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/list.h>
  25 #include <linux/async.h>
  26 #include <linux/pm.h>
  27 #include <linux/suspend.h>
  28
  29 #include "base.h"
  30
  31 MODULE_AUTHOR("Manuel Estrada Sainz");
  32 MODULE_DESCRIPTION("Multi purpose firmware loading support");
  33 MODULE_LICENSE("GPL");
  34
  35 /* Builtin firmware support */
  36
  37 #ifdef CONFIG_FW_LOADER
  38
  39 extern struct builtin_fw __start_builtin_fw[];
  40 extern struct builtin_fw __end_builtin_fw[];
  41
  42 static bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
  43 {
  44         struct builtin_fw *b_fw;
  45
  46         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
  47                 if (strcmp(name, b_fw->name) == 0) {
  48                         fw->size = b_fw->size;
  49                         fw->data = b_fw->data;
  50                         return true;
  51                 }
  52         }
  53
  54         return false;
  55 }
  56
  57 static bool fw_is_builtin_firmware(const struct firmware *fw)
  58 {
  59         struct builtin_fw *b_fw;
  60
  61         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
  62                 if (fw->data == b_fw->data)
  63                         return true;
  64
  65         return false;
  66 }
  67
  68 #else /* Module case - no builtin firmware support */
  69
  70 static inline bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
  71 {
  72         return false;
  73 }
  74
  75 static inline bool fw_is_builtin_firmware(const struct firmware *fw)
  76 {
  77         return false;
  78 }
  79 #endif
  80
  81 enum {
  82         FW_STATUS_LOADING,
  83         FW_STATUS_DONE,
  84         FW_STATUS_ABORT,
  85 };
  86
  87 static int loading_timeout = 60;        /* In seconds */
  88
  89 static inline long firmware_loading_timeout(void)
  90 {
  91         return loading_timeout > 0 ? loading_timeout * HZ : MAX_SCHEDULE_TIMEOUT;
  92 }
  93
  94 struct firmware_cache {
  95         /* firmware_buf instance will be added into the below list */
  96         spinlock_t lock;
  97         struct list_head head;
  98
  99         /*
 100          * Names of firmware images which have been cached successfully
 101          * will be added into the below list so that device uncache
 102          * helper can trace which firmware images have been cached
 103          * before.
 104          */
 105         spinlock_t name_lock;
 106         struct list_head fw_names;
 107
 108         wait_queue_head_t wait_queue;
 109         int cnt;
 110         struct delayed_work work;
 111
 112         struct notifier_block   pm_notify;
 113 };
 114
 115 struct firmware_buf {
 116         struct kref ref;
 117         struct list_head list;
 118         struct completion completion;
 119         struct firmware_cache *fwc;
 120         unsigned long status;
 121         void *data;
 122         size_t size;
 123         struct page **pages;
 124         int nr_pages;
 125         int page_array_size;
 126         char fw_id[];
 127 };
 128
 129 struct fw_cache_entry {
 130         struct list_head list;
 131         char name[];
 132 };
 133
 134 struct firmware_priv {
 135         struct timer_list timeout;
 136         bool nowait;
 137         struct device dev;
 138         struct firmware_buf *buf;
 139         struct firmware *fw;
 140 };
 141
 142 struct fw_name_devm {
 143         unsigned long magic;
 144         char name[];
 145 };
 146
 147 #define to_fwbuf(d) container_of(d, struct firmware_buf, ref)
 148
 149 /* fw_lock could be moved to 'struct firmware_priv' but since it is just
 150  * guarding for corner cases a global lock should be OK */
 151 static DEFINE_MUTEX(fw_lock);
 152
 153 static struct firmware_cache fw_cache;
 154
 155 static struct firmware_buf *__allocate_fw_buf(const char *fw_name,
 156                                               struct firmware_cache *fwc)
 157 {
 158         struct firmware_buf *buf;
 159
 160         buf = kzalloc(sizeof(*buf) + strlen(fw_name) + 1 , GFP_ATOMIC);
 161
 162         if (!buf)
 163                 return buf;
 164
 165         kref_init(&buf->ref);
 166         strcpy(buf->fw_id, fw_name);
 167         buf->fwc = fwc;
 168         init_completion(&buf->completion);
 169
 170         pr_debug("%s: fw-%s buf=%p\n", __func__, fw_name, buf);
 171
 172         return buf;
 173 }
 174
 175 static struct firmware_buf *__fw_lookup_buf(const char *fw_name)
 176 {
 177         struct firmware_buf *tmp;
 178         struct firmware_cache *fwc = &fw_cache;
 179
 180         list_for_each_entry(tmp, &fwc->head, list)
 181                 if (!strcmp(tmp->fw_id, fw_name))
 182                         return tmp;
 183         return NULL;
 184 }
 185
 186 static int fw_lookup_and_allocate_buf(const char *fw_name,
 187                                       struct firmware_cache *fwc,
 188                                       struct firmware_buf **buf)
 189 {
 190         struct firmware_buf *tmp;
 191
 192         spin_lock(&fwc->lock);
 193         tmp = __fw_lookup_buf(fw_name);
 194         if (tmp) {
 195                 kref_get(&tmp->ref);
 196                 spin_unlock(&fwc->lock);
 197                 *buf = tmp;
 198                 return 1;
 199         }
 200         tmp = __allocate_fw_buf(fw_name, fwc);
