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/timer.h>
  19 #include <linux/vmalloc.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/bitops.h>
  22 #include <linux/mutex.h>
  23 #include <linux/workqueue.h>
  24 #include <linux/highmem.h>
  25 #include <linux/firmware.h>
  26 #include <linux/slab.h>
  27 #include <linux/sched.h>
  28 #include <linux/file.h>
  29 #include <linux/list.h>
  30 #include <linux/fs.h>
  31 #include <linux/async.h>
  32 #include <linux/pm.h>
  33 #include <linux/suspend.h>
  34 #include <linux/syscore_ops.h>
  35 #include <linux/reboot.h>
  36 #include <linux/security.h>
  37 #include <linux/xz.h>
  38
  39 #include <generated/utsrelease.h>
  40
  41 #include "../base.h"
  42 #include "firmware.h"
  43 #include "fallback.h"
  44
  45 MODULE_AUTHOR("Manuel Estrada Sainz");
  46 MODULE_DESCRIPTION("Multi purpose firmware loading support");
  47 MODULE_LICENSE("GPL");
  48
  49 struct firmware_cache {
  50         /* firmware_buf instance will be added into the below list */
  51         spinlock_t lock;
  52         struct list_head head;
  53         int state;
  54
  55 #ifdef CONFIG_FW_CACHE
  56         /*
  57          * Names of firmware images which have been cached successfully
  58          * will be added into the below list so that device uncache
  59          * helper can trace which firmware images have been cached
  60          * before.
  61          */
  62         spinlock_t name_lock;
  63         struct list_head fw_names;
  64
  65         struct delayed_work work;
  66
  67         struct notifier_block   pm_notify;
  68 #endif
  69 };
  70
  71 struct fw_cache_entry {
  72         struct list_head list;
  73         const char *name;
  74 };
  75
  76 struct fw_name_devm {
  77         unsigned long magic;
  78         const char *name;
  79 };
  80
  81 static inline struct fw_priv *to_fw_priv(struct kref *ref)
  82 {
  83         return container_of(ref, struct fw_priv, ref);
  84 }
  85
  86 #define FW_LOADER_NO_CACHE      0
  87 #define FW_LOADER_START_CACHE   1
  88
  89 /* fw_lock could be moved to 'struct fw_sysfs' but since it is just
  90  * guarding for corner cases a global lock should be OK */
  91 DEFINE_MUTEX(fw_lock);
  92
  93 static struct firmware_cache fw_cache;
  94
  95 /* Builtin firmware support */
  96
  97 #ifdef CONFIG_FW_LOADER
  98
  99 extern struct builtin_fw __start_builtin_fw[];
 100 extern struct builtin_fw __end_builtin_fw[];
 101
 102 static bool fw_copy_to_prealloc_buf(struct firmware *fw,
 103                                     void *buf, size_t size)
 104 {
 105         if (!buf)
 106                 return true;
 107         if (size < fw->size)
 108                 return false;
 109         memcpy(buf, fw->data, fw->size);
 110         return true;
 111 }
 112
 113 static bool fw_get_builtin_firmware(struct firmware *fw, const char *name,
 114                                     void *buf, size_t size)
 115 {
 116         struct builtin_fw *b_fw;
 117
 118         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
 119                 if (strcmp(name, b_fw->name) == 0) {
 120                         fw->size = b_fw->size;
 121                         fw->data = b_fw->data;
 122                         return fw_copy_to_prealloc_buf(fw, buf, size);
 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         for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
 509                 size_t file_size = 0;
 510                 size_t *file_size_ptr = NULL;
 511
 512                 /* skip the unset customized path */
 513                 if (!fw_path[i][0])
 514                         continue;
 515
 516                 len = snprintf(path, PATH_MAX, "%s/%s%s",
 517                                fw_path[i], fw_priv->fw_name, suffix);
 518                 if (len >= PATH_MAX) {
 519                         rc = -ENAMETOOLONG;
 520                         break;
 521                 }
 522
 523                 fw_priv->size = 0;
 524
 525                 /*
 526                  * The total file size is only examined when doing a partial
 527                  * read; the "full read" case needs to fail if the whole
 528                  * firmware was not completely loaded.
