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 fw_status {
  95         FW_STATUS_UNKNOWN,
  96         FW_STATUS_LOADING,
  97         FW_STATUS_DONE,
  98         FW_STATUS_ABORTED,
  99 };
 100
 101 static int loading_timeout = 60;        /* In seconds */
 102
 103 static inline long firmware_loading_timeout(void)
 104 {
 105         return loading_timeout > 0 ? loading_timeout * HZ : MAX_JIFFY_OFFSET;
 106 }
 107
 108 /*
 109  * Concurrent request_firmware() for the same firmware need to be
 110  * serialized.  struct fw_state is simple state machine which hold the
 111  * state of the firmware loading.
 112  */
 113 struct fw_state {
 114         struct completion completion;
 115         enum fw_status status;
 116 };
 117
 118 static void fw_state_init(struct fw_state *fw_st)
 119 {
 120         init_completion(&fw_st->completion);
 121         fw_st->status = FW_STATUS_UNKNOWN;
 122 }
 123
 124 static inline bool __fw_state_is_done(enum fw_status status)
 125 {
 126         return status == FW_STATUS_DONE || status == FW_STATUS_ABORTED;
 127 }
 128
 129 static int __fw_state_wait_common(struct fw_state *fw_st, long timeout)
 130 {
 131         long ret;
 132
 133         ret = wait_for_completion_killable_timeout(&fw_st->completion, timeout);
 134         if (ret != 0 && fw_st->status == FW_STATUS_ABORTED)
 135                 return -ENOENT;
 136         if (!ret)
 137                 return -ETIMEDOUT;
 138
 139         return ret < 0 ? ret : 0;
 140 }
 141
 142 static void __fw_state_set(struct fw_state *fw_st,
 143                            enum fw_status status)
 144 {
 145         WRITE_ONCE(fw_st->status, status);
 146
 147         if (status == FW_STATUS_DONE || status == FW_STATUS_ABORTED)
 148                 complete_all(&fw_st->completion);
 149 }
 150
 151 #define fw_state_start(fw_st)                                   \
 152         __fw_state_set(fw_st, FW_STATUS_LOADING)
 153 #define fw_state_done(fw_st)                                    \
 154         __fw_state_set(fw_st, FW_STATUS_DONE)
 155 #define fw_state_aborted(fw_st)                                 \
 156         __fw_state_set(fw_st, FW_STATUS_ABORTED)
 157 #define fw_state_wait(fw_st)                                    \
 158         __fw_state_wait_common(fw_st, MAX_SCHEDULE_TIMEOUT)
 159
 160 static int __fw_state_check(struct fw_state *fw_st, enum fw_status status)
 161 {
 162         return fw_st->status == status;
 163 }
 164
 165 #define fw_state_is_aborted(fw_st)                              \
 166         __fw_state_check(fw_st, FW_STATUS_ABORTED)
 167
 168 #ifdef CONFIG_FW_LOADER_USER_HELPER
 169
 170 #define fw_state_aborted(fw_st)                                 \
 171         __fw_state_set(fw_st, FW_STATUS_ABORTED)
 172 #define fw_state_is_done(fw_st)                                 \
 173         __fw_state_check(fw_st, FW_STATUS_DONE)
 174 #define fw_state_is_loading(fw_st)                              \
 175         __fw_state_check(fw_st, FW_STATUS_LOADING)
 176 #define fw_state_wait_timeout(fw_st, timeout)                   \
 177         __fw_state_wait_common(fw_st, timeout)
 178
 179 #endif /* CONFIG_FW_LOADER_USER_HELPER */
 180
 181 /* firmware behavior options */
 182 #define FW_OPT_UEVENT   (1U << 0)
 183 #define FW_OPT_NOWAIT   (1U << 1)
 184 #ifdef CONFIG_FW_LOADER_USER_HELPER
 185 #define FW_OPT_USERHELPER       (1U << 2)
 186 #else
 187 #define FW_OPT_USERHELPER       0
 188 #endif
 189 #ifdef CONFIG_FW_LOADER_USER_HELPER_FALLBACK
 190 #define FW_OPT_FALLBACK         FW_OPT_USERHELPER
 191 #else
 192 #define FW_OPT_FALLBACK         0
 193 #endif
 194 #define FW_OPT_NO_WARN  (1U << 3)
 195 #define FW_OPT_NOCACHE  (1U << 4)
 196
 197 struct firmware_cache {
 198         /* firmware_buf instance will be added into the below list */
 199         spinlock_t lock;
 200         struct list_head head;
 201         int state;
 202
 203 #ifdef CONFIG_PM_SLEEP
 204         /*
 205          * Names of firmware images which have been cached successfully
 206          * will be added into the below list so that device uncache
 207          * helper can trace which firmware images have been cached
 208          * before.
 209          */
 210         spinlock_t name_lock;
 211         struct list_head fw_names;
 212
 213         struct delayed_work work;
 214
 215         struct notifier_block   pm_notify;
 216 #endif
 217 };
 218
 219 struct firmware_buf {
 220         struct kref ref;
 221         struct list_head list;
 222         struct firmware_cache *fwc;
 223         struct fw_state fw_st;
 224         void *data;
 225         size_t size;
 226         size_t allocated_size;
 227 #ifdef CONFIG_FW_LOADER_USER_HELPER
 228         bool is_paged_buf;
 229         bool need_uevent;
 230         struct page **pages;
 231         int nr_pages;
 232         int page_array_size;
 233         struct list_head pending_list;
 234 #endif
 235         const char *fw_id;
 236 };
 237
 238 struct fw_cache_entry {
 239         struct list_head list;
 240         const char *name;
 241 };
 242
 243 struct fw_name_devm {
 244         unsigned long magic;
 245         const char *name;
 246 };
 247
 248 #define to_fwbuf(d) container_of(d, struct firmware_buf, ref)
 249
 250 #define FW_LOADER_NO_CACHE      0
 251 #define FW_LOADER_START_CACHE   1
 252
 253 static int fw_cache_piggyback_on_request(const char *name);
 254
 255 /* fw_lock could be moved to 'struct firmware_priv' but since it is just
 256  * guarding for corner cases a global lock should be OK */
 257 static DEFINE_MUTEX(fw_lock);
 258
 259 static bool __enable_firmware = false;
 260
 261 static void enable_firmware(void)
 262 {
 263         mutex_lock(&fw_lock);
 264         __enable_firmware = true;
 265         mutex_unlock(&fw_lock);
 266 }
 267
 268 static void disable_firmware(void)
 269 {
 270         mutex_lock(&fw_lock);
 271         __enable_firmware = false;
 272         mutex_unlock(&fw_lock);
 273 }
 274
 275 /*
 276  * When disabled only the built-in firmware and the firmware cache will be
 277  * used to look for firmware.
