linux/drivers/firewire/core-device.c
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   1/*
   2 * Device probing and sysfs code.
   3 *
   4 * Copyright (C) 2005-2006  Kristian Hoegsberg <krh@bitplanet.net>
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the Free Software Foundation,
  18 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19 */
  20
  21#include <linux/bug.h>
  22#include <linux/ctype.h>
  23#include <linux/delay.h>
  24#include <linux/device.h>
  25#include <linux/errno.h>
  26#include <linux/firewire.h>
  27#include <linux/firewire-constants.h>
  28#include <linux/idr.h>
  29#include <linux/jiffies.h>
  30#include <linux/kobject.h>
  31#include <linux/list.h>
  32#include <linux/mod_devicetable.h>
  33#include <linux/module.h>
  34#include <linux/mutex.h>
  35#include <linux/random.h>
  36#include <linux/rwsem.h>
  37#include <linux/slab.h>
  38#include <linux/spinlock.h>
  39#include <linux/string.h>
  40#include <linux/workqueue.h>
  41
  42#include <linux/atomic.h>
  43#include <asm/byteorder.h>
  44
  45#include "core.h"
  46
  47void fw_csr_iterator_init(struct fw_csr_iterator *ci, const u32 *p)
  48{
  49        ci->p = p + 1;
  50        ci->end = ci->p + (p[0] >> 16);
  51}
  52EXPORT_SYMBOL(fw_csr_iterator_init);
  53
  54int fw_csr_iterator_next(struct fw_csr_iterator *ci, int *key, int *value)
  55{
  56        *key = *ci->p >> 24;
  57        *value = *ci->p & 0xffffff;
  58
  59        return ci->p++ < ci->end;
  60}
  61EXPORT_SYMBOL(fw_csr_iterator_next);
  62
  63static const u32 *search_leaf(const u32 *directory, int search_key)
  64{
  65        struct fw_csr_iterator ci;
  66        int last_key = 0, key, value;
  67
  68        fw_csr_iterator_init(&ci, directory);
  69        while (fw_csr_iterator_next(&ci, &key, &value)) {
  70                if (last_key == search_key &&
  71                    key == (CSR_DESCRIPTOR | CSR_LEAF))
  72                        return ci.p - 1 + value;
  73
  74                last_key = key;
  75        }
  76
  77        return NULL;
  78}
  79
  80static int textual_leaf_to_string(const u32 *block, char *buf, size_t size)
  81{
  82        unsigned int quadlets, i;
  83        char c;
  84
  85        if (!size || !buf)
  86                return -EINVAL;
  87
  88        quadlets = min(block[0] >> 16, 256U);
  89        if (quadlets < 2)
  90                return -ENODATA;
  91
  92        if (block[1] != 0 || block[2] != 0)
  93                /* unknown language/character set */
  94                return -ENODATA;
  95
  96        block += 3;
  97        quadlets -= 2;
  98        for (i = 0; i < quadlets * 4 && i < size - 1; i++) {
  99                c = block[i / 4] >> (24 - 8 * (i % 4));
 100                if (c == '\0')
 101                        break;
 102                buf[i] = c;
 103        }
 104        buf[i] = '\0';
 105
 106        return i;
 107}
 108
 109/**
 110 * fw_csr_string() - reads a string from the configuration ROM
 111 * @directory:  e.g. root directory or unit directory
 112 * @key:        the key of the preceding directory entry
 113 * @buf:        where to put the string
 114 * @size:       size of @buf, in bytes
 115 *
 116 * The string is taken from a minimal ASCII text descriptor leaf after
 117 * the immediate entry with @key.  The string is zero-terminated.
 118 * Returns strlen(buf) or a negative error code.
 119 */
 120int fw_csr_string(const u32 *directory, int key, char *buf, size_t size)
 121{
 122        const u32 *leaf = search_leaf(directory, key);
 123        if (!leaf)
 124                return -ENOENT;
 125
 126        return textual_leaf_to_string(leaf, buf, size);
 127}
 128EXPORT_SYMBOL(fw_csr_string);
 129
 130static void get_ids(const u32 *directory, int *id)
 131{
 132        struct fw_csr_iterator ci;
 133        int key, value;
 134
 135        fw_csr_iterator_init(&ci, directory);
 136        while (fw_csr_iterator_next(&ci, &key, &value)) {
 137                switch (key) {
 138                case CSR_VENDOR:        id[0] = value; break;
 139                case CSR_MODEL:         id[1] = value; break;
 140                case CSR_SPECIFIER_ID:  id[2] = value; break;
 141                case CSR_VERSION:       id[3] = value; break;
 142                }
 143        }
 144}
 145
 146static void get_modalias_ids(struct fw_unit *unit, int *id)
 147{
 148        get_ids(&fw_parent_device(unit)->config_rom[5], id);
 149        get_ids(unit->directory, id);
 150}
 151
 152static bool match_ids(const struct ieee1394_device_id *id_table, int *id)
 153{
 154        int match = 0;
 155
 156        if (id[0] == id_table->vendor_id)
 157                match |= IEEE1394_MATCH_VENDOR_ID;
 158        if (id[1] == id_table->model_id)
 159                match |= IEEE1394_MATCH_MODEL_ID;
 160        if (id[2] == id_table->specifier_id)
 161                match |= IEEE1394_MATCH_SPECIFIER_ID;
 162        if (id[3] == id_table->version)
 163                match |= IEEE1394_MATCH_VERSION;
 164
 165        return (match & id_table->match_flags) == id_table->match_flags;
 166}
 167
 168static const struct ieee1394_device_id *unit_match(struct device *dev,
 169                                                   struct device_driver *drv)
 170{
 171        const struct ieee1394_device_id *id_table =
 172                        container_of(drv, struct fw_driver, driver)->id_table;
 173        int id[] = {0, 0, 0, 0};
 174
 175        get_modalias_ids(fw_unit(dev), id);
 176
 177        for (; id_table->match_flags != 0; id_table++)
 178                if (match_ids(id_table, id))
 179                        return id_table;
 180
