drivers/base/firmware_class.c

   1 /*
   2  * firmware_class.c - Multi purpose firmware loading support
   3  *
   4  * Copyright (c) 2003 Manuel Estrada Sainz
   5  *
   6  * Please see Documentation/firmware_class/ for more information.
   7  *
   8  */
   9
  10 #include <linux/capability.h>
  11 #include <linux/device.h>
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/timer.h>
  15 #include <linux/vmalloc.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/bitops.h>
  18 #include <linux/mutex.h>
  19 #include <linux/workqueue.h>
  20 #include <linux/highmem.h>
  21 #include <linux/firmware.h>
  22 #include <linux/slab.h>
  23 #include <linux/sched.h>
  24 #include <linux/file.h>
  25 #include <linux/list.h>
  26 #include <linux/fs.h>
  27 #include <linux/async.h>
  28 #include <linux/pm.h>
  29 #include <linux/suspend.h>
  30 #include <linux/syscore_ops.h>
  31 #include <linux/reboot.h>
  32 #include <linux/security.h>
  33
  34 #include <generated/utsrelease.h>
  35
  36 #include "base.h"
  37
  38 MODULE_AUTHOR("Manuel Estrada Sainz");
  39 MODULE_DESCRIPTION("Multi purpose firmware loading support");
  40 MODULE_LICENSE("GPL");
  41
  42 /* Builtin firmware support */
  43
  44 #ifdef CONFIG_FW_LOADER
  45
  46 extern struct builtin_fw __start_builtin_fw[];
  47 extern struct builtin_fw __end_builtin_fw[];
  48
  49 static bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
  50 {
  51         struct builtin_fw *b_fw;
  52
  53         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
  54                 if (strcmp(name, b_fw->name) == 0) {
  55                         fw->size = b_fw->size;
  56                         fw->data = b_fw->data;
  57                         return true;
  58                 }
  59         }
  60
  61         return false;
  62 }
  63
  64 static bool fw_is_builtin_firmware(const struct firmware *fw)
  65 {
  66         struct builtin_fw *b_fw;
  67
  68         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
  69                 if (fw->data == b_fw->data)
  70                         return true;
  71
  72         return false;
  73 }
  74
  75 #else /* Module case - no builtin firmware support */
  76
  77 static inline bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
  78 {
  79         return false;
  80 }
  81
  82 static inline bool fw_is_builtin_firmware(const struct firmware *fw)
  83 {
  84         return false;
  85 }
  86 #endif
  87
  88 enum {
  89         FW_STATUS_LOADING,
  90         FW_STATUS_DONE,
  91         FW_STATUS_ABORT,
  92 };
  93
  94 static int loading_timeout = 60;        /* In seconds */
  95
  96 static inline long firmware_loading_timeout(void)
  97 {
  98         return loading_timeout > 0 ? loading_timeout * HZ : MAX_JIFFY_OFFSET;
  99 }
 100
 101 /* firmware behavior options */
 102 #define FW_OPT_UEVENT   (1U << 0)
 103 #define FW_OPT_NOWAIT   (1U << 1)
 104 #ifdef CONFIG_FW_LOADER_USER_HELPER
 105 #define FW_OPT_USERHELPER       (1U << 2)
 106 #else
 107 #define FW_OPT_USERHELPER       0
 108 #endif
 109 #ifdef CONFIG_FW_LOADER_USER_HELPER_FALLBACK
 110 #define FW_OPT_FALLBACK         FW_OPT_USERHELPER
 111 #else
 112 #define FW_OPT_FALLBACK         0
 113 #endif
 114 #define FW_OPT_NO_WARN  (1U << 3)
 115
 116 struct firmware_cache {
 117         /* firmware_buf instance will be added into the below list */
 118         spinlock_t lock;
 119         struct list_head head;
 120         int state;
 121
 122 #ifdef CONFIG_PM_SLEEP
 123         /*
 124          * Names of firmware images which have been cached successfully
 125          * will be added into the below list so that device uncache
 126          * helper can trace which firmware images have been cached
 127          * before.