 278  */
 279 static bool firmware_enabled(void)
 280 {
 281         bool enabled = false;
 282
 283         mutex_lock(&fw_lock);
 284         if (__enable_firmware)
 285                 enabled = true;
 286         mutex_unlock(&fw_lock);
 287
 288         return enabled;
 289 }
 290
 291 static struct firmware_cache fw_cache;
 292
 293 static struct firmware_buf *__allocate_fw_buf(const char *fw_name,
 294                                               struct firmware_cache *fwc,
 295                                               void *dbuf, size_t size)
 296 {
 297         struct firmware_buf *buf;
 298
 299         buf = kzalloc(sizeof(*buf), GFP_ATOMIC);
 300         if (!buf)
 301                 return NULL;
 302
 303         buf->fw_id = kstrdup_const(fw_name, GFP_ATOMIC);
 304         if (!buf->fw_id) {
 305                 kfree(buf);
 306                 return NULL;
 307         }
 308
 309         kref_init(&buf->ref);
 310         buf->fwc = fwc;
 311         buf->data = dbuf;
 312         buf->allocated_size = size;
 313         fw_state_init(&buf->fw_st);
 314 #ifdef CONFIG_FW_LOADER_USER_HELPER
 315         INIT_LIST_HEAD(&buf->pending_list);
 316 #endif
 317
 318         pr_debug("%s: fw-%s buf=%p\n", __func__, fw_name, buf);
 319
 320         return buf;
 321 }
 322
 323 static struct firmware_buf *__fw_lookup_buf(const char *fw_name)
 324 {
 325         struct firmware_buf *tmp;
 326         struct firmware_cache *fwc = &fw_cache;
 327
 328         list_for_each_entry(tmp, &fwc->head, list)
 329                 if (!strcmp(tmp->fw_id, fw_name))
 330                         return tmp;
 331         return NULL;
 332 }
 333
 334 static int fw_lookup_and_allocate_buf(const char *fw_name,
 335                                       struct firmware_cache *fwc,
 336                                       struct firmware_buf **buf, void *dbuf,
 337                                       size_t size)
 338 {
 339         struct firmware_buf *tmp;
 340
 341         spin_lock(&fwc->lock);
 342         tmp = __fw_lookup_buf(fw_name);
 343         if (tmp) {
 344                 kref_get(&tmp->ref);
 345                 spin_unlock(&fwc->lock);
 346                 *buf = tmp;
 347                 return 1;
 348         }
 349         tmp = __allocate_fw_buf(fw_name, fwc, dbuf, size);
 350         if (tmp)
 351                 list_add(&tmp->list, &fwc->head);
 352         spin_unlock(&fwc->lock);
 353
 354         *buf = tmp;
 355
 356         return tmp ? 0 : -ENOMEM;
 357 }
 358
 359 static void __fw_free_buf(struct kref *ref)
 360         __releases(&fwc->lock)
 361 {
 362         struct firmware_buf *buf = to_fwbuf(ref);
 363         struct firmware_cache *fwc = buf->fwc;
 364
 365         pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
 366                  __func__, buf->fw_id, buf, buf->data,
 367                  (unsigned int)buf->size);
 368
 369         list_del(&buf->list);
 370         spin_unlock(&fwc->lock);
 371
 372 #ifdef CONFIG_FW_LOADER_USER_HELPER
 373         if (buf->is_paged_buf) {
 374                 int i;
 375                 vunmap(buf->data);
 376                 for (i = 0; i < buf->nr_pages; i++)
 377                         __free_page(buf->pages[i]);
 378                 vfree(buf->pages);
 379         } else
 380 #endif
 381         if (!buf->allocated_size)
 382                 vfree(buf->data);
 383         kfree_const(buf->fw_id);
 384         kfree(buf);
 385 }
 386
 387 static void fw_free_buf(struct firmware_buf *buf)
 388 {
 389         struct firmware_cache *fwc = buf->fwc;
 390         spin_lock(&fwc->lock);
 391         if (!kref_put(&buf->ref, __fw_free_buf))
 392                 spin_unlock(&fwc->lock);
 393 }
 394
 395 /* direct firmware loading support */
 396 static char fw_path_para[256];
 397 static const char * const fw_path[] = {
 398         fw_path_para,
 399         "/lib/firmware/updates/" UTS_RELEASE,
 400         "/lib/firmware/updates",
 401         "/lib/firmware/" UTS_RELEASE,
 402         "/lib/firmware"
 403 };
 404
 405 /*
 406  * Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH'
 407  * from kernel command line because firmware_class is generally built in
 408  * kernel instead of module.
 409  */
 410 module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
 411 MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
 412
 413 static int
 414 fw_get_filesystem_firmware(struct device *device, struct firmware_buf *buf)
 415 {
 416         loff_t size;
 417         int i, len;
 418         int rc = -ENOENT;
 419         char *path;
 420         enum kernel_read_file_id id = READING_FIRMWARE;
 421         size_t msize = INT_MAX;
 422
 423         /* Already populated data member means we're loading into a buffer */
 424         if (buf->data) {
 425                 id = READING_FIRMWARE_PREALLOC_BUFFER;
 426                 msize = buf->allocated_size;
 427         }
 428
 429         path = __getname();
 430         if (!path)
 431                 return -ENOMEM;
 432
 433         for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
 434                 /* skip the unset customized path */
 435                 if (!fw_path[i][0])
 436                         continue;
 437
 438                 len = snprintf(path, PATH_MAX, "%s/%s",
 439                                fw_path[i], buf->fw_id);
 440                 if (len >= PATH_MAX) {
 441                         rc = -ENAMETOOLONG;
 442                         break;
 443                 }
 444
 445                 buf->size = 0;
 446                 rc = kernel_read_file_from_path(path, &buf->data, &size, msize,
 447                                                 id);
 448                 if (rc) {
 449                         if (rc == -ENOENT)
 450                                 dev_dbg(device, "loading %s failed with error %d\n",
 451                                          path, rc);
 452                         else
 453                                 dev_warn(device, "loading %s failed with error %d\n",
 454                                          path, rc);
 455                         continue;
 456                 }
 457                 dev_dbg(device, "direct-loading %s\n", buf->fw_id);
 458                 buf->size = size;
 459                 fw_state_done(&buf->fw_st);
 460                 break;
 461         }
 462         __putname(path);
 463
 464         return rc;
 465 }
 466
 467 /* firmware holds the ownership of pages */
 468 static void firmware_free_data(const struct firmware *fw)
 469 {
 470         /* Loaded directly? */
 471         if (!fw->priv) {
 472                 vfree(fw->data);
 473                 return;
 474         }
 475         fw_free_buf(fw->priv);
 476 }
 477
 478 /* store the pages buffer info firmware from buf */
 479 static void fw_set_page_data(struct firmware_buf *buf, struct firmware *fw)
 480 {
 481         fw->priv = buf;
 482 #ifdef CONFIG_FW_LOADER_USER_HELPER
 483         fw->pages = buf->pages;
 484 #endif
 485         fw->size = buf->size;
 486         fw->data = buf->data;
 487
 488         pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
 489                  __func__, buf->fw_id, buf, buf->data,
 490                  (unsigned int)buf->size);
 491 }
 492
 493 #ifdef CONFIG_PM_SLEEP
 494 static void fw_name_devm_release(struct device *dev, void *res)
 495 {
 496         struct fw_name_devm *fwn = res;
 497
 498         if (fwn->magic == (unsigned long)&fw_cache)
 499                 pr_debug("%s: fw_name-%s devm-%p released\n",
 500                                 __func__, fwn->name, res);
 501         kfree_const(fwn->name);
 502 }
 503
 504 static int fw_devm_match(struct device *dev, void *res,
 505                 void *match_data)
 506 {
 507         struct fw_name_devm *fwn = res;
 508
 509         return (fwn->magic == (unsigned long)&fw_cache) &&
 510                 !strcmp(fwn->name, match_data);
 511 }
 512
 513 static struct fw_name_devm *fw_find_devm_name(struct device *dev,
 514                 const char *name)
 515 {
 516         struct fw_name_devm *fwn;
 517
 518         fwn = devres_find(dev, fw_name_devm_release,
 519                           fw_devm_match, (void *)name);
 520         return fwn;
 521 }
 522
 523 /* add firmware name into devres list */
 524 static int fw_add_devm_name(struct device *dev, const char *name)
 525 {
 526         struct fw_name_devm *fwn;
 527
 528         fwn = fw_find_devm_name(dev, name);
 529         if (fwn)
 530                 return 1;
 531
 532         fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm),
 533                            GFP_KERNEL);
 534         if (!fwn)
 535                 return -ENOMEM;
 536         fwn->name = kstrdup_const(name, GFP_KERNEL);
 537         if (!fwn->name) {
 538                 devres_free(fwn);
 539                 return -ENOMEM;
 540         }
 541
 542         fwn->magic = (unsigned long)&fw_cache;
 543         devres_add(dev, fwn);
 544
 545         return 0;
 546 }
 547 #else
 548 static int fw_add_devm_name(struct device *dev, const char *name)
 549 {
 550         return 0;
 551 }
 552 #endif
 553
 554 static int assign_firmware_buf(struct firmware *fw, struct device *device,
 555                                unsigned int opt_flags)
 556 {
 557         struct firmware_buf *buf = fw->priv;
 558
 559         mutex_lock(&fw_lock);
 560         if (!buf->size || fw_state_is_aborted(&buf->fw_st)) {
 561                 mutex_unlock(&fw_lock);
 562                 return -ENOENT;
 563         }
 564
 565         /*
 566          * add firmware name into devres list so that we can auto cache
 567          * and uncache firmware for device.
