drivers/firewire/core-device.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Device probing and sysfs code.
   4  *
   5  * Copyright (C) 2005-2006  Kristian Hoegsberg <krh@bitplanet.net>
   6  */
   7
   8 #include <linux/bug.h>
   9 #include <linux/ctype.h>
  10 #include <linux/delay.h>
  11 #include <linux/device.h>
  12 #include <linux/errno.h>
  13 #include <linux/firewire.h>
  14 #include <linux/firewire-constants.h>
  15 #include <linux/idr.h>
  16 #include <linux/jiffies.h>
  17 #include <linux/kobject.h>
  18 #include <linux/list.h>
  19 #include <linux/mod_devicetable.h>
  20 #include <linux/module.h>
  21 #include <linux/mutex.h>
  22 #include <linux/random.h>
  23 #include <linux/rwsem.h>
  24 #include <linux/slab.h>
  25 #include <linux/spinlock.h>
  26 #include <linux/string.h>
  27 #include <linux/workqueue.h>
  28
  29 #include <linux/atomic.h>
  30 #include <asm/byteorder.h>
  31
  32 #include "core.h"
  33
  34 void fw_csr_iterator_init(struct fw_csr_iterator *ci, const u32 *p)
  35 {
  36         ci->p = p + 1;
  37         ci->end = ci->p + (p[0] >> 16);
  38 }
  39 EXPORT_SYMBOL(fw_csr_iterator_init);
  40
  41 int fw_csr_iterator_next(struct fw_csr_iterator *ci, int *key, int *value)
  42 {
  43         *key = *ci->p >> 24;
  44         *value = *ci->p & 0xffffff;
  45
  46         return ci->p++ < ci->end;
  47 }
  48 EXPORT_SYMBOL(fw_csr_iterator_next);
  49
  50 static const u32 *search_leaf(const u32 *directory, int search_key)
  51 {
  52         struct fw_csr_iterator ci;
  53         int last_key = 0, key, value;
  54
  55         fw_csr_iterator_init(&ci, directory);
  56         while (fw_csr_iterator_next(&ci, &key, &value)) {
  57                 if (last_key == search_key &&
  58                     key == (CSR_DESCRIPTOR | CSR_LEAF))
  59                         return ci.p - 1 + value;
  60
  61                 last_key = key;
  62         }
  63
  64         return NULL;
  65 }
  66
  67 static int textual_leaf_to_string(const u32 *block, char *buf, size_t size)
  68 {
  69         unsigned int quadlets, i;
  70         char c;
  71
  72         if (!size || !buf)
  73                 return -EINVAL;
  74
  75         quadlets = min(block[0] >> 16, 256U);
  76         if (quadlets < 2)
  77                 return -ENODATA;
  78
  79         if (block[1] != 0 || block[2] != 0)
  80                 /* unknown language/character set */
  81                 return -ENODATA;
  82
  83         block += 3;
  84         quadlets -= 2;
  85         for (i = 0; i < quadlets * 4 && i < size - 1; i++) {
  86                 c = block[i / 4] >> (24 - 8 * (i % 4));
  87                 if (c == '\0')
  88                         break;
  89                 buf[i] = c;
  90         }
  91         buf[i] = '\0';
  92
  93         return i;
  94 }
  95
  96 /**
  97  * fw_csr_string() - reads a string from the configuration ROM
  98  * @directory:  e.g. root directory or unit directory
  99  * @key:        the key of the preceding directory entry
 100  * @buf:        where to put the string
 101  * @size:       size of @buf, in bytes
 102  *
 103  * The string is taken from a minimal ASCII text descriptor leaf just after the entry with the
 104  * @key. The string is zero-terminated. An overlong string is silently truncated such that it
 105  * and the zero byte fit into @size.
 106  *
 107  * Returns strlen(buf) or a negative error code.
 108  */
 109 int fw_csr_string(const u32 *directory, int key, char *buf, size_t size)
 110 {
 111         const u32 *leaf = search_leaf(directory, key);
 112         if (!leaf)
 113                 return -ENOENT;
 114
 115         return textual_leaf_to_string(leaf, buf, size);
 116 }
 117 EXPORT_SYMBOL(fw_csr_string);
 118
 119 static void get_ids(const u32 *directory, int *id)
 120 {
 121         struct fw_csr_iterator ci;
 122         int key, value;
 123
 124         fw_csr_iterator_init(&ci, directory);
 125         while (fw_csr_iterator_next(&ci, &key, &value)) {
 126                 switch (key) {
 127                 case CSR_VENDOR:        id[0] = value; break;
 128                 case CSR_MODEL:         id[1] = value; break;
 129                 case CSR_SPECIFIER_ID:  id[2] = value; break;
 130                 case CSR_VERSION:       id[3] = value; break;
 131                 }
 132         }
 133 }
 134
 135 static void get_modalias_ids(struct fw_unit *unit, int *id)
 136 {
 137         get_ids(&fw_parent_device(unit)->config_rom[5], id);
 138         get_ids(unit->directory, id);
 139 }
 140
 141 static bool match_ids(const struct ieee1394_device_id *id_table, int *id)
 142 {
 143         int match = 0;
 144
 145         if (id[0] == id_table->vendor_id)
 146                 match |= IEEE1394_MATCH_VENDOR_ID;
 147         if (id[1] == id_table->model_id)
 148                 match |= IEEE1394_MATCH_MODEL_ID;
 149         if (id[2] == id_table->specifier_id)
 150                 match |= IEEE1394_MATCH_SPECIFIER_ID;
 151         if (id[3] == id_table->version)
 152                 match |= IEEE1394_MATCH_VERSION;
 153
 154         return (match & id_table->match_flags) == id_table->match_flags;
 155 }
 156
 157 static const struct ieee1394_device_id *unit_match(struct device *dev,
 158                                                    struct device_driver *drv)
 159 {
 160         const struct ieee1394_device_id *id_table =
 161                         container_of(drv, struct fw_driver, driver)->id_table;
 162         int id[] = {0, 0, 0, 0};
 163
 164         get_modalias_ids(fw_unit(dev), id);
 165
 166         for (; id_table->match_flags != 0; id_table++)
 167                 if (match_ids(id_table, id))
 168                         return id_table;
 169
 170         return NULL;
 171 }
