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   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/kthread.h>
  20 #include <linux/highmem.h>
  21 #include <linux/firmware.h>
  22 #include "base.h"
  23
  24 #define to_dev(obj) container_of(obj, struct device, kobj)
  25
  26 MODULE_AUTHOR("Manuel Estrada Sainz");
  27 MODULE_DESCRIPTION("Multi purpose firmware loading support");
  28 MODULE_LICENSE("GPL");
  29
  30 enum {
  31         FW_STATUS_LOADING,
  32         FW_STATUS_DONE,
  33         FW_STATUS_ABORT,
  34 };
  35
  36 static int loading_timeout = 60;        /* In seconds */
  37
  38 /* fw_lock could be moved to 'struct firmware_priv' but since it is just
  39  * guarding for corner cases a global lock should be OK */
  40 static DEFINE_MUTEX(fw_lock);
  41
  42 struct firmware_priv {
  43         char fw_id[FIRMWARE_NAME_MAX];
  44         struct completion completion;
  45         struct bin_attribute attr_data;
  46         struct firmware *fw;
  47         unsigned long status;
  48         struct page **pages;
  49         int nr_pages;
  50         int page_array_size;
  51         const char *vdata;
  52         struct timer_list timeout;
  53 };
  54
  55 #ifdef CONFIG_FW_LOADER
  56 extern struct builtin_fw __start_builtin_fw[];
  57 extern struct builtin_fw __end_builtin_fw[];
  58 #else /* Module case. Avoid ifdefs later; it'll all optimise out */
  59 static struct builtin_fw *__start_builtin_fw;
  60 static struct builtin_fw *__end_builtin_fw;
  61 #endif
  62
  63 static void
  64 fw_load_abort(struct firmware_priv *fw_priv)
  65 {
  66         set_bit(FW_STATUS_ABORT, &fw_priv->status);
  67         wmb();
  68         complete(&fw_priv->completion);
  69 }
  70
  71 static ssize_t
  72 firmware_timeout_show(struct class *class, char *buf)
  73 {
  74         return sprintf(buf, "%d\n", loading_timeout);
  75 }
  76
  77 /**
  78  * firmware_timeout_store - set number of seconds to wait for firmware
  79  * @class: device class pointer
  80  * @buf: buffer to scan for timeout value
  81  * @count: number of bytes in @buf
  82  *
  83  *      Sets the number of seconds to wait for the firmware.  Once
  84  *      this expires an error will be returned to the driver and no
  85  *      firmware will be provided.
  86  *
  87  *      Note: zero means 'wait forever'.
  88  **/
  89 static ssize_t
  90 firmware_timeout_store(struct class *class, const char *buf, size_t count)
  91 {
  92         loading_timeout = simple_strtol(buf, NULL, 10);
  93         if (loading_timeout < 0)
  94                 loading_timeout = 0;
  95         return count;
  96 }
  97
  98 static CLASS_ATTR(timeout, 0644, firmware_timeout_show, firmware_timeout_store);
  99
 100 static void fw_dev_release(struct device *dev);
 101
 102 static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
 103 {
 104         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 105
 106         if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->fw_id))
 107                 return -ENOMEM;
 108         if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
 109                 return -ENOMEM;
 110
 111         return 0;
 112 }
 113
 114 static struct class firmware_class = {
 115         .name           = "firmware",
 116         .dev_uevent     = firmware_uevent,
 117         .dev_release    = fw_dev_release,
 118 };
 119
 120 static ssize_t firmware_loading_show(struct device *dev,
 121                                      struct device_attribute *attr, char *buf)
 122 {
 123         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 124         int loading = test_bit(FW_STATUS_LOADING, &fw_priv->status);
 125         return sprintf(buf, "%d\n", loading);
 126 }
 127
 128 /* Some architectures don't have PAGE_KERNEL_RO */
 129 #ifndef PAGE_KERNEL_RO
 130 #define PAGE_KERNEL_RO PAGE_KERNEL
 131 #endif
 132 /**
 133  * firmware_loading_store - set value in the 'loading' control file
 134  * @dev: device pointer
 135  * @attr: device attribute pointer
 136  * @buf: buffer to scan for loading control value
 137  * @count: number of bytes in @buf
 138  *
 139  *      The relevant values are:
 140  *
 141  *       1: Start a load, discarding any previous partial load.
 142  *       0: Conclude the load and hand the data to the driver code.
 143  *      -1: Conclude the load with an error and discard any written data.
