lib/test_firmware.c

   1 /*
   2  * This module provides an interface to trigger and test firmware loading.
   3  *
   4  * It is designed to be used for basic evaluation of the firmware loading
   5  * subsystem (for example when validating firmware verification). It lacks
   6  * any extra dependencies, and will not normally be loaded by the system
   7  * unless explicitly requested by name.
   8  */
   9
  10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11
  12 #include <linux/init.h>
  13 #include <linux/module.h>
  14 #include <linux/printk.h>
  15 #include <linux/completion.h>
  16 #include <linux/firmware.h>
  17 #include <linux/device.h>
  18 #include <linux/fs.h>
  19 #include <linux/miscdevice.h>
  20 #include <linux/slab.h>
  21 #include <linux/uaccess.h>
  22 #include <linux/delay.h>
  23 #include <linux/kthread.h>
  24 #include <linux/vmalloc.h>
  25
  26 #define TEST_FIRMWARE_NAME      "test-firmware.bin"
  27 #define TEST_FIRMWARE_NUM_REQS  4
  28
  29 static DEFINE_MUTEX(test_fw_mutex);
  30 static const struct firmware *test_firmware;
  31
  32 struct test_batched_req {
  33         u8 idx;
  34         int rc;
  35         bool sent;
  36         const struct firmware *fw;
  37         const char *name;
  38         struct completion completion;
  39         struct task_struct *task;
  40         struct device *dev;
  41 };
  42
  43 /**
  44  * test_config - represents configuration for the test for different triggers
  45  *
  46  * @name: the name of the firmware file to look for
  47  * @sync_direct: when the sync trigger is used if this is true
  48  *      request_firmware_direct() will be used instead.
  49  * @send_uevent: whether or not to send a uevent for async requests
  50  * @num_requests: number of requests to try per test case. This is trigger
  51  *      specific.
  52  * @reqs: stores all requests information
  53  * @read_fw_idx: index of thread from which we want to read firmware results
  54  *      from through the read_fw trigger.
  55  * @test_result: a test may use this to collect the result from the call
  56  *      of the request_firmware*() calls used in their tests. In order of
  57  *      priority we always keep first any setup error. If no setup errors were
  58  *      found then we move on to the first error encountered while running the
  59  *      API. Note that for async calls this typically will be a successful
  60  *      result (0) unless of course you've used bogus parameters, or the system
  61  *      is out of memory.  In the async case the callback is expected to do a
  62  *      bit more homework to figure out what happened, unfortunately the only
  63  *      information passed today on error is the fact that no firmware was
  64  *      found so we can only assume -ENOENT on async calls if the firmware is
  65  *      NULL.
  66  *
  67  *      Errors you can expect:
  68  *
  69  *      API specific:
  70  *
  71  *      0:              success for sync, for async it means request was sent
  72  *      -EINVAL:        invalid parameters or request
  73  *      -ENOENT:        files not found
  74  *
  75  *      System environment:
  76  *
  77  *      -ENOMEM:        memory pressure on system
  78  *      -ENODEV:        out of number of devices to test
  79  *      -EINVAL:        an unexpected error has occurred
  80  * @req_firmware: if @sync_direct is true this is set to
  81  *      request_firmware_direct(), otherwise request_firmware()
  82  */
  83 struct test_config {
  84         char *name;
  85         bool sync_direct;
  86         bool send_uevent;
  87         u8 num_requests;
  88         u8 read_fw_idx;
  89
  90         /*
  91          * These below don't belong her but we'll move them once we create
  92          * a struct fw_test_device and stuff the misc_dev under there later.
