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/zstd.h>
  39 #include <linux/xz.h>
  40
  41 #include <generated/utsrelease.h>
  42
  43 #include "../base.h"
  44 #include "firmware.h"
  45 #include "fallback.h"
  46
  47 MODULE_AUTHOR("Manuel Estrada Sainz");
  48 MODULE_DESCRIPTION("Multi purpose firmware loading support");
  49 MODULE_LICENSE("GPL");
  50
  51 struct firmware_cache {
  52         /* firmware_buf instance will be added into the below list */
  53         spinlock_t lock;
  54         struct list_head head;
  55         int state;
  56
  57 #ifdef CONFIG_FW_CACHE
  58         /*
  59          * Names of firmware images which have been cached successfully
  60          * will be added into the below list so that device uncache
  61          * helper can trace which firmware images have been cached
  62          * before.
  63          */
  64         spinlock_t name_lock;
  65         struct list_head fw_names;
  66
  67         struct delayed_work work;
  68
  69         struct notifier_block   pm_notify;
  70 #endif
  71 };
  72
  73 struct fw_cache_entry {
  74         struct list_head list;
  75         const char *name;
  76 };
  77
  78 struct fw_name_devm {
  79         unsigned long magic;
  80         const char *name;
  81 };
  82
  83 static inline struct fw_priv *to_fw_priv(struct kref *ref)
  84 {
  85         return container_of(ref, struct fw_priv, ref);
  86 }
  87
  88 #define FW_LOADER_NO_CACHE      0
  89 #define FW_LOADER_START_CACHE   1
  90
  91 /* fw_lock could be moved to 'struct fw_sysfs' but since it is just
  92  * guarding for corner cases a global lock should be OK */
  93 DEFINE_MUTEX(fw_lock);
  94
  95 struct firmware_cache fw_cache;
  96 bool fw_load_abort_all;
  97
  98 void fw_state_init(struct fw_priv *fw_priv)
  99 {
 100         struct fw_state *fw_st = &fw_priv->fw_st;
 101
 102         init_completion(&fw_st->completion);
 103         fw_st->status = FW_STATUS_UNKNOWN;
 104 }
 105
 106 static inline int fw_state_wait(struct fw_priv *fw_priv)
 107 {
 108         return __fw_state_wait_common(fw_priv, MAX_SCHEDULE_TIMEOUT);
 109 }
 110
 111 static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv);
 112
 113 static struct fw_priv *__allocate_fw_priv(const char *fw_name,
 114                                           struct firmware_cache *fwc,
 115                                           void *dbuf,
 116                                           size_t size,
 117                                           size_t offset,
 118                                           u32 opt_flags)
 119 {
 120         struct fw_priv *fw_priv;
 121
 122         /* For a partial read, the buffer must be preallocated. */
 123         if ((opt_flags & FW_OPT_PARTIAL) && !dbuf)
 124                 return NULL;
 125
 126         /* Only partial reads are allowed to use an offset. */
 127         if (offset != 0 && !(opt_flags & FW_OPT_PARTIAL))
 128                 return NULL;
 129
 130         fw_priv = kzalloc(sizeof(*fw_priv), GFP_ATOMIC);
 131         if (!fw_priv)
 132                 return NULL;
 133
 134         fw_priv->fw_name = kstrdup_const(fw_name, GFP_ATOMIC);
 135         if (!fw_priv->fw_name) {
 136                 kfree(fw_priv);
 137                 return NULL;
 138         }
 139
 140         kref_init(&fw_priv->ref);
 141         fw_priv->fwc = fwc;
 142         fw_priv->data = dbuf;
 143         fw_priv->allocated_size = size;
 144         fw_priv->offset = offset;
 145         fw_priv->opt_flags = opt_flags;
 146         fw_state_init(fw_priv);
 147 #ifdef CONFIG_FW_LOADER_USER_HELPER
 148         INIT_LIST_HEAD(&fw_priv->pending_list);
 149 #endif
 150
 151         pr_debug("%s: fw-%s fw_priv=%p\n", __func__, fw_name, fw_priv);
 152
 153         return fw_priv;
 154 }
 155
 156 static struct fw_priv *__lookup_fw_priv(const char *fw_name)
 157 {
 158         struct fw_priv *tmp;
 159         struct firmware_cache *fwc = &fw_cache;
 160
 161         list_for_each_entry(tmp, &fwc->head, list)
 162                 if (!strcmp(tmp->fw_name, fw_name))
 163                         return tmp;
 164         return NULL;
 165 }
 166
 167 /* Returns 1 for batching firmware requests with the same name */
 168 int alloc_lookup_fw_priv(const char *fw_name, struct firmware_cache *fwc,
 169                          struct fw_priv **fw_priv, void *dbuf, size_t size,
 170                          size_t offset, u32 opt_flags)
 171 {
 172         struct fw_priv *tmp;
 173
 174         spin_lock(&fwc->lock);
 175         /*
 176          * Do not merge requests that are marked to be non-cached or
 177          * are performing partial reads.
 178          */
 179         if (!(opt_flags & (FW_OPT_NOCACHE | FW_OPT_PARTIAL))) {
 180                 tmp = __lookup_fw_priv(fw_name);
 181                 if (tmp) {
 182                         kref_get(&tmp->ref);
 183                         spin_unlock(&fwc->lock);
 184                         *fw_priv = tmp;
 185                         pr_debug("batched request - sharing the same struct fw_priv and lookup for multiple requests\n");
 186                         return 1;
 187                 }
 188         }
 189
 190         tmp = __allocate_fw_priv(fw_name, fwc, dbuf, size, offset, opt_flags);
 191         if (tmp) {
 192                 INIT_LIST_HEAD(&tmp->list);
 193                 if (!(opt_flags & FW_OPT_NOCACHE))
 194                         list_add(&tmp->list, &fwc->head);
 195         }
 196         spin_unlock(&fwc->lock);
 197
 198         *fw_priv = tmp;
 199
 200         return tmp ? 0 : -ENOMEM;
 201 }
 202
 203 static void __free_fw_priv(struct kref *ref)
 204         __releases(&fwc->lock)
 205 {
 206         struct fw_priv *fw_priv = to_fw_priv(ref);
 207         struct firmware_cache *fwc = fw_priv->fwc;
 208
 209         pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n",
 210                  __func__, fw_priv->fw_name, fw_priv, fw_priv->data,
 211                  (unsigned int)fw_priv->size);
 212
 213         list_del(&fw_priv->list);
 214         spin_unlock(&fwc->lock);
 215
 216         if (fw_is_paged_buf(fw_priv))
 217                 fw_free_paged_buf(fw_priv);
 218         else if (!fw_priv->allocated_size)
 219                 vfree(fw_priv->data);
 220
 221         kfree_const(fw_priv->fw_name);
 222         kfree(fw_priv);
 223 }
 224
 225 void free_fw_priv(struct fw_priv *fw_priv)
 226 {
 227         struct firmware_cache *fwc = fw_priv->fwc;
 228         spin_lock(&fwc->lock);
 229         if (!kref_put(&fw_priv->ref, __free_fw_priv))
 230                 spin_unlock(&fwc->lock);
 231 }
 232
 233 #ifdef CONFIG_FW_LOADER_PAGED_BUF
 234 bool fw_is_paged_buf(struct fw_priv *fw_priv)
 235 {
 236         return fw_priv->is_paged_buf;
 237 }
 238
 239 void fw_free_paged_buf(struct fw_priv *fw_priv)
 240 {
 241         int i;
 242
 243         if (!fw_priv->pages)
 244                 return;
 245
 246         vunmap(fw_priv->data);
 247
 248         for (i = 0; i < fw_priv->nr_pages; i++)
 249                 __free_page(fw_priv->pages[i]);
 250         kvfree(fw_priv->pages);
 251         fw_priv->pages = NULL;
 252         fw_priv->page_array_size = 0;
 253         fw_priv->nr_pages = 0;
 254         fw_priv->data = NULL;
 255         fw_priv->size = 0;
 256 }
 257
 258 int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed)
 259 {
 260         /* If the array of pages is too small, grow it */
 261         if (fw_priv->page_array_size < pages_needed) {
 262                 int new_array_size = max(pages_needed,
 263                                          fw_priv->page_array_size * 2);
 264                 struct page **new_pages;
