xref: /openbmc/linux/drivers/char/tpm/tpm_ibmvtpm.c (revision f7018c21)
1 /*
2  * Copyright (C) 2012 IBM Corporation
3  *
4  * Author: Ashley Lai <adlai@us.ibm.com>
5  *
6  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
7  *
8  * Device driver for TCG/TCPA TPM (trusted platform module).
9  * Specifications at www.trustedcomputinggroup.org
10  *
11  * This program is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU General Public License as
13  * published by the Free Software Foundation, version 2 of the
14  * License.
15  *
16  */
17 
18 #include <linux/dma-mapping.h>
19 #include <linux/dmapool.h>
20 #include <linux/slab.h>
21 #include <asm/vio.h>
22 #include <asm/irq.h>
23 #include <linux/types.h>
24 #include <linux/list.h>
25 #include <linux/spinlock.h>
26 #include <linux/interrupt.h>
27 #include <linux/wait.h>
28 #include <asm/prom.h>
29 
30 #include "tpm.h"
31 #include "tpm_ibmvtpm.h"
32 
33 static const char tpm_ibmvtpm_driver_name[] = "tpm_ibmvtpm";
34 
35 static struct vio_device_id tpm_ibmvtpm_device_table[] = {
36 	{ "IBM,vtpm", "IBM,vtpm"},
37 	{ "", "" }
38 };
39 MODULE_DEVICE_TABLE(vio, tpm_ibmvtpm_device_table);
40 
41 /**
42  * ibmvtpm_send_crq - Send a CRQ request
43  * @vdev:	vio device struct
44  * @w1:		first word
45  * @w2:		second word
46  *
47  * Return value:
48  *	0 -Sucess
49  *	Non-zero - Failure
50  */
51 static int ibmvtpm_send_crq(struct vio_dev *vdev, u64 w1, u64 w2)
52 {
53 	return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, w1, w2);
54 }
55 
56 /**
57  * ibmvtpm_get_data - Retrieve ibm vtpm data
58  * @dev:	device struct
59  *
60  * Return value:
61  *	vtpm device struct
62  */
63 static struct ibmvtpm_dev *ibmvtpm_get_data(const struct device *dev)
64 {
65 	struct tpm_chip *chip = dev_get_drvdata(dev);
66 	if (chip)
67 		return (struct ibmvtpm_dev *)TPM_VPRIV(chip);
68 	return NULL;
69 }
70 
71 /**
72  * tpm_ibmvtpm_recv - Receive data after send
73  * @chip:	tpm chip struct
74  * @buf:	buffer to read
75  * count:	size of buffer
76  *
77  * Return value:
78  *	Number of bytes read
79  */
80 static int tpm_ibmvtpm_recv(struct tpm_chip *chip, u8 *buf, size_t count)
81 {
82 	struct ibmvtpm_dev *ibmvtpm;
83 	u16 len;
84 	int sig;
85 
86 	ibmvtpm = (struct ibmvtpm_dev *)TPM_VPRIV(chip);
87 
88 	if (!ibmvtpm->rtce_buf) {
89 		dev_err(ibmvtpm->dev, "ibmvtpm device is not ready\n");
90 		return 0;
91 	}
92 
93 	sig = wait_event_interruptible(ibmvtpm->wq, ibmvtpm->res_len != 0);
94 	if (sig)
95 		return -EINTR;
96 
97 	len = ibmvtpm->res_len;
98 
99 	if (count < len) {
100 		dev_err(ibmvtpm->dev,
101 			"Invalid size in recv: count=%zd, crq_size=%d\n",
102 			count, len);
103 		return -EIO;
104 	}
105 
106 	spin_lock(&ibmvtpm->rtce_lock);
107 	memcpy((void *)buf, (void *)ibmvtpm->rtce_buf, len);
108 	memset(ibmvtpm->rtce_buf, 0, len);
109 	ibmvtpm->res_len = 0;
110 	spin_unlock(&ibmvtpm->rtce_lock);
111 	return len;
112 }
113 
114 /**
115  * tpm_ibmvtpm_send - Send tpm request
116  * @chip:	tpm chip struct
117  * @buf:	buffer contains data to send
