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 * An overlong string is silently truncated such that it and the
 119 * zero byte fit into @size.
 120 *
 121 * Returns strlen(buf) or a negative error code.
 122 */
 123int fw_csr_string(const u32 *directory, int key, char *buf, size_t size)
 124{
 125        const u32 *leaf = search_leaf(directory, key);
 126        if (!leaf)
 127                return -ENOENT;
 128
 129        return textual_leaf_to_string(leaf, buf, size);
 130}
 131EXPORT_SYMBOL(fw_csr_string);
 132
 133static void get_ids(const u32 *directory, int *id)
 134{
 135        struct fw_csr_iterator ci;
 136        int key, value;
 137
 138        fw_csr_iterator_init(&ci, directory);
 139        while (fw_csr_iterator_next(&ci, &key, &value)) {
 140                switch (key) {
 141                case CSR_VENDOR:        id[0] = value; break;
 142                case CSR_MODEL:         id[1] = value; break;
 143                case CSR_SPECIFIER_ID:  id[2] = value; break;
 144                case CSR_VERSION:       id[3] = value; break;
 145                }
 146        }
 147}
 148
 149static void get_modalias_ids(struct fw_unit *unit, int *id)
 150{
 151        get_ids(&fw_parent_device(unit)->config_rom[5], id);
 152        get_ids(unit->directory, id);
 153}
 154
 155static bool match_ids(const struct ieee1394_device_id *id_table, int *id)
 156{
 157        int match = 0;
 158
 159        if (id[0] == id_table->vendor_id)
 160                match |= IEEE1394_MATCH_VENDOR_ID;
 161        if (id[1] == id_table->model_id)
 162                match |= IEEE1394_MATCH_MODEL_ID;
 163        if (id[2] == id_table->specifier_id)
 164                match |= IEEE1394_MATCH_SPECIFIER_ID;
 165        if (id[3] == id_table->version)
 166                match |= IEEE1394_MATCH_VERSION;
 167
 168        return (match & id_table->match_flags) == id_table->match_flags;
 169}
 170
 171static const struct ieee1394_device_id *unit_match(struct device *dev,
 172                                                   struct device_driver *drv)
 173{
 174        const struct ieee1394_device_id *id_table =
 175                        container_of(drv, struct fw_driver, driver)->id_table;
 176        int id[] = {0, 0, 0, 0};
 177
 178        get_modalias_ids(fw_unit(dev), id);
 179
 180        for (; id_table->match_flags != 0; id_table++)
 181                if (match_ids(id_table, id))
 182                        return id_table;
 183
 184        return NULL;
 185}
 186
 187static bool is_fw_unit(struct device *dev);
 188
 189static int fw_unit_match(struct device *dev, struct device_driver *drv)
 190{
 191        /* We only allow binding to fw_units. */
 192        return is_fw_unit(dev) && unit_match(dev, drv) != NULL;
 193}
 194
 195static int fw_unit_probe(struct device *dev)
 196{
 197        struct fw_driver *driver =
 198                        container_of(dev->driver, struct fw_driver, driver);
 199
 200        return driver->probe(fw_unit(dev), unit_match(dev, dev->driver));
 201}
 202
 203static int fw_unit_remove(struct device *dev)
 204{
 205        struct fw_driver *driver =
 206                        container_of(dev->driver, struct fw_driver, driver);
 207
 208        return driver->remove(fw_unit(dev)), 0;
 209}
 210
 211static int get_modalias(struct fw_unit *unit, char *buffer, size_t buffer_size)
 212{
 213        int id[] = {0, 0, 0, 0};
 214
 215        get_modalias_ids(unit, id);
 216
 217        return snprintf(buffer, buffer_size,
 218                        "ieee1394:ven%08Xmo%08Xsp%08Xver%08X",
 219                        id[0], id[1], id[2], id[3]);
 220}
 221
 222static int fw_unit_uevent(struct device *dev, struct kobj_uevent_env *env)
 223{
 224        struct fw_unit *unit = fw_unit(dev);
 225        char modalias[64];
 226
 227        get_modalias(unit, modalias, sizeof(modalias));
 228
 229        if (add_uevent_var(env, "MODALIAS=%s", modalias))
 230                return -ENOMEM;
 231
 232        return 0;
 233}
 234
 235struct bus_type fw_bus_type = {
 236        .name = "firewire",
 237        .match = fw_unit_match,
 238        .probe = fw_unit_probe,
 239        .remove = fw_unit_remove,
 240};
 241EXPORT_SYMBOL(fw_bus_type);
 242
 243int fw_device_enable_phys_dma(struct fw_device *device)
 244{
 245        int generation = device->generation;
 246
 247        /* device->node_id, accessed below, must not be older than generation */
 248        smp_rmb();
 249
 250        return device->card->driver->enable_phys_dma(device->card,
 251                                                     device->node_id,
 252                                                     generation);
 253}
 254EXPORT_SYMBOL(fw_device_enable_phys_dma);
 255
 256struct config_rom_attribute {
 257        struct device_attribute attr;
 258        u32 key;
 259};
 260
 261static ssize_t show_immediate(struct device *dev,
 262                              struct device_attribute *dattr, char *buf)
 263{
 264        struct config_rom_attribute *attr =
 265                container_of(dattr, struct config_rom_attribute, attr);
 266        struct fw_csr_iterator ci;
 267        const u32 *dir;
 268        int key, value, ret = -ENOENT;
 269
 270        down_read(&fw_device_rwsem);
 271