  93          */
  94         struct test_batched_req *reqs;
  95         int test_result;
  96         int (*req_firmware)(const struct firmware **fw, const char *name,
  97                             struct device *device);
  98 };
  99
 100 static struct test_config *test_fw_config;
 101
 102 static ssize_t test_fw_misc_read(struct file *f, char __user *buf,
 103                                  size_t size, loff_t *offset)
 104 {
 105         ssize_t rc = 0;
 106
 107         mutex_lock(&test_fw_mutex);
 108         if (test_firmware)
 109                 rc = simple_read_from_buffer(buf, size, offset,
 110                                              test_firmware->data,
 111                                              test_firmware->size);
 112         mutex_unlock(&test_fw_mutex);
 113         return rc;
 114 }
 115
 116 static const struct file_operations test_fw_fops = {
 117         .owner          = THIS_MODULE,
 118         .read           = test_fw_misc_read,
 119 };
 120
 121 static void __test_release_all_firmware(void)
 122 {
 123         struct test_batched_req *req;
 124         u8 i;
 125
 126         if (!test_fw_config->reqs)
 127                 return;
 128
 129         for (i = 0; i < test_fw_config->num_requests; i++) {
 130                 req = &test_fw_config->reqs[i];
 131                 if (req->fw)
 132                         release_firmware(req->fw);
 133         }
 134
 135         vfree(test_fw_config->reqs);
 136         test_fw_config->reqs = NULL;
 137 }
 138
 139 static void test_release_all_firmware(void)
 140 {
 141         mutex_lock(&test_fw_mutex);
 142         __test_release_all_firmware();
 143         mutex_unlock(&test_fw_mutex);
 144 }
 145
 146
 147 static void __test_firmware_config_free(void)
 148 {
 149         __test_release_all_firmware();
 150         kfree_const(test_fw_config->name);
 151         test_fw_config->name = NULL;
 152 }
 153
 154 /*
 155  * XXX: move to kstrncpy() once merged.
 156  *
 157  * Users should use kfree_const() when freeing these.
 158  */
 159 static int __kstrncpy(char **dst, const char *name, size_t count, gfp_t gfp)
 160 {
 161         *dst = kstrndup(name, count, gfp);
 162         if (!*dst)
 163                 return -ENOSPC;
 164         return count;
 165 }
 166
 167 static int __test_firmware_config_init(void)
 168 {
 169         int ret;
 170
 171         ret = __kstrncpy(&test_fw_config->name, TEST_FIRMWARE_NAME,
 172                          strlen(TEST_FIRMWARE_NAME), GFP_KERNEL);
 173         if (ret < 0)
 174                 goto out;
 175
 176         test_fw_config->num_requests = TEST_FIRMWARE_NUM_REQS;
 177         test_fw_config->send_uevent = true;
 178         test_fw_config->sync_direct = false;
 179         test_fw_config->req_firmware = request_firmware;
 180         test_fw_config->test_result = 0;
 181         test_fw_config->reqs = NULL;
 182
 183         return 0;
 184
 185 out:
 186         __test_firmware_config_free();
 187         return ret;
 188 }
 189
 190 static ssize_t reset_store(struct device *dev,
 191                            struct device_attribute *attr,
 192                            const char *buf, size_t count)
 193 {
 194         int ret;
 195
 196         mutex_lock(&test_fw_mutex);
 197
 198         __test_firmware_config_free();
 199
 200         ret = __test_firmware_config_init();
 201         if (ret < 0) {
 202                 ret = -ENOMEM;
 203                 pr_err("could not alloc settings for config trigger: %d\n",
 204                        ret);
 205                 goto out;
 206         }
 207
 208         pr_info("reset\n");
 209         ret = count;
 210
 211 out:
 212         mutex_unlock(&test_fw_mutex);
 213
 214         return ret;
 215 }
 216 static DEVICE_ATTR_WO(reset);
 217
 218 static ssize_t config_show(struct device *dev,
 219                            struct device_attribute *attr,
 220                            char *buf)
 221 {
 222         int len = 0;
 223
 224         mutex_lock(&test_fw_mutex);
 225
 226         len += snprintf(buf, PAGE_SIZE,
 227                         "Custom trigger configuration for: %s\n",
 228                         dev_name(dev));
 229
 230         if (test_fw_config->name)
 231                 len += snprintf(buf+len, PAGE_SIZE,
 232                                 "name:\t%s\n",
 233                                 test_fw_config->name);
 234         else
 235                 len += snprintf(buf+len, PAGE_SIZE,
 236                                 "name:\tEMTPY\n");
 237
 238         len += snprintf(buf+len, PAGE_SIZE,
 239                         "num_requests:\t%u\n", test_fw_config->num_requests);
 240
 241         len += snprintf(buf+len, PAGE_SIZE,
 242                         "send_uevent:\t\t%s\n",
 243                         test_fw_config->send_uevent ?