 265
 266                 new_pages = kvmalloc_array(new_array_size, sizeof(void *),
 267                                            GFP_KERNEL);
 268                 if (!new_pages)
 269                         return -ENOMEM;
 270                 memcpy(new_pages, fw_priv->pages,
 271                        fw_priv->page_array_size * sizeof(void *));
 272                 memset(&new_pages[fw_priv->page_array_size], 0, sizeof(void *) *
 273                        (new_array_size - fw_priv->page_array_size));
 274                 kvfree(fw_priv->pages);
 275                 fw_priv->pages = new_pages;
 276                 fw_priv->page_array_size = new_array_size;
 277         }
 278
 279         while (fw_priv->nr_pages < pages_needed) {
 280                 fw_priv->pages[fw_priv->nr_pages] =
 281                         alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
 282
 283                 if (!fw_priv->pages[fw_priv->nr_pages])
 284                         return -ENOMEM;
 285                 fw_priv->nr_pages++;
 286         }
 287
 288         return 0;
 289 }
 290
 291 int fw_map_paged_buf(struct fw_priv *fw_priv)
 292 {
 293         /* one pages buffer should be mapped/unmapped only once */
 294         if (!fw_priv->pages)
 295                 return 0;
 296
 297         vunmap(fw_priv->data);
 298         fw_priv->data = vmap(fw_priv->pages, fw_priv->nr_pages, 0,
 299                              PAGE_KERNEL_RO);
 300         if (!fw_priv->data)
 301                 return -ENOMEM;
 302
 303         return 0;
 304 }
 305 #endif
 306
 307 /*
 308  * ZSTD-compressed firmware support
 309  */
 310 #ifdef CONFIG_FW_LOADER_COMPRESS_ZSTD
 311 static int fw_decompress_zstd(struct device *dev, struct fw_priv *fw_priv,
 312                               size_t in_size, const void *in_buffer)
 313 {
 314         size_t len, out_size, workspace_size;
 315         void *workspace, *out_buf;
 316         zstd_dctx *ctx;
 317         int err;
 318
 319         if (fw_priv->allocated_size) {
 320                 out_size = fw_priv->allocated_size;
 321                 out_buf = fw_priv->data;
 322         } else {
 323                 zstd_frame_header params;
 324
 325                 if (zstd_get_frame_header(&params, in_buffer, in_size) ||
 326                     params.frameContentSize == ZSTD_CONTENTSIZE_UNKNOWN) {
 327                         dev_dbg(dev, "%s: invalid zstd header\n", __func__);
 328                         return -EINVAL;
 329                 }
 330                 out_size = params.frameContentSize;
 331                 out_buf = vzalloc(out_size);
 332                 if (!out_buf)
 333                         return -ENOMEM;
 334         }
 335
 336         workspace_size = zstd_dctx_workspace_bound();
 337         workspace = kvzalloc(workspace_size, GFP_KERNEL);
 338         if (!workspace) {
 339                 err = -ENOMEM;
 340                 goto error;
 341         }
 342
 343         ctx = zstd_init_dctx(workspace, workspace_size);
 344         if (!ctx) {
 345                 dev_dbg(dev, "%s: failed to initialize context\n", __func__);
 346                 err = -EINVAL;
 347                 goto error;
 348         }
 349
 350         len = zstd_decompress_dctx(ctx, out_buf, out_size, in_buffer, in_size);
 351         if (zstd_is_error(len)) {
 352                 dev_dbg(dev, "%s: failed to decompress: %d\n", __func__,
 353                         zstd_get_error_code(len));
 354                 err = -EINVAL;
 355                 goto error;
 356         }
 357
 358         if (!fw_priv->allocated_size)
 359                 fw_priv->data = out_buf;
 360         fw_priv->size = len;
 361         err = 0;
 362
 363  error:
 364         kvfree(workspace);
 365         if (err && !fw_priv->allocated_size)
 366                 vfree(out_buf);
 367         return err;
 368 }
 369 #endif /* CONFIG_FW_LOADER_COMPRESS_ZSTD */
 370
 371 /*
 372  * XZ-compressed firmware support
 373  */
 374 #ifdef CONFIG_FW_LOADER_COMPRESS_XZ
 375 /* show an error and return the standard error code */
 376 static int fw_decompress_xz_error(struct device *dev, enum xz_ret xz_ret)
 377 {
 378         if (xz_ret != XZ_STREAM_END) {
 379                 dev_warn(dev, "xz decompression failed (xz_ret=%d)\n", xz_ret);
 380                 return xz_ret == XZ_MEM_ERROR ? -ENOMEM : -EINVAL;
 381         }
 382         return 0;
 383 }
 384
 385 /* single-shot decompression onto the pre-allocated buffer */
 386 static int fw_decompress_xz_single(struct device *dev, struct fw_priv *fw_priv,
 387                                    size_t in_size, const void *in_buffer)
 388 {
 389         struct xz_dec *xz_dec;
 390         struct xz_buf xz_buf;
 391         enum xz_ret xz_ret;
 392
 393         xz_dec = xz_dec_init(XZ_SINGLE, (u32)-1);
 394         if (!xz_dec)
 395                 return -ENOMEM;
 396
 397         xz_buf.in_size = in_size;
 398         xz_buf.in = in_buffer;
 399         xz_buf.in_pos = 0;
 400         xz_buf.out_size = fw_priv->allocated_size;
 401         xz_buf.out = fw_priv->data;
 402         xz_buf.out_pos = 0;
 403
 404         xz_ret = xz_dec_run(xz_dec, &xz_buf);
 405         xz_dec_end(xz_dec);
 406
 407         fw_priv->size = xz_buf.out_pos;
 408         return fw_decompress_xz_error(dev, xz_ret);
 409 }
 410
 411 /* decompression on paged buffer and map it */
 412 static int fw_decompress_xz_pages(struct device *dev, struct fw_priv *fw_priv,
 413                                   size_t in_size, const void *in_buffer)
 414 {
 415         struct xz_dec *xz_dec;
 416         struct xz_buf xz_buf;
 417         enum xz_ret xz_ret;
 418         struct page *page;
 419         int err = 0;
 420
 421         xz_dec = xz_dec_init(XZ_DYNALLOC, (u32)-1);
 422         if (!xz_dec)
 423                 return -ENOMEM;
 424
 425         xz_buf.in_size = in_size;
 426         xz_buf.in = in_buffer;
 427         xz_buf.in_pos = 0;
 428
 429         fw_priv->is_paged_buf = true;
 430         fw_priv->size = 0;
 431         do {
 432                 if (fw_grow_paged_buf(fw_priv, fw_priv->nr_pages + 1)) {
 433                         err = -ENOMEM;
 434                         goto out;
 435                 }
 436
 437                 /* decompress onto the new allocated page */
 438                 page = fw_priv->pages[fw_priv->nr_pages - 1];
 439                 xz_buf.out = kmap_local_page(page);
 440                 xz_buf.out_pos = 0;
 441                 xz_buf.out_size = PAGE_SIZE;
 442                 xz_ret = xz_dec_run(xz_dec, &xz_buf);
 443                 kunmap_local(xz_buf.out);
 444                 fw_priv->size += xz_buf.out_pos;
 445                 /* partial decompression means either end or error */
 446                 if (xz_buf.out_pos != PAGE_SIZE)
 447                         break;
 448         } while (xz_ret == XZ_OK);
 449
 450         err = fw_decompress_xz_error(dev, xz_ret);
 451         if (!err)
 452                 err = fw_map_paged_buf(fw_priv);
 453
 454  out:
 455         xz_dec_end(xz_dec);
 456         return err;
 457 }
 458
 459 static int fw_decompress_xz(struct device *dev, struct fw_priv *fw_priv,
 460                             size_t in_size, const void *in_buffer)
 461 {
 462         /* if the buffer is pre-allocated, we can perform in single-shot mode */
 463         if (fw_priv->data)
 464                 return fw_decompress_xz_single(dev, fw_priv, in_size, in_buffer);
 465         else
 466                 return fw_decompress_xz_pages(dev, fw_priv, in_size, in_buffer);
 467 }
 468 #endif /* CONFIG_FW_LOADER_COMPRESS_XZ */
 469
 470 /* direct firmware loading support */
