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/driver-api/firmware/ 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/kernel_read_file.h>
  16 #include <linux/module.h>
  17 #include <linux/init.h>
  18 #include <linux/initrd.h>
  19 #include <linux/timer.h>
  20 #include <linux/vmalloc.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/bitops.h>
  23 #include <linux/mutex.h>
  24 #include <linux/workqueue.h>
  25 #include <linux/highmem.h>
  26 #include <linux/firmware.h>
  27 #include <linux/slab.h>
  28 #include <linux/sched.h>
  29 #include <linux/file.h>
  30 #include <linux/list.h>
  31 #include <linux/fs.h>
  32 #include <linux/async.h>
  33 #include <linux/pm.h>
  34 #include <linux/suspend.h>
  35 #include <linux/syscore_ops.h>
  36 #include <linux/reboot.h>
  37 #include <linux/security.h>
  38 #include <linux/xz.h>
  39
  40 #include <generated/utsrelease.h>
  41
  42 #include "../base.h"
  43 #include "firmware.h"
  44 #include "fallback.h"
  45
  46 MODULE_AUTHOR("Manuel Estrada Sainz");
  47 MODULE_DESCRIPTION("Multi purpose firmware loading support");
  48 MODULE_LICENSE("GPL");
  49
  50 struct firmware_cache {
  51         /* firmware_buf instance will be added into the below list */
  52         spinlock_t lock;
  53         struct list_head head;
  54         int state;
  55
  56 #ifdef CONFIG_FW_CACHE
  57         /*
  58          * Names of firmware images which have been cached successfully
  59          * will be added into the below list so that device uncache
  60          * helper can trace which firmware images have been cached
  61          * before.
  62          */
  63         spinlock_t name_lock;
  64         struct list_head fw_names;
  65
  66         struct delayed_work work;
  67
  68         struct notifier_block   pm_notify;
  69 #endif
  70 };
  71
  72 struct fw_cache_entry {
  73         struct list_head list;
  74         const char *name;
  75 };
  76
  77 struct fw_name_devm {
  78         unsigned long magic;
  79         const char *name;
  80 };
  81
  82 static inline struct fw_priv *to_fw_priv(struct kref *ref)
  83 {
  84         return container_of(ref, struct fw_priv, ref);
  85 }
  86
  87 #define FW_LOADER_NO_CACHE      0
  88 #define FW_LOADER_START_CACHE   1
  89
  90 /* fw_lock could be moved to 'struct fw_sysfs' but since it is just
  91  * guarding for corner cases a global lock should be OK */
  92 DEFINE_MUTEX(fw_lock);
  93
  94 static struct firmware_cache fw_cache;
  95
  96 /* Builtin firmware support */
  97
  98 #ifdef CONFIG_FW_LOADER
  99
 100 extern struct builtin_fw __start_builtin_fw[];
 101 extern struct builtin_fw __end_builtin_fw[];
 102
 103 static void fw_copy_to_prealloc_buf(struct firmware *fw,
 104                                     void *buf, size_t size)
 105 {
 106         if (!buf || size < fw->size)
 107                 return;
 108         memcpy(buf, fw->data, fw->size);
 109 }
 110
 111 static bool fw_get_builtin_firmware(struct firmware *fw, const char *name,
 112                                     void *buf, size_t size)
 113 {
 114         struct builtin_fw *b_fw;
 115
 116         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
 117                 if (strcmp(name, b_fw->name) == 0) {
 118                         fw->size = b_fw->size;
 119                         fw->data = b_fw->data;
 120                         fw_copy_to_prealloc_buf(fw, buf, size);
 121
 122                         return true;
 123                 }
 124         }
 125
 126         return false;
 127 }
 128
 129 static bool fw_is_builtin_firmware(const struct firmware *fw)
 130 {
 131         struct builtin_fw *b_fw;
 132
 133         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
 134                 if (fw->data == b_fw->data)
 135                         return true;
 136
 137         return false;
 138 }
 139
 140 #else /* Module case - no builtin firmware support */
 141
 142 static inline bool fw_get_builtin_firmware(struct firmware *fw,
 143                                            const char *name, void *buf,
 144                                            size_t size)
 145 {
 146         return false;
 147 }
 148
 149 static inline bool fw_is_builtin_firmware(const struct firmware *fw)
 150 {
 151         return false;
 152 }
 153 #endif
 154
 155 static void fw_state_init(struct fw_priv *fw_priv)
 156 {
 157         struct fw_state *fw_st = &fw_priv->fw_st;
 158
 159         init_completion(&fw_st->completion);
 160         fw_st->status = FW_STATUS_UNKNOWN;
 161 }
 162
 163 static inline int fw_state_wait(struct fw_priv *fw_priv)
 164 {
 165         return __fw_state_wait_common(fw_priv, MAX_SCHEDULE_TIMEOUT);
 166 }
 167
 168 static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv);
 169
 170 static struct fw_priv *__allocate_fw_priv(const char *fw_name,
 171                                           struct firmware_cache *fwc,
 172                                           void *dbuf,
 173                                           size_t size,
 174                                           size_t offset,
 175                                           u32 opt_flags)
 176 {
 177         struct fw_priv *fw_priv;
 178
 179         /* For a partial read, the buffer must be preallocated. */
 180         if ((opt_flags & FW_OPT_PARTIAL) && !dbuf)
 181                 return NULL;
 182
 183         /* Only partial reads are allowed to use an offset. */
 184         if (offset != 0 && !(opt_flags & FW_OPT_PARTIAL))
 185                 return NULL;
 186
 187         fw_priv = kzalloc(sizeof(*fw_priv), GFP_ATOMIC);
 188         if (!fw_priv)
 189                 return NULL;
 190
 191         fw_priv->fw_name = kstrdup_const(fw_name, GFP_ATOMIC);
 192         if (!fw_priv->fw_name) {
 193                 kfree(fw_priv);
 194                 return NULL;
 195         }
 196
 197         kref_init(&fw_priv->ref);
 198         fw_priv->fwc = fwc;
 199         fw_priv->data = dbuf;
 200         fw_priv->allocated_size = size;
 201         fw_priv->offset = offset;
 202         fw_priv->opt_flags = opt_flags;
 203         fw_state_init(fw_priv);
 204 #ifdef CONFIG_FW_LOADER_USER_HELPER
 205         INIT_LIST_HEAD(&fw_priv->pending_list);
 206 #endif
 207
 208         pr_debug("%s: fw-%s fw_priv=%p\n", __func__, fw_name, fw_priv);
 209
 210         return fw_priv;
 211 }
 212
 213 static struct fw_priv *__lookup_fw_priv(const char *fw_name)
 214 {
 215         struct fw_priv *tmp;
 216         struct firmware_cache *fwc = &fw_cache;
 217
 218         list_for_each_entry(tmp, &fwc->head, list)
 219                 if (!strcmp(tmp->fw_name, fw_name))
 220                         return tmp;
 221         return NULL;
 222 }
 223
 224 /* Returns 1 for batching firmware requests with the same name */
 225 static int alloc_lookup_fw_priv(const char *fw_name,
 226                                 struct firmware_cache *fwc,
 227                                 struct fw_priv **fw_priv,
 228                                 void *dbuf,
 229                                 size_t size,
 230                                 size_t offset,
 231                                 u32 opt_flags)
 232 {
 233         struct fw_priv *tmp;
 234
 235         spin_lock(&fwc->lock);
 236         /*
 237          * Do not merge requests that are marked to be non-cached or
 238          * are performing partial reads.