 244                         "FW_ACTION_HOTPLUG" :
 245                         "FW_ACTION_NOHOTPLUG");
 246         len += snprintf(buf+len, PAGE_SIZE,
 247                         "sync_direct:\t\t%s\n",
 248                         test_fw_config->sync_direct ? "true" : "false");
 249         len += snprintf(buf+len, PAGE_SIZE,
 250                         "read_fw_idx:\t%u\n", test_fw_config->read_fw_idx);
 251
 252         mutex_unlock(&test_fw_mutex);
 253
 254         return len;
 255 }
 256 static DEVICE_ATTR_RO(config);
 257
 258 static ssize_t config_name_store(struct device *dev,
 259                                  struct device_attribute *attr,
 260                                  const char *buf, size_t count)
 261 {
 262         int ret;
 263
 264         mutex_lock(&test_fw_mutex);
 265         kfree_const(test_fw_config->name);
 266         ret = __kstrncpy(&test_fw_config->name, buf, count, GFP_KERNEL);
 267         mutex_unlock(&test_fw_mutex);
 268
 269         return ret;
 270 }
 271
 272 /*
 273  * As per sysfs_kf_seq_show() the buf is max PAGE_SIZE.
 274  */
 275 static ssize_t config_test_show_str(char *dst,
 276                                     char *src)
 277 {
 278         int len;
 279
 280         mutex_lock(&test_fw_mutex);
 281         len = snprintf(dst, PAGE_SIZE, "%s\n", src);
 282         mutex_unlock(&test_fw_mutex);
 283
 284         return len;
 285 }
 286
 287 static int test_dev_config_update_bool(const char *buf, size_t size,
 288                                        bool *cfg)
 289 {
 290         int ret;
 291
 292         mutex_lock(&test_fw_mutex);
 293         if (strtobool(buf, cfg) < 0)
 294                 ret = -EINVAL;
 295         else
 296                 ret = size;
 297         mutex_unlock(&test_fw_mutex);
 298
 299         return ret;
 300 }
 301
 302 static ssize_t
 303 test_dev_config_show_bool(char *buf,
 304                           bool config)
 305 {
 306         bool val;
 307
 308         mutex_lock(&test_fw_mutex);
 309         val = config;
 310         mutex_unlock(&test_fw_mutex);
 311
 312         return snprintf(buf, PAGE_SIZE, "%d\n", val);
 313 }
 314
 315 static ssize_t test_dev_config_show_int(char *buf, int cfg)
 316 {
 317         int val;
 318
 319         mutex_lock(&test_fw_mutex);
 320         val = cfg;
 321         mutex_unlock(&test_fw_mutex);
 322
 323         return snprintf(buf, PAGE_SIZE, "%d\n", val);
 324 }
 325
 326 static int test_dev_config_update_u8(const char *buf, size_t size, u8 *cfg)
 327 {
 328         int ret;
 329         long new;
 330
 331         ret = kstrtol(buf, 10, &new);
 332         if (ret)
 333                 return ret;
 334
 335         if (new > U8_MAX)
 336                 return -EINVAL;
 337
 338         mutex_lock(&test_fw_mutex);
 339         *(u8 *)cfg = new;
 340         mutex_unlock(&test_fw_mutex);
 341
 342         /* Always return full write size even if we didn't consume all */
 343         return size;
 344 }
 345
 346 static ssize_t test_dev_config_show_u8(char *buf, u8 cfg)
 347 {
 348         u8 val;
 349
 350         mutex_lock(&test_fw_mutex);
 351         val = cfg;
 352         mutex_unlock(&test_fw_mutex);
 353
 354         return snprintf(buf, PAGE_SIZE, "%u\n", val);
 355 }
 356
 357 static ssize_t config_name_show(struct device *dev,
 358                                 struct device_attribute *attr,
 359                                 char *buf)
 360 {
 361         return config_test_show_str(buf, test_fw_config->name);
 362 }
 363 static DEVICE_ATTR_RW(config_name);
 364
 365 static ssize_t config_num_requests_store(struct device *dev,
 366                                          struct device_attribute *attr,
 367                                          const char *buf, size_t count)
 368 {
 369         int rc;
 370
 371         mutex_lock(&test_fw_mutex);
 372         if (test_fw_config->reqs) {
 373                 pr_err("Must call release_all_firmware prior to changing config\n");
 374                 rc = -EINVAL;
 375                 mutex_unlock(&test_fw_mutex);
 376                 goto out;
 377         }
 378         mutex_unlock(&test_fw_mutex);
 379
 380         rc = test_dev_config_update_u8(buf, count,
