drivers/base/firmware_class.c

   1 /*
   2  * firmware_class.c - Multi purpose firmware loading support
   3  *
   4  * Copyright (c) 2003 Manuel Estrada Sainz
   5  *
   6  * Please see Documentation/firmware_class/ for more information.
   7  *
   8  */
   9
  10 #include <linux/capability.h>
  11 #include <linux/device.h>
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/timer.h>
  15 #include <linux/vmalloc.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/bitops.h>
  18 #include <linux/mutex.h>
  19 #include <linux/kthread.h>
  20 #include <linux/highmem.h>
  21 #include <linux/firmware.h>
  22 #include <linux/slab.h>
  23
  24 #define to_dev(obj) container_of(obj, struct device, kobj)
  25
  26 MODULE_AUTHOR("Manuel Estrada Sainz");
  27 MODULE_DESCRIPTION("Multi purpose firmware loading support");
  28 MODULE_LICENSE("GPL");
  29
  30 /* Builtin firmware support */
  31
  32 #ifdef CONFIG_FW_LOADER
  33
  34 extern struct builtin_fw __start_builtin_fw[];
  35 extern struct builtin_fw __end_builtin_fw[];
  36
  37 static bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
  38 {
  39         struct builtin_fw *b_fw;
  40
  41         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
  42                 if (strcmp(name, b_fw->name) == 0) {
  43                         fw->size = b_fw->size;
  44                         fw->data = b_fw->data;
  45                         return true;
  46                 }
  47         }
  48
  49         return false;
  50 }
  51
  52 static bool fw_is_builtin_firmware(const struct firmware *fw)
  53 {
  54         struct builtin_fw *b_fw;
  55
  56         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
  57                 if (fw->data == b_fw->data)
  58                         return true;
  59
  60         return false;
  61 }
  62
  63 #else /* Module case - no builtin firmware support */
  64
  65 static inline bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
  66 {
  67         return false;
  68 }
  69
  70 static inline bool fw_is_builtin_firmware(const struct firmware *fw)
  71 {
  72         return false;
  73 }
  74 #endif
  75
  76 enum {
  77         FW_STATUS_LOADING,
  78         FW_STATUS_DONE,
  79         FW_STATUS_ABORT,
  80 };
  81
  82 static int loading_timeout = 60;        /* In seconds */
  83
  84 /* fw_lock could be moved to 'struct firmware_priv' but since it is just
  85  * guarding for corner cases a global lock should be OK */
  86 static DEFINE_MUTEX(fw_lock);
  87
  88 struct firmware_priv {
  89         struct completion completion;
  90         struct bin_attribute attr_data;
  91         struct firmware *fw;
  92         unsigned long status;
  93         struct page **pages;
  94         int nr_pages;
  95         int page_array_size;
  96         struct timer_list timeout;
  97         bool nowait;
  98         char fw_id[];
  99 };
 100
 101 static void
 102 fw_load_abort(struct firmware_priv *fw_priv)
 103 {
 104         set_bit(FW_STATUS_ABORT, &fw_priv->status);
 105         wmb();
 106         complete(&fw_priv->completion);
 107 }
 108
 109 static ssize_t
 110 firmware_timeout_show(struct class *class,
 111                       struct class_attribute *attr,
 112                       char *buf)
 113 {
 114         return sprintf(buf, "%d\n", loading_timeout);
 115 }
 116
 117 /**
 118  * firmware_timeout_store - set number of seconds to wait for firmware
 119  * @class: device class pointer
 120  * @attr: device attribute pointer
 121  * @buf: buffer to scan for timeout value
 122  * @count: number of bytes in @buf
 123  *
 124  *      Sets the number of seconds to wait for the firmware.  Once
 125  *      this expires an error will be returned to the driver and no
 126  *      firmware will be provided.
 127  *
 128  *      Note: zero means 'wait forever'.
