drivers/firewire/fw-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/idr.h>
  26 #include <linux/jiffies.h>
  27 #include <linux/kobject.h>
  28 #include <linux/list.h>
  29 #include <linux/mod_devicetable.h>
  30 #include <linux/module.h>
  31 #include <linux/mutex.h>
  32 #include <linux/rwsem.h>
  33 #include <linux/semaphore.h>
  34 #include <linux/spinlock.h>
  35 #include <linux/string.h>
  36 #include <linux/workqueue.h>
  37
  38 #include <asm/atomic.h>
  39 #include <asm/byteorder.h>
  40 #include <asm/system.h>
  41
  42 #include "fw-device.h"
  43 #include "fw-topology.h"
  44 #include "fw-transaction.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 int is_fw_unit(struct device *dev);
  63
  64 static int match_unit_directory(u32 *directory, u32 match_flags,
  65                                 const struct ieee1394_device_id *id)
  66 {
  67         struct fw_csr_iterator ci;
  68         int key, value, match;
  69
  70         match = 0;
  71         fw_csr_iterator_init(&ci, directory);
  72         while (fw_csr_iterator_next(&ci, &key, &value)) {
  73                 if (key == CSR_VENDOR && value == id->vendor_id)
  74                         match |= IEEE1394_MATCH_VENDOR_ID;
  75                 if (key == CSR_MODEL && value == id->model_id)
  76                         match |= IEEE1394_MATCH_MODEL_ID;
  77                 if (key == CSR_SPECIFIER_ID && value == id->specifier_id)
  78                         match |= IEEE1394_MATCH_SPECIFIER_ID;
  79                 if (key == CSR_VERSION && value == id->version)
  80                         match |= IEEE1394_MATCH_VERSION;
  81         }
  82
  83         return (match & match_flags) == match_flags;
  84 }
  85
  86 static int fw_unit_match(struct device *dev, struct device_driver *drv)
  87 {
  88         struct fw_unit *unit = fw_unit(dev);
  89         struct fw_device *device;
  90         const struct ieee1394_device_id *id;
  91
  92         /* We only allow binding to fw_units. */
  93         if (!is_fw_unit(dev))
  94                 return 0;
  95
  96         device = fw_device(unit->device.parent);
  97
  98         for (id = fw_driver(drv)->id_table; id->match_flags != 0; id++) {
  99                 if (match_unit_directory(unit->directory, id->match_flags, id))
 100                         return 1;
 101
 102                 /* Also check vendor ID in the root directory. */
 103                 if ((id->match_flags & IEEE1394_MATCH_VENDOR_ID) &&
 104                     match_unit_directory(&device->config_rom[5],
 105                                 IEEE1394_MATCH_VENDOR_ID, id) &&
 106                     match_unit_directory(unit->directory, id->match_flags
 107                                 & ~IEEE1394_MATCH_VENDOR_ID, id))
 108                         return 1;
 109         }
 110
 111         return 0;
 112 }
 113
 114 static int get_modalias(struct fw_unit *unit, char *buffer, size_t buffer_size)
 115 {
 116         struct fw_device *device = fw_device(unit->device.parent);
 117         struct fw_csr_iterator ci;
 118
 119         int key, value;
 120         int vendor = 0;
 121         int model = 0;
 122         int specifier_id = 0;
 123         int version = 0;
 124
 125         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 126         while (fw_csr_iterator_next(&ci, &key, &value)) {
 127                 switch (key) {
 128                 case CSR_VENDOR:
 129                         vendor = value;
 130                         break;
 131                 case CSR_MODEL:
 132                         model = value;
 133                         break;
 134                 }
 135         }
 136
 137         fw_csr_iterator_init(&ci, unit->directory);
 138         while (fw_csr_iterator_next(&ci, &key, &value)) {
 139                 switch (key) {
 140                 case CSR_SPECIFIER_ID:
 141                         specifier_id = value;
 142                         break;
 143                 case CSR_VERSION:
 144                         version = value;
 145                         break;
 146                 }
 147         }
 148
 149         return snprintf(buffer, buffer_size,
 150                         "ieee1394:ven%08Xmo%08Xsp%08Xver%08X",
 151                         vendor, model, specifier_id, version);
 152 }
 153
 154 static int fw_unit_uevent(struct device *dev, struct kobj_uevent_env *env)
 155 {
 156         struct fw_unit *unit = fw_unit(dev);
 157         char modalias[64];
 158
 159         get_modalias(unit, modalias, sizeof(modalias));
 160
 161         if (add_uevent_var(env, "MODALIAS=%s", modalias))
 162                 return -ENOMEM;
 163
 164         return 0;
 165 }
 166
 167 struct bus_type fw_bus_type = {
 168         .name = "firewire",
 169         .match = fw_unit_match,
 170 };
 171 EXPORT_SYMBOL(fw_bus_type);
 172
 173 int fw_device_enable_phys_dma(struct fw_device *device)
 174 {
 175         int generation = device->generation;
 176
