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/kthread.h>
  20 #include <linux/highmem.h>
  21 #include <linux/firmware.h>
  22
  23 #define to_dev(obj) container_of(obj, struct device, kobj)
  24
  25 MODULE_AUTHOR("Manuel Estrada Sainz");
  26 MODULE_DESCRIPTION("Multi purpose firmware loading support");
  27 MODULE_LICENSE("GPL");
  28
  29 enum {
  30         FW_STATUS_LOADING,
  31         FW_STATUS_DONE,
  32         FW_STATUS_ABORT,
  33 };
  34
  35 static int loading_timeout = 60;        /* In seconds */
  36
  37 /* fw_lock could be moved to 'struct firmware_priv' but since it is just
  38  * guarding for corner cases a global lock should be OK */
  39 static DEFINE_MUTEX(fw_lock);
  40
  41 struct firmware_priv {
  42         char *fw_id;
  43         struct completion completion;
  44         struct bin_attribute attr_data;
  45         struct firmware *fw;
  46         unsigned long status;
  47         struct page **pages;
  48         int nr_pages;
  49         int page_array_size;
  50         const char *vdata;
  51         struct timer_list timeout;
  52 };
  53
  54 #ifdef CONFIG_FW_LOADER
  55 extern struct builtin_fw __start_builtin_fw[];
  56 extern struct builtin_fw __end_builtin_fw[];
  57 #else /* Module case. Avoid ifdefs later; it'll all optimise out */
  58 static struct builtin_fw *__start_builtin_fw;
  59 static struct builtin_fw *__end_builtin_fw;
  60 #endif
  61
  62 static void
  63 fw_load_abort(struct firmware_priv *fw_priv)
  64 {
  65         set_bit(FW_STATUS_ABORT, &fw_priv->status);
  66         wmb();
  67         complete(&fw_priv->completion);
  68 }
  69
  70 static ssize_t
  71 firmware_timeout_show(struct class *class,
  72                       struct class_attribute *attr,
  73                       char *buf)
  74 {
  75         return sprintf(buf, "%d\n", loading_timeout);
  76 }
  77
  78 /**
  79  * firmware_timeout_store - set number of seconds to wait for firmware
  80  * @class: device class pointer
  81  * @attr: device attribute pointer
  82  * @buf: buffer to scan for timeout value
  83  * @count: number of bytes in @buf
  84  *
  85  *      Sets the number of seconds to wait for the firmware.  Once
  86  *      this expires an error will be returned to the driver and no
  87  *      firmware will be provided.
  88  *
  89  *      Note: zero means 'wait forever'.
  90  **/
  91 static ssize_t
  92 firmware_timeout_store(struct class *class,
  93                         struct class_attribute *attr,
  94                         const char *buf, size_t count)
  95 {
  96         loading_timeout = simple_strtol(buf, NULL, 10);
  97         if (loading_timeout < 0)
  98                 loading_timeout = 0;
  99         return count;
 100 }
 101
 102 static CLASS_ATTR(timeout, 0644, firmware_timeout_show, firmware_timeout_store);
 103
 104 static void fw_dev_release(struct device *dev);
 105
 106 static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
 107 {
 108         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 109
 110         if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->fw_id))
 111                 return -ENOMEM;
 112         if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
 113                 return -ENOMEM;
 114
 115         return 0;
 116 }
 117
 118 static struct class firmware_class = {
 119         .name           = "firmware",
 120         .dev_uevent     = firmware_uevent,
 121         .dev_release    = fw_dev_release,
 122 };
 123
 124 static ssize_t firmware_loading_show(struct device *dev,
 125                                      struct device_attribute *attr, char *buf)
 126 {
 127         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 128         int loading = test_bit(FW_STATUS_LOADING, &fw_priv->status);
 129         return sprintf(buf, "%d\n", loading);
 130 }
 131
 132 /* Some architectures don't have PAGE_KERNEL_RO */
 133 #ifndef PAGE_KERNEL_RO
 134 #define PAGE_KERNEL_RO PAGE_KERNEL
 135 #endif
 136 /**
 137  * firmware_loading_store - set value in the 'loading' control file
 138  * @dev: device pointer
 139  * @attr: device attribute pointer
 140  * @buf: buffer to scan for loading control value
 141  * @count: number of bytes in @buf
 142  *
 143  *      The relevant values are:
 144  *
 145  *       1: Start a load, discarding any previous partial load.