 471 static char fw_path_para[256];
 472 static const char * const fw_path[] = {
 473         fw_path_para,
 474         "/lib/firmware/updates/" UTS_RELEASE,
 475         "/lib/firmware/updates",
 476         "/lib/firmware/" UTS_RELEASE,
 477         "/lib/firmware"
 478 };
 479
 480 /*
 481  * Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH'
 482  * from kernel command line because firmware_class is generally built in
 483  * kernel instead of module.
 484  */
 485 module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
 486 MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
 487
 488 static int
 489 fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
 490                            const char *suffix,
 491                            int (*decompress)(struct device *dev,
 492                                              struct fw_priv *fw_priv,
 493                                              size_t in_size,
 494                                              const void *in_buffer))
 495 {
 496         size_t size;
 497         int i, len, maxlen = 0;
 498         int rc = -ENOENT;
 499         char *path, *nt = NULL;
 500         size_t msize = INT_MAX;
 501         void *buffer = NULL;
 502
 503         /* Already populated data member means we're loading into a buffer */
 504         if (!decompress && fw_priv->data) {
 505                 buffer = fw_priv->data;
 506                 msize = fw_priv->allocated_size;
 507         }
 508
 509         path = __getname();
 510         if (!path)
 511                 return -ENOMEM;
 512
 513         wait_for_initramfs();
 514         for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
 515                 size_t file_size = 0;
 516                 size_t *file_size_ptr = NULL;
 517
 518                 /* skip the unset customized path */
 519                 if (!fw_path[i][0])
 520                         continue;
 521
 522                 /* strip off \n from customized path */
 523                 maxlen = strlen(fw_path[i]);
 524                 if (i == 0) {
 525                         nt = strchr(fw_path[i], '\n');
 526                         if (nt)
 527                                 maxlen = nt - fw_path[i];
 528                 }
 529
 530                 len = snprintf(path, PATH_MAX, "%.*s/%s%s",
 531                                maxlen, fw_path[i],
 532                                fw_priv->fw_name, suffix);
 533                 if (len >= PATH_MAX) {
 534                         rc = -ENAMETOOLONG;
 535                         break;
 536                 }
 537
 538                 fw_priv->size = 0;
 539
 540                 /*
 541                  * The total file size is only examined when doing a partial
 542                  * read; the "full read" case needs to fail if the whole
 543                  * firmware was not completely loaded.
 544                  */
 545                 if ((fw_priv->opt_flags & FW_OPT_PARTIAL) && buffer)
 546                         file_size_ptr = &file_size;
 547
 548                 /* load firmware files from the mount namespace of init */
 549                 rc = kernel_read_file_from_path_initns(path, fw_priv->offset,
 550                                                        &buffer, msize,
 551                                                        file_size_ptr,
 552                                                        READING_FIRMWARE);
 553                 if (rc < 0) {
 554                         if (!(fw_priv->opt_flags & FW_OPT_NO_WARN)) {
 555                                 if (rc != -ENOENT)
 556                                         dev_warn(device,
 557                                                  "loading %s failed with error %d\n",
 558                                                  path, rc);
 559                                 else
 560                                         dev_dbg(device,
 561                                                 "loading %s failed for no such file or directory.\n",
 562                                                 path);
 563                         }
 564                         continue;
 565                 }
 566                 size = rc;
 567                 rc = 0;
 568
 569                 dev_dbg(device, "Loading firmware from %s\n", path);
 570                 if (decompress) {
 571                         dev_dbg(device, "f/w decompressing %s\n",
 572                                 fw_priv->fw_name);
 573                         rc = decompress(device, fw_priv, size, buffer);
 574                         /* discard the superfluous original content */
 575                         vfree(buffer);
 576                         buffer = NULL;
 577                         if (rc) {
 578                                 fw_free_paged_buf(fw_priv);
 579                                 continue;
 580                         }
 581                 } else {
 582                         dev_dbg(device, "direct-loading %s\n",
 583                                 fw_priv->fw_name);
 584                         if (!fw_priv->data)
 585                                 fw_priv->data = buffer;
 586                         fw_priv->size = size;
 587                 }
 588                 fw_state_done(fw_priv);
 589                 break;
 590         }
 591         __putname(path);
 592
 593         return rc;
 594 }
 595
 596 /* firmware holds the ownership of pages */
 597 static void firmware_free_data(const struct firmware *fw)
 598 {
 599         /* Loaded directly? */
 600         if (!fw->priv) {
 601                 vfree(fw->data);
 602                 return;
 603         }
 604         free_fw_priv(fw->priv);
 605 }
 606
 607 /* store the pages buffer info firmware from buf */
 608 static void fw_set_page_data(struct fw_priv *fw_priv, struct firmware *fw)
 609 {
 610         fw->priv = fw_priv;
 611         fw->size = fw_priv->size;
 612         fw->data = fw_priv->data;
 613
 614         pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n",
 615                  __func__, fw_priv->fw_name, fw_priv, fw_priv->data,
 616                  (unsigned int)fw_priv->size);
 617 }
 618
 619 #ifdef CONFIG_FW_CACHE
 620 static void fw_name_devm_release(struct device *dev, void *res)
 621 {
 622         struct fw_name_devm *fwn = res;
 623
 624         if (fwn->magic == (unsigned long)&fw_cache)
 625                 pr_debug("%s: fw_name-%s devm-%p released\n",
 626                                 __func__, fwn->name, res);
 627         kfree_const(fwn->name);
 628 }
 629
 630 static int fw_devm_match(struct device *dev, void *res,
 631                 void *match_data)
 632 {
 633         struct fw_name_devm *fwn = res;
 634
 635         return (fwn->magic == (unsigned long)&fw_cache) &&
 636                 !strcmp(fwn->name, match_data);
 637 }
 638
 639 static struct fw_name_devm *fw_find_devm_name(struct device *dev,
 640                 const char *name)
 641 {
 642         struct fw_name_devm *fwn;
 643
 644         fwn = devres_find(dev, fw_name_devm_release,
 645                           fw_devm_match, (void *)name);
 646         return fwn;
 647 }
 648
 649 static bool fw_cache_is_setup(struct device *dev, const char *name)
 650 {
 651         struct fw_name_devm *fwn;
 652
 653         fwn = fw_find_devm_name(dev, name);
 654         if (fwn)
 655                 return true;
 656
 657         return false;
 658 }
 659
 660 /* add firmware name into devres list */
 661 static int fw_add_devm_name(struct device *dev, const char *name)
 662 {
 663         struct fw_name_devm *fwn;
 664
 665         if (fw_cache_is_setup(dev, name))