 144  **/
 145 static ssize_t firmware_loading_store(struct device *dev,
 146                                       struct device_attribute *attr,
 147                                       const char *buf, size_t count)
 148 {
 149         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 150         int loading = simple_strtol(buf, NULL, 10);
 151         int i;
 152
 153         switch (loading) {
 154         case 1:
 155                 mutex_lock(&fw_lock);
 156                 if (!fw_priv->fw) {
 157                         mutex_unlock(&fw_lock);
 158                         break;
 159                 }
 160                 vfree(fw_priv->fw->data);
 161                 fw_priv->fw->data = NULL;
 162                 for (i = 0; i < fw_priv->nr_pages; i++)
 163                         __free_page(fw_priv->pages[i]);
 164                 kfree(fw_priv->pages);
 165                 fw_priv->pages = NULL;
 166                 fw_priv->page_array_size = 0;
 167                 fw_priv->nr_pages = 0;
 168                 fw_priv->fw->size = 0;
 169                 set_bit(FW_STATUS_LOADING, &fw_priv->status);
 170                 mutex_unlock(&fw_lock);
 171                 break;
 172         case 0:
 173                 if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) {
 174                         vfree(fw_priv->fw->data);
 175                         fw_priv->fw->data = vmap(fw_priv->pages,
 176                                                  fw_priv->nr_pages,
 177                                                  0, PAGE_KERNEL_RO);
 178                         if (!fw_priv->fw->data) {
 179                                 dev_err(dev, "%s: vmap() failed\n", __func__);
 180                                 goto err;
 181                         }
 182                         /* Pages will be freed by vfree() */
 183                         fw_priv->pages = NULL;
 184                         fw_priv->page_array_size = 0;
 185                         fw_priv->nr_pages = 0;
 186                         complete(&fw_priv->completion);
 187                         clear_bit(FW_STATUS_LOADING, &fw_priv->status);
 188                         break;
 189                 }
 190                 /* fallthrough */
 191         default:
 192                 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
 193                 /* fallthrough */
 194         case -1:
 195         err:
 196                 fw_load_abort(fw_priv);
 197                 break;
 198         }
 199
 200         return count;
 201 }
 202
 203 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
 204
 205 static ssize_t
 206 firmware_data_read(struct kobject *kobj, struct bin_attribute *bin_attr,
 207                    char *buffer, loff_t offset, size_t count)
 208 {
 209         struct device *dev = to_dev(kobj);
 210         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 211         struct firmware *fw;
 212         ssize_t ret_count;
 213
 214         mutex_lock(&fw_lock);
 215         fw = fw_priv->fw;
 216         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
 217                 ret_count = -ENODEV;
 218                 goto out;
 219         }
 220         if (offset > fw->size)
 221                 return 0;
 222         if (count > fw->size - offset)
 223                 count = fw->size - offset;
 224
 225         ret_count = count;
 226
 227         while (count) {
 228                 void *page_data;
 229                 int page_nr = offset >> PAGE_SHIFT;
 230                 int page_ofs = offset & (PAGE_SIZE-1);
 231                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 232
 233                 page_data = kmap(fw_priv->pages[page_nr]);
 234
 235                 memcpy(buffer, page_data + page_ofs, page_cnt);
 236
 237                 kunmap(fw_priv->pages[page_nr]);
 238                 buffer += page_cnt;
 239                 offset += page_cnt;
 240                 count -= page_cnt;
 241         }
 242 out:
 243         mutex_unlock(&fw_lock);
 244         return ret_count;
 245 }
 246
 247 static int
 248 fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
 249 {
 250         int pages_needed = ALIGN(min_size, PAGE_SIZE) >> PAGE_SHIFT;
 251
 252         /* If the array of pages is too small, grow it... */
 253         if (fw_priv->page_array_size < pages_needed) {
 254                 int new_array_size = max(pages_needed,
 255                                          fw_priv->page_array_size * 2);
 256                 struct page **new_pages;
 257
 258                 new_pages = kmalloc(new_array_size * sizeof(void *),
 259                                     GFP_KERNEL);
 260                 if (!new_pages) {
 261                         fw_load_abort(fw_priv);
 262                         return -ENOMEM;
 263                 }
 264                 memcpy(new_pages, fw_priv->pages,
 265                        fw_priv->page_array_size * sizeof(void *));
 266                 memset(&new_pages[fw_priv->page_array_size], 0, sizeof(void *) *
 267                        (new_array_size - fw_priv->page_array_size));
 268                 kfree(fw_priv->pages);
 269                 fw_priv->pages = new_pages;
 270                 fw_priv->page_array_size = new_array_size;
 271         }
 272
 273         while (fw_priv->nr_pages < pages_needed) {
 274                 fw_priv->pages[fw_priv->nr_pages] =
 275                         alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
 276
 277                 if (!fw_priv->pages[fw_priv->nr_pages]) {
 278                         fw_load_abort(fw_priv);
 279                         return -ENOMEM;
 280                 }
 281                 fw_priv->nr_pages++;
 282         }
 283         return 0;
 284 }
 285
 286 /**
 287  * firmware_data_write - write method for firmware
 288  * @kobj: kobject for the device
 289  * @bin_attr: bin_attr structure
 290  * @buffer: buffer being written
 291  * @offset: buffer offset for write in total data store area
 292  * @count: buffer size
 293  *
 294  *      Data written to the 'data' attribute will be later handed to
 295  *      the driver as a firmware image.
