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         char *fw_id;
  90         struct completion completion;
  91         struct bin_attribute attr_data;
  92         struct firmware *fw;
  93         unsigned long status;
  94         struct page **pages;
  95         int nr_pages;
  96         int page_array_size;
  97         const char *vdata;
  98         struct timer_list timeout;
  99         bool nowait;
 100 };
 101
 102 static void
 103 fw_load_abort(struct firmware_priv *fw_priv)
 104 {
 105         set_bit(FW_STATUS_ABORT, &fw_priv->status);
 106         wmb();
 107         complete(&fw_priv->completion);
 108 }
 109
 110 static ssize_t
 111 firmware_timeout_show(struct class *class,
 112                       struct class_attribute *attr,
 113                       char *buf)
 114 {
 115         return sprintf(buf, "%d\n", loading_timeout);
 116 }
 117
 118 /**
 119  * firmware_timeout_store - set number of seconds to wait for firmware
 120  * @class: device class pointer
 121  * @attr: device attribute pointer
 122  * @buf: buffer to scan for timeout value
 123  * @count: number of bytes in @buf
 124  *
 125  *      Sets the number of seconds to wait for the firmware.  Once
 126  *      this expires an error will be returned to the driver and no
 127  *      firmware will be provided.
 128  *
 129  *      Note: zero means 'wait forever'.
 130  **/
 131 static ssize_t
 132 firmware_timeout_store(struct class *class,
 133                         struct class_attribute *attr,
 134                         const char *buf, size_t count)
 135 {
 136         loading_timeout = simple_strtol(buf, NULL, 10);
 137         if (loading_timeout < 0)
 138                 loading_timeout = 0;
 139         return count;
 140 }
 141
 142 static struct class_attribute firmware_class_attrs[] = {
 143         __ATTR(timeout, S_IWUSR | S_IRUGO,
 144                 firmware_timeout_show, firmware_timeout_store),
 145         __ATTR_NULL
 146 };
 147
 148 static void fw_dev_release(struct device *dev)
 149 {
 150         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 151         int i;
 152
 153         for (i = 0; i < fw_priv->nr_pages; i++)
 154                 __free_page(fw_priv->pages[i]);
 155         kfree(fw_priv->pages);
 156         kfree(fw_priv->fw_id);
 157         kfree(fw_priv);
 158         kfree(dev);
 159
 160         module_put(THIS_MODULE);
 161 }
 162
 163 static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
 164 {
 165         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 166
 167         if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->fw_id))
 168                 return -ENOMEM;
 169         if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
 170                 return -ENOMEM;
 171         if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
 172                 return -ENOMEM;
 173
 174         return 0;
 175 }
 176
 177 static struct class firmware_class = {
 178         .name           = "firmware",
 179         .class_attrs    = firmware_class_attrs,
 180         .dev_uevent     = firmware_uevent,
 181         .dev_release    = fw_dev_release,
 182 };
 183
 184 static ssize_t firmware_loading_show(struct device *dev,
 185                                      struct device_attribute *attr, char *buf)
 186 {
 187         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 188         int loading = test_bit(FW_STATUS_LOADING, &fw_priv->status);
 189         return sprintf(buf, "%d\n", loading);
 190 }
 191
 192 static void firmware_free_data(const struct firmware *fw)
 193 {
 194         int i;
 195         vunmap(fw->data);
 196         if (fw->pages) {
 197                 for (i = 0; i < PFN_UP(fw->size); i++)
 198                         __free_page(fw->pages[i]);
 199                 kfree(fw->pages);
 200         }
 201 }
 202
 203 /* Some architectures don't have PAGE_KERNEL_RO */
 204 #ifndef PAGE_KERNEL_RO
 205 #define PAGE_KERNEL_RO PAGE_KERNEL
 206 #endif
 207 /**
 208  * firmware_loading_store - set value in the 'loading' control file
 209  * @dev: device pointer
 210  * @attr: device attribute pointer
 211  * @buf: buffer to scan for loading control value
 212  * @count: number of bytes in @buf
 213  *
 214  *      The relevant values are:
 215  *
 216  *       1: Start a load, discarding any previous partial load.
 217  *       0: Conclude the load and hand the data to the driver code.
 218  *      -1: Conclude the load with an error and discard any written data.
