drivers/base/firmware_class.c

   1 /*
   2  * firmware_class.c - Multi purpose firmware loading support
   3  *
   4  * Copyright (c) 2003 Manuel Estrada Sainz
   5  *
   6  * Please see Documentation/firmware_class/ for more information.
   7  *
   8  */
   9
  10 #include <linux/capability.h>
  11 #include <linux/device.h>
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/timer.h>
  15 #include <linux/vmalloc.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/bitops.h>
  18 #include <linux/mutex.h>
  19 #include <linux/workqueue.h>
  20 #include <linux/highmem.h>
  21 #include <linux/firmware.h>
  22 #include <linux/slab.h>
  23 #include <linux/sched.h>
  24 #include <linux/file.h>
  25 #include <linux/list.h>
  26 #include <linux/async.h>
  27 #include <linux/pm.h>
  28 #include <linux/suspend.h>
  29 #include <linux/syscore_ops.h>
  30 #include <linux/reboot.h>
  31 #include <linux/security.h>
  32
  33 #include <generated/utsrelease.h>
  34
  35 #include "base.h"
  36
  37 MODULE_AUTHOR("Manuel Estrada Sainz");
  38 MODULE_DESCRIPTION("Multi purpose firmware loading support");
  39 MODULE_LICENSE("GPL");
  40
  41 /* Builtin firmware support */
  42
  43 #ifdef CONFIG_FW_LOADER
  44
  45 extern struct builtin_fw __start_builtin_fw[];
  46 extern struct builtin_fw __end_builtin_fw[];
  47
  48 static bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
  49 {
  50         struct builtin_fw *b_fw;
  51
  52         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
  53                 if (strcmp(name, b_fw->name) == 0) {
  54                         fw->size = b_fw->size;
  55                         fw->data = b_fw->data;
  56                         return true;
  57                 }
  58         }
  59
  60         return false;
  61 }
  62
  63 static bool fw_is_builtin_firmware(const struct firmware *fw)
  64 {
  65         struct builtin_fw *b_fw;
  66
  67         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
  68                 if (fw->data == b_fw->data)
  69                         return true;
  70
  71         return false;
  72 }
  73
  74 #else /* Module case - no builtin firmware support */
  75
  76 static inline bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
  77 {
  78         return false;
  79 }
  80
  81 static inline bool fw_is_builtin_firmware(const struct firmware *fw)
  82 {
  83         return false;
  84 }
  85 #endif
  86
  87 enum {
  88         FW_STATUS_LOADING,
  89         FW_STATUS_DONE,
  90         FW_STATUS_ABORT,
  91 };
  92
  93 static int loading_timeout = 60;        /* In seconds */
  94
  95 static inline long firmware_loading_timeout(void)
  96 {
  97         return loading_timeout > 0 ? loading_timeout * HZ : MAX_JIFFY_OFFSET;
  98 }
  99
 100 /* firmware behavior options */
 101 #define FW_OPT_UEVENT   (1U << 0)
 102 #define FW_OPT_NOWAIT   (1U << 1)
 103 #ifdef CONFIG_FW_LOADER_USER_HELPER
 104 #define FW_OPT_USERHELPER       (1U << 2)
 105 #else
 106 #define FW_OPT_USERHELPER       0
 107 #endif
 108 #ifdef CONFIG_FW_LOADER_USER_HELPER_FALLBACK
 109 #define FW_OPT_FALLBACK         FW_OPT_USERHELPER
 110 #else
 111 #define FW_OPT_FALLBACK         0
 112 #endif
 113 #define FW_OPT_NO_WARN  (1U << 3)
 114
 115 struct firmware_cache {
 116         /* firmware_buf instance will be added into the below list */
 117         spinlock_t lock;
 118         struct list_head head;
 119         int state;
 120
 121 #ifdef CONFIG_PM_SLEEP
 122         /*
 123          * Names of firmware images which have been cached successfully
 124          * will be added into the below list so that device uncache
 125          * helper can trace which firmware images have been cached
 126          * before.
 127          */
 128         spinlock_t name_lock;
 129         struct list_head fw_names;
 130
 131         struct delayed_work work;
 132
 133         struct notifier_block   pm_notify;
 134 #endif
 135 };
 136
 137 struct firmware_buf {
 138         struct kref ref;
 139         struct list_head list;
 140         struct completion completion;
 141         struct firmware_cache *fwc;
 142         unsigned long status;
 143         void *data;
 144         size_t size;
 145 #ifdef CONFIG_FW_LOADER_USER_HELPER
 146         bool is_paged_buf;
 147         bool need_uevent;
 148         struct page **pages;
 149         int nr_pages;
 150         int page_array_size;
 151         struct list_head pending_list;
 152 #endif
 153         const char *fw_id;
 154 };
 155
 156 struct fw_cache_entry {
 157         struct list_head list;
 158         const char *name;
 159 };
 160
 161 struct fw_name_devm {
 162         unsigned long magic;
 163         const char *name;
 164 };
 165
 166 #define to_fwbuf(d) container_of(d, struct firmware_buf, ref)
 167
 168 #define FW_LOADER_NO_CACHE      0
 169 #define FW_LOADER_START_CACHE   1
 170
 171 static int fw_cache_piggyback_on_request(const char *name);
 172
 173 /* fw_lock could be moved to 'struct firmware_priv' but since it is just
 174  * guarding for corner cases a global lock should be OK */
 175 static DEFINE_MUTEX(fw_lock);
 176
 177 static struct firmware_cache fw_cache;
 178
 179 static struct firmware_buf *__allocate_fw_buf(const char *fw_name,
 180                                               struct firmware_cache *fwc)
 181 {
 182         struct firmware_buf *buf;
 183
 184         buf = kzalloc(sizeof(*buf), GFP_ATOMIC);
 185         if (!buf)
 186                 return NULL;
 187
 188         buf->fw_id = kstrdup_const(fw_name, GFP_ATOMIC);
 189         if (!buf->fw_id) {
 190                 kfree(buf);
 191                 return NULL;
 192         }
 193
 194         kref_init(&buf->ref);
 195         buf->fwc = fwc;
 196         init_completion(&buf->completion);
 197 #ifdef CONFIG_FW_LOADER_USER_HELPER
 198         INIT_LIST_HEAD(&buf->pending_list);
 199 #endif
 200
 201         pr_debug("%s: fw-%s buf=%p\n", __func__, fw_name, buf);
 202
 203         return buf;
 204 }
 205
 206 static struct firmware_buf *__fw_lookup_buf(const char *fw_name)
 207 {
 208         struct firmware_buf *tmp;
 209         struct firmware_cache *fwc = &fw_cache;
 210
 211         list_for_each_entry(tmp, &fwc->head, list)
 212                 if (!strcmp(tmp->fw_id, fw_name))
 213                         return tmp;
 214         return NULL;
 215 }
 216
 217 static int fw_lookup_and_allocate_buf(const char *fw_name,
 218                                       struct firmware_cache *fwc,
 219                                       struct firmware_buf **buf)
 220 {
 221         struct firmware_buf *tmp;
 222
 223         spin_lock(&fwc->lock);
 224         tmp = __fw_lookup_buf(fw_name);
 225         if (tmp) {
 226                 kref_get(&tmp->ref);
 227                 spin_unlock(&fwc->lock);
 228                 *buf = tmp;
 229                 return 1;
 230         }
 231         tmp = __allocate_fw_buf(fw_name, fwc);
 232         if (tmp)
 233                 list_add(&tmp->list, &fwc->head);
 234         spin_unlock(&fwc->lock);
 235
 236         *buf = tmp;
 237
 238         return tmp ? 0 : -ENOMEM;
 239 }
 240
 241 static void __fw_free_buf(struct kref *ref)
 242         __releases(&fwc->lock)
 243 {
 244         struct firmware_buf *buf = to_fwbuf(ref);
 245         struct firmware_cache *fwc = buf->fwc;
 246
 247         pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
 248                  __func__, buf->fw_id, buf, buf->data,
 249                  (unsigned int)buf->size);
 250
 251         list_del(&buf->list);
 252         spin_unlock(&fwc->lock);
 253
 254 #ifdef CONFIG_FW_LOADER_USER_HELPER
 255         if (buf->is_paged_buf) {
 256                 int i;
 257                 vunmap(buf->data);
 258                 for (i = 0; i < buf->nr_pages; i++)
 259                         __free_page(buf->pages[i]);
 260                 kfree(buf->pages);
 261         } else
 262 #endif
 263                 vfree(buf->data);
 264         kfree_const(buf->fw_id);
 265         kfree(buf);
 266 }
 267
 268 static void fw_free_buf(struct firmware_buf *buf)
 269 {
 270         struct firmware_cache *fwc = buf->fwc;
 271         spin_lock(&fwc->lock);
 272         if (!kref_put(&buf->ref, __fw_free_buf))
 273                 spin_unlock(&fwc->lock);
 274 }
 275
 276 /* direct firmware loading support */
 277 static char fw_path_para[256];
 278 static const char * const fw_path[] = {
 279         fw_path_para,
 280         "/lib/firmware/updates/" UTS_RELEASE,
 281         "/lib/firmware/updates",
 282         "/lib/firmware/" UTS_RELEASE,
 283         "/lib/firmware"
 284 };
 285
 286 /*
 287  * Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH'
 288  * from kernel command line because firmware_class is generally built in
 289  * kernel instead of module.
