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 #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;
  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->page_array_size = 0;
 184                         fw_priv->nr_pages = 0;
 185                         complete(&fw_priv->completion);
 186                         clear_bit(FW_STATUS_LOADING, &fw_priv->status);
 187                         break;
 188                 }
 189                 /* fallthrough */
 190         default:
 191                 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
 192                 /* fallthrough */
 193         case -1:
 194         err:
 195                 fw_load_abort(fw_priv);
 196                 break;
 197         }
 198
 199         return count;
 200 }
 201
 202 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
 203
 204 static ssize_t
 205 firmware_data_read(struct kobject *kobj, struct bin_attribute *bin_attr,
 206                    char *buffer, loff_t offset, size_t count)
 207 {
 208         struct device *dev = to_dev(kobj);
 209         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 210         struct firmware *fw;
 211         ssize_t ret_count;
 212
 213         mutex_lock(&fw_lock);
 214         fw = fw_priv->fw;
 215         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
 216                 ret_count = -ENODEV;
 217                 goto out;
 218         }
 219         if (offset > fw->size) {
 220                 ret_count = 0;
 221                 goto out;
 222         }
 223         if (count > fw->size - offset)
 224                 count = fw->size - offset;
 225
 226         ret_count = count;
 227
 228         while (count) {
 229                 void *page_data;
 230                 int page_nr = offset >> PAGE_SHIFT;
 231                 int page_ofs = offset & (PAGE_SIZE-1);
 232                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 233
 234                 page_data = kmap(fw_priv->pages[page_nr]);
 235
 236                 memcpy(buffer, page_data + page_ofs, page_cnt);
 237
 238                 kunmap(fw_priv->pages[page_nr]);
 239                 buffer += page_cnt;
 240                 offset += page_cnt;
 241                 count -= page_cnt;
 242         }
 243 out:
 244         mutex_unlock(&fw_lock);
 245         return ret_count;
 246 }
 247
 248 static int
 249 fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
 250 {
 251         int pages_needed = ALIGN(min_size, PAGE_SIZE) >> PAGE_SHIFT;
 252
 253         /* If the array of pages is too small, grow it... */
 254         if (fw_priv->page_array_size < pages_needed) {
 255                 int new_array_size = max(pages_needed,
 256                                          fw_priv->page_array_size * 2);
 257                 struct page **new_pages;
 258
 259                 new_pages = kmalloc(new_array_size * sizeof(void *),
 260                                     GFP_KERNEL);
 261                 if (!new_pages) {
 262                         fw_load_abort(fw_priv);
 263                         return -ENOMEM;
 264                 }
 265                 memcpy(new_pages, fw_priv->pages,
 266                        fw_priv->page_array_size * sizeof(void *));
 267                 memset(&new_pages[fw_priv->page_array_size], 0, sizeof(void *) *
 268                        (new_array_size - fw_priv->page_array_size));
 269                 kfree(fw_priv->pages);
 270                 fw_priv->pages = new_pages;
 271                 fw_priv->page_array_size = new_array_size;
 272         }
 273
 274         while (fw_priv->nr_pages < pages_needed) {
 275                 fw_priv->pages[fw_priv->nr_pages] =
 276                         alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
 277
 278                 if (!fw_priv->pages[fw_priv->nr_pages]) {
 279                         fw_load_abort(fw_priv);
 280                         return -ENOMEM;
 281                 }
 282                 fw_priv->nr_pages++;
 283         }
 284         return 0;
 285 }
 286
 287 /**
 288  * firmware_data_write - write method for firmware
 289  * @kobj: kobject for the device
 290  * @bin_attr: bin_attr structure
 291  * @buffer: buffer being written
 292  * @offset: buffer offset for write in total data store area
 293  * @count: buffer size
 294  *
 295  *      Data written to the 'data' attribute will be later handed to
 296  *      the driver as a firmware image.