 177         /* device->node_id, accessed below, must not be older than generation */
 178         smp_rmb();
 179
 180         return device->card->driver->enable_phys_dma(device->card,
 181                                                      device->node_id,
 182                                                      generation);
 183 }
 184 EXPORT_SYMBOL(fw_device_enable_phys_dma);
 185
 186 struct config_rom_attribute {
 187         struct device_attribute attr;
 188         u32 key;
 189 };
 190
 191 static ssize_t show_immediate(struct device *dev,
 192                               struct device_attribute *dattr, char *buf)
 193 {
 194         struct config_rom_attribute *attr =
 195                 container_of(dattr, struct config_rom_attribute, attr);
 196         struct fw_csr_iterator ci;
 197         u32 *dir;
 198         int key, value, ret = -ENOENT;
 199
 200         down_read(&fw_device_rwsem);
 201
 202         if (is_fw_unit(dev))
 203                 dir = fw_unit(dev)->directory;
 204         else
 205                 dir = fw_device(dev)->config_rom + 5;
 206
 207         fw_csr_iterator_init(&ci, dir);
 208         while (fw_csr_iterator_next(&ci, &key, &value))
 209                 if (attr->key == key) {
 210                         ret = snprintf(buf, buf ? PAGE_SIZE : 0,
 211                                        "0x%06x\n", value);
 212                         break;
 213                 }
 214
 215         up_read(&fw_device_rwsem);
 216
 217         return ret;
 218 }
 219
 220 #define IMMEDIATE_ATTR(name, key)                               \
 221         { __ATTR(name, S_IRUGO, show_immediate, NULL), key }
 222
 223 static ssize_t show_text_leaf(struct device *dev,
 224                               struct device_attribute *dattr, char *buf)
 225 {
 226         struct config_rom_attribute *attr =
 227                 container_of(dattr, struct config_rom_attribute, attr);
 228         struct fw_csr_iterator ci;
 229         u32 *dir, *block = NULL, *p, *end;
 230         int length, key, value, last_key = 0, ret = -ENOENT;
 231         char *b;
 232
 233         down_read(&fw_device_rwsem);
 234
 235         if (is_fw_unit(dev))
 236                 dir = fw_unit(dev)->directory;
 237         else
 238                 dir = fw_device(dev)->config_rom + 5;
 239
 240         fw_csr_iterator_init(&ci, dir);
 241         while (fw_csr_iterator_next(&ci, &key, &value)) {
 242                 if (attr->key == last_key &&
 243                     key == (CSR_DESCRIPTOR | CSR_LEAF))
 244                         block = ci.p - 1 + value;
 245                 last_key = key;
 246         }
 247
 248         if (block == NULL)
 249                 goto out;
 250
 251         length = min(block[0] >> 16, 256U);
 252         if (length < 3)
 253                 goto out;
 254
 255         if (block[1] != 0 || block[2] != 0)
 256                 /* Unknown encoding. */
 257                 goto out;
 258
 259         if (buf == NULL) {
 260                 ret = length * 4;
 261                 goto out;
 262         }
 263
 264         b = buf;
 265         end = &block[length + 1];
 266         for (p = &block[3]; p < end; p++, b += 4)
 267                 * (u32 *) b = (__force u32) __cpu_to_be32(*p);
 268
 269         /* Strip trailing whitespace and add newline. */
 270         while (b--, (isspace(*b) || *b == '\0') && b > buf);
 271         strcpy(b + 1, "\n");
 272         ret = b + 2 - buf;
 273  out:
 274         up_read(&fw_device_rwsem);
 275
 276         return ret;
 277 }
 278
 279 #define TEXT_LEAF_ATTR(name, key)                               \
 280         { __ATTR(name, S_IRUGO, show_text_leaf, NULL), key }
 281
 282 static struct config_rom_attribute config_rom_attributes[] = {
 283         IMMEDIATE_ATTR(vendor, CSR_VENDOR),
 284         IMMEDIATE_ATTR(hardware_version, CSR_HARDWARE_VERSION),
 285         IMMEDIATE_ATTR(specifier_id, CSR_SPECIFIER_ID),
 286         IMMEDIATE_ATTR(version, CSR_VERSION),
 287         IMMEDIATE_ATTR(model, CSR_MODEL),
 288         TEXT_LEAF_ATTR(vendor_name, CSR_VENDOR),
 289         TEXT_LEAF_ATTR(model_name, CSR_MODEL),
 290         TEXT_LEAF_ATTR(hardware_version_name, CSR_HARDWARE_VERSION),
 291 };
 292
 293 static void init_fw_attribute_group(struct device *dev,
 294                                     struct device_attribute *attrs,
 295                                     struct fw_attribute_group *group)
 296 {
 297         struct device_attribute *attr;
 298         int i, j;
 299
 300         for (j = 0; attrs[j].attr.name != NULL; j++)
 301                 group->attrs[j] = &attrs[j].attr;
 302
 303         for (i = 0; i < ARRAY_SIZE(config_rom_attributes); i++) {
 304                 attr = &config_rom_attributes[i].attr;
 305                 if (attr->show(dev, attr, NULL) < 0)
 306                         continue;
 307                 group->attrs[j++] = &attr->attr;
 308         }
 309
 310         group->attrs[j] = NULL;