 568          *
 569          * device may has been deleted already, but the problem
 570          * should be fixed in devres or driver core.
 571          */
 572         /* don't cache firmware handled without uevent */
 573         if (device && (opt_flags & FW_OPT_UEVENT) &&
 574             !(opt_flags & FW_OPT_NOCACHE))
 575                 fw_add_devm_name(device, buf->fw_id);
 576
 577         /*
 578          * After caching firmware image is started, let it piggyback
 579          * on request firmware.
 580          */
 581         if (!(opt_flags & FW_OPT_NOCACHE) &&
 582             buf->fwc->state == FW_LOADER_START_CACHE) {
 583                 if (fw_cache_piggyback_on_request(buf->fw_id))
 584                         kref_get(&buf->ref);
 585         }
 586
 587         /* pass the pages buffer to driver at the last minute */
 588         fw_set_page_data(buf, fw);
 589         mutex_unlock(&fw_lock);
 590         return 0;
 591 }
 592
 593 /*
 594  * user-mode helper code
 595  */
 596 #ifdef CONFIG_FW_LOADER_USER_HELPER
 597 struct firmware_priv {
 598         bool nowait;
 599         struct device dev;
 600         struct firmware_buf *buf;
 601         struct firmware *fw;
 602 };
 603
 604 static struct firmware_priv *to_firmware_priv(struct device *dev)
 605 {
 606         return container_of(dev, struct firmware_priv, dev);
 607 }
 608
 609 static void __fw_load_abort(struct firmware_buf *buf)
 610 {
 611         /*
 612          * There is a small window in which user can write to 'loading'
 613          * between loading done and disappearance of 'loading'
 614          */
 615         if (fw_state_is_done(&buf->fw_st))
 616                 return;
 617
 618         list_del_init(&buf->pending_list);
 619         fw_state_aborted(&buf->fw_st);
 620 }
 621
 622 static void fw_load_abort(struct firmware_priv *fw_priv)
 623 {
 624         struct firmware_buf *buf = fw_priv->buf;
 625
 626         __fw_load_abort(buf);
 627 }
 628
 629 static LIST_HEAD(pending_fw_head);
 630
 631 static void kill_pending_fw_fallback_reqs(bool only_kill_custom)
 632 {
 633         struct firmware_buf *buf;
 634         struct firmware_buf *next;
 635
 636         mutex_lock(&fw_lock);
 637         list_for_each_entry_safe(buf, next, &pending_fw_head, pending_list) {
 638                 if (!buf->need_uevent || !only_kill_custom)
 639                          __fw_load_abort(buf);
 640         }
 641         mutex_unlock(&fw_lock);
 642 }
 643
 644 static ssize_t timeout_show(struct class *class, struct class_attribute *attr,
 645                             char *buf)
 646 {
 647         return sprintf(buf, "%d\n", loading_timeout);
 648 }
 649
 650 /**
 651  * firmware_timeout_store - set number of seconds to wait for firmware
 652  * @class: device class pointer
 653  * @attr: device attribute pointer
 654  * @buf: buffer to scan for timeout value
 655  * @count: number of bytes in @buf
 656  *
 657  *      Sets the number of seconds to wait for the firmware.  Once
 658  *      this expires an error will be returned to the driver and no
 659  *      firmware will be provided.
 660  *
 661  *      Note: zero means 'wait forever'.
 662  **/
 663 static ssize_t timeout_store(struct class *class, struct class_attribute *attr,
 664                              const char *buf, size_t count)
 665 {
 666         loading_timeout = simple_strtol(buf, NULL, 10);
 667         if (loading_timeout < 0)
 668                 loading_timeout = 0;
 669
 670         return count;
 671 }
 672 static CLASS_ATTR_RW(timeout);
 673
 674 static struct attribute *firmware_class_attrs[] = {
 675         &class_attr_timeout.attr,
 676         NULL,
 677 };
 678 ATTRIBUTE_GROUPS(firmware_class);
 679
 680 static void fw_dev_release(struct device *dev)
 681 {
 682         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 683
 684         kfree(fw_priv);
 685 }
 686
 687 static int do_firmware_uevent(struct firmware_priv *fw_priv, struct kobj_uevent_env *env)
 688 {
 689         if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->buf->fw_id))
 690                 return -ENOMEM;
 691         if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
 692                 return -ENOMEM;
 693         if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
 694                 return -ENOMEM;
 695
 696         return 0;
 697 }
 698
 699 static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
 700 {
 701         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 702         int err = 0;
 703
 704         mutex_lock(&fw_lock);
 705         if (fw_priv->buf)
 706                 err = do_firmware_uevent(fw_priv, env);
 707         mutex_unlock(&fw_lock);
 708         return err;
 709 }
 710
 711 static struct class firmware_class = {
 712         .name           = "firmware",
 713         .class_groups   = firmware_class_groups,
 714         .dev_uevent     = firmware_uevent,
 715         .dev_release    = fw_dev_release,
 716 };
 717
 718 static ssize_t firmware_loading_show(struct device *dev,
 719                                      struct device_attribute *attr, char *buf)
 720 {
 721         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 722         int loading = 0;
 723
 724         mutex_lock(&fw_lock);
 725         if (fw_priv->buf)
 726                 loading = fw_state_is_loading(&fw_priv->buf->fw_st);
 727         mutex_unlock(&fw_lock);
 728
 729         return sprintf(buf, "%d\n", loading);
 730 }
 731
 732 /* Some architectures don't have PAGE_KERNEL_RO */
 733 #ifndef PAGE_KERNEL_RO
 734 #define PAGE_KERNEL_RO PAGE_KERNEL
 735 #endif
 736
 737 /* one pages buffer should be mapped/unmapped only once */
 738 static int fw_map_pages_buf(struct firmware_buf *buf)
 739 {
 740         if (!buf->is_paged_buf)
 741                 return 0;
 742
 743         vunmap(buf->data);
 744         buf->data = vmap(buf->pages, buf->nr_pages, 0, PAGE_KERNEL_RO);
 745         if (!buf->data)
 746                 return -ENOMEM;
 747         return 0;
 748 }
 749
 750 /**
 751  * firmware_loading_store - set value in the 'loading' control file
 752  * @dev: device pointer
 753  * @attr: device attribute pointer
 754  * @buf: buffer to scan for loading control value
 755  * @count: number of bytes in @buf
 756  *
 757  *      The relevant values are:
 758  *
 759  *       1: Start a load, discarding any previous partial load.
 760  *       0: Conclude the load and hand the data to the driver code.
 761  *      -1: Conclude the load with an error and discard any written data.
 762  **/
 763 static ssize_t firmware_loading_store(struct device *dev,
 764                                       struct device_attribute *attr,
 765                                       const char *buf, size_t count)
 766 {
 767         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 768         struct firmware_buf *fw_buf;
 769         ssize_t written = count;
 770         int loading = simple_strtol(buf, NULL, 10);
 771         int i;
 772
 773         mutex_lock(&fw_lock);
 774         fw_buf = fw_priv->buf;
 775         if (fw_state_is_aborted(&fw_buf->fw_st))
 776                 goto out;
 777
 778         switch (loading) {
 779         case 1:
 780                 /* discarding any previous partial load */
 781                 if (!fw_state_is_done(&fw_buf->fw_st)) {
 782                         for (i = 0; i < fw_buf->nr_pages; i++)
 783                                 __free_page(fw_buf->pages[i]);
 784                         vfree(fw_buf->pages);
 785                         fw_buf->pages = NULL;
 786                         fw_buf->page_array_size = 0;
 787                         fw_buf->nr_pages = 0;
 788                         fw_state_start(&fw_buf->fw_st);
 789                 }
 790                 break;
 791         case 0:
 792                 if (fw_state_is_loading(&fw_buf->fw_st)) {
 793                         int rc;
 794
 795                         /*
 796                          * Several loading requests may be pending on
 797                          * one same firmware buf, so let all requests
 798                          * see the mapped 'buf->data' once the loading
 799                          * is completed.
