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, "firmware, attempted to load %s, but failed with error %d\n",
 357                                 path, rc);
 358                 else
 359                         break;
 360         }
 361         __putname(path);
 362
 363         if (!rc) {
 364                 dev_dbg(device, "firmware: direct-loading firmware %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                 kfree(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 firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
 567 {
 568         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 569
 570         if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->buf->fw_id))
 571                 return -ENOMEM;
 572         if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
 573                 return -ENOMEM;
 574         if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
 575                 return -ENOMEM;
 576
 577         return 0;
 578 }
 579
 580 static struct class firmware_class = {
 581         .name           = "firmware",
 582         .class_attrs    = firmware_class_attrs,
 583         .dev_uevent     = firmware_uevent,
 584         .dev_release    = fw_dev_release,
 585 };
 586
 587 static ssize_t firmware_loading_show(struct device *dev,
 588                                      struct device_attribute *attr, char *buf)
 589 {
 590         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 591         int loading = 0;
 592
 593         mutex_lock(&fw_lock);
 594         if (fw_priv->buf)
 595                 loading = test_bit(FW_STATUS_LOADING, &fw_priv->buf->status);
 596         mutex_unlock(&fw_lock);
 597
 598         return sprintf(buf, "%d\n", loading);
 599 }
 600
 601 /* Some architectures don't have PAGE_KERNEL_RO */
 602 #ifndef PAGE_KERNEL_RO
 603 #define PAGE_KERNEL_RO PAGE_KERNEL
 604 #endif
 605
 606 /* one pages buffer should be mapped/unmapped only once */
 607 static int fw_map_pages_buf(struct firmware_buf *buf)
 608 {
 609         if (!buf->is_paged_buf)
 610                 return 0;
 611
 612         vunmap(buf->data);
 613         buf->data = vmap(buf->pages, buf->nr_pages, 0, PAGE_KERNEL_RO);
 614         if (!buf->data)
 615                 return -ENOMEM;
 616         return 0;
 617 }
 618
 619 /**
 620  * firmware_loading_store - set value in the 'loading' control file
 621  * @dev: device pointer
 622  * @attr: device attribute pointer
 623  * @buf: buffer to scan for loading control value
 624  * @count: number of bytes in @buf
 625  *
 626  *      The relevant values are:
 627  *
 628  *       1: Start a load, discarding any previous partial load.
 629  *       0: Conclude the load and hand the data to the driver code.
 630  *      -1: Conclude the load with an error and discard any written data.
 631  **/
 632 static ssize_t firmware_loading_store(struct device *dev,
 633                                       struct device_attribute *attr,
 634                                       const char *buf, size_t count)
 635 {
 636         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 637         struct firmware_buf *fw_buf;
 638         ssize_t written = count;
 639         int loading = simple_strtol(buf, NULL, 10);
 640         int i;
 641
 642         mutex_lock(&fw_lock);
 643         fw_buf = fw_priv->buf;
 644         if (!fw_buf)
 645                 goto out;
 646
 647         switch (loading) {
 648         case 1:
 649                 /* discarding any previous partial load */
 650                 if (!test_bit(FW_STATUS_DONE, &fw_buf->status)) {
 651                         for (i = 0; i < fw_buf->nr_pages; i++)
 652                                 __free_page(fw_buf->pages[i]);
 653                         kfree(fw_buf->pages);
 654                         fw_buf->pages = NULL;
 655                         fw_buf->page_array_size = 0;
 656                         fw_buf->nr_pages = 0;
 657                         set_bit(FW_STATUS_LOADING, &fw_buf->status);
 658                 }
 659                 break;
 660         case 0:
 661                 if (test_bit(FW_STATUS_LOADING, &fw_buf->status)) {
 662                         int rc;
 663
 664                         set_bit(FW_STATUS_DONE, &fw_buf->status);
 665                         clear_bit(FW_STATUS_LOADING, &fw_buf->status);
 666
 667                         /*
 668                          * Several loading requests may be pending on
 669                          * one same firmware buf, so let all requests
 670                          * see the mapped 'buf->data' once the loading
 671                          * is completed.
 672                          * */
 673                         rc = fw_map_pages_buf(fw_buf);
 674                         if (rc)
 675                                 dev_err(dev, "%s: map pages failed\n",
 676                                         __func__);
 677                         else
 678                                 rc = security_kernel_fw_from_file(NULL,
 679                                                 fw_buf->data, fw_buf->size);
 680
 681                         /*
 682                          * Same logic as fw_load_abort, only the DONE bit
 683                          * is ignored and we set ABORT only on failure.