 201         if (tmp)
 202                 list_add(&tmp->list, &fwc->head);
 203         spin_unlock(&fwc->lock);
 204
 205         *buf = tmp;
 206
 207         return tmp ? 0 : -ENOMEM;
 208 }
 209
 210 static struct firmware_buf *fw_lookup_buf(const char *fw_name)
 211 {
 212         struct firmware_buf *tmp;
 213         struct firmware_cache *fwc = &fw_cache;
 214
 215         spin_lock(&fwc->lock);
 216         tmp = __fw_lookup_buf(fw_name);
 217         spin_unlock(&fwc->lock);
 218
 219         return tmp;
 220 }
 221
 222 static void __fw_free_buf(struct kref *ref)
 223 {
 224         struct firmware_buf *buf = to_fwbuf(ref);
 225         struct firmware_cache *fwc = buf->fwc;
 226         int i;
 227
 228         pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
 229                  __func__, buf->fw_id, buf, buf->data,
 230                  (unsigned int)buf->size);
 231
 232         spin_lock(&fwc->lock);
 233         list_del(&buf->list);
 234         spin_unlock(&fwc->lock);
 235
 236         vunmap(buf->data);
 237         for (i = 0; i < buf->nr_pages; i++)
 238                 __free_page(buf->pages[i]);
 239         kfree(buf->pages);
 240         kfree(buf);
 241 }
 242
 243 static void fw_free_buf(struct firmware_buf *buf)
 244 {
 245         kref_put(&buf->ref, __fw_free_buf);
 246 }
 247
 248 static struct firmware_priv *to_firmware_priv(struct device *dev)
 249 {
 250         return container_of(dev, struct firmware_priv, dev);
 251 }
 252
 253 static void fw_load_abort(struct firmware_priv *fw_priv)
 254 {
 255         struct firmware_buf *buf = fw_priv->buf;
 256
 257         set_bit(FW_STATUS_ABORT, &buf->status);
 258         complete_all(&buf->completion);
 259 }
 260
 261 static ssize_t firmware_timeout_show(struct class *class,
 262                                      struct class_attribute *attr,
 263                                      char *buf)
 264 {
 265         return sprintf(buf, "%d\n", loading_timeout);
 266 }
 267
 268 /**
 269  * firmware_timeout_store - set number of seconds to wait for firmware
 270  * @class: device class pointer
 271  * @attr: device attribute pointer
 272  * @buf: buffer to scan for timeout value
 273  * @count: number of bytes in @buf
 274  *
 275  *      Sets the number of seconds to wait for the firmware.  Once
 276  *      this expires an error will be returned to the driver and no
 277  *      firmware will be provided.
 278  *
 279  *      Note: zero means 'wait forever'.
 280  **/
 281 static ssize_t firmware_timeout_store(struct class *class,
 282                                       struct class_attribute *attr,
 283                                       const char *buf, size_t count)
 284 {
 285         loading_timeout = simple_strtol(buf, NULL, 10);
 286         if (loading_timeout < 0)
 287                 loading_timeout = 0;
 288
 289         return count;
 290 }
 291
 292 static struct class_attribute firmware_class_attrs[] = {
 293         __ATTR(timeout, S_IWUSR | S_IRUGO,
 294                 firmware_timeout_show, firmware_timeout_store),
 295         __ATTR_NULL
 296 };
 297
 298 static void fw_dev_release(struct device *dev)
 299 {
 300         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 301
 302         kfree(fw_priv);
 303
 304         module_put(THIS_MODULE);
 305 }
 306
 307 static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
 308 {
 309         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 310
 311         if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->buf->fw_id))
 312                 return -ENOMEM;
 313         if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
 314                 return -ENOMEM;
 315         if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
 316                 return -ENOMEM;
 317
 318         return 0;
 319 }
 320
 321 static struct class firmware_class = {
 322         .name           = "firmware",
 323         .class_attrs    = firmware_class_attrs,
 324         .dev_uevent     = firmware_uevent,
 325         .dev_release    = fw_dev_release,
 326 };
 327
 328 static ssize_t firmware_loading_show(struct device *dev,
 329                                      struct device_attribute *attr, char *buf)
 330 {
 331         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 332         int loading = test_bit(FW_STATUS_LOADING, &fw_priv->buf->status);
 333
 334         return sprintf(buf, "%d\n", loading);
 335 }
 336
 337 /* firmware holds the ownership of pages */
 338 static void firmware_free_data(const struct firmware *fw)
 339 {
 340         WARN_ON(!fw->priv);
 341         fw_free_buf(fw->priv);
 342 }
 343
 344 /* Some architectures don't have PAGE_KERNEL_RO */
 345 #ifndef PAGE_KERNEL_RO
 346 #define PAGE_KERNEL_RO PAGE_KERNEL
 347 #endif
 348 /**
 349  * firmware_loading_store - set value in the 'loading' control file
 350  * @dev: device pointer
 351  * @attr: device attribute pointer
 352  * @buf: buffer to scan for loading control value
 353  * @count: number of bytes in @buf
 354  *
 355  *      The relevant values are:
 356  *
 357  *       1: Start a load, discarding any previous partial load.
 358  *       0: Conclude the load and hand the data to the driver code.
 359  *      -1: Conclude the load with an error and discard any written data.
