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