 297  **/
 298 static ssize_t
 299 firmware_data_write(struct kobject *kobj, struct bin_attribute *bin_attr,
 300                     char *buffer, loff_t offset, size_t count)
 301 {
 302         struct device *dev = to_dev(kobj);
 303         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 304         struct firmware *fw;
 305         ssize_t retval;
 306
 307         if (!capable(CAP_SYS_RAWIO))
 308                 return -EPERM;
 309
 310         mutex_lock(&fw_lock);
 311         fw = fw_priv->fw;
 312         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
 313                 retval = -ENODEV;
 314                 goto out;
 315         }
 316         retval = fw_realloc_buffer(fw_priv, offset + count);
 317         if (retval)
 318                 goto out;
 319
 320         retval = count;
 321
 322         while (count) {
 323                 void *page_data;
 324                 int page_nr = offset >> PAGE_SHIFT;
 325                 int page_ofs = offset & (PAGE_SIZE - 1);
 326                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
 327
 328                 page_data = kmap(fw_priv->pages[page_nr]);
 329
 330                 memcpy(page_data + page_ofs, buffer, page_cnt);
 331
 332                 kunmap(fw_priv->pages[page_nr]);
 333                 buffer += page_cnt;
 334                 offset += page_cnt;
 335                 count -= page_cnt;
 336         }
 337
 338         fw->size = max_t(size_t, offset, fw->size);
 339 out:
 340         mutex_unlock(&fw_lock);
 341         return retval;
 342 }
 343
 344 static struct bin_attribute firmware_attr_data_tmpl = {
 345         .attr = {.name = "data", .mode = 0644},
 346         .size = 0,
 347         .read = firmware_data_read,
 348         .write = firmware_data_write,
 349 };
 350
 351 static void fw_dev_release(struct device *dev)
 352 {
 353         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 354         int i;
 355
 356         for (i = 0; i < fw_priv->nr_pages; i++)
 357                 __free_page(fw_priv->pages[i]);
 358         kfree(fw_priv->pages);
 359         kfree(fw_priv->fw_id);
 360         kfree(fw_priv);
 361         kfree(dev);
 362
 363         module_put(THIS_MODULE);
 364 }
 365
 366 static void
 367 firmware_class_timeout(u_long data)
 368 {
 369         struct firmware_priv *fw_priv = (struct firmware_priv *) data;
 370         fw_load_abort(fw_priv);
 371 }
 372
 373 static int fw_register_device(struct device **dev_p, const char *fw_name,
 374                               struct device *device)
 375 {
 376         int retval;
 377         struct firmware_priv *fw_priv = kzalloc(sizeof(*fw_priv),
 378                                                 GFP_KERNEL);
 379         struct device *f_dev = kzalloc(sizeof(*f_dev), GFP_KERNEL);
 380
 381         *dev_p = NULL;
 382
 383         if (!fw_priv || !f_dev) {
 384                 dev_err(device, "%s: kmalloc failed\n", __func__);
 385                 retval = -ENOMEM;
 386                 goto error_kfree;
 387         }
 388
 389         init_completion(&fw_priv->completion);
 390         fw_priv->attr_data = firmware_attr_data_tmpl;
 391         fw_priv->fw_id = kstrdup(fw_name, GFP_KERNEL);
 392         if (!fw_priv->fw_id) {
 393                 dev_err(device, "%s: Firmware name allocation failed\n",
 394                         __func__);
 395                 retval = -ENOMEM;
 396                 goto error_kfree;
 397         }
 398
 399         fw_priv->timeout.function = firmware_class_timeout;
 400         fw_priv->timeout.data = (u_long) fw_priv;
 401         init_timer(&fw_priv->timeout);
 402
 403         dev_set_name(f_dev, "%s", dev_name(device));
 404         f_dev->parent = device;
 405         f_dev->class = &firmware_class;
 406         dev_set_drvdata(f_dev, fw_priv);
 407         dev_set_uevent_suppress(f_dev, 1);
 408         retval = device_register(f_dev);
 409         if (retval) {
 410                 dev_err(device, "%s: device_register failed\n", __func__);
 411                 put_device(f_dev);
 412                 return retval;
 413         }
 414         *dev_p = f_dev;
 415         return 0;
 416
 417 error_kfree:
 418         kfree(f_dev);
 419         kfree(fw_priv);
 420         return retval;
 421 }
 422
 423 static int fw_setup_device(struct firmware *fw, struct device **dev_p,
 424                            const char *fw_name, struct device *device,
 425                            int uevent)