 239          */
 240         if (!(opt_flags & (FW_OPT_NOCACHE | FW_OPT_PARTIAL))) {
 241                 tmp = __lookup_fw_priv(fw_name);
 242                 if (tmp) {
 243                         kref_get(&tmp->ref);
 244                         spin_unlock(&fwc->lock);
 245                         *fw_priv = tmp;
 246                         pr_debug("batched request - sharing the same struct fw_priv and lookup for multiple requests\n");
 247                         return 1;
 248                 }
 249         }
 250
 251         tmp = __allocate_fw_priv(fw_name, fwc, dbuf, size, offset, opt_flags);
 252         if (tmp) {
 253                 INIT_LIST_HEAD(&tmp->list);
 254                 if (!(opt_flags & FW_OPT_NOCACHE))
 255                         list_add(&tmp->list, &fwc->head);
 256         }
 257         spin_unlock(&fwc->lock);
 258
 259         *fw_priv = tmp;
 260
 261         return tmp ? 0 : -ENOMEM;
 262 }
 263
 264 static void __free_fw_priv(struct kref *ref)
 265         __releases(&fwc->lock)
 266 {
 267         struct fw_priv *fw_priv = to_fw_priv(ref);
 268         struct firmware_cache *fwc = fw_priv->fwc;
 269
 270         pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n",
 271                  __func__, fw_priv->fw_name, fw_priv, fw_priv->data,
 272                  (unsigned int)fw_priv->size);
 273
 274         list_del(&fw_priv->list);
 275         spin_unlock(&fwc->lock);
 276
 277         if (fw_is_paged_buf(fw_priv))
 278                 fw_free_paged_buf(fw_priv);
 279         else if (!fw_priv->allocated_size)
 280                 vfree(fw_priv->data);
 281
 282         kfree_const(fw_priv->fw_name);
 283         kfree(fw_priv);
 284 }
 285
 286 static void free_fw_priv(struct fw_priv *fw_priv)
 287 {
 288         struct firmware_cache *fwc = fw_priv->fwc;
 289         spin_lock(&fwc->lock);
 290         if (!kref_put(&fw_priv->ref, __free_fw_priv))
 291                 spin_unlock(&fwc->lock);
 292 }
 293
 294 #ifdef CONFIG_FW_LOADER_PAGED_BUF
 295 bool fw_is_paged_buf(struct fw_priv *fw_priv)
 296 {
 297         return fw_priv->is_paged_buf;
 298 }
 299
 300 void fw_free_paged_buf(struct fw_priv *fw_priv)
 301 {
 302         int i;
 303
 304         if (!fw_priv->pages)
 305                 return;
 306
 307         vunmap(fw_priv->data);
 308
 309         for (i = 0; i < fw_priv->nr_pages; i++)
 310                 __free_page(fw_priv->pages[i]);
 311         kvfree(fw_priv->pages);
 312         fw_priv->pages = NULL;
 313         fw_priv->page_array_size = 0;
 314         fw_priv->nr_pages = 0;
 315 }
 316
 317 int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed)
 318 {
 319         /* If the array of pages is too small, grow it */
 320         if (fw_priv->page_array_size < pages_needed) {
 321                 int new_array_size = max(pages_needed,
 322                                          fw_priv->page_array_size * 2);
 323                 struct page **new_pages;
 324
 325                 new_pages = kvmalloc_array(new_array_size, sizeof(void *),
 326                                            GFP_KERNEL);
 327                 if (!new_pages)
 328                         return -ENOMEM;
 329                 memcpy(new_pages, fw_priv->pages,
 330                        fw_priv->page_array_size * sizeof(void *));
 331                 memset(&new_pages[fw_priv->page_array_size], 0, sizeof(void *) *
 332                        (new_array_size - fw_priv->page_array_size));
 333                 kvfree(fw_priv->pages);
 334                 fw_priv->pages = new_pages;
 335                 fw_priv->page_array_size = new_array_size;
 336         }
 337
 338         while (fw_priv->nr_pages < pages_needed) {
 339                 fw_priv->pages[fw_priv->nr_pages] =
 340                         alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
 341
 342                 if (!fw_priv->pages[fw_priv->nr_pages])
 343                         return -ENOMEM;
 344                 fw_priv->nr_pages++;
 345         }
 346
 347         return 0;
 348 }
 349
 350 int fw_map_paged_buf(struct fw_priv *fw_priv)
 351 {
 352         /* one pages buffer should be mapped/unmapped only once */
 353         if (!fw_priv->pages)
 354                 return 0;
 355
 356         vunmap(fw_priv->data);
 357         fw_priv->data = vmap(fw_priv->pages, fw_priv->nr_pages, 0,
 358                              PAGE_KERNEL_RO);
 359         if (!fw_priv->data)
 360                 return -ENOMEM;
 361
 362         return 0;
 363 }
 364 #endif
 365
 366 /*
 367  * XZ-compressed firmware support
 368  */
 369 #ifdef CONFIG_FW_LOADER_COMPRESS
 370 /* show an error and return the standard error code */
 371 static int fw_decompress_xz_error(struct device *dev, enum xz_ret xz_ret)
 372 {
 373         if (xz_ret != XZ_STREAM_END) {
 374                 dev_warn(dev, "xz decompression failed (xz_ret=%d)\n", xz_ret);
 375                 return xz_ret == XZ_MEM_ERROR ? -ENOMEM : -EINVAL;
 376         }
 377         return 0;
 378 }
 379
 380 /* single-shot decompression onto the pre-allocated buffer */
 381 static int fw_decompress_xz_single(struct device *dev, struct fw_priv *fw_priv,
 382                                    size_t in_size, const void *in_buffer)
 383 {
 384         struct xz_dec *xz_dec;
 385         struct xz_buf xz_buf;
 386         enum xz_ret xz_ret;
 387
 388         xz_dec = xz_dec_init(XZ_SINGLE, (u32)-1);
 389         if (!xz_dec)
 390                 return -ENOMEM;
 391
 392         xz_buf.in_size = in_size;
 393         xz_buf.in = in_buffer;
 394         xz_buf.in_pos = 0;
 395         xz_buf.out_size = fw_priv->allocated_size;
 396         xz_buf.out = fw_priv->data;
 397         xz_buf.out_pos = 0;
 398
 399         xz_ret = xz_dec_run(xz_dec, &xz_buf);
 400         xz_dec_end(xz_dec);
 401
 402         fw_priv->size = xz_buf.out_pos;
 403         return fw_decompress_xz_error(dev, xz_ret);
 404 }
 405
 406 /* decompression on paged buffer and map it */
 407 static int fw_decompress_xz_pages(struct device *dev, struct fw_priv *fw_priv,
 408                                   size_t in_size, const void *in_buffer)
 409 {
 410         struct xz_dec *xz_dec;
 411         struct xz_buf xz_buf;
 412         enum xz_ret xz_ret;
 413         struct page *page;
 414         int err = 0;
 415
 416         xz_dec = xz_dec_init(XZ_DYNALLOC, (u32)-1);
 417         if (!xz_dec)
 418                 return -ENOMEM;
 419
 420         xz_buf.in_size = in_size;
 421         xz_buf.in = in_buffer;
 422         xz_buf.in_pos = 0;
 423
