drivers/base/firmware_class.c

   1 /*
   2  * firmware_class.c - Multi purpose firmware loading support
   3  *
   4  * Copyright (c) 2003 Manuel Estrada Sainz
   5  *
   6  * Please see Documentation/firmware_class/ for more information.
   7  *
   8  */
   9
  10 #include <linux/capability.h>
  11 #include <linux/device.h>
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/timer.h>
  15 #include <linux/vmalloc.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/bitops.h>
  18 #include <linux/mutex.h>
  19 #include <linux/workqueue.h>
  20 #include <linux/highmem.h>
  21 #include <linux/firmware.h>
  22 #include <linux/slab.h>
  23 #include <linux/sched.h>
  24 #include <linux/file.h>
  25 #include <linux/list.h>
  26 #include <linux/fs.h>
  27 #include <linux/async.h>
  28 #include <linux/pm.h>
  29 #include <linux/suspend.h>
  30 #include <linux/syscore_ops.h>
  31 #include <linux/reboot.h>
  32 #include <linux/security.h>
  33 #include <linux/swait.h>
  34
  35 #include <generated/utsrelease.h>
  36
  37 #include "base.h"
  38
  39 MODULE_AUTHOR("Manuel Estrada Sainz");
  40 MODULE_DESCRIPTION("Multi purpose firmware loading support");
  41 MODULE_LICENSE("GPL");
  42
  43 /* Builtin firmware support */
  44
  45 #ifdef CONFIG_FW_LOADER
  46
  47 extern struct builtin_fw __start_builtin_fw[];
  48 extern struct builtin_fw __end_builtin_fw[];
  49
  50 static bool fw_get_builtin_firmware(struct firmware *fw, const char *name,
  51                                     void *buf, size_t size)
  52 {
  53         struct builtin_fw *b_fw;
  54
  55         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
  56                 if (strcmp(name, b_fw->name) == 0) {
  57                         fw->size = b_fw->size;
  58                         fw->data = b_fw->data;
  59
  60                         if (buf && fw->size <= size)
  61                                 memcpy(buf, fw->data, fw->size);
  62                         return true;
  63                 }
  64         }
  65
  66         return false;
  67 }
  68
  69 static bool fw_is_builtin_firmware(const struct firmware *fw)
  70 {
  71         struct builtin_fw *b_fw;
  72
  73         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
  74                 if (fw->data == b_fw->data)
  75                         return true;
  76
  77         return false;
  78 }
  79
  80 #else /* Module case - no builtin firmware support */
  81
  82 static inline bool fw_get_builtin_firmware(struct firmware *fw,
  83                                            const char *name, void *buf,
  84                                            size_t size)
  85 {
  86         return false;
  87 }
  88
  89 static inline bool fw_is_builtin_firmware(const struct firmware *fw)
  90 {
  91         return false;
  92 }
  93 #endif
  94
  95 enum fw_status {
  96         FW_STATUS_UNKNOWN,
  97         FW_STATUS_LOADING,
  98         FW_STATUS_DONE,
  99         FW_STATUS_ABORTED,
 100 };
 101
 102 static int loading_timeout = 60;        /* In seconds */
 103
 104 static inline long firmware_loading_timeout(void)
 105 {
 106         return loading_timeout > 0 ? loading_timeout * HZ : MAX_JIFFY_OFFSET;
 107 }
 108
 109 /*
 110  * Concurrent request_firmware() for the same firmware need to be
 111  * serialized.  struct fw_state is simple state machine which hold the
 112  * state of the firmware loading.
 113  */
 114 struct fw_state {
 115         struct swait_queue_head wq;
 116         enum fw_status status;
 117 };
 118
 119 static void fw_state_init(struct fw_state *fw_st)
 120 {
 121         init_swait_queue_head(&fw_st->wq);
 122         fw_st->status = FW_STATUS_UNKNOWN;
 123 }
 124
 125 static inline bool __fw_state_is_done(enum fw_status status)
 126 {
 127         return status == FW_STATUS_DONE || status == FW_STATUS_ABORTED;
 128 }
 129
 130 static int __fw_state_wait_common(struct fw_state *fw_st, long timeout)
 131 {
 132         long ret;
 133
 134         ret = swait_event_interruptible_timeout(fw_st->wq,
 135                                 __fw_state_is_done(READ_ONCE(fw_st->status)),
 136                                 timeout);
 137         if (ret != 0 && fw_st->status == FW_STATUS_ABORTED)
 138                 return -ENOENT;
 139         if (!ret)
 140                 return -ETIMEDOUT;
 141
 142         return ret < 0 ? ret : 0;
 143 }
 144
 145 static void __fw_state_set(struct fw_state *fw_st,
 146                            enum fw_status status)
 147 {
 148         WRITE_ONCE(fw_st->status, status);
 149
 150         if (status == FW_STATUS_DONE || status == FW_STATUS_ABORTED)
 151                 swake_up(&fw_st->wq);
 152 }
 153
 154 #define fw_state_start(fw_st)                                   \
 155         __fw_state_set(fw_st, FW_STATUS_LOADING)
 156 #define fw_state_done(fw_st)                                    \
 157         __fw_state_set(fw_st, FW_STATUS_DONE)
 158 #define fw_state_wait(fw_st)                                    \
 159         __fw_state_wait_common(fw_st, MAX_SCHEDULE_TIMEOUT)
 160
 161 #ifndef CONFIG_FW_LOADER_USER_HELPER
 162
 163 #define fw_state_is_aborted(fw_st)      false
 164
 165 #else /* CONFIG_FW_LOADER_USER_HELPER */
 166
 167 static int __fw_state_check(struct fw_state *fw_st, enum fw_status status)
 168 {
 169         return fw_st->status == status;
 170 }
 171
 172 #define fw_state_aborted(fw_st)                                 \
 173         __fw_state_set(fw_st, FW_STATUS_ABORTED)
 174 #define fw_state_is_done(fw_st)                                 \
 175         __fw_state_check(fw_st, FW_STATUS_DONE)
 176 #define fw_state_is_loading(fw_st)                              \
 177         __fw_state_check(fw_st, FW_STATUS_LOADING)
 178 #define fw_state_is_aborted(fw_st)                              \
 179         __fw_state_check(fw_st, FW_STATUS_ABORTED)
 180 #define fw_state_wait_timeout(fw_st, timeout)                   \
 181         __fw_state_wait_common(fw_st, timeout)
 182
 183 #endif /* CONFIG_FW_LOADER_USER_HELPER */
 184
 185 /* firmware behavior options */
 186 #define FW_OPT_UEVENT   (1U << 0)
 187 #define FW_OPT_NOWAIT   (1U << 1)
 188 #ifdef CONFIG_FW_LOADER_USER_HELPER
 189 #define FW_OPT_USERHELPER       (1U << 2)
 190 #else
 191 #define FW_OPT_USERHELPER       0
 192 #endif
 193 #ifdef CONFIG_FW_LOADER_USER_HELPER_FALLBACK
 194 #define FW_OPT_FALLBACK         FW_OPT_USERHELPER
 195 #else
 196 #define FW_OPT_FALLBACK         0
 197 #endif
 198 #define FW_OPT_NO_WARN  (1U << 3)
 199 #define FW_OPT_NOCACHE  (1U << 4)
 200
 201 struct firmware_cache {
 202         /* firmware_buf instance will be added into the below list */
 203         spinlock_t lock;
 204         struct list_head head;
 205         int state;
 206
 207 #ifdef CONFIG_PM_SLEEP
 208         /*
 209          * Names of firmware images which have been cached successfully
 210          * will be added into the below list so that device uncache
 211          * helper can trace which firmware images have been cached
 212          * before.
