drivers/base/firmware_loader/main.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * main.c - Multi purpose firmware loading support
   4  *
   5  * Copyright (c) 2003 Manuel Estrada Sainz
   6  *
   7  * Please see Documentation/firmware_class/ for more information.
   8  *
   9  */
  10
  11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  12
  13 #include <linux/capability.h>
  14 #include <linux/device.h>
  15 #include <linux/module.h>
  16 #include <linux/init.h>
  17 #include <linux/timer.h>
  18 #include <linux/vmalloc.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/bitops.h>
  21 #include <linux/mutex.h>
  22 #include <linux/workqueue.h>
  23 #include <linux/highmem.h>
  24 #include <linux/firmware.h>
  25 #include <linux/slab.h>
  26 #include <linux/sched.h>
  27 #include <linux/file.h>
  28 #include <linux/list.h>
  29 #include <linux/fs.h>
  30 #include <linux/async.h>
  31 #include <linux/pm.h>
  32 #include <linux/suspend.h>
  33 #include <linux/syscore_ops.h>
  34 #include <linux/reboot.h>
  35 #include <linux/security.h>
  36
  37 #include <generated/utsrelease.h>
  38
  39 #include "../base.h"
  40 #include "firmware.h"
  41 #include "fallback.h"
  42
  43 MODULE_AUTHOR("Manuel Estrada Sainz");
  44 MODULE_DESCRIPTION("Multi purpose firmware loading support");
  45 MODULE_LICENSE("GPL");
  46
  47 struct firmware_cache {
  48         /* firmware_buf instance will be added into the below list */
  49         spinlock_t lock;
  50         struct list_head head;
  51         int state;
  52
  53 #ifdef CONFIG_PM_SLEEP
  54         /*
  55          * Names of firmware images which have been cached successfully
  56          * will be added into the below list so that device uncache
  57          * helper can trace which firmware images have been cached
  58          * before.
  59          */
  60         spinlock_t name_lock;
  61         struct list_head fw_names;
  62
  63         struct delayed_work work;
  64
  65         struct notifier_block   pm_notify;
  66 #endif
  67 };
  68
  69 struct fw_cache_entry {
  70         struct list_head list;
  71         const char *name;
  72 };
  73
  74 struct fw_name_devm {
  75         unsigned long magic;
  76         const char *name;
  77 };
  78
  79 static inline struct fw_priv *to_fw_priv(struct kref *ref)
  80 {
  81         return container_of(ref, struct fw_priv, ref);
  82 }
  83
  84 #define FW_LOADER_NO_CACHE      0
  85 #define FW_LOADER_START_CACHE   1
  86
  87 /* fw_lock could be moved to 'struct fw_sysfs' but since it is just
  88  * guarding for corner cases a global lock should be OK */
  89 DEFINE_MUTEX(fw_lock);
  90
  91 static struct firmware_cache fw_cache;
  92
  93 /* Builtin firmware support */
  94
  95 #ifdef CONFIG_FW_LOADER
  96
  97 extern struct builtin_fw __start_builtin_fw[];
  98 extern struct builtin_fw __end_builtin_fw[];
  99
 100 static void fw_copy_to_prealloc_buf(struct firmware *fw,
 101                                     void *buf, size_t size)
 102 {
 103         if (!buf || size < fw->size)
 104                 return;
 105         memcpy(buf, fw->data, fw->size);
 106 }
 107
 108 static bool fw_get_builtin_firmware(struct firmware *fw, const char *name,
 109                                     void *buf, size_t size)
 110 {
 111         struct builtin_fw *b_fw;
 112
 113         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
 114                 if (strcmp(name, b_fw->name) == 0) {
 115                         fw->size = b_fw->size;
 116                         fw->data = b_fw->data;
 117                         fw_copy_to_prealloc_buf(fw, buf, size);
 118
 119                         return true;
 120                 }
 121         }
 122
 123         return false;
 124 }
 125
 126 static bool fw_is_builtin_firmware(const struct firmware *fw)
 127 {
 128         struct builtin_fw *b_fw;
 129
 130         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
 131                 if (fw->data == b_fw->data)
 132                         return true;
 133
 134         return false;
 135 }
 136
 137 #else /* Module case - no builtin firmware support */
 138
 139 static inline bool fw_get_builtin_firmware(struct firmware *fw,
 140                                            const char *name, void *buf,
 141                                            size_t size)
 142 {
 143         return false;
 144 }
 145
 146 static inline bool fw_is_builtin_firmware(const struct firmware *fw)
 147 {
 148         return false;
 149 }
 150 #endif
 151
 152 static void fw_state_init(struct fw_priv *fw_priv)
