drivers/base/firmware_class.c

   1 /*
   2  * firmware_class.c - Multi purpose firmware loading support
   3  *
   4  * Copyright (c) 2003 Manuel Estrada Sainz
   5  *
   6  * Please see Documentation/firmware_class/ for more information.
   7  *
   8  */
   9
  10 #include <linux/capability.h>
  11 #include <linux/device.h>
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/timer.h>
  15 #include <linux/vmalloc.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/bitops.h>
  18 #include <linux/mutex.h>
  19 #include <linux/workqueue.h>
  20 #include <linux/highmem.h>
  21 #include <linux/firmware.h>
  22 #include <linux/slab.h>
  23 #include <linux/sched.h>
  24 #include <linux/file.h>
  25 #include <linux/list.h>
  26 #include <linux/fs.h>
  27 #include <linux/async.h>
  28 #include <linux/pm.h>
  29 #include <linux/suspend.h>
  30 #include <linux/syscore_ops.h>
  31 #include <linux/reboot.h>
  32 #include <linux/security.h>
  33
  34 #include <generated/utsrelease.h>
  35
  36 #include "base.h"
  37
  38 MODULE_AUTHOR("Manuel Estrada Sainz");
  39 MODULE_DESCRIPTION("Multi purpose firmware loading support");
  40 MODULE_LICENSE("GPL");
  41
  42 /* Builtin firmware support */
  43
  44 #ifdef CONFIG_FW_LOADER
  45
  46 extern struct builtin_fw __start_builtin_fw[];
  47 extern struct builtin_fw __end_builtin_fw[];
  48
  49 static bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
  50 {
  51         struct builtin_fw *b_fw;
  52
  53         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
  54                 if (strcmp(name, b_fw->name) == 0) {
  55                         fw->size = b_fw->size;
  56                         fw->data = b_fw->data;
  57                         return true;
  58                 }
  59         }
  60
  61         return false;
  62 }
  63
  64 static bool fw_is_builtin_firmware(const struct firmware *fw)
  65 {
  66         struct builtin_fw *b_fw;
  67
  68         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
  69                 if (fw->data == b_fw->data)
  70                         return true;
  71
  72         return false;
  73 }
  74
  75 #else /* Module case - no builtin firmware support */
  76
  77 static inline bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
  78 {
  79         return false;
  80 }
  81
  82 static inline bool fw_is_builtin_firmware(const struct firmware *fw)
  83 {
  84         return false;
  85 }
  86 #endif
  87
  88 enum {
  89         FW_STATUS_LOADING,
  90         FW_STATUS_DONE,
  91         FW_STATUS_ABORT,
  92 };
  93
  94 static int loading_timeout = 60;        /* In seconds */
  95
  96 static inline long firmware_loading_timeout(void)
  97 {
  98         return loading_timeout > 0 ? loading_timeout * HZ : MAX_JIFFY_OFFSET;
  99 }
 100
 101 /* firmware behavior options */
 102 #define FW_OPT_UEVENT   (1U << 0)
 103 #define FW_OPT_NOWAIT   (1U << 1)
 104 #ifdef CONFIG_FW_LOADER_USER_HELPER
 105 #define FW_OPT_USERHELPER       (1U << 2)
 106 #else
 107 #define FW_OPT_USERHELPER       0
 108 #endif
 109 #ifdef CONFIG_FW_LOADER_USER_HELPER_FALLBACK
 110 #define FW_OPT_FALLBACK         FW_OPT_USERHELPER
 111 #else
 112 #define FW_OPT_FALLBACK         0
 113 #endif
 114 #define FW_OPT_NO_WARN  (1U << 3)
 115
 116 struct firmware_cache {
 117         /* firmware_buf instance will be added into the below list */
 118         spinlock_t lock;
 119         struct list_head head;
 120         int state;
 121
 122 #ifdef CONFIG_PM_SLEEP
 123         /*
 124          * Names of firmware images which have been cached successfully
 125          * will be added into the below list so that device uncache
 126          * helper can trace which firmware images have been cached
 127          * before.
 128          */
 129         spinlock_t name_lock;
 130         struct list_head fw_names;
 131
 132         struct delayed_work work;
 133
 134         struct notifier_block   pm_notify;
 135 #endif
 136 };
 137
 138 struct firmware_buf {
 139         struct kref ref;
 140         struct list_head list;
 141         struct completion completion;
 142         struct firmware_cache *fwc;
 143         unsigned long status;
 144         void *data;
 145         size_t size;
 146 #ifdef CONFIG_FW_LOADER_USER_HELPER
 147         bool is_paged_buf;
 148         bool need_uevent;
 149         struct page **pages;
 150         int nr_pages;
 151         int page_array_size;
 152         struct list_head pending_list;
 153 #endif
 154         const char *fw_id;
 155 };
 156
 157 struct fw_cache_entry {
 158         struct list_head list;
 159         const char *name;
 160 };
 161
 162 struct fw_name_devm {
 163         unsigned long magic;
 164         const char *name;
 165 };
 166
 167 #define to_fwbuf(d) container_of(d, struct firmware_buf, ref)
 168
 169 #define FW_LOADER_NO_CACHE      0
 170 #define FW_LOADER_START_CACHE   1
 171
 172 static int fw_cache_piggyback_on_request(const char *name);
 173
 174 /* fw_lock could be moved to 'struct firmware_priv' but since it is just
 175  * guarding for corner cases a global lock should be OK */
 176 static DEFINE_MUTEX(fw_lock);
 177
 178 static struct firmware_cache fw_cache;
 179
 180 static struct firmware_buf *__allocate_fw_buf(const char *fw_name,
 181                                               struct firmware_cache *fwc)
 182 {
 183         struct firmware_buf *buf;
 184
 185         buf = kzalloc(sizeof(*buf), GFP_ATOMIC);
 186         if (!buf)
 187                 return NULL;
 188
 189         buf->fw_id = kstrdup_const(fw_name, GFP_ATOMIC);
 190         if (!buf->fw_id) {
 191                 kfree(buf);
 192                 return NULL;
 193         }
 194
 195         kref_init(&buf->ref);
 196         buf->fwc = fwc;
 197         init_completion(&buf->completion);
 198 #ifdef CONFIG_FW_LOADER_USER_HELPER
 199         INIT_LIST_HEAD(&buf->pending_list);
 200 #endif
 201
 202         pr_debug("%s: fw-%s buf=%p\n", __func__, fw_name, buf);
 203
 204         return buf;
 205 }
 206
 207 static struct firmware_buf *__fw_lookup_buf(const char *fw_name)
 208 {
 209         struct firmware_buf *tmp;
 210         struct firmware_cache *fwc = &fw_cache;
 211
 212         list_for_each_entry(tmp, &fwc->head, list)
 213                 if (!strcmp(tmp->fw_id, fw_name))
 214                         return tmp;
 215         return NULL;
 216 }
 217
 218 static int fw_lookup_and_allocate_buf(const char *fw_name,
 219                                       struct firmware_cache *fwc,
 220                                       struct firmware_buf **buf)
 221 {
 222         struct firmware_buf *tmp;
 223
 224         spin_lock(&fwc->lock);
 225         tmp = __fw_lookup_buf(fw_name);
 226         if (tmp) {
 227                 kref_get(&tmp->ref);
 228                 spin_unlock(&fwc->lock);
 229                 *buf = tmp;
 230                 return 1;
 231         }
 232         tmp = __allocate_fw_buf(fw_name, fwc);
 233         if (tmp)
 234                 list_add(&tmp->list, &fwc->head);
 235         spin_unlock(&fwc->lock);
 236
 237         *buf = tmp;
 238
 239         return tmp ? 0 : -ENOMEM;
 240 }
 241
 242 static void __fw_free_buf(struct kref *ref)
 243         __releases(&fwc->lock)
