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
  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         int alloc_size;
  49         struct timer_list timeout;
  50 };
  51
  52 #ifdef CONFIG_FW_LOADER
  53 extern struct builtin_fw __start_builtin_fw[];
  54 extern struct builtin_fw __end_builtin_fw[];
  55 #else /* Module case. Avoid ifdefs later; it'll all optimise out */
  56 static struct builtin_fw *__start_builtin_fw;
  57 static struct builtin_fw *__end_builtin_fw;
  58 #endif
  59
  60 static void
  61 fw_load_abort(struct firmware_priv *fw_priv)
  62 {
  63         set_bit(FW_STATUS_ABORT, &fw_priv->status);
  64         wmb();
  65         complete(&fw_priv->completion);
  66 }
  67
  68 static ssize_t
  69 firmware_timeout_show(struct class *class, char *buf)
  70 {
  71         return sprintf(buf, "%d\n", loading_timeout);
  72 }
  73
  74 /**
  75  * firmware_timeout_store - set number of seconds to wait for firmware
  76  * @class: device class pointer
  77  * @buf: buffer to scan for timeout value
  78  * @count: number of bytes in @buf
  79  *
  80  *      Sets the number of seconds to wait for the firmware.  Once
  81  *      this expires an error will be returned to the driver and no
  82  *      firmware will be provided.
  83  *
  84  *      Note: zero means 'wait forever'.
  85  **/
  86 static ssize_t
  87 firmware_timeout_store(struct class *class, const char *buf, size_t count)
  88 {
  89         loading_timeout = simple_strtol(buf, NULL, 10);
  90         if (loading_timeout < 0)
  91                 loading_timeout = 0;
  92         return count;
  93 }
  94
  95 static CLASS_ATTR(timeout, 0644, firmware_timeout_show, firmware_timeout_store);
  96
  97 static void fw_dev_release(struct device *dev);
  98
  99 static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
 100 {
 101         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 102
 103         if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->fw_id))
 104                 return -ENOMEM;
 105         if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
 106                 return -ENOMEM;
 107
 108         return 0;
 109 }
 110
 111 static struct class firmware_class = {
 112         .name           = "firmware",
 113         .dev_uevent     = firmware_uevent,
 114         .dev_release    = fw_dev_release,
 115 };
 116
 117 static ssize_t firmware_loading_show(struct device *dev,
 118                                      struct device_attribute *attr, char *buf)
 119 {
 120         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 121         int loading = test_bit(FW_STATUS_LOADING, &fw_priv->status);
 122         return sprintf(buf, "%d\n", loading);
 123 }
 124
 125 /**
 126  * firmware_loading_store - set value in the 'loading' control file
 127  * @dev: device pointer
 128  * @attr: device attribute pointer
 129  * @buf: buffer to scan for loading control value
 130  * @count: number of bytes in @buf
 131  *
 132  *      The relevant values are:
 133  *
 134  *       1: Start a load, discarding any previous partial load.
 135  *       0: Conclude the load and hand the data to the driver code.
 136  *      -1: Conclude the load with an error and discard any written data.
