Pileus Git - ~andy/linux/blob - drivers/firewire/core-device.c

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