summaryrefslogtreecommitdiff
path: root/drivers/char/tpm/tpm_ibmvtpm.c
blob: 09fe45246b8cc0d65760eecff54af9bdbd2997ef (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2012-2020 IBM Corporation
 *
 * Author: Ashley Lai <ashleydlai@gmail.com>
 *
 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
 *
 * Device driver for TCG/TCPA TPM (trusted platform module).
 * Specifications at www.trustedcomputinggroup.org
 */

#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
#include <linux/slab.h>
#include <asm/vio.h>
#include <asm/irq.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/wait.h>
#include <asm/prom.h>

#include "tpm.h"
#include "tpm_ibmvtpm.h"

static const char tpm_ibmvtpm_driver_name[] = "tpm_ibmvtpm";

static const struct vio_device_id tpm_ibmvtpm_device_table[] = {
	{ "IBM,vtpm", "IBM,vtpm"},
	{ "IBM,vtpm", "IBM,vtpm20"},
	{ "", "" }
};
MODULE_DEVICE_TABLE(vio, tpm_ibmvtpm_device_table);

/**
 * ibmvtpm_send_crq_word() - Send a CRQ request
 * @vdev:	vio device struct
 * @w1:		pre-constructed first word of tpm crq (second word is reserved)
 *
 * Return:
 *	0 - Success
 *	Non-zero - Failure
 */
static int ibmvtpm_send_crq_word(struct vio_dev *vdev, u64 w1)
{
	return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, w1, 0);
}

/**
 * ibmvtpm_send_crq() - Send a CRQ request
 *
 * @vdev:	vio device struct
 * @valid:	Valid field
 * @msg:	Type field
 * @len:	Length field
 * @data:	Data field
 *
 * The ibmvtpm crq is defined as follows:
 *
 * Byte  |   0   |   1   |   2   |   3   |   4   |   5   |   6   |   7
 * -----------------------------------------------------------------------
 * Word0 | Valid | Type  |     Length    |              Data
 * -----------------------------------------------------------------------
 * Word1 |                Reserved
 * -----------------------------------------------------------------------
 *
 * Which matches the following structure (on bigendian host):
 *
 * struct ibmvtpm_crq {
 *         u8 valid;
 *         u8 msg;
 *         __be16 len;
 *         __be32 data;
 *         __be64 reserved;
 * } __attribute__((packed, aligned(8)));
 *
 * However, the value is passed in a register so just compute the numeric value
 * to load into the register avoiding byteswap altogether. Endian only affects
 * memory loads and stores - registers are internally represented the same.
 *
 * Return:
 *	0 (H_SUCCESS) - Success
 *	Non-zero - Failure
 */
static int ibmvtpm_send_crq(struct vio_dev *vdev,
		u8 valid, u8 msg, u16 len, u32 data)
{
	u64 w1 = ((u64)valid << 56) | ((u64)msg << 48) | ((u64)len << 32) |
		(u64)data;
	return ibmvtpm_send_crq_word(vdev, w1);
}

/**
 * tpm_ibmvtpm_recv - Receive data after send
 *
 * @chip:	tpm chip struct
 * @buf:	buffer to read
 * @count:	size of buffer
 *
 * Return:
 *	Number of bytes read
 */
static int tpm_ibmvtpm_recv(struct tpm_chip *chip, u8 *buf, size_t count)
{
	struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
	u16 len;
	int sig;

	if (!ibmvtpm->rtce_buf) {
		dev_err(ibmvtpm->dev, "ibmvtpm device is not ready\n");
		return 0;
	}

	sig = wait_event_interruptible(ibmvtpm->wq, !ibmvtpm->tpm_processing_cmd);
	if (sig)
		return -EINTR;

	len = ibmvtpm->res_len;

	if (count < len) {
		dev_err(ibmvtpm->dev,
			"Invalid size in recv: count=%zd, crq_size=%d\n",
			count, len);
		return -EIO;
	}

	spin_lock(&ibmvtpm->rtce_lock);
	memcpy((void *)buf, (void *)ibmvtpm->rtce_buf, len);
	memset(ibmvtpm->rtce_buf, 0, len);
	ibmvtpm->res_len = 0;
	spin_unlock(&ibmvtpm->rtce_lock);
	return len;
}