 290  */
 291 module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
 292 MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
 293
 294 static int fw_read_file_contents(struct file *file, struct firmware_buf *fw_buf)
 295 {
 296         int size;
 297         char *buf;
 298         int rc;
 299
 300         if (!S_ISREG(file_inode(file)->i_mode))
 301                 return -EINVAL;
 302         size = i_size_read(file_inode(file));
 303         if (size <= 0)
 304                 return -EINVAL;
 305         buf = vmalloc(size);
 306         if (!buf)
 307                 return -ENOMEM;
 308         rc = kernel_read(file, 0, buf, size);
 309         if (rc != size) {
 310                 if (rc > 0)
 311                         rc = -EIO;
 312                 goto fail;
 313         }
 314         rc = security_kernel_fw_from_file(file, buf, size);
 315         if (rc)
 316                 goto fail;
 317         fw_buf->data = buf;
 318         fw_buf->size = size;
 319         return 0;
 320 fail:
 321         vfree(buf);
 322         return rc;
 323 }
 324
 325 static int fw_get_filesystem_firmware(struct device *device,
 326                                        struct firmware_buf *buf)
 327 {
 328         int i, len;
 329         int rc = -ENOENT;
 330         char *path;
 331
 332         path = __getname();
 333         if (!path)
 334                 return -ENOMEM;
 335
 336         for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
 337                 struct file *file;
 338
 339                 /* skip the unset customized path */
 340                 if (!fw_path[i][0])
 341                         continue;
 342
 343                 len = snprintf(path, PATH_MAX, "%s/%s",
 344                                fw_path[i], buf->fw_id);
 345                 if (len >= PATH_MAX) {
 346                         rc = -ENAMETOOLONG;
 347                         break;
 348                 }
 349
 350                 file = filp_open(path, O_RDONLY, 0);
 351                 if (IS_ERR(file))
 352                         continue;
 353                 rc = fw_read_file_contents(file, buf);
 354                 fput(file);
 355                 if (rc)
 356                         dev_warn(device, "loading %s failed with error %d\n",
 357                                  path, rc);
 358                 else
 359                         break;
 360         }
 361         __putname(path);
 362
 363         if (!rc) {
 364                 dev_dbg(device, "direct-loading %s\n",
 365                         buf->fw_id);
 366                 mutex_lock(&fw_lock);
 367                 set_bit(FW_STATUS_DONE, &buf->status);
 368                 complete_all(&buf->completion);
 369                 mutex_unlock(&fw_lock);
 370         }
 371
 372         return rc;
 373 }
 374
 375 /* firmware holds the ownership of pages */
 376 static void firmware_free_data(const struct firmware *fw)
 377 {
 378         /* Loaded directly? */
 379         if (!fw->priv) {
 380                 vfree(fw->data);
 381                 return;
 382         }
 383         fw_free_buf(fw->priv);
 384 }
 385
 386 /* store the pages buffer info firmware from buf */
 387 static void fw_set_page_data(struct firmware_buf *buf, struct firmware *fw)
 388 {
 389         fw->priv = buf;
 390 #ifdef CONFIG_FW_LOADER_USER_HELPER
 391         fw->pages = buf->pages;
 392 #endif
 393         fw->size = buf->size;
 394         fw->data = buf->data;
 395
 396         pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
 397                  __func__, buf->fw_id, buf, buf->data,
 398                  (unsigned int)buf->size);
 399 }
 400
 401 #ifdef CONFIG_PM_SLEEP
 402 static void fw_name_devm_release(struct device *dev, void *res)
 403 {
 404         struct fw_name_devm *fwn = res;
 405
 406         if (fwn->magic == (unsigned long)&fw_cache)
 407                 pr_debug("%s: fw_name-%s devm-%p released\n",
 408                                 __func__, fwn->name, res);
 409         kfree_const(fwn->name);
 410 }
 411
 412 static int fw_devm_match(struct device *dev, void *res,
 413                 void *match_data)
 414 {
 415         struct fw_name_devm *fwn = res;
 416
 417         return (fwn->magic == (unsigned long)&fw_cache) &&
 418                 !strcmp(fwn->name, match_data);
 419 }
 420
 421 static struct fw_name_devm *fw_find_devm_name(struct device *dev,
 422                 const char *name)
 423 {
 424         struct fw_name_devm *fwn;
 425
 426         fwn = devres_find(dev, fw_name_devm_release,
 427                           fw_devm_match, (void *)name);
 428         return fwn;
 429 }
 430
 431 /* add firmware name into devres list */
 432 static int fw_add_devm_name(struct device *dev, const char *name)
 433 {
 434         struct fw_name_devm *fwn;
 435
 436         fwn = fw_find_devm_name(dev, name);
 437         if (fwn)
 438                 return 1;
 439
 440         fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm),
 441                            GFP_KERNEL);
 442         if (!fwn)
 443                 return -ENOMEM;
 444         fwn->name = kstrdup_const(name, GFP_KERNEL);
 445         if (!fwn->name) {
 446                 devres_free(fwn);
 447                 return -ENOMEM;
 448         }
 449
 450         fwn->magic = (unsigned long)&fw_cache;
 451         devres_add(dev, fwn);
 452
 453         return 0;
 454 }
 455 #else
 456 static int fw_add_devm_name(struct device *dev, const char *name)
 457 {
 458         return 0;
 459 }
 460 #endif
 461
 462
 463 /*
 464  * user-mode helper code
 465  */
 466 #ifdef CONFIG_FW_LOADER_USER_HELPER
 467 struct firmware_priv {
 468         bool nowait;
 469         struct device dev;
 470         struct firmware_buf *buf;
 471         struct firmware *fw;
 472 };
 473
 474 static struct firmware_priv *to_firmware_priv(struct device *dev)
 475 {
 476         return container_of(dev, struct firmware_priv, dev);
 477 }
 478
 479 static void __fw_load_abort(struct firmware_buf *buf)
 480 {
 481         /*
 482          * There is a small window in which user can write to 'loading'
 483          * between loading done and disappearance of 'loading'
 484          */
 485         if (test_bit(FW_STATUS_DONE, &buf->status))
 486                 return;
 487
 488         list_del_init(&buf->pending_list);
 489         set_bit(FW_STATUS_ABORT, &buf->status);
 490         complete_all(&buf->completion);
 491 }
 492
 493 static void fw_load_abort(struct firmware_priv *fw_priv)
 494 {
 495         struct firmware_buf *buf = fw_priv->buf;
 496
 497         __fw_load_abort(buf);
 498
 499         /* avoid user action after loading abort */
 500         fw_priv->buf = NULL;