118  * count:	size of buffer
119  *
120  * Return value:
121  *	Number of bytes sent
122  */
123 static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
124 {
125 	struct ibmvtpm_dev *ibmvtpm;
126 	struct ibmvtpm_crq crq;
127 	u64 *word = (u64 *) &crq;
128 	int rc;
129 
130 	ibmvtpm = (struct ibmvtpm_dev *)TPM_VPRIV(chip);
131 
132 	if (!ibmvtpm->rtce_buf) {
133 		dev_err(ibmvtpm->dev, "ibmvtpm device is not ready\n");
134 		return 0;
135 	}
136 
137 	if (count > ibmvtpm->rtce_size) {
138 		dev_err(ibmvtpm->dev,
139 			"Invalid size in send: count=%zd, rtce_size=%d\n",
140 			count, ibmvtpm->rtce_size);
141 		return -EIO;
142 	}
143 
144 	spin_lock(&ibmvtpm->rtce_lock);
145 	memcpy((void *)ibmvtpm->rtce_buf, (void *)buf, count);
146 	crq.valid = (u8)IBMVTPM_VALID_CMD;
147 	crq.msg = (u8)VTPM_TPM_COMMAND;
148 	crq.len = (u16)count;
149 	crq.data = ibmvtpm->rtce_dma_handle;
150 
151 	rc = ibmvtpm_send_crq(ibmvtpm->vdev, word[0], word[1]);
152 	if (rc != H_SUCCESS) {
153 		dev_err(ibmvtpm->dev, "tpm_ibmvtpm_send failed rc=%d\n", rc);
154 		rc = 0;
155 	} else
156 		rc = count;
157 
158 	spin_unlock(&ibmvtpm->rtce_lock);
159 	return rc;
160 }
161 
162 static void tpm_ibmvtpm_cancel(struct tpm_chip *chip)
163 {
164 	return;
165 }
166 
167 static u8 tpm_ibmvtpm_status(struct tpm_chip *chip)
168 {
169 	return 0;
170 }
171 
172 /**
173  * ibmvtpm_crq_get_rtce_size - Send a CRQ request to get rtce size
174  * @ibmvtpm:	vtpm device struct
175  *
176  * Return value:
177  *	0 - Success
178  *	Non-zero - Failure
179  */
180 static int ibmvtpm_crq_get_rtce_size(struct ibmvtpm_dev *ibmvtpm)
181 {
182 	struct ibmvtpm_crq crq;
183 	u64 *buf = (u64 *) &crq;
184 	int rc;
185 
186 	crq.valid = (u8)IBMVTPM_VALID_CMD;
187 	crq.msg = (u8)VTPM_GET_RTCE_BUFFER_SIZE;
188 
189 	rc = ibmvtpm_send_crq(ibmvtpm->vdev, buf[0], buf[1]);
190 	if (rc != H_SUCCESS)
191 		dev_err(ibmvtpm->dev,
192 			"ibmvtpm_crq_get_rtce_size failed rc=%d\n", rc);
193 
194 	return rc;
195 }
196 
197 /**
198  * ibmvtpm_crq_get_version - Send a CRQ request to get vtpm version
199  *			   - Note that this is vtpm version and not tpm version
200  * @ibmvtpm:	vtpm device struct
201  *
202  * Return value:
203  *	0 - Success
204  *	Non-zero - Failure
205  */
206 static int ibmvtpm_crq_get_version(struct ibmvtpm_dev *ibmvtpm)
207 {
208 	struct ibmvtpm_crq crq;
209 	u64 *buf = (u64 *) &crq;
210 	int rc;
211 
212 	crq.valid = (u8)IBMVTPM_VALID_CMD;
213 	crq.msg = (u8)VTPM_GET_VERSION;
214 
215 	rc = ibmvtpm_send_crq(ibmvtpm->vdev, buf[0], buf[1]);
216 	if (rc != H_SUCCESS)
217 		dev_err(ibmvtpm->dev,
218 			"ibmvtpm_crq_get_version failed rc=%d\n", rc);
219 
220 	return rc;
221 }
222 
223 /**
224  * ibmvtpm_crq_send_init_complete - Send a CRQ initialize complete message
225  * @ibmvtpm:	vtpm device struct
226  *
227  * Return value:
228  *	0 - Success
229  *	Non-zero - Failure
230  */
231 static int ibmvtpm_crq_send_init_complete(struct ibmvtpm_dev *ibmvtpm)
232 {
233 	int rc;
234 