 213          */
 214         spinlock_t name_lock;
 215         struct list_head fw_names;
 216
 217         struct delayed_work work;
 218
 219         struct notifier_block   pm_notify;
 220 #endif
 221 };
 222
 223 struct firmware_buf {
 224         struct kref ref;
 225         struct list_head list;
 226         struct firmware_cache *fwc;
 227         struct fw_state fw_st;
 228         void *data;
 229         size_t size;
 230         size_t allocated_size;
 231 #ifdef CONFIG_FW_LOADER_USER_HELPER
 232         bool is_paged_buf;
 233         bool need_uevent;
 234         struct page **pages;
 235         int nr_pages;
 236         int page_array_size;
 237         struct list_head pending_list;
 238 #endif
 239         const char *fw_id;
 240 };
 241
 242 struct fw_cache_entry {
 243         struct list_head list;
 244         const char *name;
 245 };
 246
 247 struct fw_name_devm {
 248         unsigned long magic;
 249         const char *name;
 250 };
 251
 252 #define to_fwbuf(d) container_of(d, struct firmware_buf, ref)
 253
 254 #define FW_LOADER_NO_CACHE      0
 255 #define FW_LOADER_START_CACHE   1
 256
 257 static int fw_cache_piggyback_on_request(const char *name);
 258
 259 /* fw_lock could be moved to 'struct firmware_priv' but since it is just
 260  * guarding for corner cases a global lock should be OK */
 261 static DEFINE_MUTEX(fw_lock);
 262
 263 static struct firmware_cache fw_cache;
 264
 265 static struct firmware_buf *__allocate_fw_buf(const char *fw_name,
 266                                               struct firmware_cache *fwc,
 267                                               void *dbuf, size_t size)
 268 {
 269         struct firmware_buf *buf;
 270
 271         buf = kzalloc(sizeof(*buf), GFP_ATOMIC);
 272         if (!buf)
 273                 return NULL;
 274
 275         buf->fw_id = kstrdup_const(fw_name, GFP_ATOMIC);
 276         if (!buf->fw_id) {
 277                 kfree(buf);
 278                 return NULL;
 279         }
 280
 281         kref_init(&buf->ref);
 282         buf->fwc = fwc;
 283         buf->data = dbuf;
 284         buf->allocated_size = size;
 285         fw_state_init(&buf->fw_st);
 286 #ifdef CONFIG_FW_LOADER_USER_HELPER
 287         INIT_LIST_HEAD(&buf->pending_list);
 288 #endif
 289
 290         pr_debug("%s: fw-%s buf=%p\n", __func__, fw_name, buf);
 291
 292         return buf;
 293 }
 294
 295 static struct firmware_buf *__fw_lookup_buf(const char *fw_name)
 296 {
 297         struct firmware_buf *tmp;
 298         struct firmware_cache *fwc = &fw_cache;
 299
 300         list_for_each_entry(tmp, &fwc->head, list)
 301                 if (!strcmp(tmp->fw_id, fw_name))
 302                         return tmp;
 303         return NULL;
 304 }
 305
 306 static int fw_lookup_and_allocate_buf(const char *fw_name,
 307                                       struct firmware_cache *fwc,
 308                                       struct firmware_buf **buf, void *dbuf,
 309                                       size_t size)
 310 {
 311         struct firmware_buf *tmp;
 312
 313         spin_lock(&fwc->lock);
 314         tmp = __fw_lookup_buf(fw_name);
 315         if (tmp) {
 316                 kref_get(&tmp->ref);
 317                 spin_unlock(&fwc->lock);
 318                 *buf = tmp;
 319                 return 1;
 320         }
 321         tmp = __allocate_fw_buf(fw_name, fwc, dbuf, size);
 322         if (tmp)
 323                 list_add(&tmp->list, &fwc->head);
 324         spin_unlock(&fwc->lock);
 325
 326         *buf = tmp;
 327
 328         return tmp ? 0 : -ENOMEM;
 329 }
 330
 331 static void __fw_free_buf(struct kref *ref)
 332         __releases(&fwc->lock)
 333 {
 334         struct firmware_buf *buf = to_fwbuf(ref);
 335         struct firmware_cache *fwc = buf->fwc;
 336
 337         pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
 338                  __func__, buf->fw_id, buf, buf->data,
 339                  (unsigned int)buf->size);
 340
 341         list_del(&buf->list);
 342         spin_unlock(&fwc->lock);
 343
 344 #ifdef CONFIG_FW_LOADER_USER_HELPER
 345         if (buf->is_paged_buf) {
 346                 int i;
 347                 vunmap(buf->data);
 348                 for (i = 0; i < buf->nr_pages; i++)
 349                         __free_page(buf->pages[i]);
 350                 vfree(buf->pages);
 351         } else
 352 #endif
 353         if (!buf->allocated_size)
 354                 vfree(buf->data);
 355         kfree_const(buf->fw_id);
 356         kfree(buf);
 357 }
 358
 359 static void fw_free_buf(struct firmware_buf *buf)
 360 {
 361         struct firmware_cache *fwc = buf->fwc;
 362         spin_lock(&fwc->lock);
 363         if (!kref_put(&buf->ref, __fw_free_buf))
 364                 spin_unlock(&fwc->lock);
 365 }
 366
 367 /* direct firmware loading support */
 368 static char fw_path_para[256];
 369 static const char * const fw_path[] = {
 370         fw_path_para,
 371         "/lib/firmware/updates/" UTS_RELEASE,
 372         "/lib/firmware/updates",
 373         "/lib/firmware/" UTS_RELEASE,
 374         "/lib/firmware"
 375 };
 376
 377 /*
 378  * Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH'
 379  * from kernel command line because firmware_class is generally built in
 380  * kernel instead of module.
