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         /* avoid user action after loading abort */
 563         fw_priv->buf = NULL;
 564 }
 565
 566 static LIST_HEAD(pending_fw_head);
 567
 568 /* reboot notifier for avoid deadlock with usermode_lock */
 569 static int fw_shutdown_notify(struct notifier_block *unused1,
 570                               unsigned long unused2, void *unused3)
 571 {
 572         mutex_lock(&fw_lock);
 573         while (!list_empty(&pending_fw_head))
 574                 __fw_load_abort(list_first_entry(&pending_fw_head,
 575                                                struct firmware_buf,
 576                                                pending_list));
 577         mutex_unlock(&fw_lock);
 578         return NOTIFY_DONE;
 579 }
 580
 581 static struct notifier_block fw_shutdown_nb = {
 582         .notifier_call = fw_shutdown_notify,
 583 };
 584
 585 static ssize_t timeout_show(struct class *class, struct class_attribute *attr,
 586                             char *buf)
 587 {
 588         return sprintf(buf, "%d\n", loading_timeout);
 589 }
 590
 591 /**
 592  * firmware_timeout_store - set number of seconds to wait for firmware
 593  * @class: device class pointer
 594  * @attr: device attribute pointer
 595  * @buf: buffer to scan for timeout value
 596  * @count: number of bytes in @buf
 597  *
 598  *      Sets the number of seconds to wait for the firmware.  Once
 599  *      this expires an error will be returned to the driver and no
 600  *      firmware will be provided.
 601  *
 602  *      Note: zero means 'wait forever'.
 603  **/
 604 static ssize_t timeout_store(struct class *class, struct class_attribute *attr,
 605                              const char *buf, size_t count)
 606 {
 607         loading_timeout = simple_strtol(buf, NULL, 10);
 608         if (loading_timeout < 0)
 609                 loading_timeout = 0;
 610
 611         return count;
 612 }
 613 static CLASS_ATTR_RW(timeout);
 614
 615 static struct attribute *firmware_class_attrs[] = {
 616         &class_attr_timeout.attr,
 617         NULL,
 618 };
 619 ATTRIBUTE_GROUPS(firmware_class);
 620
 621 static void fw_dev_release(struct device *dev)
 622 {
 623         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 624
 625         kfree(fw_priv);
 626 }
 627
 628 static int do_firmware_uevent(struct firmware_priv *fw_priv, struct kobj_uevent_env *env)
 629 {
 630         if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->buf->fw_id))
 631                 return -ENOMEM;
 632         if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
 633                 return -ENOMEM;
 634         if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
 635                 return -ENOMEM;
 636
 637         return 0;
 638 }
 639
 640 static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
 641 {
 642         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 643         int err = 0;
 644
 645         mutex_lock(&fw_lock);
 646         if (fw_priv->buf)
 647                 err = do_firmware_uevent(fw_priv, env);
 648         mutex_unlock(&fw_lock);
 649         return err;
 650 }
 651
 652 static struct class firmware_class = {
 653         .name           = "firmware",
 654         .class_groups   = firmware_class_groups,
 655         .dev_uevent     = firmware_uevent,
 656         .dev_release    = fw_dev_release,
 657 };
 658
 659 static ssize_t firmware_loading_show(struct device *dev,
 660                                      struct device_attribute *attr, char *buf)
 661 {
 662         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 663         int loading = 0;
 664
 665         mutex_lock(&fw_lock);
 666         if (fw_priv->buf)
 667                 loading = fw_state_is_loading(&fw_priv->buf->fw_st);
 668         mutex_unlock(&fw_lock);
 669
 670         return sprintf(buf, "%d\n", loading);
 671 }
 672
 673 /* Some architectures don't have PAGE_KERNEL_RO */
 674 #ifndef PAGE_KERNEL_RO
 675 #define PAGE_KERNEL_RO PAGE_KERNEL
 676 #endif
 677
 678 /* one pages buffer should be mapped/unmapped only once */
 679 static int fw_map_pages_buf(struct firmware_buf *buf)
 680 {
 681         if (!buf->is_paged_buf)
 682                 return 0;
 683
 684         vunmap(buf->data);
 685         buf->data = vmap(buf->pages, buf->nr_pages, 0, PAGE_KERNEL_RO);
 686         if (!buf->data)
 687                 return -ENOMEM;
 688         return 0;
 689 }
 690
 691 /**
 692  * firmware_loading_store - set value in the 'loading' control file
 693  * @dev: device pointer
 694  * @attr: device attribute pointer
 695  * @buf: buffer to scan for loading control value
 696  * @count: number of bytes in @buf
 697  *
 698  *      The relevant values are:
 699  *
 700  *       1: Start a load, discarding any previous partial load.
 701  *       0: Conclude the load and hand the data to the driver code.
 702  *      -1: Conclude the load with an error and discard any written data.