 129  **/
 130 static ssize_t
 131 firmware_timeout_store(struct class *class,
 132                         struct class_attribute *attr,
 133                         const char *buf, size_t count)
 134 {
 135         loading_timeout = simple_strtol(buf, NULL, 10);
 136         if (loading_timeout < 0)
 137                 loading_timeout = 0;
 138         return count;
 139 }
 140
 141 static struct class_attribute firmware_class_attrs[] = {
 142         __ATTR(timeout, S_IWUSR | S_IRUGO,
 143                 firmware_timeout_show, firmware_timeout_store),
 144         __ATTR_NULL
 145 };
 146
 147 static void fw_dev_release(struct device *dev)
 148 {
 149         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 150         int i;
 151
 152         for (i = 0; i < fw_priv->nr_pages; i++)
 153                 __free_page(fw_priv->pages[i]);
 154         kfree(fw_priv->pages);
 155         kfree(fw_priv);
 156         kfree(dev);
 157
 158         module_put(THIS_MODULE);
 159 }
 160
 161 static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
 162 {
 163         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 164
 165         if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->fw_id))
 166                 return -ENOMEM;
 167         if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
 168                 return -ENOMEM;
 169         if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
 170                 return -ENOMEM;
 171
 172         return 0;
 173 }
 174
 175 static struct class firmware_class = {
 176         .name           = "firmware",
 177         .class_attrs    = firmware_class_attrs,
 178         .dev_uevent     = firmware_uevent,
 179         .dev_release    = fw_dev_release,
 180 };
 181
 182 static ssize_t firmware_loading_show(struct device *dev,
 183                                      struct device_attribute *attr, char *buf)
 184 {
 185         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 186         int loading = test_bit(FW_STATUS_LOADING, &fw_priv->status);
 187         return sprintf(buf, "%d\n", loading);
 188 }
 189
 190 static void firmware_free_data(const struct firmware *fw)
 191 {
 192         int i;
 193         vunmap(fw->data);
 194         if (fw->pages) {
 195                 for (i = 0; i < PFN_UP(fw->size); i++)
 196                         __free_page(fw->pages[i]);
 197                 kfree(fw->pages);
 198         }
 199 }
 200
 201 /* Some architectures don't have PAGE_KERNEL_RO */
 202 #ifndef PAGE_KERNEL_RO
 203 #define PAGE_KERNEL_RO PAGE_KERNEL
 204 #endif
 205 /**
 206  * firmware_loading_store - set value in the 'loading' control file
 207  * @dev: device pointer
 208  * @attr: device attribute pointer
 209  * @buf: buffer to scan for loading control value
 210  * @count: number of bytes in @buf
 211  *
 212  *      The relevant values are:
 213  *
 214  *       1: Start a load, discarding any previous partial load.
 215  *       0: Conclude the load and hand the data to the driver code.
 216  *      -1: Conclude the load with an error and discard any written data.
 217  **/
 218 static ssize_t firmware_loading_store(struct device *dev,
 219                                       struct device_attribute *attr,
 220                                       const char *buf, size_t count)
 221 {
 222         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 223         int loading = simple_strtol(buf, NULL, 10);
 224         int i;
 225
 226         switch (loading) {
 227         case 1:
 228                 mutex_lock(&fw_lock);
 229                 if (!fw_priv->fw) {
 230                         mutex_unlock(&fw_lock);
 231                         break;
 232                 }
 233                 firmware_free_data(fw_priv->fw);
 234                 memset(fw_priv->fw, 0, sizeof(struct firmware));
 235                 /* If the pages are not owned by 'struct firmware' */
 236                 for (i = 0; i < fw_priv->nr_pages; i++)
 237                         __free_page(fw_priv->pages[i]);
 238                 kfree(fw_priv->pages);
 239                 fw_priv->pages = NULL;
 240                 fw_priv->page_array_size = 0;
 241                 fw_priv->nr_pages = 0;
 242                 set_bit(FW_STATUS_LOADING, &fw_priv->status);
 243                 mutex_unlock(&fw_lock);
 244                 break;
 245         case 0:
 246                 if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) {
 247                         vunmap(fw_priv->fw->data);
 248                         fw_priv->fw->data = vmap(fw_priv->pages,
 249                                                  fw_priv->nr_pages,
 250                                                  0, PAGE_KERNEL_RO);
 251                         if (!fw_priv->fw->data) {