 381                                        &test_fw_config->num_requests);
 382
 383 out:
 384         return rc;
 385 }
 386
 387 static ssize_t config_num_requests_show(struct device *dev,
 388                                         struct device_attribute *attr,
 389                                         char *buf)
 390 {
 391         return test_dev_config_show_u8(buf, test_fw_config->num_requests);
 392 }
 393 static DEVICE_ATTR_RW(config_num_requests);
 394
 395 static ssize_t config_sync_direct_store(struct device *dev,
 396                                         struct device_attribute *attr,
 397                                         const char *buf, size_t count)
 398 {
 399         int rc = test_dev_config_update_bool(buf, count,
 400                                              &test_fw_config->sync_direct);
 401
 402         if (rc == count)
 403                 test_fw_config->req_firmware = test_fw_config->sync_direct ?
 404                                        request_firmware_direct :
 405                                        request_firmware;
 406         return rc;
 407 }
 408
 409 static ssize_t config_sync_direct_show(struct device *dev,
 410                                        struct device_attribute *attr,
 411                                        char *buf)
 412 {
 413         return test_dev_config_show_bool(buf, test_fw_config->sync_direct);
 414 }
 415 static DEVICE_ATTR_RW(config_sync_direct);
 416
 417 static ssize_t config_send_uevent_store(struct device *dev,
 418                                         struct device_attribute *attr,
 419                                         const char *buf, size_t count)
 420 {
 421         return test_dev_config_update_bool(buf, count,
 422                                            &test_fw_config->send_uevent);
 423 }
 424
 425 static ssize_t config_send_uevent_show(struct device *dev,
 426                                        struct device_attribute *attr,
 427                                        char *buf)
 428 {
 429         return test_dev_config_show_bool(buf, test_fw_config->send_uevent);
 430 }
 431 static DEVICE_ATTR_RW(config_send_uevent);
 432
 433 static ssize_t config_read_fw_idx_store(struct device *dev,
 434                                         struct device_attribute *attr,
 435                                         const char *buf, size_t count)
 436 {
 437         return test_dev_config_update_u8(buf, count,
 438                                          &test_fw_config->read_fw_idx);
 439 }
 440
 441 static ssize_t config_read_fw_idx_show(struct device *dev,
 442                                        struct device_attribute *attr,
 443                                        char *buf)
 444 {
 445         return test_dev_config_show_u8(buf, test_fw_config->read_fw_idx);
 446 }
 447 static DEVICE_ATTR_RW(config_read_fw_idx);
 448
 449
 450 static ssize_t trigger_request_store(struct device *dev,
 451                                      struct device_attribute *attr,
 452                                      const char *buf, size_t count)
 453 {
 454         int rc;
 455         char *name;
 456
 457         name = kstrndup(buf, count, GFP_KERNEL);
 458         if (!name)
 459                 return -ENOSPC;
 460
 461         pr_info("loading '%s'\n", name);
 462
 463         mutex_lock(&test_fw_mutex);
 464         release_firmware(test_firmware);
 465         test_firmware = NULL;
 466         rc = request_firmware(&test_firmware, name, dev);
 467         if (rc) {
 468                 pr_info("load of '%s' failed: %d\n", name, rc);
 469                 goto out;
 470         }
 471         pr_info("loaded: %zu\n", test_firmware->size);
 472         rc = count;
 473
 474 out:
 475         mutex_unlock(&test_fw_mutex);
 476
 477         kfree(name);
 478
 479         return rc;
 480 }
 481 static DEVICE_ATTR_WO(trigger_request);
 482
 483 static DECLARE_COMPLETION(async_fw_done);
 484
 485 static void trigger_async_request_cb(const struct firmware *fw, void *context)
 486 {
 487         test_firmware = fw;
 488         complete(&async_fw_done);
 489 }
 490
 491 static ssize_t trigger_async_request_store(struct device *dev,