 172
 173 static bool is_fw_unit(struct device *dev);
 174
 175 static int fw_unit_match(struct device *dev, struct device_driver *drv)
 176 {
 177         /* We only allow binding to fw_units. */
 178         return is_fw_unit(dev) && unit_match(dev, drv) != NULL;
 179 }
 180
 181 static int fw_unit_probe(struct device *dev)
 182 {
 183         struct fw_driver *driver =
 184                         container_of(dev->driver, struct fw_driver, driver);
 185
 186         return driver->probe(fw_unit(dev), unit_match(dev, dev->driver));
 187 }
 188
 189 static int fw_unit_remove(struct device *dev)
 190 {
 191         struct fw_driver *driver =
 192                         container_of(dev->driver, struct fw_driver, driver);
 193
 194         return driver->remove(fw_unit(dev)), 0;
 195 }
 196
 197 static int get_modalias(struct fw_unit *unit, char *buffer, size_t buffer_size)
 198 {
 199         int id[] = {0, 0, 0, 0};
 200
 201         get_modalias_ids(unit, id);
 202
 203         return snprintf(buffer, buffer_size,
 204                         "ieee1394:ven%08Xmo%08Xsp%08Xver%08X",
 205                         id[0], id[1], id[2], id[3]);
 206 }
 207
 208 static int fw_unit_uevent(struct device *dev, struct kobj_uevent_env *env)
 209 {
 210         struct fw_unit *unit = fw_unit(dev);
 211         char modalias[64];
 212
 213         get_modalias(unit, modalias, sizeof(modalias));
 214
 215         if (add_uevent_var(env, "MODALIAS=%s", modalias))
 216                 return -ENOMEM;
 217
 218         return 0;
 219 }
 220
 221 struct bus_type fw_bus_type = {
 222         .name = "firewire",
 223         .match = fw_unit_match,
 224         .probe = fw_unit_probe,
 225         .remove = fw_unit_remove,
 226 };
 227 EXPORT_SYMBOL(fw_bus_type);
 228
 229 int fw_device_enable_phys_dma(struct fw_device *device)
 230 {
 231         int generation = device->generation;
 232
 233         /* device->node_id, accessed below, must not be older than generation */
 234         smp_rmb();
 235
 236         return device->card->driver->enable_phys_dma(device->card,
 237                                                      device->node_id,
 238                                                      generation);
 239 }
 240 EXPORT_SYMBOL(fw_device_enable_phys_dma);
 241
 242 struct config_rom_attribute {
 243         struct device_attribute attr;
 244         u32 key;
 245 };
 246
 247 static ssize_t show_immediate(struct device *dev,
 248                               struct device_attribute *dattr, char *buf)
 249 {
 250         struct config_rom_attribute *attr =
 251                 container_of(dattr, struct config_rom_attribute, attr);
 252         struct fw_csr_iterator ci;
 253         const u32 *dir;
 254         int key, value, ret = -ENOENT;
 255
 256         down_read(&fw_device_rwsem);
 257
 258         if (is_fw_unit(dev))
 259                 dir = fw_unit(dev)->directory;
 260         else
 261                 dir = fw_device(dev)->config_rom + 5;
 262
 263         fw_csr_iterator_init(&ci, dir);
 264         while (fw_csr_iterator_next(&ci, &key, &value))
 265                 if (attr->key == key) {
 266                         ret = snprintf(buf, buf ? PAGE_SIZE : 0,
 267                                        "0x%06x\n", value);
 268                         break;
 269                 }
 270
 271         up_read(&fw_device_rwsem);
 272
 273         return ret;
 274 }
 275
 276 #define IMMEDIATE_ATTR(name, key)                               \
 277         { __ATTR(name, S_IRUGO, show_immediate, NULL), key }
 278
 279 static ssize_t show_text_leaf(struct device *dev,
 280                               struct device_attribute *dattr, char *buf)
 281 {
 282         struct config_rom_attribute *attr =
 283                 container_of(dattr, struct config_rom_attribute, attr);
 284         const u32 *dir;
 285         size_t bufsize;
 286         char dummy_buf[2];
 287         int ret;
 288
 289         down_read(&fw_device_rwsem);
 290
 291         if (is_fw_unit(dev))
 292                 dir = fw_unit(dev)->directory;
 293         else
 294                 dir = fw_device(dev)->config_rom + 5;
 295
 296         if (buf) {
 297                 bufsize = PAGE_SIZE - 1;
 298         } else {
 299                 buf = dummy_buf;
 300                 bufsize = 1;
 301         }
 302
 303         ret = fw_csr_string(dir, attr->key, buf, bufsize);
 304
 305         if (ret >= 0) {
 306                 /* Strip trailing whitespace and add newline. */
 307                 while (ret > 0 && isspace(buf[ret - 1]))
 308                         ret--;
 309                 strcpy(buf + ret, "\n");
 310                 ret++;
 311         }
 312
 313         up_read(&fw_device_rwsem);
 314
 315         return ret;
 316 }
 317
 318 #define TEXT_LEAF_ATTR(name, key)                               \
 319         { __ATTR(name, S_IRUGO, show_text_leaf, NULL), key }
 320
 321 static struct config_rom_attribute config_rom_attributes[] = {
 322         IMMEDIATE_ATTR(vendor, CSR_VENDOR),
 323         IMMEDIATE_ATTR(hardware_version, CSR_HARDWARE_VERSION),
 324         IMMEDIATE_ATTR(specifier_id, CSR_SPECIFIER_ID),
 325         IMMEDIATE_ATTR(version, CSR_VERSION),
 326         IMMEDIATE_ATTR(model, CSR_MODEL),
 327         TEXT_LEAF_ATTR(vendor_name, CSR_VENDOR),
 328         TEXT_LEAF_ATTR(model_name, CSR_MODEL),
 329         TEXT_LEAF_ATTR(hardware_version_name, CSR_HARDWARE_VERSION),
 330 };
 331
 332 static void init_fw_attribute_group(struct device *dev,
 333                                     struct device_attribute *attrs,
 334                                     struct fw_attribute_group *group)
 335 {
 336         struct device_attribute *attr;
 337         int i, j;
 338