/**
 * ibmvtpm_crq_send_init - Send a CRQ initialize message
 * @ibmvtpm:	vtpm device struct
 *
 * Return:
 *	0 on success.
 *	Non-zero on failure.
 */
static int ibmvtpm_crq_send_init(struct ibmvtpm_dev *ibmvtpm)
{
	int rc;

	rc = ibmvtpm_send_crq_word(ibmvtpm->vdev, INIT_CRQ_CMD);
	if (rc != H_SUCCESS)
		dev_err(ibmvtpm->dev,
			"%s failed rc=%d\n", __func__, rc);

	return rc;
}

/**
 * tpm_ibmvtpm_resume - Resume from suspend
 *
 * @dev:	device struct
 *
 * Return: Always 0.
 */
static int tpm_ibmvtpm_resume(struct device *dev)
{
	struct tpm_chip *chip = dev_get_drvdata(dev);
	struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
	int rc = 0;

	do {
		if (rc)
			msleep(100);
		rc = plpar_hcall_norets(H_ENABLE_CRQ,
					ibmvtpm->vdev->unit_address);
	} while (rc == H_IN_PROGRESS || rc == H_BUSY || H_IS_LONG_BUSY(rc));

	if (rc) {
		dev_err(dev, "Error enabling ibmvtpm rc=%d\n", rc);
		return rc;
	}

	rc = vio_enable_interrupts(ibmvtpm->vdev);
	if (rc) {
		dev_err(dev, "Error vio_enable_interrupts rc=%d\n", rc);
		return rc;
	}

	rc = ibmvtpm_crq_send_init(ibmvtpm);
	if (rc)
		dev_err(dev, "Error send_init rc=%d\n", rc);

	return rc;
}

/**
 * tpm_ibmvtpm_send() - Send a TPM command
 * @chip:	tpm chip struct
 * @buf:	buffer contains data to send
 * @count:	size of buffer
 *
 * Return:
 *   0 on success,
 *   -errno on error
 */
static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
{
	struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
	bool retry = true;
	int rc, sig;

	if (!ibmvtpm->rtce_buf) {
		dev_err(ibmvtpm->dev, "ibmvtpm device is not ready\n");
		return 0;
	}

	if (count > ibmvtpm->rtce_size) {
		dev_err(ibmvtpm->dev,
			"Invalid size in send: count=%zd, rtce_size=%d\n",
			count, ibmvtpm->rtce_size);
		return -EIO;
	}

	if (ibmvtpm->tpm_processing_cmd) {
		dev_info(ibmvtpm->dev,
		         "Need to wait for TPM to finish\n");
		/* wait for previous command to finish */
		sig = wait_event_interruptible(ibmvtpm->wq, !ibmvtpm->tpm_processing_cmd);
		if (sig)
			return -EINTR;
	}

	spin_lock(&ibmvtpm->rtce_lock);
	ibmvtpm->res_len = 0;
	memcpy((void *)ibmvtpm->rtce_buf, (void *)buf, count);

	/*
	 * set the processing flag before the Hcall, since we may get the
	 * result (interrupt) before even being able to check rc.
	 */
	ibmvtpm->tpm_processing_cmd = true;

again:
	rc = ibmvtpm_send_crq(ibmvtpm->vdev,
			IBMVTPM_VALID_CMD, VTPM_TPM_COMMAND,
			count, ibmvtpm->rtce_dma_handle);
	if (rc != H_SUCCESS) {
		/*
		 * H_CLOSED can be returned after LPM resume.  Call
		 * tpm_ibmvtpm_resume() to re-enable the CRQ then retry
		 * ibmvtpm_send_crq() once before failing.
		 */
		if (rc == H_CLOSED && retry) {
			tpm_ibmvtpm_resume(ibmvtpm->dev);
			retry = false;
			goto again;
		}
		dev_err(ibmvtpm->dev, "tpm_ibmvtpm_send failed rc=%d\n", rc);
		ibmvtpm->tpm_processing_cmd = false;
	}