 311         group->groups[0] = &group->group;
 312         group->groups[1] = NULL;
 313         group->group.attrs = group->attrs;
 314         dev->groups = group->groups;
 315 }
 316
 317 static ssize_t modalias_show(struct device *dev,
 318                              struct device_attribute *attr, char *buf)
 319 {
 320         struct fw_unit *unit = fw_unit(dev);
 321         int length;
 322
 323         length = get_modalias(unit, buf, PAGE_SIZE);
 324         strcpy(buf + length, "\n");
 325
 326         return length + 1;
 327 }
 328
 329 static ssize_t rom_index_show(struct device *dev,
 330                               struct device_attribute *attr, char *buf)
 331 {
 332         struct fw_device *device = fw_device(dev->parent);
 333         struct fw_unit *unit = fw_unit(dev);
 334
 335         return snprintf(buf, PAGE_SIZE, "%d\n",
 336                         (int)(unit->directory - device->config_rom));
 337 }
 338
 339 static struct device_attribute fw_unit_attributes[] = {
 340         __ATTR_RO(modalias),
 341         __ATTR_RO(rom_index),
 342         __ATTR_NULL,
 343 };
 344
 345 static ssize_t config_rom_show(struct device *dev,
 346                                struct device_attribute *attr, char *buf)
 347 {
 348         struct fw_device *device = fw_device(dev);
 349         size_t length;
 350
 351         down_read(&fw_device_rwsem);
 352         length = device->config_rom_length * 4;
 353         memcpy(buf, device->config_rom, length);
 354         up_read(&fw_device_rwsem);
 355
 356         return length;
 357 }
 358
 359 static ssize_t guid_show(struct device *dev,
 360                          struct device_attribute *attr, char *buf)
 361 {
 362         struct fw_device *device = fw_device(dev);
 363         int ret;
 364
 365         down_read(&fw_device_rwsem);
 366         ret = snprintf(buf, PAGE_SIZE, "0x%08x%08x\n",
 367                        device->config_rom[3], device->config_rom[4]);
 368         up_read(&fw_device_rwsem);
 369
 370         return ret;
 371 }
 372
 373 static int units_sprintf(char *buf, u32 *directory)
 374 {
 375         struct fw_csr_iterator ci;
 376         int key, value;
 377         int specifier_id = 0;
 378         int version = 0;
 379
 380         fw_csr_iterator_init(&ci, directory);
 381         while (fw_csr_iterator_next(&ci, &key, &value)) {
 382                 switch (key) {
 383                 case CSR_SPECIFIER_ID:
 384                         specifier_id = value;
 385                         break;
 386                 case CSR_VERSION:
 387                         version = value;
 388                         break;
 389                 }
 390         }
 391
 392         return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version);
 393 }
 394
 395 static ssize_t units_show(struct device *dev,
 396                           struct device_attribute *attr, char *buf)
 397 {
 398         struct fw_device *device = fw_device(dev);
 399         struct fw_csr_iterator ci;
 400         int key, value, i = 0;
 401
 402         down_read(&fw_device_rwsem);
 403         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 404         while (fw_csr_iterator_next(&ci, &key, &value)) {
 405                 if (key != (CSR_UNIT | CSR_DIRECTORY))
 406                         continue;
 407                 i += units_sprintf(&buf[i], ci.p + value - 1);
 408                 if (i >= PAGE_SIZE - (8 + 1 + 8 + 1))
 409                         break;
 410         }
 411         up_read(&fw_device_rwsem);
 412
 413         if (i)
 414                 buf[i - 1] = '\n';
 415
 416         return i;
 417 }
 418
 419 static struct device_attribute fw_device_attributes[] = {
 420         __ATTR_RO(config_rom),
 421         __ATTR_RO(guid),
 422         __ATTR_RO(units),
 423         __ATTR_NULL,
 424 };
 425
 426 static int read_rom(struct fw_device *device,
 427                     int generation, int index, u32 *data)
 428 {
 429         int rcode;
 430
 431         /* device->node_id, accessed below, must not be older than generation */
 432         smp_rmb();
 433
 434         rcode = fw_run_transaction(device->card, TCODE_READ_QUADLET_REQUEST,
 435                         device->node_id, generation, device->max_speed,
 436                         (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4,
 437                         data, 4);
 438         be32_to_cpus(data);
 439
 440         return rcode;
 441 }
 442
 443 #define READ_BIB_ROM_SIZE       256
 444 #define READ_BIB_STACK_SIZE     16
 445
 446 /*
 447  * Read the bus info block, perform a speed probe, and read all of the rest of
 448  * the config ROM.  We do all this with a cached bus generation.  If the bus
 449  * generation changes under us, read_bus_info_block will fail and get retried.
 450  * It's better to start all over in this case because the node from which we
 451  * are reading the ROM may have changed the ROM during the reset.