 529                  */
 530                 if ((fw_priv->opt_flags & FW_OPT_PARTIAL) && buffer)
 531                         file_size_ptr = &file_size;
 532
 533                 /* load firmware files from the mount namespace of init */
 534                 rc = kernel_read_file_from_path_initns(path, fw_priv->offset,
 535                                                        &buffer, msize,
 536                                                        file_size_ptr,
 537                                                        READING_FIRMWARE);
 538                 if (rc < 0) {
 539                         if (rc != -ENOENT)
 540                                 dev_warn(device, "loading %s failed with error %d\n",
 541                                          path, rc);
 542                         else
 543                                 dev_dbg(device, "loading %s failed for no such file or directory.\n",
 544                                          path);
 545                         continue;
 546                 }
 547                 size = rc;
 548                 rc = 0;
 549
 550                 dev_dbg(device, "Loading firmware from %s\n", path);
 551                 if (decompress) {
 552                         dev_dbg(device, "f/w decompressing %s\n",
 553                                 fw_priv->fw_name);
 554                         rc = decompress(device, fw_priv, size, buffer);
 555                         /* discard the superfluous original content */
 556                         vfree(buffer);
 557                         buffer = NULL;
 558                         if (rc) {
 559                                 fw_free_paged_buf(fw_priv);
 560                                 continue;
 561                         }
 562                 } else {
 563                         dev_dbg(device, "direct-loading %s\n",
 564                                 fw_priv->fw_name);
 565                         if (!fw_priv->data)
 566                                 fw_priv->data = buffer;
 567                         fw_priv->size = size;
 568                 }
 569                 fw_state_done(fw_priv);
 570                 break;
 571         }
 572         __putname(path);
 573
 574         return rc;
 575 }
 576
 577 /* firmware holds the ownership of pages */
 578 static void firmware_free_data(const struct firmware *fw)
 579 {
 580         /* Loaded directly? */
 581         if (!fw->priv) {
 582                 vfree(fw->data);
 583                 return;
 584         }
 585         free_fw_priv(fw->priv);
 586 }
 587
 588 /* store the pages buffer info firmware from buf */
 589 static void fw_set_page_data(struct fw_priv *fw_priv, struct firmware *fw)
 590 {
 591         fw->priv = fw_priv;
 592         fw->size = fw_priv->size;
 593         fw->data = fw_priv->data;
 594
 595         pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n",
 596                  __func__, fw_priv->fw_name, fw_priv, fw_priv->data,
 597                  (unsigned int)fw_priv->size);
 598 }
 599
 600 #ifdef CONFIG_FW_CACHE
 601 static void fw_name_devm_release(struct device *dev, void *res)
 602 {
 603         struct fw_name_devm *fwn = res;
 604
 605         if (fwn->magic == (unsigned long)&fw_cache)
 606                 pr_debug("%s: fw_name-%s devm-%p released\n",
 607                                 __func__, fwn->name, res);
 608         kfree_const(fwn->name);
 609 }
 610
 611 static int fw_devm_match(struct device *dev, void *res,
 612                 void *match_data)
 613 {
 614         struct fw_name_devm *fwn = res;
 615
 616         return (fwn->magic == (unsigned long)&fw_cache) &&
 617                 !strcmp(fwn->name, match_data);
 618 }
 619
 620 static struct fw_name_devm *fw_find_devm_name(struct device *dev,
 621                 const char *name)
 622 {
 623         struct fw_name_devm *fwn;
 624
 625         fwn = devres_find(dev, fw_name_devm_release,
 626                           fw_devm_match, (void *)name);
 627         return fwn;
 628 }
 629
 630 static bool fw_cache_is_setup(struct device *dev, const char *name)
 631 {
 632         struct fw_name_devm *fwn;
 633
 634         fwn = fw_find_devm_name(dev, name);
 635         if (fwn)
 636                 return true;
 637
 638         return false;
 639 }
 640
 641 /* add firmware name into devres list */
 642 static int fw_add_devm_name(struct device *dev, const char *name)
 643 {
 644         struct fw_name_devm *fwn;
 645
 646         if (fw_cache_is_setup(dev, name))
 647                 return 0;
 648
 649         fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm),
 650                            GFP_KERNEL);
 651         if (!fwn)
 652                 return -ENOMEM;
 653         fwn->name = kstrdup_const(name, GFP_KERNEL);
 654         if (!fwn->name) {
 655                 devres_free(fwn);
 656                 return -ENOMEM;
 657         }
 658
 659         fwn->magic = (unsigned long)&fw_cache;
 660         devres_add(dev, fwn);
 661
 662         return 0;
 663 }
 664 #else
 665 static bool fw_cache_is_setup(struct device *dev, const char *name)
 666 {
 667         return false;
 668 }
 669
 670 static int fw_add_devm_name(struct device *dev, const char *name)
 671 {
 672         return 0;
 673 }
 674 #endif
 675
 676 int assign_fw(struct firmware *fw, struct device *device)
 677 {
 678         struct fw_priv *fw_priv = fw->priv;
 679         int ret;
 680
 681         mutex_lock(&fw_lock);
 682         if (!fw_priv->size || fw_state_is_aborted(fw_priv)) {
 683                 mutex_unlock(&fw_lock);
 684                 return -ENOENT;
 685         }
 686
 687         /*
 688          * add firmware name into devres list so that we can auto cache
 689          * and uncache firmware for device.
 690          *
 691          * device may has been deleted already, but the problem
 692          * should be fixed in devres or driver core.
 693          */
 694         /* don't cache firmware handled without uevent */
 695         if (device && (fw_priv->opt_flags & FW_OPT_UEVENT) &&
 696             !(fw_priv->opt_flags & FW_OPT_NOCACHE)) {
 697                 ret = fw_add_devm_name(device, fw_priv->fw_name);
 698                 if (ret) {
 699                         mutex_unlock(&fw_lock);
 700                         return ret;
 701                 }
 702         }
 703
 704         /*
 705          * After caching firmware image is started, let it piggyback
 706          * on request firmware.