 219  **/
 220 static ssize_t firmware_loading_store(struct device *dev,
 221                                       struct device_attribute *attr,
 222                                       const char *buf, size_t count)
 223 {
 224         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 225         int loading = simple_strtol(buf, NULL, 10);
 226         int i;
 227
 228         switch (loading) {
 229         case 1:
 230                 mutex_lock(&fw_lock);
 231                 if (!fw_priv->fw) {
 232                         mutex_unlock(&fw_lock);
 233                         break;
 234                 }
 235                 firmware_free_data(fw_priv->fw);
 236                 memset(fw_priv->fw, 0, sizeof(struct firmware));
 237                 /* If the pages are not owned by 'struct firmware' */
 238                 for (i = 0; i < fw_priv->nr_pages; i++)
 239                         __free_page(fw_priv->pages[i]);
 240                 kfree(fw_priv->pages);
 241                 fw_priv->pages = NULL;
 242                 fw_priv->page_array_size = 0;
 243                 fw_priv->nr_pages = 0;
 244                 set_bit(FW_STATUS_LOADING, &fw_priv->status);
 245                 mutex_unlock(&fw_lock);
 246                 break;
 247         case 0:
 248                 if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) {
 249                         vunmap(fw_priv->fw->data);
 250                         fw_priv->fw->data = vmap(fw_priv->pages,
 251                                                  fw_priv->nr_pages,
 252                                                  0, PAGE_KERNEL_RO);
 253                         if (!fw_priv->fw->data) {
 254                                 dev_err(dev, "%s: vmap() failed\n", __func__);
 255                                 goto err;
 256                         }
 257                         /* Pages are now owned by 'struct firmware' */
 258                         fw_priv->fw->pages = fw_priv->pages;
 259                         fw_priv->pages = NULL;
 260
 261                         fw_priv->page_array_size = 0;
 262                         fw_priv->nr_pages = 0;
 263                         complete(&fw_priv->completion);
 264                         clear_bit(FW_STATUS_LOADING, &fw_priv->status);
 265                         break;
 266                 }
 267                 /* fallthrough */
 268         default:
 269                 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
 270                 /* fallthrough */
 271         case -1:
 272         err:
 273                 fw_load_abort(fw_priv);
 274                 break;
 275         }
 276
 277         return count;
 278 }
 279
 280 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
 281
 282 static ssize_t
 283 firmware_data_read(struct kobject *kobj, struct bin_attribute *bin_attr,
 284                    char *buffer, loff_t offset, size_t count)
 285 {
 286         struct device *dev = to_dev(kobj);
 287         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 288         struct firmware *fw;
 289         ssize_t ret_count;
 290
 291         mutex_lock(&fw_lock);
 292         fw = fw_priv->fw;
 293         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
 294                 ret_count = -ENODEV;
 295                 goto out;
 296         }
 297         if (offset > fw->size) {
 298                 ret_count = 0;
 299                 goto out;
 300         }
 301         if (count > fw->size - offset)
 302                 count = fw->size - offset;
 303
 304         ret_count = count;
 305
 306         while (count) {
 307                 void *page_data;
 308                 int page_nr = offset >> PAGE_SHIFT;
 309                 int page_ofs = offset & (PAGE_SIZE-1);
 310                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 311
 312                 page_data = kmap(fw_priv->pages[page_nr]);
 313
 314                 memcpy(buffer, page_data + page_ofs, page_cnt);
 315
 316                 kunmap(fw_priv->pages[page_nr]);
 317                 buffer += page_cnt;
 318                 offset += page_cnt;
 319                 count -= page_cnt;
 320         }
 321 out:
 322         mutex_unlock(&fw_lock);
 323         return ret_count;
 324 }
 325
 326 static int
 327 fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
 328 {
 329         int pages_needed = ALIGN(min_size, PAGE_SIZE) >> PAGE_SHIFT;
 330
 331         /* If the array of pages is too small, grow it... */
 332         if (fw_priv->page_array_size < pages_needed) {
 333                 int new_array_size = max(pages_needed,
 334                                          fw_priv->page_array_size * 2);