 272        if (is_fw_unit(dev))
 273                dir = fw_unit(dev)->directory;
 274        else
 275                dir = fw_device(dev)->config_rom + 5;
 276
 277        fw_csr_iterator_init(&ci, dir);
 278        while (fw_csr_iterator_next(&ci, &key, &value))
 279                if (attr->key == key) {
 280                        ret = snprintf(buf, buf ? PAGE_SIZE : 0,
 281                                       "0x%06x\n", value);
 282                        break;
 283                }
 284
 285        up_read(&fw_device_rwsem);
 286
 287        return ret;
 288}
 289
 290#define IMMEDIATE_ATTR(name, key)                               \
 291        { __ATTR(name, S_IRUGO, show_immediate, NULL), key }
 292
 293static ssize_t show_text_leaf(struct device *dev,
 294                              struct device_attribute *dattr, char *buf)
 295{
 296        struct config_rom_attribute *attr =
 297                container_of(dattr, struct config_rom_attribute, attr);
 298        const u32 *dir;
 299        size_t bufsize;
 300        char dummy_buf[2];
 301        int ret;
 302
 303        down_read(&fw_device_rwsem);
 304
 305        if (is_fw_unit(dev))
 306                dir = fw_unit(dev)->directory;
 307        else
 308                dir = fw_device(dev)->config_rom + 5;
 309
 310        if (buf) {
 311                bufsize = PAGE_SIZE - 1;
 312        } else {
 313                buf = dummy_buf;
 314                bufsize = 1;
 315        }
 316
 317        ret = fw_csr_string(dir, attr->key, buf, bufsize);
 318
 319        if (ret >= 0) {
 320                /* Strip trailing whitespace and add newline. */
 321                while (ret > 0 && isspace(buf[ret - 1]))
 322                        ret--;
 323                strcpy(buf + ret, "\n");
 324                ret++;
 325        }
 326
 327        up_read(&fw_device_rwsem);
 328
 329        return ret;
 330}
 331
 332#define TEXT_LEAF_ATTR(name, key)                               \
 333        { __ATTR(name, S_IRUGO, show_text_leaf, NULL), key }
 334
 335static struct config_rom_attribute config_rom_attributes[] = {
 336        IMMEDIATE_ATTR(vendor, CSR_VENDOR),
 337        IMMEDIATE_ATTR(hardware_version, CSR_HARDWARE_VERSION),
 338        IMMEDIATE_ATTR(specifier_id, CSR_SPECIFIER_ID),
 339        IMMEDIATE_ATTR(version, CSR_VERSION),
 340        IMMEDIATE_ATTR(model, CSR_MODEL),
 341        TEXT_LEAF_ATTR(vendor_name, CSR_VENDOR),
 342        TEXT_LEAF_ATTR(model_name, CSR_MODEL),
 343        TEXT_LEAF_ATTR(hardware_version_name, CSR_HARDWARE_VERSION),
 344};
 345
 346static void init_fw_attribute_group(struct device *dev,
 347                                    struct device_attribute *attrs,
 348                                    struct fw_attribute_group *group)
 349{
 350        struct device_attribute *attr;
 351        int i, j;
 352
 353        for (j = 0; attrs[j].attr.name != NULL; j++)
 354                group->attrs[j] = &attrs[j].attr;
 355
 356        for (i = 0; i < ARRAY_SIZE(config_rom_attributes); i++) {
 357                attr = &config_rom_attributes[i].attr;
 358                if (attr->show(dev, attr, NULL) < 0)
 359                        continue;
 360                group->attrs[j++] = &attr->attr;
 361        }
 362
 363        group->attrs[j] = NULL;
 364        group->groups[0] = &group->group;
 365        group->groups[1] = NULL;
 366        group->group.attrs = group->attrs;
 367        dev->groups = (const struct attribute_group **) group->groups;
 368}
 369
 370static ssize_t modalias_show(struct device *dev,
 371                             struct device_attribute *attr, char *buf)
 372{
 373        struct fw_unit *unit = fw_unit(dev);
 374        int length;
 375
 376        length = get_modalias(unit, buf, PAGE_SIZE);
 377        strcpy(buf + length, "\n");
 378
 379        return length + 1;
 380}
 381
 382static ssize_t rom_index_show(struct device *dev,
 383                              struct device_attribute *attr, char *buf)
 384{
 385        struct fw_device *device = fw_device(dev->parent);
 386        struct fw_unit *unit = fw_unit(dev);
 387
 388        return snprintf(buf, PAGE_SIZE, "%d\n",
 389                        (int)(unit->directory - device->config_rom));
 390}
 391
 392static struct device_attribute fw_unit_attributes[] = {
 393        __ATTR_RO(modalias),
 394        __ATTR_RO(rom_index),
 395        __ATTR_NULL,
 396};
 397
 398static ssize_t config_rom_show(struct device *dev,
 399                               struct device_attribute *attr, char *buf)
 400{
 401        struct fw_device *device = fw_device(dev);
 402        size_t length;
 403
 404        down_read(&fw_device_rwsem);
 405        length = device->config_rom_length * 4;
 406        memcpy(buf, device->config_rom, length);
 407        up_read(&fw_device_rwsem);
 408
 409        return length;
 410}
 411
 412static ssize_t guid_show(struct device *dev,
 413                         struct device_attribute *attr, char *buf)
 414{
 415        struct fw_device *device = fw_device(dev);
 416        int ret;
 417
 418        down_read(&fw_device_rwsem);
 419        ret = snprintf(buf, PAGE_SIZE, "0x%08x%08x\n",
 420                       device->config_rom[3], device->config_rom[4]);
 421        up_read(&fw_device_rwsem);