 707          */
 708         if (!(fw_priv->opt_flags & FW_OPT_NOCACHE) &&
 709             fw_priv->fwc->state == FW_LOADER_START_CACHE)
 710                 fw_cache_piggyback_on_request(fw_priv);
 711
 712         /* pass the pages buffer to driver at the last minute */
 713         fw_set_page_data(fw_priv, fw);
 714         mutex_unlock(&fw_lock);
 715         return 0;
 716 }
 717
 718 /* prepare firmware and firmware_buf structs;
 719  * return 0 if a firmware is already assigned, 1 if need to load one,
 720  * or a negative error code
 721  */
 722 static int
 723 _request_firmware_prepare(struct firmware **firmware_p, const char *name,
 724                           struct device *device, void *dbuf, size_t size,
 725                           size_t offset, u32 opt_flags)
 726 {
 727         struct firmware *firmware;
 728         struct fw_priv *fw_priv;
 729         int ret;
 730
 731         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
 732         if (!firmware) {
 733                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
 734                         __func__);
 735                 return -ENOMEM;
 736         }
 737
 738         if (fw_get_builtin_firmware(firmware, name, dbuf, size)) {
 739                 dev_dbg(device, "using built-in %s\n", name);
 740                 return 0; /* assigned */
 741         }
 742
 743         ret = alloc_lookup_fw_priv(name, &fw_cache, &fw_priv, dbuf, size,
 744                                    offset, opt_flags);
 745
 746         /*
 747          * bind with 'priv' now to avoid warning in failure path
 748          * of requesting firmware.
 749          */
 750         firmware->priv = fw_priv;
 751
 752         if (ret > 0) {
 753                 ret = fw_state_wait(fw_priv);
 754                 if (!ret) {
 755                         fw_set_page_data(fw_priv, firmware);
 756                         return 0; /* assigned */
 757                 }
 758         }
 759
 760         if (ret < 0)
 761                 return ret;
 762         return 1; /* need to load */
 763 }
 764
 765 /*
 766  * Batched requests need only one wake, we need to do this step last due to the
 767  * fallback mechanism. The buf is protected with kref_get(), and it won't be
 768  * released until the last user calls release_firmware().
 769  *
 770  * Failed batched requests are possible as well, in such cases we just share
 771  * the struct fw_priv and won't release it until all requests are woken
 772  * and have gone through this same path.
 773  */
 774 static void fw_abort_batch_reqs(struct firmware *fw)
 775 {
 776         struct fw_priv *fw_priv;
 777
 778         /* Loaded directly? */
 779         if (!fw || !fw->priv)
 780                 return;
 781
 782         fw_priv = fw->priv;
 783         mutex_lock(&fw_lock);
 784         if (!fw_state_is_aborted(fw_priv))
 785                 fw_state_aborted(fw_priv);
 786         mutex_unlock(&fw_lock);
 787 }
 788
 789 /* called from request_firmware() and request_firmware_work_func() */
 790 static int
 791 _request_firmware(const struct firmware **firmware_p, const char *name,
 792                   struct device *device, void *buf, size_t size,
 793                   size_t offset, u32 opt_flags)
 794 {
 795         struct firmware *fw = NULL;
 796         struct cred *kern_cred = NULL;
 797         const struct cred *old_cred;
 798         bool nondirect = false;
 799         int ret;
 800
 801         if (!firmware_p)
 802                 return -EINVAL;
 803
 804         if (!name || name[0] == '\0') {
 805                 ret = -EINVAL;
 806                 goto out;
 807         }
 808
 809         ret = _request_firmware_prepare(&fw, name, device, buf, size,
 810                                         offset, opt_flags);
 811         if (ret <= 0) /* error or already assigned */
 812                 goto out;
 813
 814         /*
 815          * We are about to try to access the firmware file. Because we may have been
 816          * called by a driver when serving an unrelated request from userland, we use
 817          * the kernel credentials to read the file.
 818          */
 819         kern_cred = prepare_kernel_cred(NULL);
 820         if (!kern_cred) {
 821                 ret = -ENOMEM;
 822                 goto out;
 823         }
 824         old_cred = override_creds(kern_cred);
 825
 826         ret = fw_get_filesystem_firmware(device, fw->priv, "", NULL);
 827
 828         /* Only full reads can support decompression, platform, and sysfs. */
 829         if (!(opt_flags & FW_OPT_PARTIAL))
 830                 nondirect = true;
 831
 832 #ifdef CONFIG_FW_LOADER_COMPRESS
 833         if (ret == -ENOENT && nondirect)
 834                 ret = fw_get_filesystem_firmware(device, fw->priv, ".xz",
 835                                                  fw_decompress_xz);
 836 #endif
 837         if (ret == -ENOENT && nondirect)
 838                 ret = firmware_fallback_platform(fw->priv);
 839
 840         if (ret) {
 841                 if (!(opt_flags & FW_OPT_NO_WARN))
 842                         dev_warn(device,
 843                                  "Direct firmware load for %s failed with error %d\n",
 844                                  name, ret);
 845                 if (nondirect)
 846                         ret = firmware_fallback_sysfs(fw, name, device,
 847                                                       opt_flags, ret);
 848         } else
 849                 ret = assign_fw(fw, device);
 850
 851         revert_creds(old_cred);
 852         put_cred(kern_cred);
 853
 854  out:
 855         if (ret < 0) {
 856                 fw_abort_batch_reqs(fw);
 857                 release_firmware(fw);
 858                 fw = NULL;
 859         }
 860
 861         *firmware_p = fw;
 862         return ret;
 863 }
 864
 865 /**
 866  * request_firmware() - send firmware request and wait for it
 867  * @firmware_p: pointer to firmware image
 868  * @name: name of firmware file
 869  * @device: device for which firmware is being loaded
 870  *
 871  *      @firmware_p will be used to return a firmware image by the name
 872  *      of @name for device @device.
