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