 128          */
 129         spinlock_t name_lock;
 130         struct list_head fw_names;
 131
 132         struct delayed_work work;
 133
 134         struct notifier_block   pm_notify;
 135 #endif
 136 };
 137
 138 struct firmware_buf {
 139         struct kref ref;
 140         struct list_head list;
 141         struct completion completion;
 142         struct firmware_cache *fwc;
 143         unsigned long status;
 144         void *data;
 145         size_t size;
 146 #ifdef CONFIG_FW_LOADER_USER_HELPER
 147         bool is_paged_buf;
 148         bool need_uevent;
 149         struct page **pages;
 150         int nr_pages;
 151         int page_array_size;
 152         struct list_head pending_list;
 153 #endif
 154         const char *fw_id;
 155 };
 156
 157 struct fw_cache_entry {
 158         struct list_head list;
 159         const char *name;
 160 };
 161
 162 struct fw_name_devm {
 163         unsigned long magic;
 164         const char *name;
 165 };
 166
 167 #define to_fwbuf(d) container_of(d, struct firmware_buf, ref)
 168
 169 #define FW_LOADER_NO_CACHE      0
 170 #define FW_LOADER_START_CACHE   1
 171
 172 static int fw_cache_piggyback_on_request(const char *name);
 173
 174 /* fw_lock could be moved to 'struct firmware_priv' but since it is just
 175  * guarding for corner cases a global lock should be OK */
 176 static DEFINE_MUTEX(fw_lock);
 177
 178 static struct firmware_cache fw_cache;
 179
 180 static struct firmware_buf *__allocate_fw_buf(const char *fw_name,
 181                                               struct firmware_cache *fwc)
 182 {
 183         struct firmware_buf *buf;
 184
 185         buf = kzalloc(sizeof(*buf), GFP_ATOMIC);
 186         if (!buf)
 187                 return NULL;
 188
 189         buf->fw_id = kstrdup_const(fw_name, GFP_ATOMIC);
 190         if (!buf->fw_id) {
 191                 kfree(buf);
 192                 return NULL;
 193         }
 194
 195         kref_init(&buf->ref);
 196         buf->fwc = fwc;
 197         init_completion(&buf->completion);
 198 #ifdef CONFIG_FW_LOADER_USER_HELPER
 199         INIT_LIST_HEAD(&buf->pending_list);
 200 #endif
 201
 202         pr_debug("%s: fw-%s buf=%p\n", __func__, fw_name, buf);
 203
 204         return buf;
 205 }
 206
 207 static struct firmware_buf *__fw_lookup_buf(const char *fw_name)
 208 {
 209         struct firmware_buf *tmp;
 210         struct firmware_cache *fwc = &fw_cache;
 211
 212         list_for_each_entry(tmp, &fwc->head, list)
 213                 if (!strcmp(tmp->fw_id, fw_name))
 214                         return tmp;
 215         return NULL;
 216 }
 217
 218 static int fw_lookup_and_allocate_buf(const char *fw_name,
 219                                       struct firmware_cache *fwc,
 220                                       struct firmware_buf **buf)
 221 {
 222         struct firmware_buf *tmp;
 223
 224         spin_lock(&fwc->lock);
 225         tmp = __fw_lookup_buf(fw_name);
 226         if (tmp) {
 227                 kref_get(&tmp->ref);
 228                 spin_unlock(&fwc->lock);
 229                 *buf = tmp;
 230                 return 1;
 231         }
 232         tmp = __allocate_fw_buf(fw_name, fwc);
 233         if (tmp)
 234                 list_add(&tmp->list, &fwc->head);
 235         spin_unlock(&fwc->lock);
 236
 237         *buf = tmp;
 238
 239         return tmp ? 0 : -ENOMEM;
 240 }
 241
 242 static void __fw_free_buf(struct kref *ref)
 243         __releases(&fwc->lock)
 244 {
 245         struct firmware_buf *buf = to_fwbuf(ref);
 246         struct firmware_cache *fwc = buf->fwc;
 247
 248         pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
 249                  __func__, buf->fw_id, buf, buf->data,
 250                  (unsigned int)buf->size);
 251
 252         list_del(&buf->list);
 253         spin_unlock(&fwc->lock);
 254
 255 #ifdef CONFIG_FW_LOADER_USER_HELPER
 256         if (buf->is_paged_buf) {
 257                 int i;
 258                 vunmap(buf->data);
 259                 for (i = 0; i < buf->nr_pages; i++)
 260                         __free_page(buf->pages[i]);
 261                 vfree(buf->pages);
 262         } else
 263 #endif
 264                 vfree(buf->data);
 265         kfree_const(buf->fw_id);
 266         kfree(buf);
 267 }
 268
 269 static void fw_free_buf(struct firmware_buf *buf)
 270 {
 271         struct firmware_cache *fwc = buf->fwc;
 272         spin_lock(&fwc->lock);
 273         if (!kref_put(&buf->ref, __fw_free_buf))
 274                 spin_unlock(&fwc->lock);
 275 }
 276
 277 /* direct firmware loading support */
 278 static char fw_path_para[256];
 279 static const char * const fw_path[] = {
 280         fw_path_para,
 281         "/lib/firmware/updates/" UTS_RELEASE,
 282         "/lib/firmware/updates",
 283         "/lib/firmware/" UTS_RELEASE,
 284         "/lib/firmware"
 285 };
 286
 287 /*
 288  * Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH'
 289  * from kernel command line because firmware_class is generally built in
 290  * kernel instead of module.
