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                                     void *buf, size_t size)
  51 {
  52         struct builtin_fw *b_fw;
  53
  54         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
  55                 if (strcmp(name, b_fw->name) == 0) {
  56                         fw->size = b_fw->size;
  57                         fw->data = b_fw->data;
  58
  59                         if (buf && fw->size <= size)
  60                                 memcpy(buf, fw->data, fw->size);
  61                         return true;
  62                 }
  63         }
  64
  65         return false;
  66 }
  67
  68 static bool fw_is_builtin_firmware(const struct firmware *fw)
  69 {
  70         struct builtin_fw *b_fw;
  71
  72         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
  73                 if (fw->data == b_fw->data)
  74                         return true;
  75
  76         return false;
  77 }
  78
  79 #else /* Module case - no builtin firmware support */
  80
  81 static inline bool fw_get_builtin_firmware(struct firmware *fw,
  82                                            const char *name, void *buf,
  83                                            size_t size)
  84 {
  85         return false;
  86 }
  87
  88 static inline bool fw_is_builtin_firmware(const struct firmware *fw)
  89 {
  90         return false;
  91 }
  92 #endif
  93
  94 enum {
  95         FW_STATUS_LOADING,
  96         FW_STATUS_DONE,
  97         FW_STATUS_ABORT,
  98 };
  99
 100 static int loading_timeout = 60;        /* In seconds */
 101
 102 static inline long firmware_loading_timeout(void)
 103 {
 104         return loading_timeout > 0 ? loading_timeout * HZ : MAX_JIFFY_OFFSET;
 105 }
 106
 107 /* firmware behavior options */
 108 #define FW_OPT_UEVENT   (1U << 0)
 109 #define FW_OPT_NOWAIT   (1U << 1)
 110 #ifdef CONFIG_FW_LOADER_USER_HELPER
 111 #define FW_OPT_USERHELPER       (1U << 2)
 112 #else
 113 #define FW_OPT_USERHELPER       0
 114 #endif
 115 #ifdef CONFIG_FW_LOADER_USER_HELPER_FALLBACK
 116 #define FW_OPT_FALLBACK         FW_OPT_USERHELPER
 117 #else
 118 #define FW_OPT_FALLBACK         0
 119 #endif
 120 #define FW_OPT_NO_WARN  (1U << 3)
 121 #define FW_OPT_NOCACHE  (1U << 4)
 122
 123 struct firmware_cache {
 124         /* firmware_buf instance will be added into the below list */
 125         spinlock_t lock;
 126         struct list_head head;
 127         int state;
 128
 129 #ifdef CONFIG_PM_SLEEP
 130         /*
 131          * Names of firmware images which have been cached successfully
 132          * will be added into the below list so that device uncache
 133          * helper can trace which firmware images have been cached
 134          * before.
 135          */
 136         spinlock_t name_lock;
 137         struct list_head fw_names;
 138
 139         struct delayed_work work;
 140
 141         struct notifier_block   pm_notify;
 142 #endif
 143 };
 144
 145 struct firmware_buf {
 146         struct kref ref;
 147         struct list_head list;
 148         struct completion completion;
 149         struct firmware_cache *fwc;
 150         unsigned long status;
 151         void *data;
 152         size_t size;
 153         size_t allocated_size;
 154 #ifdef CONFIG_FW_LOADER_USER_HELPER
 155         bool is_paged_buf;
 156         bool need_uevent;
 157         struct page **pages;
 158         int nr_pages;
 159         int page_array_size;
 160         struct list_head pending_list;
 161 #endif
 162         const char *fw_id;
 163 };
 164
 165 struct fw_cache_entry {
 166         struct list_head list;
 167         const char *name;
 168 };
 169
 170 struct fw_name_devm {
 171         unsigned long magic;
 172         const char *name;
 173 };
 174
 175 #define to_fwbuf(d) container_of(d, struct firmware_buf, ref)
 176
 177 #define FW_LOADER_NO_CACHE      0
 178 #define FW_LOADER_START_CACHE   1
 179
 180 static int fw_cache_piggyback_on_request(const char *name);
 181
 182 /* fw_lock could be moved to 'struct firmware_priv' but since it is just
 183  * guarding for corner cases a global lock should be OK */
 184 static DEFINE_MUTEX(fw_lock);
 185
 186 static struct firmware_cache fw_cache;
 187
 188 static struct firmware_buf *__allocate_fw_buf(const char *fw_name,
 189                                               struct firmware_cache *fwc,
 190                                               void *dbuf, size_t size)
 191 {
 192         struct firmware_buf *buf;
 193
 194         buf = kzalloc(sizeof(*buf), GFP_ATOMIC);
 195         if (!buf)
 196                 return NULL;
 197
 198         buf->fw_id = kstrdup_const(fw_name, GFP_ATOMIC);
 199         if (!buf->fw_id) {
 200                 kfree(buf);
 201                 return NULL;
 202         }
 203
 204         kref_init(&buf->ref);
 205         buf->fwc = fwc;
 206         buf->data = dbuf;
 207         buf->allocated_size = size;
 208         init_completion(&buf->completion);
 209 #ifdef CONFIG_FW_LOADER_USER_HELPER
 210         INIT_LIST_HEAD(&buf->pending_list);
 211 #endif
 212
 213         pr_debug("%s: fw-%s buf=%p\n", __func__, fw_name, buf);
 214
 215         return buf;
 216 }
 217
 218 static struct firmware_buf *__fw_lookup_buf(const char *fw_name)
 219 {
 220         struct firmware_buf *tmp;
 221         struct firmware_cache *fwc = &fw_cache;
 222
 223         list_for_each_entry(tmp, &fwc->head, list)
 224                 if (!strcmp(tmp->fw_id, fw_name))
 225                         return tmp;
 226         return NULL;
 227 }
 228
 229 static int fw_lookup_and_allocate_buf(const char *fw_name,
 230                                       struct firmware_cache *fwc,
 231                                       struct firmware_buf **buf, void *dbuf,
 232                                       size_t size)
 233 {
 234         struct firmware_buf *tmp;
 235
 236         spin_lock(&fwc->lock);
 237         tmp = __fw_lookup_buf(fw_name);
 238         if (tmp) {
 239                 kref_get(&tmp->ref);
 240                 spin_unlock(&fwc->lock);
 241                 *buf = tmp;
 242                 return 1;
 243         }
 244         tmp = __allocate_fw_buf(fw_name, fwc, dbuf, size);
 245         if (tmp)
 246                 list_add(&tmp->list, &fwc->head);
 247         spin_unlock(&fwc->lock);
 248
 249         *buf = tmp;
 250
 251         return tmp ? 0 : -ENOMEM;
 252 }
 253
 254 static void __fw_free_buf(struct kref *ref)
 255         __releases(&fwc->lock)
 256 {
 257         struct firmware_buf *buf = to_fwbuf(ref);
 258         struct firmware_cache *fwc = buf->fwc;
 259
 260         pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
 261                  __func__, buf->fw_id, buf, buf->data,
 262                  (unsigned int)buf->size);
 263
 264         list_del(&buf->list);
 265         spin_unlock(&fwc->lock);
 266
 267 #ifdef CONFIG_FW_LOADER_USER_HELPER
 268         if (buf->is_paged_buf) {
 269                 int i;
 270                 vunmap(buf->data);
 271                 for (i = 0; i < buf->nr_pages; i++)
 272                         __free_page(buf->pages[i]);
 273                 vfree(buf->pages);
 274         } else
 275 #endif
 276         if (!buf->allocated_size)
 277                 vfree(buf->data);
 278         kfree_const(buf->fw_id);
 279         kfree(buf);
 280 }
 281
 282 static void fw_free_buf(struct firmware_buf *buf)
 283 {
 284         struct firmware_cache *fwc = buf->fwc;
 285         spin_lock(&fwc->lock);
 286         if (!kref_put(&buf->ref, __fw_free_buf))
 287                 spin_unlock(&fwc->lock);
 288 }
 289
 290 /* direct firmware loading support */
 291 static char fw_path_para[256];
 292 static const char * const fw_path[] = {
 293         fw_path_para,
 294         "/lib/firmware/updates/" UTS_RELEASE,
 295         "/lib/firmware/updates",
 296         "/lib/firmware/" UTS_RELEASE,
 297         "/lib/firmware"
 298 };
 299
 300 /*
 301  * Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH'
 302  * from kernel command line because firmware_class is generally built in
 303  * kernel instead of module.