	spin_unlock(&ibmvtpm->rtce_lock);
	return 0;
}

static void tpm_ibmvtpm_cancel(struct tpm_chip *chip)
{
	return;
}

static u8 tpm_ibmvtpm_status(struct tpm_chip *chip)
{
	return 0;
}

/**
 * ibmvtpm_crq_get_rtce_size - Send a CRQ request to get rtce size
 *
 * @ibmvtpm:	vtpm device struct
 *
 * Return:
 *	0 on success.
 *	Non-zero on failure.
 */
static int ibmvtpm_crq_get_rtce_size(struct ibmvtpm_dev *ibmvtpm)
{
	int rc;

	rc = ibmvtpm_send_crq(ibmvtpm->vdev,
			IBMVTPM_VALID_CMD, VTPM_GET_RTCE_BUFFER_SIZE, 0, 0);
	if (rc != H_SUCCESS)
		dev_err(ibmvtpm->dev,
			"ibmvtpm_crq_get_rtce_size failed rc=%d\n", rc);

	return rc;
}

/**
 * ibmvtpm_crq_get_version - Send a CRQ request to get vtpm version
 *			   - Note that this is vtpm version and not tpm version
 *
 * @ibmvtpm:	vtpm device struct
 *
 * Return:
 *	0 on success.
 *	Non-zero on failure.
 */
static int ibmvtpm_crq_get_version(struct ibmvtpm_dev *ibmvtpm)
{
	int rc;

	rc = ibmvtpm_send_crq(ibmvtpm->vdev,
			IBMVTPM_VALID_CMD, VTPM_GET_VERSION, 0, 0);
	if (rc != H_SUCCESS)
		dev_err(ibmvtpm->dev,
			"ibmvtpm_crq_get_version failed rc=%d\n", rc);

	return rc;
}

/**
 * ibmvtpm_crq_send_init_complete - Send a CRQ initialize complete message
 * @ibmvtpm:	vtpm device struct
 *
 * Return:
 *	0 on success.
 *	Non-zero on failure.
 */
static int ibmvtpm_crq_send_init_complete(struct ibmvtpm_dev *ibmvtpm)
{
	int rc;

	rc = ibmvtpm_send_crq_word(ibmvtpm->vdev, INIT_CRQ_COMP_CMD);
	if (rc != H_SUCCESS)
		dev_err(ibmvtpm->dev,
			"ibmvtpm_crq_send_init_complete failed rc=%d\n", rc);

	return rc;
}

/**
 * tpm_ibmvtpm_remove - ibm vtpm remove entry point
 * @vdev:	vio device struct
 *
 * Return: Always 0.
 */
static int tpm_ibmvtpm_remove(struct vio_dev *vdev)
{
	struct tpm_chip *chip = dev_get_drvdata(&vdev->dev);
	struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
	int rc = 0;

	tpm_chip_unregister(chip);

	free_irq(vdev->irq, ibmvtpm);

	do {
		if (rc)
			msleep(100);
		rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
	} while (rc == H_BUSY || H_IS_LONG_BUSY(rc));

	dma_unmap_single(ibmvtpm->dev, ibmvtpm->crq_dma_handle,
			 CRQ_RES_BUF_SIZE, DMA_BIDIRECTIONAL);
	free_page((unsigned long)ibmvtpm->crq_queue.crq_addr);

	if (ibmvtpm->rtce_buf) {
		dma_unmap_single(ibmvtpm->dev, ibmvtpm->rtce_dma_handle,
				 ibmvtpm->rtce_size, DMA_BIDIRECTIONAL);
		kfree(ibmvtpm->rtce_buf);
	}

	kfree(ibmvtpm);
	/* For tpm_ibmvtpm_get_desired_dma */
	dev_set_drvdata(&vdev->dev, NULL);

	return 0;
}

/**
 * tpm_ibmvtpm_get_desired_dma - Get DMA size needed by this driver
 * @vdev:	vio device struct
 *
 * Return:
 *	Number of bytes the driver needs to DMA map.
 */
static unsigned long tpm_ibmvtpm_get_desired_dma(struct vio_dev *vdev)
{
	struct tpm_chip *chip = dev_get_drvdata(&vdev->dev);
	struct ibmvtpm_dev *ibmvtpm;

