aboutsummaryrefslogtreecommitdiff
path: root/lib/test_firmware.c
blob: 787c146eb485057400b580519061762f7730da92 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
// SPDX-License-Identifier: GPL-2.0-only
/*
 * This module provides an interface to trigger and test firmware loading.
 *
 * It is designed to be used for basic evaluation of the firmware loading
 * subsystem (for example when validating firmware verification). It lacks
 * any extra dependencies, and will not normally be loaded by the system
 * unless explicitly requested by name.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/init.h>
#include <linux/module.h>
#include <linux/printk.h>
#include <linux/completion.h>
#include <linux/firmware.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/delay.h>
#include <linux/kthread.h>
#include <linux/vmalloc.h>

#define TEST_FIRMWARE_NAME	"test-firmware.bin"
#define TEST_FIRMWARE_NUM_REQS	4

static DEFINE_MUTEX(test_fw_mutex);
static const struct firmware *test_firmware;

struct test_batched_req {
	u8 idx;
	int rc;
	bool sent;
	const struct firmware *fw;
	const char *name;
	struct completion completion;
	struct task_struct *task;
	struct device *dev;
};

/**
 * test_config - represents configuration for the test for different triggers
 *
 * @name: the name of the firmware file to look for
 * @sync_direct: when the sync trigger is used if this is true
 *	request_firmware_direct() will be used instead.
 * @send_uevent: whether or not to send a uevent for async requests
 * @num_requests: number of requests to try per test case. This is trigger
 *	specific.
 * @reqs: stores all requests information
 * @read_fw_idx: index of thread from which we want to read firmware results
 *	from through the read_fw trigger.
 * @test_result: a test may use this to collect the result from the call
 *	of the request_firmware*() calls used in their tests. In order of
 *	priority we always keep first any setup error. If no setup errors were
 *	found then we move on to the first error encountered while running the
 *	API. Note that for async calls this typically will be a successful
 *	result (0) unless of course you've used bogus parameters, or the system
 *	is out of memory.  In the async case the callback is expected to do a
 *	bit more homework to figure out what happened, unfortunately the only
 *	information passed today on error is the fact that no firmware was
 *	found so we can only assume -ENOENT on async calls if the firmware is
 *	NULL.
 *
 *	Errors you can expect:
 *
 *	API specific:
 *
 *	0:		success for sync, for async it means request was sent
 *	-EINVAL:	invalid parameters or request
 *	-ENOENT:	files not found
 *
 *	System environment:
 *
 *	-ENOMEM:	memory pressure on system
 *	-ENODEV:	out of number of devices to test
 *	-EINVAL:	an unexpected error has occurred
 * @req_firmware: if @sync_direct is true this is set to
 *	request_firmware_direct(), otherwise request_firmware()
 */
struct test_config {
	char *name;
	bool sync_direct;
	bool send_uevent;
	u8 num_requests;
	u8 read_fw_idx;

	/*
	 * These below don't belong her but we'll move them once we create
	 * a struct fw_test_device and stuff the misc_dev under there later.
	 */
	struct test_batched_req *reqs;
	int test_result;
	int (*req_firmware)(const struct firmware **fw, const char *name,
			    struct device *device);
};

static struct test_config *test_fw_config;

static ssize_t test_fw_misc_read(struct file *f, char __user *buf,
				 size_t size, loff_t *offset)
{
	ssize_t rc = 0;

	mutex_lock(&test_fw_mutex);
	if (test_firmware)
		rc = simple_read_from_buffer(buf, size, offset,
					     test_firmware->data,
					     test_firmware->size);
	mutex_unlock(&test_fw_mutex);
	return rc;
}

static const struct file_operations test_fw_fops = {
	.owner          = THIS_MODULE,
	.read           = test_fw_misc_read,
};

static void __test_release_all_firmware(void)
{
	struct test_batched_req *req;
	u8 i;

	if (!test_fw_config->reqs)
		return;

	for (i = 0; i < test_fw_config->num_requests; i++) {
		req = &test_fw_config->reqs[i];
		if (req->fw)
			release_firmware(req->fw);
	}

	vfree(test_fw_config->reqs);
	test_fw_config->reqs = NULL;
}

static void test_release_all_firmware(void)
{
	mutex_lock(&test_fw_mutex);
	__test_release_all_firmware();
	mutex_unlock(&test_fw_mutex);
}


static void __test_firmware_config_free(void)
{
	__test_release_all_firmware();
	kfree_const(test_fw_config->name);
	test_fw_config->name = NULL;
}

