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

   1 /*
   2  * Device probing and sysfs code.
   3  *
   4  * Copyright (C) 2005-2006  Kristian Hoegsberg <krh@bitplanet.net>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19  */
  20
  21 #include <linux/ctype.h>
  22 #include <linux/delay.h>
  23 #include <linux/device.h>
  24 #include <linux/errno.h>
  25 #include <linux/firewire.h>
  26 #include <linux/firewire-constants.h>
  27 #include <linux/idr.h>
  28 #include <linux/jiffies.h>
  29 #include <linux/kobject.h>
  30 #include <linux/list.h>
  31 #include <linux/mod_devicetable.h>
  32 #include <linux/module.h>
  33 #include <linux/mutex.h>
  34 #include <linux/rwsem.h>
  35 #include <linux/semaphore.h>
  36 #include <linux/spinlock.h>
  37 #include <linux/string.h>
  38 #include <linux/workqueue.h>
  39
  40 #include <asm/atomic.h>
  41 #include <asm/byteorder.h>
  42 #include <asm/system.h>
  43
  44 #include "core.h"
  45
  46 void fw_csr_iterator_init(struct fw_csr_iterator *ci, 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 u32 *search_leaf(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                 last_key = key;
  73         }
  74         return NULL;
  75 }
  76
  77 static int textual_leaf_to_string(u32 *block, char *buf, size_t size)
  78 {
  79         unsigned int quadlets, length;
  80
  81         if (!size || !buf)
  82                 return -EINVAL;
  83
  84         quadlets = min(block[0] >> 16, 256u);
  85         if (quadlets < 2)
  86                 return -ENODATA;
  87
  88         if (block[1] != 0 || block[2] != 0)
  89                 /* unknown language/character set */
  90                 return -ENODATA;
  91
  92         block += 3;
  93         quadlets -= 2;
  94         for (length = 0; length < quadlets * 4 && length + 1 < size; length++) {
  95                 char c = block[length / 4] >> (24 - 8 * (length % 4));
  96                 if (c == '\0')
  97                         break;
  98                 buf[length] = c;
  99         }
 100         buf[length] = '\0';
 101         return length;
 102 }
 103
 104 /**
 105  * fw_csr_string - reads a string from the configuration ROM
 106  * @directory: device or unit directory;
 107  *             fw_device->config_rom+5 or fw_unit->directory
 108  * @key: the key of the preceding directory entry
 109  * @buf: where to put the string
 110  * @size: size of @buf, in bytes
 111  *
 112  * Returns string length (>= 0) or error code (< 0).
 113  */
 114 int fw_csr_string(u32 *directory, int key, char *buf, size_t size)
 115 {
 116         u32 *leaf = search_leaf(directory, key);
 117         if (!leaf)
 118                 return -ENOENT;
 119         return textual_leaf_to_string(leaf, buf, size);
 120 }
 121 EXPORT_SYMBOL(fw_csr_string);
 122
 123 static bool is_fw_unit(struct device *dev);
 124
 125 static int match_unit_directory(u32 *directory, u32 match_flags,
 126                                 const struct ieee1394_device_id *id)
 127 {
 128         struct fw_csr_iterator ci;
 129         int key, value, match;
 130
 131         match = 0;
 132         fw_csr_iterator_init(&ci, directory);
 133         while (fw_csr_iterator_next(&ci, &key, &value)) {
 134                 if (key == CSR_VENDOR && value == id->vendor_id)
 135                         match |= IEEE1394_MATCH_VENDOR_ID;
 136                 if (key == CSR_MODEL && value == id->model_id)
 137                         match |= IEEE1394_MATCH_MODEL_ID;
 138                 if (key == CSR_SPECIFIER_ID && value == id->specifier_id)
 139                         match |= IEEE1394_MATCH_SPECIFIER_ID;
 140                 if (key == CSR_VERSION && value == id->version)
 141                         match |= IEEE1394_MATCH_VERSION;
 142         }
 143
 144         return (match & match_flags) == match_flags;
 145 }
 146
 147 static int fw_unit_match(struct device *dev, struct device_driver *drv)
 148 {
 149         struct fw_unit *unit = fw_unit(dev);
 150         struct fw_device *device;
 151         const struct ieee1394_device_id *id;
 152
 153         /* We only allow binding to fw_units. */
 154         if (!is_fw_unit(dev))
 155                 return 0;
 156
 157         device = fw_parent_device(unit);
 158         id = container_of(drv, struct fw_driver, driver)->id_table;
 159
 160         for (; id->match_flags != 0; id++) {
 161                 if (match_unit_directory(unit->directory, id->match_flags, id))
 162                         return 1;
 163
 164                 /* Also check vendor ID in the root directory. */
 165                 if ((id->match_flags & IEEE1394_MATCH_VENDOR_ID) &&
 166                     match_unit_directory(&device->config_rom[5],
 167                                 IEEE1394_MATCH_VENDOR_ID, id) &&
 168                     match_unit_directory(unit->directory, id->match_flags
 169                                 & ~IEEE1394_MATCH_VENDOR_ID, id))
 170                         return 1;
 171         }
 172
 173         return 0;
 174 }
 175
 176 static int get_modalias(struct fw_unit *unit, char *buffer, size_t buffer_size)
 177 {
 178         struct fw_device *device = fw_parent_device(unit);
 179         struct fw_csr_iterator ci;
 180
 181         int key, value;
 182         int vendor = 0;
 183         int model = 0;
 184         int specifier_id = 0;
 185         int version = 0;
 186
 187         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 188         while (fw_csr_iterator_next(&ci, &key, &value)) {