235 	rc = ibmvtpm_send_crq(ibmvtpm->vdev, INIT_CRQ_COMP_CMD, 0);
236 	if (rc != H_SUCCESS)
237 		dev_err(ibmvtpm->dev,
238 			"ibmvtpm_crq_send_init_complete failed rc=%d\n", rc);
239 
240 	return rc;
241 }
242 
243 /**
244  * ibmvtpm_crq_send_init - Send a CRQ initialize message
245  * @ibmvtpm:	vtpm device struct
246  *
247  * Return value:
248  *	0 - Success
249  *	Non-zero - Failure
250  */
251 static int ibmvtpm_crq_send_init(struct ibmvtpm_dev *ibmvtpm)
252 {
253 	int rc;
254 
255 	rc = ibmvtpm_send_crq(ibmvtpm->vdev, INIT_CRQ_CMD, 0);
256 	if (rc != H_SUCCESS)
257 		dev_err(ibmvtpm->dev,
258 			"ibmvtpm_crq_send_init failed rc=%d\n", rc);
259 
260 	return rc;
261 }
262 
263 /**
264  * tpm_ibmvtpm_remove - ibm vtpm remove entry point
265  * @vdev:	vio device struct
266  *
267  * Return value:
268  *	0
269  */
270 static int tpm_ibmvtpm_remove(struct vio_dev *vdev)
271 {
272 	struct ibmvtpm_dev *ibmvtpm = ibmvtpm_get_data(&vdev->dev);
273 	int rc = 0;
274 
275 	free_irq(vdev->irq, ibmvtpm);
276 
277 	do {
278 		if (rc)
279 			msleep(100);
280 		rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
281 	} while (rc == H_BUSY || H_IS_LONG_BUSY(rc));
282 
283 	dma_unmap_single(ibmvtpm->dev, ibmvtpm->crq_dma_handle,
284 			 CRQ_RES_BUF_SIZE, DMA_BIDIRECTIONAL);
285 	free_page((unsigned long)ibmvtpm->crq_queue.crq_addr);
286 
287 	if (ibmvtpm->rtce_buf) {
288 		dma_unmap_single(ibmvtpm->dev, ibmvtpm->rtce_dma_handle,
289 				 ibmvtpm->rtce_size, DMA_BIDIRECTIONAL);
290 		kfree(ibmvtpm->rtce_buf);
291 	}
292 
293 	tpm_remove_hardware(ibmvtpm->dev);
294 
295 	kfree(ibmvtpm);
296 
297 	return 0;
298 }
299 
300 /**
301  * tpm_ibmvtpm_get_desired_dma - Get DMA size needed by this driver
302  * @vdev:	vio device struct
303  *
304  * Return value:
305  *	Number of bytes the driver needs to DMA map
306  */
307 static unsigned long tpm_ibmvtpm_get_desired_dma(struct vio_dev *vdev)
308 {
309 	struct ibmvtpm_dev *ibmvtpm = ibmvtpm_get_data(&vdev->dev);
310 	return CRQ_RES_BUF_SIZE + ibmvtpm->rtce_size;
311 }
312 
313 /**
314  * tpm_ibmvtpm_suspend - Suspend
315  * @dev:	device struct
316  *
317  * Return value:
318  *	0
319  */
320 static int tpm_ibmvtpm_suspend(struct device *dev)
321 {
322 	struct ibmvtpm_dev *ibmvtpm = ibmvtpm_get_data(dev);
323 	struct ibmvtpm_crq crq;
324 	u64 *buf = (u64 *) &crq;
325 	int rc = 0;
326 
327 	crq.valid = (u8)IBMVTPM_VALID_CMD;
328 	crq.msg = (u8)VTPM_PREPARE_TO_SUSPEND;
329 
330 	rc = ibmvtpm_send_crq(ibmvtpm->vdev, buf[0], buf[1]);
331 	if (rc != H_SUCCESS)
332 		dev_err(ibmvtpm->dev,
333 			"tpm_ibmvtpm_suspend failed rc=%d\n", rc);
334 
335 	return rc;
336 }
337 
338 /**
339  * ibmvtpm_reset_crq - Reset CRQ
340  * @ibmvtpm:	ibm vtpm struct
341  *
342  * Return value:
343  *	0 - Success
344  *	Non-zero - Failure
345  */
346 static int ibmvtpm_reset_crq(struct ibmvtpm_dev *ibmvtpm)
347 {
348 	int rc = 0;
349 
350 	do {
351 		if (rc)
352 			msleep(100);
353 		rc = plpar_hcall_norets(H_FREE_CRQ,
354 					ibmvtpm->vdev->unit_address);
355 	} while (rc == H_BUSY || H_IS_LONG_BUSY(rc));