 181        return NULL;
 182}
 183
 184static bool is_fw_unit(struct device *dev);
 185
 186static int fw_unit_match(struct device *dev, struct device_driver *drv)
 187{
 188        /* We only allow binding to fw_units. */
 189        return is_fw_unit(dev) && unit_match(dev, drv) != NULL;
 190}
 191
 192static int fw_unit_probe(struct device *dev)
 193{
 194        struct fw_driver *driver =
 195                        container_of(dev->driver, struct fw_driver, driver);
 196
 197        return driver->probe(fw_unit(dev), unit_match(dev, dev->driver));
 198}
 199
 200static int fw_unit_remove(struct device *dev)
 201{
 202        struct fw_driver *driver =
 203                        container_of(dev->driver, struct fw_driver, driver);
 204
 205        return driver->remove(fw_unit(dev)), 0;
 206}
 207
 208static int get_modalias(struct fw_unit *unit, char *buffer, size_t buffer_size)
 209{
 210        int id[] = {0, 0, 0, 0};
 211
 212        get_modalias_ids(unit, id);
 213
 214        return snprintf(buffer, buffer_size,
 215                        "ieee1394:ven%08Xmo%08Xsp%08Xver%08X",
 216                        id[0], id[1], id[2], id[3]);
 217}
 218
 219static int fw_unit_uevent(struct device *dev, struct kobj_uevent_env *env)
 220{
 221        struct fw_unit *unit = fw_unit(dev);
 222        char modalias[64];
 223
 224        get_modalias(unit, modalias, sizeof(modalias));
 225
 226        if (add_uevent_var(env, "MODALIAS=%s", modalias))
 227                return -ENOMEM;
 228
 229        return 0;
 230}
 231
 232struct bus_type fw_bus_type = {
 233        .name = "firewire",
 234        .match = fw_unit_match,
 235        .probe = fw_unit_probe,
 236        .remove = fw_unit_remove,
 237};
 238EXPORT_SYMBOL(fw_bus_type);
 239
 240int fw_device_enable_phys_dma(struct fw_device *device)
 241{
 242        int generation = device->generation;
 243
 244        /* device->node_id, accessed below, must not be older than generation */
 245        smp_rmb();
 246
 247        return device->card->driver->enable_phys_dma(device->card,
 248                                                     device->node_id,
 249                                                     generation);
 250}
 251EXPORT_SYMBOL(fw_device_enable_phys_dma);
 252
 253struct config_rom_attribute {
 254        struct device_attribute attr;
 255        u32 key;
 256};
 257
 258static ssize_t show_immediate(struct device *dev,
 259                              struct device_attribute *dattr, char *buf)
 260{
 261        struct config_rom_attribute *attr =
 262                container_of(dattr, struct config_rom_attribute, attr);
 263        struct fw_csr_iterator ci;
 264        const u32 *dir;
 265        int key, value, ret = -ENOENT;
 266
 267        down_read(&fw_device_rwsem);
 268
 269        if (is_fw_unit(dev))
 270                dir = fw_unit(dev)->directory;
 271        else
 272                dir = fw_device(dev)->config_rom + 5;
 273
 274        fw_csr_iterator_init(&ci, dir);
 275        while (fw_csr_iterator_next(&ci, &key, &value))
 276                if (attr->key == key) {
 277                        ret = snprintf(buf, buf ? PAGE_SIZE : 0,
 278                                       "0x%06x\n", value);
 279                        break;
 280                }
 281
 282        up_read(&fw_device_rwsem);
 283
 284        return ret;
 285}
 286
 287#define IMMEDIATE_ATTR(name, key)                               \
 288        { __ATTR(name, S_IRUGO, show_immediate, NULL), key }
 289
 290static ssize_t show_text_leaf(struct device *dev,
 291                              struct device_attribute *dattr, char *buf)
 292{
 293        struct config_rom_attribute *attr =
 294                container_of(dattr, struct config_rom_attribute, attr);
 295        const u32 *dir;
 296        size_t bufsize;
 297        char dummy_buf[2];
 298        int ret;
 299
 300        down_read(&fw_device_rwsem);
 301
 302        if (is_fw_unit(dev))
 303                dir = fw_unit(dev)->directory;
 304        else
 305                dir = fw_device(dev)->config_rom + 5;
 306
 307        if (buf) {
 308                bufsize = PAGE_SIZE - 1;
 309        } else {
 310                buf = dummy_buf;
 311                bufsize = 1;
 312        }
 313
 314        ret = fw_csr_string(dir, attr->key, buf, bufsize);
 315
 316        if (ret >= 0) {
 317                /* Strip trailing whitespace and add newline. */
 318                while (ret > 0 && isspace(buf[ret - 1]))
 319                        ret--;
 320                strcpy(buf + ret, "\n");
 321                ret++;
 322        }
 323
 324        up_read(&fw_device_rwsem);
 325
 326        return ret;
 327}
 328
 329#define TEXT_LEAF_ATTR(name, key)                               \
 330        { __ATTR(name, S_IRUGO, show_text_leaf, NULL), key }
 331
 332static struct config_rom_attribute config_rom_attributes[] = {
 333        IMMEDIATE_ATTR(vendor, CSR_VENDOR),
 334        IMMEDIATE_ATTR(hardware_version, CSR_HARDWARE_VERSION),
 335        IMMEDIATE_ATTR(specifier_id, CSR_SPECIFIER_ID),
 336        IMMEDIATE_ATTR(version, CSR_VERSION),
 337        IMMEDIATE_ATTR(model, CSR_MODEL),
 338        TEXT_LEAF_ATTR(vendor_name, CSR_VENDOR),
 339        TEXT_LEAF_ATTR(model_name, CSR_MODEL),
 340        TEXT_LEAF_ATTR(hardware_version_name, CSR_HARDWARE_VERSION),
 341};
 342
 343static void init_fw_attribute_group(struct device *dev,
 344                                    struct device_attribute *attrs,
 345                                    struct fw_attribute_group *group)
 346{
 347        struct device_attribute *attr;
 348        int i, j;