/*
 * XXX: move to kstrncpy() once merged.
 *
 * Users should use kfree_const() when freeing these.
 */
static int __kstrncpy(char **dst, const char *name, size_t count, gfp_t gfp)
{
	*dst = kstrndup(name, count, gfp);
	if (!*dst)
		return -ENOSPC;
	return count;
}

static int __test_firmware_config_init(void)
{
	int ret;

	ret = __kstrncpy(&test_fw_config->name, TEST_FIRMWARE_NAME,
			 strlen(TEST_FIRMWARE_NAME), GFP_KERNEL);
	if (ret < 0)
		goto out;

	test_fw_config->num_requests = TEST_FIRMWARE_NUM_REQS;
	test_fw_config->send_uevent = true;
	test_fw_config->sync_direct = false;
	test_fw_config->req_firmware = request_firmware;
	test_fw_config->test_result = 0;
	test_fw_config->reqs = NULL;

	return 0;

out:
	__test_firmware_config_free();
	return ret;
}

static ssize_t reset_store(struct device *dev,
			   struct device_attribute *attr,
			   const char *buf, size_t count)
{
	int ret;

	mutex_lock(&test_fw_mutex);

	__test_firmware_config_free();

	ret = __test_firmware_config_init();
	if (ret < 0) {
		ret = -ENOMEM;
		pr_err("could not alloc settings for config trigger: %d\n",
		       ret);
		goto out;
	}

	pr_info("reset\n");
	ret = count;

out:
	mutex_unlock(&test_fw_mutex);

	return ret;
}
static DEVICE_ATTR_WO(reset);

static ssize_t config_show(struct device *dev,
			   struct device_attribute *attr,
			   char *buf)
{
	int len = 0;

	mutex_lock(&test_fw_mutex);

	len += snprintf(buf, PAGE_SIZE,
			"Custom trigger configuration for: %s\n",
			dev_name(dev));

	if (test_fw_config->name)
		len += snprintf(buf+len, PAGE_SIZE,
				"name:\t%s\n",
				test_fw_config->name);
	else
		len += snprintf(buf+len, PAGE_SIZE,
				"name:\tEMTPY\n");

	len += snprintf(buf+len, PAGE_SIZE,
			"num_requests:\t%u\n", test_fw_config->num_requests);

	len += snprintf(buf+len, PAGE_SIZE,
			"send_uevent:\t\t%s\n",
			test_fw_config->send_uevent ?
			"FW_ACTION_HOTPLUG" :
			"FW_ACTION_NOHOTPLUG");
	len += snprintf(buf+len, PAGE_SIZE,
			"sync_direct:\t\t%s\n",
			test_fw_config->sync_direct ? "true" : "false");
	len += snprintf(buf+len, PAGE_SIZE,
			"read_fw_idx:\t%u\n", test_fw_config->read_fw_idx);

	mutex_unlock(&test_fw_mutex);

	return len;
}
static DEVICE_ATTR_RO(config);

static ssize_t config_name_store(struct device *dev,
				 struct device_attribute *attr,
				 const char *buf, size_t count)
{
	int ret;

	mutex_lock(&test_fw_mutex);
	kfree_const(test_fw_config->name);
	ret = __kstrncpy(&test_fw_config->name, buf, count, GFP_KERNEL);
	mutex_unlock(&test_fw_mutex);

	return ret;
}

/*
 * As per sysfs_kf_seq_show() the buf is max PAGE_SIZE.
 */
static ssize_t config_test_show_str(char *dst,
				    char *src)
{
	int len;

	mutex_lock(&test_fw_mutex);
	len = snprintf(dst, PAGE_SIZE, "%s\n", src);
	mutex_unlock(&test_fw_mutex);

	return len;
}

static int test_dev_config_update_bool(const char *buf, size_t size,
				       bool *cfg)
{
	int ret;

	mutex_lock(&test_fw_mutex);
	if (strtobool(buf, cfg) < 0)
		ret = -EINVAL;
	else
		ret = size;
	mutex_unlock(&test_fw_mutex);

	return ret;
}

static ssize_t
test_dev_config_show_bool(char *buf,
			  bool config)
{
	bool val;

	mutex_lock(&test_fw_mutex);
	val = config;
	mutex_unlock(&test_fw_mutex);