 153 {
 154         struct fw_state *fw_st = &fw_priv->fw_st;
 155
 156         init_completion(&fw_st->completion);
 157         fw_st->status = FW_STATUS_UNKNOWN;
 158 }
 159
 160 static inline int fw_state_wait(struct fw_priv *fw_priv)
 161 {
 162         return __fw_state_wait_common(fw_priv, MAX_SCHEDULE_TIMEOUT);
 163 }
 164
 165 static int fw_cache_piggyback_on_request(const char *name);
 166
 167 static struct fw_priv *__allocate_fw_priv(const char *fw_name,
 168                                           struct firmware_cache *fwc,
 169                                           void *dbuf, size_t size)
 170 {
 171         struct fw_priv *fw_priv;
 172
 173         fw_priv = kzalloc(sizeof(*fw_priv), GFP_ATOMIC);
 174         if (!fw_priv)
 175                 return NULL;
 176
 177         fw_priv->fw_name = kstrdup_const(fw_name, GFP_ATOMIC);
 178         if (!fw_priv->fw_name) {
 179                 kfree(fw_priv);
 180                 return NULL;
 181         }
 182
 183         kref_init(&fw_priv->ref);
 184         fw_priv->fwc = fwc;
 185         fw_priv->data = dbuf;
 186         fw_priv->allocated_size = size;
 187         fw_state_init(fw_priv);
 188 #ifdef CONFIG_FW_LOADER_USER_HELPER
 189         INIT_LIST_HEAD(&fw_priv->pending_list);
 190 #endif
 191
 192         pr_debug("%s: fw-%s fw_priv=%p\n", __func__, fw_name, fw_priv);
 193
 194         return fw_priv;
 195 }
 196
 197 static struct fw_priv *__lookup_fw_priv(const char *fw_name)
 198 {
 199         struct fw_priv *tmp;
 200         struct firmware_cache *fwc = &fw_cache;
 201
 202         list_for_each_entry(tmp, &fwc->head, list)
 203                 if (!strcmp(tmp->fw_name, fw_name))
 204                         return tmp;
 205         return NULL;
 206 }
 207
 208 /* Returns 1 for batching firmware requests with the same name */
 209 static int alloc_lookup_fw_priv(const char *fw_name,
 210                                 struct firmware_cache *fwc,
 211                                 struct fw_priv **fw_priv, void *dbuf,
 212                                 size_t size)
 213 {
 214         struct fw_priv *tmp;
 215
 216         spin_lock(&fwc->lock);
 217         tmp = __lookup_fw_priv(fw_name);
 218         if (tmp) {
 219                 kref_get(&tmp->ref);
 220                 spin_unlock(&fwc->lock);
 221                 *fw_priv = tmp;
 222                 pr_debug("batched request - sharing the same struct fw_priv and lookup for multiple requests\n");
 223                 return 1;
 224         }
 225         tmp = __allocate_fw_priv(fw_name, fwc, dbuf, size);
 226         if (tmp)
 227                 list_add(&tmp->list, &fwc->head);
 228         spin_unlock(&fwc->lock);
 229
 230         *fw_priv = tmp;
 231
 232         return tmp ? 0 : -ENOMEM;
 233 }
 234
 235 static void __free_fw_priv(struct kref *ref)
 236         __releases(&fwc->lock)
 237 {
 238         struct fw_priv *fw_priv = to_fw_priv(ref);
 239         struct firmware_cache *fwc = fw_priv->fwc;
 240
 241         pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n",
 242                  __func__, fw_priv->fw_name, fw_priv, fw_priv->data,
 243                  (unsigned int)fw_priv->size);
 244
 245         list_del(&fw_priv->list);
 246         spin_unlock(&fwc->lock);
 247
 248 #ifdef CONFIG_FW_LOADER_USER_HELPER
 249         if (fw_priv->is_paged_buf) {
 250                 int i;
 251                 vunmap(fw_priv->data);
 252                 for (i = 0; i < fw_priv->nr_pages; i++)
 253                         __free_page(fw_priv->pages[i]);
 254                 vfree(fw_priv->pages);
 255         } else
 256 #endif
 257         if (!fw_priv->allocated_size)
 258                 vfree(fw_priv->data);
 259         kfree_const(fw_priv->fw_name);
 260         kfree(fw_priv);
 261 }
 262
 263 static void free_fw_priv(struct fw_priv *fw_priv)
 264 {
 265         struct firmware_cache *fwc = fw_priv->fwc;
 266         spin_lock(&fwc->lock);
 267         if (!kref_put(&fw_priv->ref, __free_fw_priv))
 268                 spin_unlock(&fwc->lock);
 269 }
 270
 271 /* direct firmware loading support */
 272 static char fw_path_para[256];
 273 static const char * const fw_path[] = {
 274         fw_path_para,
 275         "/lib/firmware/updates/" UTS_RELEASE,
 276         "/lib/firmware/updates",
 277         "/lib/firmware/" UTS_RELEASE,
 278         "/lib/firmware"
 279 };
 280
 281 /*
 282  * Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH'
 283  * from kernel command line because firmware_class is generally built in
 284  * kernel instead of module.