 381  */
 382 module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
 383 MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
 384
 385 static int
 386 fw_get_filesystem_firmware(struct device *device, struct firmware_buf *buf)
 387 {
 388         loff_t size;
 389         int i, len;
 390         int rc = -ENOENT;
 391         char *path;
 392         enum kernel_read_file_id id = READING_FIRMWARE;
 393         size_t msize = INT_MAX;
 394
 395         /* Already populated data member means we're loading into a buffer */
 396         if (buf->data) {
 397                 id = READING_FIRMWARE_PREALLOC_BUFFER;
 398                 msize = buf->allocated_size;
 399         }
 400
 401         path = __getname();
 402         if (!path)
 403                 return -ENOMEM;
 404
 405         for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
 406                 /* skip the unset customized path */
 407                 if (!fw_path[i][0])
 408                         continue;
 409
 410                 len = snprintf(path, PATH_MAX, "%s/%s",
 411                                fw_path[i], buf->fw_id);
 412                 if (len >= PATH_MAX) {
 413                         rc = -ENAMETOOLONG;
 414                         break;
 415                 }
 416
 417                 buf->size = 0;
 418                 rc = kernel_read_file_from_path(path, &buf->data, &size, msize,
 419                                                 id);
 420                 if (rc) {
 421                         if (rc == -ENOENT)
 422                                 dev_dbg(device, "loading %s failed with error %d\n",
 423                                          path, rc);
 424                         else
 425                                 dev_warn(device, "loading %s failed with error %d\n",
 426                                          path, rc);
 427                         continue;
 428                 }
 429                 dev_dbg(device, "direct-loading %s\n", buf->fw_id);
 430                 buf->size = size;
 431                 fw_state_done(&buf->fw_st);
 432                 break;
 433         }
 434         __putname(path);
 435
 436         return rc;
 437 }
 438
 439 /* firmware holds the ownership of pages */
 440 static void firmware_free_data(const struct firmware *fw)
 441 {
 442         /* Loaded directly? */
 443         if (!fw->priv) {
 444                 vfree(fw->data);
 445                 return;
 446         }
 447         fw_free_buf(fw->priv);
 448 }
 449
 450 /* store the pages buffer info firmware from buf */
 451 static void fw_set_page_data(struct firmware_buf *buf, struct firmware *fw)
 452 {
 453         fw->priv = buf;
 454 #ifdef CONFIG_FW_LOADER_USER_HELPER
 455         fw->pages = buf->pages;
 456 #endif
 457         fw->size = buf->size;
 458         fw->data = buf->data;
 459
 460         pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
 461                  __func__, buf->fw_id, buf, buf->data,
 462                  (unsigned int)buf->size);
 463 }
 464
 465 #ifdef CONFIG_PM_SLEEP
 466 static void fw_name_devm_release(struct device *dev, void *res)
 467 {
 468         struct fw_name_devm *fwn = res;
 469
 470         if (fwn->magic == (unsigned long)&fw_cache)
 471                 pr_debug("%s: fw_name-%s devm-%p released\n",
 472                                 __func__, fwn->name, res);
 473         kfree_const(fwn->name);
 474 }
 475
 476 static int fw_devm_match(struct device *dev, void *res,
 477                 void *match_data)
 478 {
 479         struct fw_name_devm *fwn = res;
 480
 481         return (fwn->magic == (unsigned long)&fw_cache) &&
 482                 !strcmp(fwn->name, match_data);
 483 }
 484
 485 static struct fw_name_devm *fw_find_devm_name(struct device *dev,
 486                 const char *name)
 487 {
 488         struct fw_name_devm *fwn;
 489
 490         fwn = devres_find(dev, fw_name_devm_release,
 491                           fw_devm_match, (void *)name);
 492         return fwn;
 493 }
 494
 495 /* add firmware name into devres list */
 496 static int fw_add_devm_name(struct device *dev, const char *name)
 497 {
 498         struct fw_name_devm *fwn;
 499
 500         fwn = fw_find_devm_name(dev, name);
 501         if (fwn)
 502                 return 1;
 503
 504         fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm),
 505                            GFP_KERNEL);
 506         if (!fwn)
 507                 return -ENOMEM;
 508         fwn->name = kstrdup_const(name, GFP_KERNEL);
 509         if (!fwn->name) {
 510                 devres_free(fwn);
 511                 return -ENOMEM;
 512         }
 513
 514         fwn->magic = (unsigned long)&fw_cache;
 515         devres_add(dev, fwn);
 516
 517         return 0;
 518 }
 519 #else
 520 static int fw_add_devm_name(struct device *dev, const char *name)
 521 {
 522         return 0;
 523 }
 524 #endif
 525
 526
 527 /*
 528  * user-mode helper code
 529  */
 530 #ifdef CONFIG_FW_LOADER_USER_HELPER
 531 struct firmware_priv {
 532         bool nowait;
 533         struct device dev;
 534         struct firmware_buf *buf;
 535         struct firmware *fw;
 536 };
 537
 538 static struct firmware_priv *to_firmware_priv(struct device *dev)
 539 {
 540         return container_of(dev, struct firmware_priv, dev);
 541 }
 542
 543 static void __fw_load_abort(struct firmware_buf *buf)
 544 {
 545         /*
 546          * There is a small window in which user can write to 'loading'
 547          * between loading done and disappearance of 'loading'
 548          */
 549         if (fw_state_is_done(&buf->fw_st))
 550                 return;
 551
 552         list_del_init(&buf->pending_list);
 553         fw_state_aborted(&buf->fw_st);
 554 }
 555
 556 static void fw_load_abort(struct firmware_priv *fw_priv)
 557 {
 558         struct firmware_buf *buf = fw_priv->buf;
 559
 560         __fw_load_abort(buf);
 561 }
 562
 563 static LIST_HEAD(pending_fw_head);
 564
 565 /* reboot notifier for avoid deadlock with usermode_lock */
 566 static int fw_shutdown_notify(struct notifier_block *unused1,
 567                               unsigned long unused2, void *unused3)
 568 {
 569         mutex_lock(&fw_lock);
 570         while (!list_empty(&pending_fw_head))
 571                 __fw_load_abort(list_first_entry(&pending_fw_head,
 572                                                struct firmware_buf,
 573                                                pending_list));
 574         mutex_unlock(&fw_lock);
 575         return NOTIFY_DONE;
 576 }
 577
 578 static struct notifier_block fw_shutdown_nb = {
 579         .notifier_call = fw_shutdown_notify,
 580 };
 581
 582 static ssize_t timeout_show(struct class *class, struct class_attribute *attr,
 583                             char *buf)
 584 {
 585         return sprintf(buf, "%d\n", loading_timeout);
 586 }
 587
 588 /**
 589  * firmware_timeout_store - set number of seconds to wait for firmware
 590  * @class: device class pointer
 591  * @attr: device attribute pointer
 592  * @buf: buffer to scan for timeout value
 593  * @count: number of bytes in @buf
 594  *
 595  *      Sets the number of seconds to wait for the firmware.  Once
 596  *      this expires an error will be returned to the driver and no
 597  *      firmware will be provided.
 598  *
 599  *      Note: zero means 'wait forever'.
 600  **/
 601 static ssize_t timeout_store(struct class *class, struct class_attribute *attr,
 602                              const char *buf, size_t count)
 603 {
 604         loading_timeout = simple_strtol(buf, NULL, 10);
 605         if (loading_timeout < 0)
 606                 loading_timeout = 0;
 607
 608         return count;
 609 }
 610 static CLASS_ATTR_RW(timeout);
 611
 612 static struct attribute *firmware_class_attrs[] = {
 613         &class_attr_timeout.attr,
 614         NULL,
 615 };
 616 ATTRIBUTE_GROUPS(firmware_class);
 617
 618 static void fw_dev_release(struct device *dev)
 619 {
 620         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 621
 622         kfree(fw_priv);
 623 }
 624
 625 static int do_firmware_uevent(struct firmware_priv *fw_priv, struct kobj_uevent_env *env)
 626 {
 627         if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->buf->fw_id))
 628                 return -ENOMEM;
 629         if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
 630                 return -ENOMEM;
 631         if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
 632                 return -ENOMEM;
 633
 634         return 0;
 635 }
 636
 637 static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
 638 {
 639         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 640         int err = 0;
 641
 642         mutex_lock(&fw_lock);
 643         if (fw_priv->buf)
 644                 err = do_firmware_uevent(fw_priv, env);
 645         mutex_unlock(&fw_lock);
 646         return err;
 647 }
 648
 649 static struct class firmware_class = {
 650         .name           = "firmware",
 651         .class_groups   = firmware_class_groups,
 652         .dev_uevent     = firmware_uevent,
 653         .dev_release    = fw_dev_release,
 654 };
 655
 656 static ssize_t firmware_loading_show(struct device *dev,
 657                                      struct device_attribute *attr, char *buf)
 658 {
 659         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 660         int loading = 0;
 661
 662         mutex_lock(&fw_lock);
 663         if (fw_priv->buf)
 664                 loading = fw_state_is_loading(&fw_priv->buf->fw_st);
 665         mutex_unlock(&fw_lock);
 666
 667         return sprintf(buf, "%d\n", loading);
 668 }
 669
 670 /* Some architectures don't have PAGE_KERNEL_RO */
 671 #ifndef PAGE_KERNEL_RO
 672 #define PAGE_KERNEL_RO PAGE_KERNEL
 673 #endif
 674
 675 /* one pages buffer should be mapped/unmapped only once */
 676 static int fw_map_pages_buf(struct firmware_buf *buf)
 677 {
 678         if (!buf->is_paged_buf)
 679                 return 0;
 680
 681         vunmap(buf->data);
 682         buf->data = vmap(buf->pages, buf->nr_pages, 0, PAGE_KERNEL_RO);
 683         if (!buf->data)
 684                 return -ENOMEM;
 685         return 0;
 686 }
 687
 688 /**
 689  * firmware_loading_store - set value in the 'loading' control file
 690  * @dev: device pointer
 691  * @attr: device attribute pointer
 692  * @buf: buffer to scan for loading control value
 693  * @count: number of bytes in @buf
 694  *
 695  *      The relevant values are:
 696  *
 697  *       1: Start a load, discarding any previous partial load.