	return snprintf(buf, PAGE_SIZE, "%d\n", val);
}

static ssize_t test_dev_config_show_int(char *buf, int cfg)
{
	int val;

	mutex_lock(&test_fw_mutex);
	val = cfg;
	mutex_unlock(&test_fw_mutex);

	return snprintf(buf, PAGE_SIZE, "%d\n", val);
}

static int test_dev_config_update_u8(const char *buf, size_t size, u8 *cfg)
{
	int ret;
	long new;

	ret = kstrtol(buf, 10, &new);
	if (ret)
		return ret;

	if (new > U8_MAX)
		return -EINVAL;

	mutex_lock(&test_fw_mutex);
	*(u8 *)cfg = new;
	mutex_unlock(&test_fw_mutex);

	/* Always return full write size even if we didn't consume all */
	return size;
}

static ssize_t test_dev_config_show_u8(char *buf, u8 cfg)
{
	u8 val;

	mutex_lock(&test_fw_mutex);
	val = cfg;
	mutex_unlock(&test_fw_mutex);

	return snprintf(buf, PAGE_SIZE, "%u\n", val);
}

static ssize_t config_name_show(struct device *dev,
				struct device_attribute *attr,
				char *buf)
{
	return config_test_show_str(buf, test_fw_config->name);
}
static DEVICE_ATTR_RW(config_name);

static ssize_t config_num_requests_store(struct device *dev,
					 struct device_attribute *attr,
					 const char *buf, size_t count)
{
	int rc;

	mutex_lock(&test_fw_mutex);
	if (test_fw_config->reqs) {
		pr_err("Must call release_all_firmware prior to changing config\n");
		rc = -EINVAL;
		mutex_unlock(&test_fw_mutex);
		goto out;
	}
	mutex_unlock(&test_fw_mutex);

	rc = test_dev_config_update_u8(buf, count,
				       &test_fw_config->num_requests);

out:
	return rc;
}

static ssize_t config_num_requests_show(struct device *dev,
					struct device_attribute *attr,
					char *buf)
{
	return test_dev_config_show_u8(buf, test_fw_config->num_requests);
}
static DEVICE_ATTR_RW(config_num_requests);

static ssize_t config_sync_direct_store(struct device *dev,
					struct device_attribute *attr,
					const char *buf, size_t count)
{
	int rc = test_dev_config_update_bool(buf, count,
					     &test_fw_config->sync_direct);

	if (rc == count)
		test_fw_config->req_firmware = test_fw_config->sync_direct ?
				       request_firmware_direct :
				       request_firmware;
	return rc;
}

static ssize_t config_sync_direct_show(struct device *dev,
				       struct device_attribute *attr,
				       char *buf)
{
	return test_dev_config_show_bool(buf, test_fw_config->sync_direct);
}
static DEVICE_ATTR_RW(config_sync_direct);

static ssize_t config_send_uevent_store(struct device *dev,
					struct device_attribute *attr,
					const char *buf, size_t count)
{
	return test_dev_config_update_bool(buf, count,
					   &test_fw_config->send_uevent);
}

static ssize_t config_send_uevent_show(struct device *dev,
				       struct device_attribute *attr,
				       char *buf)
{
	return test_dev_config_show_bool(buf, test_fw_config->send_uevent);
}
static DEVICE_ATTR_RW(config_send_uevent);

static ssize_t config_read_fw_idx_store(struct device *dev,
					struct device_attribute *attr,
					const char *buf, size_t count)
{
	return test_dev_config_update_u8(buf, count,
					 &test_fw_config->read_fw_idx);
}

static ssize_t config_read_fw_idx_show(struct device *dev,
				       struct device_attribute *attr,
				       char *buf)
{
	return test_dev_config_show_u8(buf, test_fw_config->read_fw_idx);
}
static DEVICE_ATTR_RW(config_read_fw_idx);


static ssize_t trigger_request_store(struct device *dev,
				     struct device_attribute *attr,
				     const char *buf, size_t count)
{
	int rc;
	char *name;

	name = kstrndup(buf, count, GFP_KERNEL);
	if (!name)
		return -ENOSPC;

	pr_info("loading '%s'\n", name);

