summaryrefslogtreecommitdiff
path: root/drivers/misc/mei/amthif.c
blob: 79f53941779d1f321d96ac6b6727cb13e4d5ded0 (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
/*
 *
 * Intel Management Engine Interface (Intel MEI) Linux driver
 * Copyright (c) 2003-2012, Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 */

#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/aio.h>
#include <linux/ioctl.h>
#include <linux/cdev.h>
#include <linux/list.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/uuid.h>
#include <linux/jiffies.h>
#include <linux/uaccess.h>
#include <linux/slab.h>

#include <linux/mei.h>

#include "mei_dev.h"
#include "hbm.h"
#include "client.h"

const uuid_le mei_amthif_guid  = UUID_LE(0x12f80028, 0xb4b7, 0x4b2d,
					 0xac, 0xa8, 0x46, 0xe0,
					 0xff, 0x65, 0x81, 0x4c);

/**
 * mei_amthif_reset_params - initializes mei device iamthif
 *
 * @dev: the device structure
 */
void mei_amthif_reset_params(struct mei_device *dev)
{
	/* reset iamthif parameters. */
	dev->iamthif_current_cb = NULL;
	dev->iamthif_msg_buf_size = 0;
	dev->iamthif_msg_buf_index = 0;
	dev->iamthif_canceled = false;
	dev->iamthif_ioctl = false;
	dev->iamthif_state = MEI_IAMTHIF_IDLE;
	dev->iamthif_timer = 0;
	dev->iamthif_stall_timer = 0;
	dev->iamthif_open_count = 0;
}

/**
 * mei_amthif_host_init - mei initialization amthif client.
 *
 * @dev: the device structure
 *
 * Return: 0 on success, <0 on failure.
 */
int mei_amthif_host_init(struct mei_device *dev)
{
	struct mei_cl *cl = &dev->iamthif_cl;
	struct mei_me_client *me_cl;
	unsigned char *msg_buf;
	int ret;

	dev->iamthif_state = MEI_IAMTHIF_IDLE;

	mei_cl_init(cl, dev);

	me_cl = mei_me_cl_by_uuid(dev, &mei_amthif_guid);
	if (!me_cl) {
		dev_info(dev->dev, "amthif: failed to find the client");
		return -ENOTTY;
	}

	cl->me_client_id = me_cl->client_id;
	cl->cl_uuid = me_cl->props.protocol_name;

	/* Assign iamthif_mtu to the value received from ME  */

	dev->iamthif_mtu = me_cl->props.max_msg_length;
	dev_dbg(dev->dev, "IAMTHIF_MTU = %d\n", dev->iamthif_mtu);

	kfree(dev->iamthif_msg_buf);
	dev->iamthif_msg_buf = NULL;

	/* allocate storage for ME message buffer */
	msg_buf = kcalloc(dev->iamthif_mtu,
			sizeof(unsigned char), GFP_KERNEL);
	if (!msg_buf)
		return -ENOMEM;

	dev->iamthif_msg_buf = msg_buf;

	ret = mei_cl_link(cl, MEI_IAMTHIF_HOST_CLIENT_ID);

	if (ret < 0) {
		dev_err(dev->dev,
			"amthif: failed link client %d\n", ret);
		return ret;
	}

	ret = mei_cl_connect(cl, NULL);

	dev->iamthif_state = MEI_IAMTHIF_IDLE;

	return ret;
}

/**
 * mei_amthif_find_read_list_entry - finds a amthilist entry for current file
 *
 * @dev: the device structure
 * @file: pointer to file object
 *
 * Return:   returned a list entry on success, NULL on failure.
 */
struct mei_cl_cb *mei_amthif_find_read_list_entry(struct mei_device *dev,
						struct file *file)
{
	struct mei_cl_cb *cb;

	list_for_each_entry(cb, &dev->amthif_rd_complete_list.list, list)
		if (cb->file_object == file)
			return cb;
	return NULL;
}


/**
 * mei_amthif_read - read data from AMTHIF client
 *
 * @dev: the device structure
 * @file: pointer to file object
 * @ubuf: pointer to user data in user space
 * @length: data length to read
 * @offset: data read offset
 *
 * Locking: called under "dev->device_lock" lock
 *
 * Return:
 *  returned data length on success,
 *  zero if no data to read,
 *  negative on failure.
 */
int mei_amthif_read(struct mei_device *dev, struct file *file,
	       char __user *ubuf, size_t length, loff_t *offset)
{
	struct mei_cl *cl = file->private_data;
	struct mei_cl_cb *cb;
	unsigned long timeout;
	int rets;
	int wait_ret;