 146  *       0: Conclude the load and hand the data to the driver code.
 147  *      -1: Conclude the load with an error and discard any written data.
 148  **/
 149 static ssize_t firmware_loading_store(struct device *dev,
 150                                       struct device_attribute *attr,
 151                                       const char *buf, size_t count)
 152 {
 153         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 154         int loading = simple_strtol(buf, NULL, 10);
 155         int i;
 156
 157         switch (loading) {
 158         case 1:
 159                 mutex_lock(&fw_lock);
 160                 if (!fw_priv->fw) {
 161                         mutex_unlock(&fw_lock);
 162                         break;
 163                 }
 164                 vfree(fw_priv->fw->data);
 165                 fw_priv->fw->data = NULL;
 166                 for (i = 0; i < fw_priv->nr_pages; i++)
 167                         __free_page(fw_priv->pages[i]);
 168                 kfree(fw_priv->pages);
 169                 fw_priv->pages = NULL;
 170                 fw_priv->page_array_size = 0;
 171                 fw_priv->nr_pages = 0;
 172                 fw_priv->fw->size = 0;
 173                 set_bit(FW_STATUS_LOADING, &fw_priv->status);
 174                 mutex_unlock(&fw_lock);
 175                 break;
 176         case 0:
 177                 if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) {
 178                         vfree(fw_priv->fw->data);
 179                         fw_priv->fw->data = vmap(fw_priv->pages,
 180                                                  fw_priv->nr_pages,
 181                                                  0, PAGE_KERNEL_RO);
 182                         if (!fw_priv->fw->data) {
 183                                 dev_err(dev, "%s: vmap() failed\n", __func__);
 184                                 goto err;
 185                         }
 186                         /* Pages will be freed by vfree() */
 187                         fw_priv->page_array_size = 0;
 188                         fw_priv->nr_pages = 0;
 189                         complete(&fw_priv->completion);
 190                         clear_bit(FW_STATUS_LOADING, &fw_priv->status);
 191                         break;
 192                 }
 193                 /* fallthrough */
 194         default:
 195                 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
 196                 /* fallthrough */
 197         case -1:
 198         err:
 199                 fw_load_abort(fw_priv);
 200                 break;
 201         }
 202
 203         return count;
 204 }
 205
 206 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
 207
 208 static ssize_t
 209 firmware_data_read(struct kobject *kobj, struct bin_attribute *bin_attr,
 210                    char *buffer, loff_t offset, size_t count)
 211 {
 212         struct device *dev = to_dev(kobj);
 213         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 214         struct firmware *fw;
 215         ssize_t ret_count;
 216
 217         mutex_lock(&fw_lock);
 218         fw = fw_priv->fw;
 219         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
 220                 ret_count = -ENODEV;
 221                 goto out;
 222         }
 223         if (offset > fw->size) {
 224                 ret_count = 0;
 225                 goto out;
 226         }
 227         if (count > fw->size - offset)
 228                 count = fw->size - offset;
 229
 230         ret_count = count;
 231
 232         while (count) {
 233                 void *page_data;
 234                 int page_nr = offset >> PAGE_SHIFT;
 235                 int page_ofs = offset & (PAGE_SIZE-1);
 236                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 237