 335                 struct page **new_pages;
 336
 337                 new_pages = kmalloc(new_array_size * sizeof(void *),
 338                                     GFP_KERNEL);
 339                 if (!new_pages) {
 340                         fw_load_abort(fw_priv);
 341                         return -ENOMEM;
 342                 }
 343                 memcpy(new_pages, fw_priv->pages,
 344                        fw_priv->page_array_size * sizeof(void *));
 345                 memset(&new_pages[fw_priv->page_array_size], 0, sizeof(void *) *
 346                        (new_array_size - fw_priv->page_array_size));
 347                 kfree(fw_priv->pages);
 348                 fw_priv->pages = new_pages;
 349                 fw_priv->page_array_size = new_array_size;
 350         }
 351
 352         while (fw_priv->nr_pages < pages_needed) {
 353                 fw_priv->pages[fw_priv->nr_pages] =
 354                         alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
 355
 356                 if (!fw_priv->pages[fw_priv->nr_pages]) {
 357                         fw_load_abort(fw_priv);
 358                         return -ENOMEM;
 359                 }
 360                 fw_priv->nr_pages++;
 361         }
 362         return 0;
 363 }
 364
 365 /**
 366  * firmware_data_write - write method for firmware
 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 kobject *kobj, struct bin_attribute *bin_attr,
 378                     char *buffer, loff_t offset, size_t count)
 379 {
 380         struct device *dev = to_dev(kobj);
 381         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 382         struct firmware *fw;
 383         ssize_t retval;
 384
 385         if (!capable(CAP_SYS_RAWIO))
 386                 return -EPERM;
 387
 388         mutex_lock(&fw_lock);
 389         fw = fw_priv->fw;
 390         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
 391                 retval = -ENODEV;
 392                 goto out;
 393         }
 394         retval = fw_realloc_buffer(fw_priv, offset + count);
 395         if (retval)
 396                 goto out;
 397
 398         retval = count;
 399
 400         while (count) {
 401                 void *page_data;
 402                 int page_nr = offset >> PAGE_SHIFT;
 403                 int page_ofs = offset & (PAGE_SIZE - 1);
 404                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 405
 406                 page_data = kmap(fw_priv->pages[page_nr]);
 407
 408                 memcpy(page_data + page_ofs, buffer, page_cnt);
 409
 410                 kunmap(fw_priv->pages[page_nr]);
 411                 buffer += page_cnt;
 412                 offset += page_cnt;
 413                 count -= page_cnt;
 414         }
 415
 416         fw->size = max_t(size_t, offset, fw->size);
 417 out:
 418         mutex_unlock(&fw_lock);
 419         return retval;
 420 }
 421
 422 static struct bin_attribute firmware_attr_data_tmpl = {
 423         .attr = {.name = "data", .mode = 0644},
 424         .size = 0,
 425         .read = firmware_data_read,
 426         .write = firmware_data_write,
 427 };
 428
 429 static void
 430 firmware_class_timeout(u_long data)
 431 {
 432         struct firmware_priv *fw_priv = (struct firmware_priv *) data;
 433         fw_load_abort(fw_priv);
 434 }
 435
 436 static int fw_register_device(struct device **dev_p, const char *fw_name,
 437                               struct device *device)
 438 {
 439         int retval;
 440         struct firmware_priv *fw_priv = kzalloc(sizeof(*fw_priv),
 441                                                 GFP_KERNEL);
 442         struct device *f_dev = kzalloc(sizeof(*f_dev), GFP_KERNEL);
 443
 444         *dev_p = NULL;
 445
 446         if (!fw_priv || !f_dev) {
 447                 dev_err(device, "%s: kmalloc failed\n", __func__);
 448                 retval = -ENOMEM;
 449                 goto error_kfree;
 450         }
 451
 452         init_completion(&fw_priv->completion);
 453         fw_priv->attr_data = firmware_attr_data_tmpl;
 454         fw_priv->fw_id = kstrdup(fw_name, GFP_KERNEL);
 455         if (!fw_priv->fw_id) {
 456                 dev_err(device, "%s: Firmware name allocation failed\n",
 457                         __func__);
 458                 retval = -ENOMEM;
 459                 goto error_kfree;
 460         }
 461
 462         fw_priv->timeout.function = firmware_class_timeout;
 463         fw_priv->timeout.data = (u_long) fw_priv;
 464         init_timer(&fw_priv->timeout);
 465
 466         dev_set_name(f_dev, "%s", dev_name(device));
 467         f_dev->parent = device;
 468         f_dev->class = &firmware_class;
