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/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/rwsem.h>
  36 #include <linux/slab.h>
  37 #include <linux/spinlock.h>
  38 #include <linux/string.h>
  39 #include <linux/workqueue.h>
  40
  41 #include <asm/atomic.h>
  42 #include <asm/byteorder.h>
  43 #include <asm/system.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 int units_sprintf(char *buf, const u32 *directory)
 403 {
 404         struct fw_csr_iterator ci;
 405         int key, value;
 406         int specifier_id = 0;
 407         int version = 0;
 408
 409         fw_csr_iterator_init(&ci, directory);
 410         while (fw_csr_iterator_next(&ci, &key, &value)) {
 411                 switch (key) {
 412                 case CSR_SPECIFIER_ID:
 413                         specifier_id = value;
 414                         break;
 415                 case CSR_VERSION:
 416                         version = value;
 417                         break;
 418                 }
 419         }
 420
 421         return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version);
 422 }
 423
 424 static ssize_t units_show(struct device *dev,
 425                           struct device_attribute *attr, char *buf)
 426 {
 427         struct fw_device *device = fw_device(dev);
 428         struct fw_csr_iterator ci;
 429         int key, value, i = 0;
 430
 431         down_read(&fw_device_rwsem);
 432         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 433         while (fw_csr_iterator_next(&ci, &key, &value)) {
 434                 if (key != (CSR_UNIT | CSR_DIRECTORY))
 435                         continue;
 436                 i += units_sprintf(&buf[i], ci.p + value - 1);
 437                 if (i >= PAGE_SIZE - (8 + 1 + 8 + 1))
 438                         break;
 439         }
 440         up_read(&fw_device_rwsem);
 441
 442         if (i)
 443                 buf[i - 1] = '\n';
 444
 445         return i;
 446 }
 447
 448 static struct device_attribute fw_device_attributes[] = {
 449         __ATTR_RO(config_rom),
 450         __ATTR_RO(guid),
 451         __ATTR_RO(units),
 452         __ATTR_NULL,
 453 };
 454
 455 static int read_rom(struct fw_device *device,
 456                     int generation, int index, u32 *data)
 457 {
 458         int rcode;
 459
 460         /* device->node_id, accessed below, must not be older than generation */
 461         smp_rmb();
 462
 463         rcode = fw_run_transaction(device->card, TCODE_READ_QUADLET_REQUEST,
 464                         device->node_id, generation, device->max_speed,
 465                         (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4,
 466                         data, 4);
 467         be32_to_cpus(data);
 468
 469         return rcode;
 470 }
 471
 472 #define MAX_CONFIG_ROM_SIZE 256
 473
 474 /*
 475  * Read the bus info block, perform a speed probe, and read all of the rest of
 476  * the config ROM.  We do all this with a cached bus generation.  If the bus
 477  * generation changes under us, read_config_rom will fail and get retried.
 478  * It's better to start all over in this case because the node from which we
 479  * are reading the ROM may have changed the ROM during the reset.
 480  */
 481 static int read_config_rom(struct fw_device *device, int generation)
 482 {
 483         const u32 *old_rom, *new_rom;
 484         u32 *rom, *stack;
 485         u32 sp, key;
 486         int i, end, length, ret = -1;
 487
 488         rom = kmalloc(sizeof(*rom) * MAX_CONFIG_ROM_SIZE +
 489                       sizeof(*stack) * MAX_CONFIG_ROM_SIZE, GFP_KERNEL);
 490         if (rom == NULL)
 491                 return -ENOMEM;
 492
 493         stack = &rom[MAX_CONFIG_ROM_SIZE];
 494         memset(rom, 0, sizeof(*rom) * MAX_CONFIG_ROM_SIZE);
 495
 496         device->max_speed = SCODE_100;
 497
 498         /* First read the bus info block. */
 499         for (i = 0; i < 5; i++) {
 500                 if (read_rom(device, generation, i, &rom[i]) != RCODE_COMPLETE)
 501                         goto out;
 502                 /*
 503                  * As per IEEE1212 7.2, during power-up, devices can
 504                  * reply with a 0 for the first quadlet of the config
 505                  * rom to indicate that they are booting (for example,
 506                  * if the firmware is on the disk of a external
 507                  * harddisk).  In that case we just fail, and the
 508                  * retry mechanism will try again later.