 703  **/
 704 static ssize_t firmware_loading_store(struct device *dev,
 705                                       struct device_attribute *attr,
 706                                       const char *buf, size_t count)
 707 {
 708         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 709         struct firmware_buf *fw_buf;
 710         ssize_t written = count;
 711         int loading = simple_strtol(buf, NULL, 10);
 712         int i;
 713
 714         mutex_lock(&fw_lock);
 715         fw_buf = fw_priv->buf;
 716         if (!fw_buf)
 717                 goto out;
 718
 719         switch (loading) {
 720         case 1:
 721                 /* discarding any previous partial load */
 722                 if (!fw_state_is_done(&fw_buf->fw_st)) {
 723                         for (i = 0; i < fw_buf->nr_pages; i++)
 724                                 __free_page(fw_buf->pages[i]);
 725                         vfree(fw_buf->pages);
 726                         fw_buf->pages = NULL;
 727                         fw_buf->page_array_size = 0;
 728                         fw_buf->nr_pages = 0;
 729                         fw_state_start(&fw_buf->fw_st);
 730                 }
 731                 break;
 732         case 0:
 733                 if (fw_state_is_loading(&fw_buf->fw_st)) {
 734                         int rc;
 735
 736                         /*
 737                          * Several loading requests may be pending on
 738                          * one same firmware buf, so let all requests
 739                          * see the mapped 'buf->data' once the loading
 740                          * is completed.
 741                          * */
 742                         rc = fw_map_pages_buf(fw_buf);
 743                         if (rc)
 744                                 dev_err(dev, "%s: map pages failed\n",
 745                                         __func__);
 746                         else
 747                                 rc = security_kernel_post_read_file(NULL,
 748                                                 fw_buf->data, fw_buf->size,
 749                                                 READING_FIRMWARE);
 750
 751                         /*
 752                          * Same logic as fw_load_abort, only the DONE bit
 753                          * is ignored and we set ABORT only on failure.
 754                          */
 755                         list_del_init(&fw_buf->pending_list);
 756                         if (rc) {
 757                                 fw_state_aborted(&fw_buf->fw_st);
 758                                 written = rc;
 759                         } else {
 760                                 fw_state_done(&fw_buf->fw_st);
 761                         }
 762                         break;
 763                 }
 764                 /* fallthrough */
 765         default:
 766                 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
 767                 /* fallthrough */
 768         case -1:
 769                 fw_load_abort(fw_priv);
 770                 break;
 771         }
 772 out:
 773         mutex_unlock(&fw_lock);
 774         return written;
 775 }
 776
 777 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
 778
 779 static void firmware_rw_buf(struct firmware_buf *buf, char *buffer,
 780                            loff_t offset, size_t count, bool read)
 781 {
 782         if (read)
 783                 memcpy(buffer, buf->data + offset, count);
 784         else
 785                 memcpy(buf->data + offset, buffer, count);
 786 }
 787
 788 static void firmware_rw(struct firmware_buf *buf, char *buffer,
 789                         loff_t offset, size_t count, bool read)
 790 {
 791         while (count) {
 792                 void *page_data;
 793                 int page_nr = offset >> PAGE_SHIFT;
 794                 int page_ofs = offset & (PAGE_SIZE-1);
 795                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 796
 797                 page_data = kmap(buf->pages[page_nr]);
 798
 799                 if (read)
 800                         memcpy(buffer, page_data + page_ofs, page_cnt);
 801                 else
 802                         memcpy(page_data + page_ofs, buffer, page_cnt);
 803
 804                 kunmap(buf->pages[page_nr]);
 805                 buffer += page_cnt;
 806                 offset += page_cnt;
 807                 count -= page_cnt;
 808         }
 809 }
 810
 811 static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
 812                                   struct bin_attribute *bin_attr,
 813                                   char *buffer, loff_t offset, size_t count)
 814 {
 815         struct device *dev = kobj_to_dev(kobj);
 816         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 817         struct firmware_buf *buf;
 818         ssize_t ret_count;
 819
 820         mutex_lock(&fw_lock);
 821         buf = fw_priv->buf;
 822         if (!buf || fw_state_is_done(&buf->fw_st)) {
 823                 ret_count = -ENODEV;
 824                 goto out;
 825         }
 826         if (offset > buf->size) {
 827                 ret_count = 0;
 828                 goto out;
 829         }
 830         if (count > buf->size - offset)
 831                 count = buf->size - offset;
 832
 833         ret_count = count;
 834
 835         if (buf->data)
 836                 firmware_rw_buf(buf, buffer, offset, count, true);
 837         else
 838                 firmware_rw(buf, buffer, offset, count, true);
 839
 840 out:
 841         mutex_unlock(&fw_lock);
 842         return ret_count;
 843 }
 844
 845 static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
 846 {
 847         struct firmware_buf *buf = fw_priv->buf;
 848         int pages_needed = PAGE_ALIGN(min_size) >> PAGE_SHIFT;
 849
 850         /* If the array of pages is too small, grow it... */
 851         if (buf->page_array_size < pages_needed) {
 852                 int new_array_size = max(pages_needed,
 853                                          buf->page_array_size * 2);
 854                 struct page **new_pages;
 855
 856                 new_pages = vmalloc(new_array_size * sizeof(void *));
 857                 if (!new_pages) {
 858                         fw_load_abort(fw_priv);
 859                         return -ENOMEM;
 860                 }
 861                 memcpy(new_pages, buf->pages,
 862                        buf->page_array_size * sizeof(void *));
 863                 memset(&new_pages[buf->page_array_size], 0, sizeof(void *) *
 864                        (new_array_size - buf->page_array_size));
 865                 vfree(buf->pages);
 866                 buf->pages = new_pages;
 867                 buf->page_array_size = new_array_size;
 868         }
 869
 870         while (buf->nr_pages < pages_needed) {
 871                 buf->pages[buf->nr_pages] =
 872                         alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
 873
 874                 if (!buf->pages[buf->nr_pages]) {
 875                         fw_load_abort(fw_priv);
 876                         return -ENOMEM;
 877                 }
 878                 buf->nr_pages++;
 879         }
 880         return 0;
 881 }
 882
 883 /**
 884  * firmware_data_write - write method for firmware
 885  * @filp: open sysfs file
 886  * @kobj: kobject for the device
 887  * @bin_attr: bin_attr structure
 888  * @buffer: buffer being written
 889  * @offset: buffer offset for write in total data store area
 890  * @count: buffer size
 891  *
 892  *      Data written to the 'data' attribute will be later handed to
 893  *      the driver as a firmware image.