 452  */
 453 static int read_bus_info_block(struct fw_device *device, int generation)
 454 {
 455         u32 *rom, *stack, *old_rom, *new_rom;
 456         u32 sp, key;
 457         int i, end, length, ret = -1;
 458
 459         rom = kmalloc(sizeof(*rom) * READ_BIB_ROM_SIZE +
 460                       sizeof(*stack) * READ_BIB_STACK_SIZE, GFP_KERNEL);
 461         if (rom == NULL)
 462                 return -ENOMEM;
 463
 464         stack = &rom[READ_BIB_ROM_SIZE];
 465
 466         device->max_speed = SCODE_100;
 467
 468         /* First read the bus info block. */
 469         for (i = 0; i < 5; i++) {
 470                 if (read_rom(device, generation, i, &rom[i]) != RCODE_COMPLETE)
 471                         goto out;
 472                 /*
 473                  * As per IEEE1212 7.2, during power-up, devices can
 474                  * reply with a 0 for the first quadlet of the config
 475                  * rom to indicate that they are booting (for example,
 476                  * if the firmware is on the disk of a external
 477                  * harddisk).  In that case we just fail, and the
 478                  * retry mechanism will try again later.
 479                  */
 480                 if (i == 0 && rom[i] == 0)
 481                         goto out;
 482         }
 483
 484         device->max_speed = device->node->max_speed;
 485
 486         /*
 487          * Determine the speed of
 488          *   - devices with link speed less than PHY speed,
 489          *   - devices with 1394b PHY (unless only connected to 1394a PHYs),
 490          *   - all devices if there are 1394b repeaters.
 491          * Note, we cannot use the bus info block's link_spd as starting point
 492          * because some buggy firmwares set it lower than necessary and because
 493          * 1394-1995 nodes do not have the field.
 494          */
 495         if ((rom[2] & 0x7) < device->max_speed ||
 496             device->max_speed == SCODE_BETA ||
 497             device->card->beta_repeaters_present) {
 498                 u32 dummy;
 499
 500                 /* for S1600 and S3200 */
 501                 if (device->max_speed == SCODE_BETA)
 502                         device->max_speed = device->card->link_speed;
 503
 504                 while (device->max_speed > SCODE_100) {
 505                         if (read_rom(device, generation, 0, &dummy) ==
 506                             RCODE_COMPLETE)
 507                                 break;
 508                         device->max_speed--;
 509                 }
 510         }
 511
 512         /*
 513          * Now parse the config rom.  The config rom is a recursive
 514          * directory structure so we parse it using a stack of
 515          * references to the blocks that make up the structure.  We
 516          * push a reference to the root directory on the stack to
 517          * start things off.
 518          */
 519         length = i;
 520         sp = 0;
 521         stack[sp++] = 0xc0000005;
 522         while (sp > 0) {
 523                 /*
 524                  * Pop the next block reference of the stack.  The
 525                  * lower 24 bits is the offset into the config rom,
 526                  * the upper 8 bits are the type of the reference the
 527                  * block.
 528                  */
 529                 key = stack[--sp];
 530                 i = key & 0xffffff;
 531                 if (i >= READ_BIB_ROM_SIZE)
 532                         /*
 533                          * The reference points outside the standard
 534                          * config rom area, something's fishy.
 535                          */
 536                         goto out;
 537
 538                 /* Read header quadlet for the block to get the length. */
 539                 if (read_rom(device, generation, i, &rom[i]) != RCODE_COMPLETE)
 540                         goto out;
 541                 end = i + (rom[i] >> 16) + 1;
 542                 i++;
 543                 if (end > READ_BIB_ROM_SIZE)
 544                         /*
 545                          * This block extends outside standard config
 546                          * area (and the array we're reading it
 547                          * into).  That's broken, so ignore this
 548                          * device.
 549                          */
 550                         goto out;
 551
 552                 /*
 553                  * Now read in the block.  If this is a directory
 554                  * block, check the entries as we read them to see if
 555                  * it references another block, and push it in that case.
 556                  */
 557                 while (i < end) {
 558                         if (read_rom(device, generation, i, &rom[i]) !=
 559                             RCODE_COMPLETE)
 560                                 goto out;
 561                         if ((key >> 30) == 3 && (rom[i] >> 30) > 1 &&
 562                             sp < READ_BIB_STACK_SIZE)
 563                                 stack[sp++] = i + rom[i];
 564                         i++;
 565                 }
 566                 if (length < i)
 567                         length = i;
 568         }
 569
 570         old_rom = device->config_rom;
 571         new_rom = kmemdup(rom, length * 4, GFP_KERNEL);
 572         if (new_rom == NULL)
 573                 goto out;
 574
 575         down_write(&fw_device_rwsem);
 576         device->config_rom = new_rom;
 577         device->config_rom_length = length;
 578         up_write(&fw_device_rwsem);
 579
 580         kfree(old_rom);
 581         ret = 0;
 582         device->cmc = rom[2] >> 30 & 1;
 583  out:
 584         kfree(rom);
 585
 586         return ret;
 587 }
 588
 589 static void fw_unit_release(struct device *dev)
 590 {
 591         struct fw_unit *unit = fw_unit(dev);
 592
 593         kfree(unit);
 594 }
 595
 596 static struct device_type fw_unit_type = {
 597         .uevent         = fw_unit_uevent,
 598         .release        = fw_unit_release,
 599 };
 600
 601 static int is_fw_unit(struct device *dev)
 602 {
 603         return dev->type == &fw_unit_type;
 604 }
 605
 606 static void create_units(struct fw_device *device)
 607 {
 608         struct fw_csr_iterator ci;
 609         struct fw_unit *unit;
 610         int key, value, i;
 611
 612         i = 0;
 613         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 614         while (fw_csr_iterator_next(&ci, &key, &value)) {
 615                 if (key != (CSR_UNIT | CSR_DIRECTORY))
 616                         continue;
 617
 618                 /*
 619                  * Get the address of the unit directory and try to
 620                  * match the drivers id_tables against it.