 509                  */
 510                 if (i == 0 && rom[i] == 0)
 511                         goto out;
 512         }
 513
 514         device->max_speed = device->node->max_speed;
 515
 516         /*
 517          * Determine the speed of
 518          *   - devices with link speed less than PHY speed,
 519          *   - devices with 1394b PHY (unless only connected to 1394a PHYs),
 520          *   - all devices if there are 1394b repeaters.
 521          * Note, we cannot use the bus info block's link_spd as starting point
 522          * because some buggy firmwares set it lower than necessary and because
 523          * 1394-1995 nodes do not have the field.
 524          */
 525         if ((rom[2] & 0x7) < device->max_speed ||
 526             device->max_speed == SCODE_BETA ||
 527             device->card->beta_repeaters_present) {
 528                 u32 dummy;
 529
 530                 /* for S1600 and S3200 */
 531                 if (device->max_speed == SCODE_BETA)
 532                         device->max_speed = device->card->link_speed;
 533
 534                 while (device->max_speed > SCODE_100) {
 535                         if (read_rom(device, generation, 0, &dummy) ==
 536                             RCODE_COMPLETE)
 537                                 break;
 538                         device->max_speed--;
 539                 }
 540         }
 541
 542         /*
 543          * Now parse the config rom.  The config rom is a recursive
 544          * directory structure so we parse it using a stack of
 545          * references to the blocks that make up the structure.  We
 546          * push a reference to the root directory on the stack to
 547          * start things off.
 548          */
 549         length = i;
 550         sp = 0;
 551         stack[sp++] = 0xc0000005;
 552         while (sp > 0) {
 553                 /*
 554                  * Pop the next block reference of the stack.  The
 555                  * lower 24 bits is the offset into the config rom,
 556                  * the upper 8 bits are the type of the reference the
 557                  * block.
 558                  */
 559                 key = stack[--sp];
 560                 i = key & 0xffffff;
 561                 if (WARN_ON(i >= MAX_CONFIG_ROM_SIZE))
 562                         goto out;
 563
 564                 /* Read header quadlet for the block to get the length. */
 565                 if (read_rom(device, generation, i, &rom[i]) != RCODE_COMPLETE)
 566                         goto out;
 567                 end = i + (rom[i] >> 16) + 1;
 568                 if (end > MAX_CONFIG_ROM_SIZE) {
 569                         /*
 570                          * This block extends outside the config ROM which is
 571                          * a firmware bug.  Ignore this whole block, i.e.
 572                          * simply set a fake block length of 0.
 573                          */
 574                         fw_error("skipped invalid ROM block %x at %llx\n",
 575                                  rom[i],
 576                                  i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 577                         rom[i] = 0;
 578                         end = i;
 579                 }
 580                 i++;
 581
 582                 /*
 583                  * Now read in the block.  If this is a directory
 584                  * block, check the entries as we read them to see if
 585                  * it references another block, and push it in that case.
 586                  */
 587                 for (; i < end; i++) {
 588                         if (read_rom(device, generation, i, &rom[i]) !=
 589                             RCODE_COMPLETE)
 590                                 goto out;
 591
 592                         if ((key >> 30) != 3 || (rom[i] >> 30) < 2)
 593                                 continue;
 594                         /*
 595                          * Offset points outside the ROM.  May be a firmware
 596                          * bug or an Extended ROM entry (IEEE 1212-2001 clause
 597                          * 7.7.18).  Simply overwrite this pointer here by a
 598                          * fake immediate entry so that later iterators over
 599                          * the ROM don't have to check offsets all the time.