 873  *
 874  *      Should be called from user context where sleeping is allowed.
 875  *
 876  *      @name will be used as $FIRMWARE in the uevent environment and
 877  *      should be distinctive enough not to be confused with any other
 878  *      firmware image for this or any other device.
 879  *
 880  *      Caller must hold the reference count of @device.
 881  *
 882  *      The function can be called safely inside device's suspend and
 883  *      resume callback.
 884  **/
 885 int
 886 request_firmware(const struct firmware **firmware_p, const char *name,
 887                  struct device *device)
 888 {
 889         int ret;
 890
 891         /* Need to pin this module until return */
 892         __module_get(THIS_MODULE);
 893         ret = _request_firmware(firmware_p, name, device, NULL, 0, 0,
 894                                 FW_OPT_UEVENT);
 895         module_put(THIS_MODULE);
 896         return ret;
 897 }
 898 EXPORT_SYMBOL(request_firmware);
 899
 900 /**
 901  * firmware_request_nowarn() - request for an optional fw module
 902  * @firmware: pointer to firmware image
 903  * @name: name of firmware file
 904  * @device: device for which firmware is being loaded
 905  *
 906  * This function is similar in behaviour to request_firmware(), except it
 907  * doesn't produce warning messages when the file is not found. The sysfs
 908  * fallback mechanism is enabled if direct filesystem lookup fails. However,
 909  * failures to find the firmware file with it are still suppressed. It is
 910  * therefore up to the driver to check for the return value of this call and to
 911  * decide when to inform the users of errors.
 912  **/
 913 int firmware_request_nowarn(const struct firmware **firmware, const char *name,
 914                             struct device *device)
 915 {
 916         int ret;
 917
 918         /* Need to pin this module until return */
 919         __module_get(THIS_MODULE);
 920         ret = _request_firmware(firmware, name, device, NULL, 0, 0,
 921                                 FW_OPT_UEVENT | FW_OPT_NO_WARN);
 922         module_put(THIS_MODULE);
 923         return ret;
 924 }
 925 EXPORT_SYMBOL_GPL(firmware_request_nowarn);
 926
 927 /**
 928  * request_firmware_direct() - load firmware directly without usermode helper
 929  * @firmware_p: pointer to firmware image
 930  * @name: name of firmware file
 931  * @device: device for which firmware is being loaded
 932  *
 933  * This function works pretty much like request_firmware(), but this doesn't
 934  * fall back to usermode helper even if the firmware couldn't be loaded
 935  * directly from fs.  Hence it's useful for loading optional firmwares, which
 936  * aren't always present, without extra long timeouts of udev.
 937  **/
 938 int request_firmware_direct(const struct firmware **firmware_p,
 939                             const char *name, struct device *device)
 940 {
 941         int ret;
 942
 943         __module_get(THIS_MODULE);
 944         ret = _request_firmware(firmware_p, name, device, NULL, 0, 0,
 945                                 FW_OPT_UEVENT | FW_OPT_NO_WARN |
 946                                 FW_OPT_NOFALLBACK_SYSFS);
 947         module_put(THIS_MODULE);
 948         return ret;
 949 }
 950 EXPORT_SYMBOL_GPL(request_firmware_direct);
 951
 952 /**
 953  * firmware_request_platform() - request firmware with platform-fw fallback
 954  * @firmware: pointer to firmware image
 955  * @name: name of firmware file
 956  * @device: device for which firmware is being loaded
 957  *
 958  * This function is similar in behaviour to request_firmware, except that if
 959  * direct filesystem lookup fails, it will fallback to looking for a copy of the
 960  * requested firmware embedded in the platform's main (e.g. UEFI) firmware.
 961  **/
 962 int firmware_request_platform(const struct firmware **firmware,
 963                               const char *name, struct device *device)
 964 {
 965         int ret;
 966
 967         /* Need to pin this module until return */
 968         __module_get(THIS_MODULE);
 969         ret = _request_firmware(firmware, name, device, NULL, 0, 0,
 970                                 FW_OPT_UEVENT | FW_OPT_FALLBACK_PLATFORM);
 971         module_put(THIS_MODULE);
 972         return ret;
 973 }
 974 EXPORT_SYMBOL_GPL(firmware_request_platform);
 975
 976 /**
 977  * firmware_request_cache() - cache firmware for suspend so resume can use it
 978  * @name: name of firmware file
 979  * @device: device for which firmware should be cached for
 980  *
 981  * There are some devices with an optimization that enables the device to not
 982  * require loading firmware on system reboot. This optimization may still
 983  * require the firmware present on resume from suspend. This routine can be
 984  * used to ensure the firmware is present on resume from suspend in these
 985  * situations. This helper is not compatible with drivers which use
 986  * request_firmware_into_buf() or request_firmware_nowait() with no uevent set.