 894  **/
 895 static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,
 896                                    struct bin_attribute *bin_attr,
 897                                    char *buffer, loff_t offset, size_t count)
 898 {
 899         struct device *dev = kobj_to_dev(kobj);
 900         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 901         struct firmware_buf *buf;
 902         ssize_t retval;
 903
 904         if (!capable(CAP_SYS_RAWIO))
 905                 return -EPERM;
 906
 907         mutex_lock(&fw_lock);
 908         buf = fw_priv->buf;
 909         if (!buf || fw_state_is_done(&buf->fw_st)) {
 910                 retval = -ENODEV;
 911                 goto out;
 912         }
 913
 914         if (buf->data) {
 915                 if (offset + count > buf->allocated_size) {
 916                         retval = -ENOMEM;
 917                         goto out;
 918                 }
 919                 firmware_rw_buf(buf, buffer, offset, count, false);
 920                 retval = count;
 921         } else {
 922                 retval = fw_realloc_buffer(fw_priv, offset + count);
 923                 if (retval)
 924                         goto out;
 925
 926                 retval = count;
 927                 firmware_rw(buf, buffer, offset, count, false);
 928         }
 929
 930         buf->size = max_t(size_t, offset + count, buf->size);
 931 out:
 932         mutex_unlock(&fw_lock);
 933         return retval;
 934 }
 935
 936 static struct bin_attribute firmware_attr_data = {
 937         .attr = { .name = "data", .mode = 0644 },
 938         .size = 0,
 939         .read = firmware_data_read,
 940         .write = firmware_data_write,
 941 };
 942
 943 static struct attribute *fw_dev_attrs[] = {
 944         &dev_attr_loading.attr,
 945         NULL
 946 };
 947
 948 static struct bin_attribute *fw_dev_bin_attrs[] = {
 949         &firmware_attr_data,
 950         NULL
 951 };
 952
 953 static const struct attribute_group fw_dev_attr_group = {
 954         .attrs = fw_dev_attrs,
 955         .bin_attrs = fw_dev_bin_attrs,
 956 };
 957
 958 static const struct attribute_group *fw_dev_attr_groups[] = {
 959         &fw_dev_attr_group,
 960         NULL
 961 };
 962
 963 static struct firmware_priv *
 964 fw_create_instance(struct firmware *firmware, const char *fw_name,
 965                    struct device *device, unsigned int opt_flags)
 966 {
 967         struct firmware_priv *fw_priv;
 968         struct device *f_dev;
 969
 970         fw_priv = kzalloc(sizeof(*fw_priv), GFP_KERNEL);
 971         if (!fw_priv) {
 972                 fw_priv = ERR_PTR(-ENOMEM);
 973                 goto exit;
 974         }
 975
 976         fw_priv->nowait = !!(opt_flags & FW_OPT_NOWAIT);
 977         fw_priv->fw = firmware;
 978         f_dev = &fw_priv->dev;
 979
 980         device_initialize(f_dev);
 981         dev_set_name(f_dev, "%s", fw_name);
 982         f_dev->parent = device;
 983         f_dev->class = &firmware_class;
 984         f_dev->groups = fw_dev_attr_groups;
 985 exit:
 986         return fw_priv;
 987 }
 988
 989 /* load a firmware via user helper */
 990 static int _request_firmware_load(struct firmware_priv *fw_priv,
 991                                   unsigned int opt_flags, long timeout)
 992 {
 993         int retval = 0;
 994         struct device *f_dev = &fw_priv->dev;
 995         struct firmware_buf *buf = fw_priv->buf;
 996
 997         /* fall back on userspace loading */
 998         if (!buf->data)
 999                 buf->is_paged_buf = true;
1000
1001         dev_set_uevent_suppress(f_dev, true);
1002
1003         retval = device_add(f_dev);
1004         if (retval) {
1005                 dev_err(f_dev, "%s: device_register failed\n", __func__);
1006                 goto err_put_dev;
1007         }
1008
1009         mutex_lock(&fw_lock);
1010         list_add(&buf->pending_list, &pending_fw_head);
1011         mutex_unlock(&fw_lock);
1012
1013         if (opt_flags & FW_OPT_UEVENT) {
1014                 buf->need_uevent = true;
1015                 dev_set_uevent_suppress(f_dev, false);
1016                 dev_dbg(f_dev, "firmware: requesting %s\n", buf->fw_id);
1017                 kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD);
1018         } else {
1019                 timeout = MAX_JIFFY_OFFSET;
1020         }
1021
1022         retval = fw_state_wait_timeout(&buf->fw_st, timeout);
1023         if (retval < 0) {
1024                 mutex_lock(&fw_lock);
1025                 fw_load_abort(fw_priv);