 600                          */
 601                         if (i + (rom[i] & 0xffffff) >= MAX_CONFIG_ROM_SIZE) {
 602                                 fw_error("skipped unsupported ROM entry %x at %llx\n",
 603                                          rom[i],
 604                                          i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 605                                 rom[i] = 0;
 606                                 continue;
 607                         }
 608                         stack[sp++] = i + rom[i];
 609                 }
 610                 if (length < i)
 611                         length = i;
 612         }
 613
 614         old_rom = device->config_rom;
 615         new_rom = kmemdup(rom, length * 4, GFP_KERNEL);
 616         if (new_rom == NULL)
 617                 goto out;
 618
 619         down_write(&fw_device_rwsem);
 620         device->config_rom = new_rom;
 621         device->config_rom_length = length;
 622         up_write(&fw_device_rwsem);
 623
 624         kfree(old_rom);
 625         ret = 0;
 626         device->max_rec = rom[2] >> 12 & 0xf;
 627         device->cmc     = rom[2] >> 30 & 1;
 628         device->irmc    = rom[2] >> 31 & 1;
 629  out:
 630         kfree(rom);
 631
 632         return ret;
 633 }
 634
 635 static void fw_unit_release(struct device *dev)
 636 {
 637         struct fw_unit *unit = fw_unit(dev);
 638
 639         kfree(unit);
 640 }
 641
 642 static struct device_type fw_unit_type = {
 643         .uevent         = fw_unit_uevent,
 644         .release        = fw_unit_release,
 645 };
 646
 647 static bool is_fw_unit(struct device *dev)
 648 {
 649         return dev->type == &fw_unit_type;
 650 }
 651
 652 static void create_units(struct fw_device *device)
 653 {
 654         struct fw_csr_iterator ci;
 655         struct fw_unit *unit;
 656         int key, value, i;
 657
 658         i = 0;
 659         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 660         while (fw_csr_iterator_next(&ci, &key, &value)) {
 661                 if (key != (CSR_UNIT | CSR_DIRECTORY))
 662                         continue;
 663
 664                 /*
 665                  * Get the address of the unit directory and try to
 666                  * match the drivers id_tables against it.
 667                  */
 668                 unit = kzalloc(sizeof(*unit), GFP_KERNEL);
 669                 if (unit == NULL) {
 670                         fw_error("failed to allocate memory for unit\n");
 671                         continue;
 672                 }
 673
 674                 unit->directory = ci.p + value - 1;
 675                 unit->device.bus = &fw_bus_type;
 676                 unit->device.type = &fw_unit_type;
 677                 unit->device.parent = &device->device;
 678                 dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++);
 679
 680                 BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) <
 681                                 ARRAY_SIZE(fw_unit_attributes) +
 682                                 ARRAY_SIZE(config_rom_attributes));
 683                 init_fw_attribute_group(&unit->device,
 684                                         fw_unit_attributes,
 685                                         &unit->attribute_group);
 686
 687                 if (device_register(&unit->device) < 0)
 688                         goto skip_unit;
 689
 690                 continue;
 691
 692         skip_unit:
 693                 kfree(unit);
 694         }
 695 }
 696
 697 static int shutdown_unit(struct device *device, void *data)
 698 {
 699         device_unregister(device);
 700
 701         return 0;
 702 }
 703
 704 /*
 705  * fw_device_rwsem acts as dual purpose mutex:
 706  *   - serializes accesses to fw_device_idr,
 707  *   - serializes accesses to fw_device.config_rom/.config_rom_length and
 708  *     fw_unit.directory, unless those accesses happen at safe occasions
 709  */
 710 DECLARE_RWSEM(fw_device_rwsem);
 711
 712 DEFINE_IDR(fw_device_idr);
 713 int fw_cdev_major;
 714
 715 struct fw_device *fw_device_get_by_devt(dev_t devt)
 716 {
 717         struct fw_device *device;
 718
 719         down_read(&fw_device_rwsem);
 720         device = idr_find(&fw_device_idr, MINOR(devt));
 721         if (device)
 722                 fw_device_get(device);
 723         up_read(&fw_device_rwsem);
 724
 725         return device;
 726 }
 727
 728 /*
 729  * These defines control the retry behavior for reading the config
 730  * rom.  It shouldn't be necessary to tweak these; if the device
 731  * doesn't respond to a config rom read within 10 seconds, it's not
 732  * going to respond at all.  As for the initial delay, a lot of
 733  * devices will be able to respond within half a second after bus
 734  * reset.  On the other hand, it's not really worth being more
 735  * aggressive than that, since it scales pretty well; if 10 devices
 736  * are plugged in, they're all getting read within one second.