 349
 350        for (j = 0; attrs[j].attr.name != NULL; j++)
 351                group->attrs[j] = &attrs[j].attr;
 352
 353        for (i = 0; i < ARRAY_SIZE(config_rom_attributes); i++) {
 354                attr = &config_rom_attributes[i].attr;
 355                if (attr->show(dev, attr, NULL) < 0)
 356                        continue;
 357                group->attrs[j++] = &attr->attr;
 358        }
 359
 360        group->attrs[j] = NULL;
 361        group->groups[0] = &group->group;
 362        group->groups[1] = NULL;
 363        group->group.attrs = group->attrs;
 364        dev->groups = (const struct attribute_group **) group->groups;
 365}
 366
 367static ssize_t modalias_show(struct device *dev,
 368                             struct device_attribute *attr, char *buf)
 369{
 370        struct fw_unit *unit = fw_unit(dev);
 371        int length;
 372
 373        length = get_modalias(unit, buf, PAGE_SIZE);
 374        strcpy(buf + length, "\n");
 375
 376        return length + 1;
 377}
 378
 379static ssize_t rom_index_show(struct device *dev,
 380                              struct device_attribute *attr, char *buf)
 381{
 382        struct fw_device *device = fw_device(dev->parent);
 383        struct fw_unit *unit = fw_unit(dev);
 384
 385        return snprintf(buf, PAGE_SIZE, "%d\n",
 386                        (int)(unit->directory - device->config_rom));
 387}
 388
 389static struct device_attribute fw_unit_attributes[] = {
 390        __ATTR_RO(modalias),
 391        __ATTR_RO(rom_index),
 392        __ATTR_NULL,
 393};
 394
 395static ssize_t config_rom_show(struct device *dev,
 396                               struct device_attribute *attr, char *buf)
 397{
 398        struct fw_device *device = fw_device(dev);
 399        size_t length;
 400
 401        down_read(&fw_device_rwsem);
 402        length = device->config_rom_length * 4;
 403        memcpy(buf, device->config_rom, length);
 404        up_read(&fw_device_rwsem);
 405
 406        return length;
 407}
 408
 409static ssize_t guid_show(struct device *dev,
 410                         struct device_attribute *attr, char *buf)
 411{
 412        struct fw_device *device = fw_device(dev);
 413        int ret;
 414
 415        down_read(&fw_device_rwsem);
 416        ret = snprintf(buf, PAGE_SIZE, "0x%08x%08x\n",
 417                       device->config_rom[3], device->config_rom[4]);
 418        up_read(&fw_device_rwsem);
 419
 420        return ret;
 421}
 422
 423static ssize_t is_local_show(struct device *dev,
 424                             struct device_attribute *attr, char *buf)
 425{
 426        struct fw_device *device = fw_device(dev);
 427
 428        return sprintf(buf, "%u\n", device->is_local);
 429}
 430
 431static int units_sprintf(char *buf, const u32 *directory)
 432{
 433        struct fw_csr_iterator ci;
 434        int key, value;
 435        int specifier_id = 0;
 436        int version = 0;
 437
 438        fw_csr_iterator_init(&ci, directory);
 439        while (fw_csr_iterator_next(&ci, &key, &value)) {
 440                switch (key) {
 441                case CSR_SPECIFIER_ID:
 442                        specifier_id = value;
 443                        break;
 444                case CSR_VERSION:
 445                        version = value;
 446                        break;
 447                }
 448        }
 449
 450        return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version);
 451}
 452
 453static ssize_t units_show(struct device *dev,
 454                          struct device_attribute *attr, char *buf)
 455{
 456        struct fw_device *device = fw_device(dev);
 457        struct fw_csr_iterator ci;
 458        int key, value, i = 0;
 459
 460        down_read(&fw_device_rwsem);
 461        fw_csr_iterator_init(&ci, &device->config_rom[5]);
 462        while (fw_csr_iterator_next(&ci, &key, &value)) {
 463                if (key != (CSR_UNIT | CSR_DIRECTORY))
 464                        continue;
 465                i += units_sprintf(&buf[i], ci.p + value - 1);
 466                if (i >= PAGE_SIZE - (8 + 1 + 8 + 1))
 467                        break;
 468        }
 469        up_read(&fw_device_rwsem);
 470
 471        if (i)
 472                buf[i - 1] = '\n';
 473
 474        return i;
 475}
 476
 477static struct device_attribute fw_device_attributes[] = {
 478        __ATTR_RO(config_rom),
 479        __ATTR_RO(guid),
 480        __ATTR_RO(is_local),
 481        __ATTR_RO(units),
 482        __ATTR_NULL,
 483};
 484
 485static int read_rom(struct fw_device *device,
 486                    int generation, int index, u32 *data)
 487{
 488        u64 offset = (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4;
 489        int i, rcode;
 490
 491        /* device->node_id, accessed below, must not be older than generation */
 492        smp_rmb();
 493
 494        for (i = 10; i < 100; i += 10) {
 495                rcode = fw_run_transaction(device->card,
 496                                TCODE_READ_QUADLET_REQUEST, device->node_id,
 497                                generation, device->max_speed, offset, data, 4);
 498                if (rcode != RCODE_BUSY)
 499                        break;
 500                msleep(i);
 501        }
 502        be32_to_cpus(data);
 503
 504        return rcode;
 505}
 506
 507#define MAX_CONFIG_ROM_SIZE 256
 508
 509/*
 510 * Read the bus info block, perform a speed probe, and read all of the rest of
 511 * the config ROM.  We do all this with a cached bus generation.  If the bus
 512 * generation changes under us, read_config_rom will fail and get retried.