 501 }
 502
 503 #define is_fw_load_aborted(buf) \
 504         test_bit(FW_STATUS_ABORT, &(buf)->status)
 505
 506 static LIST_HEAD(pending_fw_head);
 507
 508 /* reboot notifier for avoid deadlock with usermode_lock */
 509 static int fw_shutdown_notify(struct notifier_block *unused1,
 510                               unsigned long unused2, void *unused3)
 511 {
 512         mutex_lock(&fw_lock);
 513         while (!list_empty(&pending_fw_head))
 514                 __fw_load_abort(list_first_entry(&pending_fw_head,
 515                                                struct firmware_buf,
 516                                                pending_list));
 517         mutex_unlock(&fw_lock);
 518         return NOTIFY_DONE;
 519 }
 520
 521 static struct notifier_block fw_shutdown_nb = {
 522         .notifier_call = fw_shutdown_notify,
 523 };
 524
 525 static ssize_t timeout_show(struct class *class, struct class_attribute *attr,
 526                             char *buf)
 527 {
 528         return sprintf(buf, "%d\n", loading_timeout);
 529 }
 530
 531 /**
 532  * firmware_timeout_store - set number of seconds to wait for firmware
 533  * @class: device class pointer
 534  * @attr: device attribute pointer
 535  * @buf: buffer to scan for timeout value
 536  * @count: number of bytes in @buf
 537  *
 538  *      Sets the number of seconds to wait for the firmware.  Once
 539  *      this expires an error will be returned to the driver and no
 540  *      firmware will be provided.
 541  *
 542  *      Note: zero means 'wait forever'.
 543  **/
 544 static ssize_t timeout_store(struct class *class, struct class_attribute *attr,
 545                              const char *buf, size_t count)
 546 {
 547         loading_timeout = simple_strtol(buf, NULL, 10);
 548         if (loading_timeout < 0)
 549                 loading_timeout = 0;
 550
 551         return count;
 552 }
 553
 554 static struct class_attribute firmware_class_attrs[] = {
 555         __ATTR_RW(timeout),
 556         __ATTR_NULL
 557 };
 558
 559 static void fw_dev_release(struct device *dev)
 560 {
 561         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 562
 563         kfree(fw_priv);
 564 }
 565
 566 static int do_firmware_uevent(struct firmware_priv *fw_priv, struct kobj_uevent_env *env)
 567 {
 568         if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->buf->fw_id))
 569                 return -ENOMEM;
 570         if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
 571                 return -ENOMEM;
 572         if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
 573                 return -ENOMEM;
 574
 575         return 0;
 576 }
 577
 578 static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
 579 {
 580         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 581         int err = 0;
 582
 583         mutex_lock(&fw_lock);
 584         if (fw_priv->buf)
 585                 err = do_firmware_uevent(fw_priv, env);
 586         mutex_unlock(&fw_lock);
 587         return err;
 588 }
 589
 590 static struct class firmware_class = {
 591         .name           = "firmware",
 592         .class_attrs    = firmware_class_attrs,
 593         .dev_uevent     = firmware_uevent,
 594         .dev_release    = fw_dev_release,
 595 };
 596
 597 static ssize_t firmware_loading_show(struct device *dev,
 598                                      struct device_attribute *attr, char *buf)
 599 {
 600         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 601         int loading = 0;
 602
 603         mutex_lock(&fw_lock);
 604         if (fw_priv->buf)
 605                 loading = test_bit(FW_STATUS_LOADING, &fw_priv->buf->status);
 606         mutex_unlock(&fw_lock);
 607
 608         return sprintf(buf, "%d\n", loading);
 609 }
 610
 611 /* Some architectures don't have PAGE_KERNEL_RO */
 612 #ifndef PAGE_KERNEL_RO
 613 #define PAGE_KERNEL_RO PAGE_KERNEL
 614 #endif
 615
 616 /* one pages buffer should be mapped/unmapped only once */
 617 static int fw_map_pages_buf(struct firmware_buf *buf)
 618 {
 619         if (!buf->is_paged_buf)
 620                 return 0;
 621
 622         vunmap(buf->data);
 623         buf->data = vmap(buf->pages, buf->nr_pages, 0, PAGE_KERNEL_RO);
 624         if (!buf->data)
 625                 return -ENOMEM;
 626         return 0;
 627 }
 628
 629 /**
 630  * firmware_loading_store - set value in the 'loading' control file
 631  * @dev: device pointer
 632  * @attr: device attribute pointer
 633  * @buf: buffer to scan for loading control value
 634  * @count: number of bytes in @buf
 635  *
 636  *      The relevant values are:
 637  *
 638  *       1: Start a load, discarding any previous partial load.
 639  *       0: Conclude the load and hand the data to the driver code.
 640  *      -1: Conclude the load with an error and discard any written data.
 641  **/
 642 static ssize_t firmware_loading_store(struct device *dev,
 643                                       struct device_attribute *attr,
 644                                       const char *buf, size_t count)
 645 {
 646         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 647         struct firmware_buf *fw_buf;
 648         ssize_t written = count;
 649         int loading = simple_strtol(buf, NULL, 10);
 650         int i;
 651
 652         mutex_lock(&fw_lock);
 653         fw_buf = fw_priv->buf;
 654         if (!fw_buf)
 655                 goto out;
 656
 657         switch (loading) {
 658         case 1:
 659                 /* discarding any previous partial load */
 660                 if (!test_bit(FW_STATUS_DONE, &fw_buf->status)) {
 661                         for (i = 0; i < fw_buf->nr_pages; i++)
 662                                 __free_page(fw_buf->pages[i]);
 663                         kfree(fw_buf->pages);
 664                         fw_buf->pages = NULL;
 665                         fw_buf->page_array_size = 0;
 666                         fw_buf->nr_pages = 0;
 667                         set_bit(FW_STATUS_LOADING, &fw_buf->status);
 668                 }
 669                 break;
 670         case 0:
 671                 if (test_bit(FW_STATUS_LOADING, &fw_buf->status)) {
 672                         int rc;
 673
 674                         set_bit(FW_STATUS_DONE, &fw_buf->status);
 675                         clear_bit(FW_STATUS_LOADING, &fw_buf->status);
 676
 677                         /*
 678                          * Several loading requests may be pending on
 679                          * one same firmware buf, so let all requests
 680                          * see the mapped 'buf->data' once the loading
 681                          * is completed.
