root/drivers/base/firmware_loader/fallback.c

/* [<][>][^][v][top][bottom][index][help] */

DEFINITIONS

This source file includes following definitions.
  1. __firmware_loading_timeout
  2. __fw_fallback_set_timeout
  3. fw_fallback_set_cache_timeout
  4. fw_fallback_set_default_timeout
  5. firmware_loading_timeout
  6. fw_sysfs_done
  7. fw_sysfs_loading
  8. fw_sysfs_wait_timeout
  9. to_fw_sysfs
  10. __fw_load_abort
  11. fw_load_abort
  12. kill_pending_fw_fallback_reqs
  13. timeout_show
  14. timeout_store
  15. fw_dev_release
  16. do_firmware_uevent
  17. firmware_uevent
  18. register_sysfs_loader
  19. unregister_sysfs_loader
  20. firmware_loading_show
  21. firmware_loading_store
  22. firmware_rw_data
  23. firmware_rw
  24. firmware_data_read
  25. fw_realloc_pages
  26. firmware_data_write
  27. fw_create_instance
  28. fw_load_sysfs_fallback
  29. fw_load_from_user_helper
  30. fw_force_sysfs_fallback
  31. fw_run_sysfs_fallback
  32. firmware_fallback_sysfs

   1 // SPDX-License-Identifier: GPL-2.0
   2 
   3 #include <linux/types.h>
   4 #include <linux/kconfig.h>
   5 #include <linux/list.h>
   6 #include <linux/slab.h>
   7 #include <linux/security.h>
   8 #include <linux/highmem.h>
   9 #include <linux/umh.h>
  10 #include <linux/sysctl.h>
  11 #include <linux/vmalloc.h>
  12 
  13 #include "fallback.h"
  14 #include "firmware.h"
  15 
  16 /*
  17  * firmware fallback mechanism
  18  */
  19 
  20 extern struct firmware_fallback_config fw_fallback_config;
  21 
  22 /* These getters are vetted to use int properly */
  23 static inline int __firmware_loading_timeout(void)
  24 {
  25         return fw_fallback_config.loading_timeout;
  26 }
  27 
  28 /* These setters are vetted to use int properly */
  29 static void __fw_fallback_set_timeout(int timeout)
  30 {
  31         fw_fallback_config.loading_timeout = timeout;
  32 }
  33 
  34 /*
  35  * use small loading timeout for caching devices' firmware because all these
  36  * firmware images have been loaded successfully at lease once, also system is
  37  * ready for completing firmware loading now. The maximum size of firmware in
  38  * current distributions is about 2M bytes, so 10 secs should be enough.
  39  */
  40 void fw_fallback_set_cache_timeout(void)
  41 {
  42         fw_fallback_config.old_timeout = __firmware_loading_timeout();
  43         __fw_fallback_set_timeout(10);
  44 }
  45 
  46 /* Restores the timeout to the value last configured during normal operation */
  47 void fw_fallback_set_default_timeout(void)
  48 {
  49         __fw_fallback_set_timeout(fw_fallback_config.old_timeout);
  50 }
  51 
  52 static long firmware_loading_timeout(void)
  53 {
  54         return __firmware_loading_timeout() > 0 ?