 285  */
 286 module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
 287 MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
 288
 289 static int
 290 fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv)
 291 {
 292         loff_t size;
 293         int i, len;
 294         int rc = -ENOENT;
 295         char *path;
 296         enum kernel_read_file_id id = READING_FIRMWARE;
 297         size_t msize = INT_MAX;
 298
 299         /* Already populated data member means we're loading into a buffer */
 300         if (fw_priv->data) {
 301                 id = READING_FIRMWARE_PREALLOC_BUFFER;
 302                 msize = fw_priv->allocated_size;
 303         }
 304
 305         path = __getname();
 306         if (!path)
 307                 return -ENOMEM;
 308
 309         for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
 310                 /* skip the unset customized path */
 311                 if (!fw_path[i][0])
 312                         continue;
 313
 314                 len = snprintf(path, PATH_MAX, "%s/%s",
 315                                fw_path[i], fw_priv->fw_name);
 316                 if (len >= PATH_MAX) {
 317                         rc = -ENAMETOOLONG;
 318                         break;
 319                 }
 320
 321                 fw_priv->size = 0;
 322                 rc = kernel_read_file_from_path(path, &fw_priv->data, &size,
 323                                                 msize, id);
 324                 if (rc) {
 325                         if (rc == -ENOENT)
 326                                 dev_dbg(device, "loading %s failed with error %d\n",
 327                                          path, rc);
 328                         else
 329                                 dev_warn(device, "loading %s failed with error %d\n",
 330                                          path, rc);
 331                         continue;
 332                 }
 333                 dev_dbg(device, "direct-loading %s\n", fw_priv->fw_name);
 334                 fw_priv->size = size;
 335                 fw_state_done(fw_priv);
 336                 break;
 337         }
 338         __putname(path);
 339
 340         return rc;
 341 }
 342
 343 /* firmware holds the ownership of pages */
 344 static void firmware_free_data(const struct firmware *fw)
 345 {
 346         /* Loaded directly? */
 347         if (!fw->priv) {
 348                 vfree(fw->data);
 349                 return;
 350         }
 351         free_fw_priv(fw->priv);
 352 }
 353
 354 /* store the pages buffer info firmware from buf */
 355 static void fw_set_page_data(struct fw_priv *fw_priv, struct firmware *fw)
 356 {
 357         fw->priv = fw_priv;
 358 #ifdef CONFIG_FW_LOADER_USER_HELPER
 359         fw->pages = fw_priv->pages;
 360 #endif
 361         fw->size = fw_priv->size;
 362         fw->data = fw_priv->data;
 363
 364         pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n",
 365                  __func__, fw_priv->fw_name, fw_priv, fw_priv->data,
 366                  (unsigned int)fw_priv->size);
 367 }
 368
 369 #ifdef CONFIG_PM_SLEEP
 370 static void fw_name_devm_release(struct device *dev, void *res)
 371 {
 372         struct fw_name_devm *fwn = res;
 373
 374         if (fwn->magic == (unsigned long)&fw_cache)
 375                 pr_debug("%s: fw_name-%s devm-%p released\n",
 376                                 __func__, fwn->name, res);
 377         kfree_const(fwn->name);
 378 }
 379
 380 static int fw_devm_match(struct device *dev, void *res,
 381                 void *match_data)
 382 {
 383         struct fw_name_devm *fwn = res;
 384
 385         return (fwn->magic == (unsigned long)&fw_cache) &&
 386                 !strcmp(fwn->name, match_data);
 387 }
 388
 389 static struct fw_name_devm *fw_find_devm_name(struct device *dev,
 390                 const char *name)
 391 {
 392         struct fw_name_devm *fwn;
 393
 394         fwn = devres_find(dev, fw_name_devm_release,
 395                           fw_devm_match, (void *)name);
 396         return fwn;
 397 }
 398
 399 static bool fw_cache_is_setup(struct device *dev, const char *name)
 400 {
 401         struct fw_name_devm *fwn;
 402
 403         fwn = fw_find_devm_name(dev, name);
 404         if (fwn)
 405                 return true;
 406
 407         return false;
 408 }
 409
 410 /* add firmware name into devres list */
 411 static int fw_add_devm_name(struct device *dev, const char *name)
 412 {
 413         struct fw_name_devm *fwn;
 414
 415         if (fw_cache_is_setup(dev, name))
 416                 return 0;
 417
 418         fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm),
 419                            GFP_KERNEL);
 420         if (!fwn)
 421                 return -ENOMEM;
 422         fwn->name = kstrdup_const(name, GFP_KERNEL);
 423         if (!fwn->name) {
 424                 devres_free(fwn);
 425                 return -ENOMEM;
 426         }
 427
 428         fwn->magic = (unsigned long)&fw_cache;
 429         devres_add(dev, fwn);
 430
 431         return 0;
 432 }
 433 #else
 434 static bool fw_cache_is_setup(struct device *dev, const char *name)
 435 {
 436         return false;
 437 }
 438
 439 static int fw_add_devm_name(struct device *dev, const char *name)
 440 {
 441         return 0;
 442 }
 443 #endif
 444
 445 int assign_fw(struct firmware *fw, struct device *device,
 446               unsigned int opt_flags)
 447 {
 448         struct fw_priv *fw_priv = fw->priv;
 449         int ret;
 450
 451         mutex_lock(&fw_lock);
 452         if (!fw_priv->size || fw_state_is_aborted(fw_priv)) {
 453                 mutex_unlock(&fw_lock);
 454                 return -ENOENT;
 455         }
 456
 457         /*
 458          * add firmware name into devres list so that we can auto cache
 459          * and uncache firmware for device.
 460          *
 461          * device may has been deleted already, but the problem
 462          * should be fixed in devres or driver core.
 463          */
 464         /* don't cache firmware handled without uevent */
 465         if (device && (opt_flags & FW_OPT_UEVENT) &&
 466             !(opt_flags & FW_OPT_NOCACHE)) {
 467                 ret = fw_add_devm_name(device, fw_priv->fw_name);
 468                 if (ret) {
 469                         mutex_unlock(&fw_lock);
 470                         return ret;
 471                 }
 472         }
 473
 474         /*
 475          * After caching firmware image is started, let it piggyback
 476          * on request firmware.