 422
 423        return ret;
 424}
 425
 426static ssize_t is_local_show(struct device *dev,
 427                             struct device_attribute *attr, char *buf)
 428{
 429        struct fw_device *device = fw_device(dev);
 430
 431        return sprintf(buf, "%u\n", device->is_local);
 432}
 433
 434static int units_sprintf(char *buf, const u32 *directory)
 435{
 436        struct fw_csr_iterator ci;
 437        int key, value;
 438        int specifier_id = 0;
 439        int version = 0;
 440
 441        fw_csr_iterator_init(&ci, directory);
 442        while (fw_csr_iterator_next(&ci, &key, &value)) {
 443                switch (key) {
 444                case CSR_SPECIFIER_ID:
 445                        specifier_id = value;
 446                        break;
 447                case CSR_VERSION:
 448                        version = value;
 449                        break;
 450                }
 451        }
 452
 453        return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version);
 454}
 455
 456static ssize_t units_show(struct device *dev,
 457                          struct device_attribute *attr, char *buf)
 458{
 459        struct fw_device *device = fw_device(dev);
 460        struct fw_csr_iterator ci;
 461        int key, value, i = 0;
 462
 463        down_read(&fw_device_rwsem);
 464        fw_csr_iterator_init(&ci, &device->config_rom[5]);
 465        while (fw_csr_iterator_next(&ci, &key, &value)) {
 466                if (key != (CSR_UNIT | CSR_DIRECTORY))
 467                        continue;
 468                i += units_sprintf(&buf[i], ci.p + value - 1);
 469                if (i >= PAGE_SIZE - (8 + 1 + 8 + 1))
 470                        break;
 471        }
 472        up_read(&fw_device_rwsem);
 473
 474        if (i)
 475                buf[i - 1] = '\n';
 476
 477        return i;
 478}
 479
 480static struct device_attribute fw_device_attributes[] = {
 481        __ATTR_RO(config_rom),
 482        __ATTR_RO(guid),
 483        __ATTR_RO(is_local),
 484        __ATTR_RO(units),
 485        __ATTR_NULL,
 486};
 487
 488static int read_rom(struct fw_device *device,
 489                    int generation, int index, u32 *data)
 490{
 491        u64 offset = (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4;
 492        int i, rcode;
 493
 494        /* device->node_id, accessed below, must not be older than generation */
 495        smp_rmb();
 496
 497        for (i = 10; i < 100; i += 10) {
 498                rcode = fw_run_transaction(device->card,
 499                                TCODE_READ_QUADLET_REQUEST, device->node_id,
 500                                generation, device->max_speed, offset, data, 4);
 501                if (rcode != RCODE_BUSY)
 502                        break;
 503                msleep(i);
 504        }
 505        be32_to_cpus(data);
 506
 507        return rcode;
 508}
 509
 510#define MAX_CONFIG_ROM_SIZE 256
 511
 512/*
 513 * Read the bus info block, perform a speed probe, and read all of the rest of
 514 * the config ROM.  We do all this with a cached bus generation.  If the bus
 515 * generation changes under us, read_config_rom will fail and get retried.
 516 * It's better to start all over in this case because the node from which we
 517 * are reading the ROM may have changed the ROM during the reset.
 518 * Returns either a result code or a negative error code.
 519 */
 520static int read_config_rom(struct fw_device *device, int generation)
 521{
 522        struct fw_card *card = device->card;
 523        const u32 *old_rom, *new_rom;
 524        u32 *rom, *stack;
 525        u32 sp, key;
 526        int i, end, length, ret;
 527
 528        rom = kmalloc(sizeof(*rom) * MAX_CONFIG_ROM_SIZE +
 529                      sizeof(*stack) * MAX_CONFIG_ROM_SIZE, GFP_KERNEL);
 530        if (rom == NULL)
 531                return -ENOMEM;
 532
 533        stack = &rom[MAX_CONFIG_ROM_SIZE];
 534        memset(rom, 0, sizeof(*rom) * MAX_CONFIG_ROM_SIZE);
 535
 536        device->max_speed = SCODE_100;
 537
 538        /* First read the bus info block. */
 539        for (i = 0; i < 5; i++) {
 540                ret = read_rom(device, generation, i, &rom[i]);
 541                if (ret != RCODE_COMPLETE)
 542                        goto out;
 543                /*
 544                 * As per IEEE1212 7.2, during initialization, devices can
 545                 * reply with a 0 for the first quadlet of the config
 546                 * rom to indicate that they are booting (for example,
 547                 * if the firmware is on the disk of a external
 548                 * harddisk).  In that case we just fail, and the
 549                 * retry mechanism will try again later.
 550                 */
 551                if (i == 0 && rom[i] == 0) {
 552                        ret = RCODE_BUSY;
 553                        goto out;
 554                }
 555        }
 556
 557        device->max_speed = device->node->max_speed;
 558
 559        /*
 560         * Determine the speed of
 561         *   - devices with link speed less than PHY speed,
 562         *   - devices with 1394b PHY (unless only connected to 1394a PHYs),
 563         *   - all devices if there are 1394b repeaters.