 244 {
 245         struct firmware_buf *buf = to_fwbuf(ref);
 246         struct firmware_cache *fwc = buf->fwc;
 247
 248         pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
 249                  __func__, buf->fw_id, buf, buf->data,
 250                  (unsigned int)buf->size);
 251
 252         list_del(&buf->list);
 253         spin_unlock(&fwc->lock);
 254
 255 #ifdef CONFIG_FW_LOADER_USER_HELPER
 256         if (buf->is_paged_buf) {
 257                 int i;
 258                 vunmap(buf->data);
 259                 for (i = 0; i < buf->nr_pages; i++)
 260                         __free_page(buf->pages[i]);
 261                 kfree(buf->pages);
 262         } else
 263 #endif
 264                 vfree(buf->data);
 265         kfree_const(buf->fw_id);
 266         kfree(buf);
 267 }
 268
 269 static void fw_free_buf(struct firmware_buf *buf)
 270 {
 271         struct firmware_cache *fwc = buf->fwc;
 272         spin_lock(&fwc->lock);
 273         if (!kref_put(&buf->ref, __fw_free_buf))
 274                 spin_unlock(&fwc->lock);
 275 }
 276
 277 /* direct firmware loading support */
 278 static char fw_path_para[256];
 279 static const char * const fw_path[] = {
 280         fw_path_para,
 281         "/lib/firmware/updates/" UTS_RELEASE,
 282         "/lib/firmware/updates",
 283         "/lib/firmware/" UTS_RELEASE,
 284         "/lib/firmware"
 285 };
 286
 287 /*
 288  * Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH'
 289  * from kernel command line because firmware_class is generally built in
 290  * kernel instead of module.
 291  */
 292 module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
 293 MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
 294
 295 static void fw_finish_direct_load(struct device *device,
 296                                   struct firmware_buf *buf)
 297 {
 298         mutex_lock(&fw_lock);
 299         set_bit(FW_STATUS_DONE, &buf->status);
 300         complete_all(&buf->completion);
 301         mutex_unlock(&fw_lock);
 302 }
 303
 304 static int fw_get_filesystem_firmware(struct device *device,
 305                                        struct firmware_buf *buf)
 306 {
 307         loff_t size;
 308         int i, len;
 309         int rc = -ENOENT;
 310         char *path;
 311
 312         path = __getname();
 313         if (!path)
 314                 return -ENOMEM;
 315
 316         for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
 317                 /* skip the unset customized path */
 318                 if (!fw_path[i][0])
 319                         continue;
 320
 321                 len = snprintf(path, PATH_MAX, "%s/%s",
 322                                fw_path[i], buf->fw_id);
 323                 if (len >= PATH_MAX) {
 324                         rc = -ENAMETOOLONG;
 325                         break;
 326                 }
 327
 328                 buf->size = 0;
 329                 rc = kernel_read_file_from_path(path, &buf->data, &size,
 330                                                 INT_MAX, READING_FIRMWARE);
 331                 if (rc) {
 332                         if (rc == -ENOENT)
 333                                 dev_dbg(device, "loading %s failed with error %d\n",
 334                                          path, rc);
 335                         else
 336                                 dev_warn(device, "loading %s failed with error %d\n",
 337                                          path, rc);
 338                         continue;
 339                 }
 340                 dev_dbg(device, "direct-loading %s\n", buf->fw_id);
 341                 buf->size = size;
 342                 fw_finish_direct_load(device, buf);
 343                 break;
 344         }
 345         __putname(path);
 346
 347         return rc;
 348 }
 349
 350 /* firmware holds the ownership of pages */
 351 static void firmware_free_data(const struct firmware *fw)
 352 {
 353         /* Loaded directly? */
 354         if (!fw->priv) {
 355                 vfree(fw->data);
 356                 return;
 357         }
 358         fw_free_buf(fw->priv);
 359 }
 360
 361 /* store the pages buffer info firmware from buf */
 362 static void fw_set_page_data(struct firmware_buf *buf, struct firmware *fw)
 363 {
 364         fw->priv = buf;
 365 #ifdef CONFIG_FW_LOADER_USER_HELPER
 366         fw->pages = buf->pages;
 367 #endif
 368         fw->size = buf->size;
 369         fw->data = buf->data;
 370
 371         pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
 372                  __func__, buf->fw_id, buf, buf->data,
 373                  (unsigned int)buf->size);
 374 }
 375
 376 #ifdef CONFIG_PM_SLEEP
 377 static void fw_name_devm_release(struct device *dev, void *res)
 378 {
 379         struct fw_name_devm *fwn = res;
 380
 381         if (fwn->magic == (unsigned long)&fw_cache)
 382                 pr_debug("%s: fw_name-%s devm-%p released\n",
 383                                 __func__, fwn->name, res);
 384         kfree_const(fwn->name);
 385 }
 386
 387 static int fw_devm_match(struct device *dev, void *res,
 388                 void *match_data)
 389 {
 390         struct fw_name_devm *fwn = res;
 391
 392         return (fwn->magic == (unsigned long)&fw_cache) &&
 393                 !strcmp(fwn->name, match_data);
 394 }
 395
 396 static struct fw_name_devm *fw_find_devm_name(struct device *dev,
 397                 const char *name)
 398 {
 399         struct fw_name_devm *fwn;
 400
 401         fwn = devres_find(dev, fw_name_devm_release,
 402                           fw_devm_match, (void *)name);
 403         return fwn;
 404 }
 405
 406 /* add firmware name into devres list */
 407 static int fw_add_devm_name(struct device *dev, const char *name)
 408 {
 409         struct fw_name_devm *fwn;
 410
 411         fwn = fw_find_devm_name(dev, name);
 412         if (fwn)
 413                 return 1;
 414
 415         fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm),
 416                            GFP_KERNEL);
 417         if (!fwn)
 418                 return -ENOMEM;
 419         fwn->name = kstrdup_const(name, GFP_KERNEL);
 420         if (!fwn->name) {
 421                 devres_free(fwn);
 422                 return -ENOMEM;
 423         }
 424
 425         fwn->magic = (unsigned long)&fw_cache;
 426         devres_add(dev, fwn);
 427
 428         return 0;
 429 }
 430 #else
 431 static int fw_add_devm_name(struct device *dev, const char *name)
 432 {
 433         return 0;
 434 }
 435 #endif
 436
 437
 438 /*
 439  * user-mode helper code
 440  */
 441 #ifdef CONFIG_FW_LOADER_USER_HELPER
 442 struct firmware_priv {
 443         bool nowait;
 444         struct device dev;
 445         struct firmware_buf *buf;
 446         struct firmware *fw;
 447 };
 448
 449 static struct firmware_priv *to_firmware_priv(struct device *dev)
 450 {
 451         return container_of(dev, struct firmware_priv, dev);
 452 }
 453
 454 static void __fw_load_abort(struct firmware_buf *buf)
 455 {
 456         /*
 457          * There is a small window in which user can write to 'loading'
 458          * between loading done and disappearance of 'loading'
 459          */