 291  */
 292 module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
 293 MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
 294
 295 static void fw_finish_direct_load(struct device *device,
 296                                   struct firmware_buf *buf)
 297 {
 298         mutex_lock(&fw_lock);
 299         set_bit(FW_STATUS_DONE, &buf->status);
 300         complete_all(&buf->completion);
 301         mutex_unlock(&fw_lock);
 302 }
 303
 304 static int fw_get_filesystem_firmware(struct device *device,
 305                                        struct firmware_buf *buf)
 306 {
 307         loff_t size;
 308         int i, len;
 309         int rc = -ENOENT;
 310         char *path;
 311
 312         path = __getname();
 313         if (!path)
 314                 return -ENOMEM;
 315
 316         for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
 317                 /* skip the unset customized path */
 318                 if (!fw_path[i][0])
 319                         continue;
 320
 321                 len = snprintf(path, PATH_MAX, "%s/%s",
 322                                fw_path[i], buf->fw_id);
 323                 if (len >= PATH_MAX) {
 324                         rc = -ENAMETOOLONG;
 325                         break;
 326                 }
 327
 328                 buf->size = 0;
 329                 rc = kernel_read_file_from_path(path, &buf->data, &size,
 330                                                 INT_MAX, READING_FIRMWARE);
 331                 if (rc) {
 332                         if (rc == -ENOENT)
 333                                 dev_dbg(device, "loading %s failed with error %d\n",
 334                                          path, rc);
 335                         else
 336                                 dev_warn(device, "loading %s failed with error %d\n",
 337                                          path, rc);
 338                         continue;
 339                 }
 340                 dev_dbg(device, "direct-loading %s\n", buf->fw_id);
 341                 buf->size = size;
 342                 fw_finish_direct_load(device, buf);
 343                 break;
 344         }
 345         __putname(path);
 346
 347         return rc;
 348 }
 349
 350 /* firmware holds the ownership of pages */
 351 static void firmware_free_data(const struct firmware *fw)
 352 {
 353         /* Loaded directly? */
 354         if (!fw->priv) {
 355                 vfree(fw->data);
 356                 return;
 357         }
 358         fw_free_buf(fw->priv);
 359 }
 360
 361 /* store the pages buffer info firmware from buf */
 362 static void fw_set_page_data(struct firmware_buf *buf, struct firmware *fw)
 363 {
 364         fw->priv = buf;
 365 #ifdef CONFIG_FW_LOADER_USER_HELPER
 366         fw->pages = buf->pages;
 367 #endif
 368         fw->size = buf->size;
 369         fw->data = buf->data;
 370
 371         pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
 372                  __func__, buf->fw_id, buf, buf->data,
 373                  (unsigned int)buf->size);
 374 }
 375
 376 #ifdef CONFIG_PM_SLEEP
 377 static void fw_name_devm_release(struct device *dev, void *res)
 378 {
 379         struct fw_name_devm *fwn = res;
 380
 381         if (fwn->magic == (unsigned long)&fw_cache)
 382                 pr_debug("%s: fw_name-%s devm-%p released\n",
 383                                 __func__, fwn->name, res);
 384         kfree_const(fwn->name);
 385 }
 386
 387 static int fw_devm_match(struct device *dev, void *res,
 388                 void *match_data)
 389 {
 390         struct fw_name_devm *fwn = res;
 391
 392         return (fwn->magic == (unsigned long)&fw_cache) &&
 393                 !strcmp(fwn->name, match_data);
 394 }
 395
 396 static struct fw_name_devm *fw_find_devm_name(struct device *dev,
 397                 const char *name)
 398 {
 399         struct fw_name_devm *fwn;
 400
 401         fwn = devres_find(dev, fw_name_devm_release,
 402                           fw_devm_match, (void *)name);
 403         return fwn;
 404 }
 405
 406 /* add firmware name into devres list */
 407 static int fw_add_devm_name(struct device *dev, const char *name)
 408 {
 409         struct fw_name_devm *fwn;
 410
 411         fwn = fw_find_devm_name(dev, name);
 412         if (fwn)
 413                 return 1;
 414
 415         fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm),
 416                            GFP_KERNEL);
 417         if (!fwn)
 418                 return -ENOMEM;
 419         fwn->name = kstrdup_const(name, GFP_KERNEL);
 420         if (!fwn->name) {
 421                 devres_free(fwn);
 422                 return -ENOMEM;
 423         }
 424
 425         fwn->magic = (unsigned long)&fw_cache;
 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         bool nowait;
 444         struct device dev;
 445         struct firmware_buf *buf;
 446         struct firmware *fw;
 447 };
 448
 449 static struct firmware_priv *to_firmware_priv(struct device *dev)
 450 {
 451         return container_of(dev, struct firmware_priv, dev);
 452 }
 453
 454 static void __fw_load_abort(struct firmware_buf *buf)
 455 {
 456         /*
 457          * There is a small window in which user can write to 'loading'
 458          * between loading done and disappearance of 'loading'
 459          */
 460         if (test_bit(FW_STATUS_DONE, &buf->status))
 461                 return;
 462
 463         list_del_init(&buf->pending_list);
 464         set_bit(FW_STATUS_ABORT, &buf->status);
 465         complete_all(&buf->completion);
 466 }
 467
 468 static void fw_load_abort(struct firmware_priv *fw_priv)
 469 {
 470         struct firmware_buf *buf = fw_priv->buf;
 471
 472         __fw_load_abort(buf);
 473
 474         /* avoid user action after loading abort */
 475         fw_priv->buf = NULL;
 476 }
 477
 478 #define is_fw_load_aborted(buf) \
 479         test_bit(FW_STATUS_ABORT, &(buf)->status)
 480
 481 static LIST_HEAD(pending_fw_head);
 482
 483 /* reboot notifier for avoid deadlock with usermode_lock */
 484 static int fw_shutdown_notify(struct notifier_block *unused1,
 485                               unsigned long unused2, void *unused3)
 486 {
 487         mutex_lock(&fw_lock);
 488         while (!list_empty(&pending_fw_head))
 489                 __fw_load_abort(list_first_entry(&pending_fw_head,
 490                                                struct firmware_buf,
 491                                                pending_list));
 492         mutex_unlock(&fw_lock);
 493         return NOTIFY_DONE;
 494 }
 495
 496 static struct notifier_block fw_shutdown_nb = {
 497         .notifier_call = fw_shutdown_notify,
 498 };
 499
 500 static ssize_t timeout_show(struct class *class, struct class_attribute *attr,
 501                             char *buf)
 502 {
 503         return sprintf(buf, "%d\n", loading_timeout);
 504 }
 505
 506 /**
 507  * firmware_timeout_store - set number of seconds to wait for firmware
 508  * @class: device class pointer
 509  * @attr: device attribute pointer
 510  * @buf: buffer to scan for timeout value
 511  * @count: number of bytes in @buf
 512  *
 513  *      Sets the number of seconds to wait for the firmware.  Once
 514  *      this expires an error will be returned to the driver and no
 515  *      firmware will be provided.