356 
357 	memset(ibmvtpm->crq_queue.crq_addr, 0, CRQ_RES_BUF_SIZE);
358 	ibmvtpm->crq_queue.index = 0;
359 
360 	return plpar_hcall_norets(H_REG_CRQ, ibmvtpm->vdev->unit_address,
361 				  ibmvtpm->crq_dma_handle, CRQ_RES_BUF_SIZE);
362 }
363 
364 /**
365  * tpm_ibmvtpm_resume - Resume from suspend
366  * @dev:	device struct
367  *
368  * Return value:
369  *	0
370  */
371 static int tpm_ibmvtpm_resume(struct device *dev)
372 {
373 	struct ibmvtpm_dev *ibmvtpm = ibmvtpm_get_data(dev);
374 	int rc = 0;
375 
376 	do {
377 		if (rc)
378 			msleep(100);
379 		rc = plpar_hcall_norets(H_ENABLE_CRQ,
380 					ibmvtpm->vdev->unit_address);
381 	} while (rc == H_IN_PROGRESS || rc == H_BUSY || H_IS_LONG_BUSY(rc));
382 
383 	if (rc) {
384 		dev_err(dev, "Error enabling ibmvtpm rc=%d\n", rc);
385 		return rc;
386 	}
387 
388 	rc = vio_enable_interrupts(ibmvtpm->vdev);
389 	if (rc) {
390 		dev_err(dev, "Error vio_enable_interrupts rc=%d\n", rc);
391 		return rc;
392 	}
393 
394 	rc = ibmvtpm_crq_send_init(ibmvtpm);
395 	if (rc)
396 		dev_err(dev, "Error send_init rc=%d\n", rc);
397 
398 	return rc;
399 }
400 
401 static bool tpm_ibmvtpm_req_canceled(struct tpm_chip *chip, u8 status)
402 {
403 	return (status == 0);
404 }
405 
406 static const struct tpm_class_ops tpm_ibmvtpm = {
407 	.recv = tpm_ibmvtpm_recv,
408 	.send = tpm_ibmvtpm_send,
409 	.cancel = tpm_ibmvtpm_cancel,
410 	.status = tpm_ibmvtpm_status,
411 	.req_complete_mask = 0,
412 	.req_complete_val = 0,
413 	.req_canceled = tpm_ibmvtpm_req_canceled,
414 };
415 
416 static const struct dev_pm_ops tpm_ibmvtpm_pm_ops = {
417 	.suspend = tpm_ibmvtpm_suspend,
418 	.resume = tpm_ibmvtpm_resume,
419 };
420 
421 /**
422  * ibmvtpm_crq_get_next - Get next responded crq
423  * @ibmvtpm	vtpm device struct
424  *
425  * Return value:
426  *	vtpm crq pointer
427  */
428 static struct ibmvtpm_crq *ibmvtpm_crq_get_next(struct ibmvtpm_dev *ibmvtpm)
429 {
430 	struct ibmvtpm_crq_queue *crq_q = &ibmvtpm->crq_queue;
431 	struct ibmvtpm_crq *crq = &crq_q->crq_addr[crq_q->index];
432 
433 	if (crq->valid & VTPM_MSG_RES) {
434 		if (++crq_q->index == crq_q->num_entry)
435 			crq_q->index = 0;
436 		smp_rmb();
437 	} else
438 		crq = NULL;
439 	return crq;
440 }
441 
442 /**
443  * ibmvtpm_crq_process - Process responded crq
444  * @crq		crq to be processed
445  * @ibmvtpm	vtpm device struct
446  *
447  * Return value:
448  *	Nothing
449  */
450 static void ibmvtpm_crq_process(struct ibmvtpm_crq *crq,
451 				struct ibmvtpm_dev *ibmvtpm)
452 {
453 	int rc = 0;
454 
455 	switch (crq->valid) {
456 	case VALID_INIT_CRQ:
457 		switch (crq->msg) {
458 		case INIT_CRQ_RES:
459 			dev_info(ibmvtpm->dev, "CRQ initialized\n");
460 			rc = ibmvtpm_crq_send_init_complete(ibmvtpm);
461 			if (rc)
462 				dev_err(ibmvtpm->dev, "Unable to send CRQ init complete rc=%d\n", rc);
463 			return;
464 		case INIT_CRQ_COMP_RES:
465 			dev_info(ibmvtpm->dev,
466 				 "CRQ initialization completed\n");
467 			return;
468 		default:
469 			dev_err(ibmvtpm->dev, "Unknown crq message type: %d\n", crq->msg);
470 			return;
471 		}
472 	case IBMVTPM_VALID_CMD:
473 		switch (crq->msg) {
474 		case VTPM_GET_RTCE_BUFFER_SIZE_RES:
475 			if (crq->len <= 0) {
476 				dev_err(ibmvtpm->dev, "Invalid rtce size\n");
477 				return;
478 			}
479 			ibmvtpm->rtce_size = crq->len;
480 			ibmvtpm->rtce_buf = kmalloc(ibmvtpm->rtce_size,
481 						    GFP_KERNEL);
482 			if (!ibmvtpm->rtce_buf) {
483 				dev_err(ibmvtpm->dev, "Failed to allocate memory for rtce buffer\n");
484 				return;
485 			}
486 
487 			ibmvtpm->rtce_dma_handle = dma_map_single(ibmvtpm->dev,
488 				ibmvtpm->rtce_buf, ibmvtpm->rtce_size,
489 				DMA_BIDIRECTIONAL);
490 
491 			if (dma_mapping_error(ibmvtpm->dev,
492 					      ibmvtpm->rtce_dma_handle)) {
493 				kfree(ibmvtpm->rtce_buf);
494 				ibmvtpm->rtce_buf = NULL;
495 				dev_err(ibmvtpm->dev, "Failed to dma map rtce buffer\n");
496 			}
497 
498 			return;
499 		case VTPM_GET_VERSION_RES:
500 			ibmvtpm->vtpm_version = crq->data;
501 			return;
502 		case VTPM_TPM_COMMAND_RES:
503 			/* len of the data in rtce buffer */
504 			ibmvtpm->res_len = crq->len;
505 			wake_up_interruptible(&ibmvtpm->wq);
506 			return;
507 		default:
508 			return;
509 		}
510 	}
511 	return;
512 }
513 
514 /**
515  * ibmvtpm_interrupt -	Interrupt handler
516  * @irq:		irq number to handle
517  * @vtpm_instance:	vtpm that received interrupt
518  *
519  * Returns:
520  *	IRQ_HANDLED
521  **/
522 static irqreturn_t ibmvtpm_interrupt(int irq, void *vtpm_instance)
523 {
524 	struct ibmvtpm_dev *ibmvtpm = (struct ibmvtpm_dev *) vtpm_instance;
525 	struct ibmvtpm_crq *crq;
526 
527 	/* while loop is needed for initial setup (get version and
528 	 * get rtce_size). There should be only one tpm request at any
529 	 * given time.
530 	 */
531 	while ((crq = ibmvtpm_crq_get_next(ibmvtpm)) != NULL) {
532 		ibmvtpm_crq_process(crq, ibmvtpm);
533 		crq->valid = 0;
534 		smp_wmb();
535 	}
536 
537 	return IRQ_HANDLED;
538 }
539 
540 /**
541  * tpm_ibmvtpm_probe - ibm vtpm initialize entry point
542  * @vio_dev:	vio device struct
543  * @id:		vio device id struct
544  *
545  * Return value:
546  *	0 - Success
547  *	Non-zero - Failure
548  */
549 static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev,
550 				   const struct vio_device_id *id)
551 {
552 	struct ibmvtpm_dev *ibmvtpm;
553 	struct device *dev = &vio_dev->dev;
554 	struct ibmvtpm_crq_queue *crq_q;
555 	struct tpm_chip *chip;
556 	int rc = -ENOMEM, rc1;
557 
558 	chip = tpm_register_hardware(dev, &tpm_ibmvtpm);
559 	if (!chip) {
560 		dev_err(dev, "tpm_register_hardware failed\n");
561 		return -ENODEV;
562 	}
563 
564 	ibmvtpm = kzalloc(sizeof(struct ibmvtpm_dev), GFP_KERNEL);
565 	if (!ibmvtpm) {
566 		dev_err(dev, "kzalloc for ibmvtpm failed\n");
567 		goto cleanup;
568 	}
569 
570 	crq_q = &ibmvtpm->crq_queue;
571 	crq_q->crq_addr = (struct ibmvtpm_crq *)get_zeroed_page(GFP_KERNEL);
572 	if (!crq_q->crq_addr) {
573 		dev_err(dev, "Unable to allocate memory for crq_addr\n");
574 		goto cleanup;