 800                          * */
 801                         rc = fw_map_pages_buf(fw_buf);
 802                         if (rc)
 803                                 dev_err(dev, "%s: map pages failed\n",
 804                                         __func__);
 805                         else
 806                                 rc = security_kernel_post_read_file(NULL,
 807                                                 fw_buf->data, fw_buf->size,
 808                                                 READING_FIRMWARE);
 809
 810                         /*
 811                          * Same logic as fw_load_abort, only the DONE bit
 812                          * is ignored and we set ABORT only on failure.
 813                          */
 814                         list_del_init(&fw_buf->pending_list);
 815                         if (rc) {
 816                                 fw_state_aborted(&fw_buf->fw_st);
 817                                 written = rc;
 818                         } else {
 819                                 fw_state_done(&fw_buf->fw_st);
 820                         }
 821                         break;
 822                 }
 823                 /* fallthrough */
 824         default:
 825                 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
 826                 /* fallthrough */
 827         case -1:
 828                 fw_load_abort(fw_priv);
 829                 break;
 830         }
 831 out:
 832         mutex_unlock(&fw_lock);
 833         return written;
 834 }
 835
 836 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
 837
 838 static void firmware_rw_buf(struct firmware_buf *buf, char *buffer,
 839                            loff_t offset, size_t count, bool read)
 840 {
 841         if (read)
 842                 memcpy(buffer, buf->data + offset, count);
 843         else
 844                 memcpy(buf->data + offset, buffer, count);
 845 }
 846
 847 static void firmware_rw(struct firmware_buf *buf, char *buffer,
 848                         loff_t offset, size_t count, bool read)
 849 {
 850         while (count) {
 851                 void *page_data;
 852                 int page_nr = offset >> PAGE_SHIFT;
 853                 int page_ofs = offset & (PAGE_SIZE-1);
 854                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 855
 856                 page_data = kmap(buf->pages[page_nr]);
 857
 858                 if (read)
 859                         memcpy(buffer, page_data + page_ofs, page_cnt);
 860                 else
 861                         memcpy(page_data + page_ofs, buffer, page_cnt);
 862
 863                 kunmap(buf->pages[page_nr]);
 864                 buffer += page_cnt;
 865                 offset += page_cnt;
 866                 count -= page_cnt;
 867         }
 868 }
 869
 870 static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
 871                                   struct bin_attribute *bin_attr,
 872                                   char *buffer, loff_t offset, size_t count)
 873 {
 874         struct device *dev = kobj_to_dev(kobj);
 875         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 876         struct firmware_buf *buf;
 877         ssize_t ret_count;
 878
 879         mutex_lock(&fw_lock);
 880         buf = fw_priv->buf;
 881         if (!buf || fw_state_is_done(&buf->fw_st)) {
 882                 ret_count = -ENODEV;
 883                 goto out;
 884         }
 885         if (offset > buf->size) {
 886                 ret_count = 0;
 887                 goto out;
 888         }
 889         if (count > buf->size - offset)
 890                 count = buf->size - offset;
 891
 892         ret_count = count;
 893
 894         if (buf->data)
 895                 firmware_rw_buf(buf, buffer, offset, count, true);
 896         else
 897                 firmware_rw(buf, buffer, offset, count, true);
 898
 899 out:
 900         mutex_unlock(&fw_lock);
 901         return ret_count;
 902 }
 903
 904 static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
 905 {
 906         struct firmware_buf *buf = fw_priv->buf;
 907         int pages_needed = PAGE_ALIGN(min_size) >> PAGE_SHIFT;
 908
 909         /* If the array of pages is too small, grow it... */
 910         if (buf->page_array_size < pages_needed) {
 911                 int new_array_size = max(pages_needed,
 912                                          buf->page_array_size * 2);
 913                 struct page **new_pages;
 914
 915                 new_pages = vmalloc(new_array_size * sizeof(void *));
 916                 if (!new_pages) {
 917                         fw_load_abort(fw_priv);
 918                         return -ENOMEM;
 919                 }
 920                 memcpy(new_pages, buf->pages,
 921                        buf->page_array_size * sizeof(void *));
 922                 memset(&new_pages[buf->page_array_size], 0, sizeof(void *) *
 923                        (new_array_size - buf->page_array_size));
 924                 vfree(buf->pages);
 925                 buf->pages = new_pages;
 926                 buf->page_array_size = new_array_size;
 927         }
 928
 929         while (buf->nr_pages < pages_needed) {
 930                 buf->pages[buf->nr_pages] =
 931                         alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
 932
 933                 if (!buf->pages[buf->nr_pages]) {
 934                         fw_load_abort(fw_priv);
 935                         return -ENOMEM;
 936                 }
 937                 buf->nr_pages++;
 938         }
 939         return 0;
 940 }
 941
 942 /**
 943  * firmware_data_write - write method for firmware
 944  * @filp: open sysfs file
 945  * @kobj: kobject for the device
 946  * @bin_attr: bin_attr structure
 947  * @buffer: buffer being written
 948  * @offset: buffer offset for write in total data store area
 949  * @count: buffer size
 950  *
 951  *      Data written to the 'data' attribute will be later handed to
 952  *      the driver as a firmware image.
 953  **/
 954 static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,
 955                                    struct bin_attribute *bin_attr,
 956                                    char *buffer, loff_t offset, size_t count)
 957 {
 958         struct device *dev = kobj_to_dev(kobj);
 959         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 960         struct firmware_buf *buf;
 961         ssize_t retval;
 962
 963         if (!capable(CAP_SYS_RAWIO))
 964                 return -EPERM;
 965
 966         mutex_lock(&fw_lock);
 967         buf = fw_priv->buf;
 968         if (!buf || fw_state_is_done(&buf->fw_st)) {
 969                 retval = -ENODEV;
 970                 goto out;
 971         }
 972
 973         if (buf->data) {
 974                 if (offset + count > buf->allocated_size) {
 975                         retval = -ENOMEM;
 976                         goto out;
 977                 }
 978                 firmware_rw_buf(buf, buffer, offset, count, false);
 979                 retval = count;
 980         } else {
 981                 retval = fw_realloc_buffer(fw_priv, offset + count);
 982                 if (retval)
 983                         goto out;
 984
 985                 retval = count;
 986                 firmware_rw(buf, buffer, offset, count, false);
 987         }
 988
 989         buf->size = max_t(size_t, offset + count, buf->size);
 990 out:
 991         mutex_unlock(&fw_lock);
 992         return retval;
 993 }
 994
 995 static struct bin_attribute firmware_attr_data = {
 996         .attr = { .name = "data", .mode = 0644 },
 997         .size = 0,
 998         .read = firmware_data_read,
 999         .write = firmware_data_write,
1000 };
1001
1002 static struct attribute *fw_dev_attrs[] = {
1003         &dev_attr_loading.attr,
1004         NULL
1005 };
1006
1007 static struct bin_attribute *fw_dev_bin_attrs[] = {
1008         &firmware_attr_data,
1009         NULL
1010 };
1011
1012 static const struct attribute_group fw_dev_attr_group = {
1013         .attrs = fw_dev_attrs,
1014         .bin_attrs = fw_dev_bin_attrs,
1015 };
1016
1017 static const struct attribute_group *fw_dev_attr_groups[] = {
1018         &fw_dev_attr_group,
1019         NULL
1020 };
1021
1022 static struct firmware_priv *
1023 fw_create_instance(struct firmware *firmware, const char *fw_name,
1024                    struct device *device, unsigned int opt_flags)
1025 {
1026         struct firmware_priv *fw_priv;
1027         struct device *f_dev;
1028
1029         fw_priv = kzalloc(sizeof(*fw_priv), GFP_KERNEL);
1030         if (!fw_priv) {
1031                 fw_priv = ERR_PTR(-ENOMEM);
1032                 goto exit;
1033         }
1034
1035         fw_priv->nowait = !!(opt_flags & FW_OPT_NOWAIT);