 424         fw_priv->is_paged_buf = true;
 425         fw_priv->size = 0;
 426         do {
 427                 if (fw_grow_paged_buf(fw_priv, fw_priv->nr_pages + 1)) {
 428                         err = -ENOMEM;
 429                         goto out;
 430                 }
 431
 432                 /* decompress onto the new allocated page */
 433                 page = fw_priv->pages[fw_priv->nr_pages - 1];
 434                 xz_buf.out = kmap(page);
 435                 xz_buf.out_pos = 0;
 436                 xz_buf.out_size = PAGE_SIZE;
 437                 xz_ret = xz_dec_run(xz_dec, &xz_buf);
 438                 kunmap(page);
 439                 fw_priv->size += xz_buf.out_pos;
 440                 /* partial decompression means either end or error */
 441                 if (xz_buf.out_pos != PAGE_SIZE)
 442                         break;
 443         } while (xz_ret == XZ_OK);
 444
 445         err = fw_decompress_xz_error(dev, xz_ret);
 446         if (!err)
 447                 err = fw_map_paged_buf(fw_priv);
 448
 449  out:
 450         xz_dec_end(xz_dec);
 451         return err;
 452 }
 453
 454 static int fw_decompress_xz(struct device *dev, struct fw_priv *fw_priv,
 455                             size_t in_size, const void *in_buffer)
 456 {
 457         /* if the buffer is pre-allocated, we can perform in single-shot mode */
 458         if (fw_priv->data)
 459                 return fw_decompress_xz_single(dev, fw_priv, in_size, in_buffer);
 460         else
 461                 return fw_decompress_xz_pages(dev, fw_priv, in_size, in_buffer);
 462 }
 463 #endif /* CONFIG_FW_LOADER_COMPRESS */
 464
 465 /* direct firmware loading support */
 466 static char fw_path_para[256];
 467 static const char * const fw_path[] = {
 468         fw_path_para,
 469         "/lib/firmware/updates/" UTS_RELEASE,
 470         "/lib/firmware/updates",
 471         "/lib/firmware/" UTS_RELEASE,
 472         "/lib/firmware"
 473 };
 474
 475 /*
 476  * Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH'
 477  * from kernel command line because firmware_class is generally built in
 478  * kernel instead of module.
 479  */
 480 module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
 481 MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
 482
 483 static int
 484 fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
 485                            const char *suffix,
 486                            int (*decompress)(struct device *dev,
 487                                              struct fw_priv *fw_priv,
 488                                              size_t in_size,
 489                                              const void *in_buffer))
 490 {
 491         size_t size;
 492         int i, len;
 493         int rc = -ENOENT;
 494         char *path;
 495         size_t msize = INT_MAX;
 496         void *buffer = NULL;
 497
 498         /* Already populated data member means we're loading into a buffer */
 499         if (!decompress && fw_priv->data) {
 500                 buffer = fw_priv->data;
 501                 msize = fw_priv->allocated_size;
 502         }
 503
 504         path = __getname();
 505         if (!path)
 506                 return -ENOMEM;
 507
 508         wait_for_initramfs();
 509         for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
 510                 size_t file_size = 0;
 511                 size_t *file_size_ptr = NULL;
 512
 513                 /* skip the unset customized path */
 514                 if (!fw_path[i][0])
 515                         continue;
 516
 517                 len = snprintf(path, PATH_MAX, "%s/%s%s",
 518                                fw_path[i], fw_priv->fw_name, suffix);
 519                 if (len >= PATH_MAX) {
 520                         rc = -ENAMETOOLONG;
 521                         break;
 522                 }
 523
 524                 fw_priv->size = 0;
 525
 526                 /*
 527                  * The total file size is only examined when doing a partial
 528                  * read; the "full read" case needs to fail if the whole
 529                  * firmware was not completely loaded.
 530                  */
 531                 if ((fw_priv->opt_flags & FW_OPT_PARTIAL) && buffer)
 532                         file_size_ptr = &file_size;
 533
 534                 /* load firmware files from the mount namespace of init */
 535                 rc = kernel_read_file_from_path_initns(path, fw_priv->offset,
 536                                                        &buffer, msize,
 537                                                        file_size_ptr,
 538                                                        READING_FIRMWARE);
 539                 if (rc < 0) {
 540                         if (rc != -ENOENT)
 541                                 dev_warn(device, "loading %s failed with error %d\n",
 542                                          path, rc);
 543                         else
 544                                 dev_dbg(device, "loading %s failed for no such file or directory.\n",
 545                                          path);
 546                         continue;
 547                 }
 548                 size = rc;
 549                 rc = 0;
 550
 551                 dev_dbg(device, "Loading firmware from %s\n", path);
 552                 if (decompress) {
 553                         dev_dbg(device, "f/w decompressing %s\n",
 554                                 fw_priv->fw_name);
 555                         rc = decompress(device, fw_priv, size, buffer);
 556                         /* discard the superfluous original content */
 557                         vfree(buffer);
 558                         buffer = NULL;
 559                         if (rc) {
 560                                 fw_free_paged_buf(fw_priv);
 561                                 continue;
 562                         }
 563                 } else {
 564                         dev_dbg(device, "direct-loading %s\n",
 565                                 fw_priv->fw_name);
 566                         if (!fw_priv->data)
 567                                 fw_priv->data = buffer;
 568                         fw_priv->size = size;
 569                 }
 570                 fw_state_done(fw_priv);
 571                 break;
 572         }
 573         __putname(path);
 574
 575         return rc;
 576 }
 577
 578 /* firmware holds the ownership of pages */
 579 static void firmware_free_data(const struct firmware *fw)
 580 {
 581         /* Loaded directly? */
 582         if (!fw->priv) {