 516  *
 517  *      Note: zero means 'wait forever'.
 518  **/
 519 static ssize_t timeout_store(struct class *class, struct class_attribute *attr,
 520                              const char *buf, size_t count)
 521 {
 522         loading_timeout = simple_strtol(buf, NULL, 10);
 523         if (loading_timeout < 0)
 524                 loading_timeout = 0;
 525
 526         return count;
 527 }
 528
 529 static struct class_attribute firmware_class_attrs[] = {
 530         __ATTR_RW(timeout),
 531         __ATTR_NULL
 532 };
 533
 534 static void fw_dev_release(struct device *dev)
 535 {
 536         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 537
 538         kfree(fw_priv);
 539 }
 540
 541 static int do_firmware_uevent(struct firmware_priv *fw_priv, struct kobj_uevent_env *env)
 542 {
 543         if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->buf->fw_id))
 544                 return -ENOMEM;
 545         if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
 546                 return -ENOMEM;
 547         if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
 548                 return -ENOMEM;
 549
 550         return 0;
 551 }
 552
 553 static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
 554 {
 555         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 556         int err = 0;
 557
 558         mutex_lock(&fw_lock);
 559         if (fw_priv->buf)
 560                 err = do_firmware_uevent(fw_priv, env);
 561         mutex_unlock(&fw_lock);
 562         return err;
 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                         vfree(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_post_read_file(NULL,
 664                                                 fw_buf->data, fw_buf->size,
 665                                                 READING_FIRMWARE);
 666
 667                         /*
 668                          * Same logic as fw_load_abort, only the DONE bit
 669                          * is ignored and we set ABORT only on failure.
 670                          */
 671                         list_del_init(&fw_buf->pending_list);
 672                         if (rc) {
 673                                 set_bit(FW_STATUS_ABORT, &fw_buf->status);
 674                                 written = rc;
 675                         }
 676                         complete_all(&fw_buf->completion);
 677                         break;
 678                 }
 679                 /* fallthrough */
 680         default:
 681                 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
 682                 /* fallthrough */
 683         case -1:
 684                 fw_load_abort(fw_priv);
 685                 break;
 686         }
 687 out:
 688         mutex_unlock(&fw_lock);
 689         return written;
 690 }
 691
 692 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
 693
 694 static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
 695                                   struct bin_attribute *bin_attr,
 696                                   char *buffer, loff_t offset, size_t count)
 697 {
 698         struct device *dev = kobj_to_dev(kobj);
 699         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 700         struct firmware_buf *buf;
 701         ssize_t ret_count;
 702
 703         mutex_lock(&fw_lock);
 704         buf = fw_priv->buf;
 705         if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) {
 706                 ret_count = -ENODEV;
 707                 goto out;
 708         }
 709         if (offset > buf->size) {
 710                 ret_count = 0;
 711                 goto out;
 712         }
 713         if (count > buf->size - offset)
 714                 count = buf->size - offset;
 715
 716         ret_count = count;
 717
 718         while (count) {
 719                 void *page_data;
 720                 int page_nr = offset >> PAGE_SHIFT;
 721                 int page_ofs = offset & (PAGE_SIZE-1);
 722                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 723
 724                 page_data = kmap(buf->pages[page_nr]);
 725
 726                 memcpy(buffer, page_data + page_ofs, page_cnt);
 727
 728                 kunmap(buf->pages[page_nr]);
 729                 buffer += page_cnt;
 730                 offset += page_cnt;
 731                 count -= page_cnt;
 732         }
 733 out:
 734         mutex_unlock(&fw_lock);
 735         return ret_count;
 736 }
 737
 738 static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
 739 {
 740         struct firmware_buf *buf = fw_priv->buf;
 741         int pages_needed = PAGE_ALIGN(min_size) >> PAGE_SHIFT;
 742
 743         /* If the array of pages is too small, grow it... */
 744         if (buf->page_array_size < pages_needed) {
 745                 int new_array_size = max(pages_needed,
 746                                          buf->page_array_size * 2);
 747                 struct page **new_pages;
 748
 749                 new_pages = vmalloc(new_array_size * sizeof(void *));
 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                 vfree(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, "using built-in %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 = NULL;
1097         long timeout;
1098         int ret;
1099
1100         if (!firmware_p)
1101                 return -EINVAL;
1102
1103         if (!name || name[0] == '\0') {
1104                 ret = -EINVAL;
1105                 goto out;
1106         }
1107
1108         ret = _request_firmware_prepare(&fw, name, device);
1109         if (ret <= 0) /* error or already assigned */
1110                 goto out;
1111
1112         ret = 0;
1113         timeout = firmware_loading_timeout();