 621                  */
 622                 unit = kzalloc(sizeof(*unit), GFP_KERNEL);
 623                 if (unit == NULL) {
 624                         fw_error("failed to allocate memory for unit\n");
 625                         continue;
 626                 }
 627
 628                 unit->directory = ci.p + value - 1;
 629                 unit->device.bus = &fw_bus_type;
 630                 unit->device.type = &fw_unit_type;
 631                 unit->device.parent = &device->device;
 632                 dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++);
 633
 634                 BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) <
 635                                 ARRAY_SIZE(fw_unit_attributes) +
 636                                 ARRAY_SIZE(config_rom_attributes));
 637                 init_fw_attribute_group(&unit->device,
 638                                         fw_unit_attributes,
 639                                         &unit->attribute_group);
 640
 641                 if (device_register(&unit->device) < 0)
 642                         goto skip_unit;
 643
 644                 continue;
 645
 646         skip_unit:
 647                 kfree(unit);
 648         }
 649 }
 650
 651 static int shutdown_unit(struct device *device, void *data)
 652 {
 653         device_unregister(device);
 654
 655         return 0;
 656 }
 657
 658 /*
 659  * fw_device_rwsem acts as dual purpose mutex:
 660  *   - serializes accesses to fw_device_idr,
 661  *   - serializes accesses to fw_device.config_rom/.config_rom_length and
 662  *     fw_unit.directory, unless those accesses happen at safe occasions
 663  */
 664 DECLARE_RWSEM(fw_device_rwsem);
 665
 666 DEFINE_IDR(fw_device_idr);
 667 int fw_cdev_major;
 668
 669 struct fw_device *fw_device_get_by_devt(dev_t devt)
 670 {
 671         struct fw_device *device;
 672
 673         down_read(&fw_device_rwsem);
 674         device = idr_find(&fw_device_idr, MINOR(devt));
 675         if (device)
 676                 fw_device_get(device);
 677         up_read(&fw_device_rwsem);
 678
 679         return device;
 680 }
 681
 682 /*
 683  * These defines control the retry behavior for reading the config
 684  * rom.  It shouldn't be necessary to tweak these; if the device
 685  * doesn't respond to a config rom read within 10 seconds, it's not
 686  * going to respond at all.  As for the initial delay, a lot of
 687  * devices will be able to respond within half a second after bus
 688  * reset.  On the other hand, it's not really worth being more
 689  * aggressive than that, since it scales pretty well; if 10 devices
 690  * are plugged in, they're all getting read within one second.
 691  */
 692
 693 #define MAX_RETRIES     10
 694 #define RETRY_DELAY     (3 * HZ)
 695 #define INITIAL_DELAY   (HZ / 2)
 696 #define SHUTDOWN_DELAY  (2 * HZ)
 697
 698 static void fw_device_shutdown(struct work_struct *work)
 699 {
 700         struct fw_device *device =
 701                 container_of(work, struct fw_device, work.work);
 702         int minor = MINOR(device->device.devt);
 703
 704         if (time_is_after_jiffies(device->card->reset_jiffies + SHUTDOWN_DELAY)
 705             && !list_empty(&device->card->link)) {
 706                 schedule_delayed_work(&device->work, SHUTDOWN_DELAY);
 707                 return;
 708         }
 709
 710         if (atomic_cmpxchg(&device->state,
 711                            FW_DEVICE_GONE,
 712                            FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE)
 713                 return;
 714
 715         fw_device_cdev_remove(device);
 716         device_for_each_child(&device->device, NULL, shutdown_unit);
 717         device_unregister(&device->device);
 718
 719         down_write(&fw_device_rwsem);
 720         idr_remove(&fw_device_idr, minor);
 721         up_write(&fw_device_rwsem);
 722
 723         fw_device_put(device);
 724 }
 725
 726 static void fw_device_release(struct device *dev)
 727 {
 728         struct fw_device *device = fw_device(dev);
 729         struct fw_card *card = device->card;
 730         unsigned long flags;
 731
 732         /*
 733          * Take the card lock so we don't set this to NULL while a
 734          * FW_NODE_UPDATED callback is being handled or while the
 735          * bus manager work looks at this node.
 736          */
 737         spin_lock_irqsave(&card->lock, flags);
 738         device->node->data = NULL;
 739         spin_unlock_irqrestore(&card->lock, flags);
 740
 741         fw_node_put(device->node);
 742         kfree(device->config_rom);
 743         kfree(device);
 744         fw_card_put(card);
 745 }
 746
 747 static struct device_type fw_device_type = {
 748         .release = fw_device_release,
 749 };
 750
 751 static int update_unit(struct device *dev, void *data)
 752 {
 753         struct fw_unit *unit = fw_unit(dev);
 754         struct fw_driver *driver = (struct fw_driver *)dev->driver;
 755
 756         if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) {
 757                 down(&dev->sem);
 758                 driver->update(unit);
 759                 up(&dev->sem);
 760         }
 761
 762         return 0;
 763 }
 764
 765 static void fw_device_update(struct work_struct *work)
 766 {
 767         struct fw_device *device =
 768                 container_of(work, struct fw_device, work.work);
 769
 770         fw_device_cdev_update(device);
 771         device_for_each_child(&device->device, NULL, update_unit);
 772 }
 773
 774 /*
 775  * If a device was pending for deletion because its node went away but its
 776  * bus info block and root directory header matches that of a newly discovered
 777  * device, revive the existing fw_device.