 682                          * */
 683                         rc = fw_map_pages_buf(fw_buf);
 684                         if (rc)
 685                                 dev_err(dev, "%s: map pages failed\n",
 686                                         __func__);
 687                         else
 688                                 rc = security_kernel_fw_from_file(NULL,
 689                                                 fw_buf->data, fw_buf->size);
 690
 691                         /*
 692                          * Same logic as fw_load_abort, only the DONE bit
 693                          * is ignored and we set ABORT only on failure.
 694                          */
 695                         list_del_init(&fw_buf->pending_list);
 696                         if (rc) {
 697                                 set_bit(FW_STATUS_ABORT, &fw_buf->status);
 698                                 written = rc;
 699                         }
 700                         complete_all(&fw_buf->completion);
 701                         break;
 702                 }
 703                 /* fallthrough */
 704         default:
 705                 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
 706                 /* fallthrough */
 707         case -1:
 708                 fw_load_abort(fw_priv);
 709                 break;
 710         }
 711 out:
 712         mutex_unlock(&fw_lock);
 713         return written;
 714 }
 715
 716 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
 717
 718 static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
 719                                   struct bin_attribute *bin_attr,
 720                                   char *buffer, loff_t offset, size_t count)
 721 {
 722         struct device *dev = kobj_to_dev(kobj);
 723         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 724         struct firmware_buf *buf;
 725         ssize_t ret_count;
 726
 727         mutex_lock(&fw_lock);
 728         buf = fw_priv->buf;
 729         if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) {
 730                 ret_count = -ENODEV;
 731                 goto out;
 732         }
 733         if (offset > buf->size) {
 734                 ret_count = 0;
 735                 goto out;
 736         }
 737         if (count > buf->size - offset)
 738                 count = buf->size - offset;
 739
 740         ret_count = count;
 741
 742         while (count) {
 743                 void *page_data;
 744                 int page_nr = offset >> PAGE_SHIFT;
 745                 int page_ofs = offset & (PAGE_SIZE-1);
 746                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 747
 748                 page_data = kmap(buf->pages[page_nr]);
 749
 750                 memcpy(buffer, page_data + page_ofs, page_cnt);
 751
 752                 kunmap(buf->pages[page_nr]);
 753                 buffer += page_cnt;
 754                 offset += page_cnt;
 755                 count -= page_cnt;
 756         }
 757 out:
 758         mutex_unlock(&fw_lock);
 759         return ret_count;
 760 }
 761
 762 static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
 763 {
 764         struct firmware_buf *buf = fw_priv->buf;
 765         int pages_needed = PAGE_ALIGN(min_size) >> PAGE_SHIFT;
 766
 767         /* If the array of pages is too small, grow it... */
 768         if (buf->page_array_size < pages_needed) {
 769                 int new_array_size = max(pages_needed,
 770                                          buf->page_array_size * 2);
 771                 struct page **new_pages;
 772
 773                 new_pages = kmalloc(new_array_size * sizeof(void *),
 774                                     GFP_KERNEL);
 775                 if (!new_pages) {
 776                         fw_load_abort(fw_priv);
 777                         return -ENOMEM;
 778                 }
 779                 memcpy(new_pages, buf->pages,
 780                        buf->page_array_size * sizeof(void *));
 781                 memset(&new_pages[buf->page_array_size], 0, sizeof(void *) *
 782                        (new_array_size - buf->page_array_size));
 783                 kfree(buf->pages);
 784                 buf->pages = new_pages;
 785                 buf->page_array_size = new_array_size;
 786         }
 787
 788         while (buf->nr_pages < pages_needed) {
 789                 buf->pages[buf->nr_pages] =
 790                         alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
 791
 792                 if (!buf->pages[buf->nr_pages]) {
 793                         fw_load_abort(fw_priv);
 794                         return -ENOMEM;
 795                 }
 796                 buf->nr_pages++;
 797         }
 798         return 0;
 799 }
 800
 801 /**
 802  * firmware_data_write - write method for firmware
 803  * @filp: open sysfs file
 804  * @kobj: kobject for the device
 805  * @bin_attr: bin_attr structure
 806  * @buffer: buffer being written
 807  * @offset: buffer offset for write in total data store area
 808  * @count: buffer size
 809  *
 810  *      Data written to the 'data' attribute will be later handed to
 811  *      the driver as a firmware image.
 812  **/
 813 static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,
 814                                    struct bin_attribute *bin_attr,
 815                                    char *buffer, loff_t offset, size_t count)
 816 {
 817         struct device *dev = kobj_to_dev(kobj);
 818         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 819         struct firmware_buf *buf;
 820         ssize_t retval;
 821
 822         if (!capable(CAP_SYS_RAWIO))
 823                 return -EPERM;
 824
 825         mutex_lock(&fw_lock);
 826         buf = fw_priv->buf;
 827         if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) {
 828                 retval = -ENODEV;
 829                 goto out;
 830         }
 831
 832         retval = fw_realloc_buffer(fw_priv, offset + count);
 833         if (retval)
 834                 goto out;
 835
 836         retval = count;
 837
 838         while (count) {
 839                 void *page_data;
 840                 int page_nr = offset >> PAGE_SHIFT;
 841                 int page_ofs = offset & (PAGE_SIZE - 1);
 842                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 843
 844                 page_data = kmap(buf->pages[page_nr]);
 845
 846                 memcpy(page_data + page_ofs, buffer, page_cnt);
 847
 848                 kunmap(buf->pages[page_nr]);
 849                 buffer += page_cnt;
 850                 offset += page_cnt;
 851                 count -= page_cnt;
 852         }
 853
 854         buf->size = max_t(size_t, offset, buf->size);
 855 out:
 856         mutex_unlock(&fw_lock);
 857         return retval;
 858 }
 859
 860 static struct bin_attribute firmware_attr_data = {
 861         .attr = { .name = "data", .mode = 0644 },
 862         .size = 0,
 863         .read = firmware_data_read,
 864         .write = firmware_data_write,
 865 };
 866
 867 static struct attribute *fw_dev_attrs[] = {
 868         &dev_attr_loading.attr,
 869         NULL
 870 };
 871
 872 static struct bin_attribute *fw_dev_bin_attrs[] = {
 873         &firmware_attr_data,
 874         NULL
 875 };
 876
 877 static const struct attribute_group fw_dev_attr_group = {
 878         .attrs = fw_dev_attrs,
 879         .bin_attrs = fw_dev_bin_attrs,
 880 };
 881