 737  */
 738
 739 #define MAX_RETRIES     10
 740 #define RETRY_DELAY     (3 * HZ)
 741 #define INITIAL_DELAY   (HZ / 2)
 742 #define SHUTDOWN_DELAY  (2 * HZ)
 743
 744 static void fw_device_shutdown(struct work_struct *work)
 745 {
 746         struct fw_device *device =
 747                 container_of(work, struct fw_device, work.work);
 748         int minor = MINOR(device->device.devt);
 749
 750         if (time_is_after_jiffies(device->card->reset_jiffies + SHUTDOWN_DELAY)
 751             && !list_empty(&device->card->link)) {
 752                 schedule_delayed_work(&device->work, SHUTDOWN_DELAY);
 753                 return;
 754         }
 755
 756         if (atomic_cmpxchg(&device->state,
 757                            FW_DEVICE_GONE,
 758                            FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE)
 759                 return;
 760
 761         fw_device_cdev_remove(device);
 762         device_for_each_child(&device->device, NULL, shutdown_unit);
 763         device_unregister(&device->device);
 764
 765         down_write(&fw_device_rwsem);
 766         idr_remove(&fw_device_idr, minor);
 767         up_write(&fw_device_rwsem);
 768
 769         fw_device_put(device);
 770 }
 771
 772 static void fw_device_release(struct device *dev)
 773 {
 774         struct fw_device *device = fw_device(dev);
 775         struct fw_card *card = device->card;
 776         unsigned long flags;
 777
 778         /*
 779          * Take the card lock so we don't set this to NULL while a
 780          * FW_NODE_UPDATED callback is being handled or while the
 781          * bus manager work looks at this node.
 782          */
 783         spin_lock_irqsave(&card->lock, flags);
 784         device->node->data = NULL;
 785         spin_unlock_irqrestore(&card->lock, flags);
 786
 787         fw_node_put(device->node);
 788         kfree(device->config_rom);
 789         kfree(device);
 790         fw_card_put(card);
 791 }
 792
 793 static struct device_type fw_device_type = {
 794         .release = fw_device_release,
 795 };
 796
 797 static bool is_fw_device(struct device *dev)
 798 {
 799         return dev->type == &fw_device_type;
 800 }
 801
 802 static int update_unit(struct device *dev, void *data)
 803 {
 804         struct fw_unit *unit = fw_unit(dev);
 805         struct fw_driver *driver = (struct fw_driver *)dev->driver;
 806
 807         if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) {
 808                 device_lock(dev);
 809                 driver->update(unit);
 810                 device_unlock(dev);
 811         }
 812
 813         return 0;
 814 }
 815
 816 static void fw_device_update(struct work_struct *work)
 817 {
 818         struct fw_device *device =
 819                 container_of(work, struct fw_device, work.work);
 820
 821         fw_device_cdev_update(device);
 822         device_for_each_child(&device->device, NULL, update_unit);
 823 }
 824
 825 /*
 826  * If a device was pending for deletion because its node went away but its
 827  * bus info block and root directory header matches that of a newly discovered
 828  * device, revive the existing fw_device.
 829  * The newly allocated fw_device becomes obsolete instead.