  55                 __firmware_loading_timeout() * HZ : MAX_JIFFY_OFFSET;
  56 }
  57 
  58 static inline bool fw_sysfs_done(struct fw_priv *fw_priv)
  59 {
  60         return __fw_state_check(fw_priv, FW_STATUS_DONE);
  61 }
  62 
  63 static inline bool fw_sysfs_loading(struct fw_priv *fw_priv)
  64 {
  65         return __fw_state_check(fw_priv, FW_STATUS_LOADING);
  66 }
  67 
  68 static inline int fw_sysfs_wait_timeout(struct fw_priv *fw_priv,  long timeout)
  69 {
  70         return __fw_state_wait_common(fw_priv, timeout);
  71 }
  72 
  73 struct fw_sysfs {
  74         bool nowait;
  75         struct device dev;
  76         struct fw_priv *fw_priv;
  77         struct firmware *fw;
  78 };
  79 
  80 static struct fw_sysfs *to_fw_sysfs(struct device *dev)
  81 {
  82         return container_of(dev, struct fw_sysfs, dev);
  83 }
  84 
  85 static void __fw_load_abort(struct fw_priv *fw_priv)
  86 {
  87         /*
  88          * There is a small window in which user can write to 'loading'
  89          * between loading done and disappearance of 'loading'
  90          */
  91         if (fw_sysfs_done(fw_priv))
  92                 return;
  93 
  94         list_del_init(&fw_priv->pending_list);
  95         fw_state_aborted(fw_priv);
  96 }
  97 
  98 static void fw_load_abort(struct fw_sysfs *fw_sysfs)
  99 {
 100         struct fw_priv *fw_priv = fw_sysfs->fw_priv;
 101 
 102         __fw_load_abort(fw_priv);
 103 }
 104 
 105 static LIST_HEAD(pending_fw_head);
 106 
 107 void kill_pending_fw_fallback_reqs(bool only_kill_custom)
 108 {
 109         struct fw_priv *fw_priv;
 110         struct fw_priv *next;
 111 
 112         mutex_lock(&fw_lock);
 113         list_for_each_entry_safe(fw_priv, next, &pending_fw_head,
 114                                  pending_list) {
 115                 if (!fw_priv->need_uevent || !only_kill_custom)
 116                          __fw_load_abort(fw_priv);
 117         }
 118         mutex_unlock(&fw_lock);
 119 }
 120 
 121 static ssize_t timeout_show(struct class *class, struct class_attribute *attr,
 122                             char *buf)
 123 {
 124         return sprintf(buf, "%d\n", __firmware_loading_timeout());
 125 }
 126 
 127 /**
 128  * firmware_timeout_store() - set number of seconds to wait for firmware
 129  * @class: device class pointer
 130  * @attr: device attribute pointer
 131  * @buf: buffer to scan for timeout value
 132  * @count: number of bytes in @buf
 133  *
 134  *      Sets the number of seconds to wait for the firmware.  Once
 135  *      this expires an error will be returned to the driver and no
 136  *      firmware will be provided.
 137  *
 138  *      Note: zero means 'wait forever'.
 139  **/
 140 static ssize_t timeout_store(struct class *class, struct class_attribute *attr,
 141                              const char *buf, size_t count)
 142 {
 143         int tmp_loading_timeout = simple_strtol(buf, NULL, 10);
 144 
 145         if (tmp_loading_timeout < 0)
 146                 tmp_loading_timeout = 0;
 147 
 148         __fw_fallback_set_timeout(tmp_loading_timeout);
 149 
 150         return count;
 151 }
 152 static CLASS_ATTR_RW(timeout);
 153 
 154 static struct attribute *firmware_class_attrs[] = {
 155         &class_attr_timeout.attr,
 156         NULL,
 157 };
 158 ATTRIBUTE_GROUPS(firmware_class);
 159 
 160 static void fw_dev_release(struct device *dev)
 161 {
 162         struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
 163 
 164         kfree(fw_sysfs);
 165 }
 166 
 167 static int do_firmware_uevent(struct fw_sysfs *fw_sysfs, struct kobj_uevent_env *env)
 168 {
 169         if (add_uevent_var(env, "FIRMWARE=%s", fw_sysfs->fw_priv->fw_name))
 170                 return -ENOMEM;
 171         if (add_uevent_var(env, "TIMEOUT=%i", __firmware_loading_timeout()))
 172                 return -ENOMEM;
 173         if (add_uevent_var(env, "ASYNC=%d", fw_sysfs->nowait))
 174                 return -ENOMEM;
 175 
 176         return 0;
 177 }
 178 
 179 static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
 180 {
 181         struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
 182         int err = 0;
 183 
 184         mutex_lock(&fw_lock);
 185         if (fw_sysfs->fw_priv)
 186                 err = do_firmware_uevent(fw_sysfs, env);
 187         mutex_unlock(&fw_lock);
 188         return err;
 189 }
 190 
 191 static struct class firmware_class = {
 192         .name           = "firmware",
 193         .class_groups   = firmware_class_groups,
 194         .dev_uevent     = firmware_uevent,
 195         .dev_release    = fw_dev_release,
 196 };
 197 
 198 int register_sysfs_loader(void)
 199 {
 200         return class_register(&firmware_class);
 201 }
 202 
 203 void unregister_sysfs_loader(void)
 204 {
 205         class_unregister(&firmware_class);
 206 }
 207 
 208 static ssize_t firmware_loading_show(struct device *dev,
 209                                      struct device_attribute *attr, char *buf)
 210 {
 211         struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
 212         int loading = 0;
 213 
 214         mutex_lock(&fw_lock);
 215         if (fw_sysfs->fw_priv)
 216                 loading = fw_sysfs_loading(fw_sysfs->fw_priv);
 217         mutex_unlock(&fw_lock);
 218 
 219         return sprintf(buf, "%d\n", loading);
 220 }
 221 
 222 /**
 223  * firmware_loading_store() - set value in the 'loading' control file
 224  * @dev: device pointer
 225  * @attr: device attribute pointer
 226  * @buf: buffer to scan for loading control value
 227  * @count: number of bytes in @buf
 228  *
 229  *      The relevant values are:
 230  *
 231  *       1: Start a load, discarding any previous partial load.