 564         * Note, we cannot use the bus info block's link_spd as starting point
 565         * because some buggy firmwares set it lower than necessary and because
 566         * 1394-1995 nodes do not have the field.
 567         */
 568        if ((rom[2] & 0x7) < device->max_speed ||
 569            device->max_speed == SCODE_BETA ||
 570            card->beta_repeaters_present) {
 571                u32 dummy;
 572
 573                /* for S1600 and S3200 */
 574                if (device->max_speed == SCODE_BETA)
 575                        device->max_speed = card->link_speed;
 576
 577                while (device->max_speed > SCODE_100) {
 578                        if (read_rom(device, generation, 0, &dummy) ==
 579                            RCODE_COMPLETE)
 580                                break;
 581                        device->max_speed--;
 582                }
 583        }
 584
 585        /*
 586         * Now parse the config rom.  The config rom is a recursive
 587         * directory structure so we parse it using a stack of
 588         * references to the blocks that make up the structure.  We
 589         * push a reference to the root directory on the stack to
 590         * start things off.
 591         */
 592        length = i;
 593        sp = 0;
 594        stack[sp++] = 0xc0000005;
 595        while (sp > 0) {
 596                /*
 597                 * Pop the next block reference of the stack.  The
 598                 * lower 24 bits is the offset into the config rom,
 599                 * the upper 8 bits are the type of the reference the
 600                 * block.
 601                 */
 602                key = stack[--sp];
 603                i = key & 0xffffff;
 604                if (WARN_ON(i >= MAX_CONFIG_ROM_SIZE)) {
 605                        ret = -ENXIO;
 606                        goto out;
 607                }
 608
 609                /* Read header quadlet for the block to get the length. */
 610                ret = read_rom(device, generation, i, &rom[i]);
 611                if (ret != RCODE_COMPLETE)
 612                        goto out;
 613                end = i + (rom[i] >> 16) + 1;
 614                if (end > MAX_CONFIG_ROM_SIZE) {
 615                        /*
 616                         * This block extends outside the config ROM which is
 617                         * a firmware bug.  Ignore this whole block, i.e.
 618                         * simply set a fake block length of 0.
 619                         */
 620                        fw_err(card, "skipped invalid ROM block %x at %llx\n",
 621                               rom[i],
 622                               i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 623                        rom[i] = 0;
 624                        end = i;
 625                }
 626                i++;
 627
 628                /*
 629                 * Now read in the block.  If this is a directory
 630                 * block, check the entries as we read them to see if
 631                 * it references another block, and push it in that case.
 632                 */
 633                for (; i < end; i++) {
 634                        ret = read_rom(device, generation, i, &rom[i]);
 635                        if (ret != RCODE_COMPLETE)
 636                                goto out;
 637
 638                        if ((key >> 30) != 3 || (rom[i] >> 30) < 2)
 639                                continue;
 640                        /*
 641                         * Offset points outside the ROM.  May be a firmware
 642                         * bug or an Extended ROM entry (IEEE 1212-2001 clause
 643                         * 7.7.18).  Simply overwrite this pointer here by a
 644                         * fake immediate entry so that later iterators over
 645                         * the ROM don't have to check offsets all the time.
 646                         */
 647                        if (i + (rom[i] & 0xffffff) >= MAX_CONFIG_ROM_SIZE) {
 648                                fw_err(card,
 649                                       "skipped unsupported ROM entry %x at %llx\n",
 650                                       rom[i],
 651                                       i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 652                                rom[i] = 0;
 653                                continue;
 654                        }
 655                        stack[sp++] = i + rom[i];
 656                }
 657                if (length < i)
 658                        length = i;
 659        }
 660
 661        old_rom = device->config_rom;
 662        new_rom = kmemdup(rom, length * 4, GFP_KERNEL);
 663        if (new_rom == NULL) {
 664                ret = -ENOMEM;
 665                goto out;
 666        }
 667
 668        down_write(&fw_device_rwsem);
 669        device->config_rom = new_rom;
 670        device->config_rom_length = length;
 671        up_write(&fw_device_rwsem);
 672
 673        kfree(old_rom);
 674        ret = RCODE_COMPLETE;
 675        device->max_rec = rom[2] >> 12 & 0xf;
 676        device->cmc     = rom[2] >> 30 & 1;
 677        device->irmc    = rom[2] >> 31 & 1;
 678 out:
 679        kfree(rom);
 680
 681        return ret;
 682}
 683
 684static void fw_unit_release(struct device *dev)
 685{
 686        struct fw_unit *unit = fw_unit(dev);
 687
 688        fw_device_put(fw_parent_device(unit));
 689        kfree(unit);
 690}
 691
 692static struct device_type fw_unit_type = {
 693        .uevent         = fw_unit_uevent,
 694        .release        = fw_unit_release,
 695};
 696
 697static bool is_fw_unit(struct device *dev)
 698{
 699        return dev->type == &fw_unit_type;
 700}
 701
 702static void create_units(struct fw_device *device)
 703{
 704        struct fw_csr_iterator ci;
 705        struct fw_unit *unit;
 706        int key, value, i;
 707
 708        i = 0;
 709        fw_csr_iterator_init(&ci, &device->config_rom[5]);
 710        while (fw_csr_iterator_next(&ci, &key, &value)) {
 711                if (key != (CSR_UNIT | CSR_DIRECTORY))
 712                        continue;
 713
 714                /*
 715                 * Get the address of the unit directory and try to
 716                 * match the drivers id_tables against it.
