device->bc_implemented = BC_IMPLEMENTED; 971 break; 972 } 973 /* else fall through to case address error */ 974 case RCODE_ADDRESS_ERROR: 975 device->bc_implemented = BC_UNIMPLEMENTED; 976 } 977 } 978 979 if (device->bc_implemented == BC_IMPLEMENTED) { 980 data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL | 981 BROADCAST_CHANNEL_VALID); 982 fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST, 983 device->node_id, generation, device->max_speed, 984 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL, 985 &data, 4); 986 } 987 } 988 989 int fw_device_set_broadcast_channel(struct device *dev, void *gen) 990 { 991 if (is_fw_device(dev)) 992 set_broadcast_channel(fw_device(dev), (long)gen); 993 994 return 0; 995 } 996 997 static void fw_device_init(struct work_struct *work) 998 { 999 struct fw_device *device = 1000 container_of(work, struct fw_device, work.work); 1001 struct fw_card *card = device->card; 1002 struct device *revived_dev; 1003 int minor, ret; 1004 1005 /* 1006 * All failure paths here set node->data to NULL, so that we 1007 * don't try to do device_for_each_child() on a kfree()'d 1008 * device. 1009 */ 1010 1011 ret = read_config_rom(device, device->generation); 1012 if (ret != RCODE_COMPLETE) { 1013 if (device->config_rom_retries < MAX_RETRIES && 1014 atomic_read(&device->state) == FW_DEVICE_INITIALIZING) { 1015 device->config_rom_retries++; 1016 fw_schedule_device_work(device, RETRY_DELAY); 1017 } else { 1018 if (device->node->link_on) 1019 fw_notice(card, "giving up on node %x: reading config rom failed: %s\n", 1020 device->node_id, 1021 fw_rcode_string(ret)); 1022 if (device->node == card->root_node) 1023 fw_schedule_bm_work(card, 0); 1024 fw_device_release(&device->device); 1025 } 1026 return; 1027 } 1028 1029 revived_dev = device_find_child(card->device, 1030 device, lookup_existing_device); 1031 if (revived_dev) { 1032 put_device(revived_dev); 1033 fw_device_release(&device->device); 1034 1035 return; 1036 } 1037 1038 device_initialize(&device->device); 1039 1040 fw_device_get(device); 1041 down_write(&fw_device_rwsem); 1042 minor = idr_alloc(&fw_device_idr, device, 0, 1 << MINORBITS, 1043 GFP_KERNEL); 1044 up_write(&fw_device_rwsem); 1045 1046 if (minor < 0) 1047 goto error; 1048 1049 device->device.bus = &fw_bus_type; 1050 device->device.type = &fw_device_type; 1051 device->device.parent = card->device; 1052 device->device.devt = MKDEV(fw_cdev_major, minor); 1053 dev_set_name(&device->device, "fw%d", minor); 1054 1055 BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) < 1056 ARRAY_SIZE(fw_device_attributes) + 1057 ARRAY_SIZE(config_rom_attributes)); 1058 init_fw_attribute_group(&device->device, 1059 fw_device_attributes, 1060 &device->attribute_group); 1061 1062 if (device_add(&device->device)) { 1063 fw_err(card, "failed to add device\n"); 1064 goto error_with_cdev; 1065 } 1066 1067 create_units(device); 1068 1069 /* 1070 * Transition the device to running state. If it got pulled 1071 * out from under us while we did the initialization work, we 1072 * have to shut down the device again here. Normally, though, 1073 * fw_node_event will be responsible for shutting it down when 1074 * necessary. We have to use the atomic cmpxchg here to avoid 1075 * racing with the FW_NODE_DESTROYED case in 1076 * fw_node_event(). 