 189                 switch (key) {
 190                 case CSR_VENDOR:
 191                         vendor = value;
 192                         break;
 193                 case CSR_MODEL:
 194                         model = value;
 195                         break;
 196                 }
 197         }
 198
 199         fw_csr_iterator_init(&ci, unit->directory);
 200         while (fw_csr_iterator_next(&ci, &key, &value)) {
 201                 switch (key) {
 202                 case CSR_SPECIFIER_ID:
 203                         specifier_id = value;
 204                         break;
 205                 case CSR_VERSION:
 206                         version = value;
 207                         break;
 208                 }
 209         }
 210
 211         return snprintf(buffer, buffer_size,
 212                         "ieee1394:ven%08Xmo%08Xsp%08Xver%08X",
 213                         vendor, model, specifier_id, version);
 214 }
 215
 216 static int fw_unit_uevent(struct device *dev, struct kobj_uevent_env *env)
 217 {
 218         struct fw_unit *unit = fw_unit(dev);
 219         char modalias[64];
 220
 221         get_modalias(unit, modalias, sizeof(modalias));
 222
 223         if (add_uevent_var(env, "MODALIAS=%s", modalias))
 224                 return -ENOMEM;
 225
 226         return 0;
 227 }
 228
 229 struct bus_type fw_bus_type = {
 230         .name = "firewire",
 231         .match = fw_unit_match,
 232 };
 233 EXPORT_SYMBOL(fw_bus_type);
 234
 235 int fw_device_enable_phys_dma(struct fw_device *device)
 236 {
 237         int generation = device->generation;
 238
 239         /* device->node_id, accessed below, must not be older than generation */
 240         smp_rmb();
 241
 242         return device->card->driver->enable_phys_dma(device->card,
 243                                                      device->node_id,
 244                                                      generation);
 245 }
 246 EXPORT_SYMBOL(fw_device_enable_phys_dma);
 247
 248 struct config_rom_attribute {
 249         struct device_attribute attr;
 250         u32 key;
 251 };
 252
 253 static ssize_t show_immediate(struct device *dev,
 254                               struct device_attribute *dattr, char *buf)
 255 {
 256         struct config_rom_attribute *attr =
 257                 container_of(dattr, struct config_rom_attribute, attr);
 258         struct fw_csr_iterator ci;
 259         u32 *dir;
 260         int key, value, ret = -ENOENT;
 261
 262         down_read(&fw_device_rwsem);
 263
 264         if (is_fw_unit(dev))
 265                 dir = fw_unit(dev)->directory;
 266         else
 267                 dir = fw_device(dev)->config_rom + 5;
 268
 269         fw_csr_iterator_init(&ci, dir);
 270         while (fw_csr_iterator_next(&ci, &key, &value))
 271                 if (attr->key == key) {
 272                         ret = snprintf(buf, buf ? PAGE_SIZE : 0,
 273                                        "0x%06x\n", value);
 274                         break;
 275                 }
 276
 277         up_read(&fw_device_rwsem);
 278
 279         return ret;
 280 }
 281
 282 #define IMMEDIATE_ATTR(name, key)                               \
 283         { __ATTR(name, S_IRUGO, show_immediate, NULL), key }
 284
 285 static ssize_t show_text_leaf(struct device *dev,
 286                               struct device_attribute *dattr, char *buf)
 287 {
 288         struct config_rom_attribute *attr =
 289                 container_of(dattr, struct config_rom_attribute, attr);
 290         u32 *dir;
 291         size_t bufsize;
 292         char dummy_buf[2];
 293         int ret;
 294
 295         down_read(&fw_device_rwsem);
 296
 297         if (is_fw_unit(dev))
 298                 dir = fw_unit(dev)->directory;
 299         else
 300                 dir = fw_device(dev)->config_rom + 5;
 301
 302         if (buf) {
 303                 bufsize = PAGE_SIZE - 1;
 304         } else {
 305                 buf = dummy_buf;
 306                 bufsize = 1;
 307         }
 308
 309         ret = fw_csr_string(dir, attr->key, buf, bufsize);
 310
 311         if (ret >= 0) {
 312                 /* Strip trailing whitespace and add newline. */
 313                 while (ret > 0 && isspace(buf[ret - 1]))
 314                         ret--;
 315                 strcpy(buf + ret, "\n");
 316                 ret++;
 317         }
 318
 319         up_read(&fw_device_rwsem);
 320
 321         return ret;
 322 }
 323
 324 #define TEXT_LEAF_ATTR(name, key)                               \
 325         { __ATTR(name, S_IRUGO, show_text_leaf, NULL), key }
 326
 327 static struct config_rom_attribute config_rom_attributes[] = {
 328         IMMEDIATE_ATTR(vendor, CSR_VENDOR),
 329         IMMEDIATE_ATTR(hardware_version, CSR_HARDWARE_VERSION),
 330         IMMEDIATE_ATTR(specifier_id, CSR_SPECIFIER_ID),
 331         IMMEDIATE_ATTR(version, CSR_VERSION),
 332         IMMEDIATE_ATTR(model, CSR_MODEL),
 333         TEXT_LEAF_ATTR(vendor_name, CSR_VENDOR),
 334         TEXT_LEAF_ATTR(model_name, CSR_MODEL),
 335         TEXT_LEAF_ATTR(hardware_version_name, CSR_HARDWARE_VERSION),
 336 };
 337
 338 static void init_fw_attribute_group(struct device *dev,
 339                                     struct device_attribute *attrs,
 340                                     struct fw_attribute_group *group)
 341 {
 342         struct device_attribute *attr;