 882 static const struct attribute_group *fw_dev_attr_groups[] = {
 883         &fw_dev_attr_group,
 884         NULL
 885 };
 886
 887 static struct firmware_priv *
 888 fw_create_instance(struct firmware *firmware, const char *fw_name,
 889                    struct device *device, unsigned int opt_flags)
 890 {
 891         struct firmware_priv *fw_priv;
 892         struct device *f_dev;
 893
 894         fw_priv = kzalloc(sizeof(*fw_priv), GFP_KERNEL);
 895         if (!fw_priv) {
 896                 fw_priv = ERR_PTR(-ENOMEM);
 897                 goto exit;
 898         }
 899
 900         fw_priv->nowait = !!(opt_flags & FW_OPT_NOWAIT);
 901         fw_priv->fw = firmware;
 902         f_dev = &fw_priv->dev;
 903
 904         device_initialize(f_dev);
 905         dev_set_name(f_dev, "%s", fw_name);
 906         f_dev->parent = device;
 907         f_dev->class = &firmware_class;
 908         f_dev->groups = fw_dev_attr_groups;
 909 exit:
 910         return fw_priv;
 911 }
 912
 913 /* load a firmware via user helper */
 914 static int _request_firmware_load(struct firmware_priv *fw_priv,
 915                                   unsigned int opt_flags, long timeout)
 916 {
 917         int retval = 0;
 918         struct device *f_dev = &fw_priv->dev;
 919         struct firmware_buf *buf = fw_priv->buf;
 920
 921         /* fall back on userspace loading */
 922         buf->is_paged_buf = true;
 923
 924         dev_set_uevent_suppress(f_dev, true);
 925
 926         retval = device_add(f_dev);
 927         if (retval) {
 928                 dev_err(f_dev, "%s: device_register failed\n", __func__);
 929                 goto err_put_dev;
 930         }
 931
 932         mutex_lock(&fw_lock);
 933         list_add(&buf->pending_list, &pending_fw_head);
 934         mutex_unlock(&fw_lock);
 935
 936         if (opt_flags & FW_OPT_UEVENT) {
 937                 buf->need_uevent = true;
 938                 dev_set_uevent_suppress(f_dev, false);
 939                 dev_dbg(f_dev, "firmware: requesting %s\n", buf->fw_id);
 940                 kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD);
 941         } else {
 942                 timeout = MAX_JIFFY_OFFSET;
 943         }
 944
 945         retval = wait_for_completion_interruptible_timeout(&buf->completion,
 946                         timeout);
 947         if (retval == -ERESTARTSYS || !retval) {
 948                 mutex_lock(&fw_lock);
 949                 fw_load_abort(fw_priv);
 950                 mutex_unlock(&fw_lock);
 951         } else if (retval > 0) {
 952                 retval = 0;
 953         }
 954
 955         if (is_fw_load_aborted(buf))
 956                 retval = -EAGAIN;
 957         else if (!buf->data)
 958                 retval = -ENOMEM;
 959
 960         device_del(f_dev);
 961 err_put_dev:
 962         put_device(f_dev);
 963         return retval;
 964 }
 965
 966 static int fw_load_from_user_helper(struct firmware *firmware,
 967                                     const char *name, struct device *device,
 968                                     unsigned int opt_flags, long timeout)
 969 {
 970         struct firmware_priv *fw_priv;
 971
 972         fw_priv = fw_create_instance(firmware, name, device, opt_flags);
 973         if (IS_ERR(fw_priv))
 974                 return PTR_ERR(fw_priv);
 975
 976         fw_priv->buf = firmware->priv;
 977         return _request_firmware_load(fw_priv, opt_flags, timeout);
 978 }
 979
 980 #ifdef CONFIG_PM_SLEEP
 981 /* kill pending requests without uevent to avoid blocking suspend */
 982 static void kill_requests_without_uevent(void)
 983 {
 984         struct firmware_buf *buf;
 985         struct firmware_buf *next;
 986
 987         mutex_lock(&fw_lock);
 988         list_for_each_entry_safe(buf, next, &pending_fw_head, pending_list) {
 989                 if (!buf->need_uevent)
 990                          __fw_load_abort(buf);
 991         }
 992         mutex_unlock(&fw_lock);
 993 }
 994 #endif
 995
 996 #else /* CONFIG_FW_LOADER_USER_HELPER */
 997 static inline int
 998 fw_load_from_user_helper(struct firmware *firmware, const char *name,
 999                          struct device *device, unsigned int opt_flags,
1000                          long timeout)
1001 {
1002         return -ENOENT;
1003 }
1004
1005 /* No abort during direct loading */
1006 #define is_fw_load_aborted(buf) false
1007
1008 #ifdef CONFIG_PM_SLEEP
1009 static inline void kill_requests_without_uevent(void) { }
1010 #endif
1011
1012 #endif /* CONFIG_FW_LOADER_USER_HELPER */
1013
1014
1015 /* wait until the shared firmware_buf becomes ready (or error) */
1016 static int sync_cached_firmware_buf(struct firmware_buf *buf)
1017 {
1018         int ret = 0;
1019
1020         mutex_lock(&fw_lock);
1021         while (!test_bit(FW_STATUS_DONE, &buf->status)) {
1022                 if (is_fw_load_aborted(buf)) {
1023                         ret = -ENOENT;
1024                         break;
1025                 }
1026                 mutex_unlock(&fw_lock);
1027                 ret = wait_for_completion_interruptible(&buf->completion);
1028                 mutex_lock(&fw_lock);
1029         }
1030         mutex_unlock(&fw_lock);
1031         return ret;
1032 }
1033
1034 /* prepare firmware and firmware_buf structs;
1035  * return 0 if a firmware is already assigned, 1 if need to load one,
1036  * or a negative error code
1037  */
1038 static int
1039 _request_firmware_prepare(struct firmware **firmware_p, const char *name,
1040                           struct device *device)
1041 {
1042         struct firmware *firmware;
1043         struct firmware_buf *buf;
1044         int ret;
1045
1046         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
1047         if (!firmware) {
1048                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
1049                         __func__);
1050                 return -ENOMEM;
1051         }
1052
1053         if (fw_get_builtin_firmware(firmware, name)) {
1054                 dev_dbg(device, "using built-in %s\n", name);
1055                 return 0; /* assigned */
1056         }
1057
1058         ret = fw_lookup_and_allocate_buf(name, &fw_cache, &buf);
1059
1060         /*
1061          * bind with 'buf' now to avoid warning in failure path
1062          * of requesting firmware.
1063          */
1064         firmware->priv = buf;
1065
1066         if (ret > 0) {
1067                 ret = sync_cached_firmware_buf(buf);
1068                 if (!ret) {
1069                         fw_set_page_data(buf, firmware);
1070                         return 0; /* assigned */
1071                 }
1072         }
1073
1074         if (ret < 0)
1075                 return ret;
1076         return 1; /* need to load */
1077 }
1078
1079 static int assign_firmware_buf(struct firmware *fw, struct device *device,
1080                                unsigned int opt_flags)
1081 {
1082         struct firmware_buf *buf = fw->priv;
1083
1084         mutex_lock(&fw_lock);
1085         if (!buf->size || is_fw_load_aborted(buf)) {
1086                 mutex_unlock(&fw_lock);
1087                 return -ENOENT;
1088         }
1089
1090         /*
1091          * add firmware name into devres list so that we can auto cache
1092          * and uncache firmware for device.
1093          *
1094          * device may has been deleted already, but the problem
1095          * should be fixed in devres or driver core.