 987  **/
 988 int firmware_request_cache(struct device *device, const char *name)
 989 {
 990         int ret;
 991
 992         mutex_lock(&fw_lock);
 993         ret = fw_add_devm_name(device, name);
 994         mutex_unlock(&fw_lock);
 995
 996         return ret;
 997 }
 998 EXPORT_SYMBOL_GPL(firmware_request_cache);
 999
1000 /**
1001  * request_firmware_into_buf() - load firmware into a previously allocated buffer
1002  * @firmware_p: pointer to firmware image
1003  * @name: name of firmware file
1004  * @device: device for which firmware is being loaded and DMA region allocated
1005  * @buf: address of buffer to load firmware into
1006  * @size: size of buffer
1007  *
1008  * This function works pretty much like request_firmware(), but it doesn't
1009  * allocate a buffer to hold the firmware data. Instead, the firmware
1010  * is loaded directly into the buffer pointed to by @buf and the @firmware_p
1011  * data member is pointed at @buf.
1012  *
1013  * This function doesn't cache firmware either.
1014  */
1015 int
1016 request_firmware_into_buf(const struct firmware **firmware_p, const char *name,
1017                           struct device *device, void *buf, size_t size)
1018 {
1019         int ret;
1020
1021         if (fw_cache_is_setup(device, name))
1022                 return -EOPNOTSUPP;
1023
1024         __module_get(THIS_MODULE);
1025         ret = _request_firmware(firmware_p, name, device, buf, size, 0,
1026                                 FW_OPT_UEVENT | FW_OPT_NOCACHE);
1027         module_put(THIS_MODULE);
1028         return ret;
1029 }
1030 EXPORT_SYMBOL(request_firmware_into_buf);
1031
1032 /**
1033  * request_partial_firmware_into_buf() - load partial firmware into a previously allocated buffer
1034  * @firmware_p: pointer to firmware image
1035  * @name: name of firmware file
1036  * @device: device for which firmware is being loaded and DMA region allocated
1037  * @buf: address of buffer to load firmware into
1038  * @size: size of buffer
1039  * @offset: offset into file to read
1040  *
1041  * This function works pretty much like request_firmware_into_buf except
1042  * it allows a partial read of the file.
1043  */
1044 int
1045 request_partial_firmware_into_buf(const struct firmware **firmware_p,
1046                                   const char *name, struct device *device,
1047                                   void *buf, size_t size, size_t offset)
1048 {
1049         int ret;
1050
1051         if (fw_cache_is_setup(device, name))
1052                 return -EOPNOTSUPP;
1053
1054         __module_get(THIS_MODULE);
1055         ret = _request_firmware(firmware_p, name, device, buf, size, offset,
1056                                 FW_OPT_UEVENT | FW_OPT_NOCACHE |
1057                                 FW_OPT_PARTIAL);
1058         module_put(THIS_MODULE);
1059         return ret;
1060 }
1061 EXPORT_SYMBOL(request_partial_firmware_into_buf);
1062
1063 /**
1064  * release_firmware() - release the resource associated with a firmware image
1065  * @fw: firmware resource to release
1066  **/
1067 void release_firmware(const struct firmware *fw)
1068 {
1069         if (fw) {
1070                 if (!fw_is_builtin_firmware(fw))
1071                         firmware_free_data(fw);
1072                 kfree(fw);
1073         }
1074 }
1075 EXPORT_SYMBOL(release_firmware);
1076
1077 /* Async support */
1078 struct firmware_work {
1079         struct work_struct work;
1080         struct module *module;
1081         const char *name;
1082         struct device *device;
1083         void *context;
1084         void (*cont)(const struct firmware *fw, void *context);
1085         u32 opt_flags;
1086 };
1087
1088 static void request_firmware_work_func(struct work_struct *work)
1089 {
1090         struct firmware_work *fw_work;
1091         const struct firmware *fw;
1092
1093         fw_work = container_of(work, struct firmware_work, work);
1094
1095         _request_firmware(&fw, fw_work->name, fw_work->device, NULL, 0, 0,
1096                           fw_work->opt_flags);
1097         fw_work->cont(fw, fw_work->context);
1098         put_device(fw_work->device); /* taken in request_firmware_nowait() */
1099
1100         module_put(fw_work->module);
1101         kfree_const(fw_work->name);
1102         kfree(fw_work);
1103 }
1104
1105 /**
1106  * request_firmware_nowait() - asynchronous version of request_firmware
1107  * @module: module requesting the firmware
1108  * @uevent: sends uevent to copy the firmware image if this flag
1109  *      is non-zero else the firmware copy must be done manually.
1110  * @name: name of firmware file
1111  * @device: device for which firmware is being loaded
1112  * @gfp: allocation flags
1113  * @context: will be passed over to @cont, and
1114  *      @fw may be %NULL if firmware request fails.
1115  * @cont: function will be called asynchronously when the firmware
1116  *      request is over.
1117  *
1118  *      Caller must hold the reference count of @device.