 252                                 dev_err(dev, "%s: vmap() failed\n", __func__);
 253                                 goto err;
 254                         }
 255                         /* Pages are now owned by 'struct firmware' */
 256                         fw_priv->fw->pages = fw_priv->pages;
 257                         fw_priv->pages = NULL;
 258
 259                         fw_priv->page_array_size = 0;
 260                         fw_priv->nr_pages = 0;
 261                         complete(&fw_priv->completion);
 262                         clear_bit(FW_STATUS_LOADING, &fw_priv->status);
 263                         break;
 264                 }
 265                 /* fallthrough */
 266         default:
 267                 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
 268                 /* fallthrough */
 269         case -1:
 270         err:
 271                 fw_load_abort(fw_priv);
 272                 break;
 273         }
 274
 275         return count;
 276 }
 277
 278 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
 279
 280 static ssize_t
 281 firmware_data_read(struct file *filp, struct kobject *kobj,
 282                    struct bin_attribute *bin_attr, char *buffer, loff_t offset,
 283                    size_t count)
 284 {
 285         struct device *dev = to_dev(kobj);
 286         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 287         struct firmware *fw;
 288         ssize_t ret_count;
 289
 290         mutex_lock(&fw_lock);
 291         fw = fw_priv->fw;
 292         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
 293                 ret_count = -ENODEV;
 294                 goto out;
 295         }
 296         if (offset > fw->size) {
 297                 ret_count = 0;
 298                 goto out;
 299         }
 300         if (count > fw->size - offset)
 301                 count = fw->size - offset;
 302
 303         ret_count = count;
 304
 305         while (count) {
 306                 void *page_data;
 307                 int page_nr = offset >> PAGE_SHIFT;
 308                 int page_ofs = offset & (PAGE_SIZE-1);
 309                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 310
 311                 page_data = kmap(fw_priv->pages[page_nr]);
 312
 313                 memcpy(buffer, page_data + page_ofs, page_cnt);
 314
 315                 kunmap(fw_priv->pages[page_nr]);
 316                 buffer += page_cnt;
 317                 offset += page_cnt;
 318                 count -= page_cnt;
 319         }
 320 out:
 321         mutex_unlock(&fw_lock);
 322         return ret_count;
 323 }
 324
 325 static int
 326 fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
 327 {
 328         int pages_needed = ALIGN(min_size, PAGE_SIZE) >> PAGE_SHIFT;
 329
 330         /* If the array of pages is too small, grow it... */
 331         if (fw_priv->page_array_size < pages_needed) {
 332                 int new_array_size = max(pages_needed,
 333                                          fw_priv->page_array_size * 2);
 334                 struct page **new_pages;
 335
 336                 new_pages = kmalloc(new_array_size * sizeof(void *),
 337                                     GFP_KERNEL);
 338                 if (!new_pages) {
 339                         fw_load_abort(fw_priv);
 340                         return -ENOMEM;
 341                 }
 342                 memcpy(new_pages, fw_priv->pages,
 343                        fw_priv->page_array_size * sizeof(void *));
 344                 memset(&new_pages[fw_priv->page_array_size], 0, sizeof(void *) *
 345                        (new_array_size - fw_priv->page_array_size));
 346                 kfree(fw_priv->pages);
 347                 fw_priv->pages = new_pages;
 348                 fw_priv->page_array_size = new_array_size;
 349         }
 350
 351         while (fw_priv->nr_pages < pages_needed) {
 352                 fw_priv->pages[fw_priv->nr_pages] =
 353                         alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
 354
 355                 if (!fw_priv->pages[fw_priv->nr_pages]) {
 356                         fw_load_abort(fw_priv);
 357                         return -ENOMEM;
 358                 }
 359                 fw_priv->nr_pages++;
 360         }
 361         return 0;
 362 }
 363
 364 /**
 365  * firmware_data_write - write method for firmware
 366  * @filp: open sysfs file
 367  * @kobj: kobject for the device
 368  * @bin_attr: bin_attr structure
 369  * @buffer: buffer being written
 370  * @offset: buffer offset for write in total data store area
 371  * @count: buffer size
 372  *
 373  *      Data written to the 'data' attribute will be later handed to
 374  *      the driver as a firmware image.