 830  */
 831 static int lookup_existing_device(struct device *dev, void *data)
 832 {
 833         struct fw_device *old = fw_device(dev);
 834         struct fw_device *new = data;
 835         struct fw_card *card = new->card;
 836         int match = 0;
 837
 838         if (!is_fw_device(dev))
 839                 return 0;
 840
 841         down_read(&fw_device_rwsem); /* serialize config_rom access */
 842         spin_lock_irq(&card->lock);  /* serialize node access */
 843
 844         if (memcmp(old->config_rom, new->config_rom, 6 * 4) == 0 &&
 845             atomic_cmpxchg(&old->state,
 846                            FW_DEVICE_GONE,
 847                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
 848                 struct fw_node *current_node = new->node;
 849                 struct fw_node *obsolete_node = old->node;
 850
 851                 new->node = obsolete_node;
 852                 new->node->data = new;
 853                 old->node = current_node;
 854                 old->node->data = old;
 855
 856                 old->max_speed = new->max_speed;
 857                 old->node_id = current_node->node_id;
 858                 smp_wmb();  /* update node_id before generation */
 859                 old->generation = card->generation;
 860                 old->config_rom_retries = 0;
 861                 fw_notify("rediscovered device %s\n", dev_name(dev));
 862
 863                 PREPARE_DELAYED_WORK(&old->work, fw_device_update);
 864                 schedule_delayed_work(&old->work, 0);
 865
 866                 if (current_node == card->root_node)
 867                         fw_schedule_bm_work(card, 0);
 868
 869                 match = 1;
 870         }
 871
 872         spin_unlock_irq(&card->lock);
 873         up_read(&fw_device_rwsem);
 874
 875         return match;
 876 }
 877
 878 enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, };
 879
 880 static void set_broadcast_channel(struct fw_device *device, int generation)
 881 {
 882         struct fw_card *card = device->card;
 883         __be32 data;
 884         int rcode;
 885
 886         if (!card->broadcast_channel_allocated)
 887                 return;
 888
 889         /*
 890          * The Broadcast_Channel Valid bit is required by nodes which want to
 891          * transmit on this channel.  Such transmissions are practically
 892          * exclusive to IP over 1394 (RFC 2734).  IP capable nodes are required
 893          * to be IRM capable and have a max_rec of 8 or more.  We use this fact
 894          * to narrow down to which nodes we send Broadcast_Channel updates.
 895          */
 896         if (!device->irmc || device->max_rec < 8)
 897                 return;
 898
 899         /*
 900          * Some 1394-1995 nodes crash if this 1394a-2000 register is written.
 901          * Perform a read test first.
 902          */
 903         if (device->bc_implemented == BC_UNKNOWN) {
 904                 rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST,
 905                                 device->node_id, generation, device->max_speed,
 906                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 907                                 &data, 4);
 908                 switch (rcode) {
 909                 case RCODE_COMPLETE:
 910                         if (data & cpu_to_be32(1 << 31)) {
 911                                 device->bc_implemented = BC_IMPLEMENTED;
 912                                 break;
 913                         }
 914                         /* else fall through to case address error */
 915                 case RCODE_ADDRESS_ERROR:
 916                         device->bc_implemented = BC_UNIMPLEMENTED;
 917                 }
 918         }
 919
 920         if (device->bc_implemented == BC_IMPLEMENTED) {
 921                 data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL |
 922                                    BROADCAST_CHANNEL_VALID);
 923                 fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
 924                                 device->node_id, generation, device->max_speed,
 925                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 926                                 &data, 4);
 927         }
 928 }
 929
 930 int fw_device_set_broadcast_channel(struct device *dev, void *gen)
 931 {
 932         if (is_fw_device(dev))
 933                 set_broadcast_channel(fw_device(dev), (long)gen);
 934
 935         return 0;
 936 }
 937
 938 static void fw_device_init(struct work_struct *work)
 939 {
 940         struct fw_device *device =
 941                 container_of(work, struct fw_device, work.work);
 942         struct device *revived_dev;
 943         int minor, ret;
 944
 945         /*
 946          * All failure paths here set node->data to NULL, so that we
 947          * don't try to do device_for_each_child() on a kfree()'d
 948          * device.