1119  *
1120  *      Asynchronous variant of request_firmware() for user contexts:
1121  *              - sleep for as small periods as possible since it may
1122  *                increase kernel boot time of built-in device drivers
1123  *                requesting firmware in their ->probe() methods, if
1124  *                @gfp is GFP_KERNEL.
1125  *
1126  *              - can't sleep at all if @gfp is GFP_ATOMIC.
1127  **/
1128 int
1129 request_firmware_nowait(
1130         struct module *module, bool uevent,
1131         const char *name, struct device *device, gfp_t gfp, void *context,
1132         void (*cont)(const struct firmware *fw, void *context))
1133 {
1134         struct firmware_work *fw_work;
1135
1136         fw_work = kzalloc(sizeof(struct firmware_work), gfp);
1137         if (!fw_work)
1138                 return -ENOMEM;
1139
1140         fw_work->module = module;
1141         fw_work->name = kstrdup_const(name, gfp);
1142         if (!fw_work->name) {
1143                 kfree(fw_work);
1144                 return -ENOMEM;
1145         }
1146         fw_work->device = device;
1147         fw_work->context = context;
1148         fw_work->cont = cont;
1149         fw_work->opt_flags = FW_OPT_NOWAIT |
1150                 (uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
1151
1152         if (!uevent && fw_cache_is_setup(device, name)) {
1153                 kfree_const(fw_work->name);
1154                 kfree(fw_work);
1155                 return -EOPNOTSUPP;
1156         }
1157
1158         if (!try_module_get(module)) {
1159                 kfree_const(fw_work->name);
1160                 kfree(fw_work);
1161                 return -EFAULT;
1162         }
1163
1164         get_device(fw_work->device);
1165         INIT_WORK(&fw_work->work, request_firmware_work_func);
1166         schedule_work(&fw_work->work);
1167         return 0;
1168 }
1169 EXPORT_SYMBOL(request_firmware_nowait);
1170
1171 #ifdef CONFIG_FW_CACHE
1172 static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
1173
1174 /**
1175  * cache_firmware() - cache one firmware image in kernel memory space
1176  * @fw_name: the firmware image name
1177  *
1178  * Cache firmware in kernel memory so that drivers can use it when
1179  * system isn't ready for them to request firmware image from userspace.
1180  * Once it returns successfully, driver can use request_firmware or its
1181  * nowait version to get the cached firmware without any interacting
1182  * with userspace
1183  *
1184  * Return 0 if the firmware image has been cached successfully
1185  * Return !0 otherwise
1186  *
1187  */
1188 static int cache_firmware(const char *fw_name)
1189 {
1190         int ret;
1191         const struct firmware *fw;
1192
1193         pr_debug("%s: %s\n", __func__, fw_name);
1194
1195         ret = request_firmware(&fw, fw_name, NULL);
1196         if (!ret)
1197                 kfree(fw);
1198
1199         pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
1200
1201         return ret;
1202 }
1203
1204 static struct fw_priv *lookup_fw_priv(const char *fw_name)
1205 {
1206         struct fw_priv *tmp;
1207         struct firmware_cache *fwc = &fw_cache;
1208
1209         spin_lock(&fwc->lock);
1210         tmp = __lookup_fw_priv(fw_name);
1211         spin_unlock(&fwc->lock);
1212
1213         return tmp;
1214 }
1215
1216 /**
1217  * uncache_firmware() - remove one cached firmware image
1218  * @fw_name: the firmware image name
1219  *
1220  * Uncache one firmware image which has been cached successfully
1221  * before.
1222  *
1223  * Return 0 if the firmware cache has been removed successfully
1224  * Return !0 otherwise
1225  *
1226  */
1227 static int uncache_firmware(const char *fw_name)
1228 {
1229         struct fw_priv *fw_priv;
1230         struct firmware fw;
1231
1232         pr_debug("%s: %s\n", __func__, fw_name);
1233
1234         if (fw_get_builtin_firmware(&fw, fw_name, NULL, 0))
1235                 return 0;
1236
1237         fw_priv = lookup_fw_priv(fw_name);
1238         if (fw_priv) {
1239                 free_fw_priv(fw_priv);
1240                 return 0;
1241         }
1242
1243         return -EINVAL;
1244 }
1245
1246 static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
1247 {
1248         struct fw_cache_entry *fce;
1249
1250         fce = kzalloc(sizeof(*fce), GFP_ATOMIC);
1251         if (!fce)
1252                 goto exit;
1253
1254         fce->name = kstrdup_const(name, GFP_ATOMIC);
1255         if (!fce->name) {
1256                 kfree(fce);
1257                 fce = NULL;
1258                 goto exit;
1259         }
1260 exit:
1261         return fce;
1262 }
1263
1264 static int __fw_entry_found(const char *name)
1265 {
1266         struct firmware_cache *fwc = &fw_cache;
1267         struct fw_cache_entry *fce;
1268
1269         list_for_each_entry(fce, &fwc->fw_names, list) {
1270                 if (!strcmp(fce->name, name))
1271                         return 1;
1272         }
1273         return 0;
1274 }
1275
1276 static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv)
1277 {
1278         const char *name = fw_priv->fw_name;
1279         struct firmware_cache *fwc = fw_priv->fwc;
1280         struct fw_cache_entry *fce;
1281
1282         spin_lock(&fwc->name_lock);
1283         if (__fw_entry_found(name))
1284                 goto found;
1285
1286         fce = alloc_fw_cache_entry(name);
1287         if (fce) {
1288                 list_add(&fce->list, &fwc->fw_names);