 339         for (j = 0; attrs[j].attr.name != NULL; j++)
 340                 group->attrs[j] = &attrs[j].attr;
 341
 342         for (i = 0; i < ARRAY_SIZE(config_rom_attributes); i++) {
 343                 attr = &config_rom_attributes[i].attr;
 344                 if (attr->show(dev, attr, NULL) < 0)
 345                         continue;
 346                 group->attrs[j++] = &attr->attr;
 347         }
 348
 349         group->attrs[j] = NULL;
 350         group->groups[0] = &group->group;
 351         group->groups[1] = NULL;
 352         group->group.attrs = group->attrs;
 353         dev->groups = (const struct attribute_group **) group->groups;
 354 }
 355
 356 static ssize_t modalias_show(struct device *dev,
 357                              struct device_attribute *attr, char *buf)
 358 {
 359         struct fw_unit *unit = fw_unit(dev);
 360         int length;
 361
 362         length = get_modalias(unit, buf, PAGE_SIZE);
 363         strcpy(buf + length, "\n");
 364
 365         return length + 1;
 366 }
 367
 368 static ssize_t rom_index_show(struct device *dev,
 369                               struct device_attribute *attr, char *buf)
 370 {
 371         struct fw_device *device = fw_device(dev->parent);
 372         struct fw_unit *unit = fw_unit(dev);
 373
 374         return snprintf(buf, PAGE_SIZE, "%d\n",
 375                         (int)(unit->directory - device->config_rom));
 376 }
 377
 378 static struct device_attribute fw_unit_attributes[] = {
 379         __ATTR_RO(modalias),
 380         __ATTR_RO(rom_index),
 381         __ATTR_NULL,
 382 };
 383
 384 static ssize_t config_rom_show(struct device *dev,
 385                                struct device_attribute *attr, char *buf)
 386 {
 387         struct fw_device *device = fw_device(dev);
 388         size_t length;
 389
 390         down_read(&fw_device_rwsem);
 391         length = device->config_rom_length * 4;
 392         memcpy(buf, device->config_rom, length);
 393         up_read(&fw_device_rwsem);
 394
 395         return length;
 396 }
 397
 398 static ssize_t guid_show(struct device *dev,
 399                          struct device_attribute *attr, char *buf)
 400 {
 401         struct fw_device *device = fw_device(dev);
 402         int ret;
 403
 404         down_read(&fw_device_rwsem);
 405         ret = snprintf(buf, PAGE_SIZE, "0x%08x%08x\n",
 406                        device->config_rom[3], device->config_rom[4]);
 407         up_read(&fw_device_rwsem);
 408
 409         return ret;
 410 }
 411
 412 static ssize_t is_local_show(struct device *dev,
 413                              struct device_attribute *attr, char *buf)
 414 {
 415         struct fw_device *device = fw_device(dev);
 416
 417         return sprintf(buf, "%u\n", device->is_local);
 418 }
 419
 420 static int units_sprintf(char *buf, const u32 *directory)
 421 {
 422         struct fw_csr_iterator ci;
 423         int key, value;
 424         int specifier_id = 0;
 425         int version = 0;
 426
 427         fw_csr_iterator_init(&ci, directory);
 428         while (fw_csr_iterator_next(&ci, &key, &value)) {
 429                 switch (key) {
 430                 case CSR_SPECIFIER_ID:
 431                         specifier_id = value;
 432                         break;
 433                 case CSR_VERSION:
 434                         version = value;
 435                         break;
 436                 }
 437         }
 438
 439         return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version);
 440 }
 441
 442 static ssize_t units_show(struct device *dev,
 443                           struct device_attribute *attr, char *buf)
 444 {
 445         struct fw_device *device = fw_device(dev);
 446         struct fw_csr_iterator ci;
 447         int key, value, i = 0;
 448
 449         down_read(&fw_device_rwsem);
 450         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 451         while (fw_csr_iterator_next(&ci, &key, &value)) {
 452                 if (key != (CSR_UNIT | CSR_DIRECTORY))
 453                         continue;
 454                 i += units_sprintf(&buf[i], ci.p + value - 1);
 455                 if (i >= PAGE_SIZE - (8 + 1 + 8 + 1))
 456                         break;
 457         }
 458         up_read(&fw_device_rwsem);
 459
 460         if (i)
 461                 buf[i - 1] = '\n';
 462
 463         return i;
 464 }
 465
 466 static struct device_attribute fw_device_attributes[] = {
 467         __ATTR_RO(config_rom),
 468         __ATTR_RO(guid),
 469         __ATTR_RO(is_local),
 470         __ATTR_RO(units),
 471         __ATTR_NULL,
 472 };
 473
 474 static int read_rom(struct fw_device *device,
 475                     int generation, int index, u32 *data)
 476 {
 477         u64 offset = (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4;
 478         int i, rcode;
 479
 480         /* device->node_id, accessed below, must not be older than generation */
 481         smp_rmb();
 482
 483         for (i = 10; i < 100; i += 10) {
 484                 rcode = fw_run_transaction(device->card,
 485                                 TCODE_READ_QUADLET_REQUEST, device->node_id,
 486                                 generation, device->max_speed, offset, data, 4);
 487                 if (rcode != RCODE_BUSY)
 488                         break;
 489                 msleep(i);
 490         }
 491         be32_to_cpus(data);
 492
 493         return rcode;
 494 }
 495
 496 #define MAX_CONFIG_ROM_SIZE 256
 497
 498 /*
 499  * Read the bus info block, perform a speed probe, and read all of the rest of
 500  * the config ROM.  We do all this with a cached bus generation.  If the bus
 501  * generation changes under us, read_config_rom will fail and get retried.