 304  */
 305 module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
 306 MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
 307
 308 static void fw_finish_direct_load(struct device *device,
 309                                   struct firmware_buf *buf)
 310 {
 311         mutex_lock(&fw_lock);
 312         set_bit(FW_STATUS_DONE, &buf->status);
 313         complete_all(&buf->completion);
 314         mutex_unlock(&fw_lock);
 315 }
 316
 317 static int
 318 fw_get_filesystem_firmware(struct device *device, struct firmware_buf *buf)
 319 {
 320         loff_t size;
 321         int i, len;
 322         int rc = -ENOENT;
 323         char *path;
 324         enum kernel_read_file_id id = READING_FIRMWARE;
 325         size_t msize = INT_MAX;
 326
 327         /* Already populated data member means we're loading into a buffer */
 328         if (buf->data) {
 329                 id = READING_FIRMWARE_PREALLOC_BUFFER;
 330                 msize = buf->allocated_size;
 331         }
 332
 333         path = __getname();
 334         if (!path)
 335                 return -ENOMEM;
 336
 337         for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
 338                 /* skip the unset customized path */
 339                 if (!fw_path[i][0])
 340                         continue;
 341
 342                 len = snprintf(path, PATH_MAX, "%s/%s",
 343                                fw_path[i], buf->fw_id);
 344                 if (len >= PATH_MAX) {
 345                         rc = -ENAMETOOLONG;
 346                         break;
 347                 }
 348
 349                 buf->size = 0;
 350                 rc = kernel_read_file_from_path(path, &buf->data, &size, msize,
 351                                                 id);
 352                 if (rc) {
 353                         if (rc == -ENOENT)
 354                                 dev_dbg(device, "loading %s failed with error %d\n",
 355                                          path, rc);
 356                         else
 357                                 dev_warn(device, "loading %s failed with error %d\n",
 358                                          path, rc);
 359                         continue;
 360                 }
 361                 dev_dbg(device, "direct-loading %s\n", buf->fw_id);
 362                 buf->size = size;
 363                 fw_finish_direct_load(device, buf);
 364                 break;
 365         }
 366         __putname(path);
 367
 368         return rc;
 369 }
 370
 371 /* firmware holds the ownership of pages */
 372 static void firmware_free_data(const struct firmware *fw)
 373 {
 374         /* Loaded directly? */
 375         if (!fw->priv) {
 376                 vfree(fw->data);
 377                 return;
 378         }
 379         fw_free_buf(fw->priv);
 380 }
 381
 382 /* store the pages buffer info firmware from buf */
 383 static void fw_set_page_data(struct firmware_buf *buf, struct firmware *fw)
 384 {
 385         fw->priv = buf;
 386 #ifdef CONFIG_FW_LOADER_USER_HELPER
 387         fw->pages = buf->pages;
 388 #endif
 389         fw->size = buf->size;
 390         fw->data = buf->data;
 391
 392         pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
 393                  __func__, buf->fw_id, buf, buf->data,
 394                  (unsigned int)buf->size);
 395 }
 396
 397 #ifdef CONFIG_PM_SLEEP
 398 static void fw_name_devm_release(struct device *dev, void *res)
 399 {
 400         struct fw_name_devm *fwn = res;
 401
 402         if (fwn->magic == (unsigned long)&fw_cache)
 403                 pr_debug("%s: fw_name-%s devm-%p released\n",
 404                                 __func__, fwn->name, res);
 405         kfree_const(fwn->name);
 406 }
 407
 408 static int fw_devm_match(struct device *dev, void *res,
 409                 void *match_data)
 410 {
 411         struct fw_name_devm *fwn = res;
 412
 413         return (fwn->magic == (unsigned long)&fw_cache) &&
 414                 !strcmp(fwn->name, match_data);
 415 }
 416
 417 static struct fw_name_devm *fw_find_devm_name(struct device *dev,
 418                 const char *name)
 419 {
 420         struct fw_name_devm *fwn;
 421
 422         fwn = devres_find(dev, fw_name_devm_release,
 423                           fw_devm_match, (void *)name);
 424         return fwn;
 425 }
 426
 427 /* add firmware name into devres list */
 428 static int fw_add_devm_name(struct device *dev, const char *name)
 429 {
 430         struct fw_name_devm *fwn;
 431
 432         fwn = fw_find_devm_name(dev, name);
 433         if (fwn)
 434                 return 1;
 435
 436         fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm),
 437                            GFP_KERNEL);
 438         if (!fwn)
 439                 return -ENOMEM;
 440         fwn->name = kstrdup_const(name, GFP_KERNEL);
 441         if (!fwn->name) {
 442                 devres_free(fwn);
 443                 return -ENOMEM;
 444         }
 445
 446         fwn->magic = (unsigned long)&fw_cache;
 447         devres_add(dev, fwn);
 448
 449         return 0;
 450 }
 451 #else
 452 static int fw_add_devm_name(struct device *dev, const char *name)
 453 {
 454         return 0;
 455 }
 456 #endif
 457
 458
 459 /*
 460  * user-mode helper code
 461  */
 462 #ifdef CONFIG_FW_LOADER_USER_HELPER
 463 struct firmware_priv {
 464         bool nowait;
 465         struct device dev;
 466         struct firmware_buf *buf;
 467         struct firmware *fw;
 468 };
 469
 470 static struct firmware_priv *to_firmware_priv(struct device *dev)
 471 {
 472         return container_of(dev, struct firmware_priv, dev);
 473 }
 474
 475 static void __fw_load_abort(struct firmware_buf *buf)
 476 {
 477         /*
 478          * There is a small window in which user can write to 'loading'
 479          * between loading done and disappearance of 'loading'
 480          */
 481         if (test_bit(FW_STATUS_DONE, &buf->status))
 482                 return;
 483
 484         list_del_init(&buf->pending_list);
 485         set_bit(FW_STATUS_ABORT, &buf->status);
 486         complete_all(&buf->completion);
 487 }
 488
 489 static void fw_load_abort(struct firmware_priv *fw_priv)
 490 {
 491         struct firmware_buf *buf = fw_priv->buf;
 492
 493         __fw_load_abort(buf);
 494
 495         /* avoid user action after loading abort */
 496         fw_priv->buf = NULL;
 497 }
 498
 499 #define is_fw_load_aborted(buf) \
 500         test_bit(FW_STATUS_ABORT, &(buf)->status)
 501
 502 static LIST_HEAD(pending_fw_head);
 503
 504 /* reboot notifier for avoid deadlock with usermode_lock */
 505 static int fw_shutdown_notify(struct notifier_block *unused1,
 506                               unsigned long unused2, void *unused3)
 507 {
 508         mutex_lock(&fw_lock);
 509         while (!list_empty(&pending_fw_head))
 510                 __fw_load_abort(list_first_entry(&pending_fw_head,
 511                                                struct firmware_buf,
 512                                                pending_list));
 513         mutex_unlock(&fw_lock);
 514         return NOTIFY_DONE;
 515 }
 516
 517 static struct notifier_block fw_shutdown_nb = {
 518         .notifier_call = fw_shutdown_notify,
 519 };
 520
 521 static ssize_t timeout_show(struct class *class, struct class_attribute *attr,
 522                             char *buf)
 523 {
 524         return sprintf(buf, "%d\n", loading_timeout);
 525 }
 526
 527 /**
 528  * firmware_timeout_store - set number of seconds to wait for firmware
 529  * @class: device class pointer
 530  * @attr: device attribute pointer
 531  * @buf: buffer to scan for timeout value
 532  * @count: number of bytes in @buf
 533  *
 534  *      Sets the number of seconds to wait for the firmware.  Once
 535  *      this expires an error will be returned to the driver and no
 536  *      firmware will be provided.