 375  **/
 376 static ssize_t
 377 firmware_data_write(struct file* filp, struct kobject *kobj,
 378                     struct bin_attribute *bin_attr, char *buffer,
 379                     loff_t offset, size_t count)
 380 {
 381         struct device *dev = to_dev(kobj);
 382         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 383         struct firmware *fw;
 384         ssize_t retval;
 385
 386         if (!capable(CAP_SYS_RAWIO))
 387                 return -EPERM;
 388
 389         mutex_lock(&fw_lock);
 390         fw = fw_priv->fw;
 391         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
 392                 retval = -ENODEV;
 393                 goto out;
 394         }
 395         retval = fw_realloc_buffer(fw_priv, offset + count);
 396         if (retval)
 397                 goto out;
 398
 399         retval = count;
 400
 401         while (count) {
 402                 void *page_data;
 403                 int page_nr = offset >> PAGE_SHIFT;
 404                 int page_ofs = offset & (PAGE_SIZE - 1);
 405                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 406
 407                 page_data = kmap(fw_priv->pages[page_nr]);
 408
 409                 memcpy(page_data + page_ofs, buffer, page_cnt);
 410
 411                 kunmap(fw_priv->pages[page_nr]);
 412                 buffer += page_cnt;
 413                 offset += page_cnt;
 414                 count -= page_cnt;
 415         }
 416
 417         fw->size = max_t(size_t, offset, fw->size);
 418 out:
 419         mutex_unlock(&fw_lock);
 420         return retval;
 421 }
 422
 423 static struct bin_attribute firmware_attr_data_tmpl = {
 424         .attr = {.name = "data", .mode = 0644},
 425         .size = 0,
 426         .read = firmware_data_read,
 427         .write = firmware_data_write,
 428 };
 429
 430 static void
 431 firmware_class_timeout(u_long data)
 432 {
 433         struct firmware_priv *fw_priv = (struct firmware_priv *) data;
 434         fw_load_abort(fw_priv);
 435 }
 436
 437 static int fw_register_device(struct device **dev_p, const char *fw_name,
 438                               struct device *device)
 439 {
 440         int retval;
 441         struct firmware_priv *fw_priv =
 442                 kzalloc(sizeof(*fw_priv) + strlen(fw_name) + 1 , GFP_KERNEL);
 443         struct device *f_dev = kzalloc(sizeof(*f_dev), GFP_KERNEL);
 444
 445         *dev_p = NULL;
 446
 447         if (!fw_priv || !f_dev) {
 448                 dev_err(device, "%s: kmalloc failed\n", __func__);
 449                 retval = -ENOMEM;
 450                 goto error_kfree;
 451         }
 452
 453         strcpy(fw_priv->fw_id, fw_name);
 454         init_completion(&fw_priv->completion);
 455         fw_priv->attr_data = firmware_attr_data_tmpl;
 456         fw_priv->timeout.function = firmware_class_timeout;
 457         fw_priv->timeout.data = (u_long) fw_priv;
 458         init_timer(&fw_priv->timeout);
 459
 460         dev_set_name(f_dev, "%s", dev_name(device));
 461         f_dev->parent = device;
 462         f_dev->class = &firmware_class;
 463         dev_set_drvdata(f_dev, fw_priv);
 464         dev_set_uevent_suppress(f_dev, 1);
 465         retval = device_register(f_dev);
 466         if (retval) {
 467                 dev_err(device, "%s: device_register failed\n", __func__);
 468                 put_device(f_dev);
 469                 return retval;
 470         }
 471         *dev_p = f_dev;
 472         return 0;
 473
 474 error_kfree:
 475         kfree(f_dev);
 476         kfree(fw_priv);
 477         return retval;
 478 }
 479
 480 static int fw_setup_device(struct firmware *fw, struct device **dev_p,
 481                            const char *fw_name, struct device *device,
 482                            int uevent, bool nowait)
 483 {
 484         struct device *f_dev;
 485         struct firmware_priv *fw_priv;
 486         int retval;
 487
 488         *dev_p = NULL;
 489         retval = fw_register_device(&f_dev, fw_name, device);
 490         if (retval)