 460         if (test_bit(FW_STATUS_DONE, &buf->status))
 461                 return;
 462
 463         list_del_init(&buf->pending_list);
 464         set_bit(FW_STATUS_ABORT, &buf->status);
 465         complete_all(&buf->completion);
 466 }
 467
 468 static void fw_load_abort(struct firmware_priv *fw_priv)
 469 {
 470         struct firmware_buf *buf = fw_priv->buf;
 471
 472         __fw_load_abort(buf);
 473
 474         /* avoid user action after loading abort */
 475         fw_priv->buf = NULL;
 476 }
 477
 478 #define is_fw_load_aborted(buf) \
 479         test_bit(FW_STATUS_ABORT, &(buf)->status)
 480
 481 static LIST_HEAD(pending_fw_head);
 482
 483 /* reboot notifier for avoid deadlock with usermode_lock */
 484 static int fw_shutdown_notify(struct notifier_block *unused1,
 485                               unsigned long unused2, void *unused3)
 486 {
 487         mutex_lock(&fw_lock);
 488         while (!list_empty(&pending_fw_head))
 489                 __fw_load_abort(list_first_entry(&pending_fw_head,
 490                                                struct firmware_buf,
 491                                                pending_list));
 492         mutex_unlock(&fw_lock);
 493         return NOTIFY_DONE;
 494 }
 495
 496 static struct notifier_block fw_shutdown_nb = {
 497         .notifier_call = fw_shutdown_notify,
 498 };
 499
 500 static ssize_t timeout_show(struct class *class, struct class_attribute *attr,
 501                             char *buf)
 502 {
 503         return sprintf(buf, "%d\n", loading_timeout);
 504 }
 505
 506 /**
 507  * firmware_timeout_store - set number of seconds to wait for firmware
 508  * @class: device class pointer
 509  * @attr: device attribute pointer
 510  * @buf: buffer to scan for timeout value
 511  * @count: number of bytes in @buf
 512  *
 513  *      Sets the number of seconds to wait for the firmware.  Once
 514  *      this expires an error will be returned to the driver and no
 515  *      firmware will be provided.
 516  *
 517  *      Note: zero means 'wait forever'.
 518  **/
 519 static ssize_t timeout_store(struct class *class, struct class_attribute *attr,
 520                              const char *buf, size_t count)
 521 {
 522         loading_timeout = simple_strtol(buf, NULL, 10);
 523         if (loading_timeout < 0)
 524                 loading_timeout = 0;
 525
 526         return count;
 527 }
 528
 529 static struct class_attribute firmware_class_attrs[] = {
 530         __ATTR_RW(timeout),
 531         __ATTR_NULL
 532 };
 533
 534 static void fw_dev_release(struct device *dev)
 535 {
 536         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 537
 538         kfree(fw_priv);
 539 }
 540
 541 static int do_firmware_uevent(struct firmware_priv *fw_priv, struct kobj_uevent_env *env)
 542 {
 543         if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->buf->fw_id))
 544                 return -ENOMEM;
 545         if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
 546                 return -ENOMEM;
 547         if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
 548                 return -ENOMEM;
 549
 550         return 0;
 551 }
 552
 553 static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
 554 {
 555         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 556         int err = 0;
 557
 558         mutex_lock(&fw_lock);
 559         if (fw_priv->buf)
 560                 err = do_firmware_uevent(fw_priv, env);
 561         mutex_unlock(&fw_lock);
 562         return err;
 563 }
 564
 565 static struct class firmware_class = {
 566         .name           = "firmware",
 567         .class_attrs    = firmware_class_attrs,
 568         .dev_uevent     = firmware_uevent,
 569         .dev_release    = fw_dev_release,
 570 };
 571
 572 static ssize_t firmware_loading_show(struct device *dev,
 573                                      struct device_attribute *attr, char *buf)
 574 {
 575         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 576         int loading = 0;
 577
 578         mutex_lock(&fw_lock);
 579         if (fw_priv->buf)
 580                 loading = test_bit(FW_STATUS_LOADING, &fw_priv->buf->status);
 581         mutex_unlock(&fw_lock);
 582
 583         return sprintf(buf, "%d\n", loading);
 584 }
 585
 586 /* Some architectures don't have PAGE_KERNEL_RO */
 587 #ifndef PAGE_KERNEL_RO
 588 #define PAGE_KERNEL_RO PAGE_KERNEL
 589 #endif
 590
 591 /* one pages buffer should be mapped/unmapped only once */
 592 static int fw_map_pages_buf(struct firmware_buf *buf)
 593 {
 594         if (!buf->is_paged_buf)
 595                 return 0;
 596
 597         vunmap(buf->data);
 598         buf->data = vmap(buf->pages, buf->nr_pages, 0, PAGE_KERNEL_RO);
 599         if (!buf->data)
 600                 return -ENOMEM;
 601         return 0;
 602 }
 603
 604 /**
 605  * firmware_loading_store - set value in the 'loading' control file
 606  * @dev: device pointer
 607  * @attr: device attribute pointer
 608  * @buf: buffer to scan for loading control value
 609  * @count: number of bytes in @buf
 610  *
 611  *      The relevant values are:
 612  *
 613  *       1: Start a load, discarding any previous partial load.
 614  *       0: Conclude the load and hand the data to the driver code.
 615  *      -1: Conclude the load with an error and discard any written data.
 616  **/
 617 static ssize_t firmware_loading_store(struct device *dev,
 618                                       struct device_attribute *attr,
 619                                       const char *buf, size_t count)
 620 {
 621         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 622         struct firmware_buf *fw_buf;
 623         ssize_t written = count;
 624         int loading = simple_strtol(buf, NULL, 10);
 625         int i;
 626
 627         mutex_lock(&fw_lock);
 628         fw_buf = fw_priv->buf;
 629         if (!fw_buf)
 630                 goto out;
 631
 632         switch (loading) {
 633         case 1:
 634                 /* discarding any previous partial load */
 635                 if (!test_bit(FW_STATUS_DONE, &fw_buf->status)) {
 636                         for (i = 0; i < fw_buf->nr_pages; i++)
 637                                 __free_page(fw_buf->pages[i]);
 638                         kfree(fw_buf->pages);
 639                         fw_buf->pages = NULL;
 640                         fw_buf->page_array_size = 0;
 641                         fw_buf->nr_pages = 0;
 642                         set_bit(FW_STATUS_LOADING, &fw_buf->status);
 643                 }
 644                 break;
 645         case 0:
 646                 if (test_bit(FW_STATUS_LOADING, &fw_buf->status)) {
 647                         int rc;
 648
 649                         set_bit(FW_STATUS_DONE, &fw_buf->status);
 650                         clear_bit(FW_STATUS_LOADING, &fw_buf->status);
 651
 652                         /*
 653                          * Several loading requests may be pending on
 654                          * one same firmware buf, so let all requests
 655                          * see the mapped 'buf->data' once the loading
 656                          * is completed.