 492                                            struct device_attribute *attr,
 493                                            const char *buf, size_t count)
 494 {
 495         int rc;
 496         char *name;
 497
 498         name = kstrndup(buf, count, GFP_KERNEL);
 499         if (!name)
 500                 return -ENOSPC;
 501
 502         pr_info("loading '%s'\n", name);
 503
 504         mutex_lock(&test_fw_mutex);
 505         release_firmware(test_firmware);
 506         test_firmware = NULL;
 507         rc = request_firmware_nowait(THIS_MODULE, 1, name, dev, GFP_KERNEL,
 508                                      NULL, trigger_async_request_cb);
 509         if (rc) {
 510                 pr_info("async load of '%s' failed: %d\n", name, rc);
 511                 kfree(name);
 512                 goto out;
 513         }
 514         /* Free 'name' ASAP, to test for race conditions */
 515         kfree(name);
 516
 517         wait_for_completion(&async_fw_done);
 518
 519         if (test_firmware) {
 520                 pr_info("loaded: %zu\n", test_firmware->size);
 521                 rc = count;
 522         } else {
 523                 pr_err("failed to async load firmware\n");
 524                 rc = -ENODEV;
 525         }
 526
 527 out:
 528         mutex_unlock(&test_fw_mutex);
 529
 530         return rc;
 531 }
 532 static DEVICE_ATTR_WO(trigger_async_request);
 533
 534 static ssize_t trigger_custom_fallback_store(struct device *dev,
 535                                              struct device_attribute *attr,
 536                                              const char *buf, size_t count)
 537 {
 538         int rc;
 539         char *name;
 540
 541         name = kstrndup(buf, count, GFP_KERNEL);
 542         if (!name)
 543                 return -ENOSPC;
 544
 545         pr_info("loading '%s' using custom fallback mechanism\n", name);
 546
 547         mutex_lock(&test_fw_mutex);
 548         release_firmware(test_firmware);
 549         test_firmware = NULL;
 550         rc = request_firmware_nowait(THIS_MODULE, FW_ACTION_NOHOTPLUG, name,
 551                                      dev, GFP_KERNEL, NULL,
 552                                      trigger_async_request_cb);
 553         if (rc) {
 554                 pr_info("async load of '%s' failed: %d\n", name, rc);
 555                 kfree(name);
 556                 goto out;
 557         }
 558         /* Free 'name' ASAP, to test for race conditions */
 559         kfree(name);
 560
 561         wait_for_completion(&async_fw_done);
 562
 563         if (test_firmware) {
 564                 pr_info("loaded: %zu\n", test_firmware->size);
 565                 rc = count;
 566         } else {
 567                 pr_err("failed to async load firmware\n");
 568                 rc = -ENODEV;
 569         }
 570
 571 out:
 572         mutex_unlock(&test_fw_mutex);
 573
 574         return rc;
 575 }
 576 static DEVICE_ATTR_WO(trigger_custom_fallback);
 577
 578 static int test_fw_run_batch_request(void *data)
 579 {
 580         struct test_batched_req *req = data;
 581
 582         if (!req) {
 583                 test_fw_config->test_result = -EINVAL;
 584                 return -EINVAL;
 585         }
 586
 587         req->rc = test_fw_config->req_firmware(&req->fw, req->name, req->dev);
 588         if (req->rc) {
 589                 pr_info("#%u: batched sync load failed: %d\n",
 590                         req->idx, req->rc);
 591                 if (!test_fw_config->test_result)
 592                         test_fw_config->test_result = req->rc;
 593         } else if (req->fw) {
 594                 req->sent = true;
 595                 pr_info("#%u: batched sync loaded %zu\n",
 596                         req->idx, req->fw->size);
 597         }
 598         complete(&req->completion);
 599
 600         req->task = NULL;
 601
 602         return 0;
 603 }
 604
 605 /*
 606  * We use a kthread as otherwise the kernel serializes all our sync requests
 607  * and we would not be able to mimic batched requests on a sync call. Batched
 608  * requests on a sync call can for instance happen on a device driver when
 609  * multiple cards are used and firmware loading happens outside of probe.