 502  * It's better to start all over in this case because the node from which we
 503  * are reading the ROM may have changed the ROM during the reset.
 504  * Returns either a result code or a negative error code.
 505  */
 506 static int read_config_rom(struct fw_device *device, int generation)
 507 {
 508         struct fw_card *card = device->card;
 509         const u32 *old_rom, *new_rom;
 510         u32 *rom, *stack;
 511         u32 sp, key;
 512         int i, end, length, ret;
 513
 514         rom = kmalloc(sizeof(*rom) * MAX_CONFIG_ROM_SIZE +
 515                       sizeof(*stack) * MAX_CONFIG_ROM_SIZE, GFP_KERNEL);
 516         if (rom == NULL)
 517                 return -ENOMEM;
 518
 519         stack = &rom[MAX_CONFIG_ROM_SIZE];
 520         memset(rom, 0, sizeof(*rom) * MAX_CONFIG_ROM_SIZE);
 521
 522         device->max_speed = SCODE_100;
 523
 524         /* First read the bus info block. */
 525         for (i = 0; i < 5; i++) {
 526                 ret = read_rom(device, generation, i, &rom[i]);
 527                 if (ret != RCODE_COMPLETE)
 528                         goto out;
 529                 /*
 530                  * As per IEEE1212 7.2, during initialization, devices can
 531                  * reply with a 0 for the first quadlet of the config
 532                  * rom to indicate that they are booting (for example,
 533                  * if the firmware is on the disk of a external
 534                  * harddisk).  In that case we just fail, and the
 535                  * retry mechanism will try again later.
 536                  */
 537                 if (i == 0 && rom[i] == 0) {
 538                         ret = RCODE_BUSY;
 539                         goto out;
 540                 }
 541         }
 542
 543         device->max_speed = device->node->max_speed;
 544
 545         /*
 546          * Determine the speed of
 547          *   - devices with link speed less than PHY speed,
 548          *   - devices with 1394b PHY (unless only connected to 1394a PHYs),
 549          *   - all devices if there are 1394b repeaters.
 550          * Note, we cannot use the bus info block's link_spd as starting point
 551          * because some buggy firmwares set it lower than necessary and because
 552          * 1394-1995 nodes do not have the field.
 553          */
 554         if ((rom[2] & 0x7) < device->max_speed ||
 555             device->max_speed == SCODE_BETA ||
 556             card->beta_repeaters_present) {
 557                 u32 dummy;
 558
 559                 /* for S1600 and S3200 */
 560                 if (device->max_speed == SCODE_BETA)
 561                         device->max_speed = card->link_speed;
 562
 563                 while (device->max_speed > SCODE_100) {
 564                         if (read_rom(device, generation, 0, &dummy) ==
 565                             RCODE_COMPLETE)
 566                                 break;
 567                         device->max_speed--;
 568                 }
 569         }
 570
 571         /*
 572          * Now parse the config rom.  The config rom is a recursive
 573          * directory structure so we parse it using a stack of
 574          * references to the blocks that make up the structure.  We
 575          * push a reference to the root directory on the stack to
 576          * start things off.
 577          */
 578         length = i;
 579         sp = 0;
 580         stack[sp++] = 0xc0000005;
 581         while (sp > 0) {
 582                 /*
 583                  * Pop the next block reference of the stack.  The
 584                  * lower 24 bits is the offset into the config rom,
 585                  * the upper 8 bits are the type of the reference the
 586                  * block.
 587                  */
 588                 key = stack[--sp];
 589                 i = key & 0xffffff;
 590                 if (WARN_ON(i >= MAX_CONFIG_ROM_SIZE)) {
 591                         ret = -ENXIO;
 592                         goto out;
 593                 }
 594
 595                 /* Read header quadlet for the block to get the length. */
 596                 ret = read_rom(device, generation, i, &rom[i]);
 597                 if (ret != RCODE_COMPLETE)
 598                         goto out;
 599                 end = i + (rom[i] >> 16) + 1;
 600                 if (end > MAX_CONFIG_ROM_SIZE) {
 601                         /*
 602                          * This block extends outside the config ROM which is
 603                          * a firmware bug.  Ignore this whole block, i.e.
 604                          * simply set a fake block length of 0.
 605                          */
 606                         fw_err(card, "skipped invalid ROM block %x at %llx\n",
 607                                rom[i],
 608                                i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 609                         rom[i] = 0;
 610                         end = i;
 611                 }
 612                 i++;
 613
 614                 /*
 615                  * Now read in the block.  If this is a directory
 616                  * block, check the entries as we read them to see if
 617                  * it references another block, and push it in that case.
 618                  */
 619                 for (; i < end; i++) {
 620                         ret = read_rom(device, generation, i, &rom[i]);
 621                         if (ret != RCODE_COMPLETE)
 622                                 goto out;
 623
 624                         if ((key >> 30) != 3 || (rom[i] >> 30) < 2)
 625                                 continue;
 626                         /*
 627                          * Offset points outside the ROM.  May be a firmware
 628                          * bug or an Extended ROM entry (IEEE 1212-2001 clause
 629                          * 7.7.18).  Simply overwrite this pointer here by a
 630                          * fake immediate entry so that later iterators over
 631                          * the ROM don't have to check offsets all the time.