 232  *       0: Conclude the load and hand the data to the driver code.
 233  *      -1: Conclude the load with an error and discard any written data.
 234  **/
 235 static ssize_t firmware_loading_store(struct device *dev,
 236                                       struct device_attribute *attr,
 237                                       const char *buf, size_t count)
 238 {
 239         struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
 240         struct fw_priv *fw_priv;
 241         ssize_t written = count;
 242         int loading = simple_strtol(buf, NULL, 10);
 243 
 244         mutex_lock(&fw_lock);
 245         fw_priv = fw_sysfs->fw_priv;
 246         if (fw_state_is_aborted(fw_priv))
 247                 goto out;
 248 
 249         switch (loading) {
 250         case 1:
 251                 /* discarding any previous partial load */
 252                 if (!fw_sysfs_done(fw_priv)) {
 253                         fw_free_paged_buf(fw_priv);
 254                         fw_state_start(fw_priv);
 255                 }
 256                 break;
 257         case 0:
 258                 if (fw_sysfs_loading(fw_priv)) {
 259                         int rc;
 260 
 261                         /*
 262                          * Several loading requests may be pending on
 263                          * one same firmware buf, so let all requests
 264                          * see the mapped 'buf->data' once the loading
 265                          * is completed.
 266                          * */
 267                         rc = fw_map_paged_buf(fw_priv);
 268                         if (rc)
 269                                 dev_err(dev, "%s: map pages failed\n",
 270                                         __func__);
 271                         else
 272                                 rc = security_kernel_post_read_file(NULL,
 273                                                 fw_priv->data, fw_priv->size,
 274                                                 READING_FIRMWARE);
 275 
 276                         /*
 277                          * Same logic as fw_load_abort, only the DONE bit
 278                          * is ignored and we set ABORT only on failure.
 279                          */
 280                         list_del_init(&fw_priv->pending_list);
 281                         if (rc) {
 282                                 fw_state_aborted(fw_priv);
 283                                 written = rc;
 284                         } else {
 285                                 fw_state_done(fw_priv);
 286                         }
 287                         break;
 288                 }
 289                 /* fallthrough */
 290         default:
 291                 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
 292                 /* fallthrough */
 293         case -1:
 294                 fw_load_abort(fw_sysfs);
 295                 break;
 296         }
 297 out:
 298         mutex_unlock(&fw_lock);
 299         return written;
 300 }
 301 
 302 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
 303 
 304 static void firmware_rw_data(struct fw_priv *fw_priv, char *buffer,
 305                            loff_t offset, size_t count, bool read)
 306 {
 307         if (read)
 308                 memcpy(buffer, fw_priv->data + offset, count);
 309         else
 310                 memcpy(fw_priv->data + offset, buffer, count);
 311 }
 312 
 313 static void firmware_rw(struct fw_priv *fw_priv, char *buffer,
 314                         loff_t offset, size_t count, bool read)
 315 {
 316         while (count) {
 317                 void *page_data;
 318                 int page_nr = offset >> PAGE_SHIFT;
 319                 int page_ofs = offset & (PAGE_SIZE-1);
 320                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 321 
 322                 page_data = kmap(fw_priv->pages[page_nr]);
 323 
 324                 if (read)
 325                         memcpy(buffer, page_data + page_ofs, page_cnt);
 326                 else
 327                         memcpy(page_data + page_ofs, buffer, page_cnt);