 778  * The newly allocated fw_device becomes obsolete instead.
 779  */
 780 static int lookup_existing_device(struct device *dev, void *data)
 781 {
 782         struct fw_device *old = fw_device(dev);
 783         struct fw_device *new = data;
 784         struct fw_card *card = new->card;
 785         int match = 0;
 786
 787         down_read(&fw_device_rwsem); /* serialize config_rom access */
 788         spin_lock_irq(&card->lock);  /* serialize node access */
 789
 790         if (memcmp(old->config_rom, new->config_rom, 6 * 4) == 0 &&
 791             atomic_cmpxchg(&old->state,
 792                            FW_DEVICE_GONE,
 793                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
 794                 struct fw_node *current_node = new->node;
 795                 struct fw_node *obsolete_node = old->node;
 796
 797                 new->node = obsolete_node;
 798                 new->node->data = new;
 799                 old->node = current_node;
 800                 old->node->data = old;
 801
 802                 old->max_speed = new->max_speed;
 803                 old->node_id = current_node->node_id;
 804                 smp_wmb();  /* update node_id before generation */
 805                 old->generation = card->generation;
 806                 old->config_rom_retries = 0;
 807                 fw_notify("rediscovered device %s\n", dev_name(dev));
 808
 809                 PREPARE_DELAYED_WORK(&old->work, fw_device_update);
 810                 schedule_delayed_work(&old->work, 0);
 811
 812                 if (current_node == card->root_node)
 813                         fw_schedule_bm_work(card, 0);
 814
 815                 match = 1;
 816         }
 817
 818         spin_unlock_irq(&card->lock);
 819         up_read(&fw_device_rwsem);
 820
 821         return match;
 822 }
 823
 824 enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, };
 825
 826 void fw_device_set_broadcast_channel(struct fw_device *device, int generation)
 827 {
 828         struct fw_card *card = device->card;
 829         __be32 data;
 830         int rcode;
 831
 832         if (!card->broadcast_channel_allocated)
 833                 return;
 834
 835         if (device->bc_implemented == BC_UNKNOWN) {
 836                 rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST,
 837                                 device->node_id, generation, device->max_speed,
 838                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 839                                 &data, 4);
 840                 switch (rcode) {
 841                 case RCODE_COMPLETE:
 842                         if (data & cpu_to_be32(1 << 31)) {
 843                                 device->bc_implemented = BC_IMPLEMENTED;
 844                                 break;
 845                         }
 846                         /* else fall through to case address error */
 847                 case RCODE_ADDRESS_ERROR:
 848                         device->bc_implemented = BC_UNIMPLEMENTED;
 849                 }
 850         }
 851
 852         if (device->bc_implemented == BC_IMPLEMENTED) {
 853                 data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL |
 854                                    BROADCAST_CHANNEL_VALID);
 855                 fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
 856                                 device->node_id, generation, device->max_speed,
 857                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 858                                 &data, 4);
 859         }
 860 }
 861
 862 static void fw_device_init(struct work_struct *work)
 863 {
 864         struct fw_device *device =
 865                 container_of(work, struct fw_device, work.work);
 866         struct device *revived_dev;
 867         int minor, ret;
 868
 869         /*
 870          * All failure paths here set node->data to NULL, so that we
 871          * don't try to do device_for_each_child() on a kfree()'d
 872          * device.
 873          */
 874
 875         if (read_bus_info_block(device, device->generation) < 0) {
 876                 if (device->config_rom_retries < MAX_RETRIES &&
 877                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
 878                         device->config_rom_retries++;
 879                         schedule_delayed_work(&device->work, RETRY_DELAY);
 880                 } else {
 881                         fw_notify("giving up on config rom for node id %x\n",
 882                                   device->node_id);
 883                         if (device->node == device->card->root_node)
 884                                 fw_schedule_bm_work(device->card, 0);
 885                         fw_device_release(&device->device);
 886                 }
 887                 return;
 888         }
 889
 890         revived_dev = device_find_child(device->card->device,
 891                                         device, lookup_existing_device);
 892         if (revived_dev) {
 893                 put_device(revived_dev);
 894                 fw_device_release(&device->device);
 895
 896                 return;
 897         }
 898
 899         device_initialize(&device->device);
 900
 901         fw_device_get(device);
 902         down_write(&fw_device_rwsem);
 903         ret = idr_pre_get(&fw_device_idr, GFP_KERNEL) ?