 657                          * */
 658                         rc = fw_map_pages_buf(fw_buf);
 659                         if (rc)
 660                                 dev_err(dev, "%s: map pages failed\n",
 661                                         __func__);
 662                         else
 663                                 rc = security_kernel_post_read_file(NULL,
 664                                                 fw_buf->data, fw_buf->size,
 665                                                 READING_FIRMWARE);
 666
 667                         /*
 668                          * Same logic as fw_load_abort, only the DONE bit
 669                          * is ignored and we set ABORT only on failure.
 670                          */
 671                         list_del_init(&fw_buf->pending_list);
 672                         if (rc) {
 673                                 set_bit(FW_STATUS_ABORT, &fw_buf->status);
 674                                 written = rc;
 675                         }
 676                         complete_all(&fw_buf->completion);
 677                         break;
 678                 }
 679                 /* fallthrough */
 680         default:
 681                 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
 682                 /* fallthrough */
 683         case -1:
 684                 fw_load_abort(fw_priv);
 685                 break;
 686         }
 687 out:
 688         mutex_unlock(&fw_lock);
 689         return written;
 690 }
 691
 692 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
 693
 694 static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
 695                                   struct bin_attribute *bin_attr,
 696                                   char *buffer, loff_t offset, size_t count)
 697 {
 698         struct device *dev = kobj_to_dev(kobj);
 699         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 700         struct firmware_buf *buf;
 701         ssize_t ret_count;
 702
 703         mutex_lock(&fw_lock);
 704         buf = fw_priv->buf;
 705         if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) {
 706                 ret_count = -ENODEV;
 707                 goto out;
 708         }
 709         if (offset > buf->size) {
 710                 ret_count = 0;
 711                 goto out;
 712         }
 713         if (count > buf->size - offset)
 714                 count = buf->size - offset;
 715
 716         ret_count = count;
 717
 718         while (count) {
 719                 void *page_data;
 720                 int page_nr = offset >> PAGE_SHIFT;
 721                 int page_ofs = offset & (PAGE_SIZE-1);
 722                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 723
 724                 page_data = kmap(buf->pages[page_nr]);
 725
 726                 memcpy(buffer, page_data + page_ofs, page_cnt);
 727
 728                 kunmap(buf->pages[page_nr]);
 729                 buffer += page_cnt;
 730                 offset += page_cnt;
 731                 count -= page_cnt;
 732         }
 733 out:
 734         mutex_unlock(&fw_lock);
 735         return ret_count;
 736 }
 737
 738 static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
 739 {
 740         struct firmware_buf *buf = fw_priv->buf;
 741         int pages_needed = PAGE_ALIGN(min_size) >> PAGE_SHIFT;
 742
 743         /* If the array of pages is too small, grow it... */
 744         if (buf->page_array_size < pages_needed) {
 745                 int new_array_size = max(pages_needed,
 746                                          buf->page_array_size * 2);
 747                 struct page **new_pages;
 748
 749                 new_pages = kmalloc(new_array_size * sizeof(void *),
 750                                     GFP_KERNEL);
 751                 if (!new_pages) {
 752                         fw_load_abort(fw_priv);
 753                         return -ENOMEM;
 754                 }
 755                 memcpy(new_pages, buf->pages,
 756                        buf->page_array_size * sizeof(void *));
 757                 memset(&new_pages[buf->page_array_size], 0, sizeof(void *) *
 758                        (new_array_size - buf->page_array_size));
 759                 kfree(buf->pages);
 760                 buf->pages = new_pages;
 761                 buf->page_array_size = new_array_size;
 762         }
 763
 764         while (buf->nr_pages < pages_needed) {
 765                 buf->pages[buf->nr_pages] =
 766                         alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
 767
 768                 if (!buf->pages[buf->nr_pages]) {
 769                         fw_load_abort(fw_priv);
 770                         return -ENOMEM;
 771                 }
 772                 buf->nr_pages++;
 773         }
 774         return 0;
 775 }
 776
 777 /**
 778  * firmware_data_write - write method for firmware
 779  * @filp: open sysfs file
 780  * @kobj: kobject for the device
 781  * @bin_attr: bin_attr structure
 782  * @buffer: buffer being written
 783  * @offset: buffer offset for write in total data store area
 784  * @count: buffer size
 785  *
 786  *      Data written to the 'data' attribute will be later handed to
 787  *      the driver as a firmware image.
 788  **/
 789 static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,
 790                                    struct bin_attribute *bin_attr,
 791                                    char *buffer, loff_t offset, size_t count)
 792 {
 793         struct device *dev = kobj_to_dev(kobj);
 794         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 795         struct firmware_buf *buf;
 796         ssize_t retval;
 797
 798         if (!capable(CAP_SYS_RAWIO))
 799                 return -EPERM;
 800
 801         mutex_lock(&fw_lock);
 802         buf = fw_priv->buf;
 803         if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) {
 804                 retval = -ENODEV;
 805                 goto out;
 806         }
 807
 808         retval = fw_realloc_buffer(fw_priv, offset + count);
 809         if (retval)
 810                 goto out;
 811
 812         retval = count;
 813
 814         while (count) {
 815                 void *page_data;
 816                 int page_nr = offset >> PAGE_SHIFT;
 817                 int page_ofs = offset & (PAGE_SIZE - 1);
 818                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 819
 820                 page_data = kmap(buf->pages[page_nr]);
 821
 822                 memcpy(page_data + page_ofs, buffer, page_cnt);
 823
 824                 kunmap(buf->pages[page_nr]);
 825                 buffer += page_cnt;
 826                 offset += page_cnt;
 827                 count -= page_cnt;
 828         }
 829
 830         buf->size = max_t(size_t, offset, buf->size);
 831 out:
 832         mutex_unlock(&fw_lock);
 833         return retval;
 834 }
 835
 836 static struct bin_attribute firmware_attr_data = {
 837         .attr = { .name = "data", .mode = 0644 },
 838         .size = 0,
 839         .read = firmware_data_read,
 840         .write = firmware_data_write,
 841 };
 842
 843 static struct attribute *fw_dev_attrs[] = {
 844         &dev_attr_loading.attr,
 845         NULL
 846 };
 847
 848 static struct bin_attribute *fw_dev_bin_attrs[] = {
 849         &firmware_attr_data,
 850         NULL
 851 };
 852
 853 static const struct attribute_group fw_dev_attr_group = {
 854         .attrs = fw_dev_attrs,
 855         .bin_attrs = fw_dev_bin_attrs,
 856 };
 857
 858 static const struct attribute_group *fw_dev_attr_groups[] = {
 859         &fw_dev_attr_group,
 860         NULL
 861 };
 862