 469         dev_set_drvdata(f_dev, fw_priv);
 470         dev_set_uevent_suppress(f_dev, 1);
 471         retval = device_register(f_dev);
 472         if (retval) {
 473                 dev_err(device, "%s: device_register failed\n", __func__);
 474                 put_device(f_dev);
 475                 return retval;
 476         }
 477         *dev_p = f_dev;
 478         return 0;
 479
 480 error_kfree:
 481         kfree(f_dev);
 482         kfree(fw_priv);
 483         return retval;
 484 }
 485
 486 static int fw_setup_device(struct firmware *fw, struct device **dev_p,
 487                            const char *fw_name, struct device *device,
 488                            int uevent, bool nowait)
 489 {
 490         struct device *f_dev;
 491         struct firmware_priv *fw_priv;
 492         int retval;
 493
 494         *dev_p = NULL;
 495         retval = fw_register_device(&f_dev, fw_name, device);
 496         if (retval)
 497                 goto out;
 498
 499         /* Need to pin this module until class device is destroyed */
 500         __module_get(THIS_MODULE);
 501
 502         fw_priv = dev_get_drvdata(f_dev);
 503
 504         fw_priv->nowait = nowait;
 505
 506         fw_priv->fw = fw;
 507         sysfs_bin_attr_init(&fw_priv->attr_data);
 508         retval = sysfs_create_bin_file(&f_dev->kobj, &fw_priv->attr_data);
 509         if (retval) {
 510                 dev_err(device, "%s: sysfs_create_bin_file failed\n", __func__);
 511                 goto error_unreg;
 512         }
 513
 514         retval = device_create_file(f_dev, &dev_attr_loading);
 515         if (retval) {
 516                 dev_err(device, "%s: device_create_file failed\n", __func__);
 517                 goto error_unreg;
 518         }
 519
 520         if (uevent)
 521                 dev_set_uevent_suppress(f_dev, 0);
 522         *dev_p = f_dev;
 523         goto out;
 524
 525 error_unreg:
 526         device_unregister(f_dev);
 527 out:
 528         return retval;
 529 }
 530
 531 static int
 532 _request_firmware(const struct firmware **firmware_p, const char *name,
 533                  struct device *device, int uevent, bool nowait)
 534 {
 535         struct device *f_dev;
 536         struct firmware_priv *fw_priv;
 537         struct firmware *firmware;
 538         int retval;
 539
 540         if (!firmware_p)
 541                 return -EINVAL;
 542
 543         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
 544         if (!firmware) {
 545                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
 546                         __func__);
 547                 retval = -ENOMEM;
 548                 goto out;
 549         }
 550
 551         if (fw_get_builtin_firmware(firmware, name)) {
 552                 dev_dbg(device, "firmware: using built-in firmware %s\n", name);
 553                 return 0;
 554         }
 555
 556         if (uevent)
 557                 dev_dbg(device, "firmware: requesting %s\n", name);
 558
 559         retval = fw_setup_device(firmware, &f_dev, name, device,
 560                                  uevent, nowait);
 561         if (retval)
 562                 goto error_kfree_fw;
 563
 564         fw_priv = dev_get_drvdata(f_dev);
 565
 566         if (uevent) {
 567                 if (loading_timeout > 0) {
 568                         fw_priv->timeout.expires = jiffies + loading_timeout * HZ;
 569                         add_timer(&fw_priv->timeout);
 570                 }
 571
 572                 kobject_uevent(&f_dev->kobj, KOBJ_ADD);
 573                 wait_for_completion(&fw_priv->completion);
 574                 set_bit(FW_STATUS_DONE, &fw_priv->status);
 575                 del_timer_sync(&fw_priv->timeout);
 576         } else
 577                 wait_for_completion(&fw_priv->completion);
 578
 579         mutex_lock(&fw_lock);
 580         if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status)) {
 581                 retval = -ENOENT;
 582                 release_firmware(fw_priv->fw);
 583                 *firmware_p = NULL;
 584         }
 585         fw_priv->fw = NULL;
 586         mutex_unlock(&fw_lock);
 587         device_unregister(f_dev);
 588         goto out;
 589
 590 error_kfree_fw:
 591         kfree(firmware);
 592         *firmware_p = NULL;
 593 out:
 594         return retval;
 595 }
 596
 597 /**
 598  * request_firmware: - send firmware request and wait for it
 599  * @firmware_p: pointer to firmware image
 600  * @name: name of firmware file
 601  * @device: device for which firmware is being loaded
 602  *
 603  *      @firmware_p will be used to return a firmware image by the name
 604  *      of @name for device @device.