1036         fw_priv->fw = firmware;
1037         f_dev = &fw_priv->dev;
1038
1039         device_initialize(f_dev);
1040         dev_set_name(f_dev, "%s", fw_name);
1041         f_dev->parent = device;
1042         f_dev->class = &firmware_class;
1043         f_dev->groups = fw_dev_attr_groups;
1044 exit:
1045         return fw_priv;
1046 }
1047
1048 /* load a firmware via user helper */
1049 static int _request_firmware_load(struct firmware_priv *fw_priv,
1050                                   unsigned int opt_flags, long timeout)
1051 {
1052         int retval = 0;
1053         struct device *f_dev = &fw_priv->dev;
1054         struct firmware_buf *buf = fw_priv->buf;
1055
1056         /* fall back on userspace loading */
1057         if (!buf->data)
1058                 buf->is_paged_buf = true;
1059
1060         dev_set_uevent_suppress(f_dev, true);
1061
1062         retval = device_add(f_dev);
1063         if (retval) {
1064                 dev_err(f_dev, "%s: device_register failed\n", __func__);
1065                 goto err_put_dev;
1066         }
1067
1068         mutex_lock(&fw_lock);
1069         list_add(&buf->pending_list, &pending_fw_head);
1070         mutex_unlock(&fw_lock);
1071
1072         if (opt_flags & FW_OPT_UEVENT) {
1073                 buf->need_uevent = true;
1074                 dev_set_uevent_suppress(f_dev, false);
1075                 dev_dbg(f_dev, "firmware: requesting %s\n", buf->fw_id);
1076                 kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD);
1077         } else {
1078                 timeout = MAX_JIFFY_OFFSET;
1079         }
1080
1081         retval = fw_state_wait_timeout(&buf->fw_st, timeout);
1082         if (retval < 0) {
1083                 mutex_lock(&fw_lock);
1084                 fw_load_abort(fw_priv);
1085                 mutex_unlock(&fw_lock);
1086         }
1087
1088         if (fw_state_is_aborted(&buf->fw_st))
1089                 retval = -EAGAIN;
1090         else if (buf->is_paged_buf && !buf->data)
1091                 retval = -ENOMEM;
1092
1093         device_del(f_dev);
1094 err_put_dev:
1095         put_device(f_dev);
1096         return retval;
1097 }
1098
1099 static int fw_load_from_user_helper(struct firmware *firmware,
1100                                     const char *name, struct device *device,
1101                                     unsigned int opt_flags)
1102 {
1103         struct firmware_priv *fw_priv;
1104         long timeout;
1105         int ret;
1106
1107         timeout = firmware_loading_timeout();
1108         if (opt_flags & FW_OPT_NOWAIT) {
1109                 timeout = usermodehelper_read_lock_wait(timeout);
1110                 if (!timeout) {
1111                         dev_dbg(device, "firmware: %s loading timed out\n",
1112                                 name);
1113                         return -EBUSY;
1114                 }
1115         } else {
1116                 ret = usermodehelper_read_trylock();
1117                 if (WARN_ON(ret)) {
1118                         dev_err(device, "firmware: %s will not be loaded\n",
1119                                 name);
1120                         return ret;
1121                 }
1122         }
1123
1124         fw_priv = fw_create_instance(firmware, name, device, opt_flags);
1125         if (IS_ERR(fw_priv)) {
1126                 ret = PTR_ERR(fw_priv);
1127                 goto out_unlock;
1128         }
1129
1130         fw_priv->buf = firmware->priv;
1131         ret = _request_firmware_load(fw_priv, opt_flags, timeout);
1132
1133         if (!ret)
1134                 ret = assign_firmware_buf(firmware, device, opt_flags);
1135
1136 out_unlock:
1137         usermodehelper_read_unlock();
1138
1139         return ret;
1140 }
1141
1142 #else /* CONFIG_FW_LOADER_USER_HELPER */
1143 static inline int
1144 fw_load_from_user_helper(struct firmware *firmware, const char *name,
1145                          struct device *device, unsigned int opt_flags)
1146 {
1147         return -ENOENT;
1148 }
1149
1150 static inline void kill_pending_fw_fallback_reqs(bool only_kill_custom) { }
1151
1152 #endif /* CONFIG_FW_LOADER_USER_HELPER */
1153
1154 /* prepare firmware and firmware_buf structs;
1155  * return 0 if a firmware is already assigned, 1 if need to load one,
1156  * or a negative error code
1157  */
1158 static int
1159 _request_firmware_prepare(struct firmware **firmware_p, const char *name,
1160                           struct device *device, void *dbuf, size_t size)
1161 {
1162         struct firmware *firmware;
1163         struct firmware_buf *buf;
1164         int ret;
1165
1166         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
1167         if (!firmware) {
1168                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
1169                         __func__);
1170                 return -ENOMEM;
1171         }
1172
1173         if (fw_get_builtin_firmware(firmware, name, dbuf, size)) {
1174                 dev_dbg(device, "using built-in %s\n", name);
1175                 return 0; /* assigned */
1176         }
1177
1178         ret = fw_lookup_and_allocate_buf(name, &fw_cache, &buf, dbuf, size);
1179
1180         /*
1181          * bind with 'buf' now to avoid warning in failure path
1182          * of requesting firmware.
1183          */
1184         firmware->priv = buf;
1185
1186         if (ret > 0) {
1187                 ret = fw_state_wait(&buf->fw_st);
1188                 if (!ret) {
1189                         fw_set_page_data(buf, firmware);
1190                         return 0; /* assigned */
1191                 }
1192         }
1193
1194         if (ret < 0)
1195                 return ret;
1196         return 1; /* need to load */
1197 }
1198
1199 /*
1200  * Batched requests need only one wake, we need to do this step last due to the
1201  * fallback mechanism. The buf is protected with kref_get(), and it won't be
1202  * released until the last user calls release_firmware().
1203  *
1204  * Failed batched requests are possible as well, in such cases we just share
1205  * the struct firmware_buf and won't release it until all requests are woken
1206  * and have gone through this same path.
1207  */
1208 static void fw_abort_batch_reqs(struct firmware *fw)
1209 {
1210         struct firmware_buf *buf;
1211
1212         /* Loaded directly? */
1213         if (!fw || !fw->priv)
1214                 return;
1215
1216         buf = fw->priv;
1217         if (!fw_state_is_aborted(&buf->fw_st))
1218                 fw_state_aborted(&buf->fw_st);
1219 }
1220
1221 /* called from request_firmware() and request_firmware_work_func() */
1222 static int
1223 _request_firmware(const struct firmware **firmware_p, const char *name,
1224                   struct device *device, void *buf, size_t size,
1225                   unsigned int opt_flags)
1226 {
1227         struct firmware *fw = NULL;
1228         int ret;
1229
1230         if (!firmware_p)
1231                 return -EINVAL;
1232
1233         if (!name || name[0] == '\0') {
1234                 ret = -EINVAL;
1235                 goto out;
1236         }
1237
1238         ret = _request_firmware_prepare(&fw, name, device, buf, size);
1239         if (ret <= 0) /* error or already assigned */
1240                 goto out;
1241
1242         if (!firmware_enabled()) {
1243                 WARN(1, "firmware request while host is not available\n");
1244                 ret = -EHOSTDOWN;
1245                 goto out;
1246         }
1247
1248         ret = fw_get_filesystem_firmware(device, fw->priv);
1249         if (ret) {
1250                 if (!(opt_flags & FW_OPT_NO_WARN))
1251                         dev_warn(device,
1252                                  "Direct firmware load for %s failed with error %d\n",
1253                                  name, ret);
1254                 if (opt_flags & FW_OPT_USERHELPER) {
1255                         dev_warn(device, "Falling back to user helper\n");
1256                         ret = fw_load_from_user_helper(fw, name, device,
1257                                                        opt_flags);
1258                 }
1259         } else
1260                 ret = assign_firmware_buf(fw, device, opt_flags);
1261
1262  out:
1263         if (ret < 0) {
1264                 fw_abort_batch_reqs(fw);
1265                 release_firmware(fw);
1266                 fw = NULL;
1267         }
1268
1269         *firmware_p = fw;
1270         return ret;
1271 }
1272
1273 /**
1274  * request_firmware: - send firmware request and wait for it
1275  * @firmware_p: pointer to firmware image
1276  * @name: name of firmware file
1277  * @device: device for which firmware is being loaded
1278  *
1279  *      @firmware_p will be used to return a firmware image by the name
1280  *      of @name for device @device.