 684                          */
 685                         list_del_init(&fw_buf->pending_list);
 686                         if (rc) {
 687                                 set_bit(FW_STATUS_ABORT, &fw_buf->status);
 688                                 written = rc;
 689                         }
 690                         complete_all(&fw_buf->completion);
 691                         break;
 692                 }
 693                 /* fallthrough */
 694         default:
 695                 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
 696                 /* fallthrough */
 697         case -1:
 698                 fw_load_abort(fw_priv);
 699                 break;
 700         }
 701 out:
 702         mutex_unlock(&fw_lock);
 703         return written;
 704 }
 705
 706 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
 707
 708 static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
 709                                   struct bin_attribute *bin_attr,
 710                                   char *buffer, loff_t offset, size_t count)
 711 {
 712         struct device *dev = kobj_to_dev(kobj);
 713         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 714         struct firmware_buf *buf;
 715         ssize_t ret_count;
 716
 717         mutex_lock(&fw_lock);
 718         buf = fw_priv->buf;
 719         if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) {
 720                 ret_count = -ENODEV;
 721                 goto out;
 722         }
 723         if (offset > buf->size) {
 724                 ret_count = 0;
 725                 goto out;
 726         }
 727         if (count > buf->size - offset)
 728                 count = buf->size - offset;
 729
 730         ret_count = count;
 731
 732         while (count) {
 733                 void *page_data;
 734                 int page_nr = offset >> PAGE_SHIFT;
 735                 int page_ofs = offset & (PAGE_SIZE-1);
 736                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 737
 738                 page_data = kmap(buf->pages[page_nr]);
 739
 740                 memcpy(buffer, page_data + page_ofs, page_cnt);
 741
 742                 kunmap(buf->pages[page_nr]);
 743                 buffer += page_cnt;
 744                 offset += page_cnt;
 745                 count -= page_cnt;
 746         }
 747 out:
 748         mutex_unlock(&fw_lock);
 749         return ret_count;
 750 }
 751
 752 static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
 753 {
 754         struct firmware_buf *buf = fw_priv->buf;
 755         int pages_needed = PAGE_ALIGN(min_size) >> PAGE_SHIFT;
 756
 757         /* If the array of pages is too small, grow it... */
 758         if (buf->page_array_size < pages_needed) {
 759                 int new_array_size = max(pages_needed,
 760                                          buf->page_array_size * 2);
 761                 struct page **new_pages;
 762
 763                 new_pages = kmalloc(new_array_size * sizeof(void *),
 764                                     GFP_KERNEL);
 765                 if (!new_pages) {
 766                         fw_load_abort(fw_priv);
 767                         return -ENOMEM;
 768                 }
 769                 memcpy(new_pages, buf->pages,
 770                        buf->page_array_size * sizeof(void *));
 771                 memset(&new_pages[buf->page_array_size], 0, sizeof(void *) *
 772                        (new_array_size - buf->page_array_size));
 773                 kfree(buf->pages);
 774                 buf->pages = new_pages;
 775                 buf->page_array_size = new_array_size;
 776         }
 777
 778         while (buf->nr_pages < pages_needed) {
 779                 buf->pages[buf->nr_pages] =
 780                         alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
 781
 782                 if (!buf->pages[buf->nr_pages]) {
 783                         fw_load_abort(fw_priv);
 784                         return -ENOMEM;
 785                 }
 786                 buf->nr_pages++;
 787         }
 788         return 0;
 789 }
 790
 791 /**
 792  * firmware_data_write - write method for firmware
 793  * @filp: open sysfs file
 794  * @kobj: kobject for the device
 795  * @bin_attr: bin_attr structure
 796  * @buffer: buffer being written
 797  * @offset: buffer offset for write in total data store area
 798  * @count: buffer size
 799  *
 800  *      Data written to the 'data' attribute will be later handed to
 801  *      the driver as a firmware image.
 802  **/
 803 static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,
 804                                    struct bin_attribute *bin_attr,
 805                                    char *buffer, loff_t offset, size_t count)
 806 {
 807         struct device *dev = kobj_to_dev(kobj);
 808         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 809         struct firmware_buf *buf;
 810         ssize_t retval;
 811
 812         if (!capable(CAP_SYS_RAWIO))
 813                 return -EPERM;
 814
 815         mutex_lock(&fw_lock);
 816         buf = fw_priv->buf;
 817         if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) {
 818                 retval = -ENODEV;
 819                 goto out;
 820         }
 821
 822         retval = fw_realloc_buffer(fw_priv, offset + count);
 823         if (retval)
 824                 goto out;
 825
 826         retval = count;
 827
 828         while (count) {
 829                 void *page_data;
 830                 int page_nr = offset >> PAGE_SHIFT;
 831                 int page_ofs = offset & (PAGE_SIZE - 1);
 832                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 833
 834                 page_data = kmap(buf->pages[page_nr]);
 835
 836                 memcpy(page_data + page_ofs, buffer, page_cnt);
 837
 838                 kunmap(buf->pages[page_nr]);
 839                 buffer += page_cnt;