1114         if (opt_flags & FW_OPT_NOWAIT) {
1115                 timeout = usermodehelper_read_lock_wait(timeout);
1116                 if (!timeout) {
1117                         dev_dbg(device, "firmware: %s loading timed out\n",
1118                                 name);
1119                         ret = -EBUSY;
1120                         goto out;
1121                 }
1122         } else {
1123                 ret = usermodehelper_read_trylock();
1124                 if (WARN_ON(ret)) {
1125                         dev_err(device, "firmware: %s will not be loaded\n",
1126                                 name);
1127                         goto out;
1128                 }
1129         }
1130
1131         ret = fw_get_filesystem_firmware(device, fw->priv);
1132         if (ret) {
1133                 if (!(opt_flags & FW_OPT_NO_WARN))
1134                         dev_warn(device,
1135                                  "Direct firmware load for %s failed with error %d\n",
1136                                  name, ret);
1137                 if (opt_flags & FW_OPT_USERHELPER) {
1138                         dev_warn(device, "Falling back to user helper\n");
1139                         ret = fw_load_from_user_helper(fw, name, device,
1140                                                        opt_flags, timeout);
1141                 }
1142         }
1143
1144         if (!ret)
1145                 ret = assign_firmware_buf(fw, device, opt_flags);
1146
1147         usermodehelper_read_unlock();
1148
1149  out:
1150         if (ret < 0) {
1151                 release_firmware(fw);
1152                 fw = NULL;
1153         }
1154
1155         *firmware_p = fw;
1156         return ret;
1157 }
1158
1159 /**
1160  * request_firmware: - send firmware request and wait for it
1161  * @firmware_p: pointer to firmware image
1162  * @name: name of firmware file
1163  * @device: device for which firmware is being loaded
1164  *
1165  *      @firmware_p will be used to return a firmware image by the name
1166  *      of @name for device @device.
1167  *
1168  *      Should be called from user context where sleeping is allowed.
1169  *
1170  *      @name will be used as $FIRMWARE in the uevent environment and
1171  *      should be distinctive enough not to be confused with any other
1172  *      firmware image for this or any other device.
1173  *
1174  *      Caller must hold the reference count of @device.
1175  *
1176  *      The function can be called safely inside device's suspend and
1177  *      resume callback.
1178  **/
1179 int
1180 request_firmware(const struct firmware **firmware_p, const char *name,
1181                  struct device *device)
1182 {
1183         int ret;
1184
1185         /* Need to pin this module until return */
1186         __module_get(THIS_MODULE);
1187         ret = _request_firmware(firmware_p, name, device,
1188                                 FW_OPT_UEVENT | FW_OPT_FALLBACK);
1189         module_put(THIS_MODULE);
1190         return ret;
1191 }
1192 EXPORT_SYMBOL(request_firmware);
1193
1194 /**
1195  * request_firmware_direct: - load firmware directly without usermode helper
1196  * @firmware_p: pointer to firmware image
1197  * @name: name of firmware file
1198  * @device: device for which firmware is being loaded
1199  *
1200  * This function works pretty much like request_firmware(), but this doesn't
1201  * fall back to usermode helper even if the firmware couldn't be loaded
1202  * directly from fs.  Hence it's useful for loading optional firmwares, which
1203  * aren't always present, without extra long timeouts of udev.
1204  **/
1205 int request_firmware_direct(const struct firmware **firmware_p,
1206                             const char *name, struct device *device)
1207 {
1208         int ret;
1209
1210         __module_get(THIS_MODULE);
1211         ret = _request_firmware(firmware_p, name, device,
1212                                 FW_OPT_UEVENT | FW_OPT_NO_WARN);
1213         module_put(THIS_MODULE);
1214         return ret;
1215 }
1216 EXPORT_SYMBOL_GPL(request_firmware_direct);
1217
1218 /**
1219  * release_firmware: - release the resource associated with a firmware image
1220  * @fw: firmware resource to release
1221  **/
1222 void release_firmware(const struct firmware *fw)
1223 {
1224         if (fw) {
1225                 if (!fw_is_builtin_firmware(fw))
1226                         firmware_free_data(fw);
1227                 kfree(fw);
1228         }
1229 }
1230 EXPORT_SYMBOL(release_firmware);
1231
1232 /* Async support */
1233 struct firmware_work {
1234         struct work_struct work;
1235         struct module *module;
1236         const char *name;
1237         struct device *device;
1238         void *context;
1239         void (*cont)(const struct firmware *fw, void *context);
1240         unsigned int opt_flags;
1241 };
1242
1243 static void request_firmware_work_func(struct work_struct *work)
1244 {
1245         struct firmware_work *fw_work;
1246         const struct firmware *fw;
1247
1248         fw_work = container_of(work, struct firmware_work, work);
1249
1250         _request_firmware(&fw, fw_work->name, fw_work->device,
1251                           fw_work->opt_flags);
1252         fw_work->cont(fw, fw_work->context);
1253         put_device(fw_work->device); /* taken in request_firmware_nowait() */
1254
1255         module_put(fw_work->module);
1256         kfree_const(fw_work->name);
1257         kfree(fw_work);
1258 }
1259
1260 /**
1261  * request_firmware_nowait - asynchronous version of request_firmware
1262  * @module: module requesting the firmware
1263  * @uevent: sends uevent to copy the firmware image if this flag
1264  *      is non-zero else the firmware copy must be done manually.