 328 
 329                 kunmap(fw_priv->pages[page_nr]);
 330                 buffer += page_cnt;
 331                 offset += page_cnt;
 332                 count -= page_cnt;
 333         }
 334 }
 335 
 336 static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
 337                                   struct bin_attribute *bin_attr,
 338                                   char *buffer, loff_t offset, size_t count)
 339 {
 340         struct device *dev = kobj_to_dev(kobj);
 341         struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
 342         struct fw_priv *fw_priv;
 343         ssize_t ret_count;
 344 
 345         mutex_lock(&fw_lock);
 346         fw_priv = fw_sysfs->fw_priv;
 347         if (!fw_priv || fw_sysfs_done(fw_priv)) {
 348                 ret_count = -ENODEV;
 349                 goto out;
 350         }
 351         if (offset > fw_priv->size) {
 352                 ret_count = 0;
 353                 goto out;
 354         }
 355         if (count > fw_priv->size - offset)
 356                 count = fw_priv->size - offset;
 357 
 358         ret_count = count;
 359 
 360         if (fw_priv->data)
 361                 firmware_rw_data(fw_priv, buffer, offset, count, true);
 362         else
 363                 firmware_rw(fw_priv, buffer, offset, count, true);
 364 
 365 out:
 366         mutex_unlock(&fw_lock);
 367         return ret_count;
 368 }
 369 
 370 static int fw_realloc_pages(struct fw_sysfs *fw_sysfs, int min_size)
 371 {
 372         int err;
 373 
 374         err = fw_grow_paged_buf(fw_sysfs->fw_priv,
 375                                 PAGE_ALIGN(min_size) >> PAGE_SHIFT);
 376         if (err)
 377                 fw_load_abort(fw_sysfs);
 378         return err;
 379 }
 380 
 381 /**
 382  * firmware_data_write() - write method for firmware
 383  * @filp: open sysfs file
 384  * @kobj: kobject for the device
 385  * @bin_attr: bin_attr structure
 386  * @buffer: buffer being written
 387  * @offset: buffer offset for write in total data store area
 388  * @count: buffer size
 389  *
 390  *      Data written to the 'data' attribute will be later handed to
 391  *      the driver as a firmware image.
 392  **/
 393 static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,
 394                                    struct bin_attribute *bin_attr,
 395                                    char *buffer, loff_t offset, size_t count)
 396 {
 397         struct device *dev = kobj_to_dev(kobj);
 398         struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
 399         struct fw_priv *fw_priv;
 400         ssize_t retval;
 401 
 402         if (!capable(CAP_SYS_RAWIO))
 403                 return -EPERM;
 404 
 405         mutex_lock(&fw_lock);
 406         fw_priv = fw_sysfs->fw_priv;
 407         if (!fw_priv || fw_sysfs_done(fw_priv)) {
 408                 retval = -ENODEV;
 409                 goto out;
 410         }
 411 
 412         if (fw_priv->data) {
 413                 if (offset + count > fw_priv->allocated_size) {
 414                         retval = -ENOMEM;
 415                         goto out;
 416                 }
 417                 firmware_rw_data(fw_priv, buffer, offset, count, false);
 418                 retval = count;
 419         } else {
 420                 retval = fw_realloc_pages(fw_sysfs, offset + count);
 421                 if (retval)
 422                         goto out;
 423 
 424                 retval = count;
 425                 firmware_rw(fw_priv, buffer, offset, count, false);
 426         }
 427 
 428         fw_priv->size = max_t(size_t, offset + count, fw_priv->size);
 429 out:
 430         mutex_unlock(&fw_lock);
 431         return retval;
 432 }
 433 
 434 static struct bin_attribute firmware_attr_data = {
 435         .attr = { .name = "data", .mode = 0644 },
 436         .size = 0,
 437         .read = firmware_data_read,
 438         .write = firmware_data_write,
 439 };
 440 
 441 static struct attribute *fw_dev_attrs[] = {
 442         &dev_attr_loading.attr,
 443         NULL