1281  *
1282  *      Should be called from user context where sleeping is allowed.
1283  *
1284  *      @name will be used as $FIRMWARE in the uevent environment and
1285  *      should be distinctive enough not to be confused with any other
1286  *      firmware image for this or any other device.
1287  *
1288  *      Caller must hold the reference count of @device.
1289  *
1290  *      The function can be called safely inside device's suspend and
1291  *      resume callback.
1292  **/
1293 int
1294 request_firmware(const struct firmware **firmware_p, const char *name,
1295                  struct device *device)
1296 {
1297         int ret;
1298
1299         /* Need to pin this module until return */
1300         __module_get(THIS_MODULE);
1301         ret = _request_firmware(firmware_p, name, device, NULL, 0,
1302                                 FW_OPT_UEVENT | FW_OPT_FALLBACK);
1303         module_put(THIS_MODULE);
1304         return ret;
1305 }
1306 EXPORT_SYMBOL(request_firmware);
1307
1308 /**
1309  * request_firmware_direct: - load firmware directly without usermode helper
1310  * @firmware_p: pointer to firmware image
1311  * @name: name of firmware file
1312  * @device: device for which firmware is being loaded
1313  *
1314  * This function works pretty much like request_firmware(), but this doesn't
1315  * fall back to usermode helper even if the firmware couldn't be loaded
1316  * directly from fs.  Hence it's useful for loading optional firmwares, which
1317  * aren't always present, without extra long timeouts of udev.
1318  **/
1319 int request_firmware_direct(const struct firmware **firmware_p,
1320                             const char *name, struct device *device)
1321 {
1322         int ret;
1323
1324         __module_get(THIS_MODULE);
1325         ret = _request_firmware(firmware_p, name, device, NULL, 0,
1326                                 FW_OPT_UEVENT | FW_OPT_NO_WARN);
1327         module_put(THIS_MODULE);
1328         return ret;
1329 }
1330 EXPORT_SYMBOL_GPL(request_firmware_direct);
1331
1332 /**
1333  * request_firmware_into_buf - load firmware into a previously allocated buffer
1334  * @firmware_p: pointer to firmware image
1335  * @name: name of firmware file
1336  * @device: device for which firmware is being loaded and DMA region allocated
1337  * @buf: address of buffer to load firmware into
1338  * @size: size of buffer
1339  *
1340  * This function works pretty much like request_firmware(), but it doesn't
1341  * allocate a buffer to hold the firmware data. Instead, the firmware
1342  * is loaded directly into the buffer pointed to by @buf and the @firmware_p
1343  * data member is pointed at @buf.
1344  *
1345  * This function doesn't cache firmware either.
1346  */
1347 int
1348 request_firmware_into_buf(const struct firmware **firmware_p, const char *name,
1349                           struct device *device, void *buf, size_t size)
1350 {
1351         int ret;
1352
1353         __module_get(THIS_MODULE);
1354         ret = _request_firmware(firmware_p, name, device, buf, size,
1355                                 FW_OPT_UEVENT | FW_OPT_FALLBACK |
1356                                 FW_OPT_NOCACHE);
1357         module_put(THIS_MODULE);
1358         return ret;
1359 }
1360 EXPORT_SYMBOL(request_firmware_into_buf);
1361
1362 /**
1363  * release_firmware: - release the resource associated with a firmware image
1364  * @fw: firmware resource to release
1365  **/
1366 void release_firmware(const struct firmware *fw)
1367 {
1368         if (fw) {
1369                 if (!fw_is_builtin_firmware(fw))
1370                         firmware_free_data(fw);
1371                 kfree(fw);
1372         }
1373 }
1374 EXPORT_SYMBOL(release_firmware);
1375
1376 /* Async support */
1377 struct firmware_work {
1378         struct work_struct work;
1379         struct module *module;
1380         const char *name;
1381         struct device *device;
1382         void *context;
1383         void (*cont)(const struct firmware *fw, void *context);
1384         unsigned int opt_flags;
1385 };
1386
1387 static void request_firmware_work_func(struct work_struct *work)
1388 {
1389         struct firmware_work *fw_work;
1390         const struct firmware *fw;
1391
1392         fw_work = container_of(work, struct firmware_work, work);
1393
1394         _request_firmware(&fw, fw_work->name, fw_work->device, NULL, 0,
1395                           fw_work->opt_flags);
1396         fw_work->cont(fw, fw_work->context);
1397         put_device(fw_work->device); /* taken in request_firmware_nowait() */
1398
1399         module_put(fw_work->module);
1400         kfree_const(fw_work->name);
1401         kfree(fw_work);
1402 }
1403
1404 /**
1405  * request_firmware_nowait - asynchronous version of request_firmware
1406  * @module: module requesting the firmware
1407  * @uevent: sends uevent to copy the firmware image if this flag
1408  *      is non-zero else the firmware copy must be done manually.
1409  * @name: name of firmware file
1410  * @device: device for which firmware is being loaded
1411  * @gfp: allocation flags
1412  * @context: will be passed over to @cont, and
1413  *      @fw may be %NULL if firmware request fails.
1414  * @cont: function will be called asynchronously when the firmware
1415  *      request is over.
1416  *
1417  *      Caller must hold the reference count of @device.
1418  *
1419  *      Asynchronous variant of request_firmware() for user contexts:
1420  *              - sleep for as small periods as possible since it may
1421  *                increase kernel boot time of built-in device drivers
1422  *                requesting firmware in their ->probe() methods, if
1423  *                @gfp is GFP_KERNEL.
1424  *
1425  *              - can't sleep at all if @gfp is GFP_ATOMIC.
1426  **/
1427 int
1428 request_firmware_nowait(
1429         struct module *module, bool uevent,
1430         const char *name, struct device *device, gfp_t gfp, void *context,
1431         void (*cont)(const struct firmware *fw, void *context))
1432 {
1433         struct firmware_work *fw_work;
1434
1435         fw_work = kzalloc(sizeof(struct firmware_work), gfp);
1436         if (!fw_work)
1437                 return -ENOMEM;
1438
1439         fw_work->module = module;
1440         fw_work->name = kstrdup_const(name, gfp);
1441         if (!fw_work->name) {
1442                 kfree(fw_work);
1443                 return -ENOMEM;
1444         }
1445         fw_work->device = device;
1446         fw_work->context = context;
1447         fw_work->cont = cont;
1448         fw_work->opt_flags = FW_OPT_NOWAIT | FW_OPT_FALLBACK |
1449                 (uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
1450
1451         if (!try_module_get(module)) {
1452                 kfree_const(fw_work->name);
1453                 kfree(fw_work);
1454                 return -EFAULT;
1455         }
1456
1457         get_device(fw_work->device);
1458         INIT_WORK(&fw_work->work, request_firmware_work_func);
1459         schedule_work(&fw_work->work);
1460         return 0;
1461 }
1462 EXPORT_SYMBOL(request_firmware_nowait);
1463
1464 #ifdef CONFIG_PM_SLEEP
1465 static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
1466
1467 /**
1468  * cache_firmware - cache one firmware image in kernel memory space
1469  * @fw_name: the firmware image name
1470  *
1471  * Cache firmware in kernel memory so that drivers can use it when
1472  * system isn't ready for them to request firmware image from userspace.