 296  **/
 297 static ssize_t
 298 firmware_data_write(struct kobject *kobj, struct bin_attribute *bin_attr,
 299                     char *buffer, loff_t offset, size_t count)
 300 {
 301         struct device *dev = to_dev(kobj);
 302         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 303         struct firmware *fw;
 304         ssize_t retval;
 305
 306         if (!capable(CAP_SYS_RAWIO))
 307                 return -EPERM;
 308
 309         mutex_lock(&fw_lock);
 310         fw = fw_priv->fw;
 311         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
 312                 retval = -ENODEV;
 313                 goto out;
 314         }
 315         retval = fw_realloc_buffer(fw_priv, offset + count);
 316         if (retval)
 317                 goto out;
 318
 319         retval = count;
 320
 321         while (count) {
 322                 void *page_data;
 323                 int page_nr = offset >> PAGE_SHIFT;
 324                 int page_ofs = offset & (PAGE_SIZE - 1);
 325                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 326
 327                 page_data = kmap(fw_priv->pages[page_nr]);
 328
 329                 memcpy(page_data + page_ofs, buffer, page_cnt);
 330
 331                 kunmap(fw_priv->pages[page_nr]);
 332                 buffer += page_cnt;
 333                 offset += page_cnt;
 334                 count -= page_cnt;
 335         }
 336
 337         fw->size = max_t(size_t, offset, fw->size);
 338 out:
 339         mutex_unlock(&fw_lock);
 340         return retval;
 341 }
 342
 343 static struct bin_attribute firmware_attr_data_tmpl = {
 344         .attr = {.name = "data", .mode = 0644},
 345         .size = 0,
 346         .read = firmware_data_read,
 347         .write = firmware_data_write,
 348 };
 349
 350 static void fw_dev_release(struct device *dev)
 351 {
 352         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 353         int i;
 354
 355         for (i = 0; i < fw_priv->nr_pages; i++)
 356                 __free_page(fw_priv->pages[i]);
 357         kfree(fw_priv->pages);
 358         kfree(fw_priv);
 359         put_device(dev);
 360
 361         module_put(THIS_MODULE);
 362 }
 363
 364 static void
 365 firmware_class_timeout(u_long data)
 366 {
 367         struct firmware_priv *fw_priv = (struct firmware_priv *) data;
 368         fw_load_abort(fw_priv);
 369 }
 370
 371 static int fw_register_device(struct device **dev_p, const char *fw_name,
 372                               struct device *device)
 373 {
 374         int retval;
 375         struct firmware_priv *fw_priv = kzalloc(sizeof(*fw_priv),
 376                                                 GFP_KERNEL);
 377         struct device *f_dev = kzalloc(sizeof(*f_dev), GFP_KERNEL);
 378
 379         *dev_p = NULL;
 380
 381         if (!fw_priv || !f_dev) {
 382                 dev_err(device, "%s: kmalloc failed\n", __func__);
 383                 retval = -ENOMEM;
 384                 goto error_kfree;
 385         }
 386
 387         init_completion(&fw_priv->completion);
 388         fw_priv->attr_data = firmware_attr_data_tmpl;
 389         strlcpy(fw_priv->fw_id, fw_name, FIRMWARE_NAME_MAX);
 390
 391         fw_priv->timeout.function = firmware_class_timeout;
 392         fw_priv->timeout.data = (u_long) fw_priv;
 393         init_timer(&fw_priv->timeout);
 394
 395         dev_set_name(f_dev, dev_name(device));
 396         f_dev->parent = device;
 397         f_dev->class = &firmware_class;
 398         dev_set_drvdata(f_dev, fw_priv);
 399         dev_set_uevent_suppress(f_dev, 1);
 400         retval = device_register(f_dev);
 401         if (retval) {
 402                 dev_err(device, "%s: device_register failed\n", __func__);
 403                 put_device(f_dev);
 404                 goto error_kfree1;
 405         }
 406         *dev_p = f_dev;
 407         return 0;
 408
 409 error_kfree:
 410         kfree(f_dev);
 411 error_kfree1:
 412         kfree(fw_priv);
 413         return retval;
 414 }
 415
 416 static int fw_setup_device(struct firmware *fw, struct device **dev_p,
 417                            const char *fw_name, struct device *device,
 418                            int uevent)
 419 {
 420         struct device *f_dev;
 421         struct firmware_priv *fw_priv;
 422         int retval;