 904               idr_get_new(&fw_device_idr, device, &minor) :
 905               -ENOMEM;
 906         up_write(&fw_device_rwsem);
 907
 908         if (ret < 0)
 909                 goto error;
 910
 911         device->device.bus = &fw_bus_type;
 912         device->device.type = &fw_device_type;
 913         device->device.parent = device->card->device;
 914         device->device.devt = MKDEV(fw_cdev_major, minor);
 915         dev_set_name(&device->device, "fw%d", minor);
 916
 917         BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) <
 918                         ARRAY_SIZE(fw_device_attributes) +
 919                         ARRAY_SIZE(config_rom_attributes));
 920         init_fw_attribute_group(&device->device,
 921                                 fw_device_attributes,
 922                                 &device->attribute_group);
 923
 924         if (device_add(&device->device)) {
 925                 fw_error("Failed to add device.\n");
 926                 goto error_with_cdev;
 927         }
 928
 929         create_units(device);
 930
 931         /*
 932          * Transition the device to running state.  If it got pulled
 933          * out from under us while we did the intialization work, we
 934          * have to shut down the device again here.  Normally, though,
 935          * fw_node_event will be responsible for shutting it down when
 936          * necessary.  We have to use the atomic cmpxchg here to avoid
 937          * racing with the FW_NODE_DESTROYED case in
 938          * fw_node_event().
 939          */
 940         if (atomic_cmpxchg(&device->state,
 941                            FW_DEVICE_INITIALIZING,
 942                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
 943                 PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
 944                 schedule_delayed_work(&device->work, SHUTDOWN_DELAY);
 945         } else {
 946                 if (device->config_rom_retries)
 947                         fw_notify("created device %s: GUID %08x%08x, S%d00, "
 948                                   "%d config ROM retries\n",
 949                                   dev_name(&device->device),
 950                                   device->config_rom[3], device->config_rom[4],
 951                                   1 << device->max_speed,
 952                                   device->config_rom_retries);
 953                 else
 954                         fw_notify("created device %s: GUID %08x%08x, S%d00\n",
 955                                   dev_name(&device->device),
 956                                   device->config_rom[3], device->config_rom[4],
 957                                   1 << device->max_speed);
 958                 device->config_rom_retries = 0;
 959
 960                 fw_device_set_broadcast_channel(device, device->generation);
 961         }
 962
 963         /*
 964          * Reschedule the IRM work if we just finished reading the
 965          * root node config rom.  If this races with a bus reset we
 966          * just end up running the IRM work a couple of extra times -
 967          * pretty harmless.
 968          */
 969         if (device->node == device->card->root_node)
 970                 fw_schedule_bm_work(device->card, 0);
 971
 972         return;
 973
 974  error_with_cdev:
 975         down_write(&fw_device_rwsem);
 976         idr_remove(&fw_device_idr, minor);
 977         up_write(&fw_device_rwsem);
 978  error:
 979         fw_device_put(device);          /* fw_device_idr's reference */
 980
 981         put_device(&device->device);    /* our reference */
 982 }
 983
 984 enum {
 985         REREAD_BIB_ERROR,
 986         REREAD_BIB_GONE,
 987         REREAD_BIB_UNCHANGED,
 988         REREAD_BIB_CHANGED,
 989 };
 990
 991 /* Reread and compare bus info block and header of root directory */
 992 static int reread_bus_info_block(struct fw_device *device, int generation)
 993 {
 994         u32 q;
 995         int i;
 996
 997         for (i = 0; i < 6; i++) {
 998                 if (read_rom(device, generation, i, &q) != RCODE_COMPLETE)
 999                         return REREAD_BIB_ERROR;
1000
1001                 if (i == 0 && q == 0)
1002                         return REREAD_BIB_GONE;
1003
1004                 if (q != device->config_rom[i])
1005                         return REREAD_BIB_CHANGED;
1006         }
1007
1008         return REREAD_BIB_UNCHANGED;
1009 }
1010
1011 static void fw_device_refresh(struct work_struct *work)
1012 {
1013         struct fw_device *device =
1014                 container_of(work, struct fw_device, work.work);
1015         struct fw_card *card = device->card;
1016         int node_id = device->node_id;
1017
1018         switch (reread_bus_info_block(device, device->generation)) {
1019         case REREAD_BIB_ERROR:
1020                 if (device->config_rom_retries < MAX_RETRIES / 2 &&
1021                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1022                         device->config_rom_retries++;
1023                         schedule_delayed_work(&device->work, RETRY_DELAY / 2);
1024
1025                         return;
1026                 }
1027                 goto give_up;
1028
1029         case REREAD_BIB_GONE:
1030                 goto gone;
1031
1032         case REREAD_BIB_UNCHANGED:
1033                 if (atomic_cmpxchg(&device->state,
1034                                    FW_DEVICE_INITIALIZING,
1035                                    FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1036                         goto gone;
1037
1038                 fw_device_update(work);
1039                 device->config_rom_retries = 0;
1040                 goto out;
1041
1042         case REREAD_BIB_CHANGED:
1043                 break;
1044         }
1045
1046         /*
1047          * Something changed.  We keep things simple and don't investigate
1048          * further.  We just destroy all previous units and create new ones.