 537  *
 538  *      Note: zero means 'wait forever'.
 539  **/
 540 static ssize_t timeout_store(struct class *class, struct class_attribute *attr,
 541                              const char *buf, size_t count)
 542 {
 543         loading_timeout = simple_strtol(buf, NULL, 10);
 544         if (loading_timeout < 0)
 545                 loading_timeout = 0;
 546
 547         return count;
 548 }
 549
 550 static struct class_attribute firmware_class_attrs[] = {
 551         __ATTR_RW(timeout),
 552         __ATTR_NULL
 553 };
 554
 555 static void fw_dev_release(struct device *dev)
 556 {
 557         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 558
 559         kfree(fw_priv);
 560 }
 561
 562 static int do_firmware_uevent(struct firmware_priv *fw_priv, struct kobj_uevent_env *env)
 563 {
 564         if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->buf->fw_id))
 565                 return -ENOMEM;
 566         if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
 567                 return -ENOMEM;
 568         if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
 569                 return -ENOMEM;
 570
 571         return 0;
 572 }
 573
 574 static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
 575 {
 576         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 577         int err = 0;
 578
 579         mutex_lock(&fw_lock);
 580         if (fw_priv->buf)
 581                 err = do_firmware_uevent(fw_priv, env);
 582         mutex_unlock(&fw_lock);
 583         return err;
 584 }
 585
 586 static struct class firmware_class = {
 587         .name           = "firmware",
 588         .class_attrs    = firmware_class_attrs,
 589         .dev_uevent     = firmware_uevent,
 590         .dev_release    = fw_dev_release,
 591 };
 592
 593 static ssize_t firmware_loading_show(struct device *dev,
 594                                      struct device_attribute *attr, char *buf)
 595 {
 596         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 597         int loading = 0;
 598
 599         mutex_lock(&fw_lock);
 600         if (fw_priv->buf)
 601                 loading = test_bit(FW_STATUS_LOADING, &fw_priv->buf->status);
 602         mutex_unlock(&fw_lock);
 603
 604         return sprintf(buf, "%d\n", loading);
 605 }
 606
 607 /* Some architectures don't have PAGE_KERNEL_RO */
 608 #ifndef PAGE_KERNEL_RO
 609 #define PAGE_KERNEL_RO PAGE_KERNEL
 610 #endif
 611
 612 /* one pages buffer should be mapped/unmapped only once */
 613 static int fw_map_pages_buf(struct firmware_buf *buf)
 614 {
 615         if (!buf->is_paged_buf)
 616                 return 0;
 617
 618         vunmap(buf->data);
 619         buf->data = vmap(buf->pages, buf->nr_pages, 0, PAGE_KERNEL_RO);
 620         if (!buf->data)
 621                 return -ENOMEM;
 622         return 0;
 623 }
 624
 625 /**
 626  * firmware_loading_store - set value in the 'loading' control file
 627  * @dev: device pointer
 628  * @attr: device attribute pointer
 629  * @buf: buffer to scan for loading control value
 630  * @count: number of bytes in @buf
 631  *
 632  *      The relevant values are:
 633  *
 634  *       1: Start a load, discarding any previous partial load.
 635  *       0: Conclude the load and hand the data to the driver code.
 636  *      -1: Conclude the load with an error and discard any written data.
 637  **/
 638 static ssize_t firmware_loading_store(struct device *dev,
 639                                       struct device_attribute *attr,
 640                                       const char *buf, size_t count)
 641 {
 642         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 643         struct firmware_buf *fw_buf;
 644         ssize_t written = count;
 645         int loading = simple_strtol(buf, NULL, 10);
 646         int i;
 647
 648         mutex_lock(&fw_lock);
 649         fw_buf = fw_priv->buf;
 650         if (!fw_buf)
 651                 goto out;
 652
 653         switch (loading) {
 654         case 1:
 655                 /* discarding any previous partial load */
 656                 if (!test_bit(FW_STATUS_DONE, &fw_buf->status)) {
 657                         for (i = 0; i < fw_buf->nr_pages; i++)
 658                                 __free_page(fw_buf->pages[i]);
 659                         vfree(fw_buf->pages);
 660                         fw_buf->pages = NULL;
 661                         fw_buf->page_array_size = 0;
 662                         fw_buf->nr_pages = 0;
 663                         set_bit(FW_STATUS_LOADING, &fw_buf->status);
 664                 }
 665                 break;
 666         case 0:
 667                 if (test_bit(FW_STATUS_LOADING, &fw_buf->status)) {
 668                         int rc;
 669
 670                         set_bit(FW_STATUS_DONE, &fw_buf->status);
 671                         clear_bit(FW_STATUS_LOADING, &fw_buf->status);
 672
 673                         /*
 674                          * Several loading requests may be pending on
 675                          * one same firmware buf, so let all requests
 676                          * see the mapped 'buf->data' once the loading
 677                          * is completed.
 678                          * */
 679                         rc = fw_map_pages_buf(fw_buf);
 680                         if (rc)
 681                                 dev_err(dev, "%s: map pages failed\n",
 682                                         __func__);
 683                         else
 684                                 rc = security_kernel_post_read_file(NULL,
 685                                                 fw_buf->data, fw_buf->size,
 686                                                 READING_FIRMWARE);
 687
 688                         /*
 689                          * Same logic as fw_load_abort, only the DONE bit
 690                          * is ignored and we set ABORT only on failure.