 666                 return 0;
 667
 668         fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm),
 669                            GFP_KERNEL);
 670         if (!fwn)
 671                 return -ENOMEM;
 672         fwn->name = kstrdup_const(name, GFP_KERNEL);
 673         if (!fwn->name) {
 674                 devres_free(fwn);
 675                 return -ENOMEM;
 676         }
 677
 678         fwn->magic = (unsigned long)&fw_cache;
 679         devres_add(dev, fwn);
 680
 681         return 0;
 682 }
 683 #else
 684 static bool fw_cache_is_setup(struct device *dev, const char *name)
 685 {
 686         return false;
 687 }
 688
 689 static int fw_add_devm_name(struct device *dev, const char *name)
 690 {
 691         return 0;
 692 }
 693 #endif
 694
 695 int assign_fw(struct firmware *fw, struct device *device)
 696 {
 697         struct fw_priv *fw_priv = fw->priv;
 698         int ret;
 699
 700         mutex_lock(&fw_lock);
 701         if (!fw_priv->size || fw_state_is_aborted(fw_priv)) {
 702                 mutex_unlock(&fw_lock);
 703                 return -ENOENT;
 704         }
 705
 706         /*
 707          * add firmware name into devres list so that we can auto cache
 708          * and uncache firmware for device.
 709          *
 710          * device may has been deleted already, but the problem
 711          * should be fixed in devres or driver core.
 712          */
 713         /* don't cache firmware handled without uevent */
 714         if (device && (fw_priv->opt_flags & FW_OPT_UEVENT) &&
 715             !(fw_priv->opt_flags & FW_OPT_NOCACHE)) {
 716                 ret = fw_add_devm_name(device, fw_priv->fw_name);
 717                 if (ret) {
 718                         mutex_unlock(&fw_lock);
 719                         return ret;
 720                 }
 721         }
 722
 723         /*
 724          * After caching firmware image is started, let it piggyback
 725          * on request firmware.
 726          */
 727         if (!(fw_priv->opt_flags & FW_OPT_NOCACHE) &&
 728             fw_priv->fwc->state == FW_LOADER_START_CACHE)
 729                 fw_cache_piggyback_on_request(fw_priv);
 730
 731         /* pass the pages buffer to driver at the last minute */
 732         fw_set_page_data(fw_priv, fw);
 733         mutex_unlock(&fw_lock);
 734         return 0;
 735 }
 736
 737 /* prepare firmware and firmware_buf structs;
 738  * return 0 if a firmware is already assigned, 1 if need to load one,
 739  * or a negative error code
 740  */
 741 static int
 742 _request_firmware_prepare(struct firmware **firmware_p, const char *name,
 743                           struct device *device, void *dbuf, size_t size,
 744                           size_t offset, u32 opt_flags)
 745 {
 746         struct firmware *firmware;
 747         struct fw_priv *fw_priv;
 748         int ret;
 749
 750         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
 751         if (!firmware) {
 752                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
 753                         __func__);
 754                 return -ENOMEM;
 755         }
 756
 757         if (firmware_request_builtin_buf(firmware, name, dbuf, size)) {
 758                 dev_dbg(device, "using built-in %s\n", name);
 759                 return 0; /* assigned */
 760         }
 761
 762         ret = alloc_lookup_fw_priv(name, &fw_cache, &fw_priv, dbuf, size,
 763                                    offset, opt_flags);
 764
 765         /*
 766          * bind with 'priv' now to avoid warning in failure path
 767          * of requesting firmware.
 768          */
 769         firmware->priv = fw_priv;
 770
 771         if (ret > 0) {
 772                 ret = fw_state_wait(fw_priv);
 773                 if (!ret) {
 774                         fw_set_page_data(fw_priv, firmware);
 775                         return 0; /* assigned */
 776                 }
 777         }
 778
 779         if (ret < 0)
 780                 return ret;
 781         return 1; /* need to load */
 782 }
 783
 784 /*
 785  * Batched requests need only one wake, we need to do this step last due to the
 786  * fallback mechanism. The buf is protected with kref_get(), and it won't be
 787  * released until the last user calls release_firmware().
 788  *
 789  * Failed batched requests are possible as well, in such cases we just share
 790  * the struct fw_priv and won't release it until all requests are woken
 791  * and have gone through this same path.
 792  */
 793 static void fw_abort_batch_reqs(struct firmware *fw)
 794 {
 795         struct fw_priv *fw_priv;
 796
 797         /* Loaded directly? */
 798         if (!fw || !fw->priv)
 799                 return;
 800
 801         fw_priv = fw->priv;
 802         mutex_lock(&fw_lock);
 803         if (!fw_state_is_aborted(fw_priv))
 804                 fw_state_aborted(fw_priv);
 805         mutex_unlock(&fw_lock);
 806 }
 807
 808 #if defined(CONFIG_FW_LOADER_DEBUG)
 809 #include <crypto/hash.h>
 810 #include <crypto/sha2.h>
 811
 812 static void fw_log_firmware_info(const struct firmware *fw, const char *name, struct device *device)
 813 {
 814         struct shash_desc *shash;
 815         struct crypto_shash *alg;
 816         u8 *sha256buf;
 817         char *outbuf;
 818
 819         alg = crypto_alloc_shash("sha256", 0, 0);
 820         if (IS_ERR(alg))
 821                 return;
 822
 823         sha256buf = kmalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
 824         outbuf = kmalloc(SHA256_BLOCK_SIZE + 1, GFP_KERNEL);
 825         shash = kmalloc(sizeof(*shash) + crypto_shash_descsize(alg), GFP_KERNEL);
 826         if (!sha256buf || !outbuf || !shash)
 827                 goto out_free;
 828
 829         shash->tfm = alg;
 830
 831         if (crypto_shash_digest(shash, fw->data, fw->size, sha256buf) < 0)
 832                 goto out_shash;
 833
 834         for (int i = 0; i < SHA256_DIGEST_SIZE; i++)
 835                 sprintf(&outbuf[i * 2], "%02x", sha256buf[i]);
 836         outbuf[SHA256_BLOCK_SIZE] = 0;
 837         dev_dbg(device, "Loaded FW: %s, sha256: %s\n", name, outbuf);
 838
 839 out_shash:
 840         crypto_free_shash(alg);
 841 out_free:
 842         kfree(shash);
 843         kfree(outbuf);
 844         kfree(sha256buf);
 845 }
 846 #else
 847 static void fw_log_firmware_info(const struct firmware *fw, const char *name,
 848                                  struct device *device)
 849 {}
 850 #endif
 851
 852 /* called from request_firmware() and request_firmware_work_func() */
 853 static int
 854 _request_firmware(const struct firmware **firmware_p, const char *name,
 855                   struct device *device, void *buf, size_t size,
 856                   size_t offset, u32 opt_flags)
 857 {
 858         struct firmware *fw = NULL;
 859         struct cred *kern_cred = NULL;
 860         const struct cred *old_cred;
 861         bool nondirect = false;
 862         int ret;
 863
 864         if (!firmware_p)
 865                 return -EINVAL;
 866
 867         if (!name || name[0] == '\0') {
 868                 ret = -EINVAL;
 869                 goto out;
 870         }
 871
 872         ret = _request_firmware_prepare(&fw, name, device, buf, size,
 873                                         offset, opt_flags);
 874         if (ret <= 0) /* error or already assigned */
 875                 goto out;
 876
 877         /*
 878          * We are about to try to access the firmware file. Because we may have been
 879          * called by a driver when serving an unrelated request from userland, we use
 880          * the kernel credentials to read the file.