 137  **/
 138 static ssize_t firmware_loading_store(struct device *dev,
 139                                       struct device_attribute *attr,
 140                                       const char *buf, size_t count)
 141 {
 142         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 143         int loading = simple_strtol(buf, NULL, 10);
 144
 145         switch (loading) {
 146         case 1:
 147                 mutex_lock(&fw_lock);
 148                 if (!fw_priv->fw) {
 149                         mutex_unlock(&fw_lock);
 150                         break;
 151                 }
 152                 vfree(fw_priv->fw->data);
 153                 fw_priv->fw->data = NULL;
 154                 fw_priv->fw->size = 0;
 155                 fw_priv->alloc_size = 0;
 156                 set_bit(FW_STATUS_LOADING, &fw_priv->status);
 157                 mutex_unlock(&fw_lock);
 158                 break;
 159         case 0:
 160                 if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) {
 161                         complete(&fw_priv->completion);
 162                         clear_bit(FW_STATUS_LOADING, &fw_priv->status);
 163                         break;
 164                 }
 165                 /* fallthrough */
 166         default:
 167                 printk(KERN_ERR "%s: unexpected value (%d)\n", __func__,
 168                        loading);
 169                 /* fallthrough */
 170         case -1:
 171                 fw_load_abort(fw_priv);
 172                 break;
 173         }
 174
 175         return count;
 176 }
 177
 178 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
 179
 180 static ssize_t
 181 firmware_data_read(struct kobject *kobj, struct bin_attribute *bin_attr,
 182                    char *buffer, loff_t offset, size_t count)
 183 {
 184         struct device *dev = to_dev(kobj);
 185         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 186         struct firmware *fw;
 187         ssize_t ret_count = count;
 188
 189         mutex_lock(&fw_lock);
 190         fw = fw_priv->fw;
 191         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
 192                 ret_count = -ENODEV;
 193                 goto out;
 194         }
 195         if (offset > fw->size) {
 196                 ret_count = 0;
 197                 goto out;
 198         }
 199         if (offset + ret_count > fw->size)
 200                 ret_count = fw->size - offset;
 201
 202         memcpy(buffer, fw->data + offset, ret_count);
 203 out:
 204         mutex_unlock(&fw_lock);
 205         return ret_count;
 206 }
 207
 208 static int
 209 fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
 210 {
 211         u8 *new_data;
 212         int new_size = fw_priv->alloc_size;
 213
 214         if (min_size <= fw_priv->alloc_size)
 215                 return 0;
 216
 217         new_size = ALIGN(min_size, PAGE_SIZE);
 218         new_data = vmalloc(new_size);
 219         if (!new_data) {
 220                 printk(KERN_ERR "%s: unable to alloc buffer\n", __func__);
 221                 /* Make sure that we don't keep incomplete data */
 222                 fw_load_abort(fw_priv);
 223                 return -ENOMEM;
 224         }
 225         fw_priv->alloc_size = new_size;
 226         if (fw_priv->fw->data) {
 227                 memcpy(new_data, fw_priv->fw->data, fw_priv->fw->size);
 228                 vfree(fw_priv->fw->data);
 229         }
 230         fw_priv->fw->data = new_data;
 231         BUG_ON(min_size > fw_priv->alloc_size);
 232         return 0;
 233 }
 234
 235 /**
 236  * firmware_data_write - write method for firmware
 237  * @kobj: kobject for the device
 238  * @bin_attr: bin_attr structure
 239  * @buffer: buffer being written
 240  * @offset: buffer offset for write in total data store area
 241  * @count: buffer size
 242  *
 243  *      Data written to the 'data' attribute will be later handed to
 244  *      the driver as a firmware image.