	/* Only possible if we are in timeout */
	if (!cl) {
		dev_err(dev->dev, "bad file ext.\n");
		return -ETIME;
	}

	dev_dbg(dev->dev, "checking amthif data\n");
	cb = mei_amthif_find_read_list_entry(dev, file);

	/* Check for if we can block or not*/
	if (cb == NULL && file->f_flags & O_NONBLOCK)
		return -EAGAIN;


	dev_dbg(dev->dev, "waiting for amthif data\n");
	while (cb == NULL) {
		/* unlock the Mutex */
		mutex_unlock(&dev->device_lock);

		wait_ret = wait_event_interruptible(dev->iamthif_cl.wait,
			(cb = mei_amthif_find_read_list_entry(dev, file)));

		/* Locking again the Mutex */
		mutex_lock(&dev->device_lock);

		if (wait_ret)
			return -ERESTARTSYS;

		dev_dbg(dev->dev, "woke up from sleep\n");
	}


	dev_dbg(dev->dev, "Got amthif data\n");
	dev->iamthif_timer = 0;

	if (cb) {
		timeout = cb->read_time +
			mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
		dev_dbg(dev->dev, "amthif timeout = %lud\n",
				timeout);

		if  (time_after(jiffies, timeout)) {
			dev_dbg(dev->dev, "amthif Time out\n");
			/* 15 sec for the message has expired */
			list_del(&cb->list);
			rets = -ETIME;
			goto free;
		}
	}
	/* if the whole message will fit remove it from the list */
	if (cb->buf_idx >= *offset && length >= (cb->buf_idx - *offset))
		list_del(&cb->list);
	else if (cb->buf_idx > 0 && cb->buf_idx <= *offset) {
		/* end of the message has been reached */
		list_del(&cb->list);
		rets = 0;
		goto free;
	}
		/* else means that not full buffer will be read and do not
		 * remove message from deletion list
		 */

	dev_dbg(dev->dev, "amthif cb->response_buffer size - %d\n",
	    cb->response_buffer.size);
	dev_dbg(dev->dev, "amthif cb->buf_idx - %lu\n", cb->buf_idx);

	/* length is being truncated to PAGE_SIZE, however,
	 * the buf_idx may point beyond */
	length = min_t(size_t, length, (cb->buf_idx - *offset));

	if (copy_to_user(ubuf, cb->response_buffer.data + *offset, length)) {
		dev_dbg(dev->dev, "failed to copy data to userland\n");
		rets = -EFAULT;
	} else {
		rets = length;
		if ((*offset + length) < cb->buf_idx) {
			*offset += length;
			goto out;
		}
	}
free:
	dev_dbg(dev->dev, "free amthif cb memory.\n");
	*offset = 0;
	mei_io_cb_free(cb);
out:
	return rets;
}

/**
 * mei_amthif_send_cmd - send amthif command to the ME
 *
 * @dev: the device structure
 * @cb: mei call back struct
 *
 * Return: 0 on success, <0 on failure.
 *
 */
static int mei_amthif_send_cmd(struct mei_device *dev, struct mei_cl_cb *cb)
{
	struct mei_msg_hdr mei_hdr;
	struct mei_cl *cl;
	int ret;

	if (!dev || !cb)
		return -ENODEV;

	dev_dbg(dev->dev, "write data to amthif client.\n");

	dev->iamthif_state = MEI_IAMTHIF_WRITING;
	dev->iamthif_current_cb = cb;
	dev->iamthif_file_object = cb->file_object;
	dev->iamthif_canceled = false;
	dev->iamthif_ioctl = true;
	dev->iamthif_msg_buf_size = cb->request_buffer.size;
	memcpy(dev->iamthif_msg_buf, cb->request_buffer.data,
	       cb->request_buffer.size);
	cl = &dev->iamthif_cl;

	ret = mei_cl_flow_ctrl_creds(cl);
	if (ret < 0)
		return ret;

	if (ret && mei_hbuf_acquire(dev)) {
		ret = 0;
		if (cb->request_buffer.size > mei_hbuf_max_len(dev)) {
			mei_hdr.length = mei_hbuf_max_len(dev);
			mei_hdr.msg_complete = 0;
		} else {
			mei_hdr.length = cb->request_buffer.size;
			mei_hdr.msg_complete = 1;
		}

		mei_hdr.host_addr = cl->host_client_id;
		mei_hdr.me_addr = cl->me_client_id;
		mei_hdr.reserved = 0;
		mei_hdr.internal = 0;
		dev->iamthif_msg_buf_index += mei_hdr.length;
		ret = mei_write_message(dev, &mei_hdr, dev->iamthif_msg_buf);
		if (ret)
			return ret;