 949          */
 950
 951         if (read_config_rom(device, device->generation) < 0) {
 952                 if (device->config_rom_retries < MAX_RETRIES &&
 953                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
 954                         device->config_rom_retries++;
 955                         schedule_delayed_work(&device->work, RETRY_DELAY);
 956                 } else {
 957                         fw_notify("giving up on config rom for node id %x\n",
 958                                   device->node_id);
 959                         if (device->node == device->card->root_node)
 960                                 fw_schedule_bm_work(device->card, 0);
 961                         fw_device_release(&device->device);
 962                 }
 963                 return;
 964         }
 965
 966         revived_dev = device_find_child(device->card->device,
 967                                         device, lookup_existing_device);
 968         if (revived_dev) {
 969                 put_device(revived_dev);
 970                 fw_device_release(&device->device);
 971
 972                 return;
 973         }
 974
 975         device_initialize(&device->device);
 976
 977         fw_device_get(device);
 978         down_write(&fw_device_rwsem);
 979         ret = idr_pre_get(&fw_device_idr, GFP_KERNEL) ?
 980               idr_get_new(&fw_device_idr, device, &minor) :
 981               -ENOMEM;
 982         up_write(&fw_device_rwsem);
 983
 984         if (ret < 0)
 985                 goto error;
 986
 987         device->device.bus = &fw_bus_type;
 988         device->device.type = &fw_device_type;
 989         device->device.parent = device->card->device;
 990         device->device.devt = MKDEV(fw_cdev_major, minor);
 991         dev_set_name(&device->device, "fw%d", minor);
 992
 993         BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) <
 994                         ARRAY_SIZE(fw_device_attributes) +
 995                         ARRAY_SIZE(config_rom_attributes));
 996         init_fw_attribute_group(&device->device,
 997                                 fw_device_attributes,
 998                                 &device->attribute_group);
 999
1000         if (device_add(&device->device)) {
1001                 fw_error("Failed to add device.\n");
1002                 goto error_with_cdev;
1003         }
1004
1005         create_units(device);
1006
1007         /*
1008          * Transition the device to running state.  If it got pulled
1009          * out from under us while we did the intialization work, we
1010          * have to shut down the device again here.  Normally, though,
1011          * fw_node_event will be responsible for shutting it down when
1012          * necessary.  We have to use the atomic cmpxchg here to avoid
1013          * racing with the FW_NODE_DESTROYED case in
1014          * fw_node_event().
1015          */
1016         if (atomic_cmpxchg(&device->state,
1017                            FW_DEVICE_INITIALIZING,
1018                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
1019                 PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1020                 schedule_delayed_work(&device->work, SHUTDOWN_DELAY);
1021         } else {
1022                 if (device->config_rom_retries)
1023                         fw_notify("created device %s: GUID %08x%08x, S%d00, "
1024                                   "%d config ROM retries\n",
1025                                   dev_name(&device->device),
1026                                   device->config_rom[3], device->config_rom[4],
1027                                   1 << device->max_speed,
1028                                   device->config_rom_retries);
1029                 else
1030                         fw_notify("created device %s: GUID %08x%08x, S%d00\n",
1031                                   dev_name(&device->device),
1032                                   device->config_rom[3], device->config_rom[4],
1033                                   1 << device->max_speed);
1034                 device->config_rom_retries = 0;
1035
1036                 set_broadcast_channel(device, device->generation);
1037         }
1038
1039         /*
1040          * Reschedule the IRM work if we just finished reading the
1041          * root node config rom.  If this races with a bus reset we
1042          * just end up running the IRM work a couple of extra times -
1043          * pretty harmless.