 840                 offset += page_cnt;
 841                 count -= page_cnt;
 842         }
 843
 844         buf->size = max_t(size_t, offset, buf->size);
 845 out:
 846         mutex_unlock(&fw_lock);
 847         return retval;
 848 }
 849
 850 static struct bin_attribute firmware_attr_data = {
 851         .attr = { .name = "data", .mode = 0644 },
 852         .size = 0,
 853         .read = firmware_data_read,
 854         .write = firmware_data_write,
 855 };
 856
 857 static struct attribute *fw_dev_attrs[] = {
 858         &dev_attr_loading.attr,
 859         NULL
 860 };
 861
 862 static struct bin_attribute *fw_dev_bin_attrs[] = {
 863         &firmware_attr_data,
 864         NULL
 865 };
 866
 867 static const struct attribute_group fw_dev_attr_group = {
 868         .attrs = fw_dev_attrs,
 869         .bin_attrs = fw_dev_bin_attrs,
 870 };
 871
 872 static const struct attribute_group *fw_dev_attr_groups[] = {
 873         &fw_dev_attr_group,
 874         NULL
 875 };
 876
 877 static struct firmware_priv *
 878 fw_create_instance(struct firmware *firmware, const char *fw_name,
 879                    struct device *device, unsigned int opt_flags)
 880 {
 881         struct firmware_priv *fw_priv;
 882         struct device *f_dev;
 883
 884         fw_priv = kzalloc(sizeof(*fw_priv), GFP_KERNEL);
 885         if (!fw_priv) {
 886                 fw_priv = ERR_PTR(-ENOMEM);
 887                 goto exit;
 888         }
 889
 890         fw_priv->nowait = !!(opt_flags & FW_OPT_NOWAIT);
 891         fw_priv->fw = firmware;
 892         f_dev = &fw_priv->dev;
 893
 894         device_initialize(f_dev);
 895         dev_set_name(f_dev, "%s", fw_name);
 896         f_dev->parent = device;
 897         f_dev->class = &firmware_class;
 898         f_dev->groups = fw_dev_attr_groups;
 899 exit:
 900         return fw_priv;
 901 }
 902
 903 /* load a firmware via user helper */
 904 static int _request_firmware_load(struct firmware_priv *fw_priv,
 905                                   unsigned int opt_flags, long timeout)
 906 {
 907         int retval = 0;
 908         struct device *f_dev = &fw_priv->dev;
 909         struct firmware_buf *buf = fw_priv->buf;
 910
 911         /* fall back on userspace loading */
 912         buf->is_paged_buf = true;
 913
 914         dev_set_uevent_suppress(f_dev, true);
 915
 916         retval = device_add(f_dev);
 917         if (retval) {
 918                 dev_err(f_dev, "%s: device_register failed\n", __func__);
 919                 goto err_put_dev;
 920         }
 921
 922         mutex_lock(&fw_lock);
 923         list_add(&buf->pending_list, &pending_fw_head);
 924         mutex_unlock(&fw_lock);
 925
 926         if (opt_flags & FW_OPT_UEVENT) {
 927                 buf->need_uevent = true;
 928                 dev_set_uevent_suppress(f_dev, false);
 929                 dev_dbg(f_dev, "firmware: requesting %s\n", buf->fw_id);
 930                 kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD);
 931         } else {
 932                 timeout = MAX_JIFFY_OFFSET;
 933         }
 934
 935         retval = wait_for_completion_interruptible_timeout(&buf->completion,
 936                         timeout);
 937         if (retval == -ERESTARTSYS || !retval) {
 938                 mutex_lock(&fw_lock);
 939                 fw_load_abort(fw_priv);
 940                 mutex_unlock(&fw_lock);
 941         } else if (retval > 0) {
 942                 retval = 0;
 943         }
 944
 945         if (is_fw_load_aborted(buf))
 946                 retval = -EAGAIN;
 947         else if (!buf->data)
 948                 retval = -ENOMEM;
 949
 950         device_del(f_dev);
 951 err_put_dev:
 952         put_device(f_dev);
 953         return retval;
 954 }
 955
 956 static int fw_load_from_user_helper(struct firmware *firmware,
 957                                     const char *name, struct device *device,
 958                                     unsigned int opt_flags, long timeout)
 959 {
 960         struct firmware_priv *fw_priv;
 961
 962         fw_priv = fw_create_instance(firmware, name, device, opt_flags);
 963         if (IS_ERR(fw_priv))
 964                 return PTR_ERR(fw_priv);
 965
 966         fw_priv->buf = firmware->priv;
 967         return _request_firmware_load(fw_priv, opt_flags, timeout);
 968 }
 969
 970 #ifdef CONFIG_PM_SLEEP
 971 /* kill pending requests without uevent to avoid blocking suspend */
 972 static void kill_requests_without_uevent(void)
 973 {
 974         struct firmware_buf *buf;
 975         struct firmware_buf *next;
 976
 977         mutex_lock(&fw_lock);
 978         list_for_each_entry_safe(buf, next, &pending_fw_head, pending_list) {
 979                 if (!buf->need_uevent)
 980                          __fw_load_abort(buf);
 981         }
 982         mutex_unlock(&fw_lock);
 983 }
 984 #endif
 985
 986 #else /* CONFIG_FW_LOADER_USER_HELPER */
 987 static inline int
 988 fw_load_from_user_helper(struct firmware *firmware, const char *name,
 989                          struct device *device, unsigned int opt_flags,
 990                          long timeout)
 991 {
 992         return -ENOENT;
 993 }
 994
 995 /* No abort during direct loading */
 996 #define is_fw_load_aborted(buf) false
 997
 998 #ifdef CONFIG_PM_SLEEP
 999 static inline void kill_requests_without_uevent(void) { }
1000 #endif
1001
1002 #endif /* CONFIG_FW_LOADER_USER_HELPER */
1003
1004
1005 /* wait until the shared firmware_buf becomes ready (or error) */
1006 static int sync_cached_firmware_buf(struct firmware_buf *buf)
1007 {
1008         int ret = 0;
1009
1010         mutex_lock(&fw_lock);
1011         while (!test_bit(FW_STATUS_DONE, &buf->status)) {
1012                 if (is_fw_load_aborted(buf)) {
1013                         ret = -ENOENT;
1014                         break;
1015                 }
1016                 mutex_unlock(&fw_lock);