		if (mei_hdr.msg_complete) {
			if (mei_cl_flow_ctrl_reduce(cl))
				return -EIO;
			dev->iamthif_flow_control_pending = true;
			dev->iamthif_state = MEI_IAMTHIF_FLOW_CONTROL;
			dev_dbg(dev->dev, "add amthif cb to write waiting list\n");
			dev->iamthif_current_cb = cb;
			dev->iamthif_file_object = cb->file_object;
			list_add_tail(&cb->list, &dev->write_waiting_list.list);
		} else {
			dev_dbg(dev->dev, "message does not complete, so add amthif cb to write list.\n");
			list_add_tail(&cb->list, &dev->write_list.list);
		}
	} else {
		list_add_tail(&cb->list, &dev->write_list.list);
	}
	return 0;
}

/**
 * mei_amthif_write - write amthif data to amthif client
 *
 * @dev: the device structure
 * @cb: mei call back struct
 *
 * Return: 0 on success, <0 on failure.
 *
 */
int mei_amthif_write(struct mei_device *dev, struct mei_cl_cb *cb)
{
	int ret;

	if (!dev || !cb)
		return -ENODEV;

	ret = mei_io_cb_alloc_resp_buf(cb, dev->iamthif_mtu);
	if (ret)
		return ret;

	cb->fop_type = MEI_FOP_WRITE;

	if (!list_empty(&dev->amthif_cmd_list.list) ||
	    dev->iamthif_state != MEI_IAMTHIF_IDLE) {
		dev_dbg(dev->dev,
			"amthif state = %d\n", dev->iamthif_state);
		dev_dbg(dev->dev, "AMTHIF: add cb to the wait list\n");
		list_add_tail(&cb->list, &dev->amthif_cmd_list.list);
		return 0;
	}
	return mei_amthif_send_cmd(dev, cb);
}
/**
 * mei_amthif_run_next_cmd - send next amt command from queue
 *
 * @dev: the device structure
 */
void mei_amthif_run_next_cmd(struct mei_device *dev)
{
	struct mei_cl_cb *cb;
	int ret;

	if (!dev)
		return;

	dev->iamthif_msg_buf_size = 0;
	dev->iamthif_msg_buf_index = 0;
	dev->iamthif_canceled = false;
	dev->iamthif_ioctl = true;
	dev->iamthif_state = MEI_IAMTHIF_IDLE;
	dev->iamthif_timer = 0;
	dev->iamthif_file_object = NULL;

	dev_dbg(dev->dev, "complete amthif cmd_list cb.\n");

	cb = list_first_entry_or_null(&dev->amthif_cmd_list.list,
					typeof(*cb), list);
	if (!cb)
		return;
	list_del(&cb->list);
	ret =  mei_amthif_send_cmd(dev, cb);
	if (ret)
		dev_warn(dev->dev, "amthif write failed status = %d\n", ret);
}


unsigned int mei_amthif_poll(struct mei_device *dev,
		struct file *file, poll_table *wait)
{
	unsigned int mask = 0;

	poll_wait(file, &dev->iamthif_cl.wait, wait);

	mutex_lock(&dev->device_lock);
	if (!mei_cl_is_connected(&dev->iamthif_cl)) {

		mask = POLLERR;

	} else if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE &&
		   dev->iamthif_file_object == file) {

		mask |= (POLLIN | POLLRDNORM);
		dev_dbg(dev->dev, "run next amthif cb\n");
		mei_amthif_run_next_cmd(dev);
	}
	mutex_unlock(&dev->device_lock);

	return mask;
}



/**
 * mei_amthif_irq_write - write iamthif command in irq thread context.
 *
 * @cl: private data of the file object.
 * @cb: callback block.
 * @cmpl_list: complete list.
 *
 * Return: 0, OK; otherwise, error.
 */
int mei_amthif_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
			 struct mei_cl_cb *cmpl_list)
{
	struct mei_device *dev = cl->dev;
	struct mei_msg_hdr mei_hdr;
	size_t len = dev->iamthif_msg_buf_size - dev->iamthif_msg_buf_index;
	u32 msg_slots = mei_data2slots(len);
	int slots;
	int rets;

	rets = mei_cl_flow_ctrl_creds(cl);
	if (rets < 0)
		return rets;

	if (rets == 0) {
		cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
		return 0;
	}

	mei_hdr.host_addr = cl->host_client_id;
	mei_hdr.me_addr = cl->me_client_id;
	mei_hdr.reserved = 0;
	mei_hdr.internal = 0;