 360  **/
 361 static ssize_t firmware_loading_store(struct device *dev,
 362                                       struct device_attribute *attr,
 363                                       const char *buf, size_t count)
 364 {
 365         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 366         struct firmware_buf *fw_buf = fw_priv->buf;
 367         int loading = simple_strtol(buf, NULL, 10);
 368         int i;
 369
 370         mutex_lock(&fw_lock);
 371
 372         if (!fw_buf)
 373                 goto out;
 374
 375         switch (loading) {
 376         case 1:
 377                 /* discarding any previous partial load */
 378                 if (!test_bit(FW_STATUS_DONE, &fw_buf->status)) {
 379                         for (i = 0; i < fw_buf->nr_pages; i++)
 380                                 __free_page(fw_buf->pages[i]);
 381                         kfree(fw_buf->pages);
 382                         fw_buf->pages = NULL;
 383                         fw_buf->page_array_size = 0;
 384                         fw_buf->nr_pages = 0;
 385                         set_bit(FW_STATUS_LOADING, &fw_buf->status);
 386                 }
 387                 break;
 388         case 0:
 389                 if (test_bit(FW_STATUS_LOADING, &fw_buf->status)) {
 390                         set_bit(FW_STATUS_DONE, &fw_buf->status);
 391                         clear_bit(FW_STATUS_LOADING, &fw_buf->status);
 392                         complete_all(&fw_buf->completion);
 393                         break;
 394                 }
 395                 /* fallthrough */
 396         default:
 397                 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
 398                 /* fallthrough */
 399         case -1:
 400                 fw_load_abort(fw_priv);
 401                 break;
 402         }
 403 out:
 404         mutex_unlock(&fw_lock);
 405         return count;
 406 }
 407
 408 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
 409
 410 static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
 411                                   struct bin_attribute *bin_attr,
 412                                   char *buffer, loff_t offset, size_t count)
 413 {
 414         struct device *dev = kobj_to_dev(kobj);
 415         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 416         struct firmware_buf *buf;
 417         ssize_t ret_count;
 418
 419         mutex_lock(&fw_lock);
 420         buf = fw_priv->buf;
 421         if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) {
 422                 ret_count = -ENODEV;
 423                 goto out;
 424         }
 425         if (offset > buf->size) {
 426                 ret_count = 0;
 427                 goto out;
 428         }
 429         if (count > buf->size - offset)
 430                 count = buf->size - offset;
 431
 432         ret_count = count;
 433
 434         while (count) {
 435                 void *page_data;
 436                 int page_nr = offset >> PAGE_SHIFT;
 437                 int page_ofs = offset & (PAGE_SIZE-1);
 438                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 439
 440                 page_data = kmap(buf->pages[page_nr]);
 441
 442                 memcpy(buffer, page_data + page_ofs, page_cnt);
 443
 444                 kunmap(buf->pages[page_nr]);
 445                 buffer += page_cnt;
 446                 offset += page_cnt;
 447                 count -= page_cnt;
 448         }
 449 out:
 450         mutex_unlock(&fw_lock);
 451         return ret_count;
 452 }
 453
 454 static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
 455 {
 456         struct firmware_buf *buf = fw_priv->buf;
 457         int pages_needed = ALIGN(min_size, PAGE_SIZE) >> PAGE_SHIFT;
 458
 459         /* If the array of pages is too small, grow it... */
 460         if (buf->page_array_size < pages_needed) {
 461                 int new_array_size = max(pages_needed,
 462                                          buf->page_array_size * 2);
 463                 struct page **new_pages;
 464
 465                 new_pages = kmalloc(new_array_size * sizeof(void *),
 466                                     GFP_KERNEL);
 467                 if (!new_pages) {
 468                         fw_load_abort(fw_priv);
 469                         return -ENOMEM;
 470                 }
 471                 memcpy(new_pages, buf->pages,
 472                        buf->page_array_size * sizeof(void *));
 473                 memset(&new_pages[buf->page_array_size], 0, sizeof(void *) *
 474                        (new_array_size - buf->page_array_size));
 475                 kfree(buf->pages);
 476                 buf->pages = new_pages;
 477                 buf->page_array_size = new_array_size;
 478         }
 479
 480         while (buf->nr_pages < pages_needed) {
 481                 buf->pages[buf->nr_pages] =
 482                         alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
 483
 484                 if (!buf->pages[buf->nr_pages]) {
 485                         fw_load_abort(fw_priv);
 486                         return -ENOMEM;
 487                 }
 488                 buf->nr_pages++;
 489         }
 490         return 0;
 491 }
 492
 493 /**
 494  * firmware_data_write - write method for firmware
 495  * @filp: open sysfs file
 496  * @kobj: kobject for the device
 497  * @bin_attr: bin_attr structure
 498  * @buffer: buffer being written
 499  * @offset: buffer offset for write in total data store area
 500  * @count: buffer size
 501  *
 502  *      Data written to the 'data' attribute will be later handed to
 503  *      the driver as a firmware image.