 698  *       0: Conclude the load and hand the data to the driver code.
 699  *      -1: Conclude the load with an error and discard any written data.
 700  **/
 701 static ssize_t firmware_loading_store(struct device *dev,
 702                                       struct device_attribute *attr,
 703                                       const char *buf, size_t count)
 704 {
 705         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 706         struct firmware_buf *fw_buf;
 707         ssize_t written = count;
 708         int loading = simple_strtol(buf, NULL, 10);
 709         int i;
 710
 711         mutex_lock(&fw_lock);
 712         fw_buf = fw_priv->buf;
 713         if (fw_state_is_aborted(&fw_buf->fw_st))
 714                 goto out;
 715
 716         switch (loading) {
 717         case 1:
 718                 /* discarding any previous partial load */
 719                 if (!fw_state_is_done(&fw_buf->fw_st)) {
 720                         for (i = 0; i < fw_buf->nr_pages; i++)
 721                                 __free_page(fw_buf->pages[i]);
 722                         vfree(fw_buf->pages);
 723                         fw_buf->pages = NULL;
 724                         fw_buf->page_array_size = 0;
 725                         fw_buf->nr_pages = 0;
 726                         fw_state_start(&fw_buf->fw_st);
 727                 }
 728                 break;
 729         case 0:
 730                 if (fw_state_is_loading(&fw_buf->fw_st)) {
 731                         int rc;
 732
 733                         /*
 734                          * Several loading requests may be pending on
 735                          * one same firmware buf, so let all requests
 736                          * see the mapped 'buf->data' once the loading
 737                          * is completed.
 738                          * */
 739                         rc = fw_map_pages_buf(fw_buf);
 740                         if (rc)
 741                                 dev_err(dev, "%s: map pages failed\n",
 742                                         __func__);
 743                         else
 744                                 rc = security_kernel_post_read_file(NULL,
 745                                                 fw_buf->data, fw_buf->size,
 746                                                 READING_FIRMWARE);
 747
 748                         /*
 749                          * Same logic as fw_load_abort, only the DONE bit
 750                          * is ignored and we set ABORT only on failure.
 751                          */
 752                         list_del_init(&fw_buf->pending_list);
 753                         if (rc) {
 754                                 fw_state_aborted(&fw_buf->fw_st);
 755                                 written = rc;
 756                         } else {
 757                                 fw_state_done(&fw_buf->fw_st);
 758                         }
 759                         break;
 760                 }
 761                 /* fallthrough */
 762         default:
 763                 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
 764                 /* fallthrough */
 765         case -1:
 766                 fw_load_abort(fw_priv);
 767                 break;
 768         }
 769 out:
 770         mutex_unlock(&fw_lock);
 771         return written;
 772 }
 773
 774 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
 775
 776 static void firmware_rw_buf(struct firmware_buf *buf, char *buffer,
 777                            loff_t offset, size_t count, bool read)
 778 {
 779         if (read)
 780                 memcpy(buffer, buf->data + offset, count);
 781         else
 782                 memcpy(buf->data + offset, buffer, count);
 783 }
 784
 785 static void firmware_rw(struct firmware_buf *buf, char *buffer,
 786                         loff_t offset, size_t count, bool read)
 787 {
 788         while (count) {
 789                 void *page_data;
 790                 int page_nr = offset >> PAGE_SHIFT;
 791                 int page_ofs = offset & (PAGE_SIZE-1);
 792                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 793
 794                 page_data = kmap(buf->pages[page_nr]);
 795
 796                 if (read)
 797                         memcpy(buffer, page_data + page_ofs, page_cnt);
 798                 else
 799                         memcpy(page_data + page_ofs, buffer, page_cnt);
 800
 801                 kunmap(buf->pages[page_nr]);
 802                 buffer += page_cnt;
 803                 offset += page_cnt;
 804                 count -= page_cnt;
 805         }
 806 }
 807
 808 static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
 809                                   struct bin_attribute *bin_attr,
 810                                   char *buffer, loff_t offset, size_t count)
 811 {
 812         struct device *dev = kobj_to_dev(kobj);
 813         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 814         struct firmware_buf *buf;
 815         ssize_t ret_count;
 816
 817         mutex_lock(&fw_lock);
 818         buf = fw_priv->buf;
 819         if (!buf || fw_state_is_done(&buf->fw_st)) {
 820                 ret_count = -ENODEV;
 821                 goto out;
 822         }
 823         if (offset > buf->size) {
 824                 ret_count = 0;
 825                 goto out;
 826         }
 827         if (count > buf->size - offset)
 828                 count = buf->size - offset;
 829
 830         ret_count = count;
 831
 832         if (buf->data)
 833                 firmware_rw_buf(buf, buffer, offset, count, true);
 834         else
 835                 firmware_rw(buf, buffer, offset, count, true);
 836
 837 out:
 838         mutex_unlock(&fw_lock);
 839         return ret_count;
 840 }
 841
 842 static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
 843 {
 844         struct firmware_buf *buf = fw_priv->buf;
 845         int pages_needed = PAGE_ALIGN(min_size) >> PAGE_SHIFT;
 846
 847         /* If the array of pages is too small, grow it... */
 848         if (buf->page_array_size < pages_needed) {
 849                 int new_array_size = max(pages_needed,
 850                                          buf->page_array_size * 2);
 851                 struct page **new_pages;
 852
 853                 new_pages = vmalloc(new_array_size * sizeof(void *));
 854                 if (!new_pages) {
 855                         fw_load_abort(fw_priv);
 856                         return -ENOMEM;
 857                 }
 858                 memcpy(new_pages, buf->pages,
 859                        buf->page_array_size * sizeof(void *));
 860                 memset(&new_pages[buf->page_array_size], 0, sizeof(void *) *
 861                        (new_array_size - buf->page_array_size));
 862                 vfree(buf->pages);
 863                 buf->pages = new_pages;
 864                 buf->page_array_size = new_array_size;
 865         }
 866
 867         while (buf->nr_pages < pages_needed) {
 868                 buf->pages[buf->nr_pages] =
 869                         alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
 870
 871                 if (!buf->pages[buf->nr_pages]) {
 872                         fw_load_abort(fw_priv);
 873                         return -ENOMEM;
 874                 }
 875                 buf->nr_pages++;
 876         }
 877         return 0;
 878 }
 879
 880 /**
 881  * firmware_data_write - write method for firmware
 882  * @filp: open sysfs file
 883  * @kobj: kobject for the device
 884  * @bin_attr: bin_attr structure
 885  * @buffer: buffer being written
 886  * @offset: buffer offset for write in total data store area
 887  * @count: buffer size
 888  *
 889  *      Data written to the 'data' attribute will be later handed to
 890  *      the driver as a firmware image.