	slots = mei_hbuf_empty_slots(dev);

	if (slots >= msg_slots) {
		mei_hdr.length = len;
		mei_hdr.msg_complete = 1;
	/* Split the message only if we can write the whole host buffer */
	} else if (slots == dev->hbuf_depth) {
		msg_slots = slots;
		len = (slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
		mei_hdr.length = len;
		mei_hdr.msg_complete = 0;
	} else {
		/* wait for next time the host buffer is empty */
		return 0;
	}

	dev_dbg(dev->dev, MEI_HDR_FMT,  MEI_HDR_PRM(&mei_hdr));

	rets = mei_write_message(dev, &mei_hdr,
			dev->iamthif_msg_buf + dev->iamthif_msg_buf_index);
	if (rets) {
		dev->iamthif_state = MEI_IAMTHIF_IDLE;
		cl->status = rets;
		list_del(&cb->list);
		return rets;
	}

	if (mei_cl_flow_ctrl_reduce(cl))
		return -EIO;

	dev->iamthif_msg_buf_index += mei_hdr.length;
	cl->status = 0;

	if (mei_hdr.msg_complete) {
		dev->iamthif_state = MEI_IAMTHIF_FLOW_CONTROL;
		dev->iamthif_flow_control_pending = true;

		/* save iamthif cb sent to amthif client */
		cb->buf_idx = dev->iamthif_msg_buf_index;
		dev->iamthif_current_cb = cb;

		list_move_tail(&cb->list, &dev->write_waiting_list.list);
	}


	return 0;
}

/**
 * mei_amthif_irq_read_msg - read routine after ISR to
 *			handle the read amthif message
 *
 * @dev: the device structure
 * @mei_hdr: header of amthif message
 * @complete_list: An instance of our list structure
 *
 * Return: 0 on success, <0 on failure.
 */
int mei_amthif_irq_read_msg(struct mei_device *dev,
			    struct mei_msg_hdr *mei_hdr,
			    struct mei_cl_cb *complete_list)
{
	struct mei_cl_cb *cb;
	unsigned char *buffer;

	BUG_ON(mei_hdr->me_addr != dev->iamthif_cl.me_client_id);
	BUG_ON(dev->iamthif_state != MEI_IAMTHIF_READING);

	buffer = dev->iamthif_msg_buf + dev->iamthif_msg_buf_index;
	BUG_ON(dev->iamthif_mtu < dev->iamthif_msg_buf_index + mei_hdr->length);

	mei_read_slots(dev, buffer, mei_hdr->length);

	dev->iamthif_msg_buf_index += mei_hdr->length;

	if (!mei_hdr->msg_complete)
		return 0;

	dev_dbg(dev->dev, "amthif_message_buffer_index =%d\n",
			mei_hdr->length);

	dev_dbg(dev->dev, "completed amthif read.\n ");
	if (!dev->iamthif_current_cb)
		return -ENODEV;

	cb = dev->iamthif_current_cb;
	dev->iamthif_current_cb = NULL;

	dev->iamthif_stall_timer = 0;
	cb->buf_idx = dev->iamthif_msg_buf_index;
	cb->read_time = jiffies;
	if (dev->iamthif_ioctl) {
		/* found the iamthif cb */
		dev_dbg(dev->dev, "complete the amthif read cb.\n ");
		dev_dbg(dev->dev, "add the amthif read cb to complete.\n ");
		list_add_tail(&cb->list, &complete_list->list);
	}
	return 0;
}

/**
 * mei_amthif_irq_read - prepares to read amthif data.
 *
 * @dev: the device structure.
 * @slots: free slots.
 *
 * Return: 0, OK; otherwise, error.
 */
int mei_amthif_irq_read(struct mei_device *dev, s32 *slots)
{
	u32 msg_slots = mei_data2slots(sizeof(struct hbm_flow_control));

	if (*slots < msg_slots)
		return -EMSGSIZE;

	*slots -= msg_slots;

	if (mei_hbm_cl_flow_control_req(dev, &dev->iamthif_cl)) {
		dev_dbg(dev->dev, "iamthif flow control failed\n");
		return -EIO;
	}

	dev_dbg(dev->dev, "iamthif flow control success\n");
	dev->iamthif_state = MEI_IAMTHIF_READING;
	dev->iamthif_flow_control_pending = false;
	dev->iamthif_msg_buf_index = 0;
	dev->iamthif_msg_buf_size = 0;
	dev->iamthif_stall_timer = MEI_IAMTHIF_STALL_TIMER;
	dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
	return 0;
}