 477          */
 478         if (!(opt_flags & FW_OPT_NOCACHE) &&
 479             fw_priv->fwc->state == FW_LOADER_START_CACHE) {
 480                 if (fw_cache_piggyback_on_request(fw_priv->fw_name))
 481                         kref_get(&fw_priv->ref);
 482         }
 483
 484         /* pass the pages buffer to driver at the last minute */
 485         fw_set_page_data(fw_priv, fw);
 486         mutex_unlock(&fw_lock);
 487         return 0;
 488 }
 489
 490 /* prepare firmware and firmware_buf structs;
 491  * return 0 if a firmware is already assigned, 1 if need to load one,
 492  * or a negative error code
 493  */
 494 static int
 495 _request_firmware_prepare(struct firmware **firmware_p, const char *name,
 496                           struct device *device, void *dbuf, size_t size)
 497 {
 498         struct firmware *firmware;
 499         struct fw_priv *fw_priv;
 500         int ret;
 501
 502         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
 503         if (!firmware) {
 504                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
 505                         __func__);
 506                 return -ENOMEM;
 507         }
 508
 509         if (fw_get_builtin_firmware(firmware, name, dbuf, size)) {
 510                 dev_dbg(device, "using built-in %s\n", name);
 511                 return 0; /* assigned */
 512         }
 513
 514         ret = alloc_lookup_fw_priv(name, &fw_cache, &fw_priv, dbuf, size);
 515
 516         /*
 517          * bind with 'priv' now to avoid warning in failure path
 518          * of requesting firmware.
 519          */
 520         firmware->priv = fw_priv;
 521
 522         if (ret > 0) {
 523                 ret = fw_state_wait(fw_priv);
 524                 if (!ret) {
 525                         fw_set_page_data(fw_priv, firmware);
 526                         return 0; /* assigned */
 527                 }
 528         }
 529
 530         if (ret < 0)
 531                 return ret;
 532         return 1; /* need to load */
 533 }
 534
 535 /*
 536  * Batched requests need only one wake, we need to do this step last due to the
 537  * fallback mechanism. The buf is protected with kref_get(), and it won't be
 538  * released until the last user calls release_firmware().
 539  *
 540  * Failed batched requests are possible as well, in such cases we just share
 541  * the struct fw_priv and won't release it until all requests are woken
 542  * and have gone through this same path.
 543  */
 544 static void fw_abort_batch_reqs(struct firmware *fw)
 545 {
 546         struct fw_priv *fw_priv;
 547
 548         /* Loaded directly? */
 549         if (!fw || !fw->priv)
 550                 return;
 551
 552         fw_priv = fw->priv;
 553         if (!fw_state_is_aborted(fw_priv))
 554                 fw_state_aborted(fw_priv);
 555 }
 556
 557 /* called from request_firmware() and request_firmware_work_func() */
 558 static int
 559 _request_firmware(const struct firmware **firmware_p, const char *name,
 560                   struct device *device, void *buf, size_t size,
 561                   unsigned int opt_flags)
 562 {
 563         struct firmware *fw = NULL;
 564         int ret;
 565
 566         if (!firmware_p)
 567                 return -EINVAL;
 568
 569         if (!name || name[0] == '\0') {
 570                 ret = -EINVAL;
 571                 goto out;
 572         }
 573
 574         ret = _request_firmware_prepare(&fw, name, device, buf, size);
 575         if (ret <= 0) /* error or already assigned */
 576                 goto out;
 577
 578         ret = fw_get_filesystem_firmware(device, fw->priv);
 579         if (ret) {
 580                 if (!(opt_flags & FW_OPT_NO_WARN))
 581                         dev_warn(device,
 582                                  "Direct firmware load for %s failed with error %d\n",
 583                                  name, ret);
 584                 ret = fw_sysfs_fallback(fw, name, device, opt_flags, ret);
 585         } else
 586                 ret = assign_fw(fw, device, opt_flags);
 587
 588  out:
 589         if (ret < 0) {
 590                 fw_abort_batch_reqs(fw);
 591                 release_firmware(fw);
 592                 fw = NULL;
 593         }
 594
 595         *firmware_p = fw;
 596         return ret;
 597 }
 598
 599 /**
 600  * request_firmware: - send firmware request and wait for it
 601  * @firmware_p: pointer to firmware image
 602  * @name: name of firmware file
 603  * @device: device for which firmware is being loaded
 604  *
 605  *      @firmware_p will be used to return a firmware image by the name
 606  *      of @name for device @device.
 607  *
 608  *      Should be called from user context where sleeping is allowed.
 609  *
 610  *      @name will be used as $FIRMWARE in the uevent environment and
 611  *      should be distinctive enough not to be confused with any other
 612  *      firmware image for this or any other device.
 613  *
 614  *      Caller must hold the reference count of @device.
 615  *
 616  *      The function can be called safely inside device's suspend and
 617  *      resume callback.