 426 {
 427         struct device *f_dev;
 428         struct firmware_priv *fw_priv;
 429         int retval;
 430
 431         *dev_p = NULL;
 432         retval = fw_register_device(&f_dev, fw_name, device);
 433         if (retval)
 434                 goto out;
 435
 436         /* Need to pin this module until class device is destroyed */
 437         __module_get(THIS_MODULE);
 438
 439         fw_priv = dev_get_drvdata(f_dev);
 440
 441         fw_priv->fw = fw;
 442         retval = sysfs_create_bin_file(&f_dev->kobj, &fw_priv->attr_data);
 443         if (retval) {
 444                 dev_err(device, "%s: sysfs_create_bin_file failed\n", __func__);
 445                 goto error_unreg;
 446         }
 447
 448         retval = device_create_file(f_dev, &dev_attr_loading);
 449         if (retval) {
 450                 dev_err(device, "%s: device_create_file failed\n", __func__);
 451                 goto error_unreg;
 452         }
 453
 454         if (uevent)
 455                 dev_set_uevent_suppress(f_dev, 0);
 456         *dev_p = f_dev;
 457         goto out;
 458
 459 error_unreg:
 460         device_unregister(f_dev);
 461 out:
 462         return retval;
 463 }
 464
 465 static int
 466 _request_firmware(const struct firmware **firmware_p, const char *name,
 467                  struct device *device, int uevent)
 468 {
 469         struct device *f_dev;
 470         struct firmware_priv *fw_priv;
 471         struct firmware *firmware;
 472         struct builtin_fw *builtin;
 473         int retval;
 474
 475         if (!firmware_p)
 476                 return -EINVAL;
 477
 478         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
 479         if (!firmware) {
 480                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
 481                         __func__);
 482                 retval = -ENOMEM;
 483                 goto out;
 484         }
 485
 486         for (builtin = __start_builtin_fw; builtin != __end_builtin_fw;
 487              builtin++) {
 488                 if (strcmp(name, builtin->name))
 489                         continue;
 490                 dev_info(device, "firmware: using built-in firmware %s\n",
 491                          name);
 492                 firmware->size = builtin->size;
 493                 firmware->data = builtin->data;
 494                 return 0;
 495         }
 496
 497         if (uevent)
 498                 dev_info(device, "firmware: requesting %s\n", name);
 499
 500         retval = fw_setup_device(firmware, &f_dev, name, device, uevent);
 501         if (retval)
 502                 goto error_kfree_fw;
 503
 504         fw_priv = dev_get_drvdata(f_dev);
 505
 506         if (uevent) {
 507                 if (loading_timeout > 0) {
 508                         fw_priv->timeout.expires = jiffies + loading_timeout * HZ;
 509                         add_timer(&fw_priv->timeout);
 510                 }
 511
 512                 kobject_uevent(&f_dev->kobj, KOBJ_ADD);
 513                 wait_for_completion(&fw_priv->completion);
 514                 set_bit(FW_STATUS_DONE, &fw_priv->status);
 515                 del_timer_sync(&fw_priv->timeout);
 516         } else
 517                 wait_for_completion(&fw_priv->completion);
 518
 519         mutex_lock(&fw_lock);
 520         if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status)) {
 521                 retval = -ENOENT;
 522                 release_firmware(fw_priv->fw);
 523                 *firmware_p = NULL;
 524         }
 525         fw_priv->fw = NULL;
 526         mutex_unlock(&fw_lock);
 527         device_unregister(f_dev);
 528         goto out;
 529
 530 error_kfree_fw:
 531         kfree(firmware);
 532         *firmware_p = NULL;
 533 out:
 534         return retval;
 535 }
 536
 537 /**
 538  * request_firmware: - send firmware request and wait for it
 539  * @firmware_p: pointer to firmware image
 540  * @name: name of firmware file
 541  * @device: device for which firmware is being loaded
 542  *
 543  *      @firmware_p will be used to return a firmware image by the name
 544  *      of @name for device @device.
 545  *
 546  *      Should be called from user context where sleeping is allowed.
 547  *
 548  *      @name will be used as $FIRMWARE in the uevent environment and
 549  *      should be distinctive enough not to be confused with any other
 550  *      firmware image for this or any other device.