1265  * @name: name of firmware file
1266  * @device: device for which firmware is being loaded
1267  * @gfp: allocation flags
1268  * @context: will be passed over to @cont, and
1269  *      @fw may be %NULL if firmware request fails.
1270  * @cont: function will be called asynchronously when the firmware
1271  *      request is over.
1272  *
1273  *      Caller must hold the reference count of @device.
1274  *
1275  *      Asynchronous variant of request_firmware() for user contexts:
1276  *              - sleep for as small periods as possible since it may
1277  *              increase kernel boot time of built-in device drivers
1278  *              requesting firmware in their ->probe() methods, if
1279  *              @gfp is GFP_KERNEL.
1280  *
1281  *              - can't sleep at all if @gfp is GFP_ATOMIC.
1282  **/
1283 int
1284 request_firmware_nowait(
1285         struct module *module, bool uevent,
1286         const char *name, struct device *device, gfp_t gfp, void *context,
1287         void (*cont)(const struct firmware *fw, void *context))
1288 {
1289         struct firmware_work *fw_work;
1290
1291         fw_work = kzalloc(sizeof(struct firmware_work), gfp);
1292         if (!fw_work)
1293                 return -ENOMEM;
1294
1295         fw_work->module = module;
1296         fw_work->name = kstrdup_const(name, gfp);
1297         if (!fw_work->name) {
1298                 kfree(fw_work);
1299                 return -ENOMEM;
1300         }
1301         fw_work->device = device;
1302         fw_work->context = context;
1303         fw_work->cont = cont;
1304         fw_work->opt_flags = FW_OPT_NOWAIT | FW_OPT_FALLBACK |
1305                 (uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
1306
1307         if (!try_module_get(module)) {
1308                 kfree_const(fw_work->name);
1309                 kfree(fw_work);
1310                 return -EFAULT;
1311         }
1312
1313         get_device(fw_work->device);
1314         INIT_WORK(&fw_work->work, request_firmware_work_func);
1315         schedule_work(&fw_work->work);
1316         return 0;
1317 }
1318 EXPORT_SYMBOL(request_firmware_nowait);
1319
1320 #ifdef CONFIG_PM_SLEEP
1321 static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
1322
1323 /**
1324  * cache_firmware - cache one firmware image in kernel memory space
1325  * @fw_name: the firmware image name
1326  *
1327  * Cache firmware in kernel memory so that drivers can use it when
1328  * system isn't ready for them to request firmware image from userspace.
1329  * Once it returns successfully, driver can use request_firmware or its
1330  * nowait version to get the cached firmware without any interacting
1331  * with userspace
1332  *
1333  * Return 0 if the firmware image has been cached successfully
1334  * Return !0 otherwise
1335  *
1336  */
1337 static int cache_firmware(const char *fw_name)
1338 {
1339         int ret;
1340         const struct firmware *fw;
1341
1342         pr_debug("%s: %s\n", __func__, fw_name);
1343
1344         ret = request_firmware(&fw, fw_name, NULL);
1345         if (!ret)
1346                 kfree(fw);
1347
1348         pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
1349
1350         return ret;
1351 }
1352
1353 static struct firmware_buf *fw_lookup_buf(const char *fw_name)
1354 {
1355         struct firmware_buf *tmp;
1356         struct firmware_cache *fwc = &fw_cache;
1357
1358         spin_lock(&fwc->lock);
1359         tmp = __fw_lookup_buf(fw_name);
1360         spin_unlock(&fwc->lock);
1361
1362         return tmp;
1363 }
1364
1365 /**
1366  * uncache_firmware - remove one cached firmware image
1367  * @fw_name: the firmware image name
1368  *
1369  * Uncache one firmware image which has been cached successfully
1370  * before.
