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