	mutex_lock(&test_fw_mutex);
	release_firmware(test_firmware);
	test_firmware = NULL;
	rc = request_firmware(&test_firmware, name, dev);
	if (rc) {
		pr_info("load of '%s' failed: %d\n", name, rc);
		goto out;
	}
	pr_info("loaded: %zu\n", test_firmware->size);
	rc = count;

out:
	mutex_unlock(&test_fw_mutex);

	kfree(name);

	return rc;
}
static DEVICE_ATTR_WO(trigger_request);

static DECLARE_COMPLETION(async_fw_done);

static void trigger_async_request_cb(const struct firmware *fw, void *context)
{
	test_firmware = fw;
	complete(&async_fw_done);
}

static ssize_t trigger_async_request_store(struct device *dev,
					   struct device_attribute *attr,
					   const char *buf, size_t count)
{
	int rc;
	char *name;

	name = kstrndup(buf, count, GFP_KERNEL);
	if (!name)
		return -ENOSPC;

	pr_info("loading '%s'\n", name);

	mutex_lock(&test_fw_mutex);
	release_firmware(test_firmware);
	test_firmware = NULL;
	rc = request_firmware_nowait(THIS_MODULE, 1, name, dev, GFP_KERNEL,
				     NULL, trigger_async_request_cb);
	if (rc) {
		pr_info("async load of '%s' failed: %d\n", name, rc);
		kfree(name);
		goto out;
	}
	/* Free 'name' ASAP, to test for race conditions */
	kfree(name);

	wait_for_completion(&async_fw_done);

	if (test_firmware) {
		pr_info("loaded: %zu\n", test_firmware->size);
		rc = count;
	} else {
		pr_err("failed to async load firmware\n");
		rc = -ENODEV;
	}

out:
	mutex_unlock(&test_fw_mutex);

	return rc;
}
static DEVICE_ATTR_WO(trigger_async_request);

static ssize_t trigger_custom_fallback_store(struct device *dev,
					     struct device_attribute *attr,
					     const char *buf, size_t count)
{
	int rc;
	char *name;

	name = kstrndup(buf, count, GFP_KERNEL);
	if (!name)
		return -ENOSPC;

	pr_info("loading '%s' using custom fallback mechanism\n", name);

	mutex_lock(&test_fw_mutex);
	release_firmware(test_firmware);
	test_firmware = NULL;
	rc = request_firmware_nowait(THIS_MODULE, FW_ACTION_NOHOTPLUG, name,
				     dev, GFP_KERNEL, NULL,
				     trigger_async_request_cb);
	if (rc) {
		pr_info("async load of '%s' failed: %d\n", name, rc);
		kfree(name);
		goto out;
	}
	/* Free 'name' ASAP, to test for race conditions */
	kfree(name);

	wait_for_completion(&async_fw_done);

	if (test_firmware) {
		pr_info("loaded: %zu\n", test_firmware->size);
		rc = count;
	} else {
		pr_err("failed to async load firmware\n");
		rc = -ENODEV;
	}

out:
	mutex_unlock(&test_fw_mutex);

	return rc;
}
static DEVICE_ATTR_WO(trigger_custom_fallback);

static int test_fw_run_batch_request(void *data)
{
	struct test_batched_req *req = data;

	if (!req) {
		test_fw_config->test_result = -EINVAL;
		return -EINVAL;
	}

	req->rc = test_fw_config->req_firmware(&req->fw, req->name, req->dev);
	if (req->rc) {
		pr_info("#%u: batched sync load failed: %d\n",
			req->idx, req->rc);
		if (!test_fw_config->test_result)
			test_fw_config->test_result = req->rc;
	} else if (req->fw) {
		req->sent = true;
		pr_info("#%u: batched sync loaded %zu\n",
			req->idx, req->fw->size);
	}
	complete(&req->completion);

	req->task = NULL;

	return 0;
}

/*
 * We use a kthread as otherwise the kernel serializes all our sync requests
 * and we would not be able to mimic batched requests on a sync call. Batched
 * requests on a sync call can for instance happen on a device driver when
 * multiple cards are used and firmware loading happens outside of probe.
 */
static ssize_t trigger_batched_requests_store(struct device *dev,
					      struct device_attribute *attr,
					      const char *buf, size_t count)
{
	struct test_batched_req *req;
	int rc;
	u8 i;

	mutex_lock(&test_fw_mutex);

	test_fw_config->reqs =
		vzalloc(array3_size(sizeof(struct test_batched_req),
				    test_fw_config->num_requests, 2));
	if (!test_fw_config->reqs) {
		rc = -ENOMEM;
		goto out_unlock;
	}