 423
 424         *dev_p = NULL;
 425         retval = fw_register_device(&f_dev, fw_name, device);
 426         if (retval)
 427                 goto out;
 428
 429         /* Need to pin this module until class device is destroyed */
 430         __module_get(THIS_MODULE);
 431
 432         fw_priv = dev_get_drvdata(f_dev);
 433
 434         fw_priv->fw = fw;
 435         retval = sysfs_create_bin_file(&f_dev->kobj, &fw_priv->attr_data);
 436         if (retval) {
 437                 dev_err(device, "%s: sysfs_create_bin_file failed\n", __func__);
 438                 goto error_unreg;
 439         }
 440
 441         retval = device_create_file(f_dev, &dev_attr_loading);
 442         if (retval) {
 443                 dev_err(device, "%s: device_create_file failed\n", __func__);
 444                 goto error_unreg;
 445         }
 446
 447         if (uevent)
 448                 dev_set_uevent_suppress(f_dev, 0);
 449         *dev_p = f_dev;
 450         goto out;
 451
 452 error_unreg:
 453         device_unregister(f_dev);
 454 out:
 455         return retval;
 456 }
 457
 458 static int
 459 _request_firmware(const struct firmware **firmware_p, const char *name,
 460                  struct device *device, int uevent)
 461 {
 462         struct device *f_dev;
 463         struct firmware_priv *fw_priv;
 464         struct firmware *firmware;
 465         struct builtin_fw *builtin;
 466         int retval;
 467
 468         if (!firmware_p)
 469                 return -EINVAL;
 470
 471         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
 472         if (!firmware) {
 473                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
 474                         __func__);
 475                 retval = -ENOMEM;
 476                 goto out;
 477         }
 478
 479         for (builtin = __start_builtin_fw; builtin != __end_builtin_fw;
 480              builtin++) {
 481                 if (strcmp(name, builtin->name))
 482                         continue;
 483                 dev_info(device, "firmware: using built-in firmware %s\n",
 484                          name);
 485                 firmware->size = builtin->size;
 486                 firmware->data = builtin->data;
 487                 return 0;
 488         }
 489
 490         if (uevent)
 491                 dev_info(device, "firmware: requesting %s\n", name);
 492
 493         retval = fw_setup_device(firmware, &f_dev, name, device, uevent);
 494         if (retval)
 495                 goto error_kfree_fw;
 496
 497         fw_priv = dev_get_drvdata(f_dev);
 498
 499         if (uevent) {
 500                 if (loading_timeout > 0) {
 501                         fw_priv->timeout.expires = jiffies + loading_timeout * HZ;
 502                         add_timer(&fw_priv->timeout);
 503                 }
 504
 505                 kobject_uevent(&f_dev->kobj, KOBJ_ADD);
 506                 wait_for_completion(&fw_priv->completion);
 507                 set_bit(FW_STATUS_DONE, &fw_priv->status);
 508                 del_timer_sync(&fw_priv->timeout);
 509         } else
 510                 wait_for_completion(&fw_priv->completion);
 511
 512         mutex_lock(&fw_lock);
 513         if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status)) {
 514                 retval = -ENOENT;
 515                 release_firmware(fw_priv->fw);
 516                 *firmware_p = NULL;
 517         }
 518         fw_priv->fw = NULL;
 519         mutex_unlock(&fw_lock);
 520         device_unregister(f_dev);
 521         goto out;
 522
 523 error_kfree_fw:
 524         kfree(firmware);
 525         *firmware_p = NULL;
 526 out:
 527         return retval;
 528 }
 529
 530 /**
 531  * request_firmware: - send firmware request and wait for it
 532  * @firmware_p: pointer to firmware image
 533  * @name: name of firmware file
 534  * @device: device for which firmware is being loaded
 535  *
 536  *      @firmware_p will be used to return a firmware image by the name
 537  *      of @name for device @device.
 538  *
 539  *      Should be called from user context where sleeping is allowed.
 540  *
 541  *      @name will be used as $FIRMWARE in the uevent environment and
 542  *      should be distinctive enough not to be confused with any other
 543  *      firmware image for this or any other device.