 444 };
 445 
 446 static struct bin_attribute *fw_dev_bin_attrs[] = {
 447         &firmware_attr_data,
 448         NULL
 449 };
 450 
 451 static const struct attribute_group fw_dev_attr_group = {
 452         .attrs = fw_dev_attrs,
 453         .bin_attrs = fw_dev_bin_attrs,
 454 };
 455 
 456 static const struct attribute_group *fw_dev_attr_groups[] = {
 457         &fw_dev_attr_group,
 458         NULL
 459 };
 460 
 461 static struct fw_sysfs *
 462 fw_create_instance(struct firmware *firmware, const char *fw_name,
 463                    struct device *device, enum fw_opt opt_flags)
 464 {
 465         struct fw_sysfs *fw_sysfs;
 466         struct device *f_dev;
 467 
 468         fw_sysfs = kzalloc(sizeof(*fw_sysfs), GFP_KERNEL);
 469         if (!fw_sysfs) {
 470                 fw_sysfs = ERR_PTR(-ENOMEM);
 471                 goto exit;
 472         }
 473 
 474         fw_sysfs->nowait = !!(opt_flags & FW_OPT_NOWAIT);
 475         fw_sysfs->fw = firmware;
 476         f_dev = &fw_sysfs->dev;
 477 
 478         device_initialize(f_dev);
 479         dev_set_name(f_dev, "%s", fw_name);
 480         f_dev->parent = device;
 481         f_dev->class = &firmware_class;
 482         f_dev->groups = fw_dev_attr_groups;
 483 exit:
 484         return fw_sysfs;
 485 }
 486 
 487 /**
 488  * fw_load_sysfs_fallback() - load a firmware via the sysfs fallback mechanism
 489  * @fw_sysfs: firmware sysfs information for the firmware to load
 490  * @opt_flags: flags of options, FW_OPT_*
 491  * @timeout: timeout to wait for the load
 492  *
 493  * In charge of constructing a sysfs fallback interface for firmware loading.
 494  **/
 495 static int fw_load_sysfs_fallback(struct fw_sysfs *fw_sysfs,
 496                                   enum fw_opt opt_flags, long timeout)
 497 {
 498         int retval = 0;
 499         struct device *f_dev = &fw_sysfs->dev;
 500         struct fw_priv *fw_priv = fw_sysfs->fw_priv;
 501 
 502         /* fall back on userspace loading */
 503         if (!fw_priv->data)
 504                 fw_priv->is_paged_buf = true;
 505 
 506         dev_set_uevent_suppress(f_dev, true);
 507 
 508         retval = device_add(f_dev);
 509         if (retval) {
 510                 dev_err(f_dev, "%s: device_register failed\n", __func__);
 511                 goto err_put_dev;
 512         }
 513 
 514         mutex_lock(&fw_lock);
 515         list_add(&fw_priv->pending_list, &pending_fw_head);
 516         mutex_unlock(&fw_lock);
 517 
 518         if (opt_flags & FW_OPT_UEVENT) {
 519                 fw_priv->need_uevent = true;
 520                 dev_set_uevent_suppress(f_dev, false);
 521                 dev_dbg(f_dev, "firmware: requesting %s\n", fw_priv->fw_name);
 522                 kobject_uevent(&fw_sysfs->dev.kobj, KOBJ_ADD);
 523         } else {
 524                 timeout = MAX_JIFFY_OFFSET;
 525         }
 526 
 527         retval = fw_sysfs_wait_timeout(fw_priv, timeout);
 528         if (retval < 0 && retval != -ENOENT) {
 529                 mutex_lock(&fw_lock);
 530                 fw_load_abort(fw_sysfs);
 531                 mutex_unlock(&fw_lock);
 532         }
 533 
 534         if (fw_state_is_aborted(fw_priv)) {
 535                 if (retval == -ERESTARTSYS)
 536                         retval = -EINTR;
 537                 else
 538                         retval = -EAGAIN;
 539         } else if (fw_priv->is_paged_buf && !fw_priv->data)
 540                 retval = -ENOMEM;
 541 
 542         device_del(f_dev);
 543 err_put_dev:
 544         put_device(f_dev);
 545         return retval;
 546 }
 547 
 548 static int fw_load_from_user_helper(struct firmware *firmware,
 549                                     const char *name, struct device *device,
 550                                     enum fw_opt opt_flags)
 551 {
 552         struct fw_sysfs *fw_sysfs;
 553         long timeout;
 554         int ret;
 555 
 556         timeout = firmware_loading_timeout();
 557         if (opt_flags & FW_OPT_NOWAIT) {
 558                 timeout = usermodehelper_read_lock_wait(timeout);