 343         int i, j;
 344
 345         for (j = 0; attrs[j].attr.name != NULL; j++)
 346                 group->attrs[j] = &attrs[j].attr;
 347
 348         for (i = 0; i < ARRAY_SIZE(config_rom_attributes); i++) {
 349                 attr = &config_rom_attributes[i].attr;
 350                 if (attr->show(dev, attr, NULL) < 0)
 351                         continue;
 352                 group->attrs[j++] = &attr->attr;
 353         }
 354
 355         group->attrs[j] = NULL;
 356         group->groups[0] = &group->group;
 357         group->groups[1] = NULL;
 358         group->group.attrs = group->attrs;
 359         dev->groups = (const struct attribute_group **) group->groups;
 360 }
 361
 362 static ssize_t modalias_show(struct device *dev,
 363                              struct device_attribute *attr, char *buf)
 364 {
 365         struct fw_unit *unit = fw_unit(dev);
 366         int length;
 367
 368         length = get_modalias(unit, buf, PAGE_SIZE);
 369         strcpy(buf + length, "\n");
 370
 371         return length + 1;
 372 }
 373
 374 static ssize_t rom_index_show(struct device *dev,
 375                               struct device_attribute *attr, char *buf)
 376 {
 377         struct fw_device *device = fw_device(dev->parent);
 378         struct fw_unit *unit = fw_unit(dev);
 379
 380         return snprintf(buf, PAGE_SIZE, "%d\n",
 381                         (int)(unit->directory - device->config_rom));
 382 }
 383
 384 static struct device_attribute fw_unit_attributes[] = {
 385         __ATTR_RO(modalias),
 386         __ATTR_RO(rom_index),
 387         __ATTR_NULL,
 388 };
 389
 390 static ssize_t config_rom_show(struct device *dev,
 391                                struct device_attribute *attr, char *buf)
 392 {
 393         struct fw_device *device = fw_device(dev);
 394         size_t length;
 395
 396         down_read(&fw_device_rwsem);
 397         length = device->config_rom_length * 4;
 398         memcpy(buf, device->config_rom, length);
 399         up_read(&fw_device_rwsem);
 400
 401         return length;
 402 }
 403
 404 static ssize_t guid_show(struct device *dev,
 405                          struct device_attribute *attr, char *buf)
 406 {
 407         struct fw_device *device = fw_device(dev);
 408         int ret;
 409
 410         down_read(&fw_device_rwsem);
 411         ret = snprintf(buf, PAGE_SIZE, "0x%08x%08x\n",
 412                        device->config_rom[3], device->config_rom[4]);
 413         up_read(&fw_device_rwsem);
 414
 415         return ret;
 416 }
 417
 418 static int units_sprintf(char *buf, u32 *directory)
 419 {
 420         struct fw_csr_iterator ci;
 421         int key, value;
 422         int specifier_id = 0;
 423         int version = 0;
 424
 425         fw_csr_iterator_init(&ci, directory);
 426         while (fw_csr_iterator_next(&ci, &key, &value)) {
 427                 switch (key) {
 428                 case CSR_SPECIFIER_ID:
 429                         specifier_id = value;
 430                         break;
 431                 case CSR_VERSION:
 432                         version = value;
 433                         break;
 434                 }
 435         }
 436
 437         return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version);
 438 }
 439
 440 static ssize_t units_show(struct device *dev,
 441                           struct device_attribute *attr, char *buf)
 442 {
 443         struct fw_device *device = fw_device(dev);
 444         struct fw_csr_iterator ci;
 445         int key, value, i = 0;
 446
 447         down_read(&fw_device_rwsem);
 448         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 449         while (fw_csr_iterator_next(&ci, &key, &value)) {
 450                 if (key != (CSR_UNIT | CSR_DIRECTORY))
 451                         continue;
 452                 i += units_sprintf(&buf[i], ci.p + value - 1);
 453                 if (i >= PAGE_SIZE - (8 + 1 + 8 + 1))
 454                         break;
 455         }
 456         up_read(&fw_device_rwsem);
 457
 458         if (i)
 459                 buf[i - 1] = '\n';
 460
 461         return i;
 462 }
 463
 464 static struct device_attribute fw_device_attributes[] = {
 465         __ATTR_RO(config_rom),
 466         __ATTR_RO(guid),
 467         __ATTR_RO(units),
 468         __ATTR_NULL,
 469 };
 470
 471 static int read_rom(struct fw_device *device,
 472                     int generation, int index, u32 *data)
 473 {
 474         int rcode;
 475
 476         /* device->node_id, accessed below, must not be older than generation */
 477         smp_rmb();
 478
 479         rcode = fw_run_transaction(device->card, TCODE_READ_QUADLET_REQUEST,
 480                         device->node_id, generation, device->max_speed,
 481                         (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4,
 482                         data, 4);
 483         be32_to_cpus(data);
 484
 485         return rcode;
 486 }
 487
 488 #define READ_BIB_ROM_SIZE       256
 489 #define READ_BIB_STACK_SIZE     16
 490
 491 /*
 492  * Read the bus info block, perform a speed probe, and read all of the rest of
 493  * the config ROM.  We do all this with a cached bus generation.  If the bus
 494  * generation changes under us, read_bus_info_block will fail and get retried.
 495  * It's better to start all over in this case because the node from which we
 496  * are reading the ROM may have changed the ROM during the reset.