 238                 page_data = kmap(fw_priv->pages[page_nr]);
 239
 240                 memcpy(buffer, page_data + page_ofs, page_cnt);
 241
 242                 kunmap(fw_priv->pages[page_nr]);
 243                 buffer += page_cnt;
 244                 offset += page_cnt;
 245                 count -= page_cnt;
 246         }
 247 out:
 248         mutex_unlock(&fw_lock);
 249         return ret_count;
 250 }
 251
 252 static int
 253 fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
 254 {
 255         int pages_needed = ALIGN(min_size, PAGE_SIZE) >> PAGE_SHIFT;
 256
 257         /* If the array of pages is too small, grow it... */
 258         if (fw_priv->page_array_size < pages_needed) {
 259                 int new_array_size = max(pages_needed,
 260                                          fw_priv->page_array_size * 2);
 261                 struct page **new_pages;
 262
 263                 new_pages = kmalloc(new_array_size * sizeof(void *),
 264                                     GFP_KERNEL);
 265                 if (!new_pages) {
 266                         fw_load_abort(fw_priv);
 267                         return -ENOMEM;
 268                 }
 269                 memcpy(new_pages, fw_priv->pages,
 270                        fw_priv->page_array_size * sizeof(void *));
 271                 memset(&new_pages[fw_priv->page_array_size], 0, sizeof(void *) *
 272                        (new_array_size - fw_priv->page_array_size));
 273                 kfree(fw_priv->pages);
 274                 fw_priv->pages = new_pages;
 275                 fw_priv->page_array_size = new_array_size;
 276         }
 277
 278         while (fw_priv->nr_pages < pages_needed) {
 279                 fw_priv->pages[fw_priv->nr_pages] =
 280                         alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
 281
 282                 if (!fw_priv->pages[fw_priv->nr_pages]) {
 283                         fw_load_abort(fw_priv);
 284                         return -ENOMEM;
 285                 }
 286                 fw_priv->nr_pages++;
 287         }
 288         return 0;
 289 }
 290
 291 /**
 292  * firmware_data_write - write method for firmware
 293  * @kobj: kobject for the device
 294  * @bin_attr: bin_attr structure
 295  * @buffer: buffer being written
 296  * @offset: buffer offset for write in total data store area
 297  * @count: buffer size
 298  *
 299  *      Data written to the 'data' attribute will be later handed to
 300  *      the driver as a firmware image.
 301  **/
 302 static ssize_t
 303 firmware_data_write(struct kobject *kobj, struct bin_attribute *bin_attr,
 304                     char *buffer, loff_t offset, size_t count)
 305 {
 306         struct device *dev = to_dev(kobj);
 307         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 308         struct firmware *fw;
 309         ssize_t retval;
 310
 311         if (!capable(CAP_SYS_RAWIO))
 312                 return -EPERM;
 313
 314         mutex_lock(&fw_lock);
 315         fw = fw_priv->fw;
 316         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
 317                 retval = -ENODEV;
 318                 goto out;
 319         }
 320         retval = fw_realloc_buffer(fw_priv, offset + count);
 321         if (retval)
 322                 goto out;
 323
 324         retval = count;
 325
 326         while (count) {
 327                 void *page_data;
 328                 int page_nr = offset >> PAGE_SHIFT;
 329                 int page_ofs = offset & (PAGE_SIZE - 1);
 330                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 331
 332                 page_data = kmap(fw_priv->pages[page_nr]);
 333
 334                 memcpy(page_data + page_ofs, buffer, page_cnt);
 335
 336                 kunmap(fw_priv->pages[page_nr]);
 337                 buffer += page_cnt;