 881          */
 882         kern_cred = prepare_kernel_cred(&init_task);
 883         if (!kern_cred) {
 884                 ret = -ENOMEM;
 885                 goto out;
 886         }
 887         old_cred = override_creds(kern_cred);
 888
 889         ret = fw_get_filesystem_firmware(device, fw->priv, "", NULL);
 890
 891         /* Only full reads can support decompression, platform, and sysfs. */
 892         if (!(opt_flags & FW_OPT_PARTIAL))
 893                 nondirect = true;
 894
 895 #ifdef CONFIG_FW_LOADER_COMPRESS_ZSTD
 896         if (ret == -ENOENT && nondirect)
 897                 ret = fw_get_filesystem_firmware(device, fw->priv, ".zst",
 898                                                  fw_decompress_zstd);
 899 #endif
 900 #ifdef CONFIG_FW_LOADER_COMPRESS_XZ
 901         if (ret == -ENOENT && nondirect)
 902                 ret = fw_get_filesystem_firmware(device, fw->priv, ".xz",
 903                                                  fw_decompress_xz);
 904 #endif
 905         if (ret == -ENOENT && nondirect)
 906                 ret = firmware_fallback_platform(fw->priv);
 907
 908         if (ret) {
 909                 if (!(opt_flags & FW_OPT_NO_WARN))
 910                         dev_warn(device,
 911                                  "Direct firmware load for %s failed with error %d\n",
 912                                  name, ret);
 913                 if (nondirect)
 914                         ret = firmware_fallback_sysfs(fw, name, device,
 915                                                       opt_flags, ret);
 916         } else
 917                 ret = assign_fw(fw, device);
 918
 919         revert_creds(old_cred);
 920         put_cred(kern_cred);
 921
 922 out:
 923         if (ret < 0) {
 924                 fw_abort_batch_reqs(fw);
 925                 release_firmware(fw);
 926                 fw = NULL;
 927         } else {
 928                 fw_log_firmware_info(fw, name, device);
 929         }
 930
 931         *firmware_p = fw;
 932         return ret;
 933 }
 934
 935 /**
 936  * request_firmware() - send firmware request and wait for it
 937  * @firmware_p: pointer to firmware image
 938  * @name: name of firmware file
 939  * @device: device for which firmware is being loaded
 940  *
 941  *      @firmware_p will be used to return a firmware image by the name
 942  *      of @name for device @device.
 943  *
 944  *      Should be called from user context where sleeping is allowed.
 945  *
 946  *      @name will be used as $FIRMWARE in the uevent environment and
 947  *      should be distinctive enough not to be confused with any other
 948  *      firmware image for this or any other device.
 949  *
 950  *      Caller must hold the reference count of @device.
 951  *
 952  *      The function can be called safely inside device's suspend and
 953  *      resume callback.
 954  **/
 955 int
 956 request_firmware(const struct firmware **firmware_p, const char *name,
 957                  struct device *device)
 958 {
 959         int ret;
 960
 961         /* Need to pin this module until return */
 962         __module_get(THIS_MODULE);
 963         ret = _request_firmware(firmware_p, name, device, NULL, 0, 0,
 964                                 FW_OPT_UEVENT);
 965         module_put(THIS_MODULE);
 966         return ret;
 967 }
 968 EXPORT_SYMBOL(request_firmware);
 969
 970 /**
 971  * firmware_request_nowarn() - request for an optional fw module
 972  * @firmware: pointer to firmware image
 973  * @name: name of firmware file
 974  * @device: device for which firmware is being loaded
 975  *
 976  * This function is similar in behaviour to request_firmware(), except it
 977  * doesn't produce warning messages when the file is not found. The sysfs
 978  * fallback mechanism is enabled if direct filesystem lookup fails. However,
 979  * failures to find the firmware file with it are still suppressed. It is
 980  * therefore up to the driver to check for the return value of this call and to
 981  * decide when to inform the users of errors.
 982  **/
 983 int firmware_request_nowarn(const struct firmware **firmware, const char *name,
 984                             struct device *device)
 985 {
 986         int ret;
 987
 988         /* Need to pin this module until return */
 989         __module_get(THIS_MODULE);
 990         ret = _request_firmware(firmware, name, device, NULL, 0, 0,
 991                                 FW_OPT_UEVENT | FW_OPT_NO_WARN);
 992         module_put(THIS_MODULE);
 993         return ret;
 994 }
 995 EXPORT_SYMBOL_GPL(firmware_request_nowarn);
 996
 997 /**
 998  * request_firmware_direct() - load firmware directly without usermode helper
 999  * @firmware_p: pointer to firmware image
1000  * @name: name of firmware file
1001  * @device: device for which firmware is being loaded
1002  *
1003  * This function works pretty much like request_firmware(), but this doesn't
1004  * fall back to usermode helper even if the firmware couldn't be loaded
1005  * directly from fs.  Hence it's useful for loading optional firmwares, which
1006  * aren't always present, without extra long timeouts of udev.
1007  **/
1008 int request_firmware_direct(const struct firmware **firmware_p,
1009                             const char *name, struct device *device)
1010 {
1011         int ret;
1012
1013         __module_get(THIS_MODULE);
1014         ret = _request_firmware(firmware_p, name, device, NULL, 0, 0,
1015                                 FW_OPT_UEVENT | FW_OPT_NO_WARN |
1016                                 FW_OPT_NOFALLBACK_SYSFS);
1017         module_put(THIS_MODULE);
1018         return ret;
1019 }
1020 EXPORT_SYMBOL_GPL(request_firmware_direct);
1021
1022 /**
1023  * firmware_request_platform() - request firmware with platform-fw fallback
1024  * @firmware: pointer to firmware image
1025  * @name: name of firmware file
1026  * @device: device for which firmware is being loaded
1027  *
1028  * This function is similar in behaviour to request_firmware, except that if
1029  * direct filesystem lookup fails, it will fallback to looking for a copy of the
1030  * requested firmware embedded in the platform's main (e.g. UEFI) firmware.