 632                          */
 633                         if (i + (rom[i] & 0xffffff) >= MAX_CONFIG_ROM_SIZE) {
 634                                 fw_err(card,
 635                                        "skipped unsupported ROM entry %x at %llx\n",
 636                                        rom[i],
 637                                        i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 638                                 rom[i] = 0;
 639                                 continue;
 640                         }
 641                         stack[sp++] = i + rom[i];
 642                 }
 643                 if (length < i)
 644                         length = i;
 645         }
 646
 647         old_rom = device->config_rom;
 648         new_rom = kmemdup(rom, length * 4, GFP_KERNEL);
 649         if (new_rom == NULL) {
 650                 ret = -ENOMEM;
 651                 goto out;
 652         }
 653
 654         down_write(&fw_device_rwsem);
 655         device->config_rom = new_rom;
 656         device->config_rom_length = length;
 657         up_write(&fw_device_rwsem);
 658
 659         kfree(old_rom);
 660         ret = RCODE_COMPLETE;
 661         device->max_rec = rom[2] >> 12 & 0xf;
 662         device->cmc     = rom[2] >> 30 & 1;
 663         device->irmc    = rom[2] >> 31 & 1;
 664  out:
 665         kfree(rom);
 666
 667         return ret;
 668 }
 669
 670 static void fw_unit_release(struct device *dev)
 671 {
 672         struct fw_unit *unit = fw_unit(dev);
 673
 674         fw_device_put(fw_parent_device(unit));
 675         kfree(unit);
 676 }
 677
 678 static struct device_type fw_unit_type = {
 679         .uevent         = fw_unit_uevent,
 680         .release        = fw_unit_release,
 681 };
 682
 683 static bool is_fw_unit(struct device *dev)
 684 {
 685         return dev->type == &fw_unit_type;
 686 }
 687
 688 static void create_units(struct fw_device *device)
 689 {
 690         struct fw_csr_iterator ci;
 691         struct fw_unit *unit;
 692         int key, value, i;
 693
 694         i = 0;
 695         fw_csr_iterator_init(&ci, &device->config_rom[5]);
 696         while (fw_csr_iterator_next(&ci, &key, &value)) {
 697                 if (key != (CSR_UNIT | CSR_DIRECTORY))
 698                         continue;
 699
 700                 /*
 701                  * Get the address of the unit directory and try to
 702                  * match the drivers id_tables against it.
 703                  */
 704                 unit = kzalloc(sizeof(*unit), GFP_KERNEL);
 705                 if (unit == NULL)
 706                         continue;
 707
 708                 unit->directory = ci.p + value - 1;
 709                 unit->device.bus = &fw_bus_type;
 710                 unit->device.type = &fw_unit_type;
 711                 unit->device.parent = &device->device;
 712                 dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++);
 713
 714                 BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) <
 715                                 ARRAY_SIZE(fw_unit_attributes) +
 716                                 ARRAY_SIZE(config_rom_attributes));
 717                 init_fw_attribute_group(&unit->device,
 718                                         fw_unit_attributes,
 719                                         &unit->attribute_group);
 720
 721                 fw_device_get(device);
 722                 if (device_register(&unit->device) < 0) {
 723                         put_device(&unit->device);
 724                         continue;
 725                 }
 726         }
 727 }
 728
 729 static int shutdown_unit(struct device *device, void *data)
 730 {
 731         device_unregister(device);
 732
 733         return 0;
 734 }
 735
 736 /*
 737  * fw_device_rwsem acts as dual purpose mutex:
 738  *   - serializes accesses to fw_device_idr,
 739  *   - serializes accesses to fw_device.config_rom/.config_rom_length and
 740  *     fw_unit.directory, unless those accesses happen at safe occasions
 741  */
 742 DECLARE_RWSEM(fw_device_rwsem);
 743
 744 DEFINE_IDR(fw_device_idr);
 745 int fw_cdev_major;
 746
 747 struct fw_device *fw_device_get_by_devt(dev_t devt)
 748 {
 749         struct fw_device *device;
 750
 751         down_read(&fw_device_rwsem);
 752         device = idr_find(&fw_device_idr, MINOR(devt));
 753         if (device)
 754                 fw_device_get(device);
 755         up_read(&fw_device_rwsem);
 756
 757         return device;
 758 }
 759
 760 struct workqueue_struct *fw_workqueue;
 761 EXPORT_SYMBOL(fw_workqueue);
 762
 763 static void fw_schedule_device_work(struct fw_device *device,
 764                                     unsigned long delay)
 765 {
 766         queue_delayed_work(fw_workqueue, &device->work, delay);
 767 }
 768
 769 /*
 770  * These defines control the retry behavior for reading the config
 771  * rom.  It shouldn't be necessary to tweak these; if the device
 772  * doesn't respond to a config rom read within 10 seconds, it's not
 773  * going to respond at all.  As for the initial delay, a lot of
 774  * devices will be able to respond within half a second after bus
 775  * reset.  On the other hand, it's not really worth being more
 776  * aggressive than that, since it scales pretty well; if 10 devices
 777  * are plugged in, they're all getting read within one second.
 778  */
 779
 780 #define MAX_RETRIES     10
 781 #define RETRY_DELAY     (3 * HZ)
 782 #define INITIAL_DELAY   (HZ / 2)
 783 #define SHUTDOWN_DELAY  (2 * HZ)
 784
 785 static void fw_device_shutdown(struct work_struct *work)
 786 {
 787         struct fw_device *device =
 788                 container_of(work, struct fw_device, work.work);
 789         int minor = MINOR(device->device.devt);
 790
 791         if (time_before64(get_jiffies_64(),
 792                           device->card->reset_jiffies + SHUTDOWN_DELAY)
 793             && !list_empty(&device->card->link)) {
 794                 fw_schedule_device_work(device, SHUTDOWN_DELAY);
 795                 return;
 796         }
 797
 798         if (atomic_cmpxchg(&device->state,
 799                            FW_DEVICE_GONE,
 800                            FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE)
 801                 return;
 802
 803         fw_device_cdev_remove(device);
 804         device_for_each_child(&device->device, NULL, shutdown_unit);
 805         device_unregister(&device->device);
 806
 807         down_write(&fw_device_rwsem);
 808         idr_remove(&fw_device_idr, minor);
 809         up_write(&fw_device_rwsem);
 810
 811         fw_device_put(device);
 812 }
 813
 814 static void fw_device_release(struct device *dev)
 815 {
 816         struct fw_device *device = fw_device(dev);
 817         struct fw_card *card = device->card;
 818         unsigned long flags;
 819
 820         /*
 821          * Take the card lock so we don't set this to NULL while a
 822          * FW_NODE_UPDATED callback is being handled or while the
 823          * bus manager work looks at this node.