 338                 offset += page_cnt;
 339                 count -= page_cnt;
 340         }
 341
 342         fw->size = max_t(size_t, offset, fw->size);
 343 out:
 344         mutex_unlock(&fw_lock);
 345         return retval;
 346 }
 347
 348 static struct bin_attribute firmware_attr_data_tmpl = {
 349         .attr = {.name = "data", .mode = 0644},
 350         .size = 0,
 351         .read = firmware_data_read,
 352         .write = firmware_data_write,
 353 };
 354
 355 static void fw_dev_release(struct device *dev)
 356 {
 357         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 358         int i;
 359
 360         for (i = 0; i < fw_priv->nr_pages; i++)
 361                 __free_page(fw_priv->pages[i]);
 362         kfree(fw_priv->pages);
 363         kfree(fw_priv->fw_id);
 364         kfree(fw_priv);
 365         kfree(dev);
 366
 367         module_put(THIS_MODULE);
 368 }
 369
 370 static void
 371 firmware_class_timeout(u_long data)
 372 {
 373         struct firmware_priv *fw_priv = (struct firmware_priv *) data;
 374         fw_load_abort(fw_priv);
 375 }
 376
 377 static int fw_register_device(struct device **dev_p, const char *fw_name,
 378                               struct device *device)
 379 {
 380         int retval;
 381         struct firmware_priv *fw_priv = kzalloc(sizeof(*fw_priv),
 382                                                 GFP_KERNEL);
 383         struct device *f_dev = kzalloc(sizeof(*f_dev), GFP_KERNEL);
 384
 385         *dev_p = NULL;
 386
 387         if (!fw_priv || !f_dev) {
 388                 dev_err(device, "%s: kmalloc failed\n", __func__);
 389                 retval = -ENOMEM;
 390                 goto error_kfree;
 391         }
 392
 393         init_completion(&fw_priv->completion);
 394         fw_priv->attr_data = firmware_attr_data_tmpl;
 395         fw_priv->fw_id = kstrdup(fw_name, GFP_KERNEL);
 396         if (!fw_priv->fw_id) {
 397                 dev_err(device, "%s: Firmware name allocation failed\n",
 398                         __func__);
 399                 retval = -ENOMEM;
 400                 goto error_kfree;
 401         }
 402
 403         fw_priv->timeout.function = firmware_class_timeout;
 404         fw_priv->timeout.data = (u_long) fw_priv;
 405         init_timer(&fw_priv->timeout);
 406
 407         dev_set_name(f_dev, "%s", dev_name(device));
 408         f_dev->parent = device;
 409         f_dev->class = &firmware_class;
 410         dev_set_drvdata(f_dev, fw_priv);
 411         dev_set_uevent_suppress(f_dev, 1);
 412         retval = device_register(f_dev);
 413         if (retval) {
 414                 dev_err(device, "%s: device_register failed\n", __func__);
 415                 put_device(f_dev);
 416                 return retval;
 417         }
 418         *dev_p = f_dev;
 419         return 0;
 420
 421 error_kfree:
 422         kfree(f_dev);
 423         kfree(fw_priv);
 424         return retval;
 425 }
 426
 427 static int fw_setup_device(struct firmware *fw, struct device **dev_p,
 428                            const char *fw_name, struct device *device,
 429                            int uevent)
 430 {
 431         struct device *f_dev;
 432         struct firmware_priv *fw_priv;
 433         int retval;
 434
 435         *dev_p = NULL;
 436         retval = fw_register_device(&f_dev, fw_name, device);
 437         if (retval)
 438                 goto out;
 439
 440         /* Need to pin this module until class device is destroyed */
 441         __module_get(THIS_MODULE);
 442
 443         fw_priv = dev_get_drvdata(f_dev);
 444
 445         fw_priv->fw = fw;
 446         sysfs_bin_attr_init(&fw_priv->attr_data);
 447         retval = sysfs_create_bin_file(&f_dev->kobj, &fw_priv->attr_data);
 448         if (retval) {
 449                 dev_err(device, "%s: sysfs_create_bin_file failed\n", __func__);