 551  **/
 552 int
 553 request_firmware(const struct firmware **firmware_p, const char *name,
 554                  struct device *device)
 555 {
 556         int uevent = 1;
 557         return _request_firmware(firmware_p, name, device, uevent);
 558 }
 559
 560 /**
 561  * release_firmware: - release the resource associated with a firmware image
 562  * @fw: firmware resource to release
 563  **/
 564 void
 565 release_firmware(const struct firmware *fw)
 566 {
 567         struct builtin_fw *builtin;
 568
 569         if (fw) {
 570                 for (builtin = __start_builtin_fw; builtin != __end_builtin_fw;
 571                      builtin++) {
 572                         if (fw->data == builtin->data)
 573                                 goto free_fw;
 574                 }
 575                 vfree(fw->data);
 576         free_fw:
 577                 kfree(fw);
 578         }
 579 }
 580
 581 /* Async support */
 582 struct firmware_work {
 583         struct work_struct work;
 584         struct module *module;
 585         const char *name;
 586         struct device *device;
 587         void *context;
 588         void (*cont)(const struct firmware *fw, void *context);
 589         int uevent;
 590 };
 591
 592 static int
 593 request_firmware_work_func(void *arg)
 594 {
 595         struct firmware_work *fw_work = arg;
 596         const struct firmware *fw;
 597         int ret;
 598         if (!arg) {
 599                 WARN_ON(1);
 600                 return 0;
 601         }
 602         ret = _request_firmware(&fw, fw_work->name, fw_work->device,
 603                 fw_work->uevent);
 604         if (ret < 0)
 605                 fw_work->cont(NULL, fw_work->context);
 606         else {
 607                 fw_work->cont(fw, fw_work->context);
 608                 release_firmware(fw);
 609         }
 610         module_put(fw_work->module);
 611         kfree(fw_work);
 612         return ret;
 613 }
 614
 615 /**
 616  * request_firmware_nowait: asynchronous version of request_firmware
 617  * @module: module requesting the firmware
 618  * @uevent: sends uevent to copy the firmware image if this flag
 619  *      is non-zero else the firmware copy must be done manually.
 620  * @name: name of firmware file
 621  * @device: device for which firmware is being loaded
 622  * @context: will be passed over to @cont, and
 623  *      @fw may be %NULL if firmware request fails.
 624  * @cont: function will be called asynchronously when the firmware
 625  *      request is over.
 626  *
 627  *      Asynchronous variant of request_firmware() for user contexts where
 628  *      it is not possible to sleep for long time. It can't be called
 629  *      in atomic contexts.
 630  **/
 631 int
 632 request_firmware_nowait(
 633         struct module *module, int uevent,
 634         const char *name, struct device *device, void *context,
 635         void (*cont)(const struct firmware *fw, void *context))
 636 {
 637         struct task_struct *task;
 638         struct firmware_work *fw_work = kmalloc(sizeof (struct firmware_work),
 639                                                 GFP_ATOMIC);
 640
 641         if (!fw_work)
 642                 return -ENOMEM;
 643         if (!try_module_get(module)) {
 644                 kfree(fw_work);
 645                 return -EFAULT;
 646         }
 647
 648         *fw_work = (struct firmware_work) {
 649                 .module = module,
 650                 .name = name,
 651                 .device = device,
 652                 .context = context,
 653                 .cont = cont,
 654                 .uevent = uevent,
 655         };
 656
 657         task = kthread_run(request_firmware_work_func, fw_work,
 658                             "firmware/%s", name);
 659
 660         if (IS_ERR(task)) {
 661                 fw_work->cont(NULL, fw_work->context);
 662                 module_put(fw_work->module);
 663                 kfree(fw_work);
 664                 return PTR_ERR(task);
 665         }
 666         return 0;
 667 }
 668
 669 static int __init
 670 firmware_class_init(void)
 671 {
 672         int error;
 673         error = class_register(&firmware_class);
 674         if (error) {
 675                 printk(KERN_ERR "%s: class_register failed\n", __func__);
 676                 return error;
 677         }
 678         error = class_create_file(&firmware_class, &class_attr_timeout);
 679         if (error) {
 680                 printk(KERN_ERR "%s: class_create_file failed\n",
 681                        __func__);
 682                 class_unregister(&firmware_class);
 683         }
 684         return error;
 685
 686 }
 687 static void __exit
 688 firmware_class_exit(void)
 689 {
 690         class_unregister(&firmware_class);
 691 }
 692
 693 fs_initcall(firmware_class_init);
 694 module_exit(firmware_class_exit);
 695
 696 EXPORT_SYMBOL(release_firmware);
 697 EXPORT_SYMBOL(request_firmware);
 698 EXPORT_SYMBOL(request_firmware_nowait);