	/*
	 * ibmvtpm initializes at probe time, so the data we are
	 * asking for may not be set yet. Estimate that 4K required
	 * for TCE-mapped buffer in addition to CRQ.
	 */
	if (chip)
		ibmvtpm = dev_get_drvdata(&chip->dev);
	else
		return CRQ_RES_BUF_SIZE + PAGE_SIZE;

	return CRQ_RES_BUF_SIZE + ibmvtpm->rtce_size;
}

/**
 * tpm_ibmvtpm_suspend - Suspend
 * @dev:	device struct
 *
 * Return: Always 0.
 */
static int tpm_ibmvtpm_suspend(struct device *dev)
{
	struct tpm_chip *chip = dev_get_drvdata(dev);
	struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
	int rc = 0;

	rc = ibmvtpm_send_crq(ibmvtpm->vdev,
			IBMVTPM_VALID_CMD, VTPM_PREPARE_TO_SUSPEND, 0, 0);
	if (rc != H_SUCCESS)
		dev_err(ibmvtpm->dev,
			"tpm_ibmvtpm_suspend failed rc=%d\n", rc);

	return rc;
}

/**
 * ibmvtpm_reset_crq - Reset CRQ
 *
 * @ibmvtpm:	ibm vtpm struct
 *
 * Return:
 *	0 on success.
 *	Non-zero on failure.
 */
static int ibmvtpm_reset_crq(struct ibmvtpm_dev *ibmvtpm)
{
	int rc = 0;

	do {
		if (rc)
			msleep(100);
		rc = plpar_hcall_norets(H_FREE_CRQ,
					ibmvtpm->vdev->unit_address);
	} while (rc == H_BUSY || H_IS_LONG_BUSY(rc));

	memset(ibmvtpm->crq_queue.crq_addr, 0, CRQ_RES_BUF_SIZE);
	ibmvtpm->crq_queue.index = 0;

	return plpar_hcall_norets(H_REG_CRQ, ibmvtpm->vdev->unit_address,
				  ibmvtpm->crq_dma_handle, CRQ_RES_BUF_SIZE);
}

static bool tpm_ibmvtpm_req_canceled(struct tpm_chip *chip, u8 status)
{
	return (status == 0);
}

static const struct tpm_class_ops tpm_ibmvtpm = {
	.recv = tpm_ibmvtpm_recv,
	.send = tpm_ibmvtpm_send,
	.cancel = tpm_ibmvtpm_cancel,
	.status = tpm_ibmvtpm_status,
	.req_complete_mask = 0,
	.req_complete_val = 0,
	.req_canceled = tpm_ibmvtpm_req_canceled,
};

static const struct dev_pm_ops tpm_ibmvtpm_pm_ops = {
	.suspend = tpm_ibmvtpm_suspend,
	.resume = tpm_ibmvtpm_resume,
};

/**
 * ibmvtpm_crq_get_next - Get next responded crq
 *
 * @ibmvtpm:	vtpm device struct
 *
 * Return: vtpm crq pointer or NULL.
 */
static struct ibmvtpm_crq *ibmvtpm_crq_get_next(struct ibmvtpm_dev *ibmvtpm)
{
	struct ibmvtpm_crq_queue *crq_q = &ibmvtpm->crq_queue;
	struct ibmvtpm_crq *crq = &crq_q->crq_addr[crq_q->index];

	if (crq->valid & VTPM_MSG_RES) {
		if (++crq_q->index == crq_q->num_entry)
			crq_q->index = 0;
		smp_rmb();
	} else
		crq = NULL;
	return crq;
}

/**
 * ibmvtpm_crq_process - Process responded crq
 *
 * @crq:	crq to be processed
 * @ibmvtpm:	vtpm device struct
 *
 */
static void ibmvtpm_crq_process(struct ibmvtpm_crq *crq,
				struct ibmvtpm_dev *ibmvtpm)
{
	int rc = 0;

	switch (crq->valid) {
	case VALID_INIT_CRQ:
		switch (crq->msg) {
		case INIT_CRQ_RES:
			dev_info(ibmvtpm->dev, "CRQ initialized\n");
			rc = ibmvtpm_crq_send_init_complete(ibmvtpm);
			if (rc)
				dev_err(ibmvtpm->dev, "Unable to send CRQ init complete rc=%d\n", rc);
			return;
		case INIT_CRQ_COMP_RES:
			dev_info(ibmvtpm->dev,
				 "CRQ initialization completed\n");
			return;
		default:
			dev_err(ibmvtpm->dev, "Unknown crq message type: %d\n", crq->msg);
			return;
		}
	case IBMVTPM_VALID_CMD:
		switch (crq->msg) {
		case VTPM_GET_RTCE_BUFFER_SIZE_RES:
			if (be16_to_cpu(crq->len) <= 0) {
				dev_err(ibmvtpm->dev, "Invalid rtce size\n");
				return;
			}
			ibmvtpm->rtce_size = be16_to_cpu(crq->len);
			ibmvtpm->rtce_buf = kmalloc(ibmvtpm->rtce_size,
						    GFP_ATOMIC);
			if (!ibmvtpm->rtce_buf) {
				dev_err(ibmvtpm->dev, "Failed to allocate memory for rtce buffer\n");
				return;
			}