1026                 mutex_unlock(&fw_lock);
1027         }
1028
1029         if (fw_state_is_aborted(&buf->fw_st))
1030                 retval = -EAGAIN;
1031         else if (buf->is_paged_buf && !buf->data)
1032                 retval = -ENOMEM;
1033
1034         device_del(f_dev);
1035 err_put_dev:
1036         put_device(f_dev);
1037         return retval;
1038 }
1039
1040 static int fw_load_from_user_helper(struct firmware *firmware,
1041                                     const char *name, struct device *device,
1042                                     unsigned int opt_flags, long timeout)
1043 {
1044         struct firmware_priv *fw_priv;
1045
1046         fw_priv = fw_create_instance(firmware, name, device, opt_flags);
1047         if (IS_ERR(fw_priv))
1048                 return PTR_ERR(fw_priv);
1049
1050         fw_priv->buf = firmware->priv;
1051         return _request_firmware_load(fw_priv, opt_flags, timeout);
1052 }
1053
1054 #ifdef CONFIG_PM_SLEEP
1055 /* kill pending requests without uevent to avoid blocking suspend */
1056 static void kill_requests_without_uevent(void)
1057 {
1058         struct firmware_buf *buf;
1059         struct firmware_buf *next;
1060
1061         mutex_lock(&fw_lock);
1062         list_for_each_entry_safe(buf, next, &pending_fw_head, pending_list) {
1063                 if (!buf->need_uevent)
1064                          __fw_load_abort(buf);
1065         }
1066         mutex_unlock(&fw_lock);
1067 }
1068 #endif
1069
1070 #else /* CONFIG_FW_LOADER_USER_HELPER */
1071 static inline int
1072 fw_load_from_user_helper(struct firmware *firmware, const char *name,
1073                          struct device *device, unsigned int opt_flags,
1074                          long timeout)
1075 {
1076         return -ENOENT;
1077 }
1078
1079 #ifdef CONFIG_PM_SLEEP
1080 static inline void kill_requests_without_uevent(void) { }
1081 #endif
1082
1083 #endif /* CONFIG_FW_LOADER_USER_HELPER */
1084
1085 /* prepare firmware and firmware_buf structs;
1086  * return 0 if a firmware is already assigned, 1 if need to load one,
1087  * or a negative error code
1088  */
1089 static int
1090 _request_firmware_prepare(struct firmware **firmware_p, const char *name,
1091                           struct device *device, void *dbuf, size_t size)
1092 {
1093         struct firmware *firmware;
1094         struct firmware_buf *buf;
1095         int ret;
1096
1097         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
1098         if (!firmware) {
1099                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
1100                         __func__);
1101                 return -ENOMEM;
1102         }
1103
1104         if (fw_get_builtin_firmware(firmware, name, dbuf, size)) {
1105                 dev_dbg(device, "using built-in %s\n", name);
1106                 return 0; /* assigned */
1107         }
1108
1109         ret = fw_lookup_and_allocate_buf(name, &fw_cache, &buf, dbuf, size);
1110
1111         /*
1112          * bind with 'buf' now to avoid warning in failure path
1113          * of requesting firmware.
1114          */
1115         firmware->priv = buf;
1116
1117         if (ret > 0) {
1118                 ret = fw_state_wait(&buf->fw_st);
1119                 if (!ret) {
1120                         fw_set_page_data(buf, firmware);
1121                         return 0; /* assigned */
1122                 }
1123         }
1124
1125         if (ret < 0)
1126                 return ret;
1127         return 1; /* need to load */
1128 }
1129
1130 static int assign_firmware_buf(struct firmware *fw, struct device *device,
1131                                unsigned int opt_flags)
1132 {
1133         struct firmware_buf *buf = fw->priv;
1134
1135         mutex_lock(&fw_lock);
1136         if (!buf->size || fw_state_is_aborted(&buf->fw_st)) {
1137                 mutex_unlock(&fw_lock);
1138                 return -ENOENT;
1139         }
1140
1141         /*
1142          * add firmware name into devres list so that we can auto cache
1143          * and uncache firmware for device.
1144          *
1145          * device may has been deleted already, but the problem
1146          * should be fixed in devres or driver core.
1147          */
1148         /* don't cache firmware handled without uevent */
1149         if (device && (opt_flags & FW_OPT_UEVENT) &&
1150             !(opt_flags & FW_OPT_NOCACHE))
1151                 fw_add_devm_name(device, buf->fw_id);
1152
1153         /*
1154          * After caching firmware image is started, let it piggyback
1155          * on request firmware.