 504  **/
 505 static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,
 506                                    struct bin_attribute *bin_attr,
 507                                    char *buffer, loff_t offset, size_t count)
 508 {
 509         struct device *dev = kobj_to_dev(kobj);
 510         struct firmware_priv *fw_priv = to_firmware_priv(dev);
 511         struct firmware_buf *buf;
 512         ssize_t retval;
 513
 514         if (!capable(CAP_SYS_RAWIO))
 515                 return -EPERM;
 516
 517         mutex_lock(&fw_lock);
 518         buf = fw_priv->buf;
 519         if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) {
 520                 retval = -ENODEV;
 521                 goto out;
 522         }
 523
 524         retval = fw_realloc_buffer(fw_priv, offset + count);
 525         if (retval)
 526                 goto out;
 527
 528         retval = count;
 529
 530         while (count) {
 531                 void *page_data;
 532                 int page_nr = offset >> PAGE_SHIFT;
 533                 int page_ofs = offset & (PAGE_SIZE - 1);
 534                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 535
 536                 page_data = kmap(buf->pages[page_nr]);
 537
 538                 memcpy(page_data + page_ofs, buffer, page_cnt);
 539
 540                 kunmap(buf->pages[page_nr]);
 541                 buffer += page_cnt;
 542                 offset += page_cnt;
 543                 count -= page_cnt;
 544         }
 545
 546         buf->size = max_t(size_t, offset, buf->size);
 547 out:
 548         mutex_unlock(&fw_lock);
 549         return retval;
 550 }
 551
 552 static struct bin_attribute firmware_attr_data = {
 553         .attr = { .name = "data", .mode = 0644 },
 554         .size = 0,
 555         .read = firmware_data_read,
 556         .write = firmware_data_write,
 557 };
 558
 559 static void firmware_class_timeout(u_long data)
 560 {
 561         struct firmware_priv *fw_priv = (struct firmware_priv *) data;
 562
 563         fw_load_abort(fw_priv);
 564 }
 565
 566 static struct firmware_priv *
 567 fw_create_instance(struct firmware *firmware, const char *fw_name,
 568                    struct device *device, bool uevent, bool nowait)
 569 {
 570         struct firmware_priv *fw_priv;
 571         struct device *f_dev;
 572
 573         fw_priv = kzalloc(sizeof(*fw_priv), GFP_KERNEL);
 574         if (!fw_priv) {
 575                 dev_err(device, "%s: kmalloc failed\n", __func__);
 576                 fw_priv = ERR_PTR(-ENOMEM);
 577                 goto exit;
 578         }
 579
 580         fw_priv->nowait = nowait;
 581         fw_priv->fw = firmware;
 582         setup_timer(&fw_priv->timeout,
 583                     firmware_class_timeout, (u_long) fw_priv);
 584
 585         f_dev = &fw_priv->dev;
 586
 587         device_initialize(f_dev);
 588         dev_set_name(f_dev, "%s", fw_name);
 589         f_dev->parent = device;
 590         f_dev->class = &firmware_class;
 591 exit:
 592         return fw_priv;
 593 }
 594
 595 /* one pages buffer is mapped/unmapped only once */
 596 static int fw_map_pages_buf(struct firmware_buf *buf)
 597 {
 598         buf->data = vmap(buf->pages, buf->nr_pages, 0, PAGE_KERNEL_RO);
 599         if (!buf->data)
 600                 return -ENOMEM;
 601         return 0;
 602 }
 603
 604 /* store the pages buffer info firmware from buf */
 605 static void fw_set_page_data(struct firmware_buf *buf, struct firmware *fw)
 606 {
 607         fw->priv = buf;
 608         fw->pages = buf->pages;
 609         fw->size = buf->size;
 610         fw->data = buf->data;
 611
 612         pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
 613                  __func__, buf->fw_id, buf, buf->data,
 614                  (unsigned int)buf->size);
 615 }
 616
 617 static void fw_name_devm_release(struct device *dev, void *res)
 618 {
 619         struct fw_name_devm *fwn = res;
 620
 621         if (fwn->magic == (unsigned long)&fw_cache)
 622                 pr_debug("%s: fw_name-%s devm-%p released\n",
 623                                 __func__, fwn->name, res);
 624 }
 625
 626 static int fw_devm_match(struct device *dev, void *res,
 627                 void *match_data)
 628 {
 629         struct fw_name_devm *fwn = res;
 630
 631         return (fwn->magic == (unsigned long)&fw_cache) &&
 632                 !strcmp(fwn->name, match_data);
 633 }
 634
 635 static struct fw_name_devm *fw_find_devm_name(struct device *dev,
 636                 const char *name)
 637 {
 638         struct fw_name_devm *fwn;
 639
 640         fwn = devres_find(dev, fw_name_devm_release,
 641                           fw_devm_match, (void *)name);
 642         return fwn;
 643 }
 644
 645 /* add firmware name into devres list */
 646 static int fw_add_devm_name(struct device *dev, const char *name)
 647 {
 648         struct fw_name_devm *fwn;
 649
 650         fwn = fw_find_devm_name(dev, name);
 651         if (fwn)
 652                 return 1;
 653
 654         fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm) +
 655                            strlen(name) + 1, GFP_KERNEL);
 656         if (!fwn)
 657                 return -ENOMEM;
 658
 659         fwn->magic = (unsigned long)&fw_cache;
 660         strcpy(fwn->name, name);
 661         devres_add(dev, fwn);
 662
 663         return 0;
 664 }
 665
 666 static void _request_firmware_cleanup(const struct firmware **firmware_p)
 667 {
 668         release_firmware(*firmware_p);
 669         *firmware_p = NULL;
 670 }
 671
 672 static struct firmware_priv *
 673 _request_firmware_prepare(const struct firmware **firmware_p, const char *name,
 674                           struct device *device, bool uevent, bool nowait)
 675 {
 676         struct firmware *firmware;
 677         struct firmware_priv *fw_priv = NULL;
 678         struct firmware_buf *buf;
 679         int ret;
 680
 681         if (!firmware_p)
 682                 return ERR_PTR(-EINVAL);
 683
 684         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
 685         if (!firmware) {
 686                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
 687                         __func__);
 688                 return ERR_PTR(-ENOMEM);
 689         }
 690
 691         if (fw_get_builtin_firmware(firmware, name)) {
 692                 dev_dbg(device, "firmware: using built-in firmware %s\n", name);
 693                 return NULL;
 694         }
 695
 696         ret = fw_lookup_and_allocate_buf(name, &fw_cache, &buf);
 697         if (!ret)
 698                 fw_priv = fw_create_instance(firmware, name, device,
 699                                 uevent, nowait);
 700
 701         if (IS_ERR(fw_priv) || ret < 0) {
 702                 kfree(firmware);
 703                 *firmware_p = NULL;
 704                 return ERR_PTR(-ENOMEM);
 705         } else if (fw_priv) {
 706                 fw_priv->buf = buf;
 707
 708                 /*
 709                  * bind with 'buf' now to avoid warning in failure path
 710                  * of requesting firmware.