 450                 goto error_unreg;
 451         }
 452
 453         retval = device_create_file(f_dev, &dev_attr_loading);
 454         if (retval) {
 455                 dev_err(device, "%s: device_create_file failed\n", __func__);
 456                 goto error_unreg;
 457         }
 458
 459         if (uevent)
 460                 dev_set_uevent_suppress(f_dev, 0);
 461         *dev_p = f_dev;
 462         goto out;
 463
 464 error_unreg:
 465         device_unregister(f_dev);
 466 out:
 467         return retval;
 468 }
 469
 470 static int
 471 _request_firmware(const struct firmware **firmware_p, const char *name,
 472                  struct device *device, int uevent)
 473 {
 474         struct device *f_dev;
 475         struct firmware_priv *fw_priv;
 476         struct firmware *firmware;
 477         struct builtin_fw *builtin;
 478         int retval;
 479
 480         if (!firmware_p)
 481                 return -EINVAL;
 482
 483         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
 484         if (!firmware) {
 485                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
 486                         __func__);
 487                 retval = -ENOMEM;
 488                 goto out;
 489         }
 490
 491         for (builtin = __start_builtin_fw; builtin != __end_builtin_fw;
 492              builtin++) {
 493                 if (strcmp(name, builtin->name))
 494                         continue;
 495                 dev_info(device, "firmware: using built-in firmware %s\n",
 496                          name);
 497                 firmware->size = builtin->size;
 498                 firmware->data = builtin->data;
 499                 return 0;
 500         }
 501
 502         if (uevent)
 503                 dev_info(device, "firmware: requesting %s\n", name);
 504
 505         retval = fw_setup_device(firmware, &f_dev, name, device, uevent);
 506         if (retval)
 507                 goto error_kfree_fw;
 508
 509         fw_priv = dev_get_drvdata(f_dev);
 510
 511         if (uevent) {
 512                 if (loading_timeout > 0) {
 513                         fw_priv->timeout.expires = jiffies + loading_timeout * HZ;
 514                         add_timer(&fw_priv->timeout);
 515                 }
 516
 517                 kobject_uevent(&f_dev->kobj, KOBJ_ADD);
 518                 wait_for_completion(&fw_priv->completion);
 519                 set_bit(FW_STATUS_DONE, &fw_priv->status);
 520                 del_timer_sync(&fw_priv->timeout);
 521         } else
 522                 wait_for_completion(&fw_priv->completion);
 523
 524         mutex_lock(&fw_lock);
 525         if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status)) {
 526                 retval = -ENOENT;
 527                 release_firmware(fw_priv->fw);
 528                 *firmware_p = NULL;
 529         }
 530         fw_priv->fw = NULL;
 531         mutex_unlock(&fw_lock);
 532         device_unregister(f_dev);
 533         goto out;
 534
 535 error_kfree_fw:
 536         kfree(firmware);
 537         *firmware_p = NULL;
 538 out:
 539         return retval;
 540 }
 541
 542 /**
 543  * request_firmware: - send firmware request and wait for it
 544  * @firmware_p: pointer to firmware image
 545  * @name: name of firmware file
 546  * @device: device for which firmware is being loaded
 547  *
 548  *      @firmware_p will be used to return a firmware image by the name
 549  *      of @name for device @device.
 550  *
 551  *      Should be called from user context where sleeping is allowed.
 552  *
 553  *      @name will be used as $FIRMWARE in the uevent environment and
 554  *      should be distinctive enough not to be confused with any other
 555  *      firmware image for this or any other device.