 610  */
 611 static ssize_t trigger_batched_requests_store(struct device *dev,
 612                                               struct device_attribute *attr,
 613                                               const char *buf, size_t count)
 614 {
 615         struct test_batched_req *req;
 616         int rc;
 617         u8 i;
 618
 619         mutex_lock(&test_fw_mutex);
 620
 621         test_fw_config->reqs =
 622                 vzalloc(array3_size(sizeof(struct test_batched_req),
 623                                     test_fw_config->num_requests, 2));
 624         if (!test_fw_config->reqs) {
 625                 rc = -ENOMEM;
 626                 goto out_unlock;
 627         }
 628
 629         pr_info("batched sync firmware loading '%s' %u times\n",
 630                 test_fw_config->name, test_fw_config->num_requests);
 631
 632         for (i = 0; i < test_fw_config->num_requests; i++) {
 633                 req = &test_fw_config->reqs[i];
 634                 if (!req) {
 635                         WARN_ON(1);
 636                         rc = -ENOMEM;
 637                         goto out_bail;
 638                 }
 639                 req->fw = NULL;
 640                 req->idx = i;
 641                 req->name = test_fw_config->name;
 642                 req->dev = dev;
 643                 init_completion(&req->completion);
 644                 req->task = kthread_run(test_fw_run_batch_request, req,
 645                                              "%s-%u", KBUILD_MODNAME, req->idx);
 646                 if (!req->task || IS_ERR(req->task)) {
 647                         pr_err("Setting up thread %u failed\n", req->idx);
 648                         req->task = NULL;
 649                         rc = -ENOMEM;
 650                         goto out_bail;
 651                 }
 652         }
 653
 654         rc = count;
 655
 656         /*
 657          * We require an explicit release to enable more time and delay of
 658          * calling release_firmware() to improve our chances of forcing a
 659          * batched request. If we instead called release_firmware() right away
 660          * then we might miss on an opportunity of having a successful firmware
 661          * request pass on the opportunity to be come a batched request.
 662          */
 663
 664 out_bail:
 665         for (i = 0; i < test_fw_config->num_requests; i++) {
 666                 req = &test_fw_config->reqs[i];
 667                 if (req->task || req->sent)
 668                         wait_for_completion(&req->completion);
 669         }
 670
 671         /* Override any worker error if we had a general setup error */
 672         if (rc < 0)
 673                 test_fw_config->test_result = rc;
 674
 675 out_unlock:
 676         mutex_unlock(&test_fw_mutex);
 677
 678         return rc;
 679 }
 680 static DEVICE_ATTR_WO(trigger_batched_requests);
 681
 682 /*
 683  * We wait for each callback to return with the lock held, no need to lock here
 684  */
 685 static void trigger_batched_cb(const struct firmware *fw, void *context)
 686 {
 687         struct test_batched_req *req = context;
 688
 689         if (!req) {
 690                 test_fw_config->test_result = -EINVAL;
 691                 return;
 692         }
 693
 694         /* forces *some* batched requests to queue up */
 695         if (!req->idx)
 696                 ssleep(2);
 697
 698         req->fw = fw;
 699
 700         /*
 701          * Unfortunately the firmware API gives us nothing other than a null FW
 702          * if the firmware was not found on async requests.  Best we can do is
 703          * just assume -ENOENT. A better API would pass the actual return
 704          * value to the callback.