 711                  */
 712                 firmware->priv = buf;
 713                 return fw_priv;
 714         }
 715
 716         /* share the cached buf, which is inprogessing or completed */
 717  check_status:
 718         mutex_lock(&fw_lock);
 719         if (test_bit(FW_STATUS_ABORT, &buf->status)) {
 720                 fw_priv = ERR_PTR(-ENOENT);
 721                 _request_firmware_cleanup(firmware_p);
 722                 goto exit;
 723         } else if (test_bit(FW_STATUS_DONE, &buf->status)) {
 724                 fw_priv = NULL;
 725                 fw_set_page_data(buf, firmware);
 726                 goto exit;
 727         }
 728         mutex_unlock(&fw_lock);
 729         wait_for_completion(&buf->completion);
 730         goto check_status;
 731
 732 exit:
 733         mutex_unlock(&fw_lock);
 734         return fw_priv;
 735 }
 736
 737 static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent,
 738                                   long timeout)
 739 {
 740         int retval = 0;
 741         struct device *f_dev = &fw_priv->dev;
 742         struct firmware_buf *buf = fw_priv->buf;
 743
 744         dev_set_uevent_suppress(f_dev, true);
 745
 746         /* Need to pin this module until class device is destroyed */
 747         __module_get(THIS_MODULE);
 748
 749         retval = device_add(f_dev);
 750         if (retval) {
 751                 dev_err(f_dev, "%s: device_register failed\n", __func__);
 752                 goto err_put_dev;
 753         }
 754
 755         retval = device_create_bin_file(f_dev, &firmware_attr_data);
 756         if (retval) {
 757                 dev_err(f_dev, "%s: sysfs_create_bin_file failed\n", __func__);
 758                 goto err_del_dev;
 759         }
 760
 761         retval = device_create_file(f_dev, &dev_attr_loading);
 762         if (retval) {
 763                 dev_err(f_dev, "%s: device_create_file failed\n", __func__);
 764                 goto err_del_bin_attr;
 765         }
 766
 767         if (uevent) {
 768                 dev_set_uevent_suppress(f_dev, false);
 769                 dev_dbg(f_dev, "firmware: requesting %s\n", buf->fw_id);
 770                 if (timeout != MAX_SCHEDULE_TIMEOUT)
 771                         mod_timer(&fw_priv->timeout,
 772                                   round_jiffies_up(jiffies + timeout));
 773
 774                 kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD);
 775         }
 776
 777         wait_for_completion(&buf->completion);
 778
 779         del_timer_sync(&fw_priv->timeout);
 780
 781         mutex_lock(&fw_lock);
 782         if (!buf->size || test_bit(FW_STATUS_ABORT, &buf->status))
 783                 retval = -ENOENT;
 784
 785         /*
 786          * add firmware name into devres list so that we can auto cache
 787          * and uncache firmware for device.
 788          *
 789          * f_dev->parent may has been deleted already, but the problem
 790          * should be fixed in devres or driver core.
 791          */
 792         if (!retval && f_dev->parent)
 793                 fw_add_devm_name(f_dev->parent, buf->fw_id);
 794
 795         if (!retval)
 796                 retval = fw_map_pages_buf(buf);
 797
 798         /* pass the pages buffer to driver at the last minute */
 799         fw_set_page_data(buf, fw_priv->fw);
 800
 801         fw_priv->buf = NULL;
 802         mutex_unlock(&fw_lock);
 803
 804         device_remove_file(f_dev, &dev_attr_loading);
 805 err_del_bin_attr:
 806         device_remove_bin_file(f_dev, &firmware_attr_data);
 807 err_del_dev:
 808         device_del(f_dev);
 809 err_put_dev:
 810         put_device(f_dev);
 811         return retval;
 812 }
 813
 814 /**
 815  * request_firmware: - send firmware request and wait for it
 816  * @firmware_p: pointer to firmware image
 817  * @name: name of firmware file
 818  * @device: device for which firmware is being loaded
 819  *
 820  *      @firmware_p will be used to return a firmware image by the name
 821  *      of @name for device @device.