1017                 ret = wait_for_completion_interruptible(&buf->completion);
1018                 mutex_lock(&fw_lock);
1019         }
1020         mutex_unlock(&fw_lock);
1021         return ret;
1022 }
1023
1024 /* prepare firmware and firmware_buf structs;
1025  * return 0 if a firmware is already assigned, 1 if need to load one,
1026  * or a negative error code
1027  */
1028 static int
1029 _request_firmware_prepare(struct firmware **firmware_p, const char *name,
1030                           struct device *device)
1031 {
1032         struct firmware *firmware;
1033         struct firmware_buf *buf;
1034         int ret;
1035
1036         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
1037         if (!firmware) {
1038                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
1039                         __func__);
1040                 return -ENOMEM;
1041         }
1042
1043         if (fw_get_builtin_firmware(firmware, name)) {
1044                 dev_dbg(device, "firmware: using built-in firmware %s\n", name);
1045                 return 0; /* assigned */
1046         }
1047
1048         ret = fw_lookup_and_allocate_buf(name, &fw_cache, &buf);
1049
1050         /*
1051          * bind with 'buf' now to avoid warning in failure path
1052          * of requesting firmware.
1053          */
1054         firmware->priv = buf;
1055
1056         if (ret > 0) {
1057                 ret = sync_cached_firmware_buf(buf);
1058                 if (!ret) {
1059                         fw_set_page_data(buf, firmware);
1060                         return 0; /* assigned */
1061                 }
1062         }
1063
1064         if (ret < 0)
1065                 return ret;
1066         return 1; /* need to load */
1067 }
1068
1069 static int assign_firmware_buf(struct firmware *fw, struct device *device,
1070                                unsigned int opt_flags)
1071 {
1072         struct firmware_buf *buf = fw->priv;
1073
1074         mutex_lock(&fw_lock);
1075         if (!buf->size || is_fw_load_aborted(buf)) {
1076                 mutex_unlock(&fw_lock);
1077                 return -ENOENT;
1078         }
1079
1080         /*
1081          * add firmware name into devres list so that we can auto cache
1082          * and uncache firmware for device.
1083          *
1084          * device may has been deleted already, but the problem
1085          * should be fixed in devres or driver core.
1086          */
1087         /* don't cache firmware handled without uevent */
1088         if (device && (opt_flags & FW_OPT_UEVENT))
1089                 fw_add_devm_name(device, buf->fw_id);
1090
1091         /*
1092          * After caching firmware image is started, let it piggyback
1093          * on request firmware.
1094          */
1095         if (buf->fwc->state == FW_LOADER_START_CACHE) {
1096                 if (fw_cache_piggyback_on_request(buf->fw_id))
1097                         kref_get(&buf->ref);
1098         }
1099
1100         /* pass the pages buffer to driver at the last minute */
1101         fw_set_page_data(buf, fw);
1102         mutex_unlock(&fw_lock);
1103         return 0;
1104 }
1105
1106 /* called from request_firmware() and request_firmware_work_func() */
1107 static int
1108 _request_firmware(const struct firmware **firmware_p, const char *name,
1109                   struct device *device, unsigned int opt_flags)
1110 {
1111         struct firmware *fw;
1112         long timeout;
1113         int ret;
1114
1115         if (!firmware_p)
1116                 return -EINVAL;
1117
1118         if (!name || name[0] == '\0')
1119                 return -EINVAL;
1120
1121         ret = _request_firmware_prepare(&fw, name, device);
1122         if (ret <= 0) /* error or already assigned */
1123                 goto out;
1124
1125         ret = 0;
1126         timeout = firmware_loading_timeout();
1127         if (opt_flags & FW_OPT_NOWAIT) {
1128                 timeout = usermodehelper_read_lock_wait(timeout);
1129                 if (!timeout) {
1130                         dev_dbg(device, "firmware: %s loading timed out\n",
1131                                 name);
1132                         ret = -EBUSY;
1133                         goto out;
1134                 }
1135         } else {
1136                 ret = usermodehelper_read_trylock();
1137                 if (WARN_ON(ret)) {
1138                         dev_err(device, "firmware: %s will not be loaded\n",
1139                                 name);
1140                         goto out;
1141                 }
1142         }
1143
1144         ret = fw_get_filesystem_firmware(device, fw->priv);
1145         if (ret) {
1146                 if (!(opt_flags & FW_OPT_NO_WARN))
1147                         dev_warn(device,
1148                                  "Direct firmware load for %s failed with error %d\n",
1149                                  name, ret);
1150                 if (opt_flags & FW_OPT_USERHELPER) {
1151                         dev_warn(device, "Falling back to user helper\n");
1152                         ret = fw_load_from_user_helper(fw, name, device,
1153                                                        opt_flags, timeout);
1154                 }
1155         }
1156
1157         if (!ret)
1158                 ret = assign_firmware_buf(fw, device, opt_flags);
1159
1160         usermodehelper_read_unlock();
1161
1162  out:
1163         if (ret < 0) {
1164                 release_firmware(fw);
1165                 fw = NULL;
1166         }
1167
1168         *firmware_p = fw;
1169         return ret;
1170 }
1171
1172 /**
1173  * request_firmware: - send firmware request and wait for it
1174  * @firmware_p: pointer to firmware image
1175  * @name: name of firmware file
1176  * @device: device for which firmware is being loaded
1177  *
1178  *      @firmware_p will be used to return a firmware image by the name
1179  *      of @name for device @device.