 691                          */
 692                         list_del_init(&fw_buf->pending_list);
 693                         if (rc) {
 694                                 set_bit(FW_STATUS_ABORT, &fw_buf->status);
 695                                 written = rc;
 696                         }
 697                         complete_all(&fw_buf->completion);
 698                         break;
 699                 }
 700                 /* fallthrough */
 701         default:
 702                 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
 703                 /* fallthrough */
 704         case -1:
 705                 fw_load_abort(fw_priv);
 706                 break;
 707         }
 708 out:
 709         mutex_unlock(&fw_lock);
 710         return written;
 711 }
 712
 713 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
 714
 715 static void firmware_rw_buf(struct firmware_buf *buf, char *buffer,
 716                            loff_t offset, size_t count, bool read)
 717 {
 718         if (read)
 719                 memcpy(buffer, buf->data + offset, count);
 720         else
 721                 memcpy(buf->data + offset, buffer, count);
 722 }
 723
 724 static void firmware_rw(struct firmware_buf *buf, char *buffer,
 725                         loff_t offset, size_t count, bool read)
 726 {
 727         while (count) {
 728                 void *page_data;
 729                 int page_nr = offset >> PAGE_SHIFT;
 730                 int page_ofs = offset & (PAGE_SIZE-1);
 731                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 732
 733                 page_data = kmap(buf->pages[page_nr]);
 734
 735                 if (read)
 736                         memcpy(buffer, page_data + page_ofs, page_cnt);
 737                 else
 738                         memcpy(page_data + page_ofs, buffer, page_cnt);
 739
 740                 kunmap(buf->pages[page_nr]);
 741                 buffer += page_cnt;
 742                 offset += page_cnt;
 743                 count -= page_cnt;
 744         }
 745 }
 746
 747 static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
 748                                   struct bin_attribute *bin_attr,
 749                                   char *buffer, loff_t offset, size_t count)
 750 {
 751         struct device *dev = kobj_to_dev(kobj);
 752         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 753         struct firmware_buf *buf;
 754         ssize_t ret_count;
 755
 756         mutex_lock(&fw_lock);
 757         buf = fw_priv->buf;
 758         if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) {
 759                 ret_count = -ENODEV;
 760                 goto out;
 761         }
 762         if (offset > buf->size) {
 763                 ret_count = 0;
 764                 goto out;
 765         }
 766         if (count > buf->size - offset)
 767                 count = buf->size - offset;
 768
 769         ret_count = count;
 770
 771         if (buf->data)
 772                 firmware_rw_buf(buf, buffer, offset, count, true);
 773         else
 774                 firmware_rw(buf, buffer, offset, count, true);
 775
 776 out:
 777         mutex_unlock(&fw_lock);
 778         return ret_count;
 779 }
 780
 781 static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
 782 {
 783         struct firmware_buf *buf = fw_priv->buf;
 784         int pages_needed = PAGE_ALIGN(min_size) >> PAGE_SHIFT;
 785
 786         /* If the array of pages is too small, grow it... */
 787         if (buf->page_array_size < pages_needed) {
 788                 int new_array_size = max(pages_needed,
 789                                          buf->page_array_size * 2);
 790                 struct page **new_pages;
 791
 792                 new_pages = vmalloc(new_array_size * sizeof(void *));
 793                 if (!new_pages) {
 794                         fw_load_abort(fw_priv);
 795                         return -ENOMEM;
 796                 }
 797                 memcpy(new_pages, buf->pages,
 798                        buf->page_array_size * sizeof(void *));
 799                 memset(&new_pages[buf->page_array_size], 0, sizeof(void *) *
 800                        (new_array_size - buf->page_array_size));
 801                 vfree(buf->pages);
 802                 buf->pages = new_pages;
 803                 buf->page_array_size = new_array_size;
 804         }
 805
 806         while (buf->nr_pages < pages_needed) {
 807                 buf->pages[buf->nr_pages] =
 808                         alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
 809
 810                 if (!buf->pages[buf->nr_pages]) {
 811                         fw_load_abort(fw_priv);
 812                         return -ENOMEM;
 813                 }
 814                 buf->nr_pages++;
 815         }
 816         return 0;
 817 }
 818
 819 /**
 820  * firmware_data_write - write method for firmware
 821  * @filp: open sysfs file
 822  * @kobj: kobject for the device
 823  * @bin_attr: bin_attr structure
 824  * @buffer: buffer being written
 825  * @offset: buffer offset for write in total data store area
 826  * @count: buffer size
 827  *
 828  *      Data written to the 'data' attribute will be later handed to
 829  *      the driver as a firmware image.
 830  **/
 831 static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,
 832                                    struct bin_attribute *bin_attr,
 833                                    char *buffer, loff_t offset, size_t count)
 834 {
 835         struct device *dev = kobj_to_dev(kobj);
 836         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 837         struct firmware_buf *buf;
 838         ssize_t retval;
 839
 840         if (!capable(CAP_SYS_RAWIO))
 841                 return -EPERM;
 842
 843         mutex_lock(&fw_lock);
 844         buf = fw_priv->buf;
 845         if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) {
 846                 retval = -ENODEV;
 847                 goto out;
 848         }
 849
 850         if (buf->data) {
 851                 if (offset + count > buf->allocated_size) {
 852                         retval = -ENOMEM;
 853                         goto out;
 854                 }
 855                 firmware_rw_buf(buf, buffer, offset, count, false);
 856                 retval = count;
 857         } else {
 858                 retval = fw_realloc_buffer(fw_priv, offset + count);
 859                 if (retval)
 860                         goto out;
 861
 862                 retval = count;
 863                 firmware_rw(buf, buffer, offset, count, false);
 864         }
 865
 866         buf->size = max_t(size_t, offset + count, buf->size);
 867 out:
 868         mutex_unlock(&fw_lock);
 869         return retval;
 870 }
 871
 872 static struct bin_attribute firmware_attr_data = {
 873         .attr = { .name = "data", .mode = 0644 },
 874         .size = 0,
 875         .read = firmware_data_read,
 876         .write = firmware_data_write,
 877 };
 878
 879 static struct attribute *fw_dev_attrs[] = {
 880         &dev_attr_loading.attr,
 881         NULL
 882 };
 883
 884 static struct bin_attribute *fw_dev_bin_attrs[] = {
 885         &firmware_attr_data,
 886         NULL
 887 };
 888
 889 static const struct attribute_group fw_dev_attr_group = {
 890         .attrs = fw_dev_attrs,
 891         .bin_attrs = fw_dev_bin_attrs,
 892 };
 893
 894 static const struct attribute_group *fw_dev_attr_groups[] = {
 895         &fw_dev_attr_group,
 896         NULL
 897 };
 898
 899 static struct firmware_priv *
 900 fw_create_instance(struct firmware *firmware, const char *fw_name,
 901                    struct device *device, unsigned int opt_flags)