 863 static struct firmware_priv *
 864 fw_create_instance(struct firmware *firmware, const char *fw_name,
 865                    struct device *device, unsigned int opt_flags)
 866 {
 867         struct firmware_priv *fw_priv;
 868         struct device *f_dev;
 869
 870         fw_priv = kzalloc(sizeof(*fw_priv), GFP_KERNEL);
 871         if (!fw_priv) {
 872                 fw_priv = ERR_PTR(-ENOMEM);
 873                 goto exit;
 874         }
 875
 876         fw_priv->nowait = !!(opt_flags & FW_OPT_NOWAIT);
 877         fw_priv->fw = firmware;
 878         f_dev = &fw_priv->dev;
 879
 880         device_initialize(f_dev);
 881         dev_set_name(f_dev, "%s", fw_name);
 882         f_dev->parent = device;
 883         f_dev->class = &firmware_class;
 884         f_dev->groups = fw_dev_attr_groups;
 885 exit:
 886         return fw_priv;
 887 }
 888
 889 /* load a firmware via user helper */
 890 static int _request_firmware_load(struct firmware_priv *fw_priv,
 891                                   unsigned int opt_flags, long timeout)
 892 {
 893         int retval = 0;
 894         struct device *f_dev = &fw_priv->dev;
 895         struct firmware_buf *buf = fw_priv->buf;
 896
 897         /* fall back on userspace loading */
 898         buf->is_paged_buf = true;
 899
 900         dev_set_uevent_suppress(f_dev, true);
 901
 902         retval = device_add(f_dev);
 903         if (retval) {
 904                 dev_err(f_dev, "%s: device_register failed\n", __func__);
 905                 goto err_put_dev;
 906         }
 907
 908         mutex_lock(&fw_lock);
 909         list_add(&buf->pending_list, &pending_fw_head);
 910         mutex_unlock(&fw_lock);
 911
 912         if (opt_flags & FW_OPT_UEVENT) {
 913                 buf->need_uevent = true;
 914                 dev_set_uevent_suppress(f_dev, false);
 915                 dev_dbg(f_dev, "firmware: requesting %s\n", buf->fw_id);
 916                 kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD);
 917         } else {
 918                 timeout = MAX_JIFFY_OFFSET;
 919         }
 920
 921         retval = wait_for_completion_interruptible_timeout(&buf->completion,
 922                         timeout);
 923         if (retval == -ERESTARTSYS || !retval) {
 924                 mutex_lock(&fw_lock);
 925                 fw_load_abort(fw_priv);
 926                 mutex_unlock(&fw_lock);
 927         } else if (retval > 0) {
 928                 retval = 0;
 929         }
 930
 931         if (is_fw_load_aborted(buf))
 932                 retval = -EAGAIN;
 933         else if (!buf->data)
 934                 retval = -ENOMEM;
 935
 936         device_del(f_dev);
 937 err_put_dev:
 938         put_device(f_dev);
 939         return retval;
 940 }
 941
 942 static int fw_load_from_user_helper(struct firmware *firmware,
 943                                     const char *name, struct device *device,
 944                                     unsigned int opt_flags, long timeout)
 945 {
 946         struct firmware_priv *fw_priv;
 947
 948         fw_priv = fw_create_instance(firmware, name, device, opt_flags);
 949         if (IS_ERR(fw_priv))
 950                 return PTR_ERR(fw_priv);
 951
 952         fw_priv->buf = firmware->priv;
 953         return _request_firmware_load(fw_priv, opt_flags, timeout);
 954 }
 955
 956 #ifdef CONFIG_PM_SLEEP
 957 /* kill pending requests without uevent to avoid blocking suspend */
 958 static void kill_requests_without_uevent(void)
 959 {
 960         struct firmware_buf *buf;
 961         struct firmware_buf *next;
 962
 963         mutex_lock(&fw_lock);
 964         list_for_each_entry_safe(buf, next, &pending_fw_head, pending_list) {
 965                 if (!buf->need_uevent)
 966                          __fw_load_abort(buf);
 967         }
 968         mutex_unlock(&fw_lock);
 969 }
 970 #endif
 971
 972 #else /* CONFIG_FW_LOADER_USER_HELPER */
 973 static inline int
 974 fw_load_from_user_helper(struct firmware *firmware, const char *name,
 975                          struct device *device, unsigned int opt_flags,
 976                          long timeout)
 977 {
 978         return -ENOENT;
 979 }
 980
 981 /* No abort during direct loading */
 982 #define is_fw_load_aborted(buf) false
 983
 984 #ifdef CONFIG_PM_SLEEP
 985 static inline void kill_requests_without_uevent(void) { }
 986 #endif
 987
 988 #endif /* CONFIG_FW_LOADER_USER_HELPER */
 989
 990
 991 /* wait until the shared firmware_buf becomes ready (or error) */
 992 static int sync_cached_firmware_buf(struct firmware_buf *buf)
 993 {
 994         int ret = 0;
 995
 996         mutex_lock(&fw_lock);
 997         while (!test_bit(FW_STATUS_DONE, &buf->status)) {
 998                 if (is_fw_load_aborted(buf)) {
 999                         ret = -ENOENT;
1000                         break;
1001                 }
1002                 mutex_unlock(&fw_lock);
1003                 ret = wait_for_completion_interruptible(&buf->completion);
1004                 mutex_lock(&fw_lock);
1005         }
1006         mutex_unlock(&fw_lock);
1007         return ret;
1008 }
1009
1010 /* prepare firmware and firmware_buf structs;
1011  * return 0 if a firmware is already assigned, 1 if need to load one,
1012  * or a negative error code
1013  */
1014 static int
1015 _request_firmware_prepare(struct firmware **firmware_p, const char *name,
1016                           struct device *device)
1017 {
1018         struct firmware *firmware;
1019         struct firmware_buf *buf;
1020         int ret;
1021
1022         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
1023         if (!firmware) {
1024                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
1025                         __func__);
1026                 return -ENOMEM;
1027         }
1028
1029         if (fw_get_builtin_firmware(firmware, name)) {
1030                 dev_dbg(device, "using built-in %s\n", name);
1031                 return 0; /* assigned */
1032         }
1033
1034         ret = fw_lookup_and_allocate_buf(name, &fw_cache, &buf);
1035
1036         /*
1037          * bind with 'buf' now to avoid warning in failure path
1038          * of requesting firmware.
1039          */
1040         firmware->priv = buf;
1041
1042         if (ret > 0) {
1043                 ret = sync_cached_firmware_buf(buf);
1044                 if (!ret) {
1045                         fw_set_page_data(buf, firmware);
1046                         return 0; /* assigned */
1047                 }
1048         }
1049
1050         if (ret < 0)
1051                 return ret;
1052         return 1; /* need to load */
1053 }
1054
1055 static int assign_firmware_buf(struct firmware *fw, struct device *device,
1056                                unsigned int opt_flags)
1057 {
1058         struct firmware_buf *buf = fw->priv;
1059
1060         mutex_lock(&fw_lock);
1061         if (!buf->size || is_fw_load_aborted(buf)) {
1062                 mutex_unlock(&fw_lock);
1063                 return -ENOENT;
1064         }
1065
1066         /*
1067          * add firmware name into devres list so that we can auto cache
1068          * and uncache firmware for device.
1069          *
1070          * device may has been deleted already, but the problem
1071          * should be fixed in devres or driver core.
1072          */
1073         /* don't cache firmware handled without uevent */
1074         if (device && (opt_flags & FW_OPT_UEVENT))
1075                 fw_add_devm_name(device, buf->fw_id);
1076
1077         /*
1078          * After caching firmware image is started, let it piggyback
1079          * on request firmware.