 245  **/
 246 static ssize_t
 247 firmware_data_write(struct kobject *kobj, struct bin_attribute *bin_attr,
 248                     char *buffer, loff_t offset, size_t count)
 249 {
 250         struct device *dev = to_dev(kobj);
 251         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 252         struct firmware *fw;
 253         ssize_t retval;
 254
 255         if (!capable(CAP_SYS_RAWIO))
 256                 return -EPERM;
 257
 258         mutex_lock(&fw_lock);
 259         fw = fw_priv->fw;
 260         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
 261                 retval = -ENODEV;
 262                 goto out;
 263         }
 264         retval = fw_realloc_buffer(fw_priv, offset + count);
 265         if (retval)
 266                 goto out;
 267
 268         memcpy((u8 *)fw->data + offset, buffer, count);
 269
 270         fw->size = max_t(size_t, offset + count, fw->size);
 271         retval = count;
 272 out:
 273         mutex_unlock(&fw_lock);
 274         return retval;
 275 }
 276
 277 static struct bin_attribute firmware_attr_data_tmpl = {
 278         .attr = {.name = "data", .mode = 0644},
 279         .size = 0,
 280         .read = firmware_data_read,
 281         .write = firmware_data_write,
 282 };
 283
 284 static void fw_dev_release(struct device *dev)
 285 {
 286         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
 287
 288         kfree(fw_priv);
 289         kfree(dev);
 290
 291         module_put(THIS_MODULE);
 292 }
 293
 294 static void
 295 firmware_class_timeout(u_long data)
 296 {
 297         struct firmware_priv *fw_priv = (struct firmware_priv *) data;
 298         fw_load_abort(fw_priv);
 299 }
 300
 301 static inline void fw_setup_device_id(struct device *f_dev, struct device *dev)
 302 {
 303         /* XXX warning we should watch out for name collisions */
 304         strlcpy(f_dev->bus_id, dev->bus_id, BUS_ID_SIZE);
 305 }
 306
 307 static int fw_register_device(struct device **dev_p, const char *fw_name,
 308                               struct device *device)
 309 {
 310         int retval;
 311         struct firmware_priv *fw_priv = kzalloc(sizeof(*fw_priv),
 312                                                 GFP_KERNEL);
 313         struct device *f_dev = kzalloc(sizeof(*f_dev), GFP_KERNEL);
 314
 315         *dev_p = NULL;
 316
 317         if (!fw_priv || !f_dev) {
 318                 printk(KERN_ERR "%s: kmalloc failed\n", __func__);
 319                 retval = -ENOMEM;
 320                 goto error_kfree;
 321         }
 322
 323         init_completion(&fw_priv->completion);
 324         fw_priv->attr_data = firmware_attr_data_tmpl;
 325         strlcpy(fw_priv->fw_id, fw_name, FIRMWARE_NAME_MAX);
 326
 327         fw_priv->timeout.function = firmware_class_timeout;
 328         fw_priv->timeout.data = (u_long) fw_priv;
 329         init_timer(&fw_priv->timeout);
 330
 331         fw_setup_device_id(f_dev, device);
 332         f_dev->parent = device;
 333         f_dev->class = &firmware_class;
 334         dev_set_drvdata(f_dev, fw_priv);
 335         f_dev->uevent_suppress = 1;
 336         retval = device_register(f_dev);
 337         if (retval) {
 338                 printk(KERN_ERR "%s: device_register failed\n",
 339                        __func__);
 340                 goto error_kfree;
 341         }
 342         *dev_p = f_dev;
 343         return 0;
 344
 345 error_kfree:
 346         kfree(fw_priv);
 347         kfree(f_dev);
 348         return retval;
 349 }
 350
 351 static int fw_setup_device(struct firmware *fw, struct device **dev_p,
 352                            const char *fw_name, struct device *device,
 353                            int uevent)
 354 {
 355         struct device *f_dev;
 356         struct firmware_priv *fw_priv;
 357         int retval;
 358
 359         *dev_p = NULL;
 360         retval = fw_register_device(&f_dev, fw_name, device);
 361         if (retval)
 362                 goto out;
 363
 364         /* Need to pin this module until class device is destroyed */
 365         __module_get(THIS_MODULE);
 366
