SAFE public projects git trees. - safe/jmp/linux-2.6/blob - drivers/firewire/core-device.c

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