1080          */
1081         if (buf->fwc->state == FW_LOADER_START_CACHE) {
1082                 if (fw_cache_piggyback_on_request(buf->fw_id))
1083                         kref_get(&buf->ref);
1084         }
1085
1086         /* pass the pages buffer to driver at the last minute */
1087         fw_set_page_data(buf, fw);
1088         mutex_unlock(&fw_lock);
1089         return 0;
1090 }
1091
1092 /* called from request_firmware() and request_firmware_work_func() */
1093 static int
1094 _request_firmware(const struct firmware **firmware_p, const char *name,
1095                   struct device *device, unsigned int opt_flags)
1096 {
1097         struct firmware *fw = NULL;
1098         long timeout;
1099         int ret;
1100
1101         if (!firmware_p)
1102                 return -EINVAL;
1103
1104         if (!name || name[0] == '\0') {
1105                 ret = -EINVAL;
1106                 goto out;
1107         }
1108
1109         ret = _request_firmware_prepare(&fw, name, device);
1110         if (ret <= 0) /* error or already assigned */
1111                 goto out;
1112
1113         ret = 0;
1114         timeout = firmware_loading_timeout();
1115         if (opt_flags & FW_OPT_NOWAIT) {
1116                 timeout = usermodehelper_read_lock_wait(timeout);
1117                 if (!timeout) {
1118                         dev_dbg(device, "firmware: %s loading timed out\n",
1119                                 name);
1120                         ret = -EBUSY;
1121                         goto out;
1122                 }
1123         } else {
1124                 ret = usermodehelper_read_trylock();
1125                 if (WARN_ON(ret)) {
1126                         dev_err(device, "firmware: %s will not be loaded\n",
1127                                 name);
1128                         goto out;
1129                 }
1130         }
1131
1132         ret = fw_get_filesystem_firmware(device, fw->priv);
1133         if (ret) {
1134                 if (!(opt_flags & FW_OPT_NO_WARN))
1135                         dev_warn(device,
1136                                  "Direct firmware load for %s failed with error %d\n",
1137                                  name, ret);
1138                 if (opt_flags & FW_OPT_USERHELPER) {
1139                         dev_warn(device, "Falling back to user helper\n");
1140                         ret = fw_load_from_user_helper(fw, name, device,
1141                                                        opt_flags, timeout);
1142                 }
1143         }
1144
1145         if (!ret)
1146                 ret = assign_firmware_buf(fw, device, opt_flags);
1147
1148         usermodehelper_read_unlock();
1149
1150  out:
1151         if (ret < 0) {
1152                 release_firmware(fw);
1153                 fw = NULL;
1154         }
1155
1156         *firmware_p = fw;
1157         return ret;
1158 }
1159
1160 /**
1161  * request_firmware: - send firmware request and wait for it
1162  * @firmware_p: pointer to firmware image
1163  * @name: name of firmware file
1164  * @device: device for which firmware is being loaded
1165  *
1166  *      @firmware_p will be used to return a firmware image by the name
1167  *      of @name for device @device.
1168  *
1169  *      Should be called from user context where sleeping is allowed.
1170  *
1171  *      @name will be used as $FIRMWARE in the uevent environment and
1172  *      should be distinctive enough not to be confused with any other
1173  *      firmware image for this or any other device.
1174  *
1175  *      Caller must hold the reference count of @device.
1176  *
1177  *      The function can be called safely inside device's suspend and
1178  *      resume callback.
1179  **/
1180 int
1181 request_firmware(const struct firmware **firmware_p, const char *name,
1182                  struct device *device)
1183 {
1184         int ret;
1185
1186         /* Need to pin this module until return */
1187         __module_get(THIS_MODULE);
1188         ret = _request_firmware(firmware_p, name, device,
1189                                 FW_OPT_UEVENT | FW_OPT_FALLBACK);
1190         module_put(THIS_MODULE);
1191         return ret;
1192 }
1193 EXPORT_SYMBOL(request_firmware);
1194
1195 /**
1196  * request_firmware_direct: - load firmware directly without usermode helper
1197  * @firmware_p: pointer to firmware image
1198  * @name: name of firmware file
1199  * @device: device for which firmware is being loaded
1200  *
1201  * This function works pretty much like request_firmware(), but this doesn't
1202  * fall back to usermode helper even if the firmware couldn't be loaded
1203  * directly from fs.  Hence it's useful for loading optional firmwares, which
1204  * aren't always present, without extra long timeouts of udev.
1205  **/
1206 int request_firmware_direct(const struct firmware **firmware_p,
1207                             const char *name, struct device *device)
1208 {
1209         int ret;
1210
1211         __module_get(THIS_MODULE);
1212         ret = _request_firmware(firmware_p, name, device,
1213                                 FW_OPT_UEVENT | FW_OPT_NO_WARN);
1214         module_put(THIS_MODULE);
1215         return ret;
1216 }
1217 EXPORT_SYMBOL_GPL(request_firmware_direct);
1218
1219 /**
1220  * release_firmware: - release the resource associated with a firmware image
1221  * @fw: firmware resource to release
1222  **/
1223 void release_firmware(const struct firmware *fw)
1224 {
1225         if (fw) {
1226                 if (!fw_is_builtin_firmware(fw))
1227                         firmware_free_data(fw);
1228                 kfree(fw);
1229         }
1230 }
1231 EXPORT_SYMBOL(release_firmware);
1232
1233 /* Async support */
1234 struct firmware_work {
1235         struct work_struct work;
1236         struct module *module;
1237         const char *name;
1238         struct device *device;
1239         void *context;
1240         void (*cont)(const struct firmware *fw, void *context);
1241         unsigned int opt_flags;
1242 };
1243
1244 static void request_firmware_work_func(struct work_struct *work)
1245 {
1246         struct firmware_work *fw_work;
1247         const struct firmware *fw;
1248
1249         fw_work = container_of(work, struct firmware_work, work);
1250
1251         _request_firmware(&fw, fw_work->name, fw_work->device,
1252                           fw_work->opt_flags);
1253         fw_work->cont(fw, fw_work->context);
1254         put_device(fw_work->device); /* taken in request_firmware_nowait() */
1255
1256         module_put(fw_work->module);
1257         kfree_const(fw_work->name);
1258         kfree(fw_work);
1259 }
1260
1261 /**
1262  * request_firmware_nowait - asynchronous version of request_firmware
1263  * @module: module requesting the firmware
1264  * @uevent: sends uevent to copy the firmware image if this flag
1265  *      is non-zero else the firmware copy must be done manually.
1266  * @name: name of firmware file
1267  * @device: device for which firmware is being loaded
1268  * @gfp: allocation flags
1269  * @context: will be passed over to @cont, and
1270  *      @fw may be %NULL if firmware request fails.
1271  * @cont: function will be called asynchronously when the firmware
1272  *      request is over.
1273  *
1274  *      Caller must hold the reference count of @device.
1275  *
1276  *      Asynchronous variant of request_firmware() for user contexts:
1277  *              - sleep for as small periods as possible since it may
1278  *              increase kernel boot time of built-in device drivers
1279  *              requesting firmware in their ->probe() methods, if
1280  *              @gfp is GFP_KERNEL.