 491                 goto out;
 492
 493         /* Need to pin this module until class device is destroyed */
 494         __module_get(THIS_MODULE);
 495
 496         fw_priv = dev_get_drvdata(f_dev);
 497
 498         fw_priv->nowait = nowait;
 499
 500         fw_priv->fw = fw;
 501         sysfs_bin_attr_init(&fw_priv->attr_data);
 502         retval = sysfs_create_bin_file(&f_dev->kobj, &fw_priv->attr_data);
 503         if (retval) {
 504                 dev_err(device, "%s: sysfs_create_bin_file failed\n", __func__);
 505                 goto error_unreg;
 506         }
 507
 508         retval = device_create_file(f_dev, &dev_attr_loading);
 509         if (retval) {
 510                 dev_err(device, "%s: device_create_file failed\n", __func__);
 511                 goto error_unreg;
 512         }
 513
 514         if (uevent)
 515                 dev_set_uevent_suppress(f_dev, 0);
 516         *dev_p = f_dev;
 517         goto out;
 518
 519 error_unreg:
 520         device_unregister(f_dev);
 521 out:
 522         return retval;
 523 }
 524
 525 static int
 526 _request_firmware(const struct firmware **firmware_p, const char *name,
 527                  struct device *device, int uevent, bool nowait)
 528 {
 529         struct device *f_dev;
 530         struct firmware_priv *fw_priv;
 531         struct firmware *firmware;
 532         int retval;
 533
 534         if (!firmware_p)
 535                 return -EINVAL;
 536
 537         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
 538         if (!firmware) {
 539                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
 540                         __func__);
 541                 retval = -ENOMEM;
 542                 goto out;
 543         }
 544
 545         if (fw_get_builtin_firmware(firmware, name)) {
 546                 dev_dbg(device, "firmware: using built-in firmware %s\n", name);
 547                 return 0;
 548         }
 549
 550         if (uevent)
 551                 dev_dbg(device, "firmware: requesting %s\n", name);
 552
 553         retval = fw_setup_device(firmware, &f_dev, name, device,
 554                                  uevent, nowait);
 555         if (retval)
 556                 goto error_kfree_fw;
 557
 558         fw_priv = dev_get_drvdata(f_dev);
 559
 560         if (uevent) {
 561                 if (loading_timeout > 0) {
 562                         fw_priv->timeout.expires = jiffies + loading_timeout * HZ;
 563                         add_timer(&fw_priv->timeout);
 564                 }
 565
 566                 kobject_uevent(&f_dev->kobj, KOBJ_ADD);
 567                 wait_for_completion(&fw_priv->completion);
 568                 set_bit(FW_STATUS_DONE, &fw_priv->status);
 569                 del_timer_sync(&fw_priv->timeout);
 570         } else
 571                 wait_for_completion(&fw_priv->completion);
 572
 573         mutex_lock(&fw_lock);
 574         if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status)) {
 575                 retval = -ENOENT;
 576                 release_firmware(fw_priv->fw);
 577                 *firmware_p = NULL;
 578         }
 579         fw_priv->fw = NULL;
 580         mutex_unlock(&fw_lock);
 581         device_unregister(f_dev);
 582         goto out;
 583
 584 error_kfree_fw:
 585         kfree(firmware);
 586         *firmware_p = NULL;
 587 out:
 588         return retval;
 589 }
 590
 591 /**
 592  * request_firmware: - send firmware request and wait for it
 593  * @firmware_p: pointer to firmware image
 594  * @name: name of firmware file
 595  * @device: device for which firmware is being loaded
 596  *
 597  *      @firmware_p will be used to return a firmware image by the name
 598  *      of @name for device @device.
 599  *
 600  *      Should be called from user context where sleeping is allowed.
 601  *
 602  *      @name will be used as $FIRMWARE in the uevent environment and
 603  *      should be distinctive enough not to be confused with any other
 604  *      firmware image for this or any other device.