 822  *
 823  *      Should be called from user context where sleeping is allowed.
 824  *
 825  *      @name will be used as $FIRMWARE in the uevent environment and
 826  *      should be distinctive enough not to be confused with any other
 827  *      firmware image for this or any other device.
 828  *
 829  *      Caller must hold the reference count of @device.
 830  **/
 831 int
 832 request_firmware(const struct firmware **firmware_p, const char *name,
 833                  struct device *device)
 834 {
 835         struct firmware_priv *fw_priv;
 836         int ret;
 837
 838         fw_priv = _request_firmware_prepare(firmware_p, name, device, true,
 839                                             false);
 840         if (IS_ERR_OR_NULL(fw_priv))
 841                 return PTR_RET(fw_priv);
 842
 843         ret = usermodehelper_read_trylock();
 844         if (WARN_ON(ret)) {
 845                 dev_err(device, "firmware: %s will not be loaded\n", name);
 846         } else {
 847                 ret = _request_firmware_load(fw_priv, true,
 848                                         firmware_loading_timeout());
 849                 usermodehelper_read_unlock();
 850         }
 851         if (ret)
 852                 _request_firmware_cleanup(firmware_p);
 853
 854         return ret;
 855 }
 856
 857 /**
 858  * release_firmware: - release the resource associated with a firmware image
 859  * @fw: firmware resource to release
 860  **/
 861 void release_firmware(const struct firmware *fw)
 862 {
 863         if (fw) {
 864                 if (!fw_is_builtin_firmware(fw))
 865                         firmware_free_data(fw);
 866                 kfree(fw);
 867         }
 868 }
 869
 870 /* Async support */
 871 struct firmware_work {
 872         struct work_struct work;
 873         struct module *module;
 874         const char *name;
 875         struct device *device;
 876         void *context;
 877         void (*cont)(const struct firmware *fw, void *context);
 878         bool uevent;
 879 };
 880
 881 static void request_firmware_work_func(struct work_struct *work)
 882 {
 883         struct firmware_work *fw_work;
 884         const struct firmware *fw;
 885         struct firmware_priv *fw_priv;
 886         long timeout;
 887         int ret;
 888
 889         fw_work = container_of(work, struct firmware_work, work);
 890         fw_priv = _request_firmware_prepare(&fw, fw_work->name, fw_work->device,
 891                         fw_work->uevent, true);
 892         if (IS_ERR_OR_NULL(fw_priv)) {
 893                 ret = PTR_RET(fw_priv);
 894                 goto out;
 895         }
 896
 897         timeout = usermodehelper_read_lock_wait(firmware_loading_timeout());
 898         if (timeout) {
 899                 ret = _request_firmware_load(fw_priv, fw_work->uevent, timeout);
 900                 usermodehelper_read_unlock();
 901         } else {
 902                 dev_dbg(fw_work->device, "firmware: %s loading timed out\n",
 903                         fw_work->name);
 904                 ret = -EAGAIN;
 905         }
 906         if (ret)
 907                 _request_firmware_cleanup(&fw);
 908
 909  out:
 910         fw_work->cont(fw, fw_work->context);
 911         put_device(fw_work->device);
 912
 913         module_put(fw_work->module);
 914         kfree(fw_work);
 915 }
 916
 917 /**
 918  * request_firmware_nowait - asynchronous version of request_firmware
 919  * @module: module requesting the firmware
 920  * @uevent: sends uevent to copy the firmware image if this flag
 921  *      is non-zero else the firmware copy must be done manually.
 922  * @name: name of firmware file
 923  * @device: device for which firmware is being loaded
 924  * @gfp: allocation flags
 925  * @context: will be passed over to @cont, and
 926  *      @fw may be %NULL if firmware request fails.
 927  * @cont: function will be called asynchronously when the firmware
 928  *      request is over.
 929  *
 930  *      Caller must hold the reference count of @device.
 931  *
 932  *      Asynchronous variant of request_firmware() for user contexts:
 933  *              - sleep for as small periods as possible since it may
 934  *              increase kernel boot time of built-in device drivers
 935  *              requesting firmware in their ->probe() methods, if
 936  *              @gfp is GFP_KERNEL.
 937  *
 938  *              - can't sleep at all if @gfp is GFP_ATOMIC.
 939  **/
 940 int
 941 request_firmware_nowait(
 942         struct module *module, bool uevent,
 943         const char *name, struct device *device, gfp_t gfp, void *context,
 944         void (*cont)(const struct firmware *fw, void *context))
 945 {
 946         struct firmware_work *fw_work;
 947
 948         fw_work = kzalloc(sizeof (struct firmware_work), gfp);
 949         if (!fw_work)
 950                 return -ENOMEM;
 951
 952         fw_work->module = module;
 953         fw_work->name = name;
 954         fw_work->device = device;
 955         fw_work->context = context;
 956         fw_work->cont = cont;
 957         fw_work->uevent = uevent;
 958
 959         if (!try_module_get(module)) {
 960                 kfree(fw_work);
 961                 return -EFAULT;
 962         }
 963
 964         get_device(fw_work->device);
 965         INIT_WORK(&fw_work->work, request_firmware_work_func);
 966         schedule_work(&fw_work->work);
 967         return 0;
 968 }
 969
 970 /**
 971  * cache_firmware - cache one firmware image in kernel memory space
 972  * @fw_name: the firmware image name
 973  *
 974  * Cache firmware in kernel memory so that drivers can use it when
 975  * system isn't ready for them to request firmware image from userspace.