 513 * It's better to start all over in this case because the node from which we
 514 * are reading the ROM may have changed the ROM during the reset.
 515 * Returns either a result code or a negative error code.
 516 */
 517static int read_config_rom(struct fw_device *device, int generation)
 518{
 519        struct fw_card *card = device->card;
 520        const u32 *old_rom, *new_rom;
 521        u32 *rom, *stack;
 522        u32 sp, key;
 523        int i, end, length, ret;
 524
 525        rom = kmalloc(sizeof(*rom) * MAX_CONFIG_ROM_SIZE +
 526                      sizeof(*stack) * MAX_CONFIG_ROM_SIZE, GFP_KERNEL);
 527        if (rom == NULL)
 528                return -ENOMEM;
 529
 530        stack = &rom[MAX_CONFIG_ROM_SIZE];
 531        memset(rom, 0, sizeof(*rom) * MAX_CONFIG_ROM_SIZE);
 532
 533        device->max_speed = SCODE_100;
 534
 535        /* First read the bus info block. */
 536        for (i = 0; i < 5; i++) {
 537                ret = read_rom(device, generation, i, &rom[i]);
 538                if (ret != RCODE_COMPLETE)
 539                        goto out;
 540                /*
 541                 * As per IEEE1212 7.2, during initialization, devices can
 542                 * reply with a 0 for the first quadlet of the config
 543                 * rom to indicate that they are booting (for example,
 544                 * if the firmware is on the disk of a external
 545                 * harddisk).  In that case we just fail, and the
 546                 * retry mechanism will try again later.
 547                 */
 548                if (i == 0 && rom[i] == 0) {
 549                        ret = RCODE_BUSY;
 550                        goto out;
 551                }
 552        }
 553
 554        device->max_speed = device->node->max_speed;
 555
 556        /*
 557         * Determine the speed of
 558         *   - devices with link speed less than PHY speed,
 559         *   - devices with 1394b PHY (unless only connected to 1394a PHYs),
 560         *   - all devices if there are 1394b repeaters.
 561         * Note, we cannot use the bus info block's link_spd as starting point
 562         * because some buggy firmwares set it lower than necessary and because
 563         * 1394-1995 nodes do not have the field.
 564         */
 565        if ((rom[2] & 0x7) < device->max_speed ||
 566            device->max_speed == SCODE_BETA ||
 567            card->beta_repeaters_present) {
 568                u32 dummy;
 569
 570                /* for S1600 and S3200 */
 571                if (device->max_speed == SCODE_BETA)
 572                        device->max_speed = card->link_speed;
 573
 574                while (device->max_speed > SCODE_100) {
 575                        if (read_rom(device, generation, 0, &dummy) ==
 576                            RCODE_COMPLETE)
 577                                break;
 578                        device->max_speed--;
 579                }
 580        }
 581
 582        /*
 583         * Now parse the config rom.  The config rom is a recursive
 584         * directory structure so we parse it using a stack of
 585         * references to the blocks that make up the structure.  We
 586         * push a reference to the root directory on the stack to
 587         * start things off.
 588         */
 589        length = i;
 590        sp = 0;
 591        stack[sp++] = 0xc0000005;
 592        while (sp > 0) {
 593                /*
 594                 * Pop the next block reference of the stack.  The
 595                 * lower 24 bits is the offset into the config rom,
 596                 * the upper 8 bits are the type of the reference the
 597                 * block.
 598                 */
 599                key = stack[--sp];
 600                i = key & 0xffffff;
 601                if (WARN_ON(i >= MAX_CONFIG_ROM_SIZE)) {
 602                        ret = -ENXIO;
 603                        goto out;
 604                }
 605
 606                /* Read header quadlet for the block to get the length. */
 607                ret = read_rom(device, generation, i, &rom[i]);
 608                if (ret != RCODE_COMPLETE)
 609                        goto out;
 610                end = i + (rom[i] >> 16) + 1;
 611                if (end > MAX_CONFIG_ROM_SIZE) {
 612                        /*
 613                         * This block extends outside the config ROM which is
 614                         * a firmware bug.  Ignore this whole block, i.e.
 615                         * simply set a fake block length of 0.
 616                         */
 617                        fw_err(card, "skipped invalid ROM block %x at %llx\n",
 618                               rom[i],
 619                               i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 620                        rom[i] = 0;
 621                        end = i;
 622                }
 623                i++;
 624
 625                /*
 626                 * Now read in the block.  If this is a directory
 627                 * block, check the entries as we read them to see if
 628                 * it references another block, and push it in that case.
 629                 */
 630                for (; i < end; i++) {
 631                        ret = read_rom(device, generation, i, &rom[i]);
 632                        if (ret != RCODE_COMPLETE)
 633                                goto out;
 634
 635                        if ((key >> 30) != 3 || (rom[i] >> 30) < 2)
 636                                continue;
 637                        /*
 638                         * Offset points outside the ROM.  May be a firmware
 639                         * bug or an Extended ROM entry (IEEE 1212-2001 clause
 640                         * 7.7.18).  Simply overwrite this pointer here by a
 641                         * fake immediate entry so that later iterators over
 642                         * the ROM don't have to check offsets all the time.