 497  */
 498 static int read_bus_info_block(struct fw_device *device, int generation)
 499 {
 500         u32 *rom, *stack, *old_rom, *new_rom;
 501         u32 sp, key;
 502         int i, end, length, ret = -1;
 503
 504         rom = kmalloc(sizeof(*rom) * READ_BIB_ROM_SIZE +
 505                       sizeof(*stack) * READ_BIB_STACK_SIZE, GFP_KERNEL);
 506         if (rom == NULL)
 507                 return -ENOMEM;
 508
 509         stack = &rom[READ_BIB_ROM_SIZE];
 510
 511         device->max_speed = SCODE_100;
 512
 513         /* First read the bus info block. */
 514         for (i = 0; i < 5; i++) {
 515                 if (read_rom(device, generation, i, &rom[i]) != RCODE_COMPLETE)
 516                         goto out;
 517                 /*
 518                  * As per IEEE1212 7.2, during power-up, devices can
 519                  * reply with a 0 for the first quadlet of the config
 520                  * rom to indicate that they are booting (for example,
 521                  * if the firmware is on the disk of a external
 522                  * harddisk).  In that case we just fail, and the
 523                  * retry mechanism will try again later.
 524                  */
 525                 if (i == 0 && rom[i] == 0)
 526                         goto out;
 527         }
 528
 529         device->max_speed = device->node->max_speed;
 530
 531         /*
 532          * Determine the speed of
 533          *   - devices with link speed less than PHY speed,
 534          *   - devices with 1394b PHY (unless only connected to 1394a PHYs),
 535          *   - all devices if there are 1394b repeaters.
 536          * Note, we cannot use the bus info block's link_spd as starting point
 537          * because some buggy firmwares set it lower than necessary and because
 538          * 1394-1995 nodes do not have the field.
 539          */
 540         if ((rom[2] & 0x7) < device->max_speed ||
 541             device->max_speed == SCODE_BETA ||
 542             device->card->beta_repeaters_present) {
 543                 u32 dummy;
 544
 545                 /* for S1600 and S3200 */
 546                 if (device->max_speed == SCODE_BETA)
 547                         device->max_speed = device->card->link_speed;
 548
 549                 while (device->max_speed > SCODE_100) {
 550                         if (read_rom(device, generation, 0, &dummy) ==
 551                             RCODE_COMPLETE)
 552                                 break;
 553                         device->max_speed--;
 554                 }
 555         }
 556
 557         /*
 558          * Now parse the config rom.  The config rom is a recursive
 559          * directory structure so we parse it using a stack of
 560          * references to the blocks that make up the structure.  We
 561          * push a reference to the root directory on the stack to
 562          * start things off.
 563          */
 564         length = i;
 565         sp = 0;
 566         stack[sp++] = 0xc0000005;
 567         while (sp > 0) {
 568                 /*
 569                  * Pop the next block reference of the stack.  The
 570                  * lower 24 bits is the offset into the config rom,
 571                  * the upper 8 bits are the type of the reference the
 572                  * block.
 573                  */
 574                 key = stack[--sp];
 575                 i = key & 0xffffff;
 576                 if (i >= READ_BIB_ROM_SIZE)
 577                         /*
 578                          * The reference points outside the standard
 579                          * config rom area, something's fishy.
 580                          */
 581                         goto out;
 582
 583                 /* Read header quadlet for the block to get the length. */
 584                 if (read_rom(device, generation, i, &rom[i]) != RCODE_COMPLETE)
 585                         goto out;
 586                 end = i + (rom[i] >> 16) + 1;
 587                 i++;
 588                 if (end > READ_BIB_ROM_SIZE)
 589                         /*
 590                          * This block extends outside standard config
 591                          * area (and the array we're reading it
 592                          * into).  That's broken, so ignore this
 593                          * device.
 594                          */
 595                         goto out;
 596
 597                 /*
 598                  * Now read in the block.  If this is a directory
 599                  * block, check the entries as we read them to see if
 600                  * it references another block, and push it in that case.
 601                  */
 602                 while (i < end) {
 603                         if (read_rom(device, generation, i, &rom[i]) !=
 604                             RCODE_COMPLETE)
 605                                 goto out;
 606                         if ((key >> 30) == 3 && (rom[i] >> 30) > 1 &&
 607                             sp < READ_BIB_STACK_SIZE)
 608                                 stack[sp++] = i + rom[i];
 609                         i++;
 610                 }
 611                 if (length < i)
 612                         length = i;
 613         }
 614
 615         old_rom = device->config_rom;
 616         new_rom = kmemdup(rom, length * 4, GFP_KERNEL);
 617         if (new_rom == NULL)
 618                 goto out;
 619
 620         down_write(&fw_device_rwsem);
 621         device->config_rom = new_rom;
 622         device->config_rom_length = length;
 623         up_write(&fw_device_rwsem);
 624
 625         kfree(old_rom);
 626         ret = 0;
 627         device->max_rec = rom[2] >> 12 & 0xf;
 628         device->cmc     = rom[2] >> 30 & 1;
 629         device->irmc    = rom[2] >> 31 & 1;
 630  out:
 631         kfree(rom);
 632
 633         return ret;
 634 }
 635
 636 static void fw_unit_release(struct device *dev)
 637 {
 638         struct fw_unit *unit = fw_unit(dev);
 639
 640         kfree(unit);
 641 }
 642
 643 static struct device_type fw_unit_type = {
 644         .uevent         = fw_unit_uevent,
 645         .release        = fw_unit_release,
 646 };
 647
 648 static bool is_fw_unit(struct device *dev)
 649 {
 650         return dev->type == &fw_unit_type;
 651 }
 652
 653 static void create_units(struct fw_device *device)
 654 {
 655         struct fw_csr_iterator ci;
 656         struct fw_unit *unit;
 657         int key, value, i;
 658
 659         i = 0;
 660         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 661         while (fw_csr_iterator_next(&ci, &key, &value)) {
 662                 if (key != (CSR_UNIT | CSR_DIRECTORY))
 663                         continue;
 664
 665                 /*
 666                  * Get the address of the unit directory and try to
 667                  * match the drivers id_tables against it.