			ibmvtpm->rtce_dma_handle = dma_map_single(ibmvtpm->dev,
				ibmvtpm->rtce_buf, ibmvtpm->rtce_size,
				DMA_BIDIRECTIONAL);

			if (dma_mapping_error(ibmvtpm->dev,
					      ibmvtpm->rtce_dma_handle)) {
				kfree(ibmvtpm->rtce_buf);
				ibmvtpm->rtce_buf = NULL;
				dev_err(ibmvtpm->dev, "Failed to dma map rtce buffer\n");
			}

			return;
		case VTPM_GET_VERSION_RES:
			ibmvtpm->vtpm_version = be32_to_cpu(crq->data);
			return;
		case VTPM_TPM_COMMAND_RES:
			/* len of the data in rtce buffer */
			ibmvtpm->res_len = be16_to_cpu(crq->len);
			ibmvtpm->tpm_processing_cmd = false;
			wake_up_interruptible(&ibmvtpm->wq);
			return;
		default:
			return;
		}
	}
	return;
}

/**
 * ibmvtpm_interrupt -	Interrupt handler
 *
 * @irq:		irq number to handle
 * @vtpm_instance:	vtpm that received interrupt
 *
 * Returns:
 *	IRQ_HANDLED
 **/
static irqreturn_t ibmvtpm_interrupt(int irq, void *vtpm_instance)
{
	struct ibmvtpm_dev *ibmvtpm = (struct ibmvtpm_dev *) vtpm_instance;
	struct ibmvtpm_crq *crq;

	/* while loop is needed for initial setup (get version and
	 * get rtce_size). There should be only one tpm request at any
	 * given time.
	 */
	while ((crq = ibmvtpm_crq_get_next(ibmvtpm)) != NULL) {
		ibmvtpm_crq_process(crq, ibmvtpm);
		wake_up_interruptible(&ibmvtpm->crq_queue.wq);
		crq->valid = 0;
		smp_wmb();
	}

	return IRQ_HANDLED;
}

/**
 * tpm_ibmvtpm_probe - ibm vtpm initialize entry point
 *
 * @vio_dev:	vio device struct
 * @id:		vio device id struct
 *
 * Return:
 *	0 on success.
 *	Non-zero on failure.
 */
static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev,
				   const struct vio_device_id *id)
{
	struct ibmvtpm_dev *ibmvtpm;
	struct device *dev = &vio_dev->dev;
	struct ibmvtpm_crq_queue *crq_q;
	struct tpm_chip *chip;
	int rc = -ENOMEM, rc1;

	chip = tpmm_chip_alloc(dev, &tpm_ibmvtpm);
	if (IS_ERR(chip))
		return PTR_ERR(chip);

	ibmvtpm = kzalloc(sizeof(struct ibmvtpm_dev), GFP_KERNEL);
	if (!ibmvtpm) {
		dev_err(dev, "kzalloc for ibmvtpm failed\n");
		goto cleanup;
	}

	ibmvtpm->dev = dev;
	ibmvtpm->vdev = vio_dev;

	crq_q = &ibmvtpm->crq_queue;
	crq_q->crq_addr = (struct ibmvtpm_crq *)get_zeroed_page(GFP_KERNEL);
	if (!crq_q->crq_addr) {
		dev_err(dev, "Unable to allocate memory for crq_addr\n");
		goto cleanup;
	}

	crq_q->num_entry = CRQ_RES_BUF_SIZE / sizeof(*crq_q->crq_addr);
	init_waitqueue_head(&crq_q->wq);
	ibmvtpm->crq_dma_handle = dma_map_single(dev, crq_q->crq_addr,
						 CRQ_RES_BUF_SIZE,
						 DMA_BIDIRECTIONAL);