	pr_info("batched sync firmware loading '%s' %u times\n",
		test_fw_config->name, test_fw_config->num_requests);

	for (i = 0; i < test_fw_config->num_requests; i++) {
		req = &test_fw_config->reqs[i];
		req->fw = NULL;
		req->idx = i;
		req->name = test_fw_config->name;
		req->dev = dev;
		init_completion(&req->completion);
		req->task = kthread_run(test_fw_run_batch_request, req,
					     "%s-%u", KBUILD_MODNAME, req->idx);
		if (!req->task || IS_ERR(req->task)) {
			pr_err("Setting up thread %u failed\n", req->idx);
			req->task = NULL;
			rc = -ENOMEM;
			goto out_bail;
		}
	}

	rc = count;

	/*
	 * We require an explicit release to enable more time and delay of
	 * calling release_firmware() to improve our chances of forcing a
	 * batched request. If we instead called release_firmware() right away
	 * then we might miss on an opportunity of having a successful firmware
	 * request pass on the opportunity to be come a batched request.
	 */

out_bail:
	for (i = 0; i < test_fw_config->num_requests; i++) {
		req = &test_fw_config->reqs[i];
		if (req->task || req->sent)
			wait_for_completion(&req->completion);
	}

	/* Override any worker error if we had a general setup error */
	if (rc < 0)
		test_fw_config->test_result = rc;

out_unlock:
	mutex_unlock(&test_fw_mutex);

	return rc;
}
static DEVICE_ATTR_WO(trigger_batched_requests);

/*
 * We wait for each callback to return with the lock held, no need to lock here
 */
static void trigger_batched_cb(const struct firmware *fw, void *context)
{
	struct test_batched_req *req = context;

	if (!req) {
		test_fw_config->test_result = -EINVAL;
		return;
	}

	/* forces *some* batched requests to queue up */
	if (!req->idx)
		ssleep(2);

	req->fw = fw;

	/*
	 * Unfortunately the firmware API gives us nothing other than a null FW
	 * if the firmware was not found on async requests.  Best we can do is
	 * just assume -ENOENT. A better API would pass the actual return
	 * value to the callback.
	 */
	if (!fw && !test_fw_config->test_result)
		test_fw_config->test_result = -ENOENT;

	complete(&req->completion);
}

static
ssize_t trigger_batched_requests_async_store(struct device *dev,
					     struct device_attribute *attr,
					     const char *buf, size_t count)
{
	struct test_batched_req *req;
	bool send_uevent;
	int rc;
	u8 i;

	mutex_lock(&test_fw_mutex);

	test_fw_config->reqs =
		vzalloc(array3_size(sizeof(struct test_batched_req),
				    test_fw_config->num_requests, 2));
	if (!test_fw_config->reqs) {
		rc = -ENOMEM;
		goto out;
	}

	pr_info("batched loading '%s' custom fallback mechanism %u times\n",
		test_fw_config->name, test_fw_config->num_requests);

	send_uevent = test_fw_config->send_uevent ? FW_ACTION_HOTPLUG :
		FW_ACTION_NOHOTPLUG;

	for (i = 0; i < test_fw_config->num_requests; i++) {
		req = &test_fw_config->reqs[i];
		req->name = test_fw_config->name;
		req->fw = NULL;
		req->idx = i;
		init_completion(&req->completion);
		rc = request_firmware_nowait(THIS_MODULE, send_uevent,
					     req->name,
					     dev, GFP_KERNEL, req,
					     trigger_batched_cb);
		if (rc) {
			pr_info("#%u: batched async load failed setup: %d\n",
				i, rc);
			req->rc = rc;
			goto out_bail;
		} else
			req->sent = true;
	}

	rc = count;

out_bail:

	/*
	 * We require an explicit release to enable more time and delay of
	 * calling release_firmware() to improve our chances of forcing a
	 * batched request. If we instead called release_firmware() right away
	 * then we might miss on an opportunity of having a successful firmware
	 * request pass on the opportunity to be come a batched request.
	 */

	for (i = 0; i < test_fw_config->num_requests; i++) {
		req = &test_fw_config->reqs[i];
		if (req->sent)
			wait_for_completion(&req->completion);
	}