 717                 */
 718                unit = kzalloc(sizeof(*unit), GFP_KERNEL);
 719                if (unit == NULL)
 720                        continue;
 721
 722                unit->directory = ci.p + value - 1;
 723                unit->device.bus = &fw_bus_type;
 724                unit->device.type = &fw_unit_type;
 725                unit->device.parent = &device->device;
 726                dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++);
 727
 728                BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) <
 729                                ARRAY_SIZE(fw_unit_attributes) +
 730                                ARRAY_SIZE(config_rom_attributes));
 731                init_fw_attribute_group(&unit->device,
 732                                        fw_unit_attributes,
 733                                        &unit->attribute_group);
 734
 735                if (device_register(&unit->device) < 0)
 736                        goto skip_unit;
 737
 738                fw_device_get(device);
 739                continue;
 740
 741        skip_unit:
 742                kfree(unit);
 743        }
 744}
 745
 746static int shutdown_unit(struct device *device, void *data)
 747{
 748        device_unregister(device);
 749
 750        return 0;
 751}
 752
 753/*
 754 * fw_device_rwsem acts as dual purpose mutex:
 755 *   - serializes accesses to fw_device_idr,
 756 *   - serializes accesses to fw_device.config_rom/.config_rom_length and
 757 *     fw_unit.directory, unless those accesses happen at safe occasions
 758 */
 759DECLARE_RWSEM(fw_device_rwsem);
 760
 761DEFINE_IDR(fw_device_idr);
 762int fw_cdev_major;
 763
 764struct fw_device *fw_device_get_by_devt(dev_t devt)
 765{
 766        struct fw_device *device;
 767
 768        down_read(&fw_device_rwsem);
 769        device = idr_find(&fw_device_idr, MINOR(devt));
 770        if (device)
 771                fw_device_get(device);
 772        up_read(&fw_device_rwsem);
 773
 774        return device;
 775}
 776
 777struct workqueue_struct *fw_workqueue;
 778EXPORT_SYMBOL(fw_workqueue);
 779
 780static void fw_schedule_device_work(struct fw_device *device,
 781                                    unsigned long delay)
 782{
 783        queue_delayed_work(fw_workqueue, &device->work, delay);
 784}
 785
 786/*
 787 * These defines control the retry behavior for reading the config
 788 * rom.  It shouldn't be necessary to tweak these; if the device
 789 * doesn't respond to a config rom read within 10 seconds, it's not
 790 * going to respond at all.  As for the initial delay, a lot of
 791 * devices will be able to respond within half a second after bus
 792 * reset.  On the other hand, it's not really worth being more
 793 * aggressive than that, since it scales pretty well; if 10 devices
 794 * are plugged in, they're all getting read within one second.
 795 */
 796
 797#define MAX_RETRIES     10
 798#define RETRY_DELAY     (3 * HZ)
 799#define INITIAL_DELAY   (HZ / 2)
 800#define SHUTDOWN_DELAY  (2 * HZ)
 801
 802static void fw_device_shutdown(struct work_struct *work)
 803{
 804        struct fw_device *device =
 805                container_of(work, struct fw_device, work.work);
 806        int minor = MINOR(device->device.devt);
 807
 808        if (time_before64(get_jiffies_64(),
 809                          device->card->reset_jiffies + SHUTDOWN_DELAY)
 810            && !list_empty(&device->card->link)) {
 811                fw_schedule_device_work(device, SHUTDOWN_DELAY);
 812                return;
 813        }
 814
 815        if (atomic_cmpxchg(&device->state,
 816                           FW_DEVICE_GONE,
 817                           FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE)
 818                return;
 819
 820        fw_device_cdev_remove(device);
 821        device_for_each_child(&device->device, NULL, shutdown_unit);
 822        device_unregister(&device->device);
 823
 824        down_write(&fw_device_rwsem);
 825        idr_remove(&fw_device_idr, minor);
 826        up_write(&fw_device_rwsem);
 827
 828        fw_device_put(device);
 829}
 830
 831static void fw_device_release(struct device *dev)
 832{
 833        struct fw_device *device = fw_device(dev);
 834        struct fw_card *card = device->card;
 835        unsigned long flags;
 836
 837        /*
 838         * Take the card lock so we don't set this to NULL while a
 839         * FW_NODE_UPDATED callback is being handled or while the
 840         * bus manager work looks at this node.
 841         */
 842        spin_lock_irqsave(&card->lock, flags);
 843        device->node->data = NULL;
 844        spin_unlock_irqrestore(&card->lock, flags);
 845
 846        fw_node_put(device->node);
 847        kfree(device->config_rom);
 848        kfree(device);
 849        fw_card_put(card);
 850}
 851
 852static struct device_type fw_device_type = {
 853        .release = fw_device_release,
 854};
 855
 856static bool is_fw_device(struct device *dev)
 857{
 858        return dev->type == &fw_device_type;
 859}
 860
 861static int update_unit(struct device *dev, void *data)
 862{
 863        struct fw_unit *unit = fw_unit(dev);
 864        struct fw_driver *driver = (struct fw_driver *)dev->driver;
 865
 866        if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) {
 867                device_lock(dev);
 868                driver->update(unit);
 869                device_unlock(dev);
 870        }
 871
 872        return 0;
 873}
 874
 875static void fw_device_update(struct work_struct *work)
 876{
 877        struct fw_device *device =
 878                container_of(work, struct fw_device, work.work);
 879
 880        fw_device_cdev_update(device);
 881        device_for_each_child(&device->device, NULL, update_unit);
 882}
 883
 884/*
 885 * If a device was pending for deletion because its node went away but its
 886 * bus info block and root directory header matches that of a newly discovered
 887 * device, revive the existing fw_device.