1044          */
1045         if (device->node == device->card->root_node)
1046                 fw_schedule_bm_work(device->card, 0);
1047
1048         return;
1049
1050  error_with_cdev:
1051         down_write(&fw_device_rwsem);
1052         idr_remove(&fw_device_idr, minor);
1053         up_write(&fw_device_rwsem);
1054  error:
1055         fw_device_put(device);          /* fw_device_idr's reference */
1056
1057         put_device(&device->device);    /* our reference */
1058 }
1059
1060 enum {
1061         REREAD_BIB_ERROR,
1062         REREAD_BIB_GONE,
1063         REREAD_BIB_UNCHANGED,
1064         REREAD_BIB_CHANGED,
1065 };
1066
1067 /* Reread and compare bus info block and header of root directory */
1068 static int reread_config_rom(struct fw_device *device, int generation)
1069 {
1070         u32 q;
1071         int i;
1072
1073         for (i = 0; i < 6; i++) {
1074                 if (read_rom(device, generation, i, &q) != RCODE_COMPLETE)
1075                         return REREAD_BIB_ERROR;
1076
1077                 if (i == 0 && q == 0)
1078                         return REREAD_BIB_GONE;
1079
1080                 if (q != device->config_rom[i])
1081                         return REREAD_BIB_CHANGED;
1082         }
1083
1084         return REREAD_BIB_UNCHANGED;
1085 }
1086
1087 static void fw_device_refresh(struct work_struct *work)
1088 {
1089         struct fw_device *device =
1090                 container_of(work, struct fw_device, work.work);
1091         struct fw_card *card = device->card;
1092         int node_id = device->node_id;
1093
1094         switch (reread_config_rom(device, device->generation)) {
1095         case REREAD_BIB_ERROR:
1096                 if (device->config_rom_retries < MAX_RETRIES / 2 &&
1097                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1098                         device->config_rom_retries++;
1099                         schedule_delayed_work(&device->work, RETRY_DELAY / 2);
1100
1101                         return;
1102                 }
1103                 goto give_up;
1104
1105         case REREAD_BIB_GONE:
1106                 goto gone;
1107
1108         case REREAD_BIB_UNCHANGED:
1109                 if (atomic_cmpxchg(&device->state,
1110                                    FW_DEVICE_INITIALIZING,
1111                                    FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1112                         goto gone;
1113
1114                 fw_device_update(work);
1115                 device->config_rom_retries = 0;
1116                 goto out;
1117
1118         case REREAD_BIB_CHANGED:
1119                 break;
1120         }
1121
1122         /*
1123          * Something changed.  We keep things simple and don't investigate
1124          * further.  We just destroy all previous units and create new ones.
1125          */
1126         device_for_each_child(&device->device, NULL, shutdown_unit);
1127
1128         if (read_config_rom(device, device->generation) < 0) {
1129                 if (device->config_rom_retries < MAX_RETRIES &&
1130                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1131                         device->config_rom_retries++;
1132                         schedule_delayed_work(&device->work, RETRY_DELAY);
1133
1134                         return;
1135                 }
1136                 goto give_up;
1137         }
1138
1139         create_units(device);
1140
1141         /* Userspace may want to re-read attributes. */
1142         kobject_uevent(&device->device.kobj, KOBJ_CHANGE);
1143
1144         if (atomic_cmpxchg(&device->state,
1145                            FW_DEVICE_INITIALIZING,
1146                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1147                 goto gone;
1148
1149         fw_notify("refreshed device %s\n", dev_name(&device->device));
1150         device->config_rom_retries = 0;
1151         goto out;
1152
1153  give_up:
1154         fw_notify("giving up on refresh of device %s\n", dev_name(&device->device));
1155  gone:
1156         atomic_set(&device->state, FW_DEVICE_GONE);
1157         PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1158         schedule_delayed_work(&device->work, SHUTDOWN_DELAY);
1159  out:
1160         if (node_id == card->root_node->node_id)
1161                 fw_schedule_bm_work(card, 0);
1162 }
1163
1164 void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
1165 {
1166         struct fw_device *device;
1167
1168         switch (event) {
1169         case FW_NODE_CREATED:
1170         case FW_NODE_LINK_ON:
1171                 if (!node->link_on)
1172                         break;
1173  create:
1174                 device = kzalloc(sizeof(*device), GFP_ATOMIC);
1175                 if (device == NULL)
1176                         break;
1177
1178                 /*
1179                  * Do minimal intialization of the device here, the
1180                  * rest will happen in fw_device_init().