 891  **/
 892 static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,
 893                                    struct bin_attribute *bin_attr,
 894                                    char *buffer, loff_t offset, size_t count)
 895 {
 896         struct device *dev = kobj_to_dev(kobj);
 897         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 898         struct firmware_buf *buf;
 899         ssize_t retval;
 900
 901         if (!capable(CAP_SYS_RAWIO))
 902                 return -EPERM;
 903
 904         mutex_lock(&fw_lock);
 905         buf = fw_priv->buf;
 906         if (!buf || fw_state_is_done(&buf->fw_st)) {
 907                 retval = -ENODEV;
 908                 goto out;
 909         }
 910
 911         if (buf->data) {
 912                 if (offset + count > buf->allocated_size) {
 913                         retval = -ENOMEM;
 914                         goto out;
 915                 }
 916                 firmware_rw_buf(buf, buffer, offset, count, false);
 917                 retval = count;
 918         } else {
 919                 retval = fw_realloc_buffer(fw_priv, offset + count);
 920                 if (retval)
 921                         goto out;
 922
 923                 retval = count;
 924                 firmware_rw(buf, buffer, offset, count, false);
 925         }
 926
 927         buf->size = max_t(size_t, offset + count, buf->size);
 928 out:
 929         mutex_unlock(&fw_lock);
 930         return retval;
 931 }
 932
 933 static struct bin_attribute firmware_attr_data = {
 934         .attr = { .name = "data", .mode = 0644 },
 935         .size = 0,
 936         .read = firmware_data_read,
 937         .write = firmware_data_write,
 938 };
 939
 940 static struct attribute *fw_dev_attrs[] = {
 941         &dev_attr_loading.attr,
 942         NULL
 943 };
 944
 945 static struct bin_attribute *fw_dev_bin_attrs[] = {
 946         &firmware_attr_data,
 947         NULL
 948 };
 949
 950 static const struct attribute_group fw_dev_attr_group = {
 951         .attrs = fw_dev_attrs,
 952         .bin_attrs = fw_dev_bin_attrs,
 953 };
 954
 955 static const struct attribute_group *fw_dev_attr_groups[] = {
 956         &fw_dev_attr_group,
 957         NULL
 958 };
 959
 960 static struct firmware_priv *
 961 fw_create_instance(struct firmware *firmware, const char *fw_name,
 962                    struct device *device, unsigned int opt_flags)
 963 {
 964         struct firmware_priv *fw_priv;
 965         struct device *f_dev;
 966
 967         fw_priv = kzalloc(sizeof(*fw_priv), GFP_KERNEL);
 968         if (!fw_priv) {
 969                 fw_priv = ERR_PTR(-ENOMEM);
 970                 goto exit;
 971         }
 972
 973         fw_priv->nowait = !!(opt_flags & FW_OPT_NOWAIT);
 974         fw_priv->fw = firmware;
 975         f_dev = &fw_priv->dev;
 976
 977         device_initialize(f_dev);
 978         dev_set_name(f_dev, "%s", fw_name);
 979         f_dev->parent = device;
 980         f_dev->class = &firmware_class;
 981         f_dev->groups = fw_dev_attr_groups;
 982 exit:
 983         return fw_priv;
 984 }
 985
 986 /* load a firmware via user helper */
 987 static int _request_firmware_load(struct firmware_priv *fw_priv,
 988                                   unsigned int opt_flags, long timeout)
 989 {
 990         int retval = 0;
 991         struct device *f_dev = &fw_priv->dev;
 992         struct firmware_buf *buf = fw_priv->buf;
 993
 994         /* fall back on userspace loading */
 995         if (!buf->data)
 996                 buf->is_paged_buf = true;
 997
 998         dev_set_uevent_suppress(f_dev, true);
 999
1000         retval = device_add(f_dev);
1001         if (retval) {
1002                 dev_err(f_dev, "%s: device_register failed\n", __func__);
1003                 goto err_put_dev;
1004         }
1005
1006         mutex_lock(&fw_lock);
1007         list_add(&buf->pending_list, &pending_fw_head);
1008         mutex_unlock(&fw_lock);
1009
1010         if (opt_flags & FW_OPT_UEVENT) {
1011                 buf->need_uevent = true;
1012                 dev_set_uevent_suppress(f_dev, false);
1013                 dev_dbg(f_dev, "firmware: requesting %s\n", buf->fw_id);
1014                 kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD);
1015         } else {
1016                 timeout = MAX_JIFFY_OFFSET;
1017         }
1018
1019         retval = fw_state_wait_timeout(&buf->fw_st, timeout);
1020         if (retval < 0) {
1021                 mutex_lock(&fw_lock);
1022                 fw_load_abort(fw_priv);
1023                 mutex_unlock(&fw_lock);
1024         }
1025
1026         if (fw_state_is_aborted(&buf->fw_st))
1027                 retval = -EAGAIN;
1028         else if (buf->is_paged_buf && !buf->data)
1029                 retval = -ENOMEM;
1030
1031         device_del(f_dev);
1032 err_put_dev:
1033         put_device(f_dev);
1034         return retval;
1035 }
1036
1037 static int fw_load_from_user_helper(struct firmware *firmware,
1038                                     const char *name, struct device *device,
1039                                     unsigned int opt_flags, long timeout)
1040 {
1041         struct firmware_priv *fw_priv;
1042
1043         fw_priv = fw_create_instance(firmware, name, device, opt_flags);
1044         if (IS_ERR(fw_priv))
1045                 return PTR_ERR(fw_priv);
1046
1047         fw_priv->buf = firmware->priv;
1048         return _request_firmware_load(fw_priv, opt_flags, timeout);
1049 }
1050
1051 #ifdef CONFIG_PM_SLEEP
1052 /* kill pending requests without uevent to avoid blocking suspend */
1053 static void kill_requests_without_uevent(void)
1054 {
1055         struct firmware_buf *buf;
1056         struct firmware_buf *next;
1057
1058         mutex_lock(&fw_lock);
1059         list_for_each_entry_safe(buf, next, &pending_fw_head, pending_list) {
1060                 if (!buf->need_uevent)
1061                          __fw_load_abort(buf);
1062         }
1063         mutex_unlock(&fw_lock);
1064 }
1065 #endif
1066
1067 #else /* CONFIG_FW_LOADER_USER_HELPER */
1068 static inline int
1069 fw_load_from_user_helper(struct firmware *firmware, const char *name,
1070                          struct device *device, unsigned int opt_flags,
1071                          long timeout)
1072 {
1073         return -ENOENT;
1074 }
1075
1076 #ifdef CONFIG_PM_SLEEP
1077 static inline void kill_requests_without_uevent(void) { }
1078 #endif
1079
1080 #endif /* CONFIG_FW_LOADER_USER_HELPER */
1081
1082 /* prepare firmware and firmware_buf structs;
1083  * return 0 if a firmware is already assigned, 1 if need to load one,
1084  * or a negative error code
1085  */
1086 static int
1087 _request_firmware_prepare(struct firmware **firmware_p, const char *name,
1088                           struct device *device, void *dbuf, size_t size)
1089 {
1090         struct firmware *firmware;
1091         struct firmware_buf *buf;
1092         int ret;
1093
1094         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
1095         if (!firmware) {
1096                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
1097                         __func__);
1098                 return -ENOMEM;
1099         }
1100
1101         if (fw_get_builtin_firmware(firmware, name, dbuf, size)) {
1102                 dev_dbg(device, "using built-in %s\n", name);
1103                 return 0; /* assigned */
1104         }
1105
1106         ret = fw_lookup_and_allocate_buf(name, &fw_cache, &buf, dbuf, size);
1107
1108         /*
1109          * bind with 'buf' now to avoid warning in failure path
1110          * of requesting firmware.
1111          */
1112         firmware->priv = buf;
1113
1114         if (ret > 0) {
1115                 ret = fw_state_wait(&buf->fw_st);
1116                 if (!ret) {
1117                         fw_set_page_data(buf, firmware);
1118                         return 0; /* assigned */
1119                 }
1120         }
1121
1122         if (ret < 0)
1123                 return ret;
1124         return 1; /* need to load */
1125 }
1126
1127 static int assign_firmware_buf(struct firmware *fw, struct device *device,
1128                                unsigned int opt_flags)
1129 {
1130         struct firmware_buf *buf = fw->priv;
1131
1132         mutex_lock(&fw_lock);
1133         if (!buf->size || fw_state_is_aborted(&buf->fw_st)) {
1134                 mutex_unlock(&fw_lock);
1135                 return -ENOENT;
1136         }
1137
1138         /*
1139          * add firmware name into devres list so that we can auto cache
1140          * and uncache firmware for device.