 668                  */
 669                 unit = kzalloc(sizeof(*unit), GFP_KERNEL);
 670                 if (unit == NULL) {
 671                         fw_error("failed to allocate memory for unit\n");
 672                         continue;
 673                 }
 674
 675                 unit->directory = ci.p + value - 1;
 676                 unit->device.bus = &fw_bus_type;
 677                 unit->device.type = &fw_unit_type;
 678                 unit->device.parent = &device->device;
 679                 dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++);
 680
 681                 BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) <
 682                                 ARRAY_SIZE(fw_unit_attributes) +
 683                                 ARRAY_SIZE(config_rom_attributes));
 684                 init_fw_attribute_group(&unit->device,
 685                                         fw_unit_attributes,
 686                                         &unit->attribute_group);
 687
 688                 if (device_register(&unit->device) < 0)
 689                         goto skip_unit;
 690
 691                 continue;
 692
 693         skip_unit:
 694                 kfree(unit);
 695         }
 696 }
 697
 698 static int shutdown_unit(struct device *device, void *data)
 699 {
 700         device_unregister(device);
 701
 702         return 0;
 703 }
 704
 705 /*
 706  * fw_device_rwsem acts as dual purpose mutex:
 707  *   - serializes accesses to fw_device_idr,
 708  *   - serializes accesses to fw_device.config_rom/.config_rom_length and
 709  *     fw_unit.directory, unless those accesses happen at safe occasions
 710  */
 711 DECLARE_RWSEM(fw_device_rwsem);
 712
 713 DEFINE_IDR(fw_device_idr);
 714 int fw_cdev_major;
 715
 716 struct fw_device *fw_device_get_by_devt(dev_t devt)
 717 {
 718         struct fw_device *device;
 719
 720         down_read(&fw_device_rwsem);
 721         device = idr_find(&fw_device_idr, MINOR(devt));
 722         if (device)
 723                 fw_device_get(device);
 724         up_read(&fw_device_rwsem);
 725
 726         return device;
 727 }
 728
 729 /*
 730  * These defines control the retry behavior for reading the config
 731  * rom.  It shouldn't be necessary to tweak these; if the device
 732  * doesn't respond to a config rom read within 10 seconds, it's not
 733  * going to respond at all.  As for the initial delay, a lot of
 734  * devices will be able to respond within half a second after bus
 735  * reset.  On the other hand, it's not really worth being more
 736  * aggressive than that, since it scales pretty well; if 10 devices
 737  * are plugged in, they're all getting read within one second.
 738  */
 739
 740 #define MAX_RETRIES     10
 741 #define RETRY_DELAY     (3 * HZ)
 742 #define INITIAL_DELAY   (HZ / 2)
 743 #define SHUTDOWN_DELAY  (2 * HZ)
 744
 745 static void fw_device_shutdown(struct work_struct *work)
 746 {
 747         struct fw_device *device =
 748                 container_of(work, struct fw_device, work.work);
 749         int minor = MINOR(device->device.devt);
 750
 751         if (time_is_after_jiffies(device->card->reset_jiffies + SHUTDOWN_DELAY)
 752             && !list_empty(&device->card->link)) {
 753                 schedule_delayed_work(&device->work, SHUTDOWN_DELAY);
 754                 return;
 755         }
 756
 757         if (atomic_cmpxchg(&device->state,
 758                            FW_DEVICE_GONE,
 759                            FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE)
 760                 return;
 761
 762         fw_device_cdev_remove(device);
 763         device_for_each_child(&device->device, NULL, shutdown_unit);
 764         device_unregister(&device->device);
 765
 766         down_write(&fw_device_rwsem);
 767         idr_remove(&fw_device_idr, minor);
 768         up_write(&fw_device_rwsem);
 769
 770         fw_device_put(device);
 771 }
 772
 773 static void fw_device_release(struct device *dev)
 774 {
 775         struct fw_device *device = fw_device(dev);
 776         struct fw_card *card = device->card;
 777         unsigned long flags;
 778
 779         /*
 780          * Take the card lock so we don't set this to NULL while a
 781          * FW_NODE_UPDATED callback is being handled or while the
 782          * bus manager work looks at this node.
 783          */
 784         spin_lock_irqsave(&card->lock, flags);
 785         device->node->data = NULL;
 786         spin_unlock_irqrestore(&card->lock, flags);
 787
 788         fw_node_put(device->node);
 789         kfree(device->config_rom);
 790         kfree(device);
 791         fw_card_put(card);
 792 }
 793
 794 static struct device_type fw_device_type = {
 795         .release = fw_device_release,
 796 };
 797
 798 static bool is_fw_device(struct device *dev)
 799 {
 800         return dev->type == &fw_device_type;
 801 }
 802
 803 static int update_unit(struct device *dev, void *data)
 804 {
 805         struct fw_unit *unit = fw_unit(dev);
 806         struct fw_driver *driver = (struct fw_driver *)dev->driver;
 807
 808         if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) {
 809                 down(&dev->sem);
 810                 driver->update(unit);
 811                 up(&dev->sem);
 812         }
 813
 814         return 0;
 815 }
 816
 817 static void fw_device_update(struct work_struct *work)
 818 {
 819         struct fw_device *device =
 820                 container_of(work, struct fw_device, work.work);
 821
 822         fw_device_cdev_update(device);
 823         device_for_each_child(&device->device, NULL, update_unit);
 824 }
 825
 826 /*
 827  * If a device was pending for deletion because its node went away but its
 828  * bus info block and root directory header matches that of a newly discovered
 829  * device, revive the existing fw_device.