 643                         */
 644                        if (i + (rom[i] & 0xffffff) >= MAX_CONFIG_ROM_SIZE) {
 645                                fw_err(card,
 646                                       "skipped unsupported ROM entry %x at %llx\n",
 647                                       rom[i],
 648                                       i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 649                                rom[i] = 0;
 650                                continue;
 651                        }
 652                        stack[sp++] = i + rom[i];
 653                }
 654                if (length < i)
 655                        length = i;
 656        }
 657
 658        old_rom = device->config_rom;
 659        new_rom = kmemdup(rom, length * 4, GFP_KERNEL);
 660        if (new_rom == NULL) {
 661                ret = -ENOMEM;
 662                goto out;
 663        }
 664
 665        down_write(&fw_device_rwsem);
 666        device->config_rom = new_rom;
 667        device->config_rom_length = length;
 668        up_write(&fw_device_rwsem);
 669
 670        kfree(old_rom);
 671        ret = RCODE_COMPLETE;
 672        device->max_rec = rom[2] >> 12 & 0xf;
 673        device->cmc     = rom[2] >> 30 & 1;
 674        device->irmc    = rom[2] >> 31 & 1;
 675 out:
 676        kfree(rom);
 677
 678        return ret;
 679}
 680
 681static void fw_unit_release(struct device *dev)
 682{
 683        struct fw_unit *unit = fw_unit(dev);
 684
 685        fw_device_put(fw_parent_device(unit));
 686        kfree(unit);
 687}
 688
 689static struct device_type fw_unit_type = {
 690        .uevent         = fw_unit_uevent,
 691        .release        = fw_unit_release,
 692};
 693
 694static bool is_fw_unit(struct device *dev)
 695{
 696        return dev->type == &fw_unit_type;
 697}
 698
 699static void create_units(struct fw_device *device)
 700{
 701        struct fw_csr_iterator ci;
 702        struct fw_unit *unit;
 703        int key, value, i;
 704
 705        i = 0;
 706        fw_csr_iterator_init(&ci, &device->config_rom[5]);
 707        while (fw_csr_iterator_next(&ci, &key, &value)) {
 708                if (key != (CSR_UNIT | CSR_DIRECTORY))
 709                        continue;
 710
 711                /*
 712                 * Get the address of the unit directory and try to
 713                 * match the drivers id_tables against it.
 714                 */
 715                unit = kzalloc(sizeof(*unit), GFP_KERNEL);
 716                if (unit == NULL)
 717                        continue;
 718
 719                unit->directory = ci.p + value - 1;
 720                unit->device.bus = &fw_bus_type;
 721                unit->device.type = &fw_unit_type;
 722                unit->device.parent = &device->device;
 723                dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++);
 724
 725                BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) <
 726                                ARRAY_SIZE(fw_unit_attributes) +
 727                                ARRAY_SIZE(config_rom_attributes));
 728                init_fw_attribute_group(&unit->device,
 729                                        fw_unit_attributes,
 730                                        &unit->attribute_group);
 731
 732                if (device_register(&unit->device) < 0)
 733                        goto skip_unit;
 734
 735                fw_device_get(device);
 736                continue;
 737
 738        skip_unit:
 739                kfree(unit);
 740        }
 741}
 742
 743static int shutdown_unit(struct device *device, void *data)
 744{
 745        device_unregister(device);
 746
 747        return 0;
 748}
 749
 750/*
 751 * fw_device_rwsem acts as dual purpose mutex:
 752 *   - serializes accesses to fw_device_idr,
 753 *   - serializes accesses to fw_device.config_rom/.config_rom_length and
 754 *     fw_unit.directory, unless those accesses happen at safe occasions
 755 */
 756DECLARE_RWSEM(fw_device_rwsem);
 757
 758DEFINE_IDR(fw_device_idr);
 759int fw_cdev_major;
 760
 761struct fw_device *fw_device_get_by_devt(dev_t devt)
 762{
 763        struct fw_device *device;
 764
 765        down_read(&fw_device_rwsem);
 766        device = idr_find(&fw_device_idr, MINOR(devt));
 767        if (device)
 768                fw_device_get(device);
 769        up_read(&fw_device_rwsem);
 770
 771        return device;
 772}
 773
 774struct workqueue_struct *fw_workqueue;
 775EXPORT_SYMBOL(fw_workqueue);
 776
 777static void fw_schedule_device_work(struct fw_device *device,
 778                                    unsigned long delay)
 779{
 780        queue_delayed_work(fw_workqueue, &device->work, delay);
 781}
 782
 783/*
 784 * These defines control the retry behavior for reading the config
 785 * rom.  It shouldn't be necessary to tweak these; if the device
 786 * doesn't respond to a config rom read within 10 seconds, it's not
 787 * going to respond at all.  As for the initial delay, a lot of
 788 * devices will be able to respond within half a second after bus
 789 * reset.  On the other hand, it's not really worth being more
 790 * aggressive than that, since it scales pretty well; if 10 devices
 791 * are plugged in, they're all getting read within one second.
 792 */
 793
 794#define MAX_RETRIES     10
 795#define RETRY_DELAY     (3 * HZ)
 796#define INITIAL_DELAY   (HZ / 2)
 797#define SHUTDOWN_DELAY  (2 * HZ)
 798
 799static void fw_device_shutdown(struct work_struct *work)
 800{
 801        struct fw_device *device =
 802                container_of(work, struct fw_device, work.work);
 803        int minor = MINOR(device->device.devt);
 804
 805        if (time_before64(get_jiffies_64(),
 806                          device->card->reset_jiffies + SHUTDOWN_DELAY)
 807            && !list_empty(&device->card->link)) {
 808                fw_schedule_device_work(device, SHUTDOWN_DELAY);
 809                return;
 810        }
 811
 812        if (atomic_cmpxchg(&device->state,
 813                           FW_DEVICE_GONE,
 814                           FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE)
 815                return;
 816
 817        fw_device_cdev_remove(device);
 818        device_for_each_child(&device->device, NULL, shutdown_unit);
 819        device_unregister(&device->device);
 820
 821        down_write(&fw_device_rwsem);
 822        idr_remove(&fw_device_idr, minor);
 823        up_write(&fw_device_rwsem);
 824
 825        fw_device_put(device);
 826}
 827
 828static void fw_device_release(struct device *dev)
 829{
 830        struct fw_device *device = fw_device(dev);
 831        struct fw_card *card = device->card;
 832        unsigned long flags;
 833
 834        /*
 835         * Take the card lock so we don't set this to NULL while a
 836         * FW_NODE_UPDATED callback is being handled or while the
 837         * bus manager work looks at this node.