 583                 vfree(fw->data);
 584                 return;
 585         }
 586         free_fw_priv(fw->priv);
 587 }
 588
 589 /* store the pages buffer info firmware from buf */
 590 static void fw_set_page_data(struct fw_priv *fw_priv, struct firmware *fw)
 591 {
 592         fw->priv = fw_priv;
 593         fw->size = fw_priv->size;
 594         fw->data = fw_priv->data;
 595
 596         pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n",
 597                  __func__, fw_priv->fw_name, fw_priv, fw_priv->data,
 598                  (unsigned int)fw_priv->size);
 599 }
 600
 601 #ifdef CONFIG_FW_CACHE
 602 static void fw_name_devm_release(struct device *dev, void *res)
 603 {
 604         struct fw_name_devm *fwn = res;
 605
 606         if (fwn->magic == (unsigned long)&fw_cache)
 607                 pr_debug("%s: fw_name-%s devm-%p released\n",
 608                                 __func__, fwn->name, res);
 609         kfree_const(fwn->name);
 610 }
 611
 612 static int fw_devm_match(struct device *dev, void *res,
 613                 void *match_data)
 614 {
 615         struct fw_name_devm *fwn = res;
 616
 617         return (fwn->magic == (unsigned long)&fw_cache) &&
 618                 !strcmp(fwn->name, match_data);
 619 }
 620
 621 static struct fw_name_devm *fw_find_devm_name(struct device *dev,
 622                 const char *name)
 623 {
 624         struct fw_name_devm *fwn;
 625
 626         fwn = devres_find(dev, fw_name_devm_release,
 627                           fw_devm_match, (void *)name);
 628         return fwn;
 629 }
 630
 631 static bool fw_cache_is_setup(struct device *dev, const char *name)
 632 {
 633         struct fw_name_devm *fwn;
 634
 635         fwn = fw_find_devm_name(dev, name);
 636         if (fwn)
 637                 return true;
 638
 639         return false;
 640 }
 641
 642 /* add firmware name into devres list */
 643 static int fw_add_devm_name(struct device *dev, const char *name)
 644 {
 645         struct fw_name_devm *fwn;
 646
 647         if (fw_cache_is_setup(dev, name))
 648                 return 0;
 649
 650         fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm),
 651                            GFP_KERNEL);
 652         if (!fwn)
 653                 return -ENOMEM;
 654         fwn->name = kstrdup_const(name, GFP_KERNEL);
 655         if (!fwn->name) {
 656                 devres_free(fwn);
 657                 return -ENOMEM;
 658         }
 659
 660         fwn->magic = (unsigned long)&fw_cache;
 661         devres_add(dev, fwn);
 662
 663         return 0;
 664 }
 665 #else
 666 static bool fw_cache_is_setup(struct device *dev, const char *name)
 667 {
 668         return false;
 669 }
 670
 671 static int fw_add_devm_name(struct device *dev, const char *name)
 672 {
 673         return 0;
 674 }
 675 #endif
 676
 677 int assign_fw(struct firmware *fw, struct device *device)
 678 {
 679         struct fw_priv *fw_priv = fw->priv;
 680         int ret;
 681
 682         mutex_lock(&fw_lock);
 683         if (!fw_priv->size || fw_state_is_aborted(fw_priv)) {
 684                 mutex_unlock(&fw_lock);
 685                 return -ENOENT;
 686         }
 687
 688         /*
 689          * add firmware name into devres list so that we can auto cache
 690          * and uncache firmware for device.
 691          *
 692          * device may has been deleted already, but the problem
 693          * should be fixed in devres or driver core.
 694          */
 695         /* don't cache firmware handled without uevent */
 696         if (device && (fw_priv->opt_flags & FW_OPT_UEVENT) &&
 697             !(fw_priv->opt_flags & FW_OPT_NOCACHE)) {
 698                 ret = fw_add_devm_name(device, fw_priv->fw_name);
 699                 if (ret) {
 700                         mutex_unlock(&fw_lock);
 701                         return ret;
 702                 }
 703         }
 704
 705         /*
 706          * After caching firmware image is started, let it piggyback
 707          * on request firmware.
 708          */
 709         if (!(fw_priv->opt_flags & FW_OPT_NOCACHE) &&
 710             fw_priv->fwc->state == FW_LOADER_START_CACHE)
 711                 fw_cache_piggyback_on_request(fw_priv);
 712
 713         /* pass the pages buffer to driver at the last minute */
 714         fw_set_page_data(fw_priv, fw);
 715         mutex_unlock(&fw_lock);
 716         return 0;
 717 }
 718
 719 /* prepare firmware and firmware_buf structs;
 720  * return 0 if a firmware is already assigned, 1 if need to load one,
 721  * or a negative error code
 722  */
 723 static int
 724 _request_firmware_prepare(struct firmware **firmware_p, const char *name,
 725                           struct device *device, void *dbuf, size_t size,
 726                           size_t offset, u32 opt_flags)
 727 {
 728         struct firmware *firmware;
 729         struct fw_priv *fw_priv;
 730         int ret;
 731
 732         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
 733         if (!firmware) {
 734                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
 735                         __func__);
 736                 return -ENOMEM;
 737         }
 738
 739         if (fw_get_builtin_firmware(firmware, name, dbuf, size)) {
 740                 dev_dbg(device, "using built-in %s\n", name);
 741                 return 0; /* assigned */
 742         }
 743
 744         ret = alloc_lookup_fw_priv(name, &fw_cache, &fw_priv, dbuf, size,
 745                                    offset, opt_flags);
 746
 747         /*
 748          * bind with 'priv' now to avoid warning in failure path
 749          * of requesting firmware.
 750          */
 751         firmware->priv = fw_priv;
 752
 753         if (ret > 0) {
 754                 ret = fw_state_wait(fw_priv);
 755                 if (!ret) {
 756                         fw_set_page_data(fw_priv, firmware);
 757                         return 0; /* assigned */
 758                 }
 759         }
 760
 761         if (ret < 0)
 762                 return ret;
 763         return 1; /* need to load */
 764 }
 765
 766 /*
 767  * Batched requests need only one wake, we need to do this step last due to the
 768  * fallback mechanism. The buf is protected with kref_get(), and it won't be
 769  * released until the last user calls release_firmware().
 770  *
 771  * Failed batched requests are possible as well, in such cases we just share
 772  * the struct fw_priv and won't release it until all requests are woken
 773  * and have gone through this same path.