 618  **/
 619 int
 620 request_firmware(const struct firmware **firmware_p, const char *name,
 621                  struct device *device)
 622 {
 623         int ret;
 624
 625         /* Need to pin this module until return */
 626         __module_get(THIS_MODULE);
 627         ret = _request_firmware(firmware_p, name, device, NULL, 0,
 628                                 FW_OPT_UEVENT);
 629         module_put(THIS_MODULE);
 630         return ret;
 631 }
 632 EXPORT_SYMBOL(request_firmware);
 633
 634 /**
 635  * request_firmware_direct: - load firmware directly without usermode helper
 636  * @firmware_p: pointer to firmware image
 637  * @name: name of firmware file
 638  * @device: device for which firmware is being loaded
 639  *
 640  * This function works pretty much like request_firmware(), but this doesn't
 641  * fall back to usermode helper even if the firmware couldn't be loaded
 642  * directly from fs.  Hence it's useful for loading optional firmwares, which
 643  * aren't always present, without extra long timeouts of udev.
 644  **/
 645 int request_firmware_direct(const struct firmware **firmware_p,
 646                             const char *name, struct device *device)
 647 {
 648         int ret;
 649
 650         __module_get(THIS_MODULE);
 651         ret = _request_firmware(firmware_p, name, device, NULL, 0,
 652                                 FW_OPT_UEVENT | FW_OPT_NO_WARN |
 653                                 FW_OPT_NOFALLBACK);
 654         module_put(THIS_MODULE);
 655         return ret;
 656 }
 657 EXPORT_SYMBOL_GPL(request_firmware_direct);
 658
 659 /**
 660  * firmware_request_cache: - cache firmware for suspend so resume can use it
 661  * @name: name of firmware file
 662  * @device: device for which firmware should be cached for
 663  *
 664  * There are some devices with an optimization that enables the device to not
 665  * require loading firmware on system reboot. This optimization may still
 666  * require the firmware present on resume from suspend. This routine can be
 667  * used to ensure the firmware is present on resume from suspend in these
 668  * situations. This helper is not compatible with drivers which use
 669  * request_firmware_into_buf() or request_firmware_nowait() with no uevent set.
 670  **/
 671 int firmware_request_cache(struct device *device, const char *name)
 672 {
 673         int ret;
 674
 675         mutex_lock(&fw_lock);
 676         ret = fw_add_devm_name(device, name);
 677         mutex_unlock(&fw_lock);
 678
 679         return ret;
 680 }
 681 EXPORT_SYMBOL_GPL(firmware_request_cache);
 682
 683 /**
 684  * request_firmware_into_buf - load firmware into a previously allocated buffer
 685  * @firmware_p: pointer to firmware image
 686  * @name: name of firmware file
 687  * @device: device for which firmware is being loaded and DMA region allocated
 688  * @buf: address of buffer to load firmware into
 689  * @size: size of buffer
 690  *
 691  * This function works pretty much like request_firmware(), but it doesn't
 692  * allocate a buffer to hold the firmware data. Instead, the firmware
 693  * is loaded directly into the buffer pointed to by @buf and the @firmware_p
 694  * data member is pointed at @buf.
 695  *
 696  * This function doesn't cache firmware either.
 697  */
 698 int
 699 request_firmware_into_buf(const struct firmware **firmware_p, const char *name,
 700                           struct device *device, void *buf, size_t size)
 701 {
 702         int ret;
 703
 704         if (fw_cache_is_setup(device, name))
 705                 return -EOPNOTSUPP;
 706
 707         __module_get(THIS_MODULE);
 708         ret = _request_firmware(firmware_p, name, device, buf, size,
 709                                 FW_OPT_UEVENT | FW_OPT_NOCACHE);
 710         module_put(THIS_MODULE);
 711         return ret;
 712 }
 713 EXPORT_SYMBOL(request_firmware_into_buf);
 714
 715 /**
 716  * release_firmware: - release the resource associated with a firmware image
 717  * @fw: firmware resource to release
 718  **/
 719 void release_firmware(const struct firmware *fw)
 720 {
 721         if (fw) {
 722                 if (!fw_is_builtin_firmware(fw))
 723                         firmware_free_data(fw);
 724                 kfree(fw);
 725         }
 726 }
 727 EXPORT_SYMBOL(release_firmware);
 728
 729 /* Async support */
 730 struct firmware_work {
 731         struct work_struct work;
 732         struct module *module;
 733         const char *name;
 734         struct device *device;
 735         void *context;
 736         void (*cont)(const struct firmware *fw, void *context);
 737         unsigned int opt_flags;
 738 };
 739
 740 static void request_firmware_work_func(struct work_struct *work)
 741 {
 742         struct firmware_work *fw_work;
 743         const struct firmware *fw;
 744
 745         fw_work = container_of(work, struct firmware_work, work);
 746
 747         _request_firmware(&fw, fw_work->name, fw_work->device, NULL, 0,
 748                           fw_work->opt_flags);
 749         fw_work->cont(fw, fw_work->context);
 750         put_device(fw_work->device); /* taken in request_firmware_nowait() */
 751
 752         module_put(fw_work->module);
 753         kfree_const(fw_work->name);
 754         kfree(fw_work);
 755 }
 756
 757 /**
 758  * request_firmware_nowait - asynchronous version of request_firmware
 759  * @module: module requesting the firmware
 760  * @uevent: sends uevent to copy the firmware image if this flag
 761  *      is non-zero else the firmware copy must be done manually.
 762  * @name: name of firmware file
 763  * @device: device for which firmware is being loaded
 764  * @gfp: allocation flags
 765  * @context: will be passed over to @cont, and
 766  *      @fw may be %NULL if firmware request fails.