1180  *
1181  *      Should be called from user context where sleeping is allowed.
1182  *
1183  *      @name will be used as $FIRMWARE in the uevent environment and
1184  *      should be distinctive enough not to be confused with any other
1185  *      firmware image for this or any other device.
1186  *
1187  *      Caller must hold the reference count of @device.
1188  *
1189  *      The function can be called safely inside device's suspend and
1190  *      resume callback.
1191  **/
1192 int
1193 request_firmware(const struct firmware **firmware_p, const char *name,
1194                  struct device *device)
1195 {
1196         int ret;
1197
1198         /* Need to pin this module until return */
1199         __module_get(THIS_MODULE);
1200         ret = _request_firmware(firmware_p, name, device,
1201                                 FW_OPT_UEVENT | FW_OPT_FALLBACK);
1202         module_put(THIS_MODULE);
1203         return ret;
1204 }
1205 EXPORT_SYMBOL(request_firmware);
1206
1207 /**
1208  * request_firmware_direct: - load firmware directly without usermode helper
1209  * @firmware_p: pointer to firmware image
1210  * @name: name of firmware file
1211  * @device: device for which firmware is being loaded
1212  *
1213  * This function works pretty much like request_firmware(), but this doesn't
1214  * fall back to usermode helper even if the firmware couldn't be loaded
1215  * directly from fs.  Hence it's useful for loading optional firmwares, which
1216  * aren't always present, without extra long timeouts of udev.
1217  **/
1218 int request_firmware_direct(const struct firmware **firmware_p,
1219                             const char *name, struct device *device)
1220 {
1221         int ret;
1222
1223         __module_get(THIS_MODULE);
1224         ret = _request_firmware(firmware_p, name, device,
1225                                 FW_OPT_UEVENT | FW_OPT_NO_WARN);
1226         module_put(THIS_MODULE);
1227         return ret;
1228 }
1229 EXPORT_SYMBOL_GPL(request_firmware_direct);
1230
1231 /**
1232  * release_firmware: - release the resource associated with a firmware image
1233  * @fw: firmware resource to release
1234  **/
1235 void release_firmware(const struct firmware *fw)
1236 {
1237         if (fw) {
1238                 if (!fw_is_builtin_firmware(fw))
1239                         firmware_free_data(fw);
1240                 kfree(fw);
1241         }
1242 }
1243 EXPORT_SYMBOL(release_firmware);
1244
1245 /* Async support */
1246 struct firmware_work {
1247         struct work_struct work;
1248         struct module *module;
1249         const char *name;
1250         struct device *device;
1251         void *context;
1252         void (*cont)(const struct firmware *fw, void *context);
1253         unsigned int opt_flags;
1254 };
1255
1256 static void request_firmware_work_func(struct work_struct *work)
1257 {
1258         struct firmware_work *fw_work;
1259         const struct firmware *fw;
1260
1261         fw_work = container_of(work, struct firmware_work, work);
1262
1263         _request_firmware(&fw, fw_work->name, fw_work->device,
1264                           fw_work->opt_flags);
1265         fw_work->cont(fw, fw_work->context);
1266         put_device(fw_work->device); /* taken in request_firmware_nowait() */
1267
1268         module_put(fw_work->module);
1269         kfree_const(fw_work->name);
1270         kfree(fw_work);
1271 }
1272
1273 /**
1274  * request_firmware_nowait - asynchronous version of request_firmware
1275  * @module: module requesting the firmware
1276  * @uevent: sends uevent to copy the firmware image if this flag
1277  *      is non-zero else the firmware copy must be done manually.