 559                 if (!timeout) {
 560                         dev_dbg(device, "firmware: %s loading timed out\n",
 561                                 name);
 562                         return -EBUSY;
 563                 }
 564         } else {
 565                 ret = usermodehelper_read_trylock();
 566                 if (WARN_ON(ret)) {
 567                         dev_err(device, "firmware: %s will not be loaded\n",
 568                                 name);
 569                         return ret;
 570                 }
 571         }
 572 
 573         fw_sysfs = fw_create_instance(firmware, name, device, opt_flags);
 574         if (IS_ERR(fw_sysfs)) {
 575                 ret = PTR_ERR(fw_sysfs);
 576                 goto out_unlock;
 577         }
 578 
 579         fw_sysfs->fw_priv = firmware->priv;
 580         ret = fw_load_sysfs_fallback(fw_sysfs, opt_flags, timeout);
 581 
 582         if (!ret)
 583                 ret = assign_fw(firmware, device, opt_flags);
 584 
 585 out_unlock:
 586         usermodehelper_read_unlock();
 587 
 588         return ret;
 589 }
 590 
 591 static bool fw_force_sysfs_fallback(enum fw_opt opt_flags)
 592 {
 593         if (fw_fallback_config.force_sysfs_fallback)
 594                 return true;
 595         if (!(opt_flags & FW_OPT_USERHELPER))
 596                 return false;
 597         return true;
 598 }
 599 
 600 static bool fw_run_sysfs_fallback(enum fw_opt opt_flags)
 601 {
 602         int ret;
 603 
 604         if (fw_fallback_config.ignore_sysfs_fallback) {
 605                 pr_info_once("Ignoring firmware sysfs fallback due to sysctl knob\n");
 606                 return false;
 607         }
 608 
 609         if ((opt_flags & FW_OPT_NOFALLBACK))
 610                 return false;
 611 
 612         /* Also permit LSMs and IMA to fail firmware sysfs fallback */
 613         ret = security_kernel_load_data(LOADING_FIRMWARE);
 614         if (ret < 0)
 615                 return false;
 616 
 617         return fw_force_sysfs_fallback(opt_flags);
 618 }
 619 
 620 /**
 621  * firmware_fallback_sysfs() - use the fallback mechanism to find firmware
 622  * @fw: pointer to firmware image
 623  * @name: name of firmware file to look for
 624  * @device: device for which firmware is being loaded
 625  * @opt_flags: options to control firmware loading behaviour
 626  * @ret: return value from direct lookup which triggered the fallback mechanism
 627  *
 628  * This function is called if direct lookup for the firmware failed, it enables
 629  * a fallback mechanism through userspace by exposing a sysfs loading
 630  * interface. Userspace is in charge of loading the firmware through the sysfs
 631  * loading interface. This sysfs fallback mechanism may be disabled completely
 632  * on a system by setting the proc sysctl value ignore_sysfs_fallback to true.
 633  * If this false we check if the internal API caller set the @FW_OPT_NOFALLBACK
 634  * flag, if so it would also disable the fallback mechanism. A system may want
 635  * to enfoce the sysfs fallback mechanism at all times, it can do this by
 636  * setting ignore_sysfs_fallback to false and force_sysfs_fallback to true.
 637  * Enabling force_sysfs_fallback is functionally equivalent to build a kernel
 638  * with CONFIG_FW_LOADER_USER_HELPER_FALLBACK.
 639  **/
 640 int firmware_fallback_sysfs(struct firmware *fw, const char *name,
 641                             struct device *device,
 642                             enum fw_opt opt_flags,
 643                             int ret)
 644 {
 645         if (!fw_run_sysfs_fallback(opt_flags))
 646                 return ret;
 647 
 648         if (!(opt_flags & FW_OPT_NO_WARN))
 649                 dev_warn(device, "Falling back to sysfs fallback for: %s\n",
 650                                  name);
 651         else
 652                 dev_dbg(device, "Falling back to sysfs fallback for: %s\n",
 653                                 name);
 654         return fw_load_from_user_helper(fw, name, device, opt_flags);
 655 }

/* [<][>][^][v][top][bottom][index][help] */