1141          *
1142          * device may has been deleted already, but the problem
1143          * should be fixed in devres or driver core.
1144          */
1145         /* don't cache firmware handled without uevent */
1146         if (device && (opt_flags & FW_OPT_UEVENT) &&
1147             !(opt_flags & FW_OPT_NOCACHE))
1148                 fw_add_devm_name(device, buf->fw_id);
1149
1150         /*
1151          * After caching firmware image is started, let it piggyback
1152          * on request firmware.
1153          */
1154         if (!(opt_flags & FW_OPT_NOCACHE) &&
1155             buf->fwc->state == FW_LOADER_START_CACHE) {
1156                 if (fw_cache_piggyback_on_request(buf->fw_id))
1157                         kref_get(&buf->ref);
1158         }
1159
1160         /* pass the pages buffer to driver at the last minute */
1161         fw_set_page_data(buf, fw);
1162         mutex_unlock(&fw_lock);
1163         return 0;
1164 }
1165
1166 /* called from request_firmware() and request_firmware_work_func() */
1167 static int
1168 _request_firmware(const struct firmware **firmware_p, const char *name,
1169                   struct device *device, void *buf, size_t size,
1170                   unsigned int opt_flags)
1171 {
1172         struct firmware *fw = NULL;
1173         long timeout;
1174         int ret;
1175
1176         if (!firmware_p)
1177                 return -EINVAL;
1178
1179         if (!name || name[0] == '\0') {
1180                 ret = -EINVAL;
1181                 goto out;
1182         }
1183
1184         ret = _request_firmware_prepare(&fw, name, device, buf, size);
1185         if (ret <= 0) /* error or already assigned */
1186                 goto out;
1187
1188         ret = 0;
1189         timeout = firmware_loading_timeout();
1190         if (opt_flags & FW_OPT_NOWAIT) {
1191                 timeout = usermodehelper_read_lock_wait(timeout);
1192                 if (!timeout) {
1193                         dev_dbg(device, "firmware: %s loading timed out\n",
1194                                 name);
1195                         ret = -EBUSY;
1196                         goto out;
1197                 }
1198         } else {
1199                 ret = usermodehelper_read_trylock();
1200                 if (WARN_ON(ret)) {
1201                         dev_err(device, "firmware: %s will not be loaded\n",
1202                                 name);
1203                         goto out;
1204                 }
1205         }
1206
1207         ret = fw_get_filesystem_firmware(device, fw->priv);
1208         if (ret) {
1209                 if (!(opt_flags & FW_OPT_NO_WARN))
1210                         dev_warn(device,
1211                                  "Direct firmware load for %s failed with error %d\n",
1212                                  name, ret);
1213                 if (opt_flags & FW_OPT_USERHELPER) {
1214                         dev_warn(device, "Falling back to user helper\n");
1215                         ret = fw_load_from_user_helper(fw, name, device,
1216                                                        opt_flags, timeout);
1217                 }
1218         }
1219
1220         if (!ret)
1221                 ret = assign_firmware_buf(fw, device, opt_flags);
1222
1223         usermodehelper_read_unlock();
1224
1225  out:
1226         if (ret < 0) {
1227                 release_firmware(fw);
1228                 fw = NULL;
1229         }
1230
1231         *firmware_p = fw;
1232         return ret;
1233 }
1234
1235 /**
1236  * request_firmware: - send firmware request and wait for it
1237  * @firmware_p: pointer to firmware image
1238  * @name: name of firmware file
1239  * @device: device for which firmware is being loaded
1240  *
1241  *      @firmware_p will be used to return a firmware image by the name
1242  *      of @name for device @device.
1243  *
1244  *      Should be called from user context where sleeping is allowed.
1245  *
1246  *      @name will be used as $FIRMWARE in the uevent environment and
1247  *      should be distinctive enough not to be confused with any other
1248  *      firmware image for this or any other device.
1249  *
1250  *      Caller must hold the reference count of @device.
1251  *
1252  *      The function can be called safely inside device's suspend and
1253  *      resume callback.
1254  **/
1255 int
1256 request_firmware(const struct firmware **firmware_p, const char *name,
1257                  struct device *device)
1258 {
1259         int ret;
1260
1261         /* Need to pin this module until return */
1262         __module_get(THIS_MODULE);
1263         ret = _request_firmware(firmware_p, name, device, NULL, 0,
1264                                 FW_OPT_UEVENT | FW_OPT_FALLBACK);
1265         module_put(THIS_MODULE);
1266         return ret;
1267 }
1268 EXPORT_SYMBOL(request_firmware);
1269
1270 /**
1271  * request_firmware_direct: - load firmware directly without usermode helper
1272  * @firmware_p: pointer to firmware image
1273  * @name: name of firmware file
1274  * @device: device for which firmware is being loaded
1275  *
1276  * This function works pretty much like request_firmware(), but this doesn't
1277  * fall back to usermode helper even if the firmware couldn't be loaded
1278  * directly from fs.  Hence it's useful for loading optional firmwares, which
1279  * aren't always present, without extra long timeouts of udev.
1280  **/
1281 int request_firmware_direct(const struct firmware **firmware_p,
1282                             const char *name, struct device *device)
1283 {
1284         int ret;
1285
1286         __module_get(THIS_MODULE);
1287         ret = _request_firmware(firmware_p, name, device, NULL, 0,
1288                                 FW_OPT_UEVENT | FW_OPT_NO_WARN);
1289         module_put(THIS_MODULE);
1290         return ret;
1291 }
1292 EXPORT_SYMBOL_GPL(request_firmware_direct);
1293
1294 /**
1295  * request_firmware_into_buf - load firmware into a previously allocated buffer
1296  * @firmware_p: pointer to firmware image
1297  * @name: name of firmware file
1298  * @device: device for which firmware is being loaded and DMA region allocated
1299  * @buf: address of buffer to load firmware into
1300  * @size: size of buffer
1301  *
1302  * This function works pretty much like request_firmware(), but it doesn't
1303  * allocate a buffer to hold the firmware data. Instead, the firmware
1304  * is loaded directly into the buffer pointed to by @buf and the @firmware_p
1305  * data member is pointed at @buf.
1306  *
1307  * This function doesn't cache firmware either.
1308  */
1309 int
1310 request_firmware_into_buf(const struct firmware **firmware_p, const char *name,
1311                           struct device *device, void *buf, size_t size)
1312 {
1313         int ret;
1314
1315         __module_get(THIS_MODULE);
1316         ret = _request_firmware(firmware_p, name, device, buf, size,
1317                                 FW_OPT_UEVENT | FW_OPT_FALLBACK |
1318                                 FW_OPT_NOCACHE);
1319         module_put(THIS_MODULE);
1320         return ret;
1321 }
1322 EXPORT_SYMBOL(request_firmware_into_buf);
1323
1324 /**
1325  * release_firmware: - release the resource associated with a firmware image
1326  * @fw: firmware resource to release
1327  **/
1328 void release_firmware(const struct firmware *fw)
1329 {
1330         if (fw) {
1331                 if (!fw_is_builtin_firmware(fw))
1332                         firmware_free_data(fw);
1333                 kfree(fw);
1334         }
1335 }
1336 EXPORT_SYMBOL(release_firmware);
1337
1338 /* Async support */
1339 struct firmware_work {
1340         struct work_struct work;
1341         struct module *module;
1342         const char *name;
1343         struct device *device;
1344         void *context;
1345         void (*cont)(const struct firmware *fw, void *context);
1346         unsigned int opt_flags;
1347 };
1348
1349 static void request_firmware_work_func(struct work_struct *work)
1350 {
1351         struct firmware_work *fw_work;
1352         const struct firmware *fw;
1353
1354         fw_work = container_of(work, struct firmware_work, work);
1355
1356         _request_firmware(&fw, fw_work->name, fw_work->device, NULL, 0,
1357                           fw_work->opt_flags);
1358         fw_work->cont(fw, fw_work->context);
1359         put_device(fw_work->device); /* taken in request_firmware_nowait() */
1360
1361         module_put(fw_work->module);
1362         kfree_const(fw_work->name);
1363         kfree(fw_work);
1364 }
1365
1366 /**
1367  * request_firmware_nowait - asynchronous version of request_firmware
1368  * @module: module requesting the firmware
1369  * @uevent: sends uevent to copy the firmware image if this flag
1370  *      is non-zero else the firmware copy must be done manually.