 838         */
 839        spin_lock_irqsave(&card->lock, flags);
 840        device->node->data = NULL;
 841        spin_unlock_irqrestore(&card->lock, flags);
 842
 843        fw_node_put(device->node);
 844        kfree(device->config_rom);
 845        kfree(device);
 846        fw_card_put(card);
 847}
 848
 849static struct device_type fw_device_type = {
 850        .release = fw_device_release,
 851};
 852
 853static bool is_fw_device(struct device *dev)
 854{
 855        return dev->type == &fw_device_type;
 856}
 857
 858static int update_unit(struct device *dev, void *data)
 859{
 860        struct fw_unit *unit = fw_unit(dev);
 861        struct fw_driver *driver = (struct fw_driver *)dev->driver;
 862
 863        if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) {
 864                device_lock(dev);
 865                driver->update(unit);
 866                device_unlock(dev);
 867        }
 868
 869        return 0;
 870}
 871
 872static void fw_device_update(struct work_struct *work)
 873{
 874        struct fw_device *device =
 875                container_of(work, struct fw_device, work.work);
 876
 877        fw_device_cdev_update(device);
 878        device_for_each_child(&device->device, NULL, update_unit);
 879}
 880
 881/*
 882 * If a device was pending for deletion because its node went away but its
 883 * bus info block and root directory header matches that of a newly discovered
 884 * device, revive the existing fw_device.
 885 * The newly allocated fw_device becomes obsolete instead.
 886 */
 887static int lookup_existing_device(struct device *dev, void *data)
 888{
 889        struct fw_device *old = fw_device(dev);
 890        struct fw_device *new = data;
 891        struct fw_card *card = new->card;
 892        int match = 0;
 893
 894        if (!is_fw_device(dev))
 895                return 0;
 896
 897        down_read(&fw_device_rwsem); /* serialize config_rom access */
 898        spin_lock_irq(&card->lock);  /* serialize node access */
 899
 900        if (memcmp(old->config_rom, new->config_rom, 6 * 4) == 0 &&
 901            atomic_cmpxchg(&old->state,
 902                           FW_DEVICE_GONE,
 903                           FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
 904                struct fw_node *current_node = new->node;
 905                struct fw_node *obsolete_node = old->node;
 906
 907                new->node = obsolete_node;
 908                new->node->data = new;
 909                old->node = current_node;
 910                old->node->data = old;
 911
 912                old->max_speed = new->max_speed;
 913                old->node_id = current_node->node_id;
 914                smp_wmb();  /* update node_id before generation */
 915                old->generation = card->generation;
 916                old->config_rom_retries = 0;
 917                fw_notice(card, "rediscovered device %s\n", dev_name(dev));
 918
 919                PREPARE_DELAYED_WORK(&old->work, fw_device_update);
 920                fw_schedule_device_work(old, 0);
 921
 922                if (current_node == card->root_node)
 923                        fw_schedule_bm_work(card, 0);
 924
 925                match = 1;
 926        }
 927
 928        spin_unlock_irq(&card->lock);
 929        up_read(&fw_device_rwsem);
 930
 931        return match;
 932}
 933
 934enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, };
 935
 936static void set_broadcast_channel(struct fw_device *device, int generation)
 937{
 938        struct fw_card *card = device->card;
 939        __be32 data;
 940        int rcode;
 941
 942        if (!card->broadcast_channel_allocated)
 943                return;
 944
 945        /*
 946         * The Broadcast_Channel Valid bit is required by nodes which want to
 947         * transmit on this channel.  Such transmissions are practically
 948         * exclusive to IP over 1394 (RFC 2734).  IP capable nodes are required
 949         * to be IRM capable and have a max_rec of 8 or more.  We use this fact
 950         * to narrow down to which nodes we send Broadcast_Channel updates.
 951         */
 952        if (!device->irmc || device->max_rec < 8)
 953                return;
 954
 955        /*
 956         * Some 1394-1995 nodes crash if this 1394a-2000 register is written.
 957         * Perform a read test first.
 958         */
 959        if (device->bc_implemented == BC_UNKNOWN) {
 960                rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST,
 961                                device->node_id, generation, device->max_speed,
 962                                CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 963                                &data, 4);
 964                switch (rcode) {
 965                case RCODE_COMPLETE:
 966                        if (data & cpu_to_be32(1 << 31)) {
 967                                device->bc_implemented = BC_IMPLEMENTED;
 968                                break;
 969                        }
 970                        /* else fall through to case address error */
 971                case RCODE_ADDRESS_ERROR:
 972                        device->bc_implemented = BC_UNIMPLEMENTED;
 973                }
 974        }
 975
 976        if (device->bc_implemented == BC_IMPLEMENTED) {
 977                data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL |
 978                                   BROADCAST_CHANNEL_VALID);
 979                fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
 980                                device->node_id, generation, device->max_speed,
 981                                CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 982                                &data, 4);
 983        }
 984}
 985
 986int fw_device_set_broadcast_channel(struct device *dev, void *gen)
 987{
 988        if (is_fw_device(dev))
 989                set_broadcast_channel(fw_device(dev), (long)gen);
 990
 991        return 0;
 992}
 993
 994static void fw_device_init(struct work_struct *work)
 995{
 996        struct fw_device *device =
 997                container_of(work, struct fw_device, work.work);
 998        struct fw_card *card = device->card;
 999        struct device *revived_dev;
1000        int minor, ret;
1001
1002        /*
1003         * All failure paths here set node->data to NULL, so that we
1004         * don't try to do device_for_each_child() on a kfree()'d
1005         * device.