 556  **/
 557 int
 558 request_firmware(const struct firmware **firmware_p, const char *name,
 559                  struct device *device)
 560 {
 561         int uevent = 1;
 562         return _request_firmware(firmware_p, name, device, uevent);
 563 }
 564
 565 /**
 566  * release_firmware: - release the resource associated with a firmware image
 567  * @fw: firmware resource to release
 568  **/
 569 void
 570 release_firmware(const struct firmware *fw)
 571 {
 572         struct builtin_fw *builtin;
 573
 574         if (fw) {
 575                 for (builtin = __start_builtin_fw; builtin != __end_builtin_fw;
 576                      builtin++) {
 577                         if (fw->data == builtin->data)
 578                                 goto free_fw;
 579                 }
 580                 vfree(fw->data);
 581         free_fw:
 582                 kfree(fw);
 583         }
 584 }
 585
 586 /* Async support */
 587 struct firmware_work {
 588         struct work_struct work;
 589         struct module *module;
 590         const char *name;
 591         struct device *device;
 592         void *context;
 593         void (*cont)(const struct firmware *fw, void *context);
 594         int uevent;
 595 };
 596
 597 static int
 598 request_firmware_work_func(void *arg)
 599 {
 600         struct firmware_work *fw_work = arg;
 601         const struct firmware *fw;
 602         int ret;
 603         if (!arg) {
 604                 WARN_ON(1);
 605                 return 0;
 606         }
 607         ret = _request_firmware(&fw, fw_work->name, fw_work->device,
 608                 fw_work->uevent);
 609
 610         fw_work->cont(fw, fw_work->context);
 611
 612         module_put(fw_work->module);
 613         kfree(fw_work);
 614         return ret;
 615 }
 616
 617 /**
 618  * request_firmware_nowait - asynchronous version of request_firmware
 619  * @module: module requesting the firmware
 620  * @uevent: sends uevent to copy the firmware image if this flag
 621  *      is non-zero else the firmware copy must be done manually.
 622  * @name: name of firmware file
 623  * @device: device for which firmware is being loaded
 624  * @gfp: allocation flags
 625  * @context: will be passed over to @cont, and
 626  *      @fw may be %NULL if firmware request fails.
 627  * @cont: function will be called asynchronously when the firmware
 628  *      request is over.
 629  *
 630  *      Asynchronous variant of request_firmware() for user contexts where
 631  *      it is not possible to sleep for long time. It can't be called
 632  *      in atomic contexts.
 633  **/
 634 int
 635 request_firmware_nowait(
 636         struct module *module, int uevent,
 637         const char *name, struct device *device, gfp_t gfp, void *context,
 638         void (*cont)(const struct firmware *fw, void *context))
 639 {
 640         struct task_struct *task;
 641         struct firmware_work *fw_work = kmalloc(sizeof (struct firmware_work),
 642                                                 gfp);
 643
 644         if (!fw_work)
 645                 return -ENOMEM;
 646         if (!try_module_get(module)) {
 647                 kfree(fw_work);
 648                 return -EFAULT;
 649         }
 650
 651         *fw_work = (struct firmware_work) {
 652                 .module = module,
 653                 .name = name,
 654                 .device = device,
 655                 .context = context,
 656                 .cont = cont,
 657                 .uevent = uevent,
 658         };
 659
 660         task = kthread_run(request_firmware_work_func, fw_work,
 661                             "firmware/%s", name);
 662
 663         if (IS_ERR(task)) {
 664                 fw_work->cont(NULL, fw_work->context);
 665                 module_put(fw_work->module);
 666                 kfree(fw_work);
 667                 return PTR_ERR(task);
 668         }
 669         return 0;
 670 }
 671
 672 static int __init
 673 firmware_class_init(void)
 674 {
 675         int error;
 676         error = class_register(&firmware_class);
 677         if (error) {
 678                 printk(KERN_ERR "%s: class_register failed\n", __func__);
 679                 return error;
 680         }
 681         error = class_create_file(&firmware_class, &class_attr_timeout);
 682         if (error) {
 683                 printk(KERN_ERR "%s: class_create_file failed\n",
 684                        __func__);
 685                 class_unregister(&firmware_class);
 686         }
 687         return error;
 688
 689 }
 690 static void __exit
 691 firmware_class_exit(void)
 692 {
 693         class_unregister(&firmware_class);
 694 }
 695
 696 fs_initcall(firmware_class_init);
 697 module_exit(firmware_class_exit);
 698
 699 EXPORT_SYMBOL(release_firmware);
 700 EXPORT_SYMBOL(request_firmware);
 701 EXPORT_SYMBOL(request_firmware_nowait);