1371  * @name: name of firmware file
1372  * @device: device for which firmware is being loaded
1373  * @gfp: allocation flags
1374  * @context: will be passed over to @cont, and
1375  *      @fw may be %NULL if firmware request fails.
1376  * @cont: function will be called asynchronously when the firmware
1377  *      request is over.
1378  *
1379  *      Caller must hold the reference count of @device.
1380  *
1381  *      Asynchronous variant of request_firmware() for user contexts:
1382  *              - sleep for as small periods as possible since it may
1383  *                increase kernel boot time of built-in device drivers
1384  *                requesting firmware in their ->probe() methods, if
1385  *                @gfp is GFP_KERNEL.
1386  *
1387  *              - can't sleep at all if @gfp is GFP_ATOMIC.
1388  **/
1389 int
1390 request_firmware_nowait(
1391         struct module *module, bool uevent,
1392         const char *name, struct device *device, gfp_t gfp, void *context,
1393         void (*cont)(const struct firmware *fw, void *context))
1394 {
1395         struct firmware_work *fw_work;
1396
1397         fw_work = kzalloc(sizeof(struct firmware_work), gfp);
1398         if (!fw_work)
1399                 return -ENOMEM;
1400
1401         fw_work->module = module;
1402         fw_work->name = kstrdup_const(name, gfp);
1403         if (!fw_work->name) {
1404                 kfree(fw_work);
1405                 return -ENOMEM;
1406         }
1407         fw_work->device = device;
1408         fw_work->context = context;
1409         fw_work->cont = cont;
1410         fw_work->opt_flags = FW_OPT_NOWAIT | FW_OPT_FALLBACK |
1411                 (uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
1412
1413         if (!try_module_get(module)) {
1414                 kfree_const(fw_work->name);
1415                 kfree(fw_work);
1416                 return -EFAULT;
1417         }
1418
1419         get_device(fw_work->device);
1420         INIT_WORK(&fw_work->work, request_firmware_work_func);
1421         schedule_work(&fw_work->work);
1422         return 0;
1423 }
1424 EXPORT_SYMBOL(request_firmware_nowait);
1425
1426 #ifdef CONFIG_PM_SLEEP
1427 static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
1428
1429 /**
1430  * cache_firmware - cache one firmware image in kernel memory space
1431  * @fw_name: the firmware image name
1432  *
1433  * Cache firmware in kernel memory so that drivers can use it when
1434  * system isn't ready for them to request firmware image from userspace.
1435  * Once it returns successfully, driver can use request_firmware or its
1436  * nowait version to get the cached firmware without any interacting
1437  * with userspace
1438  *
1439  * Return 0 if the firmware image has been cached successfully
1440  * Return !0 otherwise
1441  *
1442  */
1443 static int cache_firmware(const char *fw_name)
1444 {
1445         int ret;
1446         const struct firmware *fw;
1447
1448         pr_debug("%s: %s\n", __func__, fw_name);
1449
1450         ret = request_firmware(&fw, fw_name, NULL);
1451         if (!ret)
1452                 kfree(fw);
1453
1454         pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
1455
1456         return ret;
1457 }
1458
1459 static struct firmware_buf *fw_lookup_buf(const char *fw_name)
1460 {
1461         struct firmware_buf *tmp;
1462         struct firmware_cache *fwc = &fw_cache;
1463
1464         spin_lock(&fwc->lock);
1465         tmp = __fw_lookup_buf(fw_name);
1466         spin_unlock(&fwc->lock);
1467
1468         return tmp;
1469 }
1470
1471 /**
1472  * uncache_firmware - remove one cached firmware image
1473  * @fw_name: the firmware image name
1474  *
1475  * Uncache one firmware image which has been cached successfully
1476  * before.
1477  *
1478  * Return 0 if the firmware cache has been removed successfully
1479  * Return !0 otherwise
1480  *
1481  */
1482 static int uncache_firmware(const char *fw_name)
1483 {
1484         struct firmware_buf *buf;
1485         struct firmware fw;
1486
1487         pr_debug("%s: %s\n", __func__, fw_name);
1488
1489         if (fw_get_builtin_firmware(&fw, fw_name, NULL, 0))
1490                 return 0;
1491
1492         buf = fw_lookup_buf(fw_name);
1493         if (buf) {
1494                 fw_free_buf(buf);
1495                 return 0;
1496         }
1497
1498         return -EINVAL;
1499 }
1500
1501 static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
1502 {
1503         struct fw_cache_entry *fce;
1504
1505         fce = kzalloc(sizeof(*fce), GFP_ATOMIC);
1506         if (!fce)
1507                 goto exit;
1508
1509         fce->name = kstrdup_const(name, GFP_ATOMIC);
1510         if (!fce->name) {
1511                 kfree(fce);
1512                 fce = NULL;
1513                 goto exit;
1514         }
1515 exit:
1516         return fce;
1517 }
1518
1519 static int __fw_entry_found(const char *name)
1520 {
1521         struct firmware_cache *fwc = &fw_cache;
1522         struct fw_cache_entry *fce;
1523
1524         list_for_each_entry(fce, &fwc->fw_names, list) {
1525                 if (!strcmp(fce->name, name))
1526                         return 1;
1527         }
1528         return 0;
1529 }
1530
1531 static int fw_cache_piggyback_on_request(const char *name)
1532 {
1533         struct firmware_cache *fwc = &fw_cache;
1534         struct fw_cache_entry *fce;
1535         int ret = 0;
1536
1537         spin_lock(&fwc->name_lock);
1538         if (__fw_entry_found(name))
1539                 goto found;
1540
1541         fce = alloc_fw_cache_entry(name);
1542         if (fce) {
1543                 ret = 1;
1544                 list_add(&fce->list, &fwc->fw_names);
1545                 pr_debug("%s: fw: %s\n", __func__, name);
1546         }
1547 found:
1548         spin_unlock(&fwc->name_lock);
1549         return ret;
1550 }
1551
1552 static void free_fw_cache_entry(struct fw_cache_entry *fce)
1553 {
1554         kfree_const(fce->name);
1555         kfree(fce);
1556 }
1557
1558 static void __async_dev_cache_fw_image(void *fw_entry,
1559                                        async_cookie_t cookie)
1560 {
1561         struct fw_cache_entry *fce = fw_entry;
1562         struct firmware_cache *fwc = &fw_cache;
1563         int ret;
1564
1565         ret = cache_firmware(fce->name);
1566         if (ret) {
1567                 spin_lock(&fwc->name_lock);
1568                 list_del(&fce->list);
1569                 spin_unlock(&fwc->name_lock);
1570
1571                 free_fw_cache_entry(fce);
1572         }
1573 }
1574
1575 /* called with dev->devres_lock held */
1576 static void dev_create_fw_entry(struct device *dev, void *res,
1577                                 void *data)
1578 {
1579         struct fw_name_devm *fwn = res;
1580         const char *fw_name = fwn->name;
1581         struct list_head *head = data;
1582         struct fw_cache_entry *fce;
1583
1584         fce = alloc_fw_cache_entry(fw_name);
1585         if (fce)
1586                 list_add(&fce->list, head);
1587 }
1588
1589 static int devm_name_match(struct device *dev, void *res,
1590                            void *match_data)
1591 {
1592         struct fw_name_devm *fwn = res;
1593         return (fwn->magic == (unsigned long)match_data);
1594 }
1595
1596 static void dev_cache_fw_image(struct device *dev, void *data)