 902 {
 903         struct firmware_priv *fw_priv;
 904         struct device *f_dev;
 905
 906         fw_priv = kzalloc(sizeof(*fw_priv), GFP_KERNEL);
 907         if (!fw_priv) {
 908                 fw_priv = ERR_PTR(-ENOMEM);
 909                 goto exit;
 910         }
 911
 912         fw_priv->nowait = !!(opt_flags & FW_OPT_NOWAIT);
 913         fw_priv->fw = firmware;
 914         f_dev = &fw_priv->dev;
 915
 916         device_initialize(f_dev);
 917         dev_set_name(f_dev, "%s", fw_name);
 918         f_dev->parent = device;
 919         f_dev->class = &firmware_class;
 920         f_dev->groups = fw_dev_attr_groups;
 921 exit:
 922         return fw_priv;
 923 }
 924
 925 /* load a firmware via user helper */
 926 static int _request_firmware_load(struct firmware_priv *fw_priv,
 927                                   unsigned int opt_flags, long timeout)
 928 {
 929         int retval = 0;
 930         struct device *f_dev = &fw_priv->dev;
 931         struct firmware_buf *buf = fw_priv->buf;
 932
 933         /* fall back on userspace loading */
 934         if (!buf->data)
 935                 buf->is_paged_buf = true;
 936
 937         dev_set_uevent_suppress(f_dev, true);
 938
 939         retval = device_add(f_dev);
 940         if (retval) {
 941                 dev_err(f_dev, "%s: device_register failed\n", __func__);
 942                 goto err_put_dev;
 943         }
 944
 945         mutex_lock(&fw_lock);
 946         list_add(&buf->pending_list, &pending_fw_head);
 947         mutex_unlock(&fw_lock);
 948
 949         if (opt_flags & FW_OPT_UEVENT) {
 950                 buf->need_uevent = true;
 951                 dev_set_uevent_suppress(f_dev, false);
 952                 dev_dbg(f_dev, "firmware: requesting %s\n", buf->fw_id);
 953                 kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD);
 954         } else {
 955                 timeout = MAX_JIFFY_OFFSET;
 956         }
 957
 958         timeout = wait_for_completion_interruptible_timeout(&buf->completion,
 959                         timeout);
 960         if (timeout == -ERESTARTSYS || !timeout) {
 961                 retval = timeout;
 962                 mutex_lock(&fw_lock);
 963                 fw_load_abort(fw_priv);
 964                 mutex_unlock(&fw_lock);
 965         } else if (timeout > 0) {
 966                 retval = 0;
 967         }
 968
 969         if (is_fw_load_aborted(buf))
 970                 retval = -EAGAIN;
 971         else if (buf->is_paged_buf && !buf->data)
 972                 retval = -ENOMEM;
 973
 974         device_del(f_dev);
 975 err_put_dev:
 976         put_device(f_dev);
 977         return retval;
 978 }
 979
 980 static int fw_load_from_user_helper(struct firmware *firmware,
 981                                     const char *name, struct device *device,
 982                                     unsigned int opt_flags, long timeout)
 983 {
 984         struct firmware_priv *fw_priv;
 985
 986         fw_priv = fw_create_instance(firmware, name, device, opt_flags);
 987         if (IS_ERR(fw_priv))
 988                 return PTR_ERR(fw_priv);
 989
 990         fw_priv->buf = firmware->priv;
 991         return _request_firmware_load(fw_priv, opt_flags, timeout);
 992 }
 993
 994 #ifdef CONFIG_PM_SLEEP
 995 /* kill pending requests without uevent to avoid blocking suspend */
 996 static void kill_requests_without_uevent(void)
 997 {
 998         struct firmware_buf *buf;
 999         struct firmware_buf *next;
1000
1001         mutex_lock(&fw_lock);
1002         list_for_each_entry_safe(buf, next, &pending_fw_head, pending_list) {
1003                 if (!buf->need_uevent)
1004                          __fw_load_abort(buf);
1005         }
1006         mutex_unlock(&fw_lock);
1007 }
1008 #endif
1009
1010 #else /* CONFIG_FW_LOADER_USER_HELPER */
1011 static inline int
1012 fw_load_from_user_helper(struct firmware *firmware, const char *name,
1013                          struct device *device, unsigned int opt_flags,
1014                          long timeout)
1015 {
1016         return -ENOENT;
1017 }
1018
1019 /* No abort during direct loading */
1020 #define is_fw_load_aborted(buf) false
1021
1022 #ifdef CONFIG_PM_SLEEP
1023 static inline void kill_requests_without_uevent(void) { }
1024 #endif
1025
1026 #endif /* CONFIG_FW_LOADER_USER_HELPER */
1027
1028
1029 /* wait until the shared firmware_buf becomes ready (or error) */
1030 static int sync_cached_firmware_buf(struct firmware_buf *buf)
1031 {
1032         int ret = 0;
1033
1034         mutex_lock(&fw_lock);
1035         while (!test_bit(FW_STATUS_DONE, &buf->status)) {
1036                 if (is_fw_load_aborted(buf)) {
1037                         ret = -ENOENT;
1038                         break;
1039                 }
1040                 mutex_unlock(&fw_lock);
1041                 ret = wait_for_completion_interruptible(&buf->completion);
1042                 mutex_lock(&fw_lock);
1043         }
1044         mutex_unlock(&fw_lock);
1045         return ret;
1046 }
1047
1048 /* prepare firmware and firmware_buf structs;
1049  * return 0 if a firmware is already assigned, 1 if need to load one,
1050  * or a negative error code
1051  */
1052 static int
1053 _request_firmware_prepare(struct firmware **firmware_p, const char *name,
1054                           struct device *device, void *dbuf, size_t size)
1055 {
1056         struct firmware *firmware;
1057         struct firmware_buf *buf;
1058         int ret;
1059
1060         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
1061         if (!firmware) {
1062                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
1063                         __func__);
1064                 return -ENOMEM;
1065         }
1066
1067         if (fw_get_builtin_firmware(firmware, name, dbuf, size)) {
1068                 dev_dbg(device, "using built-in %s\n", name);
1069                 return 0; /* assigned */
1070         }
1071
1072         ret = fw_lookup_and_allocate_buf(name, &fw_cache, &buf, dbuf, size);
1073
1074         /*
1075          * bind with 'buf' now to avoid warning in failure path
1076          * of requesting firmware.
1077          */
1078         firmware->priv = buf;
1079
1080         if (ret > 0) {
1081                 ret = sync_cached_firmware_buf(buf);
1082                 if (!ret) {
1083                         fw_set_page_data(buf, firmware);
1084                         return 0; /* assigned */
1085                 }
1086         }
1087
1088         if (ret < 0)
1089                 return ret;
1090         return 1; /* need to load */
1091 }
1092
1093 static int assign_firmware_buf(struct firmware *fw, struct device *device,
1094                                unsigned int opt_flags)
1095 {
1096         struct firmware_buf *buf = fw->priv;
1097
1098         mutex_lock(&fw_lock);
1099         if (!buf->size || is_fw_load_aborted(buf)) {
1100                 mutex_unlock(&fw_lock);
1101                 return -ENOENT;
1102         }
1103
1104         /*
1105          * add firmware name into devres list so that we can auto cache
1106          * and uncache firmware for device.
1107          *
1108          * device may has been deleted already, but the problem
1109          * should be fixed in devres or driver core.
1110          */
1111         /* don't cache firmware handled without uevent */
1112         if (device && (opt_flags & FW_OPT_UEVENT) &&
1113             !(opt_flags & FW_OPT_NOCACHE))
1114                 fw_add_devm_name(device, buf->fw_id);
1115
1116         /*
1117          * After caching firmware image is started, let it piggyback
1118          * on request firmware.