 830  * The newly allocated fw_device becomes obsolete instead.
 831  */
 832 static int lookup_existing_device(struct device *dev, void *data)
 833 {
 834         struct fw_device *old = fw_device(dev);
 835         struct fw_device *new = data;
 836         struct fw_card *card = new->card;
 837         int match = 0;
 838
 839         if (!is_fw_device(dev))
 840                 return 0;
 841
 842         down_read(&fw_device_rwsem); /* serialize config_rom access */
 843         spin_lock_irq(&card->lock);  /* serialize node access */
 844
 845         if (memcmp(old->config_rom, new->config_rom, 6 * 4) == 0 &&
 846             atomic_cmpxchg(&old->state,
 847                            FW_DEVICE_GONE,
 848                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
 849                 struct fw_node *current_node = new->node;
 850                 struct fw_node *obsolete_node = old->node;
 851
 852                 new->node = obsolete_node;
 853                 new->node->data = new;
 854                 old->node = current_node;
 855                 old->node->data = old;
 856
 857                 old->max_speed = new->max_speed;
 858                 old->node_id = current_node->node_id;
 859                 smp_wmb();  /* update node_id before generation */
 860                 old->generation = card->generation;
 861                 old->config_rom_retries = 0;
 862                 fw_notify("rediscovered device %s\n", dev_name(dev));
 863
 864                 PREPARE_DELAYED_WORK(&old->work, fw_device_update);
 865                 schedule_delayed_work(&old->work, 0);
 866
 867                 if (current_node == card->root_node)
 868                         fw_schedule_bm_work(card, 0);
 869
 870                 match = 1;
 871         }
 872
 873         spin_unlock_irq(&card->lock);
 874         up_read(&fw_device_rwsem);
 875
 876         return match;
 877 }
 878
 879 enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, };
 880
 881 static void set_broadcast_channel(struct fw_device *device, int generation)
 882 {
 883         struct fw_card *card = device->card;
 884         __be32 data;
 885         int rcode;
 886
 887         if (!card->broadcast_channel_allocated)
 888                 return;
 889
 890         /*
 891          * The Broadcast_Channel Valid bit is required by nodes which want to
 892          * transmit on this channel.  Such transmissions are practically
 893          * exclusive to IP over 1394 (RFC 2734).  IP capable nodes are required
 894          * to be IRM capable and have a max_rec of 8 or more.  We use this fact
 895          * to narrow down to which nodes we send Broadcast_Channel updates.
 896          */
 897         if (!device->irmc || device->max_rec < 8)
 898                 return;
 899
 900         /*
 901          * Some 1394-1995 nodes crash if this 1394a-2000 register is written.
 902          * Perform a read test first.
 903          */
 904         if (device->bc_implemented == BC_UNKNOWN) {
 905                 rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST,
 906                                 device->node_id, generation, device->max_speed,
 907                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 908                                 &data, 4);
 909                 switch (rcode) {
 910                 case RCODE_COMPLETE:
 911                         if (data & cpu_to_be32(1 << 31)) {
 912                                 device->bc_implemented = BC_IMPLEMENTED;
 913                                 break;
 914                         }
 915                         /* else fall through to case address error */
 916                 case RCODE_ADDRESS_ERROR:
 917                         device->bc_implemented = BC_UNIMPLEMENTED;
 918                 }
 919         }
 920
 921         if (device->bc_implemented == BC_IMPLEMENTED) {
 922                 data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL |
 923                                    BROADCAST_CHANNEL_VALID);
 924                 fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
 925                                 device->node_id, generation, device->max_speed,
 926                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 927                                 &data, 4);
 928         }
 929 }
 930
 931 int fw_device_set_broadcast_channel(struct device *dev, void *gen)
 932 {
 933         if (is_fw_device(dev))
 934                 set_broadcast_channel(fw_device(dev), (long)gen);
 935
 936         return 0;
 937 }
 938
 939 static void fw_device_init(struct work_struct *work)
 940 {
 941         struct fw_device *device =
 942                 container_of(work, struct fw_device, work.work);
 943         struct device *revived_dev;
 944         int minor, ret;
 945
 946         /*
 947          * All failure paths here set node->data to NULL, so that we
 948          * don't try to do device_for_each_child() on a kfree()'d
 949          * device.
 950          */
 951
 952         if (read_bus_info_block(device, device->generation) < 0) {
 953                 if (device->config_rom_retries < MAX_RETRIES &&
 954                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
 955                         device->config_rom_retries++;
 956                         schedule_delayed_work(&device->work, RETRY_DELAY);
 957                 } else {
 958                         fw_notify("giving up on config rom for node id %x\n",
 959                                   device->node_id);
 960                         if (device->node == device->card->root_node)
 961                                 fw_schedule_bm_work(device->card, 0);
 962                         fw_device_release(&device->device);
 963                 }
 964                 return;
 965         }
 966
 967         revived_dev = device_find_child(device->card->device,
 968                                         device, lookup_existing_device);
 969         if (revived_dev) {
 970                 put_device(revived_dev);
 971                 fw_device_release(&device->device);
 972
 973                 return;
 974         }
 975
 976         device_initialize(&device->device);
 977
 978         fw_device_get(device);
 979         down_write(&fw_device_rwsem);
 980         ret = idr_pre_get(&fw_device_idr, GFP_KERNEL) ?