 767  * @cont: function will be called asynchronously when the firmware
 768  *      request is over.
 769  *
 770  *      Caller must hold the reference count of @device.
 771  *
 772  *      Asynchronous variant of request_firmware() for user contexts:
 773  *              - sleep for as small periods as possible since it may
 774  *                increase kernel boot time of built-in device drivers
 775  *                requesting firmware in their ->probe() methods, if
 776  *                @gfp is GFP_KERNEL.
 777  *
 778  *              - can't sleep at all if @gfp is GFP_ATOMIC.
 779  **/
 780 int
 781 request_firmware_nowait(
 782         struct module *module, bool uevent,
 783         const char *name, struct device *device, gfp_t gfp, void *context,
 784         void (*cont)(const struct firmware *fw, void *context))
 785 {
 786         struct firmware_work *fw_work;
 787
 788         fw_work = kzalloc(sizeof(struct firmware_work), gfp);
 789         if (!fw_work)
 790                 return -ENOMEM;
 791
 792         fw_work->module = module;
 793         fw_work->name = kstrdup_const(name, gfp);
 794         if (!fw_work->name) {
 795                 kfree(fw_work);
 796                 return -ENOMEM;
 797         }
 798         fw_work->device = device;
 799         fw_work->context = context;
 800         fw_work->cont = cont;
 801         fw_work->opt_flags = FW_OPT_NOWAIT |
 802                 (uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
 803
 804         if (!uevent && fw_cache_is_setup(device, name)) {
 805                 kfree_const(fw_work->name);
 806                 kfree(fw_work);
 807                 return -EOPNOTSUPP;
 808         }
 809
 810         if (!try_module_get(module)) {
 811                 kfree_const(fw_work->name);
 812                 kfree(fw_work);
 813                 return -EFAULT;
 814         }
 815
 816         get_device(fw_work->device);
 817         INIT_WORK(&fw_work->work, request_firmware_work_func);
 818         schedule_work(&fw_work->work);
 819         return 0;
 820 }
 821 EXPORT_SYMBOL(request_firmware_nowait);
 822
 823 #ifdef CONFIG_PM_SLEEP
 824 static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
 825
 826 /**
 827  * cache_firmware - cache one firmware image in kernel memory space
 828  * @fw_name: the firmware image name
 829  *
 830  * Cache firmware in kernel memory so that drivers can use it when
 831  * system isn't ready for them to request firmware image from userspace.
 832  * Once it returns successfully, driver can use request_firmware or its
 833  * nowait version to get the cached firmware without any interacting
 834  * with userspace
 835  *
 836  * Return 0 if the firmware image has been cached successfully
 837  * Return !0 otherwise
 838  *
 839  */
 840 static int cache_firmware(const char *fw_name)
 841 {
 842         int ret;
 843         const struct firmware *fw;
 844
 845         pr_debug("%s: %s\n", __func__, fw_name);
 846
 847         ret = request_firmware(&fw, fw_name, NULL);
 848         if (!ret)
 849                 kfree(fw);
 850
 851         pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
 852
 853         return ret;
 854 }
 855
 856 static struct fw_priv *lookup_fw_priv(const char *fw_name)
 857 {
 858         struct fw_priv *tmp;
 859         struct firmware_cache *fwc = &fw_cache;
 860
 861         spin_lock(&fwc->lock);
 862         tmp = __lookup_fw_priv(fw_name);
 863         spin_unlock(&fwc->lock);
 864
 865         return tmp;
 866 }
 867
 868 /**
 869  * uncache_firmware - remove one cached firmware image
 870  * @fw_name: the firmware image name
 871  *
 872  * Uncache one firmware image which has been cached successfully
 873  * before.
 874  *
 875  * Return 0 if the firmware cache has been removed successfully
 876  * Return !0 otherwise
 877  *
 878  */
 879 static int uncache_firmware(const char *fw_name)
 880 {
 881         struct fw_priv *fw_priv;
 882         struct firmware fw;
 883
 884         pr_debug("%s: %s\n", __func__, fw_name);
 885
 886         if (fw_get_builtin_firmware(&fw, fw_name, NULL, 0))
 887                 return 0;
 888
 889         fw_priv = lookup_fw_priv(fw_name);
 890         if (fw_priv) {
 891                 free_fw_priv(fw_priv);
 892                 return 0;
 893         }
 894
 895         return -EINVAL;
 896 }
 897
 898 static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
 899 {
 900         struct fw_cache_entry *fce;
 901
 902         fce = kzalloc(sizeof(*fce), GFP_ATOMIC);
 903         if (!fce)
 904                 goto exit;
 905
 906         fce->name = kstrdup_const(name, GFP_ATOMIC);
 907         if (!fce->name) {
 908                 kfree(fce);
 909                 fce = NULL;
 910                 goto exit;
 911         }
 912 exit:
 913         return fce;
 914 }
 915
 916 static int __fw_entry_found(const char *name)
 917 {
 918         struct firmware_cache *fwc = &fw_cache;
 919         struct fw_cache_entry *fce;
 920
 921         list_for_each_entry(fce, &fwc->fw_names, list) {
 922                 if (!strcmp(fce->name, name))
 923                         return 1;
 924         }
 925         return 0;
 926 }
 927
 928 static int fw_cache_piggyback_on_request(const char *name)
 929 {
 930         struct firmware_cache *fwc = &fw_cache;
 931         struct fw_cache_entry *fce;
 932         int ret = 0;
 933
 934         spin_lock(&fwc->name_lock);
 935         if (__fw_entry_found(name))
 936                 goto found;
 937
 938         fce = alloc_fw_cache_entry(name);
 939         if (fce) {