 367         fw_priv = dev_get_drvdata(f_dev);
 368
 369         fw_priv->fw = fw;
 370         retval = sysfs_create_bin_file(&f_dev->kobj, &fw_priv->attr_data);
 371         if (retval) {
 372                 printk(KERN_ERR "%s: sysfs_create_bin_file failed\n",
 373                        __func__);
 374                 goto error_unreg;
 375         }
 376
 377         retval = device_create_file(f_dev, &dev_attr_loading);
 378         if (retval) {
 379                 printk(KERN_ERR "%s: device_create_file failed\n",
 380                        __func__);
 381                 goto error_unreg;
 382         }
 383
 384         if (uevent)
 385                 f_dev->uevent_suppress = 0;
 386         *dev_p = f_dev;
 387         goto out;
 388
 389 error_unreg:
 390         device_unregister(f_dev);
 391 out:
 392         return retval;
 393 }
 394
 395 static int
 396 _request_firmware(const struct firmware **firmware_p, const char *name,
 397                  struct device *device, int uevent)
 398 {
 399         struct device *f_dev;
 400         struct firmware_priv *fw_priv;
 401         struct firmware *firmware;
 402         struct builtin_fw *builtin;
 403         int retval;
 404
 405         if (!firmware_p)
 406                 return -EINVAL;
 407
 408         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
 409         if (!firmware) {
 410                 printk(KERN_ERR "%s: kmalloc(struct firmware) failed\n",
 411                        __func__);
 412                 retval = -ENOMEM;
 413                 goto out;
 414         }
 415
 416         for (builtin = __start_builtin_fw; builtin != __end_builtin_fw;
 417              builtin++) {
 418                 if (strcmp(name, builtin->name))
 419                         continue;
 420                 printk(KERN_INFO "firmware: using built-in firmware %s\n",
 421                        name);
 422                 firmware->size = builtin->size;
 423                 firmware->data = builtin->data;
 424                 return 0;
 425         }
 426
 427         if (uevent)
 428                 printk(KERN_INFO "firmware: requesting %s\n", name);
 429
 430         retval = fw_setup_device(firmware, &f_dev, name, device, uevent);
 431         if (retval)
 432                 goto error_kfree_fw;
 433
 434         fw_priv = dev_get_drvdata(f_dev);
 435
 436         if (uevent) {
 437                 if (loading_timeout > 0) {
 438                         fw_priv->timeout.expires = jiffies + loading_timeout * HZ;
 439                         add_timer(&fw_priv->timeout);
 440                 }
 441
 442                 kobject_uevent(&f_dev->kobj, KOBJ_ADD);
 443                 wait_for_completion(&fw_priv->completion);
 444                 set_bit(FW_STATUS_DONE, &fw_priv->status);
 445                 del_timer_sync(&fw_priv->timeout);
 446         } else
 447                 wait_for_completion(&fw_priv->completion);
 448
 449         mutex_lock(&fw_lock);
 450         if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status)) {
 451                 retval = -ENOENT;
 452                 release_firmware(fw_priv->fw);
 453                 *firmware_p = NULL;
 454         }
 455         fw_priv->fw = NULL;
 456         mutex_unlock(&fw_lock);
 457         device_unregister(f_dev);
 458         goto out;
 459
 460 error_kfree_fw:
 461         kfree(firmware);
 462         *firmware_p = NULL;
 463 out:
 464         return retval;
 465 }
 466
 467 /**
 468  * request_firmware: - send firmware request and wait for it
 469  * @firmware_p: pointer to firmware image
 470  * @name: name of firmware file
 471  * @device: device for which firmware is being loaded
 472  *
 473  *      @firmware_p will be used to return a firmware image by the name
 474  *      of @name for device @device.
 475  *
 476  *      Should be called from user context where sleeping is allowed.
 477  *
 478  *      @name will be used as $FIRMWARE in the uevent environment and
 479  *      should be distinctive enough not to be confused with any other
 480  *      firmware image for this or any other device.