1031  **/
1032 int firmware_request_platform(const struct firmware **firmware,
1033                               const char *name, struct device *device)
1034 {
1035         int ret;
1036
1037         /* Need to pin this module until return */
1038         __module_get(THIS_MODULE);
1039         ret = _request_firmware(firmware, name, device, NULL, 0, 0,
1040                                 FW_OPT_UEVENT | FW_OPT_FALLBACK_PLATFORM);
1041         module_put(THIS_MODULE);
1042         return ret;
1043 }
1044 EXPORT_SYMBOL_GPL(firmware_request_platform);
1045
1046 /**
1047  * firmware_request_cache() - cache firmware for suspend so resume can use it
1048  * @name: name of firmware file
1049  * @device: device for which firmware should be cached for
1050  *
1051  * There are some devices with an optimization that enables the device to not
1052  * require loading firmware on system reboot. This optimization may still
1053  * require the firmware present on resume from suspend. This routine can be
1054  * used to ensure the firmware is present on resume from suspend in these
1055  * situations. This helper is not compatible with drivers which use
1056  * request_firmware_into_buf() or request_firmware_nowait() with no uevent set.
1057  **/
1058 int firmware_request_cache(struct device *device, const char *name)
1059 {
1060         int ret;
1061
1062         mutex_lock(&fw_lock);
1063         ret = fw_add_devm_name(device, name);
1064         mutex_unlock(&fw_lock);
1065
1066         return ret;
1067 }
1068 EXPORT_SYMBOL_GPL(firmware_request_cache);
1069
1070 /**
1071  * request_firmware_into_buf() - load firmware into a previously allocated buffer
1072  * @firmware_p: pointer to firmware image
1073  * @name: name of firmware file
1074  * @device: device for which firmware is being loaded and DMA region allocated
1075  * @buf: address of buffer to load firmware into
1076  * @size: size of buffer
1077  *
1078  * This function works pretty much like request_firmware(), but it doesn't
1079  * allocate a buffer to hold the firmware data. Instead, the firmware
1080  * is loaded directly into the buffer pointed to by @buf and the @firmware_p
1081  * data member is pointed at @buf.
1082  *
1083  * This function doesn't cache firmware either.
1084  */
1085 int
1086 request_firmware_into_buf(const struct firmware **firmware_p, const char *name,
1087                           struct device *device, void *buf, size_t size)
1088 {
1089         int ret;
1090
1091         if (fw_cache_is_setup(device, name))
1092                 return -EOPNOTSUPP;
1093
1094         __module_get(THIS_MODULE);
1095         ret = _request_firmware(firmware_p, name, device, buf, size, 0,
1096                                 FW_OPT_UEVENT | FW_OPT_NOCACHE);
1097         module_put(THIS_MODULE);
1098         return ret;
1099 }
1100 EXPORT_SYMBOL(request_firmware_into_buf);
1101
1102 /**
1103  * request_partial_firmware_into_buf() - load partial firmware into a previously allocated buffer
1104  * @firmware_p: pointer to firmware image
1105  * @name: name of firmware file
1106  * @device: device for which firmware is being loaded and DMA region allocated
1107  * @buf: address of buffer to load firmware into
1108  * @size: size of buffer
1109  * @offset: offset into file to read
1110  *
1111  * This function works pretty much like request_firmware_into_buf except
1112  * it allows a partial read of the file.
1113  */
1114 int
1115 request_partial_firmware_into_buf(const struct firmware **firmware_p,
1116                                   const char *name, struct device *device,
1117                                   void *buf, size_t size, size_t offset)
1118 {
1119         int ret;
1120
1121         if (fw_cache_is_setup(device, name))
1122                 return -EOPNOTSUPP;
1123
1124         __module_get(THIS_MODULE);
1125         ret = _request_firmware(firmware_p, name, device, buf, size, offset,
1126                                 FW_OPT_UEVENT | FW_OPT_NOCACHE |
1127                                 FW_OPT_PARTIAL);
1128         module_put(THIS_MODULE);
1129         return ret;
1130 }
1131 EXPORT_SYMBOL(request_partial_firmware_into_buf);
1132
1133 /**
1134  * release_firmware() - release the resource associated with a firmware image
1135  * @fw: firmware resource to release
1136  **/
1137 void release_firmware(const struct firmware *fw)
1138 {
1139         if (fw) {
1140                 if (!firmware_is_builtin(fw))
1141                         firmware_free_data(fw);
1142                 kfree(fw);
1143         }
1144 }
1145 EXPORT_SYMBOL(release_firmware);
1146
1147 /* Async support */
1148 struct firmware_work {
1149         struct work_struct work;
1150         struct module *module;
1151         const char *name;
1152         struct device *device;
1153         void *context;
1154         void (*cont)(const struct firmware *fw, void *context);
1155         u32 opt_flags;
1156 };
1157
1158 static void request_firmware_work_func(struct work_struct *work)
1159 {
1160         struct firmware_work *fw_work;
1161         const struct firmware *fw;
1162
1163         fw_work = container_of(work, struct firmware_work, work);
1164
1165         _request_firmware(&fw, fw_work->name, fw_work->device, NULL, 0, 0,
1166                           fw_work->opt_flags);
1167         fw_work->cont(fw, fw_work->context);
1168         put_device(fw_work->device); /* taken in request_firmware_nowait() */
1169
1170         module_put(fw_work->module);
1171         kfree_const(fw_work->name);
1172         kfree(fw_work);
1173 }
1174
1175 /**
1176  * request_firmware_nowait() - asynchronous version of request_firmware
1177  * @module: module requesting the firmware
1178  * @uevent: sends uevent to copy the firmware image if this flag
1179  *      is non-zero else the firmware copy must be done manually.
1180  * @name: name of firmware file
1181  * @device: device for which firmware is being loaded
1182  * @gfp: allocation flags
1183  * @context: will be passed over to @cont, and
1184  *      @fw may be %NULL if firmware request fails.
1185  * @cont: function will be called asynchronously when the firmware
1186  *      request is over.
1187  *
1188  *      Caller must hold the reference count of @device.
1189  *
1190  *      Asynchronous variant of request_firmware() for user contexts:
1191  *              - sleep for as small periods as possible since it may
1192  *                increase kernel boot time of built-in device drivers
1193  *                requesting firmware in their ->probe() methods, if
1194  *                @gfp is GFP_KERNEL.
1195  *
1196  *              - can't sleep at all if @gfp is GFP_ATOMIC.