1119          */
1120         if (!(opt_flags & FW_OPT_NOCACHE) &&
1121             buf->fwc->state == FW_LOADER_START_CACHE) {
1122                 if (fw_cache_piggyback_on_request(buf->fw_id))
1123                         kref_get(&buf->ref);
1124         }
1125
1126         /* pass the pages buffer to driver at the last minute */
1127         fw_set_page_data(buf, fw);
1128         mutex_unlock(&fw_lock);
1129         return 0;
1130 }
1131
1132 /* called from request_firmware() and request_firmware_work_func() */
1133 static int
1134 _request_firmware(const struct firmware **firmware_p, const char *name,
1135                   struct device *device, void *buf, size_t size,
1136                   unsigned int opt_flags)
1137 {
1138         struct firmware *fw = NULL;
1139         long timeout;
1140         int ret;
1141
1142         if (!firmware_p)
1143                 return -EINVAL;
1144
1145         if (!name || name[0] == '\0') {
1146                 ret = -EINVAL;
1147                 goto out;
1148         }
1149
1150         ret = _request_firmware_prepare(&fw, name, device, buf, size);
1151         if (ret <= 0) /* error or already assigned */
1152                 goto out;
1153
1154         ret = 0;
1155         timeout = is_nonfree_firmware(name) ? 1 : firmware_loading_timeout();
1156         if (opt_flags & FW_OPT_NOWAIT) {
1157                 timeout = usermodehelper_read_lock_wait(timeout);
1158                 if (!timeout) {
1159                         dev_dbg(device, "firmware: %s loading timed out\n",
1160                                 name);
1161                         ret = -EBUSY;
1162                         goto out;
1163                 }
1164         } else {
1165                 ret = usermodehelper_read_trylock();
1166                 if (WARN_ON(ret)) {
1167                         dev_err(device, "firmware: %s will not be loaded\n",
1168                                 name);
1169                         goto out;
1170                 }
1171         }
1172
1173         ret = fw_get_filesystem_firmware(device, fw->priv);
1174         if (ret) {
1175                 if (!(opt_flags & FW_OPT_NO_WARN))
1176                         dev_warn(device,
1177                                  "Direct firmware load for %s failed with error %d\n",
1178                                  name, ret);
1179                 if (opt_flags & FW_OPT_USERHELPER) {
1180                         dev_warn(device, "Falling back to user helper\n");
1181                         ret = fw_load_from_user_helper(fw, name, device,
1182                                                        opt_flags, timeout);
1183                 }
1184         }
1185
1186         if (!ret)
1187                 ret = assign_firmware_buf(fw, device, opt_flags);
1188
1189         usermodehelper_read_unlock();
1190
1191  out:
1192         if (ret < 0) {
1193                 release_firmware(fw);
1194                 fw = NULL;
1195         }
1196
1197         *firmware_p = fw;
1198         return ret;
1199 }
1200
1201 /**
1202  * request_firmware: - send firmware request and wait for it
1203  * @firmware_p: pointer to firmware image
1204  * @name: name of firmware file
1205  * @device: device for which firmware is being loaded
1206  *
1207  *      @firmware_p will be used to return a firmware image by the name
1208  *      of @name for device @device.
1209  *
1210  *      Should be called from user context where sleeping is allowed.
1211  *
1212  *      @name will be used as $FIRMWARE in the uevent environment and
1213  *      should be distinctive enough not to be confused with any other
1214  *      firmware image for this or any other device.
1215  *
1216  *      Caller must hold the reference count of @device.
1217  *
1218  *      The function can be called safely inside device's suspend and
1219  *      resume callback.
1220  **/
1221 int
1222 request_firmware(const struct firmware **firmware_p, const char *name,
1223                  struct device *device)
1224 {
1225         int ret;
1226
1227         /* Need to pin this module until return */
1228         __module_get(THIS_MODULE);
1229         ret = _request_firmware(firmware_p, name, device, NULL, 0,
1230                                 FW_OPT_UEVENT | FW_OPT_FALLBACK);
1231         module_put(THIS_MODULE);
1232         return ret;
1233 }
1234 EXPORT_SYMBOL(request_firmware);
1235
1236 /**
1237  * request_firmware_direct: - load firmware directly without usermode helper
1238  * @firmware_p: pointer to firmware image
1239  * @name: name of firmware file
1240  * @device: device for which firmware is being loaded
1241  *
1242  * This function works pretty much like request_firmware(), but this doesn't
1243  * fall back to usermode helper even if the firmware couldn't be loaded
1244  * directly from fs.  Hence it's useful for loading optional firmwares, which
1245  * aren't always present, without extra long timeouts of udev.
1246  **/
1247 int request_firmware_direct(const struct firmware **firmware_p,
1248                             const char *name, struct device *device)
1249 {
1250         int ret;
1251
1252         __module_get(THIS_MODULE);
1253         ret = _request_firmware(firmware_p, name, device, NULL, 0,
1254                                 FW_OPT_UEVENT | FW_OPT_NO_WARN);
1255         module_put(THIS_MODULE);
1256         return ret;
1257 }
1258 EXPORT_SYMBOL_GPL(request_firmware_direct);
1259
1260 /**
1261  * request_firmware_into_buf - load firmware into a previously allocated buffer
1262  * @firmware_p: pointer to firmware image
1263  * @name: name of firmware file
1264  * @device: device for which firmware is being loaded and DMA region allocated
1265  * @buf: address of buffer to load firmware into
1266  * @size: size of buffer
1267  *
1268  * This function works pretty much like request_firmware(), but it doesn't
1269  * allocate a buffer to hold the firmware data. Instead, the firmware
1270  * is loaded directly into the buffer pointed to by @buf and the @firmware_p
1271  * data member is pointed at @buf.
1272  *
1273  * This function doesn't cache firmware either.
1274  */
1275 int
1276 request_firmware_into_buf(const struct firmware **firmware_p, const char *name,
1277                           struct device *device, void *buf, size_t size)
1278 {
1279         int ret;
1280
1281         __module_get(THIS_MODULE);
1282         ret = _request_firmware(firmware_p, name, device, buf, size,
1283                                 FW_OPT_UEVENT | FW_OPT_FALLBACK |
1284                                 FW_OPT_NOCACHE);
1285         module_put(THIS_MODULE);
1286         return ret;
1287 }
1288 EXPORT_SYMBOL(request_firmware_into_buf);
1289
1290 /**
1291  * release_firmware: - release the resource associated with a firmware image
1292  * @fw: firmware resource to release
1293  **/
1294 void release_firmware(const struct firmware *fw)
1295 {
1296         if (fw) {
1297                 if (!fw_is_builtin_firmware(fw))
1298                         firmware_free_data(fw);
1299                 kfree(fw);
1300         }
1301 }
1302 EXPORT_SYMBOL(release_firmware);
1303
1304 /* Async support */
1305 struct firmware_work {
1306         struct work_struct work;
1307         struct module *module;
1308         const char *name;
1309         struct device *device;
1310         void *context;
1311         void (*cont)(const struct firmware *fw, void *context);
1312         unsigned int opt_flags;
1313 };
1314
1315 static void request_firmware_work_func(struct work_struct *work)
1316 {
1317         struct firmware_work *fw_work;
1318         const struct firmware *fw;
1319
1320         fw_work = container_of(work, struct firmware_work, work);
1321
1322         _request_firmware(&fw, fw_work->name, fw_work->device, NULL, 0,
1323                           fw_work->opt_flags);
1324         fw_work->cont(fw, fw_work->context);
1325         put_device(fw_work->device); /* taken in request_firmware_nowait() */
1326
1327         module_put(fw_work->module);
1328         kfree_const(fw_work->name);
1329         kfree(fw_work);
1330 }
1331
1332 /**
1333  * request_firmware_nowait - asynchronous version of request_firmware
1334  * @module: module requesting the firmware
1335  * @uevent: sends uevent to copy the firmware image if this flag
1336  *      is non-zero else the firmware copy must be done manually.
1337  * @name: name of firmware file
1338  * @device: device for which firmware is being loaded
1339  * @gfp: allocation flags
1340  * @context: will be passed over to @cont, and
1341  *      @fw may be %NULL if firmware request fails.