1006         */
1007
1008        ret = read_config_rom(device, device->generation);
1009        if (ret != RCODE_COMPLETE) {
1010                if (device->config_rom_retries < MAX_RETRIES &&
1011                    atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1012                        device->config_rom_retries++;
1013                        fw_schedule_device_work(device, RETRY_DELAY);
1014                } else {
1015                        if (device->node->link_on)
1016                                fw_notice(card, "giving up on node %x: reading config rom failed: %s\n",
1017                                          device->node_id,
1018                                          fw_rcode_string(ret));
1019                        if (device->node == card->root_node)
1020                                fw_schedule_bm_work(card, 0);
1021                        fw_device_release(&device->device);
1022                }
1023                return;
1024        }
1025
1026        revived_dev = device_find_child(card->device,
1027                                        device, lookup_existing_device);
1028        if (revived_dev) {
1029                put_device(revived_dev);
1030                fw_device_release(&device->device);
1031
1032                return;
1033        }
1034
1035        device_initialize(&device->device);
1036
1037        fw_device_get(device);
1038        down_write(&fw_device_rwsem);
1039        minor = idr_alloc(&fw_device_idr, device, 0, 1 << MINORBITS,
1040                        GFP_KERNEL);
1041        up_write(&fw_device_rwsem);
1042
1043        if (minor < 0)
1044                goto error;
1045
1046        device->device.bus = &fw_bus_type;
1047        device->device.type = &fw_device_type;
1048        device->device.parent = card->device;
1049        device->device.devt = MKDEV(fw_cdev_major, minor);
1050        dev_set_name(&device->device, "fw%d", minor);
1051
1052        BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) <
1053                        ARRAY_SIZE(fw_device_attributes) +
1054                        ARRAY_SIZE(config_rom_attributes));
1055        init_fw_attribute_group(&device->device,
1056                                fw_device_attributes,
1057                                &device->attribute_group);
1058
1059        if (device_add(&device->device)) {
1060                fw_err(card, "failed to add device\n");
1061                goto error_with_cdev;
1062        }
1063
1064        create_units(device);
1065
1066        /*
1067         * Transition the device to running state.  If it got pulled
1068         * out from under us while we did the intialization work, we
1069         * have to shut down the device again here.  Normally, though,
1070         * fw_node_event will be responsible for shutting it down when
1071         * necessary.  We have to use the atomic cmpxchg here to avoid
1072         * racing with the FW_NODE_DESTROYED case in
1073         * fw_node_event().
1074         */
1075        if (atomic_cmpxchg(&device->state,
1076                           FW_DEVICE_INITIALIZING,
1077                           FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
1078                PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1079                fw_schedule_device_work(device, SHUTDOWN_DELAY);
1080        } else {
1081                fw_notice(card, "created device %s: GUID %08x%08x, S%d00\n",
1082                          dev_name(&device->device),
1083                          device->config_rom[3], device->config_rom[4],
1084                          1 << device->max_speed);
1085                device->config_rom_retries = 0;
1086
1087                set_broadcast_channel(device, device->generation);
1088
1089                add_device_randomness(&device->config_rom[3], 8);
1090        }
1091
1092        /*
1093         * Reschedule the IRM work if we just finished reading the
1094         * root node config rom.  If this races with a bus reset we
1095         * just end up running the IRM work a couple of extra times -
1096         * pretty harmless.
1097         */
1098        if (device->node == card->root_node)
1099                fw_schedule_bm_work(card, 0);
1100
1101        return;
1102
1103 error_with_cdev:
1104        down_write(&fw_device_rwsem);
1105        idr_remove(&fw_device_idr, minor);
1106        up_write(&fw_device_rwsem);
1107 error:
1108        fw_device_put(device);          /* fw_device_idr's reference */
1109
1110        put_device(&device->device);    /* our reference */
1111}
1112
1113/* Reread and compare bus info block and header of root directory */
1114static int reread_config_rom(struct fw_device *device, int generation,
1115                             bool *changed)
1116{
1117        u32 q;
1118        int i, rcode;
1119
1120        for (i = 0; i < 6; i++) {
1121                rcode = read_rom(device, generation, i, &q);
1122                if (rcode != RCODE_COMPLETE)
1123                        return rcode;
1124
1125                if (i == 0 && q == 0)
1126                        /* inaccessible (see read_config_rom); retry later */
1127                        return RCODE_BUSY;
1128
1129                if (q != device->config_rom[i]) {
1130                        *changed = true;
1131                        return RCODE_COMPLETE;
1132                }
1133        }
1134
1135        *changed = false;
1136        return RCODE_COMPLETE;
1137}
1138
1139static void fw_device_refresh(struct work_struct *work)
1140{
1141        struct fw_device *device =
1142                container_of(work, struct fw_device, work.work);
1143        struct fw_card *card = device->card;
1144        int ret, node_id = device->node_id;
1145        bool changed;
1146
1147        ret = reread_config_rom(device, device->generation, &changed);
1148        if (ret != RCODE_COMPLETE)
1149                goto failed_config_rom;
1150
1151        if (!changed) {
1152                if (atomic_cmpxchg(&device->state,
1153                                   FW_DEVICE_INITIALIZING,
1154                                   FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1155                        goto gone;
1156
1157                fw_device_update(work);
1158                device->config_rom_retries = 0;
1159                goto out;
1160        }
1161
1162        /*
1163         * Something changed.  We keep things simple and don't investigate
1164         * further.  We just destroy all previous units and create new ones.