 824          */
 825         spin_lock_irqsave(&card->lock, flags);
 826         device->node->data = NULL;
 827         spin_unlock_irqrestore(&card->lock, flags);
 828
 829         fw_node_put(device->node);
 830         kfree(device->config_rom);
 831         kfree(device);
 832         fw_card_put(card);
 833 }
 834
 835 static struct device_type fw_device_type = {
 836         .release = fw_device_release,
 837 };
 838
 839 static bool is_fw_device(struct device *dev)
 840 {
 841         return dev->type == &fw_device_type;
 842 }
 843
 844 static int update_unit(struct device *dev, void *data)
 845 {
 846         struct fw_unit *unit = fw_unit(dev);
 847         struct fw_driver *driver = (struct fw_driver *)dev->driver;
 848
 849         if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) {
 850                 device_lock(dev);
 851                 driver->update(unit);
 852                 device_unlock(dev);
 853         }
 854
 855         return 0;
 856 }
 857
 858 static void fw_device_update(struct work_struct *work)
 859 {
 860         struct fw_device *device =
 861                 container_of(work, struct fw_device, work.work);
 862
 863         fw_device_cdev_update(device);
 864         device_for_each_child(&device->device, NULL, update_unit);
 865 }
 866
 867 /*
 868  * If a device was pending for deletion because its node went away but its
 869  * bus info block and root directory header matches that of a newly discovered
 870  * device, revive the existing fw_device.
 871  * The newly allocated fw_device becomes obsolete instead.
 872  */
 873 static int lookup_existing_device(struct device *dev, void *data)
 874 {
 875         struct fw_device *old = fw_device(dev);
 876         struct fw_device *new = data;
 877         struct fw_card *card = new->card;
 878         int match = 0;
 879
 880         if (!is_fw_device(dev))
 881                 return 0;
 882
 883         down_read(&fw_device_rwsem); /* serialize config_rom access */
 884         spin_lock_irq(&card->lock);  /* serialize node access */
 885
 886         if (memcmp(old->config_rom, new->config_rom, 6 * 4) == 0 &&
 887             atomic_cmpxchg(&old->state,
 888                            FW_DEVICE_GONE,
 889                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
 890                 struct fw_node *current_node = new->node;
 891                 struct fw_node *obsolete_node = old->node;
 892
 893                 new->node = obsolete_node;
 894                 new->node->data = new;
 895                 old->node = current_node;
 896                 old->node->data = old;
 897
 898                 old->max_speed = new->max_speed;
 899                 old->node_id = current_node->node_id;
 900                 smp_wmb();  /* update node_id before generation */
 901                 old->generation = card->generation;
 902                 old->config_rom_retries = 0;
 903                 fw_notice(card, "rediscovered device %s\n", dev_name(dev));
 904
 905                 old->workfn = fw_device_update;
 906                 fw_schedule_device_work(old, 0);
 907
 908                 if (current_node == card->root_node)
 909                         fw_schedule_bm_work(card, 0);
 910
 911                 match = 1;
 912         }
 913
 914         spin_unlock_irq(&card->lock);
 915         up_read(&fw_device_rwsem);
 916
 917         return match;
 918 }
 919
 920 enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, };
 921
 922 static void set_broadcast_channel(struct fw_device *device, int generation)
 923 {
 924         struct fw_card *card = device->card;
 925         __be32 data;
 926         int rcode;
 927
 928         if (!card->broadcast_channel_allocated)
 929                 return;
 930
 931         /*
 932          * The Broadcast_Channel Valid bit is required by nodes which want to
 933          * transmit on this channel.  Such transmissions are practically
 934          * exclusive to IP over 1394 (RFC 2734).  IP capable nodes are required
 935          * to be IRM capable and have a max_rec of 8 or more.  We use this fact
 936          * to narrow down to which nodes we send Broadcast_Channel updates.
 937          */
 938         if (!device->irmc || device->max_rec < 8)
 939                 return;
 940
 941         /*
 942          * Some 1394-1995 nodes crash if this 1394a-2000 register is written.
 943          * Perform a read test first.
 944          */
 945         if (device->bc_implemented == BC_UNKNOWN) {
 946                 rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST,
 947                                 device->node_id, generation, device->max_speed,
 948                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 949                                 &data, 4);
 950                 switch (rcode) {
 951                 case RCODE_COMPLETE:
 952                         if (data & cpu_to_be32(1 << 31)) {
 953                                 device->bc_implemented = BC_IMPLEMENTED;
 954                                 break;
 955                         }
 956                         fallthrough;    /* to case address error */
 957                 case RCODE_ADDRESS_ERROR:
 958                         device->bc_implemented = BC_UNIMPLEMENTED;
 959                 }
 960         }
 961
 962         if (device->bc_implemented == BC_IMPLEMENTED) {
 963                 data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL |
 964                                    BROADCAST_CHANNEL_VALID);
 965                 fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
 966                                 device->node_id, generation, device->max_speed,
 967                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 968                                 &data, 4);
 969         }
 970 }
 971
 972 int fw_device_set_broadcast_channel(struct device *dev, void *gen)
 973 {
 974         if (is_fw_device(dev))
 975                 set_broadcast_channel(fw_device(dev), (long)gen);
 976
 977         return 0;
 978 }
 979
 980 static void fw_device_init(struct work_struct *work)
 981 {
 982         struct fw_device *device =
 983                 container_of(work, struct fw_device, work.work);
 984         struct fw_card *card = device->card;
 985         struct device *revived_dev;
 986         int minor, ret;
 987
 988         /*
 989          * All failure paths here set node->data to NULL, so that we
 990          * don't try to do device_for_each_child() on a kfree()'d
 991          * device.