	/* Override any worker error if we had a general setup error */
	if (rc < 0)
		test_fw_config->test_result = rc;

out:
	mutex_unlock(&test_fw_mutex);

	return rc;
}
static DEVICE_ATTR_WO(trigger_batched_requests_async);

static ssize_t test_result_show(struct device *dev,
				struct device_attribute *attr,
				char *buf)
{
	return test_dev_config_show_int(buf, test_fw_config->test_result);
}
static DEVICE_ATTR_RO(test_result);

static ssize_t release_all_firmware_store(struct device *dev,
					  struct device_attribute *attr,
					  const char *buf, size_t count)
{
	test_release_all_firmware();
	return count;
}
static DEVICE_ATTR_WO(release_all_firmware);

static ssize_t read_firmware_show(struct device *dev,
				  struct device_attribute *attr,
				  char *buf)
{
	struct test_batched_req *req;
	u8 idx;
	ssize_t rc = 0;

	mutex_lock(&test_fw_mutex);

	idx = test_fw_config->read_fw_idx;
	if (idx >= test_fw_config->num_requests) {
		rc = -ERANGE;
		goto out;
	}

	if (!test_fw_config->reqs) {
		rc = -EINVAL;
		goto out;
	}

	req = &test_fw_config->reqs[idx];
	if (!req->fw) {
		pr_err("#%u: failed to async load firmware\n", idx);
		rc = -ENOENT;
		goto out;
	}

	pr_info("#%u: loaded %zu\n", idx, req->fw->size);

	if (req->fw->size > PAGE_SIZE) {
		pr_err("Testing interface must use PAGE_SIZE firmware for now\n");
		rc = -EINVAL;
		goto out;
	}
	memcpy(buf, req->fw->data, req->fw->size);

	rc = req->fw->size;
out:
	mutex_unlock(&test_fw_mutex);

	return rc;
}
static DEVICE_ATTR_RO(read_firmware);

#define TEST_FW_DEV_ATTR(name)          &dev_attr_##name.attr

static struct attribute *test_dev_attrs[] = {
	TEST_FW_DEV_ATTR(reset),

	TEST_FW_DEV_ATTR(config),
	TEST_FW_DEV_ATTR(config_name),
	TEST_FW_DEV_ATTR(config_num_requests),
	TEST_FW_DEV_ATTR(config_sync_direct),
	TEST_FW_DEV_ATTR(config_send_uevent),
	TEST_FW_DEV_ATTR(config_read_fw_idx),

	/* These don't use the config at all - they could be ported! */
	TEST_FW_DEV_ATTR(trigger_request),
	TEST_FW_DEV_ATTR(trigger_async_request),
	TEST_FW_DEV_ATTR(trigger_custom_fallback),

	/* These use the config and can use the test_result */
	TEST_FW_DEV_ATTR(trigger_batched_requests),
	TEST_FW_DEV_ATTR(trigger_batched_requests_async),

	TEST_FW_DEV_ATTR(release_all_firmware),
	TEST_FW_DEV_ATTR(test_result),
	TEST_FW_DEV_ATTR(read_firmware),
	NULL,
};

ATTRIBUTE_GROUPS(test_dev);

static struct miscdevice test_fw_misc_device = {
	.minor          = MISC_DYNAMIC_MINOR,
	.name           = "test_firmware",
	.fops           = &test_fw_fops,
	.groups 	= test_dev_groups,
};

static int __init test_firmware_init(void)
{
	int rc;

	test_fw_config = kzalloc(sizeof(struct test_config), GFP_KERNEL);
	if (!test_fw_config)
		return -ENOMEM;

	rc = __test_firmware_config_init();
	if (rc)
		return rc;

	rc = misc_register(&test_fw_misc_device);
	if (rc) {
		kfree(test_fw_config);
		pr_err("could not register misc device: %d\n", rc);
		return rc;
	}

	pr_warn("interface ready\n");

	return 0;
}

module_init(test_firmware_init);

static void __exit test_firmware_exit(void)
{
	mutex_lock(&test_fw_mutex);
	release_firmware(test_firmware);
	misc_deregister(&test_fw_misc_device);
	__test_firmware_config_free();
	kfree(test_fw_config);
	mutex_unlock(&test_fw_mutex);

	pr_warn("removed interface\n");
}

module_exit(test_firmware_exit);

MODULE_AUTHOR("Kees Cook <keescook@chromium.org>");
MODULE_LICENSE("GPL");