 976  * Once it returns successfully, driver can use request_firmware or its
 977  * nowait version to get the cached firmware without any interacting
 978  * with userspace
 979  *
 980  * Return 0 if the firmware image has been cached successfully
 981  * Return !0 otherwise
 982  *
 983  */
 984 int cache_firmware(const char *fw_name)
 985 {
 986         int ret;
 987         const struct firmware *fw;
 988
 989         pr_debug("%s: %s\n", __func__, fw_name);
 990
 991         ret = request_firmware(&fw, fw_name, NULL);
 992         if (!ret)
 993                 kfree(fw);
 994
 995         pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
 996
 997         return ret;
 998 }
 999
1000 /**
1001  * uncache_firmware - remove one cached firmware image
1002  * @fw_name: the firmware image name
1003  *
1004  * Uncache one firmware image which has been cached successfully
1005  * before.
1006  *
1007  * Return 0 if the firmware cache has been removed successfully
1008  * Return !0 otherwise
1009  *
1010  */
1011 int uncache_firmware(const char *fw_name)
1012 {
1013         struct firmware_buf *buf;
1014         struct firmware fw;
1015
1016         pr_debug("%s: %s\n", __func__, fw_name);
1017
1018         if (fw_get_builtin_firmware(&fw, fw_name))
1019                 return 0;
1020
1021         buf = fw_lookup_buf(fw_name);
1022         if (buf) {
1023                 fw_free_buf(buf);
1024                 return 0;
1025         }
1026
1027         return -EINVAL;
1028 }
1029
1030 static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
1031 {
1032         struct fw_cache_entry *fce;
1033
1034         fce = kzalloc(sizeof(*fce) + strlen(name) + 1, GFP_ATOMIC);
1035         if (!fce)
1036                 goto exit;
1037
1038         strcpy(fce->name, name);
1039 exit:
1040         return fce;
1041 }
1042
1043 static void free_fw_cache_entry(struct fw_cache_entry *fce)
1044 {
1045         kfree(fce);
1046 }
1047
1048 static void __async_dev_cache_fw_image(void *fw_entry,
1049                                        async_cookie_t cookie)
1050 {
1051         struct fw_cache_entry *fce = fw_entry;
1052         struct firmware_cache *fwc = &fw_cache;
1053         int ret;
1054
1055         ret = cache_firmware(fce->name);
1056         if (ret)
1057                 goto free;
1058
1059         spin_lock(&fwc->name_lock);
1060         list_add(&fce->list, &fwc->fw_names);
1061         spin_unlock(&fwc->name_lock);
1062         goto drop_ref;
1063
1064 free:
1065         free_fw_cache_entry(fce);
1066 drop_ref:
1067         spin_lock(&fwc->name_lock);
1068         fwc->cnt--;
1069         spin_unlock(&fwc->name_lock);
1070
1071         wake_up(&fwc->wait_queue);
1072 }
1073
1074 /* called with dev->devres_lock held */
1075 static void dev_create_fw_entry(struct device *dev, void *res,
1076                                 void *data)
1077 {
1078         struct fw_name_devm *fwn = res;
1079         const char *fw_name = fwn->name;
1080         struct list_head *head = data;
1081         struct fw_cache_entry *fce;
1082
1083         fce = alloc_fw_cache_entry(fw_name);
1084         if (fce)
1085                 list_add(&fce->list, head);
1086 }
1087
1088 static int devm_name_match(struct device *dev, void *res,
1089                            void *match_data)
1090 {
1091         struct fw_name_devm *fwn = res;
1092         return (fwn->magic == (unsigned long)match_data);
1093 }
1094
1095 static void dev_cache_fw_image(struct device *dev, void *data)
1096 {
1097         LIST_HEAD(todo);
1098         struct fw_cache_entry *fce;
1099         struct fw_cache_entry *fce_next;
1100         struct firmware_cache *fwc = &fw_cache;
1101
1102         devres_for_each_res(dev, fw_name_devm_release,
1103                             devm_name_match, &fw_cache,
1104                             dev_create_fw_entry, &todo);
1105
1106         list_for_each_entry_safe(fce, fce_next, &todo, list) {
1107                 list_del(&fce->list);
1108
1109                 spin_lock(&fwc->name_lock);
1110                 fwc->cnt++;
1111                 spin_unlock(&fwc->name_lock);
1112
1113                 async_schedule(__async_dev_cache_fw_image, (void *)fce);
1114         }
1115 }
1116
1117 static void __device_uncache_fw_images(void)
1118 {
1119         struct firmware_cache *fwc = &fw_cache;
1120         struct fw_cache_entry *fce;
1121
1122         spin_lock(&fwc->name_lock);
1123         while (!list_empty(&fwc->fw_names)) {
1124                 fce = list_entry(fwc->fw_names.next,
1125                                 struct fw_cache_entry, list);
1126                 list_del(&fce->list);
1127                 spin_unlock(&fwc->name_lock);
1128
1129                 uncache_firmware(fce->name);
1130                 free_fw_cache_entry(fce);
1131
1132                 spin_lock(&fwc->name_lock);
1133         }
1134         spin_unlock(&fwc->name_lock);
1135 }
1136
1137 /**
1138  * device_cache_fw_images - cache devices' firmware
1139  *
1140  * If one device called request_firmware or its nowait version
1141  * successfully before, the firmware names are recored into the
1142  * device's devres link list, so device_cache_fw_images can call
1143  * cache_firmware() to cache these firmwares for the device,
1144  * then the device driver can load its firmwares easily at
1145  * time when system is not ready to complete loading firmware.