575 	}
576 
577 	crq_q->num_entry = CRQ_RES_BUF_SIZE / sizeof(*crq_q->crq_addr);
578 	ibmvtpm->crq_dma_handle = dma_map_single(dev, crq_q->crq_addr,
579 						 CRQ_RES_BUF_SIZE,
580 						 DMA_BIDIRECTIONAL);
581 
582 	if (dma_mapping_error(dev, ibmvtpm->crq_dma_handle)) {
583 		dev_err(dev, "dma mapping failed\n");
584 		goto cleanup;
585 	}
586 
587 	rc = plpar_hcall_norets(H_REG_CRQ, vio_dev->unit_address,
588 				ibmvtpm->crq_dma_handle, CRQ_RES_BUF_SIZE);
589 	if (rc == H_RESOURCE)
590 		rc = ibmvtpm_reset_crq(ibmvtpm);
591 
592 	if (rc) {
593 		dev_err(dev, "Unable to register CRQ rc=%d\n", rc);
594 		goto reg_crq_cleanup;
595 	}
596 
597 	rc = request_irq(vio_dev->irq, ibmvtpm_interrupt, 0,
598 			 tpm_ibmvtpm_driver_name, ibmvtpm);
599 	if (rc) {
600 		dev_err(dev, "Error %d register irq 0x%x\n", rc, vio_dev->irq);
601 		goto init_irq_cleanup;
602 	}
603 
604 	rc = vio_enable_interrupts(vio_dev);
605 	if (rc) {
606 		dev_err(dev, "Error %d enabling interrupts\n", rc);
607 		goto init_irq_cleanup;
608 	}
609 
610 	init_waitqueue_head(&ibmvtpm->wq);
611 
612 	crq_q->index = 0;
613 
614 	ibmvtpm->dev = dev;
615 	ibmvtpm->vdev = vio_dev;
616 	TPM_VPRIV(chip) = (void *)ibmvtpm;
617 
618 	spin_lock_init(&ibmvtpm->rtce_lock);
619 
620 	rc = ibmvtpm_crq_send_init(ibmvtpm);
621 	if (rc)
622 		goto init_irq_cleanup;
623 
624 	rc = ibmvtpm_crq_get_version(ibmvtpm);
625 	if (rc)
626 		goto init_irq_cleanup;
627 
628 	rc = ibmvtpm_crq_get_rtce_size(ibmvtpm);
629 	if (rc)
630 		goto init_irq_cleanup;
631 
632 	return rc;
633 init_irq_cleanup:
634 	do {
635 		rc1 = plpar_hcall_norets(H_FREE_CRQ, vio_dev->unit_address);
636 	} while (rc1 == H_BUSY || H_IS_LONG_BUSY(rc1));
637 reg_crq_cleanup:
638 	dma_unmap_single(dev, ibmvtpm->crq_dma_handle, CRQ_RES_BUF_SIZE,
639 			 DMA_BIDIRECTIONAL);
640 cleanup:
641 	if (ibmvtpm) {
642 		if (crq_q->crq_addr)
643 			free_page((unsigned long)crq_q->crq_addr);
644 		kfree(ibmvtpm);
645 	}
646 
647 	tpm_remove_hardware(dev);
648 
649 	return rc;
650 }
651 
652 static struct vio_driver ibmvtpm_driver = {
653 	.id_table	 = tpm_ibmvtpm_device_table,
654 	.probe		 = tpm_ibmvtpm_probe,
655 	.remove		 = tpm_ibmvtpm_remove,
656 	.get_desired_dma = tpm_ibmvtpm_get_desired_dma,
657 	.name		 = tpm_ibmvtpm_driver_name,
658 	.pm		 = &tpm_ibmvtpm_pm_ops,
659 };
660 
661 /**
662  * ibmvtpm_module_init - Initialize ibm vtpm module
663  *
664  * Return value:
665  *	0 -Success
666  *	Non-zero - Failure
667  */
668 static int __init ibmvtpm_module_init(void)
669 {
670 	return vio_register_driver(&ibmvtpm_driver);
671 }
672 
673 /**
674  * ibmvtpm_module_exit - Teardown ibm vtpm module
675  *
676  * Return value:
677  *	Nothing
678  */
679 static void __exit ibmvtpm_module_exit(void)
680 {
681 	vio_unregister_driver(&ibmvtpm_driver);
682 }
683 
684 module_init(ibmvtpm_module_init);
685 module_exit(ibmvtpm_module_exit);
686 
687 MODULE_AUTHOR("adlai@us.ibm.com");
688 MODULE_DESCRIPTION("IBM vTPM Driver");
689 MODULE_VERSION("1.0");
690 MODULE_LICENSE("GPL");
691