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