 774  */
 775 static void fw_abort_batch_reqs(struct firmware *fw)
 776 {
 777         struct fw_priv *fw_priv;
 778
 779         /* Loaded directly? */
 780         if (!fw || !fw->priv)
 781                 return;
 782
 783         fw_priv = fw->priv;
 784         mutex_lock(&fw_lock);
 785         if (!fw_state_is_aborted(fw_priv))
 786                 fw_state_aborted(fw_priv);
 787         mutex_unlock(&fw_lock);
 788 }
 789
 790 /* called from request_firmware() and request_firmware_work_func() */
 791 static int
 792 _request_firmware(const struct firmware **firmware_p, const char *name,
 793                   struct device *device, void *buf, size_t size,
 794                   size_t offset, u32 opt_flags)
 795 {
 796         struct firmware *fw = NULL;
 797         bool nondirect = false;
 798         int ret;
 799
 800         if (!firmware_p)
 801                 return -EINVAL;
 802
 803         if (!name || name[0] == '\0') {
 804                 ret = -EINVAL;
 805                 goto out;
 806         }
 807
 808         ret = _request_firmware_prepare(&fw, name, device, buf, size,
 809                                         offset, opt_flags);
 810         if (ret <= 0) /* error or already assigned */
 811                 goto out;
 812
 813         ret = fw_get_filesystem_firmware(device, fw->priv, "", NULL);
 814
 815         /* Only full reads can support decompression, platform, and sysfs. */
 816         if (!(opt_flags & FW_OPT_PARTIAL))
 817                 nondirect = true;
 818
 819 #ifdef CONFIG_FW_LOADER_COMPRESS
 820         if (ret == -ENOENT && nondirect)
 821                 ret = fw_get_filesystem_firmware(device, fw->priv, ".xz",
 822                                                  fw_decompress_xz);
 823 #endif
 824         if (ret == -ENOENT && nondirect)
 825                 ret = firmware_fallback_platform(fw->priv);
 826
 827         if (ret) {
 828                 if (!(opt_flags & FW_OPT_NO_WARN))
 829                         dev_warn(device,
 830                                  "Direct firmware load for %s failed with error %d\n",
 831                                  name, ret);
 832                 if (nondirect)
 833                         ret = firmware_fallback_sysfs(fw, name, device,
 834                                                       opt_flags, ret);
 835         } else
 836                 ret = assign_fw(fw, device);
 837
 838  out:
 839         if (ret < 0) {
 840                 fw_abort_batch_reqs(fw);
 841                 release_firmware(fw);
 842                 fw = NULL;
 843         }
 844
 845         *firmware_p = fw;
 846         return ret;
 847 }
 848
 849 /**
 850  * request_firmware() - send firmware request and wait for it
 851  * @firmware_p: pointer to firmware image
 852  * @name: name of firmware file
 853  * @device: device for which firmware is being loaded
 854  *
 855  *      @firmware_p will be used to return a firmware image by the name
 856  *      of @name for device @device.
 857  *
 858  *      Should be called from user context where sleeping is allowed.
 859  *
 860  *      @name will be used as $FIRMWARE in the uevent environment and
 861  *      should be distinctive enough not to be confused with any other
 862  *      firmware image for this or any other device.
 863  *
 864  *      Caller must hold the reference count of @device.
 865  *
 866  *      The function can be called safely inside device's suspend and
 867  *      resume callback.
 868  **/
 869 int
 870 request_firmware(const struct firmware **firmware_p, const char *name,
 871                  struct device *device)
 872 {
 873         int ret;
 874
 875         /* Need to pin this module until return */
 876         __module_get(THIS_MODULE);
 877         ret = _request_firmware(firmware_p, name, device, NULL, 0, 0,
 878                                 FW_OPT_UEVENT);
 879         module_put(THIS_MODULE);
 880         return ret;
 881 }
 882 EXPORT_SYMBOL(request_firmware);
 883
 884 /**
 885  * firmware_request_nowarn() - request for an optional fw module
 886  * @firmware: pointer to firmware image
 887  * @name: name of firmware file
 888  * @device: device for which firmware is being loaded
 889  *
 890  * This function is similar in behaviour to request_firmware(), except it
 891  * doesn't produce warning messages when the file is not found. The sysfs
 892  * fallback mechanism is enabled if direct filesystem lookup fails. However,
 893  * failures to find the firmware file with it are still suppressed. It is
 894  * therefore up to the driver to check for the return value of this call and to
 895  * decide when to inform the users of errors.
 896  **/
 897 int firmware_request_nowarn(const struct firmware **firmware, const char *name,
 898                             struct device *device)
 899 {
 900         int ret;
 901
 902         /* Need to pin this module until return */
 903         __module_get(THIS_MODULE);
 904         ret = _request_firmware(firmware, name, device, NULL, 0, 0,
 905                                 FW_OPT_UEVENT | FW_OPT_NO_WARN);
 906         module_put(THIS_MODULE);
 907         return ret;
 908 }
 909 EXPORT_SYMBOL_GPL(firmware_request_nowarn);
 910
 911 /**
 912  * request_firmware_direct() - load firmware directly without usermode helper
 913  * @firmware_p: pointer to firmware image
 914  * @name: name of firmware file
 915  * @device: device for which firmware is being loaded
 916  *
 917  * This function works pretty much like request_firmware(), but this doesn't
 918  * fall back to usermode helper even if the firmware couldn't be loaded
 919  * directly from fs.  Hence it's useful for loading optional firmwares, which
 920  * aren't always present, without extra long timeouts of udev.
 921  **/
 922 int request_firmware_direct(const struct firmware **firmware_p,
 923                             const char *name, struct device *device)
 924 {
 925         int ret;
 926
 927         __module_get(THIS_MODULE);
 928         ret = _request_firmware(firmware_p, name, device, NULL, 0, 0,
 929                                 FW_OPT_UEVENT | FW_OPT_NO_WARN |
 930                                 FW_OPT_NOFALLBACK_SYSFS);
 931         module_put(THIS_MODULE);
 932         return ret;
 933 }
 934 EXPORT_SYMBOL_GPL(request_firmware_direct);
 935
 936 /**
 937  * firmware_request_platform() - request firmware with platform-fw fallback
 938  * @firmware: pointer to firmware image
 939  * @name: name of firmware file
 940  * @device: device for which firmware is being loaded
 941  *
 942  * This function is similar in behaviour to request_firmware, except that if
 943  * direct filesystem lookup fails, it will fallback to looking for a copy of the
 944  * requested firmware embedded in the platform's main (e.g. UEFI) firmware.
 945  **/
 946 int firmware_request_platform(const struct firmware **firmware,
 947                               const char *name, struct device *device)
 948 {
 949         int ret;
 950
 951         /* Need to pin this module until return */
 952         __module_get(THIS_MODULE);
 953         ret = _request_firmware(firmware, name, device, NULL, 0, 0,
 954                                 FW_OPT_UEVENT | FW_OPT_FALLBACK_PLATFORM);
 955         module_put(THIS_MODULE);
 956         return ret;
 957 }
 958 EXPORT_SYMBOL_GPL(firmware_request_platform);
 959
 960 /**
 961  * firmware_request_cache() - cache firmware for suspend so resume can use it
 962  * @name: name of firmware file
 963  * @device: device for which firmware should be cached for
 964  *
 965  * There are some devices with an optimization that enables the device to not
 966  * require loading firmware on system reboot. This optimization may still
 967  * require the firmware present on resume from suspend. This routine can be
 968  * used to ensure the firmware is present on resume from suspend in these
 969  * situations. This helper is not compatible with drivers which use
 970  * request_firmware_into_buf() or request_firmware_nowait() with no uevent set.