1197  **/
1198 int
1199 request_firmware_nowait(
1200         struct module *module, bool uevent,
1201         const char *name, struct device *device, gfp_t gfp, void *context,
1202         void (*cont)(const struct firmware *fw, void *context))
1203 {
1204         struct firmware_work *fw_work;
1205
1206         fw_work = kzalloc(sizeof(struct firmware_work), gfp);
1207         if (!fw_work)
1208                 return -ENOMEM;
1209
1210         fw_work->module = module;
1211         fw_work->name = kstrdup_const(name, gfp);
1212         if (!fw_work->name) {
1213                 kfree(fw_work);
1214                 return -ENOMEM;
1215         }
1216         fw_work->device = device;
1217         fw_work->context = context;
1218         fw_work->cont = cont;
1219         fw_work->opt_flags = FW_OPT_NOWAIT |
1220                 (uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
1221
1222         if (!uevent && fw_cache_is_setup(device, name)) {
1223                 kfree_const(fw_work->name);
1224                 kfree(fw_work);
1225                 return -EOPNOTSUPP;
1226         }
1227
1228         if (!try_module_get(module)) {
1229                 kfree_const(fw_work->name);
1230                 kfree(fw_work);
1231                 return -EFAULT;
1232         }
1233
1234         get_device(fw_work->device);
1235         INIT_WORK(&fw_work->work, request_firmware_work_func);
1236         schedule_work(&fw_work->work);
1237         return 0;
1238 }
1239 EXPORT_SYMBOL(request_firmware_nowait);
1240
1241 #ifdef CONFIG_FW_CACHE
1242 static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
1243
1244 /**
1245  * cache_firmware() - cache one firmware image in kernel memory space
1246  * @fw_name: the firmware image name
1247  *
1248  * Cache firmware in kernel memory so that drivers can use it when
1249  * system isn't ready for them to request firmware image from userspace.
1250  * Once it returns successfully, driver can use request_firmware or its
1251  * nowait version to get the cached firmware without any interacting
1252  * with userspace
1253  *
1254  * Return 0 if the firmware image has been cached successfully
1255  * Return !0 otherwise
1256  *
1257  */
1258 static int cache_firmware(const char *fw_name)
1259 {
1260         int ret;
1261         const struct firmware *fw;
1262
1263         pr_debug("%s: %s\n", __func__, fw_name);
1264
1265         ret = request_firmware(&fw, fw_name, NULL);
1266         if (!ret)
1267                 kfree(fw);
1268
1269         pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
1270
1271         return ret;
1272 }
1273
1274 static struct fw_priv *lookup_fw_priv(const char *fw_name)
1275 {
1276         struct fw_priv *tmp;
1277         struct firmware_cache *fwc = &fw_cache;
1278
1279         spin_lock(&fwc->lock);
1280         tmp = __lookup_fw_priv(fw_name);
1281         spin_unlock(&fwc->lock);
1282
1283         return tmp;
1284 }
1285
1286 /**
1287  * uncache_firmware() - remove one cached firmware image
1288  * @fw_name: the firmware image name
1289  *
1290  * Uncache one firmware image which has been cached successfully
1291  * before.
1292  *
1293  * Return 0 if the firmware cache has been removed successfully
1294  * Return !0 otherwise
1295  *
1296  */
1297 static int uncache_firmware(const char *fw_name)
1298 {
1299         struct fw_priv *fw_priv;
1300         struct firmware fw;
1301
1302         pr_debug("%s: %s\n", __func__, fw_name);
1303
1304         if (firmware_request_builtin(&fw, fw_name))
1305                 return 0;
1306
1307         fw_priv = lookup_fw_priv(fw_name);
1308         if (fw_priv) {
1309                 free_fw_priv(fw_priv);
1310                 return 0;
1311         }
1312
1313         return -EINVAL;
1314 }
1315
1316 static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
1317 {
1318         struct fw_cache_entry *fce;
1319
1320         fce = kzalloc(sizeof(*fce), GFP_ATOMIC);
1321         if (!fce)
1322                 goto exit;
1323
1324         fce->name = kstrdup_const(name, GFP_ATOMIC);
1325         if (!fce->name) {
1326                 kfree(fce);
1327                 fce = NULL;
1328                 goto exit;
1329         }
1330 exit:
1331         return fce;
1332 }
1333
1334 static int __fw_entry_found(const char *name)
1335 {
1336         struct firmware_cache *fwc = &fw_cache;
1337         struct fw_cache_entry *fce;
1338
1339         list_for_each_entry(fce, &fwc->fw_names, list) {
1340                 if (!strcmp(fce->name, name))
1341                         return 1;
1342         }
1343         return 0;
1344 }
1345
1346 static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv)
1347 {
1348         const char *name = fw_priv->fw_name;
1349         struct firmware_cache *fwc = fw_priv->fwc;
1350         struct fw_cache_entry *fce;
1351
1352         spin_lock(&fwc->name_lock);
1353         if (__fw_entry_found(name))
1354                 goto found;
1355
1356         fce = alloc_fw_cache_entry(name);
1357         if (fce) {
1358                 list_add(&fce->list, &fwc->fw_names);
1359                 kref_get(&fw_priv->ref);
1360                 pr_debug("%s: fw: %s\n", __func__, name);
1361         }
1362 found:
1363         spin_unlock(&fwc->name_lock);
1364 }
1365
1366 static void free_fw_cache_entry(struct fw_cache_entry *fce)
1367 {
1368         kfree_const(fce->name);
1369         kfree(fce);
1370 }
1371
1372 static void __async_dev_cache_fw_image(void *fw_entry,
1373                                        async_cookie_t cookie)
1374 {
1375         struct fw_cache_entry *fce = fw_entry;
1376         struct firmware_cache *fwc = &fw_cache;
1377         int ret;
1378
1379         ret = cache_firmware(fce->name);
1380         if (ret) {
1381                 spin_lock(&fwc->name_lock);
1382                 list_del(&fce->list);
1383                 spin_unlock(&fwc->name_lock);
1384
1385                 free_fw_cache_entry(fce);
1386         }
1387 }
1388
1389 /* called with dev->devres_lock held */
1390 static void dev_create_fw_entry(struct device *dev, void *res,
1391                                 void *data)
1392 {
1393         struct fw_name_devm *fwn = res;
1394         const char *fw_name = fwn->name;
1395         struct list_head *head = data;
1396         struct fw_cache_entry *fce;
1397
1398         fce = alloc_fw_cache_entry(fw_name);
1399         if (fce)
1400                 list_add(&fce->list, head);
1401 }
1402
1403 static int devm_name_match(struct device *dev, void *res,
1404                            void *match_data)
1405 {
1406         struct fw_name_devm *fwn = res;
1407         return (fwn->magic == (unsigned long)match_data);
1408 }
1409
1410 static void dev_cache_fw_image(struct device *dev, void *data)
1411 {
1412         LIST_HEAD(todo);
1413         struct fw_cache_entry *fce;
1414         struct fw_cache_entry *fce_next;
1415         struct firmware_cache *fwc = &fw_cache;
1416
1417         devres_for_each_res(dev, fw_name_devm_release,
1418                             devm_name_match, &fw_cache,
1419                             dev_create_fw_entry, &todo);
1420
1421         list_for_each_entry_safe(fce, fce_next, &todo, list) {
1422                 list_del(&fce->list);
1423
1424                 spin_lock(&fwc->name_lock);
1425                 /* only one cache entry for one firmware */
1426                 if (!__fw_entry_found(fce->name)) {
1427                         list_add(&fce->list, &fwc->fw_names);
1428                 } else {
1429                         free_fw_cache_entry(fce);
1430                         fce = NULL;
1431                 }
1432                 spin_unlock(&fwc->name_lock);
1433
1434                 if (fce)
1435                         async_schedule_domain(__async_dev_cache_fw_image,
1436                                               (void *)fce,
1437                                               &fw_cache_domain);
1438         }
1439 }
1440
1441 static void __device_uncache_fw_images(void)
1442 {
1443         struct firmware_cache *fwc = &fw_cache;
1444         struct fw_cache_entry *fce;
1445
1446         spin_lock(&fwc->name_lock);
1447         while (!list_empty(&fwc->fw_names)) {
1448                 fce = list_entry(fwc->fw_names.next,
1449                                 struct fw_cache_entry, list);
1450                 list_del(&fce->list);
1451                 spin_unlock(&fwc->name_lock);
1452
1453                 uncache_firmware(fce->name);
1454                 free_fw_cache_entry(fce);
1455
1456                 spin_lock(&fwc->name_lock);
1457         }
1458         spin_unlock(&fwc->name_lock);
1459 }
1460
1461 /**
1462  * device_cache_fw_images() - cache devices' firmware
1463  *
1464  * If one device called request_firmware or its nowait version
1465  * successfully before, the firmware names are recored into the
1466  * device's devres link list, so device_cache_fw_images can call
1467  * cache_firmware() to cache these firmwares for the device,
1468  * then the device driver can load its firmwares easily at
1469  * time when system is not ready to complete loading firmware.