1289                 kref_get(&fw_priv->ref);
1290                 pr_debug("%s: fw: %s\n", __func__, name);
1291         }
1292 found:
1293         spin_unlock(&fwc->name_lock);
1294 }
1295
1296 static void free_fw_cache_entry(struct fw_cache_entry *fce)
1297 {
1298         kfree_const(fce->name);
1299         kfree(fce);
1300 }
1301
1302 static void __async_dev_cache_fw_image(void *fw_entry,
1303                                        async_cookie_t cookie)
1304 {
1305         struct fw_cache_entry *fce = fw_entry;
1306         struct firmware_cache *fwc = &fw_cache;
1307         int ret;
1308
1309         ret = cache_firmware(fce->name);
1310         if (ret) {
1311                 spin_lock(&fwc->name_lock);
1312                 list_del(&fce->list);
1313                 spin_unlock(&fwc->name_lock);
1314
1315                 free_fw_cache_entry(fce);
1316         }
1317 }
1318
1319 /* called with dev->devres_lock held */
1320 static void dev_create_fw_entry(struct device *dev, void *res,
1321                                 void *data)
1322 {
1323         struct fw_name_devm *fwn = res;
1324         const char *fw_name = fwn->name;
1325         struct list_head *head = data;
1326         struct fw_cache_entry *fce;
1327
1328         fce = alloc_fw_cache_entry(fw_name);
1329         if (fce)
1330                 list_add(&fce->list, head);
1331 }
1332
1333 static int devm_name_match(struct device *dev, void *res,
1334                            void *match_data)
1335 {
1336         struct fw_name_devm *fwn = res;
1337         return (fwn->magic == (unsigned long)match_data);
1338 }
1339
1340 static void dev_cache_fw_image(struct device *dev, void *data)
1341 {
1342         LIST_HEAD(todo);
1343         struct fw_cache_entry *fce;
1344         struct fw_cache_entry *fce_next;
1345         struct firmware_cache *fwc = &fw_cache;
1346
1347         devres_for_each_res(dev, fw_name_devm_release,
1348                             devm_name_match, &fw_cache,
1349                             dev_create_fw_entry, &todo);
1350
1351         list_for_each_entry_safe(fce, fce_next, &todo, list) {
1352                 list_del(&fce->list);
1353
1354                 spin_lock(&fwc->name_lock);
1355                 /* only one cache entry for one firmware */
1356                 if (!__fw_entry_found(fce->name)) {
1357                         list_add(&fce->list, &fwc->fw_names);
1358                 } else {
1359                         free_fw_cache_entry(fce);
1360                         fce = NULL;
1361                 }
1362                 spin_unlock(&fwc->name_lock);
1363
1364                 if (fce)
1365                         async_schedule_domain(__async_dev_cache_fw_image,
1366                                               (void *)fce,
1367                                               &fw_cache_domain);
1368         }
1369 }
1370
1371 static void __device_uncache_fw_images(void)
1372 {
1373         struct firmware_cache *fwc = &fw_cache;
1374         struct fw_cache_entry *fce;
1375
1376         spin_lock(&fwc->name_lock);
1377         while (!list_empty(&fwc->fw_names)) {
1378                 fce = list_entry(fwc->fw_names.next,
1379                                 struct fw_cache_entry, list);
1380                 list_del(&fce->list);
1381                 spin_unlock(&fwc->name_lock);
1382
1383                 uncache_firmware(fce->name);
1384                 free_fw_cache_entry(fce);
1385
1386                 spin_lock(&fwc->name_lock);
1387         }
1388         spin_unlock(&fwc->name_lock);
1389 }
1390
1391 /**
1392  * device_cache_fw_images() - cache devices' firmware
1393  *
1394  * If one device called request_firmware or its nowait version
1395  * successfully before, the firmware names are recored into the
1396  * device's devres link list, so device_cache_fw_images can call
1397  * cache_firmware() to cache these firmwares for the device,
1398  * then the device driver can load its firmwares easily at
1399  * time when system is not ready to complete loading firmware.
1400  */
1401 static void device_cache_fw_images(void)
1402 {
1403         struct firmware_cache *fwc = &fw_cache;
1404         DEFINE_WAIT(wait);
1405
1406         pr_debug("%s\n", __func__);
1407
1408         /* cancel uncache work */
1409         cancel_delayed_work_sync(&fwc->work);
1410
1411         fw_fallback_set_cache_timeout();
1412
1413         mutex_lock(&fw_lock);
1414         fwc->state = FW_LOADER_START_CACHE;
1415         dpm_for_each_dev(NULL, dev_cache_fw_image);
1416         mutex_unlock(&fw_lock);
1417
1418         /* wait for completion of caching firmware for all devices */
1419         async_synchronize_full_domain(&fw_cache_domain);
1420
1421         fw_fallback_set_default_timeout();
1422 }
1423
1424 /**
1425  * device_uncache_fw_images() - uncache devices' firmware
1426  *
1427  * uncache all firmwares which have been cached successfully
1428  * by device_uncache_fw_images earlier
1429  */
1430 static void device_uncache_fw_images(void)
1431 {
1432         pr_debug("%s\n", __func__);
1433         __device_uncache_fw_images();
1434 }
1435
1436 static void device_uncache_fw_images_work(struct work_struct *work)
1437 {
1438         device_uncache_fw_images();
1439 }
1440
1441 /**
1442  * device_uncache_fw_images_delay() - uncache devices firmwares
1443  * @delay: number of milliseconds to delay uncache device firmwares
1444  *
1445  * uncache all devices's firmwares which has been cached successfully
1446  * by device_cache_fw_images after @delay milliseconds.