 544  **/
 545 int
 546 request_firmware(const struct firmware **firmware_p, const char *name,
 547                  struct device *device)
 548 {
 549         int uevent = 1;
 550         return _request_firmware(firmware_p, name, device, uevent);
 551 }
 552
 553 /**
 554  * release_firmware: - release the resource associated with a firmware image
 555  * @fw: firmware resource to release
 556  **/
 557 void
 558 release_firmware(const struct firmware *fw)
 559 {
 560         struct builtin_fw *builtin;
 561
 562         if (fw) {
 563                 for (builtin = __start_builtin_fw; builtin != __end_builtin_fw;
 564                      builtin++) {
 565                         if (fw->data == builtin->data)
 566                                 goto free_fw;
 567                 }
 568                 vfree(fw->data);
 569         free_fw:
 570                 kfree(fw);
 571         }
 572 }
 573
 574 /* Async support */
 575 struct firmware_work {
 576         struct work_struct work;
 577         struct module *module;
 578         const char *name;
 579         struct device *device;
 580         void *context;
 581         void (*cont)(const struct firmware *fw, void *context);
 582         int uevent;
 583 };
 584
 585 static int
 586 request_firmware_work_func(void *arg)
 587 {
 588         struct firmware_work *fw_work = arg;
 589         const struct firmware *fw;
 590         int ret;
 591         if (!arg) {
 592                 WARN_ON(1);
 593                 return 0;
 594         }
 595         ret = _request_firmware(&fw, fw_work->name, fw_work->device,
 596                 fw_work->uevent);
 597         if (ret < 0)
 598                 fw_work->cont(NULL, fw_work->context);
 599         else {
 600                 fw_work->cont(fw, fw_work->context);
 601                 release_firmware(fw);
 602         }
 603         module_put(fw_work->module);
 604         kfree(fw_work);
 605         return ret;
 606 }
 607
 608 /**
 609  * request_firmware_nowait: asynchronous version of request_firmware
 610  * @module: module requesting the firmware
 611  * @uevent: sends uevent to copy the firmware image if this flag
 612  *      is non-zero else the firmware copy must be done manually.
 613  * @name: name of firmware file
 614  * @device: device for which firmware is being loaded
 615  * @context: will be passed over to @cont, and
 616  *      @fw may be %NULL if firmware request fails.
 617  * @cont: function will be called asynchronously when the firmware
 618  *      request is over.
 619  *
 620  *      Asynchronous variant of request_firmware() for contexts where
 621  *      it is not possible to sleep.
 622  **/
 623 int
 624 request_firmware_nowait(
 625         struct module *module, int uevent,
 626         const char *name, struct device *device, void *context,
 627         void (*cont)(const struct firmware *fw, void *context))
 628 {
 629         struct task_struct *task;
 630         struct firmware_work *fw_work = kmalloc(sizeof (struct firmware_work),
 631                                                 GFP_ATOMIC);
 632
 633         if (!fw_work)
 634                 return -ENOMEM;
 635         if (!try_module_get(module)) {
 636                 kfree(fw_work);
 637                 return -EFAULT;
 638         }
 639
 640         *fw_work = (struct firmware_work) {
 641                 .module = module,
 642                 .name = name,
 643                 .device = device,
 644                 .context = context,
 645                 .cont = cont,
 646                 .uevent = uevent,
 647         };
 648
 649         task = kthread_run(request_firmware_work_func, fw_work,
 650                             "firmware/%s", name);
 651
 652         if (IS_ERR(task)) {
 653                 fw_work->cont(NULL, fw_work->context);
 654                 module_put(fw_work->module);
 655                 kfree(fw_work);
 656                 return PTR_ERR(task);
 657         }
 658         return 0;
 659 }
 660
 661 static int __init
 662 firmware_class_init(void)
 663 {
 664         int error;
 665         error = class_register(&firmware_class);
 666         if (error) {
 667                 printk(KERN_ERR "%s: class_register failed\n", __func__);
 668                 return error;
 669         }
 670         error = class_create_file(&firmware_class, &class_attr_timeout);
 671         if (error) {
 672                 printk(KERN_ERR "%s: class_create_file failed\n",
 673                        __func__);
 674                 class_unregister(&firmware_class);
 675         }
 676         return error;
 677
 678 }
 679 static void __exit
 680 firmware_class_exit(void)
 681 {
 682         class_unregister(&firmware_class);
 683 }
 684
 685 fs_initcall(firmware_class_init);
 686 module_exit(firmware_class_exit);
 687
 688 EXPORT_SYMBOL(release_firmware);
 689 EXPORT_SYMBOL(request_firmware);
 690 EXPORT_SYMBOL(request_firmware_nowait);