1156          */
1157         if (!(opt_flags & FW_OPT_NOCACHE) &&
1158             buf->fwc->state == FW_LOADER_START_CACHE) {
1159                 if (fw_cache_piggyback_on_request(buf->fw_id))
1160                         kref_get(&buf->ref);
1161         }
1162
1163         /* pass the pages buffer to driver at the last minute */
1164         fw_set_page_data(buf, fw);
1165         mutex_unlock(&fw_lock);
1166         return 0;
1167 }
1168
1169 /* called from request_firmware() and request_firmware_work_func() */
1170 static int
1171 _request_firmware(const struct firmware **firmware_p, const char *name,
1172                   struct device *device, void *buf, size_t size,
1173                   unsigned int opt_flags)
1174 {
1175         struct firmware *fw = NULL;
1176         long timeout;
1177         int ret;
1178
1179         if (!firmware_p)
1180                 return -EINVAL;
1181
1182         if (!name || name[0] == '\0') {
1183                 ret = -EINVAL;
1184                 goto out;
1185         }
1186
1187         ret = _request_firmware_prepare(&fw, name, device, buf, size);
1188         if (ret <= 0) /* error or already assigned */
1189                 goto out;
1190
1191         ret = 0;
1192         timeout = firmware_loading_timeout();
1193         if (opt_flags & FW_OPT_NOWAIT) {
1194                 timeout = usermodehelper_read_lock_wait(timeout);
1195                 if (!timeout) {
1196                         dev_dbg(device, "firmware: %s loading timed out\n",
1197                                 name);
1198                         ret = -EBUSY;
1199                         goto out;
1200                 }
1201         } else {
1202                 ret = usermodehelper_read_trylock();
1203                 if (WARN_ON(ret)) {
1204                         dev_err(device, "firmware: %s will not be loaded\n",
1205                                 name);
1206                         goto out;
1207                 }
1208         }
1209
1210         ret = fw_get_filesystem_firmware(device, fw->priv);
1211         if (ret) {
1212                 if (!(opt_flags & FW_OPT_NO_WARN))
1213                         dev_warn(device,
1214                                  "Direct firmware load for %s failed with error %d\n",
1215                                  name, ret);
1216                 if (opt_flags & FW_OPT_USERHELPER) {
1217                         dev_warn(device, "Falling back to user helper\n");
1218                         ret = fw_load_from_user_helper(fw, name, device,
1219                                                        opt_flags, timeout);
1220                 }
1221         }
1222
1223         if (!ret)
1224                 ret = assign_firmware_buf(fw, device, opt_flags);
1225
1226         usermodehelper_read_unlock();
1227
1228  out:
1229         if (ret < 0) {
1230                 release_firmware(fw);
1231                 fw = NULL;
1232         }
1233
1234         *firmware_p = fw;
1235         return ret;
1236 }
1237
1238 /**
1239  * request_firmware: - send firmware request and wait for it
1240  * @firmware_p: pointer to firmware image
1241  * @name: name of firmware file
1242  * @device: device for which firmware is being loaded
1243  *
1244  *      @firmware_p will be used to return a firmware image by the name
1245  *      of @name for device @device.
1246  *
1247  *      Should be called from user context where sleeping is allowed.
1248  *
1249  *      @name will be used as $FIRMWARE in the uevent environment and
1250  *      should be distinctive enough not to be confused with any other
1251  *      firmware image for this or any other device.
1252  *
1253  *      Caller must hold the reference count of @device.
1254  *
1255  *      The function can be called safely inside device's suspend and
1256  *      resume callback.
1257  **/
1258 int
1259 request_firmware(const struct firmware **firmware_p, const char *name,
1260                  struct device *device)
1261 {
1262         int ret;
1263
1264         /* Need to pin this module until return */
1265         __module_get(THIS_MODULE);
1266         ret = _request_firmware(firmware_p, name, device, NULL, 0,
1267                                 FW_OPT_UEVENT | FW_OPT_FALLBACK);
1268         module_put(THIS_MODULE);
1269         return ret;
1270 }
1271 EXPORT_SYMBOL(request_firmware);
1272
1273 /**
1274  * request_firmware_direct: - load firmware directly without usermode helper
1275  * @firmware_p: pointer to firmware image
1276  * @name: name of firmware file
1277  * @device: device for which firmware is being loaded
1278  *
1279  * This function works pretty much like request_firmware(), but this doesn't
1280  * fall back to usermode helper even if the firmware couldn't be loaded
1281  * directly from fs.  Hence it's useful for loading optional firmwares, which
1282  * aren't always present, without extra long timeouts of udev.
1283  **/
1284 int request_firmware_direct(const struct firmware **firmware_p,
1285                             const char *name, struct device *device)
1286 {
1287         int ret;
1288
1289         __module_get(THIS_MODULE);
1290         ret = _request_firmware(firmware_p, name, device, NULL, 0,
1291                                 FW_OPT_UEVENT | FW_OPT_NO_WARN);
1292         module_put(THIS_MODULE);
1293         return ret;
1294 }
1295 EXPORT_SYMBOL_GPL(request_firmware_direct);
1296
1297 /**
1298  * request_firmware_into_buf - load firmware into a previously allocated buffer
1299  * @firmware_p: pointer to firmware image
1300  * @name: name of firmware file
1301  * @device: device for which firmware is being loaded and DMA region allocated
1302  * @buf: address of buffer to load firmware into
1303  * @size: size of buffer
1304  *
1305  * This function works pretty much like request_firmware(), but it doesn't
1306  * allocate a buffer to hold the firmware data. Instead, the firmware
1307  * is loaded directly into the buffer pointed to by @buf and the @firmware_p
1308  * data member is pointed at @buf.
1309  *
1310  * This function doesn't cache firmware either.