1342  * @cont: function will be called asynchronously when the firmware
1343  *      request is over.
1344  *
1345  *      Caller must hold the reference count of @device.
1346  *
1347  *      Asynchronous variant of request_firmware() for user contexts:
1348  *              - sleep for as small periods as possible since it may
1349  *              increase kernel boot time of built-in device drivers
1350  *              requesting firmware in their ->probe() methods, if
1351  *              @gfp is GFP_KERNEL.
1352  *
1353  *              - can't sleep at all if @gfp is GFP_ATOMIC.
1354  **/
1355 int
1356 request_firmware_nowait(
1357         struct module *module, bool uevent,
1358         const char *name, struct device *device, gfp_t gfp, void *context,
1359         void (*cont)(const struct firmware *fw, void *context))
1360 {
1361         struct firmware_work *fw_work;
1362
1363         fw_work = kzalloc(sizeof(struct firmware_work), gfp);
1364         if (!fw_work)
1365                 return -ENOMEM;
1366
1367         fw_work->module = module;
1368         fw_work->name = kstrdup_const(name, gfp);
1369         if (!fw_work->name) {
1370                 kfree(fw_work);
1371                 return -ENOMEM;
1372         }
1373         fw_work->device = device;
1374         fw_work->context = context;
1375         fw_work->cont = cont;
1376         fw_work->opt_flags = FW_OPT_NOWAIT | FW_OPT_FALLBACK |
1377                 (uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
1378
1379         if (!try_module_get(module)) {
1380                 kfree_const(fw_work->name);
1381                 kfree(fw_work);
1382                 return -EFAULT;
1383         }
1384
1385         get_device(fw_work->device);
1386         INIT_WORK(&fw_work->work, request_firmware_work_func);
1387         schedule_work(&fw_work->work);
1388         return 0;
1389 }
1390 EXPORT_SYMBOL(request_firmware_nowait);
1391
1392 #ifdef CONFIG_PM_SLEEP
1393 static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
1394
1395 /**
1396  * cache_firmware - cache one firmware image in kernel memory space
1397  * @fw_name: the firmware image name
1398  *
1399  * Cache firmware in kernel memory so that drivers can use it when
1400  * system isn't ready for them to request firmware image from userspace.
1401  * Once it returns successfully, driver can use request_firmware or its
1402  * nowait version to get the cached firmware without any interacting
1403  * with userspace
1404  *
1405  * Return 0 if the firmware image has been cached successfully
1406  * Return !0 otherwise
1407  *
1408  */
1409 static int cache_firmware(const char *fw_name)
1410 {
1411         int ret;
1412         const struct firmware *fw;
1413
1414         pr_debug("%s: %s\n", __func__, fw_name);
1415
1416         ret = request_firmware(&fw, fw_name, NULL);
1417         if (!ret)
1418                 kfree(fw);
1419
1420         pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
1421
1422         return ret;
1423 }
1424
1425 static struct firmware_buf *fw_lookup_buf(const char *fw_name)
1426 {
1427         struct firmware_buf *tmp;
1428         struct firmware_cache *fwc = &fw_cache;
1429
1430         spin_lock(&fwc->lock);
1431         tmp = __fw_lookup_buf(fw_name);
1432         spin_unlock(&fwc->lock);
1433
1434         return tmp;
1435 }
1436
1437 /**
1438  * uncache_firmware - remove one cached firmware image
1439  * @fw_name: the firmware image name
1440  *
1441  * Uncache one firmware image which has been cached successfully
1442  * before.
1443  *
1444  * Return 0 if the firmware cache has been removed successfully
1445  * Return !0 otherwise
1446  *
1447  */
1448 static int uncache_firmware(const char *fw_name)
1449 {
1450         struct firmware_buf *buf;
1451         struct firmware fw;
1452
1453         pr_debug("%s: %s\n", __func__, fw_name);
1454
1455         if (fw_get_builtin_firmware(&fw, fw_name, NULL, 0))
1456                 return 0;
1457
1458         buf = fw_lookup_buf(fw_name);
1459         if (buf) {
1460                 fw_free_buf(buf);
1461                 return 0;
1462         }
1463
1464         return -EINVAL;
1465 }
1466
1467 static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
1468 {
1469         struct fw_cache_entry *fce;
1470
1471         fce = kzalloc(sizeof(*fce), GFP_ATOMIC);
1472         if (!fce)
1473                 goto exit;
1474
1475         fce->name = kstrdup_const(name, GFP_ATOMIC);
1476         if (!fce->name) {
1477                 kfree(fce);
1478                 fce = NULL;
1479                 goto exit;
1480         }
1481 exit:
1482         return fce;
1483 }
1484
1485 static int __fw_entry_found(const char *name)
1486 {
1487         struct firmware_cache *fwc = &fw_cache;
1488         struct fw_cache_entry *fce;
1489
1490         list_for_each_entry(fce, &fwc->fw_names, list) {
1491                 if (!strcmp(fce->name, name))
1492                         return 1;
1493         }
1494         return 0;
1495 }
1496
1497 static int fw_cache_piggyback_on_request(const char *name)
1498 {
1499         struct firmware_cache *fwc = &fw_cache;
1500         struct fw_cache_entry *fce;
1501         int ret = 0;
1502
1503         spin_lock(&fwc->name_lock);
1504         if (__fw_entry_found(name))
1505                 goto found;
1506
1507         fce = alloc_fw_cache_entry(name);
1508         if (fce) {
1509                 ret = 1;
1510                 list_add(&fce->list, &fwc->fw_names);
1511                 pr_debug("%s: fw: %s\n", __func__, name);
1512         }
1513 found:
1514         spin_unlock(&fwc->name_lock);
1515         return ret;
1516 }
1517
1518 static void free_fw_cache_entry(struct fw_cache_entry *fce)
1519 {
1520         kfree_const(fce->name);
1521         kfree(fce);
1522 }
1523
1524 static void __async_dev_cache_fw_image(void *fw_entry,
1525                                        async_cookie_t cookie)
1526 {
1527         struct fw_cache_entry *fce = fw_entry;
1528         struct firmware_cache *fwc = &fw_cache;
1529         int ret;
1530
1531         ret = cache_firmware(fce->name);
1532         if (ret) {
1533                 spin_lock(&fwc->name_lock);
1534                 list_del(&fce->list);
1535                 spin_unlock(&fwc->name_lock);
1536
1537                 free_fw_cache_entry(fce);
1538         }
1539 }
1540
1541 /* called with dev->devres_lock held */
1542 static void dev_create_fw_entry(struct device *dev, void *res,
1543                                 void *data)
1544 {
1545         struct fw_name_devm *fwn = res;
1546         const char *fw_name = fwn->name;
1547         struct list_head *head = data;
1548         struct fw_cache_entry *fce;
1549
1550         fce = alloc_fw_cache_entry(fw_name);
1551         if (fce)
1552                 list_add(&fce->list, head);
1553 }
1554
1555 static int devm_name_match(struct device *dev, void *res,
1556                            void *match_data)
1557 {
1558         struct fw_name_devm *fwn = res;
1559         return (fwn->magic == (unsigned long)match_data);
1560 }
1561
1562 static void dev_cache_fw_image(struct device *dev, void *data)
1563 {
1564         LIST_HEAD(todo);
1565         struct fw_cache_entry *fce;
1566         struct fw_cache_entry *fce_next;
1567         struct firmware_cache *fwc = &fw_cache;
1568
1569         devres_for_each_res(dev, fw_name_devm_release,
1570                             devm_name_match, &fw_cache,
1571                             dev_create_fw_entry, &todo);
1572
1573         list_for_each_entry_safe(fce, fce_next, &todo, list) {
1574                 list_del(&fce->list);
1575
1576                 spin_lock(&fwc->name_lock);
1577                 /* only one cache entry for one firmware */
1578                 if (!__fw_entry_found(fce->name)) {
1579                         list_add(&fce->list, &fwc->fw_names);
1580                 } else {
1581                         free_fw_cache_entry(fce);
1582                         fce = NULL;
1583                 }
1584                 spin_unlock(&fwc->name_lock);
1585
1586                 if (fce)
1587                         async_schedule_domain(__async_dev_cache_fw_image,
1588                                               (void *)fce,
1589                                               &fw_cache_domain);
1590         }
1591 }
1592
1593 static void __device_uncache_fw_images(void)
1594 {
1595         struct firmware_cache *fwc = &fw_cache;
1596         struct fw_cache_entry *fce;
1597
1598         spin_lock(&fwc->name_lock);
1599         while (!list_empty(&fwc->fw_names)) {
1600                 fce = list_entry(fwc->fw_names.next,
1601                                 struct fw_cache_entry, list);
1602                 list_del(&fce->list);
1603                 spin_unlock(&fwc->name_lock);
1604
1605                 uncache_firmware(fce->name);
1606                 free_fw_cache_entry(fce);
1607
1608                 spin_lock(&fwc->name_lock);
1609         }
1610         spin_unlock(&fwc->name_lock);
1611 }
1612
1613 /**
1614  * device_cache_fw_images - cache devices' firmware
1615  *
1616  * If one device called request_firmware or its nowait version
1617  * successfully before, the firmware names are recored into the
1618  * device's devres link list, so device_cache_fw_images can call
1619  * cache_firmware() to cache these firmwares for the device,
1620  * then the device driver can load its firmwares easily at
1621  * time when system is not ready to complete loading firmware.