 705          */
 706         if (!fw && !test_fw_config->test_result)
 707                 test_fw_config->test_result = -ENOENT;
 708
 709         complete(&req->completion);
 710 }
 711
 712 static
 713 ssize_t trigger_batched_requests_async_store(struct device *dev,
 714                                              struct device_attribute *attr,
 715                                              const char *buf, size_t count)
 716 {
 717         struct test_batched_req *req;
 718         bool send_uevent;
 719         int rc;
 720         u8 i;
 721
 722         mutex_lock(&test_fw_mutex);
 723
 724         test_fw_config->reqs =
 725                 vzalloc(array3_size(sizeof(struct test_batched_req),
 726                                     test_fw_config->num_requests, 2));
 727         if (!test_fw_config->reqs) {
 728                 rc = -ENOMEM;
 729                 goto out;
 730         }
 731
 732         pr_info("batched loading '%s' custom fallback mechanism %u times\n",
 733                 test_fw_config->name, test_fw_config->num_requests);
 734
 735         send_uevent = test_fw_config->send_uevent ? FW_ACTION_HOTPLUG :
 736                 FW_ACTION_NOHOTPLUG;
 737
 738         for (i = 0; i < test_fw_config->num_requests; i++) {
 739                 req = &test_fw_config->reqs[i];
 740                 if (!req) {
 741                         WARN_ON(1);
 742                         goto out_bail;
 743                 }
 744                 req->name = test_fw_config->name;
 745                 req->fw = NULL;
 746                 req->idx = i;
 747                 init_completion(&req->completion);
 748                 rc = request_firmware_nowait(THIS_MODULE, send_uevent,
 749                                              req->name,
 750                                              dev, GFP_KERNEL, req,
 751                                              trigger_batched_cb);
 752                 if (rc) {
 753                         pr_info("#%u: batched async load failed setup: %d\n",
 754                                 i, rc);
 755                         req->rc = rc;
 756                         goto out_bail;
 757                 } else
 758                         req->sent = true;
 759         }
 760
 761         rc = count;
 762
 763 out_bail:
 764
 765         /*
 766          * We require an explicit release to enable more time and delay of
 767          * calling release_firmware() to improve our chances of forcing a
 768          * batched request. If we instead called release_firmware() right away
 769          * then we might miss on an opportunity of having a successful firmware
 770          * request pass on the opportunity to be come a batched request.
 771          */
 772
 773         for (i = 0; i < test_fw_config->num_requests; i++) {
 774                 req = &test_fw_config->reqs[i];
 775                 if (req->sent)
 776                         wait_for_completion(&req->completion);
 777         }
 778
 779         /* Override any worker error if we had a general setup error */
 780         if (rc < 0)
 781                 test_fw_config->test_result = rc;
 782
 783 out:
 784         mutex_unlock(&test_fw_mutex);
 785
 786         return rc;
 787 }
 788 static DEVICE_ATTR_WO(trigger_batched_requests_async);
 789
 790 static ssize_t test_result_show(struct device *dev,
 791                                 struct device_attribute *attr,
 792                                 char *buf)
 793 {
 794         return test_dev_config_show_int(buf, test_fw_config->test_result);
 795 }
 796 static DEVICE_ATTR_RO(test_result);
 797
 798 static ssize_t release_all_firmware_store(struct device *dev,
 799                                           struct device_attribute *attr,
 800                                           const char *buf, size_t count)
 801 {
 802         test_release_all_firmware();
 803         return count;
 804 }
 805 static DEVICE_ATTR_WO(release_all_firmware);