1077 */ 1078 if (atomic_cmpxchg(&device->state, 1079 FW_DEVICE_INITIALIZING, 1080 FW_DEVICE_RUNNING) == FW_DEVICE_GONE) { 1081 device->workfn = fw_device_shutdown; 1082 fw_schedule_device_work(device, SHUTDOWN_DELAY); 1083 } else { 1084 fw_notice(card, "created device %s: GUID %08x%08x, S%d00\n", 1085 dev_name(&device->device), 1086 device->config_rom[3], device->config_rom[4], 1087 1 << device->max_speed); 1088 device->config_rom_retries = 0; 1089 1090 set_broadcast_channel(device, device->generation); 1091 1092 add_device_randomness(&device->config_rom[3], 8); 1093 } 1094 1095 /* 1096 * Reschedule the IRM work if we just finished reading the 1097 * root node config rom. If this races with a bus reset we 1098 * just end up running the IRM work a couple of extra times - 1099 * pretty harmless. 1100 */ 1101 if (device->node == card->root_node) 1102 fw_schedule_bm_work(card, 0); 1103 1104 return; 1105 1106 error_with_cdev: 1107 down_write(&fw_device_rwsem); 1108 idr_remove(&fw_device_idr, minor); 1109 up_write(&fw_device_rwsem); 1110 error: 1111 fw_device_put(device); /* fw_device_idr's reference */ 1112 1113 put_device(&device->device); /* our reference */ 1114 } 1115 1116 /* Reread and compare bus info block and header of root directory */ 1117 static int reread_config_rom(struct fw_device *device, int generation, 1118 bool *changed) 1119 { 1120 u32 q; 1121 int i, rcode; 1122 1123 for (i = 0; i < 6; i++) { 1124 rcode = read_rom(device, generation, i, &q); 1125 if (rcode != RCODE_COMPLETE) 1126 return rcode; 1127 1128 if (i == 0 && q == 0) 1129 /* inaccessible (see read_config_rom); retry later */ 1130 return RCODE_BUSY; 1131 1132 if (q != device->config_rom[i]) { 1133 *changed = true; 1134 return RCODE_COMPLETE; 1135 } 1136 } 1137 1138 *changed = false; 1139 return RCODE_COMPLETE; 1140 } 1141 1142 static void fw_device_refresh(struct work_struct *work) 1143 { 1144 struct fw_device *device = 1145 container_of(work, struct fw_device, work.work); 1146 struct fw_card *card = device->card; 1147 int ret, node_id = device->node_id; 1148 bool changed; 1149 1150 ret = reread_config_rom(device, device->generation, &changed); 1151 if (ret != RCODE_COMPLETE) 1152 goto failed_config_rom; 1153 1154 if (!changed) { 1155 if (atomic_cmpxchg(&device->state, 1156 FW_DEVICE_INITIALIZING, 1157 FW_DEVICE_RUNNING) == FW_DEVICE_GONE) 1158 goto gone; 1159 1160 fw_device_update(work); 1161 device->config_rom_retries = 0; 1162 goto out; 1163 } 1164 1165 /* 1166 * Something changed. We keep things simple and don't investigate 1167 * further. We just destroy all previous units and create new ones. 1168 */ 1169 device_for_each_child(&device->device, NULL, shutdown_unit); 1170 1171 ret = read_config_rom(device, device->generation); 1172 if (ret != RCODE_COMPLETE) 1173 goto failed_config_rom; 1174 1175 fw_device_cdev_update(device); 1176 create_units(device); 1177 1178 /* Userspace may want to re-read attributes. */ 1179 kobject_uevent(&device->device.kobj, KOBJ_CHANGE); 1180 1181 if (atomic_cmpxchg(&device->state, 1182 FW_DEVICE_INITIALIZING, 1183 FW_DEVICE_RUNNING) == FW_DEVICE_GONE) 1184 goto gone; 1185 1186 fw_notice(card, "refreshed device %s\n", dev_name(&device->device)); 1187 device->config_rom_retries = 0; 1188 goto out; 1189 1190 failed_config_rom: 1191 if (device->config_rom_retries < MAX_RETRIES && 1192 atomic_read(&device->state) == FW_DEVICE_INITIALIZING) { 1193 device->config_rom_retries++; 1194 fw_schedule_device_work(device, RETRY_DELAY); 1195 return; 1196 } 1197 1198 fw_notice(card, "giving up on refresh of device %s: %s\n", 1199 dev_name(&device->device), fw_rcode_string(ret)); 1200 gone: 1201 atomic_set(&device->state, FW_DEVICE_GONE); 1202 device->workfn = fw_device_shutdown; 1203 fw_schedule_device_work(device, SHUTDOWN_DELAY); 1204 out: 1205 if (node_id == card->root_node->node_id) 1206 fw_schedule_bm_work(card, 0); 1207 } 1208 1209 static void fw_device_workfn(struct work_struct *work) 1210 { 1211 struct fw_device *device = container_of(to_delayed_work(work), 1212 struct fw_device, work); 1213 device->workfn(work); 1214 } 1215 1216 void