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