 940                 ret = 1;
 941                 list_add(&fce->list, &fwc->fw_names);
 942                 pr_debug("%s: fw: %s\n", __func__, name);
 943         }
 944 found:
 945         spin_unlock(&fwc->name_lock);
 946         return ret;
 947 }
 948
 949 static void free_fw_cache_entry(struct fw_cache_entry *fce)
 950 {
 951         kfree_const(fce->name);
 952         kfree(fce);
 953 }
 954
 955 static void __async_dev_cache_fw_image(void *fw_entry,
 956                                        async_cookie_t cookie)
 957 {
 958         struct fw_cache_entry *fce = fw_entry;
 959         struct firmware_cache *fwc = &fw_cache;
 960         int ret;
 961
 962         ret = cache_firmware(fce->name);
 963         if (ret) {
 964                 spin_lock(&fwc->name_lock);
 965                 list_del(&fce->list);
 966                 spin_unlock(&fwc->name_lock);
 967
 968                 free_fw_cache_entry(fce);
 969         }
 970 }
 971
 972 /* called with dev->devres_lock held */
 973 static void dev_create_fw_entry(struct device *dev, void *res,
 974                                 void *data)
 975 {
 976         struct fw_name_devm *fwn = res;
 977         const char *fw_name = fwn->name;
 978         struct list_head *head = data;
 979         struct fw_cache_entry *fce;
 980
 981         fce = alloc_fw_cache_entry(fw_name);
 982         if (fce)
 983                 list_add(&fce->list, head);
 984 }
 985
 986 static int devm_name_match(struct device *dev, void *res,
 987                            void *match_data)
 988 {
 989         struct fw_name_devm *fwn = res;
 990         return (fwn->magic == (unsigned long)match_data);
 991 }
 992
 993 static void dev_cache_fw_image(struct device *dev, void *data)
 994 {
 995         LIST_HEAD(todo);
 996         struct fw_cache_entry *fce;
 997         struct fw_cache_entry *fce_next;
 998         struct firmware_cache *fwc = &fw_cache;
 999
1000         devres_for_each_res(dev, fw_name_devm_release,
1001                             devm_name_match, &fw_cache,
1002                             dev_create_fw_entry, &todo);
1003
1004         list_for_each_entry_safe(fce, fce_next, &todo, list) {
1005                 list_del(&fce->list);
1006
1007                 spin_lock(&fwc->name_lock);
1008                 /* only one cache entry for one firmware */
1009                 if (!__fw_entry_found(fce->name)) {
1010                         list_add(&fce->list, &fwc->fw_names);
1011                 } else {
1012                         free_fw_cache_entry(fce);
1013                         fce = NULL;
1014                 }
1015                 spin_unlock(&fwc->name_lock);
1016
1017                 if (fce)
1018                         async_schedule_domain(__async_dev_cache_fw_image,
1019                                               (void *)fce,
1020                                               &fw_cache_domain);
1021         }
1022 }
1023
1024 static void __device_uncache_fw_images(void)
1025 {
1026         struct firmware_cache *fwc = &fw_cache;
1027         struct fw_cache_entry *fce;
1028
1029         spin_lock(&fwc->name_lock);
1030         while (!list_empty(&fwc->fw_names)) {
1031                 fce = list_entry(fwc->fw_names.next,
1032                                 struct fw_cache_entry, list);
1033                 list_del(&fce->list);
1034                 spin_unlock(&fwc->name_lock);
1035
1036                 uncache_firmware(fce->name);
1037                 free_fw_cache_entry(fce);
1038
1039                 spin_lock(&fwc->name_lock);
1040         }
1041         spin_unlock(&fwc->name_lock);
1042 }
1043
1044 /**
1045  * device_cache_fw_images - cache devices' firmware
1046  *
1047  * If one device called request_firmware or its nowait version
1048  * successfully before, the firmware names are recored into the
1049  * device's devres link list, so device_cache_fw_images can call
1050  * cache_firmware() to cache these firmwares for the device,
1051  * then the device driver can load its firmwares easily at
1052  * time when system is not ready to complete loading firmware.
1053  */
1054 static void device_cache_fw_images(void)
1055 {
1056         struct firmware_cache *fwc = &fw_cache;
1057         DEFINE_WAIT(wait);
1058
1059         pr_debug("%s\n", __func__);
1060
1061         /* cancel uncache work */
1062         cancel_delayed_work_sync(&fwc->work);
1063
1064         fw_fallback_set_cache_timeout();
1065
1066         mutex_lock(&fw_lock);
1067         fwc->state = FW_LOADER_START_CACHE;
1068         dpm_for_each_dev(NULL, dev_cache_fw_image);
1069         mutex_unlock(&fw_lock);
1070
1071         /* wait for completion of caching firmware for all devices */
1072         async_synchronize_full_domain(&fw_cache_domain);
1073
1074         fw_fallback_set_default_timeout();
1075 }
1076
1077 /**
1078  * device_uncache_fw_images - uncache devices' firmware
1079  *
1080  * uncache all firmwares which have been cached successfully
1081  * by device_uncache_fw_images earlier
1082  */
1083 static void device_uncache_fw_images(void)
1084 {
1085         pr_debug("%s\n", __func__);
1086         __device_uncache_fw_images();
1087 }
1088
1089 static void device_uncache_fw_images_work(struct work_struct *work)
1090 {
1091         device_uncache_fw_images();
1092 }
1093
1094 /**
1095  * device_uncache_fw_images_delay - uncache devices firmwares
1096  * @delay: number of milliseconds to delay uncache device firmwares
1097  *
1098  * uncache all devices's firmwares which has been cached successfully
1099  * by device_cache_fw_images after @delay milliseconds.