 971  **/
 972 int firmware_request_cache(struct device *device, const char *name)
 973 {
 974         int ret;
 975
 976         mutex_lock(&fw_lock);
 977         ret = fw_add_devm_name(device, name);
 978         mutex_unlock(&fw_lock);
 979
 980         return ret;
 981 }
 982 EXPORT_SYMBOL_GPL(firmware_request_cache);
 983
 984 /**
 985  * request_firmware_into_buf() - load firmware into a previously allocated buffer
 986  * @firmware_p: pointer to firmware image
 987  * @name: name of firmware file
 988  * @device: device for which firmware is being loaded and DMA region allocated
 989  * @buf: address of buffer to load firmware into
 990  * @size: size of buffer
 991  *
 992  * This function works pretty much like request_firmware(), but it doesn't
 993  * allocate a buffer to hold the firmware data. Instead, the firmware
 994  * is loaded directly into the buffer pointed to by @buf and the @firmware_p
 995  * data member is pointed at @buf.
 996  *
 997  * This function doesn't cache firmware either.
 998  */
 999 int
1000 request_firmware_into_buf(const struct firmware **firmware_p, const char *name,
1001                           struct device *device, void *buf, size_t size)
1002 {
1003         int ret;
1004
1005         if (fw_cache_is_setup(device, name))
1006                 return -EOPNOTSUPP;
1007
1008         __module_get(THIS_MODULE);
1009         ret = _request_firmware(firmware_p, name, device, buf, size, 0,
1010                                 FW_OPT_UEVENT | FW_OPT_NOCACHE);
1011         module_put(THIS_MODULE);
1012         return ret;
1013 }
1014 EXPORT_SYMBOL(request_firmware_into_buf);
1015
1016 /**
1017  * request_partial_firmware_into_buf() - load partial firmware into a previously allocated buffer
1018  * @firmware_p: pointer to firmware image
1019  * @name: name of firmware file
1020  * @device: device for which firmware is being loaded and DMA region allocated
1021  * @buf: address of buffer to load firmware into
1022  * @size: size of buffer
1023  * @offset: offset into file to read
1024  *
1025  * This function works pretty much like request_firmware_into_buf except
1026  * it allows a partial read of the file.
1027  */
1028 int
1029 request_partial_firmware_into_buf(const struct firmware **firmware_p,
1030                                   const char *name, struct device *device,
1031                                   void *buf, size_t size, size_t offset)
1032 {
1033         int ret;
1034
1035         if (fw_cache_is_setup(device, name))
1036                 return -EOPNOTSUPP;
1037
1038         __module_get(THIS_MODULE);
1039         ret = _request_firmware(firmware_p, name, device, buf, size, offset,
1040                                 FW_OPT_UEVENT | FW_OPT_NOCACHE |
1041                                 FW_OPT_PARTIAL);
1042         module_put(THIS_MODULE);
1043         return ret;
1044 }
1045 EXPORT_SYMBOL(request_partial_firmware_into_buf);
1046
1047 /**
1048  * release_firmware() - release the resource associated with a firmware image
1049  * @fw: firmware resource to release
1050  **/
1051 void release_firmware(const struct firmware *fw)
1052 {
1053         if (fw) {
1054                 if (!fw_is_builtin_firmware(fw))
1055                         firmware_free_data(fw);
1056                 kfree(fw);
1057         }
1058 }
1059 EXPORT_SYMBOL(release_firmware);
1060
1061 /* Async support */
1062 struct firmware_work {
1063         struct work_struct work;
1064         struct module *module;
1065         const char *name;
1066         struct device *device;
1067         void *context;
1068         void (*cont)(const struct firmware *fw, void *context);
1069         u32 opt_flags;
1070 };
1071
1072 static void request_firmware_work_func(struct work_struct *work)
1073 {
1074         struct firmware_work *fw_work;
1075         const struct firmware *fw;
1076
1077         fw_work = container_of(work, struct firmware_work, work);
1078
1079         _request_firmware(&fw, fw_work->name, fw_work->device, NULL, 0, 0,
1080                           fw_work->opt_flags);
1081         fw_work->cont(fw, fw_work->context);
1082         put_device(fw_work->device); /* taken in request_firmware_nowait() */
1083
1084         module_put(fw_work->module);
1085         kfree_const(fw_work->name);
1086         kfree(fw_work);
1087 }
1088
1089 /**
1090  * request_firmware_nowait() - asynchronous version of request_firmware
1091  * @module: module requesting the firmware
1092  * @uevent: sends uevent to copy the firmware image if this flag
1093  *      is non-zero else the firmware copy must be done manually.
1094  * @name: name of firmware file
1095  * @device: device for which firmware is being loaded
1096  * @gfp: allocation flags
1097  * @context: will be passed over to @cont, and
1098  *      @fw may be %NULL if firmware request fails.
1099  * @cont: function will be called asynchronously when the firmware
1100  *      request is over.
1101  *
1102  *      Caller must hold the reference count of @device.
1103  *
1104  *      Asynchronous variant of request_firmware() for user contexts:
1105  *              - sleep for as small periods as possible since it may
1106  *                increase kernel boot time of built-in device drivers
1107  *                requesting firmware in their ->probe() methods, if
1108  *                @gfp is GFP_KERNEL.
1109  *
1110  *              - can't sleep at all if @gfp is GFP_ATOMIC.
1111  **/
1112 int
1113 request_firmware_nowait(
1114         struct module *module, bool uevent,
1115         const char *name, struct device *device, gfp_t gfp, void *context,
1116         void (*cont)(const struct firmware *fw, void *context))
1117 {
1118         struct firmware_work *fw_work;
1119
1120         fw_work = kzalloc(sizeof(struct firmware_work), gfp);
1121         if (!fw_work)
1122                 return -ENOMEM;
1123
1124         fw_work->module = module;
1125         fw_work->name = kstrdup_const(name, gfp);
1126         if (!fw_work->name) {
1127                 kfree(fw_work);
1128                 return -ENOMEM;
1129         }
1130         fw_work->device = device;
1131         fw_work->context = context;
1132         fw_work->cont = cont;
1133         fw_work->opt_flags = FW_OPT_NOWAIT |
1134                 (uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
1135
1136         if (!uevent && fw_cache_is_setup(device, name)) {
1137                 kfree_const(fw_work->name);
1138                 kfree(fw_work);
1139                 return -EOPNOTSUPP;
1140         }
1141
1142         if (!try_module_get(module)) {
1143                 kfree_const(fw_work->name);
1144                 kfree(fw_work);
1145                 return -EFAULT;
1146         }
1147
1148         get_device(fw_work->device);
1149         INIT_WORK(&fw_work->work, request_firmware_work_func);
1150         schedule_work(&fw_work->work);
1151         return 0;
1152 }
1153 EXPORT_SYMBOL(request_firmware_nowait);
1154
1155 #ifdef CONFIG_FW_CACHE
1156 static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
1157
1158 /**
1159  * cache_firmware() - cache one firmware image in kernel memory space
1160  * @fw_name: the firmware image name
1161  *
1162  * Cache firmware in kernel memory so that drivers can use it when
1163  * system isn't ready for them to request firmware image from userspace.