1371  *
1372  * Return 0 if the firmware cache has been removed successfully
1373  * Return !0 otherwise
1374  *
1375  */
1376 static int uncache_firmware(const char *fw_name)
1377 {
1378         struct firmware_buf *buf;
1379         struct firmware fw;
1380
1381         pr_debug("%s: %s\n", __func__, fw_name);
1382
1383         if (fw_get_builtin_firmware(&fw, fw_name))
1384                 return 0;
1385
1386         buf = fw_lookup_buf(fw_name);
1387         if (buf) {
1388                 fw_free_buf(buf);
1389                 return 0;
1390         }
1391
1392         return -EINVAL;
1393 }
1394
1395 static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
1396 {
1397         struct fw_cache_entry *fce;
1398
1399         fce = kzalloc(sizeof(*fce), GFP_ATOMIC);
1400         if (!fce)
1401                 goto exit;
1402
1403         fce->name = kstrdup_const(name, GFP_ATOMIC);
1404         if (!fce->name) {
1405                 kfree(fce);
1406                 fce = NULL;
1407                 goto exit;
1408         }
1409 exit:
1410         return fce;
1411 }
1412
1413 static int __fw_entry_found(const char *name)
1414 {
1415         struct firmware_cache *fwc = &fw_cache;
1416         struct fw_cache_entry *fce;
1417
1418         list_for_each_entry(fce, &fwc->fw_names, list) {
1419                 if (!strcmp(fce->name, name))
1420                         return 1;
1421         }
1422         return 0;
1423 }
1424
1425 static int fw_cache_piggyback_on_request(const char *name)
1426 {
1427         struct firmware_cache *fwc = &fw_cache;
1428         struct fw_cache_entry *fce;
1429         int ret = 0;
1430
1431         spin_lock(&fwc->name_lock);
1432         if (__fw_entry_found(name))
1433                 goto found;
1434
1435         fce = alloc_fw_cache_entry(name);
1436         if (fce) {
1437                 ret = 1;
1438                 list_add(&fce->list, &fwc->fw_names);
1439                 pr_debug("%s: fw: %s\n", __func__, name);
1440         }
1441 found:
1442         spin_unlock(&fwc->name_lock);
1443         return ret;
1444 }
1445
1446 static void free_fw_cache_entry(struct fw_cache_entry *fce)
1447 {
1448         kfree_const(fce->name);
1449         kfree(fce);
1450 }
1451
1452 static void __async_dev_cache_fw_image(void *fw_entry,
1453                                        async_cookie_t cookie)
1454 {
1455         struct fw_cache_entry *fce = fw_entry;
1456         struct firmware_cache *fwc = &fw_cache;
1457         int ret;
1458
1459         ret = cache_firmware(fce->name);
1460         if (ret) {
1461                 spin_lock(&fwc->name_lock);
1462                 list_del(&fce->list);
1463                 spin_unlock(&fwc->name_lock);
1464
1465                 free_fw_cache_entry(fce);
1466         }
1467 }
1468
1469 /* called with dev->devres_lock held */
1470 static void dev_create_fw_entry(struct device *dev, void *res,
1471                                 void *data)
1472 {
1473         struct fw_name_devm *fwn = res;
1474         const char *fw_name = fwn->name;
1475         struct list_head *head = data;
1476         struct fw_cache_entry *fce;
1477
1478         fce = alloc_fw_cache_entry(fw_name);
1479         if (fce)
1480                 list_add(&fce->list, head);
1481 }
1482
1483 static int devm_name_match(struct device *dev, void *res,
1484                            void *match_data)
1485 {
1486         struct fw_name_devm *fwn = res;
1487         return (fwn->magic == (unsigned long)match_data);
1488 }
1489
1490 static void dev_cache_fw_image(struct device *dev, void *data)
1491 {
1492         LIST_HEAD(todo);
1493         struct fw_cache_entry *fce;
1494         struct fw_cache_entry *fce_next;
1495         struct firmware_cache *fwc = &fw_cache;
1496
1497         devres_for_each_res(dev, fw_name_devm_release,
1498                             devm_name_match, &fw_cache,
1499                             dev_create_fw_entry, &todo);
1500
1501         list_for_each_entry_safe(fce, fce_next, &todo, list) {
1502                 list_del(&fce->list);
1503
1504                 spin_lock(&fwc->name_lock);
1505                 /* only one cache entry for one firmware */
1506                 if (!__fw_entry_found(fce->name)) {
1507                         list_add(&fce->list, &fwc->fw_names);
1508                 } else {
1509                         free_fw_cache_entry(fce);
1510                         fce = NULL;
1511                 }
1512                 spin_unlock(&fwc->name_lock);
1513
1514                 if (fce)
1515                         async_schedule_domain(__async_dev_cache_fw_image,
1516                                               (void *)fce,
1517                                               &fw_cache_domain);
1518         }
1519 }
1520
1521 static void __device_uncache_fw_images(void)
1522 {
1523         struct firmware_cache *fwc = &fw_cache;
1524         struct fw_cache_entry *fce;
1525
1526         spin_lock(&fwc->name_lock);
1527         while (!list_empty(&fwc->fw_names)) {
1528                 fce = list_entry(fwc->fw_names.next,
1529                                 struct fw_cache_entry, list);
1530                 list_del(&fce->list);
1531                 spin_unlock(&fwc->name_lock);
1532
1533                 uncache_firmware(fce->name);
1534                 free_fw_cache_entry(fce);
1535
1536                 spin_lock(&fwc->name_lock);
1537         }
1538         spin_unlock(&fwc->name_lock);
1539 }
1540
1541 /**
1542  * device_cache_fw_images - cache devices' firmware
1543  *
1544  * If one device called request_firmware or its nowait version
1545  * successfully before, the firmware names are recored into the
1546  * device's devres link list, so device_cache_fw_images can call
1547  * cache_firmware() to cache these firmwares for the device,
1548  * then the device driver can load its firmwares easily at
1549  * time when system is not ready to complete loading firmware.