 981               idr_get_new(&fw_device_idr, device, &minor) :
 982               -ENOMEM;
 983         up_write(&fw_device_rwsem);
 984
 985         if (ret < 0)
 986                 goto error;
 987
 988         device->device.bus = &fw_bus_type;
 989         device->device.type = &fw_device_type;
 990         device->device.parent = device->card->device;
 991         device->device.devt = MKDEV(fw_cdev_major, minor);
 992         dev_set_name(&device->device, "fw%d", minor);
 993
 994         BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) <
 995                         ARRAY_SIZE(fw_device_attributes) +
 996                         ARRAY_SIZE(config_rom_attributes));
 997         init_fw_attribute_group(&device->device,
 998                                 fw_device_attributes,
 999                                 &device->attribute_group);
1000
1001         if (device_add(&device->device)) {
1002                 fw_error("Failed to add device.\n");
1003                 goto error_with_cdev;
1004         }
1005
1006         create_units(device);
1007
1008         /*
1009          * Transition the device to running state.  If it got pulled
1010          * out from under us while we did the intialization work, we
1011          * have to shut down the device again here.  Normally, though,
1012          * fw_node_event will be responsible for shutting it down when
1013          * necessary.  We have to use the atomic cmpxchg here to avoid
1014          * racing with the FW_NODE_DESTROYED case in
1015          * fw_node_event().
1016          */
1017         if (atomic_cmpxchg(&device->state,
1018                            FW_DEVICE_INITIALIZING,
1019                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
1020                 PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1021                 schedule_delayed_work(&device->work, SHUTDOWN_DELAY);
1022         } else {
1023                 if (device->config_rom_retries)
1024                         fw_notify("created device %s: GUID %08x%08x, S%d00, "
1025                                   "%d config ROM retries\n",
1026                                   dev_name(&device->device),
1027                                   device->config_rom[3], device->config_rom[4],
1028                                   1 << device->max_speed,
1029                                   device->config_rom_retries);
1030                 else
1031                         fw_notify("created device %s: GUID %08x%08x, S%d00\n",
1032                                   dev_name(&device->device),
1033                                   device->config_rom[3], device->config_rom[4],
1034                                   1 << device->max_speed);
1035                 device->config_rom_retries = 0;
1036
1037                 set_broadcast_channel(device, device->generation);
1038         }
1039
1040         /*
1041          * Reschedule the IRM work if we just finished reading the
1042          * root node config rom.  If this races with a bus reset we
1043          * just end up running the IRM work a couple of extra times -
1044          * pretty harmless.
1045          */
1046         if (device->node == device->card->root_node)
1047                 fw_schedule_bm_work(device->card, 0);
1048
1049         return;
1050
1051  error_with_cdev:
1052         down_write(&fw_device_rwsem);
1053         idr_remove(&fw_device_idr, minor);
1054         up_write(&fw_device_rwsem);
1055  error:
1056         fw_device_put(device);          /* fw_device_idr's reference */
1057
1058         put_device(&device->device);    /* our reference */
1059 }
1060
1061 enum {
1062         REREAD_BIB_ERROR,
1063         REREAD_BIB_GONE,
1064         REREAD_BIB_UNCHANGED,
1065         REREAD_BIB_CHANGED,
1066 };
1067
1068 /* Reread and compare bus info block and header of root directory */
1069 static int reread_bus_info_block(struct fw_device *device, int generation)
1070 {
1071         u32 q;
1072         int i;
1073
1074         for (i = 0; i < 6; i++) {
1075                 if (read_rom(device, generation, i, &q) != RCODE_COMPLETE)
1076                         return REREAD_BIB_ERROR;
1077
1078                 if (i == 0 && q == 0)
1079                         return REREAD_BIB_GONE;
1080
1081                 if (q != device->config_rom[i])
1082                         return REREAD_BIB_CHANGED;
1083         }
1084
1085         return REREAD_BIB_UNCHANGED;
1086 }
1087
1088 static void fw_device_refresh(struct work_struct *work)
1089 {
1090         struct fw_device *device =
1091                 container_of(work, struct fw_device, work.work);
1092         struct fw_card *card = device->card;
1093         int node_id = device->node_id;
1094
1095         switch (reread_bus_info_block(device, device->generation)) {
1096         case REREAD_BIB_ERROR:
1097                 if (device->config_rom_retries < MAX_RETRIES / 2 &&
1098                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1099                         device->config_rom_retries++;
1100                         schedule_delayed_work(&device->work, RETRY_DELAY / 2);
1101
1102                         return;
1103                 }
1104                 goto give_up;
1105
1106         case REREAD_BIB_GONE:
1107                 goto gone;
1108
1109         case REREAD_BIB_UNCHANGED:
1110                 if (atomic_cmpxchg(&device->state,
1111                                    FW_DEVICE_INITIALIZING,
1112                                    FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1113                         goto gone;
1114
1115                 fw_device_update(work);
1116                 device->config_rom_retries = 0;
1117                 goto out;
1118
1119         case REREAD_BIB_CHANGED:
1120                 break;
1121         }
1122
1123         /*
1124          * Something changed.  We keep things simple and don't investigate
1125          * further.  We just destroy all previous units and create new ones.
