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