/**
 * mei_amthif_complete - complete amthif callback.
 *
 * @dev: the device structure.
 * @cb: callback block.
 */
void mei_amthif_complete(struct mei_device *dev, struct mei_cl_cb *cb)
{
	if (dev->iamthif_canceled != 1) {
		dev->iamthif_state = MEI_IAMTHIF_READ_COMPLETE;
		dev->iamthif_stall_timer = 0;
		memcpy(cb->response_buffer.data,
				dev->iamthif_msg_buf,
				dev->iamthif_msg_buf_index);
		list_add_tail(&cb->list, &dev->amthif_rd_complete_list.list);
		dev_dbg(dev->dev, "amthif read completed\n");
		dev->iamthif_timer = jiffies;
		dev_dbg(dev->dev, "dev->iamthif_timer = %ld\n",
				dev->iamthif_timer);
	} else {
		mei_amthif_run_next_cmd(dev);
	}

	dev_dbg(dev->dev, "completing amthif call back.\n");
	wake_up_interruptible(&dev->iamthif_cl.wait);
}

/**
 * mei_clear_list - removes all callbacks associated with file
 *		from mei_cb_list
 *
 * @dev: device structure.
 * @file: file structure
 * @mei_cb_list: callbacks list
 *
 * mei_clear_list is called to clear resources associated with file
 * when application calls close function or Ctrl-C was pressed
 *
 * Return: true if callback removed from the list, false otherwise
 */
static bool mei_clear_list(struct mei_device *dev,
		const struct file *file, struct list_head *mei_cb_list)
{
	struct mei_cl_cb *cb_pos = NULL;
	struct mei_cl_cb *cb_next = NULL;
	bool removed = false;

	/* list all list member */
	list_for_each_entry_safe(cb_pos, cb_next, mei_cb_list, list) {
		/* check if list member associated with a file */
		if (file == cb_pos->file_object) {
			/* remove member from the list */
			list_del(&cb_pos->list);
			/* check if cb equal to current iamthif cb */
			if (dev->iamthif_current_cb == cb_pos) {
				dev->iamthif_current_cb = NULL;
				/* send flow control to iamthif client */
				mei_hbm_cl_flow_control_req(dev,
							&dev->iamthif_cl);
			}
			/* free all allocated buffers */
			mei_io_cb_free(cb_pos);
			cb_pos = NULL;
			removed = true;
		}
	}
	return removed;
}

/**
 * mei_clear_lists - removes all callbacks associated with file
 *
 * @dev: device structure
 * @file: file structure
 *
 * mei_clear_lists is called to clear resources associated with file
 * when application calls close function or Ctrl-C was pressed
 *
 * Return: true if callback removed from the list, false otherwise
 */
static bool mei_clear_lists(struct mei_device *dev, struct file *file)
{
	bool removed = false;

	/* remove callbacks associated with a file */
	mei_clear_list(dev, file, &dev->amthif_cmd_list.list);
	if (mei_clear_list(dev, file, &dev->amthif_rd_complete_list.list))
		removed = true;

	mei_clear_list(dev, file, &dev->ctrl_rd_list.list);

	if (mei_clear_list(dev, file, &dev->ctrl_wr_list.list))
		removed = true;

	if (mei_clear_list(dev, file, &dev->write_waiting_list.list))
		removed = true;

	if (mei_clear_list(dev, file, &dev->write_list.list))
		removed = true;

	/* check if iamthif_current_cb not NULL */
	if (dev->iamthif_current_cb && !removed) {
		/* check file and iamthif current cb association */
		if (dev->iamthif_current_cb->file_object == file) {
			/* remove cb */
			mei_io_cb_free(dev->iamthif_current_cb);
			dev->iamthif_current_cb = NULL;
			removed = true;
		}
	}
	return removed;
}

/**
* mei_amthif_release - the release function
*
*  @dev: device structure
*  @file: pointer to file structure
*
*  Return: 0 on success, <0 on error
*/
int mei_amthif_release(struct mei_device *dev, struct file *file)
{
	if (dev->iamthif_open_count > 0)
		dev->iamthif_open_count--;

	if (dev->iamthif_file_object == file &&
	    dev->iamthif_state != MEI_IAMTHIF_IDLE) {

		dev_dbg(dev->dev, "amthif canceled iamthif state %d\n",
		    dev->iamthif_state);
		dev->iamthif_canceled = true;
		if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE) {
			dev_dbg(dev->dev, "run next amthif iamthif cb\n");
			mei_amthif_run_next_cmd(dev);
		}
	}

	if (mei_clear_lists(dev, file))
		dev->iamthif_state = MEI_IAMTHIF_IDLE;

	return 0;
}