 888 * The newly allocated fw_device becomes obsolete instead.
 889 */
 890static int lookup_existing_device(struct device *dev, void *data)
 891{
 892        struct fw_device *old = fw_device(dev);
 893        struct fw_device *new = data;
 894        struct fw_card *card = new->card;
 895        int match = 0;
 896
 897        if (!is_fw_device(dev))
 898                return 0;
 899
 900        down_read(&fw_device_rwsem); /* serialize config_rom access */
 901        spin_lock_irq(&card->lock);  /* serialize node access */
 902
 903        if (memcmp(old->config_rom, new->config_rom, 6 * 4) == 0 &&
 904            atomic_cmpxchg(&old->state,
 905                           FW_DEVICE_GONE,
 906                           FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
 907                struct fw_node *current_node = new->node;
 908                struct fw_node *obsolete_node = old->node;
 909
 910                new->node = obsolete_node;
 911                new->node->data = new;
 912                old->node = current_node;
 913                old->node->data = old;
 914
 915                old->max_speed = new->max_speed;
 916                old->node_id = current_node->node_id;
 917                smp_wmb();  /* update node_id before generation */
 918                old->generation = card->generation;
 919                old->config_rom_retries = 0;
 920                fw_notice(card, "rediscovered device %s\n", dev_name(dev));
 921
 922                old->workfn = fw_device_update;
 923                fw_schedule_device_work(old, 0);
 924
 925                if (current_node == card->root_node)
 926                        fw_schedule_bm_work(card, 0);
 927
 928                match = 1;
 929        }
 930
 931        spin_unlock_irq(&card->lock);
 932        up_read(&fw_device_rwsem);
 933
 934        return match;
 935}
 936
 937enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, };
 938
 939static void set_broadcast_channel(struct fw_device *device, int generation)
 940{
 941        struct fw_card *card = device->card;
 942        __be32 data;
 943        int rcode;
 944
 945        if (!card->broadcast_channel_allocated)
 946                return;
 947
 948        /*
 949         * The Broadcast_Channel Valid bit is required by nodes which want to
 950         * transmit on this channel.  Such transmissions are practically
 951         * exclusive to IP over 1394 (RFC 2734).  IP capable nodes are required
 952         * to be IRM capable and have a max_rec of 8 or more.  We use this fact
 953         * to narrow down to which nodes we send Broadcast_Channel updates.
 954         */
 955        if (!device->irmc || device->max_rec < 8)
 956                return;
 957
 958        /*
 959         * Some 1394-1995 nodes crash if this 1394a-2000 register is written.
 960         * Perform a read test first.
 961         */
 962        if (device->bc_implemented == BC_UNKNOWN) {
 963                rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST,
 964                                device->node_id, generation, device->max_speed,
 965                                CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 966                                &data, 4);
 967                switch (rcode) {
 968                case RCODE_COMPLETE:
 969                        if (data & cpu_to_be32(1 << 31)) {
 970                                device->bc_implemented = BC_IMPLEMENTED;
 971                                break;
 972                        }
 973                        /* else fall through to case address error */
 974                case RCODE_ADDRESS_ERROR:
 975                        device->bc_implemented = BC_UNIMPLEMENTED;
 976                }
 977        }
 978
 979        if (device->bc_implemented == BC_IMPLEMENTED) {
 980                data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL |
 981                                   BROADCAST_CHANNEL_VALID);
 982                fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
 983                                device->node_id, generation, device->max_speed,
 984                                CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 985                                &data, 4);
 986        }
 987}
 988
 989int fw_device_set_broadcast_channel(struct device *dev, void *gen)
 990{
 991        if (is_fw_device(dev))
 992                set_broadcast_channel(fw_device(dev), (long)gen);
 993
 994        return 0;
 995}
 996
 997static void fw_device_init(struct work_struct *work)
 998{
 999        struct fw_device *device =
1000                container_of(work, struct fw_device, work.work);
1001        struct fw_card *card = device->card;
1002        struct device *revived_dev;
1003        int minor, ret;
1004
1005        /*
1006         * All failure paths here set node->data to NULL, so that we
1007         * don't try to do device_for_each_child() on a kfree()'d
1008         * device.