 806
 807 static ssize_t read_firmware_show(struct device *dev,
 808                                   struct device_attribute *attr,
 809                                   char *buf)
 810 {
 811         struct test_batched_req *req;
 812         u8 idx;
 813         ssize_t rc = 0;
 814
 815         mutex_lock(&test_fw_mutex);
 816
 817         idx = test_fw_config->read_fw_idx;
 818         if (idx >= test_fw_config->num_requests) {
 819                 rc = -ERANGE;
 820                 goto out;
 821         }
 822
 823         if (!test_fw_config->reqs) {
 824                 rc = -EINVAL;
 825                 goto out;
 826         }
 827
 828         req = &test_fw_config->reqs[idx];
 829         if (!req->fw) {
 830                 pr_err("#%u: failed to async load firmware\n", idx);
 831                 rc = -ENOENT;
 832                 goto out;
 833         }
 834
 835         pr_info("#%u: loaded %zu\n", idx, req->fw->size);
 836
 837         if (req->fw->size > PAGE_SIZE) {
 838                 pr_err("Testing interface must use PAGE_SIZE firmware for now\n");
 839                 rc = -EINVAL;
 840                 goto out;
 841         }
 842         memcpy(buf, req->fw->data, req->fw->size);
 843
 844         rc = req->fw->size;
 845 out:
 846         mutex_unlock(&test_fw_mutex);
 847
 848         return rc;
 849 }
 850 static DEVICE_ATTR_RO(read_firmware);
 851
 852 #define TEST_FW_DEV_ATTR(name)          &dev_attr_##name.attr
 853
 854 static struct attribute *test_dev_attrs[] = {
 855         TEST_FW_DEV_ATTR(reset),
 856
 857         TEST_FW_DEV_ATTR(config),
 858         TEST_FW_DEV_ATTR(config_name),
 859         TEST_FW_DEV_ATTR(config_num_requests),
 860         TEST_FW_DEV_ATTR(config_sync_direct),
 861         TEST_FW_DEV_ATTR(config_send_uevent),
 862         TEST_FW_DEV_ATTR(config_read_fw_idx),
 863
 864         /* These don't use the config at all - they could be ported! */
 865         TEST_FW_DEV_ATTR(trigger_request),
 866         TEST_FW_DEV_ATTR(trigger_async_request),
 867         TEST_FW_DEV_ATTR(trigger_custom_fallback),
 868
 869         /* These use the config and can use the test_result */
 870         TEST_FW_DEV_ATTR(trigger_batched_requests),
 871         TEST_FW_DEV_ATTR(trigger_batched_requests_async),
 872
 873         TEST_FW_DEV_ATTR(release_all_firmware),
 874         TEST_FW_DEV_ATTR(test_result),
 875         TEST_FW_DEV_ATTR(read_firmware),
 876         NULL,
 877 };
 878
 879 ATTRIBUTE_GROUPS(test_dev);
 880
 881 static struct miscdevice test_fw_misc_device = {
 882         .minor          = MISC_DYNAMIC_MINOR,
 883         .name           = "test_firmware",
 884         .fops           = &test_fw_fops,
 885         .groups         = test_dev_groups,
 886 };
 887
 888 static int __init test_firmware_init(void)
 889 {
 890         int rc;
 891
 892         test_fw_config = kzalloc(sizeof(struct test_config), GFP_KERNEL);
 893         if (!test_fw_config)
 894                 return -ENOMEM;
 895
 896         rc = __test_firmware_config_init();
 897         if (rc)
 898                 return rc;
 899
 900         rc = misc_register(&test_fw_misc_device);
 901         if (rc) {
 902                 kfree(test_fw_config);
 903                 pr_err("could not register misc device: %d\n", rc);
 904                 return rc;
 905         }
 906
 907         pr_warn("interface ready\n");
 908
 909         return 0;
 910 }
 911
 912 module_init(test_firmware_init);
 913
 914 static void __exit test_firmware_exit(void)
 915 {
 916         mutex_lock(&test_fw_mutex);
 917         release_firmware(test_firmware);
 918         misc_deregister(&test_fw_misc_device);
 919         __test_firmware_config_free();
 920         kfree(test_fw_config);
 921         mutex_unlock(&test_fw_mutex);
 922
 923         pr_warn("removed interface\n");
 924 }
 925
 926 module_exit(test_firmware_exit);
 927
 928 MODULE_AUTHOR("Kees Cook <keescook@chromium.org>");
 929 MODULE_LICENSE("GPL");