1165         */
1166        device_for_each_child(&device->device, NULL, shutdown_unit);
1167
1168        ret = read_config_rom(device, device->generation);
1169        if (ret != RCODE_COMPLETE)
1170                goto failed_config_rom;
1171
1172        fw_device_cdev_update(device);
1173        create_units(device);
1174
1175        /* Userspace may want to re-read attributes. */
1176        kobject_uevent(&device->device.kobj, KOBJ_CHANGE);
1177
1178        if (atomic_cmpxchg(&device->state,
1179                           FW_DEVICE_INITIALIZING,
1180                           FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1181                goto gone;
1182
1183        fw_notice(card, "refreshed device %s\n", dev_name(&device->device));
1184        device->config_rom_retries = 0;
1185        goto out;
1186
1187 failed_config_rom:
1188        if (device->config_rom_retries < MAX_RETRIES &&
1189            atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1190                device->config_rom_retries++;
1191                fw_schedule_device_work(device, RETRY_DELAY);
1192                return;
1193        }
1194
1195        fw_notice(card, "giving up on refresh of device %s: %s\n",
1196                  dev_name(&device->device), fw_rcode_string(ret));
1197 gone:
1198        atomic_set(&device->state, FW_DEVICE_GONE);
1199        PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1200        fw_schedule_device_work(device, SHUTDOWN_DELAY);
1201 out:
1202        if (node_id == card->root_node->node_id)
1203                fw_schedule_bm_work(card, 0);
1204}
1205
1206void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
1207{
1208        struct fw_device *device;
1209
1210        switch (event) {
1211        case FW_NODE_CREATED:
1212                /*
1213                 * Attempt to scan the node, regardless whether its self ID has
1214                 * the L (link active) flag set or not.  Some broken devices
1215                 * send L=0 but have an up-and-running link; others send L=1
1216                 * without actually having a link.
1217                 */
1218 create:
1219                device = kzalloc(sizeof(*device), GFP_ATOMIC);
1220                if (device == NULL)
1221                        break;
1222
1223                /*
1224                 * Do minimal intialization of the device here, the
1225                 * rest will happen in fw_device_init().
1226                 *
1227                 * Attention:  A lot of things, even fw_device_get(),
1228                 * cannot be done before fw_device_init() finished!
1229                 * You can basically just check device->state and
1230                 * schedule work until then, but only while holding
1231                 * card->lock.
1232                 */
1233                atomic_set(&device->state, FW_DEVICE_INITIALIZING);
1234                device->card = fw_card_get(card);
1235                device->node = fw_node_get(node);
1236                device->node_id = node->node_id;
1237                device->generation = card->generation;
1238                device->is_local = node == card->local_node;
1239                mutex_init(&device->client_list_mutex);
1240                INIT_LIST_HEAD(&device->client_list);
1241
1242                /*
1243                 * Set the node data to point back to this device so
1244                 * FW_NODE_UPDATED callbacks can update the node_id
1245                 * and generation for the device.
1246                 */
1247                node->data = device;
1248
1249                /*
1250                 * Many devices are slow to respond after bus resets,
1251                 * especially if they are bus powered and go through
1252                 * power-up after getting plugged in.  We schedule the
1253                 * first config rom scan half a second after bus reset.
1254                 */
1255                INIT_DELAYED_WORK(&device->work, fw_device_init);
1256                fw_schedule_device_work(device, INITIAL_DELAY);
1257                break;
1258
1259        case FW_NODE_INITIATED_RESET:
1260        case FW_NODE_LINK_ON:
1261                device = node->data;
1262                if (device == NULL)
1263                        goto create;
1264
1265                device->node_id = node->node_id;
1266                smp_wmb();  /* update node_id before generation */
1267                device->generation = card->generation;
1268                if (atomic_cmpxchg(&device->state,
1269                            FW_DEVICE_RUNNING,
1270                            FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) {
1271                        PREPARE_DELAYED_WORK(&device->work, fw_device_refresh);
1272                        fw_schedule_device_work(device,
1273                                device->is_local ? 0 : INITIAL_DELAY);
1274                }
1275                break;
1276
1277        case FW_NODE_UPDATED:
1278                device = node->data;
1279                if (device == NULL)
1280                        break;
1281
1282                device->node_id = node->node_id;
1283                smp_wmb();  /* update node_id before generation */
1284                device->generation = card->generation;
1285                if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
1286                        PREPARE_DELAYED_WORK(&device->work, fw_device_update);
1287                        fw_schedule_device_work(device, 0);
1288                }
1289                break;
1290
1291        case FW_NODE_DESTROYED:
1292        case FW_NODE_LINK_OFF:
1293                if (!node->data)
1294                        break;
1295
1296                /*
1297                 * Destroy the device associated with the node.  There
1298                 * are two cases here: either the device is fully
1299                 * initialized (FW_DEVICE_RUNNING) or we're in the
1300                 * process of reading its config rom
1301                 * (FW_DEVICE_INITIALIZING).  If it is fully
1302                 * initialized we can reuse device->work to schedule a
1303                 * full fw_device_shutdown().  If not, there's work
1304                 * scheduled to read it's config rom, and we just put
1305                 * the device in shutdown state to have that code fail
1306                 * to create the device.
1307                 */
1308                device = node->data;
1309                if (atomic_xchg(&device->state,
1310                                FW_DEVICE_GONE) == FW_DEVICE_RUNNING) {
1311                        PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1312                        fw_schedule_device_work(device,
1313                                list_empty(&card->link) ? 0 : SHUTDOWN_DELAY);
1314                }
1315                break;
1316        }
1317}
1318
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