1009         */
1010
1011        ret = read_config_rom(device, device->generation);
1012        if (ret != RCODE_COMPLETE) {
1013                if (device->config_rom_retries < MAX_RETRIES &&
1014                    atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1015                        device->config_rom_retries++;
1016                        fw_schedule_device_work(device, RETRY_DELAY);
1017                } else {
1018                        if (device->node->link_on)
1019                                fw_notice(card, "giving up on node %x: reading config rom failed: %s\n",
1020                                          device->node_id,
1021                                          fw_rcode_string(ret));
1022                        if (device->node == card->root_node)
1023                                fw_schedule_bm_work(card, 0);
1024                        fw_device_release(&device->device);
1025                }
1026                return;
1027        }
1028
1029        revived_dev = device_find_child(card->device,
1030                                        device, lookup_existing_device);
1031        if (revived_dev) {
1032                put_device(revived_dev);
1033                fw_device_release(&device->device);
1034
1035                return;
1036        }
1037
1038        device_initialize(&device->device);
1039
1040        fw_device_get(device);
1041        down_write(&fw_device_rwsem);
1042        minor = idr_alloc(&fw_device_idr, device, 0, 1 << MINORBITS,
1043                        GFP_KERNEL);
1044        up_write(&fw_device_rwsem);
1045
1046        if (minor < 0)
1047                goto error;
1048
1049        device->device.bus = &fw_bus_type;
1050        device->device.type = &fw_device_type;
1051        device->device.parent = card->device;
1052        device->device.devt = MKDEV(fw_cdev_major, minor);
1053        dev_set_name(&device->device, "fw%d", minor);
1054
1055        BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) <
1056                        ARRAY_SIZE(fw_device_attributes) +
1057                        ARRAY_SIZE(config_rom_attributes));
1058        init_fw_attribute_group(&device->device,
1059                                fw_device_attributes,
1060                                &device->attribute_group);
1061
1062        if (device_add(&device->device)) {
1063                fw_err(card, "failed to add device\n");
1064                goto error_with_cdev;
1065        }
1066
1067        create_units(device);
1068
1069        /*
1070         * Transition the device to running state.  If it got pulled
1071         * out from under us while we did the intialization work, we
1072         * have to shut down the device again here.  Normally, though,
1073         * fw_node_event will be responsible for shutting it down when
1074         * necessary.  We have to use the atomic cmpxchg here to avoid
1075         * racing with the FW_NODE_DESTROYED case in
1076         * fw_node_event().
1077         */
1078        if (atomic_cmpxchg(&device->state,
1079                           FW_DEVICE_INITIALIZING,
1080                           FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
1081                device->workfn = fw_device_shutdown;
1082                fw_schedule_device_work(device, SHUTDOWN_DELAY);
1083        } else {
1084                fw_notice(card, "created device %s: GUID %08x%08x, S%d00\n",
1085                          dev_name(&device->device),
1086                          device->config_rom[3], device->config_rom[4],
1087                          1 << device->max_speed);
1088                device->config_rom_retries = 0;
1089
1090                set_broadcast_channel(device, device->generation);
1091
1092                add_device_randomness(&device->config_rom[3], 8);
1093        }
1094
1095        /*
1096         * Reschedule the IRM work if we just finished reading the
1097         * root node config rom.  If this races with a bus reset we
1098         * just end up running the IRM work a couple of extra times -
1099         * pretty harmless.
1100         */
1101        if (device->node == card->root_node)
1102                fw_schedule_bm_work(card, 0);
1103
1104        return;
1105
1106 error_with_cdev:
1107        down_write(&fw_device_rwsem);
1108        idr_remove(&fw_device_idr, minor);
1109        up_write(&fw_device_rwsem);
1110 error:
1111        fw_device_put(device);          /* fw_device_idr's reference */
1112
1113        put_device(&device->device);    /* our reference */
1114}
1115
1116/* Reread and compare bus info block and header of root directory */
1117static int reread_config_rom(struct fw_device *device, int generation,
1118                             bool *changed)
1119{
1120        u32 q;
1121        int i, rcode;
1122
1123        for (i = 0; i < 6; i++) {
1124                rcode = read_rom(device, generation, i, &q);
1125                if (rcode != RCODE_COMPLETE)
1126                        return rcode;
1127
1128                if (i == 0 && q == 0)
1129                        /* inaccessible (see read_config_rom); retry later */
1130                        return RCODE_BUSY;
1131
1132                if (q != device->config_rom[i]) {
1133                        *changed = true;
1134                        return RCODE_COMPLETE;
1135                }
1136        }
1137
1138        *changed = false;
1139        return RCODE_COMPLETE;
1140}
1141
1142static void fw_device_refresh(struct work_struct *work)
1143{
1144        struct fw_device *device =
1145                container_of(work, struct fw_device, work.work);
1146        struct fw_card *card = device->card;
1147        int ret, node_id = device->node_id;
1148        bool changed;
1149
1150        ret = reread_config_rom(device, device->generation, &changed);
1151        if (ret != RCODE_COMPLETE)
1152                goto failed_config_rom;
1153
1154        if (!changed) {
1155                if (atomic_cmpxchg(&device->state,
1156                                   FW_DEVICE_INITIALIZING,
1157                                   FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1158                        goto gone;
1159
1160                fw_device_update(work);
1161                device->config_rom_retries = 0;
1162                goto out;
1163        }
1164
1165        /*
1166         * Something changed.  We keep things simple and don't investigate
1167         * further.  We just destroy all previous units and create new ones.