1622  */
1623 static void device_cache_fw_images(void)
1624 {
1625         struct firmware_cache *fwc = &fw_cache;
1626         int old_timeout;
1627         DEFINE_WAIT(wait);
1628
1629         pr_debug("%s\n", __func__);
1630
1631         /* cancel uncache work */
1632         cancel_delayed_work_sync(&fwc->work);
1633
1634         /*
1635          * use small loading timeout for caching devices' firmware
1636          * because all these firmware images have been loaded
1637          * successfully at lease once, also system is ready for
1638          * completing firmware loading now. The maximum size of
1639          * firmware in current distributions is about 2M bytes,
1640          * so 10 secs should be enough.
1641          */
1642         old_timeout = loading_timeout;
1643         loading_timeout = 10;
1644
1645         mutex_lock(&fw_lock);
1646         fwc->state = FW_LOADER_START_CACHE;
1647         dpm_for_each_dev(NULL, dev_cache_fw_image);
1648         mutex_unlock(&fw_lock);
1649
1650         /* wait for completion of caching firmware for all devices */
1651         async_synchronize_full_domain(&fw_cache_domain);
1652
1653         loading_timeout = old_timeout;
1654 }
1655
1656 /**
1657  * device_uncache_fw_images - uncache devices' firmware
1658  *
1659  * uncache all firmwares which have been cached successfully
1660  * by device_uncache_fw_images earlier
1661  */
1662 static void device_uncache_fw_images(void)
1663 {
1664         pr_debug("%s\n", __func__);
1665         __device_uncache_fw_images();
1666 }
1667
1668 static void device_uncache_fw_images_work(struct work_struct *work)
1669 {
1670         device_uncache_fw_images();
1671 }
1672
1673 /**
1674  * device_uncache_fw_images_delay - uncache devices firmwares
1675  * @delay: number of milliseconds to delay uncache device firmwares
1676  *
1677  * uncache all devices's firmwares which has been cached successfully
1678  * by device_cache_fw_images after @delay milliseconds.
1679  */
1680 static void device_uncache_fw_images_delay(unsigned long delay)
1681 {
1682         queue_delayed_work(system_power_efficient_wq, &fw_cache.work,
1683                            msecs_to_jiffies(delay));
1684 }
1685
1686 static int fw_pm_notify(struct notifier_block *notify_block,
1687                         unsigned long mode, void *unused)
1688 {
1689         switch (mode) {
1690         case PM_HIBERNATION_PREPARE:
1691         case PM_SUSPEND_PREPARE:
1692         case PM_RESTORE_PREPARE:
1693                 kill_requests_without_uevent();
1694                 device_cache_fw_images();
1695                 break;
1696
1697         case PM_POST_SUSPEND:
1698         case PM_POST_HIBERNATION:
1699         case PM_POST_RESTORE:
1700                 /*
1701                  * In case that system sleep failed and syscore_suspend is
1702                  * not called.
1703                  */
1704                 mutex_lock(&fw_lock);
1705                 fw_cache.state = FW_LOADER_NO_CACHE;
1706                 mutex_unlock(&fw_lock);
1707
1708                 device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
1709                 break;
1710         }
1711
1712         return 0;
1713 }
1714
1715 /* stop caching firmware once syscore_suspend is reached */
1716 static int fw_suspend(void)
1717 {
1718         fw_cache.state = FW_LOADER_NO_CACHE;
1719         return 0;
1720 }
1721
1722 static struct syscore_ops fw_syscore_ops = {
1723         .suspend = fw_suspend,
1724 };
1725 #else
1726 static int fw_cache_piggyback_on_request(const char *name)
1727 {
1728         return 0;
1729 }
1730 #endif
1731
1732 static void __init fw_cache_init(void)
1733 {
1734         spin_lock_init(&fw_cache.lock);
1735         INIT_LIST_HEAD(&fw_cache.head);
1736         fw_cache.state = FW_LOADER_NO_CACHE;
1737
1738 #ifdef CONFIG_PM_SLEEP
1739         spin_lock_init(&fw_cache.name_lock);
1740         INIT_LIST_HEAD(&fw_cache.fw_names);
1741
1742         INIT_DELAYED_WORK(&fw_cache.work,
1743                           device_uncache_fw_images_work);
1744
1745         fw_cache.pm_notify.notifier_call = fw_pm_notify;
1746         register_pm_notifier(&fw_cache.pm_notify);
1747
1748         register_syscore_ops(&fw_syscore_ops);
1749 #endif
1750 }
1751
1752 static int __init firmware_class_init(void)
1753 {
1754         fw_cache_init();
1755 #ifdef CONFIG_FW_LOADER_USER_HELPER
1756         register_reboot_notifier(&fw_shutdown_nb);
1757         return class_register(&firmware_class);
1758 #else
1759         return 0;
1760 #endif
1761 }
1762
1763 static void __exit firmware_class_exit(void)
1764 {
1765 #ifdef CONFIG_PM_SLEEP
1766         unregister_syscore_ops(&fw_syscore_ops);
1767         unregister_pm_notifier(&fw_cache.pm_notify);
1768 #endif
1769 #ifdef CONFIG_FW_LOADER_USER_HELPER
1770         unregister_reboot_notifier(&fw_shutdown_nb);
1771         class_unregister(&firmware_class);
1772 #endif
1773 }
1774
1775 fs_initcall(firmware_class_init);
1776 module_exit(firmware_class_exit);