1164  * Once it returns successfully, driver can use request_firmware or its
1165  * nowait version to get the cached firmware without any interacting
1166  * with userspace
1167  *
1168  * Return 0 if the firmware image has been cached successfully
1169  * Return !0 otherwise
1170  *
1171  */
1172 static int cache_firmware(const char *fw_name)
1173 {
1174         int ret;
1175         const struct firmware *fw;
1176
1177         pr_debug("%s: %s\n", __func__, fw_name);
1178
1179         ret = request_firmware(&fw, fw_name, NULL);
1180         if (!ret)
1181                 kfree(fw);
1182
1183         pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
1184
1185         return ret;
1186 }
1187
1188 static struct fw_priv *lookup_fw_priv(const char *fw_name)
1189 {
1190         struct fw_priv *tmp;
1191         struct firmware_cache *fwc = &fw_cache;
1192
1193         spin_lock(&fwc->lock);
1194         tmp = __lookup_fw_priv(fw_name);
1195         spin_unlock(&fwc->lock);
1196
1197         return tmp;
1198 }
1199
1200 /**
1201  * uncache_firmware() - remove one cached firmware image
1202  * @fw_name: the firmware image name
1203  *
1204  * Uncache one firmware image which has been cached successfully
1205  * before.
1206  *
1207  * Return 0 if the firmware cache has been removed successfully
1208  * Return !0 otherwise
1209  *
1210  */
1211 static int uncache_firmware(const char *fw_name)
1212 {
1213         struct fw_priv *fw_priv;
1214         struct firmware fw;
1215
1216         pr_debug("%s: %s\n", __func__, fw_name);
1217
1218         if (fw_get_builtin_firmware(&fw, fw_name, NULL, 0))
1219                 return 0;
1220
1221         fw_priv = lookup_fw_priv(fw_name);
1222         if (fw_priv) {
1223                 free_fw_priv(fw_priv);
1224                 return 0;
1225         }
1226
1227         return -EINVAL;
1228 }
1229
1230 static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
1231 {
1232         struct fw_cache_entry *fce;
1233
1234         fce = kzalloc(sizeof(*fce), GFP_ATOMIC);
1235         if (!fce)
1236                 goto exit;
1237
1238         fce->name = kstrdup_const(name, GFP_ATOMIC);
1239         if (!fce->name) {
1240                 kfree(fce);
1241                 fce = NULL;
1242                 goto exit;
1243         }
1244 exit:
1245         return fce;
1246 }
1247
1248 static int __fw_entry_found(const char *name)
1249 {
1250         struct firmware_cache *fwc = &fw_cache;
1251         struct fw_cache_entry *fce;
1252
1253         list_for_each_entry(fce, &fwc->fw_names, list) {
1254                 if (!strcmp(fce->name, name))
1255                         return 1;
1256         }
1257         return 0;
1258 }
1259
1260 static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv)
1261 {
1262         const char *name = fw_priv->fw_name;
1263         struct firmware_cache *fwc = fw_priv->fwc;
1264         struct fw_cache_entry *fce;
1265
1266         spin_lock(&fwc->name_lock);
1267         if (__fw_entry_found(name))
1268                 goto found;
1269
1270         fce = alloc_fw_cache_entry(name);
1271         if (fce) {
1272                 list_add(&fce->list, &fwc->fw_names);
1273                 kref_get(&fw_priv->ref);
1274                 pr_debug("%s: fw: %s\n", __func__, name);
1275         }
1276 found:
1277         spin_unlock(&fwc->name_lock);
1278 }
1279
1280 static void free_fw_cache_entry(struct fw_cache_entry *fce)
1281 {
1282         kfree_const(fce->name);
1283         kfree(fce);
1284 }
1285
1286 static void __async_dev_cache_fw_image(void *fw_entry,
1287                                        async_cookie_t cookie)
1288 {
1289         struct fw_cache_entry *fce = fw_entry;
1290         struct firmware_cache *fwc = &fw_cache;
1291         int ret;
1292
1293         ret = cache_firmware(fce->name);
1294         if (ret) {
1295                 spin_lock(&fwc->name_lock);
1296                 list_del(&fce->list);
1297                 spin_unlock(&fwc->name_lock);
1298
1299                 free_fw_cache_entry(fce);
1300         }
1301 }
1302
1303 /* called with dev->devres_lock held */
1304 static void dev_create_fw_entry(struct device *dev, void *res,
1305                                 void *data)
1306 {
1307         struct fw_name_devm *fwn = res;
1308         const char *fw_name = fwn->name;
1309         struct list_head *head = data;
1310         struct fw_cache_entry *fce;
1311
1312         fce = alloc_fw_cache_entry(fw_name);
1313         if (fce)
1314                 list_add(&fce->list, head);
1315 }
1316
1317 static int devm_name_match(struct device *dev, void *res,
1318                            void *match_data)
1319 {
1320         struct fw_name_devm *fwn = res;
1321         return (fwn->magic == (unsigned long)match_data);
1322 }
1323
1324 static void dev_cache_fw_image(struct device *dev, void *data)
1325 {
1326         LIST_HEAD(todo);
1327         struct fw_cache_entry *fce;
1328         struct fw_cache_entry *fce_next;
1329         struct firmware_cache *fwc = &fw_cache;
1330
1331         devres_for_each_res(dev, fw_name_devm_release,
1332                             devm_name_match, &fw_cache,
1333                             dev_create_fw_entry, &todo);
1334
1335         list_for_each_entry_safe(fce, fce_next, &todo, list) {
1336                 list_del(&fce->list);
1337
1338                 spin_lock(&fwc->name_lock);
1339                 /* only one cache entry for one firmware */
1340                 if (!__fw_entry_found(fce->name)) {
1341                         list_add(&fce->list, &fwc->fw_names);
1342                 } else {
1343                         free_fw_cache_entry(fce);
1344                         fce = NULL;
1345                 }
1346                 spin_unlock(&fwc->name_lock);
1347
1348                 if (fce)
1349                         async_schedule_domain(__async_dev_cache_fw_image,
1350                                               (void *)fce,
1351                                               &fw_cache_domain);
1352         }
1353 }
1354
1355 static void __device_uncache_fw_images(void)
1356 {
1357         struct firmware_cache *fwc = &fw_cache;
1358         struct fw_cache_entry *fce;
1359
1360         spin_lock(&fwc->name_lock);
1361         while (!list_empty(&fwc->fw_names)) {
1362                 fce = list_entry(fwc->fw_names.next,
1363                                 struct fw_cache_entry, list);
1364                 list_del(&fce->list);
1365                 spin_unlock(&fwc->name_lock);
1366
1367                 uncache_firmware(fce->name);
1368                 free_fw_cache_entry(fce);
1369
1370                 spin_lock(&fwc->name_lock);
1371         }
1372         spin_unlock(&fwc->name_lock);
1373 }
1374
1375 /**
1376  * device_cache_fw_images() - cache devices' firmware
1377  *
1378  * If one device called request_firmware or its nowait version
1379  * successfully before, the firmware names are recored into the
1380  * device's devres link list, so device_cache_fw_images can call
1381  * cache_firmware() to cache these firmwares for the device,
1382  * then the device driver can load its firmwares easily at
1383  * time when system is not ready to complete loading firmware.