1146  */
1147 static void device_cache_fw_images(void)
1148 {
1149         struct firmware_cache *fwc = &fw_cache;
1150         int old_timeout;
1151         DEFINE_WAIT(wait);
1152
1153         pr_debug("%s\n", __func__);
1154
1155         /*
1156          * use small loading timeout for caching devices' firmware
1157          * because all these firmware images have been loaded
1158          * successfully at lease once, also system is ready for
1159          * completing firmware loading now. The maximum size of
1160          * firmware in current distributions is about 2M bytes,
1161          * so 10 secs should be enough.
1162          */
1163         old_timeout = loading_timeout;
1164         loading_timeout = 10;
1165
1166         dpm_for_each_dev(NULL, dev_cache_fw_image);
1167
1168         /* wait for completion of caching firmware for all devices */
1169         spin_lock(&fwc->name_lock);
1170         for (;;) {
1171                 prepare_to_wait(&fwc->wait_queue, &wait,
1172                                 TASK_UNINTERRUPTIBLE);
1173                 if (!fwc->cnt)
1174                         break;
1175
1176                 spin_unlock(&fwc->name_lock);
1177
1178                 schedule();
1179
1180                 spin_lock(&fwc->name_lock);
1181         }
1182         spin_unlock(&fwc->name_lock);
1183         finish_wait(&fwc->wait_queue, &wait);
1184
1185         loading_timeout = old_timeout;
1186 }
1187
1188 /**
1189  * device_uncache_fw_images - uncache devices' firmware
1190  *
1191  * uncache all firmwares which have been cached successfully
1192  * by device_uncache_fw_images earlier
1193  */
1194 static void device_uncache_fw_images(void)
1195 {
1196         pr_debug("%s\n", __func__);
1197         __device_uncache_fw_images();
1198 }
1199
1200 static void device_uncache_fw_images_work(struct work_struct *work)
1201 {
1202         device_uncache_fw_images();
1203 }
1204
1205 /**
1206  * device_uncache_fw_images_delay - uncache devices firmwares
1207  * @delay: number of milliseconds to delay uncache device firmwares
1208  *
1209  * uncache all devices's firmwares which has been cached successfully
1210  * by device_cache_fw_images after @delay milliseconds.
1211  */
1212 static void device_uncache_fw_images_delay(unsigned long delay)
1213 {
1214         schedule_delayed_work(&fw_cache.work,
1215                         msecs_to_jiffies(delay));
1216 }
1217
1218 #ifdef CONFIG_PM
1219 static int fw_pm_notify(struct notifier_block *notify_block,
1220                         unsigned long mode, void *unused)
1221 {
1222         switch (mode) {
1223         case PM_HIBERNATION_PREPARE:
1224         case PM_SUSPEND_PREPARE:
1225                 device_cache_fw_images();
1226                 break;
1227
1228         case PM_POST_SUSPEND:
1229         case PM_POST_HIBERNATION:
1230         case PM_POST_RESTORE:
1231                 device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
1232                 break;
1233         }
1234
1235         return 0;
1236 }
1237 #else
1238 static int fw_pm_notify(struct notifier_block *notify_block,
1239                         unsigned long mode, void *unused)
1240 {
1241         return 0;
1242 }
1243 #endif
1244
1245 static void __init fw_cache_init(void)
1246 {
1247         spin_lock_init(&fw_cache.lock);
1248         INIT_LIST_HEAD(&fw_cache.head);
1249
1250         spin_lock_init(&fw_cache.name_lock);
1251         INIT_LIST_HEAD(&fw_cache.fw_names);
1252         fw_cache.cnt = 0;
1253
1254         init_waitqueue_head(&fw_cache.wait_queue);
1255         INIT_DELAYED_WORK(&fw_cache.work,
1256                           device_uncache_fw_images_work);
1257
1258         fw_cache.pm_notify.notifier_call = fw_pm_notify;
1259         register_pm_notifier(&fw_cache.pm_notify);
1260 }
1261
1262 static int __init firmware_class_init(void)
1263 {
1264         fw_cache_init();
1265         return class_register(&firmware_class);
1266 }
1267
1268 static void __exit firmware_class_exit(void)
1269 {
1270         unregister_pm_notifier(&fw_cache.pm_notify);
1271         class_unregister(&firmware_class);
1272 }
1273
1274 fs_initcall(firmware_class_init);
1275 module_exit(firmware_class_exit);
1276
1277 EXPORT_SYMBOL(release_firmware);
1278 EXPORT_SYMBOL(request_firmware);
1279 EXPORT_SYMBOL(request_firmware_nowait);
1280 EXPORT_SYMBOL_GPL(cache_firmware);
1281 EXPORT_SYMBOL_GPL(uncache_firmware);