1311  */
1312 int
1313 request_firmware_into_buf(const struct firmware **firmware_p, const char *name,
1314                           struct device *device, void *buf, size_t size)
1315 {
1316         int ret;
1317
1318         __module_get(THIS_MODULE);
1319         ret = _request_firmware(firmware_p, name, device, buf, size,
1320                                 FW_OPT_UEVENT | FW_OPT_FALLBACK |
1321                                 FW_OPT_NOCACHE);
1322         module_put(THIS_MODULE);
1323         return ret;
1324 }
1325 EXPORT_SYMBOL(request_firmware_into_buf);
1326
1327 /**
1328  * release_firmware: - release the resource associated with a firmware image
1329  * @fw: firmware resource to release
1330  **/
1331 void release_firmware(const struct firmware *fw)
1332 {
1333         if (fw) {
1334                 if (!fw_is_builtin_firmware(fw))
1335                         firmware_free_data(fw);
1336                 kfree(fw);
1337         }
1338 }
1339 EXPORT_SYMBOL(release_firmware);
1340
1341 /* Async support */
1342 struct firmware_work {
1343         struct work_struct work;
1344         struct module *module;
1345         const char *name;
1346         struct device *device;
1347         void *context;
1348         void (*cont)(const struct firmware *fw, void *context);
1349         unsigned int opt_flags;
1350 };
1351
1352 static void request_firmware_work_func(struct work_struct *work)
1353 {
1354         struct firmware_work *fw_work;
1355         const struct firmware *fw;
1356
1357         fw_work = container_of(work, struct firmware_work, work);
1358
1359         _request_firmware(&fw, fw_work->name, fw_work->device, NULL, 0,
1360                           fw_work->opt_flags);
1361         fw_work->cont(fw, fw_work->context);
1362         put_device(fw_work->device); /* taken in request_firmware_nowait() */
1363
1364         module_put(fw_work->module);
1365         kfree_const(fw_work->name);
1366         kfree(fw_work);
1367 }
1368
1369 /**
1370  * request_firmware_nowait - asynchronous version of request_firmware
1371  * @module: module requesting the firmware
1372  * @uevent: sends uevent to copy the firmware image if this flag
1373  *      is non-zero else the firmware copy must be done manually.
1374  * @name: name of firmware file
1375  * @device: device for which firmware is being loaded
1376  * @gfp: allocation flags
1377  * @context: will be passed over to @cont, and
1378  *      @fw may be %NULL if firmware request fails.
1379  * @cont: function will be called asynchronously when the firmware
1380  *      request is over.
1381  *
1382  *      Caller must hold the reference count of @device.
1383  *
1384  *      Asynchronous variant of request_firmware() for user contexts:
1385  *              - sleep for as small periods as possible since it may
1386  *                increase kernel boot time of built-in device drivers
1387  *                requesting firmware in their ->probe() methods, if
1388  *                @gfp is GFP_KERNEL.
1389  *
1390  *              - can't sleep at all if @gfp is GFP_ATOMIC.
1391  **/
1392 int
1393 request_firmware_nowait(
1394         struct module *module, bool uevent,
1395         const char *name, struct device *device, gfp_t gfp, void *context,
1396         void (*cont)(const struct firmware *fw, void *context))
1397 {
1398         struct firmware_work *fw_work;
1399
1400         fw_work = kzalloc(sizeof(struct firmware_work), gfp);
1401         if (!fw_work)
1402                 return -ENOMEM;
1403
1404         fw_work->module = module;
1405         fw_work->name = kstrdup_const(name, gfp);
1406         if (!fw_work->name) {
1407                 kfree(fw_work);
1408                 return -ENOMEM;
1409         }
1410         fw_work->device = device;
1411         fw_work->context = context;
1412         fw_work->cont = cont;
1413         fw_work->opt_flags = FW_OPT_NOWAIT | FW_OPT_FALLBACK |
1414                 (uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
1415
1416         if (!try_module_get(module)) {
1417                 kfree_const(fw_work->name);
1418                 kfree(fw_work);
1419                 return -EFAULT;
1420         }
1421
1422         get_device(fw_work->device);
1423         INIT_WORK(&fw_work->work, request_firmware_work_func);
1424         schedule_work(&fw_work->work);
1425         return 0;
1426 }
1427 EXPORT_SYMBOL(request_firmware_nowait);
1428
1429 #ifdef CONFIG_PM_SLEEP
1430 static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
1431
1432 /**
1433  * cache_firmware - cache one firmware image in kernel memory space
1434  * @fw_name: the firmware image name
1435  *
1436  * Cache firmware in kernel memory so that drivers can use it when
1437  * system isn't ready for them to request firmware image from userspace.
1438  * Once it returns successfully, driver can use request_firmware or its
1439  * nowait version to get the cached firmware without any interacting
1440  * with userspace
1441  *
1442  * Return 0 if the firmware image has been cached successfully
1443  * Return !0 otherwise
1444  *
1445  */
1446 static int cache_firmware(const char *fw_name)
1447 {
1448         int ret;
1449         const struct firmware *fw;
1450
1451         pr_debug("%s: %s\n", __func__, fw_name);
1452
1453         ret = request_firmware(&fw, fw_name, NULL);
1454         if (!ret)
1455                 kfree(fw);
1456
1457         pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
1458
1459         return ret;
1460 }
1461
1462 static struct firmware_buf *fw_lookup_buf(const char *fw_name)
1463 {
1464         struct firmware_buf *tmp;
1465         struct firmware_cache *fwc = &fw_cache;
1466
1467         spin_lock(&fwc->lock);
1468         tmp = __fw_lookup_buf(fw_name);
1469         spin_unlock(&fwc->lock);
1470
1471         return tmp;
1472 }
1473
1474 /**
1475  * uncache_firmware - remove one cached firmware image
1476  * @fw_name: the firmware image name
1477  *
1478  * Uncache one firmware image which has been cached successfully
1479  * before.