1281  *
1282  *              - can't sleep at all if @gfp is GFP_ATOMIC.
1283  **/
1284 int
1285 request_firmware_nowait(
1286         struct module *module, bool uevent,
1287         const char *name, struct device *device, gfp_t gfp, void *context,
1288         void (*cont)(const struct firmware *fw, void *context))
1289 {
1290         struct firmware_work *fw_work;
1291
1292         fw_work = kzalloc(sizeof(struct firmware_work), gfp);
1293         if (!fw_work)
1294                 return -ENOMEM;
1295
1296         fw_work->module = module;
1297         fw_work->name = kstrdup_const(name, gfp);
1298         if (!fw_work->name) {
1299                 kfree(fw_work);
1300                 return -ENOMEM;
1301         }
1302         fw_work->device = device;
1303         fw_work->context = context;
1304         fw_work->cont = cont;
1305         fw_work->opt_flags = FW_OPT_NOWAIT | FW_OPT_FALLBACK |
1306                 (uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
1307
1308         if (!try_module_get(module)) {
1309                 kfree_const(fw_work->name);
1310                 kfree(fw_work);
1311                 return -EFAULT;
1312         }
1313
1314         get_device(fw_work->device);
1315         INIT_WORK(&fw_work->work, request_firmware_work_func);
1316         schedule_work(&fw_work->work);
1317         return 0;
1318 }
1319 EXPORT_SYMBOL(request_firmware_nowait);
1320
1321 #ifdef CONFIG_PM_SLEEP
1322 static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
1323
1324 /**
1325  * cache_firmware - cache one firmware image in kernel memory space
1326  * @fw_name: the firmware image name
1327  *
1328  * Cache firmware in kernel memory so that drivers can use it when
1329  * system isn't ready for them to request firmware image from userspace.
1330  * Once it returns successfully, driver can use request_firmware or its
1331  * nowait version to get the cached firmware without any interacting
1332  * with userspace
1333  *
1334  * Return 0 if the firmware image has been cached successfully
1335  * Return !0 otherwise
1336  *
1337  */
1338 static int cache_firmware(const char *fw_name)
1339 {
1340         int ret;
1341         const struct firmware *fw;
1342
1343         pr_debug("%s: %s\n", __func__, fw_name);
1344
1345         ret = request_firmware(&fw, fw_name, NULL);
1346         if (!ret)
1347                 kfree(fw);
1348
1349         pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
1350
1351         return ret;
1352 }
1353
1354 static struct firmware_buf *fw_lookup_buf(const char *fw_name)
1355 {
1356         struct firmware_buf *tmp;
1357         struct firmware_cache *fwc = &fw_cache;
1358
1359         spin_lock(&fwc->lock);
1360         tmp = __fw_lookup_buf(fw_name);
1361         spin_unlock(&fwc->lock);
1362
1363         return tmp;
1364 }
1365
1366 /**
1367  * uncache_firmware - remove one cached firmware image
1368  * @fw_name: the firmware image name
1369  *
1370  * Uncache one firmware image which has been cached successfully
1371  * before.
1372  *
1373  * Return 0 if the firmware cache has been removed successfully
1374  * Return !0 otherwise
1375  *
1376  */
1377 static int uncache_firmware(const char *fw_name)
1378 {
1379         struct firmware_buf *buf;
1380         struct firmware fw;
1381
1382         pr_debug("%s: %s\n", __func__, fw_name);
1383
1384         if (fw_get_builtin_firmware(&fw, fw_name))
1385                 return 0;
1386
1387         buf = fw_lookup_buf(fw_name);
1388         if (buf) {
1389                 fw_free_buf(buf);
1390                 return 0;
1391         }
1392
1393         return -EINVAL;
1394 }
1395
1396 static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
1397 {
1398         struct fw_cache_entry *fce;
1399
1400         fce = kzalloc(sizeof(*fce), GFP_ATOMIC);
1401         if (!fce)
1402                 goto exit;
1403
1404         fce->name = kstrdup_const(name, GFP_ATOMIC);
1405         if (!fce->name) {
1406                 kfree(fce);
1407                 fce = NULL;
1408                 goto exit;
1409         }
1410 exit:
1411         return fce;
1412 }
1413
1414 static int __fw_entry_found(const char *name)
1415 {
1416         struct firmware_cache *fwc = &fw_cache;
1417         struct fw_cache_entry *fce;
1418
1419         list_for_each_entry(fce, &fwc->fw_names, list) {
1420                 if (!strcmp(fce->name, name))
1421                         return 1;
1422         }
1423         return 0;
1424 }
1425
1426 static int fw_cache_piggyback_on_request(const char *name)
1427 {
1428         struct firmware_cache *fwc = &fw_cache;
1429         struct fw_cache_entry *fce;
1430         int ret = 0;
1431
1432         spin_lock(&fwc->name_lock);
1433         if (__fw_entry_found(name))
1434                 goto found;
1435
1436         fce = alloc_fw_cache_entry(name);
1437         if (fce) {
1438                 ret = 1;
1439                 list_add(&fce->list, &fwc->fw_names);
1440                 pr_debug("%s: fw: %s\n", __func__, name);
1441         }
1442 found:
1443         spin_unlock(&fwc->name_lock);
1444         return ret;
1445 }
1446
1447 static void free_fw_cache_entry(struct fw_cache_entry *fce)
1448 {
1449         kfree_const(fce->name);
1450         kfree(fce);
1451 }
1452
1453 static void __async_dev_cache_fw_image(void *fw_entry,
1454                                        async_cookie_t cookie)
1455 {
1456         struct fw_cache_entry *fce = fw_entry;
1457         struct firmware_cache *fwc = &fw_cache;
1458         int ret;
1459
1460         ret = cache_firmware(fce->name);
1461         if (ret) {
1462                 spin_lock(&fwc->name_lock);
1463                 list_del(&fce->list);
1464                 spin_unlock(&fwc->name_lock);
1465
1466                 free_fw_cache_entry(fce);
1467         }
1468 }
1469
1470 /* called with dev->devres_lock held */
1471 static void dev_create_fw_entry(struct device *dev, void *res,
1472                                 void *data)
1473 {
1474         struct fw_name_devm *fwn = res;
1475         const char *fw_name = fwn->name;
1476         struct list_head *head = data;
1477         struct fw_cache_entry *fce;
1478
1479         fce = alloc_fw_cache_entry(fw_name);
1480         if (fce)
1481                 list_add(&fce->list, head);
1482 }
1483
1484 static int devm_name_match(struct device *dev, void *res,
1485                            void *match_data)
1486 {
1487         struct fw_name_devm *fwn = res;
1488         return (fwn->magic == (unsigned long)match_data);
1489 }
1490
1491 static void dev_cache_fw_image(struct device *dev, void *data)
1492 {
1493         LIST_HEAD(todo);
1494         struct fw_cache_entry *fce;
1495         struct fw_cache_entry *fce_next;
1496         struct firmware_cache *fwc = &fw_cache;
1497
1498         devres_for_each_res(dev, fw_name_devm_release,
1499                             devm_name_match, &fw_cache,
1500                             dev_create_fw_entry, &todo);
1501
1502         list_for_each_entry_safe(fce, fce_next, &todo, list) {
1503                 list_del(&fce->list);
1504
1505                 spin_lock(&fwc->name_lock);
1506                 /* only one cache entry for one firmware */
1507                 if (!__fw_entry_found(fce->name)) {
1508                         list_add(&fce->list, &fwc->fw_names);
1509                 } else {
1510                         free_fw_cache_entry(fce);
1511                         fce = NULL;
1512                 }
1513                 spin_unlock(&fwc->name_lock);
1514
1515                 if (fce)
1516                         async_schedule_domain(__async_dev_cache_fw_image,
1517                                               (void *)fce,
1518                                               &fw_cache_domain);
1519         }
1520 }
1521
1522 static void __device_uncache_fw_images(void)
1523 {
1524         struct firmware_cache *fwc = &fw_cache;
1525         struct fw_cache_entry *fce;
1526
1527         spin_lock(&fwc->name_lock);
1528         while (!list_empty(&fwc->fw_names)) {
1529                 fce = list_entry(fwc->fw_names.next,
1530                                 struct fw_cache_entry, list);
1531                 list_del(&fce->list);
1532                 spin_unlock(&fwc->name_lock);
1533
1534                 uncache_firmware(fce->name);
1535                 free_fw_cache_entry(fce);
1536
1537                 spin_lock(&fwc->name_lock);
1538         }
1539         spin_unlock(&fwc->name_lock);
1540 }
1541
1542 /**
1543  * device_cache_fw_images - cache devices' firmware
1544  *
1545  * If one device called request_firmware or its nowait version
1546  * successfully before, the firmware names are recored into the
1547  * device's devres link list, so device_cache_fw_images can call
1548  * cache_firmware() to cache these firmwares for the device,
1549  * then the device driver can load its firmwares easily at
1550  * time when system is not ready to complete loading firmware.