1100  */
1101 static void device_uncache_fw_images_delay(unsigned long delay)
1102 {
1103         queue_delayed_work(system_power_efficient_wq, &fw_cache.work,
1104                            msecs_to_jiffies(delay));
1105 }
1106
1107 static int fw_pm_notify(struct notifier_block *notify_block,
1108                         unsigned long mode, void *unused)
1109 {
1110         switch (mode) {
1111         case PM_HIBERNATION_PREPARE:
1112         case PM_SUSPEND_PREPARE:
1113         case PM_RESTORE_PREPARE:
1114                 /*
1115                  * kill pending fallback requests with a custom fallback
1116                  * to avoid stalling suspend.
1117                  */
1118                 kill_pending_fw_fallback_reqs(true);
1119                 device_cache_fw_images();
1120                 break;
1121
1122         case PM_POST_SUSPEND:
1123         case PM_POST_HIBERNATION:
1124         case PM_POST_RESTORE:
1125                 /*
1126                  * In case that system sleep failed and syscore_suspend is
1127                  * not called.
1128                  */
1129                 mutex_lock(&fw_lock);
1130                 fw_cache.state = FW_LOADER_NO_CACHE;
1131                 mutex_unlock(&fw_lock);
1132
1133                 device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
1134                 break;
1135         }
1136
1137         return 0;
1138 }
1139
1140 /* stop caching firmware once syscore_suspend is reached */
1141 static int fw_suspend(void)
1142 {
1143         fw_cache.state = FW_LOADER_NO_CACHE;
1144         return 0;
1145 }
1146
1147 static struct syscore_ops fw_syscore_ops = {
1148         .suspend = fw_suspend,
1149 };
1150
1151 static int __init register_fw_pm_ops(void)
1152 {
1153         int ret;
1154
1155         spin_lock_init(&fw_cache.name_lock);
1156         INIT_LIST_HEAD(&fw_cache.fw_names);
1157
1158         INIT_DELAYED_WORK(&fw_cache.work,
1159                           device_uncache_fw_images_work);
1160
1161         fw_cache.pm_notify.notifier_call = fw_pm_notify;
1162         ret = register_pm_notifier(&fw_cache.pm_notify);
1163         if (ret)
1164                 return ret;
1165
1166         register_syscore_ops(&fw_syscore_ops);
1167
1168         return ret;
1169 }
1170
1171 static inline void unregister_fw_pm_ops(void)
1172 {
1173         unregister_syscore_ops(&fw_syscore_ops);
1174         unregister_pm_notifier(&fw_cache.pm_notify);
1175 }
1176 #else
1177 static int fw_cache_piggyback_on_request(const char *name)
1178 {
1179         return 0;
1180 }
1181 static inline int register_fw_pm_ops(void)
1182 {
1183         return 0;
1184 }
1185 static inline void unregister_fw_pm_ops(void)
1186 {
1187 }
1188 #endif
1189
1190 static void __init fw_cache_init(void)
1191 {
1192         spin_lock_init(&fw_cache.lock);
1193         INIT_LIST_HEAD(&fw_cache.head);
1194         fw_cache.state = FW_LOADER_NO_CACHE;
1195 }
1196
1197 static int fw_shutdown_notify(struct notifier_block *unused1,
1198                               unsigned long unused2, void *unused3)
1199 {
1200         /*
1201          * Kill all pending fallback requests to avoid both stalling shutdown,
1202          * and avoid a deadlock with the usermode_lock.
1203          */
1204         kill_pending_fw_fallback_reqs(false);
1205
1206         return NOTIFY_DONE;
1207 }
1208
1209 static struct notifier_block fw_shutdown_nb = {
1210         .notifier_call = fw_shutdown_notify,
1211 };
1212
1213 static int __init firmware_class_init(void)
1214 {
1215         int ret;
1216
1217         /* No need to unfold these on exit */
1218         fw_cache_init();
1219
1220         ret = register_fw_pm_ops();
1221         if (ret)
1222                 return ret;
1223
1224         ret = register_reboot_notifier(&fw_shutdown_nb);
1225         if (ret)
1226                 goto out;
1227
1228         return register_sysfs_loader();
1229
1230 out:
1231         unregister_fw_pm_ops();
1232         return ret;
1233 }
1234
1235 static void __exit firmware_class_exit(void)
1236 {
1237         unregister_fw_pm_ops();
1238         unregister_reboot_notifier(&fw_shutdown_nb);
1239         unregister_sysfs_loader();
1240 }
1241
1242 fs_initcall(firmware_class_init);
1243 module_exit(firmware_class_exit);