1278  * @name: name of firmware file
1279  * @device: device for which firmware is being loaded
1280  * @gfp: allocation flags
1281  * @context: will be passed over to @cont, and
1282  *      @fw may be %NULL if firmware request fails.
1283  * @cont: function will be called asynchronously when the firmware
1284  *      request is over.
1285  *
1286  *      Caller must hold the reference count of @device.
1287  *
1288  *      Asynchronous variant of request_firmware() for user contexts:
1289  *              - sleep for as small periods as possible since it may
1290  *              increase kernel boot time of built-in device drivers
1291  *              requesting firmware in their ->probe() methods, if
1292  *              @gfp is GFP_KERNEL.
1293  *
1294  *              - can't sleep at all if @gfp is GFP_ATOMIC.
1295  **/
1296 int
1297 request_firmware_nowait(
1298         struct module *module, bool uevent,
1299         const char *name, struct device *device, gfp_t gfp, void *context,
1300         void (*cont)(const struct firmware *fw, void *context))
1301 {
1302         struct firmware_work *fw_work;
1303
1304         fw_work = kzalloc(sizeof(struct firmware_work), gfp);
1305         if (!fw_work)
1306                 return -ENOMEM;
1307
1308         fw_work->module = module;
1309         fw_work->name = kstrdup_const(name, gfp);
1310         if (!fw_work->name) {
1311                 kfree(fw_work);
1312                 return -ENOMEM;
1313         }
1314         fw_work->device = device;
1315         fw_work->context = context;
1316         fw_work->cont = cont;
1317         fw_work->opt_flags = FW_OPT_NOWAIT | FW_OPT_FALLBACK |
1318                 (uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
1319
1320         if (!try_module_get(module)) {
1321                 kfree_const(fw_work->name);
1322                 kfree(fw_work);
1323                 return -EFAULT;
1324         }
1325
1326         get_device(fw_work->device);
1327         INIT_WORK(&fw_work->work, request_firmware_work_func);
1328         schedule_work(&fw_work->work);
1329         return 0;
1330 }
1331 EXPORT_SYMBOL(request_firmware_nowait);
1332
1333 #ifdef CONFIG_PM_SLEEP
1334 static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
1335
1336 /**
1337  * cache_firmware - cache one firmware image in kernel memory space
1338  * @fw_name: the firmware image name
1339  *
1340  * Cache firmware in kernel memory so that drivers can use it when
1341  * system isn't ready for them to request firmware image from userspace.
1342  * Once it returns successfully, driver can use request_firmware or its
1343  * nowait version to get the cached firmware without any interacting
1344  * with userspace
1345  *
1346  * Return 0 if the firmware image has been cached successfully
1347  * Return !0 otherwise
1348  *
1349  */
1350 static int cache_firmware(const char *fw_name)
1351 {
1352         int ret;
1353         const struct firmware *fw;
1354
1355         pr_debug("%s: %s\n", __func__, fw_name);
1356
1357         ret = request_firmware(&fw, fw_name, NULL);
1358         if (!ret)
1359                 kfree(fw);
1360
1361         pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
1362
1363         return ret;
1364 }
1365
1366 static struct firmware_buf *fw_lookup_buf(const char *fw_name)
1367 {
1368         struct firmware_buf *tmp;
1369         struct firmware_cache *fwc = &fw_cache;
1370
1371         spin_lock(&fwc->lock);
1372         tmp = __fw_lookup_buf(fw_name);
1373         spin_unlock(&fwc->lock);
1374
1375         return tmp;
1376 }
1377
1378 /**
1379  * uncache_firmware - remove one cached firmware image
1380  * @fw_name: the firmware image name
1381  *
1382  * Uncache one firmware image which has been cached successfully
1383  * before.