1126          */
1127         device_for_each_child(&device->device, NULL, shutdown_unit);
1128
1129         if (read_bus_info_block(device, device->generation) < 0) {
1130                 if (device->config_rom_retries < MAX_RETRIES &&
1131                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1132                         device->config_rom_retries++;
1133                         schedule_delayed_work(&device->work, RETRY_DELAY);
1134
1135                         return;
1136                 }
1137                 goto give_up;
1138         }
1139
1140         create_units(device);
1141
1142         /* Userspace may want to re-read attributes. */
1143         kobject_uevent(&device->device.kobj, KOBJ_CHANGE);
1144
1145         if (atomic_cmpxchg(&device->state,
1146                            FW_DEVICE_INITIALIZING,
1147                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1148                 goto gone;
1149
1150         fw_notify("refreshed device %s\n", dev_name(&device->device));
1151         device->config_rom_retries = 0;
1152         goto out;
1153
1154  give_up:
1155         fw_notify("giving up on refresh of device %s\n", dev_name(&device->device));
1156  gone:
1157         atomic_set(&device->state, FW_DEVICE_GONE);
1158         PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1159         schedule_delayed_work(&device->work, SHUTDOWN_DELAY);
1160  out:
1161         if (node_id == card->root_node->node_id)
1162                 fw_schedule_bm_work(card, 0);
1163 }
1164
1165 void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
1166 {
1167         struct fw_device *device;
1168
1169         switch (event) {
1170         case FW_NODE_CREATED:
1171         case FW_NODE_LINK_ON:
1172                 if (!node->link_on)
1173                         break;
1174  create:
1175                 device = kzalloc(sizeof(*device), GFP_ATOMIC);
1176                 if (device == NULL)
1177                         break;
1178
1179                 /*
1180                  * Do minimal intialization of the device here, the
1181                  * rest will happen in fw_device_init().
1182                  *
1183                  * Attention:  A lot of things, even fw_device_get(),
1184                  * cannot be done before fw_device_init() finished!
1185                  * You can basically just check device->state and
1186                  * schedule work until then, but only while holding
1187                  * card->lock.
1188                  */
1189                 atomic_set(&device->state, FW_DEVICE_INITIALIZING);
1190                 device->card = fw_card_get(card);
1191                 device->node = fw_node_get(node);
1192                 device->node_id = node->node_id;
1193                 device->generation = card->generation;
1194                 device->is_local = node == card->local_node;
1195                 mutex_init(&device->client_list_mutex);
1196                 INIT_LIST_HEAD(&device->client_list);
1197
1198                 /*
1199                  * Set the node data to point back to this device so
1200                  * FW_NODE_UPDATED callbacks can update the node_id
1201                  * and generation for the device.
1202                  */
1203                 node->data = device;
1204
1205                 /*
1206                  * Many devices are slow to respond after bus resets,
1207                  * especially if they are bus powered and go through
1208                  * power-up after getting plugged in.  We schedule the
1209                  * first config rom scan half a second after bus reset.
1210                  */
1211                 INIT_DELAYED_WORK(&device->work, fw_device_init);
1212                 schedule_delayed_work(&device->work, INITIAL_DELAY);
1213                 break;
1214
1215         case FW_NODE_INITIATED_RESET:
1216                 device = node->data;
1217                 if (device == NULL)
1218                         goto create;
1219
1220                 device->node_id = node->node_id;
1221                 smp_wmb();  /* update node_id before generation */
1222                 device->generation = card->generation;
1223                 if (atomic_cmpxchg(&device->state,
1224                             FW_DEVICE_RUNNING,
1225                             FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) {
1226                         PREPARE_DELAYED_WORK(&device->work, fw_device_refresh);
1227                         schedule_delayed_work(&device->work,
1228                                 device->is_local ? 0 : INITIAL_DELAY);
1229                 }
1230                 break;
1231
1232         case FW_NODE_UPDATED:
1233                 if (!node->link_on || node->data == NULL)
1234                         break;
1235
1236                 device = node->data;
1237                 device->node_id = node->node_id;
1238                 smp_wmb();  /* update node_id before generation */
1239                 device->generation = card->generation;
1240                 if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
1241                         PREPARE_DELAYED_WORK(&device->work, fw_device_update);
1242                         schedule_delayed_work(&device->work, 0);
1243                 }
1244                 break;
1245
1246         case FW_NODE_DESTROYED:
1247         case FW_NODE_LINK_OFF:
1248                 if (!node->data)
1249                         break;
1250
1251                 /*
1252                  * Destroy the device associated with the node.  There
1253                  * are two cases here: either the device is fully
1254                  * initialized (FW_DEVICE_RUNNING) or we're in the
1255                  * process of reading its config rom
1256                  * (FW_DEVICE_INITIALIZING).  If it is fully
1257                  * initialized we can reuse device->work to schedule a
1258                  * full fw_device_shutdown().  If not, there's work
1259                  * scheduled to read it's config rom, and we just put
1260                  * the device in shutdown state to have that code fail
1261                  * to create the device.
1262                  */
1263                 device = node->data;
1264                 if (atomic_xchg(&device->state,
1265                                 FW_DEVICE_GONE) == FW_DEVICE_RUNNING) {
1266                         PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1267                         schedule_delayed_work(&device->work,
1268                                 list_empty(&card->link) ? 0 : SHUTDOWN_DELAY);
1269                 }
1270                 break;
1271         }
1272 }