 605  **/
 606 int
 607 request_firmware(const struct firmware **firmware_p, const char *name,
 608                  struct device *device)
 609 {
 610         int uevent = 1;
 611         return _request_firmware(firmware_p, name, device, uevent, false);
 612 }
 613
 614 /**
 615  * release_firmware: - release the resource associated with a firmware image
 616  * @fw: firmware resource to release
 617  **/
 618 void release_firmware(const struct firmware *fw)
 619 {
 620         if (fw) {
 621                 if (!fw_is_builtin_firmware(fw))
 622                         firmware_free_data(fw);
 623                 kfree(fw);
 624         }
 625 }
 626
 627 /* Async support */
 628 struct firmware_work {
 629         struct work_struct work;
 630         struct module *module;
 631         const char *name;
 632         struct device *device;
 633         void *context;
 634         void (*cont)(const struct firmware *fw, void *context);
 635         int uevent;
 636 };
 637
 638 static int
 639 request_firmware_work_func(void *arg)
 640 {
 641         struct firmware_work *fw_work = arg;
 642         const struct firmware *fw;
 643         int ret;
 644         if (!arg) {
 645                 WARN_ON(1);
 646                 return 0;
 647         }
 648         ret = _request_firmware(&fw, fw_work->name, fw_work->device,
 649                 fw_work->uevent, true);
 650
 651         fw_work->cont(fw, fw_work->context);
 652
 653         module_put(fw_work->module);
 654         kfree(fw_work);
 655         return ret;
 656 }
 657
 658 /**
 659  * request_firmware_nowait - asynchronous version of request_firmware
 660  * @module: module requesting the firmware
 661  * @uevent: sends uevent to copy the firmware image if this flag
 662  *      is non-zero else the firmware copy must be done manually.
 663  * @name: name of firmware file
 664  * @device: device for which firmware is being loaded
 665  * @gfp: allocation flags
 666  * @context: will be passed over to @cont, and
 667  *      @fw may be %NULL if firmware request fails.
 668  * @cont: function will be called asynchronously when the firmware
 669  *      request is over.
 670  *
 671  *      Asynchronous variant of request_firmware() for user contexts where
 672  *      it is not possible to sleep for long time. It can't be called
 673  *      in atomic contexts.
 674  **/
 675 int
 676 request_firmware_nowait(
 677         struct module *module, int uevent,
 678         const char *name, struct device *device, gfp_t gfp, void *context,
 679         void (*cont)(const struct firmware *fw, void *context))
 680 {
 681         struct task_struct *task;
 682         struct firmware_work *fw_work = kmalloc(sizeof (struct firmware_work),
 683                                                 gfp);
 684
 685         if (!fw_work)
 686                 return -ENOMEM;
 687         if (!try_module_get(module)) {
 688                 kfree(fw_work);
 689                 return -EFAULT;
 690         }
 691
 692         *fw_work = (struct firmware_work) {
 693                 .module = module,
 694                 .name = name,
 695                 .device = device,
 696                 .context = context,
 697                 .cont = cont,
 698                 .uevent = uevent,
 699         };
 700
 701         task = kthread_run(request_firmware_work_func, fw_work,
 702                             "firmware/%s", name);
 703
 704         if (IS_ERR(task)) {
 705                 fw_work->cont(NULL, fw_work->context);
 706                 module_put(fw_work->module);
 707                 kfree(fw_work);
 708                 return PTR_ERR(task);
 709         }
 710         return 0;
 711 }
 712
 713 static int __init firmware_class_init(void)
 714 {
 715         return class_register(&firmware_class);
 716 }
 717
 718 static void __exit firmware_class_exit(void)
 719 {
 720         class_unregister(&firmware_class);
 721 }
 722
 723 fs_initcall(firmware_class_init);
 724 module_exit(firmware_class_exit);
 725
 726 EXPORT_SYMBOL(release_firmware);
 727 EXPORT_SYMBOL(request_firmware);
 728 EXPORT_SYMBOL(request_firmware_nowait);