1384  */
1385 static void device_cache_fw_images(void)
1386 {
1387         struct firmware_cache *fwc = &fw_cache;
1388         DEFINE_WAIT(wait);
1389
1390         pr_debug("%s\n", __func__);
1391
1392         /* cancel uncache work */
1393         cancel_delayed_work_sync(&fwc->work);
1394
1395         fw_fallback_set_cache_timeout();
1396
1397         mutex_lock(&fw_lock);
1398         fwc->state = FW_LOADER_START_CACHE;
1399         dpm_for_each_dev(NULL, dev_cache_fw_image);
1400         mutex_unlock(&fw_lock);
1401
1402         /* wait for completion of caching firmware for all devices */
1403         async_synchronize_full_domain(&fw_cache_domain);
1404
1405         fw_fallback_set_default_timeout();
1406 }
1407
1408 /**
1409  * device_uncache_fw_images() - uncache devices' firmware
1410  *
1411  * uncache all firmwares which have been cached successfully
1412  * by device_uncache_fw_images earlier
1413  */
1414 static void device_uncache_fw_images(void)
1415 {
1416         pr_debug("%s\n", __func__);
1417         __device_uncache_fw_images();
1418 }
1419
1420 static void device_uncache_fw_images_work(struct work_struct *work)
1421 {
1422         device_uncache_fw_images();
1423 }
1424
1425 /**
1426  * device_uncache_fw_images_delay() - uncache devices firmwares
1427  * @delay: number of milliseconds to delay uncache device firmwares
1428  *
1429  * uncache all devices's firmwares which has been cached successfully
1430  * by device_cache_fw_images after @delay milliseconds.
1431  */
1432 static void device_uncache_fw_images_delay(unsigned long delay)
1433 {
1434         queue_delayed_work(system_power_efficient_wq, &fw_cache.work,
1435                            msecs_to_jiffies(delay));
1436 }
1437
1438 static int fw_pm_notify(struct notifier_block *notify_block,
1439                         unsigned long mode, void *unused)
1440 {
1441         switch (mode) {
1442         case PM_HIBERNATION_PREPARE:
1443         case PM_SUSPEND_PREPARE:
1444         case PM_RESTORE_PREPARE:
1445                 /*
1446                  * kill pending fallback requests with a custom fallback
1447                  * to avoid stalling suspend.
1448                  */
1449                 kill_pending_fw_fallback_reqs(true);
1450                 device_cache_fw_images();
1451                 break;
1452
1453         case PM_POST_SUSPEND:
1454         case PM_POST_HIBERNATION:
1455         case PM_POST_RESTORE:
1456                 /*
1457                  * In case that system sleep failed and syscore_suspend is
1458                  * not called.
1459                  */
1460                 mutex_lock(&fw_lock);
1461                 fw_cache.state = FW_LOADER_NO_CACHE;
1462                 mutex_unlock(&fw_lock);
1463
1464                 device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
1465                 break;
1466         }
1467
1468         return 0;
1469 }
1470
1471 /* stop caching firmware once syscore_suspend is reached */
1472 static int fw_suspend(void)
1473 {
1474         fw_cache.state = FW_LOADER_NO_CACHE;
1475         return 0;
1476 }
1477
1478 static struct syscore_ops fw_syscore_ops = {
1479         .suspend = fw_suspend,
1480 };
1481
1482 static int __init register_fw_pm_ops(void)
1483 {
1484         int ret;
1485
1486         spin_lock_init(&fw_cache.name_lock);
1487         INIT_LIST_HEAD(&fw_cache.fw_names);
1488
1489         INIT_DELAYED_WORK(&fw_cache.work,
1490                           device_uncache_fw_images_work);
1491
1492         fw_cache.pm_notify.notifier_call = fw_pm_notify;
1493         ret = register_pm_notifier(&fw_cache.pm_notify);
1494         if (ret)
1495                 return ret;
1496
1497         register_syscore_ops(&fw_syscore_ops);
1498
1499         return ret;
1500 }
1501
1502 static inline void unregister_fw_pm_ops(void)
1503 {
1504         unregister_syscore_ops(&fw_syscore_ops);
1505         unregister_pm_notifier(&fw_cache.pm_notify);
1506 }
1507 #else
1508 static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv)
1509 {
1510 }
1511 static inline int register_fw_pm_ops(void)
1512 {
1513         return 0;
1514 }
1515 static inline void unregister_fw_pm_ops(void)
1516 {
1517 }
1518 #endif
1519
1520 static void __init fw_cache_init(void)
1521 {
1522         spin_lock_init(&fw_cache.lock);
1523         INIT_LIST_HEAD(&fw_cache.head);
1524         fw_cache.state = FW_LOADER_NO_CACHE;
1525 }
1526
1527 static int fw_shutdown_notify(struct notifier_block *unused1,
1528                               unsigned long unused2, void *unused3)
1529 {
1530         /*
1531          * Kill all pending fallback requests to avoid both stalling shutdown,
1532          * and avoid a deadlock with the usermode_lock.
1533          */
1534         kill_pending_fw_fallback_reqs(false);
1535
1536         return NOTIFY_DONE;
1537 }
1538
1539 static struct notifier_block fw_shutdown_nb = {
1540         .notifier_call = fw_shutdown_notify,
1541 };
1542
1543 static int __init firmware_class_init(void)
1544 {
1545         int ret;
1546
1547         /* No need to unfold these on exit */
1548         fw_cache_init();
1549
1550         ret = register_fw_pm_ops();
1551         if (ret)
1552                 return ret;
1553
1554         ret = register_reboot_notifier(&fw_shutdown_nb);
1555         if (ret)
1556                 goto out;
1557
1558         return register_sysfs_loader();
1559
1560 out:
1561         unregister_fw_pm_ops();
1562         return ret;
1563 }
1564
1565 static void __exit firmware_class_exit(void)
1566 {
1567         unregister_fw_pm_ops();
1568         unregister_reboot_notifier(&fw_shutdown_nb);
1569         unregister_sysfs_loader();
1570 }
1571
1572 fs_initcall(firmware_class_init);
1573 module_exit(firmware_class_exit);