1480  *
1481  * Return 0 if the firmware cache has been removed successfully
1482  * Return !0 otherwise
1483  *
1484  */
1485 static int uncache_firmware(const char *fw_name)
1486 {
1487         struct firmware_buf *buf;
1488         struct firmware fw;
1489
1490         pr_debug("%s: %s\n", __func__, fw_name);
1491
1492         if (fw_get_builtin_firmware(&fw, fw_name, NULL, 0))
1493                 return 0;
1494
1495         buf = fw_lookup_buf(fw_name);
1496         if (buf) {
1497                 fw_free_buf(buf);
1498                 return 0;
1499         }
1500
1501         return -EINVAL;
1502 }
1503
1504 static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
1505 {
1506         struct fw_cache_entry *fce;
1507
1508         fce = kzalloc(sizeof(*fce), GFP_ATOMIC);
1509         if (!fce)
1510                 goto exit;
1511
1512         fce->name = kstrdup_const(name, GFP_ATOMIC);
1513         if (!fce->name) {
1514                 kfree(fce);
1515                 fce = NULL;
1516                 goto exit;
1517         }
1518 exit:
1519         return fce;
1520 }
1521
1522 static int __fw_entry_found(const char *name)
1523 {
1524         struct firmware_cache *fwc = &fw_cache;
1525         struct fw_cache_entry *fce;
1526
1527         list_for_each_entry(fce, &fwc->fw_names, list) {
1528                 if (!strcmp(fce->name, name))
1529                         return 1;
1530         }
1531         return 0;
1532 }
1533
1534 static int fw_cache_piggyback_on_request(const char *name)
1535 {
1536         struct firmware_cache *fwc = &fw_cache;
1537         struct fw_cache_entry *fce;
1538         int ret = 0;
1539
1540         spin_lock(&fwc->name_lock);
1541         if (__fw_entry_found(name))
1542                 goto found;
1543
1544         fce = alloc_fw_cache_entry(name);
1545         if (fce) {
1546                 ret = 1;
1547                 list_add(&fce->list, &fwc->fw_names);
1548                 pr_debug("%s: fw: %s\n", __func__, name);
1549         }
1550 found:
1551         spin_unlock(&fwc->name_lock);
1552         return ret;
1553 }
1554
1555 static void free_fw_cache_entry(struct fw_cache_entry *fce)
1556 {
1557         kfree_const(fce->name);
1558         kfree(fce);
1559 }
1560
1561 static void __async_dev_cache_fw_image(void *fw_entry,
1562                                        async_cookie_t cookie)
1563 {
1564         struct fw_cache_entry *fce = fw_entry;
1565         struct firmware_cache *fwc = &fw_cache;
1566         int ret;
1567
1568         ret = cache_firmware(fce->name);
1569         if (ret) {
1570                 spin_lock(&fwc->name_lock);
1571                 list_del(&fce->list);
1572                 spin_unlock(&fwc->name_lock);
1573
1574                 free_fw_cache_entry(fce);
1575         }
1576 }
1577
1578 /* called with dev->devres_lock held */
1579 static void dev_create_fw_entry(struct device *dev, void *res,
1580                                 void *data)
1581 {
1582         struct fw_name_devm *fwn = res;
1583         const char *fw_name = fwn->name;
1584         struct list_head *head = data;
1585         struct fw_cache_entry *fce;
1586
1587         fce = alloc_fw_cache_entry(fw_name);
1588         if (fce)
1589                 list_add(&fce->list, head);
1590 }
1591
1592 static int devm_name_match(struct device *dev, void *res,
1593                            void *match_data)
1594 {
1595         struct fw_name_devm *fwn = res;
1596         return (fwn->magic == (unsigned long)match_data);
1597 }
1598
1599 static void dev_cache_fw_image(struct device *dev, void *data)
1600 {
1601         LIST_HEAD(todo);
1602         struct fw_cache_entry *fce;
1603         struct fw_cache_entry *fce_next;
1604         struct firmware_cache *fwc = &fw_cache;
1605
1606         devres_for_each_res(dev, fw_name_devm_release,
1607                             devm_name_match, &fw_cache,
1608                             dev_create_fw_entry, &todo);
1609
1610         list_for_each_entry_safe(fce, fce_next, &todo, list) {
1611                 list_del(&fce->list);
1612
1613                 spin_lock(&fwc->name_lock);
1614                 /* only one cache entry for one firmware */
1615                 if (!__fw_entry_found(fce->name)) {
1616                         list_add(&fce->list, &fwc->fw_names);
1617                 } else {
1618                         free_fw_cache_entry(fce);
1619                         fce = NULL;
1620                 }
1621                 spin_unlock(&fwc->name_lock);
1622
1623                 if (fce)
1624                         async_schedule_domain(__async_dev_cache_fw_image,
1625                                               (void *)fce,
1626                                               &fw_cache_domain);
1627         }
1628 }
1629
1630 static void __device_uncache_fw_images(void)
1631 {
1632         struct firmware_cache *fwc = &fw_cache;
1633         struct fw_cache_entry *fce;
1634
1635         spin_lock(&fwc->name_lock);
1636         while (!list_empty(&fwc->fw_names)) {
1637                 fce = list_entry(fwc->fw_names.next,
1638                                 struct fw_cache_entry, list);
1639                 list_del(&fce->list);
1640                 spin_unlock(&fwc->name_lock);
1641
1642                 uncache_firmware(fce->name);
1643                 free_fw_cache_entry(fce);
1644
1645                 spin_lock(&fwc->name_lock);
1646         }
1647         spin_unlock(&fwc->name_lock);
1648 }
1649
1650 /**
1651  * device_cache_fw_images - cache devices' firmware
1652  *
1653  * If one device called request_firmware or its nowait version
1654  * successfully before, the firmware names are recored into the
1655  * device's devres link list, so device_cache_fw_images can call
1656  * cache_firmware() to cache these firmwares for the device,
1657  * then the device driver can load its firmwares easily at
1658  * time when system is not ready to complete loading firmware.