 605  *
 606  *      Should be called from user context where sleeping is allowed.
 607  *
 608  *      @name will be used as $FIRMWARE in the uevent environment and
 609  *      should be distinctive enough not to be confused with any other
 610  *      firmware image for this or any other device.
 611  **/
 612 int
 613 request_firmware(const struct firmware **firmware_p, const char *name,
 614                  struct device *device)
 615 {
 616         int uevent = 1;
 617         return _request_firmware(firmware_p, name, device, uevent, false);
 618 }
 619
 620 /**
 621  * release_firmware: - release the resource associated with a firmware image
 622  * @fw: firmware resource to release
 623  **/
 624 void release_firmware(const struct firmware *fw)
 625 {
 626         if (fw) {
 627                 if (!fw_is_builtin_firmware(fw))
 628                         firmware_free_data(fw);
 629                 kfree(fw);
 630         }
 631 }
 632
 633 /* Async support */
 634 struct firmware_work {
 635         struct work_struct work;
 636         struct module *module;
 637         const char *name;
 638         struct device *device;
 639         void *context;
 640         void (*cont)(const struct firmware *fw, void *context);
 641         int uevent;
 642 };
 643
 644 static int
 645 request_firmware_work_func(void *arg)
 646 {
 647         struct firmware_work *fw_work = arg;
 648         const struct firmware *fw;
 649         int ret;
 650         if (!arg) {
 651                 WARN_ON(1);
 652                 return 0;
 653         }
 654         ret = _request_firmware(&fw, fw_work->name, fw_work->device,
 655                 fw_work->uevent, true);
 656
 657         fw_work->cont(fw, fw_work->context);
 658
 659         module_put(fw_work->module);
 660         kfree(fw_work);
 661         return ret;
 662 }
 663
 664 /**
 665  * request_firmware_nowait - asynchronous version of request_firmware
 666  * @module: module requesting the firmware
 667  * @uevent: sends uevent to copy the firmware image if this flag
 668  *      is non-zero else the firmware copy must be done manually.
 669  * @name: name of firmware file
 670  * @device: device for which firmware is being loaded
 671  * @gfp: allocation flags
 672  * @context: will be passed over to @cont, and
 673  *      @fw may be %NULL if firmware request fails.
 674  * @cont: function will be called asynchronously when the firmware
 675  *      request is over.
 676  *
 677  *      Asynchronous variant of request_firmware() for user contexts where
 678  *      it is not possible to sleep for long time. It can't be called
 679  *      in atomic contexts.
 680  **/
 681 int
 682 request_firmware_nowait(
 683         struct module *module, int uevent,
 684         const char *name, struct device *device, gfp_t gfp, void *context,
 685         void (*cont)(const struct firmware *fw, void *context))
 686 {
 687         struct task_struct *task;
 688         struct firmware_work *fw_work = kmalloc(sizeof (struct firmware_work),
 689                                                 gfp);
 690
 691         if (!fw_work)
 692                 return -ENOMEM;
 693         if (!try_module_get(module)) {
 694                 kfree(fw_work);
 695                 return -EFAULT;
 696         }
 697
 698         *fw_work = (struct firmware_work) {
 699                 .module = module,
 700                 .name = name,
 701                 .device = device,
 702                 .context = context,
 703                 .cont = cont,
 704                 .uevent = uevent,
 705         };
 706
 707         task = kthread_run(request_firmware_work_func, fw_work,
 708                             "firmware/%s", name);
 709
 710         if (IS_ERR(task)) {
 711                 fw_work->cont(NULL, fw_work->context);
 712                 module_put(fw_work->module);
 713                 kfree(fw_work);
 714                 return PTR_ERR(task);
 715         }
 716         return 0;
 717 }
 718
 719 static int __init firmware_class_init(void)
 720 {
 721         return class_register(&firmware_class);
 722 }
 723
 724 static void __exit firmware_class_exit(void)
 725 {
 726         class_unregister(&firmware_class);
 727 }
 728
 729 fs_initcall(firmware_class_init);
 730 module_exit(firmware_class_exit);
 731
 732 EXPORT_SYMBOL(release_firmware);
 733 EXPORT_SYMBOL(request_firmware);
 734 EXPORT_SYMBOL(request_firmware_nowait);