 481  **/
 482 int
 483 request_firmware(const struct firmware **firmware_p, const char *name,
 484                  struct device *device)
 485 {
 486         int uevent = 1;
 487         return _request_firmware(firmware_p, name, device, uevent);
 488 }
 489
 490 /**
 491  * release_firmware: - release the resource associated with a firmware image
 492  * @fw: firmware resource to release
 493  **/
 494 void
 495 release_firmware(const struct firmware *fw)
 496 {
 497         struct builtin_fw *builtin;
 498
 499         if (fw) {
 500                 for (builtin = __start_builtin_fw; builtin != __end_builtin_fw;
 501                      builtin++) {
 502                         if (fw->data == builtin->data)
 503                                 goto free_fw;
 504                 }
 505                 vfree(fw->data);
 506         free_fw:
 507                 kfree(fw);
 508         }
 509 }
 510
 511 /* Async support */
 512 struct firmware_work {
 513         struct work_struct work;
 514         struct module *module;
 515         const char *name;
 516         struct device *device;
 517         void *context;
 518         void (*cont)(const struct firmware *fw, void *context);
 519         int uevent;
 520 };
 521
 522 static int
 523 request_firmware_work_func(void *arg)
 524 {
 525         struct firmware_work *fw_work = arg;
 526         const struct firmware *fw;
 527         int ret;
 528         if (!arg) {
 529                 WARN_ON(1);
 530                 return 0;
 531         }
 532         ret = _request_firmware(&fw, fw_work->name, fw_work->device,
 533                 fw_work->uevent);
 534         if (ret < 0)
 535                 fw_work->cont(NULL, fw_work->context);
 536         else {
 537                 fw_work->cont(fw, fw_work->context);
 538                 release_firmware(fw);
 539         }
 540         module_put(fw_work->module);
 541         kfree(fw_work);
 542         return ret;
 543 }
 544
 545 /**
 546  * request_firmware_nowait: asynchronous version of request_firmware
 547  * @module: module requesting the firmware
 548  * @uevent: sends uevent to copy the firmware image if this flag
 549  *      is non-zero else the firmware copy must be done manually.
 550  * @name: name of firmware file
 551  * @device: device for which firmware is being loaded
 552  * @context: will be passed over to @cont, and
 553  *      @fw may be %NULL if firmware request fails.
 554  * @cont: function will be called asynchronously when the firmware
 555  *      request is over.
 556  *
 557  *      Asynchronous variant of request_firmware() for contexts where
 558  *      it is not possible to sleep.
 559  **/
 560 int
 561 request_firmware_nowait(
 562         struct module *module, int uevent,
 563         const char *name, struct device *device, void *context,
 564         void (*cont)(const struct firmware *fw, void *context))
 565 {
 566         struct task_struct *task;
 567         struct firmware_work *fw_work = kmalloc(sizeof (struct firmware_work),
 568                                                 GFP_ATOMIC);
 569
 570         if (!fw_work)
 571                 return -ENOMEM;
 572         if (!try_module_get(module)) {
 573                 kfree(fw_work);
 574                 return -EFAULT;
 575         }
 576
 577         *fw_work = (struct firmware_work) {
 578                 .module = module,
 579                 .name = name,
 580                 .device = device,
 581                 .context = context,
 582                 .cont = cont,
 583                 .uevent = uevent,
 584         };
 585
 586         task = kthread_run(request_firmware_work_func, fw_work,
 587                             "firmware/%s", name);
 588
 589         if (IS_ERR(task)) {
 590                 fw_work->cont(NULL, fw_work->context);
 591                 module_put(fw_work->module);
 592                 kfree(fw_work);
 593                 return PTR_ERR(task);
 594         }
 595         return 0;
 596 }
 597
 598 static int __init
 599 firmware_class_init(void)
 600 {
 601         int error;
 602         error = class_register(&firmware_class);
 603         if (error) {
 604                 printk(KERN_ERR "%s: class_register failed\n", __func__);
 605                 return error;
 606         }
 607         error = class_create_file(&firmware_class, &class_attr_timeout);
 608         if (error) {
 609                 printk(KERN_ERR "%s: class_create_file failed\n",
 610                        __func__);
 611                 class_unregister(&firmware_class);
 612         }
 613         return error;
 614
 615 }
 616 static void __exit
 617 firmware_class_exit(void)
 618 {
 619         class_unregister(&firmware_class);
 620 }
 621
 622 fs_initcall(firmware_class_init);
 623 module_exit(firmware_class_exit);
 624
 625 EXPORT_SYMBOL(release_firmware);
 626 EXPORT_SYMBOL(request_firmware);
 627 EXPORT_SYMBOL(request_firmware_nowait);