1550  */
1551 static void device_cache_fw_images(void)
1552 {
1553         struct firmware_cache *fwc = &fw_cache;
1554         int old_timeout;
1555         DEFINE_WAIT(wait);
1556
1557         pr_debug("%s\n", __func__);
1558
1559         /* cancel uncache work */
1560         cancel_delayed_work_sync(&fwc->work);
1561
1562         /*
1563          * use small loading timeout for caching devices' firmware
1564          * because all these firmware images have been loaded
1565          * successfully at lease once, also system is ready for
1566          * completing firmware loading now. The maximum size of
1567          * firmware in current distributions is about 2M bytes,
1568          * so 10 secs should be enough.
1569          */
1570         old_timeout = loading_timeout;
1571         loading_timeout = 10;
1572
1573         mutex_lock(&fw_lock);
1574         fwc->state = FW_LOADER_START_CACHE;
1575         dpm_for_each_dev(NULL, dev_cache_fw_image);
1576         mutex_unlock(&fw_lock);
1577
1578         /* wait for completion of caching firmware for all devices */
1579         async_synchronize_full_domain(&fw_cache_domain);
1580
1581         loading_timeout = old_timeout;
1582 }
1583
1584 /**
1585  * device_uncache_fw_images - uncache devices' firmware
1586  *
1587  * uncache all firmwares which have been cached successfully
1588  * by device_uncache_fw_images earlier
1589  */
1590 static void device_uncache_fw_images(void)
1591 {
1592         pr_debug("%s\n", __func__);
1593         __device_uncache_fw_images();
1594 }
1595
1596 static void device_uncache_fw_images_work(struct work_struct *work)
1597 {
1598         device_uncache_fw_images();
1599 }
1600
1601 /**
1602  * device_uncache_fw_images_delay - uncache devices firmwares
1603  * @delay: number of milliseconds to delay uncache device firmwares
1604  *
1605  * uncache all devices's firmwares which has been cached successfully
1606  * by device_cache_fw_images after @delay milliseconds.
1607  */
1608 static void device_uncache_fw_images_delay(unsigned long delay)
1609 {
1610         queue_delayed_work(system_power_efficient_wq, &fw_cache.work,
1611                            msecs_to_jiffies(delay));
1612 }
1613
1614 static int fw_pm_notify(struct notifier_block *notify_block,
1615                         unsigned long mode, void *unused)
1616 {
1617         switch (mode) {
1618         case PM_HIBERNATION_PREPARE:
1619         case PM_SUSPEND_PREPARE:
1620         case PM_RESTORE_PREPARE:
1621                 kill_requests_without_uevent();
1622                 device_cache_fw_images();
1623                 break;
1624
1625         case PM_POST_SUSPEND:
1626         case PM_POST_HIBERNATION:
1627         case PM_POST_RESTORE:
1628                 /*
1629                  * In case that system sleep failed and syscore_suspend is
1630                  * not called.
1631                  */
1632                 mutex_lock(&fw_lock);
1633                 fw_cache.state = FW_LOADER_NO_CACHE;
1634                 mutex_unlock(&fw_lock);
1635
1636                 device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
1637                 break;
1638         }
1639
1640         return 0;
1641 }
1642
1643 /* stop caching firmware once syscore_suspend is reached */
1644 static int fw_suspend(void)
1645 {
1646         fw_cache.state = FW_LOADER_NO_CACHE;
1647         return 0;
1648 }
1649
1650 static struct syscore_ops fw_syscore_ops = {
1651         .suspend = fw_suspend,
1652 };
1653 #else
1654 static int fw_cache_piggyback_on_request(const char *name)
1655 {
1656         return 0;
1657 }
1658 #endif
1659
1660 static void __init fw_cache_init(void)
1661 {
1662         spin_lock_init(&fw_cache.lock);
1663         INIT_LIST_HEAD(&fw_cache.head);
1664         fw_cache.state = FW_LOADER_NO_CACHE;
1665
1666 #ifdef CONFIG_PM_SLEEP
1667         spin_lock_init(&fw_cache.name_lock);
1668         INIT_LIST_HEAD(&fw_cache.fw_names);
1669
1670         INIT_DELAYED_WORK(&fw_cache.work,
1671                           device_uncache_fw_images_work);
1672
1673         fw_cache.pm_notify.notifier_call = fw_pm_notify;
1674         register_pm_notifier(&fw_cache.pm_notify);
1675
1676         register_syscore_ops(&fw_syscore_ops);
1677 #endif
1678 }
1679
1680 static int __init firmware_class_init(void)
1681 {
1682         fw_cache_init();
1683 #ifdef CONFIG_FW_LOADER_USER_HELPER
1684         register_reboot_notifier(&fw_shutdown_nb);
1685         return class_register(&firmware_class);
1686 #else
1687         return 0;
1688 #endif
1689 }
1690
1691 static void __exit firmware_class_exit(void)
1692 {
1693 #ifdef CONFIG_PM_SLEEP
1694         unregister_syscore_ops(&fw_syscore_ops);
1695         unregister_pm_notifier(&fw_cache.pm_notify);
1696 #endif
1697 #ifdef CONFIG_FW_LOADER_USER_HELPER
1698         unregister_reboot_notifier(&fw_shutdown_nb);
1699         class_unregister(&firmware_class);
1700 #endif
1701 }
1702
1703 fs_initcall(firmware_class_init);
1704 module_exit(firmware_class_exit);