1551  */
1552 static void device_cache_fw_images(void)
1553 {
1554         struct firmware_cache *fwc = &fw_cache;
1555         int old_timeout;
1556         DEFINE_WAIT(wait);
1557
1558         pr_debug("%s\n", __func__);
1559
1560         /* cancel uncache work */
1561         cancel_delayed_work_sync(&fwc->work);
1562
1563         /*
1564          * use small loading timeout for caching devices' firmware
1565          * because all these firmware images have been loaded
1566          * successfully at lease once, also system is ready for
1567          * completing firmware loading now. The maximum size of
1568          * firmware in current distributions is about 2M bytes,
1569          * so 10 secs should be enough.
1570          */
1571         old_timeout = loading_timeout;
1572         loading_timeout = 10;
1573
1574         mutex_lock(&fw_lock);
1575         fwc->state = FW_LOADER_START_CACHE;
1576         dpm_for_each_dev(NULL, dev_cache_fw_image);
1577         mutex_unlock(&fw_lock);
1578
1579         /* wait for completion of caching firmware for all devices */
1580         async_synchronize_full_domain(&fw_cache_domain);
1581
1582         loading_timeout = old_timeout;
1583 }
1584
1585 /**
1586  * device_uncache_fw_images - uncache devices' firmware
1587  *
1588  * uncache all firmwares which have been cached successfully
1589  * by device_uncache_fw_images earlier
1590  */
1591 static void device_uncache_fw_images(void)
1592 {
1593         pr_debug("%s\n", __func__);
1594         __device_uncache_fw_images();
1595 }
1596
1597 static void device_uncache_fw_images_work(struct work_struct *work)
1598 {
1599         device_uncache_fw_images();
1600 }
1601
1602 /**
1603  * device_uncache_fw_images_delay - uncache devices firmwares
1604  * @delay: number of milliseconds to delay uncache device firmwares
1605  *
1606  * uncache all devices's firmwares which has been cached successfully
1607  * by device_cache_fw_images after @delay milliseconds.
1608  */
1609 static void device_uncache_fw_images_delay(unsigned long delay)
1610 {
1611         queue_delayed_work(system_power_efficient_wq, &fw_cache.work,
1612                            msecs_to_jiffies(delay));
1613 }
1614
1615 static int fw_pm_notify(struct notifier_block *notify_block,
1616                         unsigned long mode, void *unused)
1617 {
1618         switch (mode) {
1619         case PM_HIBERNATION_PREPARE:
1620         case PM_SUSPEND_PREPARE:
1621         case PM_RESTORE_PREPARE:
1622                 kill_requests_without_uevent();
1623                 device_cache_fw_images();
1624                 break;
1625
1626         case PM_POST_SUSPEND:
1627         case PM_POST_HIBERNATION:
1628         case PM_POST_RESTORE:
1629                 /*
1630                  * In case that system sleep failed and syscore_suspend is
1631                  * not called.
1632                  */
1633                 mutex_lock(&fw_lock);
1634                 fw_cache.state = FW_LOADER_NO_CACHE;
1635                 mutex_unlock(&fw_lock);
1636
1637                 device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
1638                 break;
1639         }
1640
1641         return 0;
1642 }
1643
1644 /* stop caching firmware once syscore_suspend is reached */
1645 static int fw_suspend(void)
1646 {
1647         fw_cache.state = FW_LOADER_NO_CACHE;
1648         return 0;
1649 }
1650
1651 static struct syscore_ops fw_syscore_ops = {
1652         .suspend = fw_suspend,
1653 };
1654 #else
1655 static int fw_cache_piggyback_on_request(const char *name)
1656 {
1657         return 0;
1658 }
1659 #endif
1660
1661 static void __init fw_cache_init(void)
1662 {
1663         spin_lock_init(&fw_cache.lock);
1664         INIT_LIST_HEAD(&fw_cache.head);
1665         fw_cache.state = FW_LOADER_NO_CACHE;
1666
1667 #ifdef CONFIG_PM_SLEEP
1668         spin_lock_init(&fw_cache.name_lock);
1669         INIT_LIST_HEAD(&fw_cache.fw_names);
1670
1671         INIT_DELAYED_WORK(&fw_cache.work,
1672                           device_uncache_fw_images_work);
1673
1674         fw_cache.pm_notify.notifier_call = fw_pm_notify;
1675         register_pm_notifier(&fw_cache.pm_notify);
1676
1677         register_syscore_ops(&fw_syscore_ops);
1678 #endif
1679 }
1680
1681 static int __init firmware_class_init(void)
1682 {
1683         fw_cache_init();
1684 #ifdef CONFIG_FW_LOADER_USER_HELPER
1685         register_reboot_notifier(&fw_shutdown_nb);
1686         return class_register(&firmware_class);
1687 #else
1688         return 0;
1689 #endif
1690 }
1691
1692 static void __exit firmware_class_exit(void)
1693 {
1694 #ifdef CONFIG_PM_SLEEP
1695         unregister_syscore_ops(&fw_syscore_ops);
1696         unregister_pm_notifier(&fw_cache.pm_notify);
1697 #endif
1698 #ifdef CONFIG_FW_LOADER_USER_HELPER
1699         unregister_reboot_notifier(&fw_shutdown_nb);
1700         class_unregister(&firmware_class);
1701 #endif
1702 }
1703
1704 fs_initcall(firmware_class_init);
1705 module_exit(firmware_class_exit);