1470  */
1471 static void device_cache_fw_images(void)
1472 {
1473         struct firmware_cache *fwc = &fw_cache;
1474         DEFINE_WAIT(wait);
1475
1476         pr_debug("%s\n", __func__);
1477
1478         /* cancel uncache work */
1479         cancel_delayed_work_sync(&fwc->work);
1480
1481         fw_fallback_set_cache_timeout();
1482
1483         mutex_lock(&fw_lock);
1484         fwc->state = FW_LOADER_START_CACHE;
1485         dpm_for_each_dev(NULL, dev_cache_fw_image);
1486         mutex_unlock(&fw_lock);
1487
1488         /* wait for completion of caching firmware for all devices */
1489         async_synchronize_full_domain(&fw_cache_domain);
1490
1491         fw_fallback_set_default_timeout();
1492 }
1493
1494 /**
1495  * device_uncache_fw_images() - uncache devices' firmware
1496  *
1497  * uncache all firmwares which have been cached successfully
1498  * by device_uncache_fw_images earlier
1499  */
1500 static void device_uncache_fw_images(void)
1501 {
1502         pr_debug("%s\n", __func__);
1503         __device_uncache_fw_images();
1504 }
1505
1506 static void device_uncache_fw_images_work(struct work_struct *work)
1507 {
1508         device_uncache_fw_images();
1509 }
1510
1511 /**
1512  * device_uncache_fw_images_delay() - uncache devices firmwares
1513  * @delay: number of milliseconds to delay uncache device firmwares
1514  *
1515  * uncache all devices's firmwares which has been cached successfully
1516  * by device_cache_fw_images after @delay milliseconds.
1517  */
1518 static void device_uncache_fw_images_delay(unsigned long delay)
1519 {
1520         queue_delayed_work(system_power_efficient_wq, &fw_cache.work,
1521                            msecs_to_jiffies(delay));
1522 }
1523
1524 static int fw_pm_notify(struct notifier_block *notify_block,
1525                         unsigned long mode, void *unused)
1526 {
1527         switch (mode) {
1528         case PM_HIBERNATION_PREPARE:
1529         case PM_SUSPEND_PREPARE:
1530         case PM_RESTORE_PREPARE:
1531                 /*
1532                  * Here, kill pending fallback requests will only kill
1533                  * non-uevent firmware request to avoid stalling suspend.
1534                  */
1535                 kill_pending_fw_fallback_reqs(false);
1536                 device_cache_fw_images();
1537                 break;
1538
1539         case PM_POST_SUSPEND:
1540         case PM_POST_HIBERNATION:
1541         case PM_POST_RESTORE:
1542                 /*
1543                  * In case that system sleep failed and syscore_suspend is
1544                  * not called.
1545                  */
1546                 mutex_lock(&fw_lock);
1547                 fw_cache.state = FW_LOADER_NO_CACHE;
1548                 mutex_unlock(&fw_lock);
1549
1550                 device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
1551                 break;
1552         }
1553
1554         return 0;
1555 }
1556
1557 /* stop caching firmware once syscore_suspend is reached */
1558 static int fw_suspend(void)
1559 {
1560         fw_cache.state = FW_LOADER_NO_CACHE;
1561         return 0;
1562 }
1563
1564 static struct syscore_ops fw_syscore_ops = {
1565         .suspend = fw_suspend,
1566 };
1567
1568 static int __init register_fw_pm_ops(void)
1569 {
1570         int ret;
1571
1572         spin_lock_init(&fw_cache.name_lock);
1573         INIT_LIST_HEAD(&fw_cache.fw_names);
1574
1575         INIT_DELAYED_WORK(&fw_cache.work,
1576                           device_uncache_fw_images_work);
1577
1578         fw_cache.pm_notify.notifier_call = fw_pm_notify;
1579         ret = register_pm_notifier(&fw_cache.pm_notify);
1580         if (ret)
1581                 return ret;
1582
1583         register_syscore_ops(&fw_syscore_ops);
1584
1585         return ret;
1586 }
1587
1588 static inline void unregister_fw_pm_ops(void)
1589 {
1590         unregister_syscore_ops(&fw_syscore_ops);
1591         unregister_pm_notifier(&fw_cache.pm_notify);
1592 }
1593 #else
1594 static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv)
1595 {
1596 }
1597 static inline int register_fw_pm_ops(void)
1598 {
1599         return 0;
1600 }
1601 static inline void unregister_fw_pm_ops(void)
1602 {
1603 }
1604 #endif
1605
1606 static void __init fw_cache_init(void)
1607 {
1608         spin_lock_init(&fw_cache.lock);
1609         INIT_LIST_HEAD(&fw_cache.head);
1610         fw_cache.state = FW_LOADER_NO_CACHE;
1611 }
1612
1613 static int fw_shutdown_notify(struct notifier_block *unused1,
1614                               unsigned long unused2, void *unused3)
1615 {
1616         /*
1617          * Kill all pending fallback requests to avoid both stalling shutdown,
1618          * and avoid a deadlock with the usermode_lock.
1619          */
1620         kill_pending_fw_fallback_reqs(true);
1621
1622         return NOTIFY_DONE;
1623 }
1624
1625 static struct notifier_block fw_shutdown_nb = {
1626         .notifier_call = fw_shutdown_notify,
1627 };
1628
1629 static int __init firmware_class_init(void)
1630 {
1631         int ret;
1632
1633         /* No need to unfold these on exit */
1634         fw_cache_init();
1635
1636         ret = register_fw_pm_ops();
1637         if (ret)
1638                 return ret;
1639
1640         ret = register_reboot_notifier(&fw_shutdown_nb);
1641         if (ret)
1642                 goto out;
1643
1644         return register_sysfs_loader();
1645
1646 out:
1647         unregister_fw_pm_ops();
1648         return ret;
1649 }
1650
1651 static void __exit firmware_class_exit(void)
1652 {
1653         unregister_fw_pm_ops();
1654         unregister_reboot_notifier(&fw_shutdown_nb);
1655         unregister_sysfs_loader();
1656 }
1657
1658 fs_initcall(firmware_class_init);
1659 module_exit(firmware_class_exit);