1384  *
1385  * Return 0 if the firmware cache has been removed successfully
1386  * Return !0 otherwise
1387  *
1388  */
1389 static int uncache_firmware(const char *fw_name)
1390 {
1391         struct firmware_buf *buf;
1392         struct firmware fw;
1393
1394         pr_debug("%s: %s\n", __func__, fw_name);
1395
1396         if (fw_get_builtin_firmware(&fw, fw_name))
1397                 return 0;
1398
1399         buf = fw_lookup_buf(fw_name);
1400         if (buf) {
1401                 fw_free_buf(buf);
1402                 return 0;
1403         }
1404
1405         return -EINVAL;
1406 }
1407
1408 static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
1409 {
1410         struct fw_cache_entry *fce;
1411
1412         fce = kzalloc(sizeof(*fce), GFP_ATOMIC);
1413         if (!fce)
1414                 goto exit;
1415
1416         fce->name = kstrdup_const(name, GFP_ATOMIC);
1417         if (!fce->name) {
1418                 kfree(fce);
1419                 fce = NULL;
1420                 goto exit;
1421         }
1422 exit:
1423         return fce;
1424 }
1425
1426 static int __fw_entry_found(const char *name)
1427 {
1428         struct firmware_cache *fwc = &fw_cache;
1429         struct fw_cache_entry *fce;
1430
1431         list_for_each_entry(fce, &fwc->fw_names, list) {
1432                 if (!strcmp(fce->name, name))
1433                         return 1;
1434         }
1435         return 0;
1436 }
1437
1438 static int fw_cache_piggyback_on_request(const char *name)
1439 {
1440         struct firmware_cache *fwc = &fw_cache;
1441         struct fw_cache_entry *fce;
1442         int ret = 0;
1443
1444         spin_lock(&fwc->name_lock);
1445         if (__fw_entry_found(name))
1446                 goto found;
1447
1448         fce = alloc_fw_cache_entry(name);
1449         if (fce) {
1450                 ret = 1;
1451                 list_add(&fce->list, &fwc->fw_names);
1452                 pr_debug("%s: fw: %s\n", __func__, name);
1453         }
1454 found:
1455         spin_unlock(&fwc->name_lock);
1456         return ret;
1457 }
1458
1459 static void free_fw_cache_entry(struct fw_cache_entry *fce)
1460 {
1461         kfree_const(fce->name);
1462         kfree(fce);
1463 }
1464
1465 static void __async_dev_cache_fw_image(void *fw_entry,
1466                                        async_cookie_t cookie)
1467 {
1468         struct fw_cache_entry *fce = fw_entry;
1469         struct firmware_cache *fwc = &fw_cache;
1470         int ret;
1471
1472         ret = cache_firmware(fce->name);
1473         if (ret) {
1474                 spin_lock(&fwc->name_lock);
1475                 list_del(&fce->list);
1476                 spin_unlock(&fwc->name_lock);
1477
1478                 free_fw_cache_entry(fce);
1479         }
1480 }
1481
1482 /* called with dev->devres_lock held */
1483 static void dev_create_fw_entry(struct device *dev, void *res,
1484                                 void *data)
1485 {
1486         struct fw_name_devm *fwn = res;
1487         const char *fw_name = fwn->name;
1488         struct list_head *head = data;
1489         struct fw_cache_entry *fce;
1490
1491         fce = alloc_fw_cache_entry(fw_name);
1492         if (fce)
1493                 list_add(&fce->list, head);
1494 }
1495
1496 static int devm_name_match(struct device *dev, void *res,
1497                            void *match_data)
1498 {
1499         struct fw_name_devm *fwn = res;
1500         return (fwn->magic == (unsigned long)match_data);
1501 }
1502
1503 static void dev_cache_fw_image(struct device *dev, void *data)
1504 {
1505         LIST_HEAD(todo);
1506         struct fw_cache_entry *fce;
1507         struct fw_cache_entry *fce_next;
1508         struct firmware_cache *fwc = &fw_cache;
1509
1510         devres_for_each_res(dev, fw_name_devm_release,
1511                             devm_name_match, &fw_cache,
1512                             dev_create_fw_entry, &todo);
1513
1514         list_for_each_entry_safe(fce, fce_next, &todo, list) {
1515                 list_del(&fce->list);
1516
1517                 spin_lock(&fwc->name_lock);
1518                 /* only one cache entry for one firmware */
1519                 if (!__fw_entry_found(fce->name)) {
1520                         list_add(&fce->list, &fwc->fw_names);
1521                 } else {
1522                         free_fw_cache_entry(fce);
1523                         fce = NULL;
1524                 }
1525                 spin_unlock(&fwc->name_lock);
1526
1527                 if (fce)
1528                         async_schedule_domain(__async_dev_cache_fw_image,
1529                                               (void *)fce,
1530                                               &fw_cache_domain);
1531         }
1532 }
1533
1534 static void __device_uncache_fw_images(void)
1535 {
1536         struct firmware_cache *fwc = &fw_cache;
1537         struct fw_cache_entry *fce;
1538
1539         spin_lock(&fwc->name_lock);
1540         while (!list_empty(&fwc->fw_names)) {
1541                 fce = list_entry(fwc->fw_names.next,
1542                                 struct fw_cache_entry, list);
1543                 list_del(&fce->list);
1544                 spin_unlock(&fwc->name_lock);
1545
1546                 uncache_firmware(fce->name);
1547                 free_fw_cache_entry(fce);
1548
1549                 spin_lock(&fwc->name_lock);
1550         }
1551         spin_unlock(&fwc->name_lock);
1552 }
1553
1554 /**
1555  * device_cache_fw_images - cache devices' firmware
1556  *
1557  * If one device called request_firmware or its nowait version
1558  * successfully before, the firmware names are recored into the
1559  * device's devres link list, so device_cache_fw_images can call
1560  * cache_firmware() to cache these firmwares for the device,
1561  * then the device driver can load its firmwares easily at
1562  * time when system is not ready to complete loading firmware.
1563  */
1564 static void device_cache_fw_images(void)
1565 {
1566         struct firmware_cache *fwc = &fw_cache;
1567         int old_timeout;
1568         DEFINE_WAIT(wait);
1569
1570         pr_debug("%s\n", __func__);
1571
1572         /* cancel uncache work */
1573         cancel_delayed_work_sync(&fwc->work);
1574
1575         /*
1576          * use small loading timeout for caching devices' firmware
1577          * because all these firmware images have been loaded
1578          * successfully at lease once, also system is ready for
1579          * completing firmware loading now. The maximum size of
1580          * firmware in current distributions is about 2M bytes,
1581          * so 10 secs should be enough.