1096          */
1097         /* don't cache firmware handled without uevent */
1098         if (device && (opt_flags & FW_OPT_UEVENT))
1099                 fw_add_devm_name(device, buf->fw_id);
1100
1101         /*
1102          * After caching firmware image is started, let it piggyback
1103          * on request firmware.
1104          */
1105         if (buf->fwc->state == FW_LOADER_START_CACHE) {
1106                 if (fw_cache_piggyback_on_request(buf->fw_id))
1107                         kref_get(&buf->ref);
1108         }
1109
1110         /* pass the pages buffer to driver at the last minute */
1111         fw_set_page_data(buf, fw);
1112         mutex_unlock(&fw_lock);
1113         return 0;
1114 }
1115
1116 /* called from request_firmware() and request_firmware_work_func() */
1117 static int
1118 _request_firmware(const struct firmware **firmware_p, const char *name,
1119                   struct device *device, unsigned int opt_flags)
1120 {
1121         struct firmware *fw = NULL;
1122         long timeout;
1123         int ret;
1124
1125         if (!firmware_p)
1126                 return -EINVAL;
1127
1128         if (!name || name[0] == '\0') {
1129                 ret = -EINVAL;
1130                 goto out;
1131         }
1132
1133         ret = _request_firmware_prepare(&fw, name, device);
1134         if (ret <= 0) /* error or already assigned */
1135                 goto out;
1136
1137         ret = 0;
1138         timeout = firmware_loading_timeout();
1139         if (opt_flags & FW_OPT_NOWAIT) {
1140                 timeout = usermodehelper_read_lock_wait(timeout);
1141                 if (!timeout) {
1142                         dev_dbg(device, "firmware: %s loading timed out\n",
1143                                 name);
1144                         ret = -EBUSY;
1145                         goto out;
1146                 }
1147         } else {
1148                 ret = usermodehelper_read_trylock();
1149                 if (WARN_ON(ret)) {
1150                         dev_err(device, "firmware: %s will not be loaded\n",
1151                                 name);
1152                         goto out;
1153                 }
1154         }
1155
1156         ret = fw_get_filesystem_firmware(device, fw->priv);
1157         if (ret) {
1158                 if (!(opt_flags & FW_OPT_NO_WARN))
1159                         dev_warn(device,
1160                                  "Direct firmware load for %s failed with error %d\n",
1161                                  name, ret);
1162                 if (opt_flags & FW_OPT_USERHELPER) {
1163                         dev_warn(device, "Falling back to user helper\n");
1164                         ret = fw_load_from_user_helper(fw, name, device,
1165                                                        opt_flags, timeout);
1166                 }
1167         }
1168
1169         if (!ret)
1170                 ret = assign_firmware_buf(fw, device, opt_flags);
1171
1172         usermodehelper_read_unlock();
1173
1174  out:
1175         if (ret < 0) {
1176                 release_firmware(fw);
1177                 fw = NULL;
1178         }
1179
1180         *firmware_p = fw;
1181         return ret;
1182 }
1183
1184 /**
1185  * request_firmware: - send firmware request and wait for it
1186  * @firmware_p: pointer to firmware image
1187  * @name: name of firmware file
1188  * @device: device for which firmware is being loaded
1189  *
1190  *      @firmware_p will be used to return a firmware image by the name
1191  *      of @name for device @device.
1192  *
1193  *      Should be called from user context where sleeping is allowed.
1194  *
1195  *      @name will be used as $FIRMWARE in the uevent environment and
1196  *      should be distinctive enough not to be confused with any other
1197  *      firmware image for this or any other device.
1198  *
1199  *      Caller must hold the reference count of @device.
1200  *
1201  *      The function can be called safely inside device's suspend and
1202  *      resume callback.
1203  **/
1204 int
1205 request_firmware(const struct firmware **firmware_p, const char *name,
1206                  struct device *device)
1207 {
1208         int ret;
1209
1210         /* Need to pin this module until return */
1211         __module_get(THIS_MODULE);
1212         ret = _request_firmware(firmware_p, name, device,
1213                                 FW_OPT_UEVENT | FW_OPT_FALLBACK);
1214         module_put(THIS_MODULE);
1215         return ret;
1216 }
1217 EXPORT_SYMBOL(request_firmware);
1218
1219 /**
1220  * request_firmware_direct: - load firmware directly without usermode helper
1221  * @firmware_p: pointer to firmware image
1222  * @name: name of firmware file
1223  * @device: device for which firmware is being loaded
1224  *
1225  * This function works pretty much like request_firmware(), but this doesn't
1226  * fall back to usermode helper even if the firmware couldn't be loaded
1227  * directly from fs.  Hence it's useful for loading optional firmwares, which
1228  * aren't always present, without extra long timeouts of udev.
1229  **/
1230 int request_firmware_direct(const struct firmware **firmware_p,
1231                             const char *name, struct device *device)
1232 {
1233         int ret;
1234
1235         __module_get(THIS_MODULE);
1236         ret = _request_firmware(firmware_p, name, device,
1237                                 FW_OPT_UEVENT | FW_OPT_NO_WARN);
1238         module_put(THIS_MODULE);
1239         return ret;
1240 }
1241 EXPORT_SYMBOL_GPL(request_firmware_direct);
1242
1243 /**
1244  * release_firmware: - release the resource associated with a firmware image
1245  * @fw: firmware resource to release
1246  **/
1247 void release_firmware(const struct firmware *fw)
1248 {
1249         if (fw) {
1250                 if (!fw_is_builtin_firmware(fw))
1251                         firmware_free_data(fw);
1252                 kfree(fw);
1253         }
1254 }
1255 EXPORT_SYMBOL(release_firmware);
1256
1257 /* Async support */
1258 struct firmware_work {
1259         struct work_struct work;
1260         struct module *module;
1261         const char *name;
1262         struct device *device;
1263         void *context;
1264         void (*cont)(const struct firmware *fw, void *context);
1265         unsigned int opt_flags;
1266 };
1267
1268 static void request_firmware_work_func(struct work_struct *work)
1269 {
1270         struct firmware_work *fw_work;
1271         const struct firmware *fw;
1272
1273         fw_work = container_of(work, struct firmware_work, work);
1274
1275         _request_firmware(&fw, fw_work->name, fw_work->device,
1276                           fw_work->opt_flags);
1277         fw_work->cont(fw, fw_work->context);
1278         put_device(fw_work->device); /* taken in request_firmware_nowait() */
1279
1280         module_put(fw_work->module);
1281         kfree_const(fw_work->name);
1282         kfree(fw_work);
1283 }
1284
1285 /**
1286  * request_firmware_nowait - asynchronous version of request_firmware
1287  * @module: module requesting the firmware
1288  * @uevent: sends uevent to copy the firmware image if this flag
1289  *      is non-zero else the firmware copy must be done manually.
1290  * @name: name of firmware file
1291  * @device: device for which firmware is being loaded
1292  * @gfp: allocation flags
1293  * @context: will be passed over to @cont, and
1294  *      @fw may be %NULL if firmware request fails.
1295  * @cont: function will be called asynchronously when the firmware
1296  *      request is over.
1297  *
1298  *      Caller must hold the reference count of @device.