1181                  *
1182                  * Attention:  A lot of things, even fw_device_get(),
1183                  * cannot be done before fw_device_init() finished!
1184                  * You can basically just check device->state and
1185                  * schedule work until then, but only while holding
1186                  * card->lock.
1187                  */
1188                 atomic_set(&device->state, FW_DEVICE_INITIALIZING);
1189                 device->card = fw_card_get(card);
1190                 device->node = fw_node_get(node);
1191                 device->node_id = node->node_id;
1192                 device->generation = card->generation;
1193                 device->is_local = node == card->local_node;
1194                 mutex_init(&device->client_list_mutex);
1195                 INIT_LIST_HEAD(&device->client_list);
1196
1197                 /*
1198                  * Set the node data to point back to this device so
1199                  * FW_NODE_UPDATED callbacks can update the node_id
1200                  * and generation for the device.
1201                  */
1202                 node->data = device;
1203
1204                 /*
1205                  * Many devices are slow to respond after bus resets,
1206                  * especially if they are bus powered and go through
1207                  * power-up after getting plugged in.  We schedule the
1208                  * first config rom scan half a second after bus reset.
1209                  */
1210                 INIT_DELAYED_WORK(&device->work, fw_device_init);
1211                 schedule_delayed_work(&device->work, INITIAL_DELAY);
1212                 break;
1213
1214         case FW_NODE_INITIATED_RESET:
1215                 device = node->data;
1216                 if (device == NULL)
1217                         goto create;
1218
1219                 device->node_id = node->node_id;
1220                 smp_wmb();  /* update node_id before generation */
1221                 device->generation = card->generation;
1222                 if (atomic_cmpxchg(&device->state,
1223                             FW_DEVICE_RUNNING,
1224                             FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) {
1225                         PREPARE_DELAYED_WORK(&device->work, fw_device_refresh);
1226                         schedule_delayed_work(&device->work,
1227                                 device->is_local ? 0 : INITIAL_DELAY);
1228                 }
1229                 break;
1230
1231         case FW_NODE_UPDATED:
1232                 if (!node->link_on || node->data == NULL)
1233                         break;
1234
1235                 device = node->data;
1236                 device->node_id = node->node_id;
1237                 smp_wmb();  /* update node_id before generation */
1238                 device->generation = card->generation;
1239                 if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
1240                         PREPARE_DELAYED_WORK(&device->work, fw_device_update);
1241                         schedule_delayed_work(&device->work, 0);
1242                 }
1243                 break;
1244
1245         case FW_NODE_DESTROYED:
1246         case FW_NODE_LINK_OFF:
1247                 if (!node->data)
1248                         break;
1249
1250                 /*
1251                  * Destroy the device associated with the node.  There
1252                  * are two cases here: either the device is fully
1253                  * initialized (FW_DEVICE_RUNNING) or we're in the
1254                  * process of reading its config rom
1255                  * (FW_DEVICE_INITIALIZING).  If it is fully
1256                  * initialized we can reuse device->work to schedule a
1257                  * full fw_device_shutdown().  If not, there's work
1258                  * scheduled to read it's config rom, and we just put
1259                  * the device in shutdown state to have that code fail
1260                  * to create the device.
1261                  */
1262                 device = node->data;
1263                 if (atomic_xchg(&device->state,
1264                                 FW_DEVICE_GONE) == FW_DEVICE_RUNNING) {
1265                         PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1266                         schedule_delayed_work(&device->work,
1267                                 list_empty(&card->link) ? 0 : SHUTDOWN_DELAY);
1268                 }
1269                 break;
1270         }
1271 }