	if (dma_mapping_error(dev, ibmvtpm->crq_dma_handle)) {
		dev_err(dev, "dma mapping failed\n");
		goto cleanup;
	}

	rc = plpar_hcall_norets(H_REG_CRQ, vio_dev->unit_address,
				ibmvtpm->crq_dma_handle, CRQ_RES_BUF_SIZE);
	if (rc == H_RESOURCE)
		rc = ibmvtpm_reset_crq(ibmvtpm);

	if (rc) {
		dev_err(dev, "Unable to register CRQ rc=%d\n", rc);
		goto reg_crq_cleanup;
	}

	rc = request_irq(vio_dev->irq, ibmvtpm_interrupt, 0,
			 tpm_ibmvtpm_driver_name, ibmvtpm);
	if (rc) {
		dev_err(dev, "Error %d register irq 0x%x\n", rc, vio_dev->irq);
		goto init_irq_cleanup;
	}

	rc = vio_enable_interrupts(vio_dev);
	if (rc) {
		dev_err(dev, "Error %d enabling interrupts\n", rc);
		goto init_irq_cleanup;
	}

	init_waitqueue_head(&ibmvtpm->wq);

	crq_q->index = 0;

	dev_set_drvdata(&chip->dev, ibmvtpm);

	spin_lock_init(&ibmvtpm->rtce_lock);

	rc = ibmvtpm_crq_send_init(ibmvtpm);
	if (rc)
		goto init_irq_cleanup;

	rc = ibmvtpm_crq_get_version(ibmvtpm);
	if (rc)
		goto init_irq_cleanup;

	rc = ibmvtpm_crq_get_rtce_size(ibmvtpm);
	if (rc)
		goto init_irq_cleanup;

	if (!strcmp(id->compat, "IBM,vtpm20")) {
		chip->flags |= TPM_CHIP_FLAG_TPM2;
		rc = tpm2_get_cc_attrs_tbl(chip);
		if (rc)
			goto init_irq_cleanup;
	}

	if (!wait_event_timeout(ibmvtpm->crq_queue.wq,
				ibmvtpm->rtce_buf != NULL,
				HZ)) {
		dev_err(dev, "CRQ response timed out\n");
		goto init_irq_cleanup;
	}

	return tpm_chip_register(chip);
init_irq_cleanup:
	do {
		rc1 = plpar_hcall_norets(H_FREE_CRQ, vio_dev->unit_address);
	} while (rc1 == H_BUSY || H_IS_LONG_BUSY(rc1));
reg_crq_cleanup:
	dma_unmap_single(dev, ibmvtpm->crq_dma_handle, CRQ_RES_BUF_SIZE,
			 DMA_BIDIRECTIONAL);
cleanup:
	if (ibmvtpm) {
		if (crq_q->crq_addr)
			free_page((unsigned long)crq_q->crq_addr);
		kfree(ibmvtpm);
	}

	return rc;
}

static struct vio_driver ibmvtpm_driver = {
	.id_table	 = tpm_ibmvtpm_device_table,
	.probe		 = tpm_ibmvtpm_probe,
	.remove		 = tpm_ibmvtpm_remove,
	.get_desired_dma = tpm_ibmvtpm_get_desired_dma,
	.name		 = tpm_ibmvtpm_driver_name,
	.pm		 = &tpm_ibmvtpm_pm_ops,
};

/**
 * ibmvtpm_module_init - Initialize ibm vtpm module.
 *
 *
 * Return:
 *	0 on success.
 *	Non-zero on failure.
 */
static int __init ibmvtpm_module_init(void)
{
	return vio_register_driver(&ibmvtpm_driver);
}

/**
 * ibmvtpm_module_exit - Tear down ibm vtpm module.
 */
static void __exit ibmvtpm_module_exit(void)
{
	vio_unregister_driver(&ibmvtpm_driver);
}

module_init(ibmvtpm_module_init);
module_exit(ibmvtpm_module_exit);

MODULE_AUTHOR("adlai@us.ibm.com");
MODULE_DESCRIPTION("IBM vTPM Driver");
MODULE_VERSION("1.0");
MODULE_LICENSE("GPL");