1299  *
1300  *      Asynchronous variant of request_firmware() for user contexts:
1301  *              - sleep for as small periods as possible since it may
1302  *              increase kernel boot time of built-in device drivers
1303  *              requesting firmware in their ->probe() methods, if
1304  *              @gfp is GFP_KERNEL.
1305  *
1306  *              - can't sleep at all if @gfp is GFP_ATOMIC.
1307  **/
1308 int
1309 request_firmware_nowait(
1310         struct module *module, bool uevent,
1311         const char *name, struct device *device, gfp_t gfp, void *context,
1312         void (*cont)(const struct firmware *fw, void *context))
1313 {
1314         struct firmware_work *fw_work;
1315
1316         fw_work = kzalloc(sizeof(struct firmware_work), gfp);
1317         if (!fw_work)
1318                 return -ENOMEM;
1319
1320         fw_work->module = module;
1321         fw_work->name = kstrdup_const(name, gfp);
1322         if (!fw_work->name) {
1323                 kfree(fw_work);
1324                 return -ENOMEM;
1325         }
1326         fw_work->device = device;
1327         fw_work->context = context;
1328         fw_work->cont = cont;
1329         fw_work->opt_flags = FW_OPT_NOWAIT | FW_OPT_FALLBACK |
1330                 (uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
1331
1332         if (!try_module_get(module)) {
1333                 kfree_const(fw_work->name);
1334                 kfree(fw_work);
1335                 return -EFAULT;
1336         }
1337
1338         get_device(fw_work->device);
1339         INIT_WORK(&fw_work->work, request_firmware_work_func);
1340         schedule_work(&fw_work->work);
1341         return 0;
1342 }
1343 EXPORT_SYMBOL(request_firmware_nowait);
1344
1345 #ifdef CONFIG_PM_SLEEP
1346 static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
1347
1348 /**
1349  * cache_firmware - cache one firmware image in kernel memory space
1350  * @fw_name: the firmware image name
1351  *
1352  * Cache firmware in kernel memory so that drivers can use it when
1353  * system isn't ready for them to request firmware image from userspace.
1354  * Once it returns successfully, driver can use request_firmware or its
1355  * nowait version to get the cached firmware without any interacting
1356  * with userspace
1357  *
1358  * Return 0 if the firmware image has been cached successfully
1359  * Return !0 otherwise
1360  *
1361  */
1362 static int cache_firmware(const char *fw_name)
1363 {
1364         int ret;
1365         const struct firmware *fw;
1366
1367         pr_debug("%s: %s\n", __func__, fw_name);
1368
1369         ret = request_firmware(&fw, fw_name, NULL);
1370         if (!ret)
1371                 kfree(fw);
1372
1373         pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
1374
1375         return ret;
1376 }
1377
1378 static struct firmware_buf *fw_lookup_buf(const char *fw_name)
1379 {
1380         struct firmware_buf *tmp;
1381         struct firmware_cache *fwc = &fw_cache;
1382
1383         spin_lock(&fwc->lock);
1384         tmp = __fw_lookup_buf(fw_name);
1385         spin_unlock(&fwc->lock);
1386
1387         return tmp;
1388 }
1389
1390 /**
1391  * uncache_firmware - remove one cached firmware image
1392  * @fw_name: the firmware image name
1393  *
1394  * Uncache one firmware image which has been cached successfully
1395  * before.
1396  *
1397  * Return 0 if the firmware cache has been removed successfully
1398  * Return !0 otherwise
1399  *
1400  */
1401 static int uncache_firmware(const char *fw_name)
1402 {
1403         struct firmware_buf *buf;
1404         struct firmware fw;
1405
1406         pr_debug("%s: %s\n", __func__, fw_name);
1407
1408         if (fw_get_builtin_firmware(&fw, fw_name))
1409                 return 0;
1410
1411         buf = fw_lookup_buf(fw_name);
1412         if (buf) {
1413                 fw_free_buf(buf);
1414                 return 0;
1415         }
1416
1417         return -EINVAL;
1418 }
1419
1420 static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
1421 {
1422         struct fw_cache_entry *fce;
1423
1424         fce = kzalloc(sizeof(*fce), GFP_ATOMIC);
1425         if (!fce)
1426                 goto exit;
1427
1428         fce->name = kstrdup_const(name, GFP_ATOMIC);
1429         if (!fce->name) {
1430                 kfree(fce);
1431                 fce = NULL;
1432                 goto exit;
1433         }
1434 exit:
1435         return fce;
1436 }
1437
1438 static int __fw_entry_found(const char *name)
1439 {
1440         struct firmware_cache *fwc = &fw_cache;
1441         struct fw_cache_entry *fce;
1442
1443         list_for_each_entry(fce, &fwc->fw_names, list) {
1444                 if (!strcmp(fce->name, name))
1445                         return 1;
1446         }
1447         return 0;
1448 }
1449
1450 static int fw_cache_piggyback_on_request(const char *name)
1451 {
1452         struct firmware_cache *fwc = &fw_cache;
1453         struct fw_cache_entry *fce;
1454         int ret = 0;
1455
1456         spin_lock(&fwc->name_lock);
1457         if (__fw_entry_found(name))
1458                 goto found;
1459
1460         fce = alloc_fw_cache_entry(name);
1461         if (fce) {
1462                 ret = 1;
1463                 list_add(&fce->list, &fwc->fw_names);
1464                 pr_debug("%s: fw: %s\n", __func__, name);
1465         }
1466 found:
1467         spin_unlock(&fwc->name_lock);
1468         return ret;
1469 }
1470
1471 static void free_fw_cache_entry(struct fw_cache_entry *fce)
1472 {
1473         kfree_const(fce->name);
1474         kfree(fce);
1475 }
1476
1477 static void __async_dev_cache_fw_image(void *fw_entry,
1478                                        async_cookie_t cookie)
1479 {
1480         struct fw_cache_entry *fce = fw_entry;
1481         struct firmware_cache *fwc = &fw_cache;
1482         int ret;
1483
1484         ret = cache_firmware(fce->name);
1485         if (ret) {
1486                 spin_lock(&fwc->name_lock);
1487                 list_del(&fce->list);
1488                 spin_unlock(&fwc->name_lock);
1489
1490                 free_fw_cache_entry(fce);
1491         }
1492 }
1493
1494 /* called with dev->devres_lock held */
1495 static void dev_create_fw_entry(struct device *dev, void *res,
1496                                 void *data)
1497 {
1498         struct fw_name_devm *fwn = res;
1499         const char *fw_name = fwn->name;
1500         struct list_head *head = data;
1501         struct fw_cache_entry *fce;
1502
1503         fce = alloc_fw_cache_entry(fw_name);
1504         if (fce)
1505                 list_add(&fce->list, head);
1506 }
1507
1508 static int devm_name_match(struct device *dev, void *res,
1509                            void *match_data)
1510 {
1511         struct fw_name_devm *fwn = res;
1512         return (fwn->magic == (unsigned long)match_data);
1513 }
1514
1515 static void dev_cache_fw_image(struct device *dev, void *data)
1516 {
1517         LIST_HEAD(todo);
1518         struct fw_cache_entry *fce;
1519         struct fw_cache_entry *fce_next;
1520         struct firmware_cache *fwc = &fw_cache;
1521
1522         devres_for_each_res(dev, fw_name_devm_release,
1523                             devm_name_match, &fw_cache,
1524                             dev_create_fw_entry, &todo);
1525
1526         list_for_each_entry_safe(fce, fce_next, &todo, list) {
1527                 list_del(&fce->list);
1528
1529                 spin_lock(&fwc->name_lock);
1530                 /* only one cache entry for one firmware */
1531                 if (!__fw_entry_found(fce->name)) {
1532                         list_add(&fce->list, &fwc->fw_names);
1533                 } else {
1534                         free_fw_cache_entry(fce);
1535                         fce = NULL;
1536                 }
1537                 spin_unlock(&fwc->name_lock);
1538
1539                 if (fce)
1540                         async_schedule_domain(__async_dev_cache_fw_image,
1541                                               (void *)fce,
1542                                               &fw_cache_domain);
1543         }
1544 }
1545
1546 static void __device_uncache_fw_images(void)
1547 {
1548         struct firmware_cache *fwc = &fw_cache;
1549         struct fw_cache_entry *fce;
1550
1551         spin_lock(&fwc->name_lock);
1552         while (!list_empty(&fwc->fw_names)) {
1553                 fce = list_entry(fwc->fw_names.next,
1554                                 struct fw_cache_entry, list);
1555                 list_del(&fce->list);
1556                 spin_unlock(&fwc->name_lock);
1557
1558                 uncache_firmware(fce->name);
1559                 free_fw_cache_entry(fce);
1560
1561                 spin_lock(&fwc->name_lock);
1562         }
1563         spin_unlock(&fwc->name_lock);
1564 }
1565
1566 /**
1567  * device_cache_fw_images - cache devices' firmware
1568  *
1569  * If one device called request_firmware or its nowait version
1570  * successfully before, the firmware names are recored into the
1571  * device's devres link list, so device_cache_fw_images can call
1572  * cache_firmware() to cache these firmwares for the device,
1573  * then the device driver can load its firmwares easily at
1574  * time when system is not ready to complete loading firmware.