1447  */
1448 static void device_uncache_fw_images_delay(unsigned long delay)
1449 {
1450         queue_delayed_work(system_power_efficient_wq, &fw_cache.work,
1451                            msecs_to_jiffies(delay));
1452 }
1453
1454 static int fw_pm_notify(struct notifier_block *notify_block,
1455                         unsigned long mode, void *unused)
1456 {
1457         switch (mode) {
1458         case PM_HIBERNATION_PREPARE:
1459         case PM_SUSPEND_PREPARE:
1460         case PM_RESTORE_PREPARE:
1461                 /*
1462                  * kill pending fallback requests with a custom fallback
1463                  * to avoid stalling suspend.
1464                  */
1465                 kill_pending_fw_fallback_reqs(true);
1466                 device_cache_fw_images();
1467                 break;
1468
1469         case PM_POST_SUSPEND:
1470         case PM_POST_HIBERNATION:
1471         case PM_POST_RESTORE:
1472                 /*
1473                  * In case that system sleep failed and syscore_suspend is
1474                  * not called.
1475                  */
1476                 mutex_lock(&fw_lock);
1477                 fw_cache.state = FW_LOADER_NO_CACHE;
1478                 mutex_unlock(&fw_lock);
1479
1480                 device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
1481                 break;
1482         }
1483
1484         return 0;
1485 }
1486
1487 /* stop caching firmware once syscore_suspend is reached */
1488 static int fw_suspend(void)
1489 {
1490         fw_cache.state = FW_LOADER_NO_CACHE;
1491         return 0;
1492 }
1493
1494 static struct syscore_ops fw_syscore_ops = {
1495         .suspend = fw_suspend,
1496 };
1497
1498 static int __init register_fw_pm_ops(void)
1499 {
1500         int ret;
1501
1502         spin_lock_init(&fw_cache.name_lock);
1503         INIT_LIST_HEAD(&fw_cache.fw_names);
1504
1505         INIT_DELAYED_WORK(&fw_cache.work,
1506                           device_uncache_fw_images_work);
1507
1508         fw_cache.pm_notify.notifier_call = fw_pm_notify;
1509         ret = register_pm_notifier(&fw_cache.pm_notify);
1510         if (ret)
1511                 return ret;
1512
1513         register_syscore_ops(&fw_syscore_ops);
1514
1515         return ret;
1516 }
1517
1518 static inline void unregister_fw_pm_ops(void)
1519 {
1520         unregister_syscore_ops(&fw_syscore_ops);
1521         unregister_pm_notifier(&fw_cache.pm_notify);
1522 }
1523 #else
1524 static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv)
1525 {
1526 }
1527 static inline int register_fw_pm_ops(void)
1528 {
1529         return 0;
1530 }
1531 static inline void unregister_fw_pm_ops(void)
1532 {
1533 }
1534 #endif
1535
1536 static void __init fw_cache_init(void)
1537 {
1538         spin_lock_init(&fw_cache.lock);
1539         INIT_LIST_HEAD(&fw_cache.head);
1540         fw_cache.state = FW_LOADER_NO_CACHE;
1541 }
1542
1543 static int fw_shutdown_notify(struct notifier_block *unused1,
1544                               unsigned long unused2, void *unused3)
1545 {
1546         /*
1547          * Kill all pending fallback requests to avoid both stalling shutdown,
1548          * and avoid a deadlock with the usermode_lock.
1549          */
1550         kill_pending_fw_fallback_reqs(false);
1551
1552         return NOTIFY_DONE;
1553 }
1554
1555 static struct notifier_block fw_shutdown_nb = {
1556         .notifier_call = fw_shutdown_notify,
1557 };
1558
1559 static int __init firmware_class_init(void)
1560 {
1561         int ret;
1562
1563         /* No need to unfold these on exit */
1564         fw_cache_init();
1565
1566         ret = register_fw_pm_ops();
1567         if (ret)
1568                 return ret;
1569
1570         ret = register_reboot_notifier(&fw_shutdown_nb);
1571         if (ret)
1572                 goto out;
1573
1574         return register_sysfs_loader();
1575
1576 out:
1577         unregister_fw_pm_ops();
1578         return ret;
1579 }
1580
1581 static void __exit firmware_class_exit(void)
1582 {
1583         unregister_fw_pm_ops();
1584         unregister_reboot_notifier(&fw_shutdown_nb);
1585         unregister_sysfs_loader();
1586 }
1587
1588 fs_initcall(firmware_class_init);
1589 module_exit(firmware_class_exit);