1659  */
1660 static void device_cache_fw_images(void)
1661 {
1662         struct firmware_cache *fwc = &fw_cache;
1663         int old_timeout;
1664         DEFINE_WAIT(wait);
1665
1666         pr_debug("%s\n", __func__);
1667
1668         /* cancel uncache work */
1669         cancel_delayed_work_sync(&fwc->work);
1670
1671         /*
1672          * use small loading timeout for caching devices' firmware
1673          * because all these firmware images have been loaded
1674          * successfully at lease once, also system is ready for
1675          * completing firmware loading now. The maximum size of
1676          * firmware in current distributions is about 2M bytes,
1677          * so 10 secs should be enough.
1678          */
1679         old_timeout = loading_timeout;
1680         loading_timeout = 10;
1681
1682         mutex_lock(&fw_lock);
1683         fwc->state = FW_LOADER_START_CACHE;
1684         dpm_for_each_dev(NULL, dev_cache_fw_image);
1685         mutex_unlock(&fw_lock);
1686
1687         /* wait for completion of caching firmware for all devices */
1688         async_synchronize_full_domain(&fw_cache_domain);
1689
1690         loading_timeout = old_timeout;
1691 }
1692
1693 /**
1694  * device_uncache_fw_images - uncache devices' firmware
1695  *
1696  * uncache all firmwares which have been cached successfully
1697  * by device_uncache_fw_images earlier
1698  */
1699 static void device_uncache_fw_images(void)
1700 {
1701         pr_debug("%s\n", __func__);
1702         __device_uncache_fw_images();
1703 }
1704
1705 static void device_uncache_fw_images_work(struct work_struct *work)
1706 {
1707         device_uncache_fw_images();
1708 }
1709
1710 /**
1711  * device_uncache_fw_images_delay - uncache devices firmwares
1712  * @delay: number of milliseconds to delay uncache device firmwares
1713  *
1714  * uncache all devices's firmwares which has been cached successfully
1715  * by device_cache_fw_images after @delay milliseconds.
1716  */
1717 static void device_uncache_fw_images_delay(unsigned long delay)
1718 {
1719         queue_delayed_work(system_power_efficient_wq, &fw_cache.work,
1720                            msecs_to_jiffies(delay));
1721 }
1722
1723 static int fw_pm_notify(struct notifier_block *notify_block,
1724                         unsigned long mode, void *unused)
1725 {
1726         switch (mode) {
1727         case PM_HIBERNATION_PREPARE:
1728         case PM_SUSPEND_PREPARE:
1729         case PM_RESTORE_PREPARE:
1730                 kill_requests_without_uevent();
1731                 device_cache_fw_images();
1732                 break;
1733
1734         case PM_POST_SUSPEND:
1735         case PM_POST_HIBERNATION:
1736         case PM_POST_RESTORE:
1737                 /*
1738                  * In case that system sleep failed and syscore_suspend is
1739                  * not called.
1740                  */
1741                 mutex_lock(&fw_lock);
1742                 fw_cache.state = FW_LOADER_NO_CACHE;
1743                 mutex_unlock(&fw_lock);
1744
1745                 device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
1746                 break;
1747         }
1748
1749         return 0;
1750 }
1751
1752 /* stop caching firmware once syscore_suspend is reached */
1753 static int fw_suspend(void)
1754 {
1755         fw_cache.state = FW_LOADER_NO_CACHE;
1756         return 0;
1757 }
1758
1759 static struct syscore_ops fw_syscore_ops = {
1760         .suspend = fw_suspend,
1761 };
1762 #else
1763 static int fw_cache_piggyback_on_request(const char *name)
1764 {
1765         return 0;
1766 }
1767 #endif
1768
1769 static void __init fw_cache_init(void)
1770 {
1771         spin_lock_init(&fw_cache.lock);
1772         INIT_LIST_HEAD(&fw_cache.head);
1773         fw_cache.state = FW_LOADER_NO_CACHE;
1774
1775 #ifdef CONFIG_PM_SLEEP
1776         spin_lock_init(&fw_cache.name_lock);
1777         INIT_LIST_HEAD(&fw_cache.fw_names);
1778
1779         INIT_DELAYED_WORK(&fw_cache.work,
1780                           device_uncache_fw_images_work);
1781
1782         fw_cache.pm_notify.notifier_call = fw_pm_notify;
1783         register_pm_notifier(&fw_cache.pm_notify);
1784
1785         register_syscore_ops(&fw_syscore_ops);
1786 #endif
1787 }
1788
1789 static int __init firmware_class_init(void)
1790 {
1791         fw_cache_init();
1792 #ifdef CONFIG_FW_LOADER_USER_HELPER
1793         register_reboot_notifier(&fw_shutdown_nb);
1794         return class_register(&firmware_class);
1795 #else
1796         return 0;
1797 #endif
1798 }
1799
1800 static void __exit firmware_class_exit(void)
1801 {
1802 #ifdef CONFIG_PM_SLEEP
1803         unregister_syscore_ops(&fw_syscore_ops);
1804         unregister_pm_notifier(&fw_cache.pm_notify);
1805 #endif
1806 #ifdef CONFIG_FW_LOADER_USER_HELPER
1807         unregister_reboot_notifier(&fw_shutdown_nb);
1808         class_unregister(&firmware_class);
1809 #endif
1810 }
1811
1812 fs_initcall(firmware_class_init);
1813 module_exit(firmware_class_exit);