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