1049          */
1050         device_for_each_child(&device->device, NULL, shutdown_unit);
1051
1052         if (read_bus_info_block(device, device->generation) < 0) {
1053                 if (device->config_rom_retries < MAX_RETRIES &&
1054                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1055                         device->config_rom_retries++;
1056                         schedule_delayed_work(&device->work, RETRY_DELAY);
1057
1058                         return;
1059                 }
1060                 goto give_up;
1061         }
1062
1063         create_units(device);
1064
1065         /* Userspace may want to re-read attributes. */
1066         kobject_uevent(&device->device.kobj, KOBJ_CHANGE);
1067
1068         if (atomic_cmpxchg(&device->state,
1069                            FW_DEVICE_INITIALIZING,
1070                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1071                 goto gone;
1072
1073         fw_notify("refreshed device %s\n", dev_name(&device->device));
1074         device->config_rom_retries = 0;
1075         goto out;
1076
1077  give_up:
1078         fw_notify("giving up on refresh of device %s\n", dev_name(&device->device));
1079  gone:
1080         atomic_set(&device->state, FW_DEVICE_GONE);
1081         PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1082         schedule_delayed_work(&device->work, SHUTDOWN_DELAY);
1083  out:
1084         if (node_id == card->root_node->node_id)
1085                 fw_schedule_bm_work(card, 0);
1086 }
1087
1088 void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
1089 {
1090         struct fw_device *device;
1091
1092         switch (event) {
1093         case FW_NODE_CREATED:
1094         case FW_NODE_LINK_ON:
1095                 if (!node->link_on)
1096                         break;
1097  create:
1098                 device = kzalloc(sizeof(*device), GFP_ATOMIC);
1099                 if (device == NULL)
1100                         break;
1101
1102                 /*
1103                  * Do minimal intialization of the device here, the
1104                  * rest will happen in fw_device_init().
1105                  *
1106                  * Attention:  A lot of things, even fw_device_get(),
1107                  * cannot be done before fw_device_init() finished!
1108                  * You can basically just check device->state and
1109                  * schedule work until then, but only while holding
1110                  * card->lock.
1111                  */
1112                 atomic_set(&device->state, FW_DEVICE_INITIALIZING);
1113                 device->card = fw_card_get(card);
1114                 device->node = fw_node_get(node);
1115                 device->node_id = node->node_id;
1116                 device->generation = card->generation;
1117                 device->is_local = node == card->local_node;
1118                 mutex_init(&device->client_list_mutex);
1119                 INIT_LIST_HEAD(&device->client_list);
1120
1121                 /*
1122                  * Set the node data to point back to this device so
1123                  * FW_NODE_UPDATED callbacks can update the node_id
1124                  * and generation for the device.
1125                  */
1126                 node->data = device;
1127
1128                 /*
1129                  * Many devices are slow to respond after bus resets,
1130                  * especially if they are bus powered and go through
1131                  * power-up after getting plugged in.  We schedule the
1132                  * first config rom scan half a second after bus reset.
1133                  */
1134                 INIT_DELAYED_WORK(&device->work, fw_device_init);
1135                 schedule_delayed_work(&device->work, INITIAL_DELAY);
1136                 break;
1137
1138         case FW_NODE_INITIATED_RESET:
1139                 device = node->data;
1140                 if (device == NULL)
1141                         goto create;
1142
1143                 device->node_id = node->node_id;
1144                 smp_wmb();  /* update node_id before generation */
1145                 device->generation = card->generation;
1146                 if (atomic_cmpxchg(&device->state,
1147                             FW_DEVICE_RUNNING,
1148                             FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) {
1149                         PREPARE_DELAYED_WORK(&device->work, fw_device_refresh);
1150                         schedule_delayed_work(&device->work,
1151                                 device->is_local ? 0 : INITIAL_DELAY);
1152                 }
1153                 break;
1154
1155         case FW_NODE_UPDATED:
1156                 if (!node->link_on || node->data == NULL)
1157                         break;
1158
1159                 device = node->data;
1160                 device->node_id = node->node_id;
1161                 smp_wmb();  /* update node_id before generation */
1162                 device->generation = card->generation;
1163                 if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
1164                         PREPARE_DELAYED_WORK(&device->work, fw_device_update);
1165                         schedule_delayed_work(&device->work, 0);
1166                 }
1167                 break;
1168
1169         case FW_NODE_DESTROYED:
1170         case FW_NODE_LINK_OFF:
1171                 if (!node->data)
1172                         break;
1173
1174                 /*
1175                  * Destroy the device associated with the node.  There
1176                  * are two cases here: either the device is fully
1177                  * initialized (FW_DEVICE_RUNNING) or we're in the
1178                  * process of reading its config rom
1179                  * (FW_DEVICE_INITIALIZING).  If it is fully
1180                  * initialized we can reuse device->work to schedule a
1181                  * full fw_device_shutdown().  If not, there's work
1182                  * scheduled to read it's config rom, and we just put
1183                  * the device in shutdown state to have that code fail
1184                  * to create the device.
1185                  */
1186                 device = node->data;
1187                 if (atomic_xchg(&device->state,
1188                                 FW_DEVICE_GONE) == FW_DEVICE_RUNNING) {
1189                         PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1190                         schedule_delayed_work(&device->work,
1191                                 list_empty(&card->link) ? 0 : SHUTDOWN_DELAY);
1192                 }
1193                 break;
1194         }
1195 }