1582          */
1583         old_timeout = loading_timeout;
1584         loading_timeout = 10;
1585
1586         mutex_lock(&fw_lock);
1587         fwc->state = FW_LOADER_START_CACHE;
1588         dpm_for_each_dev(NULL, dev_cache_fw_image);
1589         mutex_unlock(&fw_lock);
1590
1591         /* wait for completion of caching firmware for all devices */
1592         async_synchronize_full_domain(&fw_cache_domain);
1593
1594         loading_timeout = old_timeout;
1595 }
1596
1597 /**
1598  * device_uncache_fw_images - uncache devices' firmware
1599  *
1600  * uncache all firmwares which have been cached successfully
1601  * by device_uncache_fw_images earlier
1602  */
1603 static void device_uncache_fw_images(void)
1604 {
1605         pr_debug("%s\n", __func__);
1606         __device_uncache_fw_images();
1607 }
1608
1609 static void device_uncache_fw_images_work(struct work_struct *work)
1610 {
1611         device_uncache_fw_images();
1612 }
1613
1614 /**
1615  * device_uncache_fw_images_delay - uncache devices firmwares
1616  * @delay: number of milliseconds to delay uncache device firmwares
1617  *
1618  * uncache all devices's firmwares which has been cached successfully
1619  * by device_cache_fw_images after @delay milliseconds.
1620  */
1621 static void device_uncache_fw_images_delay(unsigned long delay)
1622 {
1623         queue_delayed_work(system_power_efficient_wq, &fw_cache.work,
1624                            msecs_to_jiffies(delay));
1625 }
1626
1627 static int fw_pm_notify(struct notifier_block *notify_block,
1628                         unsigned long mode, void *unused)
1629 {
1630         switch (mode) {
1631         case PM_HIBERNATION_PREPARE:
1632         case PM_SUSPEND_PREPARE:
1633         case PM_RESTORE_PREPARE:
1634                 kill_requests_without_uevent();
1635                 device_cache_fw_images();
1636                 break;
1637
1638         case PM_POST_SUSPEND:
1639         case PM_POST_HIBERNATION:
1640         case PM_POST_RESTORE:
1641                 /*
1642                  * In case that system sleep failed and syscore_suspend is
1643                  * not called.
1644                  */
1645                 mutex_lock(&fw_lock);
1646                 fw_cache.state = FW_LOADER_NO_CACHE;
1647                 mutex_unlock(&fw_lock);
1648
1649                 device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
1650                 break;
1651         }
1652
1653         return 0;
1654 }
1655
1656 /* stop caching firmware once syscore_suspend is reached */
1657 static int fw_suspend(void)
1658 {
1659         fw_cache.state = FW_LOADER_NO_CACHE;
1660         return 0;
1661 }
1662
1663 static struct syscore_ops fw_syscore_ops = {
1664         .suspend = fw_suspend,
1665 };
1666 #else
1667 static int fw_cache_piggyback_on_request(const char *name)
1668 {
1669         return 0;
1670 }
1671 #endif
1672
1673 static void __init fw_cache_init(void)
1674 {
1675         spin_lock_init(&fw_cache.lock);
1676         INIT_LIST_HEAD(&fw_cache.head);
1677         fw_cache.state = FW_LOADER_NO_CACHE;
1678
1679 #ifdef CONFIG_PM_SLEEP
1680         spin_lock_init(&fw_cache.name_lock);
1681         INIT_LIST_HEAD(&fw_cache.fw_names);
1682
1683         INIT_DELAYED_WORK(&fw_cache.work,
1684                           device_uncache_fw_images_work);
1685
1686         fw_cache.pm_notify.notifier_call = fw_pm_notify;
1687         register_pm_notifier(&fw_cache.pm_notify);
1688
1689         register_syscore_ops(&fw_syscore_ops);
1690 #endif
1691 }
1692
1693 static int __init firmware_class_init(void)
1694 {
1695         fw_cache_init();
1696 #ifdef CONFIG_FW_LOADER_USER_HELPER
1697         register_reboot_notifier(&fw_shutdown_nb);
1698         return class_register(&firmware_class);
1699 #else
1700         return 0;
1701 #endif
1702 }
1703
1704 static void __exit firmware_class_exit(void)
1705 {
1706 #ifdef CONFIG_PM_SLEEP
1707         unregister_syscore_ops(&fw_syscore_ops);
1708         unregister_pm_notifier(&fw_cache.pm_notify);
1709 #endif
1710 #ifdef CONFIG_FW_LOADER_USER_HELPER
1711         unregister_reboot_notifier(&fw_shutdown_nb);
1712         class_unregister(&firmware_class);
1713 #endif
1714 }
1715
1716 fs_initcall(firmware_class_init);
1717 module_exit(firmware_class_exit);