1575  */
1576 static void device_cache_fw_images(void)
1577 {
1578         struct firmware_cache *fwc = &fw_cache;
1579         int old_timeout;
1580         DEFINE_WAIT(wait);
1581
1582         pr_debug("%s\n", __func__);
1583
1584         /* cancel uncache work */
1585         cancel_delayed_work_sync(&fwc->work);
1586
1587         /*
1588          * use small loading timeout for caching devices' firmware
1589          * because all these firmware images have been loaded
1590          * successfully at lease once, also system is ready for
1591          * completing firmware loading now. The maximum size of
1592          * firmware in current distributions is about 2M bytes,
1593          * so 10 secs should be enough.
1594          */
1595         old_timeout = loading_timeout;
1596         loading_timeout = 10;
1597
1598         mutex_lock(&fw_lock);
1599         fwc->state = FW_LOADER_START_CACHE;
1600         dpm_for_each_dev(NULL, dev_cache_fw_image);
1601         mutex_unlock(&fw_lock);
1602
1603         /* wait for completion of caching firmware for all devices */
1604         async_synchronize_full_domain(&fw_cache_domain);
1605
1606         loading_timeout = old_timeout;
1607 }
1608
1609 /**
1610  * device_uncache_fw_images - uncache devices' firmware
1611  *
1612  * uncache all firmwares which have been cached successfully
1613  * by device_uncache_fw_images earlier
1614  */
1615 static void device_uncache_fw_images(void)
1616 {
1617         pr_debug("%s\n", __func__);
1618         __device_uncache_fw_images();
1619 }
1620
1621 static void device_uncache_fw_images_work(struct work_struct *work)
1622 {
1623         device_uncache_fw_images();
1624 }
1625
1626 /**
1627  * device_uncache_fw_images_delay - uncache devices firmwares
1628  * @delay: number of milliseconds to delay uncache device firmwares
1629  *
1630  * uncache all devices's firmwares which has been cached successfully
1631  * by device_cache_fw_images after @delay milliseconds.
1632  */
1633 static void device_uncache_fw_images_delay(unsigned long delay)
1634 {
1635         queue_delayed_work(system_power_efficient_wq, &fw_cache.work,
1636                            msecs_to_jiffies(delay));
1637 }
1638
1639 static int fw_pm_notify(struct notifier_block *notify_block,
1640                         unsigned long mode, void *unused)
1641 {
1642         switch (mode) {
1643         case PM_HIBERNATION_PREPARE:
1644         case PM_SUSPEND_PREPARE:
1645         case PM_RESTORE_PREPARE:
1646                 kill_requests_without_uevent();
1647                 device_cache_fw_images();
1648                 break;
1649
1650         case PM_POST_SUSPEND:
1651         case PM_POST_HIBERNATION:
1652         case PM_POST_RESTORE:
1653                 /*
1654                  * In case that system sleep failed and syscore_suspend is
1655                  * not called.
1656                  */
1657                 mutex_lock(&fw_lock);
1658                 fw_cache.state = FW_LOADER_NO_CACHE;
1659                 mutex_unlock(&fw_lock);
1660
1661                 device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
1662                 break;
1663         }
1664
1665         return 0;
1666 }
1667
1668 /* stop caching firmware once syscore_suspend is reached */
1669 static int fw_suspend(void)
1670 {
1671         fw_cache.state = FW_LOADER_NO_CACHE;
1672         return 0;
1673 }
1674
1675 static struct syscore_ops fw_syscore_ops = {
1676         .suspend = fw_suspend,
1677 };
1678 #else
1679 static int fw_cache_piggyback_on_request(const char *name)
1680 {
1681         return 0;
1682 }
1683 #endif
1684
1685 static void __init fw_cache_init(void)
1686 {
1687         spin_lock_init(&fw_cache.lock);
1688         INIT_LIST_HEAD(&fw_cache.head);
1689         fw_cache.state = FW_LOADER_NO_CACHE;
1690
1691 #ifdef CONFIG_PM_SLEEP
1692         spin_lock_init(&fw_cache.name_lock);
1693         INIT_LIST_HEAD(&fw_cache.fw_names);
1694
1695         INIT_DELAYED_WORK(&fw_cache.work,
1696                           device_uncache_fw_images_work);
1697
1698         fw_cache.pm_notify.notifier_call = fw_pm_notify;
1699         register_pm_notifier(&fw_cache.pm_notify);
1700
1701         register_syscore_ops(&fw_syscore_ops);
1702 #endif
1703 }
1704
1705 static int __init firmware_class_init(void)
1706 {
1707         fw_cache_init();
1708 #ifdef CONFIG_FW_LOADER_USER_HELPER
1709         register_reboot_notifier(&fw_shutdown_nb);
1710         return class_register(&firmware_class);
1711 #else
1712         return 0;
1713 #endif
1714 }
1715
1716 static void __exit firmware_class_exit(void)
1717 {
1718 #ifdef CONFIG_PM_SLEEP
1719         unregister_syscore_ops(&fw_syscore_ops);
1720         unregister_pm_notifier(&fw_cache.pm_notify);
1721 #endif
1722 #ifdef CONFIG_FW_LOADER_USER_HELPER
1723         unregister_reboot_notifier(&fw_shutdown_nb);
1724         class_unregister(&firmware_class);
1725 #endif
1726 }
1727
1728 fs_initcall(firmware_class_init);
1729 module_exit(firmware_class_exit);