1168         */
1169        device_for_each_child(&device->device, NULL, shutdown_unit);
1170
1171        ret = read_config_rom(device, device->generation);
1172        if (ret != RCODE_COMPLETE)
1173                goto failed_config_rom;
1174
1175        fw_device_cdev_update(device);
1176        create_units(device);
1177
1178        /* Userspace may want to re-read attributes. */
1179        kobject_uevent(&device->device.kobj, KOBJ_CHANGE);
1180
1181        if (atomic_cmpxchg(&device->state,
1182                           FW_DEVICE_INITIALIZING,
1183                           FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1184                goto gone;
1185
1186        fw_notice(card, "refreshed device %s\n", dev_name(&device->device));
1187        device->config_rom_retries = 0;
1188        goto out;
1189
1190 failed_config_rom:
1191        if (device->config_rom_retries < MAX_RETRIES &&
1192            atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1193                device->config_rom_retries++;
1194                fw_schedule_device_work(device, RETRY_DELAY);
1195                return;
1196        }
1197
1198        fw_notice(card, "giving up on refresh of device %s: %s\n",
1199                  dev_name(&device->device), fw_rcode_string(ret));
1200 gone:
1201        atomic_set(&device->state, FW_DEVICE_GONE);
1202        device->workfn = fw_device_shutdown;
1203        fw_schedule_device_work(device, SHUTDOWN_DELAY);
1204 out:
1205        if (node_id == card->root_node->node_id)
1206                fw_schedule_bm_work(card, 0);
1207}
1208
1209static void fw_device_workfn(struct work_struct *work)
1210{
1211        struct fw_device *device = container_of(to_delayed_work(work),
1212                                                struct fw_device, work);
1213        device->workfn(work);
1214}
1215
1216void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
1217{
1218        struct fw_device *device;
1219
1220        switch (event) {
1221        case FW_NODE_CREATED:
1222                /*
1223                 * Attempt to scan the node, regardless whether its self ID has
1224                 * the L (link active) flag set or not.  Some broken devices
1225                 * send L=0 but have an up-and-running link; others send L=1
1226                 * without actually having a link.
1227                 */
1228 create:
1229                device = kzalloc(sizeof(*device), GFP_ATOMIC);
1230                if (device == NULL)
1231                        break;
1232
1233                /*
1234                 * Do minimal intialization of the device here, the
1235                 * rest will happen in fw_device_init().
1236                 *
1237                 * Attention:  A lot of things, even fw_device_get(),
1238                 * cannot be done before fw_device_init() finished!
1239                 * You can basically just check device->state and
1240                 * schedule work until then, but only while holding
1241                 * card->lock.
1242                 */
1243                atomic_set(&device->state, FW_DEVICE_INITIALIZING);
1244                device->card = fw_card_get(card);
1245                device->node = fw_node_get(node);
1246                device->node_id = node->node_id;
1247                device->generation = card->generation;
1248                device->is_local = node == card->local_node;
1249                mutex_init(&device->client_list_mutex);
1250                INIT_LIST_HEAD(&device->client_list);
1251
1252                /*
1253                 * Set the node data to point back to this device so
1254                 * FW_NODE_UPDATED callbacks can update the node_id
1255                 * and generation for the device.
1256                 */
1257                node->data = device;
1258
1259                /*
1260                 * Many devices are slow to respond after bus resets,
1261                 * especially if they are bus powered and go through
1262                 * power-up after getting plugged in.  We schedule the
1263                 * first config rom scan half a second after bus reset.
1264                 */
1265                device->workfn = fw_device_init;
1266                INIT_DELAYED_WORK(&device->work, fw_device_workfn);
1267                fw_schedule_device_work(device, INITIAL_DELAY);
1268                break;
1269
1270        case FW_NODE_INITIATED_RESET:
1271        case FW_NODE_LINK_ON:
1272                device = node->data;
1273                if (device == NULL)
1274                        goto create;
1275
1276                device->node_id = node->node_id;
1277                smp_wmb();  /* update node_id before generation */
1278                device->generation = card->generation;
1279                if (atomic_cmpxchg(&device->state,
1280                            FW_DEVICE_RUNNING,
1281                            FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) {
1282                        device->workfn = fw_device_refresh;
1283                        fw_schedule_device_work(device,
1284                                device->is_local ? 0 : INITIAL_DELAY);
1285                }
1286                break;
1287
1288        case FW_NODE_UPDATED:
1289                device = node->data;
1290                if (device == NULL)
1291                        break;
1292
1293                device->node_id = node->node_id;
1294                smp_wmb();  /* update node_id before generation */
1295                device->generation = card->generation;
1296                if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
1297                        device->workfn = fw_device_update;
1298                        fw_schedule_device_work(device, 0);
1299                }
1300                break;
1301
1302        case FW_NODE_DESTROYED:
1303        case FW_NODE_LINK_OFF:
1304                if (!node->data)
1305                        break;
1306
1307                /*
1308                 * Destroy the device associated with the node.  There
1309                 * are two cases here: either the device is fully
1310                 * initialized (FW_DEVICE_RUNNING) or we're in the
1311                 * process of reading its config rom
1312                 * (FW_DEVICE_INITIALIZING).  If it is fully
1313                 * initialized we can reuse device->work to schedule a
1314                 * full fw_device_shutdown().  If not, there's work
1315                 * scheduled to read it's config rom, and we just put
1316                 * the device in shutdown state to have that code fail
1317                 * to create the device.
1318                 */
1319                device = node->data;
1320                if (atomic_xchg(&device->state,
1321                                FW_DEVICE_GONE) == FW_DEVICE_RUNNING) {
1322                        device->workfn = fw_device_shutdown;
1323                        fw_schedule_device_work(device,
1324                                list_empty(&card->link) ? 0 : SHUTDOWN_DELAY);
1325                }
1326                break;
1327        }
1328}
1329