fw_node_event(struct fw_card *card, struct fw_node *node, int event) 1217 { 1218 struct fw_device *device; 1219 1220 switch (event) { 1221 case FW_NODE_CREATED: 1222 /* 1223 * Attempt to scan the node, regardless whether its self ID has 1224 * the L (link active) flag set or not. Some broken devices 1225 * send L=0 but have an up-and-running link; others send L=1 1226 * without actually having a link. 1227 */ 1228 create: 1229 device = kzalloc(sizeof(*device), GFP_ATOMIC); 1230 if (device == NULL) 1231 break; 1232 1233 /* 1234 * Do minimal initialization of the device here, the 1235 * rest will happen in fw_device_init(). 1236 * 1237 * Attention: A lot of things, even fw_device_get(), 1238 * cannot be done before fw_device_init() finished! 1239 * You can basically just check device->state and 1240 * schedule work until then, but only while holding 1241 * card->lock. 1242 */ 1243 atomic_set(&device->state, FW_DEVICE_INITIALIZING); 1244 device->card = fw_card_get(card); 1245 device->node = fw_node_get(node); 1246 device->node_id = node->node_id; 1247 device->generation = card->generation; 1248 device->is_local = node == card->local_node; 1249 mutex_init(&device->client_list_mutex); 1250 INIT_LIST_HEAD(&device->client_list); 1251 1252 /* 1253 * Set the node data to point back to this device so 1254 * FW_NODE_UPDATED callbacks can update the node_id 1255 * and generation for the device. 1256 */ 1257 node->data = device; 1258 1259 /* 1260 * Many devices are slow to respond after bus resets, 1261 * especially if they are bus powered and go through 1262 * power-up after getting plugged in. We schedule the 1263 * first config rom scan half a second after bus reset. 1264 */ 1265 device->workfn = fw_device_init; 1266 INIT_DELAYED_WORK(&device->work, fw_device_workfn); 1267 fw_schedule_device_work(device, INITIAL_DELAY); 1268 break; 1269 1270 case FW_NODE_INITIATED_RESET: 1271 case FW_NODE_LINK_ON: 1272 device = node->data; 1273 if (device == NULL) 1274 goto create; 1275 1276 device->node_id = node->node_id; 1277 smp_wmb(); /* update node_id before generation */ 1278 device->generation = card->generation; 1279 if (atomic_cmpxchg(&device->state, 1280 FW_DEVICE_RUNNING, 1281 FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) { 1282 device->workfn = fw_device_refresh; 1283 fw_schedule_device_work(device, 1284 device->is_local ? 0 : INITIAL_DELAY); 1285 } 1286 break; 1287 1288 case FW_NODE_UPDATED: 1289 device = node->data; 1290 if (device == NULL) 1291 break; 1292 1293 device->node_id = node->node_id; 1294 smp_wmb(); /* update node_id before generation */ 1295 device->generation = card->generation; 1296 if (atomic_read(&device->state) == FW_DEVICE_RUNNING) { 1297 device->workfn = fw_device_update; 1298 fw_schedule_device_work(device, 0); 1299 } 1300 break; 1301 1302 case FW_NODE_DESTROYED: 1303 case FW_NODE_LINK_OFF: 1304 if (!node->data) 1305 break; 1306 1307 /* 1308 * Destroy the device associated with the node. There 1309 * are two cases here: either the device is fully 1310 * initialized (FW_DEVICE_RUNNING) or we're in the 1311 * process of reading its config rom 1312 * (FW_DEVICE_INITIALIZING). If it is fully 1313 * initialized we can reuse device->work to schedule a 1314 * full fw_device_shutdown(). If not, there's work 1315 * scheduled to read it's config rom, and we just put 1316 * the device in shutdown state to have that code fail 1317 * to create the device. 1318 */ 1319 device = node->data; 1320 if (atomic_xchg(&device->state, 1321 FW_DEVICE_GONE) == FW_DEVICE_RUNNING) { 1322 device->workfn = fw_device_shutdown; 1323 fw_schedule_device_work(device, 1324 list_empty(&card->link) ? 0 : SHUTDOWN_DELAY); 1325 } 1326 break; 1327 } 1328 } 1329