 992          */
 993
 994         ret = read_config_rom(device, device->generation);
 995         if (ret != RCODE_COMPLETE) {
 996                 if (device->config_rom_retries < MAX_RETRIES &&
 997                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
 998                         device->config_rom_retries++;
 999                         fw_schedule_device_work(device, RETRY_DELAY);
1000                 } else {
1001                         if (device->node->link_on)
1002                                 fw_notice(card, "giving up on node %x: reading config rom failed: %s\n",
1003                                           device->node_id,
1004                                           fw_rcode_string(ret));
1005                         if (device->node == card->root_node)
1006                                 fw_schedule_bm_work(card, 0);
1007                         fw_device_release(&device->device);
1008                 }
1009                 return;
1010         }
1011
1012         revived_dev = device_find_child(card->device,
1013                                         device, lookup_existing_device);
1014         if (revived_dev) {
1015                 put_device(revived_dev);
1016                 fw_device_release(&device->device);
1017
1018                 return;
1019         }
1020
1021         device_initialize(&device->device);
1022
1023         fw_device_get(device);
1024         down_write(&fw_device_rwsem);
1025         minor = idr_alloc(&fw_device_idr, device, 0, 1 << MINORBITS,
1026                         GFP_KERNEL);
1027         up_write(&fw_device_rwsem);
1028
1029         if (minor < 0)
1030                 goto error;
1031
1032         device->device.bus = &fw_bus_type;
1033         device->device.type = &fw_device_type;
1034         device->device.parent = card->device;
1035         device->device.devt = MKDEV(fw_cdev_major, minor);
1036         dev_set_name(&device->device, "fw%d", minor);
1037
1038         BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) <
1039                         ARRAY_SIZE(fw_device_attributes) +
1040                         ARRAY_SIZE(config_rom_attributes));
1041         init_fw_attribute_group(&device->device,
1042                                 fw_device_attributes,
1043                                 &device->attribute_group);
1044
1045         if (device_add(&device->device)) {
1046                 fw_err(card, "failed to add device\n");
1047                 goto error_with_cdev;
1048         }
1049
1050         create_units(device);
1051
1052         /*
1053          * Transition the device to running state.  If it got pulled
1054          * out from under us while we did the initialization work, we
1055          * have to shut down the device again here.  Normally, though,
1056          * fw_node_event will be responsible for shutting it down when
1057          * necessary.  We have to use the atomic cmpxchg here to avoid
1058          * racing with the FW_NODE_DESTROYED case in
1059          * fw_node_event().
1060          */
1061         if (atomic_cmpxchg(&device->state,
1062                            FW_DEVICE_INITIALIZING,
1063                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
1064                 device->workfn = fw_device_shutdown;
1065                 fw_schedule_device_work(device, SHUTDOWN_DELAY);
1066         } else {
1067                 fw_notice(card, "created device %s: GUID %08x%08x, S%d00\n",
1068                           dev_name(&device->device),
1069                           device->config_rom[3], device->config_rom[4],
1070                           1 << device->max_speed);
1071                 device->config_rom_retries = 0;
1072
1073                 set_broadcast_channel(device, device->generation);
1074
1075                 add_device_randomness(&device->config_rom[3], 8);
1076         }
1077
1078         /*
1079          * Reschedule the IRM work if we just finished reading the
1080          * root node config rom.  If this races with a bus reset we
1081          * just end up running the IRM work a couple of extra times -
1082          * pretty harmless.
1083          */
1084         if (device->node == card->root_node)
1085                 fw_schedule_bm_work(card, 0);
1086
1087         return;
1088
1089  error_with_cdev:
1090         down_write(&fw_device_rwsem);
1091         idr_remove(&fw_device_idr, minor);
1092         up_write(&fw_device_rwsem);
1093  error:
1094         fw_device_put(device);          /* fw_device_idr's reference */
1095
1096         put_device(&device->device);    /* our reference */
1097 }
1098
1099 /* Reread and compare bus info block and header of root directory */
1100 static int reread_config_rom(struct fw_device *device, int generation,
1101                              bool *changed)
1102 {
1103         u32 q;
1104         int i, rcode;
1105
1106         for (i = 0; i < 6; i++) {
1107                 rcode = read_rom(device, generation, i, &q);
1108                 if (rcode != RCODE_COMPLETE)
1109                         return rcode;
1110
1111                 if (i == 0 && q == 0)
1112                         /* inaccessible (see read_config_rom); retry later */
1113                         return RCODE_BUSY;
1114
1115                 if (q != device->config_rom[i]) {
1116                         *changed = true;
1117                         return RCODE_COMPLETE;
1118                 }
1119         }
1120
1121         *changed = false;
1122         return RCODE_COMPLETE;
1123 }
1124
1125 static void fw_device_refresh(struct work_struct *work)
1126 {
1127         struct fw_device *device =
1128                 container_of(work, struct fw_device, work.work);
1129         struct fw_card *card = device->card;
1130         int ret, node_id = device->node_id;
1131         bool changed;
1132
1133         ret = reread_config_rom(device, device->generation, &changed);
1134         if (ret != RCODE_COMPLETE)
1135                 goto failed_config_rom;
1136
1137         if (!changed) {
1138                 if (atomic_cmpxchg(&device->state,
1139                                    FW_DEVICE_INITIALIZING,
1140                                    FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1141                         goto gone;
1142
1143                 fw_device_update(work);
1144                 device->config_rom_retries = 0;
1145                 goto out;
1146         }
1147
1148         /*
1149          * Something changed.  We keep things simple and don't investigate
1150          * further.  We just destroy all previous units and create new ones.