1473  * Once it returns successfully, driver can use request_firmware or its
1474  * nowait version to get the cached firmware without any interacting
1475  * with userspace
1476  *
1477  * Return 0 if the firmware image has been cached successfully
1478  * Return !0 otherwise
1479  *
1480  */
1481 static int cache_firmware(const char *fw_name)
1482 {
1483         int ret;
1484         const struct firmware *fw;
1485
1486         pr_debug("%s: %s\n", __func__, fw_name);
1487
1488         ret = request_firmware(&fw, fw_name, NULL);
1489         if (!ret)
1490                 kfree(fw);
1491
1492         pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
1493
1494         return ret;
1495 }
1496
1497 static struct firmware_buf *fw_lookup_buf(const char *fw_name)
1498 {
1499         struct firmware_buf *tmp;
1500         struct firmware_cache *fwc = &fw_cache;
1501
1502         spin_lock(&fwc->lock);
1503         tmp = __fw_lookup_buf(fw_name);
1504         spin_unlock(&fwc->lock);
1505
1506         return tmp;
1507 }
1508
1509 /**
1510  * uncache_firmware - remove one cached firmware image
1511  * @fw_name: the firmware image name
1512  *
1513  * Uncache one firmware image which has been cached successfully
1514  * before.
1515  *
1516  * Return 0 if the firmware cache has been removed successfully
1517  * Return !0 otherwise
1518  *
1519  */
1520 static int uncache_firmware(const char *fw_name)
1521 {
1522         struct firmware_buf *buf;
1523         struct firmware fw;
1524
1525         pr_debug("%s: %s\n", __func__, fw_name);
1526
1527         if (fw_get_builtin_firmware(&fw, fw_name, NULL, 0))
1528                 return 0;
1529
1530         buf = fw_lookup_buf(fw_name);
1531         if (buf) {
1532                 fw_free_buf(buf);
1533                 return 0;
1534         }
1535
1536         return -EINVAL;
1537 }
1538
1539 static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
1540 {
1541         struct fw_cache_entry *fce;
1542
1543         fce = kzalloc(sizeof(*fce), GFP_ATOMIC);
1544         if (!fce)
1545                 goto exit;
1546
1547         fce->name = kstrdup_const(name, GFP_ATOMIC);
1548         if (!fce->name) {
1549                 kfree(fce);
1550                 fce = NULL;
1551                 goto exit;
1552         }
1553 exit:
1554         return fce;
1555 }
1556
1557 static int __fw_entry_found(const char *name)
1558 {
1559         struct firmware_cache *fwc = &fw_cache;
1560         struct fw_cache_entry *fce;
1561
1562         list_for_each_entry(fce, &fwc->fw_names, list) {
1563                 if (!strcmp(fce->name, name))
1564                         return 1;
1565         }
1566         return 0;
1567 }
1568
1569 static int fw_cache_piggyback_on_request(const char *name)
1570 {
1571         struct firmware_cache *fwc = &fw_cache;
1572         struct fw_cache_entry *fce;
1573         int ret = 0;
1574
1575         spin_lock(&fwc->name_lock);
1576         if (__fw_entry_found(name))
1577                 goto found;
1578
1579         fce = alloc_fw_cache_entry(name);
1580         if (fce) {
1581                 ret = 1;
1582                 list_add(&fce->list, &fwc->fw_names);
1583                 pr_debug("%s: fw: %s\n", __func__, name);
1584         }
1585 found:
1586         spin_unlock(&fwc->name_lock);
1587         return ret;
1588 }
1589
1590 static void free_fw_cache_entry(struct fw_cache_entry *fce)
1591 {
1592         kfree_const(fce->name);
1593         kfree(fce);
1594 }
1595
1596 static void __async_dev_cache_fw_image(void *fw_entry,
1597                                        async_cookie_t cookie)
1598 {
1599         struct fw_cache_entry *fce = fw_entry;
1600         struct firmware_cache *fwc = &fw_cache;
1601         int ret;
1602
1603         ret = cache_firmware(fce->name);
1604         if (ret) {
1605                 spin_lock(&fwc->name_lock);
1606                 list_del(&fce->list);
1607                 spin_unlock(&fwc->name_lock);
1608
1609                 free_fw_cache_entry(fce);
1610         }
1611 }
1612
1613 /* called with dev->devres_lock held */
1614 static void dev_create_fw_entry(struct device *dev, void *res,
1615                                 void *data)
1616 {
1617         struct fw_name_devm *fwn = res;
1618         const char *fw_name = fwn->name;
1619         struct list_head *head = data;
1620         struct fw_cache_entry *fce;
1621
1622         fce = alloc_fw_cache_entry(fw_name);
1623         if (fce)
1624                 list_add(&fce->list, head);
1625 }
1626
1627 static int devm_name_match(struct device *dev, void *res,
1628                            void *match_data)
1629 {
1630         struct fw_name_devm *fwn = res;
1631         return (fwn->magic == (unsigned long)match_data);
1632 }
1633
1634 static void dev_cache_fw_image(struct device *dev, void *data)
1635 {
1636         LIST_HEAD(todo);
1637         struct fw_cache_entry *fce;
1638         struct fw_cache_entry *fce_next;
1639         struct firmware_cache *fwc = &fw_cache;
1640
1641         devres_for_each_res(dev, fw_name_devm_release,
1642                             devm_name_match, &fw_cache,
1643                             dev_create_fw_entry, &todo);
1644
1645         list_for_each_entry_safe(fce, fce_next, &todo, list) {
1646                 list_del(&fce->list);
1647
1648                 spin_lock(&fwc->name_lock);
1649                 /* only one cache entry for one firmware */
1650                 if (!__fw_entry_found(fce->name)) {
1651                         list_add(&fce->list, &fwc->fw_names);
1652                 } else {
1653                         free_fw_cache_entry(fce);
1654                         fce = NULL;
1655                 }
1656                 spin_unlock(&fwc->name_lock);
1657
1658                 if (fce)
1659                         async_schedule_domain(__async_dev_cache_fw_image,
1660                                               (void *)fce,
1661                                               &fw_cache_domain);
1662         }
1663 }
1664
1665 static void __device_uncache_fw_images(void)
1666 {
1667         struct firmware_cache *fwc = &fw_cache;
1668         struct fw_cache_entry *fce;
1669
1670         spin_lock(&fwc->name_lock);
1671         while (!list_empty(&fwc->fw_names)) {
1672                 fce = list_entry(fwc->fw_names.next,
1673                                 struct fw_cache_entry, list);
1674                 list_del(&fce->list);
1675                 spin_unlock(&fwc->name_lock);
1676
1677                 uncache_firmware(fce->name);
1678                 free_fw_cache_entry(fce);
1679
1680                 spin_lock(&fwc->name_lock);
1681         }
1682         spin_unlock(&fwc->name_lock);
1683 }
1684
1685 /**
1686  * device_cache_fw_images - cache devices' firmware
1687  *
1688  * If one device called request_firmware or its nowait version
1689  * successfully before, the firmware names are recored into the
1690  * device's devres link list, so device_cache_fw_images can call
1691  * cache_firmware() to cache these firmwares for the device,
1692  * then the device driver can load its firmwares easily at
1693  * time when system is not ready to complete loading firmware.
1694  */
1695 static void device_cache_fw_images(void)
1696 {
1697         struct firmware_cache *fwc = &fw_cache;
1698         int old_timeout;
1699         DEFINE_WAIT(wait);
1700
1701         pr_debug("%s\n", __func__);
1702
1703         /* cancel uncache work */
1704         cancel_delayed_work_sync(&fwc->work);
1705
1706         /*
1707          * use small loading timeout for caching devices' firmware
1708          * because all these firmware images have been loaded
1709          * successfully at lease once, also system is ready for
1710          * completing firmware loading now. The maximum size of
1711          * firmware in current distributions is about 2M bytes,
1712          * so 10 secs should be enough.
