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