1151          */
1152         device_for_each_child(&device->device, NULL, shutdown_unit);
1153
1154         ret = read_config_rom(device, device->generation);
1155         if (ret != RCODE_COMPLETE)
1156                 goto failed_config_rom;
1157
1158         fw_device_cdev_update(device);
1159         create_units(device);
1160
1161         /* Userspace may want to re-read attributes. */
1162         kobject_uevent(&device->device.kobj, KOBJ_CHANGE);
1163
1164         if (atomic_cmpxchg(&device->state,
1165                            FW_DEVICE_INITIALIZING,
1166                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1167                 goto gone;
1168
1169         fw_notice(card, "refreshed device %s\n", dev_name(&device->device));
1170         device->config_rom_retries = 0;
1171         goto out;
1172
1173  failed_config_rom:
1174         if (device->config_rom_retries < MAX_RETRIES &&
1175             atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1176                 device->config_rom_retries++;
1177                 fw_schedule_device_work(device, RETRY_DELAY);
1178                 return;
1179         }
1180
1181         fw_notice(card, "giving up on refresh of device %s: %s\n",
1182                   dev_name(&device->device), fw_rcode_string(ret));
1183  gone:
1184         atomic_set(&device->state, FW_DEVICE_GONE);
1185         device->workfn = fw_device_shutdown;
1186         fw_schedule_device_work(device, SHUTDOWN_DELAY);
1187  out:
1188         if (node_id == card->root_node->node_id)
1189                 fw_schedule_bm_work(card, 0);
1190 }
1191
1192 static void fw_device_workfn(struct work_struct *work)
1193 {
1194         struct fw_device *device = container_of(to_delayed_work(work),
1195                                                 struct fw_device, work);
1196         device->workfn(work);
1197 }
1198
1199 void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
1200 {
1201         struct fw_device *device;
1202
1203         switch (event) {
1204         case FW_NODE_CREATED:
1205                 /*
1206                  * Attempt to scan the node, regardless whether its self ID has
1207                  * the L (link active) flag set or not.  Some broken devices
1208                  * send L=0 but have an up-and-running link; others send L=1
1209                  * without actually having a link.
1210                  */
1211  create:
1212                 device = kzalloc(sizeof(*device), GFP_ATOMIC);
1213                 if (device == NULL)
1214                         break;
1215
1216                 /*
1217                  * Do minimal initialization of the device here, the
1218                  * rest will happen in fw_device_init().
1219                  *
1220                  * Attention:  A lot of things, even fw_device_get(),
1221                  * cannot be done before fw_device_init() finished!
1222                  * You can basically just check device->state and
1223                  * schedule work until then, but only while holding
1224                  * card->lock.
1225                  */
1226                 atomic_set(&device->state, FW_DEVICE_INITIALIZING);
1227                 device->card = fw_card_get(card);
1228                 device->node = fw_node_get(node);
1229                 device->node_id = node->node_id;
1230                 device->generation = card->generation;
1231                 device->is_local = node == card->local_node;
1232                 mutex_init(&device->client_list_mutex);
1233                 INIT_LIST_HEAD(&device->client_list);
1234
1235                 /*
1236                  * Set the node data to point back to this device so
1237                  * FW_NODE_UPDATED callbacks can update the node_id
1238                  * and generation for the device.
1239                  */
1240                 node->data = device;
1241
1242                 /*
1243                  * Many devices are slow to respond after bus resets,
1244                  * especially if they are bus powered and go through
1245                  * power-up after getting plugged in.  We schedule the
1246                  * first config rom scan half a second after bus reset.
1247                  */
1248                 device->workfn = fw_device_init;
1249                 INIT_DELAYED_WORK(&device->work, fw_device_workfn);
1250                 fw_schedule_device_work(device, INITIAL_DELAY);
1251                 break;
1252
1253         case FW_NODE_INITIATED_RESET:
1254         case FW_NODE_LINK_ON:
1255                 device = node->data;
1256                 if (device == NULL)
1257                         goto create;
1258
1259                 device->node_id = node->node_id;
1260                 smp_wmb();  /* update node_id before generation */
1261                 device->generation = card->generation;
1262                 if (atomic_cmpxchg(&device->state,
1263                             FW_DEVICE_RUNNING,
1264                             FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) {
1265                         device->workfn = fw_device_refresh;
1266                         fw_schedule_device_work(device,
1267                                 device->is_local ? 0 : INITIAL_DELAY);
1268                 }
1269                 break;
1270
1271         case FW_NODE_UPDATED:
1272                 device = node->data;
1273                 if (device == NULL)
1274                         break;
1275
1276                 device->node_id = node->node_id;
1277                 smp_wmb();  /* update node_id before generation */
1278                 device->generation = card->generation;
1279                 if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
1280                         device->workfn = fw_device_update;
1281                         fw_schedule_device_work(device, 0);
1282                 }
1283                 break;
1284
1285         case FW_NODE_DESTROYED:
1286         case FW_NODE_LINK_OFF:
1287                 if (!node->data)
1288                         break;
1289
1290                 /*
1291                  * Destroy the device associated with the node.  There
1292                  * are two cases here: either the device is fully
1293                  * initialized (FW_DEVICE_RUNNING) or we're in the
1294                  * process of reading its config rom
1295                  * (FW_DEVICE_INITIALIZING).  If it is fully
1296                  * initialized we can reuse device->work to schedule a
1297                  * full fw_device_shutdown().  If not, there's work
1298                  * scheduled to read it's config rom, and we just put
1299                  * the device in shutdown state to have that code fail
1300                  * to create the device.
1301                  */
1302                 device = node->data;
1303                 if (atomic_xchg(&device->state,
1304                                 FW_DEVICE_GONE) == FW_DEVICE_RUNNING) {
1305                         device->workfn = fw_device_shutdown;
1306                         fw_schedule_device_work(device,
1307                                 list_empty(&card->link) ? 0 : SHUTDOWN_DELAY);
1308                 }
1309                 break;
1310         }
1311 }