1713          */
1714         old_timeout = loading_timeout;
1715         loading_timeout = 10;
1716
1717         mutex_lock(&fw_lock);
1718         fwc->state = FW_LOADER_START_CACHE;
1719         dpm_for_each_dev(NULL, dev_cache_fw_image);
1720         mutex_unlock(&fw_lock);
1721
1722         /* wait for completion of caching firmware for all devices */
1723         async_synchronize_full_domain(&fw_cache_domain);
1724
1725         loading_timeout = old_timeout;
1726 }
1727
1728 /**
1729  * device_uncache_fw_images - uncache devices' firmware
1730  *
1731  * uncache all firmwares which have been cached successfully
1732  * by device_uncache_fw_images earlier
1733  */
1734 static void device_uncache_fw_images(void)
1735 {
1736         pr_debug("%s\n", __func__);
1737         __device_uncache_fw_images();
1738 }
1739
1740 static void device_uncache_fw_images_work(struct work_struct *work)
1741 {
1742         device_uncache_fw_images();
1743 }
1744
1745 /**
1746  * device_uncache_fw_images_delay - uncache devices firmwares
1747  * @delay: number of milliseconds to delay uncache device firmwares
1748  *
1749  * uncache all devices's firmwares which has been cached successfully
1750  * by device_cache_fw_images after @delay milliseconds.
1751  */
1752 static void device_uncache_fw_images_delay(unsigned long delay)
1753 {
1754         queue_delayed_work(system_power_efficient_wq, &fw_cache.work,
1755                            msecs_to_jiffies(delay));
1756 }
1757
1758 /**
1759  * fw_pm_notify - notifier for suspend/resume
1760  * @notify_block: unused
1761  * @mode: mode we are switching to
1762  * @unused: unused
1763  *
1764  * Used to modify the firmware_class state as we move in between states.
1765  * The firmware_class implements a firmware cache to enable device driver
1766  * to fetch firmware upon resume before the root filesystem is ready. We
1767  * disable API calls which do not use the built-in firmware or the firmware
1768  * cache when we know these calls will not work.
1769  *
1770  * The inner logic behind all this is a bit complex so it is worth summarizing
1771  * the kernel's own suspend/resume process with context and focus on how this
1772  * can impact the firmware API.
1773  *
1774  * First a review on how we go to suspend::
1775  *
1776  *      pm_suspend() --> enter_state() -->
1777  *      sys_sync()
1778  *      suspend_prepare() -->
1779  *              __pm_notifier_call_chain(PM_SUSPEND_PREPARE, ...);
1780  *              suspend_freeze_processes() -->
1781  *                      freeze_processes() -->
1782  *                              __usermodehelper_set_disable_depth(UMH_DISABLED);
1783  *                              freeze all tasks ...
1784  *                      freeze_kernel_threads()
1785  *      suspend_devices_and_enter() -->
1786  *              dpm_suspend_start() -->
1787  *                              dpm_prepare()
1788  *                              dpm_suspend()
1789  *              suspend_enter()  -->
1790  *                      platform_suspend_prepare()
1791  *                      dpm_suspend_late()
1792  *                      freeze_enter()
1793  *                      syscore_suspend()
1794  *
1795  * When we resume we bail out of a loop from suspend_devices_and_enter() and
1796  * unwind back out to the caller enter_state() where we were before as follows::
1797  *
1798  *      enter_state() -->
1799  *      suspend_devices_and_enter() --> (bail from loop)
1800  *              dpm_resume_end() -->
1801  *                      dpm_resume()
1802  *                      dpm_complete()
1803  *      suspend_finish() -->
1804  *              suspend_thaw_processes() -->
1805  *                      thaw_processes() -->
1806  *                              __usermodehelper_set_disable_depth(UMH_FREEZING);
1807  *                              thaw_workqueues();
1808  *                              thaw all processes ...
1809  *                              usermodehelper_enable();
1810  *              pm_notifier_call_chain(PM_POST_SUSPEND);
1811  *
1812  * fw_pm_notify() works through pm_notifier_call_chain().
1813  */
1814 static int fw_pm_notify(struct notifier_block *notify_block,
1815                         unsigned long mode, void *unused)
1816 {
1817         switch (mode) {
1818         case PM_HIBERNATION_PREPARE:
1819         case PM_SUSPEND_PREPARE:
1820         case PM_RESTORE_PREPARE:
1821                 /*
1822                  * kill pending fallback requests with a custom fallback
1823                  * to avoid stalling suspend.
1824                  */
1825                 kill_pending_fw_fallback_reqs(true);
1826                 device_cache_fw_images();
1827                 disable_firmware();
1828                 break;
1829
1830         case PM_POST_SUSPEND:
1831         case PM_POST_HIBERNATION:
1832         case PM_POST_RESTORE:
1833                 /*
1834                  * In case that system sleep failed and syscore_suspend is
1835                  * not called.
1836                  */
1837                 mutex_lock(&fw_lock);
1838                 fw_cache.state = FW_LOADER_NO_CACHE;
1839                 mutex_unlock(&fw_lock);
1840                 enable_firmware();
1841
1842                 device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
1843                 break;
1844         }
1845
1846         return 0;
1847 }
1848
1849 /* stop caching firmware once syscore_suspend is reached */
1850 static int fw_suspend(void)
1851 {
1852         fw_cache.state = FW_LOADER_NO_CACHE;
1853         return 0;
1854 }
1855
1856 static struct syscore_ops fw_syscore_ops = {
1857         .suspend = fw_suspend,
1858 };
1859 #else
1860 static int fw_cache_piggyback_on_request(const char *name)
1861 {
1862         return 0;
1863 }
1864 #endif
1865
1866 static void __init fw_cache_init(void)
1867 {
1868         spin_lock_init(&fw_cache.lock);
1869         INIT_LIST_HEAD(&fw_cache.head);
1870         fw_cache.state = FW_LOADER_NO_CACHE;
1871
1872 #ifdef CONFIG_PM_SLEEP
1873         spin_lock_init(&fw_cache.name_lock);
1874         INIT_LIST_HEAD(&fw_cache.fw_names);
1875
1876         INIT_DELAYED_WORK(&fw_cache.work,
1877                           device_uncache_fw_images_work);
1878
1879         fw_cache.pm_notify.notifier_call = fw_pm_notify;
1880         register_pm_notifier(&fw_cache.pm_notify);
1881
1882         register_syscore_ops(&fw_syscore_ops);
1883 #endif
1884 }
1885
1886 static int fw_shutdown_notify(struct notifier_block *unused1,
1887                               unsigned long unused2, void *unused3)
1888 {
1889         disable_firmware();
1890         /*
1891          * Kill all pending fallback requests to avoid both stalling shutdown,
1892          * and avoid a deadlock with the usermode_lock.
1893          */
1894         kill_pending_fw_fallback_reqs(false);
1895
1896         return NOTIFY_DONE;
1897 }
1898
1899 static struct notifier_block fw_shutdown_nb = {
1900         .notifier_call = fw_shutdown_notify,
1901 };
1902
1903 static int __init firmware_class_init(void)
1904 {
1905         enable_firmware();
1906         fw_cache_init();
1907         register_reboot_notifier(&fw_shutdown_nb);
1908 #ifdef CONFIG_FW_LOADER_USER_HELPER
1909         return class_register(&firmware_class);
1910 #else
1911         return 0;
1912 #endif
1913 }
1914
1915 static void __exit firmware_class_exit(void)
1916 {
1917         disable_firmware();
1918 #ifdef CONFIG_PM_SLEEP
1919         unregister_syscore_ops(&fw_syscore_ops);
1920         unregister_pm_notifier(&fw_cache.pm_notify);
1921 #endif
1922         unregister_reboot_notifier(&fw_shutdown_nb);
1923 #ifdef CONFIG_FW_LOADER_USER_HELPER
1924         class_unregister(&firmware_class);
1925 #endif
1926 }
1927
1928 fs_initcall(firmware_class_init);
1929 module_exit(firmware_class_exit);