1597 {
1598         LIST_HEAD(todo);
1599         struct fw_cache_entry *fce;
1600         struct fw_cache_entry *fce_next;
1601         struct firmware_cache *fwc = &fw_cache;
1602
1603         devres_for_each_res(dev, fw_name_devm_release,
1604                             devm_name_match, &fw_cache,
1605                             dev_create_fw_entry, &todo);
1606
1607         list_for_each_entry_safe(fce, fce_next, &todo, list) {
1608                 list_del(&fce->list);
1609
1610                 spin_lock(&fwc->name_lock);
1611                 /* only one cache entry for one firmware */
1612                 if (!__fw_entry_found(fce->name)) {
1613                         list_add(&fce->list, &fwc->fw_names);
1614                 } else {
1615                         free_fw_cache_entry(fce);
1616                         fce = NULL;
1617                 }
1618                 spin_unlock(&fwc->name_lock);
1619
1620                 if (fce)
1621                         async_schedule_domain(__async_dev_cache_fw_image,
1622                                               (void *)fce,
1623                                               &fw_cache_domain);
1624         }
1625 }
1626
1627 static void __device_uncache_fw_images(void)
1628 {
1629         struct firmware_cache *fwc = &fw_cache;
1630         struct fw_cache_entry *fce;
1631
1632         spin_lock(&fwc->name_lock);
1633         while (!list_empty(&fwc->fw_names)) {
1634                 fce = list_entry(fwc->fw_names.next,
1635                                 struct fw_cache_entry, list);
1636                 list_del(&fce->list);
1637                 spin_unlock(&fwc->name_lock);
1638
1639                 uncache_firmware(fce->name);
1640                 free_fw_cache_entry(fce);
1641
1642                 spin_lock(&fwc->name_lock);
1643         }
1644         spin_unlock(&fwc->name_lock);
1645 }
1646
1647 /**
1648  * device_cache_fw_images - cache devices' firmware
1649  *
1650  * If one device called request_firmware or its nowait version
1651  * successfully before, the firmware names are recored into the
1652  * device's devres link list, so device_cache_fw_images can call
1653  * cache_firmware() to cache these firmwares for the device,
1654  * then the device driver can load its firmwares easily at
1655  * time when system is not ready to complete loading firmware.
1656  */
1657 static void device_cache_fw_images(void)
1658 {
1659         struct firmware_cache *fwc = &fw_cache;
1660         int old_timeout;
1661         DEFINE_WAIT(wait);
1662
1663         pr_debug("%s\n", __func__);
1664
1665         /* cancel uncache work */
1666         cancel_delayed_work_sync(&fwc->work);
1667
1668         /*
1669          * use small loading timeout for caching devices' firmware
1670          * because all these firmware images have been loaded
1671          * successfully at lease once, also system is ready for
1672          * completing firmware loading now. The maximum size of
1673          * firmware in current distributions is about 2M bytes,
1674          * so 10 secs should be enough.
1675          */
1676         old_timeout = loading_timeout;
1677         loading_timeout = 10;
1678
1679         mutex_lock(&fw_lock);
1680         fwc->state = FW_LOADER_START_CACHE;
1681         dpm_for_each_dev(NULL, dev_cache_fw_image);
1682         mutex_unlock(&fw_lock);
1683
1684         /* wait for completion of caching firmware for all devices */
1685         async_synchronize_full_domain(&fw_cache_domain);
1686
1687         loading_timeout = old_timeout;
1688 }
1689
1690 /**
1691  * device_uncache_fw_images - uncache devices' firmware
1692  *
1693  * uncache all firmwares which have been cached successfully
1694  * by device_uncache_fw_images earlier
1695  */
1696 static void device_uncache_fw_images(void)
1697 {
1698         pr_debug("%s\n", __func__);
1699         __device_uncache_fw_images();
1700 }
1701
1702 static void device_uncache_fw_images_work(struct work_struct *work)
1703 {
1704         device_uncache_fw_images();
1705 }
1706
1707 /**
1708  * device_uncache_fw_images_delay - uncache devices firmwares
1709  * @delay: number of milliseconds to delay uncache device firmwares
1710  *
1711  * uncache all devices's firmwares which has been cached successfully
1712  * by device_cache_fw_images after @delay milliseconds.
1713  */
1714 static void device_uncache_fw_images_delay(unsigned long delay)
1715 {
1716         queue_delayed_work(system_power_efficient_wq, &fw_cache.work,
1717                            msecs_to_jiffies(delay));
1718 }
1719
1720 static int fw_pm_notify(struct notifier_block *notify_block,
1721                         unsigned long mode, void *unused)
1722 {
1723         switch (mode) {
1724         case PM_HIBERNATION_PREPARE:
1725         case PM_SUSPEND_PREPARE:
1726         case PM_RESTORE_PREPARE:
1727                 kill_requests_without_uevent();
1728                 device_cache_fw_images();
1729                 break;
1730
1731         case PM_POST_SUSPEND:
1732         case PM_POST_HIBERNATION:
1733         case PM_POST_RESTORE:
1734                 /*
1735                  * In case that system sleep failed and syscore_suspend is
1736                  * not called.
1737                  */
1738                 mutex_lock(&fw_lock);
1739                 fw_cache.state = FW_LOADER_NO_CACHE;
1740                 mutex_unlock(&fw_lock);
1741
1742                 device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
1743                 break;
1744         }
1745
1746         return 0;
1747 }
1748
1749 /* stop caching firmware once syscore_suspend is reached */
1750 static int fw_suspend(void)
1751 {
1752         fw_cache.state = FW_LOADER_NO_CACHE;
1753         return 0;
1754 }
1755
1756 static struct syscore_ops fw_syscore_ops = {
1757         .suspend = fw_suspend,
1758 };
1759 #else
1760 static int fw_cache_piggyback_on_request(const char *name)
1761 {
1762         return 0;
1763 }
1764 #endif
1765
1766 static void __init fw_cache_init(void)
1767 {
1768         spin_lock_init(&fw_cache.lock);
1769         INIT_LIST_HEAD(&fw_cache.head);
1770         fw_cache.state = FW_LOADER_NO_CACHE;
1771
1772 #ifdef CONFIG_PM_SLEEP
1773         spin_lock_init(&fw_cache.name_lock);
1774         INIT_LIST_HEAD(&fw_cache.fw_names);
1775
1776         INIT_DELAYED_WORK(&fw_cache.work,
1777                           device_uncache_fw_images_work);
1778
1779         fw_cache.pm_notify.notifier_call = fw_pm_notify;
1780         register_pm_notifier(&fw_cache.pm_notify);
1781
1782         register_syscore_ops(&fw_syscore_ops);
1783 #endif
1784 }
1785
1786 static int __init firmware_class_init(void)
1787 {
1788         fw_cache_init();
1789 #ifdef CONFIG_FW_LOADER_USER_HELPER
1790         register_reboot_notifier(&fw_shutdown_nb);
1791         return class_register(&firmware_class);
1792 #else
1793         return 0;
1794 #endif
1795 }
1796
1797 static void __exit firmware_class_exit(void)
1798 {
1799 #ifdef CONFIG_PM_SLEEP
1800         unregister_syscore_ops(&fw_syscore_ops);
1801         unregister_pm_notifier(&fw_cache.pm_notify);
1802 #endif
1803 #ifdef CONFIG_FW_LOADER_USER_HELPER
1804         unregister_reboot_notifier(&fw_shutdown_nb);
1805         class_unregister(&firmware_class);
1806 #endif
1807 }
